V-erbA and c-erbA proteins enhance transcriptional activation by c-jun.

The ability of different transcription factors to interact with one another is an important means by which the eucaryotic cell can integrate separate growth and differentiation signals into a coherent response. We report here an analysis of the interactions of transcription factors that are also the products of oncogenes: the erbA, jun and fos proteins. We demonstrate that the c-jun polypeptide can functionally interact with the c-erbA protein (thyroid hormone receptor) to yield an enhanced activity greater than that of either factor individually. Although the avian erythroblastosis v-erbA allele is generally thought to act as a transcriptional repressor in vertebrate cells, we also report the existence of promoter contexts where v-erbA, as well as c-erbA, can serve as 'co-activators' of c-jun function. V-erbA appears to augment retinoic acid receptor function in the same context. Our results suggest that v-erbA may have unanticipated positive effect on transcription in the neoplastic cell in addition to the repressor functions previously characterized.


Continuous subcutaneous infusion of beta 2-agonists in infantile asthma.

Eleven infants presenting with an asthmatic syndrome were treated with subcutaneous infusions of a beta 2-agonist (beta 2A) during an acute episode. This treatment was used after difficulties with or failure of beta 2A infusions and IV nebulizations. No local or general adverse reactions were observed. The serum concentrations of salbutamol obtained at a dose of 0.1 micrograms/kg/min were measured in six infants and found to be within the generally accepted therapeutic range. This mode of administration proved extremely useful, both by itself and as part of a therapeutic protocol, combined with an antibiotic, a corticosteroid, and theophylline. It avoids the difficulties of administering beta 2A intravenously or by nebulization, while preserving some degree of freedom and better general care for the child. The preferred indication is in treatment of severe acute asthmatic episodes after failure of nebulizations. The exact place in the therapeutic arsenal of infantile asthma remains to be defined.


Proliferating cell nuclear antigen in human placenta and trophoblastic disease.

Expression of proliferating cell nuclear antigen (PCNA), an auxiliary factor for the DNA polymerase delta, is closely related to cell proliferation. Using the monoclonal anti-PCNA antibody 19F4, we examined the distribution of PCNA in formalin-fixed, paraffin-embedded sections of mature and first-trimester placentas, 8 hydatidiform moles, and 7 choriocarcinomas. In normal placentas there was strong expression of PCNA in cytotrophoblastic nuclei, while the syncytium and the amnionic epithelium were PCNA unreactive. Staining of stromal cells was variable. These results are in complete agreement with the autoradiographic localization of [3H]thymidine incorporation and demonstrate that immunoreactivity for PCNA accurately defines areas of proliferative activity in routinely processed placental tissues. In choriocarcinomas and hydatidiform moles PCNA was predominantly expressed in the cytotrophoblast and intermediate trophoblast. Again, the syncytium was largely unreactive for PCNA. These findings indicate that even after neoplastic transformation the syncytium has comparatively little proliferative activity whereas the mononuclear trophoblastic cells divide actively.


What drives the translocation of proteins?

We propose that protein translocation across membranes is driven by biased random thermal motion. This "Brownian ratchet" mechanism depends on chemical asymmetries between the cis and trans sides of the membrane. Several mechanisms could contribute to rectifying the thermal motion of the protein, such as binding and dissociation of chaperonins to the translocating chain, chain coiling induced by pH and/or ionic gradients, glycosylation, and disulfide bond formation. This helps explain the robustness and promiscuity of these transport systems.


Repression of the beta-amyloid gene in a Hox-3.1-producing cell line.

Mammalian homeobox genes are widely expressed in the developing central nervous system and are postulated to control developmental processes by regulating gene expression at the transcriptional level. In vitro studies have identified consensus DNA sequences that contain an ATTA core as sites for interaction with homeodomain proteins. Such elements have been found in the upstream regulatory region of the gene encoding beta-amyloid precursor protein, which is associated with the neurological disorder Alzheimer disease. As the beta-amyloid precursor protein gene is also expressed in the developing central nervous system and appears to play a role in cellular regulatory processes, we have examined the possibility that a homeobox gene product can regulate its transcription. We demonstrate by Northern blot analyses and transfection experiments that the expression of the beta-amyloid precursor protein gene is decreased in cultured cells expressing the mouse homeobox gene Hox-3.1.


Cells that present both specific ligand and costimulatory activity are the most efficient inducers of clonal expansion of normal CD4 T cells.

Clonal expansion of naive CD4 T cells is a necessary step in most adaptive immune responses. Two distinct signals are required for clonal expansion to occur, ligation of T-cell receptors by an antigenic peptide bound to self major histocompatibility complex-encoded class II molecules (signal 1) and a costimulatory signal derived from an antigen-presenting cell (signal 2). To study whether these two signals need to be delivered by a single cell in order to induce clonal expansion of normal CD4 T cells, we have used anti-CD3 bound to Fc receptors as a ligand for the T-cell receptor to deliver signal 1 to all CD4T cells, and we have inactivated signal 2 with a newly generated monoclonal antibody or by using Fc receptor-positive cells that lack the costimulator. Costimulation was delivered by cells whose Fc receptors were blocked with anti-Fc receptor monoclonal antibody. Our results indicate that delivery of ligand and costimulator on one cell is at least 30-fold more efficient than separate delivery. No significant clonal expansion was observed when signals 1 and 2 were delivered by different cells. We have also carried out experiments using fibroblast transfectants that can deliver either or both of these two signals. These studies show that separate delivery of these two signals is at least 80-fold less efficient than their combined delivery by one cell. These findings may explain why tissues can express autoantigens and contain active antigen-presenting cells without inducing autoimmunity.


Macromolecular assemblage in the design of a synthetic AIDS vaccine.

We describe a peptide vaccine model based on the mimicry of surface coat protein of a pathogen. This model used a macromolecular assemblage approach to amplify peptide antigens in liposomes or micelles. The key components of the model consisted of an oligomeric lysine scaffolding to amplify peptide antigens covalently 4-fold and a lipophilic membrane-anchoring group to further amplify noncovalently the antigens many-fold in liposomal or micellar form. A peptide antigen derived from the third variable domain of glycoprotein gp120 of human immunodeficiency virus type 1 (HIV-1), consisting of neutralizing, T-helper, and T-cytotoxic epitopes, was used in a macromolecular assemblage model (HIV-1 linear peptide amino acid sequence 308-331 in a tetravalent multiple antigen peptide system linked to tripalmitoyl-S-glycerylcysteine). The latter complex, in liposome or micelle, was used to immunize mice and guinea pigs without any adjuvant and found to induce gp120-specific antibodies that neutralize virus infectivity in vitro, elicit cytokine production, and prime CD8+ cytotoxic T lymphocytes in vivo. Our results show that the macromolecular assemblage approach bears immunological mimicry of the gp120 of HIV virus and may lead to useful vaccines against HIV infection.


HD-Zip proteins: members of an Arabidopsis homeodomain protein superfamily.

Homeobox genes encode a large family of homeodomain proteins in animal systems. To test whether such genes are also abundant in higher plants, degenerate oligonucleotides complementary to sequences encoding the recognition helix (helix three) of the homeodomain were used to screen genomic and cDNA libraries from the plant Arabidopsis thaliana. Analysis of 8 of the 41 cDNAs isolated revealed that each encodes a presumptive homeodomain; interestingly, most of these clones also contain a leucine zipper motif tightly linked to the homeodomain. It is concluded that Arabidopsis encodes a large family of homeodomain proteins, including members that contain a homeodomain/leucine-zipper (HD-Zip) motif.


Germ-line and somatic p53 gene mutations in multifocal osteogenic sarcoma.

Multifocal osteogenic sarcoma patients without familial histories of increased tumor predisposition were examined for mutations in the highly conserved regions of the p53 gene. p53 point mutations were found in tumor DNA from each of the four patients we examined. A germ-line p53 mutation was detected in one of these patients, and a further rearrangement of the residual wild-type allele was detected in tumor tissue. p53 germ-line mutations can contribute to the enhanced predisposition to tumor development manifest in patients with multifocal osteosarcoma.


The regulation of immunological responses to parasitic infections and the development of tolerance.

It is well established that specific unresponsiveness to immunization can be induced by prolonged exposure to antigenic proteins. More generally, many parasitic infections, such as the helminth worms and the Leishmania parasites, appear to be able to persist in some of their human hosts over long periods of time, via what appears to be an ability to induce defective or inappropriate T-cell responses (= tolerance). Recent research has suggested that cytokines, produced by specific subsets of CD4+ T-cells (characterized by cytokine secretory profiles and growth properties), have an important, and often complex, role in promoting or inhibiting host protective immunity to parasitic infections. By examination of the population dynamics of the stimulation and regulation of cellular responses to infection, via the use of simple mathematical models, we show that nonlinear interactions between CD4+ T-cell subsets and their secreted cytokines can result in either host protection or immunological unresponsiveness, depending on the magnitude and duration of exposure to parasitic infection. Analyses also identify a possible mechanism to explain the stimulation of two separate peaks of enhanced T-cell-mediated responses over a wide range of levels of antigenic exposure.


Voltage-dependent block by L-cis-diltiazem of the cyclic GMP-activated conductance of salamander rods.

Block by L-cis-diltiazem of the cyclic GMP-activated conductance was studied in excised inside-out patches from the salamander rod outer segment. When L-cis-diltiazem was applied from the cytoplasmic face of the patch, current suppression increased monotonically with membrane depolarization, the ratio of blocked to unblocked current varying e-fold in 50 mV. This suggests that L-cis-diltiazem interacts with a binding site located about half-way across the membrane field, and is unable to fully traverse the cyclic GMP-activated channel. The kinetics of block were accelerated by increasing L-cis-diltiazem concentration and by depolarization. These results can be fitted by a single barrier model in which the barrier peak is located about a third of the way across the membrane field from the cytoplasmic face. Application of L-cis-diltiazem from the extracellular face of the patch also resulted in an enhancement of block with membrane depolarization. Indirect evidence supports the notion that this block resulted from partition of the unchanged form of the blocker across the membrane, and its subsequent interaction with the cytoplasmic face of the conductance.


Extracellular cations modulate the ATP sensitivity of ATP-K+ channels in rat ventromedial hypothalamic neurons.

ATP-sensitive K+ (ATP-K+) channels underlie the glucose-sensing nature of pancreatic beta-cells by way of their inhibition by intracellular ATP. Recently it has been proposed that ATP-K+ channels have a similar function in certain hypothalamic neurons that become excitable in raised concentrations of extracellular glucose. The aim of this study was to assess the ATP sensitivity of ATP-K+ channels in inside-out membrane patches excised from glucose-sensing neurons that were acutely isolated from the ventromedial nucleus of rat hypothalamus. ATP-K+ channels were less sensitive to ATP in neurons than in other tissues. Moreover, the sensitivity of neuronal ATP-K+ channels to inhibition by intracellular ATP was modulated by extracellular cations. Under physiological ionic gradients (i.e. high extracellular Na+ and low K+), intracellular ATP produced a concentration-dependent inhibition of channel activity, with a half-maximal inhibition (Ki) of 2.32 mM. A non-hydrolysable analogue of ATP, AMP(PNP), was similarly effective. In symmetrical K+ (i.e. no extracellular sodium), channel activity was tenfold more sensitive to ATP (Ki of 0.21 mM). A parallel study on ATP-K+ channels from an insulin-secreting beta-cell line (CRI-G1) showed that, in contrast to the neuronal data, extracellular cations had no effect on the ATP sensitivity of the channel.


Fatal association between dieldrin-resistant and susceptible Australian sheep blowflies, Lucilia cuprina.

A novel phenomenon of interactions between genotypes of the dieldrin-resistance (Rdl) locus of the Australian sheep blowfly (Lucilia cuprina) is described. Susceptible adult flies exposed to dieldrin-resistant (Rdl/Rdl or Rdl/S) adults, raised from larvae grown on media containing sublethal concentrations of dieldrin, display mortality related to the concentration on which the resistant flies developed. The resistant flies excrete quantities of dieldrin that are toxic to susceptible flies. These observations provide an additional mechanism to those previously identified for the rapid evolution of resistance to dieldrin by L. cuprina.


Chronic hypoxia changes the ratio of endothelin to ATP release from rat aortic endothelial cells exposed to high flow.

Endothelial cells isolated from the thoracic aorta of normoxic and chronically hypoxic rats were perfused (0.5 ml min-1) and stimulated by increased flow rate (3.0 ml min-1). The release of ATP, endothelin and vasopressin was investigated. During periods of high flow rate, endothelial cells isolated from normoxic rats increased their release of ATP and endothelin. In comparison, in hypoxic rats, ATP release during the period of high flow rate was less, whereas endothelin release was greater. Vasopressin release was not increased during periods of stimulation in either group of animals. These results suggest that, under conditions of reduced arterial oxygen tension, a dynamic balance between ATP and endothelin release could regulate the response of vessels to shear stress.


Smells are no surer: rapid improvement in olfactory discrimination is not due to the acquisition of a learning set.

The claim that rats can demonstrate the 'primate-like' learning capacity of learning set formation when trained with olfactory cues, rather than visual or auditory cues, has generated considerable interest in recent years. In this study, the claim is evaluated in detail by using a series of experimental and control procedures to determine whether rats do indeed develop the abstract 'win-stay, lose-shift' strategy which underlies learning set formation in monkeys. We report here that although exposure to a series of novel olfactory discrimination problems gives rise to progressive improvement in the rate of learning, it is not a necessary condition for the development of that rapid learning. Furthermore, even rats which fail to display progressive improvement in olfactory reversal learning show rapid learning on novel olfactory discrimination problems. Each of these findings suggests that although olfactory learning may be rapid, learning set formation does not occur over a short series of problems.


Sequence divergence and copy number of the middle- and long-wave photopigment genes in Old World monkeys.

We have studied the sequence and organization of the genes for the middle-wave (MW) and long-wave (LW) cone photopigment genes in six species of Old World monkeys. Previous studies have shown that the MW and LW pigments of all six species exhibit peak sensitivities near 535 nm and 565 nm, respectively, and thus resemble the equivalent human pigments. In the case of man, the protein components of the MW and LW photopigments differ by 15 amino acids, although only seven of these differences involve non-homologous substitutions and are therefore candidates for a role in spectral tuning. Regions corresponding to exons 4 and 5 of these genes, and including five such candidate sites, were sequenced in the Old World monkeys. In contrast to the equivalent human genes, substitutions were found at two of these sites, position 233 and 309 of the MW gene in all six species. The role of amino acid substitutions in the spectral tuning of these photopigments is discussed. A comparison of the nucleotide sequences of the MW and LW genes provides evidence for sequence homogenization within species; the role of gene conversion in the evolution of these genes is discussed. The close juxtaposition and homology of the MW and LW genes on the X chromosome is thought to underlie the high frequency of colour vision defects in man and the presence in many individuals of extra copies of the MW gene. A study of a group of talapoin (Ceropithecus talapoin) monkeys has revealed a similar numerical polymorphism for this gene to that present in man. In contrast to the situation in man, where the MW and LW genes may contain a shortened first intron, restriction digests of genomic DNA showed that the size of this intron does not differ across the six species of Old World monkeys examined.


Transient presence and functional interaction of endogenous GABA and GABAA receptors in developing rat optic nerve.

GABA (gamma-aminobutyric acid) is a major inhibitory synaptic neurotransmitter with widespread distribution in the central nervous system (CNS). GABA can also modulate axonal excitability by activation of GABAA receptors in CNS white matter regions where synapses and neuronal cell bodies are not present. Studies on cultured glia cells have revealed the synthesis of GABA in rat optic nerve O-2A progenitor cells that give rise to oligodendrocytes and type 2 astrocytes in vitro. We report here that: (i) GABA is detected by immuno-electron microscopy in intact rat optic nerve and is localized to glia and pre-myelinated axons during the first few weeks of postnatal development, but is markedly reduced or absent in the adult; and (ii) neonatal optic nerve is depolarized by GABAA receptor agonists or by the inhibition of GABA uptake. These results demonstrate the presence of functional GABAA receptors, and GABA uptake and release mechanisms in developing rat optic nerve, and suggest that excitability of developing axons can be modulated by endogenous neurotransmitter at non-synaptic sites.


Parasitic helminth infection and cognitive function in school children.

The study examines the effect of moderate to high worm burdens of Trichuris trichiura infection on the cognitive functions of 159 school children (age 9-12 years) in Jamaica, using a double-blind placebo-controlled protocol. Results were evaluated by using a forward-stepwise multiple linear regression. Removal of worms led to a significant improvement in tests of auditory short-term memory (p less than 0.017; p less than 0.013), and scanning and retrieval of long-term memory (p less than 0.001). Nine weeks after treatment, there were no longer significant differences between the treated children and an uninfected Control group in these three tests of cognitive function. It is concluded that whipworm infection has an adverse effect on certain cognitive functions which is reversible by therapy.


The ontogeny of peroxisome-proliferator-activated receptor gene expression in the mouse and rat.

The expression of the gene coding for peroxisome-proliferator-activated receptor (PPAR), a novel transacting factor belonging to the steroid superfamily, has been determined in the mouse and rat throughout development using hybridization histochemistry. Messenger RNA is demonstrable in the liver and brown fat from the fetal period onwards and, additionally, in the heart, kidney and gut post-natally. It is proposed that the upregulation of transcription of peroxisomal beta oxidation genes in specific tissues follows binding of the receptor to its natural ligand. Thus PPAR may have an important role in cold adaptation and non-shivering thermogenesis as well as in detoxification.


Sperm size and sperm competition in birds.

In a sample of 20 species of North American passerine birds we found no relation between sperm size and mating system like that previously reported in mammals (Gomendio & Roldan (Proc. R. Soc. Lond. B 243, 181 (1991)). Instead, we found a positive correlation between sperm length and the length of female sperm storage tubules (SSTS) and a negative correlation between sperm length and the number of SSTS. Both of these correlations suggest that the more than fivefold variation in sperm size we found among species can be explained by sperm competition for access to storage sites (SSTS) in females. As longer sperm appear to be able to swim faster, selection should favour long sperm when SSTS are in short supply; sperm long enough to fill an SST might also prevent access to SSTS by the sperm of other males. Conversely, selection should favour shorter sperm when there is an advantage to sperm layering within an SST promoting a last-male mating advantage. Although we conclude that sperm competition influences sperm size in birds, little is known about the interactions between sperm and SSTS. It seems clear, however, that detailed study of this interaction will provide a new dimension to the study of avian mating systems.


Voltage responses to tones of outer hair cells in the basal turn of the guinea-pig cochlea: significance for electromotility and desensitization.

Voltage responses were recorded from outer hair cells (OHCS) in the basal coil of the guinea-pig cochlea in response to tones at frequencies above the characteristic frequency (CF) presented together with a 100 Hz tone at 80 dB or 85 dB sound pressure level (SPL). The amplitude and polarity of voltage responses to a 100 Hz, 85 dB SPL tone were altered when presented together with tones at frequencies above CF according to the frequency and level of the high-frequency tone, OHC phasic (ac) (greater than 500 microV) but not tonic (dc) voltage responses were elicited by the high-frequency tone. Thus the responses of OHCS to low-frequency tones can be altered when presented together with a high-frequency tone without an apparent dc change in membrane potential. Recordings were made from an OHC during cochlear desensitization through exposure to an intense tone. The maximum voltage response to high-level low-frequency tones remained unchanged, although the OHC response to high-frequency tones became less sensitive to low-level stimuli and more linear as a function of level. It is suggested that desensitization is associated with a change in the mechanical properties of the cochlea, possibly associated with the OHCS themselves, and not with inactivation of the transducer channels. The amplitude of the OHC ac voltage response was measured at neural threshold, and the consequences of these measurements on hair cell electromotility are considered.


Effects of selective denervation and nerve growth factor on activity-mediated growth of rat parotid gland.

A dietary change from all liquid to solid food is followed by an average increase of 200% in [3H]thymidine uptake into the parotid gland of rat. However, removal of either the parasympathetic (Px) or the sympathetic (Sx) innervation to the parotid gland prior to the dietary change resulted in a partial inhibition of the increase; values for the parasympathectomized gland were 51% of those of the innervated gland, and values of the sympathectomized parotid gland were 42% of those of the innervated gland. Removal of both autonomic nerves caused a complete inhibition. Initiation of nerve growth factor (NGF) injection (1 microgram/kg body wt, two times daily for the 2 days of chow refeeding) at the time of chow refeeding had no effect on completely or partially denervated glands, and thymidine values for the denervated parotid gland of rats given NGF did not differ statistically from those of rats not given NGF. With parasympathectomy, sympathectomy, and complete denervation, weight of parotid gland was decreased from that of innervated glands, and administration of NGF had no effect on the denervation-induced decreases. The data show that both branches of the innervation to parotid gland must be intact to ensure a maximal increase in thymidine uptake with the dietary change from liquid to solid food. The level of the enzyme, beta 1-4 galactosyltransferase, involved in proliferation, also depended on the presence of intact nerves. Enzyme activity of innervated parotid gland showed an average increase of 200% with chow refeeding of rats previously on liquid diet, but with Px, the average increase was 51% of that of the innervated parotid, and with Sx, it was 41%. NGF administration did not cause any change in levels of this enzyme in any Px or PxSx parotid gland and only a small change in Sx parotid; it did increase levels of this enzyme in parotid of rats without submandibular-sublingual glands.


Biological activity and receptor binding characteristics to various human tumors of acetylated somatostatin analogs.

Several somatostatin analogs with recently synthesized acetylated N terminus were assayed in vivo for their effects on sodium pentobarbital-stimulated growth hormone (GH) levels in fed male rats and gastrin-releasing peptide (14-27)-stimulated gastrin levels in fasted male rats. The binding characteristics of these analogs to somatostatin receptors were also examined in various human tumors and normal tissues. The analog RC-101-I, injected at a dose of 0.1 micrograms/100 g body wt, significantly suppressed GH release (P less than 0.01) for at least 2 hr. Analog RC-160-II caused the longest inhibition of GH release, greater than that induced by nonacetylated parent analog RC-160, with GH levels showing significant suppression (P less than 0.01) for more than 3 hr. Analogs RC-160-II and RC-101-I and RC-160, injected at a dose of 1.0 micrograms/100 g body wt, significantly (P less than 0.01) suppressed gastrin-releasing peptide (14-27)-stimulated serum gastrin. Analog RC-101-I was active in this test at a dose of 0.1 micrograms/100 g body wt. RC-160-II showed significant binding to somatostatin-14 receptors in all investigated tissues (human colon, human colon cancer, breast cancer, human pancreas and pancreatic cancer, human prostate and prostate cancer, and rat cerebral cortex), but there were marked variations in binding affinities among various normal and cancerous tissues. The highest affinity was found in membranes of colon cancer (Ka = 18.4 nM-1) and breast cancer (Ka = 12.46 nM-1). The binding affinity of RC-160-II to somatostatin receptors in membranes of the breast cancer was similar to that of RC-160. RC-101-I showed higher binding affinity to somatostatin-14 receptors than RC-160 in human breast, pancreatic, and prostate cancer. With the exception of breast cancer tissue, the binding affinity of RC-101-I was significantly lower than that of RC-160-II in membranes of all investigated tissues. It can be concluded that acetylated somatostatin analogs RC-101-I and RC-160-II possess prolonged and enhanced biological activities in suppressing serum GH and gastrin in rats. Significant variations in binding affinities for these analogs in different tissues and various tumors suggest that differences may exist between somatostatin receptors in normal versus malignant tissues. This raises the possibility that some of these analogs could be used more selectively in the treatment of various neoplasms.


Effects of adrenoceptor blockade on cardiac hypertrophy and myocardial phospholipids.

Catecholamines have been proposed as a stimulus for the hypertrophic response to pressure overload of the heart and could also mediate the membrane lipid changes associated with cardiac hypertrophy. To address both of these possibilities, cardiac hypertrophy was induced by aortic constriction in the presence or absence of chronic alpha- or beta-adrenoceptor blockade. Heart weights and heart weight to body weight ratios in aortic-constricted rats of the adrenoceptor-blocked and vehicle-treated groups were elevated to the same extent when compared with values in sham-operated rats of each group. Analysis of the fatty acyl composition of the major phospholipid classes revealed that similar changes occurred in vehicle-treated, alpha-blocked, and beta-blocked aortic-constricted rats when compared with respective groups of sham-operated rats. Specifically, linoleic acid was reduced in the phosphatidylcholine, phosphatidylethanolamine (PE), and cardiolipin (CL) fractions in all groups of aortic-constricted rats. This reduction was accompanied by increased docosahexaenoic acid, arachidonic acid, or palmitic acid in phosphatidylcholine; docosahexaenoic acid in phosphatidylethanolamine; and oleic acid in cardiolipin fractions. Adrenoceptor blockade did not prevent or attenuate the major changes in the fatty acyl composition of phospholipids or the increase in heart weight associated with aortic constriction. This suggests that a change in the level of adrenoceptor stimulation is not the stimulus for cardiac hypertrophy or the observed alterations in phospholipid composition in the pressure-overloaded rat heart.


Endopeptidase 24.15 inhibition and opioid antinociception.

Whereas endopeptidase 24.11 cleaves the Gly-Phe bond in both Met- and Leu-enkephalin, endopeptidase 24.15 rapidly converts dynorphin A1-8, alpha and beta-neoendorphin into Leu-enkephalin, and Met-enkephalin-Arg6-Gly7-Leu8 (MERGL) into Met-enkephalin. Inhibitors of both endopeptidase 24.11 and endopeptidase 24.15 each produce antinociception, and inhibitors of endopeptidase 24.11 increase the magnitude of enkephalin antinociception. The present study compared the central antinociceptive effect of an inhibitor of endopeptidase 24.15, N-[1-(R-S)-carboxy-3-phenylpropyl]-Ala-Ala-Phe-p-aminobenzoate (cFP-AAF-pAB) with one of endopeptidase 24.11 N-[1-(RS)-carboxy-3-phenylpropyl]-Phe-p-aminobenzoate (cFP-F-pAB) upon central opioid antinociception induced by MERGL, metenkephalin and dynorphin A1-8. cFP-AAF-pAB, but not cFP-F-pAB increased MERGL antinociception on the tail-flick and jump tests. In contrast, cFP-F-pAB, but not cFP-AAF-pAB increased met-enkephalin antinociception. Whereas central dynorphin A1-8 failed to induce antinociception itself, co-administration of cFP-AAF-pAB and dynorphin A1-8 increased nociceptive thresholds. This effect was not accompanied by motor dysfunction, but was blocked by systemic pretreatment with naloxone or central pretreatment with naltrexone or nor-binaltorphamine, but not beta-funaltrexamine. These data indicate that endopeptidase 24.15 may be responsible for the degradation of specific opioid peptides (e.g., MERGL, dynorphin), and that this process may prevent the full expression of their antinociceptive properties.


[Various genetic aspects of X-linked mental retardation].

X-Linked Mental Retardation constitutes an important pathologic entity in genetics. The overall significance, history and background of the concept of X-Linked mental retardation is reviewed with a special mention to the cases referenced under the term non-specific X-Linked mental retardation. The concept of lod-score has brought some improvement in the clinical delineation of the X-Linked mental retardation syndromes with some recent reports of suggestive linkage studies. The fragile-X syndrome is discussed with a special focus on reports of X-linked mental retardation with X chromosomal deletions or duplications. Linkage and molecular studies are reported viewing genetic approaches based on restriction fragment length polymorphisms. DNA probes spanning the length of the X and Y chromosomes which may prove critical to the development of diagnostic tests are referred. Computer assistance for a compilation of clinical findings in the X-linked mental retardation syndromes is specified as a diagnostic review and assistance program to check on the various entities. A joint collaborative investigation is reported to ascertain families with X-linked mental retardation in order to develop direct and linkage studies for the diagnosis of there disorders.


Investigation of the mode of inheritance of insulin-dependent diabetes mellitus in Japanese subjects.

Previous studies have shown that insulin-dependent diabetes mellitus is positively associated with HLA-DR4 and HLA-DR9 in Japanese populations. It was proposed that susceptibility to the disease is determined by a single HLA allele associated with both DR4 and DR9. DR genotypes in a Japanese population with insulin-dependent diabetes mellitus were determined by DRB/DQB RFLP analysis. A single disease-susceptibility-allele model was tested by the antigen-genotype-frequency-among-patients method. Recessive and additive inheritance of a single susceptibility allele were rejected. The DR9-associated disease-susceptibility allele in Japanese subjects is distinct from both the DR3- and DR4-associated susceptibility alleles in white Caucasians. The data suggest further complexity in the inheritance of HLA-associated susceptibility to insulin-dependent diabetes mellitus.


DNA mutations associated with the human butyrylcholinesterase J-variant.

The J-variant of human serum butyrylcholinesterase (BChE) causes both an approximately two-thirds reduction of circulating enzyme molecules and a corresponding decrease in the level of BChE activity present in serum. Since the level of serum BChE activity and the duration of succinylcholine apnea are inversely correlated, this marked decrease in activity makes individuals with the J-variant more susceptible than usual subjects to prolonged apnea from succinylcholine. We reinvestigated the same family in which Garry et al. identified the J-variant phenotype. The atypical, fluoride, and K-variant mutations were also identified in members of the 47-person pedigree. DNA amplification by PCR, followed by direct sequencing of the amplified DNA, led to the finding that the J-variant phenotype of human serum BChE was associated with two DNA point mutations in the coding region. One of these was the mutation previously identified with the K-variant phenotype (GCA----ACA; Ala539----Thr). The other was an adenine-to-thymine transversion at nucleotide 1490, which changed amino acid 497 from glutamic acid to valine (GAA----GTA; Glu497----Val). This latter point mutation was named the J-variant mutation (formal name BCHE*497V). The J-variant mutation has not been identified without the K-variant mutation. The J-variant mutation created an RsaI-enzyme RFLP. Two additional point mutations, located in the noncoding regions of the gene, were also found to be linked with the J-variant and K-variant point mutations on the same allele. These noncoding polymorphic mutations had previously been found linked to the atypical and K-variant point mutations. A summary table shows dibucaine, fluoride, and Hoffmann-La Roche compound Ro 2-0683 inhibition numbers for 119 samples whose DNA has been sequenced. Eighteen BChE genotypes are represented.


Nonsynonymous polymorphic sites in the apolipoprotein (apo) A-IV gene are associated with changes in the concentration of apo B- and apo A-I-containing lipoproteins in a normal population.

The aims of this study were to detect polymorphic sites in the apolipoprotein (apo) A-IV gene, to establish their frequencies, to determine potential haplotypes, and to investigate the role of these polymorphisms in lipid metabolism. A sequencing study of four individuals led to the identification of two synonymous mutations (codons 9 and 54) and three nonsynonymous mutations (Val-8----Met, Gln360----His, and Thr347----Ser) and of a VNTR polymorphism within a series of three or four CTGT repeats in the noncoding region of exon 3. Frequencies of these polymorphisms were determined in 291 students by using naturally occurring (BstEII for the synonymous mutation in codon 54, HinfI for Thr347----Ser, and Fnu4HI for Gln360----His) or artificially introduced restriction-enzyme cutting sites (BstEII for the synonymous mutation in codon 9 and MamI for Val-8----Met), subsequent to PCR amplification. The four-base deletion/insertion polymorphism and its localization cis or trans to the mutations in codons 347 and 360 were studied by direct sequencing of PCR-amplified DNA from 87 students. Frequencies of the rarer alleles were .007 for apo A-IV-8:Met, .04 for the synonymous mutation in codon 9, .14 for the synonymous mutation in codon 54, .16 for apo A-IV347:Ser, .07 for apo A-IV360:His, and .39 for the four-base of insertion. Apo A-IV360:His in all cases was cis-localized to the (CTGT)3 repeat and apo A-IV347:Thr; and apo A-IV347:Ser was cis-localized to the (CTGT)4 repeat and apo A-IV360:Gln. Four haplotypes formed from these three polymorphic sites were thus found. The apo A-IV347:Ser allele was associated both with significantly lower plasma apo B concentrations in both sexes and with significantly lower LDL-cholesterol concentrations in men. Heterozygous carriers of apo A-IV360:His exhibited significantly higher concentrations of LDL-cholesterol and lower Lp(a) concentrations, compared with apo A-IV360:Gln homozygotes. We could not confirm the previously reported association of apo A-IV360:His with elevated HDL-cholesterol concentrations. In the population, the Val-8----Met polymorphism was not associated with significantly different lipid concentrations, but in a family study the Met-8 allele was associated with lower HDL-cholesterol and higher LDL-cholesterol concentrations. In conclusion, our results indicate an important role of the apo A-IV gene locus in the metabolism of apo B and, to a lesser extent, apo A-I containing lipoproteins.


Waardenburg syndrome (WS) type I is caused by defects at multiple loci, one of which is near ALPP on chromosome 2: first report of the WS consortium.

Previous studies have localized the gene for Waardenburg syndrome (WS) type I to the distal portion of chromosome 2q, near the ALPP locus. We pooled linkage data obtained from 41 WS type I and 3 WS type II families which were typed for six polymorphic loci on chromosome 2q in order to refine the location of the WS locus (WS1) and evaluate the extent of genetic heterogeneity. In the course of this work, we developed diagnostic criteria for genetic and phenotypic studies. Our findings, based on two-locus and multilocus analysis using a linkage map established from reference pedigrees, suggest that there are two or more mutations causing WS, one of which (i.e., WS1) is located on chromosome 2q, between the ALPP and FN1 loci, at distances of 7.8 cM and 11.2 cM for each marker, respectively. The results also indicate that WS1 is responsible for the illness in approximately 45% of all families in this sample. However, the odds favoring this position over a location between ALPP and SAG are only 2:1 when alternate assumptions about the proportion of linked families are considered. We conclude that a more saturated map of this region of chromosome 2q, including highly polymorphic markers, will be needed to accurately distinguish linked families and, ultimately, isolate the mutant gene.


A genetic etiology for DiGeorge syndrome: consistent deletions and microdeletions of 22q11.

DiGeorge syndrome (DGS), a developmental field defect of the third and fourth pharyngeal pouches, is characterized by aplasia or hypoplasia of the thymus and parathyroid glands and by conotruncal cardiac malformations. Cytogenetic studies support the presence of a DGS critical region in band 22q11. In the present study, we report the results of clinical, cytogenetic, and molecular studies of 14 patients with DGS. Chromosome analysis, utilizing high-resolution banding techniques, detected interstitial deletions in five probands and was inconclusive for a deletion in three probands. The remaining six patients had normal karyotypes. In contrast, molecular analysis detected DNA deletions in all 14 probands. Two of 10 loci tested, D22S75 and D22S259, are deleted in all 14 patients. A third locus, D22S66, is deleted in the eight DGS probands tested. Physical mapping using somatic cell hybrids places D22S66 between D22S75 and D22S259, suggesting that it should be deleted in the remaining six cases. Parent-of-origin studies were performed in five families. Four probands failed to inherit a maternal allele, and one failed to inherit a paternal allele. On the basis of these families, and of six maternally and five paternally derived unbalanced-translocation DGS probands in the literature, parent of origin or imprinting does not appear to play an important role in the pathogenesis of DGS. Deletion of the same three loci in all 14 DGS probands begins to delineate the region of chromosome 22 critical for DGS and confirms the hypothesis that submicroscopic deletions of 22q11 are etiologic in the vast majority of cases.


Confirmation and refinement of the genetic localization of the Coffin-Lowry syndrome locus in Xp22.1-p22.2.

The Coffin-Lowry syndrome (CLS) is an X-linked inherited disease of unknown pathogenesis characterized by severe mental retardation, typical facial and digital anomalies, and progressive skeletal deformations. Our previous linkage analysis, based on four pedigrees with the disease, suggested a localization for the CLS locus in Xp22.1-p22.2, with the most likely position between the marker loci DXS41 and DXS43. We have now extended the study to 16 families by using seven RFLP marker loci spanning the Xp22.1-p22.2 region. Linkage has been established with five markers from this part of the X chromosome: DXS274 (lod score [Z] (theta) = 3.53 at theta = .08), DXS43 (Z(theta) = 3.16 at theta = .08), DXS197 (Z(theta) = 3.03 at theta = .05), DXS41 (Z(theta) = 2.89 at theta = .08), and DXS207 (Z(theta) = 2.73 at theta = .13). A multipoint linkage analysis further placed, with a maximum multipoint Z of 7.30, the mutation-causing CLS within a 7-cM interval defined by the cluster of tightly linked markers (DXS207-DXS43-DXS197) on the distal side and by DXS274 on the proximal side. Thus, these further linkage data confirm and refine the map location for the gene responsible for CLS in Xp22.1-p22.2. As no linkage heterogeneity was detected, this validates the use of the Xp22.1-p22.2 markers for carrier detection and prenatal diagnosis in CLS families.


Evidence for linkage between the swine L blood group and the loci specifying the receptors mediating adhesion of K88 Escherichia coli pilus antigens.

Brush borders or enterocytes obtained from the small intestine of 248 pedigreed pigs were tested by adhesion assay in vitro with enterotoxigenic Escherichia (E.) coli strains, each expressing one of the three K88 pilus variants K88ab, K88ac and K88ad. All pigs were classified as belonging to one of the four adhesion phenotypes: I--K88ab(-), ac(-), ad(-); II--K88ab(-), ac(-), ad(+); III--K88ab(+), ac(+), ad(-); and IV--K88ab(+), ac(+), ad(+). Serum or red cells were typed for 15 blood group systems: A-O, B, C, D, E, F, G, H, I, J, K, L, M, N and O; for 11 biochemical polymorphisms: PI1, PI2, PO1A, A1BG, GPI, PGD, TF, HPX, ADA, PGM and AMY; the polymorphism at the IGHG1 locus. Linkage analysis was performed between the alleles at the locus (loci) specifying K88 receptors able to bind one or more different serological types of K88 E. coli and alleles for markers at other loci. Linkage was demonstrated between the locus for the L blood group system and the locus (loci) for K88 E. coli receptors (Z = 3.24), adding one locus (loci) to the previously identified linkage group IV (LGIV) [L-SLB]. The maximum likelihood estimate of the recombination fraction (theta) was 0.23. No evidence was found for linkage between any of the other biochemical and immunogenetic markers and the receptor locus (loci) of K88 E. coli.


Analysis of immunoglobulin light chain loci in sheep.

A sheep kappa cDNA probe was isolated, characterized by sequence analysis and shown to have significant sequence identity to other kappa light chains. This probe and a sheep lambda light chain probe were used to estimate the extent of various sheep immunoglobulin light chain gene loci by Southern blot analysis of genomic DNA. The results showed that the sheep has a single hybridizing kappa constant gene and three to five kappa V segment bands. Segregation of three polymorphic bands at the lambda C locus indicated that they were products of separate C segments. Restriction fragment pattern variations were obtained using light chain probes on various sheep breeds, but no pattern or individual band was characteristic for a particular breed.


Synteny mapping of the bovine IGHG2, CRC and IGF1 genes.

A panel of bovine-murine hybrid cell lines was analysed for 10 loci, including three (IGF1, IGHG2 and the calcium release channel gene [CRC]) that have previously been mapped in man, but not in cattle. The IGF and CRC genes were indirectly mapped to chromosomes 5 and 18 respectively and the syntenies of the HOX2 and GH genes and of the NP and FOS genes were confirmed. The results also show that the IGHG2 locus, which is linked to NP and FOS on human chromosome 14, is separated from these genes in cattle. By showing synteny of the IGHG2 and MPI loci, the IGHG2 locus has been indirectly mapped to chromosome 21.


Revascularization for coronary ostial stenosis in Takayasu's disease with calcified aorta.

A case in which a patient with stenoses of the right and left coronary ostia and heavy calcification of the aorta caused by Takayasu's disease was successfully treated by coronary artery bypass grafting is presented. The aortic ends of the two grafts were attached to a xenopericardial patch, which was sutured into the ascending aorta. This technique can be done without fine sutures, which are required for proximal anastomosis of a vein graft, and may reduce the risk of ostial stenosis.


Borna disease virus-infected astrocytes function in vitro as antigen-presenting and target cells for virus-specific CD4-bearing lymphocytes.

Astrocytes isolated from the brain of newborn Lewis rats and an astrocytic cell line were susceptible to infection with the neurotropic Borna disease virus in vitro. Since astrocytes also have been found to be infected in vivo it seemed appropriate to test this cell type for interaction with a Borna disease virus-specific CD4+ T cell line. Borna disease virus-infected astrocytes were found to be capable of presenting virus-specific antigen to virus-specific T cells in vitro. However, the response was significantly enhanced if the purified 38/39kDa Borna disease virus-specific protein was added exogenously to the cultures. Beside the function as antigen-presenting cells for various antigens including virus-specific protein and myelin basic protein, persistently infected astrocytes were also found to act as target cells for a CD4+ T cell line as shown in conventional 51Cr release assays after induction of MHC class II expression by gamma interferon. Infection of astrocytes alone did not cause expression of this self antigen. It could be shown that the ability of CD4+ BDV-specific T cells to mediate lysis was in part dependent on the stage of activation. Lymphocytes "activated" before testing exerted high lysis after only 4h of coincubation with target cells, whereas "resting" T cells did not cause significant lysis until 12h of coincubation. The dependence of the interaction between effector and target cells on MHC class II antigen was demonstrated by the finding that antibodies to Ia antigens reduced lysis of target cells.


On the issue of drug washout prior to polysomnographic studies in depressed patients.

In psychoneurobiological studies it is a point of controversy how long psychoactive medication has to be withdrawn to exclude drug effects on the variables to be investigated. In order to answer the question of whether the generally assumed two-week washout of psychoactive medication is sufficient for polysomnographic studies, we computed a post hoc analysis of EEG sleep recordings in 61 newly admitted depressed patients. The results indicate that after a 2-week withdrawal of tricyclic antidepressants and/or benzodiazepines there are no major drug effects on visually scored polysomnograms. In addition, the observations raise the question of whether even a 1-week drug washout may be sufficient to exclude confounding effects of prior psychoactive medication on EEG sleep.


Extrapyramidal signs in Alzheimer's disease: a 3-year follow-up study.

Occurrence of extrapyramidal signs was investigated in a follow-up study of 32 patients with probable Alzheimer's disease (AD). Bradykinesia and rigidity were observed in 39% and 11% of the neuroleptic-free patients at entry and in 72% and 61% at year 3, respectively. Tremor was not a predominant feature nor did its occurrence increase over time. Use of neuroleptics contributed to extrapyramidal signs; 75-100% of the neuroleptic-treated patients showed bradykinesia, rigidity or orofacial dyskinesia. The homovanillic acid (HVA) concentrations of the cerebrospinal fluid at entry were comparable to those of age-matched controls. Nor did HVA levels correlate with rigidity or bradykinesia in these early AD cases. Presence of bradykinesia or rigidity at the initial evaluation predicted more severe dementia and a poor prognosis over the period of 3 years, although interaction of initial clinical severity of dementia was significant. Of 15 patients with these signs 3 (20%) died and 8 (53%) needed institutional care, while of 17 patients without these signs only 1 (6%) died and 2 (12%) were institutionalized by year 3 (p less than 0.01).


Tyrosine hydroxylase-like (TH) immunoreactivity in Parkinson's disease and Alzheimer's disease.

We used tyrosine hydroxylase immunoreactivity (TH) to mark dopaminergic fibers in cerebral tissue from adult persons with Parkinson's disease (PD) or Alzheimer's disease (AD). In the PD cases we found a loss of dopaminergic neurons in the ventral tegmental area (VTA), severely reduced TH fibers in dopaminergic terminal fields (particularly in the hippocampal perforant pathway) and neurofibrillary tangles (NFT), that occurred only in the perforant pathway. In contrast, AD cases were characterized by a lack of significant neuron loss in the VTA and by mild loss of TH fibers. A decreased dopaminergic innervation of the perforant pathway in cases of PD appears to be associated with the occurrence of NFT in these structures.


The effects of alpha-2 adrenoceptor antagonist, atipamezole, on spatial learning in scopolamine-treated and aged rats.

In order to study whether noradrenergic drugs improve age-related cognitive dysfunctions the present experiments investigated whether atipamezole, a selective and specific alpha-2 antagonist, improves spatial learning impairment due to cholinergic blockade (scopolamine 0.8 mg/kg) or aging in rats. Previously, it has been shown that atipamezole dose-dependently (0.03-3.0 mg/kg) increases the turnover of noradrenaline in rat brain. According to the present results, atipamezole (0.1, 0.3, 0.6 mg/kg) did not affect spatial learning/memory when assessed in a free swim trial of the water maze task in control rats. Furthermore, atipamezole (0.1, 0.6 mg/kg) did not improve learning deficit in scopolamine treated young rats. Higher doses (greater than or equal to 1.0 mg/kg) of atipamezole could not be tested, because they induce floating behaviour in rats. In aged rats, which were screened to be impaired in the initial acquisition of the water maze task, 0.3 mg/kg atipamezole impaired further learning of this task. Because previous studies suggest that age-related learning impairment in the water maze may be, at least partly, due to a cholinergic deficit, the present results suggest that atipamezole which increases the release of noradrenaline in brain does not alleviate this learning deficit.


Production of single-stranded DNA for sequencing: an alternative approach.

We describe a simple procedure for the direct sequencing of single-stranded, PCR-amplified, target regions of human genomic DNA. At variance with previously reported procedures, purification of the desired double-stranded DNA was introduced. This additional step allowed the single-stranded amplification and sequencing of the target gene. This step is required for direct sequencing of some amplified regions of human genomic DNA. However, no individual technique seems suitable to generate and sequence all single-stranded DNA.


Drug interaction between rifampicin, isoniazid and cotrimoxazole in rabbits.

1 The results of cotrimoxazole (CTZ) co-administration (15 mg kg-1 trimethoprim + 40 mg kg-1 sulphamethoxazole) on plasma concentration and various pharmacokinetic parameters of rifampicin (RIF, 24 mg kg-1) and isoniazid (INH, 14 mg kg-1) were studied. 2 In the test group (n = 6), CTZ was administered on the 24th day of antitubercular treatment (ATT) and given for 7 d. 3 At the end of concurrent treatment with CTZ, RIF half-life (t1/2) and plasma concentration were both increased. However, there was no effect on INH half-life and plasma concentration.


Interindividual variations in enzymes controlling organophosphate toxicity in man.

1 Interindividual variations in an unexposed population have been defined for five enzymes involved in organophosphate (OP) toxicity. The enzymes measured were: red blood cell acetylcholinesterase (AChE), lymphocyte neuropathy target esterase (NTE), serum cholinesterase (ChE), serum paraoxonase and serum arylesterase. 2 AChE and arylesterase were normally distributed in the population whilst the distribution of NTE, ChE and paraoxonase deviated significantly from normal. 3 Assay precision and intra-individual variability were measured for each of the enzymes; the effect on interindividual variation was assessed. 4 Variations in enzyme activities between individuals could have profound effects on susceptibility to OP toxicity. Prior determination of these enzymes may be predictive of susceptibility. 5 Lymphocyte NTE has some limitations as an indicator of exposure to neurotoxic OPs.


Prevention of chloroquine absorption by activated charcoal.

1. The ability of activated charcoal to prevent the absorption of chloroquine was investigated in healthy volunteers, and the effect of the charcoal-chloroquine ratio on the completeness of binding was studied in vitro. 2. After an overnight fast, six subjects ingested 500 mg of chloroquine phosphate with water, and another group of six subjects ingested 25 g of charcoal suspension within 5 min of chloroquine intake. The concentrations of chloroquine in plasma and whole blood were measured by high-performance liquid chromatography for 192 h. 3. Activated charcoal reduced the areas under the plasma and whole blood chloroquine concentration-time curves (AUC) from 0 to 192 h, the total AUCs, and the peak concentrations by 99% (P less than 0.001). 4. Chloroquine was very effectively bound by activated charcoal in vitro, even at low charcoal-chloroquine ratios. For example, at a ratio of 5:1, about 98% of chloroquine was bound. 5. Activated charcoal should be very effective in reducing the absorption of that fraction of chloroquine dose which is in the stomach at the time of charcoal administration. Because the acute toxicity of chloroquine is extremely high and death usually occurs within 1-3 h of overdosage, charcoal should be given as early as possible in suspected chloroquine intoxication.


Studies on the disposition and metabolism of hydrazine in rats in vivo.

1. Rats were given various doses of hydrazine orally and their plasma and liver hydrazine levels were determined (at various times up to 270 min after dosing) by gas chromatography/mass spectrometry. 2. The increase in the peak plasma level and in the area under the plasma concentration-time curve (AUC) were not directly proportional to the dose. 3. The ratio of plasma to liver hydrazine varied with dose suggesting saturation of an uptake mechanism might be occurring. 4. In a separate experiment hydrazine was still detectable in the plasma and liver 24 h after dosing with hydrazine i.p. 5. Rats were given the same doses of hydrazine and urine was collected for 24 h after dosing and assayed for hydrazine and acetylhydrazine. The proportion of hydrazine and acetylhydrazine excreted declined with dose. 6. Liver samples were taken for histopathological examination 96 h after dosing. Only after the highest dose (81 mg kg-1) was there evidence of fatty liver, 96 h after a single dose, and a reduction in both liver and body weight.


High-dose cyclophosphamide and dexamethasone in paraquat poisoning: a prospective study.

Between March 1986 and March 1988, 47 consecutive patients, whose paraquat intoxication was confirmed by urine testing, were enrolled in a prospective study on the treatment of paraquat poisoning. Fourteen received a standard treatment regimen consisting of fluid replacement and oral absorbents, and 33 received high-dose cyclophosphamide and dexamethasone, in addition to standard therapy. The case fatality rate in both treatment groups (63 and 61%) was similar. In addition, all 26 patients whose paraquat serum concentrations were measured and who had a probability of survival of less than 65% according the survival curve of Hart et al. died, regardless of therapy. These included four in the cyclophosphamide/dexamethasone group and two in the standard treatment group who had prior survival probabilities between 50 and 65%. This indicated that the cut-off curve relating mortality and paraquat serum concentrations was similar in both treatment groups. High-dose cyclophosphamide/dexamethasone treatment is unlikely to improve the prognosis of paraquat poisoning.


Clinical features and treatment of Elapidae bites: report of three cases.

This report describes two accidents, involving snakes of the Micrurus corallinus species, where compromising respiratory function was not observed and the specific anti-elapidic serum was the single therapy used, and a third incident, probably involving Micrurus frontalis, where neostigmine was used to remedy respiratory failure.


Analysis of the immunotoxic effects of xenobiotics.

1. Current problems in immunotoxicology are reviewed with special attention to the sensitivity of the immune system to the effects of xenobiotics. 2. Sensitivity of target cells, route of exposure, dosage, mechanism of action and response of the immune system are discussed as the main factors responsible for the ultimate effects of drugs and chemicals. 3. The methodology of immunotoxicology is divided into two main steps: preclinical screening and the monitoring of exposed persons. 4. Conclusions are prescribed about future tasks in human immunotoxicology.


The immunotoxicity of tributyltin oxide (TBTO) does not increase the susceptibility of rats to experimental respiratory infection.

1. The dietary exposure of rats to tributyltin oxide at a concentration of 150 ppm for 6 weeks is known to lead to a significant reduction in relative thymic weight. 2. To determine whether this reduction in thymic weight also leads to an impairment of function sufficient to alter the host response to micro-organisms, we have examined the development of virus- and mycoplasma-induced pneumonia in TBTO-exposed rats. 3. Using a quantitative histopathological method for measuring both the extent and duration of lung lesions in TBTO-exposed rats, no statistically significant increase in the extent or persistence of virus-induced lung lesions was found in rats exposed chronically to TBTO. 4. The susceptibility of rats to Mycoplasma pulmonis infection, alone, or in conjunction with viral pneumonia, was also not increased by dietary exposure to TBTO.


Induction of DNA strand breaks in peripheral lymphocytes by soluble chromium compounds.

1. Incubation of human lymphocytes with sodium dichromate (CrVI) at 37 degrees C for 3 h resulted in a dose-dependent increase in DNA strand breaks without concurrent cytotoxicity. In contrast, chromium acetate hydroxide (CrIII) failed to induce DNA strand breaks at sub-cytotoxic concentrations. 2. DNA strand breaks were also detected in the peripheral lymphocytes of Wistar rats, 24 h after intratracheal instillation of sodium dichromate (1.3 and 2.5 mg kg-1). Instillation of chromium acetate hydroxide (up to 21.8 mg kg-1) failed to induce DNA strand breaks in peripheral lymphocytes. In accord with previous studies, hexavalent chromium was found to be more readily absorbed from the lungs into the peripheral blood than chromium in its trivalent form. 3. The results of this study indicate that fluorometric analysis of DNA unwinding (FADU) in peripheral lymphocytes might be a convenient method of measuring an important biological effect of chromium in occupationally-exposed workers.


Effects of joint exposures to selected peroxisome proliferators on hepatic acyl-CoA oxidase activity in male B6C3F1 mice.

The interaction potential of peroxisome proliferators of similar and dissimilar structure was examined in B6C3F1 mice. Mice were fed diets containing varying concentrations of ciprofibrate (Cipro), clofibrate (Clof) or di(2-ethylhexyl)phthalate (DEHP), or combinations of Cipro and Clof or Cipro and DEHP for 4 d. Induction of peroxisomal beta-oxidation, measured by increased acyl-CoA oxidase activity, was used as the endpoint for analysis. An additive response occurred following joint exposure to the structurally related compounds Cipro and Clof, whereas a possible synergistic response occurred at low dose combinations of the structurally dissimilar Cipro and DEHP. These findings represent the first report assessing the in-vivo interaction potential of structurally similar and dissimilar peroxisome proliferators and provides insight into the dose-response nature of joint exposures to certain non-genotoxic carcinogens.


Effect of lead on the blood serum, liver and brain sialoglycoconjugate levels in rats.

Rats were exposed to an acute dose of lead (Pb) to study the effect of Pb intoxication on different sialoglycoconjugates in serum, brain and liver. Serum levels of total sialic acid (TSA), perchloric acid (PCA)-soluble sialic acid (PSA), lipid-bound sialic acid (LBSA), free sialic acid (FSA) and alpha 1-acid glycoprotein (alpha 1-AG) were determined. They were also estimated in brain and liver tissues, except for LBSA and FSA. All these constituents were found to be significantly raised in the serum but not in the brain. In the case of the liver, only alpha 1-AG levels were found to be increased significantly, the rest were not altered. The levels of these sialoglycoconjugates in serum might be useful as biomarkers of heavy metal toxicity.


Cardiac toxicity following short-term exposure to methomyl in spraymen and rabbits.

A health surveillance study in 22 healthy spraymen showed significant T-wave changes (including inversion) in most of the limb leads and chest leads following 5 d exposure to methomyl, a carbamate pesticide. Significant changes in plasma cholinesterase and lactic dehydrogenase activities were also noticed. The ECG changes could be reproduced in rabbits and were dose dependent. This type of ECG change following exposure to a carbamate compound is reported for the first time in occupationally-exposed subjects. The study results indicate that these changes are probably directly related to methomyl rather than its toxicity through cholinesterase inhibition. The significance of these changes remain to be investigated.


Cigarette smoke inhibits cytosolic but not microsomal epoxide hydrolase of human lung.

The effect of cigarette smoke exposure on the activity of cytosolic and microsomal epoxide hydrolase (EH) has been investigated in human lung. Patients were classified as 'recent smokers' (n = 9) or 'non-recent smokers' (n = 10) according to whether they were or were not still smoking 1 month before surgery. Cytosolic EH was measured with [3H]trans-stilbene oxide as a substrate, whereas microsomal EH was measured with [7-3H]styrene oxide as a substrate. Microsomal EH activity did not differ between recent smokers (2.51 +/- 0.93 nmol min-1 mg-1) and non-recent smokers (2.74 +/- 1.10 nmol min-1 mg-1), whereas cytosolic EH activity was significantly lower in recent smokers (6.46 +/- 1.79 pmol min-1 mg-1) than in non-recent smokers (8.41 +/- 2.09 pmol min-1 mg-1, P less than 0.05). Cytosolic EH activity was correlated with the number of days that had passed since the cessation of smoking (r = 0.58, P less than 0.05) and the effect was dose-dependent, since the enzyme activity was inversely correlated with the number of cigarettes smoked per day (r = 0.85, P less than 0.01). This suggests that recent smoking exposure inhibits the activity of cytosolic EH but not microsomal EH, and that the inhibition increases with the number of cigarettes smoked per day. The contribution of cytosolic enzymes to xenobiotic metabolism may be remarkable in extrahepatic tissues. The inhibition of cytosolic EH by tobacco smoke may reduce the inactivation of carcinogenic epoxides in human lung tissues and so may increase a person's susceptibility to lung cancer.


Macaque CD4+ T-cell subsets: influence of activation on infection by simian immunodeficiency viruses (SIV).

Simian immunodeficiency virus (SIV) infects a small number of CD4+ T cells including "memory" T cells. The following describes the cell surface markers which may delineate subsets of CD4+ memory T cells and reviews how memory CD4+ T cells are activated and regulated through the T-cell receptor and such accessory receptors as CD28. The factors which may influence initial expression and infection of T cells by CD4 are discussed. Unlike activated and infected T cells, unstimulated CD4+ T cells have little or no SIV DNA detectable in the genomic fraction, but key activation signals may promote integration of viral DNA in memory T cells. Bacterial superantigens (SuperAg) can promote increased levels of SIV viral DNA in mature and immature T cells. Immunodeficiency virus products such as gp120, Nef, and Tat can affect CD4+ T-cell function. Whereas Nef can reduce expression of CD4, Tat reduces the expression of CD28. We hypothesize that the lack of expression of key accessory molecules on CD4 lineage T cells infected with immunodeficiency viruses may make infected T cells more susceptible to recall-antigen-induced programmed cell death.


Inhibition of Ca(2+)-induced calcitonin secretion by somatostatin: roles of voltage dependent Ca2+ channels and G-proteins.

Somatostatin has recently been applied therapeutically for hypercalcitonemia in patients with calcitonin-producing tumours. Using calcitonin-secreting cells (C-cells) of the medullary thyroid carcinoma cell line rMTC 44-2, we investigated the inhibitory action of somatostatin on calcitonin release, cytosolic Ca2+ and Ca2+ channel currents. The Ca(2+)-induced rises of the cytosolic Ca2+ and calcitonin secretion were greatly inhibited by somatostatin or its stable analogue octreotide. The effects of somatostatin were pertussis toxin-sensitive. Under voltage clamp conditions, C-cells exhibited slowly inactivating Ca2+ channel currents. Bath application of 100 nM somatostatin reversibly reduced the Ca2+ channel current by about 30%. The Ca2+ channel current and its inhibition by somatostatin were not affected by intracellularly applied cyclic AMP. Moreover, pretreating the cells with pertussis toxin had no effect on the control Ca2+ channel currents but greatly abolished its inhibition by somatostatin. The data show that somatostatin suppresses the Ca(2+)-stimulated calcitonin secretion by inhibiting voltage-dependent Ca2+ channel currents and by lowering cytosolic Ca2+. These actions of somatostatin involve pertussis toxin-sensitive G-proteins and occur independently of changes in the cyclic AMP concentration.


Haemorrhagic fever with renal syndrome: clinical aspects.

Based on clinical and pathological features a typical case of haemorrhagic fever with renal syndrome passes through five phases: (1) febrile phase, (2) hypotensive phase, (3) oliguric phase, (4) diuretic phase and (5) convalescent phase. The major manifestations are fever, pain in the back and abdomen, flushed face, prostration, proteinuria, purpura and haemorrhage and acute renal failure. Selective right auricular haemorrhage, marked congestion and haemorrhage in the renal medulla and necrosis of the anterior lobe of the pituitary gland are the three prominent pathological findings. The clinical severity depends upon the causative agents, namely Hantaan virus, Seoul virus and the European form in that order. Specific serological diagnosis of haemorrhagic fever with renal syndrome is made by demonstrating a rise in titre of specific immunofluorescent antibody against Hantaan and related viruses. The management is supportive, based on an understanding of the pathophysiology of the disease.


Haemorrhagic fever with renal syndrome, virological and epidemiological aspects.

Haemorrhagic fever with renal syndrome (HFRS) is characterized by fever, headache, abdominal pain, renal dysfunction and various haemorrhagic manifestations. The viruses causing HFRS all belong to the Hantavirus genus in the Bunyaviridae family. At least three of the different hantaviruses are associated with human disease: Hantaan, Seoul, and Puumala viruses. HFRS is endemic in a belt from Norway in the west, through Sweden, Finland, the Soviet Union, China, Korea to Japan in the east. The clinical severity of HFRS varies throughout this belt. A severe form with haemorrhagic manifestations and significant lethality (Korean haemorrhagic fever--caused by Hantaan and Seoul virus) occurs in Asia, while a milder form (nephropathia epidemica caused by Puumala virus) with less haemorrhagic manifestations and no or low lethality is found in Europe. All hantaviruses are spread by rodents where the major route of transmission to man is via aerosol from rodent urine, saliva and faeces. Although HFRS occurs with the same clinical picture in children as in adults both incidence rates and antibody prevalence rates are very low in children under 10 years. Men of working age make up the bulk of clinical cases.


Induction of myelo-monocytic My7 antigen (CD13) expression by interferon-alpha in basal cells of cutaneous T-cell lymphomas.

The My7 antigen that is expressed on the basal cells in normal skin and inflammatory disorders is absent in the lesions of cutaneous T-cell lymphoma (CTCL). Induction of My7 expression in basal cells in the cutaneous lesions of 12 patients with mycosis fungoides and three with Sézary syndrome treated with interferon-alpha 2a (IFN-alpha 2a) for 10 months was investigated. Biopsies were taken from the same area before treatment and after 2, 6 and 10 months of therapy with IFN-alpha 2a. My7 antigen was expressed on the basal cells only in those patients who showed either a complete or partial response to therapy with IFN-alpha 2a.


Eosinophilic pustular folliculitis in an HIV-positive man: response to cetirizine.

Eosinophilic pustular folliculitis is a rare condition which is being increasingly reported in HIV-positive patients. Many therapies have been used to treat this condition. We report the first successful use of the H1 antihistamine cetirizine to treat the condition and postulate that the specific antieosinophilic action of this drug may explain the beneficial clinical effect seen in our patient.


Immunohistochemical localization of dipeptidyl aminopeptidase IV in thyroid papillary carcinoma.

The localization of dipeptidyl aminopeptidase IV expressed aberrantly in thyroid carcinoma was studied by immunoelectron microscopy using a monoclonal antibody to the enzyme with special reference to enzyme-histochemical staining of the enzyme. Five thyroid papillary carcinomas were investigated including two lymph-node metastases. All cases showed the dense immunoreaction product on the apical membrane and only traces of the product on lateral membranes, endoplasmic reticulum and nuclear membranes. In one case only, the dense product was observed on basal tubular structures. Analysis, using immunogold labelling on pre-embedded cryosections, revealed that dipeptidyl aminopeptidase IV was localized on the luminal surface of cancer cells. Two different distribution patterns of dipeptidyl aminopeptidase IV activity staining, diffuse and apical patterns, reported previously were thought to be due to different amounts of dipeptidyl aminopeptidase IV in the cytoplasm of cancer cells. This enzyme-histochemical staining method is useful for pathological diagnosis of thyroid tumours and can be applied to clinical materials. The enzyme localization is revealed by the staining pattern.


Takayasu arteritis.

Takayasu Arteritis is a vasculitis of the giant cell type which affects young people. Complications of this disease can include myocardial infarction, stroke, limb loss, renal failure, and mesenteric ischemia. A case study demonstrates some of the complexities of diagnosis and treatment for this condition. Nursing care should be directed toward the alteration in tissue perfusion, prevention of infection in a patient on immunosuppressive therapy, and a variety of potential problems with coping.


Compartmentalization of the cellular immune response to the recombinant 65 kDa protein of Mycobacterium bovis BCG in patients with tuberculous pleuritis.

The recombinant 65 kDa mycobacterial protein of M. bovis BCG has been shown to be immunodominant in mice immunized with M. tuberculosis. Little is known about reactivity to this antigen in patients with tuberculous pleuritis. In this study therefore, pleural effusion and autologous peripheral blood lymphocytes obtained from patients with tuberculous and nontuberculous pleuritis were stimulated in-vitro with the recombinant 65 kDa antigen. Proliferation was assessed by 3[H] thymidine incorporation. In addition, pleural effusion lymphocytes were activated in vitro with the 65 kDa antigen and tested for cytotoxic activity in 15-hr chromium-release assays. Pleural effusion lymphocytes obtained from a high percentage (56%) of patients with tuberculous pleuritis showed significant proliferative responses to the 65 kDa antigen, while the response in autologous peripheral blood lymphocytes was significantly lower. By contrast, pleural effusion lymphocytes obtained from patients with nontuberculous effusions were not reactive to the 65 kDa antigen. In addition, 65 kDa stimulated pleural effusion lymphocytes obtained from patients with tuberculous effusions showed antigen-specific lysis of autologous targets pulsed with the 65 kDa antigen. These results indicate compartmentalization of the immune response to the 65 kDa antigen and, in addition, provide evidence for in vivo involvement of this antigen in the immune response to M. tuberculosis.


Retinoic acid induces changes in the localization of homeobox proteins in the antero-posterior axis of Xenopus laevis embryos.

We have studied the localization of the proteins of Xeb1 and Xeb2, two homeobox (hbx)-containing genes that are expressed during the early development of Xenopus laevis. Both proteins are expressed in juxtaposed and partially overlapping domains along the antero-posterior axis of Xenopus laevis embryos, with clearly defined anterior boundaries. Xeb2 is predominantly expressed in the caudal region of the hindbrain, whereas the Xeb1 protein is located in the most rostral region of the spinal cord. Furthermore, both proteins are expressed in single cells dispersed in the lateral flanks of the embryo in positions that correlate with the expression domains in the neural tube. We suggest that these cells are migratory neural crest cells that have acquired positional information in the neural tube prior to migration. The Xeb2 protein was also detected in the most posterior branchial arches and the pronephros. In stage 45 embryos, nuclei of the IX-X cranial ganglia, the lung buds and cells spreading into the forelimb rudiment express the Xeb2 antigen. The Xeb1 protein was also detected in the lung buds and the forelimb rudiment. To examine the effect of retinoic acid on expression, gastrula embryos were treated with all-trans retinoic acid (RA). Increasing concentrations of RA caused progressive truncation of anterior structures. The most severely affected embryos lacked eyes, nasal pits, forebrain, midbrain and otic vesicles, and the anterior boundary of the hindbrain seemed to be displaced rostrally. This alteration correlates with a progressive displacement of the anterior boundary of the expression domain of Xeb2. On the other hand, 10(-6) M RA induces an ectopic site of Xeb1 expression at the anterior end of the central nervous system, located just anterior to the extended domain of Xeb2 whereas expression in the spinal cord remains unaffected.


Changes in brain gene expression in schizophrenic and depressed patients.

Poly(A+) mRNA was extracted from the post-mortem brain of schizophrenics (9 subjects), unipolar depressives (5 subjects) and controls (10 subjects) and used to direct the in vitro translation of radiolabelled protein in a cell-free reticulocyte-lysate system. Protein species were analysed on two-dimensional gels. Over 200 products were detected and, from these, 74 well-resolved species were chosen for further analysis. The optical density of each product was quantified by image analysis and normalised with respect to overall gel intensity. It was found that 7 novel, uncharacterised protein species, ranging from molecular weights (Mr) 17 kDa to 38 kDa and apparent isoelectric points (pI) 5.7-7.1, changed significantly in intensity in the psychotic groups compared to controls. One species changed only in the schizophrenia group (Mr = 26 kDa, pI = 5.8, 18% of control intensity) and 3 changed only in the depressive group (Mr = 38 kDa, pI = 6.2, 540% of control; Mr = 34 kDa, pI = 6.2, 6% of control; Mr = 17 kDa, pI = 5.7, 238% of control). Three further protein species were common to both psychotic groups (one species decreased in both schizophrenia and depression, Mr = 33 kDa, pI = 5.8; two species showed opposing intensity changes, decreasing in schizophrenia and increasing in depression, Mr = 35 kDa, pI = 7.1; Mr = 23 kDa, pI = 6.1). None of these changes was a function of post-mortem delay or mode of death. It is quite likely that such protein species reflect the abundance of specific mRNAs and target gene systems associated with the disease state.(ABSTRACT TRUNCATED AT 250 WORDS)


A quantitative analysis of saccades and smooth pursuit during visual pursuit tracking. A comparison of schizophrenics with normals and substance abusing controls.

The eye movements of schizophrenic patients are characterized by decreased smooth pursuit gain and an increased frequency of saccades. However, the nature of these saccades and their function during smooth pursuit has not been clearly defined. To address this issue we examined the eye movements of 22 schizophrenic patients, 20 substance abusing patients (primarily alcohol; some with concomitant cocaine and/or cannabis abuse), and 17 normal controls during a visual pursuit task using infra-red oculography. A computerized pattern recognition algorithm divided pursuit eye movements into two basic components: smooth pursuit and saccadic eye movements. The algorithm also determined eye position error and velocity error before and after each saccade. Schizophrenic patients had lower smooth pursuit gain (p less than 0.02) and made more saccades during smooth pursuit (p less than 0.02) than either comparison group. When saccades were assigned to subcategories based on direction and position error, only the frequency of 'catch-up' saccades differentiated schizophrenic patients from the comparison groups (p less than 0.05). Smooth pursuit gain was negatively correlated with saccadic frequency among all three subject groups. Eye velocity preceding saccades was significantly lower among the schizophrenic patients, but pre or post saccadic position error did not differ among the three groups. Discrete analysis of the fine structure of visual pursuit tracking may lead to a better understanding of eye movement abnormalities in schizophrenia.


First International Conference on the Pathogenesis of Mycobacterial Infections: a summary.

Two hundred scientists representing 25 countries assembled for the First International Conference on the Pathogenesis of Mycobacterial Infections, which was held in Stockholm on 27-29 June 1990. A total of 40 speeches and 80 poster presentations covered nearly all of the recent progress made in the field of mycobacterial pathogenicity. The present report is intended as a brief summary of the research results presented during the conference and focuses on findings of broad scientific interest. However, the omission of other presented findings from this report does not constitute any judgment of their scientific quality.


False-positive flow cytometric platelet glycoprotein IIb/IIIa expression in myeloid leukemias secondary to platelet adherence to blasts.

Because neither morphologic nor routine cytochemical features are pathognomonic, the diagnosis of acute megakaryoblastic leukemia (AML-M7) is difficult, requiring either specialized ultrastructural or immunologic techniques. Because the ultrastructural techniques are cumbersome, immunologic assays for expression of several platelet-specific antigens, such as CD41a (platelet glycoprotein IIb/IIIa), have become the primary method used to detect megakaryoblastic differentiation. In our flow cytometric analysis of the immunophenotypes of over 1,000 cases of AML from patients registered to Southwest Oncology Group (SWOG) Treatment Protocols, we found that 38% of cases demonstrated CD41a reactivity. Because this frequency of CD41a expression by flow cytometry greatly exceeded the number of morphologically defined cases of AML-M7, we postulated that the reaction may be caused by platelets adherent to leukemic blasts. To investigate this hypothesis, we performed a side-by-side comparison of flow cytometric and cytospin immunofluorescence studies on 37 cases of adult de novo AML that demonstrated a wide range of CD41a expression by flow cytometric analyses. We found that the expression of CD41a detected by flow cytometric techniques was secondary to adherent platelets or platelet fragments in 85% of cases. Many of these cases also expressed the lineage-specific carbohydrate, LNF III (CD15), which may mediate platelet adhesion to mature monocytes and neutrophils. Only 15% of the CD41a flow cytometrically positive cases demonstrated true diffuse membrane and cytoplasmic positivity on cytospin slides indicative of megakaryoblastic differentiation. Cytospin immunofluorescence for CD41a should be performed on all cases of suspected AML-M7. If only flow cytometric techniques are used, adherent platelets may result in the erroneous diagnosis of this AML subtype.


Selecting dose-intense drug combinations: metastatic breast cancer.

A mathematical model previously described is applied to the problem of selecting drug combinations for metastatic breast cancer. The model accounts for the differing single-agent activities of the drugs as well as their differing profiles of toxicity. With no bone marrow protection, combinations with cisplatin offer a small improvement in total equivalent dose over therapy with the more active single-agents. Restricting consideration to the four most commonly used agents, single-agent doxorubicin has the greatest equivalent dose. With protection for leukopenia or willingness to accept a higher incidence of severe leukopenia, a combination with large doses of cyclophosphamide, doxorubicin, and fluorouracil, and a small dose of cisplatin has greatest equivalent dose. The doublets cyclophosphamide/fluorouracil or fluorouracil/cisplatin at higher doses are almost as good. With protection for leukopenia and thrombocytopenia, a cyclophosphamide/thiotepa combination at very high doses maximizes total equivalent dose. This approach can be used to identify regimens worthy of prospective evaluation.


Analysis of late graft failure after allogeneic bone marrow transplantation: detection of residual host cells using amplification of variable number of tandem repeats loci.

In an attempt to gain insight into the etiology of late graft failure, we analysed the origin of bone marrow mononuclear cells (BMMC) and peripheral blood leukocytes in patients with this syndrome by taking advantage of DNA fragment length polymorphisms in variable number of tandem repeats (VNTR) loci. Amplification of the VNTR loci in DNA from BMMC using the polymerase chain reaction revealed the persistence of host cells in two of four patients studied. One of the patients, whose cultured lymphocytes inhibited in vitro growth of donor-derived hemopoietic progenitor cells, responded to immunosuppressive therapy and donor-derived hemopoiesis was restored. In the other patient, host-derived polymorphonuclear leukocytes (PMN) appeared together with donor-derived PMN from the early post-transplant period, and he proceeded to relapse with myelodysplastic syndrome. In the other two patients in whom host cells were not detectable, the marrow hypoplasia was associated with chronic graft-versus-host disease (GVHD). The hypoplasia improved significantly as the chronic GVHD improved in response to immunosuppressive therapy. We conclude that detecting minimal residual host cells by means of amplification of VNTR loci is valuable for understanding the etiology of late graft failure in marrow transplant recipients, and could prove helpful for choosing appropriate therapy for this syndrome.


Prolonged remission of accelerated phase Philadelphia chromosome negative chronic myeloid leukemia following autologous recovery of normal hematopoietic elements after busulfan/cyclophosphamide and allogeneic marrow transplantation.

We describe here a patient with accelerated phase Philadelphia chromosome (Ph1) negative chronic myelogenous leukemia without BCR gene rearrangement, who received an allogeneic bone marrow transplant following a conditioning regimen consisting of busulfan (BU) and cyclophosphamide (CY). Hematopoiesis was restored following splenectomy performed 1 month post-transplant. There were no distinguishing cytogenetic differences between donor and host. Five years post-transplant the patient relapsed with the original disease. Restriction fragment length polymorphism (RFLP) studies performed at that time exhibited host specific DNA markers suggesting recurrent leukemia of host origin. RFLP analysis of the cells cryopreserved immediately post-transplant also revealed all cells to be of host origin. This patient experienced 5 years of remission with autologous hematopoietic recovery from an aggressive myeloproliferative disorder after high dose BU and CY without engraftment of donor hematopoietic cells.


Is the concept of frontal-subcortical dementia relevant to schizophrenia?

A syndrome of subcortical dementia has been described in conditions predominantly affecting the basal ganglia or thalamus, structures that have also been implicated in the pathogenesis of schizophrenia. There are similarities between subcortical dementia and the type II syndrome of schizophrenia, in terms of clinical features, pattern of neuropsychological deficits, pathology, biochemistry and data from brain-imaging studies. These similarities raise the possibility that certain schizophrenic symptoms, particularly negative symptoms and disturbance of movement, may reflect subcortical pathology. Neuropsychological deficits of presumed frontal lobe origin have been reported in some schizophrenic subjects. The occurrence of such deficits in a condition in which frontal lobe pathology has not been clearly demonstrated may be explicable in terms of a subcortical deafferentation of the pre-frontal cortex.


A species-specific population of tyrosine hydroxylase-immunoreactive neurons in the medial amygdaloid nucleus of the Syrian hamster.

The medial amygdaloid nucleus (Me) is part of a neural pathway that regulates sexual behavior in the male Syrian hamster. To characterize the neurochemical content of neurons in this nucleus, brains from colchicine-treated adult male and female hamsters were immunocytochemically labeled using antibodies that recognize the catecholamine-synthesizing enzymes, tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT), as well as dopamine. A large population of TH-immunoreactive (TH-IR) neurons was observed throughout Me of male and female hamsters, primarily concentrated in the midrostral and caudal portions of the nucleus. The somata were generally small to medium in size and bipolar. Brains from animals that did not receive colchicine contained a limited number of TH-IR neurons in Me as reported previously. The DBH and PNMT antisera did not label any cells in Me of colchicine-treated animals, and the dopamine antiserum labeled neurons in the same location as the caudal group of TH-IR cells. Therefore, these caudal TH-IR neurons are interpreted to be dopaminergic. The rostral group of TH-IR neurons, on the other hand, may be producing only the immediate precursor of dopamine, L-3,4-dihydroxyphenylalanine (L-DOPA). The TH-synthesizing neurons in Me of the Syrian hamster appear to be a species-specific group of cells located outside of the previously described catecholaminergic cell groups.


Selective potentiation of NMDA-induced activity and release of excitatory amino acids by dynorphin: possible roles in paralysis and neurotoxicity.

Selective antagonists of N-methyl-D-aspartate (NMDA) excitatory amino acid (EAA) receptors have been shown to protect against dynorphin-A (DYN)-induced paralysis and neurotoxicity in the spinal cord. To test the hypothesis that either DYN-induced paralysis or neurotoxicity involves an enhanced release of EAAs, we used microdialysis to monitor aspartate (Asp) and glutamate (Glu) release in both the lumbar spinal cord extracellular fluid (ECF) and the spinal cord cerebral spinal fluid (CSF) of conscious rats in response to DYN (1-13). Injection of 5 nmol of DYN produced temporary paralysis in 8 of 10 animals, but did not significantly change Asp or Glu release in either the ECF or the CSF. Injection of 20 nmol of DYN caused permanent paralysis and neuronal cell loss in all animals tested as well as a significant increase of Asp and Glu in both the ECF and the CSF, and a decrease in glutamine (Gln) release only in the ECF. Pretreatment with 1 mg/kg of the NMDA antagonist MK-801 blocked both paralysis and amino acid changes in the ECF. Pretreatment of animals with 5 mg/kg naloxone inhibited glutamate release in the ECF, but did not block paralysis, Asp release or inhibition of Gln release. As MK-801 sensitive paralysis by DYN was not mediated through enhanced EAA release, we examined whether DYN could act through postsynaptic facilitation of NMDA receptors by testing the ability of DYN to alter the magnitude of a behavioral response produced by intrathecal injection of NMDA in mice.(ABSTRACT TRUNCATED AT 250 WORDS)


Pharmacological specificity of the increase in neurotensin concentrations after antipsychotic drug treatment.

Neurotensin is an endogenous neuropeptide that produces many CNS effects that are similar to the behavioral and physiological alterations seen after administration of antipsychotic drugs to laboratory animals. As previously reported, sub-chronic (3 week) and acute (single injection) treatment with haloperidol (1 mg/kg), a clinically effective antipsychotic drug increases neurotensin concentrations in the nucleus accumbens and the caudate nucleus. In contrast, a tricyclic antidepressant (desipramine, 10 mg/kg), an anxiolytic (chlordiazepoxide, 25 mg/kg) and a histamine H1 receptor antagonist (diphenhydramine, 20 mg/kg) did not alter neurotensin concentrations in these brain regions after sub-chronic or acute treatment. These data demonstrate pharmacologic specificity to the antipsychotic drug-induced increases in regional brain neurotensin concentrations, and support the hypothesis that these changes may contribute to the clinical efficacy of these drugs.


An electron microscopic morphometric comparison of tyrosine hydroxylase immunoreactive innervation in the neostriatum and the nucleus accumbens core and shell.

The synaptic targets and size distributions of the sectioned profiles of tyrosine hydroxylase immunoreactive fibers and boutons in the neostriatum and shell and core of the nucleus accumbens were evaluated. Significantly more synaptic contacts where dendrite shafts are the postsynaptic element were observed in the shell than in the core of the nucleus accumbens or neostriatum. Relative to the core and neostriatum, a significantly greater proportion of the tyrosine hydroxylase immunoreactive innervation of the accumbal shell consisted of thin fiber and small bouton profiles. Thus, with regard to the morphometric parameters evaluated, the core of the nucleus accumbens is aligned with neostriatum and the shell is different from the core and neostriatum. In the light of these data, it is probably that the effects of the dopaminergic innervation in the core resemble the effects in neostriatum more than do those in the shell.


Basic fibroblast growth factor protects striatal neurons in vitro from NMDA-receptor mediated excitotoxicity.

Basic fibroblast growth factor (bFGF) promotes the survival and outgrowth of neurons. In this study the neuroprotective effects of bFGF were examined in 12-18-day-old cultured striatal neurons exposed to glutamic acid, kainic acid (KA), and quinolinic acid (QA), an N-methyl-D-aspartate (NMDA)-receptor agonist. Results showed that preincubation with bFGF (6 pM) from the day of plating significantly increased the survival of striatal neurons treated for 3 h with glutamate (3 mM) or QA (1 mM), but had little effect on KA (1 mM) induced toxicity. Moreover, maximum protection by bFGF against glutamate neurotoxicity was observed in cultures treated as little as 2 h before glutamate exposure. These results show that bFGF markedly protects striatal neurons from NMDA-receptor induced neurotoxicity.


Inhibitory effects of formoterol and terbutaline on the development of late phase skin reactions.

The capacity of the beta 2-agonist terbutaline and the longer-acting beta 2-agonist formoterol to suppress the development of late phase skin reactions to anti-human IgE was evaluated in 17 healthy volunteers. Anti-IgE injected intradermally per se induced an early weal and flare reaction, followed by a progressively increasing induration, the LCR, with a duration of greater than or equal to 24 hr. The LCR was inhibited by 40% when the weal was infiltrated with formoterol 250 ng 30 min after challenge (n = 9, P less than 0.01). The same anti-LCR effect was achieved by compensating for the shorter duration of action of terbutaline with repeated drug infiltration in 12.5 micrograms doses of the weal produced by anti-IgE up to 3 1/2 hr after challenge (n = 8). The data support the hypothesis that beta 2-agonists, both short- and long-acting, inhibit IgE-dependent LCRs by preferentially interacting with inflammatory events after the initial mast cell degranulation.


The effect of azelastine on the early allergic response.

To study the effect of azelastine on the immediate reaction to nasal allergen challenge, we performed a double blind, placebo-controlled cross-over clinical trial. Thirteen subjects with seasonal allergic rhinitis underwent nasal challenge with antigen 4 hr after a single oral 2 mg dose of azelastine. The response was monitored by counting the number of sneezes and by measuring the levels of histamine, prostaglandin D2, immunoreactive sulphidopeptide leukotrienes, kinis and TAME-esterase activity in recovered nasal lavages. After a single dose of azelastine, there was a significant reduction in sneezing (10 vs 2, P = 0.01) and in the median levels of recovered TAME-esterase activity (63.1 vs 17.5 c.p.m. x 10(-3), P = 0.01), immunoreactive sulphidopeptide leukotrienes (7.5 vs 2.1 ng/ml, P = 0.03) and kinins (1370 vs 251 pg/ml, P = 0.03), with no significant reduction in the median levels of histamine (3.7 vs 1.2 ng/ml, P = 0.2) and prostaglandin D2 (70 vs 70 pg/ml, P = 0.2) compared to placebo (numbers represent total increase over diluent challenge). These results suggest that azelastine does not inhibit mast cell activation but affects the consequences of released histamine, namely sneezing, increased vascular permeability and the generation of kinins. The results further suggest that other cells, in addition to mast cells, might be responsible for the generation of leukotrienes during the early allergic response, and that azelastine reduces their ability to generate this mediator or that inhibition of leukotriene release from mast cells occurs at lower drug concentrations.


[Takayasu's arteritis: a study by vascular sonography with special emphasis on carotid duplex].

Takayasu's arteritis (TA) is a chronic inflammatory disease mainly affecting young females involving the great vessels; the aorta and its major branches. Diagnosis and delineation of patterns of involvement used to depend on intra-arterial angiography in the past. With the advent of high resolution duplex ultrasonographic technique, TA can be non-invasively inspected in the vasculitis phase. Based on our ultrasound study of cervical and lower extremity vessels, 6 patients were proved to have TA by angiography. Some characteristic carotid imaging findings can be identified at the sonographic probe detectable regions, i.e., (1) The inflammatory changes of TA mainly involved the proximal parts of 3 major cervical branches from the aortic arch, but the distal parts of them and the internal carotid arteries are relatively spared. (2) The inflammatory plaques of TA are relatively homogeneous in appearance, concentric in deposition and a long extent of involvement. Differential diagnosis between TA and atherosclerotic changes can be made by the preferential sites, echogenic properties, length of involvement and manner of proliferation. Regular follow-up by ultrasonography in 2 patients showed that response to treatment and disease progression could be easily monitored.