Modulation of glutamate agonist-induced influx of calcium into neurons by gamma-L-glutamyl and beta-L-aspartyl dipeptides.

Gamma-L-Glutamate and beta-L-aspartate dipeptides, present in the mammalian brain with a yet unknown function, were shown to affect the influx of Ca2+ into cultured cerebellar granule cells. The most active peptides, gamma-L-glutamyl-L-aspartate, gamma-L-glutamyl-L-glutamate and gamma-L-glutamylglycine, enhanced the basal influx but inhibited the glutamate-activated influx of Ca2+ in a dose-dependent manner. Gamma-L-Glutamyl-L-aspartate, the strongest inhibitor of the glutamate-activated influx of Ca2+, exhibited selective Mg(2+)-dependent antagonism in the N-methyl-D-aspartate (NMDA)-activated influx of Ca2+. This finding may explain its previously shown deleterious effects on the long-term memory. On the other hand, gamma-L-glutamyl-L-aspartate enhanced alone the entry of Ca2+ into neurons. This effect was antagonized by the non-NMDA antagonists 6-nitro-7-cyanoquinoxaline-2,3-dione (CNQX) and 6,7-dinitroquinoxaline-2,3-dione (DNQX), suggesting a non-NMDA receptor-mediated action, that may also be involved in excitotoxicity in some neurodegenerative disorders.


L-homocysteic acid selectively activates N-methyl-D-aspartate receptors of rat retinal ganglion cells.

To explore the possible role of L-homocysteic acid (HCA) as a retinal transmitter, whole-cell recordings with patch electrodes were performed on isolated rat retinal ganglion cells (RGCs) in culture. HCA elicited an inward current at -60 mV. Similar to currents evoked at this potential in RGCs by N-methyl-D-aspartate (NMDA), HCA-activated currents were of relatively small amplitude (10-150 pA), and the noise level increased dramatically during the response. When HCA was co-applied with concentrations of NMDA that elicited a maximal response, the current was not increased over that of NMDA alone. HCA-evoked currents were almost completely blocked by the NMDA antagonists D-2-amino-5-phosphonovalerate (D-AP5), Mg2+, or 7-chlorokynurenate (7-Cl KYN). Unlike its effects on other preparations, even millimolar concentrations of HCA did not activate kainate-like currents. These observations suggest that HCA specifically activates the NMDA receptor-channel complex of rat RGCs.


The neuroprotective effects of dextromethorphan on guinea pig-derived hippocampal slices during hypoxia.

The purpose of this study was to determine whether dextromethorphan, an opioid class antitussive, prevents hypoxia-induced loss of nerve function in an in vitro hippocampal slice preparation. The evoked population spike (PS) was recorded from CA1 pyramidal cells of guinea pig-derived hippocampal slices. Hippocampal slices were superfused with O2 (95%)/CO2 (5%) gassed artificial cerebral spinal fluid (ACSF) at 37 degrees C. The PS did not recover during reoxygenation in slices that were made hypoxic for 30 min by exposure to N2 (95%)/CO2 (5%) gassed ACSF in place of oxygenated ACSF. The PS recovered during reoxygenation, following 30 min of hypoxia, in 9 of 10 slices treated with dextromethorphan (100 microM) and in 4 of 6 slices treated with D,L-2-amino-5-phosphono-valerate (AP-5) (100 microM), an NMDA receptor antagonist. The mean PS amplitudes, one hour after perfusion with oxygenated ACSF, were 42% and 51%, respectively, of the pre-hypoxia amplitude. The PS recovered during reoxygenation in all of seven slices superfused with lowered temperature ACSF (25 degrees C) during 30 min of hypoxia. The results show that dextromethorphan, like the NMDA antagonist AP-5 and lowered temperature, protected neurons from hypoxia-induced injury in the hippocampus.


A muscle-derived factor antagonizes the neurotoxicity of glutamate in dissociated cell cultures of chick telencephalic neurons.

Excitatory amino acids including glutamate are known to reveal considerable neurotoxicity in various nervous systems. Our previous studies revealed that the chick muscle extract contains a factor which promotes the survival of telencephalic neurons. Further investigations clearly showed that this extract contains the factor that antagonizes the neurotoxicity of glutamate in a dissociated telencephalic neuronal culture system optimized for detection of the toxicity. This factor reduced at least the toxicity mediated by non-N-methyl-D-aspartate (non-NMDA) receptor.


Effects of somatostatin on potassium currents in bullfrog sympathetic ganglion neurones: possible role of receptor subtypes.

The effects of whole somatostatin (wSS; somatostatin-28) and cyclic somatostatin (cSS; somatostatin-14) were examined on patch-clamped bullfrog sympathetic ganglion neurones. In the C-cells, where muscarine produces hyperpolarization, wSS was also inhibitory and activated an inwardly-rectifying K+ current; cSS was ineffective. By contrast, in the B-cells, where muscarine produces excitatory effects, cSS was also excitatory and was more effective than wSS in suppressing a voltage-dependent, non-inactivating K(+)-current (IM). These results are consistant with the idea that excitatory and inhibitory effects of somatostatin-derived peptides may be mediated via different receptor subtypes.


Vagal stimulation and somatostatin potentiate cardiac vagal action in the toad, Bufo marinus.

Cholinergic postganglionic neurones of the cardiac vagus in the toad, Bufo marinus, have been shown to contain the peptide somatostatin (SOM), which causes direct negative inotropic and chronotropic effects on the heart. In anaesthetised toads, high frequency stimulation (10 Hz) of cardiac vagus nerves results in prolonged cardiac slowing and potentiation of the cardiac slowing measured in response to a train of vagal stimuli at low frequency. Intravenous administration of the tetradecapeptide form of SOM also results in prolonged cardiac slowing and potentiation of cardiac vagal action. Effects on heart rate of small bolus doses of acetylcholine (ACh) were unaltered by administration of SOM, at the same time as cardiac vagal slowing was enhanced. It is suggested that SOM is released from vagal nerve endings by high frequency stimulation and enhances cardiac vagal action by a presynaptic mechanism.


Role of N-methyl-D-aspartate and opiate receptors in nociception during and after ischaemia in rats.

We have investigated the effects of systemic administration of two N-methyl-D-aspartate (NMDA) receptor antagonists and two opiate agonists on nociception during and after tail ischaemia in conscious rats. The two NMDA receptor antagonists, D-2-amino-5-phosphonovalerate (APV) and ketamine hydrochloride, did not alter tail flick latencies in rats not subjected to ischaemia but inhibited post-ischaemic hyperalgesia (PIH) in a dose-dependent manner. Neither of these agents impaired motor function of the rats, as assessed by rotarod performance, suggesting a purely sensory antinociceptive effect. The antinociceptive effect of APV during reperfusion following ischaemia was not antagonised by the mu-opiate receptor antagonist naloxone (1 mg/kg). The two opiate receptor agonists, morphine and pethidine, increased tail flick latencies in rats not subjected to ischaemia, inhibited PIH in a dose-dependent manner, and also caused significant motor malfunction, all in naloxone-reversible fashion. We conclude that the role of the NMDA receptor in mediating afferent nociceptive traffic is confined to its involvement in neuronal events mediating hyperalgesia.


[Prenatal diagnosis of mucoviscidosis: indication of enzyme determination and molecular biology techniques].

Prenatal diagnosis of cystic fibrosis established by study of RFLPs flanking the gene and, since 1989, by direct detection of the major mutation delta F508 is now widely used. However, there are still some indications of prenatal diagnosis by microvillar intestinal enzymes analysis. We propose a prenatal diagnosis strategy which combines both methods. This diagnosis strategy is applied to families with a 1/4 to 1/200 risk. Screening of delta F508 in the general population is discussed.


Effect of microcapsules of luteinizing hormone-releasing hormone antagonist SB-75 and somatostatin analog RC-160 on endocrine status and tumor growth in the Dunning R-3327H rat prostate cancer model.

Inhibitory effects of sustained delivery systems (microcapsules) of the modern antagonist of luteinizing hormone-releasing hormone [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10]LH-RH (SB-75) or the potent somatostatin analog D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) were investigated in the Dunning R-3327H rat prostate cancer model. In the first experiment, the treatment was started 4 months after tumor transplantation, when the tumors measured approximately 2 cm3. Tumor volumes and weights were significantly reduced by SB-75 microcapsules releasing 48 micrograms/day or RC-160 microcapsules releasing 38 micrograms/day given alone, as compared with the control. The combination of these two analogs showed a synergistic effect. In the second experiment, the treatment was started 7 months after tumor transplantation, when the tumors were well developed and measured about 16 cm3. In addition to a significant reduction in volume, weight, and growth rate of tumors, histological signs of tumor regression were found in the groups treated with SB-75 microcapsules releasing 72 micrograms/day given alone or in combination with RC-160 microcapsules releasing 76 micrograms/day, but not with RC-160 alone. No synergistic effect of the combination therapy was found in the second experiment. Serum testosterone levels decreased to undetectable levels and LH levels were also diminished within 2 weeks by administration of SB-75 alone or in combination with RC-160. In both experiments, the weights of testes, ventral prostate, and seminal vesicles were greatly reduced by administration of SB-75 alone or in combination with RC-160. Our results suggest that the combined therapy with microcapsules of SB-75 and RC-160, started soon after the diagnosis of prostate cancer is made, could improve therapeutic response.


Caffeine moderately antagonizes the effects of triazolam and zopiclone on the psychomotor performance of healthy subjects.

To determine whether caffeine antagonizes the decremental effects of triazolam and zopiclone on human performance, oral single doses of 0.250 mg triazolam, 7.5 mg zopiclone, or respective placebos, with and without 300 mg caffeine, were given to parallel groups of student volunteers in two double-blind studies. Objective tests and subjective visual analogue ratings were done at baseline and 30 min. and 90 min. after the intake. In Study I, triazolam produced drowsiness at 30 min. but did not differ from the placebo in other tests. Caffeine induced alerting effects in various tests and differed from triazolam in some (digit substitution, drowsiness, calmness, mental slowness) but not all variables measured. Caffeine and triazolam were interpreted as being antagonists. In Study II, zopiclone impaired digit substitution and flicker fusion, produced exophoria and lowered systolic blood pressure. Caffeine differed from zopiclone in several test functions, but it also differed from caffeine + zopiclone whereas zopiclone differed from caffeine + zopiclone only in two tests (Maddox wing, systolic blood pressure). Thus, zopiclone counteracted the effects of caffeine more easily than caffeine counteracted the decremental effects of zopiclone. We conclude that triazolam may not differ importantly from diazepam as regards their antagonism towards caffeine, whereas further research on the antagonism between zopiclone and caffeine needs to be done.


[Cancer of the pancreas. A plea for resection. 162 operated patients].

Between 1970 and 1990, 162 patients with carcinoma of the pancreas or the periampullary region were operated upon. A prospective study was conducted in 85 of them who underwent surgery after 1983. The tumour was resected in 63 patients (ductal adenocarcinoma in 43, periampullary carcinoma in 20). Biliary and/or gastrointestinal bypass was performed in 76 patients, and exploratory laparotomy in 23. The operative mortality rate was 3 percent (2/63) among patients with resection and 24 percent (24/99) among those with laparotomy with or without bypass. The longest survival (median: 33 months) was obtained in patients with periampullary tumours; it was 12 months after resection in patients with ductal adenocarcinoma and 4 months in the other cases. The preoperative estimate of unresectability was erroneous in 36.5 percent of the cases. Periampullary tumours were diagnosed only after pathological examination of the lesion removed in 47 percent. These results are in favour of radical surgery, especially since the operative mortality of resection is low and since resection, even palliative, gives a better survival rate than mere bypass.


Studies of the cloned 37-kDa subunit of activator 1 (replication factor C) of HeLa cells.

The elongation of primed DNA templates by DNA polymerase delta and DNA polymerase epsilon requires the action of two accessory proteins, proliferating cell nuclear antigen and activator 1 (A1, also called replication factor C). A1 is an enzyme that contains five different subunits (145, 40, 38, 37, and 36.5 kDa). In this paper, we describe the isolation of the gene encoding the 37-kDa subunit from HeLa cells. This gene was cloned, sequenced, and overexpressed in Escherichia coli. The amino acid sequence shows a high degree of homology to the 40-kDa subunit of A1; they both contain the identical ATP-binding motif, but in contrast to the bacterial expressed 40-kDa protein, the 37-kDa expressed protein did not bind ATP. Both the 37- and 40-kDa proteins share substantial homology with the phage T4 gene 44 protein and to a lesser extent with the tau and gamma subunits of the E. coli DNA polymerase III holoenzyme. Polyclonal antibodies against the bacterially expressed 37- and 40-kDa proteins do not crossreact and are specific in their interaction. Antibodies against the 37-kDa protein maximally inhibited (by 50%) the A1-dependent synthesis of DNA by DNA polymerase delta; antibodies against the 40-kDa protein quantitatively inhibited the same reaction. When A1-dependent synthesis of DNA was partially inhibited by antibodies against the 40-kDa subunit, the addition of antibodies against the 37-kDa subunit inhibited DNA synthesis to a greater extent than the anti-37-kDa antibody alone. These results suggest that both the 37- and 40-kDa subunits of A1 are required for the biological role of A1 and that they may function differently in this process.


Spontaneous incorporation of the glycosyl-phosphatidylinositol-linked protein Thy-1 into cell membranes.

Thy-1 is a membrane protein that is attached to the plasma membrane by a glycosyl-phosphatidylinositol anchor. Purified rat brain Thy-1 could be reincorporated into the plasma membrane of murine Thy-1- cells directly from aqueous suspension and without the use of detergents. A peripheral staining pattern similar to that observed for endogenous Thy-1 was achieved. Treatment with phosphatidylinositol-specific phospholipase C removed nearly all antibody staining due to either endogenous or inserted Thy-1. Fluorescence recovery after photobleaching (FRAP) was used to compare the lateral mobility of endogenous and inserted Thy-1. Both forms exhibited large lateral diffusion coefficients, but with a substantial immobile fraction (approximately 50%) indicating that the immobile fraction was not due either to chemical differences between inserted and native Thy-1 or to some surface Thy-1 molecules having a protein anchor. However, the inserted Thy-1 failed to activate mouse T lymphocytes upon crosslinking as assayed by [3H]thymidine uptake. Since Thy-1 could be directly labeled with rhodamine, the effect of the size of the labeling ligand on the mobility obtained by the FRAP technique could be explored. Rhodamine-conjugated MRC-OX7 monoclonal antibody or its fragments [R-F(ab)2 or R-Fab] were compared with rhodamine as labels for Thy-1. The measured diffusion coefficients were 1.6 x 10(-9), 2.0 x 10(-9), and 3.2 x 10(-9) cm2/sec for Thy-1 labeled with R-F(ab)2, R-Fab, and rhodamine, respectively; mobile fractions were all in the 40-50% range. Thus, the size of the ligand affects the lateral mobility of this labeled membrane protein to a measurable extent.


ERBB2 amplification in breast cancer analyzed by fluorescence in situ hybridization.

We illustrate the use of fluorescence in situ hybridization (FISH) for analysis of ERBB2 oncogene copy number, the level of amplification (here defined as the ratio of ERBB2 copy number to copy number of chromosome 17 centromeres), and the distribution of amplified genes in breast cancer cell lines and uncultured primary breast carcinomas. The relative ERBB2 copy number determined by FISH in 10 breast cancer cell lines correlated strongly with Southern blot results (r = 0.98) when probes for an identical reference locus were used in the two methods. Metaphase analysis of cell lines showed that amplified ERBB2 copies always occurred in intrachromosomal clusters but that the number and chromosomal location of these clusters varied among the cell lines. In interphase nuclei of primary tumors showing ERBB2 amplification (10/44), ERBB2 copies were seen as one to four clusters, also suggesting intrachromosomal localization. Regardless of the average level of amplification, all these tumors contained highly amplified cell subpopulations with at least 25, and sometimes more than 100, ERBB2 copies per cell. Tumors that did not show amplification by FISH (34/44) had an average of one to five ERBB2 copies scattered randomly in the nuclei and completely lacked cells with high copy levels. FISH results on primary tumors were concordant with slot blot results on amplification and with immunohistochemical detection of overexpression. Quantitative analysis of ERBB2 amplification by FISH may improve prognostic assessments based on the pattern of amplification and detection of heavily amplified tumor cell subpopulations.


Genotypic analysis of N-ethyl-N-nitrosourea-induced mutations by Taq I restriction fragment length polymorphism/polymerase chain reaction in the c-H-ras1 gene.

In genotypic mutation analysis DNA sequence changes are determined without the in vivo or in vitro selection of phenotypically altered cells. We have studied the induction of base-pair changes by N-ethyl-N-nitrosourea in Taq I endonuclease recognition site 2508-2511 (TCGA) of the c-H-ras1 gene in human fibroblasts by the restriction fragment length polymorphism/polymerase chain reaction (RFLP/PCR) method. This site contains the four bases, and all 12 possible single base-pair changes can be monitored. The transition of guanine to adenine at position 2510 was the major mutation detected by lambda plaque oligonucleotide hybridization and quantitative sequence analysis of the RFLP/PCR products. It involves the G residue of the CpG sequence of the coding strand. Data calibration with an internal mutant standard indicates that absolute frequencies for this transition lie in the range of 4-12 x 10(-7). The present study documents the capacity of the RFLP/PCR approach to measure mutagen-induced base-pair changes in a specific gene sequence without the selection of a phenotypically altered cell.


[Takayasu's disease. Exploration by intra-arterial digital angiography. 50 cases].

The long-term prognosis of Takayasu's disease depends on an elective surgical treatment which requires full and accurate assessment of the lesions. We present here a retrospective study of 50 patients explored before surgery by intra-arterial digital angiography. In 92 percent of the patients the thoraco-abdominal aorta and its branches were well documented on 2 orthogonal projections performed in one single session. The high-quality intra-arterial opacification made it possible to detect incipient parietal lesions and to evaluate the lesions of the small caliber branches and the downstream bed in case of occlusion. These advantages, and the absence of morbidity in our experience, make digital panarteriography a method of choice to evaluate Takayasu's disease.


Gene conversion in Neisseria gonorrhoeae: evidence for its role in pilus antigenic variation.

Antigenic variation of gonococcal pili results from the unidirectional transfer of genetic information from variant-encoding partial pilin genes to an active expression locus. Two potential mechanisms that may result in the observed alterations of gene linkage and organization are conversion and transformation. To determine the relative contributions of these two distinct pathways of recombination to pilus variation, gonococcal strains carrying defined frameshift, missense, and nonsense mutations within the pilin expression locus were constructed. Reversion to a piliated state required correction of the lesions and provided a simple means of scoring productive recombination and antigenic variation. Examination of the mutants revealed a lack of correspondence between the frequencies with which they could be transformed (10(-6) per recipient) and the incidence with which they gave rise to revertants (greater than 10(-4) per colony-forming unit per generation). Further, the rates of reversion demonstrated by these mutants were not altered by growth in the presence of DNase I, conditions that abolished intercellular transfer of chromosomal markers during cultivation. Through the use of a pilin mutant in which a frameshift mutation encompassed the introduction of a restriction endonuclease site, the symmetry of recombination that resulted in reversion could be scored by Southern hybridization. In all cases examined, the DNA alterations responsible for pilin variation were nonreciprocal events. The results favor the model that productive pilin gene rearrangements in gonococci arise by gene conversion.


Fusions near telomeres occur very early in the amplification of CAD genes in Syrian hamster cells.

Previous analyses by fluorescence in situ hybridization of structures present 20-30 cell generations after the primary events of mammalian gene amplification have shown that tens of megabases of DNA separate each copy of the selected gene in chromosomal arrays that contain up to 15 copies. Since these structures are very unstable, it is necessary to study amplified DNA as soon as possible after it has been formed to relate the structures observed to the primary mechanisms that generated them. Previously, new amplifications of the CAD gene were analyzed in colonies of 10(5) N-(phosphonoacetyl)-L-aspartate-resistant Syrian hamster BHK cells. CAD is on the p arm of chromosome B9 and the amplified genes were usually found in large extensions of B9p, with one copy in its normal position. We now report that dividing drug-resistant cells have been physically separated from static drug-sensitive cells, to allow the amplified structures to be observed only a few cell generations after they have been formed. The most informative results are that about one-third of the newly formed chromosomes carrying amplified CAD genes are dicentric and that about half of these carry two B9q arms. These observations reveal that recombination between the p telomeric regions of two B9 sister chromatids is an important primary event of amplification in this system. The resulting dicentric chromosomes can then enter bridge-breakage-fusion cycles that provide the means to increase the number of CAD genes per cell in successive generations by an asymmetric distribution at each cell division.


Identification of double-stranded RNA-binding domains in the interferon-induced double-stranded RNA-activated p68 kinase.

The double-stranded RNA (dsRNA)-binding domain of the human p68 kinase has been localized to the N-terminal half of the enzyme by using progressive deletion analysis and in vitro binding assays. To further define the domains responsible for binding to dsRNA, we cloned the mouse dsRNA-activated p65 kinase and used sequence alignment to identify conserved domains in the N-terminal region. Deletions in either of two 12-amino-acid-long and arginine- or lysine-rich regions abrogated binding to dsRNA. Moreover, in an in vivo growth inhibition assay in the yeast Saccharomyces cerevisiae, these mutants failed to exhibit a slow-growth phenotype.


A human serotonin 1D receptor variant (5HT1D beta) encoded by an intronless gene on chromosome 6.

An intronless gene encoding a serotonin receptor (5HT1D beta) has been cloned and functionally expressed in mammalian fibroblast cultures. Based on the deduced amino acid sequence, the gene encodes a 390-amino acid protein displaying considerable homology, within putative transmembrane domains (approximately 75% identity) to the canine and human 5HT1D receptors. Membranes prepared from CHO cells stably expressing the receptor bound [3H]serotonin with high affinity (Kd 4 nM) and displayed a pharmacological profile consistent, but not identical, with that of the characterized serotonin 5HT1D receptor. Most notably, metergoline and serotonergic piperazine derivatives, as a group, display 3- to 8-fold lower affinity for the 5HT1D beta receptor than for the 5HT1D receptor, whereas both receptors display similar affinities for tryptamine derivatives, including the antimigraine drug sumatriptan. Northern blot analysis revealed an mRNA of approximately 5.5 kilobases expressed in human and monkey frontal cortex, medulla, striatum, hippocampus and amygdala but not in cerebellum, olfactory tubercle, and pituitary. The 5HT1D beta gene maps to human chromosome 6. The existence of multiple neuronal 5HT1D-like receptors may help account for some of the complexities associated with [3H]serotonin binding patterns in native membranes.


The effect of SRIF on the EEG sleep of normal men.

The aim of this investigation was to evaluate EEG sleep, especially measures of delta-wave sleep, during and after the administration of somatostatin (SRIF). Eleven normal men, ages 22-37 yr, were administered saline or SRIF (0.1 microgram/kg/min IV) over 160 min at bedtime. SRIF delayed sleep-related growth hormone (GH) secretion without altering the amount of GH available during the entire night of sleep. No changes in delta-wave sleep occurred during either the first 100 min of sleep or the remainder of the night. Furthermore, all major EEG sleep variables were not significantly different between the saline and SRIF infusion night. It would not appear that the peripheral administration of this dose of SRIF or the subsequent delay of GH release has quantitative effects on EEG measures of all-night sleep.


Non-neuroleptic treatment of behavioral symptoms and agitation in Alzheimer's disease and other dementia.

Both neuroleptic and nonneuroleptic medications are widely used to treat symptomatic behaviors in dementia patients. There is a substantial body of literature suggesting that neuroleptics are modestly effective in treating these symptoms, but the magnitude of their effect is limited. Nonneuroleptic medications, such as anticonvulsants and antidepressants, have been advocated as useful in treating certain symptoms but have not been as well studied. This article critically reviews the published evidence for the effectiveness of selected nonneuroleptic medications in treating behavioral symptoms in elderly dementia patients, especially those with possible Alzheimer's disease (AD). The literature consists almost entirely of clinical series and case reports, making interpretations of the efficacy of individual medications difficult. With the singular exception of the serotonin uptake blocker citalopram, the few placebo-controlled studies are of small sample sizes, showing at best very modest efficacy for the study medication. Despite their widespread use, there is very little published, empirical evidence for the effectiveness of these agents for treating behavioral symptoms in elderly dementia patients.


Disclosure of tardive dyskinesia: effect of written policy on risk disclosure.

Over half of the states in the country have written statutory and/or regulatory policies that require psychiatrists treating inpatients within the state mental health system to disclose risks associated with treatment to voluntarily admitted patients. A severe side effect associated with the long-term use of neuroleptic medication is tardive dyskinesia (TD). A nationwide study was conducted to investigate the effect of written risk disclosure policy on psychiatrists' self-reported disclosure of the risks associated with neuroleptics to individuals diagnosed as having schizophrenia of a chronic nature. Participating in the study were 520 psychiatrists from 94 state/county mental hospitals located in 35 states. Fifty-four percent of those psychiatrists reported that they typically disclosed TD to the target patient population. The study results did not support the hypothesis that the presence of statutory and regulatory policy on disclosure of risk results in psychiatrists typically disclosing TD to patients.


Concurrent adrenal pheochromocytoma and papillary adenocarcinoma of the thyroid in a 20-year-old man.

A 20-year-old man was admitted to Kyushu University Hospital with complaints of severe headache and episodic hypertension (200/100 mmHg). Ultrasonograms and computed tomographs revealed tumors in the left adrenal region and in the right lower lobe of the thyroid gland. Total thyroidectomy and left adrenalectomy were performed. The excised thyroid tumor and adrenal tumor were pathologically diagnosed as papillary adenocarcinoma and pheochromocytoma, respectively. A chromosome analysis revealed no karyotypic abnormality. Whereas the world literature records such occurrences in women, this is the first report of a simultaneous occurrence of pheochromocytoma and papillary adenocarcinoma of the thyroid in a young man.


Natural scrapie in British sheep: breeds, ages and PrP gene polymorphisms.

One hundred and sixty-seven sheep of 32 breeds and crossbreeds affected by natural scrapie throughout Britain were tested for the presence of restriction fragment length polymorphisms of the PrP gene observed when their DNA was digested with EcoRI or HindIII. These polymorphisms have already been associated with different susceptibilities to experimental scrapie (controlled by alleles of the Sip gene) in a flock of Cheviot sheep. In two studies 86 to 92 per cent of the sheep were found to carry the PrP gene EcoRI fragment e1 which is associated with high susceptibility (or the sA allele of Sip) to experimental scrapie. The PrP gene HindIII genotypes of the natural scrapie sheep were not apparently associated with differences in susceptibility to scrapie. There was no link between the polymorphisms and the age or breed of the affected sheep.


[The relation between cognitive deficits and schizophrenic symptoms].

Reasons are given for explicitly derived requirement that experimental-psychological investigations of cognitive deficits of schizophrenics should be related to their clinical symptoms. Results which verify this relations prove to be relevant for prognosis, therapy and rehabilitation of schizophrenic patients.


[Use of pronouns: formal and functional aspects in the early phases of language development].

This article presents findings from empirical studies of the development of the use of pronouns in early child language. This presentation includes discussion of 1) when personal, reflexive, possessive, and indefinite pronominal forms appear in child-initiated contexts, 2) which errors emerge, and 3) which communicative functions utterances with pronouns have in dialogue. A first comparison of German-speaking and (American-)English-speaking children's usage is offered, focussing in particular on the use of the pronominal forms I/ich, you/du, and my/mein. This crosslinguistic comparison reveals differences in the age of first use, but simultaneously suggests similarities in functional characteristics of such usage. The findings are discussed in connection with the question of the development of children's communicative competence.


Is guanylate cyclase activation through the release of nitric oxide or a related compound involved in bradykinin-induced perivascular primary afferent excitation?

In dogs under light thiopentobarbital anesthesia, intracarotid injection of bradykinin (BK) causes a dose-dependent "pain response" represented by hyperpnea, bradycardia, vocalization and ipsilateral contraction of the sternocephalic muscle. These events result from the activation of primary afferent nerves located in the wall of the carotid vessels distributed mainly in occipital artery territory. We present evidence indicating that these BK-induced reflex phenomena are 1) mediated by the activation of B2 receptors; 2) potentiated by prostaglandin E2 (PGE2) and serotonin (5-HT) the latter acting via sub-type 5-HT3 receptors; 3) reduced by indomethacin and/or NG-nitroarginine, and 4) abolished by methylene blue. These results suggest that 5-HT plays a modulatory role on BK action; the latter depends on the release of prostaglandins and nitric oxide or a related compound and includes the activation of guanylate cyclase which appears to be involved in primary afferent excitation.


gamma-Glutamyltransferase isoenzyme pattern in workers exposed to tetrachloroethylene.

In compliance with the mandatory medical surveillance of workers exposed to tetrachloroethylene (PCE) in Italy, isoenzyme fractioning of serum gamma-glutamyltransferase (GGT) was performed on 141 workers of both sexes and on 130 control subjects. None of the workers showed any clinical symptoms of liver disease and their enzymatic profiles, including AST, ALT, 5'-NU, ALP, and GGT, were within the normal reference limits. A statistically significant increase in total GGT serum level was found in the exposed subjects, which was associated with an increase in one of the two fractions normally present in healthy individuals (GGT-2), as well as with the appearance and progressive increase of the level of a fraction (GGT-4) considered to be an expression of hepato-biliary impairment. Further research is ongoing among these workers, which will clarify whether or not electrophoretic GGT tests may be useful in detecting liver function changes due to occupational exposure to PCE.


Molecular study of 45,X conceptuses: correlation with clinical findings.

The parental origin of the single X in 45 cases (40 liveborns and 5 fetuses) with a 45,X karyotype was studied using polymorphic DNA probes. The single X was paternal in origin (Xp) in 10 cases (22.2%) and maternal (Xm) in 35 cases (77.8%). Y chromosome material was detected in 1 out of the 35 cases with a 45,Xm constitution. Analysis of parental ages and clinical data of the patients with respect to the origin of the single X revealed no significant differences between the origins.


Mapping the gene for juvenile onset neuronal ceroid lipofuscinosis to chromosome 16 by linkage analysis.

The ceroid-lipofuscinoses are a group of inherited neurodegenerative disorders characterised by the accumulation of autofluorescent lipopigment in neurones and other cell types. The underlying biochemical defect is unknown. Juvenile onset neuronal ceroid lipofuscinosis (Batten disease; Spielmeyer-Vogt disease) is an autosomal recessive trait. Linkage studies were undertaken to determine the location of the Batten disease (CLN3) mutation. Studies were carried out on 205 members of 42 families in which there were 76 affected individuals. Families originated from 7 North European countries and Canada. Serum samples from 23 families, including a total of 48 affected children, were tested for a set of "classical markers." A positive lod score was found with the haptoglobin (Hp) system. The combined male and female maximum lod score was 3.00 at theta = 0.00 and theta = 0.26, respectively. This provided an indication of localisation to the long arm of chromosome 16. Linkage analysis was then carried out in 42 families using DNA markers for loci on human chromosome 16. The maximal lod score between Batten disease and the locus D16S148 calculated for combined sexes was 6.05. No recombinants were observed. Multilocus analysis using 5 loci indicated the most likely order to be HP-D16S151-D16S150-CLN3-D16S148-D16S147. Work is in progress to refine the genetic and physical localisation of the Batten disease gene using additional markers in this region and a panel of somatic cell hybrids. Methods are now available which should allow the gene to be isolated and characterised.


Brief treatment of emergency room patients with panic attacks.

Most research on treatment for panic disorder has involved chronic forms of the illness. To determine the efficacy of early intervention, the authors examined the effects of treatment for patients with panic attacks who were seen in the emergency room, which is the first point of contact with the health delivery system for many persons with panic attacks. The subjects were 33 patients with panic attacks seen in two emergency rooms. The presence of panic attacks was confirmed with a modified version of the Structured Clinical Interview for DSM-III-R; approximately 40% of the patients met the DSM-III-R criteria for panic disorder with agoraphobia. The patients were randomly assigned to groups receiving reassurance (N = 16) or exposure instruction (N = 17). Scores on the Fear Questionnaire agoraphobia subscale, Mobility Inventory, and Beck Depression Inventory and the frequency of panic attacks were determined at baseline, 3 months, and 6 months. The subjects who received exposure instruction significantly improved over the 6-month period on depression, avoidance, and panic frequency. The reassurance subjects did not improve on any measure and eventually reported more agoraphobic avoidance. These results suggest that early intervention with exposure instruction may reduce the long-term consequences of panic attacks. The exposure instruction was of value even though the subjects had relatively low levels of avoidance at the outset of the study.


The influence of atropine dose on recovery from vecuronium-induced neuromuscular blockade.

To determine whether the dose of atropine affects the rate of neostigmine-induced recovery from vecuronium-induced neuromuscular blockade, the authors monitored isometric adductor pollicis mechanical activity in 36 anesthetized (thiopental, fentanyl, nitrous oxide) adult patients (ASA physical status 1 or 2). Once surgery was completed and twitch height had spontaneously regained 25% of its initial value, the patients were randomly allocated into three groups (A10, A15, A20; n = 12 in each group) according to the dose of atropine (10, 15, or 20 micrograms/kg) that was mixed with 40 micrograms/kg neostigmine. Twitch height, train-of-four, and 50- and 100-Hz tetanic fade were recorded for 15 min after the administration of the reversal agents. No significant differences were found among the three groups in the final twitch height (95% +/- 2%), train-of-four (87% +/- 1%, 88% +/- 2%, 89% +/- 1%), and 50-Hz tetanic fade (90% +/- 1%, 94% +/- 1%, 93% +/- 1%) (mean +/- SEM). Fifteen minutes after reversal, fade in response to 100-Hz tetanus was statistically greater in the A10 group than in the two other groups (70% +/- 3% of control versus 84% +/- 4% and 81% +/- 2%) (mean +/- SEM, P less than 0.05). The present results demonstrate that larger doses of atropine facilitate neostigmine's reversal of vecuronium neuromuscular blockade. The clinical implications of the differences observed in this study remain to be determined.


On the uptake of Wuchereria bancrofti microfilariae in vector mosquitoes of different susceptibility to filarial infections.

The quantitative uptake of Wuchereria bancrofti microfilariae by mosquito species of different susceptibility to filarial infection was studied. There was no relationship between the degree of susceptibility and the number of ingested microfilariae. However, in all tested mosquito strains the females ingested as a mean 1.2-1.9 times more microfilariae of W. bancrofti than expected.


Clinical presentation and treatment of black widow spider envenomation: a review of 163 cases.

To review cases of black widow spider envenomation to describe the clinical presentation and evaluate the efficacy of treatment. Retrospective chart review. An urban toxicology referral center. All patients attended by the toxicology service and discharged from our hospital between January 1982 and December 1990 with a diagnosis of black widow spider envenomation. Inclusion criteria were either a positive black widow spider identification or a visible envenomation site ("target lesion"). Depending on the clinical presentation, patients were categorized as grade 1, 2, or 3 in severity. The efficacy and side effects of treatment alternative were evaluated. One hundred sixty-three patients met the inclusion criteria. The most common sites of envenomation were the upper and lower extremities. The most common presenting complaint was generalized abdominal, back, and leg pain. One hundred eighteen patients initially presented to our institution, and 45 were transfers. Pain relief of grade 2 and 3 envenomations was achieved most effectively with either black widow spider-specific antivenin alone or a combination of IV opioids and muscle relaxants. Fifty-eight patients received antivenin with complete resolution of symptoms in a mean time of 31 +/- 26.7 minutes. Of the 118 patients initially seen at our institution, the mean total duration of symptoms was 9 +/- 22.7 hours in patients receiving antivenin and 22 +/- 24.9 hours in patients not receiving antivenin. Fifty-two percent of patients not receiving antivenin required hospitalization, whereas only 12% of those receiving antivenin were admitted. One patient died of severe bronchospasm after receiving antivenin. Calcium gluconate was not effective in providing symptomatic relief in this series, with 96% of the grade 2 and 3 envenomations treated initially with calcium gluconate requiring the addition of IV opioids or other analgesics for symptomatic relief. Fifty-five percent of patients initially receiving IV morphine and 70% of those initially receiving both IV morphine and benzodiazepines obtained symptomatic relief without additional medication. One hundred sixty-three envenomations by black widow spiders were reviewed and graded according to severity with treatment modalities evaluated. Although calcium gluconate usually has been considered the first-line treatment of severe envenomations by black widow spiders, we found it ineffective for pain relief compared with a combination of IV opioids and benzodiazepines. The use of antivenin significantly shortened the duration of symptoms in severe envenomations.


[Takayasu's disease disclosed by isolated involvement of the ascending aorta].

The authors report the histological discovery of a case of Takayasu syndrome affecting the ascending aorta. This involvement appearing to concern only the aorta, with no symptomatic complaints nor any laboratory abnormalities indicative of an inflammatory syndrome, corticosteroids were not prescribed. Management consisted of biennial monitoring by transthoracic and transesophageal ultrasonography of the aorta and the supra-aortic main vessels together with monitoring of laboratory parameters.


Accessibility and function of human thyroid epithelial cells in monolayer culture.

Measurement of thyroid stimulating immunoglobulins (TSI) has not yet found widespread application in the diagnosis and management of Graves' disease. One of the problems is the poor and variable sensitivity of the different assays. We therefore studied the influence of the accessibility of the basal part of human thyroid epithelial cells in monolayer culture on their cAMP response to thyroid stimulating hormone (TSH) and TSI. Test media containing either ammoniumsulphate-precipitated globulin fractions of sera from normal controls and treated or untreated patients with Graves' disease or TSH were used to stimulate cAMP production by cryopreserved human thyroid epithelial cells in monolayer culture. Incubations with and without the use of porous membrane inserts as culture surface were compared by univariate parametric and non-parametric testing. It appears that more TSH-receptors, probably on the basal part of the thyrocyte, can be exposed to the medium by using a porous membrane as culture surface as demonstrated by the increased analytical sensitivity of the semi-bioassay of TSH and TSI.


Mucin 4 (MUC4) gene: regional assignment (3q29) and RFLP analysis.

The use of a probe (JER64) containing a mucin 4 (MUC4) cDNA insert of 1.83 kb allowed to assign by in situ hybridization, the MUC4 gene to 3q29. This probe detected RFLPs with all restriction enzymes used (BamHI, HindIII, PstI, EcoRI, and TaqI). Particularly numerous alleles were observed with PstI, EcoRI and TaqI, in a small sample of unrelated DNAs (25 digested with PstI, 8 with EcoRI and 8 with TaqI). The PIC values were 0.69, 0.63 and 0.70 for PstI, EcoRI and TaqI respectively. The polymorphisms observed of variable number of tandem repeat (VNTR) type are in relation with the presence of tandemly repeated nucleotide sequences in MUC4 gene.


Genetic characterization of Legionella pneumophila serogroup 1 associated with respiratory disease in Australia.

Techniques were developed for genetic characterization of Legionella pneumophila serogroup 1 by using restriction fragment length polymorphism analysis. Allozyme analysis provided an index of the discrimination achieved by restriction fragment length polymorphism. Isolates from human cases of legionellosis were examined by both methods, and their profiles were compared with reference strains of L. pneumophila serogroup 1 obtained from the American Type Culture Collection. Eighteen distinct clones were evident among the isolates examined. Both methods could be used to trace the source of an outbreak of legionellosis caused by L. pneumophila serogroup 1.


Immunohistochemical localization of proliferating cell nuclear antigen/cyclin in human skin.

Expression of proliferating cell nuclear antigen/cyclin (PCNA/cyclin) in skin tissue specimens and cultured keratinocytes was studied using a monospecific antibody, obtained from a patient with systemic lupus erythematosus, and a monoclonal antibody. Indirect immunofluorescent staining revealed that cultured keratinocytes obtained from human foreskins expressed PCNA/cyclin as variable nuclear patterns in 15-30% of the cells. In normal human skin tissue specimens, PCNA/cyclin was demonstrated in only a few basal cells. Interestingly, PCNA/cyclin was expressed strongly in almost all the cells of the lowest layer of the epidermis adjacent to squamous cell carcinomas, whereas the tumor aggregates themselves had no positive staining. In contrast, no such characteristic staining was demonstrated in specimens of basal cell carcinoma. The staining pattern of PCNA/cyclin was different from that of Ki-67 in the skin tissue specimens. Our results suggest that PCNA/cyclin could be a useful marker of cell proliferation.


Reactive hyperemia in the nonused internal mammary artery after median sternotomy.

Doppler spectrum analysis was performed in the nonused internal mammary artery in a group of patients who underwent myocardial revascularization using the contralateral internal mammary artery and in both internal mammary arteries in a group of patients who underwent median sternotomy for cardiac surgical procedures in which the internal mammary artery was not used. In all nonused internal mammary arteries the preoperatively triphasic systolic flow pattern had postoperatively converted into a unidirectional systolic flow pattern with a large diastolic flow component, characterized by a significant increase in the diastolic flow parameters and a significant decrease in the resistance and pulsatility indices. This effect had almost subsided at 6 months postoperatively. This study indicates that the reactive hyperemia observed in the nonused internal mammary artery in the early postoperative period is mainly caused by the temporarily increased metabolic demand of the anterior thoracic wall and mediastinum, rather than by the metabolic demand of the anterior diaphragm and the contralateral rectus abdominis muscle after deprivation of their main nutritional vessel.


Competitive flow from a fully patent coronary artery does not limit acute mammary graft flow.

The shriveled, stenotic mammary graft sometimes observed after internal mammary artery (IMA) to coronary artery bypass grafting has been attributed to competitive flow from the insufficiently stenosed native coronary vessel. To study further the effects of native coronary artery competing flow on IMA graft flow, 10 dogs (mean weight, 23.5 +/- 3.69 kg) underwent coronary artery bypass grafting using the pedicled left IMA anastomosed to a normal, fully patent proximal circumflex (CFX) coronary artery. The procedure was performed through a left thoracotomy, off pump, using a brief local occlusion to perform the anastomosis. Native in situ IMA flow, CFX flow distal to the anastomosis, and IMA graft flow were measured using calibrated electromagnetic flow probes. When the CFX proximal to the anastomosis was occluded transiently, IMA flow increased to supply 100% of the previously measured distal CFX flow (60.2 +/- 7.9 mL/min). When both the IMA graft and CFX proximal to the anastomosis were patent, total distal perfusion was maintained (58.9 +/- 7.8 mL/min) and relative IMA graft flow (26.5 +/- 3.3 mL/min) was proportional to the relative diameter of the IMA graft to the native coronary artery (r = 0.96). The mean flow in the IMA in situ on the chest wall before its division was 23.8 +/- 8.1 mL/min. These results suggest that, at least acutely in a canine model, IMA graft flow is maintained above in situ levels even when grafted to a completely patent coronary artery and that acute competitive flow probably does not cause mammary artery shriveling.


Early bile duct carcinoma.

The clinocopathologic features of seven patients with early bile duct carcinoma are reported. Early bile duct carcinoma has been defined as bile duct carcinoma limited to the bile duct wall. The seven patients included six men and one woman ranging in age from 44 to 77 years. Six patients complained of jaundice and the other presented with right hypochondralgia. Ultrasonography showed a dilated proximal bile duct in the seven with a polypoid mass in three. Computerized tomography showed a dilated biliary tree in the seven together with a polypoid mass in two. Direct visualization of the bile duct with endoscopic retrograde cholangiography and/or percutaneous transhepatic cholangiography showed a polypoid tumour of the bile duct and a dilated proximal biliary tree in all seven. Each of the seven polypoid tumours were well differentiated papillary or tubular adenocarcinoma restricted to the bile duct wall with minimal stromal invasion. There was neither any lymph node metastasis nor perineural invasion. Five of the seven patients were doing well at 24-112 months after a complete resection. One patient died from multiple liver metastases 21 months after intervention. The other patient died from other diseases 138 months after operation. These seven cases can be classified as early bile duct carcinoma due to both the limited invasion and favourable prognosis. The clinical features of the seven patients were quite similar to those of usual bile duct carcinoma. However there are still no proper diagnostic clues for early bile duct carcinoma and these patients represent fortunate cases that clinicians happened to discover by chance.


Iatrogenic injuries to the extrahepatic biliary tract.

Iatrogenic injuries to the extrahepatic biliary tract continue to occur and result in significant morbidity. Over the last 10 years, 26 patients have been referred to Westmead Hospital for management of iatrogenic biliary tract injuries. Of these injuries, 22 occurred during cholecystectomy, three during hepatectomy and one during a pancreaticoduodenectomy. The principles of avoidance and repair are discussed. It is concluded that these injuries, although uncommon, continue to occur and that the best treatment results are achieved in specialized hepatobiliary units.


Long survivors after pancreatoduodenectomy for pancreas head carcinoma.

Twelve Japanese patients with pancreas head carcinoma who survived 3 years or more after a pancreatoduodenectomy and 50 who survived less than 12 months were reviewed clinicopathologically. The 12 patients who survived for greater than or equal to 3 years exhibited more favourable prognostic factors: a higher incidence of jaundice; a smaller mass; a higher prevalence of an earlier stage tumour and adenocarcinoma of differentiated type; and a lower incidence of venous invasion, lymph node metastasis, and cancer cells at the surgical margins. However the difference was not significant. Univariate log-rank analysis regarding 13 prognostic variables showed that histologic type was a significant factor but multivariate Cox regression analysis failed to reveal an independent significant parameter. Nine of the 12 long-term survivors showed lymph node metastasis and six of the 12 revealed cancer cells at the surgical margins. Six of the 12 long-term survivors died from local recurrence and/or distant metastasis 37-78 months after operation. Only two patients survived more than 5 years after the operation. At the time of writing, one of them was still alive and another was dead 78 months after the operation. Pancreatoduodenectomy for pancreas head carcinoma infrequently offers a permanent cure for the patients with pancreas head carcinoma but sometimes produces a worthwhile long-term survival, even if the resected margins were affected by malignant cells or the lymph node metastasis was evident.


Unexpected growth-stimulatory effect of somatostatin analogue on cultured human pancreatic carcinoid cells.

Therapeutic efficacy of a synthetic somatostatin analogue for the treatment of carcinoid tumors is still controversial. In vivo studies performed in our laboratory showed that a somatostatin analogue, SMS 201-995, significantly inhibited growth of human pancreatic carcinoid (BON) tumors xenotransplanted into athymic nude mice. In the present study, however, SMS 201-995 did not inhibit in vitro growth of BON cells, but rather SMS 201-995 stimulated growth in a dose-dependent fashion. The growth-stimulatory effect was likely mediated through the reduction of cyclic AMP production. Unsuccessful treatment of certain types of carcinoid tumor with SMS 201-995 may be partly due to the direct growth-stimulatory effect of SMS 201-995 on carcinoid cells.


Identification of a processed protein related to the human chaperonins (hsp 60) protein in mammalian kidney.

The chaperonin family of proteins, which includes GroEL protein of E. coli, yeast heat shock protein (hsp-60) and the ribulose-1-5-bisphosphate carboxylase (Rubis Co.) subunit binding protein of plant chloroplasts, shows strong sequence homology to the Chinese hamster ovary (CHO) mitochondrial P1 protein. We have identified a 60 kDa protein from bovine kidney which by N-terminal sequencing gives the amino acid sequence AKDVKFGADARALLMLQGVDLLADA. Bovine whole kidney membranes were delipidated, solubilized with octyl glucoside and fractionated over an affinity column using the amiloride analog 5-N pyrazine amiloride as the ligand. After extensive washing with 200 mM NaCl, the column was eluted with pH 4.0 buffer. Analysis of column fractions on a 7.5% polyacrylamide gel revealed 3-4 bands with a predominant band at 60,000 Da. Amino acid analysis after transfer to immobilon membranes demonstrated sequence identity to the human HSP (60), extending 24 amino acids from the N-terminus, but lacking the leader sequence. These data indicate that a processed form of a protein related to the human HSP (60) chaperonin is associated with a membrane fraction in the mammalian kidney, and that the processed form of the protein binds strongly to an amiloride affinity support.


Selective cell-surface expression of dipeptidyl peptidase IV with mutations at the active site sequence.

The cell surface expression of dipeptidyl peptidase IV (DPPIV) was examined in COS-1 cells transfected with its cDNA with or without mutations at the active site sequence Gly-Trp-Ser-Tyr-Gly (positions 629-633). Mutants with substitution of Trp630----Glu or Ser631----Ala were expressed on the cell surface as normally as the wild-type DPPIV, although the mutant with Ala631 had no enzyme activity. In contrast, any single substitutions of Gly at positions 629 and 633 resulted in no surface expression of the mutants, which were, instead, detected within the cells. When Tyr632 was substituted, one mutant (Tyr----Phe) was expressed on the surface, whereas the others (Tyr----Gly or Leu) were intracellularly retained. These results indicate that the surface expression of DPPIV is critically influenced by mutations at the active site sequence.


Identification of homeobox-containing genes expressed in hematopoietic blast cells.

Among putative candidates involved in commitment and differentiation of hematopoietic cells are homeoproteins, a large family of transcription factors playing a major role during development. Using a polymerase chain reaction (PCR)-derived protocol, we have investigated for Antennapedia-like homeobox-containing (HOX) gene expression in an enriched population of human hematopoietic progenitors. Nine members of HOX 1 and HOX 2 loci were isolated. Together with recent studies using established cell lines, this indicates a large representation of HOX genes in the hematopoietic compartment and suggests a participation of this class of nuclear proteins to early steps of hematopoiesis.


Ebrotidine--a new H2-receptor antagonist with mucosal strengthening activity.

The mechanism of gastric mucosal protection by ebrotidine against ethanol-induced mucosal injury was investigated in rats treated intragastrically either with the drug or vehicle. Results of macroscopic assessment revealed that ebrotidine at doses of 50mg and higher/kg body weight effectively prevented mucosal injury, and that the maximal protective effect was achieved by 1h. Physicochemical analysis established that ebrotidine evoked 30% increase in mucus gel dimension, and showed 20% increase in phospholipids, and the content of sulfo- (18%) and sialomucins (21%). This was accompanied by 1.4-fold increase in mucus gel viscosity, 16% increase in H+ retardation capacity, and 65% increase in hydrophobicity. Our data show that ebrotidine is a unique H2-antagonist capable of enhancement of the physicochemical characteristics of gastric mucus.


Effect of nitroso complexes of some transition metals on the activity of soluble guanylate cyclase.

Effects of nitroso complexes of some transition metals (Fe, Co, Cr), differing in the character of NO oxidation on the activity of human and rat platelet guanylate cyclase were studied. 3 types of nitroso complexes were used: (1) NO group carries a positive charge--a nitrosonium cation (Na2[FeNO + (CN)5]-nitroprusside); (2) NO is neutral--(K3[CrNO(CN)5 and [CoNO(NH3)5]SO4) and (3) NO is coordinated as anion NO- (K3[CoNO-(CN)5]. It is shown that the highest stimulatory effect is produced by sodium nitroprusside, whose activating action is due to the interaction of its NO group with the guanylate cyclase heme. Nitroso complexes (Co and Cr) the NO group of which is neutral stimulated guanylate cyclase activity insignificantly and this activation was not guanylate cyclase heme directed. Nitroso complex (Co) with NO coordinated as anion NO(-)--is a guanylate cyclase inhibitor. In contrast to nitroprusside, the nitroso complexes used (Co and Cr) have no hypotensive effect. It was concluded that the essential requirement for the realization of the hypotensive effect of transition metals' nitroso complexes is the ability of these compounds to activate soluble guanylate cyclase solely by the heme-dependent mechanism.


The effects of sulphasalazine and its metabolites on prostaglandin production by human mononuclear cells.

Although it has been proposed that sulphasalazine (SASP) and its metabolite 5-aminosalicylic acid (5-ASA) act therapeutically by inhibiting production of vasoactive and immunoregulatory prostaglandins (PGs), in previous in vitro studies these drugs have both inhibited and promoted PG production. This study demonstrates that SASP and 5-ASA promote or inhibit peripheral blood mononuclear cell PG production depending upon the PG measured, the concentration of the drug, and whether the cells were stimulated. Sulphapyridine, the other constituent of SASP, only inhibited production. At high concentrations of SASP and 5-ASA the viability of mononuclear cells was reduced. The enhancement of PG production and toxicity was greater with SASP than 5-ASA, while the PGs most affected by SASP were not those most affected by 5-ASA. Thus, in vitro SASP may possess properties other than those of 5-ASA and this may explain the different therapeutic properties of these two compounds.


Sulfated alkyl oligosaccharides with potent inhibitory effects on human immunodeficiency virus infection.

Compounds with medium relative molecular masses active against human immunodeficiency virus (HIV) were synthesized. Sulfated alkyl oligosaccharides such as sulfated octadecyl maltohexaoside, sulfated dodecyl laminaripentaoside and sulfated dodecyl laminari-oligomer caused 50% inhibition of virus infection in the EC50 range of 0.4-0.7 microgram/mL in vitro using the MT-4 cell line and HIV-1HTLV-IIIB virus isolate, though sulfated oligosaccharides without alkyl groups showed low anti-HIV activities. This anti-HIV activity was close to the EC50 of 0.43 microgram/mL for a highly active sulfated polysaccharide curdlan sulfate which was reported to inhibit completely the HIV infection at a concentration as low as 3.3 micrograms/mL. These compounds were also active against HIV-2 and a clinically isolated HIV-1 with reduced AZT sensitivity. For such sulfated alkyl oligosaccharides, the mechanism of inhibition of HIV infection was assumed to be the inhibition of HIV binding to the cell and to some extent the interaction of the alkyl portion with the lipid bilayer of the virus.


Beta-adrenoceptor blocking effects of two bopindolol metabolites in isolated guinea-pig atria.

The beta-adrenoceptor blocking effects of the bopindolol (Wandonorm, CAS 62658-63-3) metabolites 18-502 (indole-2,4- methylaminopropoxy(N-tert.butyl)-tartrate) and 20-785 (indole-2,4-carboxyaminopropoxy(N-tert.butyl] were studied in electrically stimulated guinea-pig left atria and in spontaneously beating guinea-pig atria in vitro. Both compounds shifted the concentration-response curve of isoprenaline to the right, but did not reduce the maximum effect of this drug. For compound 20-785, pA2 values of 7.44 (left atrium, inotropic effect) and 7.58 (right atrium, chronotropic effect) were calculated. The metabolite 18-502 had a much greater beta-adrenoceptor blocking potency, as judged from its pA2 values of 9.53 and 9.48, resp., and in the concentration of 10(-8) mol/l it caused a significant flattening of the concentration-response curve of isoprenaline. From these results, compound 20-785 can be classified as a competitive beta-adrenoceptor antagonist, while for higher concentrations of the metabolite 18-502 additional noncompetitive mechanisms of action cannot be excluded.


CD8+ CD11+ suppressor cells in HIV-infected asymptomatic patients: effect on HIV-specific cytotoxicity.

CD3+CD8+CD11+ cells were present in the peripheral blood of patients infected with asymptomatic human immunodeficiency virus (HIV) in higher percentage (10-20%) than in normal individuals (3-5%) in this study. These cells, through the release of soluble factors, significantly suppressed the effector phase of anti-HIV cytotoxic activities, both human leukocyte antigen (HLA)-class I or class II restricted, and nonrestricted. The effectors were CD8+CD11-, CD4+ T cells, and CD16+ cells for HLA-class I, class II restricted, and nonrestricted cytotoxicities, respectively. The soluble factors also inhibited natural killer cell activity. Thus, this effect was neither HLA-restricted nor antigen-specific. These CD3+CD8+CD11+ cells may be an important immunopathogenic factor in HIV disease.


Transmitter release increases intracellular calcium in perisynaptic Schwann cells in situ.

Glial cells isolated from the nervous system are sensitive to neurotransmitters and may therefore be involved in synaptic transmission. The sensitivity of individual perisynaptic Schwann cells to activity of a single synapse was investigated, in situ, at the frog neuromuscular junction by monitoring changes in intracellular Ca2+ in the Schwann cells. Motor nerve stimulation induced an increase in intracellular Ca2+ in these Schwann cells; this increase was greatly reduced when transmitter release was blocked. Furthermore, local application of the cotransmitters acetylcholine and ATP evoked Ca2+ responses even in the absence of extracellular Ca2+. Successive trains of nerve stimuli or applications of transmitters resulted in progressively smaller Ca2+ responses. We conclude that transmitter released during synaptic activity can evoke release of intracellular Ca2+ in perisynaptic Schwann cells. This Ca2+ signal may play a role in the maintenance or modulation of a synapse. These data show that synaptic transmission involves three cellular components with both postsynaptic and glial components responding to transmitter secretion.


Calcium waves in astrocytes-filling in the gaps.

Stimulus-evoked cellular responses are sometimes organized in the form of propagating waves of cytoplasmic Ca2+ increase. Ca2+ waves can be elicited in cultured astrocytes by the neurotransmitter glutamate; however, the propagation mechanism is unknown. Here, qualitative and quantitative features of propagation suggest that astrocytic Ca2+ waves are mediated by an intracellular signal that crosses intercellular junctions. The role of gap junctions in cell-cell Ca2+ wave propagation was specifically tested. Functional gap junctions were demonstrated using a noninvasive fluorescence recovery method and the gap junction blockers halothane and octanol. Gap junction closure prevented intracellular waves from propagating between cells without affecting the velocity of the intracellular wave itself. The pivotal role played by the gap junction creates the potential for dynamic changes in glial connectivity and long-range glial signaling.


Characterization of plastid 5-aminolevulinate dehydratase (ALAD; EC 4.2.1.24) from spinach (Spinacia oleracea L.) by sequencing and comparison with non-plant ALAD enzymes.

We have sequenced 5-aminolevulinate dehydratase (ALAD; EC 2.4.1.24) of a plant. A full-length cDNA clone (1727 bp) encoding this enzyme has been identified by immunoscreening a lambda gt 11 cDNA library of spinach. ALAD is not a plant-specific enzyme; however, the plant enzyme differs from the well known ALAD enzymes of bacteria, yeast and animals in structural and biochemical properties and in that it is located in the plastid. Differences and homologies can be traced back to the molecular level. The mature ALAD subunit, whose N-terminus was determined by automatic Edman degradation, is a protein of 367 amino acid residues and has a Mr of 40,132. This figure is in the range of molecular weights of non-plant ALADs. The active centre is highly conserved and the same is true for the ion-binding domain, except that 4 cysteines of the non-plant enzymes (binding Zn2+) have disappeared and a total of 6 aspartic acids meets the demands of Mg(2+)-binding. However, there are more distinct differences. Apart from a transit sequence of 56 amino acids targeting the plastid, the N-terminal part of the mature plant enzyme differs considerably from non-plant ALAD enzymes. It is rich in prolines and hydroxylated amino acids. The apparent Mr on SDS-PAGE is 45,000 or higher, but up to now posttranslational modifications have not been found.


Inhibition of quantal transmitter release in the absence of calcium influx by a G protein-linked adenosine receptor at hippocampal synapses.

Spontaneous miniature excitatory postsynaptic currents (MEPSCs) were recorded by whole-cell voltage-clamp techniques in cultured rat hippocampal pyramidal neurons. The specific adenosine A1 receptor agonist cyclopentyladenosine (CPA) reduced the frequency of MEPSCs without affecting their amplitude distribution or kinetic properties. This action was blocked by pretreatment of the cells with pertussis toxin. In the presence of divalent cation Ca2+ channel blockers, CPA was still effective in reducing the frequency of MEPSCs. It was shown that this effect cannot be explained by changes in basal Ca2+ influx. These results suggest that neurotransmitters that produce presynaptic inhibition at hippocampal synapses utilize several mechanisms, one of which may involve inhibition of some component of the quantal release apparatus that occurs independently of inhibition of Ca2+ influx.


Dexmedetomidine reduces intraocular pressure, intubation responses and anaesthetic requirements in patients undergoing ophthalmic surgery.

We studied the effects of a single i.v. dose of dexmedetomidine, a highly selective and specific alpha 2 adrenoceptor agonist, on intraocular pressure (IOP), haemodynamic and sympathoadrenal responses to laryngoscopy and tracheal intubation, and on anaesthetic requirements in ophthalmic surgery. Thirty ASA I-II patients undergoing cataract surgery were allocated randomly to receive either dexmedetomidine 0.6 microgram kg-1 or saline placebo i.v. 10 min before induction of anaesthesia in a double-blind design. After dexmedetomidine there was a 34% (95% confidence interval (CI) 27-43%) reduction in IOP (P less than 0.001) and 62% (CI 57-68%) decrease in plasma noradrenaline concentrations (P less than 0.001). After intubation, maximum heart rate was 18% (CI 3-33%, P = 0.036) and the maximum IOP 27% (CI 11-43%, P = 0.005) less in the dexmedetomidine group compared with the patients treated with placebo. Within 10 min after intubation, maximum systolic and diastolic arterial pressures were also significantly (P = 0.013 and P = 0.020) smaller in the dexmedetomidine group. The induction dose of thiopentone was smaller (23% (CI 20-26%) P = 0.012), and the use of isoflurane or fentanyl supplements during anaesthesia was less frequent in the dexmedetomidine group. The patients premedicated with dexmedetomidine recovered faster from anaesthesia (P = 0.042). These results suggest that dexmedetomidine may be a useful anaesthetic adjunct in ophthalmic surgery.


Bradycardia and vecuronium: comparison with alcuronium during cholecystectomy.

We have compared the incidence of bradycardia in two groups of patients undergoing cholecystectomy. Twenty consecutive patients were allocated randomly to receive either vecuronium (n = 8) or alcuronium (n = 12) as part of a standard anaesthetic technique. Bradycardia was defined as a heart rate less than 50 beat min-1. Five episodes of bradycardia occurred with vecuronium and none with alcuronium (P less than 0.01).


Paraphenylenediamine, a contact allergen, induces oxidative stress and ICAM-1 expression in human keratinocytes.

In an investigation of the role of keratinocytes in the pre-immunological phase of contact allergy, we have studied the effect of paraphenylenediamine (PPD) on cell proliferation, membrane lipid peroxidation and the expression of the intercellular adhesion molecule 1 (ICAM-1). Because PPD undergoes rapid autoxidation in the culture medium, the effect of PPD-modified medium on keratinocyte proliferation and ICAM-1 expression was also examined. PPD at low concentrations (up to 10 micrograms/ml) and with low exposure times (0.5 h) enhanced keratinocyte proliferation, but at high concentrations and with longer exposure times resulted in cell stasis and toxicity. These effects and the enhanced membrane lipid peroxidation that was also observed can be ascribed to the production of superoxide and hydrogen peroxide by the autoxidation of PPD in the medium. At non-cytotoxic concentrations, PPD induced ICAM-1 expression on the keratinocytes. PPD-modified medium was also cytotoxic to the keratinocytes and induced ICAM-1 expression in non-cytotoxic concentrations. It appeared that superoxide and hydrogen peroxide were not responsible for the cytotoxicity. These results are consistent with the view that oxidative stress may be an essential part of the pre-immunological phase in the induction of allergic contact dermatitis.


Tumours of Oddi: diagnosis and surgical treatment.

A retrospective review of 56 patients operated upon for tumours of Oddi was performed in order to determine optimal diagnostic and therapeutic procedures. Common presenting symptoms were jaundice (86%) and anemia (21%). Mean size of the tumour was 2.3 cm. Five tumours were benign and 51 were malignant. According to the classification of Martin, five were grade I: 10 grade II; 18 grade III; and 18 grade IV. Forty-seven patients underwent resection of the tumour: three local excisions for small benign tumors, six ampullectomies (followed in three by a Whipples' procedure for recurrence) and 41 Whipples' procedures. The hospital mortality was 5.3%, minor complications appeared in 21%. The overall five years survival was 41%. It was 75% in grade I, 50% in grade II, 40% in grade III and 10% in grade IV. The patients who received ampullectomies were alive with a follow-up of one, two and three years. All patients operated upon for a benign tumour were alive except one who died of cardiac failure. Ultrasonography and duodenoscopy are the most useful tests for the diagnosis of tumours of Oddi. Prognosis depends on the degree of infiltration of the duodenal wall and the presence of positive lymph nodes. Whipples' procedure is best but ampullectomy can be used in elderly or poor risk patients. Malignant tumours of the ampullary region are infrequent and reported to constitute between 0.02 and five percent of all cancers of the digestive tract. With wider application of endoscopic techniques, there has been an increasing interest in this group of tumours during recent years. In the literature tumours of Oddi are usually reported in the group of periampullary tumours, including tumours of the ampulla itself, duodenal wall surrounding the ampulla, the distal part of the common bile duct and head of the pancreas. We have wanted to distinguish specifically the tumours of the ampulla of Vater and have adopted the term tumour of Oddi introduced by Marchal and Hureau.(ABSTRACT TRUNCATED AT 250 WORDS)


Antigen binding thermodynamics and antiproliferative effects of chimeric and humanized anti-p185HER2 antibody Fab fragments.

The murine monoclonal antibody 4D5 (anti-p185HER2) inhibits the proliferation of human tumor cells overexpressing p185HER2 in vitro and has been "humanized" [Carter, P., Presta, L., Gorman, C. M., Ridgway, J. B. B., Henner, D., Wong, W.-L. T., Rowland, A. M., Kotts, C., Carver, M. E., & Shepard, H. M. (1992) Proc. Natl. Acad. Sci. U.S.A. (in press)] for use in human cancer therapy. We have determined the antigen binding thermodynamics and the antiproliferative activities of chimeric 4D5 Fab (ch4D5 Fab) fragment and a series of eight humanized Fab (hu4D5 Fab) fragments differing by amino acid substitutions in the framework regions of the variable domains. Fab fragments were expressed by secretion from Escherichia coli and purified from fermentation supernatants by using affinity chromatography on immobilized streptococcal protein G or staphylococcal protein A for ch4D5 and hu4D5, respectively. Circular dichroism spectroscopy indicates correct folding of the E. coli produced Fab, and scanning calorimetry shows a greater stability for hu4D5 (Tm = 82 degrees C) as compared with ch4D5 Fab (Tm = 72 degrees C). KD values for binding to the extracellular domain (ECD) of p185HER2 were determined by using a radioimmunoassay; the delta H and delta Cp for binding were determined by using isothermal titration calorimetry. ch4D5 Fab and one of the humanized variants (hu4D5-8 Fab) bind p185HER2-ECD with comparable affinity (delta G degrees = -13.6 kcal mol-1).(ABSTRACT TRUNCATED AT 250 WORDS)


Ancestry of the 4-chlorobenzoate dehalogenase: analysis of amino acid sequence identities among families of acyl:adenyl ligases, enoyl-CoA hydratases/isomerases, and acyl-CoA thioesterases.

We have deduced the nucleotide sequence of the genes encoding the three components of 4-chlorobenzoate (4-CBA) dehalogenase from Pseudomonas sp. CBS-3 and examined the origin of these proteins by homology analysis. Open reading frame 1 (ORF1) encodes a 30-kDa 4-CBA-coenzyme A dehalogenase related to enoyl-coenzyme A hydratases functioning in fatty acid beta-oxidation. ORF2 encodes a 57-kDa protein which activates 4-CBA by acyl adenylation/thioesterification. This 4-CBA:coenzyme A ligase shares significant sequence similarity with a large group of proteins, many of which catalyze similar chemistry in beta-oxidation pathways or in siderophore and antibiotic synthetic pathways. These proteins have in common a short stretch of sequence, (T,S)(S,G)G(T,S)(T,E)G(L,X)PK(G,-), which is particularly highly conserved and which may represent an important new class of "signature" sequence. We were unable to find any proteins homologous in sequence to the 16-kDa 4-hydroxybenzoate-coenzyme A thioesterase encoded by ORF3. Analysis of the chemistry and function of the proteins found to be structurally related to the 4-CBA:coenzyme A ligase and the 4-CBA-coenzyme A dehalogenase supports the proposal that they evolved from a beta-oxidation pathway.


Folding and assembly of the Escherichia coli succinyl-CoA synthetase heterotetramer without participation of molecular chaperones.

Succinyl-CoA synthetase of Escherichia coli (alpha 2B2 subunit structure) has been shown to fold and assemble without participation by molecular chaperones. Renaturation experiments showed that purified bacterial chaperone GroEL has no effect on the folding and assembly of the active tetrameric enzyme. When isolated 35S-labeled alpha or beta subunits were incubated with GroEL in the absence of ATP, there was no complex formation between the subunits and GroEL. These in vitro results were confirmed by in vivo analysis of the folding and assembly of newly synthesized succinyl-CoA synthetase subunits. When expression of the subunits was induced in E. coli strains that bear GroEL or GroES temperature-sensitive mutations, the assembly of active succinyl-CoA synthetase was not affected as the temperature was raised to 43 degrees C. These and other observations are discussed that indicate that folding and assembly of succinyl-CoA synthetase may be independent of assistance by any chaperone.


Enzyme inactivation by metal-catalyzed oxidation of coenzyme Q1.

Ubiquinol-1 in aerated aqueous solution inactivates several enzymes--alanine aminotransferase, alkaline phosphatase, Na+/K(+)-ATPase, creatine kinase and glutamine synthetase--but not isocitrate dehydrogenase and malate dehydrogenase. Ubiquinone-1 and/or H2O2 do not affect the activity of alkaline phosphatase and glutamine synthetase chosen as model enzymes. Dioxygen and transition metal ions, even if in trace amounts, are essential for the enzyme inactivation, which indeed does not occur under argon atmosphere or in the presence of metal chelators. Supplementation with redox-active metal ions (Fe3+ or Cu2+), moreover, potentiates alkaline phosphatase inactivation. Since catalase and peroxidase protect while superoxide dismutase does not, hydrogen peroxide rather than superoxide anion seems to be involved in the inactivation mechanism through which oxygen active species (hydroxyl radical or any other equivalent species) are produced via a modified Haber-Weiss cycle, triggered by metal-catalyzed oxidation of ubiquinol-1. The lack of efficiency of radical scavengers and the almost complete protection afforded by enzyme substrates and metal cofactors indicate a 'site-specific' radical attack as responsible for the oxidative damage.


Glutamine affects glutamate metabolism in isolated rat kidney cortex mitochondria.

The active state respiration of isolated rat kidney cortex mitochondria with 10 mM glutamate as single substrate is substantially increased by the addition of 10 mM glutamine. This increase in respiration was accompanied by a higher transamination rate and was found to be insensitive to the selective inhibition of either the transamination or the desamination pathway of glutamate oxidation. These data can be explained by an approximately 2-fold elevated intramitochondrial glutamate concentration observed in the additional presence of glutamine.


Accumulation of transcripts coding for prion protein in human astrocytes during infection with human immunodeficiency virus.

The abnormal isoforms of the normal cellular prion protein (PrP), also termed Scrapie-associated fibril protein, are assumed to be one causative factor of spongiform encephalopathies. The mRNA of PrP contains stem-loop structures which are very similar to the human immunodeficiency virus-1 (HIV-1) cis-acting sequence TAR within the LTR; both structures contain the pentanucleotide CUGGG in the loop, and the uridine- and adenine-bulge in the stem. In this study, using purified HIV-encoded trans-activator, Tat, and HIV-1 TAR-RNA or PrP-mRNA containing the stem-loop structure, we demonstrate by use of gel-retardation and filter binding assays that Tat binds to TAR- and PrP-RNA with the dissociation constants of 2.9 or 37.0 nM, respectively, at a molar ratio of 0.7 mol of Tat to 1 mol of RNA fragment. The Tat-RNA (TAR or PrP) complexes bind to protein(s) in the nuclear matrix, isolated from human astrocytes (glial fibrillary acidic protein positive brain cells). Infection of astrocytes with HIV-1 resulted in an increased level of PrP mRNA. The data presented led us to assume that certain sequences in the PrP mRNA might be targets for proteins acting in trans.


Characterization of human heart-infiltrating cells after transplantation. V. Suppression of donor-specific allogeneic responses by cloned T-cell lines isolated from heart biopsy specimens of patients after transplantation.

In vitro culture of heart biopsy specimens from patients after transplantation in media containing recombinant human interleukin-2 led to the exudation of host mononuclear-cell infiltrates. Cloned T-cell lines were prepared from such infiltrates and studied for donor-specific mixed lymphocyte reaction and cytotoxic T-lymphocyte activity. Although most T-cell clones (greater than 50%) showed donor-specific reactivity, a small but distinct frequency (2% to 10%) of the cloned T-cell lines did not proliferate against donor or third-party stimulator cells. Of interest was our finding that addition of these non-donor-reactive cloned T-cell lines to autologous peripheral blood mononuclear cells markedly suppressed their donor-specific, but not third-party major histocompatibility complex, unrelated proliferative response and prevented the generation of donor, but not third-party, major histocompatibility complex unrelated cytotoxic T-lymphocyte function. The suppression was not secondary to lysis of donor stimulator cells, lysis of autologous donor-specific CD4+ lymphoblasts, or by selective consumption of interleukin-2. The suppression was mediated at the initiation of sensitization (precursor cell level). These suppressor cells expressed CD3, CD8, CD45RO, and the alpha, beta T-cell receptor, but not CD4 or CD56. These cloned T-cell lines will provide unique reagents to study the molecular basis by which these cells exert their regulatory function.


Characterization of human heart-infiltrating cells after transplantation. VI. Differences in the cytokines produced by individual CD4+ cloned T-cell lines with apparently identical antiidiotype-like reactivity.

Studies of cultures and cloned T-cell lines from mononuclear cell infiltrates in cardiac biopsy specimens have provided a unique resource to study the cellular basis of human organ allograft rejection. Our laboratory has previously shown that biopsy specimens placed on autologous donor MHC-class-II-specific cloned T-cell lines from previous cardiac biopsies led to the isolation of cloned T-cell lines, which appeared to be functionally "antiidiotypic" in nature. Detailed functional analysis of such CD4+ individual antiidiotype-reactive cloned T-cell lines revealed that although some augmented the proliferative response of autologous idiotype-bearing cloned T-cell lines against donor stimulator cells, others markedly suppressed the proliferative response; thus, although each of these antiidiotype-like reactive cloned T-cell lines appears to specifically react with the same idiotype-bearing donor MHC-class-II-specific cloned T-cell line, they were functionally heterogeneous. Analysis of cytokines secreted by these individual clones showed that the antiidiotype-reactive cloned T-cell lines that suppressed the response of idiotype-bearing cells appear to secrete predominantly interferon gamma, whereas those antiidiotype-reactive cloned T-cell lines that augmented the response do not secrete interferon gamma but secrete interleukin-2, -4, and -6. These preliminary data suggest that differences in the predominant cytokines secreted by these individual antiidiotype-reactive cloned T-cell lines may account for their functional differences.


Effect of beta-agonists on expression of calpain and calpastatin activity in skeletal muscle.

Administration of beta-adrenergic agonists to domestic species can lead to skeletal muscle hypertrophy, probably by reducing the rate of myofibrillar protein breakdown. Myofibrillar breakdown is associated with the calcium-dependent proteinase system (calpains I,II and calpastatin) whose activity also changes during beta-agonist treatment. A number of growth trials using the agonists cimaterol and clenbuterol with cattle, sheep, chicken and rat are reported which suggest a general mechanism whereby beta-agonists reduce calpain I activity, but increase calpain II and calpastatin activity in skeletal muscle. Parallel changes in specific mRNAs indicate that changes in gene expression or stabilisation of mRNA could in part explain the changes in activity.


Electrophysiological effects of atracurium and vecuronium on normal and denervated hearts.

Atracurium and vecuronium offer some advantages with respect to other nondepolarizing muscle relaxants. However, their administration has been associated with episodes of bradycardia and asystole, the mechanism of which has not yet been clarified. In an effort to analyze the effects of these drugs on automaticity, refractoriness, and conduction, 30 dogs underwent heterotopic heart transplantation to establish a model in which a normal heart (recipient) and a denervated heart (donor) could coexist. The electrophysiological studies included the determination of cycle length (CL), sinoatrial conduction time (SACT), antegrade and retrograde atrio-ventricular (A-V) node and ventricular block points (ABP and RBP), as well as effective antegrade and retrograde A-V node (ARPAVN and RRPAVN) and ventricular refractory periods (VRPs) in both hearts. These parameters were measured in a basal state and after injection of pancuronium (0.5 mg/kg) in 10 animals, atracurium (0.5 mg/kg) in another 10 dogs, and vecuronium (0.12 mg/kg) in the remaining animals. The results showed that pancuronium produced a tachycardia, significantly facilitated A-V conduction in the donor and the recipient hearts, and lowered the A-V node refractoriness in the donor organ, while atracurium and vecuronium induced no changes from the baseline values, either in normal or denervated hearts. Based on the results of this study, the episodes of sustained bradycardia reported in association with atracurium and vecuronium are attributed to the absence of antagonism of vagal stimuli provoked by pancuronium, and/or by surgical or anesthetic manipulations.


Alpha 2-adrenergic agonists in cardiovascular anesthesia.

At this time, the unique attributes of alpha 2-agonists in anesthesia lie in their ability to blunt the adrenergic response to the stresses of major surgery, in patients in whom this response is especially undesirable, without incurring the penalty of respiratory depression that attends the use of opioids. It has become more and more apparent that sympathetic/adrenergic activation often has adverse consequences for patient morbidity and mortality, and modification of such activation by drugs may be a valuable option for the anesthesiologist. However, at present, the evidence supporting this statement is "soft," such as improved hemodynamic and metabolic stability. What must be done is to generate solid support in the form of well-designed outcome studies. The potential value of alpha 2-agonists is greatest in major surgery in brittle patients involving the risk of significant adverse outcome. There are plenty of adequate anesthesia regimens to cover lesser surgical interventions. In these cases, it is not the choice of a specific anesthetic agent or technique, but rather the competence and diligence of the anesthesiologist that is most important for outcome. In contrast, in major cardiovascular surgery in high-risk patients, the optimal anesthetic approach attains more importance, and is still undecided. The final consensus as to whether or not this optimal approach will include the use of alpha 2-adrenergic agonists will depend on the results of more extensive clinical investigations.


Ventral medulla stimulation increases blood pressure and spinal cord amino acid release.

Microdialysis in combination with HPLC and fluorescence detection was used to measure the release of endogenous amino acids from the region of the intermediolateral cell column of rat thoracic spinal cord in response to electrical stimulation of the rostral ventrolateral medulla (RVLM). Stimulation of the RVLM led to a marked rise in blood pressure (74 +/- 6 mm Hg) accompanied by an immediate increase in the release of glutamate (80%) and aspartate (50%). Small increases in the release of glycine and taurine were found, but there were no changes in alanine and serine release. These results suggest that the RVLM pressor pathway to the thoracic spinal cord may use, at least in part, excitatory amino acids as neurotransmitters, supporting previous pharmacological and neuroanatomical investigations of this bulbospinal pathway.


L-serine-O-phosphate blocks NMDA-evoked responses in the ampullae of Lorenzini of skates.

In the present study, we have shown by single afferent unit recording in the organs of Lorenzini that L-serine-O-phosphate (L-SOP) decreases the resting discharge frequency as well as electrically evoked responses. L-SOP in a concentration of 0.1-100 microM antagonizes responses induced by L-glutamate (L-GLU) and N-methyl-D-aspartate (NMDA) and has no effect on the responses to application of kainate (KA) and quisqualate (Q). The results obtained confirm previous observations about the existence of NMDA receptors in the afferent synapse of the ampullae of Lorenzini.


Anxiolytic-like effects of a selective 5-HT1A agonist, S20244, and its enantiomers in mice.

The action of a selective 5-HT1A agonist S20244 and its two enantiomers (+)-S20499 and (-)-S20500 were assessed in mice. The animals were confronted with a free exploratory test especially adapted to reveal behavioural sedation, and with a two-box light/dark choice situation validated for the detection of anti-anxiety agents. These drugs were found to have anxiolytic properties at low doses, like benzodiazepines. Furthermore, the drugs exhibited sedative effects at higher doses. These results closely resemble those we found after administration of two other 5-HT1A agonists, 8-OH-DPAT and MDL 73005EF (NeuroReport, 1, 267-270, 1990).


Rat supraoptic neurons are resistant to glutamate neurotoxicity.

Magnocellular neurosecretory cells of the supraoptic nucleus (SON) are thought to be endogenously resistant to glutamate toxicity. In this study, we sought physiological and morphological evidence of this resistance in rats that received multiple peri-nuclear injections of ibotenate. In this preparation, ibotenate produced a large necrotic zone encompassing the SON but not within the nucleus itself. Extracellular recordings in vivo from 68 'spared' SON neurons from lesioned rats revealed normal patterns of electrical activity. Intracellular analysis in vitro from 13 'spared' SON neurons indicated that their intrinsic membrane properties, osmosensitivity and spontaneous synaptic activity did not differ significantly from that of controls. We conclude that SON neurons retain both a morphological and a physiological resistance to glutamate neurotoxicity.


Loss of heterozygosity on chromosome 16 in hepatocellular carcinoma.

In order to understand the molecular genetics of human hepatocellular carcinoma (HCC) a common chromosomal abnormality in HCC was examined using restriction fragment length polymorphism (RFLP) analysis. Sixty-eight HCC specimens were examined for loss of heterozygosity at 11 different chromosomal arms including 1p, 5p, 11p, 11q, 13q, 14q, 15q, 16p, 16q, 18q, and 19q. Losses were not detected on chromosome 1, 5, 14, 15 or 19, and the frequencies of losses were low (11-19%) for chromosomes 11, 13 and 18. In contrast, loss of heterozygosity was frequently observed for three different loci on chromosome 16, the HBA locus at 16p13.3 (22%), the MT2 locus at 16q21-22.1 (15%) and the HP locus at 16q22.1-22.2 (39%). There was no remarkable difference in the frequencies of loss of heterozygosity at these loci among HBV related HCC, HCV related HCC and neither virus (NBNC) related HCC. Thus, the results indicate that at least three different genetic abnormalities in chromosome 16 are commonly observed in various HCC, and that this chromosome may have some important role(s) in recessive genetic changes which generate this tumour.


[Neuromediator provision of the organs of immune system in benzpyrene intoxication].

The density of adrenergic innervation and relative content of catecholamines were investigated in rat lymphoid organs under different type of benzpyrene treatment. It was found that both ante- and postnatal influence of toxicant leads to a decrease of neurotransmitter providing of the thymus, spleen, mesenterial, iliac and popliteal lymph nodes. On the contrary, when mixed ante- and postnatal benzpyrene influence has place, the adrenergic innervation density and relative content of catecholamines are increased. We suppose that benzpyrene treatment of pregnant animals has specific "training" effect for monoaminergic systems of foetus and causes the increase of neurotransmitter providing of immunocompetent organs in conditions of repeat body and toxicant meeting.


[Morphobiochemical study of the liver in systemic endotoxinemia].

Dog liver in systemic endotoxemia induced by intravenous injection of E. coli lipopolysaccharide in 2 mg/kg dosage has been studied. Morpho- and pathogenetic characteristics of developing intoxication have been specified histologically and biochemically.


[Structural-functional characteristics of the renal endocrine system after alpha-1 adrenoreceptor blockade].

Research Institute of Cardiology, Uzbek Health Ministry Structural and functional peculiarities of the renal juxtaglomerular and interstitial cells were studied after alpha 1-adreno-blockers were used. The endocrine cells were studied after a single and prolonged introduction of the agents. Administration of a single dose of the drugs led to hypergranulation in juxtaglomerular cells thus decreasing their functional activity and release of the granules from the cells. The interstitial cells function intensified. Prolonged administration of alpha 1-adrenoblockers caused a degranulation process in the juxtaglomerular cells and a decrease in their protein-synthetizing structures, namely, renin synthesis, and elevation of synthetic process in the interstitial cells.


Expression of selected human HOX-2 genes in B/T acute lymphoid leukemia and interleukin-2/interleukin-1 beta-stimulated natural killer lymphocytes.

Although the key role of human homeobox (HOX) genes in development is well established, their function in adult cells is still under scrutiny. We have analyzed, in normal adult blood cell subpopulations, acute lymphoid leukemia (ALL) cells lines, and primary blasts, the RNA expression of all HOX-2 cluster genes (5'-2.5, 2.4, 2.3, 2.2, 2.1, 2.6, 2.7, 2.8, 2.9, 3') and nine genes in the HOX-1, -3, and -4 cluster by Northern blotting, RNAse protection, and/or reverse transcriptase polymerase chain reaction (RT-PCR). The analyzed HOX-1, -3, and -4 genes were never expressed in all tested cell populations. Natural killer (NK) cells activated in interleukin-2 (IL-2)/IL-1 beta-treated cultures exhibit a gradually increasing, abundant expression of three HOX-2 genes (2.2, 2.6, 2.8), while three other genes (2.3, 2.1, 2.7) are expressed at a lower level at late culture times. However, no HOX-2 gene is expressed in quiescent lymphocytes (NK, B and T [T-cell receptor (TCR) alpha/beta, gamma/delta lymphocytes, thymocytes] cells), granulocytes, and monocytes. In B- and T-ALL cell lines, HOX-2 genes are expressed according to different patterns: (1) widespread transcription (seven of nine genes, including 2.3 and 2.6) in the Peer line bearing the TCR gamma/delta; (2) expression of 2.5, 2.2, and 2.6 in the SEZ 627 line, which derives from an HTLV-1+ T-helper leukemia; (3) transcription of 2.3 and 2.6 in both the T-ALL CEM line and four B-ALL lines (interestingly, CALLA- B-ALL lines are constantly 2.3/2.6 RNA+); (4) no HOX-2 gene expression was detected in one T- and two B-ALL lines. Primary blasts from five T- and five pre-B-ALL showed selective expression of one or more HOX-2 genes, namely 2.5, 2.2, 2.6, and 2.7. Our data are compatible with the hypothesis that selected HOX-2 genes play a role in the IL-2/IL-1 beta-induced activation and/or proliferation of normal NK lymphocytes and possibly in the oncogenetic process of some T- and B-ALL.