[Expression of c-erbB-2 protein in gastric carcinomas--correlation between immunohistochemical study and clinico-pathological factors, DNA ploidy pattern and concentration of c-erbB-2 protein in serum].

Expression of c-erbB-2 protein in carcinoma tissue was examined in 56 patients suffered from gastric carcinoma, and the correlation between the expression of c-erbB-2 protein and clinico-pathological factors, DNA ploidy pattern was also examined. Positive expression of c-erbB-2 protein in carcinoma tissue was detected in 21/56 (37.5%) cases, and the positive rate (71.4%) in tissue of differentiated carcinoma (pap, tub1, tub2) was significantly higher than that in tissue of undifferentiated carcinoma (por, sig, muc) (28.6%). No good correlation between the expression of c-erbB-2 in tissue and other clinico-pathological factors, such as ly, v, n, tumor size, stage of the tumor, and the location of the tumor was observed. In DNA ploidy, 70.6% of cases was aneuploid pattern, and 29.4% of cases was diploid pattern in positive expression of c-erbB-2 protein in carcinoma tissue. These results suggest that expression of c-erbB-2 protein is involved in promoting DNA synthesis in initial step of differentiated gastric carcinoma. The concentration of c-erbB-2 in serum of positive expression of c-erbB-2 protein in tissue was significantly higher than that in serum of negative expression of c-erbB-2 protein in tissue. Good correlation between serum concentration of c-erbB-2 protein and clinical stage of the carcinoma was observed in positive expression of c-erbB-2 protein in carcinoma tissue. The concentration of c-erbB-2 protein in serum can be a sensitive indicator for guess the Stage of the gastric carcinoma that express c-erbB-2 protein in carcinoma tissue.


Analysis of HLA class II genes in Japanese patients with idiopathic membranous glomerulonephritis.

Thirty unrelated Japanese adult patients with idiopathic membranous glomerulonephritis (IMG) and 50 unrelated Japanese normal controls were examined for HLA class II genes. Both the 3.0 kb DQB and the 6.2 kb DQA restriction fragments were simultaneously identified in 86.7% of the patients. These were significantly different from the 14% frequency of the fragments in controls (relative risk = 39.9; P = 1.7 x 10(-10)). The haplotype DR2-DQwl associated with IMG seemed to be Dw2 which was essentially different from the haplotype common to the normal Japanese population. Dw12. This was because most of the restriction fragment length polymorphism (RFLP) of DQB and DQA of the patients coincided with that of homozygous cell lines with Dw2. The DRB probe showed no significant differences in the hybridization patterns between the patient group and HLA-matched controls. These findings indicate that the specific HLA-DQ polymorphism correlates primarily with Japanese IMG.


Inhibition of leukocyte-endothelial adherence following thermal injury.

Progressive microvascular damage in the tissue adjacent to a cutaneous burn injury results in extension of burn size. The role of neutrophils (PMNs) in the pathogenesis of microvascular injury was investigated by inhibition of PMN adherence to the microvascular endothelium using monoclonal antibodies directed to the leukocyte CD18 adhesion complex or its endothelial ligand, intercellular adhesion molecule-1 (ICAM-1, CD54). A model of thermal injury was developed using New Zealand White rabbits. Under general anesthesia two sets of three full-thickness burns separated by two 5 x 30-mm zones were produced by applying brass probes heated to 100 degrees C to the animals' backs for 30 sec. Cutaneous blood flow determinations were obtained for 72 hr. Blood flow measurements were performed using a laser doppler blood flowmeter (PF3, Perimed, Piscataway, NJ). There were five experimental groups; controls given saline alone, n = 12; animals given monoclonal antibody to the PMN CD18 complex, R 15.7 prior to burn injury (pre-R15.7, n = 5); animals given R 15.7 30 min after burn injury (post-R 15.7, n = 6); animals given the anti ICAM-1 antibody, R 6.5 prior to burn (pre-R 6.5, n = 6); and animals given the R 6.5 30 min postburn injury (post-R 6.5, n = 6). BF in the marginal "zone of stasis" between burn contact sites was significantly higher in the antibody-treated animals and administration of the antibodies 30 min after injury was as effective as preburn administration in preserving blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)


Insulin-like growth factors I and II expression in the healing wound.

Demonstrating temporal variation in the expression of messenger RNA (mRNA) for growth factors may give some indication as to whether growth factor synthesis is regulated in wound healing. The aim of this study was to evaluate the expression of insulin-like growth factors (IGF) I and II in the wound. Two wound models, an incisional model and a subcutaneous sponge implant model, were used in this study. The RNA was extracted and reverse transcribed and mRNA was amplified using polymerase chain reaction (PCR). Semiquantitation of PCR products was accomplished using [3H]dGTP incorporation. Levels of expression for both IGF-I and -II were found to be low in unwounded skin and at 12 hr postwounding. However, in both wound models expression increased substantially from 1 to 21 days postwounding. Both factors also were found to be expressed by fibroblasts and polymorphonuclear leukocytes (PMN). Additionally, two transcripts were found for IGF-II, the larger of which appeared to be specific for PMN and possibly cells involved in angiogenesis. Levels of message expressed in healing wounds for IGF-I and -II appear to be regulated with the highest levels of message found at time points coinciding with fibroblast predominance in the wound. Since fibroblasts are known to both secrete and respond to IGF-I, it is possible that IGF-I and IGF-II are acting to influence fibroblast differentiation and function in the later stages of wound healing.


Demonstration of clonality, by X-linked DNA analysis, in chronic natural killer cell lymphocytosis and successful therapy with oral cyclophosphamide.

The expanded lymphocyte population in large granular lymphocyte (LGL)-leukemia carries the phenotypic characteristics of either cytotoxic T lymphocytes (CD3+,CD8+) or natural killer (NK) cells (CD3-,CD15+). In the former subset, clonality has been demonstrated by T-cell receptor gene rearrangement studies. Since NK cells do not rearrange T-cell receptor genes, the neoplastic nature of chronic NK cell lymphocytosis has not been well defined. We used X-linked DNA analysis to study the clonal nature of an expanded NK cell population in a patient with a 3-year history of relative lymphocytosis associated with anemia and neutropenia. Southern blot analysis showed no clonal T-cell receptor gene rearrangement. The majority of the circulating lymphocytes had a NK cell phenotype and demonstrated both direct NK cell-mediated cytotoxicity and antibody-dependent cellular cytotoxicity. However, the in vitro growth characteristics of these cells did not suggest that they were polyclonal expansions of normal NK cells. To determine directly the clonal origin of these cells, we performed X-linked DNA analysis. Density gradient centrifugation methods were used to isolate mononuclear cells, and NK cells were positively selected by CD16-immunoconjugated magnetic beads. The DNA of these cells was analyzed by restriction fragment length polymorphism-methylation strategy and showed a monoclonal pattern of X-chromosome inactivation while a polyclonal pattern was obtained in corresponding skin tissue. Treatment of the patient with oral cyclophosphamide resulted in complete hematologic remission. We conclude that chronic NK lymphocytosis may be clonal and responsive to immunosuppressive therapy.


Effects of reserpine on tyrosine hydroxylase mRNA levels in locus coeruleus and medullary A1 and A2 neurons analyzed by in situ hybridization histochemistry and quantitative image analysis methods.

These studies examined the effects of reserpine on concentrations of norepinephrine (NE), dopamine (DA) and epinephrine (EPI) and on levels of tyrosine hydroxylase (TH) mRNA in locus coeruleus (LC) and medullary A1 and A2 neurons. Noradrenergic neurons in these regions first were identified by immunocytochemistry and, thereafter, by in situ hybridization histochemistry. Levels of TH mRNA were measured by quantitative image analysis methods. Changes in catecholamine concentrations in micropunches of these brain regions were analyzed by HPLC. Epinephrine was not detected in any of the nuclei examined. Twenty-four hours after reserpine treatment, NE concentrations declined in A1, A2 and LC neurons by 46, 69 and 34% respectively while DA declined only in the region of A2 neurons. This reserpine-induced depletion of NE was accompanied by a 2- to 3-fold increase in TH mRNA levels in LC and A1 neurons but no change in message levels occurred in A2 cells 24 h after reserpine. Forty eight hours later, message levels in A1 and LC neurons did not differ significantly from the elevated 24 h values but TH mRNA levels in A2 neurons now were significantly elevated compared to 24 h values. TH mRNA levels 72 h after reserpine did not differ from 48 h values in A1, A2 and LC neurons. Thus, TH gene expression in A1 neurons increases after reserpine treatment in a manner equivalent to that observed in LC, adrenal medulla and superior cervical ganglia. The reason why it required 48 h for TH mRNA to increase in A2 neurons remains unclear.


Changes in tyrosine hydroxylase mRNA levels in medullary A1 and A2 neurons and locus coeruleus following castration and estrogen replacement in rats.

Temporal changes in tyrosine hydroxylase (TH) mRNA levels in medullary A1 and A2 neurons and locus coeruleus (LC) cells were studied 6, 12 and 24 h following orchidectomy in rats. Brains from intact controls and sham castrated rats also were evaluated at these same time periods. In situ hybridization histochemistry and quantitative image analysis techniques were used to quantitate levels of cytoplasmic TH mRNA. Neither the time of day nor the stress of sham castration affected TH mRNA levels in A1, A2 and LC neurons. In contrast, 6 h following castration, TH mRNA levels in A1 neurons had declined significantly. Thereafter, there was a linear increase in A1 message levels such that, by 24 h, TH mRNA values were significantly higher than those obtained in intact controls. Placement of Silastic estrogen capsules immediately after castration prevented the 6 h decline in A1 message levels. At 12 h, TH mRNA levels in A1 neurons were significantly higher in estrogen-treated rats compared to those of the castrate or intact control groups. By 24 h, message levels in A1 neurons of steroid-treated rats were comparable to the intact control. Neither castration nor estrogen treatment altered TH mRNA levels in A2 neurons. TH mRNA levels in LC neurons increased significantly 6 h after castration and estrogen produced a further significant increase in message levels. Six hours later (12 h), TH mRNA values were still higher than controls but, in the estrogen-treated group, these levels had declined to those observed in the 12 h castrate group.(ABSTRACT TRUNCATED AT 250 WORDS)


1H spectroscopic imaging of rat brain at 7 tesla.

1H magnetic resonance spectroscopic imaging has been used to obtain metabolite maps of the rat brain. The spin-echo-based technique has been evaluated with respect to water and lipid suppression and sensitivity. Metabolite maps were constructed for choline, creatine + phosphocreatine, amino acids, N-acetyl aspartate, and lactate. A spatial resolution of 3 x 3 mm (in plane) with 7-mm-thick slices was achieved routinely in 60-min (16 x 16 phase encodings) acquisitions. For higher intensity resonances, metabolite maps could be constructed in as little as 10 min. Results from phantoms and from rats under normal and focal ischemia conditions are presented.


Localized 1H NMR spectra of glutamate in the human brain.

Localized 1H NMR spectra at TE = 12 ms were obtained from cerebral cortex of human subjects using ISIS with surface suppression. The 2.29-ppm resonance was assigned to C4 glutamate with contributions from C4 glutamine and GABA using in vivo spectral editing and comparison of chemical shift with pure compounds. The measured intensity ratio between the 2.29 resonance and the creatine resonance at 3.03 ppm was in good agreement with the ratio predicted from previously reported measurements of glutamate, glutamine, and GABA concentrations in biopsied human brain tissue.


Report on a conference on organic solvents and the nervous system.

At two scientific conferences in 1985, one in Copenhagen sponsored by the Nordic Council of Ministers and the World Health Organization (WHO), the other in Raleigh, NC, it was concluded that chronic toxic encephalopathy may develop following long-term occupational exposure to organic solvents (1,2). The terms organic affective syndrome, mild and severe chronic toxic encephalopathy were suggested for this condition describing increasing severity. In May 1990, a conference on organic solvents and the nervous system was held in Copenhagen sponsored by the Commission of the European Communities and the Danish Ministry of the Environment (3). Scientists and representatives from the governments, industries, and labour organisations from the EEC and US participated.


Aminopeptidase N is a major receptor for the entero-pathogenic coronavirus TGEV.

Coronaviruses, like many animal viruses, are characterized by a restricted host range and tissue tropism. Transmissible gastroenteritis virus (TGEV), a major pathogen causing a fatal diarrhoea in newborn pig, replicates selectively in the differentiated enterocytes covering the villi of the small intestine. To investigate the molecular determinants of the infection, we characterized the surface molecule used by the virus for binding and entry into host cells. Here we report that aminopeptidase N, an ectoenzyme abundantly expressed at the apical membrane of the enterocytes, serves as a receptor for TGEV. Monoclonal antibodies were selected for their ability to block infection by TGEV of porcine cell lines. They recognized a brush-border membrane protein of M(r) 150K, which was identified as aminopeptidase N by amino-terminal sequencing. Two lines of evidence supported the view that the peptidase itself acts as a receptor. First, virions bound specifically to aminopeptidase N that was purified to homogeneity. Second, recombinant expression of aminopeptidase N conferred infectivity by TGEV to an otherwise non-permissive cell line.


Human aminopeptidase N is a receptor for human coronavirus 229E.

Human coronaviruses (HCV) in two serogroups represented by HCV-229E and HCV-OC43 are an important cause of upper respiratory tract infections. Here we report that human aminopeptidase N, a cell-surface metalloprotease on intestinal, lung and kidney epithelial cells, is a receptor for human coronavirus strain HCV-229E, but not for HCV-OC43. A monoclonal antibody, RBS, blocked HCV-229E virus infection of human lung fibroblasts, immunoprecipitated aminopeptidase N and inhibited its enzymatic activity. HCV-229E-resistant murine fibroblasts became susceptible after transfection with complementary DNA encoding human aminopeptidase N. By contrast, infection of human cells with HCV-OC43 was not inhibited by antibody RBS and expression of aminopeptidase N did not enhance HCV-OC43 replication in mouse cells. A mutant aminopeptidase lacking the catalytic site of the enzyme did not bind HCV-229E or RBS and did not render murine cells susceptible to HCV-229E infection, suggesting that the virus-binding site may lie at or near the active site of the human aminopeptidase molecule.


Pharmacological characterization of dopamine systems in the nucleus accumbens core and shell.

Recent anatomical data suggest that the nucleus accumbens can be parcellated into a core region, related to the caudate-putamen, and a shell region, associated with the limbic system. We have used pharmacological methods to characterize the dopamine innervations of the nucleus accumbens core and shell in the rat. Concentrations of both dopamine and serotonin were significantly greater in the nucleus accumbens shell than the nucleus accumbens core. Metabolite: amine ratios suggested that both dopamine and serotonin utilization are greater in the core. However, dopamine turnover (as determined by measuring the rate of decline of dopamine after alpha-methyl-p-tyrosine treatment) was not significantly different in the two accumbal sectors. Dopamine concentrations in the two nucleus accumbens sectors were decreased to an equivalent degree at both 4 and 18 h after reserpine administration. In contrast, serotonin concentrations were decreased to a significantly greater degree in the nucleus accumbens core than nucleus accumbens shell at 4 h, but not 18 h, after reserpine administration. Administration of haloperidol increased dopamine utilization in both nucleus accumbens sectors, but augmented utilization to a significantly greater degree in the nucleus accumbens core. Clozapine increased dopamine utilization to an equivalent degree in both nucleus accumbens regions. Short duration immobilization stress selectively increased dopamine utilization in the nucleus accumbens shell. These data indicate that there are significant differences between the nucleus accumbens core and nucleus accumbens shell in basal dopamine metabolism, and indicate that the core and shell dopamine innervations can be distinguished on the basis of response to both pharmacological and environmental challenges.(ABSTRACT TRUNCATED AT 250 WORDS)


Pindolol antagonizes the effects on hippocampal rhythmical slow activity of clonidine, baclofen and 8-OH-DPAT, but not chlordiazepoxide and sodium amylobarbitone.

Buspirone, benzodiazepines, barbiturates and ethanol all reliably reduce the frequency of reticular-elicited hippocampal rhythmical slow activity. In the present experiments we tested a number of drugs which are not usually used for treating generalized anxiety disorders but which have been reported to have some anxiolytic properties. Clonidine (0.3 mg/kg, i.p.), baclofen (6 mg/kg, i.p.) and 8-hydroxy-di-n-propylamino tetralin (8-OH-DPAT) (2.5 mg/kg, i.p.) all reduced the frequency of rhythmical slow activity. The effect of all three drugs was reduced by the 5-hydroxytryptamine 1a antagonist pindolol (2 mg/kg, i.p.). Pindolol had no effect on the reduction in rhythmical slow activity produced by sodium amylobarbitone, as has been previously reported for the benzodiazepine chlordiazepoxide. Flumazenil (10 mg/kg, i.p.), a benzodiazepine receptor antagonist, reduced the effects of chlordiazepoxide (5 mg/kg, i.p.), but not buspirone (10 mg/kg, i.p.). A combination of the selective beta 1 adrenergic receptor antagonist metoprolol (20 mg/kg, i.p.) and the beta 2 adrenergic receptor antagonist ICI 118,551 (4 mg/kg, i.p.) did not reduce the effects of either buspirone (10 mg/kg, i.p.) or diazepam (1 mg/kg, i.p.). These data show that there are at least two separate routes through which anxiolytic agents reduce the frequency of hippocampal rhythmical slow activity. Buspirone, clonidine, baclofen and 8-OH-DPAT act via a system dependent on 5-hydroxytryptamine 1a receptor activation. Benzodiazepines act via activation of the benzodiazepine receptor and probably share with barbiturates action at the GABA-benzodiazepine-chloride ionophore complex but do not produce their effects, directly or indirectly, by 5-hydroxytryptamine 1a receptor activation.


Baroreceptor reflex inhibition induced by the stimulation of serotonin3 receptors in the nucleus tractus solitarius of the rat.

Previous studies suggested that in the nucleus tractus solitarius, cardiovascular responses to serotonin may involve the simultaneous activation of more than one receptor subtype. In the present study, the cardiovascular effects of the local application of serotonin and different serotonin3 agonists and antagonists into the nucleus tractus solitarius were analysed in intact and unilaterally ganglionectomized rats. Unilateral injections of serotonin (5-15 nmol) produced a dose-dependent increase in blood pressure and partially antagonized the arterial baroreflex responses evoked by an i.v. injection of phenylephrine. Similar blood pressures response were obtained after unilateral microinjections of phenylbiguanide (5 nmol) and 2-methyl-serotonin (5 nmol), two serotonin3 receptor agonists. Bilateral microinjections of serotonin or phenylbiguanide produced more pronounced blood pressure effects and antagonized completely the baroreflex responses. Both blood pressure and baroreflex effects were antagonized by prior injections of specific serotonin3 antagonists such as zacopride (100 pmol) and ondansetron (100 pmol). Concomitant autoradiographic studies performed in intact and ganglionectomized rats, using [125I]iodozacopride, confirmed that serotonin3 receptors in the nucleus tractus solitarius are mainly located on vagal afferent fibers. In addition, serotonin microinjections made in the nucleus tractus solitarius ipsilateral to the ganglionectomy revealed a significant reduction in cardiovascular responses compared to intact animals. These results suggest that in the nucleus tractus solitarius of the rat, serotonin is involved in the reflex regulation of blood pressure through the stimulation of serotonin3 receptors presumably located on vagal afferent fibers. Since bicuculline antagonized the serotonin-mediated pressor responses, a serotonin3-dependent activation of an inhibitory GABAergic system within the nucleus tractus solitarius might be involved in blood pressure regulatory mechanisms.


Confirmation of X-linked inheritance and provisional mapping of the keratosis follicularis spinulosa decalvans gene on Xp in a large Dutch family.

In a large Dutch family with keratosis follicularis spinulosa decalvans (KFSD, MIM 308800), DNA linkage analysis was performed in order to locate the gene. Pedigree analysis and lod score calculation confirmed X-linked inheritance and revealed significant linkage to DNA markers on Xp. A maximum lod score of 5.70 at theta = 0.0 was obtained with DXS41 (p99.6). The KFSD gene is tentatively located on Xp21.2-p22.2.


A review of the clinical pharmacokinetics of pilocarpine, moxisylyte (thymoxamine), and dapiprazole in the reversal of diagnostic pupillary dilation.

An alpha-adrenergic blocking drug, dapiprazole, is now marketed in eyedrop form. Dapiprazole is being promoted as an agent suitable for reversing the diagnostic mydriasis produced by tropicamide or tropicamide and phenylephrine. The mechanism of action of dapiprazole is thought to be the same as that of moxisylyte (thymoxamine). The human pharmacokinetics for these drugs are reviewed and compared to pilocarpine. Published data indicate that either dapiprazole (0.5%) or moxisylyte (0.5%) enhance recovery from the mydriasis produced by tropicamide, phenylephrine, or their combination. However, because the published studies differ substantially in the doses of these mydriatics or in the miotics actually used, it is not possible to make any firm recommendations on how many drops of these new miotics should be instilled.


Identification and analysis of the ret proto-oncogene promoter region in neuroblastoma cell lines and medullary thyroid carcinomas from MEN2A patients.

The human ret proto-oncogene (proto-ret), encoding a receptor tyrosine kinase, is highly expressed in neuroblastomas, medullary thyroid carcinomas (MTCs) and pheochromocytomas, which are all tumors of cells originating from the neural crest. In studies on the transcription mechanism of proto-ret, we identified the transcription start site and the promoter region by chloramphenicol acetyl transferase (CAT) assay. A sequence upstream from the transcription start site (-167 to +98 bp) showed definite promoter activity in both proto-ret mRNA-positive neuroblastoma NB39-nu cells and proto-ret mRNA-negative HeLa cells. The promoter sequence had a high GC content and contained four tandemly repeated GC boxes without a TATA box. Putative binding sequences for SP-1, AP-2 and epidermal growth factor receptor-specific transcription factor (ETF) and also the transcription-suppressing factor, GC factor (GCF), were found in the repeated GC box region. Southern blot analysis of DNAs of neuroblastoma cell lines and primary MTCs showed that the high proto-ret expression in these tumors is not caused by gross genetic changes in the promoter region, suggesting the possible involvement of a region(s) other than the sequence from -167 to +98 bp or a minor genetic change(s) in the promoter region.


Intragenic homozygous deletion of the WT1 gene in Wilms' tumor.

One example of intragenic homozygous deletion of the WT1 gene on chromosome 11p13 was found after screening 42 samples of Wilms' tumor DNA from Japanese patients. After construction of a restriction map for the genomic sequence covering the 3' half of the gene, the deletion was analysed at the nucleotide sequence level. The deletion occurred in the patient's germline on his paternal chromosome, and most of the short arm of his maternal chromosome 11 was subsequently lost in the tumor. The size of the deletion was about 8 kb, removing exons 6 and 7 and resulting in premature termination. The deletion seemed to be created by recombination between short homologous sequences found in an Alu repeat, with a 16-bp duplication left at the junction. This case conforms to a two-hit model for the genesis of a certain group of tumors, and supports the hypothesis that WT1 is one of the recessive oncogenes responsible for Wilms' tumor.


Detection of a carrier state in Theileria parva-infected cattle by the polymerase chain reaction.

Two sets of oligonucleotide primers, one derived from a repetitive sequence and the other from the gene encoding a 67 kDa sporozoite antigen of Theileria parva, were used to amplify parasite DNA from the blood of T. parva-infected carrier cattle using the polymerase chain reaction (PCR). PCR amplification products were obtained from 15 carrier cattle infected with one of 4 different T. parva stocks. Successful amplifications were performed using DNA from 2 cattle infected with T. p. parva Pemba Mnarani, 10 cattle infected with T. p. parva Marikebuni, 2 cattle infected with T. p. bovis Boleni and 1 animal infected with T. p. lawrencei 7014. No amplification products were obtained from any of 7 cattle which had been infected with the T. p. parva Muguga stock. A synthetic oligonucleotide, which hybridized specifically to T. p. parva Marikebuni DNA among 6 T. parva stocks tested, was designed using sequence data from within the region of the T. parva genome amplified by the repetitive sequence primers. The oligonucleotide was used to probe PCR products and to increase the sensitivity and specificity of carrier animal detection. Southern blot analysis using a T. parva repetitive sequence probe demonstrated the existence of restriction fragment length polymorphisms between parasites isolated from T. p. parva Marikebuni-infected carrier cattle. The use of the PCR and other methods of carrier animal detection are discussed.


Renal effects of alpha-adrenoceptor blockade during furosemide diuresis in conscious rats.

Clearance experiments were performed in conscious rats in order to investigate whether intravenous infusion of the non-selective alpha-adrenoceptor antagonist phentolamine could block compensatory sodium reabsorption during furosemide-induced volume contraction. By measuring inulin clearance, urinary excretion rates of sodium and water, and lithium clearance, the effects on proximal and distal nephron segments were dissociated. The renal effect of intravenous infusion of 0.3 mg/kg/hr phentolamine (n = 6) was compared with time control animals (n = 9). Furosemide was administered as constant intravenous infusion (7.5 mg/kg/hr) with simultaneous phentolamine infusion at four dose levels: 0 (n = 9), 0.3 (n = 6), 1.0 (n = 7) and 3.0 mg/kg/hr (n = 6). Phentolamine infusion reduced norepinephrine-induced increase in blood pressure at all three dose levels (n = 5). Phentolamine infusion induced transient antidiuresis and a prolonged antinatriuretic response. Compared with rats given furosemide only, phentolamine attenuated dose-dependently the diuretic and natriuretic peak response to furosemide. This effect was associated with dose-dependent reductions in mean arterial pressure. The reduced natriuretic response was due to a reduced fractional sodium excretion in the distal nephron segment (at all doses of phentolamine) and a reduction of the glomerular filtration rate (1.0 and 3.0 mg/kg/hr phentolamine). The fractional lithium excretion (FELi) increased to 65 +/- 3% at 0.3 mg/kg/hr phentolamine during the natriuretic peak response of furosemide, while it only increased to 52 +/- 3% during furosemide alone. At steady-state conditions (120-180 min. after start of furosemide infusion) after infusion with furosemide plus 0.3 mg/kg/hr phentolamine the animals were still volume-depleted, but the compensatory tubular Na reabsorption in the proximal tubules was inhibited (FELi = 48 +/- 2% versus 39 +/- 1% in rats given furosemide alone). During furosemide infusion plasma epinephrine increased 700% and plasma norepinephrine increased 50%. These results are compatible with increased systemic sympathetic nervous activity and a contributory role of proximal tubular alpha-adrenoceptors in mediating compensatory sodium reabsorption during acute furosemide-induced volume contraction.


Kinetic identification of a hydrogen bonding pair in the glucoamylase-maltose transition state complex.

Molecular recognition and site-directed mutagenesis are used in combination to identify kinetically, transition state interactions between glucoamylase (GA) and the substrate maltose. Earlier studies of mutant Glu180----Gln GA had indicated a role in substrate binding for Glu180 (Sierks, M.R., Ford, C., Reilly, P.J. and Svensson, B. (1990) Protein Engng, 3, 193-198). Here, changes in activation energies calculated from measured kcat/Km values for a series of deoxygenated maltose analogues indicate hydrogen bonding between the mutant enzyme and the 3-OH group of the reducing end sugar ring. Using the same substrate analogues and determining activation energies with wild-type GA an additional hydrogen bond with the 2-OH group of maltose is attributed to an interaction with the carboxylate Glu180. This novel combination of molecular recognition and site-directed mutagenesis enables an enzyme substrate transition state contact to be identified and characterized even without access to the three dimensional structure of the enzyme. Given the distant structural relationships between glucoamylases and several starch hydrolases (Svensson,B. (1988) FEBS Lett., 230, 72-76), such identified contacts may ultimately guide tailoring of the activity of these related enzymes.


The E3L gene of vaccinia virus encodes an inhibitor of the interferon-induced, double-stranded RNA-dependent protein kinase.

A vaccinia virus-encoded double-stranded RNA-binding protein, p25, has been previously implicated in inhibition of the interferon-induced, double-stranded RNA-activated protein kinase. In this study, we have identified the vaccinia viral gene (WR strain) that encodes p25. Amino acid sequence analysis of a chymotryptic fragment of p25 revealed a close match to the vaccinia virus (Copenhagen strain) E3L gene. The WR strain E3L gene was cloned and expressed either in COS-1 cells or in rabbit reticulocyte lysates in vitro. A M(r) 25,000 polypeptide that could bind to poly(rI).poly(rC)-agarose and that reacted with p25-specific antiserum was produced in each case. In addition, COS cells expressing E3L gene products inhibited activation of the double-stranded RNA-activated protein kinase in extracts from interferon-treated cells. Removal of E3L-encoded products by adsorption with anti-p25 antiserum resulted in loss of kinase inhibitory activity. These results demonstrate that the vaccinia virus E3L gene encodes p25 and that the products of the E3L gene have kinase inhibitory activity. Comparison of the deduced amino acid sequence of the E3L gene products with the protein sequence data base revealed a region closely related to the human interferon-induced, double-stranded RNA-activated protein kinase.


Asymmetric distribution of oncogene products at mitosis.

Computer-assisted image analysis was used to demonstrate in exponentially proliferating human tumor cells the uneven postmitotic apportionment of several oncogene-encoded proteins (ras p21; erbB-2 p185; fos p55; myc p62). This observation may provide the explanation for the high degree of heterogeneity of postmitotic cells and the asynchrony in cell cycle traverse of cultured cells.


Homozygous hereditary C3 deficiency due to a partial gene deletion.

The molecular mechanism of C3 deficiency in an Afrikaans patient with recurrent pyogenic infections was studied. Restriction enzyme analysis showed a gene deletion of 800 base pairs (bp) mapping to the alpha chain of C3. Amplification of genomic DNA, using the PCR, demonstrated that the deletion included exons 22 and 23 of the C3 gene. Truncated mRNA was shown in an Epstein-Barr virus-transformed B-cell line by PCR amplification of first-strand cDNA. A consequence of this deletion was that the RNA transcribed 3' to the deletion was out of frame, resulting in formation of a stop codon 19 bp downstream from the deletion. The molecular basis of the deletion was compatible with homologous recombination between two Alu sequences located in introns 21 and 23. An unrelated nonconsanguineous relative and two of a sample of 174 Afrikaans-speaking individuals were heterozygous carriers of the same gene deletion. The wide prevalence of this null allele in this population is probably due to the effects of a small founder population. The presence of this deletion in the C3 gene is not compatible with production of any functional C3, supporting the idea that study of such patients offers a valid model for understanding physiological activities of C3 in vivo in humans.


Phosphorylation of nitrogen regulator I of Escherichia coli induces strong cooperative binding to DNA essential for activation of transcription.

We studied the effect of phosphorylation of nitrogen regulator I (NRI) on its binding properties. Both phosphorylated and unphosphorylated NRI bind linearly to a single binding site but cooperatively to two adjacent binding sites. Cooperative binding of NRI is severely affected by phosphorylation: half-maximal binding of NRI-phosphate is at 20-fold lower concentrations than that of unphosphorylated NRI. This is more due to a huge increase in the cooperativity constant--which is the strength of interaction between two NRI dimers--than to an increase in the microscopic binding constant which is the binding affinity to a single binding site. In vitro transcription and DNA footprinting experiments showed that occupation of a single binding site by NRI is not enough for efficient activation and that activation only occurs at a higher NRI concentration. We propose an activation mechanism for NRI in which the phosphorylation of NRI induces a conformational change in the N-terminal domains of the NRI-phosphate dimers, which now interact strongly with each other, leading to a tetramerization of NRI upon binding to two adjacent binding sites. We propose that not the phosphorylation of NRI itself but rather the tetramerization of NRI-phosphate on DNA binding induces the conformational change of the central domain to the active conformation.


The gene for an inherited form of deafness maps to chromosome 5q31.

Primary--i.e., nonsyndromal-postlingual deafness is inherited as an autosomal dominant phenotype in a large kindred in Costa Rica. Genetically susceptible individuals begin to lose hearing at low frequencies at about age 10 years, after language and speaking are learned. Deafness inevitably progresses by age 30 years to bilateral hearing loss of all frequencies. Intelligence, fertility, and life expectancy are normal. The family traces its ancestry to an affected founder born in Costa Rica in 1754. We have mapped the gene for deafness in this kindred to chromosome 5q31, between the markers IL9 and GRL, by linkage analysis involving 99 informative relatives.


Effects of the dopamine D2 agonists lisuride and CQ 32-084 on rat feeding behaviour.

The influence on rat-feeding behaviour of lisuride and CQ 32-084, agonists at dopamine D2 receptors, was examined using two procedures. In a first series of experiments, the apparatus was an X-maze baited with food pellets where individual fasted rats were observed for 5 min. A number of parameters were recorded: latency to tasting and feeding, interval between tasting and feeding, total feeding time, and total grooming time. Lisuride (0.05 and 0.1 mg/kg) and CQ 32-084 (0.05 and 0.5 mg/kg) behaved as stimulants of eating; lisuride (0.4 mg/kg) inhibited the phenomenon. Both drugs always antagonized grooming. Subsequently, when food intake was determined in the home cages of fasted animals lisuride reduced feeding at all doses during the first hour after treatment, while CQ 32-084 had no effect. The data show that the two compounds display different activity on ingestive behaviour according to the dose and experimental model used. Discussion centres on the possible dependence of feeding enhancement in the X-maze on the anxiolytic activity exerted by low D2 autoreceptorial doses.


Effects of yohimbine and idazoxan on motor behaviors in male rats.

Yohimbine, an alpha 2 adrenergic antagonist, facilitates copulatory behaviors in male rats. This facilitation may reflect nonspecific activation of behavior rather than a more selective activation of copulatory behaviors. The present experiments assessed the effects of yohimbine on locomotor behaviors at a dose (2.0 mg/kg) known to facilitate sexual behaviors. Experiment 1 used a computer pattern-recognition system to classify motor behaviors into specific acts and act groups. Male albino rats were tested in three conspecific conditions: estrous female, anestrous female, or no conspecific. Yohimbine decreased locomotor activity in all three conspecific conditions. Experiment 2 examined the effects of yohimbine (2.0 mg/kg) and amphetamine (1.0 mg/kg) on locomotor behavior in a photocell-equipped activity measurement system. Amphetamine increased and yohimbine decreased locomotor activity. Experiment 3 used the computer pattern-recognition system to compare the effects of yohimbine and idazoxan, another alpha 2 adrenergic antagonist, on motor behaviors. Yohimbine and idazoxan both decreased activity but produced different patterns of behavioral change. The facilitatory effects of yohimbine on copulatory behaviors at a dose of 2.0 mg/kg are apparently not mediated by nonspecific activation of behavior.


Comparative study of roles of the lobus parolfactorius and intermediate medial hyperstriatum ventrale in memory formation in the chick brain.

Two discrete areas of the chick brain, the intermediate medial hyperstriatum ventrale (IMHV) and lobus parolfactorius (LPO), were found to have different functions during the formation of memory for a 1-trial peck-avoidance paradigm. Glutamate, ouabain, and emetine, known to disrupt short-, intermediate-, and long-term memory when injected into the IMHV, were injected into the cerebellum and LPO. All amnestic agents investigated produced amnesia when injected into the IMHV; only one of these agents produced amnesia when injected into the LPO, and none of the agents produced amnesia when injected into the cerebellum. The chick brain was also found to exhibit hemispheric asymmetries: The left IMHV and LPO were more sensitive to the amnestic agents than their corresponding right structure. From these data, hypotheses for the roles of these structures during memory are proposed.


Late posttraining memory processing by entorhinal cortex: involvement of NMDA and GABAergic receptors.

The NMDA receptor antagonist, D-2-amino-5-phosphonopentanoic acid (AP5) (5 micrograms) and the GABAA receptor agonist, muscimol (0.03 microgram) were infused bilaterally into the entorhinal cortex of rats 0, 90, 180, or 360 min after training in habituation to a novel environment or in step-down inhibitory avoidance. Animals were tested for retention 22 h after training in each task. AP5 and muscimol were amnestic for both tasks when given 90 or 180 min after training, but had no effect when given 0 or 360 min after training. In contrast, intraamygdala injections or AP5 or muscimol were amnestic when given 0 but not 90 min after inhibitory avoidance training. The results indicate that the entorhinal cortex plays a late but important role in posttraining memory processing; this role involves glutamatergic NMDA receptors and is inhibited by GABAA receptors. The intervention of the entorhinal cortex in posttraining memory processing is subsequent, and could be secondary, to that of the amygdala and other limbic structures.


Mathematical models of complex dose-response relationships: implications for experimental design in psychopharmacologic research.

We develop a mathematical model to account for the complex relationship between drug dose and clinical response in psychopharmacologic research. The model specifies relationships among drug dose, drug bioavailability, pharmacokinetic factors, course moderators, clinical response and the heterogeneity of the disorder, and allows for the derivation of results that have implications for experimental design in psychopharmacologic research. These results form the basis for computer simulations which indicate that random assignment to two fixed doses is more powerful and less sensitive to heterogeneity than assignment to clinically determined doses. Fixed dose designs, however, tend to overestimate the magnitude of drug bioavailability-clinical response relationships. Clinically determined dose designs are useful in some experimental situations; their effectiveness is enhanced by systematically reducing the clinically determined dose. Larger dose reductions improve the ability to detect bioavailability-clinical response relationships.


Factors influencing urinary tract retention after elective open cholecystectomy.

We studied a retrospective cohort of 360 consecutive patients who had undergone elective cholecystectomy using general endotracheal anesthesia to determine risk factors associated with postoperative retention of the urinary tract. Male gender, increased age, a longer operating time and higher total doses of analgesic agents given postoperatively were each significantly associated with an increase in urinary tract retention. The use of postoperative intravenous patient controlled analgesia was associated with increased retention after controlling for other risk factors. Physicians should consider inserting a Foley catheter preoperatively in patients undergoing a cholecystectomy who are scheduled to receive postoperative patient controlled analgesia.


Bypass surgery for aortitis syndrome: aortocarotid bypass with saphenous vein graft.

In seven patients with Takayasu arteritis, symptomatic cerebral ischemia was successfully treated by extracranial bypass surgery. We performed 14 surgical procedures, which included aortocarotid bypass, axilloaxillary bypass, carotid-vertebral bypass, subclavian-carotid bypass, axillocarotid bypass, carotid-carotid bypass, carotid-subclavian bypass, carotid-axillary bypass, and thyreocervical-carotid anastomosis. Among those the aortocarotid bypass was the most common procedure performed--six occasions in four cases. The others were less common procedures, each performed only one time. The saphenous vein was used for the graft in 12 of the procedures. An artificial graft made of Gore-Tex (6-mm inner diameter) was utilized in two cases. Patency of the grafts was adequate and no mortality or serious postoperative complication was encountered. Asymptomatic infarction developed in one patient. We analyze these procedures in detail and stress the usefulness of aortocarotid bypass with a saphenous vein graft.


[Comparative study of vecuronium and atracurium at low doses in minor pediatric surgery under combined anesthesia].

To compare, the time of onset and time of recovery of muscular blockade after use of half doses of vecuronium and atracurium, we studied 18 children ASA I who were proposed for short lasting pediatric surgery and combined anesthesia. Patients were divided into two groups: group V (n = 10) was treated with a single dose of 0.05 mg/kg of vecuronium and group A (n = 8) with 0.25 mg/kg of atracurium. Assessment of muscular relaxation was performed by measuring the electromyographic responses to a train of four stimuli applied to the cubital nerve at the level of the hypothenar eminence. We administered 0.02 mg/kg of atropine, 5 to 10 mg/kg of thiopental, and the muscular relaxing dose together with orotracheal intubation when the first stimulus of the train of four stimuli was blocked at 90% of its initial value (T90). Maintenance of the anesthetic level was performed with 50% of N2O-O2 without inhalational anesthetics. A caudal blockade was induced by 1 ml/kg of bupivacaine at 0.25%. We measured the following parameters of muscular relaxation: T90, T10 (time at which the 10% of the first stimulus reappears), T25 (time of clinical efficacy) and IR (index of recovery). Only 60% of patients (6 out of the 10 patients of vecuronium group and 5 out of the 8 subjects of atracurium group) achieved the T90. This occurred 2.5 +/- 0.7 min after vecuronium and 3.2 +/- 0.6 min after atracurium. T10 was 13.7 +/- 4.1 min for vecuronium and 13.3 +/- 4.1 min from atracurium. T25 occurred 18.2 +/- 6.5 min after vecuronium and 19.4 +/- 2.1 min for atracurium.(ABSTRACT TRUNCATED AT 250 WORDS)


Selective adrenergic agonists and colon motility in monkeys.

Sympathetic stimulation during and after laparotomy and other surgical procedures may be a factor inducing postoperative ileus. In experiments conducted in fasting monkeys, the effects of the selective sympathetic agonists alpha 1 (phenylephrine), alpha 2 (ST-91), beta 1 (dobutamine), and beta 2 (terbutaline) on colon contractile activity were measured. Strain gauges were implanted on the colon. Recordings were made for 1 hour (control) and then for an additional hour during continuous infusion by one of a range of doses of each drug (experimental). The drug doses were chosen to cover both physiologic and pharmacologic concentrations. All of the sympathetic agonists caused a dose-dependent decrease in the frequency of colon contractions. The beta-agonists did so at a concentration that is sufficiently low to support a hypothesis that beta-stimulation leading to inhibition of smooth-muscle contraction may play an important role in the genesis of postoperative ileus.


Relationship between the cytolysins tenebrosin-C from Actinia tenebrosa and equinatoxin II from Actinia equina.

The chemical, physical and biological properties of the cytolysin tenebrosin-C from Actinia tenebrosa have been compared with those of equinatoxin II from Actinia equina. The two proteins are indistinguishable by reverse-phase and cation-exchange HPLC and capillary zone electrophoresis, and give similar peptide fragments upon cyanogen bromide cleavage (as judged by the chromatographic behaviour, ultraviolet absorption spectra, amino acid composition and N-terminal amino acid sequences of the peptides). Their cardiac stimulatory activities are identical, and their haemolytic activities are similar, with equinatoxin II having slightly greater activity. These data indicate that the two molecules are either identical in all 179 amino acid positions, or differ by no more than one or two residues. These findings are discussed in the context of the taxonomic relationship between the two species of sea anemone.


How antibodies block HIV infection: paths to an AIDS vaccine.

We are beginning to understand the mechanism that envelope proteins of the human and simian immunodeficiency viruses use to gain entry into host cells. A vaccine that can elicit antibodies that bind to the viral epitopes involved in this process would thereby prevent HIV infection. This article outlines our progress in the development of possible candidates for AIDS vaccines.


Studies on maternal transmission of scrapie in sheep by embryo transfer.

The technique of embryo transfer was used to investigate the maternal transmission of scrapie in sheep. Embryo donor ewes were experimentally infected with scrapie (all eventually developing the disease) and artificially inseminated six months later with semen from an uninfected scrapie-susceptible ram. Embryos were harvested five and six days after insemination and transferred by laparoscopy, unwashed, into recipient ewes which had been genetically selected for very low susceptibility to scrapie. Six of the 26 lambs born to these recipients developed scrapie.


Expression of the c-erbB-2 proto-oncogene product and nuclear DNA content in benign and malignant human breast parenchyma.

The expression of the c-erbB-2 proto-oncogene product was investigated immunohistochemically in 474 formalin-fixed and paraffin-embedded human breast tissue samples. The series included 32 benign and 26 hyperplastic lesions, 32 carcinomas in situ and 384 invasive breast carcinomas, 107 of which were less than 1 cm in diameter. Cytometric DNA assessments were performed on histopathologically or cytodiagnostically identified cell nuclei, using image analysis. C-erbB-2 immunoreactivity was not seen in normal parenchyma or in benign and hyperplastic lesions. Mammary carcinomas in situ were more frequently immunoreactive (59%) than invasive neoplasms (23%). Invasive tumours more than 1 cm in diameter immunoreacted more often (26%) than small invasive carcinomas (16%). C-erbB-2 expression in regional lymph node metastases was the same as in the corresponding primary tumours. Significant differences were observed between the c-erbB-2 expression in DNA diploid and aneuploid lesions; for carcinomas in situ the figures were 40% and 72%, respectively. Invasive carcinomas of DNA diploid type rarely showed c-erb-B-2 expression, irrespective of tumour size and nodal status (7-11%). DNA aneuploid tumours were more frequently immunoreactive with increasing levels during progression (32-41%). Our data indicate that genetically stable invasive mammary tumours seem rarely to express the c-erbB-2 protein, even during progression, whereas genetically unstable invasive neoplasms frequently show c-erbB-2 immunoreactivity which increases during tumour progression.


[Comparison of the effects of diltiazem and isradipine in adrenergic beta receptor blockade in patients with stable angina pectoris].

In 20 patients with stable angina II-III according to NYHA by means of ergometry the effect of short-term administration of dilthiazem (90 mg in three doses), placebo and isradipine (5 mg in three doses) in block of beta-receptors of the sympathetic nerve (metipranolol 3 x 10 mg/day) was compared. As compared with placebo, dilthiazem and isradipine retarded significantly the development of stenocardia, reduced the S-T depression in lead V5 and increased the total work output during ergometry. Based on the results of this and previous work (9) it may be stated that concurrent administration of metipranolol reduced the frequency of side-effects of isradipine and prevented the reflex rise of the heart rate following its short-terms administration. The authors conclude that starting treatment of stable angina with isradipine is safer and more effective in combination with metipranolol than when monotherapy is used. Dilthiazem must be administered with metipranolol carefully with regard to possible development of severe bradycardia and its suitable dose should be established by titration.


Onset and duration of action of vecuronium in the elderly: comparison with adults.

The onset and duration of action of vecuronium were studied in young adult (n = 30; mean age 34 +/- 11.1 (s.d.) yr), middle-aged (n = 20; mean age 60 +/- 5.8 yr) and elderly patients (n = 30; mean age 80 +/- 4.6 yr) anaesthetised with thiopentone, nitrous oxide in oxygen and halothane. Neuromuscular block was monitored by applying the train-of-four (TOF) stimulation at 2 Hz to the ulnar nerve every 12 s. Half the patients in each group received 0.08 and the other half 0.12 mg kg-1 of the relaxant. The time to return of T1 (first response in the TOF sequence) to 25% of control was 28 +/- 5.2 (s.d.), 34 +/- 7.1 and 39 +/- 10.2 min following 0.08 mg kg-1 dose (P less than 0.05 between the elderly and young adults) and 45 +/- 9.2, 48 +/- 6.2 and 69 +/- 19.2 min following 0.12 mg kg-1 dose, respectively, in the three age groups (P less than 0.05 between the elderly and the other two groups). The recovery indices (time for 25-75% recovery of T1) after the 0.08 mg kg-1 was 9.6 +/- 3.4, 13.6 +/- 5.1 and 17.4 +/- 6.1 min, respectively (P less than 0.05 between the elderly and young adults). There was no significant difference in any of the parameters between the young adults and the middle-aged. The onset of block at each dose was not significantly different between the three age groups; however, the time to maximum effect was significantly shorter with the higher dose in the young and the middle-aged, but not in the elderly. Regression analysis of the data between age and the duration of action and recovery index suggested a significant prolongation (P less than 0.05) of these parameters in the elderly.


Outcome in untreated schizophrenia: a search for symptoms and traits with prognostic meaning in patients admitted to a mental hospital in the preneuroleptic era.

A cohort of schizophrenic patients consecutively admitted to a mental hospital for the first time in 1925 was investigated in search of symptoms and traits with prognostic meaning. Since Leonhard's diagnostic system was applied, cases with mixed symptoms and a favourable outcome were excluded as being neither schizophrenic nor manic-depressive. Owing to the admission policy then prevailing, cases with clinically less striking and socially less deleterious features were underrepresented. The sample (n = 70), so demarcated, was still considered fairly appropriate for the purpose of a differential study of outcome in nuclear schizophrenia with a life-long follow-up. The best outcome group consisted of 33% of the sample; 24% formed an intermediate group, and 43% profoundly deteriorated with continuous psychotic symptoms and a total loss of social function. Marriage before index admission was the only characteristic related to a favourable outcome. Nuclear schizophrenic symptoms, thought disturbance, blunted affect and all catatonic symptoms listed in DSM-III were related to an unfavourable outcome. When prognostic subgroups were compared pairwise, no favourable trait was detectable, and there were no decisive differences between the group with the best outcome and the intermediate group. When these 2 groups were compared with the group with worst outcome, however, significant differences arose with respect to unfavourable characteristics. Predictions using a discriminant analytic procedure yielded the same results. The hypothesis that affective and atypical signs would also have prognostic meaning in nuclear schizophrenia was disproved.


[Gamma-glutamyltransferase and alcoholic hepatic disease].

Accepting the principle that Gama-gt values are elevated in alcoholic patients, the authors attempted to find out if that enzyme might be helpful in distinguishing alcoholics with or without hepatic morphologic lesion. 110 alcoholic patients with and 57 without histologically proved hepatic lesion were studied. The authors conclude that a single determination of Gama-gt lacks specificity to detect, among the alcoholic individuals, those who already carry a morphologic, nonreversible lesion.


Atrial fibrillation: current therapeutic approaches.

Atrial fibrillation is associated with potentially life-threatening strokes. Anticoagulation with warfarin or aspirin reduces the risk of embolic events in patients with chronic atrial fibrillation and mitral valve stenosis or other underlying heart disease. In patients with acute onset of atrial fibrillation, anticoagulation is not necessary before cardioversion. However, in patients with chronic atrial fibrillation, anticoagulation should be started three weeks before cardioversion and continued for four weeks after the return of normal sinus rhythm. Quinidine remains the agent most commonly used for medical cardioversion in patients who are hemodynamically stable. If a patient is hemodynamically unstable or the atrial fibrillation is not corrected with drug therapy, direct-current electrical cardioversion has a high success rate. Antiarrhythmic (quinidine) therapy is often continued indefinitely to help maintain sinus rhythm.


Diagnosis and management of the paranoid patient.

Patients with symptoms of paranoia often present to primary care physicians. The paranoia may range in severity from a mild and largely incidental finding to a psychotic symptom. In its more severe forms, paranoia may constitute the chief complaint or may interfere with the patient's ability to accept treatment for other medical conditions. After an assessment of the severity of the symptoms and consideration of an organic etiology, initial treatment is often begun with a supportive approach and the prescription of a neuroleptic medication.


Exercise-induced asthma.

Exercise-induced asthma affects approximately 10 percent of the exercising population but often goes undiagnosed. Diagnosis is generally simple if the physician is aware of the subtle symptoms that may present during or after exercise. Preventive treatment, using a combination of exercise strategies and inhaled medications, is often successful. For patients with underlying chronic asthma that is exacerbated by exercise, long-term medication with preexercise doses is recommended.


Arrhythmias during the acute phase of reperfusion therapy for acute myocardial infarction: effects of beta-adrenergic blockade.

In 107 patients with acute myocardial infarction, the incidence of ventricular arrhythmias during the acute phase of thrombolysis was examined by means of Holter monitoring. In patients with a patient infarct-related artery as assessed angiographically at 90 minutes, the occurrence of accelerated idioventricular rhythms was noted significantly more frequently than in patients with a permanent occluded vessel. This arrhythmia peaked in the first 180 minutes after the start of thrombolysis. In addition, single ventricular premature beats and runs of ventricular tachycardia were also more common in patients with successful reperfusion. The effects of acute intravenous administration of beta-blockers were examined in 66 patients without contraindications to this therapeutic approach. There were no differences in the occurrence of any type of rhythm disorders in patients with (n = 43) or without beta-blockade (n = 23). Thus ventricular arrhythmias particularly accelerated idioventricular rhythms, and single ventricular premature beats occur more frequently in patients with a patent infarct artery within the first 24 hours after thrombolysis. Acute intravenous beta-blockade does not appear to exert significant antiarrhythmic effects during this period.


Habitual fish consumption, plasma phospholipid fatty acids, and serum lipids: the Tromsø study.

We examined the cross-sectional relationships between the frequency of habitual fish consumption, plasma phospholipid fatty acids, and serum lipids and lipoproteins in 152 men and women. There was a significant association between fish consumption starting from 1 dish/wk and plasma n-3, n-6, and n-9 fatty acids. Plasma eicosapentaenoic acid (EPA; 20: 5n-3) reflected fish consumption to a greater extent than did docosahexaenoic acid (DHA;22:6n-3). Triglycerides decreased (P less than 0.05) with fish consumption. In multivariate analysis in which anthropometric and lifestyle factors were controlled for, EPA correlated inversely with triglycerides (P less than 0.05) and positively with high-density-lipoprotein (HDL) cholesterol and apolipoprotein A-I (both P less than 0.001). In contrast, DHA did not correlate with triglycerides and showed negative associations to HDL cholesterol and apolipoprotein A-I (both P less than 0.001). Platelet phospholipid EPA, but not DHA, was associated with lower triglyceride and higher HDL-cholesterol concentrations (both P less than 0.05). This study suggests that long-term intake of small amounts of fish has biological effects, and that EPA and DHA have divergent relations with lipoprotein metabolism.


Composite tumor of the main bile duct producing several regulatory peptides.

Herein we describe what is, to our knowledge, the first reported case of a composite tumor of the main bile duct with epiploon metastases. Glucagon, pancreatic polypeptide, and somatostatin-immunoreactive cells were demonstrated in these metastases, but not serotonin, gastrin, or insulin-immunoreactive cells. The clinical significance of the neuroendocrine cells in the present case is discussed.


Breast cancer in men: risk factors with hormonal implications.

Cases included in a population-based case-control study of breast cancer in men were recruited from 10 geographic areas of the United States from 1983 to 1986. Controls, matched to cases on age and geographic area, were selected by random digit dialing for men under age 65 years and from Health Care Financing Administration files for older men. Results are based on responses from 227 cases and 300 controls to questions asked in a standardized personal interview. An increased risk of breast cancer was most strongly associated with undescended testes and was also related to orchiectomy, orchitis, testicular injury, late puberty, and infertility; and a decreasing trend in risk was observed with an increasing number of children. Relative risk estimates were also elevated in relation to a history of high blood cholesterol, rapid weight gain, benign breast conditions, and possibly obesity. These findings suggest that breast cancer in men develops in response to androgen deficiency associated with testicular dysfunction and under conditions associated with excess estrogen. Risk was also found to be elevated in men with a history of amphetamine use, diabetes, and cigar smoking and reduced in men with prior head trauma.


Fenoldopam reverses cyclosporine-induced renal vasoconstriction in kidney transplant recipients.

Cyclosporine causes renal vasoconstriction and reduced renal blood flow that may contribute to chronic nephrotoxicity. This effect has not been consistently reversed by available pharmacologic agents. The efficacy of orally administered fenoldopam, a dopamine-1 (DA-1) agonist with renal vasodilator properties, was evaluated in six patients whose condition was stable 3 to 6 months following renal transplantation. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured by inulin and p-aminohippurate (PAH) clearances, respectively, at baseline, after the acute oral administration of 100 mg of fenoldopam, and following 3 weeks of chronic oral fenoldopam therapy (100 mg thrice daily). Mean ERPF increased from 3.15 +/- 0.17 mL/s/1.73 m2 (189 +/- 10 mL/min/1.73 m2) at baseline to 3.48 +/- 0.17 mL/s/1.73 m2 (209 +/- 10 mL/min/1.73 m2) 4 hours after acute administration of fenoldopam (P = 0.04). Urine flow rate and fractional excretion of sodium also increased after acute administration, but not significantly. Mean systolic (SBP) and diastolic blood pressure (DBP) decreased maximally by 18 and 6 mm Hg, respectively, and mean pulse rate increased maximally by 8 bpm between 75 and 90 minutes after both acute and chronic administration. GFR was unchanged following both acute and chronic administration. The increase in ERPF was not maintained to the end of the dosing interval during chronic administration, probably due to the short half-life of fenoldopam. However, the renal vasodilatory response was still observed 3 to 4 hours after readministration of the drug following 3 weeks of oral dosing. Thus, fenoldopam significantly reverses the renal vasoconstriction caused by cyclosporine in renal transplant recipients.(ABSTRACT TRUNCATED AT 250 WORDS)


Distinct responses of interleukin-6 and other laboratory parameters to treatment in a patient with polyarteritis nodosa--a case report.

The authors describe a patient in whom the serum levels of interleukin-6 (IL-6) and other laboratory parameters were monitored. The IL-6 and C-reactive protein (CRP) levels, which were extremely high before treatment, declined rapidly with administration of prednisolone. Rheumatoid factor, IgG, and platelets count declined more gradually. Thus, determination of the serum IL-6 level might be useful in diagnosing and monitoring polyarteritis nodosa.


Healing of segmental grafts of digital pad skin in dogs.

Pad grafts would be indicated in instances of severe paw trauma when there has been loss of the major weight-bearing pads (ie, metatarsal and metacarpal pads) as well as loss of the digital pads. A practical technique for replacing pad tissue on the remaining paw tissue could avert limb amputation for lack of weight-bearing tissue in the area. Small segmental digital pad grafts were placed in granulation tissue beds in dogs. Although the grafts were from thick pad skin, they healed well. However, intervening wound areas did not become covered with the heavier keratinized epithelium of the pads. The thinner, more rapidly growing, less keratinized epithelium from the wound edges covered most of the wound.


The autonomic nervous system modulates dry air-induced constriction in the canine lung periphery.

To determine the modulatory role of the autonomic nervous system on dry air-induced bronchoconstriction (AIB) in the canine lung periphery, we examined the effect of cholinergic, alpha- and beta-adrenergic, and total autonomic ganglionic blockade on AIB. Pretreatment with atropine significantly attenuated AIB by approximately 30%, indicating that AIB is partially mediated via a vagal reflex. Pretreatment with either phentolamine or propranolol did not affect AIB, indicating that alpha- and beta-adrenoceptors, respectively, were not activated in response to dry air challenge. In contrast, pretreatment with hexamethonium significantly potentiated AIB. In addition, exogenous vasoactive intestinal peptide (VIP), a potential neurotransmitter for the nonadrenergic-noncholinergic (NANC) inhibitory system, significantly inhibited AIB. We conclude that (1) neither alpha- or beta-adrenergic efferents are activated during dry air challenge, (2) total autonomic blockade potentiates the response to dry air, and (3) VIP attenuates AIB. Based on these observations, we speculate that NANC inhibitory activity may be stimulated during dry air challenge and antagonizes AIB.


Prevention of first bleeding in cirrhosis. A meta-analysis of randomized trials of nonsurgical treatment.

To assess the effectiveness of beta-blockers and endoscopic sclerotherapy in the prevention of first bleeding and reduction of mortality in patients with cirrhosis and esophagogastric varices. Pertinent studies were selected using MEDLINE (1980 to 1990), reference lists from published articles or reviews, and congress abstract lists. Randomized trials comparing beta-blockers or sclerotherapy with a nonactive treatment. Nine randomized clinical trials of beta-blockers and 19 trials of sclerotherapy were reviewed. Seven trials of beta-blockers and 15 of sclerotherapy were published as full papers. Crude rates of bleeding and death in treated and control groups were extracted from each trial by three independent observers according to the intention-to-treat principle. The quality of published papers was systematically assessed and scored. The Mantel-Haenszel-Peto method was used for statistical evaluation of heterogeneity and for pooling of the results. No substantial heterogeneity was found, and the incidence of bleeding in trials of beta-blockers was significantly reduced (pooled odds ratio, 0.54; 95% CI, 0.39 to 0.74), particularly in patients with large or medium-sized varices or in those with varices and a hepatic vein pressure gradient above 12 mm Hg; however, only a trend toward reduced mortality was obtained. Sclerotherapy trials were highly heterogeneous in the direction of the treatment effects on both bleeding (pooled odds ratio, 0.6; CI, 0.49 to 0.74) and mortality (pooled odds ratio, 0.76; CI, 0.61 to 0.94). The quality of the trials and the rate of bleeding in the untreated groups were the major sources of heterogeneity. The favorable results of sclerotherapy were obtained in trials with high bleeding rates among controls; several of these trials had a low quality score. Beta-blockers may be recommended for prevention of first bleeding in cirrhotic patients with varices who have a high risk for bleeding. The effectiveness of sclerotherapy remains undetermined. Further trials in high-risk patients may prove useful if improved criteria to predict bleeding risk become available.


Selective D2 receptor stimulation induces dyskinesia in parkinsonian monkeys.

Stimulation of D1 striatal receptors has been proposed as the main mechanism mediating levodopa-induced dyskinesia in Parkinson's disease. We used (+)-PHNO, a selective D2 agonist, as the only treatment in 6 cynomolgus monkeys made parkinsonian by repeated 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine administration. All animals developed choreic dyskinesia after a mean treatment period of 12.8 days (range, 1-29). Administration of the D1 antagonist SCH-23390 1 hour before administration of (+)-PHNO did not change the dyskinesia. These results indicate that drug-induced dyskinesia in a primate model of Parkinson's disease is not solely induced by D1 receptor activation.


A histochemical study by light and electron microscopy of the distribution of dipeptidyl peptidase-IV activity in the human dental pulp.

This activity was demonstrated in blood vessels, fibroblast-like cells, odontoblasts and Schwann cells surrounding non-myelinated axons. It was present on both the luminal and abluminal plasma membrane of endothelial cells. The plasma membrane of fibroblast-like cells and their processes had patches of fine electron-dense end-product corresponding to DPP-IV activity, while the plasma membrane of odontoblasts was loaded with a consistent reaction product. DPP-IV activity in the non-myelin-forming Schwann cells was in the plasma membrane of the free surface in contact with the extracellular matrix as well as in the plasma membrane in close contact with the axolemma. The plasma membrane of Schwann cells producing myelin sheath had no positive reaction for DPP-IV. The DPP-IV activity in the plasma membrane of fibroblast-like cells and odontoblasts may be associated with fibronectin-mediated adhesion to collagen, whereas the membrane-bound DPP-IV activity in endothelium and non-myelin-forming Schwann cells may be involved in cleavage of neuropeptides of other biologically active peptides.


Alcoholism detection markers in blood samples of road users.

Alcoholics as participants in road traffic are an international problem. In Germany a confiscated driving licence is only given back by the road traffic authorities to suspected alcoholics after a medico-psychological examination. The problem is: "How can alcoholics be detected among drunken road users." Traffic authorities use as a marker of alcoholism only the height of the blood alcohol concentration. The limit is a level of 1.6 g alcohol per kg blood, in some regions a level of 2.0 g/kg. Our studies show that the blood alcohol level is a very weak marker for alcoholism. Better markers are beside the GGT the alcohols methanol and isopropanol. They can be detected by congener alcohol analysis. Their concentrations are significant elevated by long-lasting drinking like it is typical for alcoholics.


Evolution of the vertebrate Hox homeobox genes.

One of the most remarkable recent findings in developmental biology has been the colinear and homologous relationships shared between the Drosophila HOM-C and vertebrate Hox homeobox gene complexes. These relationships pose the question of the functional significance of colinearity and its molecular basis. While there was much initial resistance to the validity of this comparison, it now appears the Hox/HOM homology reflects a broad degree of evolutionary conservation which has reawakened interest in comparative embryology and evolution. The evolutionary conservation of protein motifs in many gene families (including those for growth factors, secreted and membrane bound signalling factors, adhesion molecules, cytoplasmic receptor kinases, nuclear receptors and transcription factors) has lead to speculation on the extent to which these homology relationships represent common developmental processes and underlying molecular mechanisms. Structural identifies in a protein may indicate the biochemical/molecular function that a protein plays in cellular and developmental processes, without reflecting a conserved role in a cascade of developmental events. However, the analysis of genes encoding transcription factors has provided evidence suggesting that there are gene complexes in arthropods and vertebrates which are true homologues and which may share common roles in the specification of regional identity along embryonic A-P axis. These genes comprise the Hox/HOM-C homeotic complexes. This review will detail some of the evidence for this proposed relationship and will speculate on the functional implications.


Homeobox genes in vertebrate evolution.

A wide range of anatomical features are shared by all vertebrates, but absent in our closest invertebrate relatives. The origin of vertebrate embryogenesis must have involved the evolution of new regulatory pathways to control the development of new features, but how did this occur? Mutations affecting regulatory genes, including those containing homeobox sequences, may have been important: for example, perhaps gene duplications allowed recruitment of genes to new roles. Here I ask whether comparative data on the genomic organization and expression patterns of homeobox genes support this hypothesis. I propose a model in which duplications of particular homeobox genes, followed by the acquisition of gene-specific secondary expression domains, allowed the evolution of the neural crest, extensive organogenesis and craniofacial morphogenesis. Specific details of the model are amenable to testing by extension of this comparative approach to molecular embryology.


The encounter coupling model for beta-adrenergic receptor/GTP-binding protein interaction in the S49 cell. Calculation of the encounter frequency.

Experiments measuring epinephrine stimulation of the S49 cell have demonstrated that the rate of adenylate cyclase activation is partly dependent on the rate of turnover of epinephrine occupancy with respect to individual receptors. Specifically, it has been shown that a low occupancy of the full receptor population by epinephrine promotes a rate of adenylate cyclase activation significantly greater than that for a low number of receptors completely occupied by epinephrine with which the concentration of bound receptors is the same. This finding indicated that the interaction of individual receptors with GTP-binding protein (G) occurs on a time scale which is greater than the mean lifetime of the epinephrine-receptor complex; during this period of interaction (an "encounter"), a receptor can change its occupancy state in the presence of a high binding frequency agonist such as epinephrine. Here we present a general analysis, in an extension of the Collision Coupling Model of Tolkovsky and Levitzki (Biochemistry 17: 3795-3810, 1978), of the consequences of encounters (rather than pure collisions) for the relationships of receptor occupancy, receptor-agonist complex lifetime, and receptor-agonist efficiency to G/adenylate cyclase activation. Using this "encounter coupling" model of receptor/G interaction, it is demonstrated from a theoretical standpoint that the net rate of G activation can depend in part on the agonist binding frequency. The predicted dependence is consistent with the data on which the model is based, in which high binding frequency increases the activation rate. A special case of the "encounter coupling model" allows calculation of the frequency of encounters by an analysis of a previous experiment using epinephrine in which the rate of adenylate cyclase activation was measured in response to a small number of fully occupied, highly efficient receptors. Using those results and the model developed here, the encounter frequency was found to be on the order of 100/min in the intact S49 cell. This calculation relied on knowledge of the rate of inactivation of G/adenylate cyclase in intact cells. A method for the measurement of the adenylate cyclase inactivation rate is presented. Using this method, the adenylate cyclase inactivation rate constant was found to be between 0.8 and 3.0/min.


Low density lipoprotein ligand-receptor interactions in normal healthy individuals characterized by their XbaI apolipoprotein B DNA polymorphism.

A DNA restriction fragment length polymorphism (RFLP), observed with the XbaI restriction enzyme digestion of peripheral lymphocyte genomic DNA and a 3.5 kb probe 3' end of the apolipoprotein B gene, was investigated in 228 normal healthy males. Lipoprotein measurements were conducted on fasting plasma and related to the genotype; the X2X2 homozygotes (the X2 allele contains the enzyme cutting site) had significantly higher plasma cholesterol, low density (LDL) cholesterol and LDL apolipoprotein B. Thirty subjects (10 from each of the X1X1, X1X2 and X2X2 groups) were recalled and the LDL receptor activity measurements, conducted on peripheral venous blood lymphocytes, indicated no significant differences between the genotypes. However, when LDLs isolated from these individuals were assayed for ligand-receptor interaction with a human embryonic lung fibroblast cell line, significantly different maximum binding (Bmax) values in the X2 allele-bearing individuals were observed. This paradoxically elevated in vitro binding and degradation of LDL from X2X2 subjects suggests that the elevated concentrations of LDL cholesterol observed with this genotype in vivo does not result from a defective ligand-receptor interaction directly related to this polymorphism.


Imidazoline receptors. A new concept in central regulation of the arterial blood pressure.

Clonidine-like antihypertensive substances bind to nonadrenergic imidazoline specific sites within the nucleus reticularis lateralis (NRL), their medullary privileged site of action. Rilmenidine, a new central antihypertensive agent, was tested in the anesthetized rabbit. For the same hypotensive effect, cumulative doses given intracisternally proved 50 times more active than of those given systemically. Idazoxan, an alpha 2-adrenergic antagonist structurally related to the imidazolines, given centrally as pretreatment proved more potent in preventing the hypotensive effects than the same molar dose of yohimbine. When injected within the NRL area of the anesthetized rabbit, rilmenidine, like clonidine, always exhibited a hypotensive effect. The influence of clonidine and rilmenidine upon the NRL noradrenergic neurons involved in the blood pressure regulation, and upon those of the locus coeruleus (LC) involved in the sedative effect was studied by differential voltammetry. It was observed that rilmenidine was two times more selective than clonidine in inhibiting the NRL, as opposed to LC, neuronal activity. In addition, binding experiments of tritiated clonidine to human cortical and NRL membrane preparations showed that rilmenidine, as compared to clonidine, has a two to three times higher selectivity for the imidazoline receptors. In conclusion, we are now able to discriminate between the mechanism of the hypotensive effect of imidazoline-like drugs and that of their sedative action. Rilmenidine is the first example of an hypotensive drug more selective for imidazolin preferring receptors than for classical alpha 2-adrenoceptors.


Nature of [3H]rilmenidine binding to membranes of rat cerebral cortex.

The binding of [3H]rilmenidine to membranes of rat cerebral cortex was studied in order to ascertain which receptor populations this novel antihypertensive interacts with in the cortex. A catecholamine-sensitive, alpha 2-adrenoceptor binding site was identified which represented up to 50% of specific, 2 nmol/L [3H]rilmenidine binding and was displaceable by the catecholamines in the rank order epinephrine----norepinephrine----dopamine----isoproterenol. Some imidazolines such as clonidine, naphazoline, and idazoxan and the guanidino compound guanabenz completely and potently inhibited [3H]rilmenidine binding from both catecholamine-sensitive and -insensitive sites. The substituted imidazole and guanidine, cimetidine, and amiloride, respectively, showed no affinity for [3H]rilmenidine binding. The pharmacologic profile of the catecholamine-insensitive [3H]rilmenidine site in rat cerebral cortex suggests it may be novel, as it has the features of an imidazoline-guanidino-oxazoline binding site. However, its identity requires further characterization.


Characterization of imidazoline-guanidinium receptive sites in renal medulla from human kidney.

Previous studies showed that alpha 2-adrenergic receptors and imidazoline-guanidinium receptive sites (IGRS) are colocalized in rabbit and human renal proximal tubule. In the present study we investigated the localization of these two binding sites in the renal medulla from human kidney. Binding studies performed with [3H]idazoxan (IGRS ligand) and [3H]rauwolscine (alpha 2-adrenergic ligand) showed that, in membrane preparations from renal medulla, the density of IGRS was 3.6-fold higher than that of alpha 2-adrenergic receptors (134 +/- 7 v 37 +/- 5 fmol/mg protein, respectively). These data indicate that imidazoline, guanidinium, and oxazoline derivatives could induce their therapeutic effects through the interaction with IGRS and/or alpha 2-adrenergic receptors located not only in the renal proximal tubule but also in other segments of the nephron.


Imidazoline binding sites in fat cells. Localization and pharmacologic differentiation from alpha 2-adrenergic receptors.

Studies were carried out to define the cellular distribution and pharmacologic properties of the nonadrenergic [3H]idazoxan binding sites in white fat cells from various species (the term "nonadrenergic [3H]idazoxan binding sites" [NAIBS] has been retained pending a final decision about their name). NAIBS having quite similar binding properties were found in human, rat, hamster, rabbit, and dog fat cells. NAIBS are located both in plasma membranes (25 to 35%) and in intracellular membranes corresponding to the crude mitochondrial fraction of adipose tissue (65 to 75% of the total number of NAIBS found in the particulate fraction), while alpha 2-adrenergic receptors are exclusively located on the plasma membrane. NAIBS have no affinity for catecholamines but have a noticeable affinity for some imidazolinic and guanidinic derivatives. NAIBS are different from the "imidazoline receptors" which bind [3H]para-aminoclonidine in central nervous system areas. A comparative structure affinity study was performed to delineate the respective affinities of various imidazoline derivatives towards NAIBS and alpha 2-adrenergic receptors and to try to find selective ligands for both sites. Binding properties of the two sites were clearly different. Moreover, chronic administration of idazoxan and RX821002 to adult rabbits (4 mg/kg, subcutaneously for 7 days), resulted in an up-regulation of alpha 2-adrenoceptors in fat cells while the number of NAIBS was unaffected by the treatment. There is no clear demonstration of an interaction between NAIBS and G-proteins, adenylate cyclase, or lipolytic function in fat cells. Further studies are required to define their putative role in fat cells.


Distinctive features of rilmenidine possibly related to its selectivity for imidazoline receptors.

Rilmenidine is an oxazoline derivative with antihypertensive activity which was developed to enhance the dissociation between the hypotensive and adverse effect profile of centrally acting agents. Experimental studies have indicated that rilmenidine is selective for both alpha 2-adrenoceptors (v alpha 1) and newly discovered nonadrenergic imidazoline receptors in the brain and in the periphery. In experimental studies, rilmenidine differs from clonidine in that it is more selective for imidazoline receptors than for alpha 2-adrenoceptors; at equihypotensive doses, rilmenidine causes less bradycardia and reduction in cardiac output, less sedation, and little or no antinociceptive action compared to clonidine. The hypotensive effects of rilmenidine are antagonised by idazoxan and yohimbine, but idazoxan (imidazoline structure) is six times more potent than yohimbine (a selective alpha 2-antagonist). In isolated renal proximal tubule cells, where imidazoline binding has also been shown, rilmenidine inhibits reabsorption of sodium. Clinical studies comparing 1 mg rilmenidine with placebo demonstrated significant reductions in blood pressure (BP) (61% rilmenidine v 23% placebo normalized to 160/90 mm Hg). The reduction in BP was not associated with classical alpha 2 side effects such as dry mouth or daytime drowsiness. Compared with clonidine (0.15 to 0.3 mg), equihypotensive doses of rilmenidine (1 to 2 mg) induced two to three times less dry mouth, daytime drowsiness, and constipation; no orthostatic hypotension was reported. Methyldopa (0.5 to 1 mg) v rilmenidine (1 to 2 mg) indicated a comparable reduction of BP with significantly less weakness, drowsiness, orthostatic dizziness, and dry mouth on rilmenidine; there was no evidence of the "clonidine withdrawal syndrome" on drug withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)


Rilmenidine: a novel approach to first-line treatment of hypertension.

Rilmenidine (RIL) is a novel antihypertensive drug selectively acting at the sites of imidazoline receptors. Compared with diuretics, beta-blockers, Ca2+ antagonists and angiotensin converting enzyme inhibitors, the four major groups recommended by the US Joint National Committee as first-line antihypertensive drugs, RIL appears to meet the same criteria of efficacy, safety, and acceptability. Rilmenidine dose-dependently decreases blood pressure (BP), acting as a vasodilator by decreasing vascular resistance through inhibition of the adrenergic nervous system, even while the BP changes due to standing and exercise. In comparison with placebo, RIL significantly decreased BP. In double-blind comparative trials versus first-line diuretics and beta-blockers, RIL normalized BP in approximately 60% patients, showing a similar efficacy to other drugs. In contrast with hydrochlorothiazide, RIL decreased total cholesterol and did not change plasma potassium levels. No tachyphylaxis was observed during long-term treatment. Central side effects, which have contributed to the limitation of the use of alpha 2-agonists as second- or third-line therapy for hypertension, were significantly less frequent with RIL than with clonidine or methyldopa. Indeed, the incidence of dry mouth and drowsiness during double-blind comparative trials versus clonidine and methyldopa was significantly lower with RIL. This absence of central side-effects was confirmed in double-blind comparative trials versus hydrochlorothiazide and atenolol. In contrast with clonidine, no sodium retention or weight gain were observed during chronic treatment with RIL.(ABSTRACT TRUNCATED AT 250 WORDS)


The development of polyanhydrides for drug delivery applications.

This paper reviews the development of the polyanhydrides as bioerodible polymers for drug delivery applications. The topics include design and synthesis of the polymer, physical properties, techniques to fabricate the polymer into drug delivery devices, evaluation of biocompatibility, and example applications of the polyanhydrides. Discussion of the interrelationship between the physical-chemical properties of the polyanhydrides, fabrication methods, and drug release rates is included. One section is devoted to a case study to provide a historical perspective of the development a polyanhydride-based drug delivery treatment from the conception of the idea to the final stages of human clinical trials. This section includes an outline of the extensive in vitro and in vivo testing that is necessary for development of a new material for biomedical applications.


Corneal endothelial toxicity of dapiprazole hydrochloride.

A new adrenergic antagonist designed for topical use to induce pupillary miosis has been tested for direct toxicity on isolated rabbit corneal endothelium. Dapiprazole hydrochloride was perfused across endothelia in the specular microscope at concentrations from 1.25 micrograms/ml to 1000 micrograms/ml. No toxicity was observed, as determined by corneal thickness determinations over a 3 hour perfusion period, until concentrations greater than 125 micrograms/ml were reached. At 250 micrograms/ml a swelling rate of 17.8 microns/hour occurred, and at 500 micrograms/ml the swelling rate was 17.1 microns/hour; with 1000 micrograms/ml inducing a swelling rate of 23.3 microns/hour. It is evident that the drug concentration that reaches the endothelium after topical application has no toxic effect on the cornea, and that the drug should only be used as directed and not used as an anterior chamber perfusate.


Fatty acid profiles of brain phospholipid subclasses of rats fed n - 3 polyunsaturated fatty acids of marine or vegetable origin. A two generation study.

The effects of dietary n - 3 polyunsaturated fatty acids (PUFA) on fatty acid profiles of rat brain phospholipid subclasses as well as on heart phosphatidylethanolamine through two generations were examined: Three groups of rats were fed 20 weight% fat diets in which approx. 30% of the fatty acids were polyunsaturated, either 17% linoleic acid + 13% C20(-) + C22 polyunsaturates from fish oil or 17% linoleic + 13% alpha-linolenic acid from linseed oil or 30% linoleic acid. The rats of the two generations were killed as adults at 18 weeks of age. The results demonstrated that fish oil was a better source than alpha-linolenic acid for incorporation of n - 3 PUFA into the examined phospholipids. This was seen both in brain and heart tissue and in both generations of rats. In the brain phosphatidylethanolamine (PE) and phosphatidylserine (PS) similar fatty acid profiles were found in 1st and 2nd generation, but fish oil was more efficient than 18:3(n - 3) in increasing the levels of 22:6(n - 3), 20:5(n - 3), 22:5(n - 3) and reducing 20:4(n - 6) and 22:5(n - 6). Fatty acid profiles of phosphatidylinositol (PI), phosphatidylinositol-4-phosphate (PIP) and phosphatidylinositol-4,5-bisphosphate (PIP2) were affected by dietary fats. In PIP and PIP2 of 2nd generation rats 20:4(n - 6) was reduced from 36 to 29% following fish oil intake, whereas alpha-linolenic acid had no effects. The cholesterol/phospholipid ratio was not affected in the brain, neither was the degree of unsaturation of the phospholipids. In heart PE the highest levels of 20:5(n - 3)(2%) and 22:6(n - 3) (36%) were observed following fish oil intake. However, in rats fed alpha-linolenic acid a considerable increase in the level of 22:6(n - 3) was observed from the 1st (21%) to the 2nd generation (26%).


Formula alpha-linolenic (18:3(n - 3)) and linoleic (18:2(n - 6)) acid influence neonatal piglet liver and brain saturated fatty acids, as well as docosahexaenoic acid (22:6(n - 3)).

Saturated fatty acids can be synthesized de novo and play a role in determining properties of structural membranes. The effect of dietary essential fatty acids, linoleic acid (18:2(n - 6)) and alpha-linolenic acid (18:3(n - 3)), on the saturated fatty acid content of membrane phospholipid has not previously been considered in newborn nutrition. The studies report the effect of low (1% fatty acids) or high (4%) formula 18:3(n - 3) with low (16%) or high (30-35%) formula 18:2(n - 6) on the saturated and unsaturated fatty acid composition of liver and brain structural lipid of piglets fed formula from birth for 15 days. A significant inverse relationship between the formula % 18:3(n - 3), but not 18:2(n - 6), and the liver phospholipid palmitic acid (16:0) was found. This may indicate a possible effect of dietary 18:3(n - 3) on de novo synthesis of 16:0 and requires further investigation. Monounsaturated fatty acids in both liver and brain were significantly lower in response to high 18:3(n - 3) and to high 18:2(n - 6) plus low 18:1(n - 9) in the formula. Liver phospholipid and brain total lipid % docosahexaenoic acid (22:6(n - 3)) were significantly higher when formula containing 4% rather than 1% 18:3(n - 3) was fed, suggesting that 1% 18:3(n - 3) may limit tissue (n - 3) fatty acid accretion. These results suggest that future studies of essential fatty acid requirements, specifically 18:3(n - 3), should consider possible influences on the saturated fatty acids which also play a functional role in tissue structural lipids.


Development of a lethal mast cell disease in mice reconstituted with bone marrow cells expressing the v-erbB oncogene.

An animal model for malignant mastocytosis is described in mice reconstituted with bone marrow cells expressing the v-erbB oncogene. The lethal mast cell disease is characterized by massive infiltration of bone marrow, spleen, and several other visceral organs by connective tissue mast cells, which normally reside in the skin and the peritoneal cavity. As is frequently found in malignant mastocytosis, the v-erbB-induced mast cell disease was accompanied in some primary recipients by an acute myelogenous leukemia (AML) that killed all secondary recipients regardless of whether the AML was already evident in the primary host. The infiltrating mast cells stained strongly positive with berberine sulfate, suggesting that they were terminally differentiated and in vitro they showed only a weak proliferative capacity. The leukemias were clonal but apparently of different origin than the malignant mast cells, implying the transformation of two independent cell populations. Leukemic cells expressed various myeloid-specific markers as well as the B220 antigen, normally associated with the B-cell lineage. However, the Ig heavy chain genes were still in germ line configuration. In culture, these cells proliferated in the absence of exogenous growth factors and had the capacity to differentiate into mature myeloid cells. Preliminary experiments suggest that v-erbB may use parts of a signal transduction pathway normally coupled to the c-kit receptor. The v-erbB-induced malignant mast cell disease should provide a useful animal model for elucidating the cause for malignant mastocytosis in humans and to explore possible therapeutic strategies.


Open versus laparoscopic cholecystectomy: a retrospective comparative study.

Two groups of 40 patients (31 females, 9 males), matched for age and body mass index, who underwent either elective open cholecystectomy (Group I) or elective laparoscopic cholecystectomy (Group II) have been studied retrospectively to detect differences in operating time, morbidity and mortality, hospital length of stay, and use of postoperative analgesics. The two groups of patients had almost identical histories of gallstone disease. The median operating time for the patients in Group I was 45 min (range 35-95) compared with 90 min (range 50-135) in Group II. An intraoperative cholangiogram was performed in 21 of the patients in Group I and 22 patients in Group II. There were no deaths in either group. The overall complication rate was 22.5% in Group I and 10% in Group II. Median postoperative length of stay was 5 days for Group I patients (range 1-19) and 2 days for Group II patients (range 1-5). All Group I patients required postoperative intravenous or intramuscular opiates, while 10% of Group II patients did not require any analgesia at all and pain was controlled with oral analgesics alone in 16%. Median total morphine dose for Group I patients was 46.9 mg (range 9.4-180), as compared with only 15.6 mg (6.2-37.5) for Group II patients. This study concludes that laparoscopic cholecystectomy led to less complications, shorter hospital length of stay, and minimal use of postoperative analgesia.


Chronic leukaemias.

In recent years many subtypes of CLL and some CML variants have been recognized throughout the world by means of careful clinical, epidemiological, immunological, molecular biological and viral studies. Most striking has been the establishment of a close association between certain immunophenotypical subtypes of CLL and infection with HTLV-I and possibly HTLV-II. CLL has consistently been shown to have a strong genetic component and a low incidence among Asians, but a growing body of evidence also links this major leukaemia type with environmental factors including solvents, unidentified farming and other occupational exposures. In contrast, CML is characterized by few genetic associations, relatively homogenous world-wide distribution, greater frequency in Blacks than in Whites, little evidence of viral aetiology, and evidence that exposures to ionizing radiation, benzene and possibly other chemical agents are important aetiological factors. Most studies suggest that acquired rather than genetic factors are of greater importance in the aetiology of CML, but this conclusion is somewhat difficult to reconcile with the relatively small variation in incidence rates internationally. Common to both disorders in most populations are an increasing incidence with age, male predominance, and stability of incidence, survival and mortality over the years, exclusive of improved survival of CML following allogeneic bone marrow transplantation.