Regulatory interactions among axon terminals affecting the release of different transmitters from rat striatal slices under hypoxic and hypoglycemic conditions. An in vitro model of ischemia was utilized to study the effects of both oxygen and glucose depletion on transmitter release from rat striatal slices. The spontaneous and stimulation-evoked releases of tritiated dopamine, gamma-aminobutyric acid, glutamate, and acetylcholine were measured. Hypoxia increased the evoked release of glutamate and dopamine without effect on the resting release. In contrast, hypoglycemia itself increased the resting release of dopamine. Hypoxia in combination with hypoglycemia provoked a massive release of glutamate, dopamine, and gamma-aminobutyric acid. The effect on acetylcholine release was less pronounced. Ca2+ withdrawal partly reduced the effect of hypoxia combined with hypoglycemia on dopamine release and application of tetrodotoxin (1 microM) abolished it. MK-801 (3 microM), an N-methyl-D-aspartate receptor antagonist, attenuated the effect of hypoxia and hypoglycemia on [3H]dopamine release. omega-Conotoxin (0.1 microM) had a similar effect on stimulation-evoked release under a hypoxic condition. The D2 receptor antagonist sulpiride (100 microM) failed to enhance the release of [3H]acetylcholine in hypoxia combined with hypoglycemia. It was suggested that in response to hypoxia combined with hypoglycemia there is a massive release of glutamate due to the increased firing rate which in turn releases dopamine from the axon terminals through stimulation of presynaptic N-methyl-D-aspartate receptors. Dopaminergic inhibitory control on ACh release seems not to be operative under conditions of hypoxia combined with hypoglycemia.


The role of NMDA and non-NMDA excitatory amino acid receptors in the excitation of primate spinothalamic tract neurons by mechanical, chemical, thermal, and electrical stimuli. The role of excitatory amino acids (EAAs) in the excitation of monkey spinothalamic tract (STT) neurons following activation of cutaneous primary afferent fibers by noxious and non-noxious stimuli was investigated. The responses of STT neurons to either NMDA or non-NMDA EAA ligands were blocked by infusion of specific antagonists through a microdialysis fiber into the region surrounding the cells. Our results show that blockade of non-NMDA receptors results in a nearly complete elimination of the responses of STT neurons to all stimuli. Blockade of NMDA receptors results in an attenuation of the responses to noxious stimuli but, in addition, prevents the development of the sensitization of STT neurons that is often observed after intradermal injection of capsaicin. These observations further support a role of EAAs in the transmission of sensory information from primary afferent fibers to dorsal horn neurons and a role for NMDA receptors in the generation of hyperalgesia.


Long-term and short-term electrophysiological effects of estrogen on the synaptic properties of hippocampal CA1 neurons. The ovarian steroids exert both long-term and short-term actions on neurons involving different cellular mechanisms. We have investigated the long-term and short-term effects of estrogen on the electrophysiological properties of CA1 neurons utilizing intracellular recordings in hippocampal slices prepared from ovariectomized female rats. An in vivo estrogen-priming paradigm was used to examine long-term genomic actions of estrogen. Subcutaneous estrogen injections 2 d prior to recording had no effect on the intrinsic membrane properties of CA1 neurons, but increased synaptic excitability by prolonging the EPSP and inducing repetitive firing in response to Schaffer collateral stimulation. Short-term effects of estrogen that presumedly involve direct membrane interactions were tested by application of steroids directly to the slice. Superfusion of 17 beta-estradiol, but not 17 alpha-estradiol, caused a rapid and reversible increase in the amplitude of the Schaffer collateral-activated EPSP. This potentiation of the EPSP by 17 beta-estradiol still occurred in the presence of the NMDA antagonist 2-amino-5-phosphonovalerate, but was blocked by the non-NMDA antagonist 6-cyano-7-nitroquinoxaline-2,3-dione. Depolarizing responses to iontophoretic pulses of exogenous glutamate were also potentiated by 17 beta-estradiol, suggesting a post-synaptic site of action. In addition, 17 beta-estradiol potentiated the responses to alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid, kainate, and quisqualate, but not NMDA, further implicating non-NMDA receptors in the short-term action of estrogen. In contrast, 17 beta-estradiol had no effect on responses to exogenous GABA or on the Schaffer collateral-induced late IPSP.(ABSTRACT TRUNCATED AT 250 WORDS)


Synthesis and antihistaminic activity of some thiazolidin-4-ones. A new series of 2-(4- and 3-substituted phenyl)-3-[3-(N,N-dimethylamino) propyl]-1,3-thiazolidin-4-ones were synthesized, characterized, and evaluated for their ability to inhibit the contractions induced by histamine on guinea pig ileum. The measurement of pA2 values suggested that the reported compounds showed H1-antagonism. The more active compounds 5, 9, and 13 exhibited activity close to that of mepyramine.


Spatial and temporal distribution of resting female mosquitoes (Diptera: Culicidae) in the coastal plain of North Carolina. The spatial and temporal distribution of 28 species of female mosquitoes resting in natural (swamp, woods, and swamp-woods ecotone) and human-made (beneath bridges) habitats in blackwater stream-associated ecosystems in Duplin County, N.C., was determined by sampling with a D-Vac vacuum aspirator during 1984 and 1985. Two types of resting distributions were evident. In type one, species including Aedes atlanticus Dyar & Knab, Ae. canadensis (Theobald), Ae. triseriatus (Say), and Psorophora ferox (von Humboldt) rested predominantly on vegetation and were not collected beneath bridges. In type two, species including Anopheles punctipennis (Say), Culex erraticus (Dyar & Knab), Cx. peccator Dyar & Knab, Cx. pipiens L. and Cx. quinquefasciatus Say and their hybrids, Cx. restuans Theobald, Cx. territans Walker, and Uranotaenia sapphirina (Osten Sacken) rested on vegetation, in natural shelters in swamp habitats, and beneath bridges. Differences in the proportion of gravid mosquitoes among habitats were evident for Ae. canadensis, An. punctipennis, Cx. pipiens and Cx. quinquefasciatus and their hybrids, Cx. restuans, Cx. territans, Ps. ferox, and Ur. sapphirina, indicating that gonotrophic condition may influence resting site selection.


Statistical appraisal of the weight-wing length relationship of mosquitoes. The relationship between wing length and body weight of mosquitoes was examined by comparing the fit of regressions using logarithmic and cubic transformations. A two-parameter line using a double logarithmic transformation provided the best fit, and we found no evidence to justify the use of wing length cubed as a transformation. Wing length was not directly proportional to body weight, but rather increased at a lesser rate than did body weight. Equations that predict body weight from wing length may not be an appropriate substitute for weighing mosquitoes, when studying the extremes of size in populations.


Aortic valve replacement for Takayasu's arteritis. We report 12 cases of aortic valve replacement performed for Takayasu's arteritis and discuss the genesis of aortic regurgitation and the clinical outcome after aortic valve replacement. This group of twelve patients who underwent aortic valve replacement between April 1982 and March 1990 included four male and eight female patients, aged 24 to 67 years (mean age 48 years). Preoperative angiography showed systemic multiple stenoocclusive or aneurysmal dilated vascular lesions in addition to aortic regurgitation. The multiple lesions included a lesion in the aortic arch branch in nine (75%), in the pulmonary artery in seven (58%), an aneurysmal dilation in the ascending aorta of more than 6 cm in four (33%), a coronary lesion in four (33%), a thoracic aortic lesion in six (50%), and a lesion in the abdominal aorta and its visceral branch in six (50%). Simple aortic valve replacement alone was performed in two patients and in combination with another operation in ten patients, with aortic root reconstruction in two, ascending aortic plication in three, coronary artery bypass grafting in two, aortic arch branch bypass grafting in one, aortic arch branch bypass grafting and coronary ostium endarterectomy in one, and mitral valve replacement and ascending aortic plication in one. There was no operative death, and only one patient died later, 18 months after the operation, because of secondary amyloidosis. The postoperative recovery of the clinical status and cardiac function was good. Intraoperative observations suggested that aortic valve regurgitation may be caused by an extension of aortitis, although histopathologic examinations of the valve showed nonspecific findings. One of the characteristic problems in Takayasu's arteritis is the necessity for prednisolone administration in some patients preoperatively or postoperatively, or both. We conclude that aortic valve replacement for patients with Takayasu's arteritis is an effective and safe treatment. Our data related to the genesis of aortic regurgitation in Takayasu's arteritis remain insufficient to draw conclusions, and further analysis is planned.


Urinary albumin excretion, cardiovascular disease, and endothelial dysfunction in non-insulin-dependent diabetes mellitus. Raised urinary albumin excretion (UAE) is associated with an increased risk of cardiovascular disease in non-insulin-dependent diabetes mellitus (NIDDM). We have examined the role of endothelial dysfunction as a possible explanation for this association in 94 NIDDM patients by investigating UAE, new cardiovascular events, and plasma concentration of von Willebrand factor (vWF), an indicator of endothelial dysfunction. At baseline, 66 patients had normal UAE (less than 15 micrograms/min), which remained normal in 33 (group 1) and increased in 33 (to median 31.5 micrograms/min, group 2). In 28 patients, baseline UAE was abnormal (67.1 micrograms/min, group 3). Follow-up ranged between 9 and 53 months. vWF did not change in group 1 (median 128% at baseline and 123% at follow-up), but increased in group 2 (from 116 to 219%, p less than 0.0001) and group 3 (from 157 to 207%, p = 0.0005). Baseline level of and change in vWF were strongly related to the development of microalbuminuria (R2 = 0.60, p less than 0.0001), but cardiovascular risk factors were not (R2 = 0.14). Raised baseline UAE was associated with an increased risk of new cardiovascular events only in patients with vWF concentrations above the median (relative risk 3.66, 95% CI 1.3-11.9) and not in patients with lower vWF (0.19, 0.01-1.33). In addition, the cardiovascular risk associated with increased UAE was modified by low compared with high concentrations of serum high density lipoprotein cholesterol (2.86 [1.03-8.48] vs 0.15 [0.01-1.43]). Dysfunction of vascular endothelium may be a link between albuminuria and atherosclerotic cardiovascular disease in NIDDM.


Randomised controlled trial of nasal nicotine spray in smoking cessation. Studies with nicotine chewing gum and nicotine skin patches indicate that nicotine replacement can help people to give up smoking. The rapidity with which nicotine is absorbed when given as a nasal spray suggests that it might be effective for those for whom the other means of replacement are too slow. The efficacy and safety of a nasal nicotine spray as an adjunct to group treatment for stopping smoking were assessed in a randomised, double-blind, placebo-controlled trial in which 227 cigarette smokers attending the Maudsley Hospital Smokers Clinic received 4 weeks of supportive group treatment plus active nicotine (0.5 mg per shot) or placebo nasal spray. The main end-point was biochemically validated complete abstinence from smoking from the third week of group treatment until the 12-month follow-up. Side-effects were assessed by self-reports and, where necessary, by physical examination. Of subjects assigned to active treatment 26% (n = 30) were validated abstinent throughout the year, compared with 10% (n = 11) of those assigned to placebo (relative abstinence rate 2.6, 95% CI 1.5-4.5, p less than 0.001). The advantage of the active spray was greatest in the heaviest smokers. Plasma nicotine concentrations from the spray were typically between one-half and three-quarters of baseline smoking levels. Tobacco-withdrawal symptoms, craving for cigarettes, and weight gain in abstinent subjects were reduced by the active spray. Minor irritant side-effects were frequent in both active and placebo sprays, but only 2 subjects had the spray discontinued as a result. No serious adverse effects were encountered. Nasal nicotine spray combined with supportive group treatment is an effective aid to smoking cessation.


Randomised study of two doses of cisplatin with cyclophosphamide in epithelial ovarian cancer. Cisplatin is generally accepted to be the most active cytotoxic agent for the treatment of ovarian cancer but the optimum dose remains unclear. We have performed a randomised trial to assess the importance of cisplatin dose in the treatment of advanced epithelial ovarian cancer. Patients were randomly assigned treatment with 50 mg/m2 (low dose) or 100 mg/m2 (high dose) cisplatin plus 750 mg/m2 cyclophosphamide, for a maximum of six cycles with intervals of 3 weeks. We planned to recruit 300 patients, but an interim analysis on the first 165 indicated a highly significant survival difference (p = 0.0008). Recruitment was therefore stopped and the trial patients were followed-up for 12 months longer. The relative progression rate (high-dose/low-dose) after 12 months' extra follow-up was 0.55 (95% confidence interval 0.37-0.81, p = 0.003) and the relative death rate 0.53 (0.34-0.81, p = 0.003). Overall median survival was 69 weeks in the low-dose group and 114 weeks in the high-dose group. Residual disease extent before chemotherapy had an important influence--patients with lesions of less than 2 cm did best; if given high-dose cisplatin their median survival was 3 years. 56 low-dose and 45 high-dose patients completed six cycles of chemotherapy; 15 and 9 patients, respectively, were withdrawn early because of progressive disease and treatment was stopped in 6 and 25, respectively, because of unacceptable side-effects or patient refusal. Toxic effects were significantly greater in the high-dose group, especially those on the nervous system and ears, alopecia, vomiting, and anaemia. Although the higher dose of cisplatin clearly leads to better results in terms of survival, its overall clinical benefit in the management of ovarian cancer will depend on further improvements in measures to alleviate toxic effects.


Postoperative morbidity among symptom-free alcohol misusers. Retrospective studies suggest that there is an increased postoperative morbidity among alcohol misusers. We have prospectively studied the risk of alcohol intake among patients undergoing surgery. We investigated 15 symptom-free subjects who required colorectal surgery and who were drinking at least 60 g of alcohol per day. These patients were matched for sex, nutrition, age, weight, cardiovascular and pulmonary disease, diagnosis, anaesthesia, and surgery to 15 control subjects who were consuming below 25 g of alcohol daily. Those drinking at least 60 g of alcohol per day developed more postoperative complications than controls (67% vs 20%, p less than 0.05) and hospital stay was prolonged (20 vs 12 days, p less than 0.05). Preoperatively, alcohol misusers had reduced left ventricular ejection fraction (median, 54% vs 68%, p less than 0.01). Delayed hypersensitivity responses were smaller in the alcohol group before (53 mm2 vs 78 mm2, p less than 0.05) and after (18 mm2 vs 55 mm2, p less than 0.01) surgery. Alcohol misusers had longer bleeding times during the first postoperative week (p less than 0.01). Surgical stress responses, as assessed by changes in plasma cortisol and catecholamines, were higher among alcoholics (p less than 0.05). Postoperative morbidity is increased in symptom-free alcohol misusers. The mechanism is probably subclinical cardiac insufficiency, immunosuppression, and decreased haemostatic function. Preoperative alcohol consumption may be a more important risk factor than previously thought.


Prevalence of HIV-1 and HIV-2 mixed infections in Côte d'Ivoire. We have investigated the cause of dual serological reactivity to human immunodeficiency virus (HIV) types 1 and 2, a common occurrence in West Africa. Serum specimens from 111 individuals from Côte d'Ivoire classified by commercial western blot as HIV-1 (n = 15), HIV-2 (32), and dually reactive (64) were further tested by more specific serological tests (a synthetic peptide enzyme immunoassay [Pepti-LAV 1/2] and western blots prepared from antigen in which oligomeric forms of the transmembrane protein were disrupted by trichloroacetic acid [WB-TCA]). Peripheral blood mononuclear cells were tested for HIV-1 and HIV-2 with the polymerase chain reaction (PCR) and virus culture. Of 104 samples that were concordant by both WB-TCA and Pepti-LAV, 82 (79%) were confirmed by PCR results. Virus culture was concordant with serology for specimens (35/38) in which any virus was detected. Our findings indicate that mixed HIV-1/HIV-2 infections are common in Côte d'Ivoire, and suggest that natural infection by one HIV type does not prevent heterologous infection.


Virological and polymerase chain reaction studies of HIV-1/HIV-2 dual infection in Côte d'Ivoire. Dual serological reactivity to the human immunodeficiency virus (HIV) types 1 and 2 is common in Côte d'Ivoire. To assess whether dual infection is the reason for dual seropositivity we sought HIV-1 and HIV-2 proviral DNA in primary uncultured peripheral blood mononuclear cells from selected seropositive patients in Côte d'Ivoire with the polymerase chain reaction (PCR). PCR on primary lymphocytes in 36 dually seropositive samples revealed the presence of both HIV-1 and HIV-2 proviral DNA in 12 cases and the presence of HIV-1 only in 24 cases. In 18 of these 36 samples a virus was isolated and identified by PCR. HIV-1 was isolated from the 9 specimens with only HIV-1 proviral DNA in the primary lymphocytes. Among dually PCR-positive samples, 2 viral isolates reacted with both HIV-1 and HIV-2 primers; and only HIV-2 (n = 1) or HIV-1 (n = 6) strains were isolated from the other samples. The findings show that surveys based on serology may overestimate the prevalence of mixed infections in areas where both HIV-1 and HIV-2 occur.


Black-white mortality differences by family income. Death rates among US black men and women under 75 years of age are higher than for their white counterparts. The explanation for this excess risk, though attributed to socioeconomic factors, remains unclear. We calculated mortality rates by family income for blacks and whites in a representative sample of the US population (National Longitudinal Mortality Study). For persons aged less than 65 years of age, mortality rates are lower in those with higher family income for both blacks and whites, and both men and women. However, at each level of income, blacks have higher mortality than whites. Higher levels of family income are also associated with lower death rates from cardiovascular disease, cancer, and deaths from causes other than cardiovascular disease or cancer. After adjustment for income, blacks have higher death rates from each of these three general causes. For subjects below 65 years, the mortality gradient by income is larger than the gradient by race. The differences in mortality rates by race not accounted for by income may be due to other differences such as access to health care, type or quality of medical care, or behavioral risk factors that disadvantage black populations.


Childhood deaths in Africa: uses and limitations of verbal autopsies. The verbal autopsy (VA) is an epidemiological tool that is widely used to ascribe causes of death by interviewing bereaved relatives of children who were not under medical supervision at the time of death. This technique was assessed by comparison with a prospective survey of 303 childhood deaths at a district hospital in Kenya where medically confirmed diagnoses were available. Common causes of death were detected by VA with specificities greater than 80%. Sensitivity of the VA technique was greater than 75% for measles, neonatal tetanus, malnutrition, and trauma-related deaths; however, malaria, anaemia, acute respiratory-tract infection, gastroenteritis, and meningitis were detected with sensitivities of less than 50%. There may have been unwarranted optimism in the ability of VAs to detect some of the major causes of death, such as malaria, in African children. VA used in malaria-specific intervention trials should be interpreted with caution and only in the light of known sensitivities and specificities.


Classical migraine: symptoms between visual aura and headache onset. The gap between the end of the visual aura and headache onset in classical migraine has been called the free interval. In a retrospective study of twenty-five migraineurs who had noted a gap, only three reported feeling normal at that time: twenty-two described alterations in mood, detachment from the environment or other people, fears, disturbances of speech or thought, or somatic symptoms. The interval lasted less than an hour in seventeen of the twenty-two but in five persisted for 1 to 5 hours. These symptoms suggest involvement of the frontal and temporal cortices as well as the hypothalamus; they do not conform to Leão's spreading depression or a vascular mechanism, but are in keeping with a diffuse cerebral process with focal manifestations.


Immunohistochemical study of c-erbB-2 oncoprotein overexpression in human major salivary gland carcinoma: an indicator of aggressiveness. In order to analyze the correlation between immunohistochemical positivity for c-erbB-2 oncoprotein and prognosis in patients with malignant salivary gland tumors, 59 cases of malignant tumors of the major salivary glands, including 35 parotid gland, 20 submaxillary gland and 4 sublingual gland tumors, were studied immunohistochemically using a polyclonal antibody against c-erbB-2 oncoprotein. Positive staining was observed in 13 (22%) of the 59 cases. Interestingly, positive results were obtained only in adenocarcinoma (6/20) and carcinoma in pleomorphic adenoma (7/15), and not in any other histological types such as adenoid cystic carcinoma, mucoepidermoid tumor, and squamous cell carcinoma. There was no correlation between the degree of differentiation of adenocarcinoma and c-erbB-2 positivity. Since the carcinoma in pleomorphic adenoma positive for c-erbB-2 oncoprotein was adenocarcinoma, adenocarcinoma and adenocarcinoma in pleomorphic adenoma were placed together (n = 33), and the presence or absence of c-erbB-2 oncoprotein in this group was examined for correlation with patients' survival and other clinicopathological features, including clinical stage, tumor size, surgical margins, and lymph node status. The c-erbB-2-positive tumors tended to be more advanced and larger than negative tumors. Similarly, c-erbB-2-positive tumors were difficult to resect completely, were associated with lymph node metastasis more frequently, and showed lower disease-free survival than negative cases (P less than .05). We conclude that immunohistochemical positivity for c-erbB-2 is an indicator of aggressiveness in both adenocarcinoma and adenocarcinoma in pleomorphic adenoma of the major salivary glands.


Regulation of nerve growth factor and nerve growth factor receptor production by NMDA in C6 glioma cells. The synthesis of nerve growth factor (NGF) and nerve growth factor receptor (NGFR) were studied in a C6 glioma cell line by Northern blot hybridization. In response to a glutamate agonist N-methyl-D-aspartic acid (NMDA), NGF mRNA increased by up to 2-fold after 4-12 h of culture. The non-NMDA receptor agonists, quisqualate and kainate, did not induce any increase of NGF mRNA, and kainate actually produced a decrease. The increase in NGF mRNA in response to NMDA was dose-dependent at 1, 5 and 10 microM. NGF receptor (NGFR) mRNA showed changes in expression which were similar to those for NGF mRNA, but were less marked. The specific glutamate antagonist 2-aminophosphonovaleric acid (APV) blocked the increase of NGF mRNA produced by NMDA. In the absence of Ca2+, an increase of NGF mRNA was still observed but in the presence of 1 mM ethylglycol-bis-(beta-aminoethyl ether) N,N'-tetraacetic acid (EGTA), NGF mRNA production abolished. The mechanism producing an increase in NGF mRNA by NMDA may be mediated by cyclic AMP since intracellular cyclic AMP and NGF mRNA levels both increased following treatment with NMDA or dibutyryl cyclic AMP.


Modulation of tyrosine hydroxylase gene expression in the rat adrenal gland by exercise: effects of age. Both aging and exercise are associated with alterations in circulating levels of catecholamines. To determine the interactions of age and exercise on tyrosine hydroxylase (TH) activity and TH mRNA, Fischer-344 female rats aged 5 months (young) and 25 months (old) were trained by treadmill running for 10 weeks. The elevation in maximum oxygen consumption in both groups was equivalent following exercise, indicating that training had occurred. In control rats, both TH activity and TH mRNA were greater in the older groups when compared with the younger animals. In young rats, exercise decreased TH activity by 25% and TH mRNA by 27%. In older rats, exercise was not associated with a decrease in TH activity and TH mRNA. Choline acetyltransferase activity (ChAT) was decreased and glutamic acid decarboxylase activity (GAD) was increased by exercise in young rats. The decrease in ChAT activity and increase in GAD activity suggest that trans-synaptic mechanisms play a role in the exercise-induced alteration of TH gene expression. Neither ChAT nor GAD was altered by exercise in older groups. Our data suggest that the previously reported diminution in catecholamines associated with exercise may be due to a decrease in TH mRNA and a resulting decrease in TH activity. There was no effect of exercise in the old rats, supporting previous observations that the plasticity of the sympathoadrenal system diminishes with age.


Molecular aspects of the regulation of tyrosine hydroxylase by testosterone. Previous studies have demonstrated that the sympathetic hypogastric ganglia (HG) are dependent upon the continued presence of testosterone for normal development and maintenance of tyrosine hydroxylase (TH) activity. The regulation of TH by testosterone has been examined further to determine whether the reduction in TH activity following castration is associated with changes in levels of TH protein and mRNA. TH protein was measured by immunotitration of HG homogenates using a TH-specific antibody, and TH-specific mRNA was detected by hybridization of dot blots of total RNA isolated from HG with a cDNA probe coding for TH. The results show that tyrosine hydroxylase activity, protein and mRNA are coordinately reduced in a graded fashion at 1, 2 and 4 weeks following castration. Testosterone replacement therapy immediately following castration prevents the decrease in TH levels. The results indicate that gonadal steroids regulate the biosynthesis of TH in the HG. Testosterone may control TH either directly by interacting with neurons of the HG, or indirectly by altering levels of trophic factors in the target tissues.


Hippocampal neuropeptide Y mRNA is reduced in a strain of learned helpless resistant rats. The learned helpless rat is considered to be one of the better animal models of depression. A genetically inbred strain with a high vulnerability to develop helplessness (LH), as well as a highly resistant strain (NLH) have both been developed. Since the brain peptide neuropeptide Y (NPY) is involved in the regulation of a number of behaviors known to be altered in clinical depression as well as in learned helplessness, we measured the relative level of NPY mRNA in the hippocampus and cortex of control Sprague Dawley (SD), LH and NLH rats. We find that NLH rats have approximately a 30-35% decrease in basal hippocampal NPY mRNA compared with SD and LH rats. By contrast, cortical NPY mRNA and hippocampal pre-proenkephalin and somatostatin mRNA levels were not significantly different in the 3 strains. The data suggest that the regulation of NPY gene expression may be involved in the reduced vulnerability of NLH rats to develop learned helplessness.


Familial amyloid polyneuropathy related to transthyretin Gly42 in a Japanese family. A Japanese family is described in which 6 persons showed familial amyloid polyneuropathy (FAP). Mean ages of onset were 38 for 4 males and 54 for 2 females. Three of the 6 became emaciated and died after 4 to 10 years. In 5, muscular weakness and autonomic dysfunction were the initial symptoms followed by sensory disturbances. Amyloidotic cardiomyopathy was present in 3 of the subjects. Amyloid deposits showed an immunohistological relation to transthyretin (TTR). Analysis of 1 patient's TTR gene revealed a single base change (A----G) that led to amino acid substitution (Glu42----Gly). This base change produced a new restriction site for endonuclease Cfr13 I in exon 2. Polymorphic analysis of the length of the Cfr13 I-restriction fragment confirmed the base change, and made it possible to detect the mutant TTR Gly42 gene in the FAP subjects. Amino acid sequencing analysis showed a variant of TTR Gly42 in 1 patient's serum.


Case of the month: germline mosaicism in carriers of Duchenne muscular dystrophy. Carrier testing in a Duchenne muscular dystrophy (DMD) family resulted in the identification of a case of germline mosaicism. Using dystrophin cDNA probes, this phenomenon was ascertained by the demonstration of a deletion junction fragment present in the DNA of the affected patient and one sister but absent in the mother's DNA. As a result of this finding carrier risk estimations, based on restriction fragment length polymorphism (RFLP) studies, were significantly altered. The case demonstrates the importance of cDNA deletion carrier testing and the counseling implications of germline mosaicism.


Nested expression domains of four homeobox genes in developing rostral brain. Insight into the genetic control of the identity of specific regions along the body axis of vertebrates has resulted primarily from the study of vertebrate homologues of regulatory genes operating in the Drosophila trunk, but little is known about the development of most anterior regions of the body either in flies or vertebrates. Three Drosophila genes have been identified that are important in controlling the development of the head, two of which, empty spiracles and orthodenticle, have been cloned and shown to contain a homeobox. We previously cloned and characterized Emx1 and Emx2, two mouse genes related to empty spiracles that are expressed in restricted regions of the developing forebrain, including the presumptive cerebral cortex and olfactory bulbs. Here we report the identification of Otx1 and Otx2, which are related to orthodenticle. We have compared the expression domains of the four genes in the developing rostral brain of mouse embryos at a developmental stage, day 10 post coitum, when they are all expressed. Otx2 is expressed in every dorsal and most ventral regions of telencephalon, diencephalon and mesencephalon. The Otx1 expression domain is similar to that of Otx2, but contained within it. The Emx2 expression domain is comprised of dorsal telencephalon and small diencephalic regions, both dorsally and ventrally. Finally, Emx1 expression is exclusively confined to the dorsal telencephalon. Thus at the time when regional specification of major brain regions takes place, the expression domains of the four genes seem to be continuous regions contained within each other in the sequence Emx1 less than Emx2 less than Otx1 less than Otx2.


[Tardive dystonia].

[Tardive dystonia]. Two patients with tardive dystonia are presented. Tardive dystonia is a late-onset side effect of dopamine antagonist, which occurs in approximately 2% of the patients in the course of treatment with neuroleptic medication. The dystonia usually starts by affecting the musculature of face and (or) neck and is often progressive to a segmental localization. Of differential diagnostic importance are: conversion disorder, acute dystonia, Wilson's disease, idiopathic dystonia and dystonia triggered by other agents. Treatment starts with reevaluation of the need for ongoing neuroleptic treatment. Investigation of the pharmacotherapy of the dystonia concerns mostly treatment with dopamine depletors or with high doses of anticholinergic agents. Improvement of 50% of the patients is reported, although total recovery is rare. Many other substances and also some physical methods (ECT and surgery) have been used with varying results.


Lipid and lipoprotein (a) concentrations in renal transplant patients. Lipid and lipoprotein concentrations, including lipoprotein (a), were measured in 67 clinically stable renal allograft recipients and compared with age- and sex-matched controls. Median lipoprotein (a) concentrations were significantly elevated in the transplant group (P = 0.048), with the distribution of apoprotein (a) isoforms being similar between the two groups. The transplant group also demonstrated significant elevations in cholesterol (P less than 0.0001), triglycerides (P = 0.0007) and low-density lipoprotein cholesterol (P less than 0.0001). There was no significant difference in high-density lipoprotein cholesterol concentrations between the groups although there was the expected tendency for higher values in females. Lipoprotein abnormalities are common following renal transplantation and these patients also demonstrate elevated lipoprotein (a) values. This unique lipoprotein is known to be atherogenic and may contribute to the development of vascular disease, which is a common mode of death in these patients.


Reactivity of P-glycoprotein monoclonal antibodies in childhood cancers. P-Glycoprotein (P-gp), the product of the mdr-1 gene, is implicated in the development of chemoresistance in a variety of, mostly adult, cancers. Its role in paediatric tumours, most of which are non-epithelial in origin, has yet to be fully elucidated. A study was undertaken to investigate reactivity of two P-gp monoclonal antibodies (MAbs), JBS-1 and MRK16, recognising cytoplasmic and surface epitopes, respectively, of the P-gp molecule, in a variety of newly diagnosed and relapsed childhood cancers. P-gp was not expressed in any of 36 tumours examined (neuroblastoma 13, nephroblastoma 12, rhabdomyosarcoma 6, lymphoma 3, teratoma 1, Ewings 1), 14 of whom had chemoresistant disease. Reactivity to both MAbs was also investigated in patients with acute leukaemia. Out of 10 diagnostic acute lymphoblastic leukaemia (ALL) samples, a positive reaction with JSB-1 was observed in 1 patient who failed to remit on standard induction therapy and in 3 of 6 patients in ALL relapse, only 1 of whom showed low grade positivity with MRK16. Both MAbs reacted positively in 1 patient with acute non-lymphocytic leukaemia (ANLL) at diagnosis who achieved remission with teniposide and cytosine arabinoside, but relapsed 7 months later and was again positive with both Mabs. JSB-1 also showed varying degrees of positivity in 4 out of 4 other patients in ANLL relapse. It would therefore appear that P-gp is unlikely to mediate chemoresistance in most solid tumours of childhood, but may well play a major role in the development of chemoresistance in acute leukaemia.


[Beta-blockers and migraine].

[Beta-blockers and migraine]. Five beta-blocking agents are effective as long-term prophylactic treatment of migraine: propranolol, metoprolol, timolol, atenolol and nadolol. Propranolol has been most extensively studied and proved effective in 19 of 21 controlled trials. The optimal dose should be determined on a case-by-case basis, by increasing the daily dosage gradually. Among the properties of beta-blockers, the only one which appears to be correlated--albeit negatively--with effectiveness on migraine is intrinsic sympathomimetic activity (ISA): drugs without ISA are effective against migraine whereas partial agonists are not. The mode of action of beta-blockers in migraine is still poorly understood; one of the most cogent current hypotheses involves reduction of brain catecholaminergic hyperactivity.


[Calcium channel blockers and prevention of migraine]. Calcium antagonists have been proposed for the prophylactic treatment of migraine because of their putative vasodilating antispasmodic effect and of their action against the cellular consequences of brain hypoxia. Published reports of controlled double-blind studies of calcium antagonists for the prophylactic treatment of migraine are reviewed herein. The effectiveness of verapamil, diltiazem, and nifedipine in this indication cannot be considered as firmly demonstrated, when problems with trial design and the amount of available data are taken into account. Nimodipine failed to demonstrate significant effectiveness in migraine with or without an aura. In contrast, the ability of a diphenylpiperazine, flunarizine, to decrease the incidence of migraine attacks in patients with common or classical migraine has been firmly demonstrated, although there is less evidence of this agent's effectiveness on the duration and severity of attacks. The percentage of patients who respond to flunarizine seems comparable to the percentages of propranolol or pizotifen responders. However, flunarizine is associated with unpleasant (weight gain) or severe (extrapyramidal or depressive symptoms) adverse effects which limit its place to that of a second-line drug. Lastly, the analysis of these studies failed to disclose a correlation between calcium movements across the cell membrane and effectiveness for the prevention of migraine attacks. Flunarizine's effect in migraine probably involves monoamine mechanisms which bear no relation to calcium.


[Serotonin agonists and antagonists in migraine]. Serotonin agonists (for the acute treatment of attacks) and antagonists (for prophylactic treatment) are the most widely used drugs to treat migraine. However, their effectiveness is not complete and their use is limited by side effects. The activity and presumptive mode of action of these drugs provide support for the role of serotonin in the pathophysiology of migraine and suggest that the trigeminal-vascular system is at the center of the attack; however, other factors and mechanisms may also be involved.


Presence of acetyl-transferases and adenylyl-transferases in gentamicin-resistant transconjugants. The aim of this work was to test the production of aminoglycoside modifying enzymes in 20 gentamicin-resistant transconjugants obtained from clinical strains of Entero-bacteriaceae. The susceptibility to aminoglycosides was determined by disc diffusion method and agar dilution method according to European Committee for Clinical Laboratory Standards, 1988. The transfer of gentamicin-resistance R-plasmids was made by conjugation on a solid medium with recipients E. coli K12. Phosphocellulose paper binding assay with 14C acetyl. CoA and 14C.ATP by Haas and Dowding was performed to reveal the enzyme production. Four different acetyl-transferases have been found: AAC/3/I, AAC/3/-V, AAC/3/-IV which modify gentamicin, and AAC/6'/-I with activity on amikacin. Only two of the transconjugants showed adenylyl-transferase activity:AAD/2"/. Some of strains tested possessed two enzymes. The most interesting finding was that the majority of strains owned AAC/3/-IV, which modifies apramycin. This was be explained with the fact that apramycin is still in a large use for animal husbandry in Bulgaria. four different acetyl-transferases: AAC/3/-I, AAC/3/-V, AAC/3/-IV and AAC/6'/-I and the adenylyl-transferase AAD/2"/ were found to be the biochemical mechanisms of resistance to aminoglycosides in 20 gentamicin-resistant transconjugants.


Gastrointestinal decontamination. Which method is best? Why has ipecac syrup become less popular in emergency management of poisoning and overdose? When should gastric lavage, activated charcoal, cathartics, or a combination of methods be used? Which patients are candidates for whole-bowel irrigation with polyethylene glycol-electrolyte solution? Drs Harris and Kingston answer these questions and present their recommendations for each of the available management options.


Discerning malignancy in human adrenocortical neoplasms: utility of DNA flow cytometry and immunohistochemistry. In order to evaluate more objective laboratory methods that may help practicing pathologists to discern malignancy in human adrenocortical neoplasms, we have examined cellular DNA content by flow cytometry and immunohistochemical distribution of c-myc, vimentin, proliferating cell nuclear antigen (PCNA), and epidermal growth factor receptor (EGFR) in 15 cases of human adrenocortical neoplasms (nine carcinomas and six adenomas). All of these examinations were performed on routinely processed surgical pathology specimens. All carcinoma cases met Weiss's histologic criteria. Seven of eight adrenocortical carcinomas demonstrated aneuploid DNA content, while all adenomas were diploid by flow cytometry. c-myc oncoprotein was observed both in cytoplasms and nuclei in all carcinomas but only in nuclei in adenomas. Vimentin was present in all carcinoma cases examined but was also observed in three of six cases of adenoma. There were no clinical or histologic differences between vimentin-positive and vimentin-negative adenomas. Immunoreactivity of PCNA and EGFR was observed in all the cases examined. There were no significant differences in distribution or patterns of immunoreactivity between adrenocortical carcinoma and adenoma. Therefore, we conclude that only DNA ploidy examined by flow cytometry and immunolocalization patterns of c-myc oncoprotein expression have any practical value in the pathologic evaluation of adrenocortical neoplasms. Careful morphologic and/or clinical studies are still considered to be the best available methods in discerning malignancy in resected human adrenocortical neoplasms.


Neu oncogene expression in ovarian tumors: a quantitative study. We studied neu mRNA expression by slot blot analysis and protein product expression by capture ELISA and immunohistochemistry in 57 primary and metastatic ovarian neoplasms, two paraovarian leiomyosarcomas, and eight normal ovaries. Some 61% of ovarian tumors but none of the paraovarian neoplasms or normal ovaries overexpressed neu mRNA. A total of 96% of the ovarian tumors that overexpressed neu were of epithelial type. Epithelial ovarian tumors had significantly higher amounts of the neu oncogene product as determined by capture ELISA than either germ cell and stromal tumors or normal ovaries (p less than 0.025). Different subtypes of ovarian carcinomas had significantly different amounts of neu oncogene product as measured by capture ELISA; endometrioid tumors had the highest, and poorly differentiated carcinomas not otherwise specified had the lowest (p less than 0.025). ELISA values, mRNA overexpression, and immunohistochemical staining intensity did not correlate with stage at diagnosis or architectural or nuclear grade in ovarian tumors. We conclude that capture ELISA is a simple, effective way to measure the neu oncogene protein product and that there is a good correlation between ELISA levels and immunohistochemical staining intensity. However, ELISA values did not correlate with stage or histologic prognostic factors in ovarian neoplasms.


Delayed acute measles inclusion body encephalitis in a 9-year-old girl: ultrastructural, immunohistochemical, and in situ hybridization studies. A 9-yr-old girl developed delayed acute measles inclusion body encephalitis, which was different from subacute sclerosing panencephalitis (SSPE) in clinical course. Measles virus was demonstrated by electron microscopy, immunohistochemistry, and in situ hybridization. Contrary to the most previous reports, matrix (M) protein was present in the brain, cerebrospinal fluid, and serum and was demonstrated by Western blot analysis and in situ hybridization. The hybridization was performed by a nonradioactive digoxigenin method.


c-erbB-2 expression in primary gastric carcinomas and their metastases. In an attempt to evaluate the relationship between c-erbB-2 expression and/or gene amplification, DNA ploidy and morphology, wall penetration, lymphatic permeation, and vascular invasion, we studied a series of 87 primary gastric carcinomas and their respective metastases (n = 335) using immunohistochemistry and performed DNA analysis of 30 primary tumors and 10 metastases from eight cases. Flow cytometry of fresh or frozen material was performed in 79 primary tumors. Five out of 87 primary tumors (5.7%) and 17 out of 335 lymph node metastases (5.1%) showed unequivocal membrane immunostaining for c-erbB-2. Seven out of 30 primary tumors (23.3%) showed gene amplification while amplification was identified in four out of 10 metastases (40.0%) from three patients. Eight tumors (9.2%) showed c-erbB-2 protein immunoreactivity, gene amplification, or both. One of these cases showed c-erbB-2 protein immunoreactivity only in the metastatic deposits, while gene amplification could be identified in the primary tumor. Three primary tumors showed gene amplification, but immunoreactive cells could not be identified. In no case was protein overexpression identified in the absence of gene amplification. Five cases with c-erbB-2 expression/amplification were well/moderately differentiated, and all the eight cases with c-erbB-2 expression/amplification disclosed aggressive features. Lymphatic permeation/lymph node metastases were found in all the cases and seven cases showed vascular invasion as well. In one case, there was also a liver metastasis. Two cases were early gastric carcinomas (T1sm) showing lymphatic permeation/nodal metastases and venous invasion. Six cases were aneuploid.(ABSTRACT TRUNCATED AT 250 WORDS)


Nucleolar organizer regions in human esophageal disorders: comparison with proliferating cell nuclear antigen by immunostaining. A silver colloid technique to demonstrate nucleolar organizer region-associated proteins (AgNORs) was performed on sections of 15 samples of human esophageal tissue, including five nonpathological esophageal epithelium, two esophageal dysplasia of the squamous epithelium, and eight esophageal squamous cell carcinomas. Initially we examined various protocols for AgNOR staining. Staining performed on 4% paraformaldehyde-fixed paraffin-embedded specimens with an incubation time of 30 min yielded the most satisfactory results. In nonpathological esophageal epithelium, the mean number of AgNOR counts per nucleus in the four layers of esophageal epithelium was greatest in the parabasal layer and was statistically significant. No significant differences were observed among the mean number of AgNOR counts per nucleus in the nonpathological parabasal layer, dysplasia, and carcinoma. Positive correlation was observed between the PCNA labeling index of esophageal disorders and the mean number of AgNOR particles per nucleus. Therefore, in esophageal disorders, the AgNOR staining per nucleus appears to correlate with proliferative activity but is of little practical value in discerning malignancy and/or aggressive biological behaviors.


Contribution of trans-acting factor alleles to normal physiological variability: vitamin D receptor gene polymorphism and circulating osteocalcin. Osteocalcin, the most abundant noncollagenous protein in bone, is a marker of bone turnover in normal and disease states. Its synthesis is induced by calcitriol, the active hormonal form of vitamin D, through the vitamin D receptor and a specific vitamin D-responsive element in the osteocalcin gene promoter. Serum concentrations of osteocalcin are under strong genetic influence. To ascertain whether variability in circulating osteocalcin levels may reflect allelic variation in the vitamin D receptor gene, we have analyzed the relationship between frequent restriction fragment length polymorphisms (RFLPs, detected by endonucleases Bsm I, EcoRV, and Apa I) that define human vitamin D receptor alleles and serum osteocalcin in a cohort of normal subjects. In 91 Caucasian subjects, RFLPs in the vitamin D receptor gene predicted circulating osteocalcin levels (P less than 0.0001) independent of age or menopause effects. Since the osteocalcin gene and the vitamin D receptor gene are encoded on different chromosomes, the interaction between these two genes occurs in trans. Thus, common alleles of this trans-acting factor, the vitamin D receptor, are functionally different and contribute to "normal" physiological variability in osteocalcin levels. Preliminary analysis in monozygotic and dizygotic twin pairs indicates that the greater diversity in lumbar spine density between the dizygotic pairs can be explained by divergence in vitamin D receptor alleles. Variations in this receptor and other transacting factor genes may confound physiological studies of regulation of target genes and will need to be considered in future human and animal studies. This approach to genetic analysis provides a paradigm for the study of functional variation in trans-acting factors and the role such variation may play in the generation and evolution of physiological diversity.


Chemical modification of Glu-953 of the alpha chain of Na+,K(+)-ATPase associated with inactivation of cation occlusion. We have investigated the role, number, and identity of glutamate (or aspartate) residues involved in cation occlusion on Na+, K(+)-ATPase, using the carboxyl reagent N,N'-dicyclohexylcarbodiimide (DCCD). Extensive use is made of selectively trypsinized Na+,K(+)-ATPase--the so-called "19-kDa membranes"--containing a 19-kDa COOH-terminal, smaller (8-11 kDa) membrane-embedded fragments of the alpha chain, and a largely intact beta chain; these membranes have normal Rb+ and Na+ occlusion capacities. The 19-kDa peptide and a smaller (approximately 9 kDa) unidentified peptide(s) are labeled by [14C]DCCD in a Rb(+)-protectable fashion. Rb(+)-protected [14C]DCCD incorporation into the "19 kDa membranes" and into native Na+,K(+)-ATPase is linearly correlated with inactivation of Rb+ occlusion. Similar linear correlations are observed when Rb(+)-protected [14C]DCCD incorporation is measured by examination of labeling of 19-kDa peptide purified from "19-kDa membranes" or of alpha chain purified from native enzyme. Stoichiometries, estimated by extrapolation, are as follows: (for "19-kDa membranes") close to one DCCD per Rb+ site and one DCCD per 19-kDa peptide; and (for native enzyme) close to two DCCD per phosphoenzyme and two DCCD per alpha chain. We suggest that each of two K+ (or Na+) sites contains a carboxyl group, one located in the 19-kDa peptide and one elsewhere in the alpha chain. After cyanogen bromide digestion of purified, labeled alpha chain, or of 19-kDa peptide, a labeled fragment of apparent M(r) approximately 4 kDa was detected and was identified as that with NH2-terminal Lys-943. Rb(+)-protected [14C]DCCD incorporation was associated almost exclusively with Glu-953. We suggest that the cation occlusion "cage" consists of ligating groups donated by different trans-membrane segments and includes two carboxyl groups such as Glu-953 (and perhaps Glu-327) as well as neutral groups, in two K+ (or Na+) sites, but only neutral groups in the third Na+ site.


A role for microtubules in sorting endocytic vesicles in rat hepatocytes. The vectorial nature of hepatocyte receptor-mediated endocytosis (RME) and its susceptibility to cytoskeletal disruptors has suggested that a polarized network of microtubules plays a vital role in directed movement during sorting. Using as markers a well-known ligand, asialoorosomucoid, and its receptor, we have isolated endocytic vesicles that bind directly to and interact with stabilized endogenous hepatocyte microtubules at specific times during a synchronous, experimentally initiated, single wave of RME. Both ligand- and receptor-containing vesicles copelleted with microtubules in the absence of ATP but did not pellet under similar conditions when microtubules were not polymerized. When 5 mM ATP was added to preparations of microtubule-bound vesicles, ligand-containing vesicles were released into the supernatant, while receptor-containing vesicles remained immobilized on the microtubules. Release of ligand-containing vesicles from microtubules was prevented by monensin treatment during the endocytic wave. Several proteins, including the microtubule motor protein cytoplasmic dynein, were present in these preparations and were released from microtubule pellets by ATP addition concomitantly with ligand. These results suggest that receptor domains within the endosome can be immobilized by attachment to microtubules so that, following monensin-sensitive dissociation of ligand from receptor, ligand-containing vesicles can be pulled along microtubules away from the receptor domains by a motor molecule, such as cytoplasmic dynein, thereby delineating sorting.


Dopamine transporter mRNA content in human substantia nigra decreases precipitously with age. The dopamine transporter is the primary means of inactivating synaptic dopamine as well as a major site of action for psychostimulants (such as cocaine and amphetamine) and for neurotoxins that induce parkinsonism. In the present study, a human dopamine transporter partial cDNA clone obtained by polymerase chain reaction exhibited 87% and 89% identity at the nucleic acid and amino acid levels, respectively, with transmembrane domains 3-5 of the rat homolog. This clone was used to quantitate human dopamine transporter mRNA by nuclease protection assay. The postmortem content of dopamine transporter mRNA in the substantia nigrae of 18- to 57-yr-old subjects was relatively constant, while in subjects greater than 57 yr old, a precipitous (greater than 95%) decline in substantia nigra dopamine transporter mRNA was evident. In contrast, tyrosine hydroxylase mRNA in the same samples declined in a linear manner with increasing age. In situ hybridization experiments confirmed the profound loss of dopamine transporter gene expression in melanin-positive (presumptive dopamine) nigral neurons. These data may begin to shed light on compensatory changes occurring in human dopamine neurons during normal aging.


The A alpha mating locus of Schizophyllum commune encodes two dissimilar multiallelic homeodomain proteins. The A alpha mating locus is one of four multiallelic loci that govern sexual development in the basidiomycete fungus Schizophyllum commune. We have determined the nucleotide sequence encoding three A alpha mating types, A alpha 1, A alpha 3, and A alpha 4. We have found that the locus for A alpha 3 and A alpha 4 consists of two genes: Y and Z. The locus for A alpha 1 encodes only one gene, Y. The Z polypeptides encoded by different alleles exhibit 42% identity. The Y polypeptides exhibit 49-54% identity. The finding that the deduced Z and Y polypeptides have homeodomain motifs suggests that these polypeptides may be DNA-binding regulatory proteins that control the expression of developmental genes. The deduced Z polypeptide also has acidic regions that might be functionally analogous to the acidic regions in yeast GAL4 and GCN4 that activate transcription. The Y polypeptide has a serine-rich region and a basic region that shows some identity to the lysine-rich region of H1 histones.


Functional analysis of the homeodomain-related proteins of the A alpha locus of Schizophyllum commune. DNA-mediated transformation was used to correlate function with putative genes from three alternative A alpha mating-type loci (A alpha 1, A alpha 3, and A alpha 4) of Schizophyllum commune. Each DNA was tested in at least nine haploid strains, one for each of the nine A alpha mating types found in the world-wide population of S. commune. The Y and Z genes (tentatively identified by sequence analysis elsewhere) individually activate A alpha-regulated development when transformed into any strain with a different A alpha mating type. The only exceptions are when the Y alleles of A alpha 3 or A alpha 4 (i.e., Y3 or Y4, respectively) are introduced into an A alpha 1 strain (the A alpha 1 locus encodes Y1 but lacks a Z gene). These observations indicate that A alpha-regulated development is activated by the interaction (direct or indirect) of products from different genes (e.g., Z3 and Y1) rather than from different alleles of the same gene (e.g., Y1 and Y3). Therefore, the activating interaction is of the form ZiYj where i not equal to j and i and j are the A alpha mating types from which the Z and Y polypeptides, respectively, are derived. Transformations with truncated or mutagenized genes begin to define essential regions of the genes and their products. Activity is in some cases dependent upon the particular A alpha mating type of the recipient. A working hypothesis for the activation of A alpha-regulated development is proposed.


A distinct cytoplasmic domain of CD2 regulates ligand avidity and T-cell responsiveness to antigen. The T-cell glycoprotein CD2 not only contributes to intercellular adhesion but also plays a direct role in T-cell activation. Here we demonstrate that the interaction of CD2 with its ligand lymphocyte function-associated antigen 3 (CD58) is regulated by T-cell receptor-CD3 signaling. T-cell receptor-CD3 crosslinking by specific antigen or monoclonal antibodies rapidly increases the avidity with which cell-surface CD2 binds immunoaffinity-purified CD58. Mutational analysis of the CD2 cytoplasmic domain demonstrates that the carboxyl-terminal asparagine is essential for T-cell receptor-induced changes in CD2 avidity but is not essential for CD2-mediated signaling, establishing that the cytoplasmic portion of CD2 consists of distinct functional domains. Furthermore, cell lines expressing CD2 molecules incapable of avidity regulation exhibit a marked deficiency in an antigen-specific response. Thus, the regulation of CD2 adhesiveness has a profound effect on the ability of CD2 to enhance antigen responsiveness. These observations demonstrate that adhesion strengthening resulting from increased CD2 avidity contributes directly to T-cell responsiveness independently of CD2-mediated signal transduction.


Cloning, expression, and localization of a rat brain high-affinity glycine transporter. A cDNA clone encoding a glycine transporter has been isolated from rat brain by a combined PCR and plaque-hybridization strategy. mRNA synthesized from this clone (designated GLYT1) directs the expression of sodium- and chloride-dependent, high-affinity uptake of [3H]glycine by Xenopus oocytes. [3H]Glycine transport mediated by clone GLYT1 is blocked by sarcosine but is not blocked by methyl-aminoisobutyric acid or L-alanine, a substrate specificity similar to that described for a previously identified glycine-uptake system called system Gly. In situ hybridization reveals that GLYT1 is prominently expressed in the cervical spinal cord and brainstem, two regions of the central nervous system where glycine is a putative neurotransmitter. GLYT1 is also strongly expressed in the cerebellum and olfactory bulb and is expressed at lower levels in other brain regions. The open reading frame of the GLYT1 cDNA predicts a protein containing 633 amino acids with a molecular mass of approximately 70 kDA. The primary structure and hydropathicity profile of GLYT1 protein reveal that this protein is a member of the sodium- and chloride-dependent superfamily of transporters that utilize neurotransmitters and related substances as substrates.


Dermorphin-related peptides from the skin of Phyllomedusa bicolor and their amidated analogs activate two mu opioid receptor subtypes that modulate antinociception and catalepsy in the rat. Three naturally occurring dermorphin-like peptides from the skin of the frog Phyllomedusa bicolor, the related carboxyl-terminal amides, and some substituted analogs were synthesized, their binding profiles to opioid receptors were determined, and their biological activities were studied in isolated organ preparations and intact animals. The opioid binding profile revealed a very high selectivity of these peptides for mu sites and suggested the existence of two receptor subtypes, of high and low affinity. The peptides tested acted as potent mu opioid agonists on isolated organ preparations. They were several times more active in inhibiting electrically evoked contractions in guinea pig ileum than in mouse vas deferens. When injected into the lateral brain ventricle or peritoneum of rats, the high-affinity-site-preferring ligand, [Lys7-NH2]dermorphin, behaved as a potent analgesic agent. By contrast, the low-affinity-site-preferring ligand, [Trp4,Asn7-NH2]dermorphin, produced a weak antinociception but an intense catalepsy.


Two distinct mechanisms alter p53 in breast cancer: mutation and nuclear exclusion. Twenty-seven cases of inflammatory breast cancer were screened for the presence of the p53 protein by immunocytochemical methods using a monoclonal antibody directed against the p53 protein. Three groups were detected: 8 cases (30%) had high levels of p53 in the nucleus of the cancer cells; 9 cases (33%) had a complete lack of detectable staining; 10 cases (37%) showed a pattern of cytoplasmic staining with nuclear sparing. Nucleotide sequence analysis of p53 cDNAs derived from the samples with cytoplasmic staining revealed only wild-type p53 alleles in 6 out of 7 cases. An eighth case was determined to be wild type by a single-strand conformation polymorphism. In contrast, the samples containing nuclear p53 contained a variety of missense mutations and a nonsense mutation. The p53 cDNAs from 3 of the tumors that lacked detectable p53 staining were analyzed, and all 3 had wild-type nucleotide sequences. Interestingly, a case of normal lactating breast tissue also showed intense cytoplasmic staining for p53 with nuclear sparing. These data suggest that some breast cancers that contain the wild-type form of p53 protein may inactivate its tumor-suppressing activity by sequestering this protein in the cytoplasm, away from its site of action in the cell nucleus. The detection of cytoplasmic p53 in normal lactating breast tissue could suggest that this is the mechanism employed in specific physiological situations to permit transient cell proliferation. This observation could explain how some breast cancer tissues inactivate p53 function without mutation.


Regionally selective deficits in uptake sites for glutamate and gamma-aminobutyric acid in the basal ganglia in schizophrenia. In a post-mortem study of schizophrenic and control subjects, the sodium-dependent binding of D-[3H]aspartate and [3H]nipecotic acid were used to investigate uptake sites of glutamate and gamma-aminobutyric acid (GABA), respectively, in subcortical brain regions. Binding to the glutamate uptake site was substantially reduced in both the putamen and lateral pallidum of the schizophrenic subjects. Binding to the GABA uptake site was substantially reduced in the putamen; smaller reductions were apparent in the caudate nucleus and lateral pallidum. The results suggest that glutamatergic and GABAergic mechanisms in the basal ganglia are abnormal in schizophrenia. These abnormalities could be relevant to the development of psychosis but could also relate to the spectrum of mild motor disturbances often described in the disease.


Culture of neuronal cells from postnatal rat brain: application to the study of neurotrophic factors. 1. The authors developed a primary culture technique for neuronal cells from postnatal rat brains and studied the effects of neurotrophic factors on the naturally developed neurons. 2. We demonstrated changes in the neurotrophic role of nerve growth factor (NGF) during the developmental stages of the rat: NGF was shown to act as a differentiation factor in the early stages and as a survival factor later. 3. It appeared that interleukin-6 (IL-6) supported the survival of septal cholinergic neurons obtained from 10-day-old rats. IL-6, however, did not induce the differentiation of embryonic rat septal cholinergic neurons. IL-6 improved the survival of mesencephalic catecholaminergic neurons from postnatal and embryonic rat brains, which have known not to be response to NGF.


Social phobia: biological aspects and pharmacotherapy. 1. Social phobia is one of the anxiety disorders that until recently, had not been thoroughly investigated. 2. Social phobia is a relatively common anxiety disorder that appears to have a genetic basis. 3. There are certain physiological aspects of social phobia that separate it from the other anxiety disorders. 4. Support for a dopaminergic abnormality related to social phobia is supported by investigation studies and pharmacotherapy. 5. There are a number of studies reporting success in the treatment of social phobia with medications.


Neuroleptic-induced movement disorders and body iron status. 1. The distribution of iron in the human brain, what is known about its biological functions, and the interaction of neuroleptics with iron suggest that this trace metal may play an important role in the pathogenesis of neuroleptic-induced movement disorders (NIMD). 2. The availability of magnetic resonance imaging has made some of the hypotheses testable in human subjects. 3. This article is a brief overview of the current literature on the association between NIMD and brain iron.


[A possible role of neuroimmunoendocrine interactions and development of post-irradiation pathology]. On the basis of the literature a postulate is proposed that the immune system contributes to regulating the intensity and direction of endocrine and nervous system functions in normal conditions and after the effect of ionizing radiation. The role of neuroimmunoendocrine interactions and their impairment in the realization of stochastic and nonstochastic sequelae of irradiation at various levels of radiation affecting the organism under normal conditions and in a combination with other unfavourable factors.


[Current aspects of extrapyramidal disorders]. Within the past decade, the harmonious anatomic aspect of the basal ganglia has changed for inhomogeneous structures filled up with a wealth of neurotransmitters and receptor subtypes with massive vertical and horizontal interconnections, asking for new mathematical concepts like parallel distributed processing of computation to approach their respective functions. Moreover, not only the motor control, but also some important aspects of cognition, eye motions, and limbic functions seem to be processed in the basal ganglia. Their overall threshold of activity seems to be under the bipolar control of the substantia nigra and the subthalamic nucleus; this results in hyper or hypokinetic syndromes. Few practical or therapeutical results have come out from the last radiological technologies and biochemical studies of extrapyramidal disorders, but the wealth of information brings hope for new issues from the knowledge in molecular biology, neuropharmacology, and from earlier diagnosis of these diseases in the future.


[Neuromediator adaptation of the cerebral cortex and brain stem structures after radiation exposure]. In experiments with male Wistar rats a decreased receptor binding of 3H-corticosterone and impairment of neuromediator adaptation in the brain structures responsible for the regulation of animal and vegetative functions were observed 6 months after the effect of external radiation (0.5 Gy) and a mixture of external radiation and 131I (6.5 microCi/kg). These processes, being partly arrested by neurotropin, lay the neurochemical basis for the development of diencephalic syndrome.


[Recent progresses in the biology of schizophrenia]. Investigations designed to improve our understanding of the physiopathology of schizophrenia are progressing along various, but no necessarily exclusive, lines. The most important aspects of the recently established biological data and their potential value are discussed and compared to classical hypotheses and results.


Sulphasalazine therapy in rheumatoid arthritis. A two-year study and follow-up of clinical results. Sulphasalazine is among the many drugs in the secondary line of antirheumatic efficacy that have both immunosuppressive and auto-inflammatory properties. Twenty-six patients with definite rheumatoid arthritis (RA) were treated for two years with sulphasalazine in a minimum dose of 1 g per day. Four patients presented untoward effects such as: marked physical asthenia, erythema and changes of the dysproteinemia tests which all disappeared when the drug was withdrawn. The first favourable results in the joint inflammation appeared after 4 weeks. Significant clinical and biologic changes were observed at the end of the study thus suggesting the therapeutic value of sulphasalazine in RA.


Calcium-dependent transmitter secretion reconstituted in Xenopus oocytes: requirement for synaptophysin. Calcium-dependent glutamate secretion was reconstituted in Xenopus oocytes by injecting the oocyte with total rat cerebellar messenger RNA (mRNA). Co-injection of total mRNA with antisense oligonucleotides to synaptophysin message decreased the expression of synaptophysin in the oocyte and reduced the calcium-dependent secretion. A similar effect on secretion was observed for oocytes injected with total mRNA together with an antibody to rat synaptophysin. These results indicate that synaptophysin is necessary for transmitter secretion and that the oocyte expression system may be useful for dissecting the molecular events associated with the secretory process.


A mutation in codon 717 of the CHO-K1 elongation factor 2 gene prevents the first step in the biosynthesis of diphthamide. The histidine residue at position 715 of elongation factor 2 (EF-2) is posttranslationally modified in a series of enzymatic reactions to 2-[3-carboxyamido-3-(trimethylammonio)-propyl]histidine, which has been given the trivial name diphthamide. The diphthamide residue of EF-2 is the target site for ADP ribosylation by diphtheria toxin and Pseudomonas exotoxin A. ADP-ribosylated EF-2 does not function in protein synthesis. EF-2 that has not been posttranslationally modified at histidine 715 is resistant to ADP ribosylation by these toxins. In this report we show that a G-to-A transition in the first position of codon 717 of the EF-2 gene results in substitution of arginine for glycine and prevents addition of the side chain of diphthamide to histidine 715 of EF-2. EF-2 produced by the mutant gene is fully functional in protein synthesis.


The significance of HLA-DRB1 matching in clinical renal transplantation. We analyzed the genotype for HLA-DRB1 alleles by digestion of polymerase chain reaction-amplified genes with the restriction endonucleases (PCR-RFLP) method to investigate the influence of HLA-DR antigen "splits" at the DRB1 gene level on the incidence of acute graft rejection in the renal transplant. For all patients, the incidence of acute rejection was proportional to the number of the serological HLA mismatch (0% in patients with two-haplotype match; 18% with HLA-A, -B, and -DR zero mismatch; 33% with HLA-DR zero mismatch; and 48% with HLA-DR one mismatch). For the patients with serological HLA-DR zero mismatch, the incidence of acute rejection in patients with HLA-DRB1 one mismatch (10/13: 77%) was significantly higher than that in those with zero mismatch (2/27: 7%). It was concluded that genotyping for HLA-DRB1 alleles would be beneficial in predicting acute rejection in patients with serological HLA-DR zero mismatch, although no difference was noted in the graft survivals.


Mediation of skin allograft rejection in scid mice by CD4+ and CD8+ T cells. We analyzed the role of CD4+ and CD8+ T cells in H-2-disparate skin allograft rejection in the mutant mouse strain C.B-17/Icr scid with severe combined immunodeficiency. On the day of skin allografting, scid mice were adoptively transferred with negatively selected CD4+ or CD8+ splenocytes from normal unsensitized C.B-17/Icr mice. These populations were obtained using a double-mAb--plus--complement elimination protocol using anti-CD4 or anti-CD8 mAb that resulted in no detectable CD4+ or CD8+ cells by FACS and negligible numbers of cytolytic T lymphocytes by limiting dilution analysis in anti-CD8 treated populations. Spleen cells were removed from grafted mice at the time of rejection and were tested in vitro for antidonor reactivity in several assays: mixed lymphocyte culture, cell-mediated lympholysis, and LDA for CTL and for IL-2-producing HTL. The presence of Thy 1.2+, CD4+, or CD8+ cells was determined by FACS. All control C.B-17 mice and scid mice adoptively transferred with nondepleted CD4+, and CD8+ cells rejected skin allografts with similar mean survival times (15.6 +/- 1.5, 18.8 +/- 3.4, 18.0 +/- 5.4, respectively), whereas control scid mice retain skin allografts indefinitely (all greater than 100 days). C.B-17 syngeneic grafts survived indefinitely in all groups. At the time of rejection, splenocytes from scid mice receiving CD4+ cells had negligible donor-specific cytotoxicity in CML and negligible numbers of CTL by LDA, but demonstrated a good proliferative response in MLC and IL-2-producing cells by LDA (frequency = 1/1764). There were no detectable CD8+ cells present by FACS analysis. Conversely, splenocytes from scid mice adoptively transferred with CD8+ cells had strong donor-specific cytotoxicity in CML (58.8% +/- 16.1%) and CTL by LDA (frequency = 1/3448), but no significant proliferation was detected in MLC. There were no detectable CD4+ cells by FACS, but there were small numbers of IL-2-producing cells by LDA (frequency = 1/10,204). These data demonstrate that CD4+ cells adoptively transferred into scid mice are capable of mediating skin allograft rejection in the absence of any detectable CD8+ cells or significant functional cytolytic activity. The adoptive transfer of CD8+ cells also results in skin allograft rejection in the absence of detectable CD4+ cells. The detection of small numbers of IL-2 secreting cells in these mice may indicate that CD(8+)-mediated allograft rejection in this model is dependent on IL-2-secreting CD8+ cells.


Prolongation of allograft and xenograft survival in mice by anti-CD2 monoclonal antibodies. Anti-CD2 monoclonal antibodies (mAb) were used to influence graft survival in two transplantation models. Xenogeneic rat islets were transplanted intraportally into mice. Anti-CD2 mAb prolonged xenograft survival and was synergistic with UVB irradiation in prolonging survival. Anti-CD2 mAb was also more potent than an anti-CD4 mAb in this model. Allogeneic cardiac grafts were transplanted across an entire H-2 difference and anti-CD2 mAb prolonged allograft survival in a dose-dependent fashion. Kinetic experiments revealed that anti-CD2 mAb was most potent when administered at the time of allografting. A delay in administration of mAb markedly reduced its immunosuppressive effects. Furthermore, additional doses of mAb given after the initial doses provided no increased immunosuppression and anti-CD2 mAbs did not delay rejection of second-set allografts. These findings support the notion that anti-CD2 mAbs interfere with afferent immunity and that CD2 is most important during the initial steps of an immune response. Investigation of the effect of anti-CD2 mAb on cellular immune functions demonstrated, in agreement with previous results, that it caused antigenic down-modulation of CD2 with relative sparing of CD3, CD4, and CD8 cell surface expression. Concomitantly the MLR, CTL, and NK responses were suppressed.


Evidence that therapeutic strategies targeted at CD4+ cells modulate accelerated rejection of cardiac allografts in sensitized rats by different mechanisms. (LEW x BN)F1 cardiac allografts are rejected within 36 hr in LEW rats presensitized with BN skin grafts 7 days earlier (acute rejection occurs within 8 days). We have previously described the effects of individual CD4 (BWH-4), CD25 (IL-2R, ART-18) mAbs, and CsA therapeutic regimens upon cardiac allograft survival in sensitized hosts. The present studies were designed to probe an adjunctive use of ART-18 or CsA upon BWH-4-mediated suppression of accelerated graft injury. Sequential therapy with BWH-4 and ART-18 in the sensitization phase (days -7 to -1) and effector phase (from day 0, the day of cardiac transplant), respectively, prolonged graft survival additively to c. 22 days. Treatment with BWH-4 markedly diminished host humoral response against ART-18 preparation. BWH-4 given in concert with subtherapeutic dose of CsA produced graft survival comparable to that induced by mAb alone (c. 13 days) with concomitant decreased host anti-BWH-4 response. None of the combined regimens affected the frequency of circulating CD4+ cells, as compared with that exerted by BWH-4 monotherapy. Thus this study defines principles and some mechanistic aspects of optimal immunosuppressive strategies potentiating the effects of CD4-targeted therapy.


T cell subsets required for in vivo and in vitro responses to single and multiple minor histocompatibility antigens. The requirement for helper T cells in the in vivo and in vitro T cell response to a diverse panel of minor histocompatibility antigens in mice was investigated. Target H antigens included: (a) multiple antigens distinguishing H-2-matched, inbred strains, and (b) single H antigens, including H-4, H-3, and the male-specific (H-Y) antigen. The involvement of helper T cells in skin allograft rejection and CTL priming was evaluated by pretreating graft recipients with anti-CD4 antibody. Anti-CD4 treatment had no effect on rejection of H-3- and H-4-incompatible skin grafts, but slowed rejection of male and BALB.B skin grafts. Comparable pretreatment with anti-CD4 antibody in vivo eliminated the priming of H-4-specific CTL, multiple B10.BR anti-CBA/J CTL, and all but a minor C57BL/6 anti-BALB.B CTL population. However, CTL specific for the two classes of H antigens, single and multiple minor H antigens, differed in their in vitro requirements for CD4+ helper T cells: (a) multiple antigen-specific CTL required CD4+ helper T cells for optimal expansion, and (b) CTL specific for single H antigens expanded in the absence of helper T cells. The CTL specific for all tested H antigens were CD8+ T cells. These results suggest that CD4+ helper T cells are not always required for effective skin allograft rejection or CTL expansion in vitro; the requirement for helper T cells is apparently dependent upon the identity of the stimulatory minor H antigen(s). This variable dependency contrasts with the evident requirement for helper T cells in the in vivo priming of CTL specific for minor H antigens.


T cell receptor V beta gene usage in HLA-DR1-reactive human T cell populations. The predominance of V beta 8. The functional specificity and T cell receptor (TCR) V beta gene expression of three class II HLA-DR1-reactive human T cell populations were examined. WP2, a renal allograft-derived, long-term CD4+ T cell line, was specifically cytotoxic for DR1, one of the mismatched antigens present on the allograft. Initial studies of WP2 using six TCR V beta-specific mAb revealed a predominance of T cells expressing a member of the V beta 8 gene family. A smaller, yet significant, number of cells expressed TCR using V beta 5.1. Semiquantitative V beta-specific polymerase chain reaction (PCR) analyses of RNA derived from this T cell line confirmed the presence of V beta 8 and V beta 5.1 messages. The PCR signal for V beta 8 was the strongest, followed by those for V beta 4 and V beta 5. An earlier WP2 culture had a very similar PCR profile, with a dominant signal for V beta 8, although signals for V beta 4 and V beta 5 were considerably lower. Previous PCR analyses of eight other renal allograft-derived, long-term T cell lines, grown under identical in vitro conditions, revealed no other example of predominant usage of V beta 8. We established two replicate long-term, anti-DR1 mixed lymphocyte reactions using PBL from two unrelated normal donors as responder and stimulator. The MLR were given alloantigen every 10 days, and RNA was obtained from the cultured cells immediately prior to each stimulation. PCR analyses of RNA taken at 10-day intervals over a total of 60-70 days indicated that, although the MLR were initially quite heterogeneous with regard to V beta message expression, by the end of the fourth or fifth Ag cycle the predominant PCR signals observed in both MLR were for V beta 8. These results suggest that T cells using V beta 8 gene-encoded segments as part of their TCR may have a selective advantage in responses to DR1.


Scope and design of the GUSI international research program. During the 1980s a large new simulated underwater saturation diving system was constructed at GKSS, Geesthacht, Germany. This German Underwater Simulator (GUSI) has performed over 18 trimix (helium, 5% nitrogen, oxygen) dives with 115 divers at depths to 600 m, including 9 to 450 m or deeper for a total of 2672 man-days of saturation and 994 days of welding and other work. From October 1989, an international research program was initiated to permit scientists from other countries to carry out physiologic and medical research during these working dives. The results of the first year's program from 3 dives, GUSI 14, 16, and 17, all to 450 m, are described in this special edition of Undersea Biomedical Research. This brief paper gives the scope, design, and objectives of the program, the dive profiles, and the scientists and projects involved.


Effect of mental task load on fronto-central theta activity in a deep saturation dive to 450 msw. The increase of theta activity (4-7 Hz) in the electroencephalogram (EEG) during deep diving is commonly attributed to pathophysiologic mechanisms underlying the high pressure neurologic syndrome. The aim of this study was to clarify whether more precise cognitive aspects of the condition may be described in which theta activity occurs during a deep dive. Among 4 divers who were repeatedly examined during the GUSI 14 dive to 450 msw, 3 divers exhibited a pronounced correlation between short-term memory load, as varied by the memory set size of Sternberg's memory search task (MST), and the size of a distinct peak in the theta band of the EEG-power spectrum. The power of this peak was greatest in the fronto-central electrode position (Fz), increased dramatically during MST-performance at pressure, and failed to subside fully 1 day before surfacing. Despite the close dependency of observed theta activity on cognitive demands, no consistent correlation with performance measures (mean reaction time and errors) was found. In one diver, theta waves of similar morphology appeared in the resting EEG and increased significantly during the dive. We suggest two alternative explanations for the positive interaction of memory load and hyperbaric exposure on Fz-theta: a) Both factors induce a state of increased mental effort or selectivity of attention, known to be accompanied by frontal theta activity from normobaric studies. b) Pressure abnormally facilitates or patterns rhythmical excitations underlying theta activity that would occur naturally to a lesser extent during certain mental activities, learning, or repetitive short-term memory operations.


Evaluation of energy requirements from body mass, lean body mass, fat content, and energy intake in GUSI dives. This study reports the changes in body composition measured during 6 deep saturation dives, the depths and the working hours performed during the dives, and the effects of these parameters on the energy requirements. Changes in lean body mass could be avoided if the working days amounted to 40-45% of the total dive time. Energy requirement depended not only on working days but also on the diving depth. Physical work at great depth requires a disproportional increase in the energy requirements beginning between 200 and 360 m. Under working conditions at 450 msw, energy requirements increased about 30% relative to the total energy needs under normal conditions.


An investigation of cardiovascular reflexes during a trimix saturation dive to 450 msw (GUSI 17). The study examines the hypothesis that the carotid sinus heart rate baroreflex responses are changed in human subjects on exposure to 450 msw. Baroreceptor reflex changes in heart rate (expressed as ms/mmHg applied pressure) were evoked by application of negative or positive pressure to a cuff surrounding the neck. At 450 msw using trimix, the mean resting heart rate of divers slowed significantly from 64 +/- 1.3 beats/min at surface to 55 +/- 1.4 beats/min at 450 msw, respiratory rate decreased from 15 +/- 1.4 at surface to 11 +/- 2 at 450 msw, and sinus arrhythmia increased. There was no change in arterial blood pressure. Baroreceptor reflex sensitivity to an increased carotid sinus transmural pressure was reduced from 5.6 +/- 2.9 (mean +/- SEM) at surface to 2.4 +/- 0.8 ms.mmHg-1 at 450 msw; sensitivity to decreased carotid sinus transmural pressure increased from 2.2 +/- 0.4 ms.mmHg-1 at surface to 5.1 +/- 0.2 ms.mmHg-1 at 450 msw. A progressive shortening of cardiac interval during breath hold in expiration was also noted. When this shortening of interval was incorporated into the analysis of baroreceptor reflex sensitivity, no significant change in sensitivity was observed but the overall baroreflex stimulus-response relationship shifted downward.


Urinary vasopressin and aldosterone and plasma volume during a saturation dive to 450 m. Urinary vasopressin (VP), aldosterone (ALDO), osmotic substances, sodium excretion, and plasma volume were assessed in 4 healthy male divers during 2 predive control days, 2 compression days, 6 days at 46 atm abs, and 26 days of decompression with stops at 37 and 27 atm abs. At pressure the ambient gas was trimix (0.5 atm abs O2:5% N2:remainder He). All urine was collected throughout the dive. Samples were divided into daytime (0700-1900) and nighttime (1900-0700). Indocyanine green dye dilution was used to determine plasma volume at predive 1, 46, and 24 atm abs. In agreement with previous dives at 31 atm abs, there was a decrease in VP excretion during compression lasting until return to 1 atm abs (P less than 0.05). Also similar to the shallower dives at 31 atm abs, the normal diurnal pattern of VP excretion, daytime higher than nighttime (P less than 0.05), disappeared at pressure. Urine osmolality showed alterations compatible with responses to VP. In contrast to previous studies at 31 atm abs, but in agreement with a previous study at 49.5 atm abs, there was no sustained increase in urinary ALDO excretion and only a transient natriuresis during the compression phase, followed by a reduced sodium excretion. In confirmation of earlier conclusions from indirect evidence, direct measurements of plasma volume indicated a reduction of about 20% (P less than 0.05) at 46 atm abs which remained reduced after decompression to 24 atm abs.


The metabolism of piperidine-type phenothiazine antipsychotic agents. I. Sulforidazine in the rat. 1. The metabolism of the piperidine-type, phenothiazine antipsychotic agent, sulforidazine, was studied in female rats after a 20 mg/kg single oral dose. 2. Compounds identified in urine were sulforidazine, sulforidazine ring sulphoxide, the lactam of sulforidazine, the lactam of sulforidazine ring sulphoxide, two diastereomers of N-desmethylsulforidazine ring sulphoxide and a phenolic derivative of sulforidazine. 3. Metabolites were separated by h.p.l.c. prior to mass spectrometric or g.l.c.-mass spectrometric analysis. Except in the case of the phenolic metabolite, structures were confirmed by direct comparison of electron impact mass spectra and chromatographic behaviour with those of authentic samples. To facilitate identification of the phenolic metabolite the crude urinary extract was treated with a silylating reagent and analysed by h.p.l.c.-mass spectrometry with a plasmaspray interface. 4. Despite the availability of authentic standards of sulforidazine N-oxide and sulforidazine N,S-dioxide neither of these compounds could be identified in urinary extracts obtained from rats. 5. Sulforidazine underwent extensive metabolism in rats as only 2.3 +/- 0.4% (n = 5) of the dose was present as unchanged sulforidazine in 24 h urine. The lactam of sulforidazine (0.1 +/- 0.1%) was a minor metabolite whereas the lactam of sulforidazine ring sulphoxide was 3.2 +/- 2.6% dose. 6. Sulforidazine sulphoxide (12.1 +/- 1.6%) was a major metabolite and its diastereomers were present in similar amounts.


[Drug dependence in therapy of chronic pain]. The use of drugs in pain therapy is characterized by the fear of addiction. As a result strong analgesics are underused. To compensate the missing analgesic effect the additional use of psychotropic drugs is common. There is still little knowledge that just this therapeutic strategy of underuse leads to iatrogenic addiction. To avoid misunderstandings and irritations in the discussion around addiction, there must be clearly distinguished between physical and psychological dependence. There is sufficient evidence that especially tranquilizers and mixed analgesics induce the development of psychological dependence. In pain therapy there is no indication for these substances. In contrast opioids can be used without causing psychological dependence, presuming the guidelines of drug therapy in chronic pain (e.g. WHO guidelines) are attended.


[Antihypertensive therapy and modification of metabolic risk factors (glucose and lipid metabolism)]. Meta-analysis of several large interventional trials in patients with mild to moderate hypertension has shown that coronary events are reduced to a much lesser extent than expected. One of the possible explanations for this are the metabolic side-effects of diuretics and betablockers used in these trials that may counteract their beneficial blood-pressure-lowering effect. Diuretics, especially thiazide, increase total cholesterol (+5%) and LDL-cholesterol (+10%), while betablockers decrease HDL-cholesterol (-5%) and increase triglycerides (+20%). Calcium antagonists and ACE-inhibitors do not affect lipids, and alpha-blockers have some beneficial effects. Regarding the carbohydrate metabolism, diuretics and betablockers decrease insulin sensitivity, increase plasma insulin, LDL-cholesterol, and triglycerides, and reduce HDL-cholesterol. Calcium channel blockers are neutral, while alpha-blockers and ACE-inhibitors improve glucose tolerance and reduce insulin resistance. To date, the clinical relevance of this side-effects is not known. Controlled, long-term trials in hypertensive patients with calcium channel blockers, ACE-inhibitors, and alpha-blockers are needed.


[Duration of the effect and dose-response relationship of ridazolol in patients with coronary heart disease]. The dose-effect relation and duration of action of 10 mg, 20 mg, 40 mg, and 80 mg ridazolol on ischemic ST-segment depression in exercise-ECG were determined in a randomized, double-blind, acute, cross-over study of 15 patients with confirmed coronary artery disease and reproducible ST-segment depression. Maximal reduction of ST-segment depression in comparison to placebo during constant exercise was 0.16 vs. 0.25 mm (n.s.) after 10 mg, 0.09 vs. 0.25 mm (p less than 0.01) after 20 mg, 0.11 vs. 0.25 mm (p less than 0.01) after 40 mg, and 0.07 vs. 0.25 mm (p less than 0.01) after 80 mg ridazolol. A remarkable reduction of ST-segment depression under placebo was seen in the third and fifth hours after application. Systolic blood pressure under exercise was reduced significantly after 80 mg ridazolol (145 vs. 176 mm Hg; (p less than 0.05) over a period of 5 h. Heart-rate was reduced significantly after 80 mg ridazolol (102 vs. 131/min; p less than 0.05) for 5 h. Rate-pressure product after 20 mg (174 vs. 234 mm Hg/min; p less than 0.01), 40 mg (169 vs. 234 mm Hg/min; p less than 0.01), and 80 mg (153 vs. 234 mm Hg/min; p less than 0.01) ridazolol was reduced significantly over 3 to 5 h. 20, 40 and 80 mg ridazolol show a good antianginal and antihypertensive efficacy. Blood pressure and heart-rate under exercise were significantly reduced over 5 h. In contrast, improvement of ST-segment depression only lasted 1 h. Ridazolol was well tolerated.


Soluble guanylate cyclase of platelets: function and regulation in normal and pathological states. Chromatography of 105,000 x g supernatants of human and rat platelets on DEAE-cellulose yielded identical elution profiles containing 2 protein fractions (peaks I and II). Only peak II was found to possess guanylate cyclase activity. In the spectrum of the 105,000 x g supernatant of human platelets the absorption maximum was specified at 410 nm (the Soret band) which disappeared from the spectrum of the active protein fraction (peak II) but was detected in the nonactive fraction (peak I). The enzyme preparation was obtained in the heme-deficient form. In the experiments with rat platelets, the Soret band was absent from the corresponding spectra and the enzyme was not activated by sodium nitroprusside; i.e., in soluble guanylate cyclase of rat platelets, unlike the generally accepted notion, the heme is not a prosthetic group of the enzyme. It was shown that carnosine (beta-alanyl-L-histidine), a water-soluble antioxidant, inhibits guanylate cyclase activation by sodium nitroprusside. This inhibitory effect is caused by the interaction of carnosine with the guanylate cyclase heme and can be used for evaluating the degree of saturation of the enzyme with the heme. ADP-induced aggregation of human platelets (donors) is accompanied by a fall in the basal guanylate cyclase activity (with Mg2+) and the enhancement of the enzyme stimulation with sodium nitroprusside, protoporphyrin IX, arachidonic acid and L-arginine with simultaneous cGMP elevation in platelets. A hypothetic scheme of the regulatory role of cGMP in platelet aggregation is proposed. In the experiments with the acute myocardial ischemia of rats, 15 min after the surgery a sharp fall in the platelet guanylate cyclase activity accompanied by a decrease in the enzyme activity in the ischemic zone of the left ventricle of heart took place. The results provided evidence of the high sensitivity of platelet guanylate cyclase to pathological changes occurring in the myocardium at the earliest stages of the development of pathology.


Regulation of GTP biosynthesis.

Regulation of GTP biosynthesis. In the regulation of GTP biosynthesis, complex interactions are observed. A major factor is the behavior of the activity of IMPDH, the rate-limiting enzyme of de novo GTP biosynthesis, and the activity of GPRT, the salvage enzyme of guanylate production. The activities of GMP synthase, GMP kinase and nucleoside-diphosphate kinase are also relevant. In neoplastic transformation, the activities and amounts of all these biosynthetic enzymes are elevated as shown by kinetic assays and by immunotitration for IMPDH. In cancer cells, the up-regulation of guanylate biosynthesis is amplified by the concurrent decrease in activities of the catabolic enzymes, nucleotidase, nucleoside phosphorylase, and the rate-limiting purine catabolic enzyme, xanthine oxidase. The up-regulation of the capacity for GTP biosynthesis is also manifested in the stepped-up capacity of the overall pathways of de novo and salvage guanylate production. The linking with neoplasia is also seen in the elevation of the activities of IMPDH and GMP synthase and de novo and salvage pathways as the proliferative program is expressed as cancer cells enter log phase in tissue culture. The activity of GMP reductase showed no linkage with neoplastic or normal cell proliferation; however, in induced differentiation in HL-60 cells the activity increased concurrently with the decline in the activity of IMPDH. This reciprocal regulation of the two enzymes is observed in differentiation induced by retinoic acid, DMSO or TPA in HL-60 cells. In support of enzyme-pattern-targeted chemotherapy, evidence was provided for synergistic chemotherapy with tiazofurin (inhibitor of IMPDH) and hypoxanthine (competitive inhibitor of GPRT and guanine salvage activity) in patients and in tissue culture cell lines. These investigations should contribute to the clarification of the controlling factors of GMP biosynthesis, the role of the various enzymes, the behavior of GMP reductase in mammalian cells and the application of the approaches of enzyme-pattern-targeted chemotherapy in patients.


[The antidystrophic effect of the action of beta-adrenoblockaders in local damage to the nervous system]. It has been established that the lesion of the sciatic nerve, accompanied by a disturbance of normal neurotrophic provision of a kidney as a result of coming to the organ of the perverted nervous stimuli (by the neuro-conductive path through sympathetic nerves and by participation of the hypothalamus--hypophysis--peripheral glands system), leads to disturbance of functioning of mineral-corticoid receptors of kidneys. It has been also established that simultaneous pharmacological blockade of neuro-conductive and humoral pathways of transmission to the kidney of pathological stimuli from the central stump of the cut sciatic nerve prevents the development of trophic organ disturbances, tested by the state of the kidney mineral-corticoid receptor apparatus, while pharmacological stimulation of sympathetic nervous system leads to the greater disturbance of aldosterone reception by the cells of kidney channels. A valid conclusion can be made that propranolol is a substance, which may weaken possible non-adequate reactions of peripheral tissues to the action of physiologically active substances during the development of the consequences of the lesion of the nervous system and thus to prevent the development of neurogenic dystrophies.