Relationship between brain serotonin and calmodulin in young, genetically obese (ob/ob) mice.

The possible relationships between altered brain serotonin and calmodulin contents on the development of obesity were studied. Eight groups of mice separated by differences in phenotype, sex and age were used in this study. The brain contents of tryptophan, serotonin, 5-hydroxyindoleacetic acid (5-HIAA) and calmodulin were assayed. The contents of brain tryptophan showed no significant differences in any of the mice. The amount of brain serotonin in obese mice was 82% higher than that in their lean counterparts at four weeks of age, but only 11% higher at eight weeks of age. Regardless of age and sex, brain serotonin was positively correlated to the brain calmodulin in the lean mice (r = 0.559, p < 0.01), yet this was not found in obese mice. There was a strong positive correlation between serotonin and 5-HIAA in all mice (r = 0.679, p < 0.001). The elevated amount of serotonin in the brain of four-week-old obese mice is suggested to have important effects on thermoregulation in young genetically obese mice. The results also suggest that abnormal brain serotonin synthesis in obese mouse regulated by calmodulin might interact with certain factors, such as calcium ions, to complete the activation of serotonin-synthesized enzymes in the development of obesity.


Inheritance of hypertrophic cardiomyopathy in Chinese--M-mode and two-dimensional echocardiographic analysis of 28 families.

To determine the mode of inheritance and degree of penetrance of hypertrophic cardiomyopathy (HC) in Chinese, 132 family members of 28 probands with HC were assessed by M-mode and two-dimensional echocardiography. Of these 132, 103 cases were first-degree relatives of the probands. Twenty-seven (20.4%) family members, including 19 cases of first-degree relatives of the probands, had HC. Familial occurrence of HC was noted in 13 (46.4%) families. In 10 families, the affected relatives were identified in successive generations, and the mode of inheritance was most consistent with an autosomal dominant trait. The frequency with which HC was identified in relatives increased significantly with the number of subjects studied and a positive family history of sudden death. Subgroup analysis, using multivariate logistic regression analysis, revealed that increasing age was independently associated with a higher frequency of definite cases in first-degree relatives of the probands. In contrast, by multivariate analysis, there were no significant differences between frequency of definite cases in female and male relatives or in different familial relationships (parent, sibling, offspring) to the probands.


Comparison of sodium transport processes of human and rat erythrocytes in hypertension.

Erythrocytes of normotensive and hypertensive humans, as well as Sprague-Dawley, Wistar-Kyoto and spontaneously hypertensive rats, were prepared to have similar ionic compositions adequate for determining the activities of lithium-sodium (Li-Na) countertransport and sodium (Na) pump. The rate of Li-Na countertransport was significantly higher in erythrocytes of hypertensive subjects. This activity was not detected in rat erythrocytes, at two different ages, and over a six-fold of lithium (Li) content. Activities of Na pump were not significantly different among various groups. Human cells, in general, had a higher activity than rat cells; among rat cells, spontaneously hypertensive rats had a higher rate of sodium pump. Both Na-independent Li efflux and ouabain-insensitive Na efflux were significantly higher in rat erythrocytes than in human cells. Thus, employing the same methods, we have determined that while the properties of Na pump were similar in human and rat erythrocytes, Li-Na countertransport did not operate in the erythrocytes of either normotensive or hypertensive rats.


Antithrombin III activity in normal and toxemic pregnancies.

From August 1989 to October 1990, 83 pregnant Chinese women were the subjects for measuring the levels of plasma functional antithrombin III (AT III) activity. The correlations of AT III activity with perinatal outcome and the changes in maternal hepatorenal function were analyzed. The population was divided into four groups: Group I (n = 30), normal pregnancies; Group II (n = 23), mild pre-eclampsia; Group III (n = 26), severe pre-eclampsia; and Group IV (n = 4), eclampsia. The results demonstrated that: 1) AT III activity decreased with the severity of toxemia (p < 0.001), 2) AT III activity correlated with the degree of perinatal outcome and maternal morbidity, and 3) reduction of AT III activity correlated with impairment of maternal hepatorenal function. In conclusion, plasma AT III activity is a valuable parameter in the evaluation of toxemia.


Rat liver regeneration after partial hepatectomy: effects of insulin, glucagon and epidermal growth factor.

This study evaluated the role of insulin, glucagon and the epidermal growth factor (EGF) on liver regeneration after partial hepatectomy. Male Wistar rats, weighing approximately 200 g, were used. A partial hepatectomy, with resection of the medial and left lateral lobes (67.31%), was performed on the control group and seven hormone-treated groups: insulin, glucagon, EGF, insulin plus glucagon, insulin plus EGF, glucagon plus EGF, and a combination of the three hormones. The hormones were administered subcutaneously two days prior to the partial hepatectomy. The groups administered insulin were allowed to drink 20% glucose in water. Another group of rats received simulated operations, i.e., only a laparotomy was performed. The rats were killed at six, 24, 48 and 72 hours after the operation. Remnant liver weight, deoxyribonucleic acid (DNA) content, rate of DNA synthesis, mitotic index, blood glucose and serum insulin levels were measured. The results showed that: 1) the effects of single hormone administration on posthepatectomy liver regeneration were not obvious; 2) combined administration of insulin and glucagon increased the weight of the remnant liver, the DNA content, and the rate of DNA synthesis; 3) the combined administration of insulin, glucagon, and EGF increased the regeneration based on the remnant liver weight and mitotic index; and 4) there was no concordance between the change in blood glucose levels and the effect of hormones during liver regeneration.


Hepatitis B virus infection among aboriginal children in eastern Taiwan.

Hepatitis B virus (HBV) infection is endemic in Taiwan, with 15-20% of the adult population carrying the surface antigen (HBsAg). Hualien in Eastern Taiwan is relatively isolated from other parts of the island by the Central Mountains. The status of HBV infection among mountain aborigines in Hualien has not been studied on a large scale before. A survey of serum HBsAg and its antibody (anti-HBs) was conducted in 1989. A total of 3,287 children from 27 primary schools in three mountainous counties of Hualien were tested. The carrier rate (HBsAg positive) for the whole group was 31.9%, and the infection rate (HBsAg and/or anti-HBs positive) was 80.7%. Both the carrier rate and infection rate of 1,618 boys were significantly higher than those of 1,669 girls (35.7% vs 28.3% and 83.0% vs 79.3%, respectively, p < 0.001). The carrier rates of children in the first to sixth grades were 29.4%, 35.0%, 31.5%, 30.8%, 33.3% and 32.0%, and the infection rates were 74.9%, 79.0%, 80.1%, 82.6%, 83.3% and 84.1%, respectively. The infection rate increased significantly with age (p < 0.05). The results show that HBV infection is a serious problem among the children of mountain aborigines in Hualien, with nearly one-third of them carrying HBsAg. Aggressive vaccination, as well as public health education programs, are greatly needed.


Urodynamic findings in interstitial cystitis.

Fifty patients with irritative voiding symptoms and a painful bladder when full were engaged in this study to clarify the role of urodynamics in the diagnosis of interstitial cystitis (IC). Patients underwent urodynamic study, cystoscopic hydrodilatation of the bladder under general anesthesia and bladder biopsy. Twenty-eight women and two men who presented with signs of glomerulations or petechial hemorrhage of the bladder mucosa were classified as having IC, while 20 women without this characteristic were classified as having non-IC. A hypersensitive urge sensation, a small bladder capacity, a lower maximal flow rate and an abnormal flow pattern were observed in both groups of patients, but no significant difference was noted. More IC patients had a lower bladder compliance than non-IC patients (p < 0.025), and the maximal bladder capacity under anesthesia was smaller in IC patients (p < 0.05). However, there does not seem to be any definite correlation to the pathologic findings, except in patients with marked bladder inflammation, in whom a small capacity and severe clinical symptomatology were found.


Methotrexate, vinblastine, adriamycin and cisplatin (M-VAC) for advanced TCC of urothelium.

After the introduction of methotrexate, vinblastine, adriamycin and cisplatin combination (M-VAC) chemotherapy for transitional cell carcinoma (TCC) of the urothelium, the reported response and survival rates improved when compared with the previous regimens. From July 1989 to March 1991, 43 consecutive cases of invasive or metastatic TCC that had received at least one course of M-VAC treatment were collected by a computer-assisted search and analyzed. The overall response rate, including complete response (CR) and partial response (PR), was 44% (CR, 16%; PR, 28%). Tumors originating from the renal pelvis or bladder responded better than those from the ureter (kidney, 57%; bladder, 42%; and ureter 30%). Lymph node, soft tissue, lung metastases and local recurrent tumors had a greater chance of response than bone or liver metastases. Although patients from the blackfoot disease endemic area seemed to respond better than those from the nonendemic area, there was no statistically significant survival benefit. The duration of follow-up ranged from nine to 38 months. The length of survival of nonresponders ranged from one month to 19 months (median, eight months; mean, seven months). Ten of the 19 responders relapsed, and the others were still responding. Three patients (7%) survived two years, disease-free. Although the response rate improved, the chance of long-term survival was still unsatisfactory in our study.


Cognitive development of children prenatally exposed to polychlorinated biphenyls (Yu-Cheng children) and their siblings.

An intoxication episode resulting from rice-bran oil (Yu-Cheng) contaminated with polychlorinated biphenyls (PCBs) occurred in Taiwan from 1978 to 1979. After that episode, the authors found 15 Yu-Cheng children who were born to intoxicated mothers after their documented consumption of PCB-contaminated oil; these children had older siblings, born before PCB exposure, without prenatal PCB exposure. The cognitive development of these Yu-Cheng children and the youngest of their elder siblings were assessed annually from 1985 to 1990 using the Chinese version of the Wechsler Intelligence Scale for Children, Revised Version (WISC-R) for those over six years of age. Compared with their elder siblings, the Yu-Cheng children scored significantly lower (p < 0.05) on the verbal intelligence quotient, by 6.8-16.1 points; on performance IQ by 10.2-18.4 points; and on full-scale IQ by 8.9-18.5 points, during the six measurements performed from 1985 to 1990. The differences in WISC-R IQ scores between the two groups have remained unchanged during these six years of follow-up.


Pregnancy after transfer of frozen-thawed human embryos.

Cryopreservation of human embryos has been successfully applied in in vitro fertilization (IVF) and embryo transfer (ET) programs at the National Taiwan University Hospital since 1988. Our preliminary results with 120 frozen-thawed embryos in 31 transfer cycles showed that the survival rate of frozen embryos was 66%. Following transfer, the implantation rate and clinical pregnancy rate were 6.5% and 13%, respectively. Four clinical pregnancies and one preclinical pregnancy following a frozen-thawed embryo transfer were achieved. Two normal male babies have been delivered and another pregnancy is progressing without any problem.* Unfortunately, one pregnancy was terminated due to intrauterine fetal death discovered at the 10th week of gestation; chromosome abnormality (47, XX, +5) of the fetus was found. The single preclinical pregnancy showed an elevation of serum beta-human chorionic gonadotropin levels for three consecutive weeks following ET, but no definite gestational sac was visualized by transvaginal ultrasound.


Laparoscopic hysterectomy: preliminary report of 24 cases.

From March to November 1991, 24 patients underwent laparoscopic hysterectomies at Chang Gung Memorial Hospital, Taipei. The indications for hysterectomies included seven patients with adenomyosis, 14 with myoma uteri, one with intractable menorrhagia, and two with endometriosis and severe pelvic adhesions. The surgeries were performed using the techniques of videolaparoscopy, including a combination of Kleppinger bipolar forceps for hemostasis and scissors and/or CO2 laser for lysis of adhesions. The mean blood loss was 210 mL; there was one bladder injury during these procedures. Most of the patients were discharged on the second postoperative day. The advantages of a laparoscopic hysterectomy include a short hospitalization, low blood loss and less postoperative discomfort. Laparoscopic hysterectomy is a cost-effective and safe procedure.


Premenstrual tension syndrome with periodic bulimia nervosa: report of a case and review of the literature.

Premenstrual tension syndrome (PMS) is well known in its epidemiology, etiology, symptomatology and treatment. However, PMS characterized by bulimic episodes is rare. We report a case of a 20-year-old university student who suffered from uncontrollable binge eating premenstrually for six months before visiting our clinic. She was obese without any other notable family or medical history except the PMS noted for two years. A daily food diary for two consecutive menstrual cycles showed that the mean differences in caloric intake between premenstrual and postmenstrual days of two menstrual cycles were 679 and 703 calories, respectively. The greater peaks in caloric level were noted within the third to fifth days prior to the onset of menstruation. All binge episodes occurred in the premenstrual period, especially within five days prior to menstruation. In this report, we will also review the literature on the relationship between PMS and dietary intake, as well as bulimia nervosa.


Neurenteric cyst at craniocervical junction: report of a case.

The authors report a rare case of neurenteric cyst at the foramen magnum presenting with a central cord syndrome and dysfunction of the lower cranial nerves. A magnetic resonance imaging study showed a cystic lesion over the lower medulla oblongata and C1-2 spinal cord. Differentiation between a neurenteric cyst and an epidermoid cyst was difficult. Successful total removal of the cyst was performed. The lesion consisted of an enteric cyst lined with a mucus-secreting columnar epithelium, containing highly proteinaceous supernatant and thick mucus deposit. The patient recovered dramatically after surgery.


Urinary kallikrein excretion in non-insulin-dependent diabetes mellitus.

To investigate the status of urinary kallikrein excretion (UKE) in patients with non-insulin-dependent diabetes mellitus (NIDDM), we measured UKE in 31 NIDDM patients. They ranged in age from 40 to 70 years (mean, 54.3 +/- 7.8 years), comprising 18 males and 13 females. Their creatinine clearance (Ccr) was 91.6 +/- 5.5 mL/min, and the daily excretion rate of protein was 1.15 +/- 0.72 g/24 hours. Twenty-five normal persons, aged from 37 to 63 years (mean, 51.7 +/- 8.2 years), comprising 14 males and 11 females, were enrolled as controls. The NIDDM patients were further divided into two groups. Group A (n = 21) had regular blood sugar control, while Group B (n = 9) had poor blood sugar control. The autonomic nervous function was tested in 15 patients to study its relationship with UKE. UKE was measured by spectrophotometric assay of the kallikrein enzymatic product on the synthetic substrate S-2266. Autonomic function was evaluated by cardiovascular reflex tests. The results showed that UKE was elevated in Group B, but depressed in Group A (normal vs A vs B: 9.6 +/- 1.0 vs 4.8 +/- 0.9 vs 14.4 +/- 2.7 nkat/24 hours). The UKE/Ccr ratio was similarly elevated in Group B and reduced in Group A (normal vs A vs B: 0.1 +/- 0.01 vs 0.05 +/- 0.01 vs 0.18 +/- 0.04 nkat. mL/day.minute). There was no significant correlation between UKE or the UKE/Ccr ratio and the Valsalva ratio, the 30:15 ratio, or postural blood pressure change. These results suggest that NIDDM patients have abnormal urinary kallikrein excretion levels that are influenced by blood sugar control. The abnormal UKE/Ccr ratio suggests that intrarenal abnormality in the renal kallikrein-kinin system exists in NIDDM patients.


Correlation between ELISA and recombinant immunoblot assay in serum samples positive for anti-HCV.

To determine the false-positivity of antibody to hepatitis C virus (HCV) (anti-C100-3), the correlation between ELISA optical density (OD), anti-HCV titer and recombinant immunoblot assay (RIBA) in 87 anti-HCV-positive sera was analyzed. The results showed that > 90% of the serum samples with an anti-HCV OD > 2.0 or with titers > 10 x were RIBA reactive. These findings are applicable in daily clinical practice.


Superior mesenteric artery syndrome as a complication in hip spica application for immobilization: report of a case.

A 10-year-old girl who had a pelvic and femoral osteotomy for congenital dislocation of her right hip was immobilized with a hip spica. On the 28th postoperative day, she had upper abdominal pain, distention and bilious vomiting. An upper GI series demonstrated complete obstruction of the duodenum at the third portion of the duodenum in a supine position; however, the barium passed the obstruction site slowly when the patient assumed a lateral or prone position. She was successfully treated conservatively with nasogastric decompression, fluid replacement, proper positioning and hyperalimentation. Superior mesenteric artery syndrome is a rare complication in patients immobilized in a body cast or hip spica. Early diagnosis and proper treatment usually leads to an uneventful convalescence.


Non-association between 9.2 KB PvuII RFLP and seronegative spondyloarthropathies in Spain.

Several studies of DNA restriction fragment length polymorphism (RFLP) in ankylosing spondylitis (AS) have been carried out. The association between a recently identified class I HLA 9.2 kb PvuII RFLP and AS remain controversial. In order to evaluate this possible association in an Euro-Caucasian population, the genomic DNA of 42 AS patients and 18 patients with Reiter's syndrome (RS) and 42 healthy controls was analysed. Non-association between 9.2 kb PvuII RFLP and AS or RS was observed. As described previously, a strong association between this fragment and HLA-A3 and/or HLA-A9 antigens was demonstrated. A study of two families showed that this RFLP segregates with HLA-A3 and/or HLA-A9 and independently of the HLA-B27. Our findings support the view that the 9.2 kb PvuII fragment is not universally associated with AS.


Late malignancy risk in urology.

The long-term survival of children with congenital urological abnormalities is now taken for granted. In general, they have been found to grow up well after many operations and often in the face of considerable handicaps. Their survival carries with it numerous complications, the most frightening of which is the development of cancer. Successful treatment of congenital abnormalities does not excuse the patient from developing cancers to which the general population is prone, but some conditions and some treatments raise specific risks.


Physical and mental fatigue: metabolic mechanisms and importance of plasma amino acids.

There are at least 5 metabolic causes of fatigue, a decrease in the phosphocreatine level in muscle, proton accumulation in muscle, depletion of the glycogen store in muscle, hypoglycaemia and an increase in the plasma concentration ratio of free tryptophan/branched-chain amino acids. Proton accumulation may be a common cause of fatigue in most forms of exercise and may be an important factor in fatigue in those persons who are chronically physically inactive and also in the elderly: thus, the aerobic capacity markedly decreases under these conditions, so that ATP must be synthesized by the much less efficient anaerobic system. A marked increase in the plasma fatty acid level, which may occur when liver glycogen store is depleted and when hypoglycaemia results, or during intermittent exercise when the rate of fatty acid oxidation may not match the mobilisation of fatty acids, could be involved indirectly in fatigue. This is because such an increase in the plasma level of fatty acids raises the free plasma concentration of tryptophan, which can increase the entry of tryptophan into the brain, which will increase the brain level of 5-hydroxytryptamine: there is evidence that the latter may be involved in central fatigue. In this case, provision of branched-chain amino acids in order to maintain the resting plasma concentration ratio of free tryptophan/branched-chain amino acids should delay fatigue--there is prima facie evidence in support of this hypothesis. This hypothesis may have considerable clinical importance.


Transplantation of embryonic mesencephalic and medullary raphe neurons to the neostriatum of rats with unilateral 6-hydroxydopamine lesions.

The implantation of dopamine-rich mesencephalic grafts into the 6-hydroxydopamine (6-OHDA)-lesioned neostriatum of rats was accompanied by marked hyperinnervation by serotonin (5-HT) fibers. The purpose of this study was to examine the possibility that the graft-derived 5-HT hyperinnervation is governed by target-related effects present in the host neostriatum and the question of whether grafts rich in 5-HT cells can ameliorate the drug-induced motor asymmetry resulting from unilateral 6-OHDA lesions. Rats were allocated to one of two groups: lesion plus mesencephalic raphe grafts (group R5-HT/L); and lesion plus medullary raphe grafts (group C5-HT/L). A third group, sham-lesion plus mesencephalic raphe grafts (group R5-HT/S) was included. Complete recovery of (+)-amphetamine-induced rotation was observed only in rats which received 5-HT grafts derived from medullary raphe neurons. There was no marked recovery of apomorphine-induced rotation in either of the R5-HT/L and C5-HT/L groups. Immunohistochemistry showed that the R5-HT/L and C5-HT/L groups had 5-HT hyperinnervation in the neostriatum of the lesioned side. There was no target-related effect of the 6-OHDA-lesioned neostriatum specific for the different types of 5-HT tissue. It seems likely that the 5-HT tissue derived from the medullary raphe may contain additional neurotransmitters which contribute to the behavioral recovery.


Stereoselective effects of central alpha 2-adrenergic agonist medetomidine on in vivo catechol activity in the rat rostral ventrolateral medulla (RVLM).

The stereoselective central effects of a novel, highly potent and selective alpha 2-agonist medetomidine on adrenergic neuronal activity, reflected by changes in catechol oxidation current, in the rostral ventrolateral medulla of the halothane-anesthetized rat were examined using in vivo differential normal pulse voltammetry. Dexmedetomidine, the active isomer, significantly decreased catechol oxidation current to 33.4 +/- 4.5% of baseline when given centrally (1 microgram, i.c.v.) and to 10.3 +/- 3.9% of baseline when given systemically (50 micrograms/kg, i.v.). Dexmedetomidine also significantly reduced mean arterial blood pressure by 19.9% following central administration but significantly increased mean arterial blood pressure by 59.9% following systemic administration. Levomedetomidine, the inactive isomer, had no effect on catechol oxidation current or blood pressure. The depressant effects of dexmedetomidine on catechol oxidation current were reversed by the selective alpha 2-adrenoceptor antagonist atipamezole (2 micrograms, i.c.v. or 200 micrograms/kg, i.v.). The results of the present study demonstrate, to our knowledge, for the first time the central stereoselective effects of medetomidine and antagonism by atipamezole on rostral ventrolateral medulla activity in the anesthetized rat.


CNQX increases spontaneous inhibitory input to CA3 pyramidal neurones in neonatal rat hippocampal slices.

Whole-cell recordings were made from immature CA3 pyramidal neurones in the rat hippocampal slice. The addition of the glutamate receptor antagonist, CNQX, caused a robust increase in the frequency of spontaneous inhibitory post-synaptic currents (IPSC) concomitant with the expected reduction of excitatory drive to these neurones. This effect of CNQX was not shared by structurally related quinoxalinediones or kynurenic acid, which are also antagonists of non-NMDA glutamate receptors. This effect of CNQX was abolished by tetrodotoxin suggesting that an increase in interneurone spiking was responsible for the IPSCs. Recordings from stratum radiatum interneurones of CA3 confirmed this suggestion, since some interneurones were directly depolarized by CNQX. The excitation by CNQX of a small population of stratum radiatum interneurones of CA3 complicates interpretation of experiments designed to assess the consequences of blocking excitatory transmission with this drug.


Mechanisms of cholecystokinin-induced protection of cultured cortical neurons against N-methyl-D-aspartate receptor-mediated glutamate cytotoxicity.

The protective effects of cholecystokinin (CCK) against glutamate-induced cytotoxicity were examined using cultured neurons obtained from the rat cerebral cortex. Cell viability was significantly reduced when the cultures were briefly exposed to glutamate or N-methyl-D-aspartate (NMDA) and then incubated with normal medium for 60 min. A 60-min exposure to kainate also reduced cell viability. CCK protected cortical neurons against glutamate-, NMDA- and kainate-induced cytotoxicity. Glutamate- and NMDA-induced cytotoxicity was also reduced by N omega-nitro-L-arginine, a nitric oxide (NO) synthase inhibitor. However, CCK did not prevent the cytotoxic effects of sodium nitroprusside (SNP) which spontaneously releases NO. Moreover, CCK did not affect NMDA-induced Ca2+ influx measured with rhod-2, a fluorescent Ca2+ indicator. Therefore, release of a NO-like factor from the cerebral cortex was assayed using the thoracic artery in vitro. When the artery was incubated with minced cerebral tissues, glutamate elicited marked relaxation. SNP also elicited relaxation of the smooth muscle. CCK inhibited glutamate-induced relaxation but did not affect that induced by SNP. These results indicate that CCK prevents NMDA receptor-mediated cytotoxicity without reducing the Ca2+ influx. It is suggested that CCK inhibits NO-formation triggered by NMDA receptor activation.


Inhibition of glutamate release in rat hippocampus by kynurenic acid does not protect CA1 cells from forebrain ischemia.

We assessed the effect of a broad spectrum glutamatergic receptor antagonist, kynurenic acid (500 mg/kg) on ischemia-induced hippocampal glutamate release and neuronal damage. Kynurenic acid significantly decreased glutamate release during ischemia but had no effect on the hippocampal lesion. Some protection was observed in the cortex and in the striatum. These data suggested that the extracellular accumulation of glutamate during forebrain ischemia does not play a major role in the hippocampus.


Antagonism of limbic and extrapyramidal actions of intracerebrally injected dopamine by ergolines with partial D2 agonist activity in the rat.

Bromocriptine and a series of experimental ergoline D2 partial agonists (SDZ-208-911, SDZ-212-327, SDZ-208-912) were evaluated for their interactions with exogenous dopamine (DA, at ED50 = 16 micrograms) stereotaxically injected unilaterally into a limbic (superior-medial nucleus accumbens septi) or extrapyramidal (central corpus striatum) target site in rat brain. Behavioral measures to quantify responses were locomotor arousal induced by DA in accumbens and contralateral head turning with striatum. All agents, given systemically (i.p.), induced dose-dependent inhibition of behavioral responses to DA from both brain sites. In both accumbens and striatum, SDZ-212-327 was most potent and bromocriptine, least; however, bromocriptine was relatively much more potent in accumbens, and SDZ-208-912 somewhat more potent in striatum. These results add to the growing impression that agents with partial agonist actions at central DA receptors can show behaviorally inhibitory effects that may reflect paradoxical antidopaminergic actions against the full, natural agonist of DA receptors and that such effects can be regionally selective.


Immunohistochemical studies of noradrenergic-induced expression of c-fos in the rat CNS.

Previous studies have shown that stimulation of adrenergic receptors in the rat brain causes increased levels of mRNA of the immediate early gene, c-fos. The present studies were undertaken to determine if this stimulation also induces increased levels of c-fos immunoreactivity in the central nervous system (CNS). Rats were treated with the alpha-2 adrenoceptor blockers, yohimbine or atipamezole, or with restraint stress to activate central noradrenergic activity and were perfused 2 h later for immunohistochemical analysis of the cerebral cortex. Yohimbine, atipamezole and restraint stress each was found to cause increases in c-fos-like immunoreactivity (c-fos-li). Western blot analysis revealed increased c-fos protein in the cortex after yohimbine treatment. The c-fos-li response to yohimbine was blocked by prior administration of the beta receptor antagonist, dl-propranolol, and to a lesser degree by the alpha-1 antagonist, prazosin. It is concluded that adrenergic receptor stimulation in the cortex causes increased production of c-fos or fos related antigens and that this (these) immediate early gene product(s) may play a role in noradrenergic function in the CNS.


Do NMDA receptor antagonists protect against MPTP-toxicity? Biochemical and immunocytochemical analyses in black mice.

We investigated whether excitatory amino acids acting at the N-methyl-D-aspartate (NMDA) subtype of the L-glutamate receptor contribute to the dopaminergic neurotoxicity induced by systemic administration of the Parkinson's syndrome-inducing toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in C57Bl/6 mice. The MPTP-regimen chosen (30-40 mg/kg body weight subcutaneously) resulted a 60-70% depletion of striatal dopamine (DA) content and a 20% reduction of tyrosine hydroxylase immunoreactive (TH-IR) cells in the substantia nigra pars compacta 20 days after administration. Repeated systemic coadministration of the non-competitive NMDA receptor antagonist MK-801 or of the novel competitive NMDA receptor antagonist CGP 40116 did not protect against MPTP-induced striatal DA depletion 20 days after toxin administration. Additionally, no short-term protective effects of MK-801 on striatal DA content were observed 24, 48, and 96 h, respectively, after exposure to MPTP. A slight and non-significant attenuation (approximately 10%) of the MPTP-induced decrease in the number of nigral TH-IR cells was observed after MK-801- and CGP 40116-treatment. We conclude that neurotoxicity of systemically administered MPTP is not substantially antagonized by NMDA receptor antagonists in mice.


Glutamate immunoreactive terminals in the lateral amygdaloid nucleus: a possible substrate for emotional memory.

The ultrastructure and synaptic associations of terminals immunoreactive for L-glutamate (Glu) were examined in the lateral nucleus of the amygdala (AL). All results reported here involved tissue fixed only with paraformaldehyde. The specificity of the antiserum with paraformaldehyde fixation conditions was assessed and confirmed by immuno-dot blot analysis: the reactivity of anti-Glu to glutamic acid was at least 1,000 times greater than the reactivity to other amino acids. At the light microscopic level, Glu-immunoreactive punctate processes and somata were present in AL. At the electron microscopic level, many Glu-immunoreactive terminals were identified. Data analysis was performed on 365 of these labeled terminals. Glu-immunoreactive terminals were 0.3-1.5 microns in diameter and contained numerous small, clear vesicles as well as mitochondria. Many (77%) of the terminals analyzed had morphologically identifiable synaptic specializations. Most (90%) of the Glu-immunoreactive terminals with synaptic specializations formed asymmetric synapses on spines or small dendrites; synaptic specializations on soma or proximal dendrites were rarely seen (< 1%). Glu-immunoreactive terminals were qualitatively compared to terminals in AL labeled with two other antisera: anti-glutaminase, a marker for the enzyme that catalyzes the conversion of glutamine to the releasable or transmitter form of Glu, and anti-gamma-aminobutyric acid (anti-GABA), a marker for the major inhibitory amino acid transmitter in the brain. Terminals immunoreactive for glutaminase, like those immunoreactive for Glu, formed mostly asymmetric synaptic specializations on spines or small dendrites. In contrast, GABA-immunoreactive terminals usually formed symmetric synapses on soma or proximal dendrites and were never observed to form asymmetric axo-spinous contacts. Although Glu is a metabolic precursor to GABA, these data indicate that the majority of Glu-immunoreactive terminals reflect the site of synthesis and release of Glu and not of GABA. In addition, these results provide morphological evidence that Glu plays a role in excitatory neurotransmission at synapses in AL and support the growing body of data implicating excitatory amino acid-mediated synaptic plasticity in-emotional learning and memory processes in AL.


The role of nerve growth factor in collateral reinnervation by cutaneous C-fibres in the rat.

We have investigated whether chronic nerve growth factor (NGF) depletion affects the development of transmedian collateral reinnervation by C-fibres. Using a dye-labelled plasma extravasation technique in rats, the extent of transmedian innervation of the skin by C-fibres in the inferior alveolar nerve (IAN) was determined 8-10 weeks after sectioning and preventing regeneration of the contralateral IAN. Another group of animals were immunised against NGF prior to the nerve section and a third group acted as unoperated controls. A small but significant transmedian collateral reinnervation by C-fibres developed after contralateral denervation alone, but was not found in the animals also immunised against NGF. These results suggest that NGF is essential for the development of collateral reinnervation from cutaneous C-fibres.


Dissociation of mu and delta opioid receptor-mediated reductions in evoked and spontaneous synaptic inhibition in the rat hippocampus in vitro.

Modulation of gamma-aminobutyric acid (GABA)-mediated inhibition, and glutamate-mediated excitation by highly selective mu and delta opioid agonists was studied using intracellular recordings of CA1 pyramidal neuron synaptic responses in superfused hippocampal slices. Equimolar concentrations of the selective mu agonist, [Tyr-(D-Ala)-Gly-(N-Me-Phe)-Gly-ol]-enkephalin (DAGO), or the delta selective agonist, [D-Pen2,D-Pen5]-enkephalin (DPDPE), reversibly increased the amplitudes of excitatory post-synaptic potentials (EPSPs), evoked by Schaffer collateral/commissural stimulation, without altering the input resistance or resting membrane potential of these CA1 pyramidal neurons. The increased EPSP amplitudes resulting from superfusion with the enkephalin analogs were qualitatively similar to those caused by the GABAA receptor antagonist, bicuculline methiodide (BMI). Specific stimulation/recording protocols and micro-lesions of the slices were used to evoke relatively pure forms of recurrent and feed-forward GABA-mediated inhibitory post-synaptic potentials (IPSPs). The mu opioid agonist DAGO reduced both recurrent and feed-forward IPSPs, while the delta agonist DPDPE had no effect upon these responses. To test the hypothesis that the enhancement of pyramidal neuron EPSPs by delta (and mu) opioids was due to the reduction of an inhibitory potential that was coincident with the EPSP, DPDPE or the mu agonist, DAGO, were applied while recording monosynaptic IPSPs following the elimination of EPSPs by the glutamate receptor antagonists, D,L-2-amino-5-phosphonovalerate (APV) and 6,7-dinitroquinoxaline-2,3-dione (DNQX). The mu agonist, DAGO, reversibly reduced these pharmacologically isolated IPSPs, while the delta agonist, DPDPE, had no effect upon these responses. Despite the fact that the delta agonist, DPDPE, had no effect on recurrent, feed-forward or monosynaptic evoked IPSPs, this enkephalin did reversibly reduce the frequency of spontaneously occurring IPSPs, measured using whole-cell recordings with pipettes containing 65 mM KCl. The mu agonist, DAGO, and the GABAA antagonist, BMI, similarly reduced spontaneous IPSP rates. We conclude from these data that mu and delta opioid receptor activation increases EPSPs via the reduction of a form of GABAergic inhibition that is difficult to characterize, and which may be distinct from conventional feed-forward and recurrent inhibition. Furthermore, delta opioids seem to reduce this form of GABAergic inhibition selectively, while mu opioids reduced this inhibition, and conventional feed-forward and recurrent IPSPs as well.


Synergistic and persistent interaction between the D2 agonist, bromocriptine, and the D1 selective agonist, CY 208-243.

In mice pretreated with reserpine and alpha-methyl-DL-p-tyrosine (alpha MPT) to deplete central catecholamines, the D2 dopamine receptor-selective agonist, bromocriptine, at a dose of 10 mg/kg produced no locomotor activity. The D1-selective agonist, CY 208-243, generated a dose-dependent locomotor response in this animal model for Parkinson's disease; low doses elicited little or no effect while higher doses resulted in a short burst of locomotor activity (2 h). The combination of CY 208-243 and bromocriptine had a dramatic synergistic effect on locomotion. Most importantly, this combination of D1 and D2 agonists converted a brief (2 h) effect on locomotion to one which persisted for up to 6 h. These results suggest that the combination of D1 and D2 dopamine receptor agonists can affect both the intensity and the persistence of a locomotor response.


Trans-ACPD-induced phosphoinositide hydrolysis and modulation of hippocampal pyramidal cell excitability do not undergo parallel developmental regulation.

The selective metabotropic glutamate receptor agonist, trans-1-aminocyclopentane-1,3-dicarboxylic acid (trans-ACPD), stimulates phosphoinositide hydrolysis and elicits a number of electrophysiological responses in the hippocampus. If these effects are mediated by the same receptor subtype, they should undergo parallel developmental regulation. Therefore, we compared the phosphoinositide hydrolysis response and the electrophysiological responses to trans-ACPD at two different developmental stages. Trans-ACPD-stimulated phosphoinositide hydrolysis was significantly greater in hippocampal slices from immature (6-11-day-old) rats than from adults. In contrast, trans-ACPD elicited decreases in spike frequency adaptation and in the amplitude of the slow afterhyperpolarization in roughly equal percentages of immature and adult CA1 pyramidal cells. Similar results were obtained using the putative endogenous agonist, glutamate. These data support the hypothesis that certain electrophysiological effects of trans-ACPD are mediated by a metabotropic glutamate receptor that is distinct from the phosphoinositide hydrolysis-linked glutamate receptor.


NMDA receptors in the nucleus accumbens modulate intravenous cocaine but not heroin self-administration in the rat.

The role of endogenous glutamate neurotransmission within the nucleus accumbens in the modulation of intravenous (i.v.) cocaine and heroin self-administration in rats was analyzed. APV (2-amino-5-phosphonovaleric acid), a blocker of glutamate receptors of the N-methyl-D-aspartate (NMDA) type, was microinfused within the nucleus accumbens of the ventral striatum of rats trained to lever press for i.v. cocaine or heroin self-administration. APV, at the dose of 1.5 and 3.0 micrograms/side, reduced the rewarding value of cocaine while it left heroin self-administration unaffected. These results suggest that integrity of NMDA receptor function within the nucleus accumbens may be of importance for the maintenance of i.v. cocaine, but not heroin self-administration in rats.


Sustained enhancement of NMDA receptor-mediated synaptic potential by isoproterenol in rat amygdalar slices.

The effect of isoproterenol (Iso) on synaptic transmission mediated by the N-methyl-D-aspartate (NMDA) receptors (EPSPNMDA) was investigated in slices of rat amygdala using intracellular recording techniques. EPSPNMDA was isolated pharmacologically by application of a solution containing the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10 microM) and GABAA receptor blocker bicuculline (20 microM). Superfusion of Iso (15 microM) produced a long-lasting enhancement of EPSPNMDA. Pretreatment the slices with propranolol (10 microM) completely prevented the effect of Iso confirming the mediation by beta-adrenergic receptors. These results provide the direct evidence for adrenergic modulation of excitatory amino acid neurotransmission in the vertebrate central nervous system.


Regional distribution of glutamate and aspartate in adult and old human brain.

In previous studies on rat brain we found that the observed heterogeneity of the regional distribution of amino acids was much greater when small well-defined anatomical structures were assayed. We therefore reinvestigated the distribution of glutamate and aspartate in 50 discrete areas from adult and old human brain. The concentration of glutamate in the area of highest level was 4.5 and 4.7 times as high as in the area of lowest level in adult and old brain respectively; for aspartate these values were 3.0 and 6.6. Several changes in old brain were noted. The human pattern differed from that in rat.


Pharmacological characterization of lower esophageal sphincter relaxation induced by swallowing, vagal efferent nerve stimulation, and esophageal distention.

To characterize the neural pathways involved in lower esophageal sphincter relaxation, intraluminal pressures from the lower esophageal sphincter of the opossum were monitored during swallowing, vagal efferent nerve stimulation, and intraluminal balloon distention in the presence and absence of pharmacologic antagonism of putative neurotransmitters. The combination of atropine, hexamethonium, and 5-methoxydimethyltryptamine, which is known to block ganglionic transmission in the vagal inhibitory pathway to the lower esophageal sphincter, significantly antagonized LES relaxation induced by both swallowing and vagal stimulation, but did not affect the LES relaxation induced by balloon distention. Administration of the nitric oxide synthase inhibitor N omega nitro-L-arginine methyl ester, on the other hand, markedly inhibited LES relaxation induced by vagal stimulation, swallowing, and balloon distention, and this effect was reversed by administration of the nitric oxide synthase substrate L-arginine. These studies indicate that the distension-induced intramural pathway mediating LES relaxation does not involve ganglionic transmission similar to that of the vagal inhibitory pathway to the LES. However, the LES relaxation induced by all forms of stimuli appears to depend on nitric oxide as a final mediator.


Expression of the HER-2/neu proto-oncogene in serous ovarian neoplasms.

It is unclear whether HER-2/neu proto-oncogene expression in ovarian epithelial neoplasms is related to prognosis. The authors performed immunohistochemical stains on 20 serous tumors of low malignant potential (STLMP) in Stages I and II and 19 serious carcinomas in the same stages. They used three different commercial antibodies to make comparisons. Two of four Stage I STLMP in patients who experienced disease progression showed positive staining for the gene product, whereas none of seven Stage I nonprogressive STLMP showed positive staining. Five of the six Stage III nonprogressive STLMP showed positive staining, whereas none of three Stage III STLMP that progressed showed positive staining. Three carcinomas (one Stage I and two Stage III) also showed positive staining. Expression of HER-2/neu may be associated with high stage in serous ovarian neoplasms, but it is not likely to identify the small fraction of patients with STLMP who will experience disease progression.


Characterization of a B-cell immunodominant epitope of human T-lymphotropic virus type 1 (HTLV-I) envelope gp46.

The immune response elicited by a synthetic peptide derived from an immunodominant external envelope region (Env-5, amino acids 242-257) of human T-lymphotropic virus type 1 (HTLV-I) was tested in a rabbit model of HTLV-I infection. The synthetic peptide elicited a strong antibody response to the HTLV-I envelope protein gp46; however, these antibodies failed to inhibit HTLV-I-mediated cell fusion. Immunized rabbits were not protected from HTLV-I infection as determined by seroconversion to viral core proteins by immunoblot, HTLV-I p24 antigen detection in lymphocyte cultures and polymerase chain reaction for the HTLV-I provirus in lymphocyte DNA. Env-5 peptide immunization failed to induce T-cell lymphocyte proliferative responses in rabbits, but induced antibody responses in T-cell deficient Balb c nu/nu mice suggesting that the antigenic determinant represented by the Env-5 peptide is primarily a B-cell epitope. These results further define an immunodominant epitope of the HTLV-I envelope protein and suggest that potential synthetic peptide vaccines against HTLV-I infection must contain multiple antigens that induce both humoral and cellular immune reactivity.


Dual colour flow cytometry of p53 and c-erbB-2 expression related to DNA aneuploidy in primary and metastatic breast cancer.

DNA aneuploidy and p53 or c-erbB-2 expression were simultaneously measured in 29 breast tumours by two-colour flow cytometry. (i) The majority of tumours had some cells expressing either p53 (5-68%) or c-erbB-2 (1-56%). (ii) Expression of p53 and c-erbB-2 was observed mainly in the aneuploid population of mixed aneuploid and diploid tumours but there was no significant correlation with a specific DNA index. Aneuploid tumours contained higher percentages of c-erbB-2 positive cells (average 25%) than purely diploid tumours (average 15%) but this just failed to reach significance (P = 0.074). No relevant trends were noted for p53 expression. (iii) Significantly increased c-erbB-2 expression was observed in stage 2 tumours (26%) compared to stage 1 tumours (12%) (P = 0.001) with no trend evident for p53 expression. (iv) The metastatic tumour in the axillary node contained similar or slightly higher percentages of positive cells than the matched primary tumour.


Anticarcinogenic action of diallyl sulfide in hamster buccal pouch and forestomach.

The anticarcinogenic action of the garlic constituent diallyl sulfide (DAS), was examined in the hamster buccal pouch and forestomach. Groups of hamsters were topically treated, for up to 14 weeks, with a 0.5% solution of the buccal pouch and forestomach carcinogen 7,12-dimethylbenz[a]anthracene (DMBA). Prior to, during and after DMBA treatment, groups of hamsters were also treated, on alternate days, with a 1% solution of DAS. In addition to tumor formation, the induction of gamma-glutamyl transpeptidase (gamma GT) buccal pouch epithelial lesions served as an additional presumptive index of in vivo carcinogenesis/anticarcinogenesis. DAS resulted in a significant reduction in buccal pouch tumor frequency, buccal pouch tumor burden, buccal pouch gamma GT lesion frequency and forestomach tumor frequency. In a separate experiment, DAS also reduced the level of autoradiographically quantified unscheduled DNA repair synthesis (UDS) in pieces of hamster buccal pouch concurrently exposed in vitro to the potent buccal pouch carcinogen N-methyl-N-benzylnitrosamine (MBN). This study demonstrates that DAS is an effective anticarcinogenic agent in squamous mucosa of the hamster and suggests novel cost-effective strategies for the rapid identification of tissue-specific anticarcinogens and a quantitative assessment of their efficacy.


Clinical outcome of acute myocardial infarction in patients on treatment with beta-blockers or calcium antagonists. A study of 7,922 hospitalized first myocardial infarctions.

To assess the effects of current treatments with beta-blockers or calcium antagonists on the clinical outcome of acute myocardial infarction (MI), enzymatically estimated infarct sizes, circulatory arrests from ventricular tachyarrhythmias, ventricular tachycardia (VT)/ventricular fibrillation (VF), and in-hospital mortality were analyzed retrospectively from 7,922 citizens of Malmö, Sweden, hospitalized due to a first MI between 1973 and 1987. Of these patients, 296 were on treatment with calcium antagonists, 393 on treatment with a beta 1-selective beta-blocker, 482 with a nonselective beta-blocker, and 95 on combined treatment with beta-blockers and calcium antagonists at the time of admission to hospital. In a set of multivariate analyses including several clinical characteristics, patients on treatment with a nonselective beta-blocker had a significantly lower peak aspartate aminotransferase (ASAT; difference -0.70 mukat/l, 95% CL: -1.24 to -0.16), whereas no significant relations between peak ASAT and treatment with cardioselective beta-blockers or calcium antagonists were found. Treatment with cardioselective beta-blockers or calcium antagonists, in contrast to treatment with a nonselective beta-blocker, were significant predictors of the occurrence of circulatory arrests from VT/VF. The relative risk of VT/VF in patients on cardioselective beta-blockers was 1.51 (95% CI: 1.12-2.03), and in patients on calcium antagonists 1.44 (95% CI: 1.03-2.02). None of the treatments were significantly associated with in-hospital mortality. In patients on beta-blockers or calcium antagonists when suffering their first MI, nonselective beta-blockade may reduce infarct size. Treatment with beta-blockers or calcium antagonists identified patients with an increased risk of circulatory arrests from VT/VF, but neither of the treatments were significantly associated with in-hospital mortality. We suggest that only minor differences exist between the effects of chronic treatment with beta-blockers and calcium antagonists on the outcome of an acute MI.


beta Adrenergic receptor desensitisation may serve a cardioprotective role.

The aim was to test the hypothesis that beta adrenoceptor desensitisation is a form of cardioprotection whereby the myocardium is protected from the injurious effects of excessive adrenergic stimulation by isoprenaline. A new sensitive and specific method of identifying cardiac myocyte necrosis with monoclonal antimyosin was employed. Antibody labelled necrotic cardiomyocytes from male Sprague-Dawley rats (190-300 g) were identified by immunofluorescence. Homologous beta adrenoceptor desensitisation was induced by 9 d pretreatment with isoprenaline infusion (20 mg.kg-1.d-1), and heterologous desensitisation by treatment with 0.15% propylthiouracil in the diet for six weeks. The effects of isoprenaline induced cardiomyocyte injury in these animals were compared with those in control rats. In euthyroid control rats, treatment with the beta adrenergic agonist, isoprenaline, produced prolonged tachycardia and hypotension, and a significant amount of cardiac myocyte necrosis subendocardially. When the same isoprenaline challenge was given to rats pretreated for 9 d with an isoprenaline infusion, the haemodynamic response was markedly attenuated and very little myocyte necrosis was noted. In the model of heterologous desensitisation occurring in hypothyroidism, isoprenaline challenge produced markedly diminished haemodynamic response and little cardiac myocyte necrosis. In both homologous and heterologous models of beta adrenoceptor desensitisation, the susceptibility of the myocardium to isoprenaline induced cytotoxicity is markedly reduced.


Vascular atrial natriuretic factor receptors in spontaneously hypertensive rats.

The aim was to investigate vascular receptors for atrial natriuretic factor (ANF) in spontaneously hypertensive (SHR), Wistar-Kyoto (WKY), and Wistar rats (WR) at different ages. Relaxation and guanylate cyclase responses of blood vessels to atrial natriuretic factor were investigated, as was the binding of 125I-ANF to vascular membranes and ANF receptor subtypes, using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) in reducing conditions, after solubilisation and irreversible binding of 125I-ANF. Vascular relaxation responses of aorta showed an increased sensitivity to ANF in four week old SHR [pD2 = 8.9 (SEM 0.1) v 8.5(0.1) in WKY rats, p < 0.05] while sensitivity was similar for the three strains at older ages. Production of cyclic GMP in mesenteric arteries in response to 100 nmol.litre-1 ANF was greater (p < 0.05) in SHR than in WKY rats at four weeks of age, but was similar in older rats. The density of binding sites for ANF in mesenteric arteries, however, was lower in SHR at four weeks (p < 0.01), and increased in older rats, becoming similar to that of normotensive rats at 12 weeks of age. Affinity of ANF sites was similar in all strains. The proportion of high and low molecular weight ANF binding peptides in solubilised blood vessel membranes on SDS-PAGE was similar in all strains except in four week old SHR, in which binding to the high molecular weight band (presumably the guanylate cyclase containing receptor) was increased relative to the low molecular weight band (non-cyclase-coupled receptor) in comparison to other strains and ages. Activity of guanylate cyclase in response to occupancy of ANF receptors may be increased in young SHR. Normal relaxation of blood vessels in response to ANF in older SHR could result in failure to counteract the increased vasoconstrictor activity present in these rats, which could play a role in the increase in blood pressure.


Catecholaminergic cells and fibers in the brain of the lizard Anolis carolinensis identified by traditional as well as whole-mount immunohistochemistry.

Using traditional as well as whole-mount immunohistochemistry, we described the location of tyrosine hydroxylase- and dopamine beta hydroxylase-positive cells and fibers in the brain of the lizard Anolis carolinensis. Major catecholaminergic cell groups were in the ependyma in certain ventricular regions, along the periventricular floor in the preoptic region, within the anterior hypothalamic and lateral hypothalamic areas, and in the mesencephalic tegmental region, locus coeruleus, nucleus of the solitary tract, vagal motor nucleus, and rhombencephalic reticular formation. Major catecholaminergic fibers, tracts and varicosities included tuberohypophysial, mesolimbic, nigrostriatal, isthmocortical, medullohypothalamic, and coeruleospinal systems. Although the catecholaminergic systems in A. carolinensis are similar to those in the brains of other lizards studied, there are a few species differences. Our information about A. carolinensis will be used to help localize the hypothalamic asymmetry in catecholamine metabolism previously described in this lizard.


Role of CD11a/CD18-CD54 interactions in suppression of human B cell responsiveness by CD4+ suppressor T cells.

The role of leukocyte function-associated Ag-1 (LFA-1, CD11a/CD18) and intercellular adhesion molecule 1 (ICAM-1, CD54) interactions in the suppression of human B cell function by immobilized anti-CD3-activated CD4+ T cells was examined by studying the effects of mAb to these determinants. The suppressive activity was assessed by the effects of CD4+ T cells without mitomycin C treatment activated by immobilized anti-CD3 for 72 hr on the differentiation into Ig-secreting cells of B cells activated for 72 hr with immobilized anti-CD3-stimulated CD4+ T cells that had been treated with mitomycin C (T4 mito). Suppression was not observed when activated CD4+ T cells and B cells were separated by filter membranes, indicating that the suppression requires the direct interactions between anti-CD3-activated CD4+ T cells and activated B cells. In this model system, mAb to either the alpha (CD11a) or beta (CD18) chain of LFA-1 or ICAM-1 (CD54) reversed the suppression of B cell function by suppressor CD4+ T cells significantly. Reversal of suppression of B cell function was most marked when activated B cells were treated with mAb to ICAM-1 and suppressor CD4+ T cells were treated with mAb to LFA-1, but not vice versa. Studies using fluorescence-activated cell sorter revealed marked increase of expression of ICAM-1 on B cells after 72 hr of activation with immobilized anti-CD3-stimulated T4 mito. These results indicate that the interactions between LFA-1 and ICAM-1 play an important role in mediating the suppressive activity of anti-CD3-activated CD4+ T cells to B cells. Moreover, the data are consistent with a model of T-cell-mediated B cell suppression in which interactions between LFA-1 on suppressor T cells and ICAM-1 on activated B cells play a central role in the suppression of B cell function.


Continuous infusions of atracurium and vecuronium, compared with intermittent boluses of pancuronium: dose requirements and reversal.

This study was designed to determine the effect of prolonged infusion on the ease of reversal of atracurium and vecuronium, and whether factors which potentiate the block delayed reversal. In phase one, 40 patients were randomized (double blind) to determine the steady state conditions for atracurium and vecuronium. Fourteen atracurium patients and 17 vecuronium patients were evaluable. The unblinded second phase involved the steady state conditions using halothane or isoflurane and atracurium infusions. The infusion required for 95% twitch depression (TD95) for atracurium was 7.6 +/- 1.1 micrograms.kg-1 x min-1. The requirement for vecuronium changes with time: TD95 at 30 min was 1.01 +/- 0.16, at 60 min 0.89 +/- 0.12 and after 90 min 0.85 +/- 0.17 micrograms.kg-1 x min-1 (P < 0.05). The mean TD95 was 0.94 +/- 0.23 micrograms.kg-1 x min-1. Multivariate regression analysis of the infusion data revealed a vecuronium model predicting TD95 by the duration of infusion (P < 0.05) and weight (P = 0.05). Atracurium TD95 was predicted by age (P = 0.05). The addition of an inhalation agent to atracurium reduced the infusion rate by 2.01 +/- 0.28 micrograms.kg-1 x min-1 (P = 0.0001) for each increase in MAC. The mean reversal times for atracurium with three different anaesthetics and for vecuronium were not different. Reversal of pancuronium blockade, from less profound twitch depression (86.4 vs 95%) took twice as long as for atracurium and vecuronium for which the following predictors were identified: age, weight, duration of infusion, level of blockade, and type of anaesthetic, using a stepwise regression model.(ABSTRACT TRUNCATED AT 250 WORDS)


Postoperative analgesia: opioid infusions in infants and children.

The purpose of this review is to emphasise the ineffectiveness of traditional analgesic therapy in paediatric patients after surgery, to examine the sensation of pain in infants and children, and to describe the use of intravenous opioids for postoperative analgesia. The management of acute postoperative pain in the paediatric surgical population has been poor. This is despite the knowledge that infants and children have sufficient neurological development at birth to sense pain, and that the same hormonal and metabolic responses to nociceptive stimuli that occur in adult also occur in the neonate. Physicians frequently order analgesics in inappropriate doses, nurses are reluctant to administer opioids, and children themselves frequently compound the problem by refusing injections. The sophisticated techniques for providing postoperative analgesia which have been used so successfully in adults can also be used in paediatric patients. Two of these, continuous intravenous opioid infusion and patient-controlled analgesia, have proved to be very successful. Children older than six months can receive either modality safely with regular monitoring by qualified nursing staff. Infants younger than six months receiving continuous opioid infusions should be monitored in high-dependency units.


Epinephrine augments von Willebrand factor-dependent shear-induced platelet aggregation.

Shear-induced platelet aggregation (SIPA) is an important mechanism in thrombogenesis. von Willebrand factor (vWF) binding to platelet glycoprotein Ib (GP Ib) has been found to be crucial for platelet aggregation under the high shear force probably generated in stenosed coronary artery. The physiological significance of vWF-dependent SIPA has not been clarified. Blood samples were collected from 23 normal volunteers. SIPA was continuously monitored using a modified cone-plate viscometer adapted for measuring the transmitted light intensity of the material. The effects of low concentrations of epinephrine, ADP, and collagen on SIPA under both low shear (12 dyne/cm2) and high shear (108 dyne/cm2) force were investigated. All agonists tested enhanced SIPA under low shear force, whereas only epinephrine augmented SIPA under high shear force. The maximum extents of SIPA under high shear force in the absence and presence of epinephrine (10 ng/ml) were 37.9 +/- 11.5% and 59.7 +/- 13.9%, respectively. The antagonist of the alpha 2-adrenergic receptor yohimbine (1 microgram/ml) antagonized the effects of epinephrine. The monoclonal antibody NMC-4 against vWF, which was shown to inhibit its binding to GP Ib, completely abolished SIPA under high shear force, even in the presence of epinephrine. However, this antibody only partially inhibited SIPA under low shear force. Our findings suggest that epinephrine is the agonist that enhances SIPA mediated by vWF through its specific receptor. This may be clinically important because occlusion of the coronary artery often occurs in stenosed atherosclerotic vessels under sympathetic stimulation.


Lymphocyte subsets in HTLV-II-infected former blood donors: relationship to spontaneous lymphocyte proliferation.

Previous studies showed that over 70% of HTLV-seropositive blood donors from the Los Angeles area are infected with HTLV-II; further, mononuclear cells from about half of these HTLV-II+ donors exhibit spontaneous lymphocyte proliferation (SLP) during in vitro culture. To determine if HTLV-II+SLP+ donors exhibit more marked immune system changes than HTLV-II+SLP- donors, lymphocyte subsets for these two HTLV-II+ groups were compared to an uninfected control group. The percentage of lymphocytes expressing CD3 was significantly increased and the percentage expressing a CD16/56+CD3- phenotype (natural killer cells) was significantly decreased in the HTLV-II+SLP+ group (N = 34) versus the control group (N = 49). On the basis of absolute numbers, the lymphocyte number was significantly higher in the HTLV-II+SLP+ group than in the control group and reflected significant increases in the numbers of both CD4 and CD8 subsets of T cells. Analysis of proportional changes in CD4 and CD8 cell subsets revealed significant increases in the proportions of CD4 cells expressing HLA-DR, CD8 cells expressing HLA-DR, and CD8 cells expressing CD45RO for the HTLV-II+SLP+ group versus the control group. For all phenotypic parameters measured, no significant differences were noted when comparing the HTLV-II+SLP- group (N = 21) and the control group. Cell culture experiments utilizing purified CD4 cells and CD8 cells from a subset of each study group revealed that in vitro spontaneous proliferative capacity resides within both the CD4 cell and CD8 cell populations from SLP+ individuals. These findings show that changes in circulating lymphocyte subsets in HTLV-II infection are found only in association with SLP, and that the capacity to exhibit SLP characterizes both CD4 and CD8 lymphocyte subsets.


The role of T-cell subsets in the response to anti-CD3 monoclonal antibodies.

Administration of monoclonal antibodies (mAb) to CD3 elicits an immune response to the mAb and an acute toxic syndrome that has been attributed to the release of cytokines from activated T cells. To clarify the cellular basis for these effects, we used anti-lymphocyte mAb to deplete selected T-cell subsets from BALB/c mice prior to administration of anti-CD3. In our first series of experiments, anti-CD4 repeatedly blocked the immune response to anti-CD3, but did not prevent severe toxicity. This observation suggested that other T-cell subsets might contribute to anti-CD3 induced toxicity. Therefore, we treated mice with mAb to CD8 as well as mAb to CD4 prior to administration of anti-CD3. Despite depletion of > 95% of CD8+ and CD4+ T cells, toxicity was not suppressed. This finding cast doubt on the belief that toxicity is due to activation of either CD4+ or CD8+ T cells by anti-CD3. Therefore, we assessed the role of thymocytes (which are not deleted by the mAb) and gamma delta + T cells. Thymectomy did not prevent toxicity in CD4/CD8-depleted mice, demonstrating that thymocytes are not responsible for toxicity. Anti-alpha beta TCR mAb produced a toxic reaction similar to anti-CD3 whereas anti-gamma delta TCR mAb did not, suggesting that gamma delta+ T cells are not the source of toxic cytokines. In addition, we proved that anti-CD3-induced toxicity was not due to direct effects on macrophages or to other nonspecific factors associated with the hamster mAb. These findings imply that a few residual mature T cells in mice treated with mAb to CD4 and CD8 are sufficient for the full expression of the anti-CD3-induced toxic syndrome. To confirm that both CD4+ and CD8+ T cells can mediate toxicity, we showed that:(i) SCID mice, which normally do not develop anti-CD3-induced toxicity, can be rendered susceptible by reconstitution with purified CD4+ T cells; and (ii) CD4-knockout mice that lack CD4+ T cells but have normal CD8+ T cells are susceptible to anti-CD3-induced toxicity. These findings establish that both CD4+ and CD8+ cells contribute to the toxic effects of anti-CD3, and that relatively few cells are required to mediate the full effect.


Induction of intercellular adhesion molecule-1 (CD54) on isolated mouse pancreatic beta cells by inflammatory cytokines.

Insulin-dependent diabetes mellitus (IDDM) results from a T cell-dependent autoimmune destruction of insulin-producing pancreatic beta cells. In the present study, expression of adhesion molecule ICAM-1 (CD54) on pancreatic beta cells was studied in normal, obese hyperglycemic (ob/ob), and nonobese diabetic (NOD) mice. Freshly isolated pancreatic beta cells from ob/ob mice did not express ICAM-1, but treatment of the cells with IL-1-beta, TNF-alpha, or INF-gamma strongly induced its expression as measured by immunofluorescence flow cytometry. The cytokines acted in a dose- and time-dependent manner. Maximal induction by either cytokine occurred at 24 hr and thereafter expression decreased, except for INF-gamma. Immunoprecipitation from IL-1-beta-treated beta cells demonstrated a cell-surface glycoprotein with an apparent molecular weight of 95 kDa. ICAM-1 expression was undetectable on pancreatic beta cells of normal and ob/ob mice as measured by immunohistochemistry. In NOD mice at different ages (1 to 6 months) ICAM-1 was also undetectable on beta cells, in contrast to the strong expression on infiltrating mononuclear cells. The present study indicates that mouse pancreatic beta cells, under certain conditions, can express ICAM-1.


Effects of arginine vasotocin on cardiorespiratory and thermoregulatory responses in the pigeon.

1. The effects of intramuscular injections (10 ng, 100 ng, 1 mu or 10 mu/pigeon) of two preparations of synthetic arginine vasotocin (AVT), deamino-dicarba-arginine vasotocin (ddAVT) and arginine vasotocin diacetate tetrahydrate (AVTdt) on heart rate (HR), breathing frequency (BF), oxygen consumption (VO2), cloacal and foot temperatures (Tc and Tf) and shivering (S) were studied in the pigeon housed in a respiratory flow chamber maintained at a temperature of 22.5 degrees, during a 4 hr post-injection period. 2. In general, with the exception of the lowest dose, AVT-treatment produced hypothermic responses, as was indicated by Tc and Tf. 3. Both ddAVT and AVTdt produced increases in HR and BF when administered in high concentrations (10 micrograms/pigeon), the effect being more potent with AVTdt than ddAVT; with lower doses, the effects were considerably less pronounced. This increase in HR and BF is attributed to a probable compensatory response to the hypothermic effect. 4. With a 10 micrograms dose, ddAVT produced a greater decline in VO2 than AVTdt. Although other doses too evoked a drop in VO2 at certain post-injection time points, the effect was of lesser magnitude. 5. No significant shivering response was elicited, in spite of the drop in Tc. 6. It is suggested that, besides the antidiuretic function of AVT, its hypothermic effect would be of considerable importance in thermal homeostasis during flight in birds.


Trace metal (Cu and Zn) adaptation of organ systems of the American eel, Anguilla rostrata, to external concentrations of cadmium.

1. The impact of external cadmium on the concentrations of cadmium (Cd), copper (Cu) and zinc (Zn) in seven tissues of the American eel, Anguilla rostrata was investigated. Even after a week in freshwater with undetectable levels of Cd, the tissues of eels caught in fresh and/or brackish waters of the United States east coast contained Cd in kidney, liver, gut, and brain. 2. When the eels were exposed up to 16 weeks to low and high sublethal concentrations of Cd (75 and 150 micrograms/l, respectively), the highest tissue concentrations of Cd were found after two weeks of exposure. The accumulation was dose-related in all tissues studied except for the kidney. After 8 weeks of Cd exposure, the tissue levels of Cd were markedly reduced, and they were in a similarly low range after 16 weeks. At this time, the highest Cd concentrations were found in the gills and kidney. 3. After two weeks of Cd exposure, there was a drop of the tissue concentrations of Cu in liver and heart, and of Zn in gut and liver. The low concentrations of the two metals in other organs did not allow an evaluation of the Cd impact. After 16 weeks, the Cu concentrations in all tissues, with the exception of the liver, were similar to, or even higher than control levels. At the same time, Zn concentrations exceeded the control levels in heart and kidney of eels exposed to 75 and 150 micrograms Cd/l, respectively. 4. It is clear that some tissues of the eel are able to maintain or restore normal levels of Cu and Zn, up to 16 weeks, despite concomitant Cd accumulation.


Inhibition of eggshell formation in domestic fowl by indomethacin: relation to calcium and prostaglandin metabolism in the eggshell gland mucosa.

1. The involvement of prostaglandins in eggshell formation in the domestic fowl was investigated by considering the effects of the drug indomethacin on the calcium metabolism on the eggshell gland. Egglaying birds were given a single dose (100 mg) of indomethacin at the beginning of shell calcification. Fourteen hours later the birds were sacrificed and the effects of the drug were determined. There was a 21% reduction in the shell thickness of the egg present in the shell gland at the time of slaughter (P < 0.01). The calcium content of the eggshell gland mucosa was increased to 153% (P < 0.01) of the controls. In the treated birds, there was 43% more calcium (P < 0.05) present in the shell gland lumen (recovered by rinsing with Tris buffer) than in the gland lumen of control birds. Total calcium in blood plasma was decreased by 15% (P < 0.05). In homogenate and three subcellular fractions (MIII, FI and FIII) of eggshell gland mucosa, 45Ca uptake was significantly reduced (i.e. by 29%, 25%, 17% and 35%, respectively). A significant reduction (62-66%) was also observed in the synthesis of PGF2 alpha, PGE2 and TxB2 by eggshell gland mucosa homogenate. 2. The effects of indomethacin treatment on the calcium metabolism of the avian eggshell gland are discussed and compared with p,p-DDE-induced alterations in calcium metabolism and prostaglandin synthesis by the eggshell gland.


Binding of tricyclic antidepressant drugs to trophozoites of Giardia lamblia.

1. Parameters affecting the binding of the tricyclic drugs imipramine and 3-chloroimipramine to Giardia lamblia trophozoites were studied. 2. Two to three times more chlorimipramine than imipramine was bound, consistent with a similar difference in suppressing parasite growth (Weinbach et al., 1985). 3. Kinetic analysis and the ease with which bound drugs can be washed out of the parasites indicate that noncovalent forces are involved in the drug-parasite interaction. 4. Evidence is presented that such drugs probably bind to parasite protein at common binding sites. 5. The data relate to our earlier observation that chlorimipramine is about ten times more effective than metronidazole (Crouch et al., 1986) in suppressing G. lamblia growth in vitro. Tricyclic drugs, therefore, merit serious consideration as novel therapeutic agents against giardiasis.


Studies on carbohydrates extracted from native and chemically treated Biomphalaria alexandrina snails.

1. Carbohydrates were extracted from total tissue extracts of Biomphalaria alexandrina snails and were analyzed to their monosaccharides using GLC. 2. The snails were chemically treated with thioxanthone derivatives (compounds I, II, III) and the change in the monosaccharide constituents of their carbohydrates was investigated. 3. The isolated monosaccharides from native and chemically pretreated snails were injected into mice and their protective effects were examined after infection of mice with cercariae of Schistosoma mansoni. 4. The results showed that the main monosaccharides in carbohydrates of snails were galactose, glucose, fucose and mannose and that chemical treatment caused a drop in the galactose content. 5. Moreover, monosaccharide fractions from snails treated with compound III were the most effective in inducing protection against Schistosoma infection in mice.


Regulation of porcine adipose tissue lipolytic activity by adrenergic agonists and antagonists.

1. Several beta-adrenergic agonists yielded quantitatively and qualitatively different lipolytic potencies and efficacies when incubated with porcine adipose tissue slices in the presence and absence of theophylline in vitro. Some agonists were inactive without theophylline but were active with theophylline. 2. However, activity in vitro measured with theophylline was no more closely related to acute observations in vivo than activity measured in vitro without theophylline. 3. Classification of receptor subtypes or agonists and antagonists as specific for receptor subtypes could be totally different in the presence and absence of theophylline, depending on the specific agonists or antagonists selected for such studies in vitro.


Cadmium inhibits stimulus-response coupling in skate (Raja erinacea) electric organ.

1. The effects of cadmium on stimulus-response coupling in the skate (Raja erinacea) electric organ were examined. 2. Cadmium decreased the evoked electrical discharge and the evoked release of 3H-ACh in a concentration-related fashion. 3. Cadmium (100 microM) also blocked voltage-dependent 45Ca uptake. 4. Both d-tubocurarine and nifedipine blocked Ca uptake and evoked potential, but not 3H-ACh release, thus most of the 45Ca uptake measured was post-synaptic through L Ca channels. 5. Nickel, cadmium, and verapamil inhibited 3H-ACh release and evoked potential, indicating a block of pre-synaptic T Ca channels.


Transport of neurotransmitter precursors in a syncytial epithelium.

1. Tegumental transport of choline at concentrations ranging from 0.005-5.0 mM provided no evidence for saturable, carrier-mediated entry of this amine in the tegument of the rat tapeworm (Hymenolepis diminuta). 2. In contrast, the large neutral amino acid tryptophan appears to be taken up via a high-affinity transporter. In the 1st quartile of 17-day-old tapeworms (Km = 0.033 mM, Vmax = 0.7 nmol.min-1.g-1), in the 2nd quartile (Km = 0.015 mM, Vmax = 0.3 nmol.min-1.g-1), in the 3rd quartile (Km = 0.022 mM, Vmax = 0.5 nmol.min-1.g-1) and in the 4th quartile (Km = 0.025 mM, Vmax = 0.5 nmol.min-1.g-1) saturable tryptophan transport was kinetically characterized. 3. The non-saturable diffusion component (Kd) for tryptophan transport ranged from 3.8-10.2 microliters.min-1.g-1. 4. These studies suggest choline does not appear to be transported across the tapeworm tegument. Saturable transport of tryptophan via a high-affinity carrier is reported, and no regional variations in indole amino acid uptake were detected.


Liver microsomal alkoxyphenoxazone O-dealkylases of white Leghorn chickens: response to mixed function oxidase inducers.

1. The cytochrome P-450 substrates, methoxy-, ethoxy-, pentoxy- and benzyloxyphenoxazone were investigated in liver microsomes of phenobarbital- and beta-napththoflavone-induced White Leghorn chickens and compared to the rat mammalian model. 2. Thirty-two-fold increases in benzyloxyphenoxazone O-dealkylase and 27-fold increases in ethoxyphenoxazone O-dealkylase activities were observed in beta-naphthoflavone-treated chickens compared to only an 18-fold increase in ethoxyphenoxazone O-dealkylase activity in beta-naphthoflavone-treated rats. 3. Decreases in pentoxy- and benzyloxyphenoxazone O-dealkylase activities were observed in phenobarbital-treated chickens in contrast to increases of 197-fold in pentoxy- and 98-fold in benzyloxyphenoxazone O-dealkylases in the phenobarbital-treated rats.


Opposing actions of tolbutamide and glibenclamide on hypoxic pulmonary vasoconstriction.

1. We show that cromakalin and diazoxide, drugs that activate ATP-sensitive potassium (KATP) channels, abolish hypoxic pulmonary vasoconstriction (HPV) of isolated, perfused rat lungs. 2. Glibenclamide, an inhibitor of these channels, does not affect HPV, but it reverses the relaxation caused by cromakalim and diazoxide. 3. Tolbutamide, which has effects similar to glibenclamide in other tissues, paradoxically abolishes HPV, an effect reversed by glibenclamide. 4. These results suggest that: (i) pulmonary vessels contain KATP channels which are normally closed and are not opened by levels of hypoxia that cause constriction, (ii) tolbutamide acts on the pulmonary vasculature by a mechanism which differs from that of glibenclamide.


Chromatographic and immunological characterisation of neuropeptide Y-like and pancreatic polypeptide-like peptides from the nematode Ascaris suum.

1. Immunoreactivity (IR) towards neuropeptide Y (NPY) and pancreatic polypeptide (PP) has previously been demonstrated in nematodes by immunocytochemistry (ICC). 2. The PP- and NPY-IR in the nematode parasite Ascaris suum were analysed using HPLC and radioimmunoassays (RIAs) specific for either peptide. 3. Quantitative RIA data on the distribution of these IRs in the parasite disagreed with ICC data suggesting that different tissue treatments used in the two techniques lead to different antigen availability. 4. Significant quantities of PP- and NPY-IR were found in the pseudocoelomic fluid suggesting a role for this medium in the transport of peptides. 5. The parasite possessed chromatographically-distinct PP- and NPY-IRs, with each IR being composed of several distinct molecules.


Study of the glycogenolytic action of platelet activating factor in Tetrahymena pyriformis.

1. A novel action of AGEPC on non-inflammatory cells was revealed, namely the ability to stimulate glycogenolysis in Tetrahymena pyriformis cells. 2. The glycogenolytic effect of AGEPC seems to be dependent on Ca2+ transport and regulation, thus the effects are completely inhibited by Verapamil and partially by EGTA. 3. The influence of Propranolol, Labetalol, Atenolol and Theophylline in the glycogenolytic effect of AGEPC are also studied. 4. Our findings suggest that the AGEPC promoted glycogenolysis in Tetrahymena through a mechanism distinct from that of catecholamines.


Actions of APGW-amide and GW-amide on identified central neurons of the snail, Helix aspersa.

1. Actions of APGWamide and GWamide have been examined on identified central neurons of the snail, Helix aspersa. 2. In F1 neurons, both APGWamide and GWamide, 0.5-5 microM, reversibly inhibited the amplitude of evoked-IPSPs which were dopaminergic, but had no direct effect on membrane potential, cell firing rate, or dopamine-induced responses. These results indicate that the actions of APGWamide and GWamide in F1 neurons are at presynaptic sites. 3. At concentrations between 0.5 and 10 microM, APGWamide and GWamide had direct postsynaptic effects on F2 neurons. They inhibited the spike activity and hyperpolarized the membrane potential of F2 neurons in a dose-dependent manner with a reversal potential around -85 mV which is close to Ek. 4. In K+ free solution, the inhibitory effects of APGWamide and GWamide were potentiated, while they were reduced by increasing external K+ concentration. Either tetraethylammonium (10 mM) or 4-aminopyridine (500 microM) only partially prevented the inhibition induced by APGWamide and GWamide on F2 neurons. Combination of TEA (5 mM) and 4-AP (250 microM) could abolish this inhibition. However, neither 1 mM La2+ nor 10 mM Co2+ could prevent the inhibitory action of APGWamide and GWamide. This evidence indicates that the postsynaptic inhibition of APGWamide and GWamide on F2 neurons is due to an increase in K+ conductance and that both transient K channel (IA) and delay K+ channel (IK) were affected by these peptides. 4. APGWamide and GWamide exert both presynaptic and postsynaptic effects of Helix neurons, depending on the neuron under study. They are qualitatively and quantitatively similar in their presynaptic or postsynaptic actions.(ABSTRACT TRUNCATED AT 250 WORDS)


In vivo and in vitro effects of beta-endorphin and naloxone on corticosterone and cortisol release in male and female water frog, Rana esculenta.

1. beta-Endorphin and naloxone effects on corticosterone and cortisol production in male and female Rana esculenta, were studied in vivo and in vitro. 2. The in vivo and in vitro results were in agreement. 3. beta-Endorphin caused a decrease in corticosterone and cortisol release. 4. Naloxone induced an increase in the two corticosteroids at the same times as the decrease caused by beta-endorphin. 5. beta-Endorphin plus naloxone treatment did not change corticosterone and cortisol levels. 6. These results suggest that in Rana esculenta opioids are involved in the regulation of the hypothalamo-pituitary-interrenal axis; in particular, opioids directly modulated interrenal steroidogenesis.


A comparison of glutathione-dependent enzymes in liver, gills and posterior kidney of channel catfish (Ictalurus punctatus).

1. Six enzymes which collectively catalyze a number of glutathione-dependent synthetic, catabolic and detoxification reactions were examined along with glutathione status in liver, gills, and posterior kidney of channel catfish (Ictalurus punctatus). 2. Hepatic GSH concentrations were higher than those in kidney or gills. Oxidized glutathione (GSSG) concentrations were similar among the three tissues. 3. Specific (per unit protein) gamma-glutamylcysteine synthetase (GCS) activity was greater in the gills than in liver or posterior kidney. However, total organ GCS activity was greatest in the liver. 4. Specific and total hepatic glutathione peroxidase (GSH peroxidase) activities were substantially greater than those of gills or kidney. 5. Similar specific glutathione reductase (GSSG reductase) activities were observed among all three tissues. 6. All three tissues exhibited glutathione S-transferase (GST) activity towards 1-chloro-2,4-dinitrobenzene (CDNB). Specific and total organ GST activities were highest in the liver, followed by the posterior kidney and gills. 7. Gamma-glutamyltranspeptidase (GGT) activity was present in the posterior kidney, but was undetectable in the gills or liver.


Inhibitory effect of a Microcystis sp (cyanobacteria) toxin on development of preimplantation mouse embryos.

1. A soluble toxin, purified from the algae bloom of an eutrophic lake dominated by Microcystis, is a very effective inhibitor of early embryo development in a dose-response relationship. 2. Two- and 8-cell mouse embryos under the influence of Microcystis toxin do not reach the developmental stages of morula and blastocyst, respectively. 3. Actin cortex is disorganized without change in the microtubules structure. 4. Results are discussed in terms of the possible mechanisms by which the toxin arrests development considering, specifically, effects on the cytoskeleton and/or on voltage-insensitive transmembrane Ca2+ channels.


Sensitivities of Achatina giant neurones to putative amino acid neurotransmitters.

1. GABA receptors in Achatina identifiable giant neurones were classified into the muscimol I, muscimol II and baclofen types. Muscimol I and II type GABA receptors were sensitive to GABA and muscimol but insensitive to baclofen, whereas baclofen type receptors were sensitive to GABA and baclofen but insensitive to muscimol. Muscimol I and baclofen types were associated with the inhibition caused by GABA, while muscimol II type with the GABA excitation. 2. GABA, muscimol and TACA produced a transient outward current (Iout) with an increase in membrane conductance (g) of an Achatina neurone, TAN, having the muscimol I type GABA receptors. Their relative potency values (RPV) at GABA ED50 (approximately 10(-4) M) were: GABA:muscimol:TACA = 1:0.6:0.3. The GABA effects were potentiated by pentobarbitone, antagonized competitively by pitrazepin and non-competitively by picrotoxin and diazepam, and unaffected by bicuculline. The ionic mechanism of effects of GABA and its two analogues was the increase in membrane Cl- conductance (gCl). 3. GABA and (+/-)-baclofen produced a slow Iout with a g increase of another Achatina neurone, RPeNLN, having the baclofen type GABA receptors. The two compounds were almost equipotent (ED50: approximately 3 x 10(-4) M). The ionic mechanism of their effects was the increase in gk. The two compounds hardly affected the voltage-gated and slowly inactivating calcium current. Iout produced by GABA and (+/-)-baclofen were reduced by TEA, but unaffected by 4-AP, bicuculline, pitrazepin and picrotoxin. 4. Beta-hydroxy-L-glutamic acid (L-BHGA) showed the marked effects on the Achatina giant neurones; the two neurones were excited by the compound, whereas the three inhibited. D-BHGA, L-Glu, D-Glu and NMDA were less effective than L-BHGA or almost ineffective. Erythro-L-BHGA was more or less effective than threo-L-BHGA according to the neurones tested. 5. alpha-Kainic acid and domoic acid excited the two neurones, which were excited by L-BHGA. L-Quisqualic acid showed the similar effects to L-BHGA, which were mostly much stronger than L-BHGA. Erythro-L-tricholomic acid and DL-ibotenic acid showed the effects similar to L-BHGA selectively on some neurones. 6. It was pointed out that the pharmacological features of GABA on the Achatina neurones are simpler than those of L-BHGA, due to the simpler structure of the former compound having less binding sites than the latter.


Effects of ecdysteroids on reproductive physiology of Nippostrongylus brasiliensis (Nematoda) in vivo.

1. The influence of ecdysteroids (ecdysone and ecdysterone) was investigated on the control of reproduction in the parasitic nematode Nippostrongylus brasiliensis in vivo. 2. Infestive larvae (L3) were immersed in solutions of ecdysteroids (2.2 microM) at 37 degrees C for 4 hr before injection into the host. The effect on egg-laying was observed two stages later. 3. The treatment increased egg-laying, but had no influence on the timing of the reproductive period. The greatest effect was observed with ecdysone, ecdysterone only inducing a small and non-significant stimulation under our experimental conditions. 4. The physiological role of ecdysteroids in meiosis and gonadal development in nematodes is discussed.


Comparative analysis of inositol phospholipid metabolism in viral and chemical transformation of mammalian cells.

1. Inositol phospholipid metabolites were measured from virally and chemically transformed cells. 2. Increased levels of PIP and PIP2 were observed from both transformed cell lines as compared with controls. 3. Intracellular levels of IP3 were also increased approximately three folds in BPV-1 infected ID 13 cells and in 3-MC transformed NIH 3T3 cells. 4. The results suggest that phosphorylation of phosphatidylinositols and enhanced generation of IP3 second messenger molecules are the common signal transducing process leading to the cell transformation.


Characterization of cholinesterases from the parasitic nematode Trichinella spiralis.

1. Trichinella cholinesterases occur in multiple molecular forms which differ in size, kinetics, activity with butyrylthiocholine, and effects of inhibitors. 2. The 5.3 and 13S forms identified in Trichinella extracts are also found in C. elegans and other nematodes but the 7S form which occurs in other nematodes was absent from Trichinella detergent extracts. Differences in kinetic and inhibition properties among nematode species were also evident. 3. The level of cholinesterases in excretory/secretory products is low. 4. Trichinella cholinesterases did not elicit a detectable antibody response in mice.


A metabotropic L-glutamate receptor agonist: pharmacological difference between rat central neurones and crayfish neuromuscular junctions.

1. 2S,3S,4S-2-(carboxycyclopropyl)glycine (L-CCG-I), a conformationally restricted glutamate analogue, is a potent metabotropic L-glutamate receptor agonist in the mammalian central nervous system. 2. Depolarizing actions of L-CCG-I and trans-(+/-)-1-amino-1,3-cyclopentanedicarboxylic acid (trans-ACPD) in the newborn rat spinal motoneurone are temperature-sensitive, and are not depressed by 3-[(+/-)-2-carboxypiperazin-4-yl] propyl-1-phosphonic acid (CPP) and/or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). 3. L-CCG-I and trans-ACPD induced oscillatory responses in Xenopus oocytes injected with rat brain mRNA. Oocytes with oscillatory responses to L-CCG-I and trans-ACPD showed reversal potential of about -20 mV, which was very close to the equilibrium potential of chloride ions. 4. In rat hippocampal synaptoneurosomes, L-CCG-I stimulated phosphoinositide hydrolysis in a concentration dependent manner. L-CCG-I was less potent than quisqualate but more potent than trans-ACPD. 5. At low concentrations, L-CCG-I did not cause any depolarization of newborn rat spinal motoneurones, but reduced substantially amplitudes of monosynaptic reflexes. 6. At the crayfish neuromuscular junction L-CCG-I, acting presynaptically, reduced the amplitude of excitatory junctional potentials. This action was prevented by application of picrotoxin but not pertussis toxin. The actions of trans-ACPD differ from those of either L-CCG-I or ibotenate at the crayfish neuromuscular junction. 7. L-CCG-I has a potential to provide further useful information on metabotropic L-glutamate receptor function.


Isolation and primary structure of two sulfakinin-like peptides from the fleshfly, Neobellieria bullata.

1. Two novel insect myotropic peptides termed neosulfakinin-I (Neb-SK-I) and neosulfakinin-II (Neb-SK-II) were isolated from the heads of 42 thousand fleshflies, Neobellieria bullata (Diptera, Sarcophagidae). 2. A series of four, high-performance liquid chromatographic (HPLC), fractionations performed on columns with different characteristic features yielded two purified biologically active, hindgut motility stimulating fractions, suitable for amino acid sequence analysis. 3. The proposed sequences for the two peptides are: Phe-Asp-Asp-Tyr-Gly-His-Met-Arg-Phe-(NH2), (Neb-SK-I) and X-X-Glu-Glu-Gln-Phe-Asp-Asp-Tyr-Gly-His-Met-Arg-Phe-(NH2), (Neb-SK-II). 4. These sulfakinins exhibit very high homology to putative drosulfakinin sequences which, however, have not yet been isolated, but were deduced from a cloned Drosophila gene encoding these peptides. 5. Here we provide the first evidence for the expression of such peptides present in Dipterans. 6. Insect sulfakinins show structural identities with the hormonally-active portion of vertebrate gastrin II-, cholecystokinin- and caerulin-related peptides and they share common carboxy terminal sequences with invertebrate/vertebrate peptides of the FMRFamide peptide family.


Combined effect of vanadium and zinc on certain selected haematological indices in rats.

1. Two-month-old Wistar rats of both sexes received, as sole drinking liquid, an aqueous solution of ammonium metavanadate (AMV) and zinc chloride (ZC) at concentrations of 0.30 mg V/cm3 and 0.12 mg Zn/cm3 respectively, for a period of 4 weeks. 2. The reference groups received for drinking at this time: water, AMV or ZC solutions at the same concentration. 3. In all groups of animals there was a statistically significant decrease in the uptake of food, AMV or ZC, as well AMV-ZC solutions, as compared with the food and water taken up by the control group. 4. In the group of animals receiving AMV or AMV-ZC solution for drinking the body weight increment diminished significantly. 5. In the animals drinking the AMV-ZC solution a statistically significant decrease in the erythrocyte count and haemoglobin level in the peripheral blood were recorded, similar to the groups drinking AMV or ZC solution. 6. In rats drinking aqueous AMV or ZC solutions and in females receiving AMV-ZC solution the percentage of reticulocytes and polychromatophilic erythrocytes increased, moreover, in the peripheral blood. It was not, however, associated with marked percentage changes in the composition of the bone marrow cells.


Comparative effects of the polychlorinated biphenyl mixture, Aroclor 1242, on porphyrin and xenobiotic metabolism in kidney of Japanese quail and rat.

1. Aroclor 1242 (500 mg/kg, p.o.) produced a marked increase in porphyrin content of quail kidney (1800-fold), and of rat kidney but to a lesser extent (6-fold). 2. delta-Aminolevulinic acid synthetase activity was increased 12-fold in quail kidney but was unchanged in rat kidney following Aroclor 1242 treatment. 3. Uroporphyrinogen decarboxylase activity was significantly inhibited in quail kidney but not in rat kidney. 4. Renal ethoxyresorufin O-deethylase activity was induced in rat and quail whereas renal ethoxycoumarin O-deethylase and glutathione S-transferase activities were induced only in rats by Aroclor 1242.


Differential effects of 3,4,5,3',4',5'-hexachlorobiphenyl (HCB) on interrenal steroidogenesis in male and female rainbow trout Oncorhynchus mykiss.

1. The conversion of progesterone to 17 alpha-hydroxyprogesterone (17 alpha-OHP), 11-deoxycortisol (11-DOCR) and deoxycorticosterone (DOC) was significantly higher in female rainbow trout than in male trout; in contrast, the interrenal production of cortisol (CR) plus cortisone (CN) was higher in males than in females. 2. Following treatment with 1 mg/kg of HCB, the interrenal conversion of progesterone to 17 alpha-OHP and 11-DOCR was significantly increased in male and female trout but at 20 mg/kg of HCB, the production of these metabolites was increased in males and decreased in females; CR+CN production was unchanged after HCB treatment in both sexes.


Evidence for hybrid NMDA/kainate receptors from protein reconstitution studies and expression of vertebrate CNS RNAs in Xenopus oocytes.

1. A review is presented of recent advances in glutamate receptor research with particular emphasis on studies which show that some glutamate receptors in the central nervous systems (CNS) of Xenopus and rat contain a mixture of N-methyl-D-aspartate-sensitive and kainate-sensitive subunits. 2. Protein isolated from Xenopus CNS using a domoic acid affinity column exhibits complex pharmacological properties. It binds both [3H]kainate and [3H]glycine: the binding of the latter is strychnine-insensitive. 3. When reconstituted into lipid bilayers, channels gated by kainate and NMDA can be elicited and the properties of these channels are similar to those gated by kainate receptors and NMDA receptors, respectively, in studies of vertebrate central neurones in situ. 4. The protein can be fractionated into two components; one of which is sensitive only to kainate and AMPA, the other exhibiting sensitivity to both kainate and NMDA. 5. When RNA isolated from Xenopus and rat CNS is injected into Xenopus oocytes, responses to kainate and NMDA can be seen within 2-3 days. The responses to co-application of these agonists support the contention that some of the glutamate receptors expressed in oocytes contain both kainate-sensitive and NMDA-sensitive subunits.


Biochemical characterization of a variant form of cytosolic epoxide hydrolase induced by parental exposure to N-ethyl-N-nitrosourea.

1. ENU4 mice express a protein variant originally detected in a CBF1 mouse sired by a C57BL/6 mouse exposed to N-ethyl-N-nitrosourea. It appears to be an isoelectric point variant of cytosolic epoxide hydrolase. Affinity purified cytosolic epoxide hydrolase from ENU4 mice has a pI of approximately 5.1 compared to 5.6 in other mouse strains. 2. Clofibrate induced cytosolic epoxide hydrolase to similar levels in five strains of mice. However, CBF1 and ENU4 mice were more sensitive to the induction of palmitoyl CoA oxidase activity. 3. Except for isoelectric point, the physico- and immunochemical properties of cytosolic epoxide hydrolase from ENU4 mice were similar to those of the other mouse strains. Substrate specificities for five of six substrates tested were also similar.