Effect of vitamin and trace-element supplementation on immune responses and infection in elderly subjects.

Ageing is associated with impaired immune responses and increased infection-related morbidity. This study assessed the effect of physiological amounts of vitamins and trace elements on immunocompetence and occurrence of infection-related illness. 96 independently living, healthy elderly individuals were randomly assigned to receive nutrient supplementation or placebo. Nutrient status and immunological variables were assessed at baseline and at 12 months, and the frequency of illness due to infection was ascertained. Subjects in the supplement group had higher numbers of certain T-cell subsets and natural killer cells, enhanced proliferation response to mitogen, increased interleukin-2 production, and higher antibody response and natural killer cell activity. These subjects were less likely than those in the placebo group to have illness due to infections (mean [SD] 23 [5] vs 48 [7] days per year, p = 0.002). Supplementation with a modest physiological amount of micronutrients improves immunity and decreases the risk of infection in old age.


Adult coronary artery disease probably due to childhood Kawasaki disease.

We have surveyed adult survivors of childhood Kawasaki disease (KD) who had coronary artery disease that could be ascribed to KD. In response to questionnaires sent to cardiologists throughout Japan, 21 patients (17 men, 4 women, aged 20-63 years) with coronary lesions and a definite (2) or suspected (19) history of KD were reported. 5 patients had presented with acute myocardial infarction, 6 previous myocardial infarction, 9 angina pectoris, and 1 dilated cardiomyopathy. 16 patients had obstructions in two or more coronary arteries. 3 had died and 18 were alive with serious sequelae (mitral regurgitation, arrhythmias, congestive heart failure). Childhood KD should be included in the differential diagnosis of coronary artery disease in young adults.


Electrically stimulated gracilis sphincter for treatment of bladder sphincter incontinence.

Correction of total urinary incontinence due to sphincter damage is done with an artificial sphincter prosthesis or urinary diversion. In this pilot study we used graciloplasty around the bladder neck followed by electrical stimulation of this muscle with an implanted stimulator, which could be switched off and on by a magnet. Stimulus variables could be changed externally. With the stimulator on, urethral pressures of about 50 cm H2O were obtained. Of three patients who underwent the procedure, two became continent and one improved but remained incontinent. Dynamic graciloplasty can restore urinary incontinence.


Usefulness of clinical case-definitions in guiding therapy for African children with malaria or pneumonia.

The World Health Organisation has developed disease-specific clinical case-definitions to guide management of children with fever or cough, the cardinal signs of malaria and pneumonia. To assess the usefulness of the case-definitions and to investigate their interaction, we studied children with fever or cough brought to a hospital in Lilongwe, Malawi. For all children, a thick blood smear was examined for Plasmodium falciparum parasites. Chest radiography was done only for children with parasitaemia and those who satisfied the clinical case-definition for pneumonia; others were assumed to have normal chest radiographs. Of 1599 enrolled children, 566 (35%) had parasitaemia and 116 had radiographic evidence of pneumonia; 43 had both pneumonia and parasitaemia. Of the 471 children who met the clinical definition for pneumonia, 449 (95%) also met the malaria clinical definition. Among children with radiographic evidence of pneumonia, the clinical definition for malaria was not predictive of parasitaemia (sensitivity 93%, specificity 5%). Whether malaria parasitaemia was present or absent, the pneumonia clinical definition distinguished children with and without radiographic evidence of pneumonia (sensitivity and specificity > 60%). Children who satisfied the pneumonia clinical definition were more likely to have radiographic evidence of pneumonia (odds ratio 10.4, 95% confidence interval 5.2-20.7), parasitaemia (1.6, 1.2-2.2), or both at the same time (4.2, 2.1-8.4) than were children who did not meet the definition. Children who satisfy the malaria and pneumonia clinical definitions need treatment for both disorders. Scarce diagnostic methods, especially microscopy, are needed for more specific treatment of children with fever and cough.


Effect of enalapril on myocardial infarction and unstable angina in patients with low ejection fractions.

An association between raised renin levels and myocardial infarction has been reported. We studied the effects of enalapril, an angiotensin-converting enzyme (ACE) inhibitor, on the development of myocardial infarction and unstable angina in 6797 patients with ejection fractions < or = 0.35 enrolled into the two Studies of Left Ventricular Dysfunction (SOLVD) trials. Patients were randomly assigned to placebo (n = 3401) or enalapril (n = 3396) at doses of 2.5-20 mg per day in two concurrent double-blind trials with the same protocol. Patients with heart failure entered the treatment trial (n = 2569) and those without heart failure entered the prevention trial (n = 4228). Follow-up averaged 40 months. In each trial there were significant reductions in the number of patients developing myocardial infarction (treatment trial: 158 placebo vs 127 enalapril, p < 0.02; prevention trial: 204 vs 161 p < 0.01) or unstable angina (240 vs 187 p < 0.001; 355 vs 312, p < 0.05). Combined, there were 362 placebo group patients with myocardial infarction compared with 288 in the enalapril group (risk reduction 23%, 95% CI 11-34%; p < 0.001). 595 placebo group patients developed unstable angina compared with 499 in the enalapril group (risk reduction 20%, 95% CI 9-29%, p < 0.001). There was also a reduction in cardiac deaths (711 placebo, 615 enalapril; p < 0.003), so that the reduction in the combined endpoint of deaths, myocardial infarction, and unstable angina was highly significant (20% risk reduction, 95% CI 14-26%; p < 0.0001). Enalapril treatment significantly reduced myocardial infarction, unstable angina, and cardiac mortality in patients with low ejection fractions.


Detection in life of confirmed Alzheimer's disease using a simple measurement of medial temporal lobe atrophy by computed tomography.

The medial temporal lobe of the brain is important for normal cognitive function, notably for memory, and is the region with the most extensive pathological change in Alzheimer's disease (AD). We wanted to find out if atrophy of the medial temporal lobe could be detected in life in patients in whom a diagnosis of AD was subsequently established histopathologically. The minimum width of the medial temporal lobe, measured by temporal-lobe-oriented computed tomography (CT) about one year before death, in 44 patients with a histopathological diagnosis of AD (cases) was nearly half (0.56 of the median) that in 75 controls of the same age with no clinical evidence of dementia (95% confidence interval 0.51-0.61). There was little overlap between the distributions of measurements in cases and controls. A cut-off (< 0.79 MoM) selected to yield a 5% false-positive rate gave an expected detection rate of 92%. A cut-off selected to yield a false-positive rate of 1% (< 0.70 MoM) yielded a 79% detection rate. 20 of the 44 patients with histopathologically diagnosed AD had been scanned more than once before death, and the test (cut-off < 0.79 MoM) was positive in all 20 more than a year before and in 9/10 more than 2 years before death. In 10 subjects with dementia but with histopathology excluding AD, the mean minimum width of the medial temporal lobe was significantly greater than that in the cases with AD, but was not significantly different from that in controls. Medial temporal lobe CT is a non-invasive, rapid, simple and effective test for AD which could have immediate application firstly in improving the accuracy of prevalence and incidence studies and, secondly, for the identification of groups of high-risk patients in the evaluation of novel treatments for AD. In the future, it could be applied as a screening test.


Pulsed excimer laser versus continuous-wave Nd:YAG laser versus conventional angioplasty of peripheral arterial occlusions: prospective, controlled, randomised trial.

Early clinical studies of coronary and peripheral laser angioplasty showed that arterial occlusions could be recanalised by continuous-wave lasers delivered with contact probes and by pulsed lasers applied with multifibre catheters. However, whether laser-assisted angioplasty improves success rates in reopening occlusions and in long-term patency rates is unclear. We have compared the primary recanalisation and long-term patency rates after laser-assisted and conventional percutaneous transluminal angioplasty (PTA) of femoropopliteal artery occlusions in 116 consecutive symptomatic patients (excimer laser 37, Nd:YAG laser 40, PTA 39). Primary recanalisation was achieved in 81 patients (70%). The primary recanalisation rate achieved with the excimer laser was significantly lower than that with the Nd:YAG laser (49% vs 78%, p < 0.01) or with PTA (82%, p < 0.003). The overall angiographic recanalisation rate (primary and secondary recanalisation) after laser and PTA was 89%. After 3 months, clinical improvement was recorded in 76% of patients. Clinical long-term results were available in 94 (91%), and angiographic long-term results in 77 (75%), of 103 successfully recanalised patients. Life-table analysis of the long-term results revealed no significant difference of the restenosis rate between the three treatment groups. The 12-month patency rate was 60% as assessed clinically and 39% as judged by angiography. Primary and secondary recanalisation rates and long-term patency rates were significantly correlated with length of the occlusion. Our results suggest that PTA of femoropopliteal artery occlusions is only indicated if the occlusion is short (< 8 cm) and that laser-assisted angioplasty should only be used after failure of conventional PTA.


Detection of premature atherosclerosis by high-resolution ultrasonography in symptom-free hypopituitary adults.

Retrospective analysis suggests that there is increased mortality from vascular disease in hypopituitary adults, but vascular status before death is unknown. High resolution B-mode ultrasonic imaging of both carotid and femoral arteries was therefore done in 34 adult hypopituitary patients on routine replacement therapy and was compared with that in 39 matched controls. Changes were related to risk factors for vascular disease. Carotid intima-media thickness was greater in patients than in controls (mean [SD] 0.74 [0.16] vs 0.65 [0.13] mm, p < 0.02). This difference was seen in middle-aged and elderly patients. More patients than controls had one or more atheromatous plaques (65% vs 41%, p < 0.05). The percentage of individual arteries with a plaque was also higher in patients (32% vs 18%, p < 0.005). In multiple regression analysis, patients' age was the dominant factor determining carotid intima-media thickness. Symptom-free adults with hypopituitarism show an increased prevalence of atherosclerosis.


Ambulatory oxygen in chronic heart failure.

Ambulatory oxygen therapy may be of benefit in bicycle exercise tests. We have assessed the effects of ambulatory oxygen during walk tests in 12 patients with chronic heart failure. In 6 min walks with the patient breathing air, mean (SD) arterial oxygen saturation (SaO2) fell from 94.4 (3.7)% at rest to 90.1 (6.1)% (p = 0.014) on exercise. 21/min oxygen increased resting SaO2 from 93.7 (4.0)% (air cylinder) to 96.5 (3.0)% (p < 0.001) with no effect on minimum SaO2, distance, or breathlessness. During endurance walks, 4 l/min oxygen increased minimum SaO2 from 90.4 (5.6)% to 93.5 (4.7)% (p = 0.011) but also had no effect on breathlessness or distance. Ambulatory oxygen in currently available cylinders cannot be recommended for patients with chronic heart failure.


Isolation of Helicobacter pylori from human faeces.

Helicobacter pylori is arguably the commonest chronic infection in man. However, its route of transmission is unknown. We have isolated viable H pylori from the faeces of an infected individual from The Gambia. The organism was cultured on selective media after concentration of faecal bacteria by centrifugation in a buffer equilibrated with a microaerophilic gas mixture. Growth characteristics, microscopic appearances, and enzyme activities were the same as those of a typical gastric isolate of H pylori. Protein preparations derived from the new isolate and the typical strain were antigenically similar, and had very similar electrophoretic profiles (including two major protein bands of 62 and 26 kDa, corresponding to the urease enzyme subunits). With the same technique, organisms with the colony morphology, growth requirements, enzyme activities, and microscopic appearances of H pylori were isolated from the faeces of 9 of 23 randomly selected children aged 3-27 months from a Gambian village with a high prevalence of H pylori infection in early life. Faecal-oral transmission is probably important in the spread of infection in such communities.


Smoking and decreased fertilisation rates in vitro.

To examine possible mechanisms for the association between cigarette smoking and reduced fertility, we have measured the concentration of the nicotine metabolite cotinine in ovarian follicular fluid collected at the time of oocyte recovery during treatment for in-vitro fertilisation. In a group of women in whom follicular fluid cotinine could not be detected (limit of accurate measurement 20 ng/ml) 116 oocytes were collected, of which 84 became fertilised (72%), whereas among women with cotinine concentration greater than 20 ng/ml 20/45 (44%) oocytes did so (p < 0.01). The median fertilisation rates for individuals (range 1-8 eggs each) in the high and low cotinine groups were 57% and 75%, respectively (p < 0.05). These findings suggest that infertile women should be advised to stop or reduce smoking generally, and especially before treatment by in-vitro fertilisation.


Success with coronary angioplasty as seen at demonstrations of procedure.

To assess the real-life results of coronary angioplasty, unidentified participants made notes on 104 cases demonstrated live at twelve international angioplasty courses in 1991. The initially planned procedure was successful in 73% with crossover to another device in 20% for an ultimate success rate of 93%. Interventions lasted an hour on average and two devices on average were used per artery tackled. Rates of success and of complication necessitating reintervention were, for balloon angioplasty (57 cases) 81% and 19%, for directional atherectomy (16 cases) 75% and 0%, for the Rotablator (12 cases) 42% and 42%, for stent implantation (10 cases) 100% and 0%, for excimer laser angioplasty (6 cases) 17% and 33%, and for Rotacs recanalisation (3 cases) 67% and 0%, respectively. The complications were occlusions (threatened, acute, or delayed) and they were usually treated by balloon angioplasty or a stent. No death or myocardial infarction was reported. The observer attending the demonstration tended to take a less favourable view of the outcome than the clinician doing the procedure and in general the results of coronary angioplasty seemed inferior to those reported in journals. Interventions done before an audience will be unusually stressful but this will be outweighed by the fact that difficult cases with a low probability of success are rarely tackled during live courses. This survey suggests that conventional balloon angioplasty, complemented by stent implantation in selected cases, is the treatment of choice.


Seroepidemiological survey of hepatitis E in Hong Kong by recombinant-based enzyme immunoassays.

The agent that causes the enterally transmitted form of non-A, non-B hepatitis has been cloned and called hepatitis E virus (HEV). We have carried out a seroepidemiological survey on the prevalence of hepatitis E in Hong Kong. In a retrospective study, serum from 394 patients with acute viral hepatitis and 355 healthy subjects was tested for antibodies to HEV (anti-HEV) with a recombinant-based enzyme immunoassay. 65 (16.5%) patients with hepatitis were positive for IgM anti-HEV and 23 (5.8%) were also positive for IgM anti-HEV. Of 18 patients diagnosed as having acute non-A, non-B, non-C hepatitis, 6 were IgM anti-HEV positive. 17 (6%) patients in whom acute hepatitis A was diagnosed were also infected with HEV. None of 70 patients with acute hepatitis B or C or exacerbation of chronic hepatitis B was IgM anti-HEV positive. 57 (16.1%) of the healthy subjects were positive for IgG anti-HEV. The prevalence of IgG anti-HEV was higher in subjects over 20 years old than in younger subjects (24% vs 4%, p < 0.0001). IgG anti-HEV was detected in 26% of subjects who were positive for IgG antibody to HAV and in 7% of those negative for that antibody (p < 0.0001). We demonstrated the validity of the recombinant-based enzyme immunoassays for the diagnosis of hepatitis E. Our results suggest that hepatitis E accounts for a third of non-A, non-B, non-C hepatitis in Hong Kong and that coinfection of hepatitis A and E can occur.


Randomised comparison of amniocentesis and transabdominal and transcervical chorionic villus sampling.

We have compared three methods of prenatal diagnosis in two large obstetric centres in Denmark. Women were randomly assigned transabdominal (TA) chorionic villus sampling (CVS), transcervical (TC) CVS, or second-trimester amniocentesis (AC); women at high genetic risk were randomised between the two CVS groups only. Analysis of 45 epidemiological variables showed the three procedure groups to be similar at enrollment. All women were followed up until completion of pregnancy. Among 3079 women at low genetic risk total fetal loss rates were 10.9% for TC CVS, 6.3% for TA CVS, and 6.4% for AC (p < 0.001). More women had bleeding after the procedure in the CVS groups (p < 0.001), whereas more amniotic fluid leakage (p < 0.001) was reported after AC. No uterine infections occurred in any group. No case of oromandibular-limb abnormality was seen in the CVS groups, but 1 child in the AC group had aplasia of the right hand. The two CVS approaches were compared among 2882 women at low and high genetic risk who were found to have cytogenetically normal fetuses. Rates of unintentional loss after the procedure were 7.7% for TC CVS and 3.7% for TA CVS (p < 0.001; 95% Cl of difference 2.3-5.8%). At baseline ultrasound scanning after establishment of optimum sampling conditions, more TC than TA procedures (p < 0.001) were judged not to be feasible. We found that TA CVS allows better access to the placental site than TC sampling, is an easier skill to acquire, and has the potential that more villi can be aspirated when needed. The risk of fetal loss is similar after TA CVS and AC. However, losses after AC are at a later stage and are therefore more distressing. TA procedures remain the first choice for prenatal diagnosis. Since, in our hands, TC sampling carries a greater risk to the fetus, we have abandoned TC CVS in our two study centres.


Comparison of oral artemether and mefloquine in acute uncomplicated falciparum malaria.

Plasmodium falciparum malaria in Thailand is highly resistant to available antimalarials, and alternative drugs are needed urgently. Artemether is effective against falciparum malaria but associated with a high recrudescence rate. The proper dosage regimen remains to be defined. We have done a clinical trial comparing mefloquine 1250 mg in divided doses with oral artemether at 700 mg total dose given over 5 days in acute uncomplicated falciparum malaria. 46 patients, admitted to the Bangkok Hospital for Tropical Diseases, were randomised to receive either mefloquine (12) or artemether (34). Hospital follow-up was 28 days for the artemether group and 42 days for the mefloquine group. Oral artemether gave a significantly faster parasite clearance time than mefloquine (30 vs 64 h), and a significantly better cure rate (97 vs 64%) with fewer episodes of dizziness and vomiting. Oral artemether at 700 mg given over 5 days is effective and well tolerated. The cure rate with this regimen is higher than that reported by previous studies with 600 mg intramuscular artemether given over 5 days. Oral artemether can be considered as an alternative drug for multiple-drug-resistant falciparum malaria.


Protection against bradykinin-induced bronchoconstriction in asthmatic patients by neurokinin receptor antagonist.

Axon reflex mechanisms may be involved in the pathogenesis of asthma, but there has been no direct evidence that endogenous tachykinins cause bronchoconstriction in asthmatic subjects. We have studied the effect of a tachykinin receptor antagonist (FK-224) on bronchoconstriction induced by inhalation of bradykinin in asthmatic patients. In a double-blind, placebo-controlled, crossover trial, ten subjects with stable asthma were given FK-224 (4 mg) or placebo by inhalation 20 min before challenge with bradykinin (0-1250 micrograms/ml, five breaths of each concentration) given with 5 min intervals. Bradykinin caused dose-dependent bronchoconstriction in all subjects. FK-224 significantly opposed the bronchoconstrictor effect; the geometric mean of the cumulative concentration required to elicit a 35% fall in specific airway conductance was 5.3 micrograms/ml after placebo and 40 micrograms/ml after FK-224 (p < 0.001). Inhalation of bradykinin caused coughing in three subjects, which was inhibited by FK-224 in all three. Antagonism of the tachykinin receptor by FK-224 greatly inhibited both bronchoconstriction and coughing induced by bradykinin in asthmatic patients, suggesting that tachykinin release from the airway sensory nerves is involved in responses to bradykinin. Tachykinin receptor antagonists may be useful in the treatment of asthma.


Cross-contamination potential with dental equipment.

Some types of reused dental equipment, especially handpieces and their attachments for drilling and cleaning teeth, might be responsible for cross-contamination if patient material were to lodge temporarily in difficult-to-disinfect internal mechanisms. This possibility is worrisome with respect to transmission of hepatitis B and human immunodeficiency viruses (HBV, HIV). Previous cross-contamination studies have relied on laboratory experiments with bacteria or dye tracers. To assess possible risk more thoroughly, we tested 30 new prophylaxis angles and 12 new high-speed handpieces to see whether they would take up and expel contaminants in laboratory and clinical trials. In treatments of three patients, including two infected with HIV, human-specific DNA (beta-globin, HLA DQ alpha) and HIV proviral DNA were detected inside or coming back from the devices. Similarly, when handpieces were operated in contact with blood pooled from HBV-infected patients, HBV DNA was detected in samples taken from inside the equipment and from their attached air/water hoses. When we used bacteriophage phi X174 as a model virus in laboratory tests, many infective viral particles were recovered from internal mechanisms of handpieces, their connecting air/water hoses, and from water spray expelled when the equipment was reused. We recommend that reused high-speed, air-driven handpieces and prophylaxis angles should be cleaned and heat-treated between patients. Further studies are needed to determine ways of eliminating the risks associated with exhaust hoses and air/water input lines.


Cardiotoxicity after accidental herb-induced aconite poisoning.

Aconitine and its related alkaloids are known cardiotoxins with no therapeutic role in modern western medicine. The rootstocks of Aconitum plants, which contain aconite alkaloids, have been common components of Chinese herbal recipes. We have documented life-threatening intoxication in 17 Chinese subjects after accidental herb-induced aconite poisoning. All patients developed symptoms of aconite toxicity within 2 h of herb ingestion. Most developed tachyarrhythmias, including ventricular tachycardia and fibrillation from which 2 patients died. Toxicological evaluation revealed that aconites from the Aconitum rootstocks were the only plausible casual factor for intoxication. These cases point to the need for strict surveillance of herbal substances with low safety margins.


Amphotericin versus pentamidine in antimony-unresponsive kala-azar.

We compared the efficacy of amphotericin B and pentamidine isethionate in a prospective randomised trial in 120 uncomplicated and parasitologically confirmed cases of antimony-unresponsive kala-azar. Doses were twenty intramuscular injections of pentamidine 4 mg/kg on alternate days or fourteen definitive doses of amphotericin 0.5 mg/kg infused in 5% dextrose on alternate days. 48 (80%) patients given pentamidine showed initial cure and 46 (77%) showed definitive cure compared with 60 (100%) and 59 (98%) cases, respectively, on amphotericin (p < 0.001). Amphotericin also brought about quicker abatement of fever and more complete spleen regression.


Is clearance of HIV-1 viraemia at seroconversion mediated by neutralising antibodies?

The mechanism of clearance of human immunodeficiency virus-1 (HIV-1) viraemia is not fully understood. In two patients with acute HIV-1 infection, initial high titres of free infectious virus in plasma declined rapidly to undetectable levels within 4-8 weeks, an event that was coincident with seroconversion. Neutralising antibodies directed against the first autologous isolates taken during the viraemic periods could not be detected in either patient around the time of disappearance of plasma virus. In the absence of functional neutralising antibody, it is unlikely that humoral factors are responsible for the suppression of primary viraemia in early HIV infection.


Anal intraepithelial neoplasia: part of a multifocal disease process.

Invasive carcinomas of the anogenital epithelium share a common aetiological factor--human papillomavirus (HPV) type 16. Although genital intraepithelial neoplasia may be multifocal, there have been no studies of the prevalence of anal intraepithelial neoplasia in women with intraepithelial neoplasia of the genital tract. We tested the hypothesis that women with high-grade cervical intraepithelial neoplasia are at higher risk of disease in the anus than are control women of similar age with no history of anogenital neoplasia. 29 (19%) of 152 women with cervical intraepithelial neoplasia grade III had histological evidence of anal intraepithelial neoplasia. Of the 29 patients, 11 had grade III anal lesions; 2 of those women had concomitant invasive anal squamous-cell carcinomas. Only 7% (8/115) women with high-grade lesions of the cervix alone had evidence of anal intraepithelial neoplasia; by contrast, 57% (21/37) of those with more than one focus of intraepithelial neoplasia (cervix plus vulva, vagina, or both) had anal lesions. HPV 16 DNA was identified in 18 (51%) of 35 anal biopsy samples in the study group. No evidence of anal intraepithelial neoplasia was found in the control group (50 women), although 2 patients had grade I cervical lesions. HPV 16 DNA was identified in 12 (24%) of biopsy samples from the cervix and 7 (14%) from the anus in the control group; all 7 women with anal HPV 16 had concomitant cervical infection. The role of anal examination in the assessment of women with any focus of genital intraepithelial neoplasia requires further investigation.


Heterogeneity of high affinity uptake of L-glutamate and L-aspartate in the mammalian central nervous system.

Characteristics of high affinity uptake of L-glutamate are examined in order to evaluate the possible use of the uptake of [3H]L-glutamate, [3H]L-aspartate or any other suitable [3H]-labelled substrate as a marker for glutamatergic and aspartergic synapses in autoradiographic studies in the mammalian brain. Review of data on substrate specificity indicates the presence of at least two high affinity uptake systems specific for acidic amino acids in the central nervous tissue; one which takes up L-glutamate and L-aspartate and the other which is selective for L-glutamate only. Studies on ionic requirements, too, point to the existence of at least two distinct uptake systems with high affinity for L-glutamate. The Na(+)-dependent uptake system(s) handle(s) both L-glutamate and L-aspartate whereas the Na(+)-independent uptake system(s) show(s) selectivity for L-glutamate only. Available data do not favour the Na(+)-dependent binding of [3H]D-aspartate to thaw-mounted sections of frozen brain tissue as a suitable marker for glutamatergic/aspartergic synaptic nerve endings. However, there are reasons--such as the results of lesion studies and the existence of uptake sites which have a higher affinity for L-aspartate than for D-aspartate--to suggest that Na(+)-dependent binding of [3H]L-aspartate, rather than that of [3H]D-aspartate, should be further investigated as a possible marker for the glutamatergic/aspartergic synapses in the autoradiographic studies using sections of frozen brain.


An antibody to dopamine D2 receptor inhibits dopamine antagonist and agonist binding to dopamine D2 receptor cDNA transfected mouse fibroblast cells.

A polyclonal antibody to dopamine D2 receptor (D2-receptor) has been used to examine the immuno-inhibition in the binding of a D2 antagonist, [3H]YM09151-2 and an agonist, PPHT-fluorescein to dopamine receptor DNA transfected mouse fibroblast cells. The specific activity of the [3H]YM09151-2 binding to transfected (Ltk-RGB) cells is 4-5 fold higher than untransfected (Ltk-) cells. The antibody is able to inhibit the [3H]YM09151-2 binding to the cell membranes from Ltk-RGB cells (Bmax 110.56 +/- 5.26 and 76.20 +/- 5.18 fmoles/mg protein in the presence of preimmune and immune sera, respectively, with no change in the Kd). The flow cytometric analysis of the PPHT-fluorescein labeled Ltk- and Ltk-RGB cells indicated that ligand specific fluorescence is associated only with small Ltk-RGB cells (second peak) and autofluorescence with large cells (first peak). Preincubation of the Ltk-RGB cells with antibody, reduced the fluorescence intensity of the PPHT-fluorescein by 20-25% without changing the auto-fluorescence. These results suggest that peptide antibody recognize D2-receptor in both membranes and in intact cells and interact at or near the ligand binding site of the receptor.


The effect of amperozide, a new antipsychotic drug, on plasma corticosterone concentration in the rat.

Amperozide is an atypical antipsychotic drug with high affinity for the serotonin 5-HT2 receptor but with low affinity for the dopamine D1 and D2 receptors. Amperozide dose-dependently increased the level of plasma corticocorticosterone in the rat. The effect of amperozide on plasma corticosterone was not inhibited by pretreatment with the 5-HT1A receptor antagonist pindolol or the 5-HT2 receptor antagonist ritanserin. Nor was it inhibited by the dopamine D2 receptor antagonist haloperidol. In contrast to ritanserin, amperozide did not antagonize plasma corticosterone elevation elicited by the serotonin receptor agonist MK-212. Similar to the serotonin uptake inhibitor fluoxetine, amperozide (0.5 mg/kg) significantly (p < 0.05) blocked p-chloroamphetamine (PCA) induced corticosterone release 4 and 16 hrs after amperozide administration. However, amperozide significantly increased the plasma corticosterone concentration also in rats pretreated with parachlorophenylalanine (PCPA). These data suggest that other mechanisms than a 5-HT uptake inhibitory effect are involved in the acute stimulation of corticosterone by amperozide.


Opposite influence of medial preoptic D1 and D2 receptors on genital reflexes: implications for copulation.

Dopamine D1 and D2 receptors may synergize with or oppose each other's effects. We suggest that stimulation of D1 and D2 receptors in the medial preoptic area (MPOA) of male rats have opposing effects on genital reflexes. In Experiment 1 a D1 agonist injected into the MPOA increased the number of ex copula erections but decreased the number of seminal emissions. In Experiment 2 a D1 antagonist had the opposite effects (decreased erections and increased seminal emissions), as had a D2 agonist previously. We also suggest that D1 and D2 mechanisms in the MPOA have different thresholds of activation. In Experiment 3 a low dose of the mixed D1/D2 agonist apomorphine increased erections and anteroflexions, an effect blocked by the D1 antagonist. In Experiments 3 and 4 a high dose of apomorphine increased seminal emissions, an effect blocked by the D2 antagonist. Thus, low levels of dopaminergic stimulation may facilitate erections and anteroflexions (controlled by the parasympathetic system and striated muscles) via D1 receptors; higher or more prolonged stimulation may shift to seminal emission (controlled by the sympathetic system) via D2 receptors. This may explain the progression from erectile to ejaculatory mechanisms during copulation.


GABAA receptor function and regional analysis of subunit mRNAs in long-sleep and short-sleep mouse brain.

The greater sensitivity of long-sleep (LS), as compared with short-sleep (SS), mice to ethanol is due in part to differences in GABAA receptor function in specific brain regions. To determine if differences in subunit composition of GABAA receptors contribute to this differential sensitivity, we measured alpha 1 and gamma 2 subunit mRNAs with Northern analysis and in situ hybridization and gamma 2S, gamma 2L and alpha 6 subunit mRNAs with polymerase chain reaction (PCR) amplification. No differences in mRNAs in whole brain were apparent by Northern analysis. In situ hybridization revealed that alpha 1 and gamma 2 subunit mRNAs were co-localized in many brain regions but that they still had distinct patterns of hybridization. However, the few differences observed between LS and SS mice in the levels of hybridization for these subunits did not show a regional distribution consistent with ethanol sensitivity differences. Similar ratios of gamma 2L, and gamma 2S subunit mRNAs were found in LS and SS mouse cerebral cortex and hippocampus, and both mouse lines expressed essentially only gamma 2L subunit mRNA in cerebellum. mRNA for the alpha 6 subunit was detected only in cerebellum and also was qualitatively similar between LS and SS mice. Studies of muscimol-stimulated 36Cl- uptake by cortical membrane vesicles confirmed earlier findings that ethanol does not enhance function of GABAA receptors in SS mice when assayed at 30 degrees C. However, at 34 degrees C ethanol did increase this function in SS mice although the enhancement remained greater in LS mice. These functional results, together with the results showing similar levels of alpha 1, gamma 2S, gamma 2L and alpha 6 subunits in LS and SS mice, suggest that the ethanol-insensitivity of SS mouse GABAA receptors cannot be due solely to lack of subunits required for ethanol action and further suggest that differences in catalytic mechanisms affecting post-translational processing may account for some genetic differences in ethanol sensitivity of GABAA receptors.


Age-dependent regulation of GABAA receptors in neocortex.

We have shown previously that GABAA receptors labelled with the antagonist [3H]SR95531 can be regulated in a living cortical slice preparation by agonists or changes in electrical activity. Due to the important role that receptor regulation may play in controlling neural activity, we have now investigated the regulation of GABAA receptors in neocortex at different stages in postnatal life. We found that regulation by agonist stimulation and increases in bioelectric activity is age-dependent in amount and, in the latter case, in direction. Using muscimol as an agonist we observed a GABAA receptor down-regulation of between 60 and 70% at 20-30 days of age; in adults muscimol gave an 11% down-regulation. A combination of veratridine and glutamate gave a peak down-regulation of 39% at 20 days postnatal, but an up-regulation of 58% in adults. These age-dependent effects may signal a role for receptor regulation in cortical neural critical period plasticity.


Molecular cloning and primary structure of the avian Thy-1 glycoprotein.

We have previously characterised, both biochemically and immunohistochemically, a 23 kDa putative avian Thy-1 protein homologue. In this report we have examined the carbohydrates present on the protein and determined the partial protein sequence of enzymatically and CNBr-produced peptides. The protein sequences enabled us to clone an essentially full-length (1854 bp) cDNA using PCR and colony screening of an embryonic day (ED) 18 forebrain pUEX-1 cDNA library. Analysis of deduced amino acid sequence shows the 23 kDa protein to be 110 amino acids in length compared to mouse (112) and human and rat (111) while still retaining the conserved cysteine residues. The N-glycosylation site at position 61 is the same as that in the human protein, but is different from that in the rodent (position 75). Northern blot analysis of Thy-1 mRNA expression in the forebrain, cerebellum and tectum show that all three tissues have low levels at ED4 (forebrain and tectum) and ED8 (cerebellum), rising most rapidly between ED16 and the first few days post-hatch. Analysis of various tissues at hatch and adult show expression to be predominantly neuronal with very low levels in some other organs, mainly at hatch, indicating the possibility of subsets of cells, which we have also seen in histological sections, in these tissues expressing Thy-1 mRNA. Bone marrow and blood cells were also negative for Thy-1 protein.


VILIP, a cognate protein of the retinal calcium binding proteins visinin and recoverin, is expressed in the developing chicken brain.

Using a selective cloning approach we previously isolated a number of cDNAs of transcripts that are newly expressed during terminal differentiation of the chicken optic tectum. Here, we have characterized one of these cDNAs (OZ1) by Northern analysis and in situ hybridization. The OZ1 cDNA hybridizes to two transcripts of 1.6 kb and 2.9 kb which are widely expressed in the brain but not detectable in liver, heart or skeletal muscle. Cloning of overlapping cDNAs revealed that both transcripts encode the same open reading frame for a polypeptide of 191 amino acids. The deduced protein contains 4 EF-hand consensus motifs characteristic of calmodulin-like Ca(2+)-binding proteins. It displays 40% and 46% sequence identity with the retinal photoreceptor-specific Ca(2+)-binding proteins visinin and recoverin, respectively, and was termed VILIP (visinin-like protein). VILIP transcripts are also expressed in the retina. However, the expression pattern does not overlap with that of visinin or recoverin. The possible functional implications of the similarity to recoverin, which regulates guanylate cyclase activity of retinal rod cells in a Ca(2+)-dependent manner, are discussed.


A human dopamine transporter cDNA predicts reduced glycosylation, displays a novel repetitive element and provides racially-dimorphic TaqI RFLPs.

We describe a cDNA for the human dopamine transporter, which has been implicated in several human disorders linked to dopaminergic function. The cDNA predicts reduced glycosylation of the protein with respect to the rat transporter, as well as a novel repetitive element in the 3' untranslated region of the cDNA. A TaqI RFLP is also reported that shows a race-specific difference in allelic frequencies.


Alterations in mRNA of enkephalin, dynorphin and thyrotropin releasing hormone during amygdala kindling: an in situ hybridization study.

The present study examined changes in mRNA expression of various neuropeptides at several stages of amygdala kindled seizures. 35S-labelled oligonucleotide probes for mRNA of enkephalin (ENK), dynorphin (DYN) and thyrotropin releasing hormone (TRH) were hybridized to brain sections of rats sacrificed 24 h after a stage 1 or stage 5 seizure, or 2 weeks after a stage 5 seizure. Changes in expression developed as kindling progressed, with long-lasting changes in ENK and transient changes in DYN and TRH. ENK mRNA levels increased in pyriform and entorhinal cortices at stage 1 and 5 and remained elevated in the pyriform two weeks after a stage 5 seizure. In contrast, DYN mRNA was decreased bilaterally in the dentate gyrus 24 h after a stage 5 seizure, but returned to control levels two weeks after a stage 5 seizure. TRH mRNA was dramatically increased 24 h after a stage 1 or stage 5 seizure. After a stage 1 seizure two patterns developed. One showed increases in the pyriform, entorhinal and perirhinal cortices ipsilateral to the stimulation. The other pattern displayed bilateral increases in the dentate gyrus with or without the unilateral increases the limbic cortices. Twenty-four hours after a stage 5 seizure, large bilateral increases were found in these areas, but these returned to baseline levels by two weeks after a stage 5 seizure. The data demonstrate a constellation of alterations in several peptide systems with distinct spatiotemporal patterns, particularly in regions known to be important in kindling and epilepsy, such as the dentate gyrus and pyriform and entorhinal cortices. The relationship of these neuropeptide mRNA changes to those previously found in c-fos mRNA expression during the development of kindling is discussed.


Characterization and regulation of a high affinity [3H]CNQX labelled AMPA receptor in rat neocortex.

We have characterized a high affinity site of the alpha-amino-3 hydroxy-5-methyl-isoxazole-4-propionate (AMPA) receptor in in vitro living slices of adult rat neocortex using [3H]CNQX, and AMPA antagonist. [3H]CNQX labelled multiple binding sites with a Bmax of a high affinity site of approximately 470 fmol/mg protein and an apparent Kd of 11.3 nM. The high affinity site of the AMPA receptor could be down-regulated (36%) by 2 h preincubations in quisqualate, an AMPA agonist. Increases in electrical activity induced by a combination of veratridine and glutamate also led to an average decrease of the high affinity AMPA receptor number of 17%. In addition, preincubations with muscimol, a GABAA agonist, as well as glutamate agonists kainate and N-methyl-D-aspartate (NMDA) led to an average increase in high affinity AMPA receptor number of 17%, 14%, and 37%, respectively. The present results show that a ligand-gated high affinity AMPA receptor can be regulated by agonist stimulation as well as changes in neural activity.


Parallel upregulation of catecholamine-synthesizing enzymes in rat brain and adrenal gland: effects of reserpine and correlation with immediate early gene expression.

Changes in the mRNA levels of all catecholamine-synthesizing enzymes were examined 24 h after a single injection of reserpine by in situ hybridization. The responses of the midbrain dopaminergic cells in the ventral tegmental area and substantia nigra compacta, locus ceruleus and adrenal gland were studied in three groups of animals receiving either no injection, vehicle injection or reserpine 10 mg/kg subcutaneously. Increases in enzyme message signal observed by in situ hybridization were corroborated by Northern blot analysis for all four enzyme mRNAs species expressed in the locus ceruleus and adrenal gland were found while no change of enzyme message was detected the midbrain. Two distinct subpopulations of adrenomedullary cells could be distinguished by their baseline levels of enzyme mRNA expression: the majority of medullary cells have moderate adrenomedullary cells could be distinguished by their baseline levels of enzyme mRNA expression: the majority of medullary cells have moderate levels of all four enzyme mRNAs but a minority of cells show very high signal for the first three enzymes of the catecholamine synthesis pathway. To test whether reserpine elicits a selective transcriptional response of the catecholamine enzyme genes or induces other neuronal genes, cDNA probes for the growth-associated protein GAP-43 which is highly expressed and neurofilament L which is weakly expressed in monoaminergic neurons were used as independent cellular markers and showed no change in message levels. Changes in mRNA levels of the proto-oncogenes c-fos and c-jun were examined 1 h after injection of reserpine by in situ hybridization and compared to the pattern observed for the Fos protein immunohistochemically. C-fos and c-jun proto-oncogene activation was observed 1 h after reserpine in the locus ceruleus and adrenal medulla, specifically in those catecholaminergic structures that respond with increased enzyme gene transcription; in contrast, the dopaminergic neurons of the substantia nigra did not exhibit detectable proto-oncogene activation, only a small group of neurons in the ventral tegmental area showed c-fos without concomitant c-jun expression after reserpine.


Effects of arch height of the foot on ground reaction forces in running.

There is a suggested link between running injuries and arch type of the foot. However, a distinct cause and effect relationship has not been established. Feet may be functionally categorized on the basis of arch height. The purpose of this study was to compare selected ground reaction force variables in running for different arch heights. Static height of the medial longitudinal arch was measured using a caliper, arch flattening during running was determined by video analysis, and ground reaction forces during running were recorded from a KISTLER force plate. Thirty-four subjects were divided into three arch height and three arch flattening groups, and single-factor analyses of variance were conducted to compare the groups. Arch height and arch flattening were not found to be significantly related. However, the initial medial force peak in the low arch group occurred significantly later than in the normal and high arch groups, and the anterior force peak in the low flattening group was lower compared with the medium and high flattening groups (P < 0.05). Both arch measurements were ineffective in accounting for the observed variability in the ground reaction forces in running. Specifically, the impact forces did not differ for the different arch height and arch lowering groups.


Dissociation of macrophage cytolysis and ability to transfer anti-listeria resistance by concanavalin A-stimulated spleen cells.

In this study, we determined whether spleen cells from Listeria monocytogenes-immunized mice were cytolytic for Listeria-infected macrophages. Spleen cells freshly obtained from immunized donors were unable to lyse Listeria-infected macrophages unless they were first stimulated in vitro for 2-3 days with Concanavalin A (ConA) or L. monocytogenes. Spleen cells from non-immunized mice developed cytolytic activity after incubation with ConA, but not with L. monocytogenes. Cytolytic spleen cells demonstrated an equivalent ability to lyse uninfected and Listeria-infected thioglycollate elicited peritoneal macrophages. Maximal cytolysis required co-incubation of effector and target cells for 18-20 h. Spleen cell culture supernatants did not lyse macrophages, suggesting that cytolysis required direct contact. Preincubation of immune spleen cells with ConA decreased their ability to transfer anti-listeria resistance in the spleens, but not the livers of recipient mice. Depletion of CD4+ or CD8+ cells did not significantly reduce the ability of ConA-incubated Listeria-immune spleen cells to transfer resistance. Despite being cytolytic for Listeria-immune infected macrophages, ConA-stimulated non-immune spleen cells did not transfer anti-listeria resistance. These results indicate that cytolytic cells can be generated by short-term incubation of spleen cells with antigen or mitogen. The dissociation between in vitro cytolytic activity and ability to transfer protection, however, suggests that the two biological activities are not inextricably linked.


Characterization and detection of the 40 kDa fimbrial subunit of Bacteroides fragilis BE1.

The amino acid composition and amino-terminal amino acid sequence of the 40 kDa fimbrial subunit of Bacteroides fragilis were determined. No similarity with other known fimbrial subunits or protein sequences was found. The isoelectric point of the fimbriae was determined to be 3.8. The acidic nature of these fimbriae is in agreement with the amino acid composition of the fimbrial subunit. An IgM monoclonal antibody, raised against the denaturated subunit of strain BE1 fimbriae, reacted with native BE1 fimbriae and appeared to be strain specific. Bacteroides fragilis strain BE38 expressed fimbriae which did not react with the polyclonal or monoclonal antibodies directed against strain BE1 fimbriae.


Binding of Haemophilus ducreyi to extracellular matrix proteins.

A collection of Haemophilus ducreyi isolates were screened for the ability to bind to fibrinogen, fibronectin, collagen, gelatin and laminin by a particle agglutination test using latex beads coated with the individual proteins. Thirteen of 21 isolates reacted with all five extracellular matrix proteins. Binding of organisms to protein-coated latex beads was inhibited by pretreatment of the bacteria with detergent, trypsin or boiling. Two isolates did not bind to collagen and gelatin with one of these not reacting with laminin either. Seven strains which failed to react with laminin did not express pili when examined by electron microscopy. This observation suggests a specific interaction with the pili of H. ducreyi.


Bacterial spinal epidural abscess. Review of 43 cases and literature survey.

We have reviewed our experience with 43 cases of bacterial spinal epidural abscess, as well as previously reported series of cases. We found a striking male predominance of the disease, accounting for 86% of cases. Most patients had some underlying conditions that predisposed to infection, a prior infection at a distant site, or an abnormality or trauma to the spine. Presenting symptoms included backache (72%), radicular pain (47%), weakness of an extremity (35%), sensory deficit (23%), bladder or bowel dysfunction (30%), and frank paralysis (21%). Patients cared for in public hospitals tended to seek medical attention in later stages of the disease than patients admitted to private hospitals. Spinal epidural abscess was the suspected diagnosis in only 40% of the cases; the remainder of the time various other infections, tumors, neurologic diseases, or degenerative conditions were considered. Patients in whom the diagnosis of spinal epidural abscess was not initially entertained on admission suffered delays in diagnosis and experienced neurologic deterioration. Staphylococcus aureus was the predominant pathogen (65%) and was associated with positive blood cultures in nearly every case; aerobic or facultative gram-negative bacilli were next most common. Coagulase-negative staphylococci caused infection only in patients who had previous spinal instrumentation. Although analysis of CSF was abnormal in the majority of cases, abnormalities were nonspecific, Gram stain was always negative and culture was rarely diagnostic. Abscesses extended over an average of 4 vertebrae, and the majority were located in the lumbar region followed by thoracic and cervical regions. Unlike previous series, we noted an equal frequency of anterior and posterior epidural abscesses; although differences were not statistically significant, posterior abscesses tended to be more extensive but less commonly associated with radiographic abnormalities of osteomyelitis. Myelography revealed an abnormality in every case in which it was done. Computerized tomographic scanning after intrathecal injection of contrast material always provided additional useful information. Even though magnetic resonance imaging was diagnostic in only 4 of 5 cases (80%) in our series, this test is noninvasive and clearly delineates the location and nature of spinal lesion. It should, therefore, probably replace myelography as an initial definitive study in patients suspected of having spinal infection. Plain roentgenograms and nuclear scans contributed little useful information that was not already available from other radiographic procedures. Surgical drainage together with antibiotics was the treatment of choice; 35 of our 43 patients underwent operative intervention. The preoperative status clearly predicted the final neurologic outcome.(ABSTRACT TRUNCATED AT 400 WORDS)


Consecutive actions of different gene-altering mechanisms in the evolution of involucrin.

During the evolution of primates from nonprimates, the gene for involucrin was greatly altered by changes in the short tandem repeats that are present in some form in the gene of each of 17 species examined. The evolution of involucrin was not the result of a single continuum of more or less random changes, and it was not confined to the process of nucleotide substitution, the most commonly studied evolutionary change in DNA. Instead, the evolution of this gene took place through different mechanisms that shortened the length of the repeats, increased their number, and changed their codon sequence. As part of this trend, one entire segment of repeats was replaced by another located elsewhere in the coding region. To bring about these changes, specific mechanisms have been activated, deactivated, and replaced by other mechanisms. The resulting serial revisions in the involucrin gene must depend on gene-altering machinery whose synthesis or activity can be controlled.


[A case of unusual occupational allergy to bee venom].

The authors discuss an exceptional case of allergy to bee venom in a zoo-technician working on a morphological analysis of bees. During her work, the zoo-technician was repeatedly stung, initially with only small local reaction. After six-year period of work, the symptoms that followed stinging had all the characteristics of general oedema. Next years of exposure to bee venom resulted in collapse in the patient. Allergological examinations indicated work-related hypersensitivity to bee venom. The case history was supplemented with prophylactic recommendations. General principles of controlling the shock were provided.


Surface exclusion specificity of the TraT lipoprotein is determined by single alterations in a five-amino-acid region of the protein.

The TraT protein is a highly cell-surface-exposed lipoprotein specified by F-like plasmids that confers serum resistance and blocks the conjugative transfer of plasmids to cells bearing identical or closely related plasmids, a process known as surface exclusion. The TraT protein specified by the antibiotic-resistance plasmid R6-5 was purified to apparent homogeneity. When added to mating mixtures, TraT blocked the transfer of plasmids belonging to Surface Exclusion Group IV (Sfx IV) but had no significant effect on the transfer of plasmids belonging to other groups. Additionally, the purified protein has a protective effect on bacterial cells incubated in serum, indicating that it does not have to be located on the cell surface to mediate serum resistance. To localize regions of the protein that were responsible for surface exclusion specificity, the amino acid sequence of the TraT protein specified by CoIB2-K98 (Sfx II) was determined by cloning and sequencing of the corresponding gene. Comparison of the derived sequence with those of the F and R100-1 proteins indicated that surface exclusion specificity of TraT is determined by single alterations in a five-amino-acid region (residues 116-120). This was confirmed by segment swapping experiments in which the specificity of the R6-5 TraT protein (Sfx IV) was switched to that of the CoIB2-K98 protein (Sfx II). Our results suggest that the region defined by residues 116-120 is located on the external face of the outer membrane and interacts specifically with the donor cell in surface exclusion.


Characterization and functional expression in Escherichia coli of the sodium/proton/glutamate symport proteins of Bacillus stearothermophilus and Bacillus caldotenax.

The genes encoding the Na+/H+/L-glutamate symport proteins of the thermophilic organisms Bacillus stearothermophilus (gltTBs) and Bacillus caldotenax (gltTBc) were cloned by complementation of Escherichia coli JC5412 for growth on glutamate as sole source of carbon, energy and nitrogen. The nucleotide sequences of the gltTBs and gltTBc genes were determined. In both cases the translated sequences corresponded with proteins of 421 amino acid residues (96.7% amino acid identity between GltTBs and GltTBc). Putative promoter, terminator and ribosome-binding-site sequences were found in the flanking regions. These expression signals were functional in E. coli. The hydropathy profiles indicate that the proteins are hydrophobic and could form 12 membrane-spanning regions. The Na+/H+ coupled L-glutamate symport proteins GltTBs and GltTBc are homologous to the strictly H+ coupled L-glutamate transport protein of E. coli K-12 (overall 57.2% identity). Functional expression of glutamate transport activity was demonstrated by uptake of glutamate in whole cells and membrane vesicles. In accordance with previous observations (de Vrij et al., 1989; Heyne et al., 1991), glutamate uptake was driven by the electrochemical gradients of sodium ions and protons.


Alcohol delays clearance of lipoproteins from the circulation.

Long-term (18-month) consumption of high-dose ethanol ([EtOH] 24% of total calories) by squirrel monkeys results in marked elevations in plasma antiatherogenic high-density lipoprotein (HDL) cholesterol and apolipoprotein (apo) A-1, and atherogenic low-density lipoprotein (LDL) cholesterol and apo B. In an effort to determine whether alterations in lipoprotein turnover could explain the above findings, 131I-HDL apo A-1 and 125I-LDL apo B were injected into EtOH and control animals, following which in-vivo catabolic and production rates were determined. For both lipoproteins, synthetic rates were unaltered, while fractional catabolic rates (FCR) were significantly reduced in EtOH monkeys. Results from this study implicate EtOH-induced changes in hepatic metabolism as the basis for delayed lipoprotein clearance and hence elevated plasma apolipoprotein levels.


Synthesis of a yohimbine-agarose matrix useful for large-scale and micropurification of multiple alpha 2-receptor subtypes.

We have provided a detailed protocol for the synthesis of a yohimbine-agarose matrix that has been shown to be effective for isolation of the alpha 2A-adrenergic receptor from human platelet and purification of the alpha 2A-adrenergic receptor to apparent homogeneity from porcine brain cortex using chromatography on only two sequential yohimbine-agarose columns. In addition, this affinity matrix also interacts with alpha 2 receptors of the alpha 2B subtype extracted from cultured NG108-15 cells. Finally, this affinity matrix has proven useful for monitoring posttranslational modifications of the receptor in digitonin extracts of metabolically labeled cells. Thus, this affinity matrix can be exploited for the purification of multiple alpha 2-adrenergic receptor subtypes on both a macro- and microscale and should be of value to any laboratory exploring the molecular basis for alpha 2-adrenergic functions.


Follow-up care after acute myocardial infarction.

To examine the medical care received by patients following discharge from hospital after acute myocardial infarction (AMI). Community-based cross-sectional survey. 2836 consecutive patients aged 25-64 years living in the Perth Statistical Division who were admitted to hospital with AMI during 1984-1988. After one reminder the response rate was 71%. Half of all respondents were in full-time employment at the time of their AMI. At follow-up this had fallen to a third. Over 80% of patients visited a cardiologist after AMI, with half remaining under consultant care to the time of survey. However, one in five patients reported no follow-up care at the time of survey. Seventy-three per cent of patients reported undergoing at least one exercise stress test after AMI, with 61% undergoing angiography, 16% angioplasty and 24% coronary bypass surgery. Large proportions of the patients accurately reported being prescribed beta-blockers and antiplatelet agents. The pattern of prescribing at discharge corresponded closely with the use of cardioactive agents at the time of survey and with drugs reported to have been taken continuously since discharge to the time of survey. These data suggest that follow-up care after AMI is both comprehensive and widespread. Such care may have contributed significantly to the overall decline in mortality from ischaemic heart disease.


[The results and problems of surgical treatment of cancer of the duodenal papilla of Vater].

Twenty six of 28 cases (92.9%) of cancer of duodenal papilla of Vater were resected from 1981 to 1990. Twenty five pancreatoduodenectomy and one total pancreatectomy were performed. Operative death and hospital death were not observed. Three year and five year cumulative survival rates of resected cases were 58% and 52% respectively. There was relatively good correlation between pathological cancer extension and postoperative prognosis. Postoperative prognosis of the cases which had cancer extension to the pancreas was extremely poor. But the prognosis of the cases of cancer within Oddi muscle was extremely good. Immunohistochemical staining using anti CEA, anti CA19-9 and anti DUPAN 2 was studied and Grade III staining pattern was observed only in the cases which had cancer invasion to the pancreas. Preoperative diagnosis of cancer extension using endoscopic ultrasonography and appropriate choice of the operative procedure are important. Extended operation and effective adjuvant therapy are necessary for advanced cases of cancer of the duodenal papilla.


[The surface structures and biological properties of Klebsiella strains].

The electron-microscopic method has been used to study the surface structures and biological properties (adhesiveness, antibiotic-resistance, biochemical properties) in 67 strains of Klebsiella isolated from one-year-old children with intestinal infections (56) and from healthy ones (11). It is found that bacterial cells in 58.2% of strains have fimbriae of the 3d type, in 20.9%--of the 1st type. No correlation has been revealed between the type of fimbriae and the studied properties.


Cloning and mapping of telomere-associated sequences from Hordeum vulgare L.

We present a novel approach to the efficient cloning of telomere-associated sequences and demonstrate its application to the cloning and mapping of these sequences from barley. The method is a modification of the Vectorette PCR technique and allows specific amplification and cloning of subtelomeric sequences. Telomere-associated sequences isolated from barley include hypervariable, repetitive sequences. Polymorphisms detected by subtelomeric markers behaved as Mendelian factors and were mapped to the most distal positions of barley chromosomes 1, 2, and 4.


kappa-Opioid inhibition of [3H]dopamine release from rat ventral mesencephalic dissociated cell cultures.

The present study investigated the effect of opioids on [3H]dopamine release from mixed neuronal-glial cell cultures of embryonic rat ventral mesencephalon. Each of the major morphological types of dopaminergic cell was represented in these cultures. These cells exhibited specific uptake of [3H]dopamine, which was subsequently released, in a calcium-dependent manner, in response to a double pulse of elevated extracellular potassium. Spontaneous and potassium-evoked [3H]dopamine release was inhibited by kappa- but not mu- or delta-opioid agonists. The selective kappa 1 agonist (5 alpha, 7 alpha, 8 beta)-(-)-N-methyl-N-[7-(1-pyrollidinyl)-1-oxaspiro(4,5)- dec-8-yl]benzeneacetamide (U69593) produced a dose-dependent inhibition of dopamine release. The effect of U69593 was blocked by the nonselective opiate antagonist naloxone and the selective kappa opioid antagonist norbinaltorphimine. kappa-Opioid inhibition of potassium-evoked [3H]dopamine release was maintained in the presence of tetrodotoxin. These results suggest that functional kappa receptors, modulating dopamine release, are localized on the terminals of dopaminergic neurons.


Coexisting beta 1- and atypical beta-adrenergic receptors cause redundant increases in cyclic AMP in human neuroblastoma cells.

In SK-N-MC human neuroblastoma cells, the cAMP response to 10 nM isoproterenol (ISO) is mediated primarily by beta 1-adrenergic receptors. However, responses to higher concentrations of ISO (100-1000 nM) were only weakly blocked by beta 1- and beta 2-selective antagonists. When beta 1 receptors were blocked with 10 microM CGP 20712A, catecholamines still maximally activated cAMP accumulation, with only small decreases in potency. In the presence of CGP 20712A, beta blockers inhibited the response to ISO stereoselectively but with relatively low potencies. Pindolol derivatives were partial agonists with low potencies, and the atypical agonist BRL 37344 was a partial agonist with an intermediate potency. All binding sites in these cells labeled by 125I-cyanopindolol were of the beta 1 subtype. Nuclease protection assays indicated that SK-N-MC cells contain mRNA for both the human beta 1- and beta 3-adrenergic receptors, with the beta 3 subtype mRNA being expressed 25-50% more abundantly than that for the beta 1 subtype. Northern blot hybridizations showed the presence of two beta 3 mRNA transcripts of 3.1 and 2.4 kilobases. These results suggest that beta 1- and atypical beta-adrenergic receptors coexist in these cells and cause redundant increases in cAMP formation. Although molecular approaches suggest that the atypical subtype is the beta 3, the observed drug specificity differs from that reported for the expressed recombinant human beta 3 receptor.


[Bloodsucking mosquitoes on the irrigated lands of Kara-Kalpakia. I. The species composition and distribution of mass species].

Data on fauna of bloodsucking mosquitos (Culicidae), obtained during the survey in the irrigated part of Takhta-Kupyr District of Kara-Kalpakia in 1988-1989, are presented. The density of mosquito populations of mass species in different parts of the oasis is, to a great extent, caused by the presence of reservoirs of different types and also by the features of anthropogenic landscapes.


Unsurmountable antagonism of brain 5-hydroxytryptamine2 receptors by (+)-lysergic acid diethylamide and bromo-lysergic acid diethylamide.

Lysergic acid diethylamide (LSD) and its structural analogue 2-bromo-lysergic acid diethylamide (BOL) act as unsurmountable antagonists of serotonin-elicited contractions in smooth muscle preparations. Two different models, allosteric and kinetic, have been invoked to explain these findings. The present studies investigate the mechanism of antagonism of brain 5-hydroxytryptamine (5HT)2 receptors, utilizing cells transfected with 5HT2 receptor cDNA cloned from rat brain. A proximal cellular response, phosphoinositide hydrolysis, was examined in order to minimize possible postreceptor effects. Even though LSD behaved as a partial agonist and BOL as a pure antagonist, both drugs blocked the effect of serotonin in an unsurmountable manner, i.e., increasing concentrations of serotonin could not overcome the blocking effect of LSD or BOL. Radioligand binding studies showed that preincubation of membranes with either LSD or BOL reduced the density of [3H]ketanserin binding sites, suggesting that the drugs bind tightly to the 5HT2 receptor and are not displaced during the binding assay. Two additional experiments supported this hypothesis. First, the off-rate of [3H] LSD was slow (20 min), relative to that of [3H]ketanserin (approximately 4 min). Second, when the length of incubation with [3H]ketanserin was increased to 60 min, the LSD-induced decrease in Bmax was essentially eliminated. The possibility that LSD and BOL decrease [3H]ketanserin binding by interacting with an allosteric site was rejected, because neither drug altered the rate of dissociation of [3H]ketanserin. The most parsimonious interpretation of these results is that unsurmountable antagonism reflects prolonged occupancy of the receptor by slowly reversible antagonists.


Long term treatment with desipramine increases the turnover of alpha 2-adrenoceptors in the rat brain.

The aim of this study was to quantitate the turnover of alpha 2-adrenoceptors in different regions of the rat brain and its modulation during desipramine (a cyclic antidepressant drug)-induced receptor down-regulation. The recovery of [3H]clonidine (a mixed alpha 2A/B-adrenoceptor agonist) binding after irreversible inactivation by N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) (an alkylating agent for both alpha 2-adrenoceptor subtypes) was assessed in control and desipramine-treated (3 mg/kg, intraperitoneally, every 12 hr for 7-35 days) rats to study the process of alpha 2-adrenoceptor repopulation and to calculate receptor turnover parameters. In control rats, the turnover of brain alpha 2-adrenoceptors showed marked regional differences. The fastest receptor turnover rate was found in the hypothalamus and corpus striatum (receptor half-life, t1/2 = 2.1 days), compared with that in the brainstem (t1/2 = 2.6 days), cerebral cortex (t1/2 = 3.9 days), and hippocampus (t1/2 = 4.3 days). In the cerebral cortex and other brain regions, desipramine induced a time-dependent modulation of alpha 2-adrenoceptors, with significant decreases in the number of receptors (40-71%; p < 0.01) during the first 7-14 days of treatment and regulation to base-line values by 21-35 days. In the cerebral cortex, alpha 2-adrenoceptor turnover evaluated during desipramine-induced receptor down-regulation (phase of 7-14 days of treatment) revealed an increase in both the disappearance (degradation) (delta k = 122%; p < 0.05; t1/2 = 1.7 days) and appearance (synthesis) (delta r = 68%; p < 0.05) rates of the receptor. In other noradrenergic brain regions (hippocampus, brainstem, and hypothalamus) but not in the corpus striatum, desipramine (7-14 days) also increased alpha 2-adrenoceptor degradation (delta k = 97-144%) and shortened the half-life of the receptor, and it tended to increase the rate of synthesis (delta r = 51-83%). Similar results, but with a higher appearance rate, were obtained in the cerebral cortex during the phase of treatment (21-35 days) without apparent receptor down-regulation (delta k = 160%; p < 0.01; t1/2 = 1.5 days; delta r = 128%; p < 0.001). It is proposed that sustained stimulation of alpha 2-adrenoceptors by endogenous norepinephrine, after inhibition of neuronal uptake, increases their disappearance rate (degradation), leading to a reduction in receptor number. The increase in the appearance (synthesis) rate could be viewed as a later compensatory mechanism that would lead to restoration of brain alpha 2-adrenoceptor density.


Regulation of tyrosine hydroxylase gene transcription rate and tyrosine hydroxylase mRNA stability by cyclic AMP and glucocorticoid.

Tyrosine hydroxylase mRNA is induced in rat pheochromocytoma PC18 cells by cAMP analogs and glucocorticoids. Previous studies have shown that these increases in tyrosine hydroxylase mRNA are due at least in part to stimulation of the tyrosine hydroxylase gene. However, the involvement of post-transcriptional mechanisms in the regulation of tyrosine hydroxylase mRNA by these inducing agents has not been investigated. In the present study, using nuclear run-on assays we show that the relative transcription rate of the tyrosine hydroxylase gene is stimulated 2-5-fold within 20 min after treatment of PC18 cells with cAMP analogs or dexamethasone and that the rate of transcription remains elevated 2-3-fold for at least 24 hr in the continual presence of these inducing agents. Pulse-labeling experiments using 4-thiouridine indicate that the rate of synthesis of tyrosine hydroxylase mRNA is increased approximately 3-fold or 10-fold after treatment with either a cyclic AMP analog or dexamethasone, respectively. These increases in rates of synthesis agree well with the fold increases in tyrosine hydroxylase mRNA levels after treatment with these inducers. Treatment of the cells with cycloheximide lowers the basal relative transcription rate of the tyrosine hydroxylase gene 2-3-fold; however, the relative transcription rate of the tyrosine hydroxylase gene is still elevated in cells treated with either dexamethasone or cAMP analogs in the presence of cycloheximide, compared with the transcription rate of the gene in cells treated with cycloheximide alone. These results indicate that protein synthesis is not required for the short term regulation of the gene by these inducing agents. The apparent t1/2 for tyrosine hydroxylase mRNA has been estimated by two different procedures, approach to steady state kinetics and pulse-chase analysis. Both procedures yield an estimated apparent t1/2 of approximately 6-9 hr for tyrosine hydroxylase mRNA under basal culture conditions. Dexamethasone does not substantially alter this apparent t1/2 value; however, cAMP appears to lower this apparent t1/2 value transiently. Our results suggest that cAMP and glucocorticoid regulate tyrosine hydroxylase mRNA levels primarily by stimulating the transcription rate of the tyrosine hydroxylase gene; however, cAMP may also regulate the stability of the mRNA for a short period of time, such that it is induced more rapidly in the cells.


An extended developmental study of gamma-glutamyltranspeptidase in rat liver plasma membranes: identification of specific patterns of changes in activity in the adult as well as the neonatal state.

Homogenates and plasma membranes were isolated from the livers of male Fischer 344 rats ranging in age from 19 hr to 92 days postnatal. These plasma membranes exhibited comparable levels of purity: protein yields were 2-2.5%; relative specific activities of 5'-nucleotidase and ouabain-sensitive Na+/K(+)-ATPase were from 8-11 and from 12-19, respectively. 5'-nucleotidase and ouabain-sensitive Na+ K(+)-ATPase displayed distinct and different developmental patterns. The activity of gamma-glutamyltranspeptidase was found to be at exceptionally high levels in isolated plasma membranes immediately after birth and to decline precipitously thereafter achieving and maintaining low levels from days 3-21 postnatal. Liver plasma membrane gamma-glutamyltranspeptidase activity was observed to increase 9.2 fold from this low point, first rising on day 21, peaking on day 40 and returning to low levels by day 56. From day 56 day to 92 postnatal, gamma-glutamyltranspeptidase activity was expressed at a uniformly low level but a level 2 fold higher than that preceding the rise at day 40. The hormone determinants of these developmental changes in gamma-glutamyltranspeptidase activity are discussed.


Regulation of an H-ras-related transcript by parathyroid hormone in rat osteosarcoma cells.

The rat osteosarcoma cell line UMR 106-01 is a commonly used model system for the study of osteoblast function. However, it also expresses a phenotype characteristic of transformed cells. To test whether the latter could be accounted for by aberrant oncogene expression, we probed Northern blots of UMR and other osteoblastic cells with a panel of oncogene probes. These blots, when probed with a cDNA specific for v-H-ras, revealed a 7.0-kilobase (kb) H-ras-related transcript (designated HRRT) in UMR 106-01 cells that was not expressed in other osteoblastic cells. Osteoblast-enriched calvarial cells expressed the typical 1.1-kb H-ras mRNA, which was absent in UMR cells. Additionally, Western blots of lysates of UMR cells documented the presence of three proteins immunologically related to H-rasp21. To determine whether HRRT represented a recombinant retrovirus product, Northern blots were probed with a cDNA specific for the highly conserved gag-pol region of Moloney murine leukemia virus. These blots showed parallel cross-reactivity with an apparently identical transcript of 7.0 kb. The 7.0-kb transcripts detected by both v-H-ras and gag-pol probes declined to the same extent after treatment with concentrations of PTH known to inhibit proliferation of these cells. PTH regulated the abundance of HRRT in a time- and dose-dependent manner, with greatest repression of the transcript after 8 h of treatment with 10(-8) M PTH. The decrease in HRRT could not be completely accounted for by changes in transcriptional activity, as determined by nuclear run-on assays.(ABSTRACT TRUNCATED AT 250 WORDS)


The immune response evokes up- and down-modulation of beta 2-adrenergic receptor messenger RNA concentration in the male rat thymus.

Important alterations of noradrenergic activity are known to occur in specific brain regions and in different lymphoid tissues during the course of an immune response. Our recent characterization of the beta 2-adrenergic receptor (beta 2AR)-cAMP system of the rat thymus gland, the identification of a thymic beta 2AR gene expression, and the marked modulation of receptor mRNA concentration after castration and replacement with estrogen prompted us to study the ability of products of immune axis activation to modulate beta 2AR number, distribution, and expression in the male rat thymus. Moreover, the effect of adrenergic stimulation of adenylyl cyclase activity on thymus gland membrane preparations was measured. The beta 2AR present in the rat thymus undergoes marked changes in both number and distribution during the course of an immune response. At 3 days after antigenic challenge (injection of BSA in complete Freund's adjuvant), a sharp decrease of receptor number coupled with a significant loss of the autoradiographic reaction in the medullary compartment of the rat thymus gland were observed. These effects were followed by a significant increase in receptor density and number without changes in receptor affinity at 7 and 15 days post immunization, corresponding to the pick of the immune response. Parallel alterations in adenylyl cyclase activity were measured. Northern blot analysis, using a human beta 2AR cDNA as a probe, revealed dramatic alterations of the beta 2AR mRNA in the thymus, characterized by an approximately 75% decrease of mRNA level 3 days after immunization, and by a progressive increase at 7 and 15 days, with beta 2AR mRNA concentration rising to levels even higher than those found in control animals. These results suggest that the immune response evokes marked alterations of the thymic beta 2AR-cAMP signaling pathway. Moreover, antigenic stimulation triggers a down- and up-modulation of beta 2AR gene expression. Although it is presently unknown whether factor(s) released by immune axis activation act at the level of gene transcription to modulate adrenergic receptor function in the rat thymus, such down- and up-regulation of beta 2AR mRNA may play a role in the dynamic regulation of the immune response.


[Atypical cat eye syndrome. Fluorescence in situ hybridization of metaphase chromosomes].

In 1983, a chromosome analysis was carried out in a newborn preterm infant with minor anomalies (preauricular skin tag, maldescensus testis). All analysed metaphases showed a small extra chromosome, which was symmetric, dicentric and bi-satellited. In spite of in depth analysis, its origin remained obscure. Recent re-evaluation using fluorescence in situ hybridization (FISH) led to the diagnosis of a dicentric chromosome 22. The FISH technique is an important new tool in chromosome diagnostics. The phenotype of this infant only vaguely resembles the cat eye syndrome. The syndrome should be diagnosed clinically and not only based on the results of chromosome analysis.


[Discovery of the gene makes the direct molecular genetic diagnosis of Martin-Bell syndrome possible].

FORMULATION OF QUESTION: In 1991 four independent groups of geneticists succeeded in replacing the comparatively unreliable cytogenetic and indirect molecular diagnostics of the X-linked Martin-Bell-syndrome (MBS) by a more accurate approach. Fine structure analysis of the disease locus at Xq 27.3 led to the discovery of the fragile X mental retardation gene I (FMR I-gene), the mutative changes of which are responsible for the disease and can easily be detected in Southern hybridizations with gene probes out of this area. The observed changes are strong amplification of a repetitive CGG-motive in exon I of the gene in patients, a more moderate one in symptom-free carriers of the disease and changes in the promotor region of the gene to a varying extent in patients and carriers. This direct molecular diagnosis of MBS enables a safe identification of patients and carriers of the disease. A combined analysis of the observed mutations makes possible prenatal diagnosis, discriminating between carriers with and without symptoms. Especially this is necessary, since 20% of male and 50 to 70% of female mutation carriers are phenotypically normal.


[Treatment of juvenile spondylarthritis and reactive arthritis with sulfasalazine].

Eleven children suffering from juvenile spondylitis and reactive arthritis not responding to antiinflammatory therapy were treated with sulfasalazine. Eight patients showed good response, in two patients no improvement was seen and in one therapy was stopped because of side effects. This overall successful result of sulfasalazine therapy of juvenile spondylitis should encourage clinicians to plan controlled trials.


Primary sequences of two P-glycoprotein genes of Entamoeba histolytica.

Two P-glycoprotein genes (EhPgp1 and EhPgp2) from the protozoan parasite Entamoeba histolytica were sequenced from a genomic library made with the DNA of an emetine-resistant ameba mutant, which overexpresses mRNAs homologous to segments of the human mdr1 (P-glycoprotein) gene. The open reading frames for EhPgp1 and EhPgp2 were 1302 and 1310 amino acids long, respectively, and showed a 67% positional identity with each other and 41% and 40% positional identities, respectively, with human mdr1 gene. Within each ameba P-glycoprotein were the ATP-binding sites found twice in eukaryotic P-glycoproteins and once in prokaryotic transport proteins. Hydropathy plots of the ameba P-glycoproteins were nearly superimposable on that of the human mdr 1, showing 2 homologous halves, each containing an ATP-binding site and 6 hydrophobic transmembrane domains that form the putative channel. A phylogenetic tree showed that the Entamoeba P-glycoproteins are more related to the human and mouse P-glycoproteins than to the Plasmodium and Leishmania P-glycoproteins. Also identified in the E. histolytica genomic library were 2 P-glycoprotein pseudogenes, each with a frame shift and stop codons in identical places within the amino ATP-binding site. In conclusion, the 2 E. histolytica P-glycoproteins encoded by the EhPgp1 and EhPgp2 genes are similar in structure to the mammalian P-glycoproteins and so may be involved in energy-dependent drug efflux by this human parasite.


Stable amplification of a linear extrachromosomal DNA in mycophenolic acid-resistant Leishmania donovani.

Pulsed field gel electrophoretic analysis of chromosomes of MPA100 cells, a strain of Leishmania donovani that possesses an approx. 15-fold amplified IMP dehydrogenase (IMPDH) gene copy number, revealed a new 280-kb extrachromosomal DNA, IMPDH-280, that was not present in wild type parental cells. Southern blots of these pulsed field gels revealed that the vast majority of the amplified impdh genes were localized on IMPDH-280. In addition to the 700-kb wild type chromosome, the impdh probe also recognized a 740-kb chromosome in the MPA100 genome. The pulse time-dependent relative mobility of IMPDH-280 in pulsed field gels, the failure of limited gamma-irradiation to generate a new discrete DNA fragment, and the susceptibility of IMPDH-280 to lambda-exonuclease digestion, demonstrated that IMPDH-280 was a linear molecule. IMPDH-280 was also recognized by a telomere probe but not by fragments derived from amplified DNAs found in other drug-resistant Leishmania. IMPDH-280 and the drug resistance phenotype remained stable when MPA100 cells were propagated in the absence of drug for 2 years. The appearance of IMPDH-280 in MPA100 cells represents one of the first examples of an amplification of a linear extrachromosomal DNA element mediating drug resistance in Leishmania and the first instance of a linear DNA amplification that is stable in the absence of selective pressure.


Toxoplasmosis of the central nervous system in the acquired immunodeficiency syndrome.

Toxoplasmosis is the most common opportunistic infection of the central nervous system in patients with the acquired immunodeficiency syndrome (AIDS). To investigate its clinical course, we reviewed the records of 115 patients with AIDS and central nervous system toxoplasmosis treated at San Francisco General Hospital between 1981 and 1990. The most common presenting symptoms were headache (in 55 percent), confusion (52 percent), and fever (47 percent). Focal neurologic deficits were present in 79 patients (69 percent). The median CD4 cell count at presentation was 50 per cubic millimeter (50 x 10(6) per liter). Thirteen of 80 patients with clinical toxoplasmosis (16 percent) and 4 of 18 patients with pathologically proved disease (22 percent) had undetectable antitoxoplasma IgG antibodies by indirect immunofluorescence assay. Of 103 patients, 94 (91 percent) had enhancing lesions on CT. Single lesions were seen in 28 of 103 patients (27 percent) on CT, and such lesions were seen in 3 of 21 patients (14 percent) on magnetic resonance imaging. Over 90 percent of patients who eventually had clinical and radiographic improvement had evidence of improvement by day 14 of therapy. Adverse drug reactions occurred in 71 patients (62 percent) and led to a change in therapy in 50 patients (43 percent). Among the patients who survived a first episode of toxoplasmosis, the median survival was 265 days. Toxoplasmosis occurs in advanced stages of human immunodeficiency virus infection, and the absence of antitoxoplasma antibodies on immunofluorescence assay does not exclude the diagnosis. The clinical and radiographic response to therapy is usually rapid, but treatment is frequently limited by adverse drug effects.


Clinical manifestations and predictors of disease progression in drug users with human immunodeficiency virus infection.

To examine the clinical course of human immunodeficiency virus (HIV) infection in injection-drug users, we conducted a prospective study of a cohort of patients in a methadone-treatment program in New York City from July 1985 through December 1990. The patients underwent standardized evaluations at base line and semiannually thereafter and received on-site primary medical care. Rates of progression to the acquired immunodeficiency syndrome (AIDS) and major outcomes before the development of AIDS were examined by univariate analyses; the risk of AIDS was also assessed by product-limit survival analysis and proportional-hazards regression. Of 318 HIV-seropositive patients who did not yet have AIDS (171 men and 147 women), 90 were black, 179 were Hispanic, and 49 were white; the median age was 33 years. Over a median of 3.0 years of follow-up, 55 (17 percent) received a diagnosis of AIDS (incidence per 100 person-years, 5.8). Major outcomes before the development of AIDS included oral candidiasis (incidence per 100 person-years, 11.2), pyogenic bacterial infections including pneumonia and sepsis (8.0), pulmonary tuberculosis (1.2), multiple constitutional symptoms (13.6), and herpes zoster (1.3). There were 41 deaths from AIDS, and 13 seropositive patients without AIDS (4.1 percent) died of bacterial infections, as compared with only 1 of 411 seronegative patients studied (P < 0.001). The incidence of AIDS was 62 percent lower among those who took zidovudine than among those who did not (P = 0.02). In the multivariate analysis, progression to AIDS was best predicted by low numbers and percentages of CD4+ lymphocytes, nonuse of zidovudine, and the presence of oral candidiasis, bacterial infections, or tuberculosis. There was no consistent relation between progression to disease and the continued use of injection drugs. HIV-infected injection-drug users have progression to AIDS at rates comparable to those of other HIV-infected groups, but they have substantial pre-AIDS morbidity and mortality, particularly from bacterial infections, which also appear to predict disease progression.


Phylogenetic relationships of the genera Arthroderma and Nannizzia inferred from mitochondrial DNA analysis.

The phylogenetic relationship of the genera Arthroderma and Nannizzia, was investigated by mitochondrial DNA analysis based on the restriction-fragment-length polymorphisms. Phylogenetic trees made on ten species. A. benhamiae, A. insingulare, A. quadrifidum, A. simii, A. vanbreuseghemii, N. fulva, N. grubyia, N. gypsea, N. incurvata and N. otae showed no definite distinctions between the genera Arthroderma and Nannizzia. These results support the conclusion of Weitzman et al. that the genera Arthroderma and Nannizzia are congeneric.


Homeotic transformation of the occipital bones of the skull by ectopic expression of a homeobox gene.

Murine Hox genes have been postulated to play a role in patterning of the embryonic body plan. Gene disruption studies have suggested that for a given Hox complex, patterning of cell identity along the antero-posterior axis is directed by the more 'posterior' (having a more posterior rostral boundary of expression) Hox proteins expressed in a given cell. This supports the 'posterior prevalence' model, which also predicts that ectopic expression of a given Hox gene would result in altered structure only in regions anterior to its normal domain of expression. To test this model further, we have expressed the Hox-4.2 gene more rostrally than its normal mesoderm anterior boundary of expression, which is at the level of the first cervical somites. This ectopic expression results in a homeotic transformation of the occipital bones towards a more posterior phenotype into structures that resemble cervical vertebrae, whereas it has no effect in regions that normally express Hox-4.2. These results are similar to the homeotic posteriorization phenomenon generated in Drosophila by ectopic expression of genes of the homeotic complex HOM-C (refs 7-10; reviewed in ref. 3).


Positive feedback of glutamate exocytosis by metabotropic presynaptic receptor stimulation.

Glutamate is important in several forms of synaptic plasticity such as long-term potentiation, and in neuronal cell degeneration. Glutamate activates several types of receptors, including a metabotropic receptor that is sensitive to trans-1-amino-cyclopenthyl-1,3-dicarboxylate, coupled to G protein(s) and linked to inositol phospholipid metabolism. The activation of the metabotropic receptor in neurons generates inositol 1,4,5-trisphosphate, which causes the release of Ca2+ from intracellular stores and diacylglycerol, which activates protein kinase C. In nerve terminals, the activation of presynaptic protein kinase C with phorbol esters enhances glutamate release. But the presynaptic receptor involved in this protein kinase C-mediated increase in the release of glutamate has not yet been identified. Here we demonstrate the presence of a presynaptic glutamate receptor of the metabotropic type that mediates an enhancement of glutamate exocytosis in cerebrocortical nerve terminals. Interestingly, this potentiation of glutamate release is observed only in the presence of arachidonic acid, which may reflect that this positive feedback control of glutamate exocytosis operates in concert with other pre- or post-synaptic events of the glutamatergic neurotransmission that generate arachidonic acid. This presynaptic glutamate receptor may have a physiological role in the maintenance of long-term potentiation where there is an increase in glutamate release mediated by postsynaptically generated arachidonic acid.


Mutations in T-cell antigen receptor genes alpha and beta block thymocyte development at different stages.

Analysis of mice carrying mutant T-cell antigen receptor (TCR) genes indicates that TCR-beta gene rearrangement or expression is critical for the differentiation of CD4-CD8- thymocytes to CD4+CD8+ thymocytes, as well as for the expansion of the pool of CD4+CD8+ cells. TCR-alpha is irrelevant in these developmental processes. The development of gamma delta T cells does not depend on either TCR-alpha or TCR-beta.


Molecular characterization of the Arabidopsis floral homeotic gene APETALA1.

The first step in flower development is the transition of an inflorescence meristem into a floral meristem. Each floral meristem differentiates into a flower consisting of four organ types that occupy precisely defined positions within four concentric whorls. Genetic studies in Arabidopsis thaliana and Antirrhinum majus have identified early-acting genes that determine the identify of the floral meristem, and late-acting genes that determine floral organ identity. In Arabidopsis, at least two genes, APETALA1 and LEAFY, are required for the transition of an influorescence meristem into a floral meristem. We have cloned the APETALA1 gene and here we show that it encodes a putative transcription factor that contains a MADS-domain. APETALA1 RNA is uniformly expressed in young flower primordia, and later becomes localized to sepals and petals. Our results suggest that APETALA1 acts locally to specify the identity of the floral meristem, and to determine sepal and petal development.


Are vertebrate exons scanned during splice-site selection?

Pairwise recognition of splice sites as a result of a scanning mechanism is an attractive model to explain the coordination of vertebrate splicing. Such a mechanism would predict a polarity-of-site recognition in the scanned unit, but no evidence for a polarity gradient across introns has been found. We have suggested that the exon rather than the intron is the unit of recognition in vertebrates and that polyadenylation and splicing factors interact during recognition of 3'-terminal exons. Interaction is reflected in maximal rates of in vitro polyadenylation. If scanning across the exon is operating during this interaction, then insertion of a 5' splice site should depress polyadenylation. Here we report recognition in vitro and in vivo of a 5' splice site situated within a 3'-terminal exon, and a concomitant depression of polyadenylation and ultraviolet crosslinking of a polyadenylation factor. Decreased crosslinking was only found when the 3' and 5' splice sites were within 300 nucleotides of each other. These results are consistent with an exon scanning mechanism for splice-site selection.


Evidence from guinea-pig trachealis that Uptake2 of isoprenaline is enhanced by hyperpolarization of the smooth muscle.

Previous studies (Bönisch et al. 1985; Trendelenburg 1986, 1987) have provided evidence that Uptake2 of catecholamines is inhibited by depolarization of cells. The aim of this study was to further examine the relationship between Uptake2 and membrane potential by testing the hypothesis that Uptake2 is, conversely, stimulated by hyperpolarization of cells. The effects of beta-adrenoceptor agonists (isoprenaline and salbutamol) and beta-adrenoceptor antagonists (propranolol and ICI 118,551) on Uptake2 of isoprenaline were examined in guinea-pig trachealis muscle, in which stimulation of beta-adrenoceptors mediates hyperpolarization of the smooth muscle cells (Allen et al. 1985), and in rat heart, in which beta-adrenoceptor agonists do not cause hyperpolarization. In guinea-pig trachealis muscle segments, propranolol and ICI 118,551 reduced Uptake2 (as measured by the steady-state rate of corticosterone-sensitive formation of 3-O-methylisoprenaline normalized for the isoprenaline concentration) in tissues incubated in 2.5-250 nmol/l 3H-isoprenaline (in the range over which isoprenaline causes hyperpolarization of the muscle), but not in 1 nmol/l 3H-isoprenaline (which does not hyperpolarize the muscle). The normalized rates were greater in tissues incubated in 25 nmol/l than 1 nmol/l isoprenaline, and were enhanced by 2.5 mumol/l salbutamol in tissues incubated in 1 nmol/l isoprenaline. In rat hearts perfused with 1 or 25 nmol/l 3H-isoprenaline and U-0521 to inhibit catechol-O-methyltransferase, the rate of Uptake2 of isoprenaline, normalized for the isoprenaline concentration, was unaffected by the isoprenaline concentration or the presence of propranolol, ICI 118,551 or salbutamol.(ABSTRACT TRUNCATED AT 250 WORDS)


[Effects of short-term application of glutamate-containing solution on isolated rat hippocampal neurons].

The "concentration clamp" technique has been modified to realize fast and short-term application of a transmitter to whole neuron followed by its fast washout. Prolonged glutamate application evoked activation of the desensitized current. The application time was shortened to intervals when the washout corresponded to unfinished desensitization of the current. Shortening of the glutamate application term to some milliseconds resulted in arising of fast currents which maximal amplitude appreciably exceeded that of currents evoked by prolonged glutamate application. The role of both components under real synaptic conditions is discussed.