Biomedical subjects

M Weiss

Publications and source records attributed to M Weiss.

At least 523 records · Page 29Linked to original sources

PubMed1988

[Septic melioidosis following a visit to India].

A case is reported of lethal septicemic melioidosis due to Pseudomonas pseudomallei in a 40-year-old woman who had been in India. The epidemiology, clinical findings and management of this unusual disease are discussed. The diagnostic value of serological tests and in vitro sensitivity of Pseudomonas pseudomallei to various antibiotics are outlined. Melioidosis should be considered in the differential diagnosis of any febrile condition in a person returning from a tropical country.

Adult↗

PubMed1988

Segregation of linked probes to myotonic dystrophy in a family demonstrating that 152 and APOC2 are on the same side of DM on 19q.

The two markers most closely linked to the myotonic dystrophy (DM) locus on chromosome 19 are the gene that codes for apolipoprotein CII (APOC2) and the anonymous probe D19S19 (LDR152). Both of these markers show tight linkage to DM, with maximum lod scores of greater than 20 at recombination fractions of less than 0.05. We have identified, in a family in which DM segregates, an affected individual where a meiotic recombination event has occurred in which both of these linked markers have crossed over with the gene defect. This demonstrates that APOC2 and D19S19 are probably on the same side of DM.

Chromosome Mapping↗

PubMed1988

Production of and response to interleukin-2 in Graves' disease.

Interleukin-2 is a lymphokine which is believed to play a central role in the regulation of the immune response. The production of and response to interleukin-2 were determined in hyperthyroid Graves' patients together with thyroid function and serum thyrotropin receptor antibody, a marker of autoimmune activity. Interleukin-2 production by mitogen-induced peripheral blood mononuclears was markedly low in 24 of 29 patients when compared to controls. Five patients in remission had normal values. In nine patients followed during antithyroid drug therapy, interleukin-2 production returned gradually to normal levels within 4-6 months. This rise and the concomitant decrease in serum thyrotropin receptor antibody correlated with the decline in the free thyroxin index. Antithyroid drugs and triiodothyronine had no effect on interleukin-2 production in vitro. Mitogen-activated mononuclears from hyperthyroid Graves' patients did not proliferate as well as the controls in response to interleukin-2. However, seven patients treated with antithyroid drugs and three in remission responded normally. Flow cytometry using anti-Tac antibody revealed that the interleukin-2 receptor density on mononuclears from five patients was low. This parameter was normal in treated patients and those in remission. We conclude that the production of and response to interleukin-2 by peripheral blood mononuclears from hyperthyroid Graves' patients are poor, the latter being due to impaired receptor expression. Both aberrations are restored to normal by antithyroid drug therapy or in remission. The relative roles of the autoimmune process and thyroid function in modulating the interleukin-2 pathway and the question of whether antithyroid drugs act directly or through thyroid inhibition remain to be clarified.

Adult↗

PubMed1988

A diet containing n-3 and n-6 fatty acids favorably alters the renal phospholipids, eicosanoid synthesis and plasma lipids in nephrotic rats.

The nephrotic syndrome was induced in rats by intravenous adriamycin (3 mg/kg). The rats were then divided into four groups which, for six weeks, were pair-fed diets containing beef tallow (BT), fish oil (FO), a source of n-3 fatty acids, evening primrose oil (EPO), a source of n-6 fatty acids, or a combination of evening primrose oil and fish oil, 75:25 (EPO:FO). The fat content of the diets was 15%. Significant incorporation of the fatty acids into kidney phospholipids was demonstrated. Diets containing FO, EPO and EPO:FO lowered plasma triglycerides and total cholesterol levels as compared with diets containing BT. Only EPO:FO raised high density lipoprotein (HDL) cholesterol levels, as compared with BT. The combination EPO:FO prevented the tenfold suppression of aortic 6-keto-PGF1 alpha caused by FO. These changes in plasma lipids and eicosanoid production are potentially antiatherogenic and may prevent glomerular sclerosis. The combination of EPO and FO, containing n-6 and n-3 fatty acids may offer advantages over either family of fatty acids in this model of nephrotic syndrome.

Animals↗

PubMed1988

Fish oil has beneficial effects on lipids and renal disease of nephrotic rats.

The effects of fish oil on serum lipids, eicosanoid production, fibrinolysis, and renal disease of nephrotic rats were studied. Three groups of rats were given adriamycin to induce nephrotic syndrome. They were pair-fed diets containing 14% beef fat, 3%, and 14% fish oil, and killed at 4 weeks. Marked beneficial effects of the fish oil on plasma triglycerides, total cholesterol, and LDL cholesterol were observed. Fish oil suppressed dienoic eicosanoid production. Protection of renal function and morphology was achieved in the fish oil fed groups, as evidenced by lower serum creatinine levels and lesser degrees of tubular dilatation and intraluminal protein in the kidney tubules. We conclude that fish oil, rich in n-3 fatty acids, is beneficial to the plasma lipids and may prevent progression of renal disease in this model of nephrotic syndrome. These two events may be interrelated.

Animals↗

PubMed1988

Hyperbaric effects on sensorimotor reactivity studied with acoustic startle in the rat.

In three experiments, startle responses to brief intense tone-bursts (30 msec, 110 dB, 6000 Hz) and single pulse (0.1 msec) stimulation of the cochlear nucleus and the nucleus reticularis pontis caudalis are studied under high pressures of heliox (from 0 bar to 50 bars) in the rat. For each rat (N = 12), mean amplitude and latency changes in startle responses (nuchal electromyography and whole-body accelerometry) are compared at normobaric pressure and during compression, at a speed of 100 bar/H. The results indicate that high pressures decrease (50% of control size) tone evoked startle by acting on the peripheral auditory organ, probably through middle and/or inner ear barotrauma. The large increases in electrically-elicited startle (250% of control size) from the cochlear and reticular nuclei, under hyperbaric conditions, suggest that high pressures affect sensorimotor reactivity by excitatory action on synaptic transmission in the relays of the acoustic startle reflex arc at the lower brainstem and spinal levels. Startle latencies remain unaffected by the heliox high pressures studied here.

Acoustic Stimulation↗

PubMed1988

Factors influencing prostatic 5 alpha-reductase activity in possum (Trichosurus vulpecula).

1. There were marked differences in prostatic wts among individual possums, but no evidence of a seasonally related change in wt could be established. It was concluded that the wt differences are mainly due to the changes in secretory activities. After castration the prostate wts fell while after administration of testosterone or oestradiol partially reversed this process. 2. Seven steroid conversion products were isolated from prostatic homogenates incubated with [3H] testosterone; 5 alpha-androstane-3 beta,17 beta-diol forming the highest yield. 3. While the 5 alpha-reductase activity of prostates from intact possums was very low (approx. 8% of the total yield), it increased to over 50% after castration. 4. Administration of testosterone or oestradiol partially reversed the post-castration rise in 5 alpha-reductase, while 17 beta-hydroxy-5 alpha-androstane-3-one (DHT) was ineffective. Administration of porcine FSH-NIH-P2 to both intact or castrated possums caused a marked rise in prostatic 5 alpha-reductase activity. 5. It was concluded that in possum, FSH may have a direct stimulatory effect on prostatic 5 alpha-reductase activity. The results are discussed in relation to placental mammals.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

PubMed1988

Angiographic progression of coronary artery disease and the development of myocardial infarction.

There are few data on angiographic coronary artery anatomy in patients whose coronary artery disease progresses to myocardial infarction. In this retrospective analysis, progression of coronary artery disease between two cardiac catheterization procedures is described in 38 patients: 23 patients (Group I) who had a myocardial infarction between the two studies and 15 patients (Group II) who presented with one or more new total occlusions at the second study without sustaining an intervening infarction. In Group I the median percent stenosis on the initial angiogram of the artery related to the infarct at restudy was significantly less than the median percent stenosis of lesions that subsequently were the site of a new total occlusion in Group II (48 versus 73.5%, p less than 0.05). In the infarct-related artery in Group I, only 5 (22%) of 23 lesions were initially greater than 70%, whereas in Group II, 11 (61%) of 18 lesions that progressed to total occlusion were initially greater than 70% (p less than 0.01). In Group I, patients who developed a Q wave infarction had less severe narrowing at initial angiography in the subsequent infarct-related artery (34%) than did patients who developed a non-Q wave infarction (80%) (p less than 0.05). Univariate and multivariate analysis of angiographic and clinical characteristics present at initial angiography in Group I revealed proximal lesion location as the only significant predictor of evolution of lesions greater than or equal to 50% to infarction. This retrospective study suggests that myocardial infarction frequently develops from previously nonsevere lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1988

Cardiocirculatory, hormonal, and metabolic reactions to various forms of ergometric tests.

The sympathoadrenergic reaction is not only dependent on the duration and intensity of work but also on the body position and the involvement of small or large muscle masses. This observation made in field tests comparing different sports disciplines such as swimming, running, or diving encouraged us to investigate this topic under the following laboratory conditions. Twelve healthy sport students participated in ergometric tests on a bicycle ergometer in a horizontal and vertical body position as well as on a treadmill and a swim bench ergometer. The changes of plasma catecholamines (CA) obtained in the different ergometric tests were compared with those cardiocirculatory, metabolic, and hormonal parameters which can be influenced by the sympathoadrenergic stimulation. In the horizontal body position we found a smaller increase of norepinephrine at submaximal and maximal work loads combined with a similar reaction of renin, whereas the diastolic blood pressure and the mean arterial blood pressure increased more. The substrates of lipolysis and aerobic and anaerobic glycolysis did not show obvious differences depending on the body position. In the swim bench test, however, the lactate increase started earlier and was comparatively higher than in the other ergometric tests in which the maximal work load and VO2max were higher. Although a smaller muscle mass was used and a lower maximal oxygen uptake was reached, we did not find statistically different CA values during the swim bench ergometric test compared with the bicycle ergometric test in a horizontal body position. In our ergometric tests, the venous CA levels (especially norepinephrine) were predominantly influenced by the body position.

Adult↗

PubMed1988

Effects of temperature and water immersion on plasma catecholamines and circulation.

The effects of environmental air temperature of 6 degrees C and 26 degrees C on catecholamines (CA) and circulation were studied in eight male subjects during rest and during bicycle exercise at WOBLA for 45 min each. We found that resting at 6 degrees C increased the norepinephrine (NE) levels to the same levels as endurance exercises at 6 degrees C. The increase of CA levels was 2.5 to 3 times higher during work at 26 degrees C compared with 6 degrees C. During both rest and exercise at 6 degrees C we found a higher stroke volume of the heart and a reduced heart rate (HR) with no or only small effects on the oxygen uptake and blood lactate levels compared with 26 degrees C. Measurements of the skin temperatures showed large differences both at rest and during work; those of core temperature showed no changes at rest and a slightly more pronounced increase during work at 26 degrees C compared with 6 degrees C. The behavior of CA, plasma renin activity (PRA), plasma aldosterone (PA), and circulation were studied in 13 top class swimmers and 12 recreational swimmers during immersion into water of 27 degrees C for 10 min. The recreational swimmers were additionally immersed into water of 21 degrees C and 33 degrees C. Even immersion at 33 degrees C induced a small but significant increase of NE levels and of blood pressure (BP) values with no effect on the HR and blood lactate values. Epinephrine (EPI) showed a tendency to decrease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1988

Differences in sympathoadrenal, hormonal, and metabolic adaptation to submaximal and maximal arm and leg work compared with whole stroke in breast-style swimming.

During work on land adaptational reactions of circulation and hormones are influenced by the body position, the activated muscle mass, and the working extremities. The aim of this study was to explore the additional effect of water immersion during swimming on cardiocirculatory, metabolic, and hormonal regulation under different working conditions. Twelve young men not specifically trained in swimming underwent swimming tests on 3 different days. They had to swim breast stroke in total as well as isolated with legs or arms only each for 10 min at submaximal intensity and 150 m or 100 m at maximal intensity. This study was focused on changes of catecholamines (CA), heart rate (HR), blood pressure (BP), glucose, lactate, plasma renin activity (PRA), and plasma aldosterone (PA). Additionally, parameters of the electrolyte-volume homeostasis were investigated. Norepinephrine (NE) and epinephrine (EPI) increased during swimming under submaximal and maximal conditions. The augmentation of CA and HR was the highest after swimming whole stroke and the lowest after swimming arm stroke only. They were related to intensity within one type of swimming and showed a dependence on muscle mass independent from lactate or glucose levels when the different types of swimming were compared, although a positive correlation between CA and lactate levels was found. The BP was higher after leg work than after arm work, contrary to observations done on land regarding the comparable submaximal work loads. We suppose that this is an effect of water immersion and the horizontal body position whereby the central hemodynamic circulation becomes stabilized.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗

PubMed1988

Influence of exercise in water on hormonal, metabolic and adrenergic receptor changes in man.

We investigated hormonal, metabolic, and cardiovascular adaptations as well as changes of alpha 2- and beta 2-adrenergic receptors in response to three different exercise performances in water: 1000 m fin swimming with or without a neoprene suit and, additionally, 600 m diving with a breathing apparatus while performing several tasks. Eight male divers participated in the study. Blood samples were taken at rest on land, 10 min after water immersion, immediately after exercise, and after 20 min recovery. Both free and sulfoconjugated norepinephrine (NE) increased exercise-dependently. Moreover, heat loss in water caused elevation of plasma free NE. Free epinephrine (EPI) increases showed a highly significant correlation with NE except during fin swimming with a neoprene suit where EPI concentrations were constantly higher. ACTH and cortisol levels rose during exercise and paralleled those of plasma NE. Plasma aldosterone decreased in response to water immersion at rest. Blood volume regulating hormones such as plasma renin, aldosterone, and vasopressin were significantly higher during physical exercise. Moreover, increased pressure conditions during diving caused significantly higher secretion rates of all of these hormones, resulting in a higher systolic blood pressure. This clinical issue might be considered when examining diving ability. Lipolysis was elevated to the same degree after the three exercise schedules had been applied. As expected, plasma glucose also increased during physical activity. The lactate values observed after fin swimming, but not after diving with a breathing apparatus were closely related to NE. The lowest lactate levels were obtained during air-assisted diving.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗

PubMed1988

Sympathoadrenergic regulation of metabolism and cardiocirculation during and following running exercises of different intensity and duration.

In three different field studies running loads of 2 X 200 m and 400 m, 3 X 1000 m and 3000 m, and finally 10,000 m were performed by respective groups of sprinters, middle-, and long-distance runners. We investigated the effects of exercise on the sympathoadrenal system by determining catecholamine (CA) concentrations in the venous blood and urine [free norepinephrine (NE), epinephrine (EPI)] and the respective sulfoconjugates in plasma and various hormonal, metabolic, and cardiocirculatory parameters. Endurance-trained athletes showed a lower heart rate (HR) and plasma renin activity (PRA) at rest in comparison with the sprinters. The concentrations of the plasma CA reflected the intensity more than the duration of exercise. At rest and following recovery the ratio of free NE/EPI in plasma was markedly higher in the group of sprinters in comparison with the long-distance runners. During exercise, however, an opposite movement occurred resulting in a higher ratio in the latter group. The pre-start ratios of NE/EPI in urine were similar to those in plasma. The sports disciplines' specific differences in NE/EPI both at rest and during exercise suggest that the overall sympathetic activity, reflected by NE and EPI, is regulated in a quite differentiated pattern. The sulfoconjugated CA, however, increased less clearly after the middle- and long-distance bouts than the respective free CA which caused the ratio sulfates/free CA to decline. There were strong relations between the levels of free plasma NE and EPI and that of blood lactate which, however, rather reflects a parallelism subsequent to the highly intensive stimulation.

Adaptation, Physiological↗

PubMed1988

Influence of different experimental recreation treatments on sympathoadrenergic and metabolic regulation mechanisms in repeated exercises.

The influence of different recreation treatments on the sympathoadrenergic regulation, heart rate, mean blood pressure, plasma lactate, and glucose levels was investigated in a study in which the 1000 m distance was performed twice by top middle- and long-distance runners. Between the two runs, executed three times in an interval of 1 week, different regeneration strategies such as active or passive recreation as well as progressive muscle relaxation (PMR) with cognitive skill (Cl) were applied. The best running times in the second run were achieved after the PMR with Cl. After this treatment heart rate (HR) and mean arterial blood pressure (MBP) were not higher than in the other forms of regeneration, although the norepinephrine (NE) and epinephrine (EPI) increase was significantly higher after the second run compared with other treatments. The lactate and glucose levels in plasma were significantly higher after PMR with Cl than after active and passive regeneration. After the recovery period both metabolites decreased faster after PMR with Cl. The percentage of catecholamine sulfates of the total amount decreased after the first and the second run without significant differences between the three recreation treatments.

Blood Glucose↗

PubMed1988

Slow-release isosorbide-5-mononitrate--a new once daily therapeutic modality for angina pectoris.

The acute and chronic efficacy of slow-release isosorbide-5-mononitrate (IS-5-MN) in the form of Elantan long capsules (50 mg) and the tolerability to this agent were evaluated in an open study of 45 patients with chronic stable angina pectoris, treated for one year. After 3 days of replacement of previous antianginal treatment with placebo, an Elantan long capsule (50 mg) was given once daily in the morning. Exercise test was performed 6 hours after ingestion of the capsule, on placebo (after wash-out of 3 days), in the first day of treatment, and after 3 and 6 months of treatment as well as 6 and 24 hours after 12 months of treatment compared to the exercise test at the same time after discontinuation of treatment (three days on placebo). At comparable work load the drug was associated with a 26.6% reduction in ST-segment depression after 6 hours of acute treatment, 46.7% after 3 months of treatment, 52.2% after 6 months, and 66% at the end of treatment (12 months) (P less than 0.001). Even 24 hours after intake of the last capsule of Elantan long the ST-segment reduction was still 49.5%. Exercise test 24 hours after ingestion of the drug revealed that the effect still exists. In the post-treatment placebo period all values returned to pretreatment levels. The sublingual nitroglycerin consumption was reduced by 90% and the frequency of anginal attacks was reduced from 19 +/- 15 to 1.1 +/- 4.2 weekly (P less than 0.001). The drug was well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed1988

Characterization of Berne virus genomic and messenger RNAs.

From 380S particles of Berne virus (proposed family Toroviridae) one species of polyadenylated RNA was isolated. Using agarose gel electrophoresis its length was estimated as 20 kb or greater. When assayed under hypertonic transfection conditions genomic RNA was found to be infectious; RNase treatment destroyed the infectivity. The positive polarity of the molecule was confirmed by filter spot hybridization using cDNA prepared against poly(A)-selected RNA from infected cells. In embryonic mule skin cells infected with Berne virus the presence of five virus-specific, polyadenylated RNA species of 7.5, 2.1, 1.4, 0.8 and at least 20 kb was demonstrated. In vitro translation of the 7.5, 2.1 and 0.8 kb RNAs followed by immunoprecipitation showed that they encode a 151K product (possibly the precursor to the peplomer proteins), the envelope protein and the nucleocapsid protein, respectively.

Animals↗

PubMed1988

Selecting candidates for a medical school: an evaluation of a selection model based on cognitive and personality predictors.

Two studies were conducted to attempt to evaluate the selection procedures used in Hadassah Medical School. The predictors assessed were the Israeli high school matriculation examinations, a general aptitude test, an interview and a semi-projective test designed to assess personality pathology. In the first study 145 students of the 1975 and 1976 cohorts were assessed, the criteria being a combination of peer evaluations, evaluation of supervisors and academic record. Results showed the matriculation average score to be the only effective predictor for all criteria. In the second study 155 students of the 1979, 1980 and 1981 cohorts were assessed, the criteria being evaluation of supervising doctors, BSc grades and grades during the clinical period. Results again indicated that the matriculation test is the most effective predictor. In this study, however, the other variables added to the prediction of criteria based on clinical evaluations. The results were discussed, raising several possible explanations for the relatively high validity of the matriculation scores. It was suggested the matriculation scores capture personality dimensions, such as motivation and adjustment to the learning environment, which are important factors for success in medical training.

Aptitude Tests↗

PubMed1988

Linkage relationships of the protein kinase C gamma gene which exclude it as a candidate for myotonic dystrophy.

Using a cDNA probe for the gamma gene of protein kinase C (PKCG), an informative RFLP with a PIC value of 0.62 has been identified with the enzyme MspI. The polymorphic bands have been assigned to chromosome 19. Analysis of the segregation of alleles for this probe in myotonic dystrophy families show several recombinants between PKCG and myotonic dystrophy (DM) and exclude this gene as a candidate for DM. Linkage relationships between PKCG and other loci on chromosome 19 are presented which exclude PKCG from the proximal region of chromosome 19 and which are consistent with the localization being at 19q13.2----qter.

Alleles↗