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Biomedical subjects

B Bell

Publications and source records attributed to B Bell.

At least 19 recordsLinked to original sources
PubMed1992

GAL4 fusion vectors for expression in yeast or mammalian cells.

We describe two sets of vectors, one for yeast (pY1, pY2 and pY3) and one for mammalian cells (pM1, pM2, and pM3), that simplify the production of fusion proteins containing the DNA-binding domain of GAL4. This protein fragment, consisting of GAL4 amino acid (aa) residues 1-147, binds to a specific 17-bp nucleotide sequence, but is incapable of activating transcription unless fused to a protein that can contribute an activating function. Genetic strategies exploiting this property of GAL4 (aa 1-147) have been developed to characterize transcription factor functional domains, protein-protein interactions, and site-specific proteolysis. The vectors we describe allow fusion to the C terminus of GAL4 (aa 1-147) in any reading frame, and thus facilitate these experimental strategies.

Amino Acid Sequence↗
PubMed1991

Alcohol affects rat testicular interstitial fluid volume and testicular secretion of testosterone and beta-endorphin.

The effects of alcohol on testicular interstitial fluid (TIF) volume and the secretion of testosterone and beta-endorphin (beta E) into this important testicular compartment were assessed in the rat. Alcohol time- and dose-response curves were constructed for changes in TIF volume and the bioactive concentrations of testosterone and immunoreactive beta E (i-beta E). Alcohol (3 g/kg) decreased TIF volumes and increased TIF i-beta E secretion 0.5 to 6 hr after injection and decreased TIF testosterone 1 to 6 hr after injection. These effects were dose-related at 2 hr postinjection. The possible role of alcohol-induced reductions in serum luteinizing hormone and testosterone levels in mediating the effects of alcohol on TIF volume was also examined. We found that pretreating rats with human chorionic gonadotropin, which reversed alcohol-induced suppression in levels of serum gonadotropins and testosterone, failed to reverse the effects of alcohol on TIF volume and the secretion of testosterone and i-beta E. These results indicate that alcohol decreases TIF volume, inhibits TIF testosterone secretion and stimulates TIF i-beta E secretion and, furthermore, suggest that these effects are not indirectly mediated by decreased levels of gonadotropins or testosterone, but by direct effects of alcohol on gonadal function. The strong inverse correlation between TIF i-beta E and testosterone secretion after alcohol administration and previous evidence that testicular opioids inhibit the biosynthesis of testosterone suggest that alcohol may act through testicular beta E to suppress the synthesis and release of testosterone in the testes.

Animals↗
PubMed1979

Human sensitization to Ganoderma antigen.

Continuous air sampling with a Hirst volumetric spore trap over 3 yr has identified basidiospores of Ganoderma applanatum, a bracket fungus, as the most numerous fungal spores in two southern Ontario locations. The particle size is small and the calculated total spore mass approximates that of the spores of Cladosporium and Alternaria. Extracts of Ganoderma applanatum bracket fungus and spores in w/v, 1:10 concentration were prepared after collection of samples of the fungus from local woods. Skin prick tests with the extracts were performed in 294 consecutive children and adults attending two chest/allergy clinics. Of these patients, 182 (61.9%) reacted to 1 or more of the common inhalant allergen extracts and 24 (8.2%) reacted to Ganoderma antigen. There was no consistent relationship between reactivity to Ganoderma antigen and any of the common inhaled allergens. IgE-dependent sensitization to Ganoderma was confirmed by the radioallergosorbent test (RAST). Rabbit antisera to Ganoderma antigen preparations did not appear to cross-react with preparations of the various clinically important allergens. The findings indicate that Ganoderma antigen is commonly encountered, can induce human sensitization, and has unique antigenicity among common allergens of clinical importance.

Allergens↗
PubMed1978

Allergy to a product(s) of ethylene oxide gas: demonstration of IgE and IgG antibodies and hapten specificity.

Patient D.H., on chronic hemodialysis, developed severe allergic reactions after exposure to articles such as plastic tubing and hemodialysis supplies which had undergone cold sterilization with ethylene oxide (EO) gas. It was shown that human serum albumin (HSA) exposed to EO (EO-HSA) in the usual sterilization procedure selectively elicited positive skin tests and in vitro histamine release. It is now demonstrated that D.H. serum reacts selectively in a radioallergosorbent test (RAST) which utilizes discs coated with HSA and exposed to EO gas. In addition, D.H. serum contained IgG antibodies reactive with EO-HSA. This antibody activity was not detected in the sera of 27 normal subjects and 25 chronic hemodialysis patients. EO-HSA and ragweed RAST inhibition tests with a number of proteins in native form and after exposure to EO demonstrated the EO hapten specificity of the IgE antibody.

Antibodies, Anti-Idiotypic↗
PubMed1977

General practitioners in the Western Metropolitan Health Region of Sydney.

A comprehensive survey of the number of general practitioners in the Western Metropolitan Health Region of Sydney identified 753 general practitioners with one or more practice locations in the region; this was the equivalent of 711 full-time general practitioners, and represented a general practitioner-population ratio of 1:1533.

Australia↗
PubMed1976

Thyroid function and metabolic state in chronic renal failure.

Thirty-eight patients with chronic renal insufficiency who were in a dialysis program underwent studies of thyroid function and metabolic status. Mean values for serum total and free thyroxine (T4) concentrations and thyroxine-binding globulin capacity were within normal limits. Although mean serum total triiodothyronine (T3) concentration was normal, 43% of the group had low serum T3 and 54% had low serum free T3 concentrations. Serum thyrotrophin (TSH) concentrations were normal in all but four subjects who had very slight elevations. Metabolic status was assessed by various metabolic tests; mean values for each of these tests were normal, and the clinical index scores indicated that all patients were euthyroid. Results of metabolic testing were similar in patients with low and those with normal serum T3 concentrations. Low serum T3 measurements did not accurately reflect metabolic state in patients with chronic renal failure, whereas serum free T4 and TSH concentrations were reliable indicators of thyroid state.

Adolescent↗
PubMed1976

Determinants of variation between Fick and indicator dilution estimates of cardiac output during diagnostic catheterization. Fick vs. dye cardiac outputs.

Simultaneous Fick and duplicate dye cardiac outputs were done in 105 patients with various cardiovascular diseases during routine cardiac catheterization. Dye was injected into the pulmonary artery and sampled from the brachial artery. Nineteen patients had mitral and/or aortic valvular regurgitation. Eighty-four per cent of the duplicate dye cardiac outputs agreed within 10 per cent variation from the line of identity, and 98 per cent were within 25 per cent. There was no systematic difference between the Fick and dye methods. Seventy-five per cent agree within 20 per cent variation from the line of identity. However, individual variation ranged from -27 to +58 per cent. There was, also, no systematic difference between Fick and dye methods either with low cardiac index or valvular regurgitation. Variation between the two methods was less with low cardiac index and greater with higher cardiac index. The variation was not increased in the presence of valvular regurgitation. The variation in the two methods could partly be explained by errors in the measurement of arteriovenous oxygen difference and oxygen consumption. When the injection is made into the pulmonary artery and sampled from the brachial artery, dye outputs are valid irrespective of the level of resting cardiac index and valvular regurgitation as long as there are enough points to draw a straight line from semilogarithmic trace of the descending limb.

Cardiac Catheterization↗
PubMed1975

Muscial hallucinations in deafness.

Formed auditory hallucinations associated with acquired deafness have seldom been reported in the English literature. In the past year we have had the unusual opportunity of examining two deaf patients whose complaint when first seen was that of hearing music.

Age Factors↗
PubMed1975

Computer-aided management of hypertensive patients.

A computerized system has been developed which potentially enables a single expert physician to monitor a large number of hypertensive patients being seen at distant locations. The patients may receive their care directly from primary care physicians or nurse-physician surrogates. Primary care physicians can use the same data bank to monitor their own panels of patients. These goals are accomplished through a special purpose, interactive programming language which can be used to perform sophisticated data retrieval along different complexes of parameters. The physician is able to query the computer, via a terminal, about any group of patient he defines and have displayed to him the clinical data requested. The system is open-ended, enabling one query to lead to another. Four hundred and ninety-three patients have been entered into this program so far, including 29 patients with diastolic pressures greater than 115, 92 with diastolic pressures of 104 to 114, and 372 with diastolics of 90 to 104. Among patients who have been on therapy for at least six weeks, 80 per cent were at goal blood pressure. Ten to 14 weeks after therapy was initiated, 69 per cent of all patients in the program were at goal blood pressure. The system provides a useful means of monitoring a large hypertensive population of patients. Such a system can result in a more efficient utilization of medical personnel and can bring the consultative services of highly trained specialists to larger segments of the population.

Computers↗
PubMed1975

A longitudinal psychophysiological study of three-year-old Mauritian children: preliminary report.

The rationale for using the high-risk-group research design in the search for the aetiology of schizophrenia is described. A longitudinal study is being made of three-year-old Mauritian children who underwent a variety of physiological and psychological tests. Groups of these children, selected on the basis of their responses to electrodermal stimulation, are now attending nursery schools established on the island as part of this study. A control group of children do not attend nursery school. It is intended to follow-up these children over the next two decades. Mention is made of the benefits of this research to the development of para-medical and educational services in a developing country.

Child, Preschool↗
PubMed1975

Early detection and prevention of mental illness: the Mauritius project. A preliminary report.

The experimental manipulation method is in general not feasible in studies of the etiology of severe mental illness, whereas this method can be used in studies pertaining to primary prevention, because possible preventive methods would most likely be of a protective or beneficial nature. Preventive experimentation requires early detection of those individuals who will eventually become seriously mentally deviant. A study of children at a high genetic risk for schizophrenia is described. This study suggested certain autonomic nervous system variables as predictors of later serious mental breakdown. In a WHO-sponsored project in Mauritius the authors used these results for the selection of a group of children at risk for mental illness. 1,800 3-year-old Mauritian children were studied socially, psychologically, pediatrically and psychophysiologically between 1972 and 1973. 100 of these children were selected for experimental preventive intervention during their daily presence in two modern kindergartens. Members of this group were characterized by either abnormally fast autonomic recovery or autonomic nonresponding, or normal autonomic responding. A matched group of another 100 children served as a community control. The paper presents preliminary results from the screening of the 1,800 children.

Age Factors↗