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Biomedical subjects

H Smith

Publications and source records attributed to H Smith.

At least 613 records · Page 34Linked to original sources
PubMed1979

Antibodies to ribosomes in chronic active hepatitis.

A recently developed Farr-type radioimmunoassay for the detection of antibodies to tritium-labeled HeLa cell cytoplasmic ribosomes was evaluated as a serologic test in a variety of liver diseases. Ribosomal antibodies were detected in the sera of 31.4% of 70 patients with chronic active hepatitis (CAH) and primary biliary cirrhosis compared with only 4.2% of patients with chronic persistent hepatitis, acute viral hepatitis, alcoholic liver disease, and miscellaneous liver diseases (X2 = 17.89, P less than 0.001). The level of ribosomal binding activity was also significantly higher in sera of patients with CAH and primary biliary cirrhosis (15.4% vs 6.5%; t = 5.61, P less than 0.001). The antibodies were observed almost exclusively in HBsAg-negative CAH with autoimmune features and infrequently at lower titer in HBsAg-positive CAH or CAH without HBsAg or autoantibodies. Inhibition experiments with purified ribosomal RNA suggested that the ribosomal antibodies are in part reactive with ribosomal RNA. Ribosomal antibodies appear to represent another example of the exaggerated immune response associated with CAH and primary biliary cirrhosis.

Autoantibodies↗
PubMed1978

Napoleon Bonaparte's exposure to arsenic during 1816.

Analysis of hair from Napoleon showed that he was exposed to considerable amounts of arsenic during 1816. The distribution pattern of the arsenic in the hair is similar to that found after the daily ingestion of excessive amounts of arsenic.

Arsenic↗
PubMed1978

The importance of beta, the type II error and sample size in the design and interpretation of the randomized control trial. Survey of 71 "negative" trials.

Seventy-one "negative" randomized control trials were re-examined to determine if the investigators had studied large enough samples to give a high probability (greater than 0.90) of detecting a 25 per cent and 50 per cent therapeutic improvement in the response. Sixty-seven of the trials had a greater than 10 per cent risk of missing a true 25 per cent therapeutic improvement, and with the same risk, 50 of the trials could have missed a 50 per cent improvement. Estimates of 90 per cent confidence intervals for the true improvement in each trial showed that in 57 of these "negative" trials, a potential 25 per cent improvement was possible, and 34 of the trials showed a potential 50 per cent improvement. Many of the therapies labeled as "no different from control" in trials using inadequate samples have not received a fair test. Concern for the probability of missing an important therapeutic improvement because of small sample sizes deserves more attention in the planning of clinical trials.

Clinical Trials as Topic↗
PubMed1978

Career choice and performance on state licensing examinations of "Fifth Pathway" students.

Between 1975 and 1977, 340 American citizens trained in foreign medical schools (mostly Mexican) completed a year of supervised clinical training (Fifth Pathway) in New York State before beginning residency training. Analysis of 335 such students revealed a greater tendency to remain in the State for residency training as compared to graduates of New York State medical schools (P less than 0.01). A primary-care specialty was chosen by these students significantly less often than be American graduates (P less than 0.001). Their pass rate on state licensing examinations, although higher than that of other foreign-trained medical graduates, was significantly lower than that of American-trained students (P less than 0.001). Fifth Pathway programs can provide a source of United States-citizen house officers for hospitals currently staffed mainly by alien physicians. Such programs offer foreign-trained United States physicians an opportunity to improve their clinical skills before starting residencies, but evidently do not fully overcome their educational deficits.

Career Choice↗
PubMed1978

Medicaid-funded private psychiatric care in New York City. The role of foreign-trained physicians.

Data were obtained from the tax records and the Professional Registry maintained by the New York City Department of Health as well as from the Biographical Directory of the American Psychiatric Association to determine which psychiatrists were providing care under the Medicaid Program and how they compare with the pool of psychiatric practitioners in New York City. The data reveal that psychiatrists educated in foreign medical schools provide disproportionately more care to Medicaid recipients than would be anticipated from their numbers, and are a majority of those who received more than +30,000 in payments in 1976. Furthermore, these psychiatrists account for 80 per cent of those delivering care at the two largest "shared health facilities," commonly referred to as "Medicaid mills." These findings indicate that although the Title XIX Program has facilitated the access of the poor to the private psychiatric sector, in New York City their access is biased toward treatment by foreign-educated psychiatrists.

Foreign Medical Graduates↗
PubMed1978

A specific and reversible macromolecular inhibitor of phenylalanine ammonia-lyase and cinnamic acid-4-hydroxylase in gherkins.

A non-dialysable inhibitor of phenylalanine ammonia-lyase (L-phenylalanine ammonia-lyase, EC 4.3.1.5) has been partially purified from dark-grown gherkin hypocotyls. On extraction of tissue it is found both in the soluble (106 000 X g supernatant) and microsomal (106 000 X g pellet) fractions and can be extracted from the microsomal membranes with 10 mM sodium cholate and 1 M KCl. The soluble and microsomal fractions have similar properties, suggesting the presence of the same active component. The inhibitor is small (Mr less than 20 000), thermolabile, sensitive to proteolytic digestion, and apparently hydrophobic. Purification of the inhibitor was achieved by chromatography on DEAE-cellulose by gel filtration on Sephadex G-50. The inhibitor preparations inhibit phenylalanine ammonia-lyase isolated from a number of plant tissues and also cinnamic acid-4-hydroxylase (trans-cinnamate, NADPH:oxygen oxidoreductase (4-hydroxylating), EC 1.14.13.11) from gherkins and peas, but not a wide range of other enzymes. The evidence suggests that inhibition of the two enzymes is due to the same substance, but this has not yet been confirmed. Kinetic experiments show that the inhibitor is competitive with phenylalanine for the lyase and that its association with the lyase is reversible. Further, a mixture of inhibitor and lyase can be separated on non-denaturing polyacrylamide gels without loss of lyase activity. The activities of phenylalanine ammonia-lyase and cinnamic acid 4-hydroxylase are often concurrently regulated and both have regulatory roles in phenol metabolism; it is suggested that the inhibitor may be specifically involved in controlling their activities in vivo.

Ammonia-Lyases↗
PubMed1978

Assessment of patients with suspected viral haemorrhagic fever.

We reviewed our two-year (1967-7) experience of patients who might have had an African-derived haemorrhagic fever: only two out of 46 suspects had such infections, and these were successfully contained. Malaria was the most frequent diagnosis in these patients recently returned from Africa, especially if malarial prophylaxis had been inadequate. Altogether 26% of patients had become ill before travelling to Britain. It is impossible to ensure absolute safety even with draconian measures, but the degree of isolation recommended (based on epidemiological factors that included return from Africa within the previous three weeks, visiting country districts, exposure to possible cases, or infected material and illness despite adequate malarial prophylaxis) has proved effective and acceptable.

Adolescent↗
PubMed1978

The effect of high-sodium and low-sodium intakes on blood pressure and other related variables in human subjects with idiopathic hypertension.

Nineteen patients with hypertension in whom all known causes of blood pressure elevation had been ruled out were classified as "salt-sensitive" or "nonsalt-sensitive" from the changes in blood pressure with changes in sodium intake from 9 meq to 249 meq/day. With the diet containing 249 meq sodium per day, there were no statistically significant differences in plasma sodium, potassium, chloride, aldosterone, cortisol or renin activity, or in urinary potassium, aldosterone or 17-hydroxycorticosteroids between the two groups. The "salt-sensitive" patients retained more sodium on the high-sodium diet than did the patients who were not sensitive to salt ("nonsalt-sensitive"); accordingly, sodium induced more weight gain in the salt-sensitive patients.

Adult↗
PubMed1978

A comparison of the effects of timolol and epinephrine on intraocular pressure.

We conducted a double-masked, six-week crossover study comparing bilateral twice-a-day therapy with timolol maleate (0.1%, 0.25%, and 0.5%) and epinephrine hydrochloride (0.5%, 1.0%, 2.0%) in 36 otherwise untreated patients. Increasing concentrations of each drug were administered until an arbitrary level of control was achieved before each of the six-week follow-up periods. Seventeen patients were controlled by both drugs and four patients were controlled by neither drug. Timolol, but not epinephrine, was effective in ten patients, whereas epinephrine, but not timolol, was effective in two patients. Three patients did not complete the study. The mean decrease in intraocular pressure from baseline was significantly greater with timolol than with epinephrine both before crossover and overall at both the lowest and highest concentrations of drug used. Significantly toxicity was produced in four patients during treatment with epinephrine, but in no patients during treatment with timolol.

Adult↗
PubMed1978

Effects of acute endotoxemia and glucose administration on circulating leukocyte populations in normal and diabetic subjects.

Effects of intravenous endotoxin and glucose administration on circulating leukocyte populations were compared in seven normal subjects and seven patients with juvenile-onset diabetes by means of automated cytochemical differential counting to quantitate each cell type. Both groups had comparable control cell counts that were unaffected by glucose tolerance testing but altered significantly by endotoxin. Different patterns of response to endotoxin were observed for different circulating cell types. The response of diabetics was parallel to that of normals but showed lower neutrophil and monocyte rebound, longer lasting depression of lymphocytes and eosinophils, and greater rebound of basophils on the day following endotoxin exposure. Characterization of distinctive normal response patterns of circulating leukocyte populations to endotoxin and comparison with responses in diabetes revealed abnormalities under conditions of stress that may impair the diabetic's ability to cope with acute infection.

Adult↗