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Biomedical subjects

M S Oh

Publications and source records attributed to M S Oh.

At least 55 records · Page 3Linked to original sources
PubMed1990

The association between community physician's attendance at a medical center's CME courses and their patient referrals to the medical center.

This study attempts to quantify an overall association between CME course attendance and referrals. Attendance at formal CME courses given by the University of Michigan Medical School and referrals to the University Hospitals were examined over a two-year period. Attendance and referrals were linked to physicians in Michigan identified through the Michigan Department of Licensing and Regulation and through the American Medical Association. For physicians who are office-based and likely to be in active practice (age less than 70), those who attended at least one of the University's CME courses referred more patients than those who did not attend one (means of 1.9 referrals per physician and 1.3 referrals per physician, p less than .001). The causal direction of the relationship is not clear, but probably operates in both directions. It is reasonable for medical center marketers to consider CME as an indirect method for marketing clinical services. It is also reasonable for CME directors to identify referring physicians as high-priority groups for marketing CME. Both marketing efforts may be significantly enhanced by linking data bases for referrals and for CME attendance. CME directors must also ensure that marketing efforts do not compromise the objectivity and integrity of the content of the institution's CME program.

Data Collection↗
PubMed1990

Prevention of myelinolysis in rats by dexamethasone or colchicine.

The purpose of the present investigation was to determine whether dexamethasone, an agent known to preserve the blood-brain barrier, and colchicine, an agent that impairs mobilization of macrophages, can prevent demyelinating lesions associated with rapid correction of hyponatremia in the experimental animal. Hyponatremia was induced in rats with Pitressin and water. After 4 days hyponatremic rats received hypertonic saline alone or hypertonic saline plus dexamethasone or colchicine. All of the 9 rats that received only 5% NaCl developed demyelinating disease, while 3 of 6 rats treated with dexamethasone and 5 of 15 rats treated with colchicine showed no CNS abnormality. The results of our investigation might help understand the pathogenetic mechanism of central pontine myelinolysis in humans, a disease attributed to rapid correction of hyponatremia.

Animals↗
PubMed1990

Determinants of magnitude of pseudohyperkalemia in thrombocytosis.

The release of potassium from platelets is a well-known cause of pseudohyperkalemia in thrombocytosis. In predicting the magnitude of pseudohyperkalemia associated with thrombocytosis, previous investigations considered only the amount of potassium released from platelets during blood clotting, although the increment in serum potassium during blood clotting depends on the quantity of potassium released from platelets as well as the volume of distribution of the released potassium, which is inversely proportionate to the hematocrit. The present study proposes a new mathematical formula to predict the magnitude of increase in serum potassium during blood clotting, and accuracy of this formula has been tested in a patient with thrombocytosis.

Humans↗
PubMed1989

The first kidney stone.

The proper approach to diagnosis and management in patients with a first episode of a calcium-containing kidney stone is controversial, and we have reviewed the literature in a search for objective information. Six large retrospective studies show the "natural cumulative recurrence rate of renal stones" to be 14% at 1 year, 35% at 5 years, and 52% at 10 years. Randomized studies of the use of either thiazides or allopurinol suggest a modest beneficial effect of about 35% over placebo. Considering that the risk of this specific therapy is about 5%, the morbidity associated with renal stones is limited, and relatively less invasive procedures can often replace nephrolithotomy, we conclude that use of specific drug therapy, namely thiazides or allopurinol, is not warranted in patients with a first kidney stone and, therefore, that extensive metabolic evaluation is unnecessary.

Allopurinol↗
PubMed1989

Comparison of surrogate and subject reports of dietary practices, smoking habits and weight among married couples in the Tecumseh Diet Methodology Study.

Agreement between surrogate and subject reports of current food frequencies and other eating habits, smoking behavior and weight was assessed in 1982-1983 for 180 husbands and wives, aged 45 through 64 years. Agreement was measured by per cent exact agreement and weighted kappa for frequencies of 30 itemized foods or food groups, and for surrogate- and subject-based quintiles of frequencies of eight broad food groups and of vitamin A and C consumption indexes. Surrogate and subject mean frequencies were generally similar, but at the individual level of analysis, agreement varied widely. Agreement was greatest, among the food items and groups, for alcoholic beverages, and among the other items, for smoking status. Extreme misclassification by quintile was very small, but only 40% of persons self-classified in either extreme quintile were similarly classified by their spouses. This level of misclassification may result in the dilution of real relationships between diet and health.

Aged↗
PubMed1989

Danger of central pontine myelinolysis in hypotonic dehydration and recommendation for treatment.

Isotonic saline is the fluid most commonly used for treatment of asymptomatic hypotonic dehydration, but as shown in the case presented in this article, rapid increase in serum sodium may follow administration of isotonic saline, leading to the development of central pontine myelinolysis (CPM). Because the necessity of rapid correction is less, whereas the risk of CPM is greater with chronic asymptomatic hyponatremia than with acute hyponatremia, use of a half normal saline might be more appropriate than normal saline for treating certain patients with hypotonic dehydration with asymptomatic hyponatremia. The calculations indicate that half normal saline will expand the extracellular volume quite effectively, but the rate of increase in serum sodium will be considerably slower than that with normal saline.

Dehydration↗
PubMed1988

Correspondence between perceptions of change in diet and 15-year change in diet reports in the Tecumseh Diet Methodology Study.

As part of an effort to assess the most reliable method of obtaining information about long-term dietary intake, a study was conducted of the correspondence between perception of change in diet and measured change in reported diet from 1967 to 1982. Respondents were 1,201 men and women participants in the Tecumseh Food Frequency Study of 1967-1969 who were 45-64 years of age in 1982-1983, the time of the Diet Methodology Study. Perceptions of change were obtained by asking respondents directly if they thought they currently ate each of 12 food groups more often, less often, or as often as they did during the year of their earlier interview. Measured change was obtained by subtracting each respondent's baseline frequency for each of the 12 food groups from his or her current frequency. For 10 of the 12 food groups, correspondence was found between perception of change and measured change; fats and oils added at the table and meat were the exceptions. Significant linear relationships were found between perceptions and measured change for all food groups except fats and oils. However, greatly varying coefficients were associated with terms such as more often or as often as before, thereby limiting the potential utility of combining perceptions of change with current frequencies to obtain a reliable measure of baseline frequencies.

Data Collection↗
PubMed1987

Reproducibility of reports of frequency of food use in the Tecumseh Diet Methodology Study.

Frequency reports in 1967-1969 for 83 foods were compared to frequency reports for the same foods asked retrospectively in 1982-1983 about use in 1967-1969 for 1,184 respondents aged 45-64 in the Tecumseh Community Health Study cohort. Food frequency reports of the current (1982-1983) diet were also compared to baseline reports to indicate diet stability and to retrospective reports to indicate the influence of current diet on retrospective reporting. Comparisons were also made for 13 food groups and vitamin A and C indices. Short-term reproducibility of seven foods, measured by two reports 1-3 weeks apart in 1967-1969, was compared to long-term reproducibility for the same foods. Short-term reproducibility was consistently greater than long-term. Reproducibility was associated positively with stability of use. For the two nutrient indices and nine of the ten food groups examined, mean intake estimated from the retrospective report differed significantly from mean intake from the baseline report. Agreement between retrospective and current reports exceeded agreement between retrospective and baseline reports, indicating that retrospective reports were greatly influenced by current behavior; yet, the retrospective reports were better indicators of baseline consumption than were the current reports. While misclassification from use of the retrospective report to measure baseline consumption was large, risk differences may still be detected with usual sample sizes.

Ascorbic Acid↗
PubMed1986

The effects of occupation and smoking on respiratory disease mortality.

The effects of occupation and smoking on respiratory symptoms and ventilatory lung function were examined in 1957 among random samples of men 25 to 34 and 55 to 64 yr of age from 4 occupational categories (miners, foundry workers, mixed dust and chemical workers, and non-dust-exposed workers) living in an industrial English town. Mortality has been established 20 yr after the initial survey. This report focuses on the effects of smoking, lung function, and respiratory symptoms among the older men. All-cause mortality was very similar in the nondusty, foundry, and mixed dust groups, but slightly lower in the miners and ex-miners. In contrast, smokers had 2 times the death rates of nonsmokers. There was consistency in the smoking effect within each occupational group. Poor lung function and to some extent bronchitic symptoms in 1957 were predictive of mortality by 1977, regardless of smoking habits. However, the effect of symptoms in the absence of concomitant poor lung function, though consistent, was small.

Adult↗
PubMed1985

Metabolic utilization and renal handling of D-lactate in men.

This study was carried out to investigate the renal handling of d- and l-lactate and the extent of their metabolism in men. Ten healthy male subjects were given an intravenous (IV) infusion of a racemic mixture of d- and l-lactate. At an infusion rate of 1.0 to 1.3 meq/kg body weight of each isomer, d-lactate achieved a concentration in plasma of 1.7 to 3.0 meq/L, and l-lactate 2.8 to 4.2 meq/L. At these levels, fractional excretion of d-lactate ranged from 40% to 65%, while fractional excretion of l-lactate was always less than 5%. At a higher infusion rate, 1.8 to 2.0 meq/kg/h, plasma concentrations of d- and l-lactate reached 4.5 to 6.0 meq/L, and 4.0 to 6.7 meq/L, respectively. Fractional excretion of d-lactate then ranged from 61% to 100%, while that of l-lactate ranged from 9% to 30%. At plasma concentrations of d-lactate less than 3.0 meq/L, reabsorption of l-lactate was nearly complete, but when plasma d-lactate exceeded 3.0 meq/L, reabsorption of l-lactate was considerably impaired. Similarly, for a given concentration of plasma d-lactate, its reabsorption was more efficient when the plasma l-lactate concentration and fractional excretion of l-lactate were low than when they were high. At an infusion rate of d-lactate of 1.0 to 1.3 meq/L, about 90% of the infused lactate was metabolized, and at a higher infusion rate, still more than 75% of the infused lactate was metabolized.(ABSTRACT TRUNCATED AT 250 WORDS)

Creatinine↗
PubMed1985

A mechanism of hypoxemia during hemodialysis. Consumption of CO2 in metabolism of acetate.

The present study is an investigation of the role of acetate metabolism in dialysis-induced hypoxemia and of the relative roles of acetate metabolism, bicarbonate loss, and CO2 gas (g) loss in causation of hypoxemia. The loss of CO2 (g) measured in 23 patients during acetate dialysis was found to be negligible (0.21 +/- 0.01 mmol/min). The HCO-3 loss was substantial (3.4 +/- 0.5 mmol/min), but its predicted effect on dialysis hypoxemia was modest. The infusion of acetate at 4 mmol/min into 6 normal volunteers decreased the respiratory exchange ratio (R) from 0.83 +/- 0.06 to 0.71 +/- 0.06 with constant O2 consumption (VO2) and reduced net CO2 production (VCO2). In another experiment, the infusion of sodium acetate into 9 normal volunteers resulted in a similar reduction in R (from 0.82 +/- 0.04 to 0.71 +/- 0.04) and arterial pO2 (from 92.3 +/- 1.1 to 78.3 +/- 1.7 mm Hg). The results indicate that acetate metabolism can lead to reduction in R and hypoxemia and suggest that the same mechanism is responsible for hypoxemia during hemodialysis using acetate dialysate.

Acetates↗
PubMed1985

Bartter's syndrome due to a defect in salt reabsorption in the distal convoluted tubule.

Bartter's syndrome is generally attributed to a primary defect in salt reabsorption either in the ascending limb of Henle's loop or in the proximal tubule. 2 siblings presented here have all the clinical and biochemical features of Bartter's syndrome but seem to have defective salt reabsorption in the distal convoluted tubule. A surreptitious use of diuretics was ruled out. Free water clearance was reduced in both patients and also was low after the addition of furosemide when compared with controls. Urine osmolalities following overnight dehydration were 883 and 1,000 mosm/l. The reduced maximal free water clearance argues against a proximal defect, and the normal urine concentration against a Henle's loop defect. Low free water clearance after furosemide suggests a defect in the distal convoluted tubule.

Absorption↗
PubMed1985

Minoxidil in a once-a-day step-3 antihypertensive program.

Convenience of medicine-taking and lack of side effects are two major factors that favor compliance. Using a simple and convenient once-a-day regimen of minoxidil, nadolol, and chlorthalidone, we treated successfully 30 patients with moderate to severe hypertension. All patients were previously taking at least three medications, usually three to four times a day. Treatment was started with nadolol (160 mg) and chlorthalidone (50 mg) once daily. If diastolic blood pressure remained above 90 mmHg, minoxidil was added at a starting dose of 2.5 mg/day and increased weekly until blood pressure was controlled or the maximum dose of 100 mg/day was reached. The average blood pressure decreased from 170.9/107.0 mmHg (sitting) and 174.1/110.8 mmHg (standing), before the addition of minoxidil, to 138.8/86.7 mmHg (sitting) and 140.0/89.5 mmHg (standing), at the third month of minoxidil therapy. At the sixth month of minoxidil therapy, the figures were 140.9/86.3 and 141.9/89.8 mmHg. With this single-dose program, smooth blood pressure control throughout 24 hours was documented by 24-hour ambulatory blood-pressure monitoring. Hypertrichosis was common but was bothersome only to women patients. Pericardial effusions occurred in five patients, but they were all small and asymptomatic. Subjective side effects of the regimen were usually so mild that all patients who completed the study decided to remain on the same regimen.

Chlorthalidone↗
PubMed1983

Mortality of Reserve Mining Company employees in relation to taconite dust exposure.

Analysis of mortality among men who were employed by Reserve Mining Company from 1952 to 1976 has been carried out. Follow-up was conducted with standard methods, including searches by the Social Security Administration. Occupational exposures to dust were based on personal samples taken over the past five years by the industrial hygiene department of the company. Smoking habits were obtained by mailed questionnaires or telephone interviews. A modified life table method was used to compare death rates of the employees with those expected for white males in the state of Minnesota. Comparisons were also made with US rates for white males. The results showed that the death rates for all causes were significantly below expectation. Deaths from malignant diseases were marginally below those expected for the state. Exposures to total dust, to silica dust, or to fiber were low. There was no relationship between mortality and estimated lifetime dust exposures, nor was there any suggestion that deaths from malignant neoplasms were increased after 15 to 20 years latency. In contrast, there was a strong relationship between smoking habits and mortality from all causes, from cardiovascular diseases, and from cancer. This study does not suggest any increase in cancer mortality from taconite exposure.

Adult↗