Search PubMed⌕ Search

Biomedical subjects

M B Lee

Publications and source records attributed to M B Lee.

At least 73 records · Page 4Linked to original sources
PubMed1989

The inexact use of Fisher's Exact Test in six major medical journals.

We reviewed the use of Fisher's Exact Test in 71 articles published between 1983 and 1987 in six medical journals. Thirty-three of 56 selected articles did not specify use of a one- or two-tailed test, and 12 (36%) of these actually used the one-tailed test. Five (42%) of these 12 articles contained at least one table in which the standard significance level of P less than .05 was no longer met when a two-tailed analysis was run instead. Eleven (65%) of 17 articles with a statistical consultant compared with 10 (28%) of 36 articles without a consultant specified use of a one- or two-sided test. The use of Fisher's Exact Test without specification as a one- or two-tailed version may misrepresent the statistical significance of data. A uniform specification statement should be required for all manuscripts to correct such potential errors in interpretation.

Periodicals as Topic↗
PubMed1989

Corticosteroids as adjunctive therapy in bacterial meningitis. A meta-analysis of clinical trials.

A meta-analysis of all nine available controlled trials of corticosteroids for adjunctive therapy for bacterial meningitis was performed. Risks of various outcomes were assessed for control and treatment groups from each study, and risk differences were determined. For each outcome a weighted average of the individual risk differences was calculated. The results show that corticosteroid administration did not reduce the risk of death or neurologic abnormality at hospital discharge or follow-up examination. Based on statistically combined results of the three most recent trials, there is evidence that dexamethasone reduces the risk of bilateral moderate or more severe hearing loss (risk difference, -9%; 95% confidence limits, -15% and -3%). However, this may be true only for children with meningitis caused by Haemophilus influenzae type b. There are inadequate data in adults or in children with meningitis due to other organisms to demonstrate the benefit of dexamethasone administration. Further study is necessary to fully assess the benefits and risks of corticosteroids for adjunctive therapy for bacterial meningitis.

Adrenal Cortex Hormones↗
PubMed1989

Relative contribution of obesity and body fat distribution to alterations in glucose insulin homeostasis: predictive values of selected indices in premenopausal women.

Obesity and fat topography are risk factors for hyperinsulinemia, insulin resistance, and diabetes mellitus. The relative contribution of obesity and body fat distribution indices to fasting and oral glucose-stimulated C peptide, insulin, and glucose concentrations were determined in 33 healthy premenopausal women. Obesity level was assessed by hydrostatic weighing and fat topography by computerized tomography-derived intraabdominal fat area, waist to hip ratio, subscapular skinfold thickness and the ratio of subscapular to triceps skinfold thickness. Both fat mass and regional fat distribution indices were associated closely with changes in insulin secretion. Fat topography indices were more closely correlated (p less than 0.001) to insulin response than were fat mass indices (p less than 0.01). The subscapular skinfold thickness had the greatest integrity for reflecting fat mass and fat distribution as they relate to the metabolic profile. The subscapular skinfold thickness may help identify individuals at risk for noninsulin dependent diabetes mellitus.

Adipose Tissue↗
PubMed1989

Consensus among bone marrow transplanters for diagnosis, grading and treatment of chronic graft-versus-host disease. Committee of the International Bone Marrow Transplant Registry.

A questionnaire comprised of a series of clinical vignettes illustrating potential difficulties in diagnosis, grading and treatment of chronic graft-versus-host disease (GVHD) was completed by 65 bone marrow transplant physicians from 51 transplant centers worldwide. The concordance index (CI) for responses to each question was calculated using the formula CI = 2p-1, where p was the percentage agreement among respondents. Possible responses ranged from 0 (no agreement) to 1.00 (perfect agreement). Responses indicated moderate (CI = 0.55), high (CI = 0.88) and moderate (CI = 0.54) agreement among transplanters for diagnosis, grading and treatment of chronic GVHD, respectively. Disagreement was observed in (1) diagnosis of uncommon manifestations of chronic GVHD; (2) in interpretation of symptoms which occur less than 2 months after transplant; (3) in interpretation of persistent stable symptoms; and (4) in deciding whether to treat chronic GVHD limited to skin. The results point to potential problem areas in designing and interpreting clinical trials to prevent or treat chronic GVHD and highlight the need for improved diagnostic criteria.

Adolescent↗
PubMed1988

Relationship of anthropometric measurements of body fat distribution to metabolic profile in premenopausal women.

Regional fat distribution has emerged as an independent predictor of metabolic aberrations including glucose intolerance, hyperinsulinemia, insulin resistance, hyperlipidemia and hypertension. We investigated the comparative efficacy of various body fat distribution indices in predicting these aberrations. The relationship of circumferential ratios, skinfold measurements, and computerized tomography (CT)-derived indices of intra- and extra-abdominal fat distribution to the metabolic variables and blood pressure was examined in a cohort of healthy premenopausal women. All indices denoting preponderance of fat in the central, upper body or abdominal region were predictive of the metabolic profile. The subscapular skinfold, subscapular-triceps ratio, waist-hip ratio (WHR), and the CT derived intra-abdominal fat area (CT-IFA) were closely related to alterations in glucose and insulin concentrations independent of age and obesity. The WHR and CT-IFA were better predictors of plasma triglyceride levels and blood pressure profile and thus the overall aberrations than skinfold measurements. Despite a high degree of intercorrelation between the anthropometric indices measured, only the relationship of WHR to CT-IFA remained significant after adjusting for the effects of age and degree of adiposity, suggesting that WHR indexes not only the relative distribution of truncal to gluteofemoral subcutaneous fat but also the abundance of intra-abdominal or visceral fat depots. The greater reproducibility of CT-IFA and WHR also suggests that these measurements are the most useful in predicting the regional obesity-associated metabolic abnormalities with their morbidity and mortality risks.

Adipose Tissue↗
PubMed1988

Glucose metabolism in obesity: influence of body fat distribution.

The dose-response relationships between portal venous insulin concentrations and hepatic glucose production and between peripheral insulin concentrations and peripheral glucose utilization were determined in 8 nonobese and 17 obese premenopausal women with either upper or lower body fat localization. The glucose production dose-response curves for the two obese groups were shifted to the right at all levels of portal insulinemia. The upper body obese women had a greater rightward shift compared to the lower body obese women. The peripheral glucose utilization dose-response curve was shifted to the right in the lower body obese women, but maximal glucose utilization was normal. The upper body obese women had both a greater rightward shift and a marked reduction in maximal glucose utilization. The insulin concentrations that had half-maximal effects on glucose production and utilization were similar in each group. These results indicate that the liver is not inherently more sensitive to insulin than peripheral tissues. Obesity is associated with a moderate diminution of hepatic and peripheral insulin sensitivity. Upper body fat localization in obese women is characterized by a greater diminution in insulin sensitivity and decline in peripheral insulin responsivity than is lower body fat localization. The marked peripheral insulin resistance in the former group may account for the increased prevalence of glucose intolerance.

Adult↗
PubMed1986

Recurrence potential of thin primary melanomas.

Between April 1971 and January 1985, the University of California at Los Angeles (UCLA) Division of Surgical Oncology has seen 649 patients diagnosed with thin primary melanomas, as defined by a Clark level less than IV and Breslow depth less than 0.76 mm. Thirty-six patients, whose primary diagnosis was confirmed by UCLA pathologists, presented with or subsequently developed melanoma metastases. Twenty-four (67%) had Clark level II lesions, whereas the remaining 12 (33%) had Clark level III lesions. Metastases were noted more frequently in men than in women, with a man-to-woman ratio of 3 to 2. The site of the primary lesion in this group was most frequently on the trunk (16 of 36 cases, 44%), followed by the head and neck (9 of 36 cases, 25%) and arm and shoulder (7 of 36 cases, 19%). Metastasizing thin lesions were least likely to occur on the leg and hip (4 of 36 cases, 11%). Twenty of these lesions were recently reexamined, and 17 of 20 cases (85%) demonstrated evidence of regression. Twenty-eight patients (78%) had their first metastases to regional lymph nodes. Fifteen remained alive with no evidence of disease at a median follow-up of 99 months. Twenty patients died from systemic metastases, and one patient was alive with brain metastasis at the time of this article. Although infrequent, metastases from thin melanomas do occur, suggesting the need for careful long-term follow-up and immediate investigation of adenopathy even in low-risk patients.

Adult↗
PubMed1985

The use of a platelet nucleotide assay as a possible diagnostic test for malignant hyperthermia.

A bioassay, using high-performance liquid chromatography (HPLC) analysis of platelet adenosine nucleotides and hypoxanthine, was studied for its potential use as a test for MH susceptibility. A protocol for the assay was developed, based on the method outlined by Solomons and Masson. The HPLC procedure was a rapid, efficient, sensitive, and highly reproducible technique for measuring ATP, ADP, AMP, and hypoxanthine in platelets. Conditions of extraction and storage were critical for preventing degradation of the nucleotides. Extraction of nucleotides at icebath temperature was found necessary. Storage of platelet extract in PCA, even at -20 degrees C, showed loss of ATP and ADP; hence, neutralization with KOH was essential before storage. Contrary to the findings of Solomons et al., the present study demonstrated that neither ATP depletion nor per cent reduction in nucleotide ratios in platelets treated with halothane can be used as a definitive test for the diagnosis of MH susceptibility. The reason for this disagreement is unclear; however, differences in methods and altitude are implicated. It is possible that the platelet is not affected by malignant hyperthermia and thus cannot serve as a test system for the detection of the syndrome.

Adenine Nucleotides↗
PubMed1978

The occurrence and distribution of 5-hydroxytryptamine in Hymenolepis diminuta and H. nana.

The presence of 5-HT in Hymenolepis diminuta and Hymenolepis nana was detected by 2 biochemical methods and as yellow fluorescence in a histochemical method. In H. diminuta, 5-HT was found in a concentration of about 1.2 micron/g; this amount did not vary significantly in worms aged 6 to 18 days or more or in various regions of the worm. In H. nana, 5-HT was found in a concentration of about 1.8 micron/g. It was histochemically localized in H. diminuta and H. nana in a pattern similar to that of acetylcholinesterase previously described in these 2 cestodes, and it may be the opposing neuro-transmitter to acetylcholine. The lack of 5-HT in the vestigial rostellum of H. diminuta may be correlated with loss of function of this organ.

Animals↗