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Biomedical subjects

A Donner

Publications and source records attributed to A Donner.

At least 181 records · Page 10Linked to original sources
PubMed1979

The use of correlation and regression in the analysis of family resemblance.

The use of correlation and regression as applied to the analysis of family resemblance is discussed. The application of these statistical techniques to family data is not routine because the number of siblings per family is in general variable. Topics dealt with include estimation of sib-sib (intraclass) correlation, parent-child (interclass) correlation and regression of child on parent. An example is given.

Adolescent↗
PubMed1979

Case-control study of hair dye use by patients with breast cancer and endometrial cancer.

A case-control study was undertaken of use of permanent and semipermanent hair dyes by women with cancers of several sites, including breast and endometrium. In London, Ontario, 50 cases of of breast cancer and in Toronto 35 cases of breast cancer and 36 cases of endometrial cancer were identified in cancer treatment centers. In London, controls were selected from hospitalized women with diseases other than cancer; in Toronto, controls were selected from women living in the same neighborhood as the patients with cancer. The results did not suggest an increased risk of either breast or endometrial cancer in users of permanent or permanent and semipermanent dyes combined. Although the numbers of cases and controls were small, the consistency of the results for both sites, in both study centers, and the absence of any clear positive relationship between various measures of intensity of use and risk of cancer provided evidence that a large increase in risk was not missed.

Adult↗
PubMed1977

Clinical spectrum of gonococcal infection in women.

The medical records of 278 women infected with Neisseria gonorrhoeae during a 6-month period were reviewed. These represented 75% of the infections in women at Boston City Hospital during this time. Women who presented to the venereal-disease clinic because they had had contact with an infected man and women who were found to be infected during routine examinations in the obstetrics-and-gynaecology clinic were usually free of symptoms or had non-specific symptoms such as vaginal discharge. However, these women accounted for only 108 (39%) of the 278 infections. Most of the infections were in women who presented to the emergency-care areas of the hospital with symptomatic gonococcal infections. At least 86 (31%) of the 278 infections were in women who had pelvic inflammatory disease. These data indicate that the clinical spectrum of gonococcal infection varies according to where the patients are seen and that the widely held concept that most gonococcal infections in women are asymptomatic may be erroneous.

Adolescent↗
PubMed1977

Hepatotoxicity of erythromycin estolate during pregnancy.

Women in the second half of pregnancy, who were infected with genital mycoplasmas and who gave written informed consent, were randomly assigned to receive capsules of identical appearance containing erythromycin estolate, clindamycin hydrochloride, or a placebo for 6 weeks. Levels of serum glutamic oxalacetic transaminase (SGOT) were determined before and during treatment by a fluorometric method. All pretreatment levels of SGOT were normal (<41 units). Participants who received erythromycin estolate had significantly more abnormally elevated levels of SGOT (16/161, 9.9%) than did those who received clindamycin (4/168, 2.4%, P < 0.01) or those who received placebo (3/165, 1.8%, P < 0.01). Elevated levels of SGOT ranged from 44 to 130 U. Serum bilirubin levels were normal. Gamma-glutamyl transpeptidase activity was abnormal in six of six participants who had abnormal levels of SGOT while receiving erythromycin estolate. There were few associated symptoms, and all levels of SGOT returned to normal after cessation of treatment. The treatment of pregnant women with erythromycin estolate may be inadvisable.

Aspartate Aminotransferases↗
PubMed1975

Plasma lipids and lipoproteins in vegetarians and controls.

The possible effect of diet on plasma lipids was investigated in a group of vegetarians. Seventy-three men and 43 women who had adhered to a vegetarian diet for an average of three years were studied in the fasting state and compared with a randomly selected group of controls matched for age and sex. Mean cholesterol levels in milligrams per deciliter for vegetarians and controls, respectively, were 126 and 184; low-density lipoprotein, 73 and 118; very-low-density lipoprotein, 11.8 and 17.2; high-density lipoproteins, 42 and 49; and mean triglyceride levels 59 and 86. Mean weight and subscapular skinfold thicknesses were 58 kg and 6 mm for vegetarians and 73 kg and 17 mm for controls. Similar differences in lipid levels were found between subgroups of 42 vegetarians and controls with identical mean weights. Multiple regression analyses showed that consumption of dairy foods and eggs, but not body weight, was associated with the lipoprotein and cholesterol findings.

Adolescent↗
PubMedDate not supplied

The exclusion of patients from a clinical trial.

In designing a clinical trial, the investigator must often decide whether or not to exclude certain patients from randomization. Using Bayesian analysis this paper proposes a criterion for making this decision, based on an extension of Colton's model for the choice between two medical treatments.

Bayes Theorem↗
PubMedDate not supplied

Approaches to sample size estimation in the design of clinical trials--a review.

Over the last decade, considerable interest has focused on sample size estimation in the design of clinical trials. The resulting literature is scattered over many textbooks and journals. This paper presents these methods in a single review and comments on their application in practice.

Clinical Trials as Topic↗
PubMedDate not supplied

Analysis of data arising from a stratified design with the cluster as unit of randomization.

This paper discusses statistical techniques for the analysis of dichotomous data arising from a design in which the investigator randomly assigns each of two clusters of possibly varying size to interventions within strata. The problem addressed is that of assessing the statistical significance of the intervention effect over all strata. We propose a weighted paired t-test based on the empirical logistic transform for designs that randomize large aggregate clusters in each of several strata.

Biometry↗
PubMedDate not supplied

Value of flumazenil in benzodiazepine self-poisoning.

The efficacy of the benzodiazepine-antagonist flumazenil (Ro 15-1788) was evaluated in 26 patients with coma due to benzodiazepine self poisoning, alone or in combination with alcohol or other psychoactive drugs. 77% of the patients responded to the administration of a mean dose of 1.73 mg (range 0.2 to 8 mg) with immediate awakening or an improvement of at least 2 coma grades. In the patients without response (n = 3) or with minor improvement (n = 3) other psychoactive drugs turned out to be predominantly responsible for their comatose state. Adverse effects of flumazenil treatment such as altered blood pressure or increased heart rate were observed, but were generally mild. An acute benzodiazepine withdrawal syndrome was seen in 2 cases. In conclusion, flumazenil proved to be effective in the treatment of severe benzodiazepine intoxication. Beyond that, in cases of mixed overdosage or initially unknown diagnosis the antidote assisted in the clarification of the clinical condition.

Adolescent↗
PubMedDate not supplied

Cluster randomization trials in tropical medicine: a case study.

Field trials in tropical medicine are often designed so that intact social units (e.g., families, schools, communities) rather than independent individuals are randomized to an intervention group. Reasons are diverse, but include administrative convenience, a desire to reduce the effect of treatment contamination, and the need to avoid ethical issues that might otherwise arise. Dependencies among cluster members typical of such designs must be considered when determining sample size and analysing the resulting data. Failure to do so can result in false conclusions that the treatment is effective. The purpose of this paper is to compare different methods which can be used to construct tests of the effect of treatment when outcomes are binary (e.g., infected/uninfected). The discussion will be illustrated using data from a trial which randomly assigned families to either a control group or a screening and treatment programme for imported intestinal parasites.

Asia, Southeastern↗
PubMedDate not supplied

Orogenital contact and the isolation of Neisseria gonorrhoeae, Mycoplasma hominis, and Ureaplasma urealyticum from the pharynx.

Men and women who came to clinics in Boston underwent pharyngeal examinations, and pharyngeal specimens were obtained for cultures for Neisseria gonorrhoeae, Mycoplasma hominis, and Ureaplasma urealyticum. Fifty-one (4.9%) of 1,037 participants had gonococcal pharyngeal infection. M. hominis and U. urealyticum were recovered from the pharynges of 149 (14.3%) and 154 (14.8%) of 1,044 participants, respectively. The history of ever having performed fellatio was associated with pharyngeal infection with N. gonorrhoeae (P less than 0.02), M. hominis (P less than 0.05), and U. urealyticum (P less than 0.006). A history of fellatio was also associated with a history of a recent sore throat. There was, however, no association between pharyngeal infection with N. gonorrhoeae, M. hominis, or U. urealyticum and a recent sore throat. Cunnilingus was not associated with symptoms or signs or pharyngitis or with the isolation of gonococci or genital mycoplasmas from the pharynx. The pharyngitis associated with fellatio remains a microbiologic enigma.

Female↗
PubMedDate not supplied

Problems in design of stroke treatment trials.

Critical evaluation of the literature was use to identify remediable flaws in the design of clinical trials of stroke treatment. Trials of dexamethasone, dextran, and glycerol were reviewed. Available studies have in common major weaknesses in case selection (failure to exclude arteriolar strokes due to hemorrhage or lacunar infarction), and failure to estimate required sample size. Problems of case selection can be avoided with computerized tomography; the sample size required to show superiority of active treatment over placebo can be estimated using standard formulas. Prognostic stratification is suggested as a method of overcoming problems of unbalanced allocation. Further studies with improved design are required to evaluate the prospects for medical limitation of cerebral infarct size.

Adult↗
PubMedDate not supplied

Expression of the RB protein, allelic imbalance of the RB gene and amplification of the CDK4 gene in metaplasias, dysplasias and carcinomas in Barrett's oesophagus.

In the present study, the role of allelic loss at the retinoblastoma gene (RB), expression of the retinoblastoma protein (pRb) and amplification at the CDK4 gene in the metaplasia--dysplasia--carcinoma sequence in Barrett's oesophagus (BO) was investigated. Samples of metaplastic specialised epithelium (SE; n = 28), low-grade dysplasia (LGD; n = 21), high-grade dysplasia (HGD; n = 19) and invasive adenocarcinoma (CA; n = 35) derived from 36 oesophagectomy specimens were included. Of the cases that were informative for the RB gene (n = 27), loss of heterozygosity (LOH) was found in none of the 22 SE, in none of the 14 LGD, in 1 of the 12 HGD (8.3%) and in 5 of the 27 CA (18.5%). Immunohistochemically, an enhanced expression of pRb protein in LGD, HGD and CA as compared with SE was found in most cases. In 4 carcinoma samples, however, a marked reduction (3 cases) or complete absence (1 case) of pRb protein expression was found. Two out of these 4 CA samples showed LOH in the RB gene whilst one case was heterozygous and one case was homozygous. In contrast to the positive controls used, CDK4 amplification was not detectable by means of differential PCR in any of the samples under investigation. The present study indicated that allelic loss of the RB gene occurs late in the metaplasia--dysplasia--carcinoma sequence in BO. Immunohistochemically determined loss of pRb protein expression may indicate LOH of the RB gene. CDK4 gene amplification does not seem to play a role in the development of oesophageal adenocarcinoma.

Adenocarcinoma↗