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Biomedical subjects

R Cooper

Publications and source records attributed to R Cooper.

At least 289 records · Page 16Linked to original sources
PubMed1985

Cardiac function in acute hypothyroidism.

It has been established that chronic hypothyroidism may affect cardiac function by several mechanisms. It is not known how long the patient has to be hypothyroid for cardiac involvement to develop. This study was undertaken to assess the effect of a short period of hypothyroidism (10 days) on cardiac function. Nine patients who had had total thyroidectomy, had received ablative radioiodine for thyroid cancer and were euthyroid on replacement therapy were studied while both euthyroid and hypothyroid. Cardiac assessment was performed by X-ray, ECG, echocardiography and gated blood-pool scans. After 10 days of hypothyroidism, the left-ventricular ejection fraction failed to rise after exercise in 4 of the 9 patients studied, which was significant (P less than 0.002). No significant changes in cardiac size or function at rest were detected. This functional abnormality in the absence of any demonstrable change in cardiac size and the absence of pericardial effusion with normal basal function suggest that short periods of hypothyroidism may reduce cardiac reserve, mostly because of alterations in metabolic function.

Acute Disease↗
PubMed1985

High-density lipoprotein cholesterol and angiographic coronary artery disease in black patients.

The clinical epidemiology of coronary artery disease (CAD) among black patients has not been well described, particularly in relation to the impact of the major risk factors. Lipoprotein profiles and other risk factors were measured in 114 black patients undergoing cardiac catheterization for probable CAD. Patients (coronary narrowing of 50% or greater; n = 63) were compared to those without significant stenoses (n = 51). Total cholesterol and low-density lipoprotein cholesterol (LDLC) were both significantly associated with the presence of CAD in men and women; however, high-density lipoprotein cholesterol (HDLC) had discriminatory value only for women. The ratio of total cholesterol to HDLC (TC:HDL) separated patients from control subjects in both sexes, most efficiently among women, and was the only lipid variable associated with CAD in the age group over 55 years. Hypertension and angina were frequent in both groups and did not identify those with disease. In summary, LDLC was the best predictor among the lipids for men (likelihood ratio = 9.4) and TC:HDL was the best indicator of disease among women (likelihood ratio = 15.7). Low HDLC levels may, in part, account for the increased incidence of CAD among black women. Further population studies of factors leading to reduced HDLC, namely, obesity and diabetes, are needed.

Adult↗
PubMed1985

Neurophysiological signs of brain damage due to glue sniffing.

Recordings of the brain electrical responses to pattern reversal (checkerboard) visual stimuli showed significantly increased latencies in a group of 12 young people who had been sniffing glue over a prolonged period. Only small improvements were observed in two people who had repeat recordings after 6 months' abstinence. These results show that chronic glue sniffing can lead to long lasting brain damage.

Adhesives↗
PubMed1985

Congenital bilateral renal hypoplasia in Large White pigs.

Bilateral renal hypoplasia and/or agenesis was detected in 6 of 26 pure-bred Large White piglets in 2 consecutive litters. The affected piglets were all dead at birth. The defect was characterised by a variable nephrogenic zone beneath the renal capsule and by a greatly reduced number of glomeruli which were hypertrophied. The piglets were born to the same sow but they were sired by different boars. Both boars and the sow were related through their pedigree. A genetic basis for the defect, probably involving a recessive gene defect inherited in a simple Mendelian manner, seems likely.

Animals↗
PubMed1985

Occurrence of Cryptosporidium oocysts in fecal samples submitted for routine microbiological examination.

During a 7-month period, 2,252 fecal samples submitted for routine microbiological examination from 1,621 patients were screened for Cryptosporidium oocysts by the auramine staining method with Kinyoun acid-fast stain as the confirmatory stain. Cryptosporidium oocysts were detected in fecal samples from 19 (1.2%) patients, 18 of whom had gastroenteritis. Diarrheic stools from 14 of these 18 patients were negative for the usual enteropathogens but contained the oocysts in moderate to large numbers. Although Cryptosporidium oocysts were found in patients of all ages, they occurred slightly more frequently in infants and children than in the rest. Cryptosporidium species was one of the common enteropathogens identified in fecal samples submitted for routine parasitological examination during the period of the survey and was second only to Giardia species in terms of frequency. Considering cryptosporidiosis in the differential diagnosis of gastroenteritis in immunocompetent persons and including a search for Cryptosporidium oocysts in routine parasitological examinations of fecal samples appear warranted.

Adolescent↗
PubMed1985

Hormonal and biochemical responses to transcendental meditation.

This study was designed to assess whether transcendental meditation (TM) could influence various endocrine responses in 10 experienced male meditators. Nine matched subjects, uninformed of the TM procedure, acted as controls. Meditators successfully practised their technique for 40 min in the morning while controls relaxed for this period. No significant differences emerged between these 2 groups with respect to carbohydrate metabolism (plasma glucose, insulin and pancreatic glucagon concentrations), pituitary hormones (growth hormone and prolactin) or the 'stress' hormones, cortisol and total catecholamines-although meditators tended to have higher mean catecholamine levels. Plasma free fatty acids were significantly elevated in meditators 40 min after completing the period of TM. No clear evidence was thus obtained that any of the stress, or stress-related, hormones were suppressed during or after meditation in the particular setting examined.

Adult↗
PubMed1985

Catacandins, novel anticandidal antibiotics of bacterial origin.

Two novel antibiotics, catacandin A and catacandin B, were isolated from the fermentation broth of the bacterium, Lysobacter gummosus, by extraction and adsorption, reverse-phase and gel filtration chromatography. On the basis of their physico-chemical properties, they are acyltetramic acids that are easily distinguishable from others in this class. Catacandin A and catacandin B possess good anticandidal activity.

Anti-Bacterial Agents↗
PubMed1985

Novel potentiators of beta-lactam antibiotics. Isolation of SQ28,504 and SQ28,546 from Chromobacterium violaceum.

Two novel compounds, SQ28,504 and SQ28,546 are produced by Chromobacterium violaceum. These compounds enhance the antibacterial activity of beta-lactam antibiotics against Gram-negative organisms. Both SQ28,504 and SQ28,546 induce morphological changes in the presence of beta-lactam antibiotics. Only SQ28,546 has weak antimicrobial activity against several Gram-negative organisms.

Anti-Bacterial Agents↗
PubMed1984

Thyroglobulin may be undetectable in the serum of patients with metastatic disease secondary to differentiated thyroid carcinoma. Follow-up of differentiated thyroid carcinoma.

To assess the value of serum thyroglobulin (Tg) levels in the follow-up of differentiated thyroid carcinoma after ablative therapy simultaneous Tg estimations and radioiodine (131I) scans were performed on patients during an 18-month follow-up period. In this study, 287 scans were performed on 200 patients who were not receiving Thyroxine (T4) replacement at the time, i.e., off T4. Wherever possible, Tg was also estimated while the patient was receiving T4. All sera were screened for Tg autoantibodies which were detected on 67 occasions in 44 patients (22%). Of the 220 sera without Tg autoantibodies (156 patients), 17 were accompanied by scan evidence of functioning thyroid tissue, although Tg was undetectable (less than 5 micrograms/l) either on or off T4. Serum Tg was only detectable off T4 in a further five patients (six scans) who simultaneously had scan evidence of functioning thyroid tissue. In seven patients the finding of detectable Tg preceded scan evidence of recurrence. Thus, serum Tg is useful in the follow-up of differentiated thyroid cancer after ablative therapy. However, some patients with recurrence or metastasis will be missed if Tg alone is relied on, particularly if thyroxine treatment is continued.

Adenocarcinoma↗
PubMed1984

Localization of the L1Md family of repeated sequences in the mouse albumin-alpha-fetoprotein gene complex.

Studies on the beta-globin gene complex in the mouse have demonstrated the existence of repeated DNA sequences interspersed throughout the intergenic regions (1,2). These sequences are members of families of middle repetitive sequences and have been mapped to specific intergenic sites in the 60 kbp beta-globin complex. In this study we present evidence that members of this middle repetitive family of DNA sequences, the L1Md family, are interspersed throughout the mouse albumin and alpha-fetoprotein gene complex. Unlike those of the beta-globin complex, all of which are found in the intergenic regions, these sequences are localized within intron 12 of the albumin gene and intron 3 of the AFP gene as well as twice in the 13.5 kbp intergenic region that links the albumin gene to the AFP gene.

Animals↗
PubMed1984

Changes in cerebral blood flow in patients with severe congestive cardiac failure before and after captopril treatment.

The intravenous 133xenon injection method was used to estimate global cerebral blood flow before and after treatment with captopril in nine patients with severe heart failure. The pretreatment mean blood pressure was 94.9 mm Hg (S.D. 13.9) and fell to 85.1 mm Hg (S.D. 18.1) after treatment with captopril for between four and 15 days. The cerebral blood flow before captopril was 61.1 ml/100 g per minute (S.D. 6.9), which was less than the value of 75.8 ml/100 g per minute found in control subjects. After treatment with captopril the cerebral blood flow increased to 73.8 ml/100 g per minute (S.D. 11.8, p less than 0.01). The fraction of carbon dioxide in the expired air was not significantly different in the two studies (4.1 +/- 0.88 versus 3.97 +/- 0.65). It is concluded that cerebral blood flow is reduced in severe heart failure and can be restored by treatment with captopril, but the reasons for the reduced flow and its improvement after converting enzyme inhibition are not known.

Adult↗
PubMed1984

A note on the biologic concept of race and its application in epidemiologic research.

Use of the category of race in epidemiologic research presupposes scientific validity for a system that divides man into subspecies. Although the significance of race may be clear-cut in many practical situations, an adequate theoretical construct based on biologic principles does not exist. Anthropologists have in large measure abandoned the biologic concept of race, and its persistent widespread use in epidemiology is a scientific anachronism. The assumption that race designates important genetic factors in a population is in most cases false. Racial definitions should be seen as primarily social in origin and should be clues to environmental-rather than genetic-causes of disease. An understanding of the social forces leading to racial differentials in health will give further direction to preventive campaigns.

Adult↗
PubMed1984

Prevalence of diabetes/hyperglycemia and associated cardiovascular risk factors in blacks and whites: Chicago Heart Association Detection Project in Industry.

Prevalence rates of diabetes, asymptomatic hyperglycemia, and cardiovascular risk factors were examined in an employed population of 28,895 whites and 2607 blacks, ages 25 to 64 years. Diabetes had been previously diagnosed in this population among approximately 3% of the males of both races and 2% of the females. Plasma glucose 1 hour after a 50 gm oral load was highest among white males (141 mg/dl), similar and at intermediary levels among black males (134 mg/dl) and white females (135 mg/dl), and lowest among black females (126 mg/dl). A divergent pattern of obesity was observed, however, with black females being by far the most overweight. Preliminary mortality data for males suggest that both blacks and whites with diabetes have sizably higher death rates than those without diabetes; a black-white differential is not apparent.

Adult↗