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Biomedical subjects

R Cooper

Publications and source records attributed to R Cooper.

At least 361 records · Page 20Linked to original sources
PubMed1980

The association between urinary sodium excretion and blood pressure in children.

This study explored the association between sodium excretion and blood pressure (BP). A new method was used to minimize the measurement error introduced by the large intrinsic variability of 24-hour sodium excretion. The ratio of intra- to interindividual variation was used to estimate the number of measurements needed to characterize the individual. When seven consecutive 24-hour samples were collected from 73 children, ages 11-14 years, a significant correlation between mean individual sodium excretion and BP was demonstrated. The independent relationship persisted when controlling for height, weight, pulse, age, sex and race (p = 0.045), but was eliminated by simultaneously considering mean creatinine excretion. Although the cross-sectional association described is quantitatively weak, a linear relationship between BP and sodium over the range consumed in this society could be important for prevention.

Adolescent↗
PubMed1980

Qualitative change in gonadotropin during normal aging in the male rat.

In the present work we have compared a pituitary LH extract and circulating LH from adult male rats (5 months old) with those from rats 10, 13, or 24 months old. The pituitary and circulating forms of LH prepared from old animals had a higher apparent molecular weight, judged by gel filtration, than LH preparations from younger animals. This difference may be due to increased sialic acid content of the larger form, since simultaneous neuraminidase treatment of this gonadotropin preparation and our internal reference standard ([125I]LH prepared from a normal adult rat) abolished the apparent size difference. In addition, the larger form prepared from old rats was cleared more slowly from the circulation of immature females than the form prepared from young rats. The apparent increase in sialation during normal aging could be mimicked in young animals which were castrated. Injections of testosterone propionate reversed the effect in both castrates and old animals. The data suggest that the diminished levels of metabolically active testosterone or other steroid metabolites in old male rats may result in qualitative alterations in the stored and released forms of LH.

Aging↗
PubMed1980

Complement activation in Staphylococcus aureus bacteraemia.

Serum levels of complement components C3, C4 and factor B were measured in twenty-five patients with Staphylococcus aureus bacteraemia. The levels of C3 were depressed in nine patients, five of whom also had low C4 levels, indicating activation of complement via the classical pathway. Two patients with low C3 levels also had low factor B levels, one of these being in association with a low C4 level, which indicates activation of both the classical and alternative pathways, the latter being via the C3b feedback cycle. The protein A content of the S. aureus cultures, as shown by the indirect haemagglutination titre, was high in nine patients with C3 hypocomplementaemia. There was some correlation between the presence of a high protein A content of the S. aureus culture and a low serum C3 level in the patient. Some clinical evidence of immune complex disease was found in three patients. Complement activation in S. aureus bacteraemia is most likely due to complex formation resulting from the interaction between the Fc portion of IgG and staphylococcal protein A. These complexes may also result in clinical symptoms of immune complex disease.

Adult↗
PubMed1980

Serratia endocarditis. A follow-up report.

Seventeen new cases of Serratia marcescens endocarditis observed in the San Francisco Bay Area since June 1974 are presented. Fifteen patients had a history of illicit intravenous drug use and four patients had prosthetic heart valves. Seven patients with infection of right-sided heart valves did well, although surgery was required in two for persistent fever or recurrent pulmonary emboli. Only three of ten patients with left-sided infection survived despite synergistic antibiotic combinations and high serum bactericidal titers. Fifteen isolates of Serratia from patients with endocarditis were serotyped, and none of these serotypes corresponded to the pigmented strain aerosolized by the US Army in the Bay Area in 1951. The isolation of the same Serratia strain from two patients and their shared injection paraphernalia provided insight into the pathogenesis of endocarditis in the intravenous drug user. A revised therapeutic approach to this difficult infection is presented.

California↗
PubMed1979

Group B streptococci in blacks.

Vaginal swabs were taken from 60 Black women attending a family planning clinic and from 60 attending a special clinic for sexually transmitted diseases. Using selective media, the isolation rate for group B streptococci was 26,7% in the former group and 40,0% in the latter. The isolation rates of other streptococcal serogroups are also given. All group B streptococci isolated were uniformly sensitive to penicillin but resistant to gentamicin. Clinical details of 7 patients with group B streptococcal septicaemia are also given.

Adult↗
PubMed1979

Chemotherapy versus chemoimmunotherapy in advanced adenocarcinoma of the colon and rectum: a prospective randomized study.

The combination of vincristine, methyl-CCNU, and methotrexate with or without MER-BCG achieved a 2% complete response (CR) and a 11% partial response (PR) with a median duration of 25-29 weeks in 124 evaluable patients with advanced adenocarcinoma of the colon and rectum. Responses were seen in previously untreated patients and in patients refractory to 5-fluorouracil. The median survival of these objective responders (CR + PR) was 57 weeks. The addition of MER-BCG did not appear to influence response rate or duration of survival and was accompanied by significant toxicity. Response was significantly correlated with performance status, sex, and disease free interval and survival with alkaline phosphatase and performance status. Patients with advanced colorectal carcinoma should be stratified according to these variables.

Adenocarcinoma↗
PubMed1979

Assessment of the association between habitual salt intake and high blood pressure: methodological problems.

Despite the finding in cross-cultural comparisons that habitual sodium intake correlates with levels of blood pressure, similar studies from within population groups have yielded inconsistent results. The data presented in this report indicate that in industrialized societies the high degree of intra-individual variability of sodium intake, compared to much smaller inter-individual differences, may obscure potential biological correlations. A quantitative statistical method is presented to assess and minimize the effect of the large intra-individual variation in daily urinary sodium excretion.

Adult↗
PubMed1979

HLA-B17 and the HLA-A1, B17 haplotype in acute myelogenous leukemia.

Seventy-nine Caucasians with acute myelogenous leukemia (AML) were genotyped to determine whether AML, the induction of remission or patient survival were associated with particular HLA phenotypes or haplotypes. HLA-B17 and B27 were increased in AML patients over 40 years of age. Combined analysis of four independent studies indicates that HLA-B17 is significantly but weakly associated with AML, relative risk = 1.48 (.01 less than P less than .025). The A1, B17 and Aw24, Bw35 haplotypes occurred more frequently in the AML group as compared to racial and geographic controls (uncorrected P = 0.0068 and 0.0098, respectively Fisher's Exact Test). Induction of remission occurred less frequently in patients with the B17 phenotype as compared to patients lacking this antigen (P = 0.047). Patient survival was associated with remission status (P = 0.002) but was not significantly associated with particular HLA phenotypes or haplotypes. These results indicate that a gene or genes in the HLA-B region of the major histocompatibility complex can influence susceptibility to AML and also the response to chemotherapy.

Adolescent↗
PubMed1979

Home blood pressure monitoring and changes in plasma catecholamines during once or twice daily treatment with atenolol in patients with mild hypertension.

1. The effects of atenolol on diurnal blood pressure control, heart rate and plasma catecholamines were studied in nine hypertensives, six of whom also received diuretics. The patients completed a double-blind trial in which the effects of once and twice daily administration of atenolol were compared with placebo. 2. Atenolol (100 mg) given once a day produced significant reduction in diurnal blood pressures recorded at home but the effect was slightly less than either 50 mg given twice a day or 200 mg once a day. 3. Effects on heart rate and blood pressure were seen within 36 hours of the first dose, and were near maximal at 72 hours. After cessation of the drug, mean resting heart rate increased gradually and reached pre-treatment levels five days later, suggesting strong tissue binding of atenolol. Blood pressure increased more slowly over 8--10 days. 4. Plasma noradrenaline levels were increased at rest with atenolol. This argues strongly against the antihypertensive effect of atenolol being due to a reduction of sympathetic nerve activity. 5. Once daily administration of atenolol in this group of patients with mild hypertension produced satisfactory diurnal blood pressure control and beta blockade without "rebound" hypertension on cessation of therapy.

Adult↗
PubMed1979

Some conceptual difficulties with the term 'schizophrenia': an alternative model.

The term 'schizophrenic' is used in two distinct ways: namely to describe a particular type of illness and also as a label for the person suffering from this illness. If we concentrate on the 'illness' conception of schizophrenia it readily becomes apparent that its definition and nature varies somewhat from one proponent to another. Added to this is the problem that the major conceptions of schizophrenia are based on disjunctive concepts. The basic argument of this paper is that while all clinical conceptions of schizophrenia have assumed the existence of a disease-entity syndrome, no attempt has ever been made to test its logical alternative: namely a random-symptom model. Some data will be presented which are at least compatible with this alternative and some of the theoretical implications spelt out.

Diagnosis, Differential↗