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Biomedical subjects

R G Cooper

Publications and source records attributed to R G Cooper.

At least 91 records · Page 5Linked to original sources
PubMed1984

Adjuvant chemotherapy and the practicing oncologist.

There are several clinical criteria that can be utilized to determine which patients will have a high versus a low potential for recurrence. With the use of these criteria, the clinician will be able to select an adjuvant program that will reduce the anticipated rate of recurrence.

Adult↗
PubMed1984

Multiple indicators of stress in an 'active' job--cardiothoracic surgery.

Eight members of a cardiac surgery team were monitored for a variety of stress indicators. These included self-reports of felt stress, observations of behavior related to ECG activity, and measurements of urinary cortisol and 3-methoxy-4-hydroxy-mandelic acid (VMA). Observations were made on 12 separate days spread over a 3-month period. Results indicate moderate to low levels of perceived stress with high levels of satisfaction and high levels of support. ECG data showed wide individual variation; heart rates even during operations were not excessively high (mean, 100 beats per minute). VMA levels were within the normal range. Cortisol levels were above the normal range on 72% of measurements and mean levels were positively related to length of experience. Days when self-perceived stress was reported were associated with higher levels of cortisol but not of VMA. The study failed to support predictions about responses to "active" jobs derived from Karasek's job-strain model.

Cardiac Surgical Procedures↗
PubMed1984

Polymorphic hydroxylation of perhexiline maleate in man.

Long term perhexiline maleate therapy causes peripheral neuropathy and hepatic damage in certain subjects. An association between these adverse reactions and a genetically determined relative inability to hydroxylate debrisoquine has been described. This association could indicate either that the effects of perhexiline impair debrisoquine oxidation thus producing a phenocopy, or that perhexiline is polymorphically hydroxylated and that the polymorphism is controlled by the same alleles as control the debrisoquine polymorphism. To test the second possibility, a study investigating the hydroxylation status of a population of healthy volunteer subjects has been performed using perhexiline maleate. Hydroxylation phenotyping was performed on 50 normal volunteers. A standard oral dose was given and plasma and urinary perhexiline, 4-monohydroxyperhexiline (MI metabolite), and 4'monohydroxyperhexiline (MIII metabolite) was measured. The 24-hour plasma perhexiline concentration, the 24-hour plasma MI metabolite concentration, and 12 to 24-hour urinary MI metabolite excretion were clearly bimodal, suggesting the existence of a polymorphism for perhexiline hydroxylation. Poor metabolisers represent 6% of the population studied. Known poor metabolisers of debrisoquine are also poor metabolisers of perhexiline, while known extensive metabolisers of debrisoquine are also extensive metabolisers of perhexiline, indicating that in white British subjects the hydroxylation polymorphism is under identical genetic control for both compounds. The poor metaboliser sub-group exhibited the highest plasma perhexiline levels. Perhexiline phenotyping separates the poor and extensive metaboliser phenotypes much more clearly than other tests and defines a sub-group at risk from perhexiline toxicity. Pretreatment phenotyping using this test, followed by exclusion of poor metabolisers from perhexiline therapy, should substantially reduce the incidence of major adverse effects.

Adult↗
PubMed1980

Perception of numbers by human infants.

Infants are capable of discriminating, representing, and remembering particular small numbers of items. A perceptual enumeration process called subitizing, present in 2-year-olds, probably underlies this capacity. This finding indicates that some number capacity is present before the onset of verbal counting, and it suggests that verbal counting may have precursors present during infancy.

Habituation, Psychophysiologic↗
PubMed1980

Adverse effect of radiotherapy on adjuvant chemotherapy for carcinoma of the breast.

Twenty-seven women with primary carcinoma of the breast with greater than or equal to 4 metastatic axillary nodes received prophylactic radiotherapy in addition to adjuvant vincristine, prednisone, cyclophosphamide, methotrexate and fluorouracil chemotherapy. When compared with 73 women who received chemotherapy alone, the relapse rate per month for the patients with radiation therapy was fourfold greater, p = less than 0.0001. Recurrence in 17 of 27 contrasts with relapse in 13 of 73 patients who did not undergo irradiation. By eight years, 14 of 27 patients who received radiotherapy had died, contrasted with nine of 73 who received chemotherapy alone. The results for the irradiated subset were found not to be due to patient selection nor to shortening or underdosing of chemotherapy. Immunosuppression from radiation and systematic delay in initiating chemotherapy remain among the possible explanations. These data support the use of adjuvant chemotherapy and argue against the prophylactic use of radiotherapy following mastectomy for carcinoma of the breast.

Adult↗
PubMed1979

Adjuvant chemotherapy of breast cancer.

One hundred women with primary breast cancer with 4 or more metastatic axillary nodes were treated for 9 months postoperatively with vincristine, prednisone, cyclophosphamide, methotrexate, and fluorouracil (VPCMF). Sixty-five women have been observed for a minimum of 5 years or until failure and the rest for 3 years or more. For 73 women who received adjuvant chemotherapy only, observed for 5 1/2 years median, disease-free status by life table analysis is 68% at 8 years. No significance difference was found between response of pre- and postmenopausal women in disease-free interval or survival. Mortality compared to expectation was sharply reduced; only 9 of 73 have died. These findings demonstrate the long term effectiveness of relatively short-term surgical adjuvant combination chemotherapy in pre- and post-menopausal patients with breast cancer at high risk.

Adult↗
PubMed1978

Thermal destruction of folacin in microwave and conventional heating.

Folacin derivatives were found to vary greatly in thermal stability. It is worth mention that pteroylmonoglutamic acid (PGA), the folate used therapeutically and in food supplementation, was extremely stable to heat under the experimental conditions, that is, at 100 degrees C. in neutral solution. Under these conditions, 5-formyl-THFA also exhibited marked stability; neither form was affected significantly by microwave radiation. In view of the increasing data indicating the abundance of 5-methyl-THFA and other derivatives of THFA in foods, the thermal lability of these forms was especially interesting. THFA was found to be an extremely labile folate, while 5-methyl-THFA had intermediate stability among the forms tested. Microwave heating of 5-methyl-THFA resulted in a faster rate of degradation than conventional heating at the same temperature. The mechanism of this action needs further research.

Cooking↗
PubMed1975

Chromosome studies in acute leukemias developing in patients with multiple myeloma.

Chromosomal findings are reported in three patients with acute myelomonocytic leukemia and in one with reticulosarcoma leukemia who had been treated for multiple myeloma with melphalan and X-ray. All four patients had striking chromosomal anomalies. An iatrogenic causation of aneuploidy is suggested. This is supported by chromosomal findings in patients with acute leukemia following polycythemia vera and Hodgkin's disease; practically all of the leukemias have been aneuploid. A comparison is made of such "secondary" acute leukemias with "primary" acute leukemias that are aneuploid in only 40% of the cases. Chromosomal changes are not considered to be the initial event in leukemogenesis.

Aneuploidy↗