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Biomedical subjects

C White

Publications and source records attributed to C White.

At least 253 records · Page 14Linked to original sources
PubMed1987

Chronic schizophrenic disorder. II. Reaction time, social performance and arousal.

Reaction time, set index, critical flicker frequency, two-flash threshold, a sustained performance task and psychophysiological parameters from people with chronic schizophrenic disorder (n = 14) and a control group (n = 12) were analysed to assess the association between arousal, attentional dysfunction and social dysfunction in schizophrenia. Shorter reaction time, rated ability to mime and, in the schizophrenic group, scores on Venable's ward activity scale correlated with each other. In the schizophrenic group, prolonged reaction time latency correlated positively with skin conductance level in the right hand and negatively with skin conductance variability in the left hand, the latter being in the opposite direction to that for the control group. The results may provide support for the hypothesis that lateralised cerebral dysfunction is associated with performance deficits in people with chronic schizophrenic symptoms.

Adult↗
PubMed1987

A monoclonal antibody to squamous cell carcinoma.

Monoclonal antibody 17.13.Cl.10 is a murine IgM kappa monoclonal antibody (Mab) that stains frozen section squamous cell carcinoma (SCC) homogeneously and intensely with a sensitivity greater than 98%, including 106/107 SCC specimens from the head and neck. It was produced using a human laryngeal SCC as immunogen and screened using frozen section human tissue. Monoclonal antibody 17.13.Cl.10 faintly stains the basal layer of normal squamous epithelium, does not stain normal organ tissue other than myoepithelial cells, and reacts with few non-SCC tumors. It, therefore, may be a useful adjunct to standard histopathologic criteria for the diagnosis of SCC. It may prove helpful in the investigation of tumor-associated antigens. Despite major technical and immunologic problems, monoclonal antibodies to functional tissue-specific tumor-associated antigens have the potential to play a major role in imaging and in treatment in the future.

Animals↗
PubMed1986

Health, fitness, physical activity, and morbidity of middle aged male factory workers. I.

A description of the fitness, physical activity of lifestyle, and some aspects of health status and attitudes in a population of male factory workers aged 35-60 is presented as the first part of a report on a study of morbidity in this population. A total of 1394 subjects were included, undergoing medical examination, fitness testing by bicycle ergometry, assessment of body fat, and interview questionnaire. The inter-relation of fitness, body composition, habitual exertion, health risk factors, and attitudes to exercise are discussed. Fitness levels are compared with those reported in other studies and discussed in terms of capacity for walking and running and in relation to criteria for health benefit. In these two latter respects fitness appears to be inadequate among the great majority of those tested, although it is comparable with that reported by several other recent studies. Fitness is associated with physical activity of leisure but not that of work. Only relatively strenuous physical activity in leisure time appears to be related to fitness, and is only participated in by some 28% of the sample. Cycling has the strongest association with fitness of all the physical activity variables. Blood pressure and percentage body fat are also associated, inversely, with fitness, the latter not unexpectedly because of the weight related measure of fitness.

Adult↗
PubMed1985

A randomized multicenter trial of cyclophosphamide, Novantrone and 5-fluorouracil (CNF) versus cyclophosphamide, Adriamycin and 5-fluorouracil (CAF) in patients with metastatic breast cancer.

As of August 1984, 115 women with advanced breast cancer have been randomized to receive a combination of either cyclophosphamide, Novantrone (mitoxantrone) and 5-fluorouracil (CNF) or cyclophosphamide, Adriamycin (doxorubicin) and 5-fluorouracil (CAF). Seventy-one percent of all patients were post-menopausal and 44% of CNF patients and 57% of CAF patients were estrogen receptor (ER) negative. Slightly over 30% of all patients had received hormonal therapy or chemotherapy in an adjuvant setting. Hematologic toxicity was similar in regard to platelet counts but slightly lower nadirs were experienced with CNF therapy than with CAF. However, there were fewer dosage decreases with CNF. Significantly less nausea and vomiting were observed with the CNF regimen compared to CAF. Moreover, alopecia was reduced appreciably in patients who received CNF. The response rate to CNF for the first 38 eligible and evaluable patients was 42%, and for 53 eligible and evaluable patients who received CAF the response rate was 45%, a non-significant difference. Median response durations were similar also, 140 days for CNF and 168 days for the CAF regimen. Time to treatment failure was similar for both regimens. CNF is an effective regimen for patients with advanced breast cancer, with less toxicity than CAF.

Adult↗
PubMed1985

Neurospora trehalase and its structural gene.

We have isolated Neurospora trehalaseless mutants and mapped the trehalase structural gene to linkage group I. The structural gene mutations not only affect thermostability and other characteristics of the enzyme but also affect the production of an inhibitor of the wild-type trehalase. The inhibitor appears to be the mutant trehalase. We suggest that the mutant subunits act as inhibitors by entering into the multimeric forms of the enzyme and altering the ability of the normal wild-type subunits to catalyze the cleavage of trehalose.--Wild type trehalase has been purified to near homogeneity, and its characteristics have been studied. It was purified as a tetramer, with each subunit having a molecular weight of 88,000.--We have studied the regulation of trehalase and found the production of trehalase to be glucose repressible. Cells begin to produce trehalase 60 min after being transferred to glucose-free medium.

Genes↗
PubMed1985

Estrogen replacement therapy and fibrocystic breast disease in postmenopausal women.

The association between estrogen replacement therapy and fibrocystic breast disease was assessed in a hospital-based case-control study undertaken in Connecticut from 1979 to 1981. The cases were 143 postmenopausal women with biopsy-confirmed fibrocystic breast disease, and the controls were 355 postmenopausal women with other surgical conditions. Use of estrogen replacement therapy was positively associated with fibrocystic breast disease; the odds of disease increased with duration of use, reaching an approximately fivefold excess odds for those who had taken menopausal estrogens for 10 or more years. There was no evidence that the positive association between estrogen replacement therapy and the occurrence of fibrocystic breast disease could be explained by differential medical care utilization or other possible risk factors of biopsied fibrocystic breast disease.

Adult↗
PubMed1985

Medical examination of school entrants: later school problems and absenteeism of attenders and non-attenders.

Children who were scheduled for medical examination before entering school were followed in school one or two years later. Non-attenders had a two-fold risk of repeating grades, special class placement, referral for speech/language problems, teacher-reported learning or behavior problems, failure of vision or hearing screening, and transfer between schools. Absenteeism was also significantly more common. Children not brought in for preventive health care are at greater risk than others for difficulties in school.

Absenteeism↗
PubMed1985

Time period compared to birth cohort in Connecticut incidence rates for twenty-five malignant neoplasms.

Out of necessity and convenience many reports on population-based rates for cancer are limited to analyses by time period of diagnosis, and just how often cohort effects are important in cancer data has not been fully explored. To address this question, Connecticut cancer incidence rates for the years 1940-79 were fitted to the model: Log (incidence rate) = constant + age effect + period effect + birth cohort effect + error term. Data for each cancer site and sex were categorized into 10-year intervals by time period and age group. Significance testing for the curvilinear effects (which are estimable functions) of age (A), period (P), and cohort (C) in the 44 data sets led to no clear choice of model for three data sets; an APC model for 20, an AP model for 7, and an AC model for 14. These choices were corroborated by the RA2 index. Limitations in the interpretation of the results were enumerated. Presentation of population-based cancer rates by implicitly assuming an AP model is valuable (e.g., for studying age distribution in different regions or for age-adjustment in examining international variation or time trends). However, the assumption of an AP model may often be incorrect, as was shown to be the case for most of these 44 data sets. The implications for monitoring trends and generating etiologic hypotheses were discussed in light of the results for cutaneous malignant melanoma and cancers of the cervix, breast, ovary, lung, and bladder.

Adult↗
PubMed1985

Risk factors for fibrocystic breast disease and its histopathologic components.

The relationship between various sociodemographic, reproductive, and other factors to the occurrence of fibrocystic breast disease was evaluated in a case-control study undertaken at five Connecticut hospitals from 1979 to 1981. The study groups comprised 590 women with biopsy-proven fibrocystic breast disease and 1,018 women with other surgical conditions. Among the premenopausal women, multivariate analysis suggested that high socioeconomic status, Jewish religion, low parity, a history of benign breast disease, a history of breast cancer in the mother or a sister, and low Quetelet index were associated with increased odds ratios (OR) for fibrocystic breast disease. Similar analysis for the postmenopausal women revealed increased OR for women with high socioeconomic status, a late age at menopause, and a history of benign breast disease. Current smokers as well as those who had had a tubal sterilization had significantly reduced odds of fibrocystic disease. There was no convincing evidence of linear trends according to degree of epithelial atypia for any of the variables considered. Although some variation in the OR emerged in the analysis according to selected histologic components, the results provided little evidence that women with biopsy specimens exhibiting gross cysts, sclerosing adenosis, papillary hyperplasia, or papillomatosis showed epidemiologic similarities with breast cancer patients.

Adult↗
PubMed1985

Secretion of a cysteine proteinase from a hormone-independent cell population of cultured explants of murine mammary gland.

Cultured explants of mouse mammary gland were investigated for their capacity to secrete a cathepsin B-like cysteine proteinase. This enzyme had been shown previously to be secreted excessively from cultured explants of human breast tumors and spontaneous mouse mammary carcinomas. We now show that secretion is also observed from cultured explants of mammary gland. Lactating tissue and tissues obtained from mid- and late-pregnant mice were found to secrete the cysteine proteinase at very high rates, but secretion was also detectable from explants of virgin mammary glands and from tissues obtained from retired breeders. However, in all cases, it was found that secretion was greatest from explants maintained in hormone-free medium and did not depend on the maintenance of normal mammary gland function. Secretion was greatly reduced in the presence of the lactogenic hormone combination of insulin, prolactin, and hydrocortisone, and this suppression was found to be due to hydrocortisone. Insulin and prolactin, while resulting in better tissue maintenance in culture, had no effect on the secretion. Enzyme release was reversibly inhibited by cycloheximide and required the presence of viable tissue, ruling out the possibility that the accumulation of enzyme activity in the culture medium is due to dying cells. The presence of metabolically active cells in explants cultured in the absence of hormones was also demonstrated by the incorporation of radiolabeled precursors into protein and DNA. DNA synthesis in cultured explants of lactating tissue was not stimulated by the addition of hormones. Histological studies revealed that, while large areas of the explants showed severe degeneration after culture without added hormones, clusters of cells persisted which displayed a relatively high mitotic activity and which showed a lack of normal epithelial organization. These observations suggest the presence of a hormone-independent cell population in the mammary gland, which secretes the stable cysteine proteinase. The secretion process itself, however, is inhibited by corticosteroids.

Animals↗
PubMed1984

Exogenous hormone use and fibrocystic breast disease by histopathologic component.

In a hospital-based case-control study of 590 women with biopsy-proven fibrocystic breast disease and 1,018 control women with other surgical conditions, no linear relationship was evident between the use of oral contraceptives or of estrogen replacement therapy and the degree of epithelial atypia of the fibrocystic lesions. Case-control and intracase comparisons suggested that oral contraceptive use might be associated with an increased occurrence of sclerosing adenosis among the premenopausal women and of gross cysts among the postmenopausal women. Estrogen replacement therapy, which was positively associated with fibrocystic breast disease as a whole among the post-menopausal women, was most frequently used among the cases whose biopsy specimens exhibited gross cysts, papillomatosis or papillary hyperplasia.

Adult↗
PubMed1984

Production of an insulin-like growth factor by osteosarcoma.

To test the possibility that osteosarcoma cells produce their own growth factors, we measured levels of insulin and somatomedin C (SMC), an insulin-like growth factor, in culture media of two cell lines derived from patients with that disease. SMC but not insulin levels increased three- to ten-fold over a period of 7 days paralleling the increases in cell number. Production of SMC was inhibited by cycloheximide.

Cell Division↗
PubMed1984

Angiotensin II receptors of human and primate adrenal fasciculata and glomerulosa: correlations of binding and steroidogenesis.

Subcellular fraction and collagenase-dispersed isolated adrenal fasciculata and glomerulosa cells from human and primate adrenal glands and cortisol-producing tumors have been utilized to study angiotensin II (Ang II) receptors and steroid biosynthesis. The receptor density of glomerulosa was threefold higher than that fasciculata. A benign cortisol-producing adenoma did not differ from normal fasciculata, but a malignant tumor had significantly lower affinity binding. Agonist and antagonist analogues of Ang II competed for binding sites commensurate with known biologic activity. The Kd Analogue binding also had corresponding changes in cortisol biosynthesis. The ED50 for aldosterone biosynthesis by glomerulosa cells was significantly lower at 55 pmol/L. Fewer receptors in human fasciculata as compared to glomerulosa and a less sensitive response to Ang II are consistent with previous in vitro observations in other species. These studies suggest that there may be a biologically relevant Ang II receptor of human and primate adrenal fasciculata that share many characteristics with the receptor of the glomerulosa.

Adenoma↗
PubMed1984

Oral contraceptive use and fibrocystic breast disease among pre- and postmenopausal women.

The association between use of oral contraceptives and fibrocystic breast disease was assessed among women aged 20-74 years in a hospital-based case-control study conducted between November 1979 and November 1981 in Connecticut. The study groups comprised 633 women with biopsy-proven fibrocystic breast disease and 1,062 controls who had been admitted, as inpatients or outpatients, to general surgical services. For the premenopausal women, there was no evidence that long-term use of oral contraceptives was associated with a decreased frequency of fibrocystic breast disease among either current or past users. For the postmenopausal women, previous oral contraceptive exposure was associated with an increased occurrence of cystic disease. These findings contradict previous investigations reporting a negative association between oral contraceptive use and the development of fibrocystic breast disease.

Adult↗
PubMed1984

Caffeine consumption and fibrocystic breast disease: a case-control epidemiologic study.

In a hospital-based case-control study that included 634 women with fibrocystic breast disease and 1,066 comparison women in Connecticut, the occurrence of fibrocystic breast disease was positively associated with average daily consumption of caffeine. Women who consumed 31-250 mg of caffeine/day had a 1.5-fold increase in the odds of disease, whereas women who drank over 500 mg/day had a 2.3-fold increase in the odds. The association with caffeine consumption was especially high among women with atypical lobular hyperplasia and with sclerosing adenosis with concomitant papillomatosis or papillary hyperplasia, both of which have been associated with an increased breast cancer risk. The association was specific to fibrocystic breast disease in that there was no association of caffeine consumption with fibroadenoma or other forms of benign breast disease.

Adult↗
PubMed1983

Normokalemic nonazotemic adrenal insufficiency.

Two patients had adrenal insufficiency with severe hyponatremia and profound central nervous system symptoms. In both adrenal insufficiency was diagnosed clinically. Neither patient had either hyperkalemia or azotemia.

Adrenal Insufficiency↗