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Biomedical subjects

C White

Publications and source records attributed to C White.

At least 271 records · Page 15Linked to original sources

Population-based comparative study of campylobacter and salmonella enteritis in South Australia.

A total of 658 cases of campylobacter enteritis was reported in South Australia in the 18 months from March, 1980. Although Campylobacter sp. may cause more gastrointestinal disease than Salmonella sp. during some time periods, our data suggest that the reverse applies over all. However, since campylobacter enteritis tends to affect older persons who possibly are investigated less frequently, the relative prevalence of campylobacter infection may have been understated. Both diseases are notified among preschoolers to a disproportionate extent; however, Campylobacter sp. show a greater predisposition that Salmonella sp. for affecting teenagers and young adults. Persons with campylobacter infection are more likely to be residents of metropolitan areas than their counterparts with salmonella enteritis. Virtually all persons with campylobacter infection experience some diarrhoea; three-quarters have abdominal pain; approximately one-third report blood, and a similar proportion mucus in their stools. Children are more likely than adults to have mucus, and possibly blood, in their stools.

Adolescent↗

Echocardiographic studies in anaemic patients before and after blood transfusions.

Echocardiographic studies were undertaken in 15 patients with acute blood loss and 15 patients with chronic anaemia, before and after blood transfusion. Clinically adequate blood transfusions resulted in a 5 mm increase in mean left ventricular internal dimensions at end systole in those with acute blood loss and a 3 mm increase in those with chronic anaemia. None of these patients developed acute pulmonary oedema. This study provides base-line data for changes in ventricular dimension resulting from the standard medical management of patients with acute and chronic blood loss. Functional aortic valvular insufficiency was documented in some cases and pericardial effusion resolving after blood transfusion was common.

Aged↗

A case-control study of cancer of the endometrium.

A hospital-based case-control study of the epidemiology of endometrial cancer in women aged 45-74 years was carried out in Connecticut from 1977 to 1979. In total, 167 cases and 903 controls were included. Elevated risks were associated with the following factors: overweight, nulliparity, few pregnancies, use of estrogen replacement therapy, older age at menopause, and a history of ovarian or endometrial cancer in mother or a sister. Whites were more frequently affected than blacks, and better-educated women more often than less-educated women. Use of oral contraceptives was associated with a decreased risk, although the decrease did not reach statistical significance.

Age Factors↗

Partial reversal of radiation-induced immunosuppression by T-lymphocyte lysate.

BN rats were irradiated with 500 rad of 60Co 1 day before immunization with 0.1 mg of ovalbumin in alum hydroxide gel. The onset of reaginic and haemagglutinating antibody synthesis was suppressed to a non-detectable level for at least 3-4 weeks. When these irradiated rats were injected intraperitoneally with 10(8) viable or sonicated thymocytes 1 day after irradiation, the suppressed reaginic and haemagglutinating antibody synthesis was successfully restored. This suggests that: (i) thymocytes can restore the radiation-induced immunosuppression, but viability of thymocytes is not essential in this immune restoration; (ii) active biological molecules exist in the cytoplasmic pool of the normal thymocytes which can restore the radiation-induced immunosuppression; and (iii) the thymus not only plays a central role in the normal morphological development of the lymphoid system and its functional immunological maturation, but may also play an important role in the reversal of radiation-induced immunosuppression. To investigate tissue specificity of the factors that are actively engaged in the restoration of the suppressed immune response, peripheral lymphocytes, spleen cells, bone marrow cells and kidney cells were also tested. The results demonstrated that both peripheral lymphocytes and spleen cells could restore the suppressed immune response, but not bone marrow cells or kidney cells. This suggests that the active factors may be present only in T lymphocytes. Since the active factors could be found in the tissues other than thymocytes and non-stimulated lymphocytes, they appear to be different from thymosin, transfer factor or lymphokines derived from sensitized lymphocytes, and they were most likely not synthesized de novo.

Animals↗

An epidemiologic study of epithelial carcinoma of the ovary.

A case-control study to identify risk factors for epithelial ovarian cancer was undertaken among women in the age group 45-74 years who had been admitted to seven hospitals in Connecticut between July, 1977, and March, 1979. Characteristics that were found to increase the risk of epithelial ovarian cancer included being white, never having been pregnant, having a late age at menopause, having a family history of cancer of the ovary or endometrium, and having a long estimated number of years of ovulation. Prior use of post-menopausal estrogens did not alter the risk for epithelial ovarian cancer, but there was some indication that oral contraceptives protect against ovarian cancer. Women with ovarian cancer were somewhat more likely to have had a history of an underactive thyroid and were somewhat less likely to have had a history of an overactive thyroid than controls, although these trends were not statistically significant.

Aged↗

A radiographic method for measuring steady-state functional residual capacity in the supine patient. A method suitable for sleep studies.

We have devised a method to measure functional residual capacity (FRC) in the recumbent, spontaneously breathing patient. Simultaneous anteroposterior and lateral chest radiographs were exposed at the end of an exhalation, as determined by tracings of flow sensed by a nasal thermistor. The volume of the lungs was then planimetrically measured. Functional residual capacity was sequentially measured in 20 supine subjects, both by a helium dilution technique and by the radiographic technique. Planimetric measurement of FRC correlated well with the helium dilution technique, with a range of FRC measurements from 1.53 to 6.41 L (r = 0.94). This method of measuring lung volume should be useful in evaluating changes in FRC associated with different sleep stages and in explaining the mechanisms causing nocturnal oxygen desaturation in patients with chronic obstructive lung disease.

Functional Residual Capacity↗

Exogenous estrogens and other factors in the epidemiology of breast cancer.

In a hospital-based case-control study of the epidemiology of breast cancer undertaken in Connecticut from 1977 to 1979, there was no evidence of an increase in risk for breast cancer among women who had used oral contraceptives or estrogen-replacement therapy. In fact, there was some suggestion of a decrease in risk for breast cancer with increasing length of use of oral contraceptives. Higher than average risks were found among women who had never give birth to a child, women with a late age at menopause, women, with an early age at menarche, women who had given birth to their first child at a relatively late age, women with previous benign breast disease, and women with a history of breast cancer in a sister or mother. Heavy women were at high risk for premenopausal breast cancer. The association between heaviness and postmenopausal breast cancer was strongest among women who had had their last menstrual period more than 5 years before the diagnosis of breast cancer.

Age Factors↗

Cold lymphocytotoxins: an important cause of acute tubular necrosis occurring immediately after transplantation.

Cold-reactive lymphocytotoxins, present in some renal-transplant recipients, may be an important cause of the acute tubular necrosis (ATN) that commonly occurs immediately after transplantation. In a study of transplantation of optimally preserved cadaveric kidneys obtained from heart-beating donors, ATN was found in 10 of 17 recipients with cold antibodies and in only 1 of 21 recipients without such antibodies. Warming of the allograft after completion of anastomosis significantly reduced the incidence of ATN at 18% in recipients with cold antibodies. When pairs of reicpients with cold antibodies were transplanted with identically preserved cadaveric kidneys from single donors ATN was observed only in recipients whose donor kidney was not warmed. ATN may result from antibody-medicated damage to vascular endothelial cells during the brief period when the recipient's blood starts flowing into a "cold" allograft.

Acute Kidney Injury↗

The parameterization of predictive value for multisite screening.

In the design of a medical screening program, it is standard practice to employ the parameters of sensitivity and specificity of the test, together with the population disease prevalence, in order to obtain the predictive values of the test. Multiphasic screening, i.e. the use of two or more tests on the same occasion to screen for more than a single disease, has stimulated the need for a formulation of the joint predictive value of these tests employed in combination. In this communication a parameterization of joint predictive value is presented in the context of multisite cancer screening. The resulting parameters are related to the separate disease prevalences, as well as to the sensitivities and specificities of the separate tests, under the assumption of statistical independence among cancer screens.

Humans↗

Social milieu of a residential treatment center for severely or profoundly handicapped young children.

Severely or profoundly handicapped young children who lived in a residential treatment center were subjects in a modified time-sampled observation study of social behavior, state, and physical context. The study was conducted for 3 successive years. Although system-level changes in the ecology of the institution over the 3 years did not appear to affect the social-interaction indices, the developmental ages of the children were positively related to social opportunities and social behavior.

Child Development↗