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Biomedical subjects

T Parker

Publications and source records attributed to T Parker.

At least 19 recordsLinked to original sources
PubMed1992

Prevalence of antibodies to hepatitis C virus among patients with cryptogenic chronic hepatitis and cirrhosis.

Many cases of chronic hepatitis and cirrhosis cannot be attributed to a known cause and are collectively referred to as cryptogenic chronic liver disease. We have evaluated the role of the hepatitis C virus in the pathogenesis of this condition in a retrospective serum analysis for antibody to hepatitis C virus in 129 patients with cryptogenic liver disease. Other causes of chronic hepatitis and cirrhosis were ruled out by clinical, serum biochemical and serological techniques. All 129 patients were HBcAg negative, but 28 (22%) had antibody to HBcAg. Sera were tested by radioimmunoassays using recombinant peptides for antibodies to nonstructural (C100-3 and C33c) and structural regions (C22) of HCV. Among the 129 patients, 61 (47%) had antibody to C100-3, 76 (59%) had antibody to C33c and 74 (57%) had antibody to C22. Seventy-nine (61%) were reactive with at least one and 76 (59%) were reactive with at least two HCV peptides (this is the criterion used for hepatitis C virus antibody reactivity). A proportion of patients with chronic hepatitis and cirrhosis (55 of 91; 60%) similar to that of patients without cirrhosis (21 of 38; 55%) had hepatitis C virus antibody. No significant clinical, serum biochemical or histological differences were noted between the group of patients with hepatitis C virus antibody and those without this antibody reactivity. Thus more than half the patients with cryptogenic chronic liver disease had hepatitis C virus antibody, suggesting that chronic HCV infection plays a major role in the origin of cryptogenic chronic hepatitis and cirrhosis.

Adult↗
PubMed1992

Transfer of staff training from workshops to group homes: a failure to generalize across settings.

Two experiments were conducted to assess acquisition and generalization of skills acquired in a workshop by trainees who were primary caregivers on the staffs of group homes for developmentally disabled clients. In Study 1, 31 staff trainees received an intensive, 1-week workshop in behavioral theory and treatment techniques. When assessed at the workshop site, these staff trainees showed increased treatment skills, relative to 18 staff trainees who did not participate in the workshop. In Study 2, pre- and postworkshop observations were taken on 53 developmentally disabled clients in group homes where the staff trainees worked. These observations provided no evidence that the workshop had any effect on group home client functioning. Future training programs for caregivers may be more successful if they occur in the group home, involve clients in the home, and enlist the support of supervisory staff, rather than focusing only on primary caregivers.

Activities of Daily Living↗
PubMed1991

Protocol for genetic testing in Huntington disease: three years of experience in Minnesota.

Molecular genetic testing for Huntington disease (HD) by linkage analysis of DNA markers close to the HD gene has been possible since the mid-1980s. Because of ethical and practical concerns about this kind of testing, most groups performing the test in the past have operated under lengthy research protocols designed to assess the psychological morbidity of the presymptomatic diagnosis of a fatal disease. Our approach to HD testing is service-oriented, and our testing process has been designed to be flexible, to meet the varying needs of our patients. Between 1988 and 1990, 87 inquiries about the test have been received; 22 inquiries had family structures which were unsuitable for linkage analysis. Eleven of the 37 individuals who entered the testing program have not completed it. Of 19 patients who have received DNA results, seven received an increased risk of carrying the HD gene, and ten, a decreased risk. For two additional individuals, nonpaternity resulted in a negligible risk for HD. Several of those consulted, or their spouses, have had continuing outpatient counseling since completing the test; none have required hospitalization. Our short-term results indicate that molecular genetic testing for HD can be performed safely in a clinical setting using our protocol. As molecular genetic testing for HD and other diseases moves out of research centers and into clinics, clinicians must devise practical strategies for providing the medical, genetic, and psychological services needed for the growing number of individuals who will seek such testing.

Genetic Linkage↗
PubMed1990

Hepatitis C-associated hepatocellular carcinoma.

In the United States, a large percentage of patients with hepatocellular carcinoma are serologically negative for hepatitis B. We conducted a retrospective study to determine the prevalence of hepatitis C antibody in the sera of 59 patients with hepatocellular carcinoma who were HBsAg-negative and had no evidence of alcoholic liver disease, primary biliary cirrhosis, autoimmune hepatitis, hemochromatosis or alpha 1-antitrypsin deficiency. Twenty patients (34%) were hepatitis C antibody-positive and hepatitis B core antibody-negative. All twenty patients had underlying cirrhosis, and seven (35%) had histories of transfusions. Eleven (19%) additional patients were also hepatitis C antibody-positive but were hepatitis B core antibody-positive as well. Twenty-one (36%) patients were both hepatitis C antibody- and hepatitis B core antibody-negative and seven (12%) were hepatitis C antibody-negative but hepatitis B core antibody-positive. The prevalence of hepatitis C antibody was also determined among three other population groups serving as controls and found to be 14% in 28 HbsAg-positive patients with hepatocellular carcinoma, 44% in 76 patients with cryptogenic cirrhosis and 0.5% in 200 consecutive volunteer blood donors. We conclude that hepatitis C antibody is prevalent among patients with hepatocellular carcinoma and may therefore be a common causative agent of this disease. A significant number of patients with and without cirrhosis, negative for hepatitis C antibody and hepatitis B core antibody, remain without a discernible cause for this malignancy. Perhaps a second- or third-generation test will detect hepatitis C antibody in some of these patients.

Carcinoma, Hepatocellular↗
PubMed1979

Prostaglandins V (1). Synthesis and pharmacology of (+/-)-11-deoxy-10-hydroxyprostaglandin E1 methyl ester.

(+/-)-Deoxy-10-hydroxy-PGE1 methyl ester (Va) has been synthesised via conjugate addition of the cuprate (III) to the 5-tetrahydropyranyloxycyclopentenone (IId). Va was found to be 0.1 times as active as PGE1 as a uterine stimulant in the anaesthetized pregnant rat, 0.25 times as active as PGE1 in causing vasodepression in the anaesthetized cat, and approximately equiactive to PGE1 in inducing bronchoconstriction.

Alprostadil↗
PubMed1978

The ultrastructure of mouse testicular interstitial tissue containing plutonium-239 and its significance in explaining the observed distribution of plutonium in the testis.

The technique of autoradiography with Araldite-embedded sections was used to study the distribution of 239Pu in mouse testis at various times post-injection. Adjacent sections were examined with both the light microscope and electron microscope. The autoradiographs showed that from 1 week to 3 months postinjection, most 239Pu in located in interstitial tissue. The major change in distribution observed was that the early diffuse deposit in interstitial tissue is concentrated in macrophages with increasing time post-injection. This is a real change of distribution as the amount of 239Pu in mouse testis remains constant from 1 week to 3 months post-injection. Study of the ultrastructure of interstitial tissue indicated that the accumulation of 239Pu in macrophages may be brought about in two ways. First, there may be phagocytosis of dead cells containing 239Pu. Second, 239Pu may follow the transfer of waste products of hormone synthesis from Leydig cells into macrophages. The significance of these observations is discussed with regard to the deposition of 239Pu in human testis.

Animals↗
PubMed1978

Schooling, environment, and cognitive development: a cross-cultural study.

The purpose of this study was to investigate the influence of schooling and general environmental conditions on the development of memory and cognitive skills in young children. The subjects were 824 5- and 6-year-old children living in jungle villages and in slum settlements of Lima, Peru. Half of the children in both the jungle and city were Mestizo, and half were Quechua Indians. Some 6-year-olds of each cultural group and in each location attended school; others did not. Memory tasks were presented in different modes of representation, that is, verbal, pictorial, and enactive; and cognitive tasks in "concrete" and "abstract" versions. A sample of parents in each group was interviewed concerning environmental conditions. In addition, samples of upper-middle-class children in Lima and poor children in Detroit were tested to assess the generality of the findings. Attendance at school was related to improvement in performance on all tasks. Improvement was equivalent for both locations, both cultural groups, and each social class. Attendance at school also was accompanied by reduced within-group variability on some tasks and by greater differentiation of cognitive processes within children. Location and cultural group interacted differentially by task according to a complex pattern of relations. There were no indications that the organization of memory or cognitive processes differed as a function of social class, age, location, or cultural group. The results were interpreted in terms of children's opportunities to acquire specific memory and cognitive skills from schooling and from their general experience in a particular environment.

Age Factors↗