PubMed Health⌕ Search

Biomedical subjects

J Feinstein

Publications and source records attributed to J Feinstein.

8 recordsLinked to original sources
PubMed2000

What is not a bird of paradise? Molecular and morphological evidence places Macgregoria in the Meliphagidae and the Cnemophilinae near the base of the corvoid tree.

The cnemophiline 'birds of paradise' (Cnemophilinae) and Macgregor's 'bird of paradise' (Macgregoria) have traditionally been included in the Paradisaeidae although their relationships within the group have been enigmatic and subject to repeated discussion in the literature. Here we use sequences from two mitochondrial genes, cytochrome b and cytochrome oxidase I, along with a suite of morphological characters, to investigate their relationships to paradisaeids and other members of the passerine Parvorder Corvida. The combined data strongly support the removal of both groups from the birds of paradise: the cnemophilines are basal members of the Corvoidea and Macgregoria is a member of the Meliphagoidea and embedded in the honeyeaters (Meliphagidae) close to the genus Melipotes. The amount of sequence divergence among basal passeriforms and members of the Corvida, as well as available fossil evidence for Australian corvidans, suggest that cnemophilines represent an ancient lineage within the corvoid radiation. Because cnemophilines and Macgregoria have been placed at the base of the paradisaeid tree, hypotheses of morphological, behavioural and ecological character-state transformations within the family will require reanalysis.

Animals↗
PubMed1998

Factors that influence biochemical failure after radiation therapy for stage T1c prostate cancer.

More patients are now being diagnosed with nonpalpable prostate cancer after a needle biopsy is performed for an elevated prostate-specific antigen (PSA) level (stage T1c). The purpose of this study was to identify prognostic factors that are associated with biochemical failure after definitive external beam radiation therapy. This study included 75 patients with the diagnosis of T1c prostate cancer who were referred to four radiation oncology centers in the West Chicago area from 1992 to 1995. All patients were treated with megavoltage external beam radiotherapy to doses between 66 and 70 Gy. Biochemical failure was defined as three consecutive rising PSA values of at least 10% of the prior reading in posttreatment serial measurements. The mean age of the patients was 72 years. The mean follow-up was 1.7 years (range, 1-3 1/2 years). Of the 75 patients, 72 (96%) are clinically with no evidence of disease, three of the 75 are alive with disease, and 60 (80%) remain biochemically free of disease (bNED). The significant factors for bNED status were an initial PSA level of <15 ng/ml (p = 0.0001), achievement of a posttreatment nadir PSA level of < or = 1.5 ng/ml (p = 0.0001), and a Gleason score of <6 (p = 0.034). Multisextant involvement with tumor or bilobar disease was not significant. On multivariate analysis, an initial PSA level of <15 ng/ml (p = 0.0001), Gleason score of <6 (p = 0.02), and nadir PSA level of < or = 1.5 ng/ml (p = 0.03) were significant predictors of bNED survival. Men with T1c prostate cancer comprise a heterogeneous group. Patients with a high PSA level (>15 ng/ml) and high Gleason score (>6) are at increased risk for biochemical failure. Failure to achieve a posttreatment nadir PSA level of < or = 1.5 ng/ml is a predictor of ultimate biochemical failure.

Adenocarcinoma↗
PubMed1990

Modulation of resting membrane potential of human and rat hepatocytes by sex steroids.

The effect of sex steroids on the regulation of hepatocyte resting membrane potential (Em) was investigated. In adult rat liver snips, Em was significantly lower in males than females. In prepubertal animals no sex related difference was observed and the Em was comparable to that of adult females. Exposure of the human liver cell line, HepG2 cells, to 10 microM testosterone resulted in a significant hyperpolarization. These data indicate that the more negative Em found in male animals is specifically due to the influence of testosterone. In addition, they also suggest that sex hormone regulation of Em is maintained by HepG2 cells. This cell line may prove to be a good model for the study of liver cell function.

Animals↗
PubMed1979

Adipose cell size in obese Africans: evidence against the existence of insulin resistance in some patients.

Aspects of adipose tissue cellularity were examined in 15 non-diabetic premenopausal African women with simple obesity living in Johannesburg. A smaller group of six non-obese Black women served as controls. Adipose tissue was obtained by biopsy from the deltoid, gluteal, and abdominal regions, and the mean fat cell size for each site was determined. Fasting plasma glucose, insulin, and lipid levels, and the glucose and insulin responses to a 100 g oral glucose load, in these subjects provided metabolic data for correlative analyses. As expected, the overall mean and regional adipocyte sizes were significantly larger in the overweight subjects. Significant regional variations in fat cell size were also seen, the gluteal region adipocytes being larger than those of other sites in both obese and non-obese women. A significant positive correlation was found between fat cell size and the percentage of ideal body weight. There was no significant relationship between adipocyte size, however, and any of the metabolic variables measured--notably basal or stimulated plasma insulin. Nearly half of the overweight women showed large adipocytes with normal plasma insulin concentrations. A proportion of African women with hypertrophic obesity do not appear to demonstrate any classical metabolic features of insulin resistance; this may be related partly to their high carbohydrate intake and unusual degree of physical activity. Our results do not, however, indicate that hyperinsulinaemia is completely absent in obese Black women.

Adipose Tissue↗