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Biomedical subjects

B Park

Publications and source records attributed to B Park.

At least 55 records · Page 3Linked to original sources
PubMed1994

Low density lipoprotein receptors in rat adipose cells: subcellular localization and regulation by insulin.

The distribution of LDL receptors within subcellular compartments of isolated rat adipose cells and the effects of insulin on their expression have been assessed. By immunoblotting with specific anti-rat LDL receptor antibodies, LDL receptors were 2.3- and 4.5-fold enriched in endoplasmic reticulum-rich high-density microsomes (HDM) and Golgi complex-rich low-density microsomes (LDM), respectively, compared to plasma membranes (PM). This distribution was similar in cultured cells in which total receptors were increased 2.5-fold compared to freshly isolated cells. After correction for enzyme recoveries, LDL receptors were distributed approximately 4% in HDM, approximately 73% in LDM, and approximately 23% in PM. Insulin decreased total LDL receptors in adipose cells approximately 44%, with a 48% and 49% decrease in HDM and LDM, respectively, without any changes in PM. In contrast, insulin caused an increase of glucose transporters in PM while also decreasing glucose transporters in LDM. When adipose cells were depleted of potassium to inhibit receptor-mediated endocytosis, insulin again caused a decrease of LDL receptors in LDM but now increased LDL receptors in PM. Insulin increased the rate of LDL receptor synthesis approximately 24%, but decreased their half life approximately 40%. Thus, in isolated adipose cells the majority of LDL receptors appear to be located in an intracellular compartment that co-sediments with the Golgi complex rather than located in the PM. The LDL receptors localized in intracellular compartments seem to be functionally regulated as insulin acutely diminishes the number of receptors by apparently accelerating their rate of degradation through, as yet, incompletely determined mechanisms.

Adipose Tissue↗
PubMed1993

Definition and assessment of accuracy in social stereotypes.

A perennial issue in the study of social stereotypes concerns their accuracy. Yet, there is no clear concept of the various ways in which stereotypes may be accurate or inaccurate and how one would assess their accuracy. This article is designed to rectify this situation. Three forms of stereotype inaccuracy are identified: stereotypic inaccuracy, valence inaccuracy, and dispersion inaccuracy. The implications of each form are discussed, along with how each can be assessed using a full-accuracy design. Past research that has attempted to examine stereotype accuracy is reviewed, and new data on the issue are presented. Although of perennial interest, the theoretical and methodological difficulties of assessing stereotype accuracy are substantial. The goal in this article is to alert the researcher to these difficulties and point toward their solution.

Humans↗
PubMed1992

Role of meaningful subgroups in explaining differences in perceived variability for in-groups and out-groups.

Five aspects of the complexity of the knowledge representation of business and engineering majors were examined to see whether these differed by group membership and whether these differences were related to differences in perceived variability. Significantly more subgroups were generated when describing the in-group than the out-group; this difference predicted the relative tendency to see the in-group as more variable, and when controlled for statistically, out-group homogeneity effects were eliminated. Familiarity, redundancy, number of attributes used to describe the group, and the deviance of the subgroups from the larger group generally showed differences for in-group and out-group but did not show consistent evidence of mediation. In a 2nd study, Ss who were asked to sort group members into meaningful subgroups perceived greater variability relative to those who did not perform the sorting task.

Adult↗
PubMed1992

Principles of ultrasound and measurement of intramuscular fat.

A review of basic engineering concepts of ultrasound is presented for the layperson with implications toward the use of ultrasound on beef animals. The use of ultrasound for determining quality traits such as percentage of intramuscular fat is discussed in detail. Results of both A-mode and B-mode preliminary investigations are presented. Preliminary results show that intramuscular fat may be predicted using an A-mode transducer coupled with frequency analysis.

Adipose Tissue↗
PubMed1991

Accuracy in the judgment of in-group and out-group variability.

The accuracy of in-group and out-group variability judgments was examined by comparing those judgments with the variability of self-ratings provided by random samples of group members. Following Park and Judd (1990), perceptions of both group dispersion and group stereotypicality were examined. Accuracy was examined both by within-subject sensitivity correlations and by simple discrepancies between perceived and actual variability estimates. In-group-out-group differences in sensitivity were shown, particularly for judgments of stereotypicality. These differences were related to differences in the degree to which out-group variability is underestimated relative to in-group variability (i.e., the out-group homogeneity effect). Out-group stereotypicality judgments were overestimated, supporting the view that out-group stereotypes are overgeneralizations. Whether dispersion judgments were over- or underestimated depended on their measurement.

Adult↗
PubMed1989

Serum antibodies to cow's milk proteins in pediatric inflammatory bowel disease: Crohn's disease vs. ulcerative colitis.

Serum antibodies to five cow's milk proteins, alpha-casein, bovine serum albumin (BSA), beta-lactoglobulin A and B (BLG-a, BLG-b) and alpha-lactalbumin (ALA) were investigated in young patients with inflammatory bowel disease, 56 with Crohn's disease (CD), 24 with ulcerative colitis (UC). IgG antibodies against BSA and BLG-a and -b were higher in Crohn's disease patients as compared to those with ulcerative colitis and controls. The IgG anti-BSA were higher in the group of CD patients with higher score of disease activity. Additionally, IgA antibodies to alpha-casein were higher in CD and UC compared to control. These findings may be due to increased uptake of dietary antigens or enhanced immunological response occurring in CD patients.

Adolescent↗
PubMed1989

Serum antibodies to cow's milk proteins in pediatric inflammatory bowel disease. Crohn's disease versus ulcerative colitis.

Serum antibodies to five cow's milk proteins (alpha-casein, bovine serum albumin, beta-lactoglobulin A and B, and alpha-lactalbumin) were investigated in young patients with inflammatory bowel disease (56 Crohn's disease, 24 ulcerative colitis). IgG antibodies against bovine serum albumin, beta-lactoglobulin A and beta-lactoglobulin B were higher in Crohn's disease patients than in those with ulcerative colitis or the controls. IgG anti-bovine serum albumin antibodies were higher in those Crohn's disease patients who had higher scores of disease activity. Finally, IgA antibodies to alpha-casein were higher in patients with Crohn's disease and ulcerative colitis when compared to controls. These findings may be due to increased uptake of dietary antigens or enhanced immunological response occurring in Crohn's disease patients.

Adolescent↗
PubMed1989

Social cognition.

Explore the source record for details and available documents.

Cognition↗
PubMed1986

Immunological aspects in patients with chronic active hepatitis--cellular immune responses.

We studied host immune parameters which might be related to the activity and the pathogenetic mechanism of chronic active hepatitis. The subjects consisted of 45 cases with hepatitis B virus surface antigen (HBsAg)-positive chronic active hepatitis (CAH), 44 HBsAg-negative CAH, 22 with inactive chronic hepatitis, and 45 cases of normal persons, hepatitis B virus (HBV) carriers, or the patients with acute myocardial infarction. The in vitro assay for the in vivo activated lymphocytes was performed by measuring spontaneous thymidine uptake (SLT) of lymphocytes isolated from peripheral blood. SLT was significantly (p < 0.001) elevated in cases with HBsAg-positive (1227 +/- 806 cpm) and-negative CAH (1017 +/- 559 cpm) compared to the patients with inactive chronic hepatitis (347 +/- 79 cpm) and to the control group (320 +/- 106 cpm). SLT values observed in 7 cases with active disease (group I and II), in which remission and relapsing phase could be assessable, were elevated from 648 +/- 121 cpm in remission phase to 1548 +/- 606 cpm one to two weeks before the appearance of biochemical evidence (SGPT) of relapse. This pattern of SLT elevation, however, was not observed in patients with inactive hepatitis. Neither the abnormal distribution of T-cell subsets nor the presence of conventional HBV markers were related to the elevated SLT value. Our findings may therefore indicate that SLT might be useful in assessment of the disease activity in patients with CAH.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

Chromosomes and causation of human cancer and leukemia. XLVIII. T-cell acute leukemia in ataxia telangiectasia.

Cytogenetic and immunologic studies were performed on the cells of an 18-year-old female with ataxia telangiectasia (AT) associated with acute lymphocytic leukemia (ALL). At the onset of the leukemia 15.4% of peripheral blood cells stimulated with phytohemagglutinin (PHA) contained a tandem translocation of the long arm of chromosome #14, i.e., t(14;14). To ascertain if these karyotypically abnormal cells and the leukemic cells had a common lineage, chromosome analyses were performed on bone marrow cells. Examination of the marrow cells on the seven occasions when leukemic cells were present in the marrow, including times when they were predominant, showed only a normal karyotype without the presence of t(14;14). However, an abnormal clone, which had the karyotype 45,XX,-9,t(9;6)(q12;q13), was identified in the marrow cells on the last examination during the terminal phase of the leukemia. Immunologically, the ALL was classified as an atypical type which had characteristics in common with certain T-cell subsets. We suggest that the malignant cells did not originate from the preexisting cells with a tandem duplication of the 14q.

Adolescent↗