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Biomedical subjects

N Lin

Publications and source records attributed to N Lin.

At least 91 records · Page 5Linked to original sources
PubMed1983

Impact of legislation raising the legal drinking age in Massachusetts from 18 to 20.

On April 16, 1979, Massachusetts raised its legal drinking age from 18 to 20 years. Massachusetts was compared with New York State, exclusive of New York City and Nassau County. New York State retained an 18-year-old drinking age. Random telephone surveys with approximately 1,000 16-19 year olds in each state were undertaken prior to the law's enactment and twice at yearly intervals after the law to assess the law's impact on teenage drinking, driving after drinking, and non-fatal accident involvement. Fatal crash data reported to the US Department of Transportation by each state from April 16, 1976-April 15, 1981 were also analyzed. After the law, although the modes of procuring alcohol changed. No significant changes were observed in Massachusetts relative to New York in the proportion of surveyed teenagers who reported that they drank or in the volume of their consumption. The proportion of teenagers who drove after drinking heavily (six or more drinks at one time) did not decline in Massachusetts relative to New York. However, the frequency that teenagers reported driving after any drinking declined significantly in Massachusetts. Frequency of teenage driving after marijuana use and non-fatal teenage accidents declined at comparable rates in both states. The numbers of teenage nighttime single vehicle fatal accidents declined more in Massachusetts than New York, in the 18-19 year age group. Overall fatal accident trends among 16-19 year olds in the two states were similar.

Accidents, Traffic↗
PubMed1981

Properties of a human alpha-interferon purified from E. coli extracts.

A human alpha interferon, designated HuIFN-alpha A, produced in E. coli by direct expression of cloned cDNA [Goeddel et al., Nature 287, 411--416 (1980)] has been purified from bacterial extracts and characterized. The protein has a molecular weight (19,400 by SDS/PAGE) and amino acid composition consistent with the DNA sequence. The pI was determined to be 6.1. The molecule has a specific activity of 1.5 x 10(8) NIH reference units/mg of protein. The sequence of the first 35 amino acids is identical to that expected from the nucleotide sequence. About 50% of the molecules begin with the expected cysteine, and 50% begin with the initiator methionine which E. coli apparently did not remove efficiently. Analysis of a trypsin digest of the native molecule showed that all four of the molecule's cysteines are involved in disulfide bonds: Cys1 is bonded to Cys98, and Cys29 is bonded to Cys 138.

Amino Acids↗
PubMed1981

Social support scales: a methodological note.

The relationship between social support and depression has implications for researchers studying schizophrenia. In this article, the authors attempt to conceptualize social support and assess the reliability and validity of its various measures. They then evaluate the ability of social support, along with stressors, to explain psychiatric symptoms. Representative data from a community survey of adults, ages 17-70, suggest that social support measures show strong relationships to depression and other psychiatric symptoms. The implications of these and other findings for the study of schizophrenia are discussed.

Depressive Disorder↗
PubMed1980

Polycythemia vera. Physical separation of normal and neoplastic committed granulocyte-macrophage progenitors.

In previous studies of two patients with polycythemia vera (PV) who were heterozygous at the X-linked locus for glucose-6-phosphate dehydrogenase (G6PD), only A type enzyme was found in nonlymphoid blood cells. However, some erythroid and granulocytic colonies grown in vitro were type B and therefore arose from presumably normal progenitors. One patient had enough type B colonies (8%) that studies of the physical characteristics of normal and PV clonal colony-forming cells could be undertaken. When marrow cells were separated by velocity sedimentation at unit gravity, most PV clonal granulocyte-macrophage progenitors (CFU-C) (type A G6PD) sedimented between 6.4 and 7.2 mm/h, whereas most residual normal, type B CFU-C sedimented less than or equal to 5.9 mm/h (P = 0.04)., When blood cells were separated over a discontinuous buoyant density gradient, PV clonal CFU-C equilibrated at densities < 1.065 g/ml, whereas residual normal CFU-C were found greater than or equal to 1.065 g/ml (P < 0.01). PV clonal and residual normal erythroid burst-forming progenitors were not separable by either method. Thus PV clonal CFU-C are larger and less dense cells than are residual normal CFU-C.

Erythrocytes↗
PubMed1980

Polycythemia vera. Further in vitro studies of hematopoietic regulation.

Further in vitro studies of hematopoietic regulation were carried out in two patients with polycythemia vera who were also heterozygotes (Gd(B)/Gd(A)) for glucose-6-phosphate-dehydrogenase (G-6-PD). While only G-6-PD type A was detectable in circulating erythrocytes, granulocytes and platelets, cultures of peripheral blood and marrow from one patient revealed a substantial number of G-6-PD type B erythroid burst-forming units (BFU-E) and granulocyte/macrophage colony-forming units. Detailed analysis demonstrated: (a) where detectable, normal BFU-E and granulocyte/macrophage colony-forming units were found with similar frequencies; (b) the same frequencies for normal progenitors characterized cultures of peripheral blood and marrow; (c) inhibition of normal erythroid differentiation between BFU-E and the more mature erythroid colony-forming unit; (d) a decline in the prevalence of normal colony-forming units with time, suggesting that disease progression is associated with further suppression of normal hematopoiesis by products of the abnormal clone.

Bone Marrow Cells↗
PubMed1979

Locus of control and symptoms of psychological distress among Chinese-Americans.

A sample of Chinese-Americans in the District of Columbia was drawn to examine the relationship between the locus of control, the personality factor, and two indices of symptoms of psychological distress. The findings indicated that the externals scored higher on symptomatology than did the internals. A multivariate analysis further compared the predictive utility of locus of control with other determinants of psychiatric symptoms, i.e., sex, marital status, SES, kinship and friendship tie, and amount of life change. The evidence showed that locus of control is an important determinant of Chinese-Americans' symptomatology. It accounted for a greater proportion of the variance in the two indices of psychological distress than did the other independent variables.

Acculturation↗
PubMed1978

Analysis of erythropoiesis by erythroid colony formation in culture.

The development of clonal assays for hemopoietic progenitors has provided new tools for the analysis of normal and abnormal cell regulation. Such assays have been applied to erythropoiesis and have demonstrated classes of precursors which differ significantly in their growth potential, physical characteristics, and sensitivity to the hormone, erythropoietin. A formal geneology of these classes has been established and insight into the factors that regulate the numbers of the classes provided by studies in anemic and polycythemic animals. The results suggest that commitment to the earliest erythroid progenitors recognizable in culture is not controlled by erythropoietin, whereas the most differentiated elements demonstrate a requirement for the hormone for their maintenance. Recognition of differences in the factors that control erythroid differentiation predict that a variety of mechanisms will be found to account for different forms of erythroid failure in man.

Anemia↗
PubMed1977

The stress-buffering role of social support. Problems and prospects for systematic investigation.

Over the pase 20 years, a sizable body of literature has developed which serves to establish that stressful life events are associated with the onset, incidence, and prevalence of a wide range of physical and psychiatric disorders. As measured by the Holmes and Rahe Social Readjustment Rating Scale, or similar instruments, the stressful life events are fundamentally sociological in nature. Yet, paradoxically, the research has been largely limited in the relevant basic sociological theory and data brought to or yielded from investigation. Recently, however, several prominent researchers have emphasized the importance of studying the role of social support systems as possible buffers or mediators of stress. The most basic objective of this paper is to contribute to the advancement of such studies by clearly identifying key empirical, theoretical and methodological problems and suggesting some approaches to their resolution. Specifically, this paper offers: a) a selective review of the essential status of empirical knowledge; b) an examination of the nature and significance of social support systems; c) clarification of methodological and theoretical problems; and d) detailed proposals for approaching problems of measurement and research design.

Animals↗
PubMed1970

Communication in the physical and the social sciences.

Although composed of similar elements and structured similarly, the communications systems associated with the physical sciences and the social sciences differ markedly with respect to the operation and use of these elements. For both groups of disciplines, as information flows through the system it encounters lags and filtering, and much of a scientist's communication behavior is an effort to compensate for these factors. Because the lags and filtering within each system differ in loci and extent, the members of different disciplines adjust to them differently, and the overall information flow patterns in the physical and in the social sciences differ.

Communication↗