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Biomedical subjects

S L Martin

Publications and source records attributed to S L Martin.

At least 127 records · Page 7Linked to original sources
PubMed1980

Rapid duplication and loss of genes coding for the alpha chains of hemoglobin.

Rapid cycles of gene duplication and loss appear to have been going on in the region coding for the alpha chain of adult hemoglobin. This is inferred from restriction endonuclease analysis of the alpha gene region in five species of apes, whose common ancestor lived about 10 million years ago. Because all five species resemble humans in having duplicate alpha genes, the duplicate state of this region is probably at least as old as the common ancestor of all these species. However, the alpha polypeptides within these species are about 10 times more alike than is expected for 10 million years of divergent evolution. Thus, the alpha polypeptides within each species have been evolving in concert. Changes in gene number have also taken place in the apes. Whereas the predominant number of alpha genes per chromosome is two for most species, it is three for chimpanzees. Concerted evolution appears also to have occurred, but far more slowly, in the region coding for the adult beta-like chains of hemoglobin. Consideration of the structural differences between the two regions leads to the hypothesis that the lengths of the noncoding regions are important determinants of the rates at which genes are gained and lost by intergenic recombination.

Adaptation, Biological↗
PubMed1980

Silent delta-globin gene in Old World monkeys.

The delta polypeptide chain is present in the adult hemoglobin of all higher primates except Old World monkeys. Because Old World monkeys have evolved from higher primate ancestors, it can be concluded that the ability to synthesize this polypeptide has been lost relatively recently. It is shown here that the gene for delta globin exists in two of these species, the rhesus monkey (Macaca mulatta) and the baboon (Papio papio). Restriction endonuclease fragments of monkey genomic DNA bearing the delta- and beta-globin genes were detected after hybridization of human globin cDNA probes to filter-bound primate DNAs according to the Southern method. A restriction map prepared for rhesus DNA was identical in overall organization to the map of the human region. This indicates that large deletions or additions of DNA are not responsible for the Old World monkeys' lack of delta globin.

Animals↗
PubMed1980

Biochemical and immunological investigations on hypothyroidism in dogs.

Circulating antibody titers (1:20 to 1:2560) against thyroglobulin were demonstrated in 48% of pet dogs with hypothyroidism by the chromic chloride passive hemagglutination test. Four of six dogs with acanthosis nigricans (1:20) and one of six male dogs with hyperestrogenism (1:40) had low titers of antibody against thyroglobulin whereas clinically normal pet dogs and dogs with other selected endocrinopathies (hypoadrenocorticism, cortisol-excess, diabetes mellitus) or obesity were consistently negative. Circulating immune complexes evaluated by the mastocytoma cell-assay were present in the sera of 20% of pet dogs with hypothyroidism but were absent in clinically normal dogs. Although variations in dose significantly altered the quantitative response of the thyroid gland to thyrotropin the qualitative pattern of response was similar for T3 but not T4 in clinically normal laboratory beagles. The peak increases for serum triiodothyronine and thyroxine were observed either at eight (0.1 and 0.2 I.U bTSH/5 lbs) or 12 (1.0 I.U. bTYSH/5 lbs) hours postthyrotropin. Dogs with naturally occurring hypothyroidism had a decreased serum T3 and T4 at baseline and eight hours postthyrotropin (1.0 I.U. bTSH/5 lbs) compared to clinically normal pet dogs, laboratory beagles and dogs with other clinical endocrinopathies. The consistent lack of a significant increase of serum T3 and T4 in response to thyrotropin was necessary for the separation of certain hypothyroid from euthyroid pet dogs in which the baseline level of thyroid hormones were equivocal.

Animals↗
PubMed1979

The genetics of PLT response. II. HLA-DRw is a major PLT-stimulating determinant.

PLT response is restricted by the HLA-D region. The present study was undertaken to help define the role of HLA-DRw in PLT restimulation. Haplotype-primed intrafamily PLT cells were made against specificities HLA-DRw1, HLA-DRw3, and HLA-DRw7; each PLT was then restimulated with cells from a 35-member unrelated panel. Restimulation values for each PLT were subjected to bimodal clustering analysis. In addition, blocking experiments were performed with other intrafamily and homozygous typing cell PLT after preincubation with B cell alloantisera. The results show a high correlation (0.881 less than or equal to r less than or equal to 1.00) between the HLA-DRw specificity of the priming haplotype and the HLA-DRw specificity of unrelated panel cells that restimulate in PLT. When stimulating cells were absorbed with the corresponding DRw alloantisera or p29,34 heteroantiserum (against B cell specific antigens), PLT restimulation was significantly blocked. However, the PLT cells treated with antisera showed no effect. The results strongly suggest that HLA-DRw is the principal PLT-stimulating determinant.

Binding, Competitive↗
PubMedDate not supplied

Who gets screened during pregnancy for partner violence?

CONTEXT: Despite recommendations to screen prenatal care patients for partner violence, the prevalence of such screening is unknown. OBJECTIVES: To estimate the statewide prevalence of partner violence screening during prenatal care among a representative sample of North Carolina women with newborns and to compare women screened for partner violence with women not screened. DESIGN, SETTING, AND PARTICIPANTS: This investigation examines data gathered through the North Carolina Pregnancy Risk Assessment Monitoring System, a random sample of more than 2600 recently postpartum women who were delivered of newborns between July 1997 and December 1998. MAIN OUTCOME MEASURES: Self-reports of violence, health service factors, and sociodemographic characteristics. ANALYSIS: The prevalence of screening was computed, and odds ratios and 95% confidence intervals were used to examine bivariate and multivariable associations between being screened for partner violence and other factors. RESULTS: Thirty-seven percent of women reported being screened for partner violence during prenatal care. Logistic regression analysis found that women were more likely to be screened if they received prenatal care from (1) a public provider paid by a public source; (2) a private provider paid by a public source; or (3) a public provider paid by a private source. CONCLUSIONS: These findings suggest that the majority of prenatal care patients in North Carolina are not screened for partner violence. Screening appears to be most highly associated with whether a woman is a patient in the public sector or the private sector, and with the source of payment for prenatal care. Arch Fam Med. 2000;9:1093-1099

Adolescent↗
PubMedDate not supplied

The DNA sequence and comparative analysis of human chromosome 20.

The finished sequence of human chromosome 20 comprises 59,187,298 base pairs (bp) and represents 99.4% of the euchromatic DNA. A single contig of 26 megabases (Mb) spans the entire short arm, and five contigs separated by gaps totalling 320 kb span the long arm of this metacentric chromosome. An additional 234,339 bp of sequence has been determined within the pericentromeric region of the long arm. We annotated 727 genes and 168 pseudogenes in the sequence. About 64% of these genes have a 5' and a 3' untranslated region and a complete open reading frame. Comparative analysis of the sequence of chromosome 20 to whole-genome shotgun-sequence data of two other vertebrates, the mouse Mus musculus and the puffer fish Tetraodon nigroviridis, provides an independent measure of the efficiency of gene annotation, and indicates that this analysis may account for more than 95% of all coding exons and almost all genes.

Animals↗
PubMedDate not supplied

Local and national uses of a Road to Recovery evaluation.

Evaluation fellows from the George Washington University School of Public Health and Health Services conducted an evaluation of the Road to Recovery program of the Mid-Atlantic division of the American Cancer Society. The evaluation included qualitative analysis of program operation, mailed surveys, in-depth interviews with patients and drivers, and interviews with social workers from treatment centers. Results indicated that patients and drivers were satisfied with the program. Patients appreciated the ability of drivers to provide personalized, reliable service. The recruitment of sufficient drivers to meet transportation demand was a problem. High staff turnover and a lack of electronic tracking of standard information hindered program monitoring. A Mid-Atlantic Advisory Transportation Group reviewed the findings and made recommendations for service improvement. The Mid-Atlantic division evaluation contributed to an "evaluation synthesis" in which participants from the three divisions that had conducted Road to Recovery evaluations examined study data and made recommendations for reorganizing the national transportation program. A Transportation Program Design Team then held fact-finding meetings and adopted goals and objectives for a new national transportation program. The primary lesson learned was the far-reaching effects that a single program evaluation may have for various stakeholders and for an organization.

Cooperative Behavior↗