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Biomedical subjects

M Dresser

Publications and source records attributed to M Dresser.

6 recordsLinked to original sources
PubMed1998

Meiotic recombination in C. elegans initiates by a conserved mechanism and is dispensable for homologous chromosome synapsis.

Chromosome segregation at meiosis I depends on pairing and crossing-over between homologs. In most eukaryotes, pairing culminates with formation of the proteinaceous synaptonemal complex (SC). In budding yeast, recombination initiates through double-strand DNA breaks (DSBs) and is thought to be essential for SC formation. Here, we examine whether this mechanism for initiating meiotic recombination is conserved, and we test the dependence of homologous chromosome synapsis on recombination in C. elegans. We find that a homolog of the yeast DSB-generating enzyme, Spo11p, is required for meiotic exchange in this metazoan, and that radiation-induced breaks partially alleviate this dependence. Thus, initiation of recombination by DSBs is apparently conserved. However, homologous synapsis is independent of recombination in the nematode, since it occurs normally in a C. elegans spo-11 null mutant.

Animals↗
PubMed1992

Variation in health service use among HIV-infected patients.

The effects of sociodemographic factors on health service use among people with human immunodeficiency virus (HIV) infection are assessed. Data are from a survey of 939 clients of the Robert Wood Johnson Foundation's AIDS Health Services Program in nine communities across the country. Dependent variables are the number of outpatient visits, use of the emergency room, and whether the respondent had been admitted as an inpatient. In the 3 months before the interview, the sample averaged 7.46 outpatient physician/clinic visits: 35.9% reported an emergency room visit, and 29.9% had been hospitalized. The data suggested differential patterns of health service use, such that those who are white, male, and non-intravenous drug users have higher rates of outpatient clinic/physician use, whereas those who are nonwhite, female, and intravenous drug users have higher rates of emergency room use. Whether these observed differences are attributable to the system's response to different socioeconomic groups, or to differences in individual orientations toward use of medical care is discussed.

Black or African American↗
PubMed1987

A new method for the cytological analysis of autoantibody specificities using whole-mount, surface-spread meiotic nuclei.

A new method for the cytological analysis of antinuclear antibody binding offers several advantages over conventional techniques. Nuclei in meiosis, prepared by surface-spreading spermatocytes, provide a detailed examination of the constituents of the nucleus--euchromatin, heterochromatin, sex chromatin, nucleoli, centromeres, and dense patches that seem related to RNA metabolism--and each of these structures can be seen to change in morphology and antibody labeling during the course of meiotic prophase. Results using sera from humans and mice with autoimmune disease, and using several mouse monoclonal antibodies, demonstrate the potential of this method for clinical and research applications, both for more common antibody types and for those that bind epitopes which are unique to germ cells.

Animals↗
PubMed1981

Structural studies of lambda transducing bacteriophage carrying bacterial deoxyribonucleic acid from the metBJLF region of the Escherichia coli chromosome.

The structures of several lambda dmet and related lambda darg transducing phage were studied by restriction fragment mapping and electron microscopic measurements of homoduplexes and heteroduplexes. A new transducing phage (lambda dmet141), in which metF is the only functional gene of the cluster, was isolated. In contrast, lambda dmet117, which expresses the entire metBJLF cluster, has only 3 kilobases more bacterial deoxyribonucleic acid (DNA) than lambda dmet141. An EcoRI restriction fragment of lambda dmet117, which carries the leftmost 6 kilobases of the bacterial DNA insert, was isolated and shown to contain a functional copy of metB. Small structural differences at the attachment sites of some of the phage were shown to result from different sites of lambda integration in the two parent insertion lysogens.

Attachment Sites, Microbiological↗