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Biomedical subjects

E Davis

Publications and source records attributed to E Davis.

At least 37 records · Page 2Linked to original sources
PubMed1998

Genomic organization of four beta-1,4-endoglucanase genes in plant-parasitic cyst nematodes and its evolutionary implications.

The genomic organization of genes encoding beta-1,4-endoglucanases (cellulases) from the plant-parasitic cyst nematodes Heterodera glycines and Globodera rostochiensis (HG-eng1, Hg-eng2, GR-eng1, and GR-eng2) was investigated. HG-eng1 and GR-eng1 both contained eight introns and structural domains of 2151 and 2492bp, respectively. HG-eng2 and GR-eng2 both contained seven introns and structural domains of 2324 and 2388bp, respectively. No significant similarity in intron sequence or size was observed between HG-eng1 and HG-eng2, whereas the opposite was true between GR-eng1 and GR-eng2. Intron positions among all four cyst nematode cellulase genes were conserved identically in relation to the predicted amino acid sequence. HG-eng1, GR-eng1, and GR-eng2 had several introns demarcated by 5'-GCellipsisAG-3' in the splice sites, and all four nematode cellulase genes had the polyadenylation and cleavage signal sequence 5'-GAUAAA-3'-both rare occurences in eukaryotic genes. The 5'- flanking regions of each nematode cellulase gene, however, had signature sequences typical of eukaryotic promoter regions, including a TATA box, bHLH-type binding sites, and putative silencer, repressor, and enhancer elements. Database searches and subsequent phylogenetic comparison of the catalytic domain of the nematode cellulases placed the nematode genes in one group, with Family 5, subfamily 2, glycosyl hydrolases from Scotobacteria and Bacilliaceae as the most homologous groups. The overall amino acid sequence identity among the four nematode cellulases was from 71 to 83%, and the amino acid sequence identity to bacterial Family 5 cellulases ranged from 33 to 44%. The eukaryotic organization of the four cyst nematode cellulases suggests that they share a common ancestor, and their strong homology to prokaryotic glycosyl hydrolases may be indicative of an ancient horizontal gene transfer.

3' Untranslated Regions↗
PubMed1998

Prostate stem cell antigen: a cell surface marker overexpressed in prostate cancer.

The identification of cell surface antigens is critical to the development of new diagnostic and therapeutic modalities for the management of prostate cancer. Prostate stem cell antigen (PSCA) is a prostate-specific gene with 30% homology to stem cell antigen 2, a member of the Thy-1/Ly-6 family of glycosylphosphatidylinositol (GPI)-anchored cell surface antigens. PSCA encodes a 123-aa protein with an amino-terminal signal sequence, a carboxyl-terminal GPI-anchoring sequence, and multiple N-glycosylation sites. PSCA mRNA expression is prostate-specific in normal male tissues and is highly up-regulated in both androgen-dependent and -independent prostate cancer xenografts. In situ mRNA analysis localizes PSCA expression in normal prostate to the basal cell epithelium, the putative stem cell compartment of the prostate. There is moderate to strong PSCA expression in 111 of 126 (88%) prostate cancer specimens examined by in situ analysis, including high-grade prostatic intraepithelial neoplasia and androgen-dependent and androgen-independent tumors. Flow cytometric analysis demonstrates that PSCA is expressed predominantly on the cell surface and is anchored by a GPI linkage. Fluorescent in situ hybridization analysis localizes the PSCA gene to chromosome 8q24.2, a region of allelic gain in more than 80% of prostate cancers. A mouse homologue with 70% amino acid identity and similar genomic organization to human PSCA has also been identified. These results support PSCA as a target for prostate cancer diagnosis and therapy.

Amino Acid Sequence↗
PubMed1998

Patients report positive nutrition counseling outcomes.

OBJECTIVE: Assess outcomes of patient nutrition counseling. DESIGN: A descriptive study based on the results of a telephone interview performed 2 to 8 weeks after counseling. SUBJECTS/SETTING: Subjects were 400 adult patients referred for nutrition counseling at 2 academic health centers. Of these, 274 patients received nutrition counseling during hospitalization and 126 as outpatients. STATISTICAL ANALYSIS: Descriptive statistics were used to summarize data and the Mann-Whitney U statistic and logistic regressions were used to test significant differences (P < .05) between inpatient and outpatient counseling outcomes. RESULTS: Most patients (83%) gave a partial or full description of their diet modifications and 79% had a moderate or good understanding of their diet. Most patients reported that the dietitian's advice was suited to their special needs (88%) and that they knew what to eat (83%). A majority (62%) had made dietary changes, but 17% said they had had trouble changing their diets as suggested. After talking with a dietitian, 57% felt better emotionally, 37% felt better physically, 64% felt in control of their condition, and 43% noticed improved health indicators. Initial analysis indicated that outpatients reported better outcomes than inpatients; further analysis showed that these differences could be attributed to younger ages among the outpatient sample. APPLICATIONS/CONCLUSIONS: Patient nutrition counseling has positive outcomes. Therefore, key counseling points should be introduced or reinforced in inpatient settings, in conjunction with multiple-session protocols during the pre- and/or posthospitalization continuum of care. Dietitians, managers, administrators, and credentialing agencies should work together to secure and promote the necessary physical, personnel, and financial resources to make this happen.

Adult↗
PubMed1998

Endotoxin treatment of equine infectious anaemia virus-infected horse macrophage cultures decreases production of infectious virus.

Lentiviruses replicate in cells of the immune system, and activation of immune cells has been shown to modulate virus replication. To determine the effects of macrophage activation on replication of equine infectious anaemia virus (EIAV), primary horse macrophage cultures (HMCs) were established from 20 different horses, infected with an avirulent strain of EIAV, and stimulated with 5 microg/ml of bacterial endotoxin. Supernatants collected from HMCs were assayed for the presence of tumour necrosis factor (TNF-alpha) and for production of infectious virus. Results indicated that EIAV replication in vitro varied significantly (P < or = 0.0001) from horse to horse, regardless of the treatment of HMCs. Also, EIAV replication was significantly (P < or = 0.0001) decreased in HMCs stimulated with bacterial endotoxin as compared to untreated HMCs. No significant correlation was found between virus replication and production of TNF-alpha following treatment of virus-infected cells with bacterial endotoxin. However, when HMCs were treated with endotoxin prior to virus infection, inhibition of EIAV replication was proportional to increasing levels of endotoxin. PCR and RT-PCR were used to amplify EIAV proviral DNA and mRNA sequences, respectively, at various time-points following infection. The results indicated that the early events of EIAV replication, up to and including transcription of multiple-spliced mRNAs, were not inhibited by treatment of EIAV-infected macrophages with bacterial endotoxin. This suggests that endotoxin treatment inhibits a posttranscriptional step in the virus replication cycle.

Animals↗
PubMed1998

A map of 75 human ribosomal protein genes.

We mapped 75 genes that collectively encode >90% of the proteins found in human ribosomes. Because localization of ribosomal protein genes (rp genes) is complicated by the existence of processed pseudogenes, multiple strategies were devised to identify PCR-detectable sequence-tagged sites (STSs) at introns. In some cases we exploited specific, pre-existing information about the intron/exon structure of a given human rp gene or its homolog in another vertebrate. When such information was unavailable, selection of PCR primer pairs was guided by general insights gleaned from analysis of all mammalian rp genes whose intron/exon structures have been published. For many genes, PCR amplification of introns was facilitated by use of YAC pool DNAs rather than total human genomic DNA as templates. We then assigned the rp gene STSs to individual human chromosomes by typing human-rodent hybrid cell lines. The genes were placed more precisely on the physical map of the human genome by typing of radiation hybrids or screening YAC libraries. Fifty-one previously unmapped rp genes were localized, and 24 previously reported rp gene localizations were confirmed, refined, or corrected. Though functionally related and coordinately expressed, the 75 mapped genes are widely dispersed: Both sex chromosomes and at least 20 of the 22 autosomes carry one or more rp genes. Chromosome 19, known to have a high gene density, contains an unusually large number of rp genes (12). This map provides a foundation for the study of the possible roles of ribosomal protein deficiencies in chromosomal and Mendelian disorders.

Animals↗
PubMed1998

Recent developments in domestic partner benefits.

Domestic partner benefits have become increasingly common, particularly among large employers, as firms respond to stiff competition for highly skilled employees and also to equity issues. A lawsuit filed in response to the City of San Francisco's domestic partner amendment to an existing ordinance has drawn renewed attention to the subject in recent months.

Certification↗
PubMed1998

Variation is the rule.

Explore the source record for details and available documents.

Attitude of Health Personnel↗
PubMed1997

Structural instability of mutant beta-cell glucokinase: implications for the molecular pathogenesis of maturity-onset diabetes of the young (type-2).

The catalytic function and thermal stability of wild-type and mutant recombinant human pancreatic beta-cell glucokinase was investigated. The mutants E70K and E300K, which are thought to be the cause of impaired insulin production by the pancreatic beta-cell and decreased glucose uptake by the liver of patients with maturity-onset diabetes of the young, were found to be functionally indistinguishable from the wild-type, i.e. their kcat.S0.5, inflection point and h were normal. However, these two mutants showed markedly reduced stability under a variety of test conditions. Glucokinase instability, not low enzyme catalytic activity, may be the cause of diabetes mellitus with E70K and E300K mutants.

Diabetes Mellitus, Type 2↗
PubMed1997

Lymphocyte and monocyte subset changes during cardiopulmonary bypass: effects of aging and gender.

Complications of cardiopulmonary bypass (CPB) may be associated with either immune suppression or immune activation, but the specific effects of CPB on many lymphocyte and monocyte subsets are unclear. In addition, the increasing age of patients undergoing cardiac surgery raises the possibility of even greater effects on the immune system in elderly patients. We measured immunophenotypic alterations of circulating lymphocytes and monocytes after CPB in male and female cardiac surgery patients who were either younger than 60 or older than 75 years of age. The total lymphocyte counts in all patients decreased postoperatively; older patients had significantly lower counts at all time points. The absolute decline was greatest among T cells and particularly CD4+ T cells, which reached an average nadir of 251 cells/microl on postoperative day 1 in the older patients. The percentages of CD8+, CD4+CD45RA+, and CD4+CD45RO+ T cells did not change significantly, whereas the percentages of B cells and natural killer cells increased. Both T and B lymphocytes and monocytes showed evidence of activation, with increased percentages of CD3+HLADr+, CD3+IL2R+, and CD19+CD23+ lymphocytes and increased expression of CD11b on monocytes. By contrast, expression of class II major histocompatibility antigen (HLADr) monocytes decreased significantly. We conclude that CPB produces a profound alteration in the pool of circulating lymphocytes and monocytes, evidenced by decreased numbers of lymphocyte subsets including CD4+ cells and decreased expression of monocyte surface membrane proteins important for antigen presentation; CPB also activates a variety of specific circulating mononuclear cell subsets. Older patients showed patterns of lymphocyte and monocyte activation comparable to those of younger patients; however, they had consistently lower lymphocyte numbers and a trend toward decreased monocyte HLADr expression, potentially placing them at greater risk for infectious complications. Gender had no effect.

Age Factors↗
PubMed1997

Transesophageal echocardiography and the perioperative management of valvular heart disease.

Transesophageal echocardiography (TEE) is an integral part of decision-making and monitoring in the perioperative period for patients undergoing valvular heart surgery. Multiplanar probes with improved pre- and intraoperative evaluation, eg, improved accuracy of estimation of mitral regurgitation jet size, have led to a more precise surgical approach. In the intensive care unit, TEE is proving invaluable in diagnosing occult causes of clinical instability that are usually surgically correctable. Advances in imaging technology with three- and four-dimensional TEE will facilitate preoperative decision-making, determine intraoperative approaches to valvular surgery, and provide earlier recognition of complications in the intensive care unit.

Aortic Valve↗