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Biomedical subjects

G Foster

Publications and source records attributed to G Foster.

At least 73 records · Page 4Linked to original sources
PubMed1999

Phenotypic and phylogenetic characterization of a new Corynebacterium species from dogs: description of Corynebacterium auriscanis sp. nov.

Six strains of a previously undescribed catalase-positive coryneform bacterium isolated from clinical specimens from dogs were characterized by phenotypic and molecular genetic methods. Biochemical and chemotaxonomic studies revealed that the unknown bacterium belonged to the genus Corynebacterium sensu stricto. Comparative 16S rRNA gene sequencing showed that the six strains were genealogically highly related and constitute a new subline within the genus Corynebacterium; this subline is close to but distinct from C. falsenii, C. jeikeium, and C. urealyticum. The unknown bacterium from dogs was distinguished from all currently validated Corynebacterium species by phenotypic tests including electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as a new species, Corynebacterium auriscanis. The type strain of C. auriscanis is CCUG 39938(T).

Animals↗
PubMed1999

Prediction of perinatal outcome in fetuses suspected to have intrauterine growth restriction: Doppler US study of fetal cerebral, renal, and umbilical arteries.

PURPOSE: To determine and compare the diagnostic performance of fetal middle cerebral (MCA), renal (RA), and umbilical (UA) arterial Doppler ultrasonography (US) for prediction of adverse perinatal outcome in suspected intrauterine growth restriction (IUGR). MATERIALS AND METHODS: Two hundred ninety-three small-for-gestational age fetuses (24-39 weeks at recruitment and US-estimated weight or abdominal circumference below 10th percentile) were prospectively examined with Doppler US of the UA, MCA, and RA. Clinicians were blinded to MCA and RA Doppler measurements. RESULTS: Seventy-six fetuses (25.9%) had at least one major or minor adverse perinatal outcome. Major outcomes included stillbirth, neonatal death, neurologic complication, and necrotizing enterocolitis. The MCA pulsatility index (PI), compared with the UA PI and RA PI, was more sensitive (72.4% vs 44.7% and 8.3%) but less specific (58.1% vs 86.6% and 92.6%) in predicting adverse outcome. The UA PI had the highest positive likelihood ratio (ratio, 3.3); the MCA PI had the lowest negative likelihood ratio (ratio, 0.48). When gestational age at the first Doppler US examination was less than 32 weeks, the MCA PI had a sensitivity of 95.5% and negative predictive value of 97.7% for major adverse outcome (negative likelihood ratio, 0.10). CONCLUSION: In suspected IUGR, while an abnormal UA PI is a better predictor of adverse perinatal outcome than an abnormal MCA or RA PI, a normal MCA PI may help to identify fetuses without major adverse perinatal outcome, especially before 32 weeks gestational age.

Brain↗
PubMed1998

Causes of death of wild birds of the family Fringillidae in Britain.

The provision of supplementary food for wild birds in gardens during the winter months is common in the UK, but it is possible that it may precipitate infectious diseases in the birds. This paper describes the results of postmortem examinations of 116 wild finches carried out over a period of four years. The two commonest causes of death in areas where high mortality had been reported were infections with the bacteria Salmonella typhimurium DT40 and Escherichia coli O86. Coccidia of the genera Atoxoplasma or Isospora were found in several of the birds but were considered to be incidental. Megabacteria were also identified in some of the birds, for the first time in flocks of wild birds in the UK, but they were not considered to be significant.

Animals↗
PubMed1998

Isolation of translactone-containing triterpenes with thrombin inhibitory activities from the leaves of Lantana camara.

Methanolic extracts prepared from the leaves of Lantana camara have been found to inhibit human thrombin. An assay, in which thrombin activity is measured as a function of clot formation from fibrinogen, was used to guide the fractionation and purification of five principal active constituents (1-5), which were all characterized as 5,5-trans-fused cyclic lactone-containing euphane triterpenes.

Carbohydrate Sequence↗
PubMed1998

A simple clinical model for the diagnosis of deep-vein thrombosis combined with impedance plethysmography: potential for an improvement in the diagnostic process.

OBJECTIVES: We recently demonstrated the utility of a clinical model combined with ultrasonography to assist the diagnostic approach in patients with suspected deep-vein thrombosis (DVT). In this study we also sought to demonstrate that the model is useful with impedance plethysmography, a less accurate and less utilized diagnostic test. The original clinical model is slightly cumbersome to use; thus at the completion of the study we attempted to develop a simpler scoring system with a goal of maintaining accuracy. DESIGN: An open, nonrandomized, multicentre trial. SETTING: Three centres, two in Canada, and one in Italy. SUBJECTS: Ambulatory patients with suspected deep-vein thrombosis. INTERVENTIONS: All patients were assessed clinically to determine the probability for deep-vein thrombosis prior to performing impedance plethysmography and venography. We compared the accuracy of impedance plethysmography between the three pretest probability categories of high, moderate and low. All of the above were performed and interpreted by independent observers. When the study was completed, we revised the clinical model by first performing a simple regression analysis then a multiple logistic regression analysis; a scoring system was devised using the latter. RESULTS: Impedance plethysmography is significantly more sensitive and less specific for all DVT in patients with high pretest probability for deep-vein thrombosis (P = 0.001). The post- test probability (positive predictive value) for deep-vein thrombosis with an abnormal impedance plethysmography result was significantly different (P = 0.0001) between the three pretest probability categories. Multiple regression analysis has provided a new model with only nine variables and a simple scoring system. The retrospective application of the revised clinical model, which is simpler to use, suggests it will provide similar results as the original clinical model when combined with impedance plethysmography. The combination of impedance plethysmography and the clinical model suggests patients are likely to have false positive results if they have a low or moderate pretest probability for deep-vein thrombosis and false negative results if the pretest probability is high. The combination of a low pretest probability and a normal impedance plethysmography result may exclude the need for serial testing, and represented more than 50% of our patient population. CONCLUSIONS: The use of the clinical model in conjunction with impedance plethysmography would decrease the number of false positive and negative diagnoses and could markedly decrease the need for serial impedance plethysmography. Combining the clinical model with impedance plethysmography could overcome the fact that impedance plethysmography is clearly less accurate than venous ultrasound imaging. The use of the revised clinical model may increase acceptability and utility, but prospective testing is required before widespread use.

Diagnosis, Differential↗
PubMed1998

Isolation of Escherichia coli O86:K61 producing cyto-lethal distending toxin from wild birds of the finch family.

Escherichia coli was recovered from selected tissues of 43 out of a total of 46 finches found dead in the Scottish Highlands during April-May of 1994 and 1995. The isolates did not ferment sorbitol, rhamnose, sucrose or melibiose; they belonged to serogroup O86:K61, produced cytolethal distending toxin (CLDT) and possessed the eae gene sequence. The consistent recovery of organisms producing CLDT and possessing the eae gene suggests that these organisms may have played a significant role in the finch mortalities.

Adhesins, Bacterial↗
PubMed1998

Cardiovascular disease risk factors are lower in African-American vegans compared to lacto-ovo-vegetarians.

OBJECTIVE: This study was undertaken to determine if African-American strict vegetarians (vegans) exhibit lower blood pressure (BP) and a more favorable serum lipid profile than their lacto-ovo vegetarian (LOV) counterparts, and if plasma ascorbic acid (AA) concentrations could explain any group differences in these cardiovascular disease (CVD) risk factors. METHODS: Habitual dietary intake, anthropometric characteristics, blood pressure, and blood lipids and ascorbic acid concentrations were determined in African-American study participants (male vegans, n = 14, age = 45.6 years; male LOV, n = 49, age = 49.8; female vegans, n = 31, age = 51.1, female LOV, n = 94, age = 52.1) recruited from Seventh-Day Adventist Churches in several cities in the northeastern United States. RESULTS: Body mass index (BMI) was significantly lower in the vegans (24.7 +/- 1.9 kg/m2) compared to LOV (26.4 +/- 0.45 kg/m2). There were no diet or gender differences in BP. Serum total cholesterol (3.75 +/- 0.12 vs. 4.51 +/- 0.10 mmol/L), LDL-cholesterol (2.06 +/- 0.13 vs. 2.65 +/- 0.09 mmol/l), and triglycerides (0.94 +/- 0.07 vs. 1.17 +/- 0.04 mmol/L) were significantly (p < 0.05) lower in vegans compared to LOV, but there were no dietary group differences in HDL-C. The ratio of total to HDL-cholesterol was significantly lower in vegans than in LOV (3.0 +/- 0.13 vs. 3.7 +/- 0.13). There were no dietary group differences in plasma AA concentrations. However, in the entire sample, plasma AA was inversely associated with BP (SBP: r = -0.46, p < 0.001, DBP: r = -0.32, p < 0.001), but unrelated to the serum lipid concentrations. CONCLUSION: African-American vegans exhibit a more favorable serum lipid profile than lacto-ovo-vegatarians and plasma AA is inversely related to BP in African-American vegetarians but does not explain any of the differences in CVD risk factors between vegans and lacto-ovo vegetarians.

Anthropometry↗
PubMed1998

Strategies for providing care and support to children orphaned by AIDS.

As a result of the severe HIV/AIDS epidemic in sub-Saharan countries such as Zimbabwe, where between 25-30% of the adult population are estimated to be infected, there are a growing number of orphans requiring care and support. Traditionally, orphans have been absorbed within the extended family but this is becoming more difficult because of the large number of young adults dying. The burden of care and support is falling on the very young and the very old. A number of strategies have been introduced to provide this care and support. Institutions, though popular, are very expensive to run, have limited capacity and only really cater for physical needs. Interventions which simply react to those who present to them may not reach the most needy and may encourage dependency. Community-based orphan care has been identified as the best and most cost-effective way of caring for orphans. An example of a community-based orphan visiting programme is presented. In the last six months of 1996, the FOCUS programme's 88 volunteers made a total of 9,634 visits to 3,192 orphans in 798 families at an average cost of US+1.55 per visit. The key elements of such programmes have been identified. They need to be implemented by a community-based organization (CBO) within a defined community. Volunteers should be selected from within the community. They need to be trained and supported as they enumerate orphans, identify the most needy and carry out regular visits. The volunteers should keep records of all their activities. These records can then be used as a basis for monitoring the programme. In order to cope with the increasing number of orphans in resource-poor settings like Zimbabwe, it is essential that such programmes be replicated and scaled up. This not only an economic necessity but is also a way of providing appropriate and effective services to those who need them.

Child↗
PubMed1998

Today's children--challenges to child health promotion in countries with severe AIDS epidemics.

Recent declines in infant and child mortality rates (IMR and CMR) are being reversed due to AIDS. Greatest impacts are in southern African countries with severe HIV epidemics and lower non-AIDS IMR/CMR. Zimbabwe and Zambia's IMR were estimated to be 40% and 30% higher in 1996; CMR by 2010 was projected to increase fourfold in Zimbabwe, threefold in Botswana and to double in Kenya and Zambia due to AIDS. HIV indirectly impacts children through orphanhood, TB and poverty. By 1996, life expectancy fell to 36 in Zambia, 42 in Zimbabwe and 40 in Uganda. One-third of children may become vulnerable after maternal orphanhood since elderly and juvenile caregivers are frequently uninformed about nutrition, oral rehydration, immunization and diagnosing serious illness. Resurgence of adult and paediatric TB affects children through increasing orphanhood and increased child mortality. AIDS-induced poverty among survivors leads to deterioration in children's health and increased vulnerability of adolescent survivors to HIV infection. The situation is set to worsen, especially in communities experiencing the cumulative impact of repeated parental deaths. Reducing the number and vulnerability of children and adolescents becoming HIV infected and increasing support to affected children are important strategies to improve child health in countries with severe epidemics.

AIDS-Related Opportunistic Infections↗
PubMed1998

Corynebacterium phocae sp. nov., isolated from the common seal (Phoca vitulina).

Phenotypic and phylogenetic studies were performed on four strains of a Gram-positive non-acid-fast coryneform-like organism isolated from the nasal cavities of common seals (Phoca vitulina). Chemotaxonomic investigations revealed the presence of corynomycolic acids in the unidentified isolates, which is consistent with corynebacteria. 16S rRNA gene sequence analysis demonstrated that the strains from seals represent a hitherto unknown subline within the genus Corynebacterium sensu stricto. Based on the results of the phylogenetic analysis and phenotypical criteria, it is proposed that the bacterium should be classified as a new species, Corynebacterium phocae. The type strain of Corynebacterium phocae is CCUG 38205T.

Animals↗
PubMed1998

Actinobacillus scotiae sp. nov., a new member of the family Pasteurellaceae Pohl (1979) 1981 isolated from porpoises (Phocoena phocoena).

Phenotypic and phylogenetic studies were performed on a Gram-negative, rod-shaped bacterium isolated from three porpoises. Biochemical and physiological studies indicated that the bacterium was related to the family Pasteurellaceae. Comparative 16S rRNA gene sequencing studies confirmed these findings and demonstrated that the bacterium represents a hitherto unknown subline. The nearest phylogenetic relative of the unknown bacterium was Actinobacillus delphinicola, an organism also originating from sea mammals, although a sequence divergence of 3% demonstrated that the newly isolated bacterium is a distinct species. On the basis of the results of the phylogenetic analysis and phenotypic criteria, it is proposed that the bacterium should be classified as a new species, Actinobacillus scotiae sp. nov. The type strain of Actinobacillus scotiae sp. nov. is NCTC 12922T (= M2000/95/1T).

Actinobacillus↗
PubMed1997

The characterisation of Brucella strains isolated from marine mammals.

Small Gram negative coccobacilli isolated from seals, porpoises, dolphins and from an otter road casualty were identified as Brucellae by their colonial and cell morphology, staining characteristics, biochemical activity, agglutination by monospecific antisera and susceptibility to lysis by Brucella specific bacteriophage. Their characterisation, including metabolic profiles, is described. These strains could not be assigned to recognised nomen species of the genus Brucella and it is suggested that they comprise a new nomen species to be called B. maris (sp. nov., type strain 2/94). It is further suggested the nomen species be subdivided into three biovars corresponding to their CO2 requirement, metabolic activity on galactose, dominant antigen and animal host.

Animals↗
PubMed1997

Identification of a subpopulation of human renal microvascular endothelial cells with capacity to form capillary-like cord and tube structures.

Endothelial specialization is a prominent feature within distinct capillary beds of organs such as mammalian kidney, yet immunological markers for functionally distinct subpopulations of cultured endothelial cells from tissue sources such as kidney have not been available. We developed a simple and reproducible isolation and culture procedure to recover human renal microvascular endothelial cells (HRMEC) from the cortex of unused donor kidneys. This procedure yields highly purified preparations of cells that display endothelial markers that include Factor VIII antigen, acetyl-LDL receptors, and determinants that bind Ulex europaeus lectin. HRMEC assemble into capillary-like cord and tube structures when plated on the surface of basement membrane-like matrix (BMM) in media containing phorbol myristate acetate. To further define subpopulations of HRMEC, we generated a panel of monoclonal antibodies and screened for those recognizing cell surface determinants. One monoclonal antibody recovery from this screen recognized a cell surface protein expressed on a subpopulation of HRMEC that we have designated PEC-1 (pioneer endothelial cell antigen-1). Cells expressing PEC-1 extended long, interconnecting filopodial processes in response to phorbol myristate acetate and assembled into capillary-like structures when plated on BMM. Anti-PEC-1 immunoprecipitated proteins of 25 and 27 kDa. Magnetic bead separation of PEC-1 (+) cells selected cells that assemble into capillary-like cord and tube structures. The remaining PEC-1 (-) HRMEC population formed matrix adherent patches. In the kidney, the PEC-1 determinant is expressed on a small subpopulation of microvascular glomerular cells and is prominently expressed on the apical membrane of proximal tubule cells. The PEC-1 determinant discriminates among subpopulations of HRMEC, identifying a subpopulation that contributes to assembly of capillary-like structures.

Adult↗
PubMed1997

Perceptions of children and community members concerning the circumstances of orphans in rural Zimbabwe.

Focus group discussions and interviews were held with 40 orphans, 25 caretakers and 33 other community workers from a rural area near Mutare, Zimbabwe. Orphan concerns included feeling different from other children, stress, stigmatization, exploitation, schooling, lack of visits and neglect of support responsibilities by relatives. Many community members, while recognizing their limitations due to poverty, were already actively helping orphans and caretakers. Extended family networks are the primary resource for orphans, though some relatives exploit orphans or fail to fulfil their responsibilities. Interventions are suggested which support community coping mechanisms by strengthening the capacities of families to care for orphans. Outside organizations can develop partnerships with community groups, helping them to respond to the impact of AIDS, by building upon existing concern for orphan families. They can help affected communities to develop orphan support activities which encourage caring responses by community leaders and relatives and which discourage property-grabbing and orphan neglect. Material support channelled through community groups to destitute families at critical times can strengthen family coping mechanisms. Income-generating activities should build upon communities' existing capabilities and benefit the most vulnerable orphan households. Some communities are responding to the AIDS disaster by adaptations to cope with devastating changes taking place in their communities.

Acquired Immunodeficiency Syndrome↗