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Biomedical subjects

V George

Publications and source records attributed to V George.

At least 55 records · Page 3Linked to original sources
PubMed1996

The Women's Health Trial Feasibility Study in Minority Populations: design and baseline descriptions.

The Women's Health Trial: Feasibility Study in Minority Populations (WHT:FSMP), a randomized trial of 2208 women, was conducted to investigate three questions. First, can women from minority and low-socioeconomic-status populations be recruited in numbers sufficient to evaluate a dietary intervention designed to lower fat intake. Second, the efficacy of a low fat, increased fruit/vegetable/ grain product intervention for reducing fat consumption. Third, will participation in the intervention lower plasma cholesterol and estradiol levels relative to the controls. The baseline results showed that an adequate number of minority and low SES women could be recruited to test the study hypotheses. A diverse study population of postmenopausal women consuming a high fat diet was recruited: 28% of participants were Black, 16% were Hispanic, 11% had less than a high school level of education, and 15.5% had household incomes of < $15,000.

Aged↗
PubMed1996

CAMP test for the identification of Vibrio cholerae 0139.

The confirmation of the identity of Vibrio cholerae serogroup 01 and serogroup 0139 is usually done by slide agglutination tests using specific antisera. Antiserum to V. cholerae 01 is freely available but not antiserum to V. cholerae 0139, thus making specific identification of the latter more difficult. A modified CAMP (Christie Atkins and Muench - Paterson) test has been described as a possibility in the identification of V. cholerae 0139 and we have evaluated this on 197 strains of organisms including 48 V. cholerae 0139, 50 V. cholerae 01, 49 non-01, non-139 V. cholerae and 50 Aeromonas species. The test had a sensitivity of 98.9 per cent and a specificity of 92.9 per cent in the identification of these strains, when compared with faeces culture as the gold standard.

Agglutination Tests↗
PubMed1995

Statistical validity for testing associations between genetic markers and quantitative traits in family data.

In genetic analysis it is often of interest to analyze associations between traits of unknown genetic etiology and genetic markers from pedigree data. Statistical methods that assume independence of pedigree members cannot be used because they disregard the statistical dependencies of members in a pedigree. For quantitative traits, a regression model proposed by George and Elston [Genet Epidemiol 4:193-201, 1987] uses an asymptotic likelihood ratio test and incorporates a correlation structure that allows for statistical dependence among the pedigree members. The statistical validity of this test is assessed for finite samples by measuring the discrepancy between the empirical and theoretical chi-square distributions. The variance of the mean of the dependent variable is determined to be related to this discrepancy and can be used to determine whether a pedigree structure is large enough for making valid statistical inferences on the basis of the asymptotic test. A multi-generational pedigree of 200 or so individuals should in many cases be sufficient for valid results when using the asymptotic likelihood ratio test for the association between markers and continuous traits.

Family↗
PubMed1995

Heart Watch: national survey of continuous electrocardiographic monitoring in U.S. hospitals.

How is electrocardiographic monitoring being carried out in various settings? From results of a national survey, the authors describe unit characteristics and monitoring equipment and identify staff roles for carrying out related activities. Although much diversity was found, involvement in monitoring activities was highly consistent with the varying skill mixes in critical care, intermediate care, and "other" units responding. Data regarding the role of monitor technicians in this process raise questions about the viability of this role.

Allied Health Personnel↗
PubMed1994

Cardiac function in malnourished children.

The cardiovascular status of severely malnourished children was characterized before, during, and after nutritional rehabilitation. In most children with third-degree malnutrition, cardiac mass was decreased on admission to the hospital and recovered subsequent to nutritional therapy. All children had echocardiographic and Doppler measurements indicative of impaired ventricular function which significantly improved during the course of hospitalization, as evidenced in part by the change in fractional shortening (P = 0.015), mean velocity of circumferential fiber shortening (P = 0.038), and systolic time interval (P = 0.030). We conclude that children with primary third-degree malnutrition not only have cardiac muscle wasting, but also have inherent ventricular dysfunction as the result of severe malnutrition that responds to nutritional therapy. Particular care with fluid administration is imperative in the first week of therapy, when heart function is the most compromised.

Child, Preschool↗
PubMed1994

Identification of gram positive cocci isolated from urine.

A total of 195 strains of Gram positive cocci isolated from urine, in pure culture and in counts of > 10(3) colony forming units/ml, during January-September 1992, were speciated using schema recently described by Facklam and Washington, and Kloos and Lambe. Seventy three (85%) of the 86 enterococci were identified as Enterococcus faecalis while 11 (13%) were E. faecium. Eighteen (29%) of the 62 staphylococcal isolates were Staphylococcus aureus; 20 (45%) of the 44 coagulase negative staphylococci were speciated as Staph. haemolyticus. Of the 47 strains of beta haemolytic streptococci isolated, 45 (96%) were group B; one was group G and the other group F. Our results show the diverse species of Gram positive cocci associated with bacteriuria and the need to speciate them in a diagnostic laboratory. In the context of a larger number of tests required for the speciation of Gram positive cocci, we recommend a simplified scheme which we found feasible on a routine basis.

Gram-Positive Cocci↗
PubMed1993

Immunogold labelling of Listeria monocytogenes virulence-related factors within Caco-2 cells.

We demonstrated by immunoelectron microscopy that listeriolysin O (LLO), phospholipases and other putative virulence-related proteins produced by Listeria monocytogenes were primarily cell-wall-associated when the bacterium infected Caco-2 tissue culture cell monolayers. Antibodies made to LLO, serogroup 1/2a reacted poorly with serogroup 4b cells and vice-versa, indicating fundamental structural differences in the two proteins. Finally, comet-tail pseudopod structures shown to be involved in cell-to-cell passage of Listeria in Caco-2 cells did not possess detectable Listeria antigens on their anterior surface or within their structure, suggesting that the phagocytic process is primarily host-cell-dependent once it is initiated by the bacterial cell.

Antibodies, Bacterial↗
PubMed1993

Antigen presentation by a continuous human microvascular endothelial cell line, HMEC-1, to human T cells.

Endothelial cells line the vessels and lymphatics of the body, acting as a barrier between the blood and extravascular tissue. These cells are, therefore, in a prime position to play a role in lymphocyte activation. Indeed, it has been shown that primary endothelial cells in culture are capable of presenting particulate and soluble antigens to T cells and that this response is not dependent on macrophages. Recently, we developed an immortalized line of human microvascular endothelial cells, CDC/EU.HMEC-1 (HMEC-1). This endothelial line has the advantage not only of being devoid of contaminating cells but also of being a continuous cell line and therefore not subject to a restricted number of useful passages. The focus of this study was to determine whether HMEC-1 cells (like primary endothelial cells) could present antigen to T cells in the absence of macrophages. We demonstrate that a cloned and purified endothelial cell line can independently provide all the necessary signals for antigen-specific T-cell activation.

Antigen-Presenting Cells↗
PubMed1992

Viral susceptibility of an immortalized human microvascular endothelial cell line.

CDC/EU.HMEC-1 is the first immortalized human microvascular endothelial cell line that retains morphologic, phenotypic, and functional characteristics of a normal human microvascular endothelial cell. This study evaluates a variety of viruses and their effects on this human endothelial cell line. The data indicate that adenoviruses, some herpesviruses, reoviruses and most picornaviruses grow well in HMEC-1, with distinctive cytopathic effects. The paramyxoviruses, however, do not appear to propagate, nor does HIV. The findings indicate that microvascular endothelial cells may act as a reservoir of these viruses; it also suggests the possibility that microvascular endothelium could be involved in the processing and presentation of antigen to immune cells.

Adenoviridae↗
PubMed1991

Further evidence for the presence of "small eaters" and "large eaters" among women.

One hundred thirty-four women, aged 36 +/- 4 (mean +/- SD) y, BMI 20 +/- 3 kg/m2, perceiving themselves as having either a low or high energy intake (EI), participated in a study to determine variations in EI. Information on EI and activity level was obtained from repeated 7-d records. The 40 subjects with the lowest EI (in kcal/kg body wt) were categorized as small eaters (SEs); the 40 subjects with the highest EI were considered to be large eaters (LEs). The absolute (in kcal) and relative (in kcal/kg body wt) EIs of the SE and LE groups were 1488 +/- 312 and 27 +/- 4 for the SE group, respectively and 2393 +/- 509 and 47 +/- 6 for the LE group, respectively. There was no significant difference in activity level or fat-free mass (FFM) between the groups. However, LEs weighed significantly less (51 vs 55 kg) and were leaner (22% body fat vs 33%) than were SEs. Individuals with similar FFM and activity level can vary significantly in EI needs.

Adult↗
PubMed1991

Cytopathogenic effects in enterocytelike Caco-2 cells differentiate virulent from avirulent Listeria strains.

We have developed a simple test that differentiates between virulent and avirulent Listeria species as defined by the mouse 50% lethal doses (LD50S). The assay is based on trypan blue-revealed cytopathogenic effects that are produced during the infection of the human enterocytelike cell line Caco-2. These effects were elicited only by Listeria strains that had an intraperitoneal mouse LD50 less than 10(8) and were not produced by nonhemolytic, avirulent strains of Listeria monocytogenes generated spontaneously or by Tn916 mutagenesis or by avirulent Listeria species. A negative test was also obtained with hemolysin-producing, avirulent L. monocyotogenes NCTC5105 and Listeria ivanovii KC1786. The test was negative with avirulent L. monocytogenes strains which are strong inducers of opacity in egg yolk agar. However, a strain which has a low LD50, such as 10(4), may show less severe cytopathogenic effects than a strain having a higher LD50, such as 10(6). The test has been effectively used to screen for virulent listerial isolates, spontaneous mutants, and transposon-induced mutants.

Animals↗
PubMed1990

Nonhemolytic Listeria monocytogenes mutants that are also noninvasive for mammalian cells in culture: evidence for coordinate regulation of virulence.

We identified nonhemolytic mutants of Listeria monocytogenes that were severely deficient in their ability to invade mammalian nonprofessional phagocytes. These mutants were generated spontaneously or by means of transposon Tn916 mutagenesis. In terms of their extracellular proteins, the noninvasive mutants were deficient not only in the sulfhydryl-activated hemolysin (listeriolysin) but also in an antigenically unrelated extracellular protein with an apparent molecular weight of 32,000 which could induce opacity in egg yolk and is considered to be a phospholipase. Our results suggest the existence of a common genetic control between the expression of listeriolysin and that of other determinants, including a phospholipase and determinants involved in the ability of L. monocytogenes to enter mammalian cells.

Animals↗
PubMed1990

Effect of dietary fat content on total and regional adiposity in men and women.

The relationship between dietary fat intake, adiposity and regional subcutaneous fat distribution was studied in 344 men and 335 women (aged 35-55 years). Three-day food records were used to estimate total energy intake (EI) and percent intake of all macronutrients. Subjects were categorized as having an EI that was low (lower quantile) or high (upper quantile) in fat. Results showed that both men and women with a higher percent of EI in the form of fat weighed significantly (P less than 0.05) more, and had higher subcutaneous adiposity indices than subjects with a low fat intake. There was also a significant difference for both sexes between low and high fat intake groups in trunk and extremity skinfolds and trunk/extremity skinfolds ratio adjusted for the sum of skinfolds. However, this effect was not present when correlations between percent fat intake and body composition or regional fat distribution variables adjusted for total fat intake per unit of body mass were computed. These results suggest that a greater EI in the form of fat influences total adiposity, as well as regional subcutaneous fat distribution, only when high fat consumers are compared to low fat consumers.

Adipose Tissue↗
PubMed1989

Mammalian tissue culture growth, viral replication, and cultivation using serum replacement factor.

Variability, cost, and availability of fetal bovine serum are in question; thus, we examined whether using a serum replacement factor in multiple mammalian tissue cultures could support not only cell growth, but also viral replication, expression, and retention of phenotypic markers. By using a serum replacement in defined media, we demonstrated multipassage cell growth of several different cell lines and viral cultivation and replication equivalent to fetal bovine serum. Moreover, by supplementing media with a serum replacement factor we observed at least a 28% financial savings.

Animals↗
PubMed1989

Evidence for the existence of small eaters and large eaters of similar fat-free mass and activity level.

The objective of this study was to identify individuals of the same age, sex, activity level and fat-free mass who differed in their level of energy intake (EI). Estimates of energy intake and physical activity level were derived from three-day food and activity records from 430 individuals 17-54 years of age. Body composition was measured by underwater weighing and body fat and fat-free mass were obtained. Subjects were grouped into four categories based on age and sex (females aged 17-34 and 35-54 years and males aged 17-34 and 35-54 years). Subjects were identified as small eaters (SE) or large eaters (LE) according to kJ of EI per kg body weight, SE being from the lower quartile and LE from the upper quartile of their distributions. The results showed that, on average, LE consumed almost twice as many kJ per kg body weight as SE (about 200 versus 100). In addition middle-aged male and female SE were significantly (P less than 0.001) heavier than middle-aged male and female LE respectively. The mean body weight for the male SE was 82 +/- 12 kg (mean +/- s.d.) against 69 +/- 9 kg for the LE, while it was 66 +/- 10 kg against 52 +/- 5 kg for the female SE and LE. The male and female SE also had a significantly higher percentage body fat in both age groups. In general, there was no difference in fat-free mass and activity level between the SE and LE. It is concluded that there exist groups of individuals who have a considerable difference in their EI and adiposity even though they have similar levels of activity and fat-free mass.

Activities of Daily Living↗
PubMed1986

Characterization of a p43 human thymocyte antigen.

Two murine monoclonal antibodies (MoAbs), designated WM-25 and WM-35, have been prepared which react with human thymocyte cell surface membrane antigens. Both antigens were found to be expressed by normal and leukaemic immature human thymocytes. However, comparative examination by tissue section staining, immunoprecipitation, and electrophoresis, as well as competitive binding studies, demonstrated clear differences in the antigens detected by these two MoAbs. Antibody WM-35 identified a 48 kilodalton (kD) protein expressed on epidermal Langerhans cells as well as thymocytes, and appears similar to the previously reported Mabs OKT-6 and NA1-34. In contrast, MoAb WM-25 immunoprecipitated a 43 kD antigen, non-covalently associated with a 12 kD light chain, which was not present on Langerhans cells. Competitive binding and sequential immunoprecipitation studies confirmed that the 48 and 43 kD proteins are antigenically distinct. These results support the concept of at least two forms of thymocyte antigens within Cluster of Differentiation One (CD-1).

Adult↗