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Biomedical subjects

V George

Publications and source records attributed to V George.

At least 37 records · Page 2Linked to original sources

The Women's Health Trial Feasibility Study in Minority Populations: changes in dietary intakes.

This randomized clinical trial examined the feasibility of low-fat dietary interventions among postmenopausal women of diverse backgrounds. During 1992-1994, 2,208 women aged 50-79 years, 28% of whom were black and 16% Hispanic, enrolled at clinics in Atlanta, Georgia, Birmingham, Alabama, and Miami, Florida. Intervention/support groups met periodically with a nutritionist to reduce fat intake to 20% of energy and to make other diet modifications. At 6 months postrandomization, the intervention group reduced fat intake from 39.7% of energy at baseline to 26.4%, a reduction of 13.3% of energy, compared with 2.3% among controls. Saturated fatty acid and cholesterol intakes were reduced, but intakes of fruits and vegetables, but not grain products, increased. Similar effects were observed at 12 and 18 months. Black and non-Hispanic white women had similar levels of reduction in fat, but the decrease in Hispanic women was less. Changes did not vary significantly by education. While bias in self-reported intakes may have resulted in somewhat overestimated changes in fat intake, the reported reduction was similar to the approximately 10% of energy decrease found in most trials and suggests that large changes in fat consumption can be attained in diverse study populations and in many subgroups.

Aged↗

Linkage and association analyses of alcoholism using a regression-based transmission/disequilibrium test.

Recently, George et al. proposed a regression-based transmission/disequilibrium test for linkage using information on the parent-to-offspring transmission status of an allele at a marker locus. We extended this test by simultaneously testing for any population association by incorporating the presence/absence status of the associated allele as a covariate in the model. We used this method to analyze markers on chromosomes 1 through 21 of the Collaborative Study on the Genetics of Alcoholism data on alcoholism for possible association and linkage. We found nominal significance (at the 0.02 level) at eight different regions for linkage, though statistical significance may not be concluded due to multiple testing. The strongest evidence of linkage was observed for markers D4S2639 and D12S397 with p-values less than 0.005. We also found strong association between the trait and alleles 149 of D7S691 and 131 of D21S1437.

Age Factors↗

Association and linkage analysis of ICD-10 diagnosis for alcoholism.

We analyzed the GAW11 data on alcoholism provided by the Collaborative Study on the Genetics of Alcoholism (COGA) using an extension of a new test of linkage and association for quantitative traits developed by George et al. [1999]. This method determines linkage between marker loci and quantitative traits, when allelic association is present between the trait and marker loci, by regressing the disease trait on the parental transmission of the allele of interest. We found no strong evidence of linkage to any markers. However, we found several markers suggestive of possible linkage that may deserve further investigation.

Alcoholism↗

A test of transmission/disequilibrium for quantitative traits in pedigree data, by multiple regression.

The transmission/disequilibrium (TD) test (TDT), proposed, by Spielman et al., for binary traits is a powerful method for detection of linkage between a marker locus and a disease locus, in the presence of allelic association. As a test for linkage disequilibrium, the TDT makes the assumption that any allelic association present is due to linkage. Allison proposed a series of TD-type tests for quantitative traits and calculated their power, assuming that the marker locus is the disease locus. All these tests assume that the observations are independent, and therefore they are applicable, as a test for linkage, only for nuclear-family data. In this report, we propose a regression-based TD-type test for linkage between a marker locus and a quantitative trait locus, using information on the parent-to-offspring transmission status of the associated allele at the marker locus. This method does not require independence of observations, thus allowing for analysis of pedigree data as well, and allows adjustment for covariates. We investigate the statistical power and validity of the test by simulating markers at various recombination fractions from the disease locus.

Computer Simulation↗

The awesome Asthma School Days Program: educating children, inspiring a community.

Program planners developed an educational program to improve the health of children with asthma in grades three to five in Milwaukee (Wis.) Public Schools. During 1997-1998, 1,400 students from 74 elementary schools participated in the Awesome Asthma School Days education program. In a cross-sectional survey, about 40% of children reported play interrupted and sleep disturbed by asthma, more than 50% of children reported exposure to smoke in their home, most children lacked asthma self-care tools, and most children with persistent symptoms did not use an anti-inflammatory inhaler. The educational program improved students' expectations about normal play and sleep and improved their understanding of asthma. Leaders in Milwaukee used the survey results to develop a community action plan. The educational program, surveys, community partnerships, and strategic plans can be replicated in other schools.

Adult↗

Prostate-specific antigen expression and lipochrome pigment granules in the differential diagnosis of prostatic adenocarcinoma versus seminal vesicle-ejaculatory duct epithelium.

BACKGROUND: Lipochrome pigment granules (LPGs) and prostate-specific antigen (PSA) localization have been cited as helpful adjuncts in differentiating atypical histologic patterns of seminal vesicle-ejaculatory duct (SVED) from prostatic adenocarcinoma. However, LPGs have been described in both benign and neoplastic prostatic acini, and PSA expression within the intraprostatic SVED has not been fully explored. DESIGN: Fifty radical prostatectomy specimens were studied for LPGs and 9 cases for PSA expression. RESULTS: Two morphologic types of LPGs (type 1 and type 2) were observed. The reproducibility in classifying LPGs was evaluated by kappa statistics, which demonstrated a strong agreement between 4 observers. Type 1 was restricted to SVED in all 50 specimens. Type 2 was subclassified into 2A and 2B. Type 2 LPGs were observed in prostatic acini of different zones, high-grade prostatic intraepithelial neoplasia, prostatic adenocarcinoma, and occasionally with type 1 LPG in SVED. Focal reactivity for PSA in the distal portion of SVED near urethra was noted in 1 of 9 cases. CONCLUSION: Awareness about morphologic differences between the 2 types of LPGs could help to avoid a potential diagnostic pitfall of misinterpreting SVED epithelium for adenocarcinoma. Caution is recommended in interpreting PSA expression, since rare focal PSA reactivity was observed in the distal SVED.

Adenocarcinoma↗

Acinetobacter meningitis following head trauma.

A case of acinetobacter meningitis following head injury in a patient who developed cerebrospinal fluid otorrhea, and did not have any neurosurgical procedure, is presented. Previously reported cases are cited, with a review of the literature. Pefloxacin monotherapy is associated with a poor clinical response.

Acinetobacter Infections↗

Recruitment strategies in the women's health trial: feasibility study in minority populations. WHT:FSMP Investigators Group. Women's Health Trial:Feasibility Study in Minority Populations.

The Women's Health Trial:Feasibility Study in Minority Populations (WHT:FSMP) examined the feasibility of recruiting postmenopausal women from a broad range of racial and socioeconomic backgrounds into a primary prevention trial requiring marked reductions in dietary fat. Postmenopausal women aged 50-79 yr who had no history of cardiovascular disease or cancer and who consumed 36% or more total energy from fat qualified to participate. We randomized the women into dietary intervention (60%) or control (40%) groups; we aimed to randomize 750 women in 18 months in each of the three clinical centers. All centers achieved goals for randomization based on ethnicity, and two centers exceeded overall recruitment goals. The greatest source of randomized participants was mass mailing, followed by items in the media, referrals, and community outreach. Recruitment yields were generally similar for the ethnic groups but lower for less-educated participants. The experience of WHT:FSMP indicates that postmenopausal women from the African-American, Hispanic, and non-Hispanic white communities can be recruited into dietary intervention studies for the prevention of disease.

Black or African American↗

Ethnomedical information and in vitro screening for angiotensin-converting enzyme inhibition of plants utilized as traditional medicines in Gujarat, Rajasthan and Kerala (India).

Plants utilized as traditional medicines in India have been investigated for their ability to inhibit the angiotensin converting enzyme (ACE). In total, 75 species belonging to 42 families have been investigated and new ethnomedical information has been obtained for 41 species. Four species were found to possess a high ACE inhibiting ability and were low in their tannin content.

Angiotensin-Converting Enzyme Inhibitors↗

Angiotensin converting enzyme (ACE) inhibitors from Jasminum azoricum and Jasminum grandiflorum.

Bioactivity-guided fractionation of extracts of the aerial parts of Jasminum azoricum var. travancorense, using an in vitro ACE inhibition assay, led to isolation of three oligomeric, iridoid-type compounds, which were named sambacein I-III. Their structures are based on spectroscopic and chemical evidence. Similarly, fractionation of extracts of aerial parts of J. grandiflorum resulted in the isolation of the previously reported ACE inhibitor, oleacein. The IC50 values of purified ACE inhibitors were 26-36 microM. Moreover, 2-(3,4-dihydroxyphenyl)-ethanol, isoquercitrin and ursolic acid were isolated from J. grandiflorum. Sambaceins and oleacein are formed from genuine iridoid glucosides during processing of the plant material. NMR spectroscopy was used to measure the level of the ACE inhibitors in the traditional medicines prepared in Kerala from these Jasminum species.

Angiotensin-Converting Enzyme Inhibitors↗

Brain abscess as the presenting feature of melioidosis.

Central nervous system involvement in melioidosis is rare and there are only a few reports of the causative organism, Burkholderia pseudomallei, causing a brain abscess. We report a patient who presented to us with a brain abscess due to this organism and emphasize the need for a high degree of suspicion for this disease in tropical countries and treatment with the appropriate antibiotics, as the mortality associated with this disease is very high.

Adult↗

Charges for childhood asthma by hospital characteristics.

BACKGROUND: The ownership, location, and teaching status of hospitals affect their missions, policies, finances, and operations. OBJECTIVE: This study assesses the relationship of hospital ownership, location, and teaching status with charges and length of stay for children with asthma, the most common reason for pediatric admission after birth. METHODS: All 28 545 complete records of patients </=18 years of age with the principal diagnosis asthma in 1994 were extracted from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample, providing a stratified sample of 735 nonfederal, acute-care hospitals in 17 states. Multiple regression analysis on log transformed data was used to calculate mean total charges and average length of stay (ALOS) after adjusting for illness severity and mortality risk (four All Patient Refined-Diagnosis Related Group classes based on secondary diagnoses and procedures); payer (Medicaid, private, uninsured, other); patient age, sex, income (four categories based on ZIP code of residence); state; bed size (three categories varying by location); hospital ownership; location; teaching status; and admission month. RESULTS: Asthma severity did not differ significantly by hospital location or teaching status. Nonprofit hospitals treated a slightly higher proportion of children with major or extreme severity asthma than either public or for-profit hospitals. Urban teaching hospitals treated more children with asthma who lived in low-income neighborhoods, were uninsured, or received Medicaid coverage than urban nonteaching hospitals. For-profit hospitals admitted fewer children with asthma from low-income areas than did public hospitals. The ALOS was 2.5 days and did not differ significantly by hospital ownership, location, or teaching status. However, the mean total charges, after adjusting for all other significant covariates, was higher at for-profit ($4203) than at nonprofit ($3640) or public hospitals ($3620). Average charges also were higher at urban teaching ($4230) and lower at rural institutions ($2910) compared with urban nonteaching hospitals ($3424). CONCLUSIONS: Despite similar ALOS, mean charges for childhood asthma varied significantly by hospital ownership, location, and teaching status. Implications. Additional clinical and outpatient data are needed to study variations in quality of care by hospital characteristics. With the proliferation of investor-owned hospitals, both the reasons for and the impact of higher average charges at for-profit institutions require additional investigation. With the expanding needs of the medically underserved, socially just policies are required for financing hospitals that care for a disproportionate share of economically disadvantaged children.

Adolescent↗

Health at work in the general practice.

BACKGROUND: Poor mental health and high stress levels have been reported in staff working in general practice. Little is known about how practices are tackling these and other issues of health at work in the absence of an established occupational healthcare service. AIM: To establish the extent of knowledge and good practice of health at work policies for staff working in general practice. METHOD: Practice managers in 450 randomly selected general practices in England were interviewed by telephone, and the general practitioner (GP) with lead responsibility for workplace health in the same practice was surveyed by postal questionnaire. We surveyed the existence and implementation of practice policies, causes and effects of stress on practice staff, and agreement between practice managers and GPs on these issues. RESULTS: Seventy-one per cent of GPs and 76% of practice managers responded, with at least one reply from 408 (91%) practices and responses from both the practice manager and GPs from 252 (56%) practices. Seventy-nine per cent of practices had a policy on monitoring risks and hazards. The proportion of practices with other workplace health policies ranged from 21% (policy to minimize stress) to 91% (policy on staff smoking). There was a tendency for practices to have policies but not to implement them. The three causes of stress for practice staff most commonly cites by both GP and practice manager responders were 'patient demands', 'too much work', and 'patient abuse/aggression'. Sixty-five per cent of GPs felt that stress had caused mistakes in their practices. Although there was general agreement between the two groups, there was a considerable lack of agreement between responders working in the same practices. CONCLUSIONS: The study revealed substantial neglect of workplace health issues with many practices falling foul of health and safety legislation. This report should help general practices identify issues to tackle to improve their workplace health, and the Health at Work in the NHS project to focus on areas where their targeted help will be most worthwhile.

Family Practice↗

Effect of molecular weight on the diffusion of contrast media into cartilage.

STUDY DESIGN: A comparison of contrast enhancement in the intervertebral disc from two magnetic resonance imaging contrast media in experimental animals. OBJECTIVES: To test the effect of molecular weight on the diffusion of ionic contrast media into the intervertebral disc. SUMMARY OF BACKGROUND DATA: Intravenously administered gadopentetate diffuses similarly into the fibrocartilage of intervertebral discs and herniated disc fragments. Differentiation between recurrent disc fragments and scar tissue via magnetic resonance imaging is optimized by using contrast media, which result in different contrast enhancement of these two tissues. Contrast media of higher molecular weight diffuse more slowly into cartilage; hypothetically, therefore, such media will produce better contrast between scar tissue and recurrent disc fragments. METHODS: Gadopentetate (molecular weight 546) or gadolinium-polylysine (molecular weight 40,000) was injected intravenously into rabbits. The signal intensities of intervertebral disc and muscle tissue were recorded by magnetic resonance imaging at baseline and at pre-determined intervals for 2 hours after injection of the contrast medium. Contrast enhancement in these tissues was calculated in each animal for each contrast medium, and differences in enhancement were tested for significance by a growth-curve model. RESULTS: Contrast enhancement in the intervertebral disc was significantly less with gadolinium-polylysine than with gadopentetate. In muscle, no significant difference between the two media was observed. CONCLUSIONS: Molecular weight affects the diffusion of paramagnetic contrast media into the intervertebral disc. Contrast media of a high molecular weight may produce better contrast between recurrent herniated disc fragments and scar tissue than contrast media of lower molecular weight. This possibility should be rested in further studies.

Animals↗

Associations of race/ethnicity, education, and dietary intervention with the validity and reliability of a food frequency questionnaire: the Women's Health Trial Feasibility Study in Minority Populations.

This report describes the associations of race/ethnicity and years of education with the validity, reliability, and bias of a self-administered food frequency questionnaire (FFQ) designed to be sensitive to low-fat, regional, and ethnic dietary patterns. Data were from the Women's Health Trial Feasibility Study in Minority Populations, a randomized clinical trial conducted between 1992 and 1994 to test the feasibility of a low-fat dietary intervention that targeted low-income, black, and Hispanic women. Of 1,015 participants eligible for these analyses, 28.1% were black, 16.2% were Hispanic, and 12.3% had not completed high school. The analyses focused on percentage of energy obtained from fat, and used 4-day food records as the criterion instrument. Validity at baseline, defined as the correlation between FFQs and food records, was lower among blacks than among whites (0.26 vs. 0.49; p < 0.001), did not differ between Hispanics and whites, and was lower among women with fewer years of education (0.19, 0.35, 0.49, and 0.42 for <12, 12, 13-15, and > or =16 years of education, respectively; for trend, p < 0.05). Six months after randomization, validity increased in most race/ethnicity and education subgroups, and differences across groups became small and statistically nonsignificant. Validity increased significantly among participants receiving the dietary intervention, while increases among control women were somewhat smaller. Reliability, defined as the correlation between baseline and 6-month measures among controls, was similar across racial/ethnic and educational groups. Bias at baseline, defined as the mean value from the FFQ minus the mean from the food record, was 4.6 percentage points of energy from fat; it was lowest among blacks (p < 0.01) and did not differ by years of education. These results suggest that special protocols which address participant training may be necessary when using self-administered FFQs in minority or poorly educated populations.

Aged↗

Testing for treatment effect in the presence of regression toward the mean.

We are often faced with the statistical problem of evaluating the effect of a treatment in the extreme of a population. This requires taking measurements on truncated random variables and, hence, it becomes necessary to take proper account of the effect of regression toward the mean. The usual statistical procedures are inappropriate for testing treatment effect in the presence of regression toward the mean. Likelihood ratio and score tests based on truncated distributions should provide valid statistical inferences in these situations. We conducted simulation studies to investigate the properties of these methods and found that the likelihood ratio test performs well even when the sample size is moderate, whereas the score test does not seem to control the nominal significance level. We compared the likelihood ratio test to a regression-based t-test, assuming the mean of the baseline distribution to be known, and found the likelihood ratio test more powerful. In the case where the baseline mean is unknown, we also investigated Wald's test and compared it with the likelihood ratio test and score test with respect to validity and power using simulation. Wald's test and the score test do not control the nominal significance level unless the sample size is extremely large. Overall, the likelihood ratio test has the best performance among all the methods studied. The proposed likelihood ratio test is illustrated using an example of a cholesterol study.

Biometry↗