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Biomedical subjects

T Rice

Publications and source records attributed to T Rice.

At least 91 records · Page 5Linked to original sources
PubMed1996

A comparison of the effect of universal use of gloves and gowns with that of glove use alone on acquisition of vancomycin-resistant enterococci in a medical intensive care unit.

OBJECTIVE: To determine the efficacy of the use of gloves and gowns compared with that of the use of gloves alone for the prevention of nosocomial transmission of vancomycin-resistant enterococci. DESIGN: Epidemiologic study and controlled, nonrandomized clinical trial. SETTING: University-affiliated, 900-bed, urban teaching hospital in which vancomycin-resistant enterococci are endemic. PATIENTS: 181 consecutive patients admitted to the medical intensive care unit for 48 hours or more. INTERVENTION: It was determined that all hospital employees would always use gloves and gowns when attending 8 particular beds in the medical intensive care unit and would always use gloves alone when attending 8 others. Compliance with precautions was monitored weekly. Rectal surveillance cultures were taken from patients daily. Cultures of environmental surfaces, such as those of bed rails, bedside tables, and other frequently touched objects in patient rooms and common areas, were taken monthly. Pulsed-field gel electrophoresis was used for molecular epidemiologic typing of vancomycin-resistant enterococci. MEASUREMENTS: The number of patients becoming colonized by vancomycin-resistant enterococci; the number of days to acquisition of vancomycin-resistant enterococci; and other measurements, including nosocomial infections, length of hospital stay, and mortality rates. RESULTS: The 93 patients in glove-and-gown rooms and the 88 patients in glove-only rooms had similar demographic and clinical characteristics. Fifteen (16.1%) patients in the glove-and-gown group and 13 (14.8%) in the glove-only group had vancomycin-resistant enterococci on admission to the medical intensive care unit. Twenty-four (25.8%) patients in the glove-and-gown group and 21 (23.9%) in the glove-only group acquired vancomycin-resistant enterococci in the medical intensive care unit. The mean times to colonization among the patients who became colonized were 8.0 days in the glove-and-gown group and 7.1 days in the glove-only group. None of these comparisons were statistically significant. Risk factors for acquisition of vancomycin-resistant enterococci induced length of stay in the medical intensive care unit, use of enteral feeding, and use of sucralfate. Compliance with precautions was 79% in glove-and-gown rooms and 62% in glove-only rooms (P < 0.001). Only 25 of 397 (6.3%) environmental cultures were positive for vancomycin-resistant enterococci. Nineteen types of vancomycin-resistant enterococci were documented by pulsed-field gel electrophoresis during the study period. CONCLUSIONS: Universal use of gloves and gowns was no better than universal use of gloves only in preventing rectal colonization by vancomycin-resistant enterococci in a medical intensive care unit of a hospital in which vancomycin-resistant enterococci are endemic. Because the use of gowns and gloves together may be associated with better compliance and may help prevent transmission of other infectious agents, this finding may not be applicable to outbreaks caused by single strains or hospitals in which the prevalence of vancomycin-resistant enterococci is low.

Adult↗
PubMed1996

A major gene for resting metabolic rate unassociated with body composition: results from the Québec Family Study.

A major gene hypothesis for resting metabolic rate (RMR) was investigated using segregation analysis (POINTER) of data on families participating in Phase 2 of the Québec Family Study. Complete analyses were conducted on RMR adjusted for age, and also on RMR adjusted for age and other covariates, primarily fat mass (FM) and fat-free mass (FFM). Prior to adjustment for covariates, support for a major gene hypothesis was equivocal-i.e., there was evidence for either a major gene or a multifactorial component (i.e., polygenic and/or familial environment). The multifactorial model was preferred over the major gene model, although the latter did segregate according to Mendelian expectations. However, after the effects of FM and FFM were accounted for, a major gene effect was unambiguous and compelling. The putative locus accounted for 57% of the variance, affected 7% of the sample, and led to high values of RMR. The lack of a significant multifactorial effect suggested that the familial etiology of RMR adjusted for FM and FFM was likely to be entirely a function of the major locus. Comparing the RMR results from pre- and post-adjustment for FM and FFM suggests a plausible hypothesis. We know from earlier studies in this sample that there is a putative major gene for FM and a major non-Mendelian effect for FFM. The current study leads us to speculate that: (1) the gene(s) affecting body size and body composition also may have an effect on RMR, and further (2) removal of the effect of the major gene(s) for body size and composition allowed for detection of an additional major gene affecting only the RMR. Thus, RMR appears to be an oligogenic trait.

Adipose Tissue↗
PubMed1996

Genetic pleiotropy for resting metabolic rate with fat-free mass and fat mass: the Québec Family Study.

Shared genetic and familial environmental causes for the associations among resting metabolic rate (RMR), fat-free mass (FFM), and fat mass (FM) were investigated in families participating in phase 2 of the Québec Family Study. A multivariate familial correlation model assessing the pattern of significant cross-trait correlations between family members (e.g., RMR in parents with FFM in offspring) was used to infer the etiology of the associations. For each of FM and FFM with RMR, significant sibling, parent-offspring, and intraindividual cross-trait correlations suggests the associations are familial. Furthermore, the lack of significant spouse cross-trait correlations suggests that the familial aggregation is primarily genetic. Bivariate heritability estimates suggest that as much as 45% to 50% of the shared variance between FFM and RMR may be genetic, and as much as 28% to 34% for FM and RMR. This study supports the notion that the gene(s) affecting each of FFM and FM also influence the RMR. Moreover, the lack of any familial associations between FFM and FM suggests that the effects of each body size component on RMR are independent, i.e., more than one genetic source on the RMR-body size association. The possibility that RMR is an oligogenic trait (i.e., more than one underlying genetic etiology) should be further investigated using more complex multivariate segregation methods until specific genes can be tested.

Adipose Tissue↗
PubMed1996

Familial clustering of abdominal visceral fat and total fat mass: the Québec Family Study.

The evidence for common familial factors underlying total fat mass (estimated from underwater weighing) and abdominal visceral fat (assessed from CT scan) was examined in families participating in phase 2 of the Québec Family Study (QFS) using a bivariate familial correlation model. Previous QFS investigations suggest that both genetic (major and polygenic) and familial environmental factors influence each phenotype, accounting for between 55% to 71% of the phenotypic variance in fat mass, and between 55% to 72% for abdominal visceral fat. The current study suggests that the bivariate familial effect ranges from 29% to 50%. This pattern suggests that there may be common familial determinants for abdominal visceral fat and total fat mass, as well as additional familial factors which are specific to each. The relatively high spouse cross-trait correlations usually suggest that a large percent of the bivariate familial effect may be environmental in origin. However, if mating is not random, then the spouse resemblance may reflect either genetic or environmental causes, depending on the source [i.e., through similar genes or cohabitation (environmental) effects]. Finally, there are significant sex differences in the magnitude of the familial cross-trait correlations involving parents, but not offspring, suggesting complex generation (i.e., age) and sex effects. For example, genes may turn on or off as a function of age and sex, and/or there may be an accumulation over time of effects due to the environment which may vary by sex. Whether the common familial factors are genetic (major and/or polygenic), environmental, or some combination of both, and whether the familial expression depends on sex and/or age warrants further investigation using more complex models.

Abdomen↗
PubMed1996

Familial correlations in the Québec family study: cross-trait familial resemblance for body fat with plasma glucose and insulin.

This study represents one component in our investigation of the familial factors underlying the insulin resistance (or metabolic) syndrome involving obesity, hyperinsulinaemia, glucose intolerance, dyslipidaemia, and hypertension. Here we examine the cross-trait familial resemblance between four measures of body size (two assessing total fat [body mass index and sum of six skinfolds] and two assessing fat patterning [ratio of trunk skinfold sum to extremity skinfold sum, adjusted and unadjusted for total subcutaneous fat]) with fasting plasma levels of glucose, insulin, and the ratio of insulin to glucose (IGR) in non-diabetic families participating in phase 1 of the Québec Family Study. A bivariate familial correlation model assessed both intraindividual (e.g. father's body size with father's insulin) and interindividual (e.g. father's body size with son's insulin) cross-trait associations. Intraindividual correlations suggested a greater degree of cross-trait associations for body fat (rather than fat distribution) measures with insulin and the IGR (rather than with glucose) levels. While the intraindividual correlations were significant for most cross-trait comparisons, only the sum of six skinfolds evidenced any familial association (i.e. interindividual resemblance) with insulin and the IGR. Specifically, cross-trait parent-offspring (but not sibling or spouse) correlations were significant, with a bivariate familiality estimate (i.e. polygenic and/or common familial environment) of about 8%. While the lack of sibling correlations does not suggest a simple familial hypothesis, a more complex genetic effect underlying the common covariation between total body fat with insulin and IGR cannot be ruled out.

Adolescent↗
PubMed1996

Familial aggregation of abdominal visceral fat level: results from the Quebec family study.

The purpose of this study was to investigate the importance of familial aggregation in abdominal visceral fat (AVF) level as assessed by computed tomography (CT). Four measures of abdominal adipose tissue, obtained from an abdominal scan between the fourth and fifth Lumbar vertebrae (L4-L5) taken in 366 adult subjects from 100 French-Canadian nuclear families, were considered in this study. Total abdominal fat, AVF, subcutaneous abdominal fat, obtained by computing the difference between total and AVF tissue areas, and the visceral to total abdominal fat ratio were measured. Spouses, parent-offspring, and sibling correlations were computed by maximum likelihood methods after adjustment of the four phenotypes for age and for age and total fat mass (FM) derived from underwater weighing. Significant familial aggregation was found for all phenotypes, whether adjusted or not for body FM. However, after adjustment of data for body FM, in addition to age, all spouse correlations became nonsignificant, suggesting that the familial aggregation of abdominal fat is primarily genetic. Heritability estimates reached 42% and 56% for subcutaneous fat and AVF, respectively. These results suggest that genetic factors are major determinants of the familial aggregation observed in the amount of abdominal fat, irrespective of total body fat content, and that AVF seems more influenced by genetic factors than abdominal subcutaneous adipose tissue. These findings imply that some individuals are more at risk than others to exhibit the various metabolic complications associated with upper-body obesity because of their inherited tendency to store abdominal fat in the visceral depot rather than in the subcutaneous depot.

Abdomen↗
PubMed1996

Do physicians cost shift?

This study analyzes whether physicians charge their privately insured patients more-a practice known as cost shifting-in response to Medicare payment reductions. As part of congressional legislation in 1989 and 1990, Medicare reduced its payment rates for selected procedures by as much as 30 percent. Here we examine whether reductions in Medicare rates increase how much physicians charge privately insured patients. Our data provide no evidence that physicians respond to Medicare payment reductions by shifting costs to their privately insured patients.

Aged↗
PubMed1996

In rats, atrial natriuretic peptide secretion is regulated differently in the right and left atria.

Recent studies have suggested the secretion of Atrial Natriuretic Peptide (ANP) is regulated by receptor mediated activation of protein kinase C, which causes the autocrine release of prostaglandins. Prostaglandins stimulate ANP secretion via the adenylate cyclase second messenger system. This report examined the response of right and left atrial ANP secreting cells to the three endothelin isopeptides and to cyclooxygenase inhibition. Our results show that right atrial ANP secretion is stimulated by endothelin 1 and 2 but not 3. In addition, right atrial ANP secretion is reduced by inhibition of cyclooxygenase. In contrast, left atrial ANP secretion is stimulated by endothelin 2 and 3 but not 1. Inhibition of cyclooxygenase did not affect left atrial ANP secretion. These results show the regulation of ANP secretion is different between the two atrial chambers. Right atrial cells appear to contain the prostaglandin-mediated response to protein-kinase C activation, whereas left atrial cells regulate ANP secretion differently.

Animals↗
PubMed1996

Medigap reform legislation of 1990: have the objectives been met?

The 1990 medigap reform legislation had multiple objectives: To simplify the insurance market in order to facilitate policy comparison, provide consumer choice, provide market stability, promote competition, and avoid adverse selection. Based on case study interviews with a cross-section of individuals and organizations, we report that most of these objectives have been achieved. Consumers of medigap plans are able to make more informed choices, largely because they can adequately compare policies based on standard benefits. Marketing abuses have apparently declined, as evidenced by a decrease in the number of consumer complaints. Finally, no major detrimental impact on the insurance industry was detected. Beneficiaries still face some confusion in this market, however, such as understanding the rating methodologies used to set premiums and how this may affect their choices. Confusion could increase with the growth of managed care options.

Aged↗
PubMed1996

Major gene for abdominal visceral fat area in the Québec Family Study.

OBJECTIVES: The abdominal visceral fat depot is considered to be the most atherogenic, diabetogenic and hypertensiogenic fat depot of the human body. Although the amount of abdominal visceral fat is correlated with total body fat, there remain considerable inter-individual differences in visceral fat at any level of body fat content. No study has been reported to date on the contribution of genetic factors to the variability in abdominal visceral fat level. DESIGN: Abdominal visceral fat area was assessed by computerized tomography in 382 adult men and women from 100 families of the Québec Family Study. After adjustment for the effects of age and age plus total fat mass (assessed by underwater weighing), a major gene hypothesis for abdominal visceral fat area was investigated using segregation (POINTER) analyses. RESULTS: Segregation analysis of the age-adjusted variable indicated that variability in visceral fat area was accounted for by a major gene transmitted according to Mendelian expectations. Data support an autosomal recessive locus, associated with high levels of abdominal visceral fat, accounting for 51% of the phenotypic variance and affecting 10% of the sample. An additional 21% of the variance was due to multifactorial (polygenic and/or familial environment) sources. However, after adjusting for total fat mass, support for a major gene for abdominal visceral fat was less strong. CONCLUSIONS: These results suggest that the familial etiology of abdominal visceral fat level involves a major autosomal recessive locus. Given the critical role of abdominal visceral fat in the metabolic complications of obesity, it will now be important to identify the gene responsible for the high levels of abdominal visceral fat observed in some adults and to investigate whether this gene is the same as that which influences total body fat content.

Abdomen↗
PubMed1996

Resistance to interleukin 6 in human non-small cell lung carcinoma cell lines: role of receptor components.

The role of interleukin 6 (IL-6) in regulating the growth of three human non-small cell lung carcinoma (NSCLC) cell lines (NSCLC-3, NSCLC-5, and NSCLC-7, derived from a primary lesion, a brain lesion, and lymph node metastases, respectively) was examined. Although IL-6 alone did not alter the growth of these cells, the addition of soluble IL-6 receptor (sIL-6R) led to the inhibition of proliferation of one of the NSCLC cell lines, NSCLC-5. This antiproliferative effect was neutralized by antibodies to IL-6 and the IL-6R binding and signaling component (gp130). The IL-6-related cytokines, leukemia inhibitory factor and oncostatin M, inhibited proliferation of NSCLC-5 cells but were ineffective in NSCLC-3 and NSCLC-7 cells. NSCLC-7 cells (but not NSCLC-3 or NSCLC-5 cells) secreted biologically active IL-6 and expressed IL-6R. However, antibodies to IL-6 or gp130 failed to alter the proliferation of NSCLC-7 cells. All three cell lines expressed gp130 mRNA and protein. The level of expression of gp130 protein varied in the three cell lines (NSCLC-7 > NSCLC-3 > NSCLC-5). The examination of tyrosine phosphorylation of gp130 (as an early event in IL-6 signal transduction) revealed that gp130 could be phosphorylated in all cell lines after stimulation with IL-6 and/or IL-6 + sIL-6R. These results demonstrate that the mechanisms responsible for IL-6 resistance in different NSCLC cell lines vary and involve defects at either one or more levels of the IL-6 signaling cascade. In the NSCLC-5 cell line, IL-6 resistance (which can be reversed in the presence of sIL-6R) is due to the transcriptional inactivation of the IL-6R gene. In contrast, in the other two cell lines (NSCLC-3 and NSCLC-7), defect(s) in the signaling cascade downstream of gp130 phosphorylation, together with a lack of expression of IL-6R in NSCLC-3 cells, result in IL-6 resistance.

Antigens, CD↗
PubMed1995

Major gene influence on the propensity to store fat in trunk versus extremity depots: evidence from the Québec Family Study.

Regional fat distribution is related to higher risks of cardiovascular morbidity and mortality, independent of general obesity. In particular, a centralized pattern of fat deposition, characterized by greater abdominal stores relative to extremity stores, is associated with a higher propensity to metabolic complications. Motivated by these considerations, we have initiated a systematic investigation of several measures of regional fat distribution aimed at the identification of possible major gene effects. Two measures approximate the size of subcutaneous fat stores: the sum of six skinfold thicknesses (SF6 = abdominal + suprailiac + subscapular + calf + triceps + biceps), and the sum of three trunk skinfold thicknesses (TSF3 = abdominal + suprailiac + subscapular). Both of these phenotypes are highly correlated with total fat mass, 0.83 and 0.78 for SF6 and TSF3, respectively. The trunk to extremity ratio [TER = TSF3/ (calf + triceps + biceps)] is perhaps the most important of these phenotypes insofar as it is an index of centralized obesity; it is modestly correlated with fat mass (r = 0.18). Each of these phenotypes was adjusted for total fat mass by regression prior to analysis so that we could examine genetic effects on these measures of regional fat distribution without the confounding influence of the determinants of fat mass itself. Segregation analysis of SF6 and TSF3 controlled for total fat mass suggests the presence of a major effect underlying the observed phenotypic distribution; however, tests on the transmission probabilities did not substantiate the segregation of a Mendelian gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1995

Medigap regulation: lessons for health care reform.

Congress enacted legislation in 1990 that dramatically changed the rules for selling supplemental health insurance, or "Medigap" policies, to the elderly. Most notably, policy coverage was standardized. Insurance carriers are allowed to sell only the ten specified packages of benefits, which reduces consumer choice but facilitates comparison shopping. This legislation is important in its own right and also offers lessons for U.S. health care reform. To examine the changes brought about by this legislation and analyze their implications for health care reform, we conducted site visits to nine states and interviewed insurer representatives, executive branch officials, congressional staff, and various interest groups for two years.

Aged↗
PubMed1995

Balance billing under Medicare: protecting beneficiaries and preserving physician participation.

Medicare's experience with balance billing provides valuable lessons for policy making for national or state health care reform. Medicare developed several policies to encourage physicians to become participating providers who accept Medicare-allowed charges as payment in full. Only nonparticipating physicians are permitted to bill for additional amounts beyond that paid by Medicare, and there are limits on the amount of balance billing per claim. As shown by the analysis of claims presented in this article, Medicare has successfully provided financial protection to beneficiaries. In 1986, more than 60 percent of expenditures for physician services were on assigned claims for which there could be no balance billing; by 1990, 80 percent of expenditures were on assigned claims. Balance billing decreased by about 30 percent during the same period. Although these policies have been successful in reducing total expenditures for balance billing, they may not provide financial protection to the most economically vulnerable beneficiaries. Using survey and claims data, we found that the poor have lower balance billing expenditures for services provided by primary care physicians, but that there is no relationship between poverty status and balance billing expenditures for services of nonprimary care physicians. In addition, most low-income beneficiaries are liable for balance bills. Under health care reform, adoption of Medicare's incentive-based approach with mandatory assignment for the poor would allow for some choice based on price and would provide financial protection for all consumers.

Aged↗
PubMed1995

Can regulation improve long-term care insurance? Lessons from the Medigap experience.

This article uses recent experiences from the Medigap market to draw conclusions about the advisability of alternative methods of regulating the market for long-term care insurance. The analysis is based in part on interviews of state insurance regulators, insurance companies, and interest-group representatives. The authors conclude that some regulation of the market is appropriate, but that the structure and extent of regulation found in the Medigap market would likely be inappropriate for the long-term care insurance market at this time.

Aged↗
PubMed1995

Familial clustering of multiple measures of adiposity and fat distribution in the Québec Family Study: a trivariate analysis of percent body fat, body mass index, and trunk-to-extremity skinfold ratio.

OBJECTIVE: To assess whether independent or common (pleiotropic) familial factors (i.e., genetic and/or common environment) underlie the observed associations among measures of body mass, body fat, and its distribution. DESIGN: A familial correlation model involves both parents and offspring, and gives rise to three types of familial correlations (spouse, parent-offspring, and sibling). A pattern of significant familial correlations suggests that the trait is determined by familial factors (i.e., genetic and/or environmental heritability). Cross-trait familial correlations are also estimated, both within individuals (intraindividual) and between family members (interindividual). Interindividual cross-trait familial correlations (e.g., trait 1 in parents with trait 2 in offspring) lead to the same type of familial inferences regarding bivariate heritabilities. SUBJECTS AND MEASURES: Measures of total body fat (% body fat-%BF), fat distribution (trunk/extremity skinfold ratio-TER), and body mass index (BMI) were assessed in 1239 individuals from 309 nuclear families participating the Québec Family Study. RESULTS: All three adiposity measures are cross-correlated within individuals. However, interindividual cross-trait correlations, which alone are capable of suggesting common familial determinants, are significant only for BMI with each of %BF and TER (bivariate heritabilities of 10% and 18%, respectively), and not for %BF and TER. CONCLUSION: Although all three adiposity measures are correlated within individuals, there appear to be entirely different underlying genes and/or environmental factors influencing the adiposity phenotypes of total body fat and fat distribution. The BMI, however, apparently shares some familial determinants with both total body fat and fat distribution.

Adolescent↗