{\it In vivo\/} magnetic resonance studies of experimental liver disease: Carbon tetrachloride hepatotoxicity and alcohol-induced fatty liver in rat

Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) were used to non-invasively determine if cirrhosis induced by carbon tetrachloride (CCl$\sb4$) and phospholipase-D (PLD) could be distinguished from fatty infiltration in rat. MRS localization and water suppression methods were developed, implemented and evaluated in terms of their application to in vivo proton NMR studies of experimental liver disease. MRS studies were also performed to quantitate fatty infiltration resulting from carbon tetrachloride (CCl$\sb4$) or alcohol (ethanol) administration and the MRS results were confirmed using biochemical total lipid analysis and histology. $\rm T\sb1$ weighted MR images acquired weekly, 48 hours post administration, demonstrated only a slight increase in overall liver intensity with CCl$\sb4$ or alcohol administration, which is consistent with previously reported results. The MR images were able to detect nodules resulting from CCl$\sb4$+PLD induced cirrhosis as hypointense regions, also consistent with previous reports. Localized in vivo water and lipid proton $\rm T\sb1$ relaxation time measurements were performed and demonstrated no statistically significant trends for either agent. In vivo proton spectra were also acquired using stimulated echo techniques to quantitatively follow the changes in liver lipid content. The changes in liver lipid content observed using MRS were verified by total lipid analysis using the Folch technique and histology. The in vivo $\rm T\sb1$ and lipid quantification data str inconsistent with the previous hypothesis that the changes in $\rm T\sb1$ weighted images were the result of increased "free" water content and, therefore, increased water $\rm T\sb1$ relaxation times. These data indicate that the long term changes are more likely the result of changes in lipid content. The data are also shown to agree with the accepted hypothesis that the time course and mechanism of fatty infiltration are different for CCl$\sb4$ and alcohol. The hypothesis that the lipids resulting from either protocol are from the same lipid fraction(s), presumably triglycerides, is also supported. And lastly, on the basis of MR images and quantitative MRS lipid information, it was shown that cirrhosis could be distinguished from fatty infiltration. ^

A cladistic analysis of apolipoprotein B gene variation and plasma lipid and apolipoprotein B levels, using familial data

Any functionally important mutation is embedded in an evolutionary matrix of other mutations. Cladistic analysis, based on this, is a method of investigating gene effects using a haplotype phylogeny to define a set of tests which localize causal mutations to branches of the phylogeny. Previous implementations of cladistic analysis have not addressed the issue of analyzing data from related individuals, though in human studies, family data are usually needed to obtain unambiguous haplotypes. In this study, a method of cladistic analysis is described in which haplotype effects are parameterized in a linear model which accounts for familial correlations. The method was used to study the effect of apolipoprotein (Apo) B gene variation on total-, LDL-, and HDL-cholesterol, triglyceride, and Apo B levels in 121 French families. Five polymorphisms defined Apo B haplotypes: the signal peptide Insertion/deletion, Bsp 1286I, XbaI, MspI, and EcoRI. Eleven haplotypes were found, and a haplotype phylogeny was constructed and used to define a set of tests of haplotype effects on lipid and apo B levels.^ This new method of cladistic analysis, the parametric method, found significant effects for single haplotypes for all variables. For HDL-cholesterol, 3 clusters of evolutionarily-related haplotypes affecting levels were found. Haplotype effects accounted for about 10% of the genetic variance of triglyceride and HDL-cholesterol levels. The results of the parametric method were compared to those of a method of cladistic analysis based on permutational testing. The permutational method detected fewer haplotype effects, even when modified to account for correlations within families. Simulation studies exploring these differences found evidence of systematic errors in the permutational method due to the process by which haplotype groups were selected for testing.^ The applicability of cladistic analysis to human data was shown. The parametric method is suggested as an improvement over the permutational method. This study has identified candidate haplotypes for sequence comparisons in order to locate the functional mutations in the Apo B gene which may influence plasma lipid levels. ^

Functional analysis of anionic phospholipids in cell metabolism in {\it Escherichia coli\/}

The major goal of this work was to understand the function of anionic phospholipid in E. coli cell metabolism. One important finding from this work is the requirement of anionic phospholipid for the DnaA protein-dependent initiation of DNA replication. An rnhA mutation, which bypasses the need for the DnaA protein through induction of constitutive stable DNA replication, suppressed the growth arrest phenotype of a $pgsA$ mutant in which the synthesis of anionic phospholipid was blocked. The maintenance of plasmids dependent on an $oriC$ site for replication, and therefore DnaA protein, was also compromised under conditions of limiting anionic phospholipid synthesis. These results provide support for the involvement of anionic phospholipids in normal initiation of DNA replication at oriC in vivo by the DnaA protein. In addition, structural and functional requirements of two major anionic phospholipids, phosphatidylglycerol and cardiolipin, were examined. Introduction into cells of the ability to make phosphatidylinositol did not suppress the need for the naturally occurring phosphatidylglycerol. The requirement for phosphatidylglycerol was concluded to be more than maintenance of the proper membrane surface charge. Examination of the role of cardiolipin revealed its ability to replace the zwitterionic phospholipid, phosphatidylethanolamine, in maintaining an optimal membrane lipid organization. This work also reported the DNA sequence of the cls gene, which encodes the CL synthase responsible for the synthesis of cardiolipin. ^

A systematic review and meta-analysis of diabetes disease management programs

Context. Despite the rapid growth of disease management programs, there are still questions about their efficacy and effectiveness for improving patient outcomes and their ability to reduce costs associated with chronic disease. ^ Objective. To determine the effectiveness of disease management programs on improving the results of HbA1c tests, lipid profiles and systolic blood pressure (SBP) readings among diabetics. These three quantitative measures are widely accepted methods of determining the quality of a patient's diabetes management and the potential for future complications. ^ Data Sources. MEDLINE and CINAHL were searched from 1950 to June 2008 using MeSH terms designed to capture all relevant studies. Scopus pearling and hand searching were also done. Only English language articles were selected. ^ Study Selection. Titles and abstracts for the 2347 articles were screened against predetermined inclusion and exclusion criteria, yielding 217 articles for full screening. After full article screening, 29 studies were selected for inclusion in the review. ^ Data Extraction. From the selected studies, data extraction included sample size, mean change over baseline, and standard deviation for each control and experimental arm. ^ Results. The pooled results show a mean HbA1c reduction of 0.64%, 95% CI (-0.83 to -0.44), mean SBP reduction of 7.39 mmHg (95% CI to -11.58 to -3.2), mean total cholesterol reduction of 5.74 mg/dL (95% CI, -10.01 to -1.43), and mean LDL cholesterol reduction of 3.74 mg/dL (95% CI, -8.34 to 0.87). Results for HbA1c, SBP and total cholesterol were statistically significant, while the results for LDL cholesterol were not. ^ Conclusions. The findings suggest that disease management programs utilizing five hallmarks of care can be effective at improving intermediate outcomes among diabetics. However, given the significant heterogeneity present, there may be fundamental differences with respect to study-specific interventions and populations that render them inappropriate for meta-analysis. ^

Selection of body fat distribution indices in adults and associations with plasma lipid metabolism variables

Body fat distribution is a cardiovascular health risk factor in adults. Body fat distribution can be measured through various methods including anthropometry. It is not clear which anthropometric index is suitable for epidemiologic studies of fat distribution and cardiovascular disease. The purpose of the present study was to select a measure of body fat distribution from among a series of indices (those traditionally used in the literature and others constructed from the analysis) that is most highly correlated with lipid-related variables and is independent of overall fatness. Subjects were Mexican-American men and women (N = 1004) from a study of gallbladder disease in Starr County, Texas. Multivariate associations were sought between lipid profile measures (lipids, lipoproteins, and apolipoproteins) and two sets of anthropometric variables (4 circumferences and 6 skinfolds). This was done to assess the association between lipid-related measures and the two sets of anthropometric variables and guide the construction of indices.^ Two indices emerged from the analysis that seemed to be highly correlated with lipid profile measures independent of obesity. These indices are: 2*arm circumference-thigh skinfold in pre- and post-menopausal women and arm/thigh circumference ratio in men. Next, using the sum of all skinfolds to represent obesity and the selected body fat distribution indices, the following hypotheses were tested: (1) state of obesity and centrally/upper distributed body fat are equally predictive of lipids, lipoproteins and apolipoproteins, and (2) the correlation among the lipid-related measures is not altered by obesity and body fat distribution.^ With respect to the first hypothesis, the present study found that most lipids, lipoproteins and apolipoproteins were significantly associated with both overall fatness and anatomical location of body fat in both sex and menopausal groups. However, within men and post-menopausal women, certain lipid profile measures (triglyceride and HDLT among post-menopausal women and apos C-II, CIII, and E among men) had substantially higher correlation with body fat distribution as compared with overall fatness.^ With respect to the second hypothesis, both obesity and body fat distribution were found to alter the association among plasma lipid variables in men and women. There was a suggestion from the data that the pattern of correlations among men and post-menopausal women are more comparable. Among men correlations involving apo A-I, HDLT, and HDL$\sb2$ seemed greatly influenced by obesity, and A-II by fat distribution; among post-menopausal women correlations involving apos A-I and A-II were highly affected by the location of body fat.^ Thus, these data point out that not only can obesity and fat distribution affect levels of single measures, they also can markedly influence the pattern of relationship among measures. The fact that such changes are seen for both obesity and fat distribution is significant, since the indices employed were chosen because they were independent of one another. ^