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Selective DNA pooling (SDP) is a cost-effective means for an initial scan for linkage between marker and quantitative trait loci (QTL) in suitable populations. The method is based on scoring marker allele frequencies in DNA pools from the tails of the population trait distribution. Various analytical approaches have been proposed for QTL detection using data on multiple families with SDP analysis. This article presents a new experimental procedure, fractioned-pool design (FPD), aimed to increase the reliability of SDP mapping results, by 'fractioning' the tails of the population distribution into independent subpools. FPD is a conceptual and structural modification of SDP that allows for the first time the use of permutation tests for QTL detection rather than relying on presumed asymptotic distributions of the test statistics. For situations of family and cross mapping design we propose a spectrum of new tools for QTL mapping in FPD that were previously possible only with individual genotyping. These include: joint analysis of multiple families and multiple markers across a chromosome, even when the marker loci are only partly shared among families; detection of families segregating (heterozygous) for the QTL; estimation of confidence intervals for the QTL position; and analysis of multiple-linked QTL. These new advantages are of special importance for pooling analysis with SNP chips. Combining SNP microarray analysis with DNA pooling can dramatically reduce the cost of screening large numbers of SNPs on large samples, making chip technology readily applicable for genomewide association mapping in humans and farm animals. This extension, however, will require additional, nontrivial, development of FPD analytical tools.

A selective DNA pooling approach was applied to identify QTL for conjugated linoleic acid ( CLA), vaccenic acid ( VA) and Δ9-desaturase (D9D) milk content in Italian Brown Swiss dairy cattle. Milk samples from 60 animals with higher values (after correction for environmental factors) and 60 animals with lower values for each of these traits from each of five half-sib families were pooled separately. The pools were genotyped using the Illumina Bovine SNP50 BeadChip. Sire allele frequencies were compared between high and low tails at the sire and marker level for SNPs for which the sires were heterozygous. An r procedure was implemented to perform data analysis in a selective DNA pooling design. A correction for multiple tests was applied using the proportion of false positives among all test results. BTA 19 showed the largest number of markers in association with CLA. Associations between SNPs and the VA and Δ9-desaturase traits were found on several chromosomes. A bioinformatics survey identified genes with an important role in pathways for milk fat and fatty acids metabolism within 1 Mb of SNP markers associated with fatty acids contents. [ABSTRACT FROM AUTHOR]

Inflammatory demyelination and axon damage in the corpus callosum are prominent features of multiple sclerosis (MS) and may partially account for impaired performance on complex tasks. The objective of this article was to characterize quantitative callosal MRI abnormalities and their association with disability. In 69 participants with MS and 29 healthy volunteers, lesional and extralesional callosal MRI indices were estimated via diffusion tensor tractography. expanded disability status scale (EDSS) and MS functional composite (MSFC) scores were recorded in 53 of the participants with MS. All tested callosal MRI indices were diffusely abnormal in MS. EDSS score was correlated only with age (r = 0.51). Scores on the overall MSFC and its paced serial auditory addition test (PASAT) and 9-hole peg test components were correlated with callosal fractional anisotropy (r = 0.27, 0.35, and 0.31, respectively) and perpendicular diffusivity (r =-0.29, -0.30, and -0.31) but not with overall callosal volume or callosal lesion volume; the PASAT score was more weakly correlated with callosal magnetization-transfer ratio (r = 0.21). Anterior callosal abnormalities were associated with impaired PASAT performance and posterior abnormalities with slow performance on the 9-hole peg test. In conclusion, abnormalities in the corpus callosum can be assessed with quantitative MRI and are associated with cognitive and complex upper-extremity dysfunction in MS. [ABSTRACT FROM AUTHOR]

Reports on the outcome of a study done on the bovine Growth Hormone gene (bGH) to see if it would be suitable as a gene for milk production in cows. Evaluation of different breeds of cows.

Bone gamma-carboxyglutamic acid containing protein (BGP) has been utilized effectively as a serum marker of bone turnover in healthy normals and in individuals with a variety of metabolic bone disorders including postmenopausal osteoporosis and Paget's disease. The utility of this serum marker in other bone disorders, including that associated with the maintenance of patients on long-term parenteral nutrition, still requires definition. Because of our interest in this clinical syndrome and the availability of serum and of bone formation rates (BFR) measured directly from double tetracycline labeling in 11 long-term parenteral nutrition patients, we measured BGP levels in these patients and attempted to correlate this measure with BFR. Serum vitamin D metabolites, immunoreactive parathyroid hormone (PTH), and alkaline phosphatase (alk phos) were also measured. Serum BGP was only weakly and not significantly correlated (r = 0.24, p = NS) with bone formation rate for the group as a whole. However, in a subgroup of 10 patients without hyperparathyroidism, there was strong and significant correlation (r = 0.81, P less than 0.01) between BGP and BFR. There was also a strong correlation between bone formation rate and serum 1,25 dihydroxyvitamin D [1,25(OH)2D] levels (r = 0.89, P less than 0.01, n = 11). The mechanism of this association could not be established. A correlation of borderline significance was observed between bone formation rate and serum alk phos (r = 0.60, P = 0.05, n = 11). The current data suggest that additional studies may help to more fully define the utility of serum measurements in quantifying bone dynamics in parenteral nutrition patients, and that measures of vitamin D metabolites, BGP, and alk phos may prove useful. [ABSTRACT FROM AUTHOR]

Objective: To determine the association between obesity measures and albuminuria in adults with type 2 diabetes.Research Design and Methods: In the Look AHEAD (Action for Health in Diabetes) Study, BMI and waist circumference were measured among 4,985 participants while total percent body fat was measured by whole-body DEXA scans among 1,351 participants. Odds of albuminuria by quartiles of BMI, waist circumference, and percent total body fat were calculated using logistic regression analysis while adjusting for covariates.Results: The highest quartile of BMI (odds ratio [OR] 1.72 [95% CI 1.40-2.11]) and waist circumference (OR 1.75 [95% CI 1.42-2.15]) was significantly associated with albuminuria compared with the lowest quartile after adjustment for covariates. No associations were noted between quartiles of percent total body fat and albuminuria in any model.Conclusions: Increased BMI and abdominal obesity are associated with albuminuria in overweight and obese adults with type 2 diabetes. [ABSTRACT FROM AUTHOR]

An abstract of the article "Optical coherence tomography in optic neuritis and MS," by M. Pulicken, E. Gordon-Lipkin, L. J. Balcer, G. R. Cutter and P. Calabresi is presented.