Overview of the Rapid Response data.

The Type I Diabetes Genetics Consortium (T1DGC) Rapid Response Workshop was established to evaluate published candidate gene associations in a large collection of affected sib-pair (ASP) families. We report on our quality control (QC) and preliminary family-based association analyses. A random sample of blind duplicates was analyzed for QC. Quality checks, including examination of plate-panel yield, marker yield, Hardy-Weinberg equilibrium, mismatch error rate, Mendelian error rate, and allele distribution across plates, were performed. Genotypes from 2324 families within nine cohorts were obtained from a panel of 21 candidate genes, including 384 single-nucleotide polymorphisms on two genotyping platforms performed at the Broad Institute Center for Genotyping and Analysis (Cambridge, MA, USA). The T1DGC Rapid Response project, following rigorous QC procedures, resulted in a 2297 family, 9688 genotyped individual database on a single-candidate gene panel. The available data include 9005 individuals with genotype data from both platforms and 683 individuals genotyped (276 in Illumina; 407 in Sequenom) on only one platform.

A comparison of the process issues in expressing the same recombinant enzyme periplasmically in Escherichia coli and extracellularly in Streptomyces lividans.

The choice of a host for the production of a biological molecule will have a significant effect on isolation and purification procedures employed. This paper makes a comparison between the production of a single enzyme, a recombinant alpha-amylase, in Escherichia coli and Streptomyces lividans, on a small scale. It defines the differences in the cultivation and in the isolation stages and also describes the impact of the expression system on later downstream processing steps. At the cultivation stage, the specific productivity of the E. coli in units per gram per hour is four times that of the S. lividans while the total biomass yields are of the same order. The initial volume for downstream processing of S. lividans is six-fold larger and the total protein released into the extracellular medium is three times greater than E. coli, however, the recoverable yield from the E. coli is a fifth of that obtained from the S. lividans and requires three additional stages prior to chromatography. Even with these stages the final specific activity is 64% of the S. lividans. The results indicate the need to consider the whole process when making such comparisons.

The Kidney Outcomes Prediction and Evaluation (KOPE) study: a prospective cohort investigation of patients undergoing hemodialysis. Study design and baseline characteristics.

PURPOSE: The purpose of the Kidney Outcomes Prediction and Evaluation (KOPE) study, was to more fully characterize the end-stage renal disease (ESRD) population with respect to social, psychological, and clinical characteristics, and to prospectively study the biomedical, social, and psychological factors that influence a range of ESRD outcomes in a large observational study of black and white patients on hemodialysis. This paper focuses on the KOPE study design as well as characteristics of patients at baseline. METHODS: KOPE was a prospective cohort investigation of patients treated at four dialysis centers in Forsyth County, North Carolina. Participants were interviewed at the dialysis centers, semi-annually over a 3 1/2 year period. Prevalent cases who were being treated with hemodialysis at the initiation of the study were enrolled into KOPE. Incident cases were subsequently enrolled as they presented to the participating units for hemodialysis. A total of 304 prevalent and 162 incident cases were enrolled into the study. The baseline health and sociodemographic characteristics of KOPE participants reported in this paper were obtained from medical records and Southeast Kidney Council data. Laboratory values taken within a 30-day interval around the baseline interview are also reported. RESULTS: KOPE participants differ from national statistics on race, age, and gender. Differences between KOPE participants and patients living in the region, but who did not participate in the study, can be explained by our recruitment criteria. CONCLUSIONS: KOPE will enable the characterization of the ESRD population, identification of factors related to poor outcomes, and identification of opportunities for interventions to prevent death and morbidity.

Transvaginal ultrasonography compared with endometrial biopsy for the detection of endometrial disease. Postmenopausal Estrogen/Progestin Interventions Trial.

BACKGROUND: Transvaginal ultrasonography is a noninvasive procedure that may be used to detect endometrial disease. However, its usefulness in screening for asymptomatic disease in postmenopausal women before or during treatment with estrogen or estrogen-progesterone replacement is not known. METHODS: We compared the sensitivity and specificity of transvaginal ultrasonography and endometrial biopsy for the detection of endometrial disease in 448 postmenopausal women who received estrogen alone, cyclic or continuous estrogen-progesterone, or placebo for three years. RESULTS: Concurrent ultrasonographic and biopsy results were available for 577 examinations in the 448 women, 99 percent of whom were undergoing routine annual follow-up. Endometrial thickness was less than 5 mm in 45 percent of the examinations, 5 to 10 mm in 41 percent, more than 10 mm in 12 percent, and not measured in 2 percent, and it was higher in the women receiving estrogen alone than in the other groups. Biopsy detected 11 cases of serious disease: 1 case of adenocarcinoma, 2 cases of atypical simple hyperplasia, and 8 cases of complex hyperplasia. Biopsy also detected simple hyperplasia in 20 cases. At a threshold value of 5 mm for endometrial thickness, transvaginal ultrasonography had a positive predictive value of 9 percent for detecting any abnormality, with 90 percent sensitivity, 48 percent specificity, and a negative predictive value of 99 percent. With this threshold, a biopsy would be indicated in more than half the women, only 4 percent of whom had serious disease. CONCLUSIONS: Transvaginal ultrasonography has a poor positive predictive value but a high negative predictive value for detecting serious endometrial disease in asymptomatic postmenopausal women.

Factors determining more efficient large-scale release of a periplasmic enzyme from E. coli using lysozyme.

Large scale use of lysozyme for periplasmic release has been impeded by the cost of the pure enzyme and its subsequent presence as a contaminant in later downstream processing steps. In this paper, we discuss the use of lysozyme for pilot scale recovery of a periplasmic enzyme from E. coli. The effects of concentration of sucrose, lysozyme and cells on periplasmic enzyme release were examined. Lysozyme concentration can be reduced 5-fold from previous reports and a reduction in sucrose concentration from 20 to 15% (w/v) allows an improvement in centrifugal harvesting by reducing viscosity. High levels of release were still achieved using this technique and further improvements in yield were obtained by optimising other components of the releasing mixture. Results show that some release is still achieved in circumstances where no lysozyme use is possible. Results also indicate that a substantial proportion (up to 70%) of lysozyme remains bound to the cellular debris after its action and is removed with this material.

Stability of immunoadsorbents comprising antibody fragments. Comparison of Fv fragments and single-chain Fv fragments.

Immunoadsorbents comprising Fv fragments specific for hen egg lysozyme were used to recover the enzyme from a 20-fold excess of bovine albumin. We designed automatic equipment to run this model purification system for 100 cycles non-stop and monitored the deterioration of the immunoadsorbents during the cycling procedure. Only minor losses (approximately 25%) in the immunoadsorbents' capacity were detected; this correlated well with ligand loss (measured by enzyme-linked immunosorbent assay) which was approximately 0.2% per cycle. A surprising finding was that the use of "single-chain" Fv fragments conferred only a minor advantage with respect to stability of the immunoadsorbents.