Evaluation of the MagNA Pure LC used with the TRUGENE HBV Genotyping Kit.

BACKGROUND: The current manual sample processing method recommended for use with the TRUGENE HBV Genotyping Kit (TRUGENE HBV; Bayer HealthCare LLC, Tarrytown, NY) is labor-intensive and may be prone to specimen cross-contamination. Recent evaluations of the MagNA Pure LC (MP; Roche Applied Science, Indianapolis, IN) suggest that it is suitable for automated, contamination-free extraction and purification of viral nucleic acids from large-volume (1.0 mL) serum or plasma specimens. OBJECTIVES: We evaluated the MP Total Nucleic Acid Isolation Kit--Large Volume (Roche Applied Science) in conjunction with TRUGENE HBV to establish the analytical sensitivity (threshold titer) of the assay, in HBV DNA International Units (IU)/mL, for obtaining consistent, interpretable sequence data from TRUGENE HBV. STUDY DESIGN: HBV analytical standards, prepared as 10 replicates (1.0 mL each) at each of the following concentrations: 200, 1000, 5000, and 10,000 IU/mL, were processed by MP and analyzed by TRUGENE HBV according to manufacturer's instructions. Performance of TRUGENE HBV used in conjunction with MP sample processing was evaluated further using 22 clinical serum specimens containing low titers of HBV DNA. RESULTS: All replicates of HBV analytical standards at 1000, 5000, and 10,000 IU/mL yielded interpretable TRUGENE HBV sequences, whereas interpretable sequences were obtained in 90% (9 of 10) of the replicates at 200 IU/mL. TRUGENE HBV sequences were interpretable in 86% (19 of 22) of the clinical specimens studied. CONCLUSIONS: MP sample processing is efficient and suitable for use with TRUGENE HBV. When combined with MP sample processing, TRUGENE HBV yielded interpretable sequences from HBV analytical standards and clinical serum specimens with HBV DNA titers of > or =200 IU/mL.     

In Vitro and in Vivo Evaluation of Whole and Half Tablets of Sustained-Release Adinazolam Mesylate

The mechanism of release from sustained-release adinazolam mesylate tablets was assessed by the Higuchi equation and by analysis of drug release profiles through 60% released using the Peppas equation. Computed values of the diffusional exponent, n, ranged from 0.59 to 0.66. Values of n in this range are consistent with a mixed mechanism of release, with diffusion of drug through the hydrated polymer matrix and relaxation of this matrix being the principal processes controlling release. The rate of in vitro drug release was increased for half tablets relative to whole tablets and is attributed to an increase in the surface to volume ratio of half tablets of about 16%. This increase in surface-to-volume ratio of half tablets was reflected by an increase in the constant, k, from the Peppas equation of 20–23% and by an increase in the slope of Higuchi plots of 12–18% for four lots of tablets. In vivo/in vitro relationships from two bioavailability studies were thoroughly evaluated. Using either a linear or a quadratic relationship, an in vivo/in vitro correlation exists for sustained-release adinazolam mesylate tablets.     

Role of five platelet membrane glycoprotein polymorphisms in branch retinal vein occlusion.

To determine whether polymorphisms of platelet surface glycoprotein associated with arterial thrombosis are risk factors for branch retinal vein occlusion. A case-control study in which 69 patients with branch retinal vein occlusion and 147 controls who attended the eye clinic for nonvascular complications participated. DNA was extracted from whole blood and analyzed for genotyping of platelet glycoprotein polymorphisms by polymerase chain reactions and specific restricted enzymes. No relationship was found between the four platelet glycoprotein polymorphisms i.e. GPIa C807T, VNTR and Kozak of glycoprotein Ibalpha, the HPA-1 of glycoprotein IIIa and the occurrence of branch retinal vein occlusion. The HPA-2 polymorphism was found in 18 out 60 (30%) patients with branch retinal vein occlusion in comparison with 27 out 142 (19%) of controls, with an estimated odds ratio of 1.8 (95% confidence interval, 0.91-3.65). The four platelet glycoprotein polymorphisms are not risk factors for branch retinal vein occlusion and therefore it seems unnecessary to screen those patients for it. A larger study is required, however, to determine whether HPA-2 is a novel risk factor for branch retinal vein occlusion.     

Conserved sequence of the TgsGP gene in Group 1 Trypanosoma brucei gambiense

The trypanosome responsible for the majority of cases of human trypanosomiasis in Africa is Group 1 Trypanosoma brucei gambiense. Currently the most reliable test for the parasite is based on a single gene, which encodes a 47 kDa receptor-like T. b. gambiense-specific glycoprotein, TgsGP, expressed in the flagellar pocket of bloodstream forms. Although TgsGP has been demonstrated in T. b. gambiense throughout its geographic range, similar genes have been demonstrated in other T. brucei sspp. isolates, and there are no data on the extent of sequence variation in TgsGP. Here we have carried out a comparison of TgsGP sequences in a range of Group 1 T. b. gambiense isolates and compared the gene to homologues in other T. brucei sspp. in order to provide information to support the use of this gene as the key identification target for Group 1 T. b. gambiense. We demonstrate that the sequence of TgsGP is well conserved in Group 1 T. b. gambiense across the endemic range of gambian human trypanosomiasis and confirm that this gene is a suitable target for specific detection of this parasite. The TgsGp-like genes in some isolates of T. b. brucei, T. b. rhodesiense and Group 2 T. b. gambiense are closely similar to VSG Tb10.v4.0178, which may be the ancestral gene from which TgsGP was derived.