Self monitoring of blood glucose in blind diabetic patients

Blind diabetic patients face particular difficulties in blood glucose self monitoring (BGSM). We investigated the quality of BGSM in blind and severely visually impaired diabetic patients and assessed the effects of training in BGSM using a blood glucose meter with voice edition of values and a modified test strip holder for easier placement of blood samples on the strip (One Touch II talk (OT II)). Twenty-six insulin-treated diabetic patients (23 IDDM and 3 NIDDM) participated. At baseline the quality of BGSM was checked in 14 patients who already regularly performed BGSM without external help. Thereafter all 26 patients received an extensive instruction in BGSM for blind patients. At re-examination, after a mean period of 41 days, the quality of BGSM performed by the patients without assistance was checked in three different blood samples. Blood glucose was measured in the same sample by a routine laboratory method. At baseline the mean absolute difference between BGSM and the reference method was -0.3 mmol l(-1) (range; +/- SD) (-7.7-4.8; +/- 2.6 mmol l(-1)); 74% of BGSM measurements deviated by more than 10% from the reference values and 43% by more than 20%. At follow-up all 26 patients reported daily BGSM without external help. The mean absolute difference between BGSM and the reference method was -0.1 (-2.7-2.8; +/- 0.9 mmol l(-1)); 25% of BGSM measurements deviated by more than 10 % from the laboratory reference values and 5% by more than 20%. The results of this study suggest that a substantial number of blind diabetic patients do not perform BGSM on their own at all and in those who do the reliability of the results is poor. However, after extensive instruction, the majority of blind diabetic patients should be able to perform BGSM and to obtain reliable results.     

Atomic force microscopic imaging of seeded fibril formation and fibril branching by the Alzheimer's disease amyloid-beta protein

BACKGROUND: Amyloid plaques composed of the fibrillar form of the amyloid-beta protein (Abeta) are the defining neuropathological feature of Alzheimer's disease (AD). A detailed understanding of the time course of amyloid formation could define steps in disease progression and provide targets for therapeutic intervention. Amyloid fibrils, indistinguishable from those derived from an AD brain, can be produced in vitro using a seeded polymerization mechanism. In its simplest form, this mechanism involves a cooperative transition from monomeric Abeta to the amyloid fibril without the buildup of intermediates. Recently, however, a transient species, the Abeta amyloid protofibril, has been identified. Here, we report studies of Abeta amyloid protofibril and its seeded transition into amyloid fibrils using atomic force microscopy. RESULTS: Seeding of the protofibril-to-fibril transition was observed. Preformed fibrils, but not protofibrils, effectively seeded this transition. The assembly state of Abeta influenced the rate of seeded growth, indicating that protofibrils are fibril assembly precursors. The handedness of the helical surface morphology of fibrils depended on the chirality of Abeta. Finally, branched and partially wound fibrils were observed. CONCLUSIONS: The temporal evolution of morphologies suggests that the protofibril-to-fibril transition is nucleation-dependent and that protofibril winding is involved in that transition. Fibril unwinding and branching may be essential for the post-nucleation growth process. The protofibrillar assembly intermediate is a potential target for AD therapeutics aimed at inhibiting amyloid formation and AD diagnostics aimed at detecting presymptomatic disease.     

Catechol O-methyltransferase inhibitor tolcapone has minor influence on performance in experimental memory models in rats

DNA-based immunization is a promising new technique for generating antibodies in laboratory animals for diagnostic purposes in biological science. The main advantages are the elimination of time and labor and the technically demanding steps of antigen purification. The DNA sequence of the protein of interest, cloned in a suitable in vivo expression vector that is administered intramuscularly or intradermally, is sufficient to induce an immune response in animals. We report the induction of antibodies to tobacco mosaic virus (TMV) coat protein (CP) as a highly immunogenic structural protein and potato virus Y (PVY) P1 protein (P1) as a nonstructural protein. The appropriate nucleotide sequences were introduced in a mammalian expression vector (pSG5) and injected intramuscularly into New Zealand White rabbits (Oryctolagus cuniculus). By 10 days post-injection (dpi) a specific immune response was detected against TMV-CP, while it took about 5 weeks for a response to PVY P1. In both cases the antibody titers were significantly above the corresponding pre-immune serum, however, they were considerably below the titer of the matching conventionally produced antiserum. To our knowledge, this is the first report of DNA-based immunization in order to generate antibodies to plant viral proteins, but further improvements are necessary to increase antibody titers before this promising new technique can be introduced broadly in plant science for diagnostic purposes.     

Characterization to species level of Mycobacterium avium complex strains from human immunodeficiency virus-positive and -negative patients

Forty human clinical Mycobacterium avium-M. intracellulare complex strains isolated in Greece were characterized to the species level by PCR with three sets of primers specific for one or both species. M. avium predominated in both human immunodeficiency virus-positive and -negative patients, but the frequency of M. intracellulare isolation appeared to be higher in the latter.