Influence of demographic, surgical and implant variables on wear rate and osteolysis in ABG I hip arthroplasty

Periprosthetic osteolysis is associated with accelerated wear rates. The goal of this study was to investigate the influence of demographic and technical variables on wear rates and size of osteolytic lesions. Eighty retrieved ABG I prostheses were analyzed according to prospectively established criteria. There were 22 men and 58 women with an average age of 52 years (34-65) at the time of revision. The average time from index surgery to revision was 67 months (26 to 106). Polyethylene wear measurements were performed using a Universal-type measuring microscope. The average linear wear and volumetric wear rate was 0.363 mm per year (0-0.939, SD 0.241) and 161 mm(3) per year (0-467, SD 118.2), respectively. The wear rates were significantly higher (a) in patients with primary osteoarthritis in comparison with postdysplastic hips, (b) in hips where zirconia prosthetic heads articulated against the polyethylene liner, and (c) in cups placed laterally to Kohler's line. Risk that linear wear rate could be more than 0.2 mm per year was three times higher in patients who were operated in 1997 and later (OR 3.0, 95 % CI 1.126-7.993, p = 0.03). A strong association was revealed between magnitude of wear and size of femoral osteolysis.     

The effect of polyphenolic extract from pine bark, Pycnogenol on the level of glutathione in children suffering from attention deficit hyperactivity disorder (ADHD)

Attention deficit hyperactivity disorder (ADHD) belongs to the neurodevelopmental disorders characterized by impulsivity, distractibility and hyperactivity. In the pathogenesis of ADHD genetic and non-genetic factors play an important role. It is assumed that one of non-genetic factors should be oxidative stress. Pycnogenol, an extract from the pine bark, consists of bioflavonoids, catechins, procyanidins and phenolic acids. Pycnogenol acts as powerful antioxidant, chelating agent; it stimulates the activities of some enzymes, like SOD, eNOS, and exhibits other biological activities. AIM: The aim of this randomized, double-blind, placebo-controlled trial was to investigate the influence of administered Pycnogenol or placebo on the level of reduced (GSH) and oxidized (GSSG) glutathione in children suffering from ADHD and on total antioxidant status (TAS). This is the first investigation of the redox glutathione state in relation to ADHD. RESULTS: One month of Pycnogenol administration (1 mg/kg body weight/day) caused a significant decrease in GSSG and a highly significant increase in GSH levels as well as improvement of GSH/GSSG ratio in comparison to a group of patients taking a placebo. TAS in children with ADHD was decreased in comparison with reference values. Pycnogenol administration normalizes TAS of ADHD children.     

Capillary electrophoresis determination of thiopurine methyl transferase activity in erythrocytes

Thiopurine S-methyltransferase (TPMT) catalyzes methylation of thiopurine drugs (e.g. 6-mercaptopurine, azathioprine). Decreased activity of TPMT is associated with hematopoietic toxicity after administration of standard doses of the drugs. We developed capillary electrophoretic method for determination of TPMT enzyme activity in erythrocytes. Limit of quantification of the method is 1.5 μmol/L (S/N = 6). The recovery of 6-methylmercaptopurine was 87.5–94.8%, imprecision value (as CV, n = 10) was 1.68% (within-day) and 2.53% (between-day). Erythrocyte TPMT activities were measured in 60 healthy adult volunteers.     

2-Methylsorbic acid,an antifungal metabolite of Penicillium vermiculatum

Summary 2-Methylsorbic acid (MA), (2Z,4E)-2-methyl-2,4-hexadienoic acid, is a new metabolite of Penicillium vermiculatum. Antifungal activity of this acid was higher than that of sorbic acid or the bromoderivatives bromomethylsorbic acid and bromosorbic acid. MA suppressed the growth of Talaromyces flavus and germination of its conidia. In P. vermiculatum this acid lowered production of vermiculin and inhibited proteosynthesis in Saccharomyces cerevisiae. Correspondence to: B. Proksa     

Inhibitory effect of stobadine on FMLP-induced chemiluminescence in human whole blood and isolated polymorphonuclear leukocytes.

The chemiluminescence (CL) technique with luminol and isoluminol was used to characterize the effect of stobadine on reactive oxygen metabolites (ROM) generation in human whole blood and in isolated polymorphonuclear leukocytes (PMNL) stimulated with N-formyl-methionyl-leucyl-phenyl-alanine (FMLP). In whole blood and in isolated PMNL, stobadine in the concentrations of 1, 10 and 100 micromol/L significantly inhibited the CL signal after FMLP, which activated predominantly extracellular generation of ROM. The same concentrations of stobadine were effective on CL in a cell-free system. On the other hand, myeloperoxidase (MPO) liberation was decreased by stobadine only in the concentration of 100 micromol/L. The results showed stobadine to act as a potent inhibitor/scavenger of extracellularly produced ROM in human PMNL and indicated interference of stobadine with ROM as well as with signalling events resulting in NADPH-oxidase activation and MPO liberation.     

The α-amylase inhibitor acarbose does not affect the parasitoid Venturia canescens when incorporated into the diet of its host Ephestia kuehniella

Amylase inhibitors (AIs) are suitable candidates for protecting plants and their products from attacks by herbivorous and granivorous insects. However, detailed studies of the suppressive effects of AIs on target and non‐target insects are necessary before their application in post‐harvest protection. To address this issue, laboratory bioassays were used to test the effect of the non‐proteinaceous inhibitor acarbose on a stored product pest, the flour moth Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae), and its parasitoid Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae). Two sublethal concentrations (0.001 and 0.0001%, wt/wt) of acarbose were incorporated into the diet of parasitized and unparasitized larvae of E. kuehniella. Development time and fresh body weight of the larvae, together with the size of the wasps, were compared for insects reared on acarbose‐treated and control diets. On the diet containing 0.001% acarbose, the developmental time was longer and relative weight gains of the E. kuehniella larvae were lower, but the weight of the larvae prior to pupation was similar to that of the control. The acarbose did not have a suppressive effect on the parasitoid V. canescens; in fact the wasps that emerged from the hosts reared on a diet containing 0.0001% acarbose were on average larger and heavier than the controls. These results demonstrate that it might be possible to enhance the control of stored product pests by using both biological control and AIs.     

An F1 genetic screen for maternal-effect mutations affecting embryonic pattern formation in Drosophila melanogaster

Large-scale screens for female-sterile mutations have revealed genes required maternally for establishment of the body axes in the Drosophila embryo. Although it is likely that the majority of components involved in axis formation have been identified by this approach, certain genes have escaped detection. This may be due to (1) incomplete saturation of the screens for female-sterile mutations and (2) genes with essential functions in zygotic development that mutate to lethality, precluding their identification as female-sterile mutations. To overcome these limitations, we performed a genetic mosaic screen aimed at identifying new maternal genes required for early embryonic patterning, including zygotically required ones. Using the Flp-FRT technique and a visible germline clone marker, we developed a system that allows efficient screening for maternal-effect phenotypes after only one generation of breeding, rather than after the three generations required for classic female-sterile screens. We identified 232 mutants showing various defects in embryonic pattern or morphogenesis. The mutants were ordered into 10 different phenotypic classes. A total of 174 mutants were assigned to 86 complementation groups with two alleles on average. Mutations in 45 complementation groups represent most previously known maternal genes, while 41 complementation groups represent new loci, including several involved in dorsoventral, anterior-posterior, and terminal patterning.     

Efficient synthesis of ruthenium complexes of the type (R-bpy)2RuCl2 and [(R-bpy)2Ru(L-L)]Cl2 by microwave-activated reactions (R: H, Me, tert-But) (L-L: substituted bibenzimidazoles, bipyrimidine, and phenanthroline)

Complexes of the type (R-bpy)₂RuCl₂ (R: H, Me, tert-but) were synthesised by microwave-activated reactions of [Ru(cod)Cl₂]_n with substituted 2,2′-bipyridines in dimethylformamide as the solvent. The complexes were isolated in high yields and high purity from the reaction mixture. Microwave-assisted or thermal reaction of the (R-bpy)₂RuCl₂ solutions with substituted bibenzimidazoles, 1,10 phenanthroline or bipyrimidine in dmf/water mixtures resulted in the formation of mixed ligand complexes of the type [(R-bpy)₂Ru(L-L)]Cl₂. The complexes were characterised by NMR spectroscopy and MS. Furthermore, their photochemical and electrochemical properties were investigated and the solid state structure of (4-tert-butyl-bpy)₂RuCl₂ (3), [(4-tert-butyl-bpy)₂Ru(tetramethylbibenzimidazole)](PF₆)₂ (4), and [(4-tert-butyl-bpy)₂Ru(bipyrimidine] (PF₆)₂ (5) was determined by X-ray diffraction analysis of single crystals.     

Calcium current in rat cardiomyocytes is modulated by the carboxyl-terminal ahnak domain

Ahnak, a protein of 5643 amino acids, interacts with the regulatory beta-subunit of cardiac calcium channels and with F-actin. Recently, we defined the binding sites among the protein partners in the carboxyl-terminal domain of ahnak. Here we further narrowed down the beta(2)-interaction sites to the carboxyl-terminal 188 amino acids of ahnak by the recombinant ahnak protein fragments P3 (amino acids 5456-5556) and P4 (amino acids 5556-5643). The effects of these P3 and P4 fragments on the calcium current were investigated under whole-cell patch clamp conditions on rat ventricular cardiomyocytes. P4 but not P3 increased significantly the current amplitude by 22.7 +/- 5% without affecting its voltage dependence. The slow component of calcium current inactivation was slowed down by both P3 and P4, whereas only P3 slowed significantly the fast one. The composite recombinant protein fragment P3-P4 induced similar modifications to the ones induced by each of the ahnak fragments. In the presence of carboxyl-terminal ahnak protein fragments, isoprenaline induced a similar relative increase in current amplitude and shift in current kinetics. The actin-stabilizing agents, phalloidin and jasplakinolide, did not modify the effects of these ahnak protein fragments on calcium current in control conditions nor in the presence of isoprenaline. Hence, our results suggest that the functional effects of P3, P4, and P3-P4 on calcium current are mediated by targeting the ahnak-beta(2)-subunit interaction rather than by targeting the ahnak-F-actin interaction. More specifically they suggest that binding of the beta(2)-subunit to the endogenous subsarcolemmal giant ahnak protein re-primes the alpha(1C)/beta(2)-subunit interaction and that the ahnak-derived proteins relieve the beta(2)-subunit from this inhibition.