Ticks and mosquitoes as vectors of Borrelia burgdorferi s. l. in the forested areas of Szczecin

The aim of the study was to determine the infection level of adult forms and larvae of ticks and mosquitoes with Borrelia burgdorferi in the forested areas of Szczecin. A total of 1699 ticks Ixodes ricinus, including 1422 nymphs, 277 adult forms and 2862 mosquito females representing the genera Aedes (89.6%) and Culex (10.4%) were collected between the years 2004 and 2005. A further 3746 larvae and 1596 pupae of Culex pipiens pipiens were colleted from water bodies. Borrelia burgdorferi s. l. was detected in the arthropods by the method of indirect immunofluorescence assay (IFA). A positive immunological reaction was detected in 16.6% of the adult forms and in 16.5% of the nymphs of Ixodes ricinus. Spirochetes were also detected in 1.7% of mosquito females, 3.2% of larvae and in 1.6% of pupae of Culex pipiens pipiens. The results of the present study confirm that contact with ticks constitutes the main risk of contracting Lyme disease, although mosquitoes play a role as vectors as well.     

Mitochondrial DNA recombination in a free-ranging Australian lizard

Mitochondrial DNA (mtDNA) is the traditional workhorse for reconstructing evolutionary events. The frequent use of mtDNA in such analyses derives from the apparent simplicity of its inheritance: maternal and lacking bi-parental recombination. However, in hybrid zones, the reproductive barriers are often not completely developed, resulting in the breakdown of male mitochondrial elimination mechanisms, leading to leakage of paternal mitochondria and transient heteroplasmy, resulting in an increased possibility of recombination. Despite the widespread occurrence of heteroplasmy and the presence of the molecular machinery necessary for recombination, we know of no documented example of recombination of mtDNA in any terrestrial wild vertebrate population. By sequencing the entire mitochondrial genome (16761bp), we present evidence for mitochondrial recombination in the hybrid zone of two mitochondrial haplotypes in the Australian frillneck lizard (Chlamydosaurus kingii).     

Determination of roxithromycin in human plasma by HPLC with fluorescence and UV absorbance detection: application to a pharmacokinetic study

A selective HPLC method with fluorescence detection for the determination of roxithromycin (ROX) in human plasma was described. After solid-phase extraction (SPE), ROX and erythromycin (internal standard, I.S.) were derivatized by treatment with 9-fluorenylmethyl chloroformate (FMOC-Cl). Optimal resolution of fluorescence derivatives of ROX and I.S. was obtained during one analytical run using reversed phase, C(18) column. The mobile phase was composed of potassium dihydrogenphosphate solution, pH 7.5 and acetonitrile. Fluorescence of the compounds was measured at the maximum excitation, 255 nm and emission, 313 nm, of ROX derivatives. Validation parameters of the method were also established. After SPE, differences in recoveries of ROX and erythromycin from human plasma were observed. The linear range of the standard curve of ROX in plasma was 0.5-10.0 mg/l. The validated method was successfully applied for pharmacokinetic studies of ROX after administration of a single tablet of ROX.     

Purification and analysis of a 5kDa component of enamel matrix derivative

High performance liquid chromatography (HPLC) methods were used to analyse a 5kDa component purified from enamel matrix derivative (EMD), the active ingredient in Emdogain, a commercial product for periodontal tissue regeneration. After initial purification by size-exclusion chromatography (SEC) on a 100 cm x 5 cm column (Bio-Gel P-30 Fine, 280 nm), collected fractions were analysed by size-exclusion HPLC (SE HPLC; TSK-Gel Super SW2000, 220 nm). The fractions containing only the 5kDa component were analysed by reversed-phase high-pressure chromatography (RP HPLC; YMC-Pack ODS-A, 200 nm), revealing four peaks of the 5kDa component. From 1200 mg of EMD (of which 9% is the 5kDa component), approximately 65 mg of lyophilised 5kDa component were obtained, corresponding to a recovery of 60%. The SE HPLC method was mainly suitable for qualitative analysis, whereas the RP HPLC method was appropriate for both qualitative and quantitative analysis.     

Determination of treosulfan in plasma and urine by HPLC with refractometric detection; pharmacokinetic studies in children undergoing myeloablative treatment prior to haematopoietic stem cell transplantation

A direct and selective HPLC method with refractometric detection was worked out for determination of treosulfan in plasma and urine of children. Before injection onto reverse phase column plasma samples with treosulfan and barbital (I.S.) were clarified using filtration. The mobile phase was composed of phosphate buffer, pH 5 and acetonitrile. The linear range of the standard curve of treosulfan spanned concentrations of 10.0-2000.0 microg/ml and 50.0-10000.0 microg/ml in plasma and urine, respectively, and covered the levels found in biological fluids after infusion of the drug. The limit of detection amounted to 5 microg/ml for plasma and 25 microg/ml for urine. Intra- and inter-day precision and accuracy of the measurement fulfilled analytical criteria accepted in pharmacokinetic studies. Recovery of treosulfan as well as stability in biological fluids was also calculated. The validated method was successfully applied in pharmacokinetic studies of treosulfan administered to children prior to haematopoietic stem cell transplantation. Differences between pharmacokinetics of treosulfan in children and adults were also studied.     

Neural tube defects, micronutrient deficiencies, and Helicobacter pylori: a new hypothesis

BACKGROUND: Previous findings for the Texas Neural Tube Defects Project suggested that while maternal access to nutrients is adequate, bioavailability of nutrients to the fetus is compromised in NTD-affected pregnancies. Helicobacter pylori could cause nutrient loss to the fetus. Folate, B12, and ferritin are depleted in H. pylori infection; these same deficiencies are related to NTD risk. METHODS: Using H. pylori IgG ELISA Test System, we tested for H. pylori serum antibodies in participants in the population-based case-control study component of the Texas Neural Tube Defect Project conducted along the Texas-Mexico border. Case-women had pregnancies affected by NTD (anencephalus, spina bifida, encephalocele) and resided and delivered in one of the 14 Texas-Mexico border counties from 1995 through 2000. Control-women were study area residents delivering normal live births during the same period. RESULTS: Of 225 case- and 378 control-women, 103 cases and 156 controls provided questionnaire and H. pylori antibody data. H. pylori seropositivity was modestly associated with NTD-affected pregnancies (OR 1.4; 95% CI: 0.8-2.4). ORs of 2.0 or greater were seen in women younger than age 25 and with less than 7 years education. CONCLUSIONS: Our findings intimate that H. pylori could play a role in NTD causation in certain populations. While results did not provide compelling support for this proposal, subgroup findings prompt us to advocate an evaluation of this hypothesis in developing nations among populations with higher prevalence of H. pylori, marginal nutrient intake, and young childbearing age.     

Choosing the right sigmoid growth function using the unified‐models approach

Growth of the young is an important part of the life history in birds. However, modelling methods have paid little attention to the choice of regression model used to describe its pattern. The aim of this study was to evaluate whether a single sigmoid model with an upper asymptote could describe avian growth adequately. We compared unified versions of five growth models of the Richards family (the four‐parameter U‐Richards and the three‐parameter U‐logistic, U‐Gompertz, U‐Bertalanffy and U4‐models) for three traits (body mass, tarsus‐length and wing‐length) for 50 passerine species, including species with varied morphologies and life histories. The U‐family models exhibit a unified set of parameters for all models. The four‐parameter U‐Richards model proved a good choice for fitting growth curves to various traits – its extra d‐parameter allows for a flexible placement of the inflection point. Which of the three‐parameter U‐models was the best performing varied greatly between species and between traits, as each three‐parameter model had a different fixed relative inflection value (fraction of the upper asymptote), implying a different growth pattern. Fixing the asymptotes to averages for adult trait value generally shifted the model preference towards one with lower relative inflection values. Our results illustrate an overlooked difficulty in the analysis of organismal growth, namely, that a single traditional three‐parameter model does not suit all growth data. This is mostly due to differences in inflection placement. Moreover, some biometric traits require more attention when estimating growth rates and other growth‐curve characteristics. We recommend fitting either several three‐parameter models from the U‐family, where the parameters are comparable between models, or only the U‐Richards model.     

Human Sperm Characteristics with Regard to Cobalt,Chromium, and Lead in Semen and Activity of Catalase in Seminal Plasma

Biological Trace Element Research - We analyzed cobalt (Co), chromium (Cr), and lead (Pb) concentrations in human semen and catalase CAT activity in seminal plasma and the effects of their...