Complicated relationship between autism with regression and epilepsy

We retrospectively evaluated a set of 205 children with autism and compared it to the partial sub-set of 71 (34.6%) children with a history of regression. From 71 children with regression, signs of epileptic processes were present in 43 (60.6%), 28 (65.12%) suffered clinical epileptic seizures, and 15 (34.9%) just had an epileptiform abnormality on the EEG. In our analysis, autistic regression is substantially more associated with epileptic process symptoms than in children with autism and no history of regression. More than 90% of children with a history of regression also show IQ < 70 and reduced functionality. Functionality and IQ further worsens with the occurrence of epileptic seizures (98% of children with regression and epilepsy have IQ < 70). We proved that low IQ and reduced functionality significantly correlate rather with epileptic seizures than just sub-clinical epileptiform abnormality on EEG. Clinical epileptic seizures associated with regression significantly influence the age of regression and its clinical type. The age of regression is higher compared to children with regression without epileptic seizures (in median: 35 months of age in patients with seizures while only 24 months in other patients). Patients with seizures revealed regression after 24th months of age in 68% of cases, while patients without seizures only in 27%. However, coincidence with epilepsy also increased the occurrence of regression before the 18th month of age (23% of patients), while only 4% of patients without epilepsy revealed regression before the 18th month. Epileptic seizures are significantly associated especially with behaviour regression rather than speech regression or regression in both behaviour and speech. Also epileptic seizures diagnosed before correct diagnosis of autism were significantly associated with delayed regression (both behavioural and speech regression).     

Coplanar polychlorinated biphenyl-induced CYP1A1 is regulated through caveolae signaling in vascular endothelial cells

Polychlorinated biphenyls (PCBs) are persistent environmental contaminants that can induce inflammatory processes in the vascular endothelium. We hypothesize that the plasma membrane microdomains called caveolae are critical in endothelial activation and toxicity induced by PCBs. Caveolae are particularly abundant in endothelial cells and play a major role in endothelial trafficking and the regulation of signaling pathways associated with the pathology of vascular diseases. We focused on the role of caveolae and their major protein component, caveolin-1 (Cav-1), on aryl hydrocarbon receptor (AhR)-mediated induction of cytochrome P450 1A1 (CYP1A1) by coplanar PCBs. Endothelial cell exposure to PCB77 increased both caveolin-1 and CYP1A1 levels in a time-dependent manner in total cell lysates, with a maximum increase at 6h. Furthermore, PCB77 accumulated mainly in the caveolae-rich fraction, as determined by gas chromatograph-mass spectrometry. Immunoprecipitation analysis revealed that PCB77 increased AhR binding to caveolin-1. Silencing of caveolin-1 significantly attenuated PCB77-mediated induction of CYP1A1 and oxidative stress. Similar effects were observed in caveolin-1 null mice treated with PCB77. These data suggest that caveolae may play a role in regulating vascular toxicity induced by persistent environmental pollutants such as coplanar PCBs. This may have implications in understanding mechanisms of inflammatory diseases induced by environmental pollutants.     

Multipotent properties of myofibroblast cells derived from human placenta

Human uterine fibroblasts (HuF) isolated from the maternal part (decidua parietalis) of a term placenta provide a useful model of in vitro cell differentiation into decidual cells (decidualization, a critical process for successful pregnancy). After isolation, the cells adhere to plastic and have either a small round or spindle-shaped morphology that later changes into a flattened pattern in culture. HuF robustly proliferate in culture until passage 20 and form colonies when plated at low densities. The cells express the mesenchymal cell markers fibronectin, integrin-β1, ICAM-1 (CD54), and collagen I. Flow cytometry of HuF has detected the presence of CD34, a marker of the hematopoietic stem cell lineage, and an absence of CD10, CD11b/Mac, CD14, CD45, and HLA type II. Furthermore, they also express the pluripotency markers SSEA-1, SSEA-4, Oct-4, Stro-1, and TRA-1–81 as detected by confocal microscopy. Treatment for 14–21 days with differentiation-inducing media leads to the differentiation of HuF into osteoblasts, adipocytes, and chondrocytes. The presence of α-smooth muscle actin, calponin, and myosin light-chain kinase in cultured HuF implies their similarity to myofibroblasts. Treatment of the HuF with dimethyl sufoxide causes reversion to the spindle-shaped morphology and a loss of myofibroblast characteristics, suggesting a switch into a less differentiated phenotype. The unique abilities of HuF to exhibit multipotency, even with myofibroblast characteristics, and their ready availability and low maintenance requirements make them an interesting cell model for further exploration as a possible tool for regenerative medicine. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized user. This work was supported by National Institutes of Health Grant HD-44713 (to Z.S.).     

A duplication dup(4)(q28q35.2) de novo in a newborn

We report here a case of a newborn with hypotrophy and somatic stigmatization: microcephaly, facial dysmorphism, heart defect and immunodeficiency syndrome. The proband's karyotype was 46,XY,dup(4)(q28q35.2) de novo with chromosomal breaks in 4% of metaphases. We demonstrate the usefulness of a combination of physical examination, classical cytogenetics, FISH and PCR techniques in order to establish correct diagnosis because of overlap of some clinical and cytogenetic features of Nijmegen breakage syndrome (NBS) and duplication 4q in our patient. Although FISH technique detected translocation t(14q;21q) in 4 metaphases, deletion 657del5 in exon 6 of the NBS1 gene associated with NBS in Slavic population was not confirmed. We compare in this report similarity of the clinical picture of our patient, NBS cases and other patients carrying a duplication of the distal part of 4q as described in the literature.     

Distribution and ecology of cytotypes of the Aster amellus aggregates in the Czech Republic

BACKGROUND AND AIMS: Polyploidy is viewed as an important mechanism of sympatric speciation, but only a few studies have documented patterns of distribution and ecology of different cytotypes in their contact zone. Aster amellus agg. (Asteraceae) is one of the species with documented multiple ploidy levels. The aim of this study was to determine spatial distribution and ecology of two cytotypes, diploid (2n = 18) and hexaploid (2n = 54), of Aster amellus agg. at their contact zone in the Czech Republic. METHODS: Root-tip squashes and flow cytometry were used to determine the ploidy of 2175 individuals from 87 populations. To test whether some differences in ecology between the two ploidy levels exist, in each locality relevés were recorded and abiotic conditions of the sites were studied by estimating potential direct solar radiation, Ellenberg indicator values and above-ground biomass. KEY RESULTS: Together with diploid and hexaploids, minorite cytotypes (triploid, pentaploid and nonaploid) were found. No significant ecological differences between diploid and hexaploid cytotypes were found. In spite of this, no population consisting of both of the two basic cytotypes was found. CONCLUSIONS: The results of this study show that the contact zone of diploid and hexaploid cytotypes in the Czech Republic is much more diffuse than indicated in previous records. Although populations of both cytotypes occur in close proximity (the closest populations of different cytotypes were 500 m apart), each individual population consists of only one basic ploidy level. This was unexpected since there are no clear differences in abiotic conditions between populations. Taken together with the absence of an intermediate tetraploid cytotype and with reference to published world distributional patterns of different ploidy levels, this suggests a secondary contact zone. Detailed genetic study is, however, necessary to confirm this.     

The effects of reactive oxygen and nitrogen species during yeast replicative ageing

Free radicals are considered the most important cause of cellular ageing. We have investigated ageing process in the yeast Saccharomyces cerevisiae. We have compared the wild type strain with the mutant cells with constitutively active Ras oncogen, which generates increased amounts of free radicals. Increased generation of oxygen-derived free radicals resulted in the Ras mutant cells accumulation of lipofuscin-like pigments during ageing. Ageing wild type cells did not accumulate lipofuscin-like pigments. This is quite unique feature among known biological models. It may be caused by increased concentration of alpha tocopherol (the most prominent lipophilic antioxidant) in the wild type cells. In contrast, the Ras mutant cells contained decreased levels of alpha tocopherol even in the young cells. This observation indicates that the increased free radical generation can overwhelm the endogenous antioxidant system. We have documented the involvement of nitrogen-derived free radicals in the yeast metabolism. Protein nitrotyrosine, a marker of the reactive nitrogen species, has significantly increased in the senescent Ras mutant cells. The wild type cells contained basic level of nitrotyrosine corresponding to its concentration found in non-activated mammalian macrophages.     

In vitro interactions of coumarins with iron

Coumarins are a large group of natural substances with diverse pharmacological properties that may predetermine some of them for the prevention and/or treatment of cardiovascular diseases and also other pathologies. Free iron participates in the production of reactive oxygen species (ROS) and plays an important role in the pathogenesis of cardiovascular diseases. Therefore, chelation of iron may attenuate some ROS consequences, but on the other hand, reduction of ferric ions to ferrous ones is unfavourable and leads to intensification of ROS production. In this study, we have examined the interaction of iron with coumarins which has been rarely analyzed.     

Terminal restriction fragment length measurement errors are affected mainly by fragment length, G + C nucleotide content and secondary structure melting point

Several methods of molecular analysis of microbial diversity, including terminal restriction fragment length polymorphism (T-RFLP) analysis are based on measurement of the DNA fragment length. Significant variation between sequence-determined and measured length of restriction fragments (drift) has been observed, which can affect the efficiency of the identification of microorganisms in the analyzed communities. In the past, this variation has been attributed to varying fragment length and purine content. In this study, principal component analysis and multiple regression analysis were applied to find the contributions of those and several other fragment characteristics. We conclude that secondary structure melting point and G + C nucleotide content, besides the fragment length, contribute to the variation observed, whereas the contribution of purine content is less important. Incomplete denaturation of the sample at the start of electrophoretic separation of fragments has been excluded as a major cause of the variation observed. Our regression model explains the observed drift variation by approximately 56%, with standard deviation of the prediction equal to approximately 1.3 bp.     

Structure of activated thrombin-activatable fibrinolysis inhibitor, a molecular link between coagulation and fibrinolysis

Thrombin-activatable fibrinolysis inhibitor (TAFI) is a metallocarboxypeptidase (MCP) that links blood coagulation and fibrinolysis. TAFI hampers fibrin-clot lysis and is a pharmacological target for the treatment of thrombotic conditions. TAFI is transformed through removal of its prodomain by thrombin-thrombomodulin into TAFIa, which is intrinsically unstable and has a short half-life in vivo. Here we show that purified bovine TAFI activated in the presence of a proteinaceous inhibitor renders a stable enzyme-inhibitor complex. Its crystal structure reveals that TAFIa conforms to the alpha/beta-hydrolase fold of MCPs and displays two unique flexible loops on the molecular surface, accounting for structural instability and susceptibility to proteolysis. In addition, point mutations reported to enhance protein stability in vivo are mainly located in the first loop and in another surface region, which is a potential heparin-binding site. The protein inhibitor contacts both the TAFIa active site and an exosite, thus contributing to high inhibitory efficiency.