Age and Gender Trends in the Prevalence of Markers for Hepatitis E Virus Exposure in the Heterogeneous Bulgarian Population.

The prevalence of hepatitis E virus (HEV) in the Bulgarian population remains underestimated. The aim of the present study was to evaluate age and gender trends in HEV prevalence in the heterogeneous Bulgarian population. Stored serum samples from blood donors and different patient sub-populations-kidney recipients (KR), patients with Guillain-Barre syndrome (GBS), Lyme disease (LD), patients with liver involvement and a clinical diagnosis other than viral hepatitis A and E (non-AE), hemodialysis (HD) and HIV-positive patients (HIV)-were retrospectively investigated for markers of past and recent/ongoing HEV infection. The estimated overall seroprevalence of past infection was 10.6%, ranging from 5.9% to 24.5% for the sub-populations evaluated, while the seroprevalence of recent/ongoing HEV infection was 7.5%, ranging from 2.1% to 20.4%. The analysis of the individual sub-populations showed a different prevalence with respect to sex. In regard to age, the cohort effect was preserved, as a multimodal pattern was observed only for the GBS sub-population. Molecular analysis revealed HEV 3f and 3e. The type of the population is one of the main factors on which the anti-HEV prevalence depends, highlighting the need for the development of guidelines related to the detection and diagnosis of HEV infection with regard to specific patient populations.

Yeasts from temperate forests.

Yeasts are ubiquitous in temperate forests. While this broad habitat is well-defined, the yeasts inhabiting it and their life cycles, niches, and contributions to ecosystem functioning are less understood. Yeasts are present on nearly all sampled substrates in temperate forests worldwide. They associate with soils, macroorganisms, and other habitats and no doubt contribute to broader ecosystem-wide processes. Researchers have gathered information leading to hypotheses about yeasts' niches and their life cycles based on physiological observations in the laboratory as well as genomic analyses, but the challenge remains to test these hypotheses in the forests themselves. Here, we summarize the habitat and global patterns of yeast diversity, give some information on a handful of well-studied temperate forest yeast genera, discuss the various strategies to isolate forest yeasts, and explain temperate forest yeasts' contributions to biotechnology. We close with a summary of the many future directions and outstanding questions facing researchers in temperate forest yeast ecology. Yeasts present an exciting opportunity to better understand the hidden world of microbial ecology in this threatened and global habitat.

The effect of antithrombotic therapy on the recurrence of placenta-mediated diseases in pregnancy.

OBJECTIVES: To analyze the recurrence rate of placenta-mediated diseases (PMDs) such as preeclampsia (PE) and/or intrauterine growth restriction (IUGR), intrauterine fetal death (IUFD), and placental abruption (PA) in high-risk patients on antithrombotic therapy (AT) because of a previous obstetrical history for such complications. METHODS: The study group (SG) included 150 patients to whom either 100 mg of aspirin or low-molecular weight heparin (LMWH) was administered due to a previous history of PMDs. The AT in the SG was started before 16 gestational weeks (g.w.). The patients in the first control group (CG-1) were 150 who also had a previous obstetrical history of PMDs, but did not receive antithrombotic therapy (AT) throughout their ongoing pregnancies. The second CG (CG-2) comprised 320 patients with a previous history of normally developing pregnancies and without AT throughout their ongoing pregnancies. RESULTS: The total percentage of PE in pregnant patients from the SG was 25.3% (38/150 patients), with 22.2% (10/45) in the SG on AT only with LDA (SG-LDA group), 25% (17/68) in the SG on AT only with LMWHs (SG-LMWH group) and 29.7% (11/37) in the SG on combined AT with LDA and LMWHs (SG-LDA + LMWH group), as opposed to 18.67% (28/150) in CG-1 and 0.62% (2/320) in CG-2. The recurrent severe PE/total PE ratio in the SG was 44.7% (17/38), with 30% (3/10) in the SG-LDA group, 47% (8/17) in the SG-LMWH group and 54% (6/11) in the SG-LDA + LMWH group, against 75% (21/28) in CG-1. There were no cases with severe PE in CG-2. All cases with recurrent IUGR from the SG were equal to 13.3% (20/150), with 13.3% (6/45) in the SG-LDA group, 11.76% (8/68) in the SG-LMWH group and 16.2% (6/37) in the SG-LDA + LMWH group, as compared to 30% (45/150) in CG-1 and 5% (16/320) in CG-2. As a whole, the overall recurrence rate of PMDs in the SG was 38.67% (58/150), with 35.56% (16/45) in the SG-LDA group, 36.76% (25/68) in the SG-LMWH group and 45.9% (17/37) in the SG-LDA + LMWH group, as compared to 50.67% (76/150) in CG-1 and 5.94% (19/320) in CG-2. CONCLUSION: AT had a partial beneficial effect on the prophylaxis of recurrent PMDs. On the one hand, AT led to a significant reduction in the recurrent severe PE/total PE ratio, as well as in the total PMDs' recurrence rate in the SG as compared to the one in CG-1. On the other hand, the percentage of recurrent PMDs still remained significantly higher in the SG as compared to CG-2. Pregnant patients with previous PMDs still need close surveillance in subsequent pregnancies as they remain at a high risk for complications.

DNA barcoding revealed Nematodospora valgi gen. nov., sp. nov. and Candida cetoniae sp. nov. in the Lodderomyces clade.

During a yeast biodiversity survey conducted in 2009-2011 in Bulgaria (South Eastern Europe) five strains of a novel ascomycetous yeast species were isolated from the beetle Valgus hemipterus (Cetoniinae) collected from two localities, namely Osogovska Planina Mountain and Nature Park Zlatni Pyasatsi. Phylogenetic analysis using combined sequences of the D1/D2 domains of the large subunit ribosomal DNA (LSU rDNA) and the internal transcribed spacers 1 + 2 regions (ITS1+2) placed the novel species on a separate branch near the basal part of the Lodderomyces clade. The novel species has a unique ascospore morphology distinct from those of the closely related teleomorphic genus Lodderomyces. Based on phylogenetic analysis and morphology of the ascospores we propose Nematodospora valgi gen. nov., sp. nov. to accommodate these isolates (MB811804 D37S(T), MB802458). Two strains of a novel anamorphic yeast species were isolated from the beetles Cetonia aurata and Oxythyrea funesta (Cetoniinae) collected in East Rhodopies and Sofia city, respectively. DNA barcoding analysis placed the new yeast species within the Candida parapsilosis subclade. Here, we present the description of a new yeast species, Candida cetoniae sp. nov. (IMB1R2(T), MB803501) to accommodate these two strains. The ecology and biogeography of the insect-associated yeasts of the Lodderomyces clade is discussed.

New X-chromosomal interactors of dFMRP regulate axonal and synaptic morphology of brain neurons in Drosophila melanogaster.

Fragile X syndrome is a neuro-developmental disease caused by transcriptional inactivation of the gene FMR1 (fragile X mental retardation 1) and loss of its protein product FMRP. FMRP has multiple neuronal functions which are implemented together with other proteins. To better understand these functions, the aim of this study was to reveal new protein interactors of dFMRP. In a forward genetic screen, we isolated ethyl-metanesulphonate-induced X-chromosomal modifier mutations of dfmr1. Four of them were identified and belong to the genes: peb/hindsight, rok, shaggy and ras. They are dominant suppressors of the dfmr1 overexpression wing phenotype 'notched wings'. These mutations dominantly affected the axonal and synaptic morphology of the lateral ventral neurons (LNv's) in adult Drosophila brains. Heterozygotes for each of them displayed effects in the axonal growth, pathfinding, branching and in the synapse formation of these neurons. Double heterozygotes for both dfmr1-null mutation and for each of the suppressor mutations showed robust genetic interactions in the fly central nervous system. The mutations displayed severe defects in the axonal growth and synapse formation of the LNv's in adult brains. Our biochemical studies showed that neither of the proteins - Rok, Shaggy, Peb/Hnt or Ras - encoded by the four mutated genes regulates the protein level of dFMRP, but dFMRP negatively regulates the protein expression level of Rok in the brain. Altogether, these data suggest that Rok, Shaggy, Peb/Hnt and Ras are functional partners of dFMRP, which are required for correct wing development and for neuronal connectivity in Drosophila brain.

A cross-talk of decidual stromal cells, trophoblast, and immune cells: a prerequisite for the success of pregnancy.

Embryo implantation and formation of a functional placenta are complex processes that require a plethora of regulatory mechanisms involving both mother and embryo cells. Recently, an important role in this complicated cells and factors network was assigned to the decidual stromal cells (DSC) and trophoblast cells. Decidualization includes biochemical changes that trigger DSC to produce a number of factors required for the implantation and induction of immunotolerance in maternal immune system. Immunotolerance is achieved by a cascade of strictly controlled events starting with selective homing of immune cells to the feto-maternal site, regulated proliferation, and predominant differentiation into a regulatory type of immune cells. Furthermore, cytotoxic effector functions are reduced owing to the influence of steroid hormones, factors, cytokines, and inhibitory receptors. Altogether the entire immune system of the mother is switched to tolerogenic functional state which is a prerequisite for the successful maintenance of pregnancy.

Stem cells in the reproductive system.

This review article summarizes current knowledge on regulation, functions, and capacities of stem cells in the female and male reproductive tract. Major locations in which pluripotent cells reside and from where they can be isolated are the ovaries, the endometrium, the decidua, and the testis. They include oocytes, embryonic stem cells, trophoblast stem cells, and spermatogonial stem cells, but also several side populations, which can be obtained after certain isolation and culture procedures. The potential of pluripotent cells in the reproductive tract to differentiate is manifold, but heterogenous, depending upon their respective origin. As stem cells have a potential for future application in transplantation and regenerative medicine, this article also reviews the literature on major histocompatibility complex expression on stem cells of the reproductive tract, because of its immunogenic effects, but also because of its potential expression of HLA-G, a potent immunomodulator mainly associated with trophoblast cells.

Photodynamic efficacy of water-soluble Si(IV) and Ge(IV) phthalocyanines towards Candida albicans planktonic and biofilm cultures.

Water-soluble phthalocyanine complexes of silicon (SiPc1) and germanium (GePc1) were synthesized. The absorbance of SiPc1 in water was with minor aggregation while GePc1 strongly aggregated in water. The fluorescence data in water showed low quantum yields of 0.073 (SiPc1) and 0.01 (GePc1) and similar lifetimes of 4.07 ns and 4.27 ns. The uptake of SiPc1 into Candida albicans cells was two orders of magnitude lower as compared to GePc1 and for both was dependent on the cell density. Fungal cells in suspension were completely inactivated after SiPc1 (1.8 µM) at soft light radiation (50 J cm(-2), 60 mW cm(-2)). The fungal biofilm formed on denture acrylic resin was inactivated with 3 log after fractionated light irradiation.

Non-aggregated Ga(III)-phthalocyanines in the photodynamic inactivation of planktonic and biofilm cultures of pathogenic microorganisms.

Visible light-absorbing cationic water-soluble gallium(III) phthalocyanines (GaPcs) peripherally substituted with four and eight methylpyridyloxy groups were synthesized and investigated as antimicrobial photodynamic sensitizers. The inserted large gallium ion in the phthalocyanine ligand is axially substituted by one hydroxyl group which prevents aggregation of the complexes in aqueous solution. The cellular uptake and the photodynamic activity for the representative strains of the Gram positive bacteria methicillin-resistant Staphylococcus aureus(MRSA) and Enterococcus faecalis, of the Gram negative bacterium Pseudomonas aeruginosa and of the fungus Candida albicans in planktonic phase were studied. The tetra-methylpyridyloxy substituted GaPc1 showed lower cellular uptake compared to the octa-methylpyridyloxy substituted GaPc2. The photodynamic activity of the GaPcs was studied in comparison to methylene blue (MB) and a photodynamically active Zn(II)-phthalocyanine with the same substitution (ZnPcMe). Photodynamic treatment with 3.0 µM GaPc1 at mild light conditions (50 J cm(-2), 60 mW cm(-2)) resulted in a high photoinactivation of the microorganisms in the planktonic phase nevertheless the dark toxicity of GaPc1 towards MRSA and E. faecalis. GaPcs against fungal biofilm grown on polymethylmethacrylate (PMMC) resin showed a complete inactivation at a higher concentration of GaPc2 (6.0 µM) and of the referent sensitizer ZnPcMe. However, the bacterial biofilms were not susceptible to treatment of GaPcs with only 1-2 log reduction of the biofilm. The bacterial biofilm E. faecalis was effectively inactivated only with MB. The water-soluble octa-methylpyridyloxy substituted GaPc2 has a potential value for photodynamic treatment of C. albicans biofilms formed on denture acrylic resin.

Rare mutations in the PIK3CA gene contribute to aggressive endometrial cancer.

The molecular basis of endometrial cancer (EC), a common gynecologic malignancy, often includes mutational activation of the PIK3CA and KRAS genes. We aimed to determine the distribution of mutations in the two genes depending on patient clinocopathological characteristics. We sequenced exon 1 of the KRAS gene and exons 9 and 20 of the PIK3CA gene in 108 consecutive EC tumor samples. PIK3CA mutations were present in 24 of the 108 (22.2%) cases and KRAS mutations in 18 of the 108 (16.7%) cases. PIK3CA mutations occurred more frequently in KRAS-mutated samples (7/18, 38.9%; p = 0.06) than in KRAS wild type (17/90, 18.9%) and showed a very high frequency in metastatic tumors (4/9, 44.4%; p = 0.1) and in samples displaying serous differentiation-serous and mixed endometrioid/serous tumors (6/12, 50.0%; p = 0.021)-where KRAS mutations were rare (11.1% and 16.7%, respectively) and did not exist independently of a PIK3CA mutation. Non-hotspot (i.e., non-E542K, -E545K, and -H1047R) mutations in the PIK3CA gene showed higher frequency in metastatic cases (3/9, 33.3%; p = 0.05). Tumors displaying serous differentiation showed a particular pattern-they harbored exclusively mutations in PIK3CA exon 20 (5/12, 41.7%; p = 0.005) and most of these were non-hotspot (4/12, 33.3%; p = 0.02). In all other comparisons exons 9 and 20 mutation distribution did not differ. These results suggest the need for further exploration of the significance of PIK3CA mutations in respect to aggressive EC.

CHEK2 I157T and endometrial cancer.

Endometrial cancer (EC) is the most common malignancy of the female reproductive system in the industrialized world. Similar to other common diseases, gene variations are believed to be able to alter an individual's predisposition to developing the disease. The CHEK2 gene encodes a tumor suppressor that takes part in various cell processes, including cell cycle regulation, DNA repair, and apoptosis. The polymorphic variant Ile157Thr in exon 3 of the gene has been demonstrated to enhance the risk of several types of cancer and at the same time to reduce the risk for developing other cancer types. To study the significance of CHEK2 I157T for EC, we have genotyped 268 patients and 449 female controls. We found carriers of I157T more often among controls than we did among patients (2.45% vs. 1.75%), but the difference was not statistically significant. Case-only analysis revealed that the variant is overrepresented in patients diagnosed at 75 or more years of age (9.09%, p = 0.05) and in those with deep myometrial invasion (3.85%, p = 0.06). The highest frequency was observed in patients with both the aforementioned characteristics (20%, p = 0.01). Tumors of I157T carriers showed endometrioid, clear cell, and mucinous morphology, which suggested that the variant may not be restricted to a certain histotype of the disease and could even be overrepresented in rare ones. This study is the first to explore the association between germline CHEK2 I157T and EC. It suggests the need for further large-scale evaluation of the role this variant plays in endometrial carcinogenesis.

[Endometriosis and the role of the integrins in the pathogenesis of the endometriosis].

The endometriosis is gynecological disease what is characterized with the presence of endometrial lesions are composed of endometrial epithelial and stromal cells outside of the uterus. There are many theories for the development of the disease endometriosis. The most widely accepted theory is the theory what is postulated the endometriosis is a result of retrograde menstruation. The essential stage in the process of development of endometrial lesions is the process of adhesion of endometrial cells on the peritoneal surface and on the organs, are situated in the peritoneal cavity. The adhesion molecules (integrins) have the most essential role in this first stage. The integrins are cell surface receptors with glycoprotein structure. They have part in process of adhesion of the endometrial cells to the proteins from EC matrix outside the uterus. The integrins have part like signal molecules in the processes of proliferation and invasion of endometrial implants. They are very essential molecules what influence the viability of endometrial implants as well as the angiogenesis in the new forming endometrial implants. Improvement of the studies, related to the roles of the integrins in the pathogenesis of endometriosis would be give new possibilities to search more effective methods for therapy of the endometriosis.

Prediction of hybridization and melting for double-stranded nucleic acids.

This article presents a general statistical mechanical approach to describe self-folding together with the hybridization between a pair of finite length DNA or RNA molecules. The model takes into account the entire ensemble of single- and double-stranded species in solution and their mole fractions at different temperatures. The folding and hybridization models deal with matched pairs, mismatches, symmetric and asymmetric interior loops, bulges, and single-base stacking that might exist at duplex ends or at the ends of helices. All possible conformations of the single- and double-stranded species are explored. Only intermolecular basepairs are considered in duplexes at this stage.In particular we focus on the role of stacking between neighboring nucleotide residues of single unfolded strands as an important source of enthalpy change on helix formation which has not been modeled computationally thus far. Changes in the states of the single strands with temperature are shown to lead to a larger heat effect at higher temperature. An important consequence of this is that predictions of enthalpies, which are based on databases of nearest-neighbor energy parameters determined for molecules or duplexes with lower melting temperatures compared with the melting temperatures of the oligos for which they are used as a predictive tool, will be underestimated.