As in other bacterial pathogens, the virulence determinants of
Listeria species are clustered in genomic islands scattered along the chromosome. This review summarizes current knowledge about the ...structure, distribution and role in pathogenesis of
Listeria virulence loci. Hypotheses about the mode of acquisition and evolution of these loci in this group of Gram-positive bacteria are presented and discussed.
BACKGROUND: The objective of this study was to estimate the frequency of Y chromosome microdeletions in the Slovenian population of infertile men and to analyse the consequences of mutation in ...respect to clinical severity and prognosis. METHODS: In a controlled clinical study at the university-based medical genetics service and infertility clinic, 226 infertile men undergoing ICSI were tested. The main outcome measures included polymerase chain reaction amplification of 16 genes and gene families and 42 sequence-tagged sites in the non-recombining region of the Y chromosome, semen, testicular volume and testicular histological analysis, serum FSH concentrations, fertilization and respective pregnancy rates. RESULTS: The incidence of deletions was 4.4%: 8.6% in men with azoospermia and 1.5% in men with oligoasthenoteratozoospermia. Isolated gene deletions were not identified. No statistically significant differences in clinical outcome measures were found in patients with mutations versus patients without mutations. High fertilization (49%) and pregnancy (43%) rates with sperm of patients with Y chromosome deletions were obtained. CONCLUSIONS: Testing for gene-specific microdeletions does not contribute significantly to the sensitivity of microdeletion test. Fertilization and pregnancy rates obtained using sperm of patients with Y chromosome deletions were comparable with those achieved in conventional IVF.
Summary
A 45‐year‐old male with azoospermia was presented to us with primary infertility. We found that he had been taking testosterone due to erectile dysfunction. Upon its discontinuation, the ...normozoospermia was restored. This led to a pregnancy. In men aged 40–50, the diagnostic work up of testosterone deficiency should be in accordance with the current guidelines. Moreover, no testosterone prescription should be made without having inquired about parenthood desires. In men of the reproductive age with recent‐onset azoospermia, consider the possibility of an iatrogenic cause, primarily due to the testosterone replacement therapy. The treatment is simple: to discontinue the therapy.
Studies suggest that exercise may be neuroprotective when implemented before the clinical presentation of Parkinson's disease (PD). Levels of brain-derived neurotrophic factor (BDNF), theorized to ...play a role in neuroprotection, are affected by its genotype and exercise. Here we explore this previously unstudied interaction on age at diagnosis and severity of symptoms.
76 participants with PD submitted buccal cells to determine BDNF genotype, completed the modified Lifetime Physical Activity Questionnaire to determine exercise habits, and were assessed using the Movement Disorder Society – Unified Parkinson's Disease Rating Scale III (MDS-UPDRS-III) and the Mini-Balance Evaluations Test (MBT). For aim 1 (age at diagnosis), 60 participants (age = 69.6 ± 7.4; males = 45, females = 15) were analyzed. For aim 2 (severity of symptoms), 54 participants (age = 70.0 ± 7.6; males = 41, females = 13) were analyzed.
The final hierarchical regression model for age at diagnosis produced an R2 = 0.146, p = .033; however, the only significant variable in the final model was average moderate physical activity from ages 20s to 40s (p = .009). The regression for MDS-UPDRS III was not significant; however, the regression for MBT was, p = .0499. In the final model, 23.1% of the variance was explained. Years since diagnosis (p = .014) and average vigorous physical activity from ages 20s to 40s (p = .047) were the only predictors in the final model.
While a strong interaction between BDNF genotype and lifetime physical activity was not observed, our results suggest that lifetime exercise may be neuroprotective in PD. Specifically, higher amounts of moderate PA were associated with an older age at diagnosis.
•This is the first study to show that pre-diagnosis exercise is associated with age at diagnosis.•Higher amounts of moderate physical activity were associated with an older age at diagnosis.•Every hour increase in weekly moderate physical activity from ages 20–40 was associated with a PD diagnosis 3 months later.
A rodent plague on prairie diversity Howe, H. F.; Brown, J. S.; Zorn-Arnold, B.
Ecology letters,
January 2002, Letnik:
5, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Selective vole (Microtus pennsylvanicus) suppression of prairie grasses and forbs in experimental restorations suggests why many of the plants are likely to be uncommon in nature. Vole herbivory ...reduced densities of legumes and grasses and increased unpalatable forbs in replicated plantings in Illinois: six otherwise common species (Dalea purpurea, Desmanthus illinoensis, Elymus canadensis, Panicum virgatum, Phalaris arundinacea, Sorghastrum nutans) declined 27–89% in abundance, whereas two species (Echinacea purpurea and Rudbeckia hirta) increased by 61% and 1023%. Species number dropped by 19% and plant diversity (Simpson’s D) by 37% in one treatment to which voles had access. Plots were planted with 18 prairie species of the region, but in even distributions of 35 or 350 seeds species−1 m−2, rather than skewed in favour of large C4 grasses common in native remnants. Manipulation of plant composition and vole access revealed what are likely to be formative effects of rodent herbivory on vegetative composition. These experimental tallgrass communities appear to be assembling from plant species that voles prefer not to eat.
We assessed the role of the actin‐polymerizing protein, ActA, in host cell invasion by Listeria monocytogenes. An in frame ΔactA mutant was constructed in a hyperinvasive strain of prfA* genotype, in ...which all genes of the PrfA‐dependent virulence regulon, including actA, are highly expressed in vitro. Loss of ActA production in prfA* bacteria reduced entry into Caco‐2, HeLa, MDCK and Vero epithelial cells to basal levels. Reintroduction of actA into the ΔactA prfA* mutant fully restored invasiveness, demonstrating that ActA is involved in epithelial cell invasion. ActA did not contribute to internalization by COS‐1 fibroblasts and Hepa 1‐6 hepatocytes. Expression of actA in Listeria innocua was sufficient to promote entry of this non‐invasive species into epithelial cell lines, but not into COS‐1 and Hepa 1‐6 cells, indicating that ActA directs an internalization pathway specific for epithelial cells. Scanning electron microscopy of infected Caco‐2 human enterocytes suggested that this pathway involves microvilli. prfA* bacteria, but not wild‐type bacteria (which express PrfA‐dependent genes very weakly in vitro) or prfA*ΔactA bacteria, efficiently invaded differentiated Caco‐2 cells via their apical surface. Microvilli played an active role in the phagocytosis of the prfA* strain, and actA was required for their remodelling into pseudopods mediating bacterial uptake. Thus, ActA appears to be a multifunctional virulence factor involved in two important aspects of Listeria pathogenesis: actin‐based motility and host cell tropism and invasion.
Summary
The aim of this study was to examine whether there is an association among genetic variability in leptin (LEP) and leptin receptor (LEPR) genes and male infertility. We performed a ...case–control study and were searching for an association between polymorphisms of LEP and LEPR genes and male infertility. The study group consisted of 317 patients with idiopathic infertility and a control group of 241 fertile men from Slovenia. Four single nucleotide polymorphisms (SNPs) in LEP gene and four single nucleotide polymorphisms (SNPs) in LEPR gene were chosen and genotyped. Statistically significant SNP was further validated in additional 255 infertile patients and 168 controls from Serbia and Macedonia. In the Slovenian population, we found a statistically significant difference in genotype distribution for rs10244329 polymorphism in LEP gene (recessive genotype model, p value = 0.048). The trend toward statistically significant difference in genotype distribution for rs10244329 polymorphism was confirmed in the Serbian and Macedonian populations (p value = 0.07). Our data suggest that genetic variability in the LEP gene might be associated with male infertility warranting further confirmation and mechanistic investigations.
Abstract To elucidate the effects of inflammation on sperm quality, this study analysed classical sperm characteristics, leukocytes and elastase in neat semen, and sperm apoptotic markers, i.e. ...changes in plasma membrane phospholipid asymmetry, mitochondrial membrane potential (MMP), DNA integrity and intracellular reactive oxygen species (ROS), in semen prepared by density gradient using flow cytometry from 348 men of infertile couples. Increased leukocytes (⩾0.1 × 106 /ml) were associated with a decreased sperm concentration, motility and normal morphology ( P ⩽ 0.001). Sperm necrosis and DNA denaturation were increased (31.3 versus 26.6%, P = 0.020; 15.5 versus 11.5%, P = 0.011, respectively), whereas spermatozoa with normal MMP were decreased (64.1 versus 70.0%, P = 0.004). High leukocyte levels (⩾1 × 106 /ml) were not associated with any of the observed sperm parameters. At low elastase concentration (100–290 μg/l), DNA denaturation was higher (16.1 versus 10.5%, P = 0.024) compared with very low elastase concentration (<100 μg/l). A high elastase concentration (290–1000 μg/l) was associated with higher ROS index compared with low elastase concentration (1.28 versus 1.01, P = 0.016). Slightly increased leukocytes and elastase are associated with slightly poorer sperm characteristics and/or increased sperm necrosis, DNA denaturation and intracellular ROS and decreased MMP.
PDF
