A Potential Association between Helicobacter pylori CagA EPIYA and Multimerization Motifs with Cytokeratin 18 Cleavage Rate during Early Apoptosis

Background and Aims: Helicobacter pylori is a highly diverse pathogen, which encounters epithelial cells as the initial defense barrier during its lifelong infection. The structure of epithelial cells can be disrupted through cleavage of microfilaments. Cytokeratin 18 (CK18) is an intermediate filament, the cleavage of which is considered an early event during apoptosis following activation of effector caspases. Methods: Helicobacter pylori strains were isolated from 76 dyspeptic patients. cagA 3’ variable region and CagA protein status were analyzed by PCR and western blotting, respectively. Eight hours post‐co‐culture of AGS cells with different H. pylori strains, flow cytometric analysis was performed using M30 monoclonal antibody specific to CK18 cleavage‐induced neo‐epitope. Results: Higher rates of CK18 cleavage were detected during co‐culture of AGS cells with H. pylori strains bearing greater numbers of cagA EPIYA‐C and multimerization (CM) motifs. On the other hand, H. pylori strains with greater numbers of EPIYA‐B relative to EPIYA‐C demonstrated a decrease in CK18 cleavage rate. Thus, H. pylori‐mediated cleavage of CK18 appeared proportional to the number of CagA EPIYA‐C and CM motifs, which seemed to be downplayed in the presence of EPIYA‐B motifs. Conclusions: Our observation associating the heterogeneity of cagA variants with the potential of H. pylori strains in the induction of CK18 cleavage as an early indication of apoptosis in gastric epithelial cells supports the fact that apoptosis may be a type‐specific trait. However, additional cagA‐targeted experiments are required to clearly identify the role of EPIYA and CM motifs in apoptosis and/or the responsible effector molecules.     

Interstitial lung disease and pulmonary fibrosis in Hermansky-Pudlak syndrome type 2, an adaptor protein-3 complex disease

Pulmonary fibrosis develops in Hermansky-Pudlak syndrome (HPS) types 1 and 4. Limited information is available about lung disease in HPS type 2 (HPS-2), which is characterized by abnormal function of the adaptor protein-3 (AP-3) complex. To define lung disease in HPS-2, one child and two adults with HPS-2 were evaluated at the National Institutes of Health on at least two visits, and another child was evaluated at the University of Texas Health Science Center San Antonio. All four subjects with HPS-2 had findings of interstitial lung disease (ILD) on a high-resolution computed tomography scan of the chest. The predominant feature was ground glass opacification. Subject 1, a 14-year-old male, and subject 4, a 4-year-old male, had severe ILD, pulmonary fibrosis, secondary pulmonary hypertension and recurrent lung infections. Lung biopsy performed at 20 months of age in subject 1 revealed interstitial fibrosis and prominent type II pneumocyte hyperplasia without lamellar body enlargement. Subject 2, a 27-year-old male smoker, had mild ILD. Subject 3, a 22-year-old male nonsmoker and brother of subject 2, had minimal ILD. Severe impairment of gas exchange was found in subjects 1 and 4 and not in subjects 2 or 3. Plasma concentrations of transforming growth factor-β1 and interleukin-17A correlated with severity of HPS-2 ILD. These data show that children and young adults with HPS-2 and functional defects of the AP-3 complex are at risk for ILD and pulmonary fibrosis.     

Functional response,switching, and prey-stage preference of Scolothrips longicornis (Thysanoptera: Thripidae) on Schizotetranychus smirnovi (Acari: Tetranychidae)

The objective of this study was to evaluate the efficiency of Scolothrips longicornis Priesner (Thysanoptera: Thripidae) as a biocontrol agent of Schizotetranychus smirnovi Wainstein (Acari: Tetranychidae), a key pest of almond trees in the southwest of Iran. To achieve a strategy for the control of this pest, it is important to understand foraging behavior (Functional response, switching, and prey-stage preference) of S. longicornis. The predator exhibited a type III functional response when it was offered S. smirnovi protonymphs at seven densities (2, 4, 8, 16, 32 .64 and 128). Based on the random predator equation, the estimated attack rate (a), handling time (T_h), and maximum rate of predation were 0.0048 h^?1, 0.4816 h, and 49.84 per day, respectively. Using the Murdoch's model, switching behavior was observed in S. longicornis. The predator switched from one stage when it becomes rare to another more abundant stage. S. longicornis fed on all stages but preferred S. smirnovi larvae and protonymphs. The results of this study revealed that S. longicornis could be used in the integrated management of S. smirnovi. However, further field studies are needed to verify this hypothesis.     

Sickness Absence following Coronary Revascularisation. A National Study of Women and Men of Working Age in Sweden 1994-2006

Background

Evidence based and gender specific knowledge about sickness absence following coronary revascularisation is lacking. The objective was to investigate sickness absence after a first coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) among women and men in a national Swedish study.

Materials and Methods

All patients 30–63 years of age, who underwent a first CABG (n = 22,985, 16% women) or PCI (40,891, 22% women) in Sweden between 1994 and 2006 were included. Information on sickness absence, co-morbidity, and other patient characteristics was obtained from national registers. Long-term sickness absence (LTSA) was defined as >180 and >90 sick-leave days in the first sick-leave spell following CABG and PCI, respectively. Prevalence ratio (PR) and 95% confidence interval (CI) of LTSA were calculated.

Findings

LTSA followed the interventions in 41% and 36% for CABG and PCI patients, respectively. Women had more often LTSA compared with men, (CABG PR = 1.23: 95% CI 1.19–1.28 and PCI PR = 1.19; 95% CI 1.16–1.23). A history of sickness absence the year before the intervention increased the risk for LTSA after the intervention in both genders. Among women, older age, or being self employed or unemployed was associated with a lower risk for LTSA. Among men previous cardiovascular disease, diabetes and low socio-economic position increased the risk. During the observation period, there was no change in sickness absence rates among PCI patients but an increase among CABG patients adjusting for patient characteristics.

Conclusion

This national study covering a 13-year period shows that long-term sickness absence following coronary revascularisation is common in Sweden, especially among women, and is associated with socio-economic position, co-morbidity, and sickness absence during the year before the intervention. Gender specific scientific knowledge about use and effects of sickness absence following coronary revascularisation is warranted for the patients, the treating physicians, the healthcare sector, and the society.     

Association between cagA and vacA genotypes and pathogenesis in a Helicobacter pylori infected population from South-eastern Sweden

ABSTRACT: BACKGROUND: Chronic gastritis, peptic ulcer disease, and gastric cancer have been shown to be related toinfection with Helicobacter pylori (H. pylori). Two major virulence factors of H. pylori,CagA and VacA, have been associated with these sequelae of the infection. In this study, totalDNA was isolated from gastric biopsy specimens to assess the cagA and vacA genotypes. RESULTS: Variations in H. pylori cagA EPIYA motifs and the mosaic structure of vacA s/m/i/dayregions were analysed in 155 H. pylori-positive gastric biopsies from 71 individuals usingPCR and sequencing. Analysis of a possible association between cagA and vacA genotypesand gastroduodenal pathogenesis was made by logistic regression analysis. We found that H. pylori strains with variation in the number of cagA EPIYA motif variants present in the samebiopsy correlated with peptic ulcer, while occurrence of two or more EPIYA-C motifs wasassociated with atrophy in the gastric mucosa. No statistically significant relation betweenvacA genotypes and gastroduodenal pathogenesis was observed. CONCLUSIONS: The results of this study indicate that cagA genotypes may be important determinants in thedevelopment of gastroduodenal sequelae of H. pylori infection. In contrast to other studies,vacA genotypes were not related to disease progression or outcome. In order to fullyunderstand the relations between cagA, vacA and gastroduodenal pathogenesis, themechanisms by which CagA and VacA act and interact need to be further investigated.     

Synthesis and SAR study of 4,5-diaryl-1H-imidazole-2(3H)-thione derivatives,as potent 15-lipoxygenase inhibitors

A series of 4,5-diaryl-1H-imidazole-2(3H)-thione was synthesized and their inhibitory potency against soybean 15-lipoxygenase and free radical scavenging activities were determined. Compound 11 showed the best IC₅₀ for 15-LOX inhibition (IC₅₀ = 4.7 μM) and free radical scavenging activity (IC₅₀ = 14 μM). Methylation of SH at C₂ position of imidazole has dramatically decreased the 15-LOX inhibition and radical scavenging activity as it can be observed in the inactive compound 14 (IC₅₀ >250 μM). Structure activity similarity (SAS) showed that the most important chemical modification in this series was methylation of SH group and Docking studies revealed a proper orientation for SH group towards Fe core of the 15-LOX active site. Therefore it was concluded that iron chelating could be a possible mechanism for enzyme inhibition in this series of compounds.     

Association of interacting genes in the toll-like receptor signaling pathway and the antibody response to pertussis vaccination

Background

Activation of the Toll-like receptor (TLR) signaling pathway through TLR4 may be important in the induction of protective immunity against Bordetella pertussis with TLR4-mediated activation of dendritic and B cells, induction of cytokine expression, and reversal of tolerance as crucial steps. We examined whether single nucleotide polymorphisms (SNPs) in genes of the TLR4 pathway and their interaction are associated with the response to whole-cell vaccine (WCV) pertussis vaccination in 490 one-year-old children.

Methodology/Principal Findings

We analyzed associations of 75 haplotype-tagging SNPs in genes in the TLR4 signaling pathway with pertussis toxin (PT)-IgG titers. We found significant associations between the PT-IgG titer and SNPs in CD14, TLR4, TOLLIP, TIRAP, IRAK3, IRAK4, TICAM1, and TNFRSF4 in one or more of the analyses. The strongest evidence for association was found for two SNPs (rs5744034 and rs5743894) in TOLLIP that were almost completely in linkage disequilibrium, provided statistically significant associations in all tests with the lowest p-values, and displayed a dominant mode of inheritance. However, none of these single gene associations would withstand correction for multiple testing. In addition, Multifactor Dimensionality Reduction Analysis, an approach that does not need correction for multiple testing, showed significant and strong two and three locus interactions between SNPs in TOLLIP (rs4963060), TLR4 (rs6478317) and IRAK1 (rs1059703).

Conclusions/Significance

We have identified significant interactions between genes in the TLR pathway in the induction of vaccine-induced immunity. These interactions underline that these genes are functionally related and together form a true biological relationship in a protein-protein interaction network. Practically all our findings may be explained by genetic variation in directly or indirectly interacting proteins at the extra- and intracytoplasmic sites of the cell membrane of antigen-presenting cells, B cells, or both. Fine tuning of interacting proteins in the TLR pathway appears important for the induction of an optimal vaccine response.     

Influence of psychosocial work-related factors on conventional risk factors of ischemic heart disease and homocysteine in Slovenian male workers

The influence of psychosocial work-related factors on the conventional risk factors of ischemic heart disease (IHD), particularly on the lipid changes and their effect on homocysteine is studied in this paper. Employed males aged 35 to 55 with angina pectoris or a myocardial infarction (IHD group) were compared to a group of individuals without ischemic heart disease (Control Group). Psychosocial factors were assessed using a Swedish Theorell questionnaire. The IHD Group was found to be at a higher risk of IHD due to higher work demands (OR = 1.25), worse job control (OR = 1.23), frequent smoking (OR = 2.2), leadership positions (OR = 3.97), higher BMI (p = 0.059) and higher levels of triglycerides (p = 0.005) and LDL-cholesterol (OR = 1.65). The level of HDL-cholesterol was significantly lower (1.0 vs. 1.4 mmol/L, p < 0.001, OR = 1.64), while the level of C-reactive protein (9.1 vs. 1.8 mg/L) and Interleukin-6 (6.5 vs. 1.6 ng/L) was higher. Homocysteine levels showed borderline significance (p = 0.056). Our study suggests a possible influence of psychosocial work-related factors on IHD risk factors, most of all on low HDL-cholesterol. No connection was found between psychosocial factors and the homocysteine level, shown to be an IHD risk factor at lower levels of approximately 10 micromol/L.     

HGF/SF Induces Mesothelial Cell Migration and Proliferation by Autocrine and Paracrine Pathways

Mesothelial repair differs from that of other epithelial-like surfaces as healing does not occur solely by centripetal in-growth of cells as a sheet from the wound margins. Mesothelial cells lose their cell-cell junctions, divide, and adopt a fibroblast-like morphology while scattering across and covering the wound surface. These features are consistent with a cellular response to hepatocyte growth factor/scatter factor (HGF/SF). In this study, we examined the ability of mesothelial cells to secrete HGF/SF and investigated its possible role as an autocrine regulator of mesothelial cell motility and proliferation. We found that human primary mesothelial cells expressed HGF/SF mRNA and secreted active HGF/SF into conditioned medium as determined by ELISA and in a scattering bioassay. These cells also expressed the HGF/SF receptor, Met, as shown by RT-PCR and by Western blot analysis and immunofluorescence. Incubation of mesothelial cells with neutralizing antibodies to HGF/SF decreased cell migration to 25% of controls, whereas addition of HGF/SF disrupted cell-cell junctions and induced scattering and enhanced mesothelial cell migration. Furthermore, HGF/SF showed a small but significant mitogenic effect on all mesothelial cell lines examined. In conclusion, HGF/SF is produced by mesothelial cells and induces both motility and proliferation of these cells. These data are consistent with HGF/SF playing an autocrine role in mesothelial healing.