Prevalence and risk factors of Helicobacter pylori infection in military personnel: a systematic review and meta-analysis

Background and Aims: Helicobacter pylori infection is prevalent and recognized as a major cause of gastrointestinal diseases in the world. Previous studies on the prevalence of H. pylori infection in military personnel have shown some conflicting results. This study aimed to estimate the pooled prevalence of H. pylori infection and evaluate its risk factors in military personnel. Methods: The PubMed, EMBASE, and Cochrane Library databases were searched. We pooled the prevalence of H. pylori infection in military personnel using a random-effect model. Metaregression analysis was used to explore the sources of heterogeneity. Pooled proportion of H. pylori infection with 95% confidence interval (CI) was calculated. Results: Sixteen studies were included. Meta-analysis showed that the overall prevalence of H. pylori infection was 32% (95% CI = 31–33) in military personnel. There was a significant heterogeneity. Metaregression analysis showed that study region (P = 0.0004) and publication year (P = 0.023) were the potential sources of heterogeneity. In the subgroup analysis by study region, the highest prevalence was found in Asia (50.2%; 95% CI = 49–51.4). In the subgroup analysis by diagnostic methods for H. pylori, the highest prevalence was found when urea breath test was employed (47.9%; 95% CI = 46.5–49.3). The most common risk factor for H. pylori infection was familial aggregation, followed by living environment and age. Conclusion: H. pylori infection is common in military personnel. In future, we may require appropriate population screening for H. pylori infection by multiple diagnostic tests and increase the knowledge and awareness of the bacterial transmission among military personnel.

Risk factors for ruptured intracranial aneurysms

Background & objectives: The treatment of unruptured intracranial aneurysms (IAs) remains controversial; the ability to predict the risk of rupture for an aneurysm would be of clinical value. The aim of this study was to determine and evaluate the predictive value of the risk factors of IA rupture. Methods: This retrospective study involved 379 consecutive patients with 441 aneurysms between August 2011 and July 2014. Based on clinical data and computed tomography angiography findings, the potential of risk factors to predict the aneurysmal rupture was assessed using statistical methods. Results: Age, hypertension, heart disease, diabetes mellitus, cerebral atherosclerosis, aneurysms located at the internal carotid artery (ICA) and neck width (N) correlated negatively with rupture risk. Aneurysms located at the anterior communicating artery, bifurcation, irregularity, with a daughter sac, aneurysm height, maximum size, aspect ratio (AR), height-to-width ratio and bottleneck factor were significantly and positively correlated with rupture risk. The multivariate logistic regression model revealed that bifurcation aneurysm, irregular aneurysm and high AR increased the rupture risk, while cerebral atherosclerosis, aneurysm located on the ICA and greater N decreased the risk. Receiver operating characteristic analysis of AR curve values differed according to circumstances. Interpretation & conclusions: Cerebral atherosclerosis, location in the ICA and larger N were the protective factors against aneurysm rupture, and IAs located at bifurcations, irregular shape and increased AR indicated a greater rupture risk.

Effects of fluoride on proliferation and mineralization in periodontal ligament cells in vitro

Fluoride, which is often added to toothpaste or mouthwash in order to protect teeth from decay, may be a novel therapeutic approach for acceleration of periodontal regeneration. Therefore, we investigated the effects of fluoride on proliferation and mineralization in human periodontal ligament cells in vitro. The periodontal ligament cells were stimulated with various concentrations of NaF added into osteogenic inductive medium. Immunohistochemistry of cell identification, cell proliferation, alkaline phosphatase (ALP) activity assay, Alizarin red S staining and quantitative real-time-polymerase chain reaction (RT-PCR) were performed. Moderate concentrations of NaF (50-500 μmol/L) had pro-proliferation effects, while 500 μmol/L had the best effects. ALP activity and calcium content were significantly enhanced by 10 μmol/L NaF with osteogenic inductive medium. Quantitative RT-PCR data varied in genes as a result of different NaF concentrations and treatment periods. We conclude that moderate concentrations of NaF can stimulate proliferation and mineralization in periodontal ligament cells. These in vitro findings may provide a novel therapeutic approach for acceleration of periodontal regeneration by addition of suitable concentrations of NaF into the medication for periodontitis treatment, i.e., into periodontal packs and tissue patches.

Effects of 5-aza-2′deoxycytidine on RECK gene expression and tumor invasion in salivary adenoid cystic carcinoma

Reversion-inducing cysteine-rich protein with kazal motifs (RECK), a novel tumor suppressor gene that negatively regulates matrix metalloproteinases (MMPs), is expressed in various normal human tissues but downregulated in several types of human tumors. The molecular mechanism for this downregulation and its biological significance in salivary adenoid cystic carcinoma (SACC) are unclear. In the present study, we investigated the effects of a DNA methyltransferase (DNMT) inhibitor, 5-aza-2′deoxycytidine (5-aza-dC), on the methylation status of the RECK gene and tumor invasion in SACC cell lines. Methylation-specific PCR (MSP), Western blot analysis, and quantitative real-time PCR were used to investigate the methylation status of the RECK gene and expression of RECK mRNA and protein in SACC cell lines. The invasive ability of SACC cells was examined by the Transwell migration assay. Promoter methylation was only found in the ACC-M cell line. Treatment of ACC-M cells with 5-aza-dC partially reversed the hypermethylation status of the RECK gene and significantly enhanced the expression of mRNA and protein, and 5-aza-dC significantly suppressed ACC-M cell invasive ability. Our findings showed that 5-aza-dC inhibited cancer cell invasion through the reversal of RECK gene hypermethylation, which might be a promising chemotherapy approach in SACC treatment.

Plasma levels and placental expression of vaspin in pregnant women with diabetes mellitus

The present study aimed to investigate visceral adipose tissue-specific serpin (vaspin) concentrations in serum and term placentas and relate these values to insulin resistance and lipid parameters in women with gestational diabetes mellitus (GDM). A total of 30 GDM subjects and 27 age-matched pregnant women with normal glucose tolerance (NGT, control) were included. Serum glucose, glycated hemoglobin (HbA1c), lipid profile, insulin, and vaspin were measured at the end of pregnancy, and homeostasis model of assessment-insulin resistance (HOMA-IR) values were calculated. Vaspin mRNA and protein levels in placentas were measured by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blotting, respectively. Serum vaspin levels were significantly lower in the GDM group than in controls (0.49±0.24 vs 0.83±0.27 ng/mL, respectively; P<0.01). Three days after delivery, serum vaspin levels were significantly decreased in subjects with GDM (0.36±0.13 vs 0.49±0.24 ng/mL, P<0.01). However, in the GDM group, serum vaspin levels were not correlated with the parameters evaluated. In contrast, in the control group, serum vaspin levels were positively correlated with triglycerides (TG; r=0.45, P=0.02) and very low-density lipoprotein cholesterol (VLDL-C; r=0.42, P=0.03). Placental mRNA vaspin (0.60±0.32 vs 0.68±0.32, P=0.46) and protein (0.30±0.08 vs 0.39±0.26; P=0.33) levels in the GDM group did not differ significantly from those in the control group, but were negatively correlated with neonatal birth weight in the GDM group (r=-0.48, P=0.03; r=-0.88; P<0.01). Our findings indicated that vaspin may be an important adipokine involved in carbohydrate and lipid metabolism and may also play a role in fetal development.

Expression of beclin 1 in primary salivary adenoid cystic carcinoma and its relation to Bcl-2 and p53 and prognosis

Beclin 1 plays a critical role in autophagy and functions as a haploinsufficient tumor suppressor. The expression and prognostic significance of beclin 1 in head and neck adenoid cystic carcinoma (ACC) are largely unexplored. Therefore, we investigated the expression of beclin 1, Bcl-2, and p53 in head and neck ACC tissue. Tissue samples from 35 cases (15 females, 20 males) of head and neck ACC were utilized for immunohistochemistry. Beclin 1 expression was observed in 32 cases (91.4%) and considered to be high in 15 cases (42.9%) and low in 20 cases (57.1%). Beclin 1 expression was significantly correlated with a histological growth pattern (P=0.046) and histological grade (P=0.037). Beclin 1 expression was inversely correlated with Bcl-2 expression (P=0.013) and significantly associated with overall survival (P=0.006). Bcl-2 and p53 expression were observed in 21 cases (60.0%) and 16 cases (45.7%). Bcl-2 expression was significantly correlated with perineural invasion (P=0.041) and not associated with overall survival (P=0.053). p53 expression was directly correlated with beclin 1 expression (P=0.044). Our results indicated that beclin 1 may be a novel, promising prognostic factor for clinical outcome in head and neck ACC patients and may play a part in the development of head and neck ACC by interacting with Bcl-2 and p53.

Ox-LDL increases OX40L in endothelial cells through a LOX-1-dependent mechanism

Oxidative low-density lipoprotein (Ox-LDL) is a key risk factor for the development of atherosclerosis, and it can stimulate the expression of a variety of inflammatory signals. As a new and highly sensitive inflammation index, OX40L may be a key to understanding the mechanisms that regulate interactions between cells within the vessel wall and inflammatory mediators during the development of atherosclerosis. To investigate whether Ox-LDL regulates OX40L expression through an oxidized LDL-1 receptor (LOX-1)-mediated mechanism, we investigated the effect of different concentrations of Ox-LDL (50, 100, 150 µg/mL) on endothelial cell proliferation and apoptosis. Stimulation with Ox-LDL increased OX40L protein 1.44-fold and mRNA 4.0-fold in endothelial cells, and these effects were inhibited by blocking LOX-1. These results indicate that LOX-1 plays an important role in the chronic inflammatory process in blood vessel walls. Inhibiting LOX-1 may reduce blood vessel inflammation and provide a therapeutic option to limit atherosclerosis progression.