Molecular Mechanisms of Antibiotic Resistance and Novel Treatment Strategies for Helicobacter pylori Infections.

Helicobacter pylori infects approximately 50% of the world's population and is considered the major etiological agent of severe gastric diseases, such as peptic ulcers and gastric carcinoma. Increasing resistance to standard antibiotics has now led to an ever-decreasing efficacy of eradication therapies and the development of novel and improved regimens for treatment is urgently required. Substantial progress has been made over the past few years in the identification of molecular mechanisms which are conducive to resistant phenotypes as well as for efficient strategies to counteract strain resistance and to avoid the use of ineffective antibiotics. These involve molecular testing methods, improved salvage therapies, and the discovery of novel and potent antimicrobial compounds. High rates of prevalence and gastric cancer are currently observed in Asian countries, including Japan, China, Korea, and Taiwan, where concomitantly intensive research efforts were initiated to explore advanced eradication regimens aimed at reducing the risk of gastric cancer. In this review, we present an overview of the known molecular mechanisms of antibiotic resistance and discuss recent intervention strategies for H. pylori diseases, with a view of the research progress in Asian countries.

Tumour necrosis factor-α as a prognostic biomarker of severe malaria: a systematic review and meta-analysis.

BACKGROUND: Tumour necrosis factor-alpha (TNF-α) levels are reportedly altered during malaria. In this systematic review and meta-analysis, we aimed to collect and compare data on TNF-α levels between patients with malaria of varying severity and healthy asymptomatic positive controls. METHODS: We searched PubMed, Scopus and Web of Science for studies that reported TNF-α levels in malaria cases of different severity and healthy asymptomatic positive controls using a combination of search terms. The quality of the included studies was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology checklist. To compare the TNF-α levels among fatal cases, severe cases, uncomplicated cases and healthy asymptomatic positive controls, we applied the random-effects model that assumed the existence of variations between studies. The effect estimate was pooled mean difference (MD) with a 95% confidence interval (CI). RESULTS: From 1694 studies, we included 31 studies that met our eligibility criteria for systematic review and meta-analysis. Patients with severe malaria showed higher mean TNF-α levels than those with uncomplicated malaria (P < 0.001, pooled MD = 79.02 pg/ml, 95% CI: 63.68-94.35 pg/ml, I2: 99.5%, n = 26 studies). Furthermore, fatal cases had no difference in the mean TNF-α levels in comparison with survived cases (P = 0.055, pooled MD = 82.38 pg/ml, 95% CI: -1.93 to 166.69 pg/ml, I2: 99.54%, n = 5 studies). Finally, patients with uncomplicated malaria showed higher mean TNF-α levels than those with asymptomatic malaria (P < 0.001, pooled MD = 45.10 pg/ml, 95% CI: 18.45-71.76 pg/ml, I2: 97.09%, n = 5 studies). CONCLUSION: This systematic review and meta-analysis confirmed the increase of TNF-α levels in patients with severe malaria. Therefore, TNF-α may be alternatively used as a prognostic biomarker of severe malaria. TRIAL REGISTRATION: Not applicable.

Peganum harmala Extract Has Antiamoebic Activity to Acanthamoeba triangularis Trophozoites and Changes Expression of Autophagy-Related Genes.

Peganum harmala, a well-known medicinal plant, has been used for several therapeutic purposes as it contains numerous pharmacological active compounds. Our study reported an anti-parasitic activity of P. harmala seed extract against Acanthamoeba triangularis. The stress induced by the extract on the surviving trophozoites for Acanthamoeba encystation and vacuolization was examined by microscopy, and transcriptional expression of Acanthamoeba autophagy-related genes was investigated by quantitative PCR. Our results showed that the surviving trophozoites were not transformed into cysts, and the number of trophozoites with enlarged vacuoles were not significantly different from that of untreated control. Molecular analysis data demonstrated that the mRNA expression of tested AcATG genes, i.e., ATG3, ATG8b, and ATG16, was at a basal level along the treatment. However, upregulation of AcATG16 at 24 h post treatment was observed, which may indicate an autophagic activity of this protein in response to the stress. Altogether, these data revealed the anti-Acanthamoeba activity of P. harmala extract and indicated the association of autophagy mRNA expression and cyst formation under the extract stress, representing a promising plant for future drug development. However, further identification of an active compound and a study of autophagy at the protein level are needed.

Cancer risk perception and preventive behaviors among grilled meat vendors.

BACKGROUND: Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that cause cancers in humans. Exposure results from incomplete burning of organic materials. Grilled meat vendors are occupationally exposed to PAHs in smoke from continuously burning charcoal and meat, which may have chance to get cancer. Individual risk perception is a critical antecedent of preventive behavior However relatively little is known about the cancer risk perception and preventive behaviors among grilled meat vendors. OBJECTIVE: The present study aimed to examine cancer risk perception and preventive behaviors and factors associated with preventive behaviors among grilled meat vendors in Bangkok, Thailand. MATERIAL AND METHOD: A cross-sectional survey was used in the present study. The subjects consisted of 40 males and 82 females grilled meat vendors who conducted their jobs at Victory Monument, Bang Lumpoo, Pratunam, Jakkawat or Patumwan. They were interviewed regarding cancer risk perception and preventive behaviors. Multiple logistic regression analysis was used to analyze data. RESULTS: Average cancer risk perception score was 23.3 +/- 3.3 out of 32. About 79.5% of the subjects had high risk perception. The prevalence of good preventive behaviors was 86.1%. The three most frequent preventive behaviors among the subjects during grilling meat were using good quality charcoal (65.6%), ventilation fan (41.0%) and wearing long sleeves shirt (36.1%). Only 10.7% always used gloves. Multiple logistic regression analysis showed 2 factors were independently associated with preventive behaviors: educational level and risk perception. The subjects who had higher educational level or risk perception were more likely to develop better behaviors than those who had a lower educational level and perception (p < 0.05). CONCLUSION: In conclusion, the present study found that the educational background and cancer risk perception were associated with preventive behaviors among grilled meat vendors. To improve the preventive behaviors among grilled meat vendors, interventions focusing on cancer risk perceptions and considering educational background among target group are recommended.

Cryptosporidium and Giardia detection in environmental waters of southwest coastal areas of Thailand.

The aim of this study was to investigate water samples collected in coastal areas of Southern Thailand in the years of 2005 and 2008 for their contamination by the protozoan parasites Cryptosporidium and Giardia. One hundred eighteen water samples of different origin were collected from six Tsunami affected southern provinces of Thailand in early 2005, and they have been analyzed using standardized methodology. Fifteen out of 118 samples (12.7%) were positive for Cryptosporidium spp. and nine (7.6%) positive for Giardia spp. Additional 42 samples from two same areas were examined 3 years later, in the early 2008. Five out of 42 (11.9%) samples were positive for Cryptosporidium spp., and three out of 42 (7.1%) were positive for Giardia spp.. Both protozoans were found in reservoir, river/canal, and pond waters. It appears no significant differences (p < 0.05) between Cryptosporidium and Giardia (oo)cysts levels during the two monitoring periods; however, the number of the investigated areas and samples in the second period was significantly less than in the first period. This is the first description on Cryptosporidium and Giardia (oo)cysts in water sources of Thailand, and it suggests the need for water quality control in the interest of public health safety.

The epidemiology of HIV-1 subtypes in infected patients from northeastern Thailand.

In total, 117 HIV-1 infected patients from several provinces in Northeastern Thailand were analysed. All blood samples collected from individuals were confirmed by EIA and Western blot and partially by HIV-1 gag-, pol- and env-PCR. By serotyping with a V3-peptide ELISA, 108 (92.3%) of the sera samples belonged to subtype E, 9 (7.7%) were serotype B. For 10 Thai HIV-1 infections, the serotype and genotype were determined. The genotype was determined by phylogenetic analysis of directly sequenced PCR amplicons, 8 were subtype E, 2 subtype B. For these patients the serotype did correlate with the genotype. Tracing back the origin of Thai patients, it seems that most were infected within early years of the epidemic and the Thai subtype B infected patients have been imported directly from foreign countries via sexual contact. The findings suggest there are two district subtypes in Thailand with the majority being subtype E. The relatively high prevalence of subtype B in Northeastern Thailand may be due to the increasing intermix of the two strains (subtypes E and B) and the migration for employment from foreign countries. This may lead to public health concerns regarding surveillance of HIV-1 subtypes and the regulation of potentially infected workers returning from abroad to the country.