Distribution of Microbiota in Fine Particulate Matter Particles in Guangzhou, China.

OBJECTIVE: High PM 2.5 concentration is the main feature of increasing haze in developing states, but information on its microbial composition remains very limited. This study aimed to determine the composition of microbiota in PM 2.5 in Guangzhou, a city located in the tropics in China. METHODS: In Guangzhou, from March 5 th to 10 th, 2016, PM 2.5 was collected in middle volume air samplers for 23 h daily. The 16S rDNA V4 region of the PM 2.5 sample extracted DNA was investigated using high-throughput sequence. RESULTS: Among the Guangzhou samples, Proteobacteria, Bacteroidetes, Firmicutes, Cyanobacteria, and Actinobacteria were the dominant microbiota accounting for more than 90% of the total microbiota, and Stenotrophomonas was the dominant gram-negative bacteria, accounting for 21.30%-23.57%. We examined the difference in bacterial distribution of PM 2.5 between Beijing and Guangzhou at the genus level; Stenotrophomonas was found in both studies, but Escherichia was only detected in Guangzhou. CONCLUSION: In conclusion, the diversity and specificity of microbial components in Guangzhou PM 2.5 were studied, which may provide a basis for future pathogenicity research in the tropics.

Association of variants of miRNA processing genes with cervical precancerous lesion risk in a southern Chinese population.

The miRNA processing genes play essential roles in the biosynthesis of mammalian miRNAs, and their genetic variants are involved in the development of various cancers. Our study aimed to determine the potential association between miRNA processing gene polymorphisms and cervical precancerous lesions. Five single nucleotide polymorphisms (SNPs), including Ran-GTP (RAN) rs14035, exportin-5 (XPO5) rs11077, DICER1 rs3742330, DICER1 rs13078, and TARBP2 rs784567, were genotyped in a case-control study to estimate risk factors of cervical precancerous lesions. The gene-environment interactions and haplotype association were estimated. We identified a 27% decreased risk of cervical precancerous lesions for individuals with minor G allele in DICER1 rs3742330 (odds ratio (OR) = 0.73, 95% confidence interval (95% CI) = 0.58-0.92, P = 0.009). The AG and AG/GG genotypes in DICER1 rs3742330 were also found to decrease the risk of cervical precancerous lesions (AG compared with AA: OR = 0.51, 95% CI = 0.35-0.73, P <0.001; AG/GG compared with AA: OR = 0.54, 95% CI = 0.39-0.77, P = 0.001). The GT haplotype in DICER1 had a risk effect on cervical precancerous lesions compared with the AT haplotype (OR = 1.36, 95% CI = 1.08-1.73, P = 0.010). A two-factor (DICER1 rs3742330 and human papillomavirus (HPV) infection) and two three-factor (model 1: rs3742330, passive smoking, and HPV infection; model 2: rs3742330, abortion history, and HPV infection) interaction models for cervical precancerous lesions were identified. In conclusion, the genetic variants in the miRNA processing genes and interactions with certain environmental factors might contribute to the risk of cervical precancerous lesions in southern Chinese women.

Association of LPP and TAGAP Polymorphisms with Celiac Disease Risk: A Meta-Analysis.

Background: Lipoma preferred partner (LPP) and T-cell activation Rho GTPase activating protein (TAGAP) polymorphisms might influence the susceptibility to celiac disease. Therefore, we performed a meta-analysis by identifying relevant studies to estimate the risks of these polymorphisms on celiac disease. Methods: The PubMed, Web of Science and Embase databases were searched (up to October 2016) for LPP rs1464510 and TAGAP rs1738074 polymorphisms. Results: This meta-analysis included the same 7 studies for LPP rs1464510 and TAGAP rs1738074. The minor risk A allele at both rs1464510 and rs1738074 carried risks (odds ratios) of 1.26 (95% CI: 1.22-1.30) and 1.17 (95% CI: 1.14-1.21), respectively, which contributed to increased risks in all celiac disease patients by 10.72% and 6.59%, respectively. The estimated lambdas were 0.512 and 0.496, respectively, suggesting that a co-dominant model would be suitable for both gene effects. Conclusions: This meta-analysis provides robust estimates that polymorphisms in LPP and TAGAP genes are potential risk factors for celiac disease in European and American. Prospective studies and more genome-wide association studies (GWAS) are needed to confirm these findings, and some corresponding molecular biology experiments should be carried out to clarify the pathogenic mechanisms of celiac disease.

[Relationship between intestinal mucosal inflammation and mental disorders in patients with irritable bowel syndrome].

OBJECTIVE: To examine the relationship between inflammation and the comorbidity of mental disorders with irritable bowel syndrome (IBS) by comparing intestinal mucosa inflammatory biomarkers in patients with and without mental disorders. METHODS: A total of 43 consecutive IBS patients fulfilling the Rome III criteria and 15 volunteers serving as controls without digestive symptoms were recruited and interviewed with Composite International Diagnostic Interview (CIDI) by the well-trained staff and thus classified as with or without mental disorders. All subjects underwent colonoscopy and biopsies were acquired from the mucosa of distal ileum and colon. CD3(+) lymphocytes, mast cells, 5-HT positive cells and (indoleamine 2,3-dioxygenase) IDO positive cells were identified immunohistologically in mucosa biopsies in volunteers (n = 13), IBS patients without mental disorder (n = 24) and IBS patients with mental disorder (n = 19). RESULTS: The incidence of mental disorders in IBS patients was significantly higher than that in the volunteers (19/43 vs 2/15, P = 0.012), including 9 patients with anxiety disorders and 8 with mood disorders. (1) The number of mast cells in IBS patients with mental disorder and that in IBS patients without mental disorder has no statistical significance ((16.7 ± 3.6)/HP vs (15.4 ± 3.1)/HP in distal ileum, (12.8 ± 2.2)/HP vs (12.3 ± 2.5)/HP in sigmoid, both P > 0.05). Similar results were seen in 5-HT positive cells ((3.7 ± 0.9)/HP vs (3.4 ± 0.8)/HP in distal ileum, (6.1 ± 1.8)/HP vs (5.2 ± 1.8)/HP in sigmoid, both P > 0.05). In distal ileum, the number of CD3(+) cells in IBS patients with mental disorder has no statistical significance with that in the IBS patients without mental disorder ((62 ± 16)/HP vs (55 ± 22)/HP, P > 0.05). Similar results were seen in IDO positive cells (6(2, 8)/HP vs 2(1, 5)/HP, P > 0.05). (2) The number of IDO positive cells from distal ileum in IBS patients with anxiety disorder was significantly higher than that in the IBS patients without mental disorder (6 (4,8) vs 2 (1,5), P = 0.018). The number of mast cells from distal ileum in the IBS patients with mood disorder were significantly higher than that in those without mental disorders ((18.3 ± 3.2)/HP vs (15.4 ± 3.1)/HP, P = 0.032). CONCLUSIONS: Mental disorders in the IBS patients may be associated with intestinal mucosal inflammation. The activation of IDO may cause the comorbidity of IBS with anxiety disorder while the activation of mast cells probably leads to the comorbidity of IBS with mood disorder.

[The effects of pronase on drugs concentrations for treatment of Helicobacter pylori infection in gastric tissue].

OBJECTIVE: To evaluate the effect of pronase on amoxicillin and metronidazole concentrations in gastric tissue. METHODS: C57BL/6 mice were randomly divided into experimental group (n = 70) and control group (n = 70). Amoxicillin (28.6 mg/kg), metronidazole (22.5 mg/kg) and omeprazole (138.2 mg/kg) were administered orally to C57BL/6 mice, combined with pronase (110 mg/kg) or same amount of sterile PBS. Gastric tissue and blood plasma samples were taken at 10 point-in-time (7 mice/time) from 15 min up to 360 min after administration. Concentrations of amoxicillin and metronidazole were detected by high performance liquid chromatography. Gastritis index of gastric mucosa (hematoxylin-eosin staining) and the gastric tissue expressions of mucin 5AC (Western blot) were detected at 120 min and 360 min after administration. RESULTS: The time to peak concentration of amoxicillin and metronidazole in gastric tissue appeared earlier than that in blood plasma (15 min vs 60 min). Tissue concentrations of amoxicillin and metronidazole of experimental group were significantly higher than those of control, and they were mainly at 15 min to 90 min (P < 0.05). Plasma concentrations of amoxicillin and metronidazole of experimental group at 15 min and 30 min were higher than those of control (P < 0.05). There was no difference in gastritis index between experimental group and control at 120 min and 360 min after administration (0.28 ± 0.18 vs 0.14 ± 0.14, P > 0.05; 0.43 ± 0.20 vs 0.28 ± 0.18, P > 0.05). The expressions of mucin 5AC in experimental group were lower than those of control (0.036 ± 0.006 vs 0.197 ± 0.058; P < 0.05; 0.039 ± 0.008 vs 0.208 ± 0.072, P < 0.05). CONCLUSIONS: Pronase can significantly enhance the drugs penetration from mucus into gastric tissue. Concentrations of amoxicillin and metronidazole of experimental group in local gastric tissue and plasma are higher than those of control, especially in improving concentrations of gastric tissue and prolongation of exposed time.

[A case report of collagenous gastritis in a young Chinese woman and literatures review].

OBJECTIVE: Collagenous gastritis is a rare entity, characterized by the deposition of a subepithelial collagen band with an inflammatory infiltrate in the mucosa. This report describes the first case of collagenous gastritis occurring in a young Chinese woman and reviews the literatures. METHODS: The patient underwent the gastroscopy screening, and the biopsy specimens were treated with HE staining, Masson staining, Congo red staining and Warthin-Starry staining.Patients' clinical data was discussed and followed up. RESULTS: A twenty-year-old girl had intermittent epigastric pain for 4 years, abdominal distention, hiccup and weight loss for two months. The gastric endoscopy revealed diffuse white nodular appearance of the mucosa in angular incisura and antrum. Pathologic examination of the gastric biopsies from the antrum and angular showed a subepithelial collagen deposition with moderate infiltrates of lymph plasma cells and eosinophils of the lamina propria. The collagen band measured up to 120.3 µm (mean 43.8 µm). Prednisone 20 mg/d for 4 weeks led to clinical remission and weight gain. CONCLUSION: There are about 40 cases in literatures to date, and the cause and pathogenesis of collagenous gastritis remain unknown. According to the clinical and pathological characteristics, the patient in this article is the subtype of collagenous gastritis that occurring in children and young adults. Specific therapy has not been established, the gluten-free diet and glucocorticosteroid may be helpful to relieve symptoms in collagenous gastritis patients.

[Role of peroxisome proliferators-activated receptor-gamma in the chemical prevention therapy of sulindac for precancerous lesions of rats].

OBJECTIVE: To understand whether peroxisome proliferators-activated receptor-gamma (PPAR-gamma) plays an important role in the chemopreventive effect of sulindac on precancerous lesions (aberrant crypt foci, ACF) of rats. METHODS: Male Sprague-Dawley rats were used in this study and raised in Special Pathogen Free room. Sulindac was the main research object. Carcinogenic agent, 1, 2-dimethylhydrazine (DMH), was used to induce colonic precancerous lesions. Pioglitazone was chosen as agonist of PPAR-gamma and GW9662 used as a specific complete antagonist of PPAR-gamma. ACFs were induced according to the protocol certified in prior experiments. There were 7 groups, named as Negative control group, DMH group, Sulindac group, Sulindac+GW9662 group, Pioglitazone group, Pioglitazone+GW9662 group and GW9662 group. The experiment period was 12 weeks. At the end of the experiment, all rats were sacrificed by euthanasia. Half of the colon including the rectum was taken and immersed in formalin at 4 degrees Celsius overnight, and then recorded the number and size of ACF with the help of anatomic microscope stained by methylene blue. RESULTS: (1) Sulindac and agonist of PPAR-gamma could significantly inhibit DMH-induced ACFs of rats from 137.8+/-59.4 to 73.9+/-32.1 and 96.4+/-32.6 with a decrease of 45.7% (P<0.01) and 30.0%(P<0.05) compared with DMH group. Antagonist of PPAR-gamma could counteract the chemopreventive effect of sulindac with an increase from 73.9+/-32.1 to 106.3+/-33.9; (2) The expression of PPAR-gamma in colorectal mucosa increased significantly during the DMH induction period compared with negative control group, the relative values of gray were 0.304+/-0.288 and 2.292+/-1.380 (P<0.01), sulindac and pioglitazone could decrease the expression of PPAR-gamma remarkably compared with DMH group, the relative values of gray were 1.023+/-1.115 and 0.352+/-0.187 (P<0.01), and the application of GW9662, antagonist of PPAR-gamma could promote the expression of PPAR-gamma in some degree, and the relative values of gray were 1.279+/-0.303 and 0.998+/-0.295 (P>0.05). CONCLUSION: The expression of PPAR-gamma had risen in DMH-induced ACFs of rats significantly. Sulindac and agonist of PPAR-Gamma (pioglitazone) could inhibit the formation of ACF, and followed by a decrease of PPAR-gamma. Antagonist of PPAR-gamma could interfere with the effect of sulindac. PPAR-gamma might play an important role in the chemopreventive effect of sulindac on colorectal pre-cancerous lesions of rats and activation of PPAR-gamma pathway could inhibit the initiation and evolvement of ACF induced by DMH.

[Effect of different heat treatment on mechanical properties and microstructure of laser welding CoCr-NiCr dissimilar alloys].

OBJECTIVE: To evaluate the effect of heat treatment and porcelain-fused-to-metal (PFM) processing on mechanical properties and microstructure of laser welding CoCr-NiCr dissimilar alloys. METHODS: Samples of CoCr-NiCr dissimilar alloys with 0.5 mm thickness were laser-welded single-side under the setting parameters of 280 V, 10 ms pulse duration. After being welded, samples were randomly assigned to three groups, 10 each. Group1 and 2 received heat treatment and PFM processing, respectively. Group 3 was control group without any treatment. Tensile strength, microstructure and element distribution of samples in the three groups were tested and observed using tensile test, metallographic examinations, scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS) analysis. RESULTS: After heat treatment and PFM processing, tensile strength of the samples were (537.15 +/- 43.91) MPa and (534.58 +/- 48.47) MPa respectively, and elongation rates in Group 1 and 2 were (7.65 +/- 0.73)% and (7.40 +/- 0.45)%. Ductile structure can be found on tensile fracture surface of samples and it was more obvious in heat treatment group than in PFM group. The results of EDS analysis indicated that certain CoCr alloy diffused towards fusion zone and NiCr side after heat treatment and PFM processing. Compared with PFM processing group, the diffusion in the heat treatment group was more obvious. CONCLUSIONS: Heat treatment and PFM processing can improve the mechanical properties and microstructure of welded CoCr-NiCr dissimilar alloy to a certain degree. The improvements are more obvious with heat treatment than with porcelain treatment.

Microwave antigen retrieval blocks endogenous peroxidase activity in immunohistochemistry.

Endogenous peroxidase activity blocking is one of the most critical steps for a successful immunostaining. A traditional procedure for this purpose was to use diluted hydrogen peroxide (H2O2) solution to gain a better visualization. Our current study was designed to test if the conventional antigen retrieval (AR) step with microwave oven could also inhibit endogenous peroxidase. Tissue sections were treated in following different ways before incubating with 3, 3' diaminobenzidine tetrahydrochloride reaction mixture: (1) microwave alone, (2) 0.3% or 3% of H2O2 before AR, or (3) 0.3% or 3% of H2O2 after AR. Surprisingly, we found that all different treatments completely eliminated the endogenous enzymatic activity, mostly in eosinophils and erythrocytes, suggesting that microwave exposure itself is able to block the endogenous peroxidase. The results were validated in most gastrointestinal tract mucosa from human and some tissues from mice, including blood enriched tissues, such as liver and spleen. We have obtained perfect immunostaining without any H2O2 blocking procedure. On the basis of our observation, we conclude that blockage of endogenous peroxidase with H2O2 in immunostaining could be omitted and replaced by microwave oven heating.