[Risk factors for progression to chronic kidney disease in patients with cardiac valve replacement surgery-associated acute kidney injury].

Objective: To explore the risk factors for progression to chronic kidney disease (CKD) in patients with cardiac valve replacement surgery-associated acute kidney injury (AKI). Methods: A retrospective, nested case-control study was conducted at Fuwai Central China Cardiovascular Hospital. The study subjects were patients who underwent cardiac valve replacement surgery from January 1, 2018 to December 31, 2020, with a baseline estimated glomerular filtration rate (eGFR)>60 ml·min-1·(1.73 m2)-1 and postoperative complication of AKI. The patients were followed up for 90 days after discharge from hospital. The endpoint event was defined as progression to CKD 90 days after the occurrence of cardiac valve replacement surgery-associated AKI. The patients were divided into CKD group and non-CKD group based on whether they experienced endpoint event. The baseline clinical data were compared between the two groups. The measurement data with non-normal distribution was represented as M (Q1,Q3). Logistic regression model was used to analyze the risk factors of endpoint event. The receiver-operating characteristic (ROC) curve was drawn to evaluate the performance for predicting CKD in cardiac valve replacement surgery-associated AKI patients. Results: A total of 149 cardiac valve replacement surgery-associated AKI patients (86 males and 63 females) were included in the study, aged (59.0±10.2) years. There were 27 patients (18.1%) who progressed to new-onset CKD 90 days after the occurrence of cardiac valve replacement surgery-associated AKI. Compared with non-CKD group, patients in CKD group had older age [66 (58, 70) vs 59 (53, 64) years], lower baseline eGFR [76.3 (65.8, 98.5) vs 92.7 (78.5, 101.6) ml·min-1·(1.73 m2)-1], higher proportion of preoperative hypertension [51.9% (14/27) vs 27.9% (34/122)] and serum creatinine at discharge [136 (101, 165) vs 86 (65, 104) µmol/L], and the differences were statistically significant (all P<0.05). The multivariate logistic regression analysis results revealed that older age (OR=1.063, 95%CI: 1.001-1.129, P=0.047), preoperative hypertension (OR=3.070, 95%CI: 1.105-8.532, P=0.031) and higher serum creatinine at discharge (OR=1.026, 95%CI:1.013-1.038, P<0.001) were risk factors for progression to CKD in patients with cardiac valve replacement surgery-associated AKI. The clinical risk model including age, preoperative hypertension, preoperative baseline eGFR, and serum creatinine at discharge produced a moderate performance for predicting progression to CKD in patients with cardiac valve replacement surgery-associated AKI [the area under the curve (AUC)=0.865, 95%CI: 0.790-0.940, P<0.001]. Conclusion: Older age, preoperative hypertension and higher serum creatinine at discharge are risk factors for progression to CKD in patients with cardiac valve replacement surgery-associated AKI.

[MiR-340 mediates the involvement of high mobility group box 1 in the pathogenesis of liver fibrosis].

Objective: To explore the pathogenic mechanism of the miR-340/high mobility group box 1 (HMGB1) axis in the formation of liver fibrosis. Methods: A rat liver fibrosis model was established by injecting CCl(4) intraperitoneally. miRNAs targeting and validating HMGB1 were selected with gene microarrays after screening the differentially expressed miRNAs in rats with normal and hepatic fibrosis. The effect of miRNA expressional changes on HMGB1 levels was detected by qPCR. Dual luciferase gene reporter assays (LUC) was used to verify the targeting relationship between miR-340 and HMGB1. The proliferative activity of the hepatic stellate cell line HSC-T6 was detected by thiazolyl blue tetrazolium bromide (MTT) assay after co-transfection of miRNA mimics and HMGB1 overexpression vector, and the expression of extracellular matrix (ECM) proteins type I collagen and α-smooth muscle actin (SMA) was detected by western blot. Statistical analysis was performed by analysis of variance and the LSD-t test. Results: Hematoxylin-eosin and Masson staining results showed that the rat model of liver fibrosis was successfully established. Gene microarray analysis and bioinformatics prediction had detected eight miRNAs possibly targeting HMGB1, and animal model validation had detected miR-340. qPCR detection results showed that miR-340 had inhibited the expression of HMGB1, and a luciferase complementation assay suggested that miR-340 had targeted HMGB1. Functional experiments results showed that HMGB1 overexpression had enhanced cell proliferation activity and the expression of type I collagen and α-SMA, while miR-340 mimics had not only inhibited cell proliferation activity and the expression of HMGB1, type I collagen, and α-SMA, but also partially reversed the promoting effect of HMGB1 on cell proliferation and ECM synthesis. Conclusion: miR-340 targets HMGB1 to inhibit the proliferation and ECM deposition in hepatic stellate cells and plays a protective role during the process of liver fibrosis.

[Expression profiles of long non-coding RNAs in human liver cell line LO2 with stable expression of hepatitis B x gene].

OBJECTIVE: To investigate the differential expression profiles of long non-coding RNAs (lncRNAs) in human liver cell line LO2 with stable expression of hepatitis B x (HBx) gene, and to screen out the lncRNAs which play an important role in HBV-related liver cancer. METHODS: The lncRNA microarray was used to establish the differential expression profiles of lncRNAs, and the methods such as scatter plots and cluster analysis were used to obtain the HBx-related lncRNAs with differential expression. The qRT-PCR was used to verify some lncRNAs with differential expression. The t-test was used to compare the expression of lncRNAs between the two microarray groups, and hierarchical cluster analysis was used for the original data of lncRNAs with differential expression. RESULTS: Compared with the control group transfected with blank plasmids (L02/pcDNA3.0), LO2/HBx cells had 323 lncRNAs with > 2-fold upregulation and 421 lncRNAs whose expression was reduced by more than 50% (P < 0.05). The results of qRT-PCR verified 4 upregulated lncRNAs (TCONS_00006195, ENST00000557524, NR_037597, and ENST00000539975) and 3 downregulated lncRNAs (ENST00000508424, ENST00000447433, and uc001lva.4), which were consistent with the results of microassay. CONCLUSION: HBx-related lncRNAs are successfully screened out, which lays a foundation for further investigation of the role of lncRNAs in the pathogenesis of liver cancer.

Maternal investment increases with altitude in a frog on the Tibetan Plateau.

Reproducing females can allocate energy between the production of eggs or offspring of different size or number, both of which can strongly influence fitness. The physical capacity to store developing offspring imposes constraints on maximum clutch volume, but individual females and populations can trade off whether more or fewer eggs or offspring are produced, and their relative sizes. Harsh environments are likely to select for larger egg or offspring size, and many vertebrate populations compensate for this reproductive investment through an increase in female body size. We report a different trade-off in a frog endemic to the Tibetan Plateau, Rana kukunoris. Females living at higher altitudes (n = 11 populations, 2000-3500 m) produce larger eggs, but without a concomitant increase in female body size or clutch size. The reduced diel and seasonal activity at high altitudes may impose constraints on the maximum body size of adult frogs, by limiting the opportunity for energy accumulation. Simultaneously, producing larger eggs likely helps to increase the rate of embryonic development, causing tadpoles to hatch earlier. The gelatinous matrix surrounding eggs, more of which is produced by large females, may help buffer developing embryos from temperature fluctuations or offer protection from ultraviolet radiation. High-altitude frogs on the Tibetan Plateau employ a reproductive strategy that favours large egg size independent of body size, which is unusual in amphibians. The harsh and unpredictable environmental conditions at high altitudes can thus impose strong and opposing selection pressures on adult and embryonic life stages, both of which can simultaneously influence fitness.

Risk factors and psychological condition of pruritus in type 2 diabetes mellitus: a retrospective, propensity score-matched study.

OBJECTIVE: Our aim is to characterize patients with pruritus in type 2 diabetes, determine independent risk factors and explore the impact of the psychological condition of these patients. MATERIALS AND METHODS: This is a retrospective study. From October 1, 2020, to September 30, 2021, 944 individuals with T2DM who had medical treatment were identified from the database. Electronic medical record information including patient characteristics, complications, laboratory data, and medication usage was obtained from the database. Propensity score matching, univariate analysis and a multivariable logistic regression model were used in this study. Based on observation, we discussed the psychological impact of pruritus on these patients. RESULTS: There were 97 patients with T2DM who suffered from pruritus. After propensity score matching based on age, gender, and family history of diabetes etc., 97 pairs of subjects were matched. 97 patients were categorized as the Pruritus group and 97 patients as the Non-pruritus group. In univariate analysis, there were 5 variables significantly related to pruritus, including BMI, absolute eosinophils, percentage of eosinophils, diabetic kidney disease, diabetic retinopathy. After multivariable logistic regression, BMI (OR 1.094, 95%CI 1.010-1.185) and diabetic retinopathy (OR 2.440, 95%CI 1.229-4.847) were considered significant. Patients with pruritus in T2DM suffer greatly in psychological condition in many ways. CONCLUSIONS: For patients with pruritus complicated by T2DM, BMI and diabetic retinopathy may be independent risk factors. Mental health problems such as anxiety and depression might exacerbate by pruritus. The intimate partner relationship was also challenged due to the restless sleep caused by their partner. Frequent monitoring of BMI and diabetic retinopathy and psychological assessment may be warranted in these patients.

miR-142-3p Inhibits the Metastasis of Hepatocellular Carcinoma Cells by Regulating HMGB1 Gene Expression.

BACKGROUND: Non-coding small RNAs are involved in organism development, and their aberrant regulation induces various diseases, including hepatocellular carcinoma (HCC), but their exact mechanisms have not been determined. OBJECTIVE: The aim was to investigate the role of miR-142-3p on HMGB1 expression in hepatocellular carcinoma. METHODS: Expression levels of miR-142-3p in HCC tissues and cultured cells were measured by RT-PCR. The invasion and metastasis abilities of HepG2 cells according to Transwell migration and invasion assays, and protein expression was measured by western blotting. RESULTS: The present study reported that miR-142-3p promotes the invasion and migration of HCC cells. miR-142-3p levels are lower in HCC tissues than in adjacent non-cancerous tissues, suggesting a tumor suppressor role for miR-142-3p. Highmobility group box protein 1 (HMGB1) is an oncogene that promotes the metastasis of HCC. miR-142-3p or HMGB1 knockdown alone inhibits the invasion and migration of HCC cells, and HMGB1 overexpression impedes the effect of miR-142-3p. Further studies showed that HMGB1 is a direct target gene of miR-142-3p in HCC. miR-142-3p represses HMGB1 gene transcription by directly binding to the 3' untranslated region (UTR) of HMGB1, thereby inhibiting cancer cell invasion and migration. CONCLUSION: This study, for the first time, reports that miR-142-3p is a novel tumor suppressor that inhibits the invasion and migration of HCC cells by directly regulating gene transcription of HMGB1. Thus, miR-142-3p may be a potential diagnostic and therapeutic biomarker for HCC patients.

[Bibliometric analysis of scientific articles on evidence-based nursing of burn in the mainland of China].

OBJECTIVE: To analyze the current research status of evidence-based nursing of burn in the mainland of China, in order to provide basis for the improvement of scientificity of burn nursing practice. METHODS: Chinese scientific articles on evidence-based nursing of burn in the mainland of China published from January 1997 to December 2015 were retrieved from Chinese Biology Medicine disc, Chinese Journals Full-text Database, Wanfang Database, and VIP Database. From the results retrieved, date with regard to publication year, region of affiliation of the first author, journal distribution, literature type, literature quality assessment, topic of evidence-based research, fund program support, implementation of evidence-based practice steps, and language and quantity of reference. Data were processed with Microsoft Excel software. RESULTS: A total of 50 articles conforming to the criteria were retrieved. (1) Articles about evidence-based nursing of burn arose in 2004. Compared with that in the previous year, there was no obvious increase in the number of relevant articles in each year from 2004 to 2011. The number of literature in 2012 was obviously increased than that in each year from 2004 to 2011, while the number of literature in each year from 2012 to 2015 was not obviously increased compared with that in the previous year. (2) The regions of affiliation of the first author were distributed in 13 provinces, 3 minority autonomous regions, and 3 municipalities, with the largest distribution in East China, and Northwest China and Southwest China in the follow. (3) The articles were published in 32 domestic journals, with 9 (28.12%) nursing journals, 5 (15.62%) burn medical related journals, and 18 (56.25%) other journals. Twenty (40%) articles were published in Source Journal for Chinese Scientific and Technical Papers. (4) Regarding the literature type, 31 (62%) articles dealt with clinical experiences, 17 (34%) articles dealt with scientific research, and 2 (4%) articles dealt with case report. (5) There were 21 quantitative study articles and 29 narrative study articles, all with low quality. (6) The topics of evidence-based research in these articles were mainly burn rehabilitation, burn nursing technology, pediatric burn, inhalation injury and airway management, and complications of burn injury. Only one study was supported by fund program. (7) Only one article described complete evidence-based practice steps. (8) The literature cited 57 English articles as references, with an average of 1.14, and 316 Chinese articles, with an average of 6.32. CONCLUSIONS: The concept of evidence-based nursing of burn has been initially formed in the mainland of China. The number of relevant articles is on the rise, but the quality needs to be further improved. There is an urgent need to improve nurses' understanding of evidence-based nursing and their command of the method of evidence-based practice through on-job training, so as to improve the scientificity and effectiveness of burn nursing.

[Surveillance for HIV infection in MSM selected through respondent driven sampling in Beijing, 2005-2012].

Objective: To understand the HIV prevalence among men who have sex with men (MSM) and discuss the feasibility of respondent driven sampling (RDS) as a tool to conduct long term HIV surveillance in MSM in Beijing. Methods: From 2005 to 2012 RDS was used to recruit MSM for face-to-face interview with structured questionnaire to collect their demographic characteristics and HIV risk-related behavior. Blood samples were collected from them for HIV test. Results: A total of 427, 540, 607, 614, 616, 602, 579 and 600 MSM were surveyed, respectively, from 2005 to 2012. The HIV infection prevalence increased from 4.2%(95%CI: 1.9-7.0) in 2005 to 10.1% (95%CI: 7.2-13.2) in 2012 (P=0.02). Meanwhile, HIV prevalence substantially increased among MSM aged >25 years, in floating population and with lower education level (≤high school), from 6.4%(95%CI: 2.2-9.5), 3.3%(95%CI: 1.8-5.4) and 5.5% (95%CI: 2.2-8.9) in 2005 to 7.6% (95%CI: 5.4-10.3, P=0.04), 10.7% (95% CI: 7.8-14.6, P=0.04) and 10.4% (95% CI:7.2-14.3, P=0.04) in 2012, respectively. Moreover, the HIV infection prevalence in MSM aged ≤25 years old and with higher education level (>high school) increased from 1.7%(95%CI: 0.4-3.1) in 2009 and 1.1%(95%CI: 0.2-1.7) in 2007 to 13.7%(95%CI: 7.2-20.4) and 9.1%(95%CI: 4.7-13.8) in 2012, respectively, the differences were not significant. Furthermore, the HIV infection prevalence in MSM who had 2-9 male sex partners in the last six months increased from 4.0% (95% CI: 1.0-8.0) in 2005 to 12.6% (95% CI: 8.7-16.7) in 2012 (P=0.02). Conclusions: Studies have shown that RDS is an effective and feasible sampling method for long term HIV surveillance in MSM. The HIV infection prevalence in MSM in Beijing increased from 2005 to 2012, especially among those with older age, in floating population and with lower educational level. More attention should be paid to MSM with younger age and with higher educational level.

Telomerase activity of peripheral blood lymphocytes in patients with chronic hepatitis B.

Chronic hepatitis B is the immunocompromising condition. The decrease of lymphocyte telomerase is linked to immunosenescence in hosts. To know whether telomerase activity of lymphocytes is involved in immunopathogenesis in patients with chronic hepatitis B, telomerase activity of peripheral lymphocytes was determined in such patients. The results showed that telomerase activity in resting peripheral lymphocytes of healthy subjects was detectable at low level, and obviously increased (P<0.001) after stimulation in vitro with phytohaemagglutinin (PHA). Telomerase activity of lymphocytes decreased with age in both groups with or without PHA stimulation. Telomerase activity of resting lymphocytes in patients with chronic hepatitis B was also observed at detectable level and markedly upregulated after PHA stimulation. The decreased telomerase activity of resting lymphocytes was found in patients with chronic hepatitis B (n=14, 0.32+/-0.27) compared to that in healthy subjects (n=17, 0. 52+/-0.28; P<0.05). However, there was no difference present between these two groups in telomerase activity of activated lymphocytes with PHA. In addition, no effect of recombinant human interleukin-12 (rhIL-12) on telomerase expression was observed in either the patient group or the healthy group. We concluded that the decreased telomerase activity of lymphocytes in chronic hepatitis B patients is present, which may be partly responsible for immunosuppressive condition in such patients.

Effect of IL-4 on peripheral blood lymphocyte proliferation: implication in immunopathogenesis of H. pylori infection.

Interleukin (IL) 4 is a type 2 cytokine which has a negative immunoregulatory role in human infection. IL-4 suppresses the production of interferon-gamma and enhances IL-10 synthesis. However, the effect of IL-4 on proliferative response of lymphocytes remains to be elucidated. We have previously reported an increase in production of IL-4 in subjects with Helicobacter pylori (H. pylori) infection. To evaluate whether the increased IL-4 is responsible for the down-regulation of immune responses in H. pylori infection, we observed the proliferative response of peripheral blood lymphocytes (PBL) co-cultured with phythaemagglutinin (PHA) or H. pylori in the presence and absence of added IL-4. As we have previously shown, PHA and H. pylori may increase PBL proliferation (P < 0.001). An increase in PBL proliferation was observed when PBL were co-cultured with PHA (P < 0.001) or H. pylori (P < 0.001) in the presence of IL-4 compared to that in the absence of IL-4. The optimal dose of IL-4 to give maximal lymphocyte proliferation is 50 pg/ml for the PHA-stimulated group or 100 pg/ml for the H. pylori-stimulated group. The data suggest that the increased IL-4 does not directly contribute to suppressed lymphocyte proliferation in H. pylori infection. Further studies will be required to determine the role of IL-4 in other aspects of down-regulation of immune responses in H. pylori infection.

The determination of neutrophil membrane fluidity in patients with hepatitis B: a fluorescence polarization study.

Although numerous studies on abnormality of neutrophil function in patients with viral hepatitis have previously been reported, little is known about mechanisms of neutrophil dysfunction. To investigate mechanisms of neutrophil dysfunction in these patients, neutrophil membrane fluidity was measured by fluorescence polarization technique in 76 hepatitis patients. The results showed that membrane fluidity of neutrophils from patients with chronic active hepatitis (CAH) or subfulminant hepatic failure (SFHF) was much lower than that in normal controls (p < 0.01), but such a difference could not be found in patients with acute hepatitis (p > 0.05). Furthermore, recombinant interleukin-2 could significantly increase membrane fluidity, while lipopolysaccharide decreased membrane fluidity of neutrophils (p < 0.01, p < 0.001). The present study indicates that there is abnormal membrane fluidity of neutrophils in patients with CAH and SFHF. Neutrophil dysfunction in hepatitis patients may be partly due to altered membrane fluidity.

Effect of IL-12 on T-cell immune responses in patients with chronic HCV infection.

As the host's immune responses may determine the outcome of hepatitis C virus (HCV) infection, and interleukin (IL)-12 plays an essential role in host defense against infectious diseases, we studied the antigen-specific and non-specific cellular immune responses in patients with chronic HCV infection. A proliferative response to phytohemagglutinin (PHA) was found in all 20 patients. Of the 20, 8 (40%) displayed a lymphocyte proliferation in response to HCV antigen c22, 2 (10%) to c33, 6 (30%) to c100-3, and 1 (5%) to NS5. The addition of rhIL-12 to cultures of peripheral blood mononuclear cells (PBMC) stimulated with PHA significantly enhanced the proliferative responses in normal controls as well as in HCV-infected subjects. The increased proliferation was also observed in HCV-infected patients when PBMC were co-cultured with HCV antigens c22 and c100-3 in the presence of rhIL-12. The production of interferon gamma (IFNgamma), IL-2, IL-4 and IL-10 was observed in 7 (58.3%), 5 (41.7%), 3 (25.0%) and 5 (41.7%) HCV-infected individuals stimulated with c22, and in 4 (33.3%), 2 (16.7%), 2 (16.7%) and 2 (16.7%) with c100-3, respectively. All HCV-infected individuals had increased production of cytokines IFNgamma, IL-2, IL-4 and IL-10 in supernatants of PBMC after stimulation with PHA. IL-12 significantly augmented Th1 cytokine production in HCV-infected individuals stimulated with PHA and with HCV antigens. In conclusion, deficient cellular immune responses are present in HCV-infected patients and IL-12 can enhance the immune responses in these patients.

Up-regulation of CD44 and ICAM-1 expression on gastric epithelial cells by H. pylori.

Interaction between lymphocytes and epithelial cells may play a key role in Helicobacter pylori (H. pylori)-associated gastric mucosal inflammation. This interaction process is at least partially mediated by various cell adhesion molecules. The aims of the present study were to assess using flow cytometric analysis whether H. pylori directly or supernatants from H. pylori-activated peripheral blood mononuclear cells (PBMC) can affect the expression of adhesion molecules on the gastric epithelial cell line AGS in vitro. The results showed that resting AGS cells expressed CD44 and ICAM-1. Co-culture of AGS with H. pylori or cytokine-rich supernatants from H. pylori-activated PBMC resulted in up-regulation of expression of CD44 and ICAM-1 on AGS cells. These data suggest that H. pylori directly and indirectly through inflammatory cytokines may contribute to alternations in adhesion molecule expression on gastric epithelial cells. This may be of pathological significance in H. pylori-associated gastric mucosal inflammation and carcinogenesis.

Helicobacter pylori-induced lipid peroxidation in peripheral blood lymphocytes.

Several lines of evidence implicate Helicobacter pylori infection in the pathogenesis of gastritis and peptic ulceration. To investigate whether H. pylori can cause lipid peroxidation in lymphocytes in vitro and to look for experimental evidence of lipid peroxidation induced by H. pylori, the lipid peroxide (LPO) level in peripheral blood lymphocytes was measured using the thiobarbituric acid fluorescence method. In the absence of added H. pylori, the LPO level in lymphocytes was 0.133 +/- 0.033 nmol/10(6) cells, and in the co-culture of H. pylori with peripheral blood mononuclear cells 0.340 +/- 0.097 nmol/10(6) cells. A significant difference was found between the two groups (p < 0.001). Antioxidants, either superoxide dismutase or catalase, could inhibit LPO production in lymphocytes. The present data provide further evidence that H. pylori can induce lipid peroxidation, which may be responsible for the pathogenesis of H. pylori-associated mucosal damage.

Diversity of Helicobacter pylori among Chinese persons with H. pylori infection.

To determine whether there is diversity among clinical isolates of Helicobacter pylori in Chinese patients with peptic ulcer disease, 40 strains of H. pylori were isolated from antral biopsy specimens obtained at the gastroenterology clinic of Xiangya Hospital from January 1996 to June 1998. Total protein profile by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and DNA diversity by polymerase chain reaction-random amplified polymorphic DNA (PCR-RAPD) fingerprinting were performed with these isolates. All the isolates from peptic ulcer disease were relatively homogeneous in protein profiles, but they showed a great DNA sequence diversity by PCR-RAPD fingerprinting. In Chinese patients H. pylori demonstrated an enormous diversity. The diversity among clinical isolates of H. pylori could be distinctly demonstrated and this observation will be helpful in the management of intrafamilial and recurrent H. pylori infection. PCR-RAPD fingerprinting is an efficient method of distinguishing between clinical isolates of H. pylori.

Increased gastric production of interleukin-8 and tumour necrosis factor in patients with Helicobacter pylori infection.

AIMS: To investigate the role of interleukin-8 (IL-8) and tumour necrosis factor (TNF) in patients infected with Helicobacter pylori. METHODS: The study population comprised 52 patients with dyspepsia attending for upper gastrointestinal endoscopy. Of these patients, 35 were infected with H pylori. IL-8 and TNF concentrations in plasma, gastric juice, and gastric biopsy homogenate supernatant fluid were measured by radioimmunoassay and L929 cell bioassay, respectively. RESULTS: The concentrations of IL-8 and TNF in gastric juice and gastric biopsy homogenates were substantially greater in patients infected with H pylori. In H pylori positive patients IL-8 concentrations in gastric juice and gastric biopsy homogenates were higher in those with moderate gastritis than in those with mild gastritis. There was a positive correlation between IL-8 and TNF concentrations in gastric juice and gastric biopsy homogenate supernatant fluid from H pylori positive patients. There were no significant differences between H pylori positive and negative patients with respect to IL-8 and TNF plasma concentrations. CONCLUSION: This study suggests that increased gastric production of IL-8 and TNF may be implicated in the pathogenesis of H pylori associated gastroduodenal disease.

Identification of helicobacter species in human liver samples from patients with primary hepatocellular carcinoma.

AIMS: Several studies have shown the presence of helicobacter species in the human biliary tract and in the intestinal tract of animals. Experimental infection by Helicobacter hepaticus in mice causes chronic hepatitis and hepatocellular carcinoma (HCC). This study investigated whether helicobacter species could be detected in the liver of patients with HCC. METHODS: Liver samples from 20 patients with primary liver carcinoma diagnosed by histopathology and 16 controls without primary liver carcinoma were studied. Histology with standard and immunohistochemical stains, culture, and polymerase chain reaction (PCR) amplification using helicobacter genus specific 16S rRNA primers were used to detect the presence of bacteria. Amplified products were identified by Southern hybridisation and sequencing. A search for other genes specific for Helicobacter pylori was also performed. RESULTS: Helicobacter species 16S rDNA was found in eight of 20 samples of primary liver carcinoma, whereas none of the controls harboured this rDNA. Six helicobacter specific PCR amplicons were sequenced and were found to have 98.5-99.0% similarity to the 16S rDNA of H pylori. Of the eight positive samples, seven were positive in PCR using 26 kDa protein primers and six showed morphological and immunohistochemical evidence of H pylori. The cagA and glmM genes were detected in only two samples. The vacA and rps4 genes were not detected. CONCLUSIONS: Helicobacter can be present in the liver of patients with primary liver carcinoma and is probably linked to the carcinogenic process in the liver.

Growth of Helicobacter pylori in candle jars.

Culture of Helicobacter pylori requires micro-aerobic conditions which are usually generated by a commercial gas-generator system. However, the commercial gas-generator pack is not available in most hospitals in developing countries. The present study showed that H. pylori grew well in a candle jar system that provided micro-aerobic condition; this gave similar cultural results to a commercial gas-generator system. Therefore, the candle jar system can be used for H. pylori micro-aerobic culture in developing countries where commercial systems are not available.

Polycolonization of Helicobacter pylori among Chinese subjects.

OBJECTIVE: To investigate the situation among Chinese patients with regard to infection with multiple strains of Helicobacter pylori. METHODS: Biopsy specimens for culture of H. pylori were obtained from gastric antrum, body and fundus of 20 patients during endoscopic investigation of upper gastrointestinal symptoms. H. pylori was identified by culture from one site in 16 and two or more sites in 10 of the 16 patients. Five isolated colonies of six strains of H. pylori from gastric antrum were subcultured and used for further analysis. Antibiotic susceptibility to metronidazole and clarithromycin was determined by disk diffusion test. Protein profiles of isolates were compared by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). DNA diversity of the isolates was determined by arbitrarily primed polymerase chain reaction (AP-PCR) fingerprinting. RESULTS: Of the 10 patients with multiple isolates, 70% (7/10) exhibited variation in susceptibility to metronidazole and 20% (2/10) to clarithromycin between different sites. In 83% of (5/6) single colonies, no variability was seen in metronidazole and clarithromycin susceptibility; they were either susceptible or resistant. Protein profiles of all isolates by SDS-PAGE were similar. Isolates from different patients produced clearly different AP-PCR fingerprints. In 50% of H. pylori strains isolated from different sites of the stomach, genetic diversity was demonstrated by different AP-PCR fingerprints. In 67% (4/6) strains, five single-colony fingerprints were similar. CONCLUSIONS: Genetic variability has been found in H. pylori strains. Individual patients are infected with a single predominant genotype at a single site but can be colonized by multiple strains, and they may show different antibiotic susceptibilities. Individual colonies of the H. pylori population from a single site may not always yield identical DNA fingerprints and antibiotic sensitivities.

Helicobacter pylori cagA and vacA cytotoxin genes in Changsha, China.

Cytotoxin-associated protein (cagA) and the vacuolating cytotoxin (vacA) encoded by cagA and vacA genes are virulence determinants of Helicobacter pylori. In earlier studies among Chinese patients, all H. pylori strains were cagA-positive and vacAs1a/m2 type. Here, we determine the cagA, vacA and allele status of H. pylori strains isolated from patients with upper gastrointestinal symptoms in Changsha, China. Forty strains of H. pylori isolated from patients with peptic ulcer disease between March 1997 and August 1999 were recovered from storage at -80 degrees C and studied by the polymerase chain reaction (PCR) for cagA and vacA genotypes. cagA was positive in 75% of H. pylori isolates. Patients with peptic ulcer demonstrated cagA in 83% (15/18), compared with 68% (15/22) patients with superficial gastritis. vacAs1 allele was carried in 82.5% (33/40) isolates, of which 52.5% (21/40) were subtype vacAs1a/m2 and 17.5% (7/40) were subtype vacAs1b/m2.