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Exopolysaccharides (EPS) are macromolecules with environment beneficial properties. Currently, numerous studies focus on the absorption of heavy metals by EPS, but less attention has been paid to the effects of EPS on the plants. This study explored the effects of EPS from Lactobacillus plantarum LPC-1 on the structure and function of cell walls in rice seedling roots under cadmium (Cd) stress. The results showed that EPS could regulate the remodeling process of the cell walls of rice roots. EPS affects the synthesis efficiency and the content of the substances that made up the cell wall, and thus plays an essential role in limiting the uptake and transport of Cd in rice root. Furthermore, EPS could induce plant resistance to heavy metals by regulating the lignin biosynthesis pathway in rice roots. Finally, the cell wall remodeling induced by EPS likely contributes to plant stress responses by activating the reactive oxygen species (ROS) signaling.

Background Chronic atrophic gastritis (CAG) is a common disease of the digestive system with pathological characteristics of a decreasing number, or disappearance, of inherent glands of the gastric mucosa. CAG has been defined as a precancerous condition of gastric cancer. Intestinal metaplasia or intraepithelial neoplasia accompanying atrophied glands of the stomach is regarded as one of the most important precancerous lesions of gastric cancer. As a common malignant tumour, gastric cancer remains without a satisfactory therapy and its pathogenesis remains unclear, seriously threatening human life. Therefore, some scholars have proposed to prevent the incidence of gastric cancer by avoiding precancerous lesions. If CAG can be reversed, the incidence of gastric cancer can be substantially reduced. To reverse and prevent CAG and study its pathogenesis and therapy, it is necessary to develop an ideal, safe, stable, animal model. Aim To study a rapid, stable, and safe method of establishing a mouse model of human CAG. Methods Six-week-old Kunming mice were divided into a phosphate buffered solution control group, a Helicobacter pylori (H. pylori) group, an N-methyl-N'-nitroguanidine (MNNG) group, an ammonia water group, and a group combining H. pylori, MNNG, and ammonia water (hereinafter referred to as the combined group). The mice were administrated with drinking water containing ammonia or infected with H. pylori through gavage. At the 30th, 60th, 90th, and 120th day after the last H. pylori infection, mice were selected randomly to collect their gastric mucosa for hematoxylin eosin staining, terminal nick-end labelling staining detection, and immunohistochemical staining for Bax and Bcl-2. In addition, H. pylori was isolated, cultured, and identified, and its extent of colonisation calculated. Blood was collected to detect inflammatory factors interleukin (IL)-1β, IL-8, and tumor necrosis factor (TNF)-α and immune function markers CD4 and CD8 to confirm successful establishment of the CAG model. Results The combined group showed slight CAG at the 90th day and moderate CAG at the 120th day, while other groups did not show CAG at that time. Conclusion The combination of H. pylori, MNNG, and ammonia is an effective method of developing a mouse model of human CAG.

Purpose: A opposite expression levels and roles of miR-330-5p in hepatocellular carcinoma (HCC) have been reported in previous studies, so the clinicopathological implications and the prospective molecular mechanism of miR-330-5p in HCC require elaboration.Materials and methods: To examine the mRNA expression profile of hsa-miR-330-5p in HCC, a in-house RT-qPCR was performed, and the expression data was extracted from sequencing data and gene microarrays from the datasets of The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), ONCOMINE, ArrayExpress, and Sequence Read Archive (SRA). To have an overview of the clinical value of miR-330-5p, all possible data were integrated to calculate the standard mean difference (SMD) and area under the curve (AUC) from summary receiver operating characteristic curve (sROC). The target genes of miR-330-5p were also predicted and the relative signaling pathways were investigated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses.Results: According to the integrative analysis, the expression value of miR-330-5p in HCC was higher than in non-tumor tissue (SMD=0.47, 95CI%=0.31-0.63), and high expression of miR-330-5p was related with advanced HCC stage (SMD=0.27, 95CI%=0.08-0.46), poor differentiation (SMD=0.39, 95CI%=0.21-0.58) and poor prognosis (HR=1.91, Log-rank P=0.014). GLUD1, GOT1 and GLS2 were highly likely to be targeted by miR-330-5p, and the progression and prognosis of HCC might be influenced via the miR-330-5p–GLUD1/GOT1/GLS2 axis.Conclusion: The result showed a high-expressed level of miR-330-5p was in the HCC tissue compared with non-tumor tissue, and the overexpression of miR-330-5p indicated poor progression and prognosis in HCC.

Background: The expression level and clinical significance of integrin subunit beta 4 (ITGB4) in head and neck squamous cell carcinoma (HNSCC) remain unclear. Materials and Methods: Expression of I...

IL24 mRNA is known to have an apoptotic effect on cancer cells but not on noncancer cells. However, the expression level of the IL24 mRNA in head and neck squamous cell carcinoma (HNSCC) and its subgroups is rarely studied. In this study, the clinical implication of IL24 mRNA was evaluated in the common subgroups of HNSCC, including oral squamous cell carcinoma (OSCC), nasopharyngeal carcinoma (NPC), and laryngeal squamous cell carcinoma (LSCC) for analysis. Substantial IL24 mRNA expression data were calculated from several databases, such as the Gene Expression Omnibus (GEO), ArrayExpress, Sequence Read Archive (SRA), ONCOMINE, and The Cancer Genome Atlas (TCGA) databases. We ultimately collected a total of 41 microarrays and RNA-seq including 1,564 HNSCC and 603 noncancer tissue samples. IL24 mRNA was highly expressed in OSCC, LSCC, and NPC as shown by the separated standard mean difference (SMD), as well as HNSCC as a whole part (SMD = 1.47, 95% confdence interval (CI) = 1.24−1.70, P<0.0001). In all subgroups, the IL24 mRNA upregulation had the ability to distinguish cancer from noncancer tissue with area under the curves (AUCs) of the summary receiver operating characteristic (sROC) higher than 0.85. In conclusion, IL24 mRNA may be used as a potential marker for cancer screening, and its clinical diagnostic value needs to be further studied. It also provides a new idea for the treatment of the IL24 gene in HNSCC and its subgroups in the future.

AIM To explore the induction effects and mechanism of Solanum lyratum Thumb (ST) on human hepatocellular carcinoma SMMC-7721 cells through the mitochondrial pathway. METHODS The experiments were conducted on three groups: an experimental group (with ST ethanol extracts’ concentration being 2.5, 5 and 10 mg/L), a negative control group (with only nutrient solution, 0 mg/L ST ethanol extracts), and a positive control group (2.5 mg/L DDP). The inhibition rate of cell proliferation was checked by using the methyl thiazolyl tetrazolium method, and cell apoptosis was tested by TUNEL method. Furthermore, RT-PCR was used to examine mRNA expression of Fas, FasL, caspase-8, caspase-3, p53 and Bcl-2 genes. RESULTS Compared with the negative control group, the inhibition and apoptosis rates of the experimental group with different concentrations of ST extracts on human hepatocellular carcinoma SMMC-7721 cells significantly increased (P < 0.05). Besides, the mRNA expression of FasL and Bcl-2 significantly decreased (P < 0.05) while the mRNA expression of Fas, caspase-8, caspase-3 and p53 increased significantly. When compared with the positive control group, the experimental groups with 5 mg/L ST ethanol extracts showed effects similar to the positive control group. CONCLUSION ST ethanol extracts induced the apoptosis of hepatocellular carcinoma SMMC-7721 cells through up-regulated Fas, caspase-8, caspse-3 and p53, and down-regulated FasL and Bcl-2 in the mitochondrial pathway.

To explore the therapeutic efficacy of manual reduction combined with percutaneous vertebroplasty in treating osteoporotic vertebral compression fractures(OVCFs) with intravertebral clefts.The clinical data of 94 patients with osteoporotic vertebral compression fractures with intravertebral clefts treated from January 2014 to January 2017 were retrospectively analyzed. The patients were divided into group A and group B according to different operative methods. In group A, 45 patients were treated with unilateral approach PVP, including 17 males and 28 females, aged (75.35±11.82) years old, with a bone density T-value of (-4.28±0.65) g/cm³; in group B, 49 patients treated with manual reduction combined with unilateral approach PVP, including 19 males and 30 females, aged (76.79±9.64) years old, with a bone density T-value of (-4.33±0.72) g/cm³. The operation time, bone cement injection volume and postoperative complications of two groups were recorded. The VAS and ODI scores of two groups were analyzed respectively at 1, 12, 18 months after operation. Vertebral height and kyphosis Cobb angle of two groups were compared immediately after surgery and 12, 18 months after operation. The distribution of bone cement in the vertebral body was observed and its distribution excellent rate was calculated.There was no significant difference in operation time between two groups. The amount of bone cement injection was(8.42±1.24) ml in group A and(9.19±1.09) ml in group B, and the difference between two groups was statistically significant(In the treatment of osteoporotic vertebral compression fractures with intravertebral clefts, the manual reduction combined with PVP is more effective than single PVP, which can effectively prevent vertebral body recollapse and improve the long-term efficacy of patients.

In our previous work, indolizinoquinolinedione derivative 1 was identified as a Top1 catalytic inhibitor. Herein, a series of 6-substituted indolizinoquinolinedione derivatives were synthesized through modification of the parent compound 1. Top1 cleavage and relaxation assays indicate that none of these novel compounds act as classical Top1 poison, and that the compounds with alkylamino terminus at C-6 side chain, including 8, 11-16, 18-21, 25, 26 and 28-30, are the most potent Top1 catalytic inhibitors. Top1-mediated unwinding assay demonstrated that 14, 22 and 26 were Top1 catalytic inhibitors without Top1-mediated unwinding effect. Moreover, MTT results showed that compounds 26, 28-30 exhibit significant cytotoxicity against human leukemia HL-60 cells, and that compound 26 exerts potent cytotoxicity against A549 lung cancer cells at nanomolar range.

Uniformity is an important index of the template electrochemical etching. Due to the uneven current distribution between the two electrodes, the etching depth of the workpiece center and edge are significantly different,and the deviation of which is up to 15% or more. In this study, the causes of edge effect is analyzed. A compensation method is proposed and proved by experiments.The results show that: this method is simple, and the uniformity can be reduced to about 3%. It is suitable for the processing of high uniformity requirements in microstructure machining.

Robotics is an interdisciplinary science and should be treated as a part of System Integration. Automotive industry with its assembly line requirements continues to be the main robot consumer. Besides automotive industry, other sectors like for instance metal machining, health and semiconductor industry are interwoven with robotics. Robot is a high value added product so it is worth of development. Therefore, goal of this paper is to demonstrate how to design fully operational rotary delta robot. Firstly, we elaborate kinematic model of the Delta type robot and then construct me-chanical structure thus producing a simulation model of delta robot. Finally, delta robot is simulated and the results confirm the model is OK.

Helicobacter pylori (H. pylori) is a kind of chronic infectious pathogen which can cause chronic gastritis, peptic ulcer, gastric cancer and other diseases. The genetic structure of the pathogenic genes of H. pylori varies largely, which contributes to the differences in virulence among various strains, and in clinical symptoms. Virulence genes of H. pylori can be categorized into three main classes: those related to adhesion and colonization, those related to gastric mucosal injury, and others. This review focuses on the relationship between genetic polymorphisms of the three classes of virulence genes of H. pylori and diseases. Most of the genetic polymorphisms of the main virulence factors of H. pylori are summarized in this paper.

The riveting quality has an important influence on the performance of the aircraft structure. The amount of interference can be an important indicator of the quality of riveted structure. The relationship between the clearance between rivet and hole and uniformity of interference is researched theoretically and experimentally against the aviation panel riveted structure. First, the riveting deformation stages are divided, and the deformation law is theoretically analyzed. The test scheme is designed and carried out based on the actual situation. Then, the experiment result is monitored and compensated. Finally, the relationship between the clearance between rivet and hole and uniformity of interfere is given out with the slope of interference as the uniform evaluation index.

Fatigue damage of airframe often caused by riveting defects, which resulting in failure of aircraft structure in service. Based on the theory of classical fatigue fracture, the effects of Interference-fit gap on capabilities of safe service are examined and a new method of measuring the dimension of Interference-fit gap under the different conditions is introduced by cutting test and fatigue test of typical aluminum alloy 2024-T3 in aero industries. And the admissible value of Interference-fit gap for riveting is given, which offered the technological basis to achieve long fatigue of the aircraft.

Differential scanning calorimetry was used to study melt and solidification and microstructure of austenitic stainless steels containing boron. The liquidus and solidus temperatures decreased because of the boron content, and boron inhibited the formation of δ-Fe. A large content of eutectic boride structure was detected when the boron content was higher. The boride was M2B, and the crystal structure was orthorhombic. The crystal structure and elemental composition of M2B were investigated in detail by SEM-EDS and XRD analysis.

By means of power linkage chart method, the model of closed loop pumping system of concrete pump was set up and simulation was carried out in the Matlab. The results show that the hydraulic shock in the closed loop did not occur at the rapid commutation of piston pump and it actually happened when the concrete was pushed forward after compression. The main piston pump commutation is soft action and this shock can be eliminated effectively by means of “SN” control. Closed loop delivery system is used more widely in high volume concrete pumps and is featured by advantages like energy saving, smooth commutation and low hydraulic shock. In this paper, by means of power linkage chart method, the model of the system was set up and dynamics equations set of the system was obtained. A simulation model was set up by means of simulation toolkit in Matlab language – Simulink, in order to have simulation study of commutation shock of the pumping system and shock due to pushing load and obtain the transient performance of model in time domain.

With the development of science and technology, ordered microstructures with special functions have aroused intense research interest .It has been widely used in many fields. This paper summaries the research status in application of the orderly function structure and looks into its future development.

XopN was originally identified from Xanthomonas campestris pv. vesicatoria as an effector translocated into plant cells via the type III secretion system (T3SS), and is required for pathogenicity. We report here that the xopN homologue in the X. campestris pv. campestris genome, named xopXccN, also encodes a T3SS effector and is required for full virulence. We further demonstrate that expression of xopXccN is positively regulated by the key hrp (hypersensitive response and pathogenicity) regulators HrpG and HrpX.

Xanthomonas campestris pathovar campestris causes black rot, a vascular disease on cruciferous plants, including Arabidopsis thaliana . The gene XC1553 from X. campestris pv. campestris strain 8004 encodes a protein containing leucine-rich repeats (LRRs) and appears to be restricted to strains of X. campestris pv. campestris. LRRs are found in a number of type III-secreted effectors in plant and animal pathogens. These prompted us to investigate the role of the XC1553 gene in the interaction between X. campestris pv. campestris and A. thaliana . Translocation assays using the hypersensitive-reaction-inducing domain of X. campestris pv. campestris AvrBs1 as a reporter revealed that XC1553 is a type III effector. Infiltration of Arabidopsis leaf mesophyll with bacterial suspensions showed no differences between the wild-type strain and an XC1553 gene mutant; both strains induced disease symptoms on Kashmir and Col-0 ecotypes. However, a clear difference was observed when bacteria were introduced into the vascular system by piercing the central vein of leaves. In this case, the wild-type strain 8004 caused disease on the Kashmir ecotype, but not on ecotype Col-0; the XC1553 gene mutant became virulent on the Col-0 ecotype and still induced disease on the Kashmir ecotype. Altogether, these data show that the XC1553 gene, which was renamed avrAC Xcc8004 , functions as an avirulence gene whose product seems to be recognized in vascular tissues.

STUDY DESIGN This study is a result of manual and radiologic measurements of 50 isolated anatomic specimens of C1 and five patients of atlantoaxial instability treated by screw fixation via posterior arch and lateral mass. OBJECTIVES To investigate the feasibility of screw placement via posterior arch and lateral mass in atlas. SUMMARY OF BACKGROUND DATA Several types of posterior approaches have been adopted for stabilization and fusion of atlantoaxial complex. Before this study, Gallie in 1939 gave a report on a posterior wiring technique that depended on a structural bone graft. Since then, double-looped wiring with two bone grafts and Halifax clamp technique had been introduced. A transarticular screw fixation technique was introduced by Magerl and Seeman in 1987, and a C1 lateral mass screw fixation technique was described by Harms in 2001. However, the feasibility of screw fixation in atlas via posterior arch and lateral mass has not been addressed until now. METHODS Fifty dry samples of atlas were measured manually and radiologically with vernier calipers, protractors, and CT. The parameters of posterior arch, lateral mass, vertebral artery groove, axis length of screw path via posterior arch and lateral mass, the entry point, and screw direction were measured. Five patients of atlantoaxial instability were treated with this technique and the radiographs and CT scans were evaluated after surgery. RESULTS The longest trajectory distance of the screw path was about 30 mm. The outer thickness at the thinnest part of groove was 4.58 mm, and it was found to be

To explore the therapeutic efficacy of unilateral multiple channels approach in percutaneous vertebroplasty (PVP) for osteoporotic vertebral fractures.A retrospective review (from March 2003 to October 2012) was conducted on 685 consecutive patients, a total of 885 vertebrae were involved. Eighty-two cases (99 vertebrae) with bone cement leakage when less than 0.3 ml bone cement was injected to fill the fracture were given PVP procedure by unilateral multiple channels approach. 38 cases were male (45 vertebrae) and 44 cases were female (54 vertebrae). The average age was 75.4 years old (from 69 to 92). The operation time, amount of injected bone cement and complications were recorded. Rate of excellent and good outcomes was studied by measuring the cement distribution on the X-ray film. The visual analogue scale (VAS) score and Oswestry disability index (ODI) system were used to evaluate the pain relief and improvement of daily activity function respectively at preoperation and 1 hour, 1 month, 3 months and 6 months after operation.All these ninety-nine vertebrae were treated in 82 cases with PVP of unilateral multiple channels approach. The average operation time was 33 minutes. The rate of excellent and good outcomes of cement distribution was 98.8%. The VAS score was (8.40 +/- 0.73) before surgery,and (2.50 +/- 0.43), (2.00 +/- 0.33), (1.80 +/- 0.28), (2.10 +/- 0.17) at 1 hour, 1 month,3 months and 6 months respectively after operation. ODI was (40.94 +/- 2.72) before surgery, (9.64 +/- 2.60) at 1 month after surgery, (8.52 +/- 2.30) at 3 months after surgery and (7.77 +/- 2.15) at the final follow-up. The differences of the VAS and ODI between pre-operation and post-operation had statistical significance (P0.01). No spine or nerve injuries occurred intraoperatively.The unilateral multiple channels approach in percutaneous vertebroplasty can obviously relieve the pain and effectively improve the functional activity, provide a satisfied cement distribution in vertebral body with cement leakage after a small amount infusion.

XopXccN and XopN are important type III secreted (T3S) virulence effector proteins ofXanthomonas campestris pv. campestris (Xcc) and Xanthomonas campestris pv.vesicatoria (Xcv), respectively. They were placed in the same T3S effector class based on sequence homology. It has been demonstrated that Xcv XopN suppresses pathogen-associated molecular pattern-triggered immune responses during Xcv infection. Here, we present evidence showing that Xcv XopN cannot replace XopXccN for the virulence ofXcc. In addition, we employed two-dimensional different gel electrophoresis to investigate the differentially expressed proteins affected by Xcc XopXccN in the host plant Chinese radish. The results demonstrated that nine proteins mainly associated with plant photosystems were suppressed by XopXccN. RT-PCR analysis showed that several proteins were repressed by XopXccN at the transcriptional level. Moreover, XopXccN could suppress the generation of reactive oxygen species (ROS) and callose deposition in plants. Taken together, our results revealed that XopXccN is involved in plant defense through interference with photosystems, ROS generation, and callose deposition in planta. Key words: XopXccN, T3S effector, Xanthomonas campestris pv. campestris, 2D-DIGE.

Xanthomonas campestris pv. campestris is the pathogen of black rot of cruciferous plants. The pathogenicity of the pathogen depends on the type III secretion system (T3SS) that translocates directly effector proteins into plant cells, where they play important roles in the molecular interaction between the pathogen and its hosts. The T3SS of Xanthomonas spp. is encoded by a cluster of hypersensitive response and pathogenicity (hrp) genes. It has been demonstrated that the expression of hrp genes and some type III secreted (T3S)-effector genes is coactivated by the key hrp regulatory protein HrpX. The regulation by HrpX can be mediated by the binding of HrpX protein to a cis-regulatory element named the plant-inducible promoter (PIP) box present in the promoter region of HrpX-regulated genes. A genome screen revealed that X. campestris pv. campestris 8004 possesses 56 predicted genes with the PIP box. Nine of these genes have been shown to encode T3S effectors, Hrp, and Hrp-associated proteins. In this study, we employed an established T3S effector translocation assay with the hypersensitive-reaction-inducing domain of X. campestris pv. campestris AvrBs1 as a reporter to characterize the remaining 47 genes with the PIP box and showed that 6 of them, designated as XopXccE1, XopXccP, XopXccQ, XopXccR1, XopXccLR, and AvrXccB, harbor a functional translocation signal in their N-terminal regions, indicating that they are T3S effectors of X. campestris pv. campestris. We provided evidence to demonstrate that all these effectors are expressed in an HrpX-dependent manner and their translocation into plant cells relies on the translocon protein HrpF and the chaperone HpaB. Mutational analyses demonstrated that all these effectors, except AvrXccB, are individually required for full virulence and growth of X. campestris pv. campestris in the host plant Chinese radish.

Xanthomonas campestris pathovar campestris causes black rot, a vascular disease on cruciferous plants, including Arabidopsis thaliana. The gene XC1553 from X. campestris pv. campestris strain 8004 encodes a protein containing leucine-rich repeats (LRRs) and appears to be restricted to strains of X. campestris pv. campestris. LRRs are found in a number of type III-secreted effectors in plant and animal pathogens. These prompted us to investigate the role of the XC1553 gene in the interaction between X. campestris pv. campestris and A. thaliana. Translocation assays using the hypersensitive-reaction-inducing domain of X. campestris pv. campestris AvrBs1 as a reporter revealed that XC1553 is a type III effector. Infiltration of Arabidopsis leaf mesophyll with bacterial suspensions showed no differences between the wild-type strain and an XC1553 gene mutant; both strains induced disease symptoms on Kashmir and Col-0 ecotypes. However, a clear difference was observed when bacteria were introduced into the vascular system by piercing the central vein of leaves. In this case, the wild-type strain 8004 caused disease on the Kashmir ecotype, but not on ecotype Col-0; the XC1553 gene mutant became virulent on the Col-0 ecotype and still induced disease on the Kashmir ecotype. Altogether, these data show that the XC1553 gene, which was renamed avrAC(Xcc8004), functions as an avirulence gene whose product seems to be recognized in vascular tissues.

To assess the efficacy of medial wedged proximal tibial osteotomy for treating knee osteoarthritis with varus deformity.From July 1996 to September 1999, 19 patients with knee osteoarthritis accompanied by varus deformity were treated by medial wedged proximal tibial osteotomy combined with internal fixation. Full-length anterior-posterior radiographs were taken preoperatively, 8 weeks and 2 years postoperatively. The parameters including the femorotibial angle, the tibial angle, the femoral angle, the femoral condyle-tibial plateau angle, and the medial joint space, were measured from these radiographs. The function of knee was evaluated according to the 100-point rating scale standard of knee.The mean postoperative score had been significantly improved from 48.6 +/- 16.6 points to 81.7 +/- 14.8 points after 2 years of operation. The medial joint space had been increased from 2.2 +/- 1.6 mm to 4.9 +/- 1.5 mm and the femoral condyle-tibial angle had been decreased from 7.4 degrees +/- 3.1 degrees to 1.7 degrees +/- 3.1 degrees. There were complications in 3 cases: 2 cases of superficial wound infections and 1 case of intra-articular fracture. There were no delayed union and recurrence of varus deformity.Medial wedged proximal tibial osteotomy combined with internal fixation provides an efficacious approach to treat knee osteoarthritis with varus deformity.

AIM: To investigate the rate of Helicobacter pylori (H. pylori) resistance to clarithromycin among ethnic minority patients in Guangxi, explore the underlying mechanisms, and analyze factors influencing genotype distribution of H. pylori isolates. METHODS: H. pylori strains were isolated, cultured and subjected to drug sensitivity testing. The 23S rRNA gene of H. pylori isolates was amplified by PCR and analyzed by PCR-RFLP and direct sequencing to detect point mutations. REP-PCR was used for genotyping of H. pylori isolates, and NTsys_2 software was used for clustering analysis based on REP-PCR DNA fingerprints. Factors potentially influencing genotype distribution of H. pylori isolates were analyzed. RESULTS: The rate of clarithromycin resistance was 31.3%. A2143G and A2144G mutations were detected in the 23S rRNA gene of all clarithromycin-resistant H. pylori isolates. At a genetic distance of 78%, clarithromycin-resistant H. pylori isolates could be divided into six groups. Significant clustering was noted among H. pylori isolates from patients with peptic ulcer or gastritis. CONCLUSION: The rate of clarithromycin resistance is relatively high in ethnic minority patients in Guangxi. Main mechanisms of clarithromycin resistance are A2143G and A2144G mutations in the 23S rRNA gene. Clarithromycin-resistant H. pylori isolates can be divided into six groups based on REP-PCR DNA fingerprints. Several factors such as disease type may influence the genotype distribution of H. pylori isolates.