Nitrite oxidoreductase(NXR) is the key enzyme responsible for the oxidation of NO2-to NO3-in nitrite-oxidizing bacteria.Since NXR is a dissoluble enzyme,located at the inner side of the membranes of cells,its function is dependent on the electron transfer chain related to membranes.This paper reviews the advances in study on NXR,including the structure,catalysis mechanism and the impact of different factors.New techniques applied in recent studies and research prospects are also presented.

Objective To analyze the clinical and endoscopic characteristics of fundic gland polyps (FGPs).Methods A case-control study was carried out at the Afifliated Beijing Shijitan Hospital of Capital Medical University from 2008 to 2015. The patients who accepted an upper endoscopy and found the gastric polyps for the ifrst time (diagnosed by pathology) were included in the study. Then, we analyzed the clinic and pathological characteristics of FGPs and non-FGPs.Results During the study period, 867 patients were enrolled, and 319 (36.8%) patients had FGPs. Compared the cases with the controls, the size of FGPs was smaller, an average is (0.40 ± 0.15) cm, single accounted for 67.7%, and 88.1% of FGPs were located at fundus and body. Helicobacter pylori infection of the cases detected was found in 6.1%, less than non-FGPs. There were statistically signiifcant differences observed in these aspects. From 2008 to 2015, the proportion of FGPs in gastric polyps and the detection rate of FGPs are both gradually elevated.Conclusions FGPs are the common gastric polyps, and its detection rate is gradually elevated. Most of the FGPs are mainly located at fundus and body, and single. Helicobacter pylori infection detected in the patients who have FGPs is rare.

Objective To investigate the value of colonoscopy with narrow band imaging (NBI) in predicting the histology of colorectal polypoid lesions. Methods A total of 173 colorectal polypoid lesions from 125 patients were included in the study. The lesions were diagnosed as neoplastic (adenoma or cancer)or non-neoplastic based on pit patterns and/or capillary patterns (CP), which was compared with the results of pathology, and the sensitivity, specificity and accuracy of each method were evaluated. Results In differentiation between neoplastic and non-neoplastic lesions, the sensitivity, specificity and accuracy of CP (94. 83% , 91. 23% and 93.64% , respectively), and those of CP combined with pit patterns (95. 69% ,96.49% and 95. 59% , respectively) were significantly higher than those of conventional colonoscopy (80. 17% , 84.21% and 81.50% , respectively, P<0.05). In differentiation between adenoma and cancer,the sensitivity, specificity and accuracy of CP were 86.90% , 100.00% and 87.93% , respectively.Conclusion NBI is superior to conventional colonoscopy in differentiation between neoplastic and non-neoplastic lesions, as well as in differentiation between adenoma and carcinoma.

AIM:To observe and analyze the change of visual field and retinal nerve fiber layer thickness of primary open-angle glaucoma ( POAG ) after the Ex-press glaucoma shunt implantation.
●METHODS:A total of 14 patients (24 eyes) with POAG were underwent Ex-press glaucoma shunt implantation. Visual acuity, intraocular pressure ( lOP ) , mean defect ( MD) , pattern standard deviation ( PSD ) , retinal nerve fiber layer thickness ( RNFLT ) , and corneal endothelial cell number were collected preoperatively. Visual acuity and lOP were collected in 1wk, 1 and 3mo postoperatively respectively. Also, MD, PSD, RNFLT, and corneal endothelial cell number were collected preoperatively and 3mo postoperatively respectively. Complication, the additional treatment, success rate were analyzed.
●RESULTS:There was no significant difference (P>0. 05) in visual acuity preoperative and postoperative 1wk, 1, 3mo. Visual acuity did not significantly reduce after operation. Compared with preoperative, there was significant decreased (P<0. 05) in lOP after 1wk, 1, 3mo postoperative, respectively. lOP keep stead in postoperative 3mo. The reduction of RNFLT had significant difference (P<0. 05) between preoperative and postoperative 3mo. Compared with preoperation, MD and PSD had no significant difference ( P > 0. 05 ) after postoperative 3mo. Corneal endothelial cell number decrease had significant difference (Z=-2. 585, P=0. 01) between preoperative and postoperative 3mo. Success rate: complete success: 79. 2% ( 19 eyes ); partial success:8. 3% (2 eyes);failure:12. 5% (3 eyes).
●CONCLUSION: Ex-press glaucoma shunt implantation could efficiently decrease the lOP in POAG patients. Although it results in reduction of RNFLT in short time. The visual acuity and visual field keep stable after operation. lt is a safe and effective device for treating primary open-angle glaucoma.

Objective To establish an appropriate preterm hypoxic-ischemic brain injury animal model. Methods A total of 32 pregnant New Zealand white rabbits at gestational day 25 were selected. The uterine blood supply in pregnant rabbits was blocked for 30, 35, 37, 40 minutes respectively, while in the control group it was not blocked. Then the pregnant rabbits were subjected to cesarean section 24 hours (at embryonic day 26, A group) or 5 days (at embryonic day 30, B group) after the experimental procedure. The general conditions of the newborn rabbits were recorded. The degree of neurobehavioral impairment in newborn rabbits was evaluated. The histological changes of brain tissue were observed. Results In A group, all newborn rabbits survived with ischemia for 30 minutes, while the stillbirth rates increased from 31.0% to 100% with ischemia from 35 to 40 minutes. In survived nowborn rabbits, the brain water content and the number of apoptotic brain cells were increased with prolonged ischemia. All these differences were statistically significant (all P<0.05). In B group, the stillbirth rates increased to 50.0% and 65.7% respectively with ischemia for 35 or 37 minutes. The birth weight of survived newborn rabbits were significantly lower than that in the control group. The neurobehavioral test scores were significantly lower in ischemic groups than that in the control group. All these differences were statistically significant (all P<0.05). The pathological examination of brain tissue found that the white matter damage in B group was more obvious than that in A group. Conclusions Continuous blockage of uterine blood supply in pregnant rabbits at gestational day 25 causes stillbirth, neurobehavioral damages and white matter injury as well as fetal rabbit intrauterine growth restriction, which can be used for the preparation of preterm hypoxic-ischemic brain injury animal model.

Humans ; Male ; Middle Aged ; Pacemaker, Artificial ; adverse effects ; Tricuspid Valve Stenosis ; etiology

Objective To investigate the levels of activated Stat3 (p‐Stat3) and the expression levels of SOCS3 as well as their clinical significance and its impact on the pathogenesis ,progression ,and prognosis in patients with gastric cancer .Methods The levels of p‐Stat3 and SOCS3 were tested in 53 cases of gastric cancer tissues (test group) and 27 cases of adjacent non cancerous tis‐sues (control group) by immunohistochemistry (IHC) .The clinical pathological and follow up data were analyzed .Results The levels of activated p Stat3 were significantly higher in gastric cancer tissues than in non cancerous tissues .The levels of SOCS3 were lower in cancer tissues than in non cancerous control tissues (P<0 .05) .p‐Stat3 showed significantly different levels among TNM stages and tumor differentiation ,and the expression levels of SOCS3 were negatively associated with cancer invasion ,lymph node metastasis and TNM stages in cancer patients (P<0 .05) .Furthermore ,a negative correlation was observed between the levels of activated p‐Stat3 and SOCS3 in gastric cancer tissues (r= -0 .492 ,P<0 .05) .Kaplan Meier survival analyses indicated that the p‐tat3 levels were negatively correlated with total survival of gastric cancer patients ,the higher the levels of p‐Stat3 was ,the lower the total survival rate would be (χ2 = -5 .05 ,P<0 .05) .On the contrary ,the levels of SOCS3 showed a positive correlation with total survival (χ2 =10 .852 ,P<0 .05) .Conclusion Increased a p‐Stat3 and decreased expression of negative Stat3 regulator SOCS3 may play important roles in the development and progression of gastric cancer ,both of which would potentially serve as prognostic mark‐ers for gastric cancer .

ObjectiveTo determine the features of antrum gastritis by magnified narrow band imaging (M-NBI) and to evaluate the feasibility of target biopsy with M-NBI.MethodsA total of 69 consecutive patients who underwent M-NBI were recruited in the study.The gastric mucosa of antrum was observed under M-NBI and the gastric microstructure patterns were classified into 5 type.M-NBI findings were compared with the conventional histological findings.In addition,the interobserver agreement was assessed.ResultsA total of 173 gastric antral sites from 69 patients were examined by M-NBI.Type A was mainly normal sites (89.8％,44/49),while type B and C were chronic inflammation (53.3％,24/45 )and active inflammation (74.3％,26/35).Compared with the type A group,the inflammatory degree in type B (P＜0.001 ) group and type C group (P＜0.001) was significantly higher.The sensitivity,specificity,accuracy of the type B and type C pattern for predicting antrum gastritis were 87.5％,78.0％ and 81.5％.The sensitivity,specificity,accuracy of the type D and type E pattern for predicting intestinal metaplasia of antrum were 83.8％,90.4％ and 77.5％,respectively.The kappa value for the interobserver agreement was 0.734 [ 95％ CI(0.591-0.977 ) ].ConclusionMicrostructure features of antrum gastritis determined by M-NBI are highly correlated with histopathology,and can evidently help diagnosis.

ObjectiveTo investigate the influence of TGF-β receptor subtypes expression and their downstream signaling Smad proteins on rat renal interstitial fibrosis induced by unilateral ureteral obstruction(UUO).MethodsA total of 90 rats were randomly divided into three groups:normal control(CON),sham operation (SOR) and UUO group,and sacrificed 1,3,7,14 and 21 days after operation.Serum creatinine and urea nitrogen were detected to assess renal function.PAS and Masson staining were performed to observe histological damage in the kidneys.Quantitative RT-PCR was used to define expression of mRNA encoding TGF-β receptor subtypes and their downstream signaling Smad proteins in kidney tubular cells.Real-time PCR,Western blotting and immunofluorescence were used to monitor the time-related expression of the TGF-β receptor subtypes and their downstream signaling Smad proteins in kidney.ResultsCompared with the CON group,serum creatinine and urea nitrogen in UUO groups increased at day 3 after operation (P＜0.05) and reached their peak 21 days after operation (P＜0.01).Obvious inflammatory cell infiltration was observed in UUO group 3 days after operation,while renal tubular atrophy and renal interstitial fibrosis were observed in UUO group14 days after operation.The mRNA expressions of ALK-5,ALK-7 and TGF-βR Ⅱ increased significantly in UUO group 3 days after operation (all P＜0.05) and reached their peaks 14 days after operation (all P＜0.01).The mRNA expression of ALK-6 decreased significantly in UUO group 3 days after operation(P＜0.05) and reached its lowest level 14 days after operation (P＜0.01).The changes in the protein level of those receptors were consistent with their mRNA expressions.The protein expressions of Smad2/3 and p-Smad2/3 increased significantly in UUO group at day 3(all P＜0.05) and reached their peak at day 14 after operation(all P＜0.01).ConclusionExpressions of TGF-β receptor subtypes ALK-5,ALK-6,ALK-7,TGF-βR Ⅱ and their downstream signaling Smad2 and Smad3 proteins may influence the progress of renal interstitial fibrosis,tubular atrophy and inflammatory cell infiltration in UUO model rats.

Small interfering RNA (siRNA) is the initiator of RNA interference and inhibits gene expression by targeted degradation of specific messenger RNA. siRNA-mediated gene regulation has high efficiency and specificity and exhibits great significance in the treatment of diseases. However, the naked or unmodified siRNA has poor stability, easy to degrade by nuclease, short half-life, and low intracellular delivery. As an emerging non-viral nucleic acid delivery system, ionizable lipid nanoparticles play an important role in improving the druggability of siRNA. At present, one siRNA drug based on ionizable lipid nanoparticles has been approved for the treatment of rare disease. This review introduces the research progress in ionizable lipid nanoparticles for siRNA delivery, focusing on the effect of each component of lipid nanoparticles on the efficiency of siRNA-mediated gene silencing, which provides new references for the studies on ionizable lipid nanocarriers for siRNA delivery.