Preliminary observation on the differential expression of metformin in preventing noise-induced hearing loss in inner ear protein group of rats / 中华劳动卫生职业病杂志

Objective: To study the protective effects of metformin on noise-induced hearing loss (NIHL) and its differential protein omics expression profile. Methods: In January 2021, 39 male Wistar rats were randomly divided into control group, noise exposure group and metformin+noise exposure group, with 13 rats in each group. Rats in the noise exposure group and metformin+noise exposure group were continuously exposed to octave noise with sound pressure level of 120 dB (A) and center frequency of 8 kHz for 4 h. Rats in the metformin+noise exposure group were treated with 200 mg/kg/d metformin 3 d before noise exposure for a total of 7 d. Auditory brainstem response (ABR) was used to test the changes of hearing thresholds before noise exposure and 1, 4, 7 d after noise exposure in the right ear of rats in each group. Tandem mass tag (TMT) quantitative proteomics was used to identify and analyze the differentially expressed protein in the inner ear of rats in each group, and it was verified by immunofluorescence staining with frozen sections. Results: The click-ABR thresholds of right ear in the noise exposure group and metformin+noise exposure group were significantly higher than those in the control group 1, 4, 7 d after noise exposure (P<0.05) . The click-ABR threshold of right ear in the metformin+noise exposure group were significantly lower than that in the noise exposure group (P<0.05) . Compared with the noise exposure group, 1035 up-regulated proteins and 1145 down-regulated proteins were differentially expressed in the metformin+noise exposure group. GO enrichment analysis showed that the significantly differentially expressed proteins were mainly involved in binding, molecular function regulation, signal transduction, and other functions. Enrichment analysis of KEGG pathway revealed that the pathways for significant enrichment of differentially expressed proteins included phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt) signaling pathway, focal adhesion, diabetic cardiomyopathy, mitogen, and mitogen-activated protein kinase (MAPK) signaling pathway. Immunofluorescence experiments showed that compared with the noise exposure group, the fluorescence intensity of insulin-like growth factor 1 receptor (IGF1R) in the metformin+noise exposure group was increased, and the fluorescence intensity of eukaryotic translation initiation factor 4E binding protein 1 (eIF4EBP1) was decreased. Conclusion: Noise exposure can lead to an increase in rat hearing threshold, and metformin can improve noise-induced hearing threshold abnormalities through multiple pathways and biological processes.

Relationship between preoperative inflammatory indexes and prognosis of patients with rectal cancer and establishment of prognostic nomogram prediction model / 中华肿瘤杂志

Objective: To compare the prognostic evaluation value of preoperative neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and systemic immune-inflammation index (SII) in rectal cancer patients. Nomogram survival prediction model based on inflammatory markers was constructed. Methods: The clinical and survival data of 585 patients with rectal cancer who underwent radical resection in the First Affiliated Hospital of Xi'an Jiao tong University from January 2013 to December 2016 were retrospectively analyzed. The optimal cut-off values of NLR, PLR, LMR, and SII were determined by the receiver operating characteristic (ROC) curve. The relationship between different NLR, PLR, LMR and SII levels and the clinic pathological characteristics of the rectal cancer patients were compared. Cox proportional risk model was used for univariate and multivariate regression analysis. Nomogram prediction models of overall survival (OS) and disease-free survival (DFS) of patients with rectal cancer were established by the R Language software. The internal validation and accuracy of the nomograms were determined by the calculation of concordance index (C-index). Calibration curve was used to evaluate nomograms' efficiency. Results: The optimal cut-off values of preoperative NLR, PLR, LMR and SII of OS for rectal cancer patients were 2.44, 134.88, 4.70 and 354.18, respectively. There was statistically significant difference in tumor differentiation degree between the low NLR group and the high NLR group (P<0.05), and there were statistically significant differences in T stage, N stage, TNM stage, tumor differentiation degree and preoperative carcinoembryonic antigen (CEA) level between the low PLR group and the high PLR group (P<0.05). There was statistically significant difference in tumor differentiation degree between the low LMR group and the high LMR group (P<0.05), and there were statistically significant differences in T stage, N stage, TNM stage, tumor differentiation degree and preoperative CEA level between the low SII group and the high SII group (P<0.05). The multivariate Cox regression analysis showed that the age (HR=2.221, 95%CI: 1.526-3.231), TNM stage (Ⅲ grade: HR=4.425, 95%CI: 1.848-10.596), grade of differentiation (HR=1.630, 95%CI: 1.074-2.474), SII level (HR=2.949, 95%CI: 1.799-4.835), and postoperative chemoradiotherapy (HR=2.123, 95%CI: 1.506-2.992) were independent risk factors for the OS of patients with rectal cancer. The age (HR=2.107, 95%CI: 1.535-2.893), TNM stage (Ⅲ grade, HR=2.850, 95%CI: 1.430-5.680), grade of differentiation (HR=1.681, 95%CI: 1.150-2.457), SII level (HR=2.309, 95%CI: 1.546-3.447), and postoperative chemoradiotherapy (HR=1.837, 95%CI: 1.369-2.464) were independent risk factors of the DFS of patients with rectal cancer. According to the OS and DFS nomograms predict models of rectal cancer patients established by multivariate COX regression analysis, the C-index were 0.786 and 0.746, respectively. The calibration curve of the nomograms showed high consistence of predict and actual curves. Conclusions: Preoperative NLR, PLR, LMR and SII levels are all correlated with the prognosis of rectal cancer patients, and the SII level is an independent prognostic risk factor for patients with rectal cancer. Preoperative SII level can complement with the age, TNM stage, differentiation degree and postoperative adjuvant chemoradiotherapy to accurately predict the prognosis of rectal cancer patients, which can provide reference and help for clinical decision.

Exploration on the MiniCEX-DOPS evaluation in standardized residency training of respiratory and critical care medicine / 中华医学教育探索杂志

Objective:To explore the effect of mini-clinical evaluation exercise (MiniCEX) and direct observation of procedural skills (DOPS) formative evaluation in standardized residency training of respiratory and critical care medicine.Methods:The residents who participated in standardized residency training of Zhongshan Hospital, Fudan Unviersity in 2019 were collected in study group, and the residents received the training in previous were collected in control group. The graduation examination scores, the effect of progressive rotations and the satisfaction of residents and examiners were compared between the two groups.Results:The scores of medical history writing, operation and clinical abilities were higher in the study group who were received MiniCEX-DOPS formative evaluation than those in the control group ( P<0.05). The scores of MiniCEX-DOPS evaluation in the third rotation were better than those in the first rotation ( P<0.05). The residents and examiners were generally satisfied with MiniCEX-DOPS evaluation. Conclusion:MiniCEX-DOPS evaluation is effective in residents training of respiratory and critical care medicine, and it is worth popularizing.

Simultaneous detection and characterization of toxigenic Clostridium difficile directly from clinical stool specimens / 医学前沿

We employed a multiplex polymerase chain reaction (PCR) coupled with capillary electrophoresis (mPCR-CE) targeting six Clostridium difficile genes, including tpi, tcdA, tcdB, cdtA, cdtB, and a deletion in tcdC for simultaneous detection and characterization of toxigenic C. difficile directly from fecal specimens. The mPCR-CE had a limit of detection of 10 colony-forming units per reaction with no cross-reactions with other related bacterial genes. Clinical validation was performed on 354 consecutively collected stool specimens from patients with suspected C. difficile infection and 45 isolates. The results were compared with a reference standard combined with BD MAX Cdiff, real-time cell analysis assay (RTCA), and mPCR-CE. The toxigenic C. difficile species were detected in 36 isolates and 45 stool specimens by the mPCR-CE, which provided a positive rate of 20.3% (81/399). The mPCR-CE had a specificity of 97.2% and a sensitivity of 96.0%, which was higher than RTCA (x = 5.67, P = 0.017) but lower than BD MAX Cdiff (P = 0.245). Among the 45 strains, 44 (97.8%) were determined as nonribotype 027 by the mPCR-CE, which was fully agreed with PCR ribotyping. Even though ribotypes 017 (n = 8, 17.8%), 001 (n = 6, 13.3%), and 012 (n = 7, 15.6%) were predominant in this region, ribotype 027 was an important genotype monitored routinely. The mPCR-CE provided an alternative diagnosis tool for the simultaneous detection of toxigenic C. difficile in stool and potentially differentiated between RT027 and non-RT027.

The Taxonomic Status of Spermophilus in the Plague Area of Dingbian County, Shaanxi Province, China / 生物医学与环境科学（英文）

This study was conducted to define the taxonomic status of Spermophilus in the plague area of Dingbian County in Shaanxi Province, China, through the two-factor variance analysis of morphological characteristics, DNA barcoding, and chromosome karyotype analysis. The Spermophilus samples collected from Dingbian and Zhengxiang Baiqi Counties exhibited significant differences in their morphological measurements. All Spermophilus samples form two distinct branches in neighbor-joining (NJ) tree. One branch included the Spermophilus samples collected from Inner Mongolia, and the other branch included samples collected from the plague foci of Shaanxi Province and the Ningxia Region. The Spermophilus samples collected from Dingbian County had a chromosome number of 2n = 38 in 84.40% of all their cells. The Spermophilus species collected from the plague area of Dingbian County was categorized as Spermophilus alashanicus (S.alashamicus). The findings reported in this study are epidemiologically significant for monitoring plague in this region of west-central China.

In vitro and in vivo anti-tumor effects of a combination therapy of curcumin and celastrol to gastric cancer / 中成药

AIM To evaluate anti-gastric cancer effects and benefits of the combination therapy of celastrol and curcumin in vitro and in vivo.METHODS Curcumin,celastrol and curcumin + celastrol applied to BGC823 gastric cancer cells had their impact on the cells growth and apoptosis in vitro checked by CCK-8 assay and flow cytometry of AnnexinV-FITC/PI;and their in vivo anti-tumor effect,systemic toxicity,and influence to the survival time evaluated by using BGC823-bearing gastric tumor mouse models induced by subcutaneous implantation.RESULTS IC50 of curcumin,celastrol and curcumin + celastrol on BGC823 cell were found to be at (57.47 ± 5.22),(2.11 ±0.07) and (0.22 ±0.01) μmol/L,respectively.Curcumin + celastrol achieved a most optimal BGC823 cell apoptosis rate of (73.07 ±3.82)％ at concentrations of (10 mol/L +2 mol/L);and they left a positive impact on the BGC823 gastric tumor-bearing mice,given a (64.87 ±4.16)％ inhibitory rate,and a 50.5-day median survival time.Additionally,the combination therapy demonstrated its less side effects in terms of the body weight,spleen and liver of the nude mice,and significantly improved serum concentrations of TNF-α and IL-6.CONCLUSION Combination of curcumin and celastrol shows significantly synergistic anti-gastric cancer effects in vitro and in vivo.

Direct cloning, expression of a thermostable xylanase gene from the metagenomic DNA of cow dung compost and enzymatic production of xylooligosaccharides from corncob.

OBJECTIVES: To acquire a thermostable xylanase, that is suitable for xylooligosaccharide production from pretreated corncobs, the metagenomic method was used to obtain the gene from an uncultured environmental microorganism. RESULTS: A thermostable xylanase-encoding gene (xyn10CD18) was cloned directly from the metagenomic DNA of cow dung compost. When xyn10CD18 was expressed in Bacillus megaterium MS941, extracellular xylansae activity at 106 IU/ml was achieved. The purified recombinant Xyn10CD18 was optimally active at pH 7 and 75 °C as measured over 10 min. It retained over 55% of its initial activity at 70 °C and pH 7 after 24 h. Its action on birchwood xylan for 18 h liberated xylooligosaccharides with 2°-4° of polymerization, with xylobiose and xylotetraose as the main products. When pretreated corncobs were hydrolyzed by Xyn10CD18 for 18 h, the xylooligosaccharides (DP 2-4) products increased to 80% and the xylose was just increased by 3%. CONCLUSION: Xyn10CD18 is a thermostable endoxylanase and is a promising candidate for biomass conversion and xylooligosaccharide production.

Purification and characterization of a thermostable xylanase from Paenibacillus sp. NF1 and its application in xylooligosaccharides production.

High levels of extracellular xylanase activity (211.79 IU/mg) produced by Paenibacillus sp. NF1 were detected when it was submerged-cultured. After three consecutive purification steps using Octyl-Sepharose, Sephadex G75, and Q-Sepharose columns, a thermostable xylanase (XynNF) was purified to homogeneity and showed a molecular mass of 37 kDa according to SDS-PAGE. The specific activity of the purified XynNF was up to 3,081.05 IU/mg with a 14.55-fold purification. The activity of XynNF was stimulated by Ca(2+), Ba(2+), DTT, and ß-mercaptoethanol, but was inhibited by Fe(3+), Zn(2+), Fe(2+), Cu(2+), SDS, and EDTA. The purified XynNF displayed a greater affinity for oat spelt xylan with the maximal enzymatic activity at 60°C and pH 6.0. XynNF, which was shown to be cellulose-free, with high stability at high temperature (70°C-80°C) and low pH range (pH 4.0-7.0), is potentially valuable for various industrial applications. The end products of high efficient oat spelt xylan hydrolysis by XynNF (an endoxylanase) containing 95.8% xylooligosaccharides of 2-4 degree of polymerization (DP2-4) with the enrichment of xylobiose (61.5%) indicated that XynNF is a promising candidate for xylooligosaccharides production.

Establishment of standardized resident training model in the department of respiratory in line with the discipline characteristics / 中华医学教育探索杂志

Standardized resident training is necessary for residents.The article focused on the establishment of standardized resident training model in the department of respiratory in Zhongshan Hospital of Fudan University.Zhongshan Hospital developed reasonable training plan,formulated strict evaluation and examination system and emphasized on cultivating practical,innovative and independent talents.Detailed measures included strengthening the basic knowledge and practical skills,developing independent learning ability,communication ability and innovative thinking and promoting medical ethics.All these experiences and explorations of standardized resident training in the department of respiratory will be beneficial.

Effects of retinol acid and triiodothyronine on alleviating the impairment of cognitive function by sleep deprivation / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the effects of retinol acid (RA) and triiodothyronine (T3) on alleviating the impairment of cognitive function by sleep deprivation (SD).</p><p><b>METHODS</b>Male Wistar rats were divided into 4 groups: control group (C group), sleep deprivation group (SD group), sleep deprivation + RA group (SD + RA group) and sleep deprivation + T3 group (SD + T3 group). Open field test (OFT) was used to observe the nervous behavior of the rats after SD and electrophysiological brain stereotactic method was used to test long-term potentiation (LTP) in dentate gyrus (DG) of the rats. Ng protein expression was determined by Western blot.</p><p><b>RESULTS</b>Compared with the SD group, the number of crossing in OFT, the changes of amplitude of population spike (PS) and the expression of Ng protein in hippocampus were higher significantly in the SD + RA and SD + T3 groups. All of these had not significant difference comparing with the C group.</p><p><b>CONCLUSION</b>RA and T3 may alleviate the restrain state of neural system after SD by augmenting the expression of Ng protein in hippocampus.</p>

Effect of chronic noise exposure on expression of N-methyl-D-aspartic acid receptor 2B and Tau phosphorylation in hippocampus of rats / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the effect of chronic noise exposure on expression of N-methyl-D-aspartic acid receptor 2B (NR2B) and tau phosphorylation in hippocampus of rats.</p><p><b>METHODS</b>Twenty-four male SD rats were divided in control group and chronic noise exposure group. NR2B expression and tau phosphorylation in hippocampus of rats were detected after chronic noise exposure (100 dB SPL white noise, 4 h/d×30d) and their mechanisms underlying neuronal apoptosis in hippocampus of rats with TUNEL staining.</p><p><b>RESULTS</b>The NR2B expression decreased significantly after chronic noise exposure which resulted in tau hyperphosphorylation and neural apoptosis in hippocampus of rats. Immunohistochemistry showed that the tau hyperphosphorylation was most prominent in dentate gyrus (DG) and CA1 region of rat hippocampus.</p><p><b>CONCLUSION</b>The abnormality of neurotransmitter system, especially Glu and NR2B containing NMDA receptor, and tau hyperphosphorylation in hippocampus of rats, may play a role in chronic noise-induced neural apoptosis and cognition impairment.</p>

[Treatment of ankylosis of the knee through a mini-incision assisted by arthroscope].

OBJECTIVE: To investigate therapeutic effects of mini-incision assisted by arthroscope for the treatment of ankylosis of knee. METHODS: From July 2007 to August 2009, 18 patients with ankylosis of knee were treated with mini-incision assisted by arthroscope. Among the patients, 15 patients were male and 3 patients were female, ranging in age from 27 to 56 years, with an average of 33.6 years. Before operation, 5 patients had comminuted fractures in the distal end of femur (including 1 patient with open fracture), 9 patients had comminuted fractures of tibial plateau, 2 patients had comminuted fractures of patella, 1 patient had comminuted fractures of patella combined with comminuted fracture of capitulum fibulae and injuries of complex structure at lateral knee, and 1 patient had floating knee. The duration between the primary operation and the arthrolysis ranged from 6 to 31 months (averaged, 10.6 months). The therapeutic effects were evaluated according to Judet criteria. RESULTS: All the patients were followed up, and the duration ranged from 3 to 25 months (averaged, 11.4 months). All the patients had incision healing at the first stage without infection, wound dehiscence and liquifaction necrosis. The preoperative knee flexed motion ranged from 30 degrees to 80 degrees, with a mean of (44.72 +/- 11.60) degrees; and postoperative knee flexed range of motion improved to an average of (109.17 +/- 10.31) degrees (ranged, 95 degrees to 135 degrees). According to Judet evaluation, 16 patients got an excellent result, 2 good. CONCLUSION: Treatment of ankylosis of the knee through a mini-incision assisted by arthroscope has advantages such as reducing the complications of incision on knee, little trauma and early recovery, which is a good operative mode to treat ankylosis of the knee after operation or trauma.

Treatment of ankylosis of the knee through a mini-incision assisted by arthroscope / 中国骨伤

<p><b>OBJECTIVE</b>To investigate therapeutic effects of mini-incision assisted by arthroscope for the treatment of ankylosis of knee.</p><p><b>METHODS</b>From July 2007 to August 2009, 18 patients with ankylosis of knee were treated with mini-incision assisted by arthroscope. Among the patients, 15 patients were male and 3 patients were female, ranging in age from 27 to 56 years, with an average of 33.6 years. Before operation, 5 patients had comminuted fractures in the distal end of femur (including 1 patient with open fracture), 9 patients had comminuted fractures of tibial plateau, 2 patients had comminuted fractures of patella, 1 patient had comminuted fractures of patella combined with comminuted fracture of capitulum fibulae and injuries of complex structure at lateral knee, and 1 patient had floating knee. The duration between the primary operation and the arthrolysis ranged from 6 to 31 months (averaged, 10.6 months). The therapeutic effects were evaluated according to Judet criteria.</p><p><b>RESULTS</b>All the patients were followed up, and the duration ranged from 3 to 25 months (averaged, 11.4 months). All the patients had incision healing at the first stage without infection, wound dehiscence and liquifaction necrosis. The preoperative knee flexed motion ranged from 30 degrees to 80 degrees, with a mean of (44.72 +/- 11.60) degrees; and postoperative knee flexed range of motion improved to an average of (109.17 +/- 10.31) degrees (ranged, 95 degrees to 135 degrees). According to Judet evaluation, 16 patients got an excellent result, 2 good.</p><p><b>CONCLUSION</b>Treatment of ankylosis of the knee through a mini-incision assisted by arthroscope has advantages such as reducing the complications of incision on knee, little trauma and early recovery, which is a good operative mode to treat ankylosis of the knee after operation or trauma.</p>

Effects of noise exposure on event-related potential P300 and mechanism in hippocampus of rats / 中国应用生理学杂志

<p><b>AIM</b>To study the effects of noise on event-related potential(ERP) and its mechanism in hippocampus in rats.</p><p><b>METHODS</b>Male SD rats were divided into 2 groups: control group (CG) and noise exposure group(NG). The rats in NG were exposed to white noise 105 dB SPL for 2.5 h/d x 20 d. P300 were recorded at parietal bone in rats. The Nissl body, NMDAR2B and [Ca2+]i of neurons in hippocampus were analyzed.</p><p><b>RESULTS</b>The peak latency (PL) of ERP P3a, P3 and P3b in NG were significantly longer than that in CG in the 14th and 20th exposure day. The amount of Nissl body in dentate gyrus (DG) and CA1 region and NMDAR2B in DG, CA1 and CA3 region of hippocampus of NG were significantly decreased than those of CG as well, while the concentration of Ca2+ in neurons increased markedly in NG.</p><p><b>CONCLUSION</b>Decreased Nissl body and NMDAR2B and increased [Ca2+]i in hippocampus in long-term noise exposed rats might cause the change of ERP P300.</p>

A study on the transdifferentiation of adipose mesenchymal stem cells into hepatocytes / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the possibility of transdifferentiation of adipose mesenchymal stem cells (AMSCs) into hepatocytes.</p><p><b>METHODS</b>Human omentum adipose tissue was dispersed with collagenase I. Cells collected were cultured in a DMEM-F12 medium containing 2% FBS supplemented with 20 ng/ml HGF, 10 ng/ml FGF4, 1xITS and 0.1 micromol/L dexasmison. The cells of the control group were also cultured in the same kind of medium but without any cytokines serving as a control. The expression of hepatic transcriptional factors such as GATA4 and HNF1 were checked by RT-PCR. At the end of the induction, hepatocyte markers were analysed by flow cytometry, and cytokeratin expressions were examined using cyto-immunofluorescence methods.</p><p><b>RESULTS</b>AMSCs grew like fibroblasts and were passaged easily. Most of the third passaged AMSCs were positive against anti-CD29, anti-CD44 antibodies, but negative for the anti-CD34 and anti-CD45 ones. The hepatic transcriptional factor was expressed gradually to higher levels during the induction time. AFP and Alb positive cells were 30.0% and 17.8% of the total cultured cells, and the rate of cells positive to the two markers was 6.9%. The inducted cells were positive for CK18 and CK19 antibodies at the end of the induction. The cells in the control group were negative when checked by these methods.</p><p><b>CONCLUSIONS</b>AMSCs could be directed to differentiate into hepatocytes in vitro by a cytokine cocktail with a low concentration FBS culture system.</p>

Detection and Assay of Beta-lactamase and Drug Resistance of Stenotrophomonas maltophilia / 中华医院感染学杂志

OBJECTIVE To study the drug resistance of Stenotrophomonas maltophilia in order to direct clinical drug application.METHODS The S.maltophilia was identified and its sensitivity was analyzed with VITEK2-AMS.The extended-spectrum beta-lactamases(ESBLs) and metallo ?-lactamase(MBL) were screened by double-disk synergy test and double-disk confirmatory test.RESULTS The resistance rate of S.maltophilia to cefoperazone-sulbactam,levofloxacin and SMZ-TMP was the lowest,accounted for 12.50%,13.64% and 14.77%,respectively.The ESBLs positive rate was 69.32%,the MBL positive rate was 69.32%.CONCLUSIONS The multidrug resistance of S.maltophilia is serious and full dose use of two or more antibacterials is recommended.

[Mutation effect of ultra high pressure on microbe].

(Ultra) high pressure had many influences on microbe. It could regulate the expression of gene and protein, influence DNA's structure and function as well as change cell morphology and cell component. These effects not only make (ultra) high pressure to be applied into food sterilization, conserving and some processing, but also indicate it would play an important role in mutagenic breeding of microbe. Pressure can change the structure and function of microbe, yet it is possible that (ultra) high pressure could induce mutation of microbe. Now the feasibility of (ultra) high pressure's mutation effect was discussed according to the effects of it on microbe, some examples and author's studying.

Comparison of the cytotoxicity in vitro among six types of nano-silver base inorganic antibacterial agents / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the biocompatibility of nano-silver base inorganic antibacterial agents and compare the cytotoxicity in vitro among six types of nano-silver base inorganic antibacterial agents.</p><p><b>METHODS</b>FUMAT T200-4, HN300, Novaron, Kangwang, MOD and SR1000 were diluted to different concentrations, such as 100 g/L, 50 g/L, 25 g/L and 12.5 g/L. The cytotoxicity in vitro of these agents on rat's fibroblast was assayed with MTT method. And the grades of cytotoxicity were compared.</p><p><b>RESULTS</b>High concentrations of nano-silver base inorganic antibacterial agents had cytotoxic effects on rat's fibroblasts L-929. As the concentration decreased, the cytotoxicity decreased. No cytotoxic effects were observed at or below the concentration of 25 g/L. FUMAT T200-4, Kongwang and SR1000, with the carrier of phosphate zirconium, had less cytotoxity than the others.</p><p><b>CONCLUSIONS</b>Nano-Silver base inorganic antibacterial agents, such as FUMAT T200-4, Kangwang, SR1000, have good biocompatibility. And they have the possibility of clinical application. The safe concentration of these agents is at or below 25 g/L.</p>

Study of the protective effect of L-arginine on relative ischemic/reperfusion injury in myocardium of rat / 中国应用生理学杂志

<p><b>AIM</b>To explore the protective effect of L-arginine on isolated rat heart with ischemia/reperfusion injury.</p><p><b>METHODS</b>24 wistar rats were randomly divided into 3 groups (each 8): control group, ischemia group, L-arginine group. The myocardiac relatively ischemia/reperfusion models in vitro were set up by using weak current stimulating isolated rat hearts. During the pre-ischemia, post-ischemia 15 min and post-ischemia 30 min, the coronary fluid was collected for testing contents of MDA and activities of both CK and LDH. Cardiac functional indexes were recorded through Pclab. At the time of 5 min, 10 min, 20 min, 30 min after ischemia, the recovery of PRP, + DP/dt(max) and - DP/dt(max) were calculated.</p><p><b>RESULTS</b>(1) During the reperfusion, L-arginine group achieved better recovery of cardiac function than that of the ischemia group. (2) MDA content, CK and LDH activities both in the coronary fluid and in the myocardium of L-arginine group were lower than those of the ischemia group, while SOD activities in the myocardium of L-arginine group were higher than that of the ischemia group.</p><p><b>CONCLUSION</b>To some extent, L-arginine could protect the myocardium from ischemia/reperfusion injury.</p>