Characteristics of Gram-positive cocci infection and the therapeutic effect after liver transplantation / 中南大学学报(医学版)

OBJECTIVES@#Gram-positive cocci is the main pathogen responsible for early infection after liver transplantation (LT), posing a huge threat to the prognosis of liver transplant recipients. This study aims to analyze the distribution and drug resistance of Gram-positive cocci, the risk factors for infections and efficacy of antibiotics within 2 months after LT, and to guide the prevention and treatment of these infections.@*METHODS@#In this study, data of pathogenic bacteria distribution, drug resistance and therapeutic efficacy were collected from 39 Gram-positive cocci infections among 256 patients who received liver transplantation from donation after citizens' death in the Third Xiangya Hospital of Central South University from January 2019 to July 2022, and risk factors for Gram-positive cocci infection were analyzed.@*RESULTS@#Enterococcus faecium was the dominant pathogenic bacteria (33/51, 64.7%), followed by Enterococcus faecalis (11/51, 21.6%). The most common sites of infection were abdominal cavity/biliary tract (13/256, 5.1%) and urinary tract (10/256, 3.9%). Fifty (98%) of the 51 Gram-positive cocci infections occurred within 1 month after LT. The most sensitive drugs to Gram-positive cocci were teicoplanin, tigecycline, linezolid and vancomycin. Vancomycin was not used in all patients, considering its nephrotoxicity. Vancomycin was not administered to all patients in view of its nephrotoxicity.There was no significant difference between the efficacy of daptomycin and teicoplanin in the prevention of cocci infection (P>0.05). Univariate analysis indicated that preoperative Model for End-Stage Liver Disease (MELD) score >25 (P=0.005), intraoperative red blood cell infusion ≥12 U (P=0.013) and exposure to more than 2 intravenous antibiotics post-LT (P=0.003) were related to Gram-positive cocci infections. Multivariate logistic regression analysis revealed that preoperative MELD score >25 (OR=2.378, 95% CI 1.124 to 5.032, P=0.024) and intraoperative red blood cell transfusion ≥ 12 U (OR=2.757, 95% CI 1.227 to 6.195, P=0.014) were independent risk factors for Gram-positive cocci infections after LT. Postoperative Gram-positive cocci infections were reduced in LT recipients exposing to more than two intravenous antibiotics post-LT (OR=0.269, 95% CI 0.121 to 0.598, P=0.001).@*CONCLUSIONS@#Gram-positive cocci infections occurring early after liver transplantation were dominated by Enterococcus faecalis infections at the abdominal/biliary tract and urinary tract. Teicoplanin, tigecycline and linezolid were anti-cocci sensitive drugs. Daptomycin and teicoplanin were equally effective in preventing cocci infections due to Gram-positive cocci. Patients with high preoperative MELD score and massive intraoperative red blood cell transfusion were more likely to suffer Gram-positive cocci infection after surgery. Postoperative Gram-positive cocci infections were reduced in recipients exposing to more than two intravenous antibiotics post-LT.

Impact of catheter-tissue contact force on lesion size during right ventricular outflow tract ablation in a swine model / 中华医学杂志(英文版)

BACKGROUND@#The catheter-tissue contact force (CF) is one of the significant determinants of lesion size and thus has a considerable impact on the effectiveness of ablation procedures. This study aimed to evaluate the impact of CF on the lesion size during right ventricular outflow tract (RVOT) ablation in a swine model.@*METHODS@#Twelve Guangxi Bama miniature male pigs weighing 40 to 50 kg were studied. After general anesthesia, a ThermoCool SmartTouch contact-sensing ablation catheter was introduced to the RVOT via the femoral vein under the guidance of the CARTO 3 system. The local ventricular voltage amplitude and impedance were measured using different CF levels. We randomly divided the animals into the following four groups according to the different CF levels: group A (3-9 g); group B (10-19 g); group C (20-29 g); and group D (30-39 g). Radiofrequency ablations were performed at three points in the free wall and septum of the RVOT in power control mode at 30 W for 30 s while maintaining the saline irrigation rate at 17 mL/min. At the end of the procedures, the maximum depth, surface diameter, and lesion volume were measured and recorded. A linear regression analysis was performed to determine the relationship between continuous variables.@*RESULTS@#A total of 72 ablation lesions were created in the RVOT of the 12 Bama pigs. The maximum depth, surface diameter, and volume of the lesions measured were well correlated with the CF (free wall: β = 0.105, β = 0.162, β = 3.355, respectively, P < 0.001; septum: β = 0.093, β = 0.150, β = 3.712, respectively, P < 0.001). The regional ventricular bipolar voltage amplitude, unipolar voltage amplitude, and impedance were weakly positively associated with the CF (β = 0.065, β = 0.125, and β = 1.054, respectively, P < 0.001). There was a significant difference in the incidence of steam pops among groups A, B, C, and D (free wall: F = 7.3, P = 0.032; septum: F = 10.5, P = 0.009); and steam pops occurred only when the CF exceeded 20 g. Trans-mural lesions were observed when the CF exceeded 10 g in the free wall, while the lesions in the septum were non-trans-mural even though the CF reached 30 g.@*CONCLUSIONS@#CF seems to be a leading predictive factor for the size of formed lesions in RVOT ablation. Maintaining the CF value between 3 and 10 g may be reasonable and effective for creating the necessary lesion size and reducing the risk of complications, such as steam pops and perforations.

Epidemiological survey and study of hepatitis E virus among HIV-infected population in Hubei Province / 中华疾病控制杂志

Objective To determinate the seroprevalence of hepatitis E virus (HEV) exposition among HIV-infected people in Hubei Province so as to provide basic data for effective prevention and control of HIV and hepatitis E virus． Methods A total of 335 serum samples of HIV-infected people were collected from January to June 2017．Serum samples were subjected to anti-HEV IgG andanti-HEV IgM screening. Data were statistically analyzed. Results In 335 HIV-infected people，0.89% (3/335) of serum samples were anti-HEV IgM positive and 41.49% (139/335) of them were anti-HEV IgG positive．The anti-HEV IgG positive rate was not linearly correlated with age ( 2linear=0.756，P=0.385), and there was no significant difference between the age groups (P>0.05). There was no significant difference in anti-HEV IgG positive rate between different gender( 2=0.085，P=0.771)．Anti-HEV IgG positive rate for the crowd with CD4 value ≤ 200 cell/μl was higher than that with CD4 ＞200 cell/μl，but showed no significant difference( 2=1.016，P=0.314)，and CD4 indexes of three positive anti-HEV IgM patients were 222, 446 and 198 in cell/μl．The anti-HEV IgG positive rate in HIV-infected population in eastern Hubei (30.77%, 32/1 041) was statistically different from that in central Hubei (47.92%, 46/96) ( 2=6.169，P=0.013) , and it was also different from that in southeastern Hubei (45.79%， 49/107) ( 2=5.034，P=0.025). Conclusions There were higher HEV infection rate among HIV-infected people in Hubei Province; thus, it is essential to positively carry out double-way screening for these two diseases at the same time, and effective prevention and control of these viruses are required.

AxiaLif application in lumbosacral vertebral fusion / 中国组织工程研究

BACKGROUND: Lumbosacral vertebral fusion operation is an important treatment for lumbosacral vertebral degenerative disease. Traditional open surgery has great trauma; postoperative recovery time is longer; there are more complications. To reduce the damage to normal tissue and increase the rate of healing, scholars in and outside China improve the lumbar spine fusion surgery, and lumbar fusion becomes a tendency of the development of minimally invasive surgery. In 2004, Cragg introduced lumbosacral vertebral axial fusion (AxiaLIF, axial lumbar intervertebral fusion). The operation is through posterior rectal wall and presacral space approach, axially nailing for fusion of L5/S1. Muscle, ligament and blood vessels of the spine were retained. Mechanical stability was similar to that of traditional fusion. Osseous fusion rate was high at the operation segment. This is in line with the concept of minimally invasive surgery of the spine. OBJECTIVE: To summarize the advantages and disadvantages of traditional and present fusion techniques from traditional lumbar fusion and present lumbar fusion angle, and to explore the application of AxiaLIF in lumbosacral fusion. METHODS: We retrieved PubMed, Web of Science, and Springer database with the English key words of "Axial interbody fusion and (properties or evaluation), biomechanics, spine mechanical test, spine and (kinematics or motion)", and Chinese Journal Full-Text Database with the Chinese key words of "Axial fusion, biomechanics research assessment, biomechanics, anterior sacral space, minimally invasive spine" for studies concerning lumbar fusion, complications, biomechanics, and humanistic medicine that had been published in recent 5 years. Repetitive studies were excluded, and 46 studies were analyzed and discussed. RESULTS AND CONCLUSION: In the past 90 years, scholars in and outside China had studied the methods of lumbar fusion from various levels, analyzed and summarized the advantages and disadvantages of various operative methods, and identified the indications of lumbar spinal fusion. By comparing characteristics of open surgery and minimally invasive surgery, this study suggested that minimally invasive lumbar fusion has become a trend. In-depth understanding of biomechanical stability, complications, and postoperative recovery time after AxiaLIF is still a long way to go in future medical research.

NLRP3 inflammasome signaling as an early molecular response is negatively controlled by miR-186 in CFA-induced prosopalgia mice

The NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most frequently studied in the central nervous system and has been linked to neuropathic pain. In this study, a post-translational mechanism of microRNA (miR)-186 via regulating the expression of NLRP3 in the complete Freund's adjuvant (CFA)-treated mice was investigated. The injection of CFA was used to induce trigeminal neuropathic pain in mice. miRs microarray chip assay was performed in trigeminal ganglions (TGs). CFA treatment significantly increased the mRNA expression of NLRP3, interleukin (IL)-1β, and IL-18 in TGs compared to the control group. Moreover, 26 miRs were differentially expressed in TGs from trigeminal neuropathic pain mice, and the expression of miR-186 showed the lowest level of all the miRs. Further examination revealed that NLRP3 was a candidate target gene of miR-186. We delivered miR-186 mimics to CFA-treated mice. The head withdrawal thresholds of the CFA-treated mice were significantly increased by miR-186 mimics injection compared with CFA single treatment. The mRNA and protein expression of NLRP3, IL-1β, and IL-18 in TGs from trigeminal neuropathic pain mice were significantly inhibited by miR-186 mimics treatment compared to the CFA group. miR-186 was able to suppress the neuropathic pain via regulating the NLRP3 inflammasome signaling.

Targeting Myocyte-specific Enhancer Factor 2D Contributes to the Suppression of Cardiac Hypertrophic Growth by MiR-92b-3p in Cardiomyocytes / 中山大学学报(医学科学版)

[Objective]To investigate the role and the potential target of miR-92b-3p in angiotensin Ⅱ(Ang-Ⅱ)-induced mouse cardiac hypertrophy.[Methods]Ang-Ⅱ-induced cardiac hypertrophy models were established in adult C57BL/6 mice. AgomiR-92b-3p,the cholesterol-modified miR-92b-3p mimic,was delivered to increase the level of miR-92b-3p in mouse myocar?dium via tail vein injection. In the present study,three groups of mice were used in the animal experiment as follows,the agomiR-negative control(agomiR-NC)+saline group,the agomiR-NC+Ang-Ⅱgroup and the agomiR-92b-3p+Ang-Ⅱgroup. A cell model of cardiac hypertrophy was also established in Ang-Ⅱ-induced neonatal mouse cardiomyocytes in this study Luciferase activity was assayed after transfection using a luciferase reporter assay system. The expression of Myocyte-specific enhancer factor 2D( MEF2D) and hypertrophy-related genes atrial natriuretic peptide (ANP),cardiac muscle α-actin (ACTA1) and β-myosin heavy chain (MHC)at mRNA and protein levels in Ang-Ⅱ-induced hypertrophic myocardium and cardiomyocytes were detected by qRT-PCR and Western blot,respectively.[Results]The expression of ANP,ACTA1,β-MHC were markedly increased in Ang-Ⅱ-induced hypertrophic myocardium and cardiomyocytes. Dual luciferase reporter assay revealed that MEF2D is a potential target gene of miR-92b-3p. And miR-92b-3p can reduce the expression of MEF2D at the post-transcriptional level. Functionally,miR-92b-3p mimic, consistent with MEF2D siRNA,inhibited cell size increase and protein expression of ANP,ACTA1 andβ-MHC in Ang-II-treated mouse cardiomyocytes.[Conclusions]MEF2D is a novel target of miR-92b-3p,a target gene of miR-92b-3,which mediates the ef?fect of miR-92b-3p on attenuating cardiomyocyte hypertrophy.

Safety analysis of atrial septal defect closure using Da Vinci surgical system / 医疗卫生装备

Objective To analyze the safety of atrial septal defect closure using Da Vinci surgical system. Methods Totally 23 atrial septal defect patients hospitalized from July to December 2016 underwent atrioseptopexy by using Da Vinci surgical system. The effect of atrioseptopexy was observed under cardiopulmonary bypass conditions. Results All the patients had the operation completed successfully, with the operating time being (2.8 ±0.5)h, the intraoperative cardiopulmonary bypass time being (35.4±18.4)min, aortic clamping time being (25.9±8.4)min, postoperative mechanical ventilation time being (5.7±1.5)h, amount of thoracic drainage fluid from 50 to 300 ml and postoperative hospital stay being (7 ±5.1)d. The follow-up 1 and 3 months after discharge showed there were no complications and death occurred, and the examinations by chest X-ray film and heart color ultrasound found no abnormality. Conclusion Da Vinci surgical system gains advantages in safety, reliability, patient satisfaction, operative incision and surgical trauma, and thus is worthy promoting clinically.

Effect of combining acupuncture and auricular point sticking on heart rate variability in patients with post-stroke depression / 针灸推拿医学（英文版）

Objective: To investigate the effect of combining acupuncture and auricular point sticking on heart rate variability (HRV) in patients with post-stroke depression (PSD). Methods: A total of 80 cases with PSD were randomized into a treatment group and a control group. The control group was intervened by oral administration of paroxetine hydrochloride, whereas the treatment group received acupuncture plus auricular point sticking base on the same oral administration. The Hamilton depression rating scale (HAMD) and HRV were measured before and after treatment in both groups. Results: The individual and global scores of HAMD significantly dropped after 8 weeks of treatment in both groups (all P<0.05). In the treatment group, anxiety/somatization factor, sleep disturbance, hopelessness factor, cognition factor and global score were significantly different from those in the control group (all P<0.05). The 24 h standard deviation of all normal-to-normal R-R interval (SDNN), standard deviation of 5-minute average of normal R-R intervals (SDANN), root mean square of successive differences (RMSSD), percent of differences between adjacent normal R-R intervals >50 ms (PNN50) and high frequency (HF) were increased while low frequency (LF) and LF/HF decreased significantly after 8 weeks of treatment in both groups (P<0.05). All items in the treatment group were significantly different from those in the control group (all P<0.05). Conclusion: Combining acupuncture and auricular point sticking can enhance the conventional medical treatment for HRV in patients with PSD.

Comparison of joint quality control and equivalence between two SPECT machines / 医疗卫生装备

Objective To conduct a joint quality control between domestic dual-head variable-angle NET632 SPECT device and imported device to evaluate the application effectiveness.Methods The domestic NET632 SPECT was marked as the trial device,and the imported Philips Brightview XCT was marked as the comparative device.The same quality control methods were applied to the two devices for both pre-trial quality control and in-trial weekly quality control.The Qc data were recorded and analyzed.Results Static images of a thyroid phantom and tomographic images of a complex performance phantom demonstrated nearly the same image quality.The images from both devices were within acceptable range.The noise and cold-region resolution of the trial devices were slightly worse while the hot-region resolution was slightly better than those of the comparative device.In the weekly QC procedures,slightly worse intrinsic spatial resolution and linearity,and better non-uniformity and energy resolution were observed on the trial device.All QC indices of both devices were within acceptable range.Conclusion The domestic dual-head NET632 SPECT has equivalent performances when compared with the imported device and is worthy applying clinically.

Design of shelter-tent channel in mobile hospital / 医疗卫生装备

Objective To design a channel in the mobile hospital to solve the existing problems.Methods The technical form and characteristics of the existing channel were analyzed,and the requirements of the mobile hospital and channel shelter were considered comprehensively,then the selection of technical form and structure design of the channel shelter was explored from the aspects of airtightness,heat preservation and etc.The feasibility was verified by trial-manufacture and test.Results A shelter-tent channel was designed and the experiments showed its effectiveness when fulfilling the requirements of the mobile hospital.Conclusion The channel gains reasonable and feasible design,and has its performances meeting the desired requirements.

miR-199a-5p enhances expression of myocardial fibrosis-related genes by targeting SIRT1 / 中国病理生理杂志

AIM:To investigate the role of microRNA (miR)-199a-5p in myocardial fibrosis and the potential target of miR-199a-5p.METHODS:C57BL/6 mouse cardiac fibroblasts were isolated and cultured for cellular experimen-tal study.Dual-luciferase reporter assay was performed to confirm the interaction between miR-199a-5p and the 3'-untrans-lated region (3'-UTR) of silent information regulator 1 (SIRT1).The expression of SIRT1 and fibrosis markers collagen (Col) 1a1, Col3a1 and α-smooth muscle actin (α-SMA) at mRNA and protein levels was determined by RT-qPCR and Western blot, respectively.RESULTS:The expression levels of miR-199a-5p, Col1a1, Col3a1 andα-SMA were marked-ly increased in cardiac fibroblasts after treatment with angiotensin Ⅱ(AngⅡ).The over-expression of miR-199a-5p signif-icantly increased the expression of Col1a1, Col3a1 andα-SMA in cardiac fibroblasts.Moreover, the results of dual-lucifer-ase reporter assay revealed that miR-199a-5p interacted with the 3'-UTR of SIRT1.miR-199a-5p inhibited SIRT1 expres-sion at post-transcriptional level.Meanwhile, miR-199a-5p mimic, in parallel to SIRT1 siRNA, inhibited SIRT1 expres-sion, increased the expression of Col1a1, Col3a1 and α-SMA in cardiac fibroblasts.Inactivation of NF-κB signaling con-tributed to the decrease in miR-199a-5p in Ang II-treated cardiac fibroblasts .CONCLUSION:SIRT1 is a target gene of miR-199a-5p, which mediates the pro-fibrotic effect of miR-199a-5p on cardiac fibroblasts .

Comparison of joint quality control and equivalence between two SPECT machines / 医疗卫生装备

Objective To conduct a joint quality control between domestic dual-head variable-angle NET632 SPECT device and imported device to evaluate the application effectiveness.Methods The domestic NET632 SPECT was marked as the trial device,and the imported Philips Brightview XCT was marked as the comparative device.The same quality control methods were applied to the two devices for both pre-trial quality control and in-trial weekly quality control.The Qc data were recorded and analyzed.Results Static images of a thyroid phantom and tomographic images of a complex performance phantom demonstrated nearly the same image quality.The images from both devices were within acceptable range.The noise and cold-region resolution of the trial devices were slightly worse while the hot-region resolution was slightly better than those of the comparative device.In the weekly QC procedures,slightly worse intrinsic spatial resolution and linearity,and better non-uniformity and energy resolution were observed on the trial device.All QC indices of both devices were within acceptable range.Conclusion The domestic dual-head NET632 SPECT has equivalent performances when compared with the imported device and is worthy applying clinically.

Design of shelter-tent channel in mobile hospital / 医疗卫生装备

Objective To design a channel in the mobile hospital to solve the existing problems.Methods The technical form and characteristics of the existing channel were analyzed,and the requirements of the mobile hospital and channel shelter were considered comprehensively,then the selection of technical form and structure design of the channel shelter was explored from the aspects of airtightness,heat preservation and etc.The feasibility was verified by trial-manufacture and test.Results A shelter-tent channel was designed and the experiments showed its effectiveness when fulfilling the requirements of the mobile hospital.Conclusion The channel gains reasonable and feasible design,and has its performances meeting the desired requirements.

miR-199a-5p enhances expression of myocardial fibrosis-related genes by targeting SIRT1 / 中国病理生理杂志

AIM:To investigate the role of microRNA (miR)-199a-5p in myocardial fibrosis and the potential target of miR-199a-5p.METHODS:C57BL/6 mouse cardiac fibroblasts were isolated and cultured for cellular experimen-tal study.Dual-luciferase reporter assay was performed to confirm the interaction between miR-199a-5p and the 3'-untrans-lated region (3'-UTR) of silent information regulator 1 (SIRT1).The expression of SIRT1 and fibrosis markers collagen (Col) 1a1, Col3a1 and α-smooth muscle actin (α-SMA) at mRNA and protein levels was determined by RT-qPCR and Western blot, respectively.RESULTS:The expression levels of miR-199a-5p, Col1a1, Col3a1 andα-SMA were marked-ly increased in cardiac fibroblasts after treatment with angiotensin Ⅱ(AngⅡ).The over-expression of miR-199a-5p signif-icantly increased the expression of Col1a1, Col3a1 andα-SMA in cardiac fibroblasts.Moreover, the results of dual-lucifer-ase reporter assay revealed that miR-199a-5p interacted with the 3'-UTR of SIRT1.miR-199a-5p inhibited SIRT1 expres-sion at post-transcriptional level.Meanwhile, miR-199a-5p mimic, in parallel to SIRT1 siRNA, inhibited SIRT1 expres-sion, increased the expression of Col1a1, Col3a1 and α-SMA in cardiac fibroblasts.Inactivation of NF-κB signaling con-tributed to the decrease in miR-199a-5p in Ang II-treated cardiac fibroblasts .CONCLUSION:SIRT1 is a target gene of miR-199a-5p, which mediates the pro-fibrotic effect of miR-199a-5p on cardiac fibroblasts .

Clinical study on acupuncture for treatment of chronic functional constipation / 中国针灸

<p><b>OBJECTIVE</b>To discuss the effect of acupuncture for treatment of chronic functional constipation (CFC).</p><p><b>METHODS</b>Ninety cases were treated with acupuncture. The following two groups of acupoints were used alternatively once every other day. The acupoints in the first group were Tianshu (ST 25), Qihai (CV 6), Shangjuxu (ST 37) etc., and Zhongliao (BL 33), Xialiao (BL 34), Dachangshu (BL 25) etc. in the second group, electroacupuncture was used at Zhongliao (BL 33), Xialiao (BL 34), Tianshu (ST 25) and Shangjuxu (ST 37), once a day, 10 times constituting one course. The defecation frequency, difficulty degree of defecation, defecation time, endless sensation of defecation, stool quality and awareness of defecation were observed and the Patient Assessment of Constipation Quality of Life (PAC-QOL) was evaluated by constipation patients' diaries.</p><p><b>RESULTS</b>The scores of defecation frequency, difficulty degree of defecation, defecation time, endless sensation of defecation, stool quality, awareness of defecation and PAC-QOL were obviously improved after treatment (all P < 0.01). The total effective rate was 67.7% (61/90). The effect of acupuncture for chronic functional constipation in different dynamic mechanism was different. The effect of slow transit constipation (STC) was better than that of spastic pelvic floor syndrome (SPFS) (P < 0.05), and the effect of constipation caused by irritable bowel syndrome (IBS-C) was better than that of SPFS and relaxant pelvic floor syndrome (RPFS) (both P < 0.05). Fifty-two cases were effectively followed up. Three cases were cured, 6 cases were remarkably effective, 23 cases were effective and 20 cases were ineffective after 1 month of treatment. Three cases were cured, 5 cases were remarkably effective, 16 cases were effective and 28 cases were ineffective after 3 months.</p><p><b>CONCLUSION</b>The effect of acupuncture for CFC with exact etiology, disease location and classification diagnosis is definite, but different dynamic mechanism has different effect. The treatment programs for SPFS and RPFS need to be optimized to improve the therapeutic effect.</p>

Effects of As2O3 on apoptosis and Bcl-2/Bax expression of rat spermatogenic cells / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the occurrence of germ cell apoptosis and the expression of Bcl-2/Bax after aniso-doses arsenic (As2O3) administration in the testes of the adult male rats.</p><p><b>METHOD</b>Forty healthy male Sprague-Dawley rats were divided randomly into four groups and were administered respectively with 0 (control group), 0.375, 0.75, 1.5 mg x kg(-1) of As2O3 by intragastric administration consecutively for 16 weeks. The numbers of testicular sperm head were counted and the coefficient of testicular viscera and daily sperm production (DSP) were calculated in every group. The apoptosis of germ cell were assessed by in situ terminal deoxynucleotityl transferase mediated dTUP nick end labeling (TUNEL) technique. The expression of Bel-2/Bax in spermatogenic cells of different grades were located and quantitated by the method of immunohistochemistry.</p><p><b>RESULT</b>(1) In the testes of As2O3-treated rats, the coefficient of testicular viscera, the number of testicular sperm head and DSP in the middle and high dose groups decreased significantly, compared with those in the control group (P < 0.01); however the apoptosis index of germ cell (AI) significantly increased compared with that in the control group (P < 0.01). Bcl-2 expression of middle dose group and high dose group decreased significantly compared with that in the control group (P < 0.01). Bax expression of middle dose group and high dose group increased significantly compared with that in the control group (P < 0.01); (2)The dependability analysis between DSP and AI showed a negative correlation (r = -0. 563, P <0. 01). (3) The negative correlation was significant between AI and Bcl-2 expression of spermatogenic cells (r = -0.825, P < 0.01); The positive correlation was significant between AI and Bax expression of spermatogenic cells (r = 0.710, P < 0.01).</p><p><b>CONCLUSION</b>One of the mechanisms of male reproduction toxicity of As2O3 might be that Bcl-2 expression is inhibited and Bax expression is encouraged which induces the decrease of quantity of sperm cells.</p>

Isolation and Identification of BLN-2 Producing Poly-?-Glutamic Acid and Studies on Its Solid-state Fermentation / 微生物学通报

A poly-?-glutamic acid producing strain--BLN-2, was isolated from the soybean products. According to the biochemical characteristics and 16S rRNA, the strain was identified as Bacillus subtilis. Using soybeans as culture, the solid-state fermentation conditions of BLN-2 have been studied. The results showed that the optimal carbon and nitrogen sources of BLN-2 were glucose, fructose, NaNO3 and KNO3, respectively. The orthrogonal experiments showed, when the final concentration of the fructose which was added to the soybean culture was 0.5%, the glucose, NaNO3 and KNO3 final concentraion were 2.0%, the production of ?-PGA was the highest--89.05 g/kg. It is 48.42% higher than other comparable soybean medium under the same conditions.

Identification and Simulation Mutation of a High-productive Strain of Poly(?-glutamic acid) Independent of Glutamic Acid / 微生物学通报

A high productive poly ?-glutamic acid(?-PGA) strain PGA-N in a culture medium containing no L-glutamine was isolated from fermentation products.With the following identifications of colony mor-phology,physiological and biochemistry experiments,and genetics,the strain PGA-N was classified as a Bacillus licheniformis.According to the product environment,the base culture medium having no L-glutamine was simulated.In order to enhance the production of the strain PGA-N,the fermentation condi-tions,such as carbon source,nitrogen source,were optimized and the ?-glutamic acid production reached 5.16 g/L after getting the optimum formulation of this culture medium.PGA-N was mutagenized with com-bination of NTG and UV.A mutant PGA-N-C10 was screened which PGA production was increased from 5.16 g/L to 8.82 g/L.The study also investigated the effects of agitation speed on the cell biomass,?-PGA production and the ?-PGA molecular weight.The ?-PGA yield of PGA-N-C10 was as high as 11.00 g/L when the agitation speed was 400 r/min.