Effects of imipenem combined with glutamine in the treatment of severe acute pancreatitis with abdominal infection in mainland China: a meta-analysis

SUMMARY OBJECTIVE: The aim of this study was to explore the efficacy of imipenem combined with glutamine in the treatment of severe acute pancreatitis with abdominal infection in mainland China using meta-analysis. METHODS: We searched China National Knowledge Network, Wanfang Medical Network, Chinese Science Citation Database, PubMed, and Embase Databases for publications of imipenem combined with glutamine in the treatment of severe acute pancreatitis abdominal infection. The search time limit was from the establishment of the database to April 10, 2021. Stata software version 12.0 was used for statistical analysis; the combined effect size odds ratio and standardized mean difference values were calculated for the count data and measurement data, respectively; and the heterogeneity test was performed in this study. RESULTS: A total of five randomized controlled trials were included. A total of 499 cases were included, with 251 in the observation group and 248 in the control group. Meta-analysis results showed that the efficacy of imipenem combined with glutamine in the treatment of severe acute pancreatitis with abdominal infection was significantly better than that of imipenem alone (odds ratio=0.78, 95%CI 0.71-0.86, p=0.040). CONCLUSION: Imipenem combined with glutamine can significantly improve the efficacy in the treatment of severe acute pancreatitis with abdominal cavity infection.

Effect of thermophilic bacterium HB27 manganese superoxide dismutase in a rat model of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) / 亚洲男科学杂志(英文版)

We investigated the therapeutic effects of superoxide dismutase (SOD) from thermophilic bacterium HB27 on chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and its underlying mechanisms. A Sprague-Dawley rat model of CP/CPPS was prepared and then administered saline or Thermus thermophilic (Tt)-SOD intragastrically for 4 weeks. Prostate inflammation and fibrosis were analyzed by hematoxylin and eosin staining, and Masson staining. Alanine transaminase (ALT), aspartate transaminase (AST), serum creatinine (CR), and blood urea nitrogen (BUN) levels were assayed for all animals. Enzyme-linked immunosorbent assays (ELISA) were performed to analyze serum cytokine concentrations and tissue levels of malondialdehyde, nitric oxide, SOD, catalase, and glutathione peroxidase. Reactive oxygen species levels were detected using dichlorofluorescein diacetate. The messenger ribonucleic acid (mRNA) expression of tissue cytokines was analyzed by reverse transcription polymerase chain reaction (RT-PCR), and infiltrating inflammatory cells were examined using immunohistochemistry. Nuclear factor-κB (NF-κB) P65, P38, and inhibitor of nuclear factor-κBα (I-κBα) protein levels were determined using western blot. Tt-SOD significantly improved histopathological changes in CP/CPPS, reduced inflammatory cell infiltration and fibrosis, increased pain threshold, and reduced the prostate index. Tt-SOD treatment showed no significant effect on ALT, AST, CR, or BUN levels. Furthermore, Tt-SOD reduced inflammatory cytokine expression in prostate tissue and increased antioxidant capacity. This anti-inflammatory activity correlated with decreases in the abundance of cluster of differentiation 3 (CD3), cluster of differentiation 45 (CD45), and macrophage inflammatory protein 1α (MIP1α) cells. Tt-SOD alleviated inflammation and oxidative stress by reducing NF-κB P65 and P38 protein levels and increasing I-κBα protein levels. These findings support Tt-SOD as a potential drug for CP/CPPS.

Investigation of Volume Load in Outpatients with Hypertension and Analysis of Influencing Factors / 中山大学学报(医学科学版)

@#【Objective】To assess the difference in volume load between different blood pressure control levels in outpatients with hypertension. To investigate the effect of clinical factors on volume load in outpatients with hypertension. To analyze the clinical baseline characteristics and use of antihypertensive drugs in outpatients with hypertension. 【Methods】 A total of 514 outpatients with hypertension were included from July to November 2017. Clinical indicators including gender，age，height，weight，years of hypertension，blood pressure levels，treatment options for hypertension and comorbidities of these patients were recorded. The body volume load was evaluated by detecting the ratio of extracellular fluid（ECW）to total body water（TBW）using a Bioimpedance Analyzer. Whole body ECW/TBW≥0.39 was defined as high volume load. The effects of clinical factors on the volume load of hypertensive patients and whether there was a difference in volume load between different antihypertensive therapy were analyzed. 【Results】The blood pressure compliance rate of outpatients with hypertension was 15.37% ，which was still very low. Male patients had lower blood pressure compliance rate than female patients. Blood pressure was more difficult to control in patients with older age ，higher body mass index （BMI），higher waist-to-hip ratio（WHR）or longer duration of hypertension. The higher the blood pressure grading，the higher the proportion of combination medication. Diuretics were still the most widely used antihypertensive drugs. Age ，gender and different hypertension grades were the main factors affecting the volume load of hypertensive patients. Volume load was higher in female，older or higher systolic blood pressure（SBP）patients. Among them，age was the most important factor affecting the volume load of hypertensive patients.【Conclusion】The blood pressure compliance rate of outpatients with hypertension was still low. Effectively reducing the volume load was one of the important means to control blood pressure，which was more important in female，older or higher SBP patients.

Effect of Taiji Quan on Sleep Quality of Patients with Chronic Insomnia Disorder / 中国康复理论与实践

Objective:To explore the effect of Taiji Quan on the sleep quality of patients with chronic insomnia disorder (CID) and its mechanism. Methods:From January, 2015 to December, 2017, 31 patients with CID were enrolled in the sleep disorder clinic. Before and 24 weeks after Taiji Quan exercise, the Pittsburgh Sleep Quality Index (PSQI) was used to assess their sleep quality, the serum levels of tumor necrosis factor (TNF)-α, TNF-β, soluble tumor necrosis factor receptor (sTNF-R)1 and sTNF-R2 were detected with protein chip, and the correlation between the total score of PSQI and the serum levels of TNF-α, TNF-β, sTNF-R1 and sTNF-R2 were analyzed after exercise. Results:After Taiji Quan exercise, the scores of PSQI factors (subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, daytime dysfunction) and the total score of PSQI decreased (t > 4.080, P < 0.05). The serum levels of TNF-α and TNF-β decreased (t > 13.580, P < 0.01), however, the serum levels of sTNF-R1 and sTNF-R2 significantly increased (t > 160.189, P < 0.001). The serum levels of TNF-α and TNF-β were positively correlated with the total score of PSQI (r > 0.638, P < 0.001), while the serum levels of sTNF-R1 and sTNF-R2 were negatively correlated with the total score of PSQI (r > 0.532, P<0.001). Conclusion:Taiji Quan exercise could help to improve the sleep quality of patients with CID. The mechanism may be related to the decrease of the serum levels of TNF-α and TNF-β, and the increase of the serum levels of sTNF-R1 and sTNF-R2.

Correlation between LDL-C/HDL-C Ratio and the Severity of Coronary Artery Lesion in Patients with Coronary Heart Disease / 中山大学学报(医学科学版)

[Objective]To explore the correlations between different indices of lipoprotein cholesterol and apolipopro-tein of coronary heart disease(CHD)patients,especially that between low density lipoprotein cholesterol(LDL-C)and high density lipoprotein cholesterol(HDL-C)and that between apolipoprotein A1(apoA1)and apolipoprotein B100 (apoB100),as well as the correlations between these indices,indices ratios and the severity of coronary artery lesion.[Methods]301 coronary heart disease patients hospitalized to accept percutaneous coronary intervention(PCI)in the Third Affiliated Hospital of Sun Yat-sen University during 2013-2014 were recruited in the study. Fasting serum lipid indices including triglycerides(TG),total cholesterol(TC),LDL-C,HDL-C,apoA1 and apoB100 were examined before surgery.Gensini score was calculated to evaluate the severity of coronary artery lesion. 153 patients whose Gensini score was less than 50 were assigned to Group A,while 148 patients with Gensini score greater than or equal 50 were distributed to Group B.[Results]Positive correlations were found between LDL-C and HDL-C(r=0.161,P=0.005), apoA1 and apoB100(r=0.358,P<0.001),apoB100 and LDL-C(r=0.487,P<0.001),apoA1 and LDL-C(r=0.178, P=0.002)by linear correlation analysis. No significant correlation was found between apoB100 and HDL-C. None of LDL-C,HDL-C,TC was correlated with Gensini score. However,LDL-C/HDL-C ratio was positively correlated with Gensini score(r=0.148,P=0.01). The results showed no significant correlations between apoB100,apoB100/apo A1 ratio and Gensini score but negative correlation between apoA1 and Gensini score(r=-0.129,P=0.025). The positive correlation between HDL-C/LDL-C ratio and Gensini score was still valid after multi-factors adjustment (β=5.071,P=0.018).[Conclusion]Of patients with coronary heart disease,there exist some correlations between LDL-C and HDL-C,apoA1 and apoB100,while the correlation between LDL-C and HDL-C is relatively weak.The LDL-C/HDL-C ratio,weakly positively correlated with the severity of coronary artery lesion,is a risk factor of coronary artery lesion,while the level of apoA1,negatively correlated with the severity of coronary artery lesion,could play a protective role.

Survey and analysis on clinical engineering departments in Guangdong under new regulations / 医疗卫生装备

Objective To investigate the status quo of clinical engineering departments (CED) in Guangdong province, to find out the main problems and challenges, and to give some suggestions on promoting the development of clinical engineering. Methods Questionnaires were issued to directors or engineers in hospitals on department missions, staff composition, quality control and obstructive factors for discipline development. Statistical analysis was executed for the questionnaires. Results Only 53.19% of the CED operated independently. The daily CE practice in Guangdong hospitals included carrying out procurement, installation, maintenance and archiving. Only 28.0%of the hospitals had QC instruments. The education backgrounds were mainly restrained in undergraduate degree and junior college degree, accounting for 80.0%. Totally 39.0% of the clinical engineers majored in biomedical engineering. The personnel with primary or intermediate professional titles accounted for 61.96%. There was 0.68 engineer per 100 beds or 0.23 engineer per ten million Yuan medical equipment. The top 3 factors that hindered the development of CE were inadequacy of professional staff, low education level and absence of laws and regulations. Conclusion CED in Guangdong province drops behind the outstanding institutions in China, and has to be promoted with the efforts of supervision facilities and etc.

Surgical treatment with cable dragged reduction and cantilever beam internal fixation by posterior approach for odontoid fracture associated with atlantoaxial dislocation / 中国骨伤

<p><b>OBJECTIVE</b>To explore the clinical effects of surgical treatment with cable dragged reduction and cantilever beam internal fixation by posterior approach for odontoid fracture associated with atlantoaxial dislocation.</p><p><b>METHODS</b>The clinical data of 12 patients with odontoid fracture associated with atlantoaxial dislocation from January 2008 to December 2013 were retrospectively analyzed. There were 8 males and 4 females, ranging in age from 21 to 53 years with an average of 37.2 years. Eleven cases were fresh fracture and 1 case was old fracture, all patients complicated with atlantoaxial anterior dislocation. According to Anderson-D' Alonzo typing method modified by Grauer, 3 cases were type IIA, 5 cases were type IIB, 3 cases were type IIC, and 1 case was type IIIA. All patients underwent surgical treatment with cable dragged reduction and cantilever beam internal fixation by posterior approach. JOA score and ADI method were respectively used to evaluate the nerve function and reductive condition of atlantoaxial dislocation.</p><p><b>RESULTS</b>All patients were followed up from 6 months to 2 years with an average of 1 year and 3 months. At 1 week, 6 months after operation, and final follow up, JOA scores were 13.2±1.3, 13.5±1.4, 14.3±1.5, respectively, and these data were obviously better than that of preoperative 8.3±1.4(<0.05). Postoperative X rays and CT showed satisfactory reduction of atlantoaxial dislocation. At 1 week, 6 months after operation, and final follow up, ADI were (2.2±0.4), (2.4±0.6), (2.3±0.5) mm, respectively, and these data were obviously better than that of preoperative.(5.8±1.2) mm(<0.05). All screws and cables had good location without looseness and breakage, and bone graft got fusion.</p><p><b>CONCLUSIONS</b>Surgical treatment with cable dragged reduction and cantilever beam internal fixation by posterior approach for odontoid fracture associated with atlantoaxial dislocation is a good method, with advantage of firm fixation and high safety. It could obtain good clinical effects.</p>

Clinical effect of preoperative visualization technique-guided pedicle screw fixation on multi-segmental lumbar fracture and dislocation / 实用医学杂志

Objective To analyze the clinical effect of pedicle screw fixation in the treatment of multi-segmental lumbar fracture and dislocation under the guidance of visualization technique. Methods A total of 21 patients with multi-segmental lumbar fracture and dislocation were selected from November 2012 to November 2013. Before the screw implantation, the structure of bilateral pedicle was observed through Mimics software and the implantation parameters were measured. The position of pedicle screws by postoperative CT scan, operation time, and the satisfaction of the patients were assessed. The percentages of anterior vertebral height and Cobb′s angle were measured before operation, 2 weeks and 8 months after operation. Results All patients were satisfied with informed consent score and the way of pedicle screw and the selection of plant were more reasonable. With better screw position, shorter operative time and less blood loss and adverse reactions, pedicle screw fixation achieved good effect. Conclusion With high security and considerable clinical value, pedicle screw fixation in the treatment of multi-segmental lumbar fracture and dislocation under the guidance of visualization technique has exact and good effecct.

Radiation protection effect of rhIL-12 on monkey hematopoietic system / 中国实验血液学杂志

This study was aimed to investigate the radioprotective effects of recombinant human interleukin-12 (rhIL-12) on monkey hematopoietic system, and to provide experimental evidence for future clinical prophylaxis and treatment for patients who suffered from acute radiation syndrome. In in vitro study, the effect of rhIL-12 in different concentrations (0, 1, 5, 25, 125 and 625 ng/ml) on colony forming capacity of human or monkey bone marrow-derived mononuclear cells was examined in methylcellulose H4434 medium. In in vivo study, the acute radiation syndrome model was established in 11 Rhesus monkeys which received lethal total body irradiation by 6 Gy (60)Co γ in single time irradiation. The irradiated monkeys were randomly divided into 3 subgroups: control group (n = 4) which received subcutaneous PBS injection, rhIL-12 single-dose group (n = 3) which received subcutaneous single injection of rhIL-12 (4 µg/kg) at 2 h after irradiation, and multiple-dose group (n = 4) which received subcutaneous injection of rhIL-12 (1 µg/kg per injection) at 2 h, day 3, 6 and 9 after irradiation respectively. Peripheral blood cells were counted before and after irradiation every other day. The survival status of animals were observed daily. In vitro test results showed that different concentrations of rhIL-12 obviously promoted human and healthy monkeys' bone marrow mononuclear cells to form various hematopoietic progenitor cell colonies, especial CFU-E and CFU-GM. All animals in control group died within 22 d after lethal total body irradiation, average survival time was (20.3 ± 1.2) d. Only one monkey in multiple-dose group died due to anemia on day 17. All monkeys in single-dose group survived. Compared with control group, rhIL-12-administrated monkeys' white blood cell count, hemoglobin level, platelet and reticulocyte counts showed faster recovery from high dose radiation. It is concluded that the rhIL-12 treatment can promote the bone marrow hematopoietic stem/progenitor cell colony formation in vitro and protect lethally-irradiated monkeys. There is an obvious therapeutic effect of rhIL-12 on monkeys suffered from bone marrow failure caused by severe acute radiation exposure.

Ototoxicity of kanamycin sulfate in adult rats and its underlying mechanisms / 生理学报

The aim of the present study was to assess the ototoxicity of kanamycin sulfate (KM) in adult rats and its underlying mechanism. Forty male Sprague-Dawley rats (6-7 weeks old) were randomly divided into the experimental group and the control group. The animals in the experimental group were injected subcutaneously with KM (500 mg/kg per day) for two weeks, and the control group received equal volume of normal saline. To assess the ototoxicity of KM, the auditory brainstem response (ABR) was recorded to monitor the changes in hearing thresholds, and the density of spiral ganglion cells (SGCs) and morphology of cochlea were observed using surface preparations and frozen sections of cochlea. The results showed that the hearing threshold of rats in the experimental group was elevated by more than 60 dB across all the frequencies two weeks after the first administration of KM. And in the experimental group, the density of SGCs became lower, and organ of Corti suffered loss of hair cells. The loss of outer hair cells (OHCs) was more severe than that of inner hair cells (IHCs), correlated with the density decrease of SGCs. We conclude that the ototoxicity of KM in the adult rats was apparent and the underlying mechanism is associated with the loss of SGCs and hair cells.

The effects of atorvastatin on C-reactive protein induced Toll-like receptor 4 expression on CD14+ monocyte / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effects of atorvastatin on C-reactive protein (CRP) induced Toll-Like receptor 4 (TLR4)expression on CD14+ monocyte, and the production of proinflammatory cytokines tumor necrosis factor alpha (TNFalpha), interleukin-6 (IL-6), matrix metalloproteinases-9 (MMP-9), and to study the anti-inflammatory mechanisms of statins.</p><p><b>METHODS</b>The monocytes were isolated from blood of healthy volunteers by the Ficoll density gradient and stimulated by CRP with different doses (5, 25, 50, 100 microg/ml) and different exposure time (6, 12, 24, 48 h). Cells were also incubated with atorvastatin of different doses (1.0, 2.5, 5.0, 7.5, 10.0 micromol/L) in the presence of CRP 50 microg/ml. The protein expression of TLR4 was measured by flow cytometry, mRNA expression of TLR4 and of myeloid differentiation protein (MD2)was detected by quantitative PCR. TNFalpha, IL-6, MMP-9 concentrations in supernatants of cultured medium were measured by ELISA.</p><p><b>RESULTS</b>(1) Compared with the un-stimulated control group, enhanced TLR4 protein expression was already detected at a concentration of 5 microg/ml of CRP and increased in a dose-dependent manner (32.22 +/- 2.80)%, (49.94 +/- 5.58)%, (74.82 +/- 3.24)% and (90.82 +/-2.88)% at 5, 25, 50 and 100 microg/ml CRP. (2) TLR4 protein expression on 50 microg/ml CRP stimulated cells also increased in a time-dependent manner (29.80 +/- 2.70)%, (47.44 +/- 4.41)%, (81.71 +/- 2.92)% and (50.57 +/- 3.34)% after 6 h, 12 h, 24 h, 48 h. (3) When monocytes were incubated with CRP 50 microg/ml and atorvastatin (1.0, 2.5, 5.0, 7.5, 10.0 micromol/L), protein expression [(68.17 +/- 1.71)%, (52.43 +/- 1.38)%, (27.72 +/- 4.55)%, (17.46 +/- 3.20)%, (9.99 +/- 2.81)%] and mRNA expression (82.72%, 67.34%, 48.16%, 30.88%, 13.85%) of TLR4 as well as mRNA expression of MD2 (81.78%, 71.04%, 47.85%, 27.06%, 18.30%) were reduced in a dose-dependent manner. (4) Level of TNFalpha, IL-6 and MMP-9 in supernatants was significantly reduced by atorvastatin (2.5 micromol/L) compared with control group (P < 0.01). When monocyte incubated with CRP 50 microg/ml and atorvastatin 10.0 micromol/L, the level of TNFalpha, IL-6, MMP-9 decreased to (25.8 +/- 2.5) microg/ml, (128.2 +/- 14.7) pg/ml, (65.2 +/- 12.3) ng/ml, respectively.</p><p><b>CONCLUSION</b>CRP increased the protein expression of TLR4 on CD14+ monocyte in a dose-dependent and time-dependent manner. Atorvastatin can inhibit the signal transduction of TLR4 and reduce proinflammatory cytokines release induced by CRP on CD14 monocyte, and this might be one of the anti-inflammatory mechanisms of atorvastatin.</p>

Association between hemoglobin scavenger receptor CD163 expression and coronary atherosclerotic severity in patients with coronary heart disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the association between hemoglobin scavenger receptor (CD163) expression levels on monocytic surfaces and coronary atherosclerotic severity in patients with coronary heart disease (CHD) as well as the roles of CD163 in inflammation and lipidperoxidation.</p><p><b>METHODS</b>Eighty-four patients were diagnosed as CHD according to the results of coronary angiography and ACC/AHA diagnostic criteria. The patients were divided into 3 groups: acute myocardial infarction (AMI) group (n = 30), unstable angina (UA) group (n = 30), stable angina (SA) group (n = 24). Another 20 patients with normal coronary artery served as control. Expression levels of CD163 on monocytes were detected by means of flow cytometry, and the results were shown as mean fluorescence intensity (mfi). All patients underwent coronary angiography and the results were further evaluated by Jenkins score. Serum CRP and LDL-C were also measured.</p><p><b>RESULTS</b>The expression levels of CD163 on monocytes in peripheral blood were significantly higher in CHD patients compared to controls (P < 0.01) in the order of AMI group [(84.4 +/- 6.9) mfi] > UA group [(64.1 +/- 5.5) mfi, P < 0.01 vs. AMI] > SA group [(46.7 +/- 6.5) mfi, P < 0.01 vs. AMI and UA] > control group [(22.0 +/- 6.1) mfi, P < 0.01 vs. AMI, UA and SA]. The expression levels of CD163 on monocytes in patients with CHD were positively correlated with Jenkins score (r = 0.9107, P < 0.01), CRP (r = 0.766, P < 0.01) and LDL-C (r = 0.749, P < 0.01).</p><p><b>CONCLUSIONS</b>Expression levels of CD163 was significantly increased in patients with CHD and positively correlated with coronary heart disease severity and serum CRP and LDL-C.</p>

Inhibition of bFGF gene expression and tumor angiogenesis of orthotopic implantation of human gastric carcinoma by N-desulfated heparin / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the effect of N-desulfated heparin on tumor metastasis, tumor angiogenesis and basic fibroblast growth factor(bFGF) gene expression of orthotopically implanted human gastric carcinoma in NOD-SCID mice.</p><p><b>METHODS</b>Human gastric cancer SGC-7901 tissues were orthotopically implanted into the stomach of the NOD-SCID mice. Twenty mice were randomly divided into two groups which received either intravenous injection of 0.9% NaCl solution(0.9%NaCl solution group) or 10 mg/kg N-desulfated heparin (N-desulfated heparin group) twice a week for three weeks. Mice were sacrificed six weeks after tumor implantation. Tissues from stomach and other organs were obtained for histopathological evaluation. The intratumoral microvessel density (MVD) in tumor was evaluated immunohistochemically. Real time PCR was used to detect bFGF mRNA expression.</p><p><b>RESULTS</b>The tumor metastasis rates were 9/10 in 0.9% NaCl solution group and 2/10 in N-desulfated heparin group(P<0.05).MVD was 9.1+/-3.4 in 0.9% NaCl solution group and 4.7+/-1.8 in N-desulfated heparin group (t=3.617,P<0.05). bFGF mRNA expression was lower in N-desulfated heparin group(2.60+/-0.56%)than that in 0.9% NaCl solution group(30.65+/-6.84%).</p><p><b>CONCLUSION</b>N-desulfated heparin can inhibit the metastasis of gastric cancer through inhibiting tumor bFGF gene expression and tumor angiogenesis with no obvious anticoagulant activity.</p>

Effect of the sera of rabbits fed with Tongxinluo on MMP-9 and TIMP-1 expression and secretion in U937 monocyte-derived macrophages / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of the sera of rabbits fed with Tongxinluo on the expression and secretion of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in U937 monocyte-derived macrophages.</p><p><b>METHODS</b>Atherosclerosis was induced in rabbits by high-cholesterol feeding, and the serum was obtained from the rabbits after administration of the aqueous solution of Tongxinluo or simvastatin by gavage. U937 monocyte-derived macrophages were incubated with the sera at different concentrations for 24 hours, and the changes in MMP-9 and TIMP-1 gene expression and secretion were detected by RT-PCR and enzyme-linked immunosorbent assay, respectively.</p><p><b>RESULTS</b>The serum of rabbits fed with Tongxinluo concentration-dependently inhibited the expression and secretion of MMP-9 in U937 macrophages, but did not affect TIMP-1 expression or secretion.</p><p><b>CONCLUSION</b>Tongxinluo may stabilize the atherosclerotic plaques by inhibiting the expression and secretion of MMP-9.</p>

Directed molecular evolution of nitrite oxido-reductase by DNA-shuffling / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To develop directly molecular evolution of nitrite oxido-reductase using DNA-shuffling technique because nitrobacteria grow extremely slow and are unable to nitrify effectively inorganic nitrogen in wastewater treatment.</p><p><b>METHODS</b>The norB gene coding the ndtrite oxido-reductase in nitrobacteria was cloned and sequenced. Then, directed molecular evolution of nitrite oxido-reductase was developed by DNA-shuffling of 15 norB genes from different nitrobacteria.</p><p><b>RESULTS</b>After DNA-shuffling with sexual PCR and staggered extension process PCR, the sequence was different from its parental DNA fragments and the homology ranged from 98% to 99%. The maximum nitrification rate of the modified bacterium of X16 by DNA-shuffling was up to 42.9 mg/L x d, which was almost 10 times higher than that of its parental bacteria. Furthermore, the modified bacterium had the same characteristics of its parental bacteria of E. coli and could grow rapidly in normal cultures.</p><p><b>CONCLUSION</b>DNA-shuffling was successfully used to engineer E. coli, which had norB gene and could degrade inorganic nitrogen effectively.</p>

Effects of irbesartan on nitric oxide system in the heart of diabetic rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of irbesartan for heart protection and on heart nitric oxide (NO) system in diabetic rats.</p><p><b>METHODS</b>Thirty adult male Wistar rats were randomly divided into three equal groups, namely control group, diabetes group and irbesartan group. Streptozotocin (STZ, 50 mg/kg) was injected to the abdomen to induce diabetes in the rats. After treatment for 12 weeks, the rats were sacrificed and the urine volume, body weight, ratio of heart to body weight, plasma glucose and glycosylated hemoglobin (HbA1c) were measured. NO levels in the serum and myocardium were determined. Inducible nitric oxide synthase (iNOS) expression was determined by immunohistochemistry, and iNOS mRNA detected by RT-PCR.</p><p><b>RESULTS</b>Urine volume, ratio of heart to body weight, plasma glucose, HbA1C, NO levels in the urine, blood and myocardium in diabetic and irbesartan rats were significantly greater than those of normal controls (P<0.05). The ratio of heart to body weight and NO levels of urine, serum and heart tissue in rats of irbesartan group were significantly decreased as compared with those of diabetes rats (P<0.05). Myocardium iNOS mRNA and protein expression decreased significantly in irbesartan group, but not in diabetes group.</p><p><b>CONCLUSIONS</b>The abnormality in NO and iNOS mRNA expression might be related to diabetic cardiomyopathy. Irbesartan can decrease iNOS mRNA and protein expressions and reduce NO levels in STZ-induced diabetic rats.</p>

Effects of Sini decoction on vascular stenosis after iliac artery balloon injury and oxidative stress in rabbits / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of Sini decoction (SND) in preventing vascular restenosis and protecting against oxidative stress after rabbit iliac artery balloon injury.</p><p><b>METHODS</b>Twenty-four male New Zealand albino rabbits were equally randomized into control group, model group and SND group. Rabbits in the control group were fed with common forage, and those in the model and SND groups with high-fat diet. Two weeks later, the iliac arteries of the rabbits in the latter two groups were subjected to balloon injury. Four weeks after the operation, the rabbits were killed and the vascular structure was observed by scanning electron microscope and optical microscope, with the serum cholesterol level, superoxide dismutase (SOD) activity and malondialdehyde (MDA) level determined.</p><p><b>RESULTS</b>Scanning electron microscopy showed that the endothelial cell lining in the iliac artery of the control and SND group remain regular, but the arteries in the model group presented with desquamated and exposure of the collagen fibril beneath the endothelium. Optical microscope revealed narrowed vascular lumen, thicken intima and numerous arteriosclerotic plaques in the model group in comparison with the control group, whereas the vascular lumen and intima thickness remained basically normal in SND group. The levels of total cholesterol, low-density lipoprotein cholesterol and triglyceride were decreased with high-density lipoprotein cholesterol levels increased in SND group, which was not observed in the model group. The serum SOD activity was higher in the control group than in the model and SND groups, but SND group had higher serum SOD activity than the model group. The serum MDA level was lower in the control group than in the other two groups, but SND group had lower MDA level than the model group.</p><p><b>CONCLUSION</b>SND can alleviate intimal hyperplasia and vascular stenosis in injured rabbit iliac artery, possibly in relation to increased SOD activity and decreased lipid peroxidation as a result of SND treatment.</p>

Paraquat induces selective dopaminergic nigrostriatal degeneration in aging C57BL/6 mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Paraquat (PQ; 1, 1'-dimethyl-4, 4'-bipyridinium), a widely used herbicide that is structurally similar to the known dopaminergic neurotoxicant MPTP (1-methyl-1, 2, 3, 6-tetrahydropyridine), has been suggested as a potential etiologic factor for the development of Parkinson's disease (PD). Aging is an accepted risk factor for idiopathic Parkinson's disease. The aim of this study was to test the hypothesis that paraquat could induce PD-like nigrostriatal dopaminergic degeneration in aging C57BL/6 mice.</p><p><b>METHODS</b>Senile male C57BL/6 mice were intraperitoneally injected with either saline or PQ at 2-day intervals for a total of 10 doses. Locomotor activity and performance on the pole test were measured 7 days after the last injection and animals were sacrificed one day later. Level of dopamine (DA) and its metabolites levels in the striatum were measured by high-performance liquid chromatography with an electrochemical detector (HPLC-ECD), and numbers of tyrosine hydroxylase (TH) positive neurons were estimated using immunohistochemistry.</p><p><b>RESULTS</b>Locomotor activities were significantly decreased and the behavioral performance on the pole test were significantly impaired in the PQ treated group. Level of DA and its metabolites levels in the striatum were declined by 8 days after the last injection. Immunohistochemical analyses showed that PQ was associated with a reduction in numbers of tyrosine hydroxylase positive neurons.</p><p><b>CONCLUSIONS</b>Long-term repeated exposes to PQ can selectively impair the nigrostriatal dopaminergic system of senile mice, suggesting that PQ could play an important role in the pathogenesis of Parkinson's disease (PD). Our results also validate a novel model of PD induced by exposure to a toxic environmental agent.</p>

Cloning and expression of human manganese superoxide dismutase cDNA in Pichia pastoris / 生物工程学报

Human manganese superoxide dismutase (hMn-SOD) cDNA was amplified by RT-PCR from total RNA of human liver cell (L02), and cloned into yeast expression vector pPIC9K containing AOX1 promoter and the alpha-factor signal peptide sequence. The resultant pPIC9K-MnSOD was transformed to P. pastoris GS115, screened for Mut+ carrying multiple copies of hMn-SOD. The positive transformants were fermented in flasks and induced by 0.5% methanol. After 4 days of methanol induction, the expressed hMn-SOD was up to 32% of the total proteins in the supernatant by SDS-PAGE with specific activity of 247.7 u/mg.

A study on detecting and identifying enteric pathogens with PCR / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To develop a rapid and definite diagnostic test of bacterial enteritis caused by pathogenic enterobacteria, the most frequent etiologic agent of infectious enteritis in the world.</p><p><b>METHODS</b>A set of conventional PCR assays were applied to detect and identify salmonella, shigella, and E. coli O157:H7 directly from pure culture and fecal samples. The general primers of pathogenic enterobacteria were located on the uidA gene, which were found not only in E. coli nuclear acid, but also in shigella and salmonella genes. Shigella primer was from ipaH gene whose coded invasive plasmid relative antigen existed both in plasmid and in genome. The primers of salmonella were designed from the 16SrRNA sequence. The primer of E. coli O157:H7 was taken from eaeA gene. Five random primers were selected for RAPD. The detection system included common PCR, semi-nested PCR and RAPD.</p><p><b>RESULTS</b>This method was more sensitive, specific and efficient and its processing was rapid and simple. For example, the method could be used to specifically detect and identify salmonella, shigella, and E. coli O157:H7, and its sensitivity ranged from 3 to 50 CFU, and its detection time was 4 hours.</p><p><b>CONCLUSION</b>This PCR method, therefore, can serve as a routine and practical protocol for detecting and identifying pathogenic microorganisms from clinical samples.</p>