AIM: To synthesize biodegradable poly lactic acid (PLA) through the optimization and selection of process and catalyst.METHODS: This experiment was performed at the Research Center for Green Chemistry and Technology in the School of Municipal and Environmental Engineering of Harbin Institute of Technology from February 2003 to October 2004. Biodegradable poly L-lactic acid (PLLA) was synthesis by melt polycondensation using L-lactic acid (LA) as material. Firstly, oligo L-lactic acid (OLLA) was prepared by dehydrating aqueous solution of LA without catalyst. And then, the mixture of OLLA and catalyst was heated at a certain temperature and pressure for a period of time to get the product of PLLA. The structure of PLLA was characterized by Fourier transform infrared (FTIR) spectra and 1H- nuclear magnetic resonance (1H-NMR) spectra. The polydispersity was determined by gel permeation chromatography (GPC).RESULTS: OLLA with the viscosity average molecular weight (Mη) of 6 500 g/mol was prepared by the following steps: the solution of LA without catalyst was dehydrated at 140 ℃, first at reduced pressure of 30 kPa for 2 hours, and then at 5 kPa for 4 hours. SnCl2-p-toluenesulfonic acid (TSA) system was the effective catalyst for the polycondensation of OLLA. After the mixture of OLLA and catalysts polycondensed at 165 ℃ and 5 kPA for about 8 hours, PLLA with the Mη of 65 000 g/mol was obtained by using SnCl2-TSA system as catalyst with the SnCl2 amount of 0.4wt% to OLLA and equal mol ratio of SnCl2 and TSA.CONCLUSION:PLLA with a certain practicability was obtained under the optimal process and catalyst. Oligomerization of LA played an important role on improving the molecular weight of PLLA.

Objective To investigate the serum levels of soluble human leukocyte antigen (sHLA)-G in patients with polymyositis (PM) or dermatomyositis (DM),and to analyze its association with clinical features and possible role in the pathogenesis of PM/DM.Methods Serum sHLA-G levels of 26 patients with PM,70 patients with DM and 35 matched healthy controls were measured by ELISA.The relationship between the sHLA-G levels and clinical features or seroimmunological data in the patients with PM/DM was analyzed.Results Serum levels of sHLA-G in PM/DM patients were significantly higher compared to healthy controls [(44±70) U/ml vs (4±5) U/ml,P＜0.01].There was statistically significant difference between DM patients and PM patients [(54±81) U/ml vs (27±41) U/ml,P=0.004].The incidence of dysphagia was significantly higher in sHLA-G elevated group than those in sHLA-G normal group (P=0.001).Additionally,Spearman rank correlation analysis showed that the serum sHLA-G levels were positively correlated with serum C3 (r=0.284,P=0.021),but negatively correlated with CD3+ T cells (r=-0.233,P=0.047) and CD4+ T cells (r=-0.287,P=0.015) in the peripheral blood in patients with PM/DM.Serum levels of sHLA-G in non-treated PM/DM patients were significantly higher compared to treated patients [(77±99) U/ml vs (34±52) U/ml,P=0.021].No relationship between serum sHLA-G levels and PM/DM disease activity,or different drug therapy was found.Conclusion Serum levels of sHLA-G are increased in PM/DM patients.The increased production of sHLA-G,paralleled with higher incidence of dysphagia and lower level of CD3+ T cells and CD4+ T cells,indicates that sHLA-G may play an important role in the pathogenesis of PM/DM.

Female ; Humans ; Laser Therapy ; methods ; Middle Aged ; Semicircular Canals ; surgery ; Vertigo ; etiology ; surgery

OBJECTIVETo study the effect of electro-acupuncture (EA) at points along Foot Yangming Channel on metabolite of ulcerative colitis (UC) rats' cerebral cortex and to identify key metabolites by referring to Pi/Wei-brain related theory in Chinese medicine (CM).

METHODSThe UC rat model was set up by dextran sulfate sodium (DSS) method. Male SD rats were randomly divided into the model group and the EA group, 13 in each group. Another 13 rats were recruited as the blank control group. Rats in the blank control group and the model group received no EA. EA was performed at Zusanli (ST36), Shangjuxu (ST37), and Tianshu (ST25) for 5 days by using disperse-dense wave. Then all rats were sacrificed. Their recto-colon and the ileocecal junction were pathomorphologically observed by light microscope and transmission electron microscope (TEM). Cerebral cortexes were extracted. Water-soluble and lipid-soluble brain tissue metabolites were respectively extracted for metabolic research using 1H nuclear magnetic resonance (1H-NMR).

RESULTSEA could obviously improve the general condition of UC model rats, decrease the value of DAI, reduce the infiltration of inflammatory cells in the intestinal tract, stabilize structures such as mitochondria, endoplasmic reticulum and so on (P <0.05). 1HNMR analysis showed that in the model group, contents of glutamic acid, cholesterol, very low density lipoproein (VLDL) in the pallium obviously decreased, while alanine and low density lipoprotein (LDL) significantly increased. After EA, levels of lactic acid, glutamic acid, total cholesterol (TC), and VLDL all increased, and levels of alanine and LDL decreased. All indices were approximate to those of the blank control group.

CONCLUSIONEA at Foot Yangming channel was found to have some effect on metabolites in the brain tissue of UC model rats, which had specific metabonomic material basis and mechanism based on the Pi/Wei-brain related theory.

Acupuncture Points ; Animals ; Cerebral Cortex ; metabolism ; Colitis, Ulcerative ; Electroacupuncture ; Lipids ; Male ; Rats, Sprague-Dawley

In 2013, the World Health Organization reported the first case of human infection with a new influenza A (H7N9) virus in China. This has caused damage and panic within certain areas in China. Therefore, analysis of this virus with bioinformatics technology is very necessary. Neuraminidase (NA) is one of the most important antigens of the influenza virus and an important target for anti-flu drugs. In this study, the nucleotide and protein sequences of NA gene of A/H7N9 influenza viruses were retrieved from the NCBI database, and MEGA 5.0 software was employed to construct a phylogenetic tree based on the nucleotide coding sequence; BioEdit software was used to align the nucleotide and protein sequences of NA and calculate the homologies of nucleotides and amino acids and then to analyze the important mutation sites of NA gene. The results demonstrated that the spread of influenza virus H7N9 showed certain geographical and temporal relations. The H7N9 virus isolated from China in 2013 belonged to Euroasiatic serotype, and its NA stalk region hadobvious variation, which may be one of the reasons that this virus infects human. These analyses may be very helpful for understanding the evolutionary relationship and mutation trend of A/H7N9 influenza viruses.
Databases, Genetic ; Evolution, Molecular ; Humans ; Influenza A Virus, H7N9 Subtype ; enzymology ; genetics ; Mutation ; Neuraminidase ; chemistry ; genetics ; Phylogeny ; Sequence Analysis

Adult ; Aged ; Aged, 80 and over ; Female ; Hospital Costs ; Humans ; Intestinal Obstruction ; surgery ; Male ; Middle Aged ; Postoperative Complications ; Stents ; adverse effects ; economics

OBJECTIVETo evaluate the impact of nicotine- and tar-free cigarette smoke extract (fCSE) on the serum testosterone (T) level and erectile function of male rats.

METHODSWe randomized 30 male SD rats to three groups of equal number to receive subcutaneous injection of PBS (1.0 ml / 300 g body weight per day), fCSE (1.0 ml/300 g body weight per day), and reduced glutathione hormone (GSH, 200 mg per kg body weight per day) in addition to fCSE (fCSE + GSH), respectively, all for 8 weeks. Then we evaluated the erectile function of the rats by measuring the maximal intracavernous pressure (MICP), mean arterial pressure (MAP), ICP/MAP ratio, time of stimulation to MICP (Tmax), and cavernosal filling fate (CFR). We determined the serum T level, the activities of superoxide dismutase (SOD) , malondialdehyde (MDA), and nitric oxide synthase (NOS) in the cavernosal tissue, and also observed the morphological changes of the corpus cavernosum.

RESULTSCompared with the controls, the rats of the fCSE group showed obvious decreases in the levels of serum T ([5.37 ± 1.43] vs [3.22 ± 1.11] μg/L), NOS ([2.90 ± 0.27] vs [1.67 ± 0.18] U/mg) , and SOD ([18.41 ± 1.09] vs [13.36 ± 1.18] U/mg prot) and erectile function-related indexes MICP ([85.92 ± 6.36] vs [58.99 ± 10.76] mmHg), MICP/MAP (0.86 ± 0.09 vs [0.56 ± 0.08]), and CFR (2.14 ± 0.44 vs 0.89 ± 0.44), but markedly increased Tmax ([29.90 ± 5.78] vs [42.90 ± 8.56]s), with a positive correlation between the serum T level and CFR (r = 0. 364, P < 0.05). Masson staining revealed a lower ratio of the corpus cavernosum smooth muscle tissue to collagen fiber in the fCSE group (0.27 ± 0.04) than in the control (0.98 ± 0.12). Compared with the fCSE group, the fCSE + GSH group exhibited significantly improved MICP ([58.99 ± 10.76 ] vs [77.95 ± 7.71] mmHg), MICP/MAP (0.56 ± 0.08 vs 0.77 ± 0.09), and CFR (0.89 ± 0.44] vs 1.76 ± 0.42) and shortened Tmax ([42.90 ± 8.56 ] vs [32.10 ± 5.84 ] s). The ratio of the corpus cavernosum smooth muscle tissue to collagen fiber was higher in the fCSE + GSH than in the fCSE group (0.77 ± 0.09 vs 0.27 ± 0.04) but still lower than in the control (0.98 ± 0.12).

CONCLUSIONNicotine- and tar-free cigarette smoke extract reduces the serum T level and erectile function of rats, which is related to oxidative stress. Antioxidant therapy can improve erectile function but has a limited value for morphological protection of the penile tissue.

Animals ; Erectile Dysfunction ; chemically induced ; Male ; Malondialdehyde ; metabolism ; Muscle, Smooth ; pathology ; Nicotine ; Nitric Oxide Synthase ; metabolism ; Penile Erection ; drug effects ; Penis ; pathology ; Rats ; Rats, Sprague-Dawley ; Smoke ; adverse effects ; Superoxide Dismutase ; metabolism ; Tars ; Tobacco ; adverse effects

Objective To examine the concentrations of hepatocyte growth factor(HGF)and vascular endothelial growth factor (VEGF)in the patients with diabetic neovascular glaucoma(NVG),proliferative retinopathy without neovascularization of the iris(PDR) and idiopathic macular role(IMH),and to determine the relationship between HGF and VEGF.Design Prospective case series. Participants 14 patients(14 eyes)with NVG,22 patients(22 eyes)with non-NVI PDR,19 patients(19 eyes)with IMH.Methods The double-antibody sandwich enzyme-linked immunosorbent assay(ELISA)was used to measure the intravitreous level of HGF and VEGF.Main Outcome Measures The concentrations of HGF and VEGF in the same specimens.Results The concentrations of HGF (mean?SD)in vitreous of NVG group,PDR group and IMH group were(12908.42?2946.46)、(9770.86?3802.99)、(4160.54?2044.80)pg/ ml,respectively(Kruskal-Walls test,X~2=32.36,P=0.000).In addition,significant differences were observed between groups of the concentrations of HGF(P＜0.01,respectively).The intravitreous concentrations of VEGF(mean?SD)in three groups were(823.50?718.58)、(821.82?786.27)、(22.73?3.20)pg/ml(X~2=28.30,P=0.O00),respectively(Kruskal-Walls test,X~2=32.36,P=0.000).There was no significant correlation between the concentrations of HGF and those of VEGF in the same specimens from each group(P＞0.05, respectively).Conclusions The intravitreous concentrations of HGF in the patients with diabetic NVG are obviously higher than those with IMH and non-NVI PDR,suggesting that HGF appears to be associated with mediating the neovascularization of retina and iris in NVG.However,it is not found there is any relationship between the intravitreous levels of HGF and VEGF.

425 halophilic bacteria strains were isolated by using six different media from thirty salt-soil samples collected from Heijing ancient salt mine,Yunnan. By the growth on NaCl grandient concentration and other screening methods,79 strains of extremely halophilic microorganisms were chosen for further research. Based on colonies color,shape and size,15 stains were selected to be sequenced. The sequencing results revealed that 11 of them were haloarchaea. According to the phylogenetic analysis,they belong to four genera of the family Halobacteriaceae. The blast results showed that the similarities of six sequences were higher than 97 % with the validly described species of the following four genera: Halorubrum,Natronococcus,Natrialba,Halalkalicoccus. The similarities of other five sequences with any validly described species were less than 97 %,therefore,the taxonomic positions of the following five strains YIM-ARC 0032,YIM-ARC 0036,YIM-ARC 0037,and YIM-ARC 0050 could be determined according to further polyphasic taxonomy data.The results indicated that there was a considerable diversity of haloarcheaea in salt-mine environment of Heijing ancient salt mine,Yunnan and it was worth continuing to research on this area.

OBJECTIVETo evaluate erectile function in men with renal failure before and after kidney transplantation and the effects of different methods of renal arterial anastomosis.

METHODSFifty-five married males, aged 22-50 years, who had received kidney transplantation at least one year before and whose serum creatinine was under 200 micromol/L , were selected in the study. The end-to-end revascularization to the internal iliac artery was accomplished in 39 of them, and the end-to-side revascularization to the external iliac artery was conducted in 16. Their erectile function was investigated according to the International Index of Erectile Function-5 (IIEF-5) before kidney transplantation and 3, 6 and 9 months after it. The effects of different methods of renal arterial anastomosis were evaluated and hypophyseal hormones determined in 25 of them.

RESULTSIIEF-5 was higher in the patients 3, 6 and 9 months after transplantation than before it (P < 0.05) and 6 and 9 months after transplantation than 3 months after it (P < 0.05) , so was it in the patients with less than 12 months hemodialysis than those with over 12 months (P < 0.05) and in the patients with end-to-side revascularization to the external iliac artery than those with end-to-end revascularization to the internal iliac artery (P < 0.05). The differences between the level of hypophyseal hormones and that of sex hormones before transplantation were significant (P < 0.05).

CONCLUSIONErectile function and the level of hypophyseal hormones were improved after kidney transplantation, and the patients who received end-to-side revascularization to the external iliac artery experienced better erectile function recovery than those who underwent end-to-end revascularization to the internal iliac artery.

Adult ; Anastomosis, Surgical ; methods ; Erectile Dysfunction ; etiology ; Humans ; Kidney Transplantation ; Male ; Middle Aged ; Penile Erection ; Pituitary Hormones ; metabolism ; Renal Artery ; surgery ; Surveys and Questionnaires