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.

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.

To investigate the possible mechanisms underlying the difference of NMDA and non-NMDA receptors in spinal nociception originating in skin and muscle, release of aspartate (Asp) and glutamate (Glu) in the spinal dorsal horn was detected by stimulation of cutaneous and muscular nerves in cats using microdialysis technique. Asp and Glu were increased respectively by (323±55)% and (169±16)% following stimulation of cutaneous nerve, but by (150±16)% and (218±42)% respectively following stimulation of muscular nerve. Asp increase was approximately three times higher than that of Glu following cutaneous nerve-stimulation (P<0.01), while Glu increase was approximately twice as high as that of Asp following muscular nerve-stimulation (P<0.05). It is likely that nociceptive cutaneous and muscular inputs preferentially elicite release of Asp and Glu respectively, resulting in a functional differentiation of NMDA and non-NMDA receptor in the mediation of different nociceptive information.

Objective To investigate the fulfillment of improved water measures for endemic fluomsis and to find out the trend of prevalence in Qinghai Province in order to provide scientific basis and technical support for the government to formulate control strategies for endemic fluorosis.Methods Usage and management of reforming water facilities in Huzhu County were generally surveyed.Yanya Village,Caijiabu Town,Huzhu County was chosen as the surveillance spot.The household drinking water was surveyed.The dental fluorosis and urine fluoride content of children aged 8-12 years and adult above 16 years were examined.Skeletal fluorosis of adult was checked.The fluomsis content in drinking water and urine was determined with F-ion selective electrode method.The dental fluowsis was examined with Dean index.Skeletal fluorosis was diagnosed according to eountry standard(GB 16396-1996.WS 192-1999).Results The rate of water-improving was 60%(36/60)in Huzhu County.The mean of fluoride content in drinking water Was 1.25 mg/L The prevalence rate of dental fluorosis of children aged 8-12 years was 90.20%(46/51);that of adult was 88.89%(48/54).The dental fluorosis index of children was 1.77,that of adult was 2.95.The prevalence rate of skeletal fluorosis was 98.15% indicated by clinical data,18.87% by X-ray.The ufine fluorosis content of children was 2.27 mg/L,that of adult was 2.00 mg/L.Conclusion The disease condition of endemic fluorosis in Qinshai is serious,defluofidation is slow in effect.

OBJECTIVETo study the stereoselective glucuronidation of carvedilol (CARV) by three Chinese liver microsomes.

METHODSThe metabolites of CARV were identified by a hydrolysis reaction with beta-glucuronidase and HPLC-MS/MS. The enzyme kinetics for CARV enantiomers glucuronidation was determined by a reversed phase-high pressure liquid chromatography (RP-HPLC) assay using (S)-propafenone as internal standard after precolumn derivatization with 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosylisothiocyanate.

RESULTSTwo CARV glucuronides were found in three Chinese liver microsomes incubated with CARV. The non-linear regression analysis showed that the values of K(m) and V(max) for (S)-CARV and (R)-CARV enantiomers were (118+/-44) micromol/L, (2 500+/-833) pmol/(min.mg protein) and (24+/-7) micromol/L, (953+/-399) pmol/(min.mg protein), respectively.

CONCLUSIONThese results suggested that there was a significant (P<0.05) stereoselective glucuronidation of CARV enantiomers in three Chinese liver microsomes, which might partly explain the enantioselective pharmacokinetics of CARV.

Carbazoles ; metabolism ; China ; Glucuronic Acid ; metabolism ; Glucuronides ; metabolism ; Microsomes, Liver ; metabolism ; Propanolamines ; metabolism ; Stereoisomerism

The cerebral cortex contains a large variety of neuronal cells, which connect with each other via synapses to form different neural networks and fundamental elements for brain functions such as sense, movement, learning, language and decision making. Information processing in the cerebral cortex requires the activation of individual neurons and their recurrent networks,that is,the generation of action potential (AP) (excitability of single neurons) and network activity (excitability of neural networks).Initiation of AP occurs at the axon and is determined by axonal ion channels as well as intrinsic biophysical properties.The excitability of recurrent networks is not only determined by the excitability of different types of neurons, but also regulated by the unique properties of neurotransmitter release in distinct synapses including excitatory and inhibitory ones.Traditionally,it is believed that the all-or-none AP is the only mode of information transmission-digital mode.Recent studies have shown that the subthreshold membrane potential fluctuations regulate AP-induced the synaptic transmission-analog mode. At the network level, the network activity is relatively stable, resulting from a dynamic balance of excitation and inhibition. The microcircuits of recurrent inhibition mediated by distinct inhibitory interneuron types and the modes of synaptic transmission,such as the analog mode of signal communication and asyn-chronous neurotransmitter release,play critical roles in maintaining the excitation and inhibition balance. Together,we present here some new insights into the mechanisms underlying the excitability of distinct types of cortical neurons and their interconnected networks.

AIMTo assess the antioxidative properties and the mechanism of action of dihydromyricetin (DMY) from Ampelopsis grossedentata.

METHODSThe antioxidative properties of DMY were measured by scavenging 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and inhibiting lipid peroxidation induced by FeSO4-edetic acid in linoleic acid. The mechanism of antioxidative properties of DMY was tested by measuring the chelating activities of DMY for Fe2+ with ultraviolet spectrum (UV) method.

RESULTSThe specific absorption of DPPH radical solution at 517 nm was reduced 73.3%-91.5% when DMY was added into the reaction solution in the concentration range from 0.01% to 0.04%. DMY was shown to greatly inhibit the increase of lipid peroxidation (LPO) values in linolei acid system catalyzed by FeSO4-edetic acid. The reaction rates (A532.min-1) of lipid peroxidation were 0.0021-0.0004 in the concentration range from 0.01% to 0.04% and the inhibition activities of DMY was found to be in a concentration-dependent manner. The mechanism of antioxidative properties of DMY was chelating Fe2+ in the Fe(2+)-dependent lipid peroxidation system.

CONCLUSIONDMY showed great antioxidative effect and would be a good natural antioxidant.

Ampelopsis ; chemistry ; Antioxidants ; isolation & purification ; pharmacology ; Chelating Agents ; pharmacology ; Flavonols ; chemistry ; isolation & purification ; pharmacology ; Free Radical Scavengers ; isolation & purification ; pharmacology ; Lipid Peroxidation ; drug effects ; Molecular Structure ; Plants, Medicinal ; chemistry

OBJECTIVETo summarize the Chinese experience in pathologic diagnosis of liver biopsies after orthotopic liver transplantation (OLTx).

METHODS1123 post-transplant liver biopsies from 665 OLTx patients from the Shanghai Eastern Hepatobiliary Surgery Hospital, Tianjin First Central Hospital, Guangzhou Sun Yat-sen University and Chongqing Southwest Hospital were retrospectively analyzed. All liver biopsies were stained with hematoxylin and eosin. Immunohistochemical studies for cytomegalovirus, HBsAg, CK19, CD4 and CD8 were also performed in selected examples.

RESULTSIn the involved hospitals, 4 to 12 types of complications were encountered after OLTx. The number of liver biopsies performed for each patient ranged from 1 to 9 (mean = 2.2). The timing of these biopsies varied from the second to the 2877 th post-transplant day. The 5 most common complications were acute cellular rejection (35.6%), ischemic-reperfusion injury (13.4%), biliary stricture (5.6%), drug complication (5.0%) and chronic rejection (4.7%). The 5 earliest complications after OLTx were primary non-function (occurring at day 4.7 +/- 2.1), ischemic-reperfusion injury (occurring at day 14.0 +/- 4.0), acute cellular rejection (occurring at day 32.1 +/- 62.9), hepatic artery thrombosis / stricture (occurring at day 62.9 +/- 74.2) and cytomegalovirus infection (occurring at day 107.7 +/- 93.0).

CONCLUSIONSThis study has evaluated the types, incidence and timing of major complications occurring after OLTx. The most important issue is the distinction between rejection and non-rejection pathology. Thorough understanding of atypical pathologic features of these complications is necessary. The Banff Schema (rejection activity index) for grading liver allograft rejection is useful for monitoring anti-rejection therapy and should be used routinely.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Biopsy, Needle ; Child ; Child, Preschool ; Cholestasis, Intrahepatic ; pathology ; Female ; Graft Rejection ; pathology ; Hepatic Artery ; pathology ; Humans ; Infant ; Liver Transplantation ; pathology ; Male ; Middle Aged ; Postoperative Complications ; pathology ; Reperfusion Injury ; pathology ; Retrospective Studies ; Thrombosis ; pathology

OBJECTIVETo investigate the mortality of HIV infected clients from methadone maintenance treatment (MMT) clinics in Yili Kazakh autonomous prefecture as well as the factors associated with mortality of HIV infected clients.

METHODSA retrospective cohort study was performed. Data of 860 cases were collected from National Methadone Maintenance Treatment database, National AIDS/HIV database and antiretroviral therapy (ART) treatment database for adults. Information collected included demographic information of HIV infected clients, methadone daily treatment information, CD4 testing information, ART treatment information and death information. Recruiting began from August, 2005 through May, 2011. Cox proportional regression was used to identify factors associated with mortality. The proportional hazard assumption was assessed using Schoenfeld's residuals test. Missing values were imputed using the multiple linear regression method. R software (version 2.13.0) was used to perform data analysis.

RESULTSA total of 860 HIV positive MMT clients were analyzed. The methadone dose for study subjects was (38.2 ± 20.7) mg/d. 27.8% (239/860) of study subjects participated in ART treatment, 38.7% (333/860) had never tested for CD4 count. The age for study subjects was (32.9 ± 6.4) years old. Among all these subjects, 67.3% (579/860) were married. During the observation period, 151 deaths were observed in 2192.9 person years. The average observation time was 2.6 year for each subject. The all-cause mortality rate was 68.9‰. Cox proportion model showed that ART treatment (HR = 0.53, 95%CI: 0.32 - 0.88), baseline CD4 count at 200 - 350 cells/µl (HR = 0.35, 95%CI: 0.20 - 0.60), baseline CD4 count more than 350 cells/µl (HR = 0.16, 95%CI: 0.09 - 0.29), and marriage (HR = 0.55, 95%CI: 0.37 - 0.82) were associated with less mortality compared with control group. Age (more than 45 years old) (HR = 5.20, 95%CI: 2.60 - 10.20) and sharing needles (HR = 1.40, 95%CI: 1.02 - 2.00) were risk factors associated with death.

CONCLUSIONHigh mortality rate was observed among HIV infected clients. Methadone clinic should provide ART treatment or ART referral services.

Acquired Immunodeficiency Syndrome ; drug therapy ; mortality ; Adolescent ; Adult ; Anti-HIV Agents ; therapeutic use ; China ; Female ; HIV Infections ; drug therapy ; mortality ; Humans ; Male ; Methadone ; therapeutic use ; Middle Aged ; Retrospective Studies ; Survival Rate ; Young Adult

OBJECTIVETo discuss the effect of different positive criteria on the sensitivity and specificity of sputum cytology screening for lung cancer among Yunnan tin miners.

METHODS9223 Yunnan tin miners who received at least one annual sputum cytology screening for lung cancer during the period between 1992 and 1999 were recruited in the study. At time of enrollment, all participants were aged over 40 years old, had at least 10 years of employment as an underground miner and(or) smelter, and had not been diagnosed with malignancy. In our study, a true positive was categorized as having at least one prior positive sputum screening and a diagnosis of lung cancer, while a true negative, by our definition, signified negative sputum examinations and no diagnosis of lung cancer during the follow up time. Based on different positive criteria, sensitivity and specificity of sputum cytology were computed and receiver operating characteristic (ROC) curve analysis was conducted. Z statistic was used to test the differences of the area under ROC based on Hanley and McNeil method.

RESULTSBy the end of following up on December 31, 2001, a total 500 lung cancer cases were diagnosed among 9223 participants: most were squamous cell carcinoma (55.8% (222/398)) and central lung cancers (68.5% (316/461)). 150 lung cancer cases had a previous positive sputum screening result. When positive criteria were taken as grave atypical metaplasia, moderate atypical metaplasia and slight atypical metaplasia, the corresponding sensitivities were 30.0% (150/500), 36.4% (182/500), 53.0% (265/500) respectively; while the corresponding specificities were 98.9% (8628/8723), 95.1% (8611/8723), 77.9% (7033/8723) respectively. The areas under ROC curve according to different positive criterias were 0.645 (95%CI: 0.635 - 0.654), 0.657 (95%CI: 0.668 - 0.667), 0.655 (95%CI: 0.645 - 0.664) respectively. There were no significant differences found in the comparisons between grave and moderate atypical metaplasia, grave and slight atypical metaplasia, moderate and slight atypical metaplasia(Z statistics were 0.780, 0.645, 0.209 respectively, all P values > 0.05).

CONCLUSIONWhile the standard of positive criteria for diagnosis of lung cancer decreased, the sensitivity of sputum cytology screening increased and the specificity decreased. Since there were no significant differences of accuracy for different positive criteria.

Cytodiagnosis ; methods ; standards ; Female ; Humans ; Lung Neoplasms ; diagnosis ; Male ; Mass Screening ; methods ; Sensitivity and Specificity ; Sputum ; cytology