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.

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 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.

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 explore the awareness on sever acute respiratory syndrome (SARS) and public health emergencies among general publics.

METHODSA cluster sampling method was implemented in Harbin and Jiagedaqi district of Daxinanling of Heilongjiang province. Research subjects were divided into three groups as city, township and rural areas and were given questionnaires to fill in. Data was analyzed with Epi-data and SPSS.

RESULTS2003 available questionnaires were collected. The general publics well understood the knowledge on public health emergencies and the SARS with the whole recognition rate more than 60 percent. During the epidemics, people in city, town and countryside were calm (71.7%). The rates of attitude towards the government were significantly different among the subjects living with the city, town or rural areas. The city group expressed the highest favor to the government and media, 71.8% of them gave the credit on the control of SARS to the effective method taken by the government and 65.0% of them showed that they had enough confidence on the governmental ability of dealing with crises while the countryside group trusted the hospitals and relative specialists the most.

CONCLUSIONIt is essential for the government to interact and communicate with the publics through media, medical and related institutions when confronting with the public health emergencies. Publicity on health knowledge and coping system on emergency should play key roles in the development of an effective public health system while the government should lead the battle.

China ; Data Collection ; Emergencies ; Health Knowledge, Attitudes, Practice ; Humans ; Public Health ; Rural Population ; Severe Acute Respiratory Syndrome ; Urban Population

OBJECTIVETo reassess the prognostic factors of diffuse large B cell lymphoma (DLBCL) treated with R-CHOP therapy.

METHODSOne hundred and twenty five patients were enrolled in this study from Feb. 2000 to Sep. 2006. They received 6 courses of R-CHOP regimen consisting of rituximab 375 mg/ m2, intravenously, d 1; cyclophosphamide 750 mg/m2, bolus intravenously, d 2; doxorubicin 50 mg/m2, bolus intravenously, d 2; vincristine 1.4 mg/m2, bolus intravenously, d 2 and prednisone 60 mg, orally, d 2 - 6. All the patients were evaluated and followed up after the treatment.

RESULTSEighty six patients (68.8%) achieved complete response (CR), 16 (12.8%) partial response (PR), 11 (12.8%) stable disease (SD) and 12 (9.6%) progressive disease (PD). In univariate analysis, performance status (PS), clinical stage, LDH level, extranodal disease, international prognostic index (IPI) and bulky disease were statistically significantly correlated with the induction of CR; however, only PS, clinical stage and bulky disease remained significant in multi-variate analysis (P = 0.0098, 0.000 and 0.004, respectively). Twenty four month for time to treatment failure (TTF) rate, overall survival (OS) rate, and disease free survival (DFS) rate was (59.7 +/- 5. 3)%, (67.1 +/- 5.6)% and (77.6 +/- 5.8)%, respectively. In univariate analysis, LDH, clinical stage and PS exerted significant effect on TTF and OS rate, but not on DFS rate; age and extranodal disease was not related with TTF, OS and DFS rate. In multi-variate analysis, achieved CR was the only prognostic factor for TTF (P =0.001) and bulky disease had influence on DFS rate. LDH level, PS, and achieved CR was correlated with the OS rate in multi-variate setting (P = 0.002, 0.009 and 0.001 respectively).

CONCLUSIONIPI score has its limitation in predicting the prognosis in the R-CHOP era in DLBCL. Other two relevant prognostic factors are bulky disease and achieved CR after 6 courses of treatment.

Adolescent ; Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Cyclophosphamide ; therapeutic use ; Doxorubicin ; therapeutic use ; Female ; Follow-Up Studies ; Humans ; Lymphoma, Large B-Cell, Diffuse ; drug therapy ; Male ; Middle Aged ; Prednisone ; therapeutic use ; Prognosis ; Treatment Outcome ; Vincristine ; therapeutic use ; Young Adult