A central portion of nifS, designated nifS', was amplified from Azotobacter vinelandii. The nifS' was cloned into pUC18 to make pUCS. Then pUCS was integrated into Azotobacter vindandii chromosome DNA by homologous recombination. This nifS disruption mutants were generated by single cross-over event and selected by Amp resistence on BBGN medium. The nifS disruption mutant (named SU1) was affirmed by southern blot and PCR amplification. SU1 grows rapidly on BBGN, but very slowly on Burk's N-free medium. This phenomenon showes that SU1 nearly lost its nitrogen fixation ability because of the disruption of nifS. The successful construction of SU1 is helpful for further research on the effect of nifS on the structure and function of nitrogenase component-Ⅰ and Ⅱ.

OBJECTIVETo compare changes of hypothalamus-pituitary-adrenal axis (HPAA) in different rat models of Gan stagnation (GS), Pi deficiency (PD), Gan stagnation Pi deficiency (GSPD) syndromes, and to observe interventional effect of Chaishu Sijun Decoction (CSD, capable of soothing Gan-qi invigorating Pi) on them.

METHODSSeventy Wistar rats were divided into the normal control group (group 1), the GS group (group 2), the PD group (group 3), the GSPD group (group 4), the GS intervention group (group 5), the PD intervention group (group 6), and the GSPD intervention group (group 7) according to random digit table, 10 in each group. Rats in group 1 received no treatment. Rats in group 2 and 5 were modeled by chronic restraint method. Rats in group 3 and 6 were modeled by excess fatigue plus alimentary abstinence method. Rats in group 4 and 7 were modeled by chronic restraint, excess fatigue, and alimentary abstinence method. At the 2nd weekend of modeling, CSD at 2.86 g/kg was fed to rats in group 5, 6, and 7 by gastrogavage for 2 successive weeks. Equal volume of distilled water was given to rats in the rest 4 groups. On the 29th day, rats were killed, adrenal weight weighed, and adrenal index calculated. Levels of plasma and hypothalamus corticotropin-releasing hormone (CRH), plasma and pituitary adrenocorticotrophic hormone (ACTH), and plasma corticosterone (CORT) were determined using radioimmunity.

RESULTSCompared with group 1, adrenal index significantly decreased in group 2, 3, and 4 (P < 0.05). Of them, plasma and hypothalamus CRH, plasma CORT increased significantly in group 2 and 4 (P < 0.05). Besides, plasma and pituitary ACTH increased in group 4 (P < 0.05). Plasma and pituitary ACTH, as well as plasma CORT decreased significantly in group 3 (P < 0.05). Compared with group 2, 3, and 4, adrenal index increased significantly in group 5, 6, and 7 (P < 0.05). Compared with group 2, plasma CORT, hypothalamus CRH, and pituitary ACTH decreased significantly in group 5 (P < 0.05). Compared with group 3, plasma ACTH and CORT increased significantly in group 6 (P < 0.05). Compared with group 4, plasma CRH, ACTH, CORT, hypothalamus CRH, and pituitary ACTH decreased in group 7 (P < 0.05).

CONCLUSIONSThe function of HPA .axis was damaged to varying degrees in rats of the three models in this experiment. Hyperactivity of HPA axis existed in GS syndrome and GSPD syndrome. Impairment of feedback regulation in hypothalamus and pituitary was accompanied in GSPD syndrome. Hypofunction of HPA axis existed in PDS. CSD, capable of soothing Gan-qi invigorating'Pi, showed improvement on disarranged HPAA, but with optimal effect on GSPD syndrome. CSD had higher correlation with GSPD syndrome.

Adrenocorticotropic Hormone ; metabolism ; Animals ; Corticosterone ; Corticotropin-Releasing Hormone ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Hypothalamo-Hypophyseal System ; metabolism ; Hypothalamus ; metabolism ; Medicine, Chinese Traditional ; Models, Animal ; Pituitary Gland ; metabolism ; Pituitary-Adrenal System ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo evaluate whether the rapid viral response (RVR) to combinational therapy with interferon and rabavirin can be used to predict the sustained viral response (SVR) in chronic hepatitis C patients.

METHODSAccording to their clinical characteristics, all patients in this study were given pegylated or conventional interferon injection and different dose of ribavirin according to their weight. Patients were injected Pegasys (pegierferon alpha-2a) 180 microg or 135 microg once a week, or pegyintron 50-80 microg once a week, or conventional interferon 3-5 MU every two days, in combination with a dose of 600-1500 mg/d ribavirin. The serum HCV RNA load was determined at 0, 4, 12 week, and then every 12 weeks. After the viral response obtained, the patients were treated for another 24-72 weeks and followed up 24 weeks. The main parameter to evaluate the efficacy was SVR rate. The influence factors associated with rapid viral response were investigated.

RESULTSRVR was obtained at week 4 in 84.2% of the 120 patients. The HCV RNA baseline of RVR group was (5.883+/-1.246) lg copies/ml, which was significantly lower than that of the group without RVR [(6.502+/-0.693) lg copies/ml, t=2.15, P=0.034]. 97 patients with RVR who finished treatment and follow-up, 90.7% of these patients obtained SVR, but the SVR rate in patients (82.4%) without RVR was lower than that in patients with RVR (x2=0.371, P=0.543). In this study, RVR rate was not associated with HCV genotype and the dose of interferon used. In the naive patients, the RVR to pegylated interferon was 87.8%, which was significantly higher than that in retreat patients (x2=4.651, P=0.031).

CONCLUSIONHigh RVR rate could be obtained in chronic hepatitis C patients treated combined with interferon and ribavirin. RVR rate is associated with the HCV RNA baseline load in both naive and retreat patients but not correlated to HCV genotype. RVR could predict the SVR.

Administration, Cutaneous ; Adolescent ; Adult ; Aged ; Antiviral Agents ; administration & dosage ; therapeutic use ; Child ; Drug Therapy, Combination ; Female ; Genotype ; Hepacivirus ; drug effects ; genetics ; Hepatitis C, Chronic ; blood ; drug therapy ; pathology ; Humans ; Interferon-alpha ; administration & dosage ; therapeutic use ; Male ; Middle Aged ; Polyethylene Glycols ; administration & dosage ; therapeutic use ; Predictive Value of Tests ; RNA, Viral ; blood ; Recombinant Proteins ; Recurrence ; Ribavirin ; administration & dosage ; therapeutic use ; Time Factors ; Treatment Outcome ; Viral Load ; Young Adult

Naringenin (1) was transformed to three metabolites (2-4) by Mucor sp. Based on LCMS(n)-IT-TOF and NMR spectroscopic data, 2-4 were identified as naringenin-7-O-sulphate, naringenin-4'-O-sulphate, and naringenin-5-O-sulphate, respectively. These results might provide hints to the mammalian/human metabolism of naringenin.
Biotransformation ; Drugs, Chinese Herbal ; chemistry ; metabolism ; Flavanones ; chemistry ; metabolism ; Magnetic Resonance Spectroscopy ; Molecular Structure ; Mucor ; metabolism ; Sulfates ; metabolism

BACKGROUNDTo study the predictive factors associated with clinical deterioration in SARS patients.

METHODSThe clinical data of 60 SARS patients were analyzed by logistic regression and Cox's proportional hazards analysis.

RESULTSIn logistic regression models, both older age (P=0.009) and severe lymphopenia (P=0.004) were significant predictors of clinical deterioration. In Cox's proportional hazard models, severe lymphopenia was significant predictor associated with prolongation of stay in hospital.

CONCLUSIONOlder age and severe lymphopenia seem to be statistically significant for predicting the clinical deterioration in SARS patients.

Adult ; Aged ; Disease Progression ; Female ; Humans ; Logistic Models ; Lymphopenia ; virology ; Male ; Middle Aged ; Predictive Value of Tests ; Prognosis ; Proportional Hazards Models ; Random Allocation ; SARS Virus ; Severe Acute Respiratory Syndrome ; complications ; diagnosis ; immunology ; virology

Objective To evaluate the efficacy of mechanical thrombectomy on embolic cerebral infarction with magnetic resonance diffusion weighted imaging (DWI). Methods Forty New Zealand white rabbits were performed carotid artery injection of blood clot emboli to induce the animal models of acute cerebral infarction; these models were equally randomized into 4 groups (n=10);non-treatment group was given no treatment; mechanical thrombectomy via femoral artery was performed under DSA 6, 8 and 12 h after the inducement in the 3 treatment groups, respectively. MR-DWI, T1WI and T2WI were performed and the apparent diffusion coefficient (ADC) and infarct volume were calculated in each group 6, 8, 12 and 24 h after the inducement. Results DWI demonstrated the ischemic area in all the 40 rabbit models at hyper-acute stage (within 6 h of inducement) with hyperintensity, while T1WI and T2WI showed normal signals. MR-DWI, T1WI and T2WI had significant difference in the relevance ratio of cerebral infarction in these rabbit models at acute stage (within 24 h of inducement, P＜0.05). The DAC value was gradually decreased and the ischemic area was gradually increased at acute stage in the rabbit models of non-treatment group and group of performing mechanical thrombectomy at the 12thh of inducement, however, rabbit models of groups of performing mechanical thrombectomy at the 6th and 8th h of inducement enjoyed the opposite position. The DAC value was higher and the ischemic area was lower 24 h after the inducement in the rabbit models of groups of performing mechanical thrombectomy the 6th and 8th h of inducement as compared with those in the non-treatment group and group of performing mechanical thrombectomy at the 12th h of inducement. Conclusion Mechanical thrombectomy at early stage enjoys significant good results; MR-DWI is a sensitive way in dynamic observing the treatment efficacy of acute cerebral infarction.

Adult ; Aged ; Aneurysm, False ; physiopathology ; Carotid Arteries ; diagnostic imaging ; pathology ; Epistaxis ; diagnostic imaging ; etiology ; pathology ; therapy ; Female ; Humans ; Male ; Middle Aged ; Radiography

The prenylation of aromatic compounds plays an important role in the natural product research because it not only gives rise to an astounding diversity of primary and secondary metabolites in plants, fungi and bacteria but also enhances the bioactivities and bioavailabilities of these compounds. However, further investigation of prenylated aromatic compounds is frequently hindered due to their low content in nature and difficulties in chemical synthesis. Cloning aromatic prenyltransferase genes followed by heterologous expression would be attractive tools for the chemoenzymatic synthesis of bioactive molecules. This review summarizes the classifications, structural investigations, enzymatic catalysis and other progress in aromatic prenyltransferases originated from microorganisms.
Bacteria ; enzymology ; Dimethylallyltranstransferase ; biosynthesis ; chemistry ; classification ; Fungi ; enzymology ; Molecular Structure ; Substrate Specificity ; Synthetic Biology

BACKGROUNDTo survey a diarrhea outbreak in Guangan city and analyze the cause of the disease.

METHODSThe population enrolled in the surveillance came from four different settings and was randomly sampled. Stool specimens collected from diarrhea patients were tested ordinarily for enteric bacteria and further examined for viral pathogens with PAGE, ELISA and RT-PCR.

RESULTSIn total, 4,567 persons were surveyed, among them 942 had acute diarrhea (prevalence 20.63%). The incidence was higher in rural area (28.6%) than in urban area (19.6%) (chi-square =22.29, P less than 0.005) with a peak in May 10 through 25 four human caliciviruses were detected from stool specimens by ELISA and RT-PCR in specimens from 4 and 1 patients, respectively.

CONCLUSIONHuman calicivirus probably was the cause of this diarrhea outbreak in Guangan city.

Acute Disease ; epidemiology ; Adolescent ; Adult ; Age Distribution ; Caliciviridae Infections ; epidemiology ; virology ; Child ; China ; epidemiology ; Diarrhea ; epidemiology ; virology ; Disease Outbreaks ; Feces ; virology ; Female ; Humans ; Male ; Middle Aged ; Norovirus ; isolation & purification ; Young Adult

Objective To improve the CR image quality and to promote the digital image standard constitution by analyzing the common problems and malpractiees in application of computed radiography. Methods Phenomenon and reasons of 107 CR junk-films from nine three-"A"-hospitals were analyzed, discussed,recorded,and statistised by 20 radiologists,radiographers and engineers.Results Among 107 junk fihns,there are 36 cases(33.64%)of incorrect operations,29 cases(27.10%)of artifacts in reading and transferring the data of IP,15 cases(14.02%)of artifacts in IP system,and 13 cases (12.15%)of selection of inappropriate radiographic parameters,and 9 eases(8.41%)of printer-failures, and 5 eases(4.67%)of inappropriate post-processing techniques.By analyzing the reasons of 107 junk films we found that 60.74% were due to less responsibilities and incorrect operations,and 35.51% were due to new problems in CR techniques,and other were due to inappropriate post-processing techniques. Conclusion Responsibilities,operation regulations,digital image quality standards,studying of new techniques and appropriate use of the post-processing techniques are the key points for improving the CR image quality and the diagnosis level.