The biochemical mechanism of degrading keratins by S.fradiae var S-221 was primarily studied.The compounds (Na_ 2 SO_ 4 , Na_ 2 SO_ 3 and sulfdryl acohol), which respecitively enhance specific activity of keratinase, activate keratinase intensively and mainly act on the disulfide bonds reductase in the keratinase, Na_ 2 SO_ 3 activates intensively both disulfide bonds reductase and polypeptide hydrolytase at 0.01 mol/L, whereas Na_ 2 S_ 2 O_ 3 , which acts on the disulfide bonds reductase, inhibits keratinase.On the condition that substrate, keratins exists, S.fradiae var S-221 is induced to produce exo-keratinase, which is a multiproteinase, containing disulfide bonds reductase, which is a key enzyme degrading keratins, then, with polypeptidic, hydrolytase, graduately hydrolyzates denatured keratins into polypeptides, oligopeptides and free amino acids, so that keratins have been decomposed completely.Sulfur in the keratins was transferred into sulfhydryl compounds, H_ 2 S and sulfates in the course of keratinolysine.

Cervical Intraepithelial Neoplasia ; diagnosis ; virology ; DNA, Viral ; isolation & purification ; Female ; Human papillomavirus 16 ; genetics ; isolation & purification ; Human papillomavirus 18 ; genetics ; isolation & purification ; Humans ; Molecular Diagnostic Techniques ; methods ; Papillomaviridae ; genetics ; isolation & purification ; Papillomavirus Infections ; diagnosis ; virology ; RNA, Messenger ; metabolism ; United States ; United States Food and Drug Administration ; Uterine Cervical Neoplasms ; diagnosis ; virology

By inquiring the medical students under the background of grouping teaching between the mainland students and the oversea Chinese students,we have got something about their attitude toward the credit system.The result will help us to improve the teaching renovation in medical education.The questionnaire including implementing of credit system,standard credit system, grouping teaching,curriculum,tutor system of the undergraduates,the administration of education,and so on.Then we analyze and get the result.

Animals ; Burns ; drug therapy ; metabolism ; physiopathology ; Interleukin-18 ; genetics ; metabolism ; Lactulose ; therapeutic use ; Lipopolysaccharides ; blood ; Liver ; metabolism ; physiopathology ; Lung ; metabolism ; physiopathology ; Male ; Multiple Organ Failure ; prevention & control ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar

Virginiamycin acetyltransferase D (VatD) plays a vital rule in streptogramins resistance by chemically inactivating streptogramin A. Therefore, it is desirable to discover novel small molecular weight inhibitors of VatD via state-of-the-art virtual screening techniques. This "cocktail" strategy by combining VatD inhibitor with streptogramins may provide new therapeutic opportunity for resistant bacteria infections. Structure-based virtual screening method (molecular docking) was applied to rank and score a chemical database containing 300 000 commercially available compounds against the VatD substrate binding site. Twenty six out of the 200 top scored compounds from the docking calculation were selected and submitted to the VatD enzymatic inhibition assay. The plasmid pRSET B/vatD was constructed and transformed into E. coli (trxB) host cells for over-expression, and VatD enzyme was purified and validated by showing acetyltransferase activity to Virginiamycin M1. Three out of these 26 tested compounds showed enzymatic inhibition on VatD with IC50 168.6, 91.0 and 55.2 micromol x L(-1), separately. Other compounds could not be dissolved in the system and/or had little effect on the enzyme (IC50 > 200 micromol x L(-1)). To our knowledge, it is first time that small molecular weight organic compounds were identified as VatD inhibitors. It is expected that the VatD inhibitors identified at present study could serve as lead compounds for the further development of the novel therapeutic agents to overcome streptogramins resistance.
Acetyltransferases ; antagonists & inhibitors ; genetics ; metabolism ; Catalysis ; drug effects ; Drug Design ; Drug Resistance, Bacterial ; Enzyme Inhibitors ; chemistry ; metabolism ; pharmacology ; Escherichia coli ; genetics ; Genetic Vectors ; Kinetics ; Molecular Structure ; Plasmids ; Streptogramin Group A ; chemistry ; metabolism ; pharmacology ; Transformation, Genetic

Objective To investigate the expression of matrix metalloproteinase-9 (MMP-9) and determine the biologic significance of MMP-9 in the meningioma recurrence and regrowth after surgery. Methods The expression level of MMP-9 were examined by immunohistochemistry (Envision method) in 74 patients with meningioma, including 30 with primary meningioma without recurrence (control), and 44 with meningioma recurrence and regrowth after surgery (71 samples, experimental). The relation between recurrence-free survival (RFS) and the expression of MMP-9 in different grades of meningioma with different operation frequency and resection degree was analyzed in these 101 samples. Results The mean expression of MMP-9 in the experimental group was significantly higher as compared with that in the control group (P<0.05); increased expression of MMP-9 was found following the increase of operation frequency in the experimental group; no obviously decreased expression of MMP-9 was found following the increase of recession degree in the experimental group, but the expression of MMP-9 in patients with grade II meningioma was significantly increased than that in patients with grade I meningioma and the RFS was statistically decreased (P<0.05). Conclusion MMP-9 may be involved in recurrence and regrowth of grade II meningioma, and increased expression of MMP-9 can be considered as an indicator for a high risk of recurrence and regrowth of meningioma.

Abstract: Objective To analyze the occupational hazards of enterprises in Pingshan district of Shenzhen in 2017. Methods Occupational hazards were analyzed in 200 enterprises in Pingshan district of Shenzhen City selected using stratified Results random sampling method. A total of 24 industries were involved in the 200 enterprises. The declaration rate of ， occupational hazards was 91.5% and the exposure rate of occupational hazards among workers was 49.2%. The regular monitoring rate of occupational hazard factors in workplaces of the enterprises was 79.5%. There were 129 kinds of occupational ， ， hazard factors of which 19 factors exceeded the national occupational exposure limit accounting for 14.7%. The over standard ， ， ， ， ， ， ， ， rates of noise silica dust cotton dust methanol toluene and other dust were 28.7% 13.6% 11.8% 5.86% 0.5% and ， ， 0.4% respectively. There were 13 kinds of occupational hazard factors in the workplace of metal products industry all of which （ ） exceeded the occupational exposure limit. The exposure rate 56.7% of occupational hazard factors in workers was the highest. Conclusion ， ， The main occupational hazard factors were noise dust and chemical factor and the major occupational hazard industry was metal manufacturing in Pingshan district of Shenzhen City.

OBJECTIVETo observe the effects of Shuyu Ningxin Recipe (SNR) on the praxiology and the expressions of hippocampal brain-derived neurotrophic factor (BDNF) and its receptor tyrosine kinase B (TrkB) of model rats with chronic stress-induced depression, thus exploring its anti-depression mechanisms.

METHODSSixty adult SD rats were randomly divided into 6 groups, i.e., the normal control group, the model group, the fluoxetine group, the high dose SNR group, the medium dose SNR group, and the low dose SNR group, 10 in each group. All rats were subjected to establish chronic stress-induced depression model for 21 consecutive days. Except those in the normal control group, rats in the rest groups received gastrogavage from the 22nd day. Mice in the model group were administered with normal saline by gastrogavage. SNR at 25.0, 7.5, and 2.5 g/kg was respectively administered to rats in the high dose SNR group, the medium dose SNR group, and the low dose SNR group by gastrogavage. Fluoxetine suspension (12 mg/kg) was given to rats in the fluoxetine group by gastro-gavage. All medication lasted for 3 successive weeks. The weight, open-field test, and the immobility time in forced swimming test were determined before modeling, 3 weeks (after successful modeling), and 6 weeks (by the end of medication). The expressions of hippocampal BDNF and TrkB were measured after the brain tissues were drawn by the end of the experiment.

RESULTSCompared with the normal control group, the body weight grew slowly, the behavior index decreased, the immobility time in forced swimming test was prolonged, and the expressions of BDNF and TrkB were weaken in the model group (P <0.05, P <0.01).The body weight increased, the behavior was improved, the immobility time in forced swimming test was shortened, and the expressions of BDNF and TrkB were enhanced in the high dose SNR group and the fluoxetine group by the and of medication, showing statistical difference when compared with the model group (P <0.05, P <0.01).

CONCLUSIONSNR could exert anti-depression by improving the expression levels of hippocampal BDNF and TrkB.

Animals ; Behavior, Animal ; Brain-Derived Neurotrophic Factor ; metabolism ; Depression ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Hippocampus ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Receptor, trkB ; metabolism ; Stress, Psychological ; metabolism

OBJECTIVETo investigate the functional reconstruction technique for partial lower lip defects.

METHODS7 patients with lower lip cancer (3 cases of basal cell carcinoma, 2 cases squamous cell carcinoma and 2 cases papillary carcinoma) underwent excision. The full-thickness lower lip defects were one-third to two-third of the total lower lip length. All the defects were reconstructed with V-Y island advancement flaps based on the mental neurovascular bundle.

RESULTSThere was no flap loss. No recurrence was observed during the follow-up period of 3 months to one year. Both the aesthetic appearance, muscle function and sensation of the reconstructed lower lip were satisfactory.

CONCLUSIONSMental neurovascular V-Y island advancement flap is an ideal method for functional repair of partial lower lip defect.

Aged ; Carcinoma, Basal Cell ; surgery ; Chin ; innervation ; Female ; Humans ; Lip ; injuries ; Lip Neoplasms ; surgery ; Male ; Middle Aged ; Reconstructive Surgical Procedures ; methods ; Surgical Flaps ; blood supply

AIMTo study the synthesis and antitumour activities of some aryl-substituted pteridines.

METHODSA series of aryl-substituted pteridines were synthesized from 4, 6-diamino-5-nitrosopyrimidines by cyclization with 4-aminophenylacetonitriles. The antitumour activities were tested by MTT method.

RESULTSNine new compounds (I-III) were synthesized and their structures were characterized by EA, IR, 1HNMR and MS spectra. Compounds I-III showed antitumour activities in vitro.

CONCLUSIONCompounds I-III showed remarkable antitumour activities in vitro. No interaction was determined between the title compounds and calf thymus DNA. It indicated that these compounds possibly inhibit dihydrofolate reductase (DHFR) or other enzymes on which folic acid depends.

Adenocarcinoma ; pathology ; Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Cell Line, Tumor ; drug effects ; Humans ; KB Cells ; drug effects ; Lung Neoplasms ; pathology ; Molecular Structure ; Pteridines ; chemical synthesis ; chemistry ; pharmacology