Using the semi-empirical MNDO/H method several systems simulating the reaction of tetrahetral intermediate formation in the active site of serine proteases have been studied. The role played by elements of the《catalytic triad》in increasing the reactivity of serine hydroxyl has been discussed.The formation of a strong hydrogen bond between His and Asp was shown to be important in lowering the activation energy in the reaction of Ser with substrate.The change in position of the proten located between Ser and His and between His and Asp was analysed.The influence of substrate distortion on the energy of intermediate formation has been considered.

As originated from hematopoietic stem cell clonal diseases,bcr-abl-negative chronic myeloproliferative neoplasms (MPN) include polycythemia vera (PV),essential thrombocythemia (ET) and primary myelofibrosis (PMF).With the discovery of JAK2 mutations,many new mutations have been identified.With the in-depth study of gene mutation,the pathogenesis of MPN has been gradually uncovered.Novel drugs have been developed accordingly.

Objective To observe the anatomical features of muscular branches of radial nerve in the forearm. Methods Forty seven adult embalmed cadaver arms were dissected under 4? loupe magnification. The radial nerve was identified in the interval between the brachioradialis and brachialis at the upper arm 10 cm proximal to the lateral humeral epicondyle (LHE). The nerve and branches were dissected and observed. The number of branches entering the muscles was counted and the following measurements were performed along the radial nerve and branches with a vernier caliper (accurate to 0.1 mm): distances from the origin point and muscle entry point of each branch to the LHE, the distance between the LHE and the styloid process of ulna (SPU). Data were pooled among all specimens (n=47) to calculate mean and standard deviation. Results In 35 of 47 (74.5%) specimens, the deep branch of the radial nerve coursed along the line between the LHE and the SPU. In all specimens, extensor indicis was the last muscle to be innervated. The average distance from the LHE to the origin point of extensor indicis branch was (160.6?12.1) mm, and that from the LHE to the SPU was (231.7?14.6) mm. The average proportionality between these two distances was 0.7?0.1. There was a large variation in branch number. The muscle with the highest branch number (4.6 averaged) was the extensor digitorum communis and that with the lowest number (1.1 averaged) were extensor policis longus and extensor indicis proprius. In 29 of 47 (61.7%), extensor carpi radialis brevis (ECRB) branch originated from the superficial branch of the radial nerve. In 15 of 47 (31.9%), the branch came from the deep branch of the radial nerve. In 3 of 47 (6.4%), the branch emanated from the radial nerve as 1 branch of a trifurcation (with the other branches being the deep branch and the superficial branch of the radial nerve). Conclusion With the forearm being pronated, the proximal 7/10 of the line between the LHE and the SPU can be considered as the projection on body surface of the deep branch of the radial nerve. The deep branch of the radial nerve may be damaged by operators improper dragging and detaching in surgery with the following reasons: branch lengths of extensor digitorum, extensor carpi ulnaris and extensor digiti minimi are short relatively, and origin points of these branches are more close than others to the point through which the deep branch of the radial nerve come out supinator. Differences in muscle architecture and function may be the reason that there is such variation in branch number. Discrepancies between studies about the ECRB branch origin may be related with the fault committed by researchers in dissecting.

To observe the regulative effect of electroacupuncture(EA) on plasma levels of some brain gut peptides in dogs, contents of gastric secretin(GT), vasoactive intestinal peptide(VIP), somatostatin(SS) and endothelin(ET) in plasma were simultaneously measured by radioactive immunonassay method in the dogs with or without EA stimulation at different acupoints. The results showed that in the Zusanli(st 36) group, after EA stimulation, an increase was observed in plasma contents of GT and VIP( P

AIM: To establish a model of primary cultured neuron injury induced by D-galactose for the research in Alzheimer's disease. METHODS: Primary rat neurons cultured for 6 days were exposed to 50 mmol D-galactose for 72 h. The neural growth and neurite density were observed with HE stain and microscope, the neural metabolism rate and apoptosis rate were examined with MTT, immuno-enzyme assay and flow cytometry, respectively, and the aldose reductase mRNA expression was also detected with RT-PCR. RESULTS: The neural growth and development in neurons treated with D-galactose was retarded, the neural metabolism rate decreased from 0.762?0 030( n= 33) to 0 543?0 064( n= 11)( P

Objective To investigate the effects of ubiquitin isopeptidase inhibitor Ⅰ on proliferation and apoptosis of human leukemic K562 cells.Methods Human leukemic K562 cells were treated with different concentration of ubiquitin isopeptidase inhibitor Ⅰ.Cell proliferation was monitored by MTT assay.Cell apoptosis was analyzed by flow cytometry after Annexin V/PI staining,and mRNA expression levels of bcl-2,bax and Caspase-3 were quantified by reverse transcription-polymerase chain reaction (RT-PCR).Results MTT assay showed that the proliferation of K562 cells was markedly inhibited by ubiquitin isopeptidase inhibitor Ⅰ in a time-and-dose dependent manner.The Annexin V positive rate of K562 cells after treatment with ubiquitin isopeptidase inhibitor Ⅰ was significantly increased by FCM analysis (P ＜ 0.05).The early apoptosis rate of K562 cells treated with 100 nmol/L ubiquitin isopeptidas inhibitor Ⅰ by 72 h,was obviously increased compared to control cells [(15.4±1.3) ％ vs (4.1±0.9) ％,P ＜ 0.01].The mRNA levels of Caspase-3 and bax were up-regulated and bcl-2 was down-regulated after treated with ubiquitin isopeptidase inhibitor Ⅰ,and the differences were statistically significant from control cells (P ＜ 0.05).Conclusion Ubiquitin isopeptidase inhibitor Ⅰ has inhibitory effect on proliferation and inductive effect on apoptosis of K562 leukemia cells,implying its possible application in treating leukemia.

Objective To investigate the regulation of electroacupuncture(EA)on gastric mucosal blood flow(GMBF) and its relation to the contents of plasma and gastric mucosal calcitonin gene-related peptide(CGRP) in dogs.Methods Twenty dogs were randomly divided into four groups:blank control group,no meridian point group,Shangjuxu group and Zusanli point group.By using laser doppler flowmeter(LDF)and radioimmunoassay method,GMBF,contents of CGRP were simultaneously measured,with or without EA stimulation at different acupoints in expermental dogs.Results In the Zusanli group,after EA stimulation, an increase was observed in plasma CGRP content(P

Objective Evaluate the diagnostic value of PET/CT in the preoperative advanced gastric carcinoma comparing with mult;-slice spiral computed tomography. Methods Thirty-nine advanced gastric carcinoma patients taking PET/CT and abstract 40 advanced gastric carcinoma patients performing MSCT before operation,were done the TNM staging, and the Results were compared with the operation histopathology. Results For diagnosing primary lesions, regional lymph nodes, N3 lymph nodes ,PET/CT was accurate in 92.3% , 66.7% and 100.0%.Instead, MSCT was accurate in 82.0% , 50.0% and 62.5%. Conclusions (1) PET/CT and MSCT have high accuracy in diagnosing primary lesions and regional lymph nodes. But for detecting the N3 lymph nodes and distant metastasis, PET/CT has higher accuracy than MSCT. PET/CT combining abdominoscopy may decrease or avoid exploratory laparotomy.

To explore the mechanism of electroacupunture (EA) of Zusanli (ST36)in protecting gastric mucosa of dogs.Twenty mongrel dogs were randomly allocated to four groups: blank control group (Group A), non acupoint group (Group B), Shangjuxu (ST37) group (Group C) and Zusanli (ST36) group (Group D). Dynamic gastric mucosal blood flow (GMBF) was monitored by laser Doppler flowmeter and calcitonin gene related peptide (CGRP) contents in plasma and gastric mucosa were measured simultaneously by radioimmunoassay method. After sixty minutes of EA, GMBF and CGRP contents in plasma and gastric mucosa were increased in Group D (P

For the current situation of the time background and the cultivation of innovation ability of undergraduates, the problems of fracture classification, function evaluation and postoperative rehabilitation were realized by a software research team which mainly consisted of medical undergrad-uates. We put the project into practice in forms of software production and software promotion trial separately in the field of teaching and clinical practice to encourage students to be involved in learn-ing in the process of software production of professional knowledge. The implementation of the project worked well, and developed the well-designed relevant mobile software which was convenient in clini-cal practice and acquired computer software copyright, indicating that it can effectively motivate the undergraduates' innovation interest and consciousness through participating in the various links and the software production process, and it can also contribute to the cultivation of the comprehensive practical and innovation ability of medical undergraduates.