Objective It has been known that the C-terminal domain of rodent Muc3 underwent proteolytic digestion.G/S within the motif of cleavage,LSKGSIVV,was one of the important pivots for digestion.The present investigation was aiming at exploring the unknown relationship between the integrity of SEA module and the proteolytic digestion.Method Truncated rodent Muc3 C-terminal domains(p20t and p20SEA) were produced by site-directed mutagenesis to insert a stop code in the required place.Proteins were detected by SDS/PAGE and Western blotting.Deglycosylation of the expressed protein was performed by digestion using N-glycosidase F.Results Muc3 C-terminal domain was posttranslationally cleaved to produce a V5-tagged 30kDa extracellular glycopeptide and a Myc-tagged 49kDa membrane-associated glycopeptide.The 30kDa N-terminal fragment shifted to 22kDa after deglycosylation.The truncated rodent Muc3 C-terminal domain containing complete SEA module,but without the following residues after SEA module,was 30kDa Mw as detected with anti-V5 antibody,and it was shifted to 22kDa after deglycosylation.But the truncated rodent Muc3 C-terminal domain containing incomplete SEA module(p20t) of 26-30kDa Mw was shifted to 26kDa after deglycosylation.Conclusion There was proteolytic digestion in both complete rodent C-terminal domain and complete SEA module without residues after SEA module.But proteolytic digestion does not occur in the incomplete SEA module of rodent Muc3.So it may be concluded that the integrity of SEA module of rodent Muc3 was also a crucial condition for its proteolytic digestion.

Objective To explore the existing molecular pattern of rodent Muc3 carboxyl-terminal domain. Methods Muc3 carboxyl-terminal domain was expressed by a transient expression system and detected with SDS/PAGE and Western blotting. Identification of interaction between two proteolytically cleaved fragments was carried out by using both metabolic labeling and immunoprecipitation of expressed proteins and affinity purification of His-tagged proteins. Results Experiments with heterologous cells transfected with cDNA encoding the 381-residue C-terminal domain of rodent Muc3 showed that a definitive proteolytic cleavage occurred during the process in the endoplasmic reticulum. The products consisted of a V5-tagged 30 000 extracellular peptide, a Myc-tagged 49 000 membrane-associated peptide and non-cleaved 55 000 of whole-length protein. Two fragments remained associated by non-covalent SDS-sensitive interactions. Conclusion The proteolytic cleavage may be a prelude to later release of the large extracellular domains at cell surfaces. But the interaction between two cleaved fragments may be an important factor to interfere with the later release of the extracellular domain.

Objective The study was to explore the relationship between Helicobacter pylori ( H.pylori ) infection and aberrant mucin expression in gastric mucosa. Methods H.pylori infection was diagnosed by Warthin Starry staining method, and different kinds of mucin were detected using the immunohistochemical method. Results Positive staining of MUC2 mucin was found in 14 out of 21 patients with mucosa positive for H.pylori ( 66 7%), whereas only 6 cases showed MUC2 mucin expression in 18 H.pylori negative patients (33 3%) ( P 0 05). Conclusion H.pylori infection may alter the expression of some mucin genes in pericancerous gastric mucosa and destroy the gastric mucosa barrier

Objective To investigate the effects of transcription factor achaete scute-like 2(Ascl2)on epithelial-mesenchymal transition (EM T ) associated microRNAs .Methods Colon cancer LS174T cells were transfected with shRNA-Ascl2 vector and shRNA-control vector respectively ,then the transfected cells were selected with G 418 and stably transfected cell lines were estab-lished .Real-time PCR and Western-blot analysis were used to determine the interference effect .Transwell invasion experiment were used to observe the effects of Ascl2 RNA interference on cell invasion capability in vitro .MicroRNA chip analysis was used to de-tect the change of EMT-associated microRNA expression ,and real-time PCR experiment was used to validate the microarray re-sults .Results The mRNA and protein expressions were significantly reduced after Ascl2 interference (P<0 .01) .The numbers of invading cells were significantly decreased after Ascl2 interference (P<0 .01) .MicroRNA chip analysis found microRNA-200 fami-ly (including microRNA-200b ,microRNA-200a ,microRNA-429 ,microRNA-200c ,microRNA-141) was more than 2-fold upregula-tion after Ascl2 interference (P< 0 .01) .Conclusion Ascl2 regulates the invasion and metastasis of colon cancer cell ,possibly through transcription regulation of microRNA-200 family ,and then regulation of EM T .

The purpose of this clinical study was to evaluate the protective effect of continuous potassic warm blood perfusion on myocardium during warm blood extraeorporeal circalation. Warm blood cardiopulmonary bypass and continuous potassic warm blood perfusion for myocardial protection were used in 39 cases undergoing coronary bypass. 15% potassium chloride was mixed with oxygenated warm blood for continuous myocardial perfusion to induce cardiac arrest. The average nasopharyngeal temperature was maintained at 33.5℃. The warm blood was delivered at a rate of 150 to 200 ml/min; 15% potassium chloride was pumped at a high flow rate of 120 to 160 ml/h and then at a low flow rate of 15 to 20ml/h when electrocardiogram showed straight line. The results showed that 38 cases (97.4%) had spontaneous return of normal sinus rhythm shortly after removal of the aortic crossclamp. Myocardial positive inotropic agents were seldom used and hemodynamics kept stable. Cardiac functions showed fast recovery and there were not serious complications such as perioperative myocardial infarction, low output syndrome and arrhythmia. It is indicated that continuous potassic warm blood perfusion for myocardial protection may have a remarkable results to prevent myocardial anoxemia and reperfusion injury during CPB.

Objective To investigate TFF3 (rTFF3) protein expression profile in the adult and embryonic Wistar rats by using indigenous anti-rTFF3 polyclonal antibody and to explore the effect of TFF3 on the early embryonic development and its molecular pattern(s) existing in the intestinal mucosa. Method Anti-rTFF3 polyclonal serum was raised from the immunized New Zealand rabbit by synthetic N-terminal peptide of rTFF3. rTFF3 protein in the tissues was then detected by the self-made anti-rTFF3 polyclonal antibody with the immunohistochemical method. rTFF3 protein in the intestinal mucosa was detected by SDS/PAGE and Western blot. Result The anti-rTFF3 polyclonal antibody was sensitive and specific to rTFF3 molecule. rTFF3 was expressed extensively in the mucosa of small intestine, large intestine and epithelium of bile duct of adult Wistar rats, and it was also present in the late embryonic intestinal mucosa (two-week gestation and without mature goblet cell in the intestine). rTFF3 existed in the form of complexes, molecular weights of which were 250kD and 55kD respectively. Conclusion rTFF3 protein is located mainly in the goblet cells of the intestine. Its presentation seems to precede the maturation of goblet cells, and it might be involved in embryonic development. The majority of active rTFF3 molecules exist in a complex form, which might interact with unknown protein(s), and only a minor portion is in the form of a monomer.

Objective The C-terminal domain of rodent Muc3 is proteolytically cleaved.This study is to explore the relationship between N-linked oligosaccharides in SEA module and the proteolytic cleavage within C-terminal domain of rodent Muc3.Methods Truncated rodent Muc3 C-terminal domains with complete SEA module(p20SEA) were produced by site-directed mutagenesis to insert a stop code in the required place.Proteins were detected by pulse/chase and immunoprecipitation method,or SDS/PAGE and Western blot.Inhibition of glycosylation of the expressed protein was performed by using tunicamycin.Results Muc3 C-terminal domain was posttranslationally cleaved to produce a V5-tagged 30 000 extracellular glycopeptide and a Myc-tagged 49 000 membrane-associated glycopeptide.Treatment with tunicamycin to transfected COS-1 cells led to the abundant production of 60 000 uncleaved and whole-length Muc3 C-terminal domain,the 30 000 N-terminal fragment shifted to 22 000 and 49 000 C-terminal fragment shifted to 41 000 after deglycosylation.The truncated Muc3 C-terminal domain containing complete SEA module but without the following residues led to production of 36 000 uncleaved and whole-length protein,and 30 000 cleaved product shifted to 22 000 after deglycosylation.Conclusion Proteolytic cleavage in both complete rodent C-terminal domain and complete SEA module without the following residues were partially inhibited by tunicamycin.

Advanced studying doctors play important roles in the clinical services, and how to train them to improve training quality is worth investigating. We classified them into three types such as the clinical skills-improved, the special skills-trained and clinical knowledge eextensively-spread, then employed the individual teaching methods and emphasized the medical ethics during the training, which is not only beneficial to us, but also of great importance and necessity to advanced studying doctors themselves.

Recent meta-analysis based on both clinical trials and epidemiological studies has revealed the relationship of dietary cholesterol,blood cholesterol level and cholesterol lowering drugs (statins) with colorectal cancer.This review summarises the advances in current evidences of linking cholesterol metabolism and risk of colorectal cancer and the underlying molecular mechanisms based on pharmacogenetics and molecular pathology.

Objective To investigate the curative effect and safety of microinvasive percutaneous nephrolithotomy (MPCNL) and ureteroscope lithotripsy (URSL) in treatment of children′s (≤6 years old) middle and upper segment ureteral calculi. Methods Eighty children (≤6 years old) with middle and upper segment ureteral calculi were selected, and they were divided into observation group and control group according to random number table method with 40 cases each. The children of observation group were treated with MPCNL, and the children of control group were treated with URSL. The operation time, hospitalization time, calculi clearance rate of the first phase, decline situation of the postoperative hemoglobin and hematocrit and complication were compared between 2 groups. Results The operation time and hospitalization time in observation group were significantly shorter than those in control group:(45.43 ± 9.76) min vs. (68.32 ± 11.28) min and (8.12 ± 1.03) d vs. (13.45 ± 2.34) d, the calculi clearance rate of the first phase was significantly higher than that in control group: 100.0% (40/40) vs. 62.5%(25/40), the incidence of complication was significantly lower than that in control group:20.0%(8/40) vs. 60.0% (24/40), and there were statistical differences (P<0.05). There were no statistical differences in the decline situation of the postoperative hemoglobin and hematocrit between 2 groups (P>0.05). Conclusions The MPCNL in treatment of children′s middle and upper segment ureteral calculi has short operation time, high calculi clearance rate of the first phase, and low incidence of perioperative complication. Compared with URSL, the URSL is safe and efficient, and it is worthy of clinical application.