1998年 · 第111卷第04期

p53 mutation and over-expression can be taken as one of the most common genetic aberrations in human tumors. We studied mutant p53 over-expression in hydatidiform mole, invasive mole and choriocarcinoma using streptavidin-peroxidase immunohistobiochemistry, and found that the expression of mutant p53 is remarkably increased in the invasive mole and choriocarcinoma.

OBJECTIVE To investigate the role of bifidobacteria preparation in the prevention of diarrhea in severely burned patients. METHODS Forty-three severely burned patients who were inflicted by diarrhea were included in this study. The changes of intestinal microflora were observed. RESULTS The intestinal flora of all patients with diarrhea changed greatly before treatment. The proportions of bifidobacteria and bacteroid decreased significantly, whereas those of aerobe and Candida increased relatively. The ratio of anaerobe to aerobe decreased. As a result, the patients' intestinal flora were distorted. After six days treatment of bifidobacteria, diarrhea in most patients ceased and the intestinal microflora restored. CONCLUSIONS Bifidobacteria feeding plays an important role in restoring intestinal microflora and stopping diarrhea in severely burned patients.

The proliferation of vascular smooth muscle cells (VSMCs) is one of the major pathological characteristics of essential hypertension. The proliferation rate of cultured VSMCs from simultaneously hypertensive rat (SHR) is much higher than that of VSMCs from Wistar-Kyoto (WKY) rat and the characteristic is heritable.

OBJECTIVE To evaluate the effectiveness of initiating thrombolysis for patients with acute myocardial infarction (AMI) in the Accident and Emergency Department. METHODS From January 1993 to December 1995, all AMI patients who were admitted to the United Christian Hospital and given thrombolytic therapy were studied. The patients' demographic data, time and mode of presentation, site of myocardial infarction, treatment modality and timing, and complications related to AMI or treatment were recorded prospectively in our AMI database. The frequency of thrombolysis administered in Accident and Emergency Department and Coronary Care Unit, as well as the median door-to-needle time (time interval between hospital arrival to initiation of thrombolytic therapy) were compared. Cases of inappropriate thrombolysis and complication were also analyzed. RESULTS Over these 3 years, 257 patients received thrombolysis in the United Christian Hospital. The percentage of patients receiving thrombolysis in Accident and Emergency Department increased from 3.2% in 1993 to 12.3% in 1994, and to 39.4% in 1995. The median time interval between arrival to hospital and thrombolysis (door-to-needle time) was 25 minutes, compared with 81 minutes in the Coronary Care Unit. The door-to-needle time also improved over these 3 years: from 95 minutes in 1993 to 75 minutes in 1995 in Coronary Care Unit group, and from 35 minutes in 1993 to 20 minutes in 1995 in the Accident and Emergency Department group. Over these 3 years, 2 cases of inappropriate thrombolysis were reported but these did not result in any mortality. Four complications from thrombolytic therapy were reported, and these were managed appropriately by the staff in Accident and Emergency Department and did not result in mortality. CONCLUSIONS Starting thrombolytic therapy in Accident and Emergency Department is safe and effectively decreases the door-to-needle time.

OBJECTIVE To investigate molecular events of exocytosis in cultured human pheochromocytoma cells with stimulation. METHODS The cultured pheochromocytoma cells prepared from human adrenal pheochromocytoma tumor were stimulated for the release of catecholamines by depolarization with the administration of 50 mmol/L KCl. Transmission electron microscopy (TEM) and high resolution scanning electron microscopy (HR-SEM) combined with autoradiography and cytochemistry were used to observe molecular mechanisms of exocytotic release of catecholamines from the stimulated cells labelled with 3H-noradrenaline and the filipin-treated cells. RESULTS TEM and HR-SEM observations of the stimulated cells labelled with 3H-noradrenaline revealed that the initial exocytotic fusion pores even less than 10 nm in diameter in human pheochromocytoma cells can be clearly observed in a single lipid bilayer. Furthermore, HR-SEM examinations of the filipin-treated cells showed that the derangement of the particles of the filipin-sterol complexes (FSCs) in the fused membranes of granule and plasma membranes occurred as the exocytotic fusion pores opened. In addition, the aggreates of the FSCs particles were consistently demonstrated around the openings of the differently sized closing exocytotic pores. CONCLUSIONS Based on our results, it is suggested that the rearrangement of the sterol molecules in the fused membranes of granule and plasma membranes plays an important role in the opening and closing mechanisms of exocytotic fusion pores. We hope that morphological data obtained in this study can provide some new insights into the understanding of molecular mechanisms of exocytosis, particularly the opening and closing of exocytotic fusion pores in relation to the distribution of the membrane sterols.

OBJECTIVE To evaluate the minimally invasive surgery in coronary artery bypass grafting and the feasibility for revascularization of triple vessel coronary artery disease. METHODS Nine female patients, aged 49.1 to 81.6 years (mean 64.3), were operated on for triple vessel disease through minimally invasive surgical techniques. The surgeries were performed through limited left parasternal incision under femorofemoral extracorporeal circulation. The myocardium was protected by antegrade infusion of cold blood cardioplegic solution while the aorta was cross-clamped. Under direct vision, the left saphenous vein grafts were connected sequentially to the diagonal branch, obtuse marginal branch and posterior descending branch, and the left internal thoracic arterial graft was anastomosed to the left anterior descending artery in each patient. RESULTS The number of distal anastomoses was 3 to 4 with a mean of 3.7. The aortic crossclamp time was 52 to 130 minutes (82±25 minutes). The duration of extracorporeal circulation was 78 to 151 minutes (115±29 minutes). The postoperative course was uneventful in all patients. The postoperative length of stay was 4 to 12 days (7.2±2.0 days). Follow-up (4.2 to 8.7 months, mean 6.4) was complete in all patients and there were no late deaths or angina. Coronary angiography of 2 patients showed patent grafts. All patients were satisfied with the good cosmetic healing of the incision. CONCLUSIONS Our experience demonstrates that minimally invasive surgery in coronary artery bypass grafting is technically feasible and may be an alternative approach in surgical revascularization of triple vessel coronary artery disease, especially in female patients.

OBJECTIVE To evaluate the protective effect of the angiotensin-converting enzyme inhibitor perindopril on diabetic glomerulopathy in rats with experimentally induced diabetes and explore its possible mechanisms. METHODS Ninety-two adult male Wistar rats were randomly allocated into diabetes mellitus (DM), diabetes mellitus + perindopril (DMP) and control (C) groups. According to the duration of diabetes or observation (1, 3, 6 months), each group was randomly subdivided into DM1, DM3, DM6; DMP1, DMP3, DMP6; and C1, C3, C6 groups. Diabetes was induced by intraperitoneal injection of streptozotocin. The rats in the DMP groups received perindopril 1 mg·kg-1·d-1, through gastric intubation. Urinary protein excretion rate was determined by the method of Coomassie brilliant blue. Plasma renin activity, renal tissue renin activity, and plasma and renal tissue angiotensin II concentration were assayed by radioimmunoassay (RIA). Renal tissue total RNA was extracted by the Chomezymskis AGPC method. Renal angiotensinogen mRNA expression level was assessed by slot blot hybridization using a full length rat angiotensinogen cDNA probe labelled with32P-dCTP and a random primer. RESULTS There was increased activity of the renin angiotensin system in diabetic rats. Perindopril decreased proteinuria and delayed the progression of glomerular basement membrane thickening. However, it did not reduce the expansion of the mesangial matrix (P<0.05). Renin activity increased and angiotensin II concentration decreased significantly in both plasma and renal tissue in diabetes + perindopril groups (P<0.05). CONCLUSIONS Perindopril may help prevent the progression of diabetic glomerulopathy, and the inhibition of renin angiotensin system activity may be a mechanism for this action.

OBJECTIVE To investigate the pathogenetic role of endogenous angiotensin II (Ang II) in the mechanism of stress ulcer in obstructive jaundice rats and to detect the effect of angiotensin converting enzyme inhibitor (ACEI) on stress ulcer in obstructive jaundice rats. METHODS After common bile duct ligation (CBDL) in Wistar rats, the content of plasma and gastric mucosal Ang II, gastric mucosal blood flow (GMBF) and gastric mucosal damage were measured, and the relationship among them was analyzed. RESULTS The plasma Ang II contents increased much more significantly at 1, 3, 7 and 14 days following CBDL than those in non-CBDL rats (P<0.05,<0.01,<0.01 and<0.01, respectively). Within 120 minutes following cold-restraint stress, plasma and gastric mucosal Ang II contents were elevated, GMBF decreased, and ulcer index and gastric mucosal damage increased more significantly than those in non-cold-restraint stress rats (P<0.05,<0.05,<0.01,<0.01 and<0.05, respectively). Administration of an ACEI, enalaprili, to CBDL rats (5 mg.kg-1.day-1, orally for two days) before stress reduced both the plasma and gastric mucosal Ang II levels, inhibited the decrease of GMBF and decreased ulcer index and gastric mucosal damage (P<0.001,<0.01,<0.01,<0.01 and<0.05, respectively). CONCLUSIONS The endogenous Ang II plays a significant pathogenetic role in the development of stress ulcer in obstructive jaundice rats, and ACEI may prevent stress ulcer.

OBJECTIVE To make a better understanding of the molecular mechanisms involved in recurrence and metastasis of the hepatocellular carcinoma (HCC), some invasion related oncogenes, and growth factors have been investigated. METHODS The studies were separately carried out, the results of which were summarized in this article with relation to tumor size and invasiveness of HCC. RESULTS The aberration rates of p53 and CDKN2 in HCC were 45.9% and 36.4% respectively, which were higher in invasive HCC compared with non-invasive HCC. H-ras expression was positive in 29.3% of HCC, which was associated with recurrence and extrahepatic metastasis of HCC. Intralesional injection of H-ras antisense gene markedly inhibited the tumor growth and metastasis of HCC in nude mice. The positive rates of transforming growth factor (TGF)-alpha, epidermal growth factor receptor (EGFR) and c-erbB-2 were 45.7%, 47.1% and 92.3% respectively. The expression of EGFR was closely related to TGF-alpha, which was related to HCC recurrence. But no obvious difference of TGF-alpha or c-erbB-2 expression was found between HCC with and without recurrence, or with and without extrahepatic metastasis. Expression of nm23/tissue inhibitor of metalloproteinase (TIMP)-2 was positively associated with the prognosis of HCC patients (Log-rank, P<0.001). The alterative rates of above-mentioned genes and growth factors in small HCC were slightly lower than that in large ones, but no significant difference was shown except the p53 mutation. CONCLUSIONS The p53/CDKN2 mutation, over-expression of H-ras/EGFR, were associated with the invasiveness and recurrence of HCC. H-ras antisense gene might be of potential implication in the control of HCC recurrence and metastasis. Expression of nm23/TIMP-2 was closely related to the prognosis of HCC patients. Biological characteristics remained critical points to the prognosis even in small HCC.

OBJECTIVE To investigate the expression of exogenous γ-interferon gene in human hepatocellular carcinoma cells following retroviral transduction and the effect on the expression of surface HLA class I molecules. METHODS Retroviral vector pLXSN was used to introduce human γ-interferon (IFN-γ) gene into four different human hepatocellular carcinoma cell lines (HCC). The G418-resistant colonies were isolated and cloned. The integration and expression of IFN-γ gene were determined by PCR and RT-PCR analysis. A bioassay method was used to test the amount of IFN-γ secreted by gene modified HCC cells. The expression of HLA class I molecules in HCC cells were analyzed by flow cytometry using indirect fluorescence staining. RESULTS Four different HCC cell lines were successfully transduced with human IFN-γ gene using retroviral vector. The integration and expression of IFN-γ gene were shown only in the transduced cells. All four genetically modified HCC cells can secrete varied amount of IFN-γ and demonstrate a significant up-regulation of surface HLA class I antigens. One specific HLA class I antigen, HLA-A2, has almost the same degree of increase as that of the total HLA class I molecules after transduction with IFN-γ gene. CONCLUSIONS Gene modification with IFN-γ gene can significantly enhance the expression of HLA class I molecules in HCC cells and may increase its immunogenicity. These gene modified tumor vaccines can be helpful in tumor biotherapy.

OBJECTIVE There is little information available regarding local vasomotor regulating processes in chronic heart failure. In this study, we tested the hypothesis that chronic heart failure impaired the endothelial function, and long term captopril treatment might reverse endothelial activity through tissue endothelin (ET) pathway. METHODS Forty Sprague-Dawley rats were divided into 4 groups including 15 rats in each of the sham-operated with or without captopril-treated groups and 5 rats in each of large infarcted with or without captopril-treated groups. RESULTS Concentration-response curves obtained in aortic rings without endothelium revealed no difference in nitroprusside-induced relaxation. With endothelium, rightward shifting was noted only in the untreated large infarct group during acetylcholine-induced relaxation. As compared to the non-treated group, plasma ET-1 concentrations were lower in the captopril-treated with or without large infarct groups. However, endothelin-like immunoreactivity in endothelial cells and cytoplasma of smooth muscle cells of the media of the aorta were lower only in the non-treated large infarct group. CONCLUSIONS Endothelial function was impaired in the chronic heart failure model. Coverting enzyme inhibitor might improve endothelial function through the Local endothelin pathway.

OBJECTIVE Experiments were designed to investigate the effect of Euro-Collins (EC) solution and University of Wisconsin (UW) solution on function of pulmonary arterial endothelium. METHODS Third order canine pulmonary artery segments were preserved in cold (4 ℃) UW (group 1, n = 8) or EC (group 2, n = 9) solutions for 16 hours. The preserved (group 1 and 2) and control (group 3, n = 7) pulmonary arterial segments with and without endothelium were studied in vitro in organ chambers to measure isometric tension. RESULTS The endothelium-dependent relaxation to acetylcholine and adenosine diphosphate of group 1 and 3 were significantly better than those of group 2. CONCLUSIONS We concluded that endothelium-dependent relaxation of canine pulmonary arterial endothelium to receptor-dependent acetylcholine and adenosine diphosphate were impaired after preservation with Euro-Collins solution. However, endothelium-dependent relaxation of pulmonary segments were well maintained after preservation with University of Wisconsin solution.

OBJECTIVE To observe the effects of antisense TGFα on the growth of human pancreatic carcinoma cell line cells. METHODS A recombinant retroviral vector expressing antisense TGFα was constructed, and transfected the ecotropic packaging cell line ψ-2 with lipofectin. After the amphotropic packaging cell line PA317 was transfected with the virus supernatant of ψ-2, the replication-defective, amphotropic retroviral supernatant was used to infect human pancreatic carcinoma cell line PC-7. Following puromycin selection, puromycin-resistant colonies were pooled and expanded to a cell line PC-7/AS-TGFα. RESULTS The retroviral integration in the genomes of ψ-2, PA317 and transformant PC-7 cells was confirmed by Southern blot hybridization. Northern blot hybridization showed a down regulation of endogenous TGFα in PC-7/AS-TGFα cell line. The high levels of growth inhibition and reduction of3H-TdR incorporation in PC-7/AS-TGFα were evident. Also, the soft agar colony-formation and tumorigenicity in nude mice were significantly suppressed by antisense TGFα. CONCLUSIONS The antisense TGFα expressing vector can block the target gene expression, suppress the cell growth and partially reverse the malignant phenotype of pancreatic carcinoma cells.

Primary Ewing's sarcoma of the maxilla is exceedingly rare. Only more than 30 cases have been reported in the English literature. As far as we know Ewing's sarcoma of the maxilla has not been reported in the Chinese literature. A case of Ewing's sarcoma of the maxilla is presented and the entity is discussed.