AIM To observe the therapeutic effect of weile jiaonang (WLJN) for peptic ulcer (PU) and its toxicity toanimals, and to find out the nontoxic Chinese medicines in replacing those chemical medicines with sideeffect.METHODS Five hundred and forty patients with PU were divided into three groups, therapeutic group byWLJN, control group taking famotidine and combined group with WLJN and famotidine. One hundred andeighty patients in each group were studied. The diagnosis of 540 patients with PU is in accordance with thebasis provided by the National Scientific Congress of Digestive System Disease convened in Hangzhou, 1978.The study followed the criterion provided by this Congress.RESULTS Total effective rate in therapeutic group was 93.3%, and 93.3% in control group. Combinedgroup achieved a total effective rate of 100%. For all three groups, there was no significant differencestatistically, but the control group appeared obvious side effects. The result of acute toxic experiments onwhite mice showed that there no death and toxic side effect even the highest dosage was given, which wasequivalant to 120 times to the dosage of patients. The result of chronic toxic experiment showed there was noobvious pathologic change in three dosed groups. The tails of mice in dosed groups were more smooth delicateand cleaner than those in control group.CONCLUSION Through observation in clinic and exprimental animal, it is proved that weilejiaonang isparticularly effective and safe Chinese patent drug against PU.
作者: 刊期: 2000年第03期
AIM Endoscopic ultrasonography (EUS) guided pancreatic pseudocysts drainage is an ideal therapeuticprocedure. We perform it in just one step by using the self-made drainage stent.ETHODS We made an aperture at the tip of the needle outer sheath, and tied the outer sheath with theself-made stent by suture. EUS-guided pancreatic pseudocysts drainage was performed in five patients. Nopatient had visible endosmotic bulge on the gastrointestinal wall. Mean pseudocyst diameter was 4.5 cm(pancreatic head 1, body 2, tail 4). We determined the optimal site for puncture and advanced the needlyand stent into cyst. Taking out the needle made the stent separated from the sheath.RESULTS No hemorrhage happened among these patients. One patient suffering from fever up to 40℃recovered within two days after operation. All the cysts diminished insige after 7 days and resolvedcompletely after 6.8 weeks in average. Cyst resolution was accompanied by symptomatic improvement in allpatients. During a follow-up of 6 months no cyst recurred.CONCLUSION EUS-guided drainage of pseudocysts is a safe and effective procedure, which performs thejust in one process and diminishes the patients' distness.
作者: 刊期: 2000年第03期
AIM To study the clinical significance of alterations of serum hyaluronic acid in rats with carbontetrachioride-induced liver fibrosis.METHODS Rat liver fibrosis model was induced by carbon tetrachloride (CC14). The rats were divided intofive groups; group 1 (control): 0 week with no CCl4-inducing; group 2, 3, 4 and 5: 3, 6, 9 and 12 weeksafter CCl4-induction respectively. Serum HA level was analysed among various liver fibrosis groups andcontrol, and then compared the HA findings with the hepatic histopathology.RESULTS During rat liver fibrosis, serum HA levels of the liver fibrosis groups (group 2: 7.98ng/mL;group 3: 20.10 ng/mL; group 4:229.73 ng/mL; group 5:324,74 ng/mL) were significantly higher thanthat of control group (group 1:0.21 ng/mL) (P<0.01), in which group 4 and group 5 are much higher1094 times (229.73ng/mL/0.21 ng/mL) and 1546 times (324.74 ng/mL/0.21 ng/mL) than group 1respectively. When compared with each other, the serum HA levels are 38 times (7.98ng/mL/0.21 ng/mL; P<0.01, group 2 vs group 1); 2.5 times (20.10ng/mL/7.98 ng/mL; P<0.01, group 3 vsgroup 2); 11.4 times (229.73 ng/mL/20.10 ng/mL; P<0.01, group 4 vs group 3); 1.4 times (324.74 ng/mL/229.73 ng/mL; P<0.01, group 5 vs group 4) respectively.CONCLUSION The results demonstrated that the dynamic alterations of serum HA play an important rolein the early clinical diagnosis and staging of liver cirrhosis.
作者: 刊期: 2000年第03期
AIM To investigate the diagnostic significance of cytology and telomerase activity in the exfoliated cells ofcardia obtained from endoscopic brushing in the cardiac cancer.METHODS The techniques of the qualitative TRAP-silver staining and quantitative TRAP-PCR-ELISAwere employed to detect telomerase activity in the exfoliated cells of cardia obtained from endoscopicbrushing in 72 cases with cardial lesions, cytological diagnosis was made at the same time.RESULTS Telomerase activity with cardiac cancer group (1.521 ± 0. 192) was significantly higher than thatwith cardialitis group (0.065± 0.014). Positive rate of telomerase activity detected in cardiac cancer group(88.89%) was significantly higher than that with cardialitis group (11.11%), the former was significantlyhiger than cytological examination (77.78%). The diagnostic rate of cardiac cancer reached 93.33% iftelomerase activity and cytology were examined at the same time.CONCLUSION Cytology and telomerase activity in the exfoliated cardiac cells may be an effective andsensitive methods in the diagnosis of cardiac cancer. This research can be a basis for the mass screening ofcardiac cancer.
作者: 刊期: 2000年第03期
AIM To study the clinical and pathological features of hypoplasia of exocrine pancreas with myocardialnecrosis.METHODS One ease of hypoplasia of exocrine pancreas with myocardial necrosis was autopsied. Theclinical signs and pathological changes were analyzed.RESULTS A 15-month-old boy with hypoplasia of exocrine pancreas was reported. The main clinicalfeatures were steatorrhea and marked underdevelopment. He died of acute heart failure afterhospitalization. Autopsy showed that there were aplasia of exocrine portion and fatty metaplasia ofpancreas, the myocardium revealed focal necrosis and sear formation.CONCLUSION Atrophy of exocrine pancreas and myocardial necrosis exist at the same time, suggestingthat there may be some relationship between them. It was likely that the damaged pancreatic tissue releasedsome active materials that may harm the myocardium or decrease pancreatic juice that results in lack ofnutrient and myocardial necrosis.
作者: 刊期: 2000年第03期
AIM To investigate the effects of low dosage of nitric oxide synthesis (NOS) inhibitor NG-nitro-L-argininemethyl ester (L-NAME) in long-term treatment on hyperdynamic circulatory state in rats with cirrhosis.METHODS Cirrhosis model was induced in male SD rats by injection of 60% CC14 oily solutionsubcutaneously. Cirrhotic rats were treated with L-NAME (0.5 mg·kg-1·d-1) by gavage for two weeks. Meanarterial pressure (MAP), cardiac output (CO), cardiac index (CI), splanchnic vascular resistance (SVR),splanchnic blood flow (SBF) and serum NO levels were determinded in L-NAME-treated, L-NAME-untreated cirrhotic rats and controls by using 57Co-Labled microsphere technique and a fluorometric assay,respectively.RESULTS Untreated cirrhotic rats had significantly lower MAP, SVR and higher PP, CO, CI, SBF andNO concentration than controls ( 14.42±0,47 kPa vs 17.05±0.34 kPa, 2.974±0.186 kPa·mL-1·min-1 vs4.234±0.118 kPa·mL-1·min-1, 1.665±0.067 kPa vs 1.123±0.096 kPa, 189.99±9.26 mL/min vs 135.5±3.55 mL/min, 55.89±1.82 mL-1·min-1·100g-1 BW vs 39.68±1.64 mL-1·min-1·100g-1 BW, 4.60±1.25μmol/L vs 0.53±0.26 μmol/L, P<0.01, respectively). In treated cirrhotic rats, L-NAME significantlyattenuated the increase of CO, CI, SBF, NO concentration and the decrease of MAP and SVR. In treatedcirrhotic rats, L-NAME induced a marked decrement of NO concentration than untreated cirrhotic rats(1.471 ±0.907 μmol/L vs 4.204±1.253 μmol/L, P<0.01).CONCLUSION The endogenous NO may play an important role in the changes of hemodynamics pattern incirrhosis,and hyperdynamic circulatory state in rats with cirrhosis can be ameliorated by long-term low doseL-NAME treatment.
作者: 刊期: 2000年第03期
AIM To study the combined expression of gastrointestinal hormone substance P and anti-apoptosis gene Bcl-2 in gastric carcinoma and its significance.METHODS Substance P and Bcl-2 protein expression was examined by the S-P immunohistochemicalmethod in 33 cases of gastric carcinoma, 17 adjacent the carcinoma and 13 normal gastric mucoma.RESULTS Positive expression of SP in gastric carcinoma was higher than that of both adjacent and normalmucosa (P < 0.001). There was no statistical difference in the positive expression between adjacent andnormal mucosa (P > 0.05). The expression of bcl-2 both in gastric carcinoma and adjacent tissues werehigher than that of normal gastric mucosa (P< 0.05-0.01). But the positive expression of Bcl-2 had nostatistical significance between gastric carcinoma and adjacent tissues.CONCLUSION Both gastrointestinal hormone SP and Bcl-2 gene have synergistic expression in gastriccarcinoma, indicating that they all take part in the occurrence of gastric carcinoma. Abnormal expression ofBcl-2 gene occurred in benign gastric pathological changes, once they become carcinoma, the positiveexpression of cell is no more increased, possibly because that there is no more increase of the intensity of Bcl-2 inhibition of cell apoptosis.
作者: 刊期: 2000年第03期
AIM To study the antitumor effect of Zhenhuang Injection (ZHI) on the mice bearing transplanted tumor.METHODS The solid type of H22 transplantation hepotocarcinoma, ascitic type of S-180 sarcoma and ascitictype of LⅡ malignant lymphoma of mice were treated at three doses (crude drug 1.25g/kg, 2.5g/kg,5.0 g/kg of body weight) of ZH1. The solid tumor group and ascitic tumor group were injected intravenously.and intraperitoneally. The experiment was repeated three times.RESULTS The tumor-inhibition rate of H22 hepatocarcinoma in moderate and large doses was 30.23% -35.67% (P<0.01) and 46.36%-54.07% (P<0.01) respectively; the survival rate of ascitic type of S-180sarcoma and ascitic type of LⅡ malignant lymphoma in large dose group was 77.23% - 86.91% (P<0.01)and 75.42%-79.04% (P<0.01), respectively.CONCLUSION ZHI has a certain tumor-inhibiting effect. Under the tolerant dose, the effect improveswith the increase of dose.
作者: 刊期: 2000年第03期
AIM To study the relationship between the lipid peroxide (LPO) and superoxide dismutase (SOD) and thepathogenesis of gastrointestinal cancers.METHODS We investigated the SOD activity and LPO levels in blood and mucosa of patients withesophageal (EC), gastric (GC) and colorectal cancer (CC), gastric ulcer (GU) and compared with normalesophagus (NE), stomach (NS) and colon (NC). respectively, 287 patients who underwent endoscopy werestudied. SOD activity of the tissue and blood was determined using SUN's adrenaline auto oxidation method.LPO levels were determined according to YU's method.RESULTS The SOD activity and LPO level in blood and mucosa are shown in the Table 1 (x±Sx).Table 1 SOD and LPO in blood and tissues of patients with gastrointestinal cancers SOD(U/mg protein) LPO(U/mg)Groups n Tissue blood Tissue BloodNormal stomachGastric ulcerGastric cancerNormal esophagusEsophageal cancerNormal colonColon cancer 60 42 43 32 52 28 30 1.90±0.18 0.64±0.40a 0.37±0.24a 1.17±0.70 0.39±0.30a 0.81±0.36 0.31±0.17b 33.70±1.73 25.50±0.67b 27.86±1.02b 30.80±3.78 28.23±10.63 20.97±4.77 19.35±7.32 0.01±0.004 0.05±0.010b 0.06±0.021b 0.014±0.005 0.061±0.033b 0.012±0.003 0.069±0.015b 0.83±0.01 0.11±0.02 0.12±0.03 0.08±0.02 0.11±0.02 0.08±0.03 0.11±0.02aP<0.001, bp<0.01 vs corresponding normal controls, respectively.CONCLUSION SOD activity of the tissue is significantly decreased in EC. GC and CC. LPO levels weresignificantly higher than those of corresponding normal tissue. These results suggest that mucosal SOD andLPO levels are closely related to the pathogenesis of the gastrointestinal cancers.
作者: 刊期: 2000年第03期
AIM To observe the effects of Innovar and Atropine on Visceral pull response.METHODS Patients were randomly divided into two groups. The experimental group was treated by DanNang Xue blockade with Innovar 4 mL and Atropine 0.5 mg (n = 40) and the control group was treated byabdominal vagus blockade with 10 mL of 10 g/L Lidocaine (n = 40). Dan Nang Xue was chosen for insertionof No 5 needle (5 cm in length) after local sterilization. The acupoint of Dan Nang Xue is located at theoutside of knee-jont and it is one-finger wider below Yanglingquan can be found. A sensitive point. Theneedle was inserted between tibia and fibulae, lifted, thrusted and twirled until the patient felt ache. Innovarand Atropine were injected on Dan Nang Xue and the acupoint was gently messaged.RESULTS Patients in the experimental group remained quiet during operation. Neither nausea or vomitingnor uncomfortable reaction was complained, 85% of the patients belonged to grade m. Acupunctureenhanced the peristalsis of gallbladder and biliary secretions. Atropine relieved muscular spasm andprevented vomiting. A low heart rate was noted in the control during abdominal survey and gallbladder pull(P<0.05).CONCLUSION Dan Nang Xue blockade with innovar and atropine can prevent visceral pull response.
作者: 刊期: 2000年第03期
AIM To determine whether MAP can be detected in archival paraffin embedded full thickness samples ofintestinal tissue from patients in China with Crohn's disease (CD), ulcerative colitis (UC), and in controlsubjects (NIBD) having surgery for bowel cancer.METHODS Optimized procedures for the removal of paraffin, recovery of tissue and access to MAP DNA,followed by MAP-specific nested IS900 PCR. Confirmation of specific amplification by Southern blotting andDNA sequencing.RESULTS IS900 PCR positive tests identified MAP in 9 (69%) of 13 CD, 1 of 3 UC and 2 (14%) of 14NIBD in the presence of correctly reporting positive and negative sample and reagent control reactions. DNAsequence analysis of the 298bp IS900 PCR amplification product from MAP in 2 Chinese CD patientsdemonstrated 99% homology with the GenBank IS900 sequence accession number X16293.CONCLUSION Although larger numbers of Chinese samples need to be studied, these initial results areconsistent with an exposure of human populations in China to MAP, and an involvement of this pathogen inchronic inflammation of the intestine of the Crohn's disease type. The results are in agreement with similarpositive studies reported from China, from Western Europe and elsewhere.
作者: 刊期: 2000年第03期
AIM To investigate the epidemiological features of HCV prevalence, a seroepidemiological survey on HCVinfection has been carried out in Fujian since 1992.METHODS Using stratified multistage random cluster sampling, 3809 serum samples collected from 1237families in the diseases surveillance points were tested by UBI HCV EIA kit.RESULTS The results showed that the prevalence rate was 3.99%. The rate in male and female was3.63% and 4.25%, and in urban and rural 3.12% and 4.6% respectively (P>0.05). There was lower ratein children aged under 10 years. The highest rate was in 20 - 24 years old. The rates in different areas wereranged from 1.39% to 6.08% (P<0.05). The intrafamilial transmission was not important, indicating nointrafamilial aggregation. The superinfection of HCV with HAV, HBV and HEV were existed. The HCVinfection was slightly correlated with the history of hepatitis and transfusion.CONCLUSION It suggests that the HCV transmission among the population in Fujian is mainly sporadicinfection.
作者: 刊期: 2000年第03期
AIM To observe the effect of repair of intrathoracic esophageal perforation with gastric seromuscularpatch.METHODS Twelve patients with intrathoracic esophageal perforation, none of whom were associated withcarcinoma, underwent primary repair with a gastric seromuscular patch and omental pedicle flap between1996 and 1999. Four perforations were iatrogenic and 8 were spontaneous. The interval from perforation tooperation was less than 12 hours in 4 patients, 12 to 24 hours in 3, and more than 24 hours in 5. The principleof repair included: ① To expose health mucosa and submucosa for the primary repair. The leading edge ofthe mucosa is grasped and the adjacent esophageal muscle is mobilized away from the submucosa until there isa 3 to 7 mm circumferential rim of normal submucosa. ② The gastric seromucular patch and omental pedicleflap require continuity of the right gastric piple, omental vessels and the rami. ③ To assure the blood flow ofthe esophagus when the necrotic mediastinal and esophageal tissue are debrided, the normal esophageal tissueoften extends well beyond the 3/4 diameter of the esophagus. ④ The mediastinal pleural is not closed inorder to drain. The catchers nasogastric tube decompression of the stomach is continued until thepostoperative ileus resolves.RESULTS Eleven of the 12 patients underwent primary repair, one patient had leak at the site of repairand died.CONCLUSION Meticulous repair of an intrathoracic esophageal perforation using a gastric seromuscularpatch is the preferred approach regardless of the duration of the injury.
作者: 刊期: 2000年第03期
AIM To investigate DNA methylation status in gastric cancer and its relationship with folate metabolism.METHODS Serum before operation, the gastric mucosa from the lesion, and the surrounding area inpatients with gastric cancer and the remote normal-appearing mucosa of the resected stomach were collectedrespectively. The serum folate, mucosal tissue folate, S-adenosylmethionine ( SAM ), S-adenosylhomocysteine (SAH), and the DNA methylation levels were determined.RESULTS The tissue folate was significantly lower than that in ulcers, especially in the surrounding andnormal mucosa (0.38±0.13, 0.50±0.17 vs 0.53±0.50, 0.79±0.82ng/mg protein, P < 0.01), and itdecreased gradually in the lesion areas. The DNA methylation status showed similar decreasing trend incancers compared with the methylation increasing trend in ulcers. The SAM level ascended in the lesion areaswith a higher. concentration in cancer mueosa (63.5±43.0 vs 25.9±11.9nmol/g tissue, P < 0.01 ). Theaccumulation of SAH in the surrounding and normal mucosa of cancers was observed (17.3±24.6, 15.5±8.6vs 14.6±4.2, 10.0±1.9nmol/g tissue, P < 0.05 - 0.01). There were significantly negative correlationsbetween tissue folate and the SAM and SAH levels in the three areas.CONCLUSION Patients with gastric cancer have the regional folate deficiency in the stomach mucosa,although the serum folate level remains normal. This disturbs the local SAM and SAH metabolism withaccumulation of SAH and DNA hypomethylation which has been known as an important molecularmechanism for carcinogenesis. Folic acid can modulate DNA methylation status by its effect in one-carbongroup metabolism and thus affect the process of the carcinogenesis. Therefore, this may be an access for theprevention of gastric cancer.
作者: 刊期: 2000年第03期
AIM To study the change of trace elements in the hair of patients with esophageal carcinoma and the role oftrace elements in its development and progress.METHODS The hair of 60 normal people and 126 patients was collected and was divided into groupsaccording to the patients' pathologic changes. The atomic absorption method and fluorescence method wereused to measure the trace elements of copper, zinc, iron, calcium and selenium.RESULTS Zinc in the hair of various patients: a remarkable difference was found between normal people(182mg· kg 1)and the patients (103- 81.6mg·kg 1) (t = 3.79, P<0.01 Duncan' new multiple rangemethod). There was a certain difference between simple hyperplasia and cancer (t = 3.21, P<0.01 ). As forcopper, a great difference existed between normal people (12.01mg· kg-l) and patients with dysphagia (15.16mg·kg-1) and cancer (17.02-17.15mg·kg-1) (t=2.43, P<0.05). No change of zinc and copperwas observed in cancer patients (t = 1.61, P >0.05). The ratio of zinc to copper increased with thedevelopment of pathologic change. The selenium levels in patients (0.46-0.67mg·kg-1) was below that ofnormal people (l.03mg·kg-1), while iron and calcium levels in the patients decreased with the developmentof pathologic process.CONCLUSION Both zinc and copper play an important role in the pathologic change of esophagealcarcinoma. Zinc and copper in the hair changed with development of the pathologic process. Zinc revealedpositive correlation ( r = -0. 889, P < 0.01 while copper showed negative correlation ( r = 0.921, P < 0.01 ).The ratio of copper to zinc in the hair is of great diagnostic value.
作者: 刊期: 2000年第03期
AIM To study the biopathologic characteristics of the transitional mucosa (TM) adjacent to rectalcarcinoma and the resecting length of bowel.METHODS Immunohistochemical and mucin histochemical methods were used in 81 cases to observe theexpression of PCNA and the changing regulations of TM adjacent to rectal carcinoma.RESULTS The PCNA expression rate was the highest in cancer and gradually decreased in atypicaldysplasia, TM and normal mucosa (P<0.01). The range of TM adjacent to the mucinous adenocarcinomawas more extensive than that to the papilla adenocarcinoma and the tubular adenocarcinoma (P< 0.01 ). Therange of TM adjacent to the rectal carcinoma in Dukes C stage was more extensive than that in stage A, B(P<0.01, P<0.05).CONCLUSION The TM of rectal carcinoma possesses certain potential of malignancy. The range of TMadjacent to rectal carcinoma is closely related to the pathological type and advancement of rectal carcinoma.
作者: 刊期: 2000年第03期
AIM To investigate a mixture of traditional Chinese medicine (TCM) in the prevention of chronic colitis inrats.METHODS Sixty rats were divided into 3 groups. Colitis was induced by trinitrobenzene-sulfonic acid(TNB). On day 10, all the survived rats were killed, the mortality and intestinal obstruction rate werecalculated, the colonic lesion score was assessed and collagenase activity and collagen concentration weremeasured.RESULTS The survival rate was much lower and intestinal obstruction rate much higher in TNB than thosein TCM, they were 53% and 81% vs. 80% and 24% (P<0.05 and P<0.01, respectively). There were alsosignificant differences in colonic stricture score and colonic weight between TNB and TCM groups (1.75±1.2 vs 0.22±0.67 and 0.57±0.36 vs 0.31±0.10, P<0.01 and P<0.05, respectively). No hydroxyprolineand collagenase activity differences were found between the two groups.CONCLUSION This mixture of TCM prevents the formation of intestinal stricture, increases the survivalrate and decreases intestinal obstruction rate in a rat model of chronic colitis.
作者: 刊期: 2000年第03期
AIM To study the development of D (somatostatin-secreting) and P (bombesin-secreting) cells ofproventriculus from Shao ducks at different ages.METHODS Ninety Shao ducks were divided into nine groups, 10 ducks per group. The ducks were slayedgroupby group at the nine time points of week 0 (after hatching), 1, 2, 4, 6, 10, 14, 18 and 22.Proventriculus samples from each duck were collected, fixed by Bouin solution and embedded with paraffin.gections were made and stained with an avidin-biotin-peroxidase complex kit (Dako Co., Ltd. ) to visualizeD and P cells of each proventriculus. Thirty glandular lobes per duck were observed for enumeration of Dand P cells.RESULTS ① Both D and P cells were mostly oval or polygonal shape with dumpy cytoplasmic processesand located in the inner and central area of the glandular lobe. ② The D and P cells peaked at wk 18 and 6respectively. ③ There was no apparent correlation between D cells and the body weight until wk 4. Negativecorrelation was observed from wk 6 and reached a marked level at 18wk (r = -0.829, P<0.05).Individuals with maximum body weight had less D cells than those with minimum body weight from wk 10-wk 18.CONCLUSION The morphology and distribution of D and P cells in the proventriculus of Shao ducks weresimilar to Peking ducks, gooses and chickens. Both D and P cells had continuing development during thepostnatal period, though the rates of their development were different. If appeared that beyond a definitenumber of D cells, they were negatively correlated with the body weight.
作者: 刊期: 2000年第03期
AIM To investigate the expression of endothelial NO synthase (eNOS), inducible NO synthase (iNOS)protein and eNOS mRNA gene in the splanchnic organs of liver cirrhosis and portal hypertensive rats.METHODS In control and CCl4-induced liver cirrhotic rats, the expression of eNOS and iNOS proteins wasdetected by immunohistochemical method, and eNOS mRNA was detected by in situ hybridization.RESULTS The expression of eNOS protein and eNOS mRNA increased in most organs of the cirrhotic rats,including bronchial and alveolar epithelial cells, renal tubular epithelial cells and mesenchyma, endothelialand adventitial cells of aorta and superior mesenteric artery, whereas no significant increase of iNOS proteinwas found. In the hepatic tissue, NOS protein and eNOS mRNA were present in mesenchymal cells and vesseladventitial cells, no difference was observed in the expression between control and cirrhotic rats.CONCLUSION The expression of NOS varied in region. In splanchnic organs and vasculars there was anincreased expression of eNOS which induced aplanchnic vasodilation and increased the inflow of portal vein,while in the liver tissue and blood vessel showed no increased expression, which may be associated withincreased intrahepatic vascular resistance.
作者: 刊期: 2000年第03期
AIM To increase the production of recombinant des (1 - 3) IGF- I by increasing the copy number of genecarried on an expression vector, and to partially purify the expressed des (1 - 3) IGF-Ⅰ , as well as compareits bio-activity with standard IGF-Ⅰ.METHODS Second copy of des (1 - 3) IGF-Ⅰ gene was inserted into pExSecl/IGF-Ⅰ expression vectorconstructed by our previous work and carryed already one des (1 -3) IGF-Ⅰ gene, to form PExSec1/2 (IGF-Ⅰ) expression plasmid, which carried two copies of tandem des (1 - 3) IGF-Ⅰ gene. This plasmid wastranformed into a protease-deficient E. coli strain BL21 (DE3). The engineered bacteria was cultured andinduced at low temperature. The expressed product was purified through ultra-filtration and gel-filtration.The bio-activity of partially purified protein was tested by MTT method and compared with standard IGF-Ⅰ.RESULTS The amount of des (1-3) IGF-Ⅰ expressed by pExSec 1/2 (IGF-Ⅰ) reached up to 19% -22%of the total soluble bacterial protein, which is about 7% higher than that of des (1 -3) IGF-Ⅰ expressed bypExSec1/IGF-Ⅰ. The purity of recombinant des (1 - 3) IGF-Ⅰ reached 49% and 82% respectively after thetreatments by ultra-filtration and gel-filtration. The result of MTT assay showed that the bio-activity of des(1- 3) 1GF-I after gel-filtration was about 77% of that of standard IGF-Ⅰ at the same concentration.CONCLUSION The yield of recombinant des (1 - 3) IGF-Ⅰ was increased about 7% by construction ofexpression plasmid with two copies of des (1 -3) IGF-Ⅰ gene, compared with only one copy of gene,preliminarily purified des (1 -3) IGF-Ⅰ showed relatively high biological activity, which was about 77% ofthat of standard IGF-Ⅰ.
作者: 刊期: 2000年第03期