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Objective:To study the feasibility of establishing gastrointestinal anastomosis by magnetic compression technique in rabbits.Methods:Ten healthy New Zealand rabbits were selected as models for gastrointestinal anastomosis by magnetic compression technique. Daughter and parent magnets suitable for gastrointestinal anastomosis in rabbits were designed and manufactured. A daughter magnet was inserted into the stomach through the purse fistula in the lack of blood vessel area of gastric body, and was pushed into the duodenum along the intestinal tract. And then a parent magnet was inserted through the stomach fistula. The daughter and parent magnets were automatically attracted and pressed the gastric and intestinal walls after they were adjusted in the proper position. The stomach fistula was closed with purse string suture. After ischemia, necrosis, detachment of the tissues between magnets, gastrointestinal anastomosis was established, and the magnets and necrotic tissues were expelled together from the body through the digestive tract. Survival of experimental animals was observed. Anastomotic specimens were obtained one month after operation. The blasting pressure of anastomotic stoma was measured, and the healing of anastomotic stoma was observed with naked eyes.Results:According to the pre-designed operative route, 10 New Zealand rabbits all successfully completed the operation and survived one month after surgery. No complications occurred during perioperative period. The operation time was 35.80±4.71 min (range 28.00-43.00 min), and the magnet discharge time was 11.40±1.56 days (range 9.00-14.00 days). Anastomotic specimens were obtained one month after the operation. Gross observation showed that the anastomotic stoma of gastrointestinal bypass anastomosis healed well, and the surrounding tissues adhered slightly. The anastomotic bursting pressure was 103.00±7.95 mmHg (range 94.00-113.00 mmHg) (1 mmHg=0.133 kPa).Conclusion:The establishment of gastrointestinal anastomosis by magnetic compression technique in rabbits is simple and effective.
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Objective:To design magnets to locate colorectal neoplasms based on magnetic tracer technology, and to test its feasibility and safety by animal experiments.Methods:The magnets used for endoscopic localization of colorectal tumors consist of a tracer magnet and a pursuit magnet, both of which are ring-shaped Nd-Fe-B magnets. Eight healthy Beagle dogs were used as animal models. Tumor locations were assumed in the different parts of the colon and rectum under colonoscopy. The tracer magnet was sent to the hypothetical tumors by endoscopic soft tissue clamp and fixed near the tumors. After 24 hours, laparoscopic surgery was performed under general anesthesia. The pursuit magnet was inserted near the resected colon or rectum through the main operating hole. The tracer magnet was absorbed to the pursuit magnet to identify the location of tumors.Results:The tracer magnet and pursuit magnet were successfully designed and processed. The suction force between the tracer magnet and the pursuit magnet at zero distance was 16 N. All the 8 Beagle dogs successfully received indwelling of magnets under colonoscopy, and no magnets fell off after 24 hours. After the placement of pursuit magnet under laparoscopy, the two magnets attracted each other rapidly and accurately, and successfully completed localization of tumor site without any damage during the operation.Conclusion:Colonoscopy combined with laparoscopy for colorectal neoplasms localization based on magnetic tracer technique is simple, accurate, safe and feasible.
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Objective To verify the feasibility and safety of stomach tumor marker localization based on magnetic tracer technique in dogs.Methods Six male Beagle dogs were examined by gastroscopy.Then tracer magnets were sent to the "tumor" locations assumed in advance and fixed near the "tumors" by endoscopic soft tissue clamp.Laparoscopic gastric tumor localization was performed under general anesthesia 24 hours later.The tracer magnet was placed near the tumor on the surface of the stomach through the operating hole after the conventional establishment of laparoscope puncture parallel mirror to explore the tracer magnet.After the two magnets were attracted,the location of the tracer magnet seen under the laparoscope was the location of the gastric tumor,so as to complete the labeling and positioning of the lesion.Results All the 6 Beagle dogs were successfully implanted with tracer magnets under gastroscopy.Twenty-four hours after the gastroscopy,the pursuit magnet was successfully implanted during laparoscopic surgery.The two magnets automatically attracted each other and formed a sandwich structure of "tracer magnet-gastric wall-pursuit magnet ",which completed the location and identification of gastric tumor under the laparoscopy.Conclusion Gastroscopy combined with laparoscopy based on magnetic tracer technique is simple,accurate,safe and feasible.
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Objective:Investigated the effect of recombinant urease A subunit and catalase vaccines on protection against Helicobacter pylori (HP) infection Methods:Recombinant plasmids expressing UreA or KatA were constructed Expression was induced with IPTG,analyzed by SDS PAGE and Western blot UreA and KatA were purified with Bulk GST purification module Results:The recombinant plasmids could express GST UreA and GST KatA fusion proteins,which accounted for 35% and 19% of total bacteria proteins respectively,and could specially react with antibody against GST The purity of the purified UreA and KatA was over 95% Conclusion:The work laid a foundation for further studies of HP vaccine The recombinant vaccines may play an important role in preventing and treating HP infection and related diseases
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Objective Compared with corresponding monovalent vaccine and pure vaccine vector, live attenuated Salmonella typhimurium expressing bivalent antigens of Helicobacter pylori (H. pylori) , UreB/HpaA was constructed by introducing a flexible and tenacious linker into urease subunit B (UreB) and HpaA of H. pylori and its protection against H. pylori infection in mice was then investigated. Methods UreB/hpaA fusion gene was amplified form H. pylori genomic DNA using sequence overlap extension PCR (SOE-PCR). UreB/HpaA bivalent live vaccine was constructed using attenuated Salmonella typhimurium vaccine vector SL3261, and its stability in vivo was observed in C57BL/6 mice. Evaluation of protection against H. pylori infection was performed in native female C57BL/6 mice by oral immunization with a single dose of the live SL3261 vaccine strain expressing UreB/HpaA (10 8 CFU). Results Sequencing results showed that encoding sequence (GGTGGAGGC) of three glycine residues was inserted into the position between ureB and hpaA fusion gene as an adapter. Bivalent live vaccine strain could be recovered from spleen and Peyer's patches for a longer time (at least 10 days). Bivalent live vaccine induced marked elevation of the levels of serum specific IgG1 and IgG2A in mouse. The immune protection rate of UreB and HpaA bivalent live vaccine was 77.3% (17/22). However only 50.0% (12/24) of the mice immunized with SL3261 vaccine strain expressing UreB and 43.5% (10/23) of the mice immunized with SL3261 vaccine strain expressing HpaA were completely protected against H. pylori challenge. Conclusions Oral immunization of mice with bivalent UreB/HpaA live vaccine could induce protective immunity against H. pylori , and the protection rate of bivalent vaccine appears to be higher than that of monovalent vaccine.
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Objective To investigate the effects of oral recombinant attenuated Salmonella ophimurium urease B subunit and catalase in the treatmeat of H.pylori infection in a H.pylori infected mouse model. Methods Thirty C57BL/6 mice were randomized into three groups and challenged twice by oral administration of H.pylori in three days. Four weeks after the second challenge, the mice were immunized by oral administration of recombinant attenuated Salmonella typhimurium urease B subunit (group A), recombinant attenuated Salmonella typhimurium catalase (group B), or saline (group C) respectively, and all mice were sacrificed 4 weeks after the immunization. The stomachs were collected for rapid urease test, modified Giemsa stain and quantitative culture to observe the gastric H.pylori densities, and HE stain was performed to assess the presence of inflammation. Lymph cells from the spleens were served for lymphoproliferation assay. Results Gastric H.pylori densities of group A, B and C were 1.58?10 5 CFU/g, 4.88?10 5 CFU/g and 1.92?10 6CFU/g respectively. H.pylori densities of therapeutic groups were significantly decreased ( P
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Objective To evaluate the diagnostic potential of capsule endoscopies (CE) for suspected small bowel diseases. Methods From September 2002 to June 2003, 23 patients (12 males, 11 females ) , age ranged 10 to 75 years old, with suspected small bowel diseases, were referred to our department to perform CE using Given M2A Video Capsule System. All patients had undergone previous negative endo-scopic evaluation at least once with esophago-gastro-duodenoscopy and total colonoscopy. Additional diagnostic work-up including small bowel enteroclysis, selective angiography, scintigraphy and puch enteroscopy, were performed, totally 36 procedures. Two endoscopists independently reviewed capsule images to arrive a consensus diagnosis. The initial diagnostic yield was quantified, and the value of CE was assessed. Of the 23 patients, 18 suffered from obscure gastrointestinal bleeding, 3 abdominal pain, and 2 chronic diarrhea. Results Twenty-four studies in 23 patients were evaluated. During CE patients have not complained of any uncomfortable feeling, only one patient had repeated the procedure because the capsule lodged at the inferior segment of esophagus near the Z line. Of the 23 patients, 20 had positive findings with a diagnostic yield of 86. 8% . The positive findings included inflammatory lesions in 10 patients (Crohns disease 7 , aphthous ulcer 3 ) , vascular abnormalities 9 ( phlebectasis 6, angioma 2, angiodysplasia 1) , submucosal nodulation 2 , diverticula 2, jejunal stromal tumor 1. Four of 23 patients had more than one lesion. Diagnosis of 6 patients was confirmed by surgery and /or pathology. Nineteen capsules passed in the direction with the camera facing forward, while the other 4 backward. Generally, it delayed in passing through the pylorus and ileocecal valves. Capsules reached cecum in 17 patients (73. 9% ) . Conclusion CE provided clearly the small intestinal images, and is an efficient tool in diagnosing small bowel diseases with a high diagnostic yield.
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AIM: To study the role of endothelin-1 (ET-1) in portal hypertension (PHT) induced by endotoxin. METHODS: Collagenase in situ perfusion was adopted to separate hepatic stellate cells (HSCs). HSCs was cultured on concretized collagen. ET-1 anti-sense oligonucleotide was added into the culture medium and then LPS was also added up to the concentration of 1 000 ?g/L. The diameters of the concretized collagen were measured. Sense and mis-sense oligonucleotide were applied as control. ET-1 in the culture medium was detected by radioimmunoassay and ET-1 mRNA in HSCs was detected by RT-PCR. ?-actin of HSCs was detected by Western blotting. RESULTS: The diameter of concretized collagen on which HSCs pretreated with ET-1 anti-sense oligonucleotide was 93.3%?3.8% the size of the primary. The diameter of concretized collagen of the control groups were 70.1%?4.8% and 70.5%?3.9% (P