Advances in mechanism and application of the heating effect in breeding of microorganism are reviewed in this paper. Heat produces mutagenesis effect and screening effect. Heating mutagenesis effect is occurred through the substitution of G-C base pair induced by heat, and heating screening effect produces higher forward mutation rate induced by other mutagens.

Objective To evaluate the biocompatibility of vessel extracellular matrix (VECM) with bladder smooth muscle cells of rabbits,and to discuss the feasibility of vessel extracellular matrix as a matrix for urinary tract reconstruction.Methods Primary cuhured bladder smooth muscle cells (RBSMCs) iso- lated from New Zealand rabbits were implanted on VECM (1?10~6 cells/ml).The effect of VECM on meta- bolic activity,attachment,proliferation of RBSMCs were monitored in vitro by inverted light microscopy and scanning electron microscopy.The extracts of VECM and emulsion were prepared as experimental group and positive controls separately.The culture medium was used as negative control,and simple culture medium without cells was used as blank control.The cell viability was monitored by MTT method after 1-,3-,5-d see- ding.The in vivo tissue response to VECM was investigated by implanting into the subcutaneous sites of the rabbits.Results VECM exhibited nontoxic and bioactive effect on RBSMCs.RBSMCs could be attached to and proliferated on VECM and remained their morphologies.The cell proliferation rates of experimental group were 95.61%、98.34%、102.91%,respectively,after 1,3,5 d;those of negative control group were 100.00% ,respectively;and those of positive control group were 35.14%、38.95%、32.66%,respectively. There was significant difference in the rate between experimental group and positive control (P＜0.01),and no significant difference in the rate between experimental group and negative control (P＞0.05).In vivo, VECM demonstrated favorable tissue compatibility without tissue necrosis and fibrosis.Conclusions VECM exhibits nontoxic and bioactive effects on primary cultured bladder smooth muscle cells.It is a suit- able material for urinary tract reconstruction.

Gymnastics ; physiology ; Humans ; Workload

Objective To study the level of serum lipids and body-fat content of high-fat diet induced pbesity rats(DIO).explore the relationship between intracellular caleium and ventrieufar arrhythmia.Methods Sixty male Sprague-Dawley(SD)rats were divided into control group(15)and experiment group(45),high-fat diet was administrated for 12 weeks to established obesity model,15 rats were selected into obesity group according to their body weight gain.The standard 2-lead electrocardiograph was used to detect the incidence and scores of arrhythmia induced by barium chloride(BaCl2,0.1 mg/kg)for 1 hour on every 8 rats from different groups respectively.Body-fat content.the level of serum total cholesterol(TC),triglyceride(TG),low density lipopmtein cholesterol (LDL-C) and high density lipopmtein cholesterol (HDL-C)were measured.The epididymal(EP),retroperitoneal (RE) and mesenteric(ME)white adipose pads was measured to obtain the body fat content.Single ventricular myrocytes of rats were isolated by enzymatic dissociation.The confocal laser scanning microscope was used to record basic intraceUular calcium level([Ca2+]i).Results The body-fat content in obesity group[(7.71±0.74)%] was significantly higher than control group[(4.69±0.37)%](t＝3.650,P＜0.05).The level of serum TC,TGand LDL-C were significantly higher(t＝3.801,2.778,3.536.P＜0.05) in obesity group[(1.26±0.04),(0.58±0.10),(0.51±0.04)mmol/L]than those in control group[(0.92±0.08),(0.29+0.03),(0.31±0.04) mmol/L].The level of serum HDL-C wa8 decreased gradually from control group[(0.53±0.05)mmol/L] toobesity group[(0.52±0.02)mmol/L],but there waft no significant difference between them(t＝0.186,P＞0.05).The incidence of arrhythmia induced by BaCl2(0.1 mg/kg)in obesity group was significantly higher than controlgroup(X2＝5.333,P＜0.05),and the scores of arrhythmla was increased in obesity group(2.5±0.6)too.The fluorescence intensity standing for[Ca2+]i was increased significantly(t＝2.409,P＜0.05)from obesity group(247.96±20.03)to control group (174.25±23.13).Conclusion As the free cytosolic calcium begin to accumulate,the arrhythmia morbidity is increased in obesity rats.

Australia ; Environmental Monitoring ; Humans ; Occupational Health ; Safety Management ; methods ; organization & administration

OBJECTIVETo evaluate the feasibility of reconstruction of rabbit urethra using urethral extracellular matrix.

METHODSExtracellular matrix was obtained from the urethra of 20 donor New Zealand rabbits. In experimental group, 20 rabbits underwent segmental urethral resection (about 1.0 to 1.5 cm in length) and the defects were replaced by a tube of extracellular matrix. The serum TNFalpha was detected by ELISA to assess the immunity response preoperatively and 12, 24, 48 h postoperatively. The regenerated urethral segments were taken for histologic and pathologic study 10 days, 3 weeks, 6 weeks and 24 weeks after operation. The urodynamics, urethroscopy and urethrography were also performed.

RESULTSThe serum TNFalpha in experiment group slightly rised, with no significant difference when compared with that in control group. 10 days after operation, epithelial cell migrated into the extracellular matrix from two ends, and small vessels were also found. 3 weeks later, several layers of urothelium covered the whole surface of the matrix tube. 6 weeks later, the irregularly arranged smooth muscle fibers were fist observed by Van Gieson staining. 24 weeks after operation, the smooth muscle cells increased, the appearance of the regenerated urethra segments were very similar to normal urethral wall components. The urethrography and urodynamic evaluation revealed no difference between the normal and the regenerated urethral tube.

CONCLUSIONSThe urethral extracellular matrix might be an ideal replacement material for urethral defect.

Absorbable Implants ; Animals ; Biocompatible Materials ; Extracellular Matrix ; transplantation ; Male ; Rabbits ; Reconstructive Surgical Procedures ; methods ; Regeneration ; Tumor Necrosis Factor-alpha ; metabolism ; Urethra ; surgery

OBJECTIVEReview and discuss anesthesia and operative approach of resection of the trachea for different tracheal diseases, especially for the resection of long-segment of trachea. At the same time to introduce the method of reconstruction of long-segment of trachea with Zhao's (two-stage procedure with memory-alloy mesh) artificial trachea.

METHODSRetrospective study of 18 cases of tracheal resection, analysis of the relation between the choice of anesthetic and operative approach.

RESULTSGeneral anesthesia through cut open the trachea with local anesthesia in 2 cases, general anesthesia through previous tracheotomy in 2 cases, extracorporeal circulation in 2 cases, general anesthesia through endotracheal tube in 12 cases. There were no anesthetic or operative death. Local resection in 3 cases, segmental resection in 15 cases. The longest segmental resection was 8.0 cm. Primary anastomosis after segmental resection in 8 cases, Reconstruction with Zhao's artificial trachea in 7 cases. Postoperative follow-up was 5 months to 8 years. Four cases died from systemic metastasis or other reasons at 4, 11 and 12 months, respectively.

CONCLUSIONSDifferent methods of anesthetic and operative procedures should be used for different patients. Extracorporeal circulation used for patient with highest dangerous condition, or, for which could be inserted endotracheal tube by tracheotomy with local anesthesia. Conservative local resection performed only for patients with very bad general condition. Segmental resection less than 5 cm long could be reconstructed with primary reanastomosis. Resection longer than 5.5 cm could be reconstructed with Zhao's artificial trachea.

Adolescent ; Adult ; Aged ; Anesthesia, General ; methods ; Anesthesia, Local ; Artificial Organs ; Extracorporeal Circulation ; Female ; Humans ; Intubation, Intratracheal ; Male ; Middle Aged ; Prosthesis Implantation ; Retrospective Studies ; Thoracotomy ; Tracheal Diseases ; surgery ; Tracheotomy ; methods

OBJECTIVETo evaluate the clinical practice of laparoscopic rectopexy in the treatment of severe rectal prolapse.

METHODSFrom March 1998 to February 2007, 4 cases of complete rectal prolapse, including 1 male and 3 female,ranged 21-82 years old, were treated by laparoscopic rectopexy. In one case, the posterior wall of rectum was freed and elevated, and pre-rectal introcession was closed by silk suture, then the posterior wall was suspended and fixed on sacral promontory fascia, finally the sigmoid colon was fixed by sutures on the fascia of left psoas major. In other three cases, insertion of mesh was performed. Rectum was freed and elevated to the level of levalor ani. A sheet of T-shape polypropylene mesh was placed posterior to the rectum, whose lower margin was at the level of levator ani and wrapped around the rectum covering except the anterior wall. The free margin of the mesh was sutured on the muscular layer of rectum, then the mesh was put posterior to the rectum and fixed on the sacral promontory fascia by clipping to repair hernia. After that, the pelvic peritoneum was closed, and finally the sigmoid colon was fixed by sutures on the fascia of left psoas major.

RESULTSFour operation procedures were completed successfully. There was no conversion operation. The time was consumed 92.5 (80-100) min, and the bleeding amount was 6.5 (5-10) ml. No post-operative complications were found. Urine incontinence and encopresis were relieved. No recurrence and constipation was found after 2 months to 3 years follow up postoperatively.

CONCLUSIONLaparoscopic rectopexy is a safe, workable and effective procedure, which can reduce operative trauma and shorten hospitalization time.

Aged ; Aged, 80 and over ; Female ; Humans ; Laparoscopy ; Male ; Rectal Prolapse ; surgery ; Rectum ; surgery ; Young Adult

Adult ; Blood Donors ; China ; epidemiology ; Female ; Genotype ; HIV Infections ; complications ; epidemiology ; virology ; Hepacivirus ; genetics ; Hepatitis C ; complications ; epidemiology ; virology ; Humans ; Male ; Middle Aged

BACKGROUNDUrethral reconstruction for both congenital and acquired etiologies remains a challenge for most urologic surgeons. Tissue engineering has been proposed as a strategy for urethral reconstruction. The purpose of this study was to determine whether a naturally derived extracellular matrix substitute developed for urethral reconstruction would be suitable for urethral repair in an animal model.

METHODSA urethral segmental defect was created in 20 male rabbits. The urethral extracellular matrix, obtained and processed from rabbit urethral tissue, was trimmed and transplanted to repair the urethral defect. Then, the regenerated segment was studied histologically by haematoxylin-eosin staining and Van Gieson staining at 10 days, 3 weeks, 6 weeks, and 24 weeks postoperation. Retrograde urethrography was used to evaluate the function of the regenerated urethras of 4 rabbits 10 and 24 weeks after the operation. The urodynamics of 4 rabbits from the experimental group and control group I were assessed and compared. In addition, 4 experimental group rabbits were examined by a urethroscope 24 weeks after the operation.

RESULTSAt 10 days after operation, epithelial cells had migrated from each side, and small vessels were observed in the extracellular matrix. The matrix and adjacent areas of the host tissue were infiltrated with inflammatory cells. The epithelium covered the extracellular matrix fully at 3 weeks postoperation. Well-formed smooth-muscle cells were first confirmed after 6 weeks, at which point the inflammatory cells had disappeared. At 24 weeks postoperation, the regenerated tissue was equivalent to the normal urethra. Urethrography and urodynamic evaluations showed that there was no difference between normal tissue and regenerated tissue.

CONCLUSIONSUrethral extracellular matrix appears to be a useful material for urethral repair in rabbits. The matrix can be processed easily and has good characteristics for tissue handling and urethral function.

Animals ; Extracellular Matrix ; metabolism ; Rabbits ; Tissue Engineering ; methods ; Urethra ; pathology ; surgery