Application of modified no-touch technique in rabbit arteriovenous fistula model and its effect on venous neointimal hyperplasia.

BACKGROUND: To investigate the technical advantages of a modified no-touch technique (MNTT) in constructing arteriovenous fistulas (AVF) compared to the conventional technique (CT) and assess its potential to reduce neointimal hyperplasia in the outflow vein. METHODS: Forty-seven New Zealand rabbits were randomly divided into three groups: control, CT, and MNTT. Rabbits in control group were observed using ultrasound and then euthanized to obtain external jugular vein (EJV) for Hematoxylin-eosin (H-E). We established common carotid artery (CCA)-EJV AVF using MNTT in the MNTT group and the CT in the CT group. AVF patency and complications were compared between the CT and MNTT groups. Rabbits with patent AVF in both groups were observed using ultrasound 2 weeks after surgery to evaluate changes in the vessel diameter and blood flow spectrum of the AVFs. H-E staining measured the intima thickness of EJV adjacent to the anastomosis and histologic characteristics of the AVF at 2 and 4 weeks after surgery. RESULTS: Five rabbits died after surgery with common symptoms of sneezing, coughing, runny nose, anorexia, and diarrhea; two in the MNTT group and three in the CT group. There were significant differences in the diameter (p = 0.010) and peak systolic velocities (PSV) (p = 0.001) of EJV between the CT and MNTT groups 2 weeks after surgery. Spiral laminar flow (SLF) was observed in CCA and EJV adjacent to anastomosis in the MNTT group. Additionally, histological observations showed less venous neointimal hyperplasia in the MNTT group than in the CT group 4 weeks after surgery. CONCLUSION: The rabbit model of CCA-EJV AVF established using MNTT demonstrated fewer complications, larger vein diameters, and reduced venous neointimal hyperplasia, indicating that this maybe an ideal animal model to further investigate the application of MNTT in AVF surgery.

MicroRNA-296-5p inhibits cell proliferation by targeting HMGA1 in colorectal cancer.

An increasing body of evidence indicates the involvement of microRNAs (miRNAs/miRs) in the initiation and progression of colorectal cancer (CRC). miR-296-5p was recently identified as a tumor suppressor in a variety of human cancer types; however, its function in CRC remains largely unknown. The present study demonstrated that the expression of miR-296-5p was significantly downregulated in CRC tissues and cell lines. The overexpression of miR-296-5p markedly inhibited proliferation, and induced cell cycle arrest and apoptosis in CRC cells. Bioinformatics analysis suggested that high mobility group AT-hook 1 (HMGA1) may be a target of miR-296-5p in CRC cells. Further experiments showed that miR-296-5p bound the 3'-untranslated region of HMGA1 and decreased its expression in CRC cells. HMGA1 was overexpressed in CRC tissues and was inversely correlated with the expression of miR-296-5p. The restoration of HMGA1 significantly reversed the inhibitory effect of miR-296-5p on the proliferation of CRC cells. Overall, the findings of the present study indicate that miR-296-5p suppressed the progression of CRC, at least partially via targeting HMGA1. Thus, miR-296-5p is a potential target for novel therapies in CRC.

Comparison of Yang-Monti ileal ureter-bladder anastomosis versus Yang-Monti ileal ureter-ureteral anastomosis for the treatment of ureteral stenosis: a randomized controlled trial in a miniature pig model.

BACKGROUND: The aim of the present study was to establish an animal model of Yang-Monti ileal ureter-bladder anastomosis and Yang-Monti ileal ureter-ureteral anastomosis and compare the advantages and disadvantages of the two surgical methods. METHODS: Fourteen 12-month-old male Chinese miniature pigs weighing 21 ± 1.38 kg were randomly divided into two groups. Group A (n = 7) underwent end-to-end anastomosis of the left Yang-Monti ileal ureter, left ileal ureter and left lower ureter; group B (n = 7) underwent anastomosis of the left Yang-Monti ileal ureter, left ileal ureter and bladder. In both groups, the contralateral kidney was removed at 1 week postoperatively. The incision length and operation time of the two groups were compared. Changes in serum creatinine and urea nitrogen were observed preoperatively, and at 2, 6 and 12 weeks postoperatively. Venous pyelography and cystography were performed at 12 weeks postoperatively to determine the ureteral patency and vesicoureteral reflux. At 12 months postoperatively, urinary culture was performed, and the diameter and histological changes of the intestinal ureter were assessed. RESULTS: Surgery was successfully completed in all 14 pigs. In group A, one pig died due to an anesthetic accident, and one pig died from a lung infection on postoperative day 4. In group B, one pig died from adhesive intestinal obstruction on postoperative day 7. The overall survival rate was 78.6%, and the 11 surviving pigs had no urinary or intestinal fistulae. Compared with group B, group A had a significantly longer surgical incision (30.86 ± 2.41 cm versus 26.71 ± 3.64 cm; p = 0.01) and shorter operation time (181.29 ± 15.10 min versus 157.71 ± 20.49 min; p = 0.02). The serum creatinine and urea nitrogen concentrations did not significantly differ between groups. All pigs had normal renal function pre- and postoperatively. There was no stenosis or obstruction on venous pyelography. The narrowest diameter of the ureter was significantly smaller in group B (5.90 ± 0.30 mm) than in group A (7.26 ± 1.06 mm; p = 0.01), but no contrast agent returned to the upper urinary tract in either group. Escherichia coli was detected on urine culture. In group A, one pig had obstruction of the ureteral ureter, while another had stenosis of the lower ureteral anastomosis. In group B, one pig had pelvic and intestinal ureteral dilatation; however, all anastomoses were patent. The ileal ureteral diameter was significantly larger in group A (9.40 ± 2.35 mm) than group B (6.62 ± 0.37 mm; p = 0.02). Two pigs in group A had separation of the transitional epithelium and columnar epithelial mucosa, with granulation tissue hyperplasia. The pigs with stenosis and obstruction had smooth fibrous tissue and smooth muscle of the anastomosis. In both groups, the two types of epithelial tissue were close together, and the intestinal villi were mildly atrophied and shortened. CONCLUSIONS: An animal model of Yang-Monti ileal ureter-bladder anastomosis was successfully established. Compared with Yang-Monti ileal ureter-ureteral anastomosis, Yang-Monti ileal ureter-bladder anastomosis is simpler, more reliable, and results in fewer complications.

Diagnostic value of blue laser imaging combined with magnifying endoscopy for precancerous and early gastric cancer lesions.

BACKGROUND/AIMS: Blue laser imaging (BLI) is a new technique for detailed examination of upper gastrointestinal lesions. This study aimed to evaluate the diagnostic value of BLI combined with magnifying endoscopy for precancerous and early gastric cancer lesions. MATERIALS AND METHODS: A total of 249 gastric lesions detected via conventional white light endoscopy (WLE) based on assessments of mucosal shape and color were included in this study. The accuracy of diagnosis of precancerous or early cancer lesions white light magnification alone, BLI-contrast magnification, and BLI-bright magnification was determined according to the VS criteria. RESULTS: For white light magnification alone, BLI-contrast magnification, and BLI-bright magnification, the concordance rates for lesions were 76.7%, 85.1%, and 86.7%, respectively, and the Kappa values were 0.571, 0.730, and 0.760, respectively. For the screening of high-grade intraepithelial neoplasia or early gastric cancer, the diagnostic sensitivities of white light magnification alone, BLI-contrast magnification, and BLI-bright magnification were 72.0%, 92.0%, and 92.0%, respectively; the specificities were 95.5%, 98.2%, and 99.1%, respectively; the consistencies were 93.2%, 97.6%, and 98.4%, respectively; and the Kappa values were 0.642, 0.871, and 0.911, respectively. For diagnoses of high-grade intraepithelial neoplasia or early gastric cancer, the concordance between endoscopic and pathological diagnosis was significantly higher for BLI-contrast and BLI-bright magnification than for white light magnification alone (p<0.05). CONCLUSION: BLI combined with magnifying endoscopy may improve diagnostic accuracy for early gastric cancer and precancerous lesions.

PTEN inhibits the invasion and metastasis of gastric cancer via downregulation of FAK expression.

The tumor suppressor gene phosphatase and tensin homolog (PTEN) is essential in inhibiting tumor growth and metastasis. However, the mechanism by which PTEN restricts gastric cancer progression and metastasis remains largely elusive. Here we demonstrated that PTEN overexpression or knockdown in gastric cancer cells led to the downregulation or upregulation of focal adhesion kinase (FAK), and decreased or increased cell invasion, respectively. Moreover, FAK overexpression could rescue the inhibition of cell invasion by PTEN. These results were further confirmed in orthotropic gastric cancer nude mice model. In addition, in human gastric cancer tissues, PTEN protein level was conversely correlated with FAK protein level. Mechanistically, we found that PTEN inhibited PI3K/NF-κB pathway and inhibited the DNA binding of NF-κB on FAK promoter. Taken together, our data reveal a novel mechanism that PTEN inhibits the growth and invasion of gastric cancer via the downregulation of FAK expression and suggest that exploiting PTEN/PI3K/NF-κB/FAK axis is a promising approach to treat gastric cancer metastasis.