[Comparison of different reconstruction procedures after distal gastrectomy in patients with gastric cancer].

Objective: To systematically compare the effect of Roux-en-Y with Billroth Ⅰ or Billroth Ⅱ in gastric cancer patients after distal gastrectomy by meta-analysis. Methods: Systematic search was conducted on the relevant electronic databases of Pubmed, Embase, Wanfang Database, CNKI and VIP from the established time to August 18, 2019. The randomized controlled trials about comparison of Roux-en-Y with Billroth Ⅰ or Billroth Ⅱ were strictly screened and analyzed by the software of Revman 5.3. Procedure and postoperative outcomes were analyzed, respectively. Results: A total of 783 relevant literatures were systematically retrieved, and 6 randomized controlled trials, including 954 patients, finally met the inclusion criteria after strict screening. The results of meta-analysis showed that operative time of Billroth Ⅰ was significantly shorter than that of Roux-en-Y (MD=-37.60, 95%CI:-50.79--24.40, P<0.001), intraoperative bleeding (MD=-21.64, 95%CI:-32.20--11.07, P<0.001) and the number of delayed gastric emptying (RR=0.52, 95%CI: 0.31-0.86, P=0.01) of Billroth Ⅰ were both significantly less than those of Roux-en-Y, while bile reflux (RR=8.17, 95%CI: 2.21-31.53, P=0.002) and residual gastritis (RR=1.75, 95%CI:1.43-2.14, P<0.000 01) of Billroth Ⅰ were both significantly higher than those of Roux-en-Y, other outcomes showed no significant difference. Compared with Roux-en-Y, operative time of Billroth Ⅱ was significantly shorter (MD=-19.73, 95%CI:-32.82--6.64, P=0.003), while bile reflux (RR=17.63, 95%CI: 4.50-69.02, P<0.001), residual gastritis (RR=1.94, 95%CI:1.15-3.26, P=0.01) and reflux esophagitis (RR=3.13, 95%CI: 1.31-7.45, P=0.01) of Billroth Ⅱ were all significantly higher, and there was no significant difference in other outcomes. Conclusion: Compared with Billroth Ⅰ and Billroth Ⅱ, the operation time of Roux-en-Y in gastric cancer patients undergoing distal gastrectomy is longer, but the incidences of bile reflux and residual gastritis are both lower, and the postoperative quality of life seems better.

[A meta-analysis of perioperative hyperoxia for the surgical site infections in patients with general surgery].

OBJECTIVE: To systemically analyze the effect of perioperative hyperoxia for the surgical site infections in patients with general surgery. METHODS: Electronic databases consisting of Pubmed, Embase, Cochrane Library, Wanfang Database, CNKI and VIP were systemically searched from established time to November 18, 2015. The randomized controlled trials about perioperative high and low-concentration oxygen for the surgical site infections in patients with general surgery were screened strictly and analyzed by the software of Revman 5.3. The included trials were stratified according to the colorectal or non-colorectal surgery, the duration of oxygen inhalation and the kinds of mixed gas to perform subgroup analyses. Sensitivity analysis was conducted by removing the low-quality trials, etc. The outcome was the surgical site infections. RESULTS: There were 989 relevant articles were searched out. At last, 9 randomized controlled trials consisting of 3 281 patients were included. The 80% oxygen group and 30% oxygen group consists of 1 644 and 1 637 patients, respectively. The rates of surgical site infection were 15.1% (248/1 644) and 17.5% (286/1 637) in the two group. Heterogeneity existed between the included trials and random-effect model was used, the RR=0.80, 95%CI: 0.60-1.08, P=0.15. Therefore, statistically significant difference was not found for the surgical site infections in the general surgery between the perioperative high and low-concentration oxygen. However, the results of subgroup analyses showed that the perioperative hyperoxia decreaced the surgical site infections significant in the subgroups of colorectal surgery and intraoperative plus postoperative 6 h oxygen inhalation. CONCLUSIONS: Perioperative hyperoxia does not reduce surgical site infections in patients with general surgery. However, the results of two subgroup analyses (colorectal surgery and intraoperative plus postoperative 6 h oxygen inhalation trials) show a significantly benefit for perioperative hyperoxia in decreasing surgical site infections.

[DOTAP liposome-mediated transfection of human adipose-derived stemcells with pIRES2-EGFP-VEGF plasmid and target gene expression].

Objective:To explore liposome-mediated transfection of human adipose-derived stem cells (hASCs) with vascular endothelial growth factor(VEGF) gene and to investigate the expression of VEGF after transfection.Method:Lipoaspirate was digested using collagenase.Cell pellet was harvested and subcultured to passage 4.Phenotype was detected with flow cytometry and multilineage differentiation was induced for the identification of hASCs.hASCs was transfected with pIRES2-EGFP-VEGF plasmid using DOTAP liposome.The intracellular expression of VEGF was detected by immunofluorescent staining and the VEGF concentration in supernatant was analyzed by ELISA.Result:1 ml lipoaspirate yielded(4.38±0.21)×105 cells.hASCs on passage 4 showed high expression of CD90(81.49%) and low expression of CD19(6.37%),CD31(14.91%),CD34(17.56%) and CD45(15.39%).GFP and VEGF were observed in transfected hASCs.The transfection efficiency was(43.69±18.53)%.Untransfected hASCs did not express GFP but low level of VEGF.The optical density of VEGF intransfected hASCs is 2.13 fold of untransfected hASCs.The VEGF concentration in supernatant of transfected hASCs significantly increased over time and exhibit statistic differences compared with untransfected hASCs(P<0.05).Conclusion:hASCs were successfully transfected with pIRES2-EGFP-VEGF plasmid using DOTAP liposome.The post-transfection expression and secretion of VEGF remarkably increased.

Detection and prevalence of pathogenic Yersinia enterocolitica in refrigerated and frozen dairy products by duplex PCR and dot hybridization targeting the virF and ail genes.

Pathogenic Yersinia enterocolitica is involved in yersiniosis through expression of chromosome-borne or plasmid-borne virulence factors. Yersinia enterocolitica is a cold-tolerant pathogen frequently isolated from refrigerated or frozen foods. However, little attention has been focused on the prevalence of pathogenic Y. enterocolitica in refrigerated or frozen dairy samples in China. In this study, we developed a new duplex PCR targeting the plasmid-borne virF gene and chromosome-borne ail gene for detection of pathogenic Y. enterocolitica isolates. We established a detection limit for the duplex PCR of 6.5 × 10(2)cfu/mL in artificially contaminated dairy samples. In addition, the duplex PCR could detect directly 4.5 to 5.7 cfu of Y. enterocolitica in 5 mL of brain heart infusion broth after 6 h of enrichment at 28 °C. A newly developed dot hybridization assay further confirmed specificity of the duplex PCR for detection of virulent Y. enterocolitica. Furthermore, 13 Y. enterocolitica and 5 pathogenic strains, from 88 commercial frozen or refrigerated dairy products, were detected successfully by the China National Standard method (GB/T4789.8-2008) and the duplex PCR, respectively. Finally, biotypes and serotypes of pathogenic Y. enterocolitica strains were further characterized. The duplex PCR developed here is reliable for large-scale screening, routine monitoring, and risk assessment of pathogenic Y. enterocolitica in refrigerated or frozen dairy products.

Down-regulation of TCF21 is associated with poor survival in clear cell renal cell carcinoma.

Transcription factor 21 (TCF21) has been identified as a candidate tumor suppressor at 6q23-q24 that is epigenetically inactivated in many types of human cancers. We recently found that TCF21 methylation level was significantly increased in clear cell renal cell carcinoma (ccRCC). The purpose of this study was to investigate the prognostic impact of TCF21 expression in ccRCC and analyze the relationship between TCF21 expression and methylation level. We used real-time PCR and immunohistochemical staining to detect the expression of TCF21, and used methylation specific-PCR (MS-PCR) to determine the methylation status of TCF21 in ccRCC samples and cell line 786-O. The results showed that TCF21 expression level in ccRCC samples was significantly lower than in normal adjacent tissue samples (NAT samples). The Kaplan-Meier survival analysis demonstrated that TCF21 was a significant prognosticator of cancer-specific survival (p=0.001). Furthermore, the DNA demethylating agent 5'-azacytidine restored part of TCF21 expression by suppressing TCF21 methylation in 786-O. The methylation level of TCF21 in ccRCC samples was much higher than in NAT samples. These results suggest that the expression of TCF21 was an independent prognostic factor for poor survival in patients with ccRCC. Aberrant methylation was an important reason for the down-regulation the expression of TCF21, and may be associated with tumorigenesis in ccRCC.

Bioresorbable microporous stents deliver recombinant adenovirus gene transfer vectors to the arterial wall.

The use of intravascular stents as an adjunct for percutaneous transluminal revascularization is limited by two principal factors, acute thrombosis and neointimal proliferation, resulting in restenosis. To overcome these limitations, we have investigated the potential of microporous bioresorbable polymer stents formed from poly(L-lactic acid) (PLLA)/poly(epsilon-caprolactone) (PCL) blends to function both to provide mechanical support and as reservoirs for local delivery of therapeutic molecules and particles to the vessel wall. Tubular PLLA/PCL stents were fabricated by the flotation-precipitation method, and helical stents were produced by a casting/winding technique. Hybrid structures in which a tubular sheath is deposited on a helical skeleton were also generated. Using a two-stage solvent swelling technique, polyethylene oxide has been incorporated into these stents to improve hydrophilicity and water uptake, and to facilitate the ability of these devices to function as drug carriers. Stents modified in this manner retain axial and radial mechanical strength sufficient to stabilize the vessel wall against elastic recoil caused by vasoconstrictive and mechanical forces. Because of the potential of direct gene transfer into the vessel wall to ameliorate thrombosis and neointimal proliferation, we have investigated the capacity of these polymer stents to function in the delivery of recombinant adenovirus vectors to the vessel wall. In vitro, virus stock was observed to readily absorb into, and elute from these devices in an infectious form, with suitable kinetics. Successful gene transfer and expression has been demonstrated following implantation of polymer stents impregnated with a recombinant adenovirus carrying a nuclear-localizing betaGal reporter gene into rabbit carotid arteries. These studies suggest that surface-modified polymer stents may ultimately be useful adjunctive devices for both mechanical support and gene transfer during percutaneous transluminal revascularization.

Influence of cardiopulmonary bypass on platelet and neutrophil accumulations in internal organs.

The authors employed gamma scintigraphy to quantify the post bypass accumulations of platelets and neutrophils in the lung, liver, and heart of adult pigs subjected to a standard 90 min regimen of normothermic cardiopulmonary bypass (CPB). Coated and uncoated microporous polypropylene oxygenator circuits were studied for Cobe Duo (Arvada, CO) oxygenators (amphophilic silicone-caprolactone oligomer [SMA] coating, n = 8 each) and Medtronic Maxima (Irvine, CA) oxygenators (Carmeda heparin coating, n = 5 each). Images of cells in the organs (deposited + blood pool) were corrected for tissue absorption and other factors and compared for a 2 hr period post CPB, using repeat measures ANOVA and rank tests. Platelet accumulations in internal organs correlated positively with whole blood platelet counts and negatively with platelet deposits in oxygenators during CPB. In general, uncoated CPB circuits significantly reduced platelet and neutrophil accumulations in lung, liver, and heart versus preCPB controls for the post CPB interval, for both systems. The SMA treatment significantly increased platelet accumulations versus uncoated controls in lung, liver, and heart for the 2 hr period, including the majority of the post CPB sampling intervals; platelet densities did not reach preCPB levels. Neutrophil accumulations were unaffected by the SMA coating. Carmeda heparin treatment significantly increased platelet accumulations in the liver, but not lung or heart. Despite preservation of circulating neutrophils observed with the Carmeda heparin treatment, neutrophil accumulations in internal organs were not elevated post CPB.

Improved bioresorbable microporous intravascular stents for gene therapy.

Drug imbibing microporous stents are under development at a number of centers to enhance healing of the arterial wall after balloon coronary angioplasty procedures. The authors improved the mechanical strength and reservoir properties of a biodegradable microporous stent reported to this Society in 1994. A combined tubular/helical coil stent is readily fabricated by flotation/precipitation and casting/ winding techniques. A two stage solvent swelling technique allows precise adjustment of the surface hydrophilic/hydrophobic balance. These developments permit seven-fold improvement in drug capacity without significantly altering mechanical properties. Stents modified in this manner retain tensile and compressive strength and are suitable for remote deployment. Elution kinetics of these modified stents suggest they are suitable for gene delivery. Successful gene transfer and transmural expression have been demonstrated after implantation of stents impregnated with a recombinant adenovirus carrying a nuclear localizing beta-galactosidase reporter gene into rabbit carotid arteries. These studies suggest that surface modified, bioresorbable polymer stents ultimately may be useful adjunctive devices for gene transfer during percutaneous transluminal revascularization.

p53 mutations, O6-alkylguanine DNA alkyltransferase activity, and sensitivity to procarbazine in human brain tumors.

BACKGROUND: In human brain tumors, sensitivity to procarbazine as measured by sensitivity in a xenograft tumor model correlated inversely with amounts of the DNA repair enzyme O6-alkylguanine DNA alkyltransferase (AT). METHODS: To test the hypothesis that mutations of the p53 tumor suppressor gene in human tumors also can correlate with the response to chemotherapy, p53 mutations2 were identified in primary human malignant brain tumors and cell lines in which AT activity and procarbazine sensitivity in a xenograft model was ascertained. RESULTS: Mutations were identified in 7 of 21 (33%) specimens tested. Specimens containing p53 mutations tended to exhibit an increased growth delay in procarbazine-treated xenografts and lower amounts of AT. CONCLUSIONS: p53 mutations in brain tumors may contribute to procarbazine sensitivity by failing to induce arrest at the G1/S cell-cycle checkpoint, thereby preventing the repair of procarbazine-induced genetic alterations.

Allelic loss at chromosomes 3p, 8p, 13q, and 17p associated with poor prognosis in head and neck cancer.

BACKGROUND: Little is known about the molecular genetic events that contribute to the pathogenesis of squamous cell carcinoma of the upper aerodigestive tract. Previous molecular genetic studies have been limited to the identification of mutations of the p53 (also known as TP53) tumor suppressor gene, activation of a limited set of oncogenes, allelic loss at 3p and other locations, and occasional association with human papillomavirus infection. PURPOSE: Our purpose was to screen tumor tissue and blood from patients with squamous cell carcinoma of the upper aerodigestive tract for loss of heterozygosity at polymorphic loci corresponding to each of the autosomal chromosomes and to identify the locations of additional putative tumor suppressor genes, other than RB (also known as RB1) and p53, that may contribute to the pathogenesis of this disease. METHODS: Tumor tissue and blood were obtained from 68 consecutive patients with squamous cell carcinoma of the upper aerodigestive tract. In all cases, tumor tissue was obtained from the center of the surgical specimen. The relative absence of non-neoplastic tissue was confirmed by frozen-section histologic examination of immediately adjacent tissue. Initially, 30 paired tissue and blood samples were tested for loss of heterozygosity by polymerase chain reaction (PCR) to amplify 43 different highly polymorphic sequences containing small oligonucleotide repeats. After PCR amplification, with unique oligonucleotides flanking the repeat, visualization and sizing of the alleles on DNA sequencing gels were performed. Specific loss of heterozygosity was distinguished from random genetic loss due to generalized chromosomal instability if it occurred in more than 20% of specimens tested for a particular marker. RESULTS: Significant loss of heterozygosity (> 20%) occurred at alleles at chromosome bands 3p21 (32%), 3p25-26 (56%), 8pter-21.1 (31%), 13q14 (27%), and 17p12 (45%). Loss of heterozygosity at more than two loci was significant with a poor prognosis (P = .039). CONCLUSIONS: These findings demonstrate that squamous cell carcinoma of the upper aerodigestive tract exhibits genetic alterations at multiple loci and that allelic loss at more than two locations is indicative of a poor prognosis (the likelihood of the patient dying of disease). IMPLICATIONS: While tumor suppressor genes at 3p (VHL), 13q (RB), and 17p (p53) have been identified, altered genes at other loci on 3p and on 8p have not yet been characterized. Furthermore, the genotype at these loci for squamous cell carcinoma of the upper aerodigestive tract has prognostic importance and may identify the patients who should receive the most aggressive treatment.

p53, retinoblastoma, and human papillomavirus in squamous cell carcinoma and adjacent normal mucosa of the upper aerodigestive tract.

OBJECTIVE: The primary objective of this study was to determine the incidence of p53 and retinoblastoma tumor suppressor gene mutations and human papillomavirus infection in squamous cell carcinoma and adjacent normal mucosa of the upper aerodigestive tract. The secondary objective was to associate these findings with clinical and histopathologic features. DESIGN: Point mutations of p53 were identified by single-strand conformation polymorphism analysis and confirmed by direct DNA sequence analysis. Polymerase chain reaction-based methods were used to identify loss of heterozygosity of the retinoblastoma tumor suppressor gene and the presence of human papillomavirus sequences. SETTING: University-based tertiary care center. PATIENTS OR OTHER PARTICIPANTS: Forty-five consecutive cases of upper aerodigestive tract squamous cell carcinoma. RESULTS: Eleven point mutations of p53 were identified in tumor samples (24%). No functional p53 mutations were detected in adjacent normal tissue from eight of these individuals nor was there evidence of p53 alteration in normal tissue adjacent to 12 of 30 additional tumors tested that demonstrated conformational alterations by single-strand conformation polymorphism analysis. The p53 mutations were significantly associated with local invasion. Loss of heterozygosity (which has a 20% chance of random occurrence in tumors) was detected at the retinoblastoma locus in 15% of the tumors tested. Five of the specimens (11%) were positive for human papillomavirus sequences (two of which also contained p53 mutations). CONCLUSIONS: These findings suggest that p53 but not retinoblastoma or human papillomavirus is an important prognostic factor and is involved as a late event in the pathogenesis of upper aerodigestive tract squamous cell carcinoma.