Laparoscopy is non-inferior to open surgery for rectal cancer: A systematic review and meta-analysis.

BACKGROUND: Laparoscopic surgery has been endorsed by clinical guidelines for colon cancer, but not for rectal cancer on account of unapproved oncologic equivalence with open surgery. AIMS: We started this largest-to-date meta-analysis to comprehensively evaluate the safety and efficacy of laparoscopy in the treatment of rectal cancer compared with open surgery. MATERIALS & METHODS: Both randomized and nonrandomized controlled trials comparing laparoscopic proctectomy and open surgery between January 1990 and March 2020 were searched in PubMed, Cochrane Library and Embase Databases (PROSPERO registration number CRD42020211718). The data of intraoperative, pathological, postoperative and survival outcomes were compared between two groups. RESULTS: Twenty RCTs and 93 NRCTs including 216,615 patients fulfilled the inclusion criteria, with 48,888 patients received laparoscopic surgery and 167,727 patients underwent open surgery. Compared with open surgery, laparoscopic surgery group showed faster recovery, less complications and decreased mortality within 30 days. The positive rate of circumferential margin (RR = 0.79, 95% CI: 0.72 to 0.85, p < 0.0001) and distal margin (RR = 0.75, 95% CI: 0.66 to 0.85 p < 0.0001) was significantly reduced in the laparoscopic surgery group, but the completeness of total mesorectal excision showed no significant difference. The 3-year and 5-year local recurrence, disease-free survival and overall survival were all improved in the laparoscopic surgery group, while the distal recurrence did not differ significantly between the two approaches. CONCLUSION: Laparoscopy is non-inferior to open surgery for rectal cancer with respect to oncological outcomes and long-term survival. Moreover, laparoscopic surgery provides short-term advantages, including faster recovery and less complications.

[A/G polymorphism at position 49 in exon 1 of CTLA-4 gene in Chinese women with unexplained recurrent spontaneous abortion].

OBJECTIVE: To investigate whether A/G polymorphism at position 49 in exon 1 of cytotoxic T lymphocyte antigen-4 (CTLA-4) gene confers the susceptibility to unexplained recurrent spontaneous abortion in Chinese population. METHODS: One hundred and sixty-eight restrictive Chinese women with unexplained recurrent spontaneous abortion (URSA) and 117 women with normal pregnancy as control were included in this study. Polymerase chain reaction restrictive fragment length polymorphism (PCR-RFLP) was used to detect the polymorphism at position 49 in exon 1 of CTLA-4 gene. The frequency of alleles G/A, genotypes AA/AG/GG and phenotypes A+ (AA + AG)/G+ (GG + AG) of CTLA-4 were compared between URSA patients and controls. RESULTS: The different distributions of alleles G/A, genotype AA/AG/GG and phenotypes A+/G+ of CTLA-4 were observed between URSA patients and controls. The frequencies of both G allele [68.4% (230/336) vs 59.4% (139/234), P < 0.05] and GG genotype [48.8% (82/168) vs 33.3% (39/117), P < 0.05] were significantly higher in URSA group than that in control group, while the frequencies of AG genotype [39.3% (66/168) vs 52.1% (61/117), P < 0.05] and A+ (AA + AG) phenotype [51.2% (86/168) vs 66.7% (78/117), P < 0.05] were significantly lower in URSA group than that in control group. CONCLUSIONS: The results suggest that A/G polymorphism in exon-1 of CTLA-4 might confer the susceptibility to RSA in Chinese women.

New insights into myeloid-derived suppressor cells and their roles in feto-maternal immune cross-talk.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of myeloid cells that suppress both innate and adaptive immune responses through multiple mechanisms. In recent years, much of our knowledge of the function of MDSCs has come from cancer studies. However, a few recent advances have begun to characterize MDSCs in feto-maternal immune cross-talk. The microenvironment at the fetal-maternal interface is a complex milieu of trophoblasts and maternally-derived cells, which are biased to tolerogenic and Th2-type responses. Current data reveal that MDSCs accumulate at the fetal-maternal interface in healthy pregnancies. Yet, little is known about how MDSCs develop and why the response of MDSCs is heavily granulocytic. In this review, we discuss recent findings on the molecular mechanisms that regulate the expansion and function of MDSCs, in addition to various roles of MDSCs implicated in the modulation of feto-maternal immune cross-talk. Understanding the roles of MDSCs in inducing maternal-fetal tolerance, which is compromised in patients suffering from pregnancy complications, including preeclampsia, intrauterine growth restriction, spontaneous abortion, and preterm birth, we thus propose that the immunomodulatory activity of MDSCs should be carefully considered for the therapeutic approaches targeting pregnancy complications.

[Preliminary research on bacterial diversity of Parece Vela Basin, Pacific Ocean by culture-independent method].

The environmental DNA was directly extracted from the sediment in Parece Vela Basin, Pacific Ocean, at a depth of 5010 m. Bacterial 16S rRNA gene library of 32 clones was generated using bacterial universal primers and 16S rDNA sequences were analyzed phylogenetically. 17 phylotypes were obtained. The library was dominated by gamma-Proteobacteria, alpha-Proteobacteria and marine uncultured bacteria. Sixty-two percent of the cloned sequences was highly related to the known bacteria in the genus Halomonas, Alcanivorax, Pseudomonas, Acinetobacter, Pseudoalteromonas (> 96% sequence similarity), while some of the cloned sequences showed less affiliation with known taxa (< 94% sequence similarity) and may represent novel taxa.

Association of HLA-DQB1 coding region with unexplained recurrent spontaneous abortion.

BACKGROUND: DNA analysis has shown a lack of significant compatibility between couples affected by unexplained recurrent spontaneous abortion (URSA) compared with normal fertile couples, [8] although one study that made use of a PCR-sequence-specific oligonucleotide (SSO) method did observe evidence of significant compatibility in the HLA-DQA1 and DQB1 alleles between patients and aborted fetuses. [9] This study was designed to investigate whether URSA were associated with particular DQ alleles or promoter alleles. METHODS: Thirty-two patients with URSA and 54 women who had had at least one successful pregnancy were included in this study. HLA-DQ genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The HLA-DQB1 promoter was detected by the SSO and sequence-specific primer (SSP) methods. The DQA1, DQB1, and DQB1 promoter (QBP) gene frequencies in the patients were compared with the gene frequencies in normal controls. The data were analyzed statistically with the chi(2) and Fisher's exact tests. RESULTS: The results showed that the frequency of DQB1 * 0604/0605 was significantly higher and the frequency of DQB1 * 0501/0502 was significantly lower in the patient group as compared with the normal controls. In addition, the frequencies of the DQA1 * 01-DQB1 * 0604/0605 and QBP6.2-DQB1 * 0604/0605 haplotypes were overrepresented in the patients relative to the controls. Our results did not show any differences between URSA patients and the controls with regard to DQA1 and QBP allele frequencies. CONCLUSIONS: Our data suggest that URSA is associated with the HLA-DQB1 coding region, and is not associated with its upstream regulatory region. The DQB1 * 0604/0605, DQA1 * 01-DQB1 * 0604/0605, and QBP6.2-DQB1 * 0604/0605 haplotypes may confer susceptibility to URSA, while the DQB1 * 0501/0502 allele may protect women from URSA.

[C677T and A1298C mutation of the methylenetetrahydrofolate reductase gene in unexplained recurrent spontaneous abortion].

OBJECTIVE: To investigate the association between the C677T and A1298C mutation of 5,10-methylenetetrahydrofolate reductase (MTHFR) gene and unexplained recurrent spontaneous abortion (URSA) in Chinese population. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect the mutation of C677T and A1298C of MTHFR in 148 cases with URSA and 82 normal controls. RESULTS: (1) The distribution frequencies of C667T associated 3 genotypes between the URSA and control group showed statistically significant difference (P = 0.012). The frequencies of C677T genotypes were: CC (33.3%), CT (53.1%), TT (13.6%) in URSA group and CC (52.4%), CT (51.5%), TT (6.1%) in control group, respectively. And the frequency of CC genotype in URSA group was decreased significantly (P = 0.005), while the frequency of T allele in URSA was increased (P < 0.005). (2) The prevalence of the MTHFR A1298C associated 3 genotypes and A/C alleles in URSA group did not differ significantly from the control. (3) According to the linkage analysis of C677T and A1298C, 8 linkage genotypes were found, and the frequency of 677CC/1298AA in URSA was significantly lower compared with the control, the linkage of 677 (CT + TT)/1298CC was only observed in URSA group. CONCLUSIONS: The mutations of MTHFR C677T and A1298C play a role in the mechanism of unexplained recurrent spontaneous abortion.

A prospective, randomized trial of Roux-en-Y reconstruction with isolated pancreatic drainage versus conventional loop reconstruction after pancreaticoduodenectomy.

BACKGROUND: Postoperative pancreatic fistula (POPF) is a major and serious complication after pancreaticoduodenectomy (PD). There have been no prospective randomized trials evaluating POPF rates in Roux-en-Y reconstruction (RYR) with isolated pancreatic drainage versus conventional loop reconstruction (CLR). The authors hypothesized that RYR decreases the incidence and severity of POPF in patients after PD. METHODS: Between January 2006 and April 2012, the findings for 216 patients were analyzed in this multicenter, prospective trial in China. After providing appropriate preoperative informed consent, patients were randomly assigned to either RYR or CLR after completion of pancreaticoduodenal resection. We referred to the Johns Hopkins fistula definition and classified POPF as grade A, B, or C according to the International Study Group of Pancreatic Fistula classification. RESULTS: The incidence of POPF was similar in the RYR (15.7%, 17/107) and CLR (17.6%, 19/109) groups. Both univariate and multivariate logistic regression analyses revealed that the factor most highly associated with POPF was ampullary or duodenal disease (P < .05). The incidence of type B POPF was higher in the CLR than in the RYR group. Furthermore, patients with POPF in the CLR group had a significantly longer postoperative hospital stay (31.9 ± 6.9 days) and higher total hospital costs than did the patients in the RYR group (P < .05). CONCLUSION: These data do not support the hypothesis that RYR is associated with a lower incidence of POPF than is CLR. However, they do indicate that RYR may contribute to decreasing fistula severity, duration of stay, and hospital expense.

[The application of desocclusol and manual mechanical method in endodontic retreatment].

PURPOSE: To investigate the clinical method to remove a gutta-percha and root canal sealers. METHODS: 168 root canals which had been filled with gutta-percha were selected,all root canals needed endodontic retreatment.The root canal fillings were removed and the root canal was re-prepared with the method of desocclusol and manual mechanical method. Then the root canal was filled again with lateral condensation technique. RESULTS: With manual mechanical method and desocclusol,all original root canal fillings were removed completely. The combined method could effectively prevent the formation of step,root canal-side wear,broken equipment or other complications during the course of retreatment.The success rate of retreatment was 89.3%. CONCLUSIONS: Combined manual mechanical method with desocclusol could improve the success rate of recanalization of the root canal and saved time and effort. It is a method which could reduce the intensity and improve the efficiency of dentists, and worthy of wide clinical application.

Role of cyclooxygenase-2 signaling pathway dysfunction in unexplained recurrent spontaneous abortion.

BACKGROUND: Experimental evidence indicates that cyclooxygenase-2 (COX-2) plays a critical role in blastocyst implantation; however, little is known of the role of COX-2 in unexplained recurrent spontaneous abortion (URSA). METHODS: We evaluated the expression level and potential signaling pathway of COX-2 in 30 cases of URSA who were excluded the abnormality of chromosomes, anatomy, endocrine, infectious, autoimmune diseases and in 30 normal pregnancies. RESULTS: The mRNA and the protein expression level of COX-2 in the URSA group (-0.238 +/- 0.848, 0.368 +/- 0.089, respectively) were significantly lower than that in the control group (1.943 +/- 3.845, 1.046 +/- 0.108, respectively) (both, P < 0.01). The expression of prostaglandins PGF(2a), PGD(2), PGE(2), and PGI(2), in the URSA group ((2326.0 +/- 295.6) pg/ml, (2164.0 +/- 240.5) pg/ml, (238.7 +/- 26.4) pg/ml, (2337.0 +/- 263.0) pg/ml, respectively) were significantly lower than that in the control group ((3450.0 +/- 421.7) pg/ml, (3174.0 +/- 415.6) pg/ml, (323.5 +/- 43.8) pg/ml, (3623.0 +/- 460.4) pg/ml, respectively) (P < 0.05). The mRNA expression level of PPARbeta and RXRalpha (0.859 +/- 0.653, -0.172 +/- 0.752, respectively) in URSA group was significantly lower than that in the control group (1.554 +/- 1.735, 0.777 +/- 2.482, respectively) (both P< 0.05). The mRNA and protein expression levels of vascular endothelial growth factor-A (VEGF-A) in the URSA group (2.010 +/- 1.522, 0.35 +/- 0.46) was significantly lower than that in the control group (4.569 +/- 2.430, 0.750 +/- 0.350) (both P < 0.05). CONCLUSIONS: COX-2 and the COX-2-derived PGI(2) signaling pathway possibly play an important role in successful embryo implantation, and their decreased expression may result in URSA. The decreased expression may influence the expression of VEGF-A which interferes with placental angiogenesis causing failure of embryo implantation, leading to spontaneous abortion.

Relationship between expression of chemokine receptors CCR3, CCR5 and CXCR3 on CD4(+) T cells and spontaneous abortion in mice.

BACKGROUND: Previous studies have shown that local immune cells in the feto-maternal interface are recruited from peripheral blood, and that chemokines and their receptors play an initial and key role in this recruitment process. In this study, we aimed to determine whether spontaneous abortion is associated with the expression of chemokine receptors CCR3, CCR5, and CXCR3 on CD4(+) T cells. METHODS: Peripheral blood, spleen, and thymus were collected from the spontaneous abortion mouse model CBA/JxDBA/2 (SA group, n = 14), the normal pregnant mouse model CBA/JxBALB/c (NP group, n = 13), and normal non-pregnant CBA/J mice (NNP group, n = 11). The number of chemokine receptors CCR3, CCR5, and CXCR3 expressed on CD4(+) T cells was measured by double-label flow cytometry (FCM) method. RESULTS: In peripheral blood, the SA group had significantly lower CCR3 expression (P < 0.01) and higher CCR5 and CXCR3 expression (P < 0.01) on CD4(+) T cells than did the NP group. But comparing these chemokines between the SA and NNP groups, there was no significant difference (P > 0.05). In spleen, the SA group expressed significantly lower CCR3 expression (P < 0.01) and higher CCR5 and CXCR3 expression (P < 0.05) on CD4(+) T cells than did the NP group. When compared with the NNP group, the SA group had significantly higher CCR3 expression (P < 0.01), but was not statistically different with regards to the other two chemokines (P > 0.05). In thymus, the SA group had significantly lower CCR3 expression (P < 0.05) and higher CXCR3 expression (P < 0.05) on CD4(+) T cells than the NP group, with no significant difference in CCR5 expression (P > 0.05). Compared with the NNP group, the SA group had higher CCR3 expression (P < 0.01), but there was no statistical difference in CXCR3 and CCR5 expression (P > 0.05) between the two groups. CONCLUSION: The abnormal expression of CCR3, CCR5 and CXCR3 on CD4(+) T cells may play an important role in the pathogenesis of spontaneous abortion.

Expression of chemokine receptors CCR3, CCR5 and CXCR3 on CD4(+) T cells in CBA/JxDBA/2 mouse model, selectively induced by IL-4 and IL-10, regulates the embryo resorption rate.

BACKGROUND: Chemokines and their receptors have been a research focus in transplantation immunology. Chemokines and their receptors play a role in lymphocyte recruitment and differentiation process. This study aimed to observe whether IL-4 and IL-10 may regulate the expression of chemokine receptors CCR3, CCR5 and CXCR3 on CD4(+) T cells in CBA/JxDBA/2 mouse model and to explore the role of CCR3, CCR5, CXCR3 in immune tolerance in pregnancy. METHODS: The mouse model of spontaneous abortion (CBA/JxDBA/2) and the normal pregnant mouse model (CBA/JxBALB/c) were used. CBA/JxDBA/2 mice were injected with IL-4 (CBA/JxDBA/2-IL-4), IL-4 and IL-10 (CBA/JxDBA/2-IL-4+IL-10), or normal saline (CBA/JxDBA/2-NS) as a control. The expression of CCR3, CCR5 and CXCR3 on CD4(+) T cells from mouse peripheral blood was measured by the double-labelled FCM method, and the embryo resorption rate was also examined. RESULTS: The embryo resorption rate in the CBA/JxDBA/2 group without any treatment was significantly higher than that in the CBA/JxBALB/c group (17.9% vs 3.7%, P < 0.01). The embryo resorption rate in the CBA/JxDBA/2 group immunized with IL-4 or IL-4 together with IL-10 was significantly decreased, compared with that in the control and NS groups respectively. CCR3 expression on CD4(+) T cells in the CBA/JxDBA/2 group without any treatment was significantly lower than that in the CBA/JxBALB/c group (0.3738 +/- 0.3575 vs 1.2190 +/- 0.2772, P < 0.01); both CCR5 (3.0900 +/- 1.5603 vs 1.2390 +/- 0.6361, P < 0.01) and CXCR3 (2.4715 +/- 0.9074 vs 0.9200 +/- 0.5585, P < 0.01) expressions on CD4(+) T cells of the CBA/JxDBA/2 group without any treatment were significantly higher than those of the CBA/JxBALB/c group. Significant up-regulation of CCR3 and down-regulation of CXCR3 were found in the CBA/JxDBA/2 group treated with IL-4 (CCR3: 2.0360 +/- 0.6944, CXCR3: 1.3510 +/- 0.5263, P < 0.01) or IL-4 and IL-10 (CCR3: 1.8160 +/- 1.0947, CXCR3:1.0940 +/- 0.7168, P < 0.01). Because of the CCR5, IL-4 and IL-10 (1.9400 +/- 0.8504 vs 3.0900 +/- 1.5603, P < 0.05), but IL-4 alone (2.5310 +/- 1.3595 vs 3.0900 +/- 1.5603, P > 0.05) treatment significantly decreased the expression of CCR5 in CBA/JxDBA/2. CONCLUSIONS: The abnormal expression of CCR3, CCR5 and CXCR3 on CD4(+) T cells may play an important role in the pathogenesis of spontaneous abortion. The pregnancy immune tolerance may be induced through selective induction of CCR3, CCR5 and CXCR3 expressions by IL-4 together with IL-10.

Purification and characterization of a monofunctional catalase from an alkaliphilic Bacillus sp. F26.

An alkaline catalase has been purified and characterized from a slightly halophilic and alkaliphilic bacterium Bacillus sp. F26. The purification was performed with a four step procedure consisting of ammonium sulfate precipitation, ion exchange, gel filtration and hydrophobic interaction chromatography, and finally achieved a 58.5-fold-purifying over the crude extract. The purified catalase was composed of two identical subunits with a native molecular mass of 140 kD. The native enzyme showed the typical Soret band appearing at 408 nm. The pyridine hemochrome spectrum indicated the presence of protoheme IX as the prosthetic group. The apparent Km value for enzyme activity on H2O2 was calculated to be 32.5 mmol/L. The activity of this catalase was not reduced by dithionite but was strongly inhibited by cyanide, azide, and 3-amino-1,2,4-triazole (the specific inhibitor of monofunctional catalase). No peroxidase activity of this enzyme was detected when using o-dianisidine, diaminobenzidine (DAB) and p-phenylenediamine as electron donor. Moreover, the N-terminal sequence of this catalase exhibited substantial similarity to the monofunctional catalase subgroup rather than catalase-peroxidase or Mn-catalase one. Therefore, we characterize the purified catalase as a monofunctional catalase. Besides, this monofunctional catalase was thermosensitive and its activity exhibited pH-independent over pH 5-9 but showed a sharp maximum at pH 11. An activity half-life of approximately 49 h was measured when the enzyme was incubated at 20 degrees C and pH 11. To our knowledge, pH 11 is the most alkaline condition for optimum catalysis and enzyme stability among the catalases reported up to now. Furthermore, this monofunctional catalase also showed excellent halo-alkali-stability with a half-life of approximately 90 h at 0.5 mol/L NaCl and pH 10.5. On the other hand, so far as we know, the characterized catalase is the first dimeric monofunctional catalase from alkaliphiles and is also the first monofunctional catalase derived from a natural soda lake, which could partially reflect the oxidative stress response in the corresponding environment.