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Background Numerous studies have sought associations between matrix metalloproteinase 9 (MMP-9) polymorphisms and breast cancer risk. However, these studies have yielded conflicting results. Hence, we performed an updated meta-analysis to clarify the effects of four MMP-9 gene polymorphisms (rs3918242, rs2250889, rs3787268, and rs17576) on breast cancer risk. Methods A comprehensive literature search for eligible studies was conducted in five electronic databases, including PubMed, Embase and Web of Science, up to March 1, 2020. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations in random-effects models. For the reduction of type I errors, a trial sequential analysis (TSA) was performed. Results Twenty-one studies (8813 breast cancer cases and 9323 controls) were included in the quantitative analysis. For rs3918242, the overall ORs were significant under allelic comparison (OR A vs. G = 1.34; 95% CI 1.03, 1.74, P = 0.028) and the recessive genetic model (OR AA vs. GG+GA = 1.40; 95% CI 1.06, 1.84, P = 0.016). For rs2250889, the ORs were significant under homozygote comparison (OR GG vs. CC = 2.57; 95% CI 1.22, 5.42, P = 0.013), heterozygote comparison (OR GC vs. CC = 2.48; 95% CI 1.17, 5.23, P = 0.018), and the dominant genetic model (OR GG+GC vs. CC = 2.53; 95% CI 1.23, 5.20, P = 0.012). No associations were observed for rs3787268 or rs17576. The subgroup analyses indicated that the risk effect of the rs3918242 A allele was observed only among Asians. TSA showed that the findings for rs3918242, rs3787268, and rs17576 were robust, but many more patients are needed before definitive conclusions can be made for rs2250889. Conclusion Our meta-analysis suggests that MMP-9 rs3918242, but not rs3787268 and rs17576 polymorphisms, may be risk factors for breast cancer. The effect of rs2250889 needs further confirmation with a larger sample size.

Mold shell with higher thermal conductivity was introduced in the article. Reinforced by the carbon fiber, the new type sol silicate mold shell could be made with much less layers while without reducing its strength. Therefore, the new-type mold shell should have higher thermal conductivity. Then measure its thickness, bend strength, analyze the dendritic crystal of the casting manufactured with the new-type mold shell. It was proved that the thickness had reduced by 25% and the bend strength did not decrease. And it performs better in the detection: the dendrite crystals are refined, the primary and secondary dendrite arm space are decreased, the secondary dendrite arms are restrained.

Tailings dam due to earthquake action may lead to severe slippage damage, and setting antiseismic measure is an effective method to prevent damage. Dynamic nonlinear finite element method is used in the efforts to analyze the earthquake reaction and the deformation characteristic. To reduce dam seismic deformation, the reinforcement effect of geotextiles, rock pressure and stone column is studied. Finally, a synthetically antiseismic measure that is composed of geotextiles-reinforced in sub-dam, rock pressure out of starter dam and densification foundation is proposed. It is found that the synthetically antiseismic measure produces better antiseismic effect, and offers a consult for the antiseismic design of tailings dam.

It analyses different kinds of risk factors of real estate investment, and establishes a suit of scientific index system about the risk assessment of real estate investment. And this paper not only establishes the risk assessment model of real estate projects in view of fuzzy-synthetical evaluation, but also uses this model to make a risk assessment of Ganzhou Tianyue real estate project, showing the feasibility of the model by examples.

We explored the utility of time-resolved angiography with interleaved stochastic trajectories dynamic contrast-enhanced magnetic resonance imaging (TWIST DCE-MRI), readout segmentation of long variable echo-trains diffusion-weighted magnetic resonance imaging- diffusion-weighted magnetic resonance imaging (RESOLVE-DWI), and echo-planar imaging- diffusion-weighted magnetic resonance imaging (EPI-DWI) for distinguishing between malignant and benign breast lesions. This retrospective analysis included female patients with breast lesions seen at a single center in China between January 2016 and April 2016. Patients were allocated to a benign or malignant group based on pathologic diagnosis. All patients received routine MRI, RESOLVE-DWI, EPI-DWI, and TWIST DCE-T1WI. Variables measured included quantitative parameters (Ktrans, Kep, and Ve), semiquantitative parameters (rate of contrast enhancement for contrast agent inflow [W-in], rate of contrast decay for contrast agent outflow [W-out], and time-to-peak enhancement after contrast agent injection [TTP]) and apparent diffusion coefficient (ADC) values for RESOLVE-DWI (ADCr) and EPI-DWI (ADCe). Receiver-operating characteristic (ROC) curve analysis was used to evaluate the diagnostic utility of each parameter for differentiating malignant from benign breast lesions. A total of 87 patients were included (benign, n = 20; malignant, n = 67). Compared with the benign group, the malignant group had significantly higher Ktrans, Kep and W-in and significantly lower W-out, TTP, ADCe, and ADCr (all P

Flying capacitor multilevel inverters are increasingly used in industry applications. In order to improve the harmonic performance of the output voltage under low modulation index region, the paper presents a novel PWM method for flying capacitor multilevel inverters based on the idea of controlling freedom degree. The novel PWM method can balance the flying capacitor voltage in a certain period. The validity of the novel PWM method is demonstratedby the experimental results.

Inflammatory bowel disease (IBD) includes two similar yet distinct conditions called ulcerative colitis (UC) and Crohn's disease (CD). These diseases affect the digestive system and cause the inflammation of intestinal tissue, form sores and bleed easily. Most children with IBD are diagnosed in late childhood and adolescence. However, both UC and CD have been reported as early as in infancy. Most information pertaining to the epidemiology of IBD is based upon adult studies. Symptoms include abdominal pain, cramping, fatigue and diarrhea. Genetic factors play a significant role in determining IBD susceptibility. Epidemiological data support a genetic contribution to the pathogenesis of IBD. Recently, numerous new genes have been identified as being involved in the genetic susceptibility to IBD: TNF-308A, CARD15 (NOD2), MIF-173, N-acetyltransferase 2 (NAT2), NKG2D (natural killer cell 2D), STAT6 (signal transducer and activator of transcription 6), CTLA-4 (cytotoxic T lymphocyte antigen-4), MICA-MICB (major histocompatibility complex A and B), HLA-DRB1, HLA class-II, IL-18, IL-4, MICA-A5, CD14, TLR4, Fas-670, p53 and NF-kappaB. The characterization of these novel genes has the potential to identify therapeutic agents and aid clinical assessment of phenotype and prognosis in patients with IBD (UC and CD).

Ulcerative colitis (UC) is an inflammatory destructive disease of the large intestine occurred usually in the rectum and lower part of the colon as well as the entire colon. Drug therapy is not the only choice for UC treatment and medical management should be as a comprehensive whole. Azulfidine, Asacol, Pentasa, Dipentum, and Rowasa all contain 5-aminosalicylic acid (5-ASA), which is the topical anti-inflammatory ingredient. Pentasa is more commonly used in treating Crohn's ileitis because Pentasa capsules release more 5-ASA into the small intestine than Asacol tablets. Pentasa can also be used for treating mild to moderate UC. Rowasa enemas are safe and effective in treating ulcerative proctitis and proctosigmoiditis. The sulfa-free 5-ASA agents (Asacol, Pentasa, Dipentum and Rowasa) have fewer side effects than sulfa-containing Azulfidine. In UC patients with moderate to severe disease and in patients who failed to respond to 5-ASA compounds, systemic (oral) corticosteroids should be used. Systemic corticosteroids (prednisone, prednisolone, cortisone, etc.) are potent and fast-acting drugs for treating UC, Crohn's ileitis and ileocolitis. Systemic corticosteroids are not effective in maintaining remission in patients with UC. Serious side effects can result from prolonged corticosteroid treatment. To minimize side effects, corticosteroids should be gradually reduced as soon as the disease remission is achieved. In patients with corticosteroid-dependent or unresponsive to corticosteroid treatment, surgery or immunomodulator is considered. Immunomodulators used for treating severe UC include azathioprine/6-MP, methotrexate, and cyclosporine. Integrated traditional Chinese and Western medicine is safe and effective in maintaining remission in patients with UC.

The potential role of genetic intervention extends from diseases caused by single gene defects, through severe viral infections, to polygenic disorders, such as diabetes mellitus and arteriosclerosis. However, gene therapy can be defined as the introduction and expression of an exogenous gene in human cells for therapeutic benefit, and is conventionally restricted to human diseases associated with single gene defects. There are wider opportunities for genetic intervention and these include strategies to reduce or block gene expression as well as the introduction of nonmammalian genes. The rapid progress in our understanding of some of the molecular mechanisms involved in the pathogenesis of cancer and metabolic disorders, coupled with the development of gene delivery vector technology, has urged us to consider novel genetic approaches to digestive diseases. There is no shortage of ideas and applications for genetic intervention in human diseases, but there are great limitations not only with the efficiency and targeting of the present generation of gene transfer vectors but also with our incomplete understanding of transcription control.

In recent years, the advances in therapy of ulcera-tive colitis (UC) have been characterized mainly by the more extensive use of immunosuppression. Cy-closporin (CSA) may become a drug of choice to treat severe UC, but its long-term effect is insufficient. Topically, glucocorticosteroids (GCS) are hopeful in right ileocolonic UC, but no action for maintenance therapy[1-3]. The most significant development in recent years is the introduction of im-munomodulatory treatments using cytokines and an-ticytokines. Immunomodulation therapy creates great expectations since early reset of the immunos-tat might be able to control inflammation in a long term. Current treatment strategies are anti-inflam-matory and to modulate the immune response. Stan-dard therapies with sulphasalazine (SAS) or 5-aminosalicylic acids ( 5-ASA, mesalazine or mesalamine), GCS and antibiotics yield a fair im-mediate success, but long-term response to these therapies is poor. The greatest advance has been the introduction of immunosuppressive strategies. The indexes like the clinical activity index (CAI) proposed by Rachmilewitz[1], although useful, have not received general acknowledgement. Patients with an inflammatory bowel disease (IBD), such as UC or Crohn’s disease, have recur-rent symptoms with high morbidity. Mild disease requires only sympt omatic relief and dietary manipu-lation. Mild to moderate disease can be managed with 5-ASA, including olsalazine and mesalamine. Mesalamine enemas and suppositories are useful in treating proctosigmoiditis. Corticosteroids are beneficial in patients with more severe symptoms, but side effects limit their use, particularly for chronic therapy. Immunosuppressant therapy may be considered in patients with refractory disease that is not amenable to surgery. IBD in pregnant women can be managed with 5-ASA and corticosteroids[2]. Since longstanding IBD is associated with an increased risk of colon cancer, periodic colonoscopy is warranted. Since lesions in UC are quite diffuse and uniform endoscopic indexes used are quite straightfor-ward, clinical activity, endoscopic activity and his-tology show a reasonable correlation and it is useful to monitor disease activity also with flexible proc-tosigmoidoscopy. The persistence of active inflam-matory lesions at histology in the presence of endo-scopic remission predicts relapse. Bresci G et al[3] reported that the activity of the disease was evaluated by a Clinical Activity Index and an Endoscopic Index. Of 112 cases of UC observed, 95 showed no change in extent and were studied as examples of non-progressive UC, and in this group the extension of the disease was: pancolitis in 19%, left sided col-itis in 39%, proctosigmoiditis in 17% and proctitis in 25%. A colectomy had to be performed in 5%. None of the enrolled cases developed a cancer dur-ing the follow up. The patients with ulcerative pancolitis or left-sided colitis were treated with 5-ASA-1.6g/d in a delayed-release formulation, while the patients with proctosigmoiditis or proctitis were treated with 5-ASA enem as 4 g/d. The patients with more than one relapse/ year accounted for 39%. The proportion of patients with only one relapse/ year was 53%. The patients with steady re-mission for all the seven years of the trial were only 8%, but with a statistically significant difference between the groups with initial diagnosis of proc-tosigmoiditis or proctitis and the group with initial diagnosis of pancolitis or left-sided colitis (12% vs 5%). Among the patients with continuous remis-sion, 37% showed colonic alterations, with an en-doscopic score higher than 4 but a clinical score less than 6. Side effects were observed in 6% of patients but without treatment withdrawal. Non-progressive UC throughout the colon has a relatively good prog-nosis, which seems to be independent of the location of the disease, even if Bresci G et al[3] have found a statistically significant higher percentage of patients with steady remission among the patients with more distal diseases.

To study the effects of Rheum tanguticum polysaccharide(-1) (RTP(-1)) on ulcerative colitis in rats induced by 2, 4, 6-trinitrophene sulphonic acid (TNBS) and their possible mechanism.RTP1 (200 mg.kg(-1), i.g.) extracted from Rheum tanguticum Maxim. ex Regel was administrated to rats with colitis induced by TNBS for 5 d, 7 d, 10 d and 14 d, respectively. The effects of RTP1 and dexamethasone (DX, 0.2 mg.kg(-1), i.g.) were contrastively investigated. The MPO level and SOD activity were determined by chromatometry. The expansion and protein expression of CD4+T lymphocytes isolated from colon mucosae and mesenteric lymph nodes of colitis rats were performed by immunohistochemical analysis and Western-blot methods.Treatments of RTP1 (200 mg.kg(-1), i.g.) significantly reduced diarrhea, mortality, colon mass, ulcer areas and MPO level in colon mucosae on days 5, 7, 10 and 14 (5.2+/-1.4, 5.4+/-0.7, 5.2+/-1.8, P0.05. 3.4+/-0.8, P0.01. 16.1+/-12.1, P0.01. 31.8+/-8.6, 17.7+/-5.3, 12.7+/-4.1, P0.05). The effects of RTP1 were similar to those noted above in DX group, but there were no immunosuppressive effects of DX in RTP(-1) group, such as body mass loss, thymus and spleen atrophy. The decreased number and down-regulated protein levels of CD4+T cells isolated from the colon of colitis rats treated with RTP1 were found.RTP1 shows significantly protective effects but lower side effects on rats with colitis induced by TNBS. The mechanism may be due to the resistance to over expansion of CD4.

Strengthen international academic cooperation and exchanges: prospects in the 21st century: Summary of the First World Chinese Congress of Digestion

Endoscopic evaluation of gastrointestinal tract lesions in patients with iron-deficiency anemia

Substance P, vasoactive intestinal peptide, and leu-enkephalin in plasma and gastric juice of patients with precancerous lesions and gastric cancer