973 resultados para sparse matrix technique


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Purpose: Prostate cancer is the most common tumor in males in Brazil. Single nucleotide polymorphisms have been demonstrated to exist in the promoter regions of matrix metalloproteinase genes and they are associated with the development and progression of some cancers. We investigated the correlation between MMP1, 2, 7 and 9 polymorphisms with susceptibility to prostate cancer, and classic prognostic parameters of prostate cancer. Materials and Methods: Genomic DNA was extracted using conventional protocols. The DNA sequence containing the polymorphic site was amplified by realtime polymerase chain reaction using TaqMan (R) fluorescent probes. Results: For the MMP1 gene the polymorphic allele was more common in the control group than in the prostate cancer group (p <0.001). For the MMP9 gene the incidence of the polymorphic homozygote genotype was higher in the prostate cancer group (p <0.001). For higher stage tumors (pT3) a polymorphic allele in the MMP2 gene was more common (p = 0.026). When considering Gleason score, the polymorphic homozygote genotype of MMP9 was more common in Gleason 6 or less tumors (p = 0.003), while a polymorphic allele in the MMP2 gene was more common in Gleason 7 or greater tumors (p = 0.042). Conclusions: MMP1 and MMP2 may protect against prostate cancer development and MMP9 may be related to higher risk. In contrast, MMP9 polymorphism was associated with a lower Gleason score and MMP2 polymorphism was associated with nonorgan confined disease.

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Background: Enucleation of small lesions located near the hepatic surface can be achieved with low morbidity and mortality. This article describes a simple laparoscopic technique for enucleation of liver tumors. Methods: After inspection and intraoperative ultrasonography, Glisson`s capsule is marked with eletrocautery 2 cm away from the tumor margin. Ultrasonography is used to ascertain surgical margin right before liver transection. Hemihepatic ischemia is applied and marked area is anchored by stitches. The suture is held together by metallic clips and upward traction is performed, facilitating the transection of the parenchyma and correct identification of vascular and biliary structures. Results: This technique has been successfully employed in six consecutive patients. There were four men and two women, mean age 50.3 years. Four patients underwent liver resection for malignant disease and two for benign liver neoplasm. Pathologic surgical margins were free in all cases and mean hospital stay was 2 days. No postoperative mortality was observed. Conclusion: This technique may facilitate laparoscopic nonanatomical liver resection and reduce risk of positive surgical margins. It is also useful in combination with anatomical laparoscopic liver resections such as right or left hemihepatectomies in patients with bilateral liver tumors as occurred in one of our patients.

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Melanonychia, from the Greek melaina, means black and is the result of an increased deposition of melanin on the nail plate, originating in the nail matrix. It may have different causes, including subungueal melanoma, making early etiologic diagnosis very important.

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Experience with laparoscopic liver resections has increased in recent years, and so have the number of patients operated on by minimally invasive techniques. Specimen extraction is an important step of laparoscopic liver resection. The size of the specimen, is Usually a limitation for the use Of laparoscopy. The aim of this paper is to describe a new technique combining Pfannenstiel suprapubic incision and obstetric forceps to remove a large specimen from laparoscopic liver resections. The present technique allows an expeditious extraction of intact specimens, even huge ones, through a standard suprapubic Pfannenstiel incision. This technique has additional functional and cosmetic advantages over other techniques of specimen retrieval. We believe that the described technique is feasible, can be easily and rapidly performed, and facilitates laparoscopic liver resection by reducing the technical difficulties for specimen removal and may also be used in other abdominal laparoscopic interventions that deal with large surgical specimens.

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Bleeding is not uncommon following endoscopic sphincterotomy. Supra-papillary puncture (SPP) might be safer than standard cannulation (SC) techniques in patients with coagulopathy. The aim of the study was to compare the safety and effectiveness of SPP and SC. This was a prospective case control intervention study. Decompensated cirrhotic patients with coagulopathy and choledocolithiasis underwent SC and SPP methods for biliary access. One hundred five patients (56 [53.3%] men, mean [SD] age 56 [15.8]) underwent ERCP. SC and SPP were performed in 63 and 42 patients, respectively. Biliary access was achieved in 56/63 (89%) and 40/42 (95%) of patients undergoing SC and SPP, respectively (P = 0.13; 95% CI [-0.16; 0.03]). Complications occurred in 10/63 (15.8%) patients undergoing SC and 5/42 (11.9%) SPP (P = 0.28; 95% CI [-0.17, 0.16]). Five (7.9%) and two (3.2%) episodes of post-sphincterotomy bleeding was seen in the SC and SPP groups, respectively (P = 0.36; 95% CI [-0.16, 0.05]). In contrast, three (4.8%) episodes of pancreatitis were seen in the SC and none in the SPP group (P = 0.05; 95% CI [0.001; 0.004]). A cost-effectiveness analysis demonstrated that SPP is an acceptable alternative at an ICER of US$ 5,974.92 per additional successful procedure. SPP is a safe and effective technique for the management of common bile duct stones in decompensated cirrhotic patients. Conditional to the willingness-to-pay and to the local ERCP-related costs, SPP is also a cost-effective alternative to the SC methods. SPP is associated with a lower rate of complications but larger studies to validate these findings are necessary.

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Objective: To analyze the prognostic effect of epidermal growth factor receptor (EGFR), matrix metalloproteinases 2 and 9, and vascular endothelial growth factor expression in patients with locally recurrent oral carcinoma after salvage surgery. Design: Retrospective cohort study. Settings: Tertiary center cancer hospital. Patients: The charts of 111 patients with local recurrence of oral carcinomas were retrospectively analyzed. The previous treatment consisted of surgery in 33 patients (30.0%), radiotherapy with or without chemotherapy in 46 patients (41.0%), and surgery with adjuvant radiotherapy in 32 patients (29.0%). The expression of EGFR, matrix metalloproteinases 2 and 9, and vascular endothelial growth factor was analyzed with a tissue microarray immunohistochemical technique. Main Outcome Measures: Overall survival and cancer-specific survival (CSS). Results: The recurrences were diagnosed in less than 1 year in 69 patients (62.2%) and in more than 1 year in 42 patients (37.8%). The prognosis was worse in the group with the disease-free interval of less than 1 year (P=.01). Patients with more advanced disease (clinical stage of recurrence, III/IV) had worse rates of CSS (P=.04). Cases that were positive for EGFR had a 3-year CSS of 27.2%, while EGFR-negative cases had a 3-year CSS of 64.3% (P=.001). The expression of matrix metalloproteinases 2 (P=.83) and 9 (P=.15) and vascular endothelial growth factor (P=.86) was not significant in this group. In multivariate analysis, only the disease-free interval and the overexpression of EGFR were associated with a higher risk of cancer death. Conclusions: Local recurrence in oral carcinomas carries a poor prognosis. A disease-free interval of more than 1 year and a EGFR-negative expression are the main prognostic factors related to better CSS in patients treated with salvage surgery.

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Prostate cancer (PCa) is the most common type of malignant tumor in Brazilian males. Single nucleotide polymorphisms (SNPs) have been demonstrated to be present in the promoter region of matrix metalloproteinase (MMP) genes and have been associated with the development and progression of some cancers. In this study, our aim was to investigate the association between the polymorphisms of MMP1, 2, 7, and 9 and susceptibility, and their correlation with the classic prognostic parameters of PCa. For genes MMP1, 2 and 9, the frequencies of the polymorphic homozygote genotypes were higher in the control group than in the PCa group (P<0.0001). We conclude that the MMP1, 2 and 9 polymorphisms are more common in the control group than in patients with PCa, and may have a protective effect in the development of this neoplasia.

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Background: Basal cell carcinomas (BCC), squamous cell carcinomas (SCC) and cutaneous malignant melanoma (MM) are solid skin cancers derived from different cell types, with different ability to metastasize. Several subtypes of integrins and matrix metalloproteinases (MMP) have been related to malignization and metastasis processes. This work aimed at a quantitative evaluation of skin cancers expressing eight integrins and MMP2 genes. Methods: Expression of integrins and MMP2 genes was evaluated on fresh tumor biopsies from BCC, SCC and MM, and respective controls, by the reverse transcriptase polychain reaction (RT-PCR) technique. Results: More than 90% tumors expressed alpha 6a, beta 1, beta 3 and beta 6 (non-melanoma), and alpha 5a, alpha 6a and MMP2 (MM). Up to 100% controls also expressed beta 1 and beta 3. The results were significant for alpha 6a in BCC (p = 0.026), alpha 6b in SCC (p = 0.035), alpha 2a in BCC (p = 0.003), beta 5 and beta 6 in BCC (p = 0.005). MMP2 was expressed in 100% MM (p = 0.0004). Conclusion: Integrin subunits alpha 2a and alpha 6a would be interesting targets for BCC anti-tumor therapy, as well as alpha 6b in case of SCC. The elevated number of BCC expressing alpha 2 and alpha 6, and of MM expressing alpha v and MMP2, corroborate literature data.

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Background: Double-balloon enteroscopy (DBE) allows evaluation and therapy for various small bowel diseases. In this series the outcome of a 4-year experience in a tertiary hospital school in Brazil is reported. Methods: A total of 457 consecutive DBE were performed in 418 patients from August 2004 to August 2008. 93 patients with several indications, whose aim was not the evaluation of suspected diseases of the small bowel mucosa, were excluded, therefore leaving 364 DBE in 325 patients for analysis. Data were retrospectively collected with regard to clinical, endoscopic findings, therapy and complications. Results: Among the 364 DBE performed in 325 patients, 143/325 were males (44%) and 182/325 females (56%) with a mean age of 48.6 +/- 15.7 years (range 17-89). Mean investigation time was 64 +/- 22 min (range 35-135). The depth of insertion beyond the ligament of Treitz was 230 +/- 85 cm (range 30-500) by the antegrade approach and 140 +/- 75 cm (range 0-320) by the retrograde approach. Total enteroscopy was achieved in 41.66% of the attempts (30 of 72 patients). Overall diagnostic yield was 54.95% (200 of 364 procedures) ranging from 0 to 100% in this series, depending on the indication. Angiodysplasia was the main diagnosis in 24.5% (49 of 200 procedures) and endoscopic treatment, including biopsies, hemostasis, tattooing and polypectomy were performed in 65.38% (238 of 364 procedures). No major complications were reported. Conclusions: DBE is a feasible, safe and well-tolerated procedure allowing endoscopic therapy. Selection of indications increases its diagnostic yield. Copyright (C) 2009 S. Karger AG, Basel

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The immunopathologic and inflammatory mechanisms involved in periodontal disease (PD) include the participation of host resident, inflammatory cells and chemical mediators. Metalloproteinases (MMPs) and nitric oxide (NO) play essential role in extracellular matrix turnover of periodontal tissue destruction. In this study, by means of RT-PCR through semi-quantitative densitometric scanning methods, the expression of MMPs -2 and -9 and inducible NO synthase (iNOS) was temporally and spatially investigated during the destructive mechanisms of experimentally induced PD in rats. Samples from different periods were microscopically analyzed and compared with the contralateral side (control). Our results showed significant expression of MMP-9 and iNOS in tissues affected by PD, as compared with controls, three days after PD induction, simultaneously with the beginning of alveolar bone loss. At 7 days post induction, only the MMP-9 mRNA presented a significantly higher expression, as compared with the respective controls. Thus, in the rat ligature-induced PD, MMP-9 and iNOS might importantly participate in the early stages of the disease, including inflammatory cell migration, tissue destruction and alveolar bone resorption. Also, we may suggest that the exuberant presence of PMNs may be related to the important expression of iNOS and MMP-9 found at 3 days post induction.

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The strong inflammatory reaction that occurs in the heart during the acute phase of Trypanosoma cruzi infection is modulated by cytokines and chemokines produced by leukocytes and cardiomyocytes. Matrix metalloproteinases (MMPs) have recently emerged as modulators of cardiovascular inflammation. In the present study we investigated the role of MMP-2 and MMP-9 in T. cruzi-induced myocarditis, by use of immunohistochemical analysis, gelatin zymography, enzyme-linked immunosorbent assay, and real-time polymerase chain reaction to analyze the cardiac tissues of T. cruzi-infected C57BL/6 mice. Increased transcripts levels, immunoreactivity, and enzymatic activity for MMP-2 and MMP-9 were observed by day 14 after infection. Mice treated with an MMP inhibitor showed significantly decreased heart inflammation, delayed peak in parasitemia, and improved survival rates, compared with the control group. Reduced levels of cardiac tumor necrosis factor-alpha, interferon-gamma, serum nitrite, and serum nitrate were also observed in the treated group. These results suggest an important role for MMPs in the induction of T. cruzi-induced acute myocarditis.

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Introduction: Fibrinolyis is one of the first line therapies in high risk pulmonary embolism (PE) according to current guidelines. Previous studies showed that brinolytic therapy with tPA (tissue plasminogen activator, or alteplase) upregulates the concentrations of matrix metalloproteinases (MMPs) and contributes to hemorrhagic transformation after cardioembolic stroke. However, no previous study has described the circulating MMPs levels following fibrinolysis for acute PE. Materials and Methods: We serially measured the circulating levels of MMPs (MMP-9 and MMP-2) and their endogenous inhibitors, the tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in alteplase and in streptokinase-treated patients with acute PE by gelatin zymography and by enzyme-linked immunosorbent assays, respectively. Results: We found that therapy of PE streptokinase or with alteplase is associated increased pro-MMP-9, but not MMP-2, concentrations for up to 24 hours, whereas no significant changes were found in TIMP-1 or TIMP-2 concentrations. This alteration returned to normal 3 to 5 days after thrombolysis. This is the first study reporting on MMPs alterations following fibrinolysis for acute PE. Conclusions: We found transient increases in circulating pro-MMP-9 levels following fibrinolysis for acute PE. Our findings support the hypothesis that increased MMP-9 levels may underlie the risk of intracerebral hemorrhage or other bleeding complication of thrombolysis for acute PE, and the use of MMP inhibitors may decrease such risk. (C) 2010 Elsevier Ltd. All rights reserved.