140 resultados para Average nusselt number


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Background Standardization of total mesorectal excision (TME) had a great impact on decreasing local recurrence rates for the treatment of rectal cancer. However, exact numbers and distribution of lymph nodes (LN) along the mesorectum remains controversial with some studies suggesting that few LNs are present in the distal third of the mesorectum. Methods Eighteen fresh cadavers without a history of rectal cancer were studied. The rectum was removed by TME and then was divided into right lateral, posterior and left lateral sides, which were further subdivided into 3 levels (upper, middle and lower). A pathologist determined the number and sizes of the LNs in each of the nine areas, b linded to their anatomical origin. Results Overall, the mesorectum had a mean of 5.7 LNs (SD=3.7) and on average each LN had a maximum diameter of 3.0 mm (SD=2.7). There was no association between the mean number or size of LNs with gender, BMI, or age. There was a significantly higher prevalence of LNs in the posterior location (2.8 per mesorectum) than in the two lateral locations (0.8 and 1.2 per mesorectum; p=0.02). The distribution of LNs in the three levels of the rectum was not significant. Conclusions The distribution of LNs reinforces the fact that TME should always include the distal third of the mesorectum. Care must be taken to not violate the posterior aspect of the mesorectum.

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Medulloblastoma (MB) is the most common malignant brain tumor of children. To identify the genetic alterations in this tumor type, we searched for copy number alterations using high-density microarrays and sequenced all known protein-coding genes and microRNA genes using Sanger sequencing in a set of 22 MBs. We found that, on average, each tumor had 11 gene alterations, fewer by a factor of 5 to 10 than in the adult solid tumors that have been sequenced to date. In addition to alterations in the Hedgehog and Wnt pathways, our analysis led to the discovery of genes not previously known to be altered in MBs. Most notably, inactivating mutations of the histone-lysine N-methyltransferase genes MLL2 or MLL3 were identified in 16% of MB patients. These results demonstrate key differences between the genetic landscapes of adult and childhood cancers, highlight dysregulation of developmental pathways as an important mechanism underlying MBs, and identify a role for a specific type of histone methylation in human tumorigenesis.

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Objective: To assess, in patients undergoing glossectomy, the influence of the palatal augmentation prosthesis on the speech intelligibility and acoustic spectrographic characteristics of the formants of oral vowels in Brazilian Portuguese, specifically the first 3 formants (F1 [/a,e,u/], F2 [/o,o,u/], and F3 [/a,o/]). Design: Speech evaluation with and without a palatal augmentation prosthesis using blinded randomized listener judgments. Setting: Tertiary referral center. Patients: Thirty-six patients (33 men and 3 women) aged 30 to 80 (mean [SD], 53.9 [10.5]) years underwent glossectomy (14, total glossectomy; 12, total glossectomy and partial mandibulectomy; 6, hemiglossectomy; and 4, subtotal glossectomy) with use of the augmentation prosthesis for at least 3 months before inclusion in the study. Main Outcome Measures: Spontaneous speech intel-ligibility (assessed by expert listeners using a 4-category scale) and spectrographic formants assessment. Results: We found a statistically significant improvement of spontaneous speech intelligibility and the average number of correctly identified syllables with the use of the prosthesis (P < .05). Statistically significant differences occurred for the F1 values of the vowels /a,e,u/; for F2 values, there was a significant difference of the vowels /o,o,u/; and for F3 values, there was a significant difference of the vowels la,61 (P < .001). Conclusions: The palatal augmentation prosthesis improved the intelligibility of spontaneous speech and syllables for patients who underwent glossectomy. It also increased the F2 and F3 values for all vowels and the F I values for the vowels /o,o,u/. This effect brought the values of many vowel formants closer to normal.

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Successful surgical treatment of deep bowel endometriosis depends on obtaining detailed information about the lesions, prior to the procedure. The objective of this study was to determine the capability of transvaginal ultrasonography with bowel preparation (TVUS-BP) to predict the presence of one or more rectosigmoid nodules and the deepest bowel layer affected by the disease. A prospective study of 194 patients with clinical and TVUS-BP suspected deep endometriosis submitted to videolaparoscopy. Image data were compared with surgical and histological results. With respect to bowel nodule detection and presence of at least two rectosigmoid lesions, TVUS-BP had a sensitivity of 97 and 81%, specificity 100 and 99%, positive predictive value (PPV) 100 and 93% and negative predictive value (NPV) 98 and 96%, respectively. Regarding diagnosis of infiltration of the submucosal/mucosal layer, TVUS-BP had a sensitivity of 83%, specificity 94%, PPV 77%, NPV 96%. These findings show that TVUS-BP is an adequate exam for evaluating the presence of one or more rectosigmoid nodules and the deepest layer affected in deep infiltrating bowel endometriosis, confirming the importance of this technique for defining the most appropriate surgical strategy to be implemented.

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The present study was designed to explore the correlation between the frequency of micronuclei in Trad-MN, measured across 28 biomonitoring stations during the period comprised between 11 of May and 2 of October, 2006, and adjusted mortality rates due to cardiovascular, respiratory diseases and cancer in Sao Jose dos Campos, Brazil, an area with different sources of air pollution. For controlling purposes, mortality rate due to gastrointestinal diseases (an event less prone to be affected by air pollution) was also considered in the analysis. Spatial distribution of micronuclei frequency was determined using average interpolation. The association between health estimators and micronuclei frequency was determined by measures of Pearson`s correlation. Higher frequencies of micronuclei were detected in areas with high traffic and close to a petrochemical pole. Significant associations were detected between micronuclei frequency and adjusted mortality rate due to cardiovascular diseases (r = 0.841, p = 0.036) and cancer (r = 0.890, p = 0.018). The association between mortality due to chronic obstructive pulmonary diseases was positive but did not reach statistical significance (r = 0.640, p = 0.172), probably because of the small number of events. Gastrointestinal mortality did not exhibit significant association with micronuclei frequency. Because the small number of observations and the nature of an ecological study, the present findings must be considered with caution and considered as preliminary. Further studies, performed in different conditions of contamination and climate should be done before considering Trad-MN in the evaluation of human health risk imposed by air pollutants. (C) 2009 Elsevier Ltd. All rights reserved.

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In a cross-sectional study involving 62 patients with systemic lupus erythematosus (SLE), we found that patients with biopsy-proven lupus nephritis (LN) had higher titers of anti-C1q antibodies than active SLE without nephritis patients. Anti-C1q was associated with a negative predictive value of 94.59%, a positive predictive value of 52%, a sensitivity of 86.66% and a specificity of 74.47% for the diagnosis of LN. We conclude that high titers of anti-C1q antibodies are strongly associated with the presence of active LN, and the negative predictive value of this test for diagnosing LN is very high; therefore, it can influence therapeutic decisions and reduce the number of renal biopsies in patients with SLE. Copyright (C) 2011 S. Karger AG, Basel

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The purpose of this study was to determine whether bone marrow-derived cells can differentiate into myofibroblasts, as defined by alpha-smooth muscle actin (SMA) expression, that arise in the corneal stroma after irregular phototherapeutic keratectomy and whose presence within the cornea is associated with corneal stromal haze. C578L/6J-GFP chimeric mice were generated through bone marrow transplantation from donor mice that expressed enhanced green fluorescent protein (GFP) in a high proportion of their bone marrow-derived cells. Twenty-four GFP chimeric mice underwent haze-generating corneal epithelial scrape followed by irregular phototherapeutic keratectomy (PTK) with an excimer laser in one eye. Mice were euthanized at 2 weeks or 4 weeks after PTK and the treated and control contralateral eyes were removed and cryo-preserved for sectioning for immunocytochemistry. Double immunocytochemistry for GFP and myofibroblast marker alpha-smooth muscle actin (SMA) were performed and the number of SMA+GFP+, SMA+GFP, SMA-GFP+ and SMA GFP cells, as well as the number of DAPI+ cell nuclei, per 400x field of stroma was determined in the central, mid-peripheral and peri-limbal cornea. In this mouse model, there were no SMA+ cells and only a few GFP+ cells detected in unwounded control corneas. No SMA+ cells were detected in the stroma at two weeks after irregular PTK, even though there were numerous GFP+ cells present. At 4 weeks after irregular PTK, all corneas developed mild to moderately severe corneal haze. In each of the three regions of the corneas examined, there were on average more than 9x more SMA+GFP+ than SMA+GFP myofibroblasts. This difference was significant (p < 0.01). There were significantly more (p < 0.01) SMA GFP+ cells, which likely include inflammatory cells, than SMA+GFP+ or SMA+GFP cells, although SMA GFP cells represent the largest population of cells in the corneas. In this mouse model, the majority of myofibroblasts developed from bone marrow-derived cells. It is possible that all myofibroblasts in these animals developed from bone marrow-derived cells since mouse chimeras produced using this method had only 60-95% of bone marrow-derived cells that were GFP+ and it is not possible to achieve 100% chimerization. This model, therefore, cannot exclude the possibility of myofibroblasts also developed from keratocytes and/or corneal fibroblasts. (C) 2010 Elsevier Ltd. All rights reserved.

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Objectives To determine TCR excision circle (TREC) levels, a marker of recent thymic emigrants, in the peripheral lymphocyte pool of rheumatoid factor-negative (RF circle divide) polyarticular juvenile idiopathic arthritis (JIA) children. Materials and methods We studied TREC levels in peripheral blood mononuclear cells (PBMC) in 30 RF circle divide polyarticular JIA children with active disease and in 30 age- and gender-matched healthy controls. Signal-joint TREC concentration was determined by real-time quantitative-PCR as the number of TREC copies/mu g PBMC DNA gauged by a standard curve with known number of TREC-containing plasmids. Results TREC levels in PBMC were significantly lower in JIA (4.90 +/- 3.86 x 10(4) TRECs/mu g DNA) as compared to controls (10.45 +/- 8.45 x 10(4) TRECs/mu g DNA, p=0.001). There was an inverse correlation between age and TREC levels in healthy children (r=-0.438, p=0.016) but not in JIA. No clinical association was observed between TREC levels and disease activity and use of oral steroids and methotrexate. Conclusions The finding of decreased PBMC TREC levels in RF circle divide polyarticular JIA children is consistent with a low proportion of recent thymus emigrants. This may interfere with the equilibrium between populations of polyclonal and naive T cells versus oligoclonal memory auto-reactive T cells and, therefore, may hinder the maintenance of immune tolerance in this disease.

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Purpose: To evaluate the ability of the GDx Variable Corneal Compensation (VCC) Guided Progression Analysis (GPA) software for detecting glaucomatous progression. Design: Observational cohort study. Participants: The study included 453 eyes from 252 individuals followed for an average of 46 +/- 14 months as part of the Diagnostic Innovations in Glaucoma Study. At baseline, 29% of the eyes were classified as glaucomatous, 67% of the eyes were classified as suspects, and 5% of the eyes were classified as healthy. Methods: Images were obtained annually with the GDx VCC and analyzed for progression using the Fast Mode of the GDx GPA software. Progression using conventional methods was determined by the GPA software for standard automated achromatic perimetry (SAP) and by masked assessment of optic disc stereophotographs by expert graders. Main Outcome Measures: Sensitivity, specificity, and likelihood ratios (LRs) for detection of glaucoma progression using the GDx GPA were calculated with SAP and optic disc stereophotographs used as reference standards. Agreement among the different methods was reported using the AC(1) coefficient. Results: Thirty-four of the 431 glaucoma and glaucoma suspect eyes (8%) showed progression by SAP or optic disc stereophotographs. The GDx GPA detected 17 of these eyes for a sensitivity of 50%. Fourteen eyes showed progression only by the GDx GPA with a specificity of 96%. Positive and negative LRs were 12.5 and 0.5, respectively. None of the healthy eyes showed progression by the GDx GPA, with a specificity of 100% in this group. Inter-method agreement (AC1 coefficient and 95% confidence intervals) for non-progressing and progressing eyes was 0.96 (0.94-0.97) and 0.44 (0.28-0.61), respectively. Conclusions: The GDx GPA detected glaucoma progression in a significant number of cases showing progression by conventional methods, with high specificity and high positive LRs. Estimates of the accuracy for detecting progression suggest that the GDx GPA could be used to complement clinical evaluation in the detection of longitudinal change in glaucoma. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references. Ophthalmology 2010; 117: 462-470 (C) 2010 by the American Academy of Ophthalmology.

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P>Natural killer (NK) cells bridge the interface between innate and adaptive immunity and are implicated in the control of herpes simplex virus 2 (HSV-2) infection. In subjects infected with human immunodeficiency virus 1 (HIV-1), the critical impact of the innate immune response on disease progression has recently come into focus. Higher numbers of NK cells are associated with lower HIV-1 plasma viraemia. Individuals with the compound genotype of killer cell immunoglobulin-like receptor (KIR) 3DS1 and human leucocyte antigen (HLA)-Bw4-80I, or who have alleles of KIR3DL1 that encode proteins highly expressed on the NK cell surface, have a significant delay in disease progression. We studied the effect of HSV-2 co-infection in HIV-1-infected subjects, and show that HSV-2 co-infection results in a pan-lymphocytosis, with elevated absolute numbers of CD4+ and CD8+ T cells, and NK cells. The NK cells in HSV-2 co-infected subjects functioned more efficiently, with an increase in degranulation after in vitro stimulation. The number of NK cells expressing the activating receptors NKp30 and NKp46, and expressing KIR3DL1 or KIR3DS1, was inversely correlated with HIV-1 plasma viral load in subjects mono-infected with HIV-1, but not in subjects co-infected with HSV-2. This suggests that HSV-2 infection mediates changes within the NK cell population that may affect immunity in HIV-1 infection.

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Tetralogy of Fallot (TOF), the most common severe congenital heart malformation, occurs sporadically, without other anomaly, and from unknown cause in 70% of cases. Through a genome-wide survey of 114 subjects with TOF and their unaffected parents, we identified 11 de novo copy number variants (CNVs) that were absent or extremely rare (<0.1%) in 2,265 controls. We then examined a second, independent TOF cohort (n = 398) for additional CNVs at these loci. We identified CNVs at chromosome 1q21.1 in 1% (5/512, P = 0.0002, OR = 22.3) of nonsyndromic sporadic TOF cases. We also identified recurrent CNVs at 3p25.1, 7p21.3 and 22q11.2. CNVs in a single subject with TOF occurred at six loci, two that encode known (NOTCH1, JAG1) disease-associated genes. Our findings predict that at least 10% (4.5-15.5%, 95% confidence interval) of sporadic nonsyndromic TOF cases result from de novo CNVs and suggest that mutations within these loci might be etiologic in other cases of TOF.

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Background: Since its introduction, laparoscopic colorectal surgery has raised intense debate and controversies regarding its safety and effectiveness. Methods: This multicentric registry reports the experience of 28 Brazilian surgical teams specializing in laparoscopic colorectal surgery. Results: Between 1992 and 2007, 4744 patients (1994 men-42% and 2750 women-58%) were operated upon, with ages ranging from 13 to 94 years (average 57.5y). Benign diseases were diagnosed in 2356 patients (49.6%). Most diseases were located in 50.7% of the left and sigmoid colon, 28.2% in the rectum and anal canal. 8.0% in the right colon, and diffuse 7.0%. There were 181 (3.8%) intraoperative complications (from 0% to 14%). There were 261 (5.5%) reported conversions to laparotomy (from 0% to 16.5%), mainly during the early experience (n = 119 - 59.8%). Postoperative complications were registered in 683 (14.5%) patients (from 5.0% to 50%). Mortality occurred in 43 patients (0.8%). Surgeons who performed less than 50 cases reported similar rates of intraoperative (4.2% vs. 3.8%,- P = 0.7), postoperative complications (20.8% vs. 14.3%; P = 0.07), and mortality (1.0% vs. 0.9%; P = 0.5) but the conversion rate was higher (10.4% vs. 5.4%; P = 0.04). Two thousand three hundred and eighty-nine (50.4%) malignant tumors were operated upon, and histologic classification showed 2347 (98%) adenocarcinomas, 30 (0.6%) spinocelular carcinomas, and 12 (0.2%) other histologic types. Tumor recurrence rate was 16.3% among patients followed more than I year. After an average follow-Lip of 52 months, 19 (0.8%) parietal recurrences were reported, 18 of which were in port sites and I in a patient with disseminated disease. There was no incisional recurrence in the ports used to withdraw the pathologic specimen. Compared with other registries, there was a 75% increase in the number of groups pet-forming laparoscopic colorectal surgery and a decrease in conversions (from 10.5%. to 5.5%) and mortality (from 1.5% to 0.9%) rates. Conclusions: (1) The number of patients operated upon increased expressively during the last years; (2) operative indications for benign and malignant diseases were similar, and diverticular disease of the colon comprised 40% of the benign ones; (3) conversion and mortality rates decreased over time; (4) Surgeon`s experience did not influence the complication rates, but was associated with a lower conversion; and (5) oncologic outcome expressed by recurrence rates showed results similar to those reported in conventional surgery.

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The human brain is often considered to be the most cognitively capable among mammalian brains and to be much larger than expected for a mammal of our body size. Although the number of neurons is generally assumed to be a determinant of computational power, and despite the widespread quotes that the human brain contains 100 billion neurons and ten times more glial cells, the absolute number of neurons and glial cells in the human brain remains unknown. Here we determine these numbers by using the isotropic fractionator and compare them with the expected values for a human-sized primate. We find that the adult male human brain contains on average 86.1 +/- 8.1 billion NeuN-positive cells (""neurons"") and 84.6 +/- 9.8 billion NeuN-negative (""nonneuronal"") cells. With only 19% of all neurons located in the cerebral cortex, greater cortical size (representing 82% of total brain mass) in humans compared with other primates does not reflect an increased relative number of cortical neurons. The ratios between glial cells and neurons in the human brain structures are similar to those found in other primates, and their numbers of cells match those expected for a primate of human proportions. These findings challenge the common view that humans stand out from other primates in their brain composition and indicate that, with regard to numbers of neuronal and nonneuronal cells, the human brain is an isometrically scaled-up primate brain. J. Comp. Neurol. 513:532-541, 2009. (c) 2009 Wiley-Liss, Inc.

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PURPOSE: To report clinical outcomes of the treatment of ocular Demodex folliculorum with oral ivermectin. DESIGN: Noncomparative, interventional case series. METHODS: Setting. Institutional. Study Population. Twenty-four eyes of 12 patients (3 male and 9 female; mean age +/- standard deviation, 50.4 +/- 21.0 years) with refractory posterior blepharitis with the presence of D. folliculorum in lash samples were enrolled in this study. Intervention. Patients were instructed to take 1 dose of oral ivermectin (200 mu g/kg). All patients were instructed to repeat the treatment after 7 days. Main outcome measures. Tear meniscus height, Schirmer I test results, noninvasive tear film break-up time (BUT), quantification of the absolute number of D. folliculorum found in the lashes, and corneal fluorescein and rose bengal staining scores were obtained from all patients 1 day before and 28 days after treatment. RESULTS: Statistical improvement was observed in the absolute number of D. folliculorum found in the lashes after the treatment with oral ivermectin. Average values of Schirmer I test results and tear film break-up time improved statistically after the treatment of oral ivermectin. No statistical improvement was observed in average lacrimal meniscus height or value of corneal fluorescein and rose bengal staining after treatment with oral ivermectin. CONCLUSIONS: Ivermectin successfully reduced the number of D. folliculorum found in the lashes of patients with refractory blepharitis. Oral ivermectin may be very useful as a complement in the treatment of D. folliculorum infestation with ocular manifestation, especially in cases of unsuccessful treatment related to patient compliance. (Am J Ophthalmol 2011;151:1030-1034. (C) 2011 by Elsevier Inc. All rights reserved.)

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Context.-Studies analyzing the concordance of biopsy and radical prostatectomy (RP) Gleason scores have limitations. Some included 2 or more centers, used historical controls from the early prostate specific antigen era or lacked a clear definition of the biopsy schemes. Furthermore, most did not control the results for prostate volume. Objective.-To confirm whether prediction of RP Gleason score can be optimized by taking more biopsy cores in a contemporary series of patients, with pathologic samples analyzed by the same pathologist, and controlling these results for prostate volume. Design.-The study comprised a retrospective case-control analysis of 393 patients with prostate cancer treated with RP. Patients were divided into 3 groups: those in group 1 underwent a 6-core biopsy; group 2, an 8-core biopsy; and group 3, a 10 or more-core biopsy. Concordance rates between biopsy and RP Gleason scores, as well as the rates of undergrading and overgrading, were determined for each biopsy scheme. Results.-Concordance rates were 60.9%, 58.3%, and 64.6% for patients from groups 1, 2, and 3, respectively (P = .18). When we analyzed patients with prostate volumes of less than 50 cm(3), concordance rates were 58.3%, 58.3%, and 65.1% for each group, respectively (P = .03). Among patients with prostate volumes of 50 cm3 or more, concordance rates were 70%, 58.1%, and 63.6%, respectively (P = .66). Conclusions.-Taking 10 or more cores can improve the prediction of RP Gleason score in patients with prostate volumes of less than 50 cm3. For patients with prostate volumes of 50 cm3 or more, increasing the biopsy cores to 10 or more did not improve prediction of RP Gleason score.