NITRIC OXIDE MEDIATES LUNG VASCULAR PERMEABILITY AND LYMPH-BORNE IL-6 AFTER AN INTESTINAL ISCHEMIC INSULT

Acute lung injury following intestinal I/R depends on neutrophil-endothelial cell interactions and on cytokines drained from the gut through the lymph. Among the mediators generated during I/R, increased serum levels of IL-6 and NO are also found and might be involved in acute lung injury. Once intestinal ischemia itself may be a factor of tissue injury, in this study, we investigated the presence of IL-6 in lymph after intestinal ischemia and its effects on human umbilical vein endothelial cells (HUVECs) detachment. The involvement of NO on the increase of lung and intestinal microvascular permeability and the lymph effects on HUVEC detachment were also studied. Upon anesthesia, male Wistar rats were subjected to occlusion of the superior mesenteric artery during 45 min, followed by 2-h intestinal reperfusion. Rats were treated with the nonselective NO synthase (NOS) inhibitor L-NAME (N(omega)-nitro-L-arginine methyl ester) or with the selective inhibitor of iNOS aminoguanidine 1 h before superior mesenteric artery occlusion. Whereas treatment with L-NAME during ischemia increased both IL-6 levels in lymph and lung microvascular permeability, aminoguanidine restored the augmented intestinal plasma extravasation due to ischemia and did not induce IL-6 in lymph. On the other hand, IL-6 and lymph of intestinal I/R detached the HUVECs, whereas lymph of ischemic rats upon L-NAME treatment when incubated with anti-IL-6 prevented HUVEC detachment. It is shown that the intestinal ischemia itself is sufficient to increase intestinal microvascular permeability with involvement of iNOS activation. Intestinal ischemia and absence of constitutive NOS activity leading to additional intestinal stress both cause release of IL-6 and increase of lung microvascular permeability. Because anti-IL-6 prevented the endothelial cell injury caused by lymph at the ischemia period, the lymph-borne IL-6 might be involved with endothelial cell activation. At the reperfusion period, this cytokine does not seem to be modulated by NO.

Beyond the average: Detecting global singular nodes from local features in complex networks

Deviations from the average can provide valuable insights about the organization of natural systems. The present article extends this important principle to the systematic identification and analysis of singular motifs in complex networks. Six measurements quantifying different and complementary features of the connectivity around each node of a network were calculated, and multivariate statistical methods applied to identify singular nodes. The potential of the presented concepts and methodology was illustrated with respect to different types of complex real-world networks, namely the US air transportation network, the protein-protein interactions of the yeast Saccharomyces cerevisiae and the Roget thesaurus networks. The obtained singular motifs possessed unique functional roles in the networks. Three classic theoretical network models were also investigated, with the Barabasi-Albert model resulting in singular motifs corresponding to hubs, confirming the potential of the approach. Interestingly, the number of different types of singular node motifs as well as the number of their instances were found to be considerably higher in the real-world networks than in any of the benchmark networks. Copyright (C) EPLA, 2009

Concentric characterization and classification of complex network nodes: Application to an institutional collaboration network

Differently from theoretical scale-free networks, most real networks present multi-scale behavior, with nodes structured in different types of functional groups and communities. While the majority of approaches for classification of nodes in a complex network has relied on local measurements of the topology/connectivity around each node, valuable information about node functionality can be obtained by concentric (or hierarchical) measurements. This paper extends previous methodologies based on concentric measurements, by studying the possibility of using agglomerative clustering methods, in order to obtain a set of functional groups of nodes, considering particular institutional collaboration network nodes, including various known communities (departments of the University of Sao Paulo). Among the interesting obtained findings, we emphasize the scale-free nature of the network obtained, as well as identification of different patterns of authorship emerging from different areas (e.g. human and exact sciences). Another interesting result concerns the relatively uniform distribution of hubs along concentric levels, contrariwise to the non-uniform pattern found in theoretical scale-free networks such as the BA model. (C) 2008 Elsevier B.V. All rights reserved.

Performance of IFAT, ELISA, direct parasitological examination and PCR on lymph node aspirates for canine visceral leishmaniasis diagnosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Implication of RNA-Binding Protein La in Proliferation, Migration and Invasion of Lymph Node-Metastasized Hypopharyngeal SCC Cells

The 5-year survival rate for oral cavity cancer is poorer than for breast, colon or prostate cancer, and has improved only slightly in the last three decades. Hence, new therapeutic strategies are urgently needed. Here we demonstrate by tissue micro array analysis for the first time that RNA-binding protein La is significantly overexpressed in oral squamous cell carcinoma (SCC). Within this study we therefore addressed the question whether siRNA-mediated depletion of the La protein may interfere with known tumor-promoting characteristics of head and neck SCC cells. Our studies demonstrate that the La protein promotes cell proliferation, migration and invasion of lymph node-metastasized hypopharyngeal SCC cells. We also reveal that La is required for the expression of beta-catenin as well as matrix metalloproteinase type 2 (MMP-2) within these cells. Taken together these data suggest a so far unknown function of the RNA-binding protein La in promoting tumor progression of head and neck SCC.

Decreased production of TNF-alpha by lymph node cells indicates experimental autoimmune encephalomyelitis remission in Lewis rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sentinel node detection in cervical cancer with Tc-99m-phytate

Objectives. The aim of this study was to investigate the feasibility of sentinel lymph node (SLN) identification using radioisotopic lymphatic mapping with technetium-99 m-labeled phytate in patients undergoing radical hysterectomy with pelvic lymphadenectomy for treatment of early cervical cancer.Methods. Between July 2001 and February 2003, 56 patients with cervical cancer 1160 stage I (it 53) or stage 11 (it 3) underwent sentinel lymph node detection with preoperative lymphoscintigraphy (Te-99m-labeled phytate injected into the uterine cervix, at 3, 6, 9, and 12 o'clock, at a dose of 55-74 MBq in a volume of 0.8 ml) and intratoperative lymphatic mapping with a handheld gamma probe, Radical hysterectomy was aborted in three cases because parametrial invasion was found intraoperatively and we performed only sentinel node resection. The remaining 53 patients underwent radical hysterectomy with complete pelvic lymphadenectomy, Sentinel nodes were detected using a handheld gamma-probe and removed for pathological assessment during the abdominal radical hysterectomy and pelvic lymphadenectomy.Results. One or more sentinel nodes were detected in 52 out of 56 eligible patients (92.8%). A total of 120 SLNs were detected by lymphoscintigraphy (mean 2.27 nodes per patient) and intraoperatively by gamma probe, Forty-four percent of SLNs were found in the external iliac area, 39% in the obturator region, 8.3% in interiliae region, and 6.7),) in the common iliac area. Unilateral sentinel nodes were found in thirty-one patients (59%). The remaining 21 patients (4100 had bilateral sentinel nodes, Microscopic nodal metastases were confirmed in 17 (32%) cases. In 10 of these patients, only SLNs had metastases. The 98 sentinel node.,, that were negative on hematoxylin and eosin were submitted to cytokeratin immunohistochemical analysis. Five (5.1%) micrometastases were identified with this technique. The sensitivity of the sentinel node was 82.3% (CI 95% - 56.6-96.2) and the negative predictive value was 92.1% (CI 95% 78.6 98.3) the accuracy of sentinel node in predicting the lymph node status was 94.2%,Conclusion. Preoperative lymphoscintigraphy and intraoperative lymphatic mapping with Tc-99-labeled phytate are effective in identifying sentinel nodes in patients undergoing radical hysterectomy and to select women in whom lymph node dissection call be avoided. (c) 2005 Elsevier B.V. All rights reserved.

QK-Means: A clustering technique based on community detection and K-Means for deployment of cluster head nodes

Wireless Sensor Networks (WSN) are a special kind of ad-hoc networks that is usually deployed in a monitoring field in order to detect some physical phenomenon. Due to the low dependability of individual nodes, small radio coverage and large areas to be monitored, the organization of nodes in small clusters is generally used. Moreover, a large number of WSN nodes is usually deployed in the monitoring area to increase WSN dependability. Therefore, the best cluster head positioning is a desirable characteristic in a WSN. In this paper, we propose a hybrid clustering algorithm based on community detection in complex networks and traditional K-means clustering technique: the QK-Means algorithm. Simulation results show that QK-Means detect communities and sub-communities thus lost message rate is decreased and WSN coverage is increased. © 2012 IEEE.

Canine visceral leishmaniasis due to Leishmania (L.) infantum chagasi in Amazonian Brazil: comparison of the parasite density from the skin, lymph node and visceral tissues between symptomatic and asymptomatic, seropositive dogs

A leishmaniose visceral canina (LVC) é reconhecida pelas características clínicas da doença e é altamente letal. A infecção, entretanto, pode ser totalmente assintomática em alguns cães soropositivos, o que tem levantado questão polêmica sobre a possibilidade desses animais, serem ou não uma fonte importante da infecção para o flebotomíneo, Lutzomyia longipalpis, o principal vetor da leishmaniose visceral americana (LVA). Neste estudo foram examinados 51 cães com LVC aguda, provenientes de área endêmica de LVA no Estado do Pará, Brasil, e a carga parasitária, formas amastigotas de, na pele, linfonodo poplíteo e vísceras (fígado e baço) foi comparada com a de nove cães assintomáticos soropositivos (IFAT-IgG). Fragmentos de biópsia desses tecidos obtidos post-mortem foram processados para análise através de imunohistoquímica, usando um anticorpo policlonal contra Leishmania sp. Os testes do Qui-quadrado (X²) e Mann Whitney foram usados para avaliar as médias da densidade de macrófagos infectados (p < 0,05). Os resultados mostraram que não houve diferença (p > 0,05) na densidade de macrófagos infectados da pele (10,7/mm² x 15,5/mm²) e do linfonodo (6,3/mm² x 8,3/mm²) entre cães assintomáticos e sintomáticos. Entretanto, a densidade de macrófagos infectados da víscera de cães sintomáticos (5,3/mm²) foi maior (p < 0,05) que a de cães assintomáticos (1,4/mm²). Estes resultados sugerem, fortemente, que cães naturalmente infectados por L. (L.) i. chagasi, assintomáticos ou sintomáticos, podem servir como fonte de infecção, principalmente, considerando-se que a densidade de macrófagos infectados da pele (10,7/mm² x 15,5/mm²), local onde o flebotomíneo vetor Lu. longipalpis realiza a hematofagia, foi maior (p < 0,05) que as do linfonodo (6,3/mm² x 8.3/mm²) e vísceras (1,4/mm2x 5,3/mm2).

Diagnóstico de paratuberculose por biópsia retal em búfalos

Foram realizadas biópsias retais de 140 búfalos, machos e fêmeas, das raças Murrah e mestiços de Murrah com Mediterrâneo, com idade acima de três anos, em uma propriedade no município de São Mateus, Maranhão, Brasil. Adicionalmente foram realizadas necropsias de 11 búfalos, para realizar um estudo comparativo entre os achados das biópsias retais e de tecidos de íleo e linfonodo mesentérico. A propriedade apresentava histórico de animais com emagrecimento progressivo e diarreia não responsiva a antimicrobianos. Os búfalos apresentavam sinais clínicos caracterizados por diarreia, estado nutricional regular a ruim, desidratação e edema submandibular. Nas biópsias retais seis búfalos apresentaram lesões sugestivas da paratuberculose na Hematoxilina-Eosina (HE), sendo estas caracterizadas por inflamação granulomatosa multifocal moderada na lâmina própria com macrófagos epitelioides. Em quatro animais foram observadas adicionalmente células gigantes do tipo Langhans. Em 15 búfalos foi observado infiltrado linfocitário multifocal leve na lâmina própria. Pela coloração de Ziehl-Neelsen (ZN), 4,3% (6/140) apresentaram bacilos álcool-ácido resistentes (BAAR) e na PCR em tempo real (qPCR), 5,71% (7/140) tiveram amplificação do material genético. Foram necropsiados 11 búfalos, à necropsia foram observados aumento de linfonodos mesentéricos com áreas esbranquiçadas na superfície de corte; intestino delgado e grosso com dobras transversais evidentes, mucosa espessada e irregular, de aspecto reticulado, placas de Peyer evidentes e conteúdo líquido e marrom. Ainda se viam áreas espessadas em torno da válvula ileocecal e vasos linfáticos evidentes. As lesões histológicas localizadas no intestino delgado e linfonodos mesentéricos de quatro búfalos foram compatíveis com lesões já descritas na literatura, e apresentaram BAAR e amplificação de material genético na qPCR. A concordância entre a biópsia retal e a análise dos tecidos de íleo e linfonodo mesentérico, segundo o teste Kappa (K=0,792), foi alta. A biópsia retal realizada demonstrou ser promissora e pode ser empregada, juntamente com outras técnicas, para auxiliar no diagnóstico ante mortem em búfalos de rebanhos com suspeita de paratuberculose; pela mesma foi possível detectar animais positivos através da coloração de ZN e qPCR. Os resultados obtidos podem ser utilizados no controle da enfermidade para selecionar e eliminar animais positivos do rebanho, diminuindo gradualmente, a disseminação do agente no ambiente, e a consequente contaminação de outros animais.

Topoisomerase expression in oral squamous cell carcinoma: relationship with cancer stem cells profiles and lymph node metastasis

BACKGROUND: The relationship between predictive proteins and tumors presenting cancer stem cells (CSCs) profiles in oral tumors is still poorly understood. This study aims to identify the relationship between topoisomerases I, II alpha, and III alpha and putative CSCs immunophenotype in oral squamous cell carcinoma (OSCC) and determine its influence on prognosis. METHODS: The following data were retrieved from 127 patients: age, gender, primary anatomic site, smoking and alcohol intake, recurrence, metastases, histologic classification, treatment, and survival. An immunohistochemical study for topoisomerases I, II alpha, and III alpha was performed in a tissue microarray containing 127 paraffin blocks of OSCCs. RESULTS: In univariate analysis, topoisomerases expression showed significant differences according to CSCs profiles and p53 immunoexpression, but not with survival. Topoisomerases II alpha and III alpha also showed significant relationship with lymph node metastasis. The multivariate test confirmed these associations. CONCLUSIONS: The results that all topoisomerases correlates with OSCC CSCs may indicate a role for topoisomerases in head and neck carcinogenesis. Notwithstanding, it is plausible that other members of topoisomerases family could represent novel therapeutical targets in oral squamous cell carcinoma. J Oral Pathol Med (2012) 41: 762-768