Padronização da pesquisa de linfonodos sentinelas em estômago por métodos combinados

Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas, Pós-Graduação em Ciências da Cirurgia, Campinas, 2012.Introdução - Com os estudos de Gould et al. (1960), Cabanas (1977) e Morton et al. (1992), estabeleceu-se o conceito da pesquisa do linfonodo sentinela. Esse se baseia na teoria de que ao identificar a presença ou ausência de metástase no primeiro linfonodo que recebe a drenagem linfática a partir do tumor (sentinela), poderia representar o estado de acometimento dos outros linfonodos. Isto evitaria a realização desnecessária de linfadenectomias. Com o passar dos anos, foi consagrada para ser aplicada em casos de melanoma e câncer de mama. Nesta última década, tenta-se estender os princípios da utilização da pesquisa de linfonodo sentinela para os cânceres do aparelho digestivo. Entretanto, no caso do estômago, existem algumas dificuldades, como: presença de sistema de drenagem linfática multidirecional, ocorrência de metástases saltatórias e identificação de mais de um linfonodo sentinela por indivíduo. Objetivo - Criar e padronizar um modelo animal para o treinamento de pesquisa de linfonodos sentinelas em estômago. Método - Trinta e dois coelhos, saudáveis, foram submetidos à anestesia exclusivamente intramuscular. Por meio de laparotomia, foi injetado na subserosa da parede anterior do corpo gástrico, 0,1 ml de fitato marcado com tecnécio-99m (0,2 mCi), em seguida pelo mesmo orifício, de 0,2 ml de Azul Patente V® 2,5%. A cavidade abdominal foi avaliada, in vivo , para pesquisa de suspeitas de linfonodos azuis (corados em azul) e com detector manual de radiação gamma aos 5, 10 e 20 minutos para detecção de suspeitas de linfonodos radioativos (radioatividade identificada superior a 10X o valor apresentado pelo fundo). Após 20 minutos, realizou-se ressecção e exérese total do estômago, baço e suspeitas de linfonodos, para posterior avaliação da radioatividade ex vivo . A seguir, encaminharam-se as suspeitas de linfonodos para estudo histológico para identificação de tecido linfóide. Resultados - Foram identificados linfonodos em 30 coelhos (93,75%) com média de 2,2 por animal. Das 90 suspeitas de linfonodos detectadas, em 70 casos (77,77%) obteve-se confirmação histológica para tecido linfóide. Dessas, a maioria foi identificada e localizada na região entre o esôfago e o fundo gástrico durante a avaliação in vivo aos 5 minutos. Dois coelhos faleceram durante os experimentos (Taxa de mortalidade = 6,25%). Conclusão - O modelo experimental em coelhos para pesquisa de linfonodos sentinelas em estômago por métodos combinados foi factível, de fácil execução e baixa mortalidade, podendo ser usado para treinamento.Abstract : Introduction - The concept of sentinel lymph node was established by the studies of Gould et al. (1960), Cabanas (1977) and Morton et al. (1992). It is based on the theory that, whenever the presence or absence of metastasis is identified in the first lymph node that receives the lymphatic drainage from the tumor (sentinel) the status of involvement of other lymph nodes might be infered. This could avoid the performance of unnecessary lymphadenectomies. Over the years, its use was consecrated by its application in melanoma and breast cancer. In the last decade, attempts have been made to extend the principles of sentinel lymph node investigation to cancers of the digestive tract. In the case of stomach cancer, additional difficulties were found, such as multiple and aberrant lymphatic routes, the occurrence of skip metastasis and the possible identification of more than one sentinel lymph node in the same patient. Aim - To develop and evaluate an animal model for training sentinel lymph node navigation in the stomach. Methods - Thirtytwo healthy rabbits, were prepped and given intramuscular anesthesia. Through a formal laparotomy, they received a subserosal injection of 0.1 ml of phytate labeled with technetium-99m (0.2 mCi) in the anterior wall of the gastric corpus, followed by 0.2 ml of Blue Patent ® V 2.5%, through the same puncture site. Suspicious lymph nodes were searched in-vivo at 5, 10 and 20 minutes, both visually (Blue Patent stained lymph nodes) and with a manual gamma radiation detector (to detect suspected radioactive lymph nodes, displaying radioactivity levels over 10X the value displayed by the background). En-block resection of the stomach, spleen, visible limph nodes and local fat tissue was then performed and the specimen was assessed "ex vivo" for radioactivity. Suspected lymph nodes were sent for histological study to evaluate the presence of lymphoid tissue. Results Radiolabeled or stained lymph nodes were identified in 30 rabbits (93.75%) with an average of 2.2 specimens per animal; of the 90 suspicious lymph nodes detected, histology confirmed lymphoid tissue in 70 cases (77.77%). Most lymph nodes were identified at the 5-minute in-vivo evaluation and their most common location was found to be in the region between the esophagus and the gastric fundus. Two rabbits died during the procedure resulting in a 6.25% mortality. Conclusion - The rabbit model proved adequate for training in sentinel node navigation in the stomach by combined methods (dye and radiocolloid) being easy to execute and associated with low mortality

Tunghang (Asia) Co., Ltd v Shenzhen Haizhongbao Aquatic Products Trading Co., Ltd

This book focuses on Chinese cases on the CISG decided by Chinese courts of all levels, mainly from 1990 to 2005. During this period, the number of cases grew gradually

Database Mining of Zeolite Structures

Zeolites are widely used in industrial applications such as ion exchange, gas separation and adsorption, and organic catalysis. In particular, in petroleum refining and petrochemical productions, zeolites are catalysts of utmost importance. In order to classify the known zeolites and correlate the structures with their unique properties, an online Database of Zeolite Structures was established in 1996 and continuously developed by Baerlocher and McCusker at ETH-Zürich. The database contains a lot of useful structural information such as unit cell dimensions, space group, atomic coordinates of tetrahedra (T) atoms, secondary building units (SBUs), composite building units (CBUs), natural tilings, simulated powder X-ray diffraction (PXRD), etc. It has served the zeolite community for more than 20 years and has made great contributions to the development of zeolites and zeolite-related fields. In this article, we take a further step to mine the intrinsic structural information on zeolites including characteristic unit cell dimensions, butterfly layers, zeolites containing the same building layers, ABC-6 zeolite family, and recently discovered embedded isoreticular <b>RHO</b> family. The database mining of zeolite structures will shed light not only on structural correlations of related existing zeolites but also the structure determination and the further prediction of novel zeolite structures based on the existing ones, which will facilitate the target synthesis of energetically feasible hypothetical zeolite structures

A workflow of massive identification and application of intron markers using snakes as a model

<a></a><a>NEXUS alignments for phylogenetic analyses</a> and the candidate database of our newly-developed intron markers (nucleotide sequence of the1,273 marker candidates)<br

Misfit Stresses Caused by Atomic Size Mismatch: The Origin of Doping-Induced Destabilization of Dicalcium Silicate

Density functional theory (DFT) simulations are carried out to systemically investigate doping in dicalcium silicate (Ca₂SiO₄: C₂S), a major phase in calcium silicate cements. By evaluating the energetics of defect formation mechanisms for species involving Na⁺, K⁺, Mg²⁺, Sr²⁺, Al³⁺, Fe³⁺, B³⁺, and Ge⁴⁺, we find a strong site preference for all cationic substitutions. As a result, distinct defects form at low dopant concentrations (i.e., ≤ 0.52 atom %), in which, expectedly, larger dopants prefer (larger) Ca²⁺ sites, while smaller dopants favor (smaller) Si⁴⁺ sites, with charge balance being ensured by the formation of vacancies. Such site preferences arise due to local atomic distortions, which are induced when doping occurs at unfavorable substitution sites. Interestingly, we note that the formation enthalpy of each substitutional defect is proportional to the size mismatch between the dopant and the native cations. This indicates that the destabilization of the C₂S structure has its origins in an “atomic size misfit” which develops while accommodating defects in the C₂S lattice. The outcomes resulting from this work provide insights that are needed to select dopants to optimize cement performance by compositional design

Micro-CT scan images of the autograft group (A, B) and scaffold group (C, D) at 4 weeks (A, C) and 16 weeks (B, D) postoperatively.

<p>(E) The average bone tunnel area in the scaffold group was significantly smaller than that in the autograft group at week 4. There was no significant difference between the two groups at week 16. * Significant difference between groups.</p

Histological observation of grafts in the autograft group (A, B) and scaffold group (C, D) by H&E staining at 4 weeks (A, C) and 16 weeks (B, D) postoperatively.

<p>Histological observation of grafts in the autograft group (A, B) and scaffold group (C, D) by H&E staining at 4 weeks (A, C) and 16 weeks (B, D) postoperatively.</p

Macroscopic view of grafts in the autograft group (A, B) and scaffold group (C, D) at 4 weeks (A, C) and 16 weeks (B, D) postoperatively.

<p>The arrows point to the grafts in the knee cavity.</p

Statistical evaluation of differences in failure load (A) and stiffness (B) between the autograft group and scaffold group at 4 and 16 weeks postoperatively.

<p>* Significant difference between groups.</p

A rolled-up shaft of silk-collagen scaffold, (A), with the two ends clamped by forceps.

<p>(B) Gross observation of ACL reconstruction (the black arrow points to the silk-collagen graft). (C) The auto-semitendinosus tendon (arrow) was harvested before exposing the knee joint. (D) Gross observation of ACL reconstruction (the black arrow points to the autograft).</p