Cirugía derivativa más radioterapia intraoperatoria y externa en el carcinoma de páncreas localizado e irresecable

Presentamos una serie de 25 casos de carcinomas de páncreas localmente avanzados e irresecables, sin metástasis a distancia, tratados con cirugía derivativa, radioterapia intraoperatoria e irradiación externa: 18 tumores de cabeza (16 con ictericia obstructiva) y 7 de cuerpo. Se realizó derivación biliar en 18 y gastroyeyunostomía en 19. La mortalidad operatoria fue nula, con una morbilidad del 16%. A largo plazo se produjeron 3 hemorragias digestivas, 2 ictericias obstructivas, una colangitis y una obstrucción intestinal. Se obtuvo un 72% de control local de la enfermedad y todos los fallecidos por progresión tumoral desarrollaron metástasis hepáticas y/o peritoneales. Presentaban dolor pancreático 22 pacientes y 20 experimentaron remisión del mismo en una a 2 semanas. La analgesia fue definitiva en 12 y reapareció el dolor tardíamente en ocho. La supervivencia media fue de 9 meses (rango 4-24). La revisión de la literatura pone de manifiesto la indicación de la radioterapia externa tanto en el carcinoma de páncreas irresecable y no metastásico como en los resecados. La asociación de radioterapia intraoperatoria tiene, así mismo, un papel importante en cuanto a supervivencia, paliación del dolor y de la progresión local. El 5-fluorouracilo asociado al tratamiento radioterápico prolonga significativamente la supervivencia con una morbilidad razonable

Versatile Graphene-Based Platform for Robust Nanobiohybrid Interfaces

Technologically useful and robust graphene-based interfaces for devices require the introduction of highly selective, stable, and covalently bonded functionalities on the graphene surface, whilst essentially retaining the electronic properties of the pristine layer. This work demonstrates that highly controlled, ultrahigh vacuum covalent chemical functionalization of graphene sheets with a thiol-terminated molecule provides a robust and tunable platform for the development of hybrid nanostructures in different environments. We employ this facile strategy to covalently couple two representative systems of broad interest: metal nanoparticles, via S-metal bonds, and thiol-modified DNA aptamers, via disulfide bridges. Both systems, which have been characterized by a multi-technique approach, remain firmly anchored to the graphene surface even after several washing cycles. Atomic force microscopy images demonstrate that the conjugated aptamer retains the functionality required to recognize a target protein. This methodology opens a new route to the integration of high-quality graphene layers into diverse technological platforms, including plasmonics, optoelectronics, or biosensing. With respect to the latter, the viability of a thiol-functionalized chemical vapor deposition graphene-based solution-gated field-effect transistor array was assessed

Lymphoma of the gastric stump: report of a case

We report a case of primary lymphoma on a previously resected stomach in a 62-year-old man. The patient was treated 22 years earlier with a partial gastrectomy and Billroth II reconstruction for a benign gastric ulcer. The rarity of this entity and its possible relationship with pseudolymphoma or lymphoid nodular hyperplasia is discussed, and the literature is reviewed

MAP entropy estimation: applications in robust image filtering

We introduce a new approach for image filtering in a Bayesian framework. In this case the probability density function (pdf) of thelikelihood function is approximated using the concept of non-parametric or kernel estimation. The method is based on the generalizedGaussian Markov random fields (GGMRF), a class of Markov random fields which are used as prior information into the Bayesian rule, whichprincipal objective is to eliminate those effects caused by the excessive smoothness on the reconstruction process of images which arerich in contours or edges. Accordingly to the hypothesis made for the present work, it is assumed a limited knowledge of the noise pdf,so the idea is to use a non-parametric estimator to estimate such a pdf and then apply the entropy to construct the cost function for thelikelihood term. The previous idea leads to the construction of Maximum a posteriori (MAP) robust estimators, since the real systems arealways exposed to continuous perturbations of unknown nature. Some promising results of three new MAP entropy estimators (MAPEE) forimage filtering are presented, together with some concluding remarks

Application of Photogrammetry in Biomedical Science

Peer reviewedPostprin

Cáncer de esófago (I): Valoración epidemiológica, clínica y diagnóstica según el tipo histológico

From 1975 to 1991, sixty-eight patients were treated with surgery for esophageal cancer at the Clinica Universitaria de Navarra. This study involves an analysis of epidemiologic and predisposing risk factors in relation with the histologic type of tumor: epidermoid carcinoma vs. adenocarcinoma. The difference in mean age of males (60,5 yrs.) as compared with that of females (48,7 yrs.) was statistically significant (p < 0,05). Likewise, the mean age of patients with epidermoid carcinoma (57,8 yrs.) was significant lower (p < 0,01) as compared with that of those with adenocarcinoma (66,3 yrs.). Smoking and alcoholism were common in the group of patients with epidermoid carcinoma, while Barrett's esophagus and hiatal hernia were frequently seen in patients with adenocarcinoma. Dysphagia was the most frequent symptom both at the start of disease (75%) and with the diagnosis established (96,7%). There was no significant difference in the symptomatology of patients with one type of tumor or the other. The efficacy of ancillary diagnostic procedures such as barium swallow, esophagoscopy, computerized tomography and biopsy were likewise assessed. The most frequent site of tumor was at the middle third, with majority of patients being at clinical stage 1-2 of disease at the time of diagnosi

Plasma levels of leukotriene B4 during hepatic allograft rejection

At the present time, rejection is the most frequent cause of graft dysfunction in liver transplantation. Differential diagnosis between this and other possible causes of dysfunction—preservation injury, vascular, biliary, viral—may well be difficult, as the clinical and analytical findings are often similar; moreover, no markers specific to rejection are available, and histological studies are necessary for a definitive diagnosis. For this reason, markers indicating activity within the immune system need to be established so as to provide a more specific means of distinguishing rejection from other causes of graft dysfunction. The immune response to an allograft is complex, and the intricate mechanisms regulating it are still not entirely understood. Nevertheless, several specialists have drawn connections among changes in the lymphocyte subpopulations, rises in the interleukin-2 levels, expression of the interleukin-2 receptor, and alteration in the expression of antigens belonging to class II in the greater complex of histocompatibility, with rejection of the allograft. Leukotriene B4 (LTB4) is a derivative of the metabolism of arachidonic acid via 5- lipoxygenase, whose in vitro behaviour is to encourage rejection by favoring leukocyte aggregation, proliferation of T lymphocytes, interleukin-1 and -2 secretion, and the development of "natural killer" cell subpopulations. This study examines the role of LTB4 in mediating the immune response to the hepatic allograft in order to assess its usefulness in early diagnosis of rejection

An alternative approach to the tomographic reconstruction of smooth refractive index distributions

Continuous, mathematically smooth Phase Objects with radial symmetry are reconstructed from cross sections of their refractive index distribution by a novel method, consisting of a linear combination of Gaussian basis functions, whose technical details are discussed. As an application example, this approach is used to get a fast and accurate estimation of the temperature distribution of an actual soldering tip

Mechanical Biosensors in Biological and Food Area: a Review

A review of state the art about the structure, classification and operation of biosensors applied in food and biological areas is presented. This review is focused to mechanical biosensors that use mill, micro and nanocantilevers. Basic concepts of atomic force microscopy and optical systems, used as testing platform of biosensors are described. The most funcionalized strategies and geometrical configurations are also explained. Mathematical methods for evaluating the performance in static and dynamic mode of the mechanical biosensors are reviewed and examples of application in biological and food areas are provided. An overall description of the operational effect of operation conditions and design variables on the sensitivity devices is also proposed. A brief description of the design processes and manufacturing of cantilevers based silicon technology as well as information about BioMEMS and BioNEMS are provided. Finally, overall tends in research, development and commercialization of biosensors are described briefly as well as probable areas of development in food biosensors. Thereby, this review provides an overall view of biosensors, as an exploratory guide to identify the most important aspects of this technology