Influência da vagotomia gástrica proximal sobre a zona de alta pressão esofagogástrica do cão.

The influence of parietal cell vagotomy (PCV) on esophagogastric high pressure zone (HPZ) (pressure and length) was studied in 30 dogs. The animals were divided in 3 groups: group 1, 10 dogs submitted to PCV with gastric denervation until the esophagogastric junction; group 2, 10 dogs submitted to PCV with gastric denervation into esophagogastric junction and 3 cm above this; group 3 (control), 10 dogs submitted to laparotomy only. In the postoperative period (immediate and later) it wasn't observed any alteration of pressure and length of esophagogastric HPZ in three studied groups.

Cáncer gástrico en pacientes de Méderi – Hospital Universitario Mayor entre los años 2011 - 2014

Introducción: El cáncer gástrico es uno de los más frecuentes a nivel mundial y Colombia se sitúa entre los países de mayor incidencia en este tipo de patología. Objetivo: Describir las características epidemiológicas, clínicas, el tratamiento administrado y los desenlaces inmediatos de los pacientes con diagnóstico de cáncer gástrico atendidos en el Hospital Universitario Mayor de Bogotá entre los años 2011 y 2014. Metodología: Se realizó un estudio observacional descriptivo con diagnóstico de cáncer gástrico. Se realizaron análisis univariados por medio de proporciones para las variables cualitativas y medidas de tendencia central para las variables cuantitativas según la distribución. Resultados: Un total de 189 pacientes fueron analizados. El dolor fue el síntoma más frecuente en los pacientes (30.7%) y el principal signo encontrado fue una masa palpable en abdomen (9,5%). Los pacientes fueron sometidos a diferentes abordajes terapéuticos, la mayoría recibieron manejo paliativo no quirúrgico (52.9%) y la opción quirúrgica más usada en los pacientes fue la gastrectomía total (20.6%), y la subtotal (16,4) seguidas de quimioterapia y/o radiación perioperatoria. Los pacientes que sobrevivieron a los 2 años fueron 7,4% del total. Conclusiones: El registro de los pacientes con cáncer gástrico es bueno en el Méderi-Hospital Universitario Mayor es bueno y permite caracterizar los pacientes, la presentación de la patología y los resultados del tratamiento que concuerdan con los presentados en contextos similares en la literatura.

Does troncular vagotomy modify the proliferative gastric lesions induced in rats by duodenogastric reflux?

Purpose: to investigate if combining VT to DGR through the pylorus can modulate the biological behavior of PL induced by DGR and to verify if TV alone can induce morphologic lesions in the gastric mucosa. Methods: 62 male Wistar rats were assigned to four groups: 1 - Control (CT) gastrotomy; 2 - Troncular Vagotomy (TV) plus gastrotomy; 3 - Duodenogastric reflux through the pylorus (R) and 4 - Troncular vagotomy plus DGR (RTV). The animals were killed at the 54 week of the experiment. DGR was obtained by anastomosing a proximal jejunal loop to the anterior gastric wall. TV was performed through isolation and division of the vagal trunks. Gastrotomy consisted of 1 cm incision at the anterior gastric wall. PL were analyzed gross and histologically in the antral mucosa, at the gastrojejunal stoma and at the squamous portion of the gastric mucosa. Results: Groups R and RTV developed exophytic lesions in the antral mucosa (R=90.9%; RTV=100%) and at the gastrojejunal stoma (R=54.54%; RTV=63.63%). Histologically they consisted of proliferative benign lesions, without cellular atypias, diagnosed as adenomatous hyperplasia. Both groups exposed to DGR presented squamous hyperplasia at the squamous portion of the gastric mucosa (R= 54.5%; RTV= 45.4%). TV, alone, did not induce gross or histological alterations in the gastric mucosa. TV did note change the morphologic pattern of the proliferative lesions induced by DGR. Conclusions: DGR induces the development of PL in the pyloric mucosa and at the gastrojejunal stoma. TV does not change the morphologic pattern of the proliferative lesions induced by DGR. TV alone is not able to induce morphologic lesions in the gastric mucosa.

Effects of meal size and proximal-distal segmentation on gastric activity

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

Alterations of the gastric stump and not resected stomach mucosa after truncal vagotomy in rats

PURPOSE:To evaluate morphological changes of the gastric stump and not resected stomach mucosa after the completion of truncal vagotomy.METHODS:Eighty male Wistar rats were divided into four groups: CT, TV, RY and RYTV. In CT group, abdominal viscera were manipulated and the abdominal cavity was closed, in TV vagal trunks were isolated and sectioned, in RY a partial Roux-en-Y gastrectomy was performed and in RYTV the vagal trunks were sectioned and a partial Roux-en-Y gastrectomy was performed. At the 54th week after surgery, the rats were euthanized. The findings were submitted to histological analyses.RESULTS:None macroscopic or histological alterations in groups TV and CT was observed. Specimens from RY and RYTV groups did not show alterations in the gastric stump mucosa. At the jejunal side of the gastroenterostomy we found shallow ulcerative lesions always single, well-defined and with variable diameter 3 to 6 mm, six times in the RY group and none in the RYTV group (RY>RYTV, p=0.008). Neoplastic or preneoplastic lesions were not diagnosed in all groups.CONCLUSION:Truncal vagotomy is a safe and non-carcinogenic method in not resected and partially resected stomach.

Alternate current biosusceptometry for the assessment of gastric motility after proximal gastrectomy in rats: a feasibility study

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

Altered plasma response to zinc and iron tolerance test after Roux-en-Y gastric bypass

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

Scintigraphic validation of AC Biosusceptometry to study the gastric motor activity and the intragastric distribution of food in humans

Abnormal intragastric distribution of food (IDF) and a phasic contractility in the proximal stomach have been related to dyspeptic symptoms. Thus, the behaviour of the stomach and the proximal region, in particular, continues to attract attention and demand for reliable and comfortable techniques. The aims of this study were to employ AC Biosus-ceptometry (ACB) and scintigraphy to evaluate IDF and gastric motor activity in humans. Fifteen healthy volunteers ingested 60 mL of yogurt containing 2 mCi of Tc-99m and 4 g of ferrite. Each volunteer had gastric motility and IDF evaluated twice on separate days; on one occasion by ACB and another by scintigraphy. Digital signal processing was performed in MatLab (Mathworks Inc., Natick, MA, USA). Results were expressed as mean +/- SD. Similar results of distal accumulation time (P < 0.001) were obtained for scintigraphy (6.93 +/- 3.25 min) and for ACB (7.04 +/- 3.65 min). Fast Fourier Transform revealed two dominant frequencies (P > 0.9). Besides the well-know frequency of 3 cpm, our results showed identical frequencies in proximal stomach recordings (P < 0.001) for scintigraphic (1.01 +/- 0.01 cpm) and ACB (0.98 +/- 0.06 cpm). In summary, our data showed that scintigraphy and ACB are promising techniques to evaluate several aspects of gastric motility. Moreover, ACB is non-invasive, radiation-free and deserves the same importance as conventional methods for this kind of analysis.

Distribuição intragástrica de refeições com 60 ml e 180 ml: três segmentações proximal-distal empregando a cintilografia

Pós-graduação em Biologia Geral e Aplicada - IBB

The critical role and regulation of transcription factor FoxM1 in gastric cancer development and progression

The mammalian Forkhead Box (Fox) transcription factor (FoxM1) is implicated in tumorgenesis. However, the role and regulation of FoxM1 in gastric cancer remain unknown.^ I examined FoxM1 expression in 86 cases of primary gastric cancer and 57 normal gastric tissue specimens. I found weak expression of FoxM1 protein in normal gastric mucosa, whereas I observed strong staining for FoxM1 in tumor-cell nuclei in various gastric tumors and lymph node metastases. The aberrant FoxM1 expression is associated with VEGF expression and increased angiogenesis in human gastric cancer. A Cox proportional hazards model revealed that FoxM1 expression was an independent prognostic factor in multivariate analysis. Furthermore, overexpression of FoxM1 by gene transfer significantly promoted the growth and metastasis of gastric cancer cells in orthotopic mouse models, whereas knockdown of FoxM1 expression by small interfering RNA did the opposite. Next, I observed that alteration of tumor growth and metastasis by elevated FoxM1 expression was directly correlated with alteration of VEGF expression and angiogenesis. In addition, promotion of gastric tumorigenesis by FoxM1 directly and significantly correlated with transactivation of vascular endothelial growth factor (VEGF) expression and elevation of angiogenesis. ^ To further investigate the underlying mechanisms that result in FoxM1 overexpression in gastric cancer, I investigated FoxM1 and Krüppel-like factor 4 (KLF4) expressions in primary gastric cancer and normal gastric tissue specimens. Concomitance of increased expression of FoxM1 protein and decreased expression of KLF4 protein was evident in human gastric cancer. Enforced KLF4 expression suppressed FoxM1 protein expression. Moreover, a region within the proximal FoxM1 promoter was identified to have KLF4-binding sites. Finally, I found an increased FoxM1 expression in gastric mucosa of villin-Cre -directed tissue specific Klf4-null mice.^ In summary, I offered both clinical and mechanistic evidence that dysregulated expression of FoxM1 play an important role in gastric cancer development and progression, while KLF4 mediates negative regulation of FoxM1 expression and its loss significantly contributes to FoxM1 dysregulation. ^

The proximal first exon architecture of the murine ghrelin gene is highly similar to its human orthologue

BACKGROUND: The murine ghrelin gene (Ghrl), originally sequenced from stomach tissue, contains five exons and a single transcription start site in a short, 19 bp first exon (exon 0). We recently isolated several novel first exons of the human ghrelin gene and found evidence of a complex transcriptional repertoire. In this report, we examined the 5' exons of the murine ghrelin orthologue in a range of tissues using 5' RACE. -----FINDINGS: 5' RACE revealed two transcription start sites (TSSs) in exon 0 and four TSSs in intron 0, which correspond to 5' extensions of exon 1. Using quantitative, real-time RT-PCR (qRT-PCR), we demonstrated that extended exon 1 containing Ghrl transcripts are largely confined to the spleen, adrenal gland, stomach, and skin. -----CONCLUSION: We demonstrate that multiple transcription start sites are present in exon 0 and an extended exon 1 of the murine ghrelin gene, similar to the proximal first exon organisation of its human orthologue. The identification of several transcription start sites in intron 0 of mouse ghrelin (resulting in an extension of exon 1) raises the possibility that developmental-, cell- and tissue-specific Ghrl mRNA species are created by employing alternative promoters and further studies of the murine ghrelin gene are warranted.

Mitigating surgical risk in patients undergoing hip arthroplasty for fractures of the proximal femur

Recently the National Patient Safety Agency in the United Kingdom published a report entitled "Mitigating surgical risk in patients undergoing hip arthroplasty for fractures of the proximal femur". A total of 26 deaths had been reported to them when cement was used at hemiarthroplasty between October 2003 and October 2008. This paper considers the evidence for using cement fixation of a hemiarthroplasty in the treatment of hip fractures.

Comparison of 3D finite element analysis derived stiffness and BMD to determine the failure load of the excised proximal femur

Introduction: Bone mineral density (BMD) is currently the preferred surrogate for bone strength in clinical practice. Finite element analysis (FEA) is a computer simulation technique that can predict the deformation of a structure when a load is applied, providing a measure of stiffness (Nmm−1). Finite element analysis of X-ray images (3D-FEXI) is a FEA technique whose analysis is derived froma single 2D radiographic image. Methods: 18 excised human femora had previously been quantitative computed tomography scanned, from which 2D BMD-equivalent radiographic images were derived, and mechanically tested to failure in a stance-loading configuration. A 3D proximal femur shape was generated from each 2D radiographic image and used to construct 3D-FEA models. Results: The coefficient of determination (R2%) to predict failure load was 54.5% for BMD and 80.4% for 3D-FEXI. Conclusions: This ex vivo study demonstrates that 3D-FEXI derived from a conventional 2D radiographic image has the potential to significantly increase the accuracy of failure load assessment of the proximal femur compared with that currently achieved with BMD. This approach may be readily extended to routine clinical BMD images derived by dual energy X-ray absorptiometry. Crown Copyright © 2009 Published by Elsevier Ltd on behalf of IPEM. All rights reserved

Generation of a 3D proximal femur shape from a single projection 2D radiographic image.

Summary Generalized Procrustes analysis and thin plate splines were employed to create an average 3D shape template of the proximal femur that was warped to the size and shape of a single 2D radiographic image of a subject. Mean absolute depth errors are comparable with previous approaches utilising multiple 2D input projections. Introduction Several approaches have been adopted to derive volumetric density (g cm-3) from a conventional 2D representation of areal bone mineral density (BMD, g cm-2). Such approaches have generally aimed at deriving an average depth across the areal projection rather than creating a formal 3D shape of the bone. Methods Generalized Procrustes analysis and thin plate splines were employed to create an average 3D shape template of the proximal femur that was subsequently warped to suit the size and shape of a single 2D radiographic image of a subject. CT scans of excised human femora, 18 and 24 scanned at pixel resolutions of 1.08 mm and 0.674 mm, respectively, were equally split into training (created 3D shape template) and test cohorts. Results The mean absolute depth errors of 3.4 mm and 1.73 mm, respectively, for the two CT pixel sizes are comparable with previous approaches based upon multiple 2D input projections. Conclusions This technique has the potential to derive volumetric density from BMD and to facilitate 3D finite element analysis for prediction of the mechanical integrity of the proximal femur. It may further be applied to other anatomical bone sites such as the distal radius and lumbar spine.

Sensitivity of proximal femoral stiffness and areal bone mineral density to changes in bone geometry and density

Areal bone mineral density (aBMD) is the most common surrogate measurement for assessing the bone strength of the proximal femur associated with osteoporosis. Additional factors, however, contribute to the overall strength of the proximal femur, primarily the anatomical geometry. Finite element analysis (FEA) is an effective and widely used computerbased simulation technique for modeling mechanical loading of various engineering structures, providing predictions of displacement and induced stress distribution due to the applied load. FEA is therefore inherently dependent upon both density and anatomical geometry. FEA may be performed on both three-dimensional and two-dimensional models of the proximal femur derived from radiographic images, from which the mechanical stiffness may be redicted. It is examined whether the outcome measures of two-dimensional FEA, two-dimensional, finite element analysis of X-ray images (FEXI), and three-dimensional FEA computed stiffness of the proximal femur were more sensitive than aBMD to changes in trabecular bone density and femur geometry. It is assumed that if an outcome measure follows known trends with changes in density and geometric parameters, then an increased sensitivity will be indicative of an improved prediction of bone strength. All three outcome measures increased non-linearly with trabecular bone density, increased linearly with cortical shell thickness and neck width, decreased linearly with neck length, and were relatively insensitive to neck-shaft angle. For femoral head radius, aBMD was relatively insensitive, with two-dimensional FEXI and threedimensional FEA demonstrating a non-linear increase and decrease in sensitivity, respectively. For neck anteversion, aBMD decreased non-linearly, whereas both two-dimensional FEXI and three dimensional FEA demonstrated a parabolic-type relationship, with maximum stiffness achieved at an angle of approximately 15o. Multi-parameter analysis showed that all three outcome measures demonstrated their highest sensitivity to a change in cortical thickness. When changes in all input parameters were considered simultaneously, three and twodimensional FEA had statistically equal sensitivities (0.41±0.20 and 0.42±0.16 respectively, p = ns) that were significantly higher than the sensitivity of aBMD (0.24±0.07; p = 0.014 and 0.002 for three-dimensional and two-dimensional FEA respectively). This simulation study suggests that since mechanical integrity and FEA are inherently dependent upon anatomical geometry, FEXI stiffness, being derived from conventional two-dimensional radiographic images, may provide an improvement in the prediction of bone strength of the proximal femur than currently provided by aBMD.