Crawling Waves Speed Estimation Based on the Dominant Component Analysis Paradigm.

A novel method for estimating the shear wave speed from crawling waves based on the amplitude modulation-frequency modulation model is proposed. Our method consists of a two-step approach for estimating the stiffness parameter at the central region of the material of interest. First, narrowband signals are isolated in the time dimension to recover the locally strongest component and to reject distortions from the ultrasound data. Then, the shear wave speed is computed by the dominant component analysis approach and its spatial instantaneous frequency is estimated by the discrete quasi-eigenfunction approximations method. Experimental results on phantoms with different compositions and operating frequencies show coherent speed estimations and accurate inclusion locations.

Left ventricular geometry during unloading and the end-systolic pressure volume relationship: Measurement with a modified real-time MRI-based method in normal sheep.

The left ventricular (LV) end-systolic (ES) pressure volume relationship (ESPVR) is the cornerstone of systolic LV function analysis. We describe a 2D real-time (RT) MRI-based method (RTPVR) with separate software tools for 1) semi-automatic level set-based shape prior method (LSSPM) of the LV, 2) generation of synchronized pressure area loops and 3) calculation of the ESPVR. We used the RTPVR method to measure ventricular geometry, ES pressure area relationship (ESPAR) and ESPVR during vena cava occlusion (VCO) in normal sheep. 14 adult sheep were anesthetized and underwent measurement of LV systolic function. Ten of the 14 sheep underwent RTMRI and eight of the 14 underwent measurement with conductance catheter; 4 had both RTMRI and conductance measurements. 2D cross sectional RTMRI were performed at apex, mid-ventricle and base levels during separate VCOs. The Dice similarity coefficient was used to compare LSSPM and manual image segmentation and thus determine LSSPM accuracy. LV cross-sectional area, major and minor axis length, axis ratio, major axis orientation angle and ESPAR were measured at each LV level. ESPVR was calculated with a trapezoidal rule. The Dice similarity coefficient between LSSPM and manual segmentation by two readers was 87.31±2.51% and 88.13±3.43%. All cross sections became more elliptical during VCO. The major axis orientation shifted during VCO but remained in the septo-lateral direction. LV chamber obliteration at the apical level occurred during VCO in 7 of 10 sheep that underwent RTMRI. ESPAR was non-linear at all levels. Finally, ESPVR was non-linear because of apical collapse. ESPVR measured by conductance catheter (EES,Index = 2.23±0.66 mmHg/ml/m2) and RT (EES,Index = 2.31±0.31 mmHg/ml/m2) was not significantly different. LSSPM segmentation of 2D RT MRI images is accurate and allows calculation of LV geometry, ESPAR and ESPVR during VCO. In the future, RTPVR will facilitate determination of regional systolic material parameters underlying ESPVR.

Closure of mesenteric defect can lead to decrease in internal hernias after Roux-en-Y gastric bypass.

BACKGROUND: Although most surgeons believe that internal hernia (IH) defects should be closed, no general consensus has yet been reached. The published studies have reported conflicting obstruction incidence estimates and variations in location. Some have also argued that closed hernia sites recur. METHODS: A retrospective review of 2079 Roux-en-Y gastric bypass procedures performed by 1 surgeon from 2001 to 2009 was conducted. Chi-square analysis compared those performed from 2001 to August 2003 (group 1) with those from September 2003 to 2009 (group 2) for the incidence of IH. Since September 2003, the jejunojejunal anastomotic mesenteric defect has been closed with a running, permanent suture. In contrast, before September 2003, the defect was not closed. RESULTS: A total of 37 patients presented with symptomatic IH from 2001 to 2009. A significant difference was found in the proportion of those patients who experienced IH in group 1 (n = 36) compared with those who did so in group 2 (n = 1; P <.001). Group 1 developed 35 IHs (10%) at the jejunojejunal anastomotic mesenteric defect and 6 (1.7%) at Petersen's defect. The median interval to presentation was 20 months (range 5-34). Of the 35 patients, 5 (1.4%) presented acutely with pain or bowel obstruction. Group 2 developed no IHs at the mesenteric defect (0%) and 1 at Petersen's defect (.1%). The interval to presentation was 9 months. CONCLUSION: The incidence of IH after laparoscopic Roux-en-Y gastric bypass can be reduced with closure of mesenteric defects. IHs can present either acutely with pain and obstructive symptoms or chronically with vague, intermittent postprandial pain.

Outcomes of laparoscopic bariatric surgery after renal transplant.

Obesity has been associated with poor graft and patient survival after kidney transplantation, requiring functional increase of anti-rejection drugs. Weight loss surgery may be a good alternative in this clinical scenario. The aim of this report is to describe the outcomes of bariatric procedures performed in patients after kidney transplantation at our institution. A retrospective chart review of a prospectively collected database was conducted to analyze the outcomes of morbidly obese patients after kidney transplantation who underwent laparoscopic bariatric procedures between November 2004 and October 2007. Our series included five patients who underwent a bariatric procedure following kidney transplantation. All patients were females, with a mean age of 40.8 years (range 30-48) and mean body mass index (BMI) of 52.2 (range 48-69). Percent of excess weight loss (%EWL) at 2 years was over 50% for all patients; other comorbidities that might affect postoperative renal function were diabetes mellitus in 2/5 patients, hypertension in 5/5 patients, and chronic heart failure in 1/5 patients. Four patients had laparoscopic Roux-en-Y gastric bypass and one had laparoscopic sleeve gastrectomy. There were no postoperative complications in any patients, and no alteration to the dosages of the immunosuppressant drugs were recorded after bariatric surgery. Laparoscopic bariatric surgical techniques may be used safely and effectively to control obesity in renal transplant patients.

Sistema de información para catastro parcelario (SICAP)

Recomendaciones: Deben considerarse las siguientes recomendaciones para el buen funcionamiento del sistema de información para catastro parcelario (SICAP). -Los requerimientos par el funcionamiento del SICAP son: Una computadora superior a Pentium II, Arc View 3.2 y Microsoft Access 2000. -Se recomienda hacer copias de respaldo por lo menos cada mes, para evitar pérdida de información, por malos manejos del SICAP. -Guardar los cambios en Arc View como proyecto para no perder los escrips y la configuración de la interfaz del SICAP.