Developmentally regulated multisensory integration for prey localization in the medicinal leech

Medicinal leeches, like many aquatic animals, use water disturbances to localize their prey, so they need to be able to determine if a wave disturbance is created by prey or by another source. Many aquatic predators perform this separation by responding only to those wave frequencies representing their prey. As leeches' prey preference changes over the course of their development, we examined their responses at three different life stages. We found that juveniles more readily localize wave sources of lower frequencies (2 Hz) than their adult counterparts (8–12 Hz), and that adolescents exhibited elements of both juvenile and adult behavior, readily localizing sources of both frequencies. Leeches are known to be able to localize the source of waves through the use of either mechanical or visual information. We separately characterized their ability to localize various frequencies of stimuli using unimodal cues. Within a single modality, the frequency–response curves of adults and juveniles were virtually indistinguishable. However, the differences between the responses for each modality (visual and mechanosensory) were striking. The optimal visual stimulus had a much lower frequency (2 Hz) than the optimal mechanical stimulus (12 Hz). These frequencies matched, respectively, the juvenile and the adult preferred frequency for multimodally sensed waves. This suggests that, in the multimodal condition, adult behavior is driven more by mechanosensory information and juvenile behavior more by visual. Indeed, when stimuli of the two modalities were placed in conflict with one another, adult leeches, unlike juveniles, were attracted to the mechanical stimulus much more strongly than to the visual stimulus

Profilaxis antibiótica en cirugía

Existe una abundantísima documentación en la literatura acerca de la eficacia de los antibióticos utilizados profilácticamente en cirugía (1-10). Probablemente lo más útil para el trabajo diario de un hospital sea la adopción de pautas concretas que permitan ser evaluadas periódicamente a través de la colaboración, entre otros, de anestesistas, cirujanos y microbiólogos (11,12). En esta línea hemos revisado, de una manera intencionadamente esquemática, diversas facetas relativas a la profilaxis antibiótica en cirugía. Para ello comentaremos algunos aspectos generales de profilaxis de la infección postquirúrgica, unas breves normas para la utilización profiláctica de antibióticos y resumiremos determinadas indicaciones en función del tipo de intervención

Association of increased Visfatin/PBEF/NAMPT circulating concentrations and gene expression levels in peripheral blood cells with lipid metabolism and fatty liver in human morbid obesity

BACKGROUND AND AIMS: Nicotinamide phosphoribosyltransferase (NAMPT) is an adipokine with physiological effects on the control of glucose homeostasis as well as potentially involved in inflammation. The association of circulating NAMPT concentrations with obesity has not been clearly established. The aim of the present work was to evaluate the effect of obesity on circulating concentrations and gene expression levels of NAMPT in human peripheral blood cells (PBCs) as well as its involvement in inflammation, glucose and lipid metabolism. METHODS AND RESULTS: Forty-four serum samples obtained from 14 lean and 30 obese volunteers were used to analyse the circulating concentrations of NAMPT. In addition, PBC, omental adipose tissue (OM) and liver biopsy samples obtained from a subgroup of subjects were used to determine transcript levels of NAMPT by Real-time PCR. Glucose and lipid profile as well as several inflammatory factors and hepatic enzymes were analysed. NAMPT circulating concentrations (P<0.01) and gene expression levels in PBC (P<0.05) were significantly increased in obese patients as compared to lean subjects. Total-cholesterol (P=0.016), HDL-cholesterol (P=0.036) and triglycerides (P=0.050) were significant and independent determinants of circulating concentrations of NAMPT (P<0.01). Moreover, a positive correlation (P<0.01) was found with the hepatic enzymes alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase after BMI adjustment. CONCLUSION: Our work shows that NAMPT circulating concentrations and mRNA expression levels in PBC are increased in obese patients and that plasma NAMPT levels are related to inflammation, lipid metabolism and hepatic enzymes suggesting a potential involvement in fatty liver disease and in the obesity-associated inflammatory stat

The obestatin receptor (GPR39) is expressed in human adipose tissue and is down-regulated in obesity-associated type 2 diabetes mellitus

The G protein-coupled receptor 39 (GPR39) has recently been identified as the receptor for obestatin, a peptidic hormone involved in energy homeostasis. However, the expression levels of this receptor in human adipose tissue in obesity and obesity-associated type 2 diabetes mellitus (T2DM) remain unknown. Therefore, we evaluated the actual presence of GPR39 mRNA in human adipose tissue and whether GPR39 expression levels are altered in obesity and obesity-associated T2DM. DESIGN: Omental adipose tissue biopsies obtained from 15 women were used in the study. Patients were classified as lean (body mass index 20.8 +/- 1.0 kg/m(2)), obese normoglycaemic (body mass index 48.4 +/- 2.1 kg/m(2)) and obese T2DM patients (body mass index 52.6 +/- 4.9 kg/m(2)). Anthropometric measurements and biochemical profiles were assessed for each subject. Real-time RT-PCR analyses were performed to quantify transcript levels of GPR39 and adiponectin. RESULTS: Obese T2DM patients exhibited significantly lower GPR39 expression levels compared to lean (P = 0.016) and obese normoglycaemic subjects (P = 0.008), while no differences between lean and obese normoglycaemic patients were observed. The mRNA expression levels of GPR39 were negatively correlated to fasting glucose concentrations (r = -0.581, P = 0.023), while exhibiting a positive correlation to adiponectin mRNA expression levels (r = 0.674, P = 0.006). CONCLUSION: GPR39 is expressed in human adipose tissue. The reduced expression levels of GPR39 in omental adipose tissue observed in obese patients with T2DM suggest an involvement of obestatin signalling in glucose homeostasis and T2DM development

Expression of caveolin-1 in human adipose tissue is upregulated in obesity and obesity-associated type 2 diabetes mellitus and related to inflammation

Caveolin-1 (CAV-1) plays important roles in many aspects of cellular biology, including vesicular transport, cholesterol homeostasis and signal transduction. The aim of the present study was to explore gene expression levels of CAV-1 in human adipose tissue in obesity and obesity-associated type 2 diabetes mellitus (T2DM) and to analyse its potential implication in the inflammatory state associated with obesity. DESIGN AND METHODS: Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) obtained from 15 females were used in the study. Patients were classified as lean (BMI 20.8 +/- 1.0 kg/m(2)) or obese (BMI 50.5 +/- 2.6 kg/m(2)). The obese group was further subclassified as normoglycaemic (NG) or patients with T2DM. Anthropometric measurements as well as circulating metabolites, hormones and adipokines were determined. Real-time polymerase chain reaction (PCR) analyses were performed to quantify transcript levels of CAV-1 and monocyte chemoattractant protein (MCP-1). RESULTS: The presence of CAV-1 protein was detected in VAT and SAT by immunohistochemistry. Both obese NG and with T2DM patients exhibited significantly higher CAV-1 expression levels in VAT and SAT compared with lean subjects (P < 0.05). No differences between obese NG and T2DM patients were observed in VAT. However, obese T2DM patients were found to have higher CAV-1 expression levels in SAT (P < 0.05) compared with obese NG patients. A significant correlation was found between CAV-1 mRNA expression levels in VAT and different circulating inflammatory markers such as sialic acid (SA) (P < 0.001) and fibrinogen (P < 0.001) as well as with MCP1 mRNA expression (P < 0.05). CONCLUSION: Our findings show for the first time the upregulation of mRNA CAV-1 expression levels in VAT and SAT of obese NG and obese T2DM patients compared with lean controls, suggesting a role for CAV-1 in obesity and T2DM development. The association with different inflammatory markers further suggests an implication of CAV-1 in the low-grade inflammation accompanying obesity

Involvement of leptin in the association between percentage of body fat and cardiovascular risk factors

OBJECTIVES: Recent epidemiologic studies have shown that obesity is associated with elevated blood concentrations of prothrombotic-proinflammatory factors and markers of endothelial dysfunction such as fibrinogen, C-reactive protein (CRP), von Willebrand factor (vWF), and homocysteine. We have assessed whether these markers are associated with percentage of body fat (BF), insulin sensitivity as well as with leptin concentrations. DESIGN AND METHODS: Twenty-five men aged 49.6 +/- 12.7 yr (mean +/- SD) underwent whole-body air displacement plethysmography (Bod-Pod(R)) for estimating BF. Blood analyses for leptin and several other metabolic and cardiovascular markers were carried out. RESULTS: Obese subjects had higher levels as compared to controls of BF (37.5 +/- 5.1 vs. 26.0 +/- 6.6, p < 0.01), fibrinogen (3.30 +/- 0.43 vs. 2.67 +/- 0.11, p < 0.01), vWF (136.4 +/- 50.4% vs. 81.6 +/- 12.6%, p < 0.05), and leptin (17.6 +/- 8.7 vs. 6.2 +/- 3.3, p < 0.01), lower concentrations of HDL-cholesterol (1.09 +/- 0.20 vs. 1.51 +/- 0.10, p < 0.001) and lower QUICKI (1/[log(Ins(0)) + log(Glu(0))]) (0.31 +/- 0.03 vs. 0.34 +/- 0.02, p < 0.05). No significant changes were observed in CRP (5.7 +/- 3.4 vs. 3.8 +/- 1.6, p = 0.327) and homocysteine (9.4 +/- 4.2 vs. 8.3 +/- 0.9, p = 0.749). A positive correlation was observed between BF and fibrinogen (r = 0.67, p = 0.0003). Plasma leptin concentrations were correlated with fibrinogen (r = 0.71, p = 0.0001) and CRP (r = 0.43, p = 0.044). After adjustment for BF leptin emerged as a significant predictor of fibrinogen (beta = 0.47, p = 0.023; R(2) = 0.59, p < 0.001). QUICKI was positively correlated with HDL-cholesterol (r = 0.59, p = 0.010) and negatively with fibrinogen (r = -0.53, p = 0.025), CRP (r = -0.52, p = 0.028) and vWF (r = -0.56, p = 0.013). CONCLUSIONS: Increased BF and impaired insulin sensitivity are associated with increased concentrations of cardiovascular risk factors. Leptin seems to be involved in this elevation and emerges as a predictor of circulating fibrinogen concentrations

Portal Revascularization in the Setting of Cavernous Transformation Through a Paracholedocal Vein: A Case Report

Diffuse thrombosis of the entire portal system (PVT) and cavernomatous transformation of the portal vein (CTPV) represents a demanding challenge in liver transplantation. We present the case of a patient with nodular regenerative hyperplasia and recurrent episodes of type B hepatic encephalopathy concomitant with PVT as well as CTPV, successfully treated with orthotopic liver transplantation. The portal inflow to the graft was carried out through the confluence of 2 thin paracholedochal varicose veins, obtaining good early graft function and recovery of the encephalopatic episodes. This alternative should be kept in mind as an option to assure hepatopetal splanchnic flow in those cases of diffuse thrombosis and cavernomatous transformation of portal vein. CI - Copyright (c) 2010 Elsevier Inc. All rights reserved

The celiac axis compression syndrome (CACS): critical review in the laparoscopic era

The celiac axis compression syndrome (CACS) due to median arcuate ligament (MAL) was first described by Harjola in 1963; originating postpandrial abdominal pain, weight loss, epigastric bruit and celiac axis stenosis > 75% in angiographic studies. This clinical condition has been the origin of controversies about its pathogenesis, diagnosis and its long term clinical results. Advances in diagnostic imaging as 64 multidetector–row CT (MDCT), 3-D reconstruction, magnetic resonance (MR) and color duplex ultrasonography, provide better understanding of the syndrome and allow to identify the best candidates for surgical division of MAL fibers. Since the introduction of laparoscopic approach, and also endovascular procedures, in 2000, a new perspective has established in this challenging syndrome. With the occasion of our own experience, a critical review of the syndrome is presented