Magnetite mineralization inside cross-linked protein crystals

Crystallization in confined spaces is a widespread process in nature that also has important implications for the stability and durability of many man-made materials. It has been reported that confinement can alter essential crystallization events, such as nucleation and growth and, thus, have an impact on crystal size, polymorphism, morphology, and stability. Therefore, the study of nucleation in confined spaces can help us understand similar events that occur in nature, such as biomineralization, design new methods to control crystallization, and expand our knowledge in the field of crystallography. Although the fundamental interest is clear, basic models at the laboratory scale are scarce mainly due to the difficulty in obtaining well-defined confined spaces allowing a simultaneous study of the mineralization process outside and inside the cavities. Herein, we have studied magnetite precipitation in the channels of cross-linked protein crystals (CLPCs) with different channel pore sizes, as a model of crystallization in confined spaces. Our results show that nucleation of an Fe-rich phase occurs inside the protein channels in all cases, but, by a combination of chemical and physical effects, the channel diameter of CLPCs exerted a precise control on the size and stability of those Fe-rich nanoparticles. The small diameters of protein channels restrain the growth of metastable intermediates to around 2 nm and stabilize them over time. At larger pore diameters, recrystallization of the Fe-rich precursors into more stable phases was observed. This study highlights the impact that crystallization in confined spaces can have on the physicochemical properties of the resulting crystals and shows that CLPCs can be interesting substrates to study this process

Time-related efficacy of liver cell isografts in fulminant hepatic failure

We and others have reported that dispersed liver cells transplanted into the spleen parenchyma of syngeneic rats remained functional and viable for a long time. This report describes our results with hepatocellular transplantation as a therapeutic method in a model of fulminant hepatic failure (FHF) in the rat. 60 male Sprague-Dawley rats weighing 200-250 g were used. The FHF was reached through an Eck's fistula with 2/3 hepatectomy at the same time. This model produced lethal hepatic failure in a highly reproducible manner. Liver cells were isolated by the collagenase method. 40 X 10(6) hepatocytes suspended in Hanks' balanced salt solution were transplanted into the spleen parenchyma 24 hr before (group 1), at the same time as (group 2), and 24 hr after (group 3) FHF was achieved. Additional sham-operated animals (groups 4 and 5) and a control group (group 6) were used. The hepatocellular transplantation markedly increased the survival of the animals with induced FHF to 80% (group 1) and 60% (group 2)--but not in group 3 (20%),--compared with 10% in the control group. This study shows that dispersed liver cells transplanted into the spleen can provide sufficient support to allow animals with lethal hepatic failure to survive and recover. Nevertheless the efficacy of transplantation is a time-related phenomenon with the FHF induction

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

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

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

Pancreatectomía central en tumores benignos del cuello del páncreas

The surgical treatment of benign tumors of the neck of the pancreas usually consists of enucleation or formal pancreatectomy. Central pancreatectomy has been put forward because it has fewer major complications and can preserve endocrine and exocrine function. Between January 1999 and march 2003, three patients with benign tumors of the neck of the pancreas underwent central pancreatectomy. all patients underwent computed tomography scans, intraoperative ultrasound and frozen-section analysis. pathologic examination showed two mucinous cystadenomas and one serous cystadenoma. after a mean follow-up of 34 months, none of the patients has shown major complications or local recurrence, or has developed diabetes. In conclusion, central pancreatectomy is a useful technique for selected benign or low-grade malignant pancreatic tumors of the neck of the pancreas

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