Search

Resumen Las infecciones hospitalarias causadas por bacilos gram negativos resistentes a carbapenems (BGNCR) están asociadas al aumento de morbimortalidad y gasto sanitario. La identificación mediante cultivos de vigilancia y las medidas de control de infecciones permiten reducir su diseminación. El objetivo del estudio fue evaluar el impacto de un programa de vigilancia integrado a protocolos de control de infecciones sobre la incidencia de BGNCR y conocer su epidemiología molecular en una unidad de cuidados intensivos. Se realizaron auditorías seguidas de un programa de cultivo de vigilancia activa y caracterización molecular de BGNCR, antes y después de la implementación de programas de prevención y control de infecciones. El screening microbiológico se realizó en medios cromogénicos; la caracterización molecular de p-lactamasas (blaKPC, bla0XA-48-like, blaVIM, blaiMP, blaNDM, blaSHV y blaCTx-M) por PCR y la tipificación molecular por PFGE y MLST para Klebsiella pneumoniae. El protocolo desarrollado permitió reducir la colonización global de 16,92% al 9,67%. La diseminación de K. pneumoniae fue a expensas de diversos clones portadores de KPC-2 asociada a BLEE SHV-2 y CTX-M-15, y distribuidos en varios secuenciotipos (ST17, ST13, ST2256, ST353); no se observó persistencia de un clon particular y ningún aislamiento presentó factores de virulencia asociados a hipervi-rulencia. Los aislamientos de Acinetobacter baumannii fueron mayoritariamente productores de IMP-1. El análisis PFGE individualizó 3 clusters, asumiendo que la diseminación fue clonal. Abstract Hospital-acquired infections caused by carbapenem-resistant Gram-negative bacteria (CRGNB) have been increasingly reported worldwide and are associated with high rates of mortality especially in intensive care units(ICUs). Early identification through rectal surveillance cultures and implementation of infection control measures(ICM) including contact precautions, staff education on cleaning and hand hygiene may reduce the spread of these microorganisms. The aim of this work was to assess the impact of enhanced ICM on CRGNB colonization and to describe the molecular epidemiology of these bacteria in a polyvalent ICU in a tertiary level hospital. A prospective study including audits and active surveillance culture program, with molecular characterization, was conducted before and after the implementation of prevention programs and infection control measures. Microbiological screening was performed in chromogenic media; PCR targeting p-lactamases genes (ó/qkpc, óíQndm, blaviM and blaoxA-48, blasHv and ó/qctx-m), molecular typing by PFGE; and MLST in K. pneumoniae were performed. CRGNB colonization was reduced from 16.92% to 9.67% upon implementing the infection control measures. In K. pneumoniae the most frequent carbapenemase type was KPC-2 associated with SHV-2 and CTX-M-15, and was disseminated in various STs (ST17, ST13, ST2256, ST353); there was no persistence of particular clones and virulence factors showed no association with hypervirulence. IMP-1 carbapenemase predominated in A. baumannii and the PFGE analysis individualized 3 clusters, assuming that the dissemination in the ICU was clonal. The early detection of patients colo-nized with CRBGN by using epidemiological surveillance cultures and the implementation of prophylactic measures are key to reducing the incidence of these microorganisms.

Lipocalin-2 (Lcn2) is an innate immune protein elevated by several orders of magnitude in various inflammatory conditions including aging and obesity. Recent studies have shown that Lcn2 is secreted by adipocytes in response to inflammation and is categorized as a new adipokine cross-linking innate immunity and metabolic disorders including obesity. However, the involvement of Lcn2 and its function during the progression of obesity is largely unknown. Recently, browning of white adipose tissue (WAT) has gained attention as a therapeutic strategy to combat obesity. Herein, we have shown that treatment of mature 3T3-L1 adipocytes with recombinant Lcn2 (rec-Lcn2) resulted in the up-regulation of thermogenic and beige/brown markers (UCP1, PRDM16, ZIC-1 and TBX1) and increased mitochondrial activity. Additionally, global Lcn2 genetic knockout (Lcn2KO) mice exhibited accelerated weight gain and visceral fat deposition with age, when compared to wild type (WT) mice. Taken together, both in vitro and in vivo studies suggest that Lcn2 is a naturally occurring adipokine, and may serve as an anti-obesity agent by upregulating the thermogenic markers resulting in the browning of WAT. Therefore, Lcn2 and its downstream signaling pathways could be a potential therapeutic target for obesity.

Coronary artery disease (CAD) is the leading cause of morbidity and mortality worldwide. Recently, triglyceride rich lipoproteins are proposed to contribute to CAD risk; its concentrations would be partly determined by lipoprotein lipase (LPL) and endothelial lipase (EL). Epicardial adipose tissue (EAT), a visceral AT surrounding myocardium and coronary arteries, emerged as an important actor in CAD; the increase in its volume could be a consequence of LPL and EL. Circulating enzymes levels would be conditioned by local tissue factors. Our aim was to evaluate LPL, EL and their regulators levels in serum and EAT from CAD patients, searching for possible parallelisms and their role in the lipoprotein profile.In serum, EAT and subcutaneous AT (SAT) from patients undergoing coronary artery bypass graft (CABG, n = 25) or valve replacement (No CABG, n = 25), LPL, EL and glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein-1 (GPIHBP1) expression were evaluated. Besides, Apoprotein (Apo)CII, CIII and AV were determined in serum, along with lipoprotein profile.Insulin-resistance markers were higher in CABG (p 0.05). Serum LPL levels were decreased (p = 0.045), while EL levels increased (p 0.001) in CABG, without differences in EAT or SAT. Circulating GPIHBP1 concentrations were decreased in CABG (p = 0.047), while EAT GPIHBP1 expression was increased (p 0.001). ApoCII and ApoAV concentrations were higher in CABG (p = 0.016 and p = 0.047, respectively), without differences in ApoCIII concentrations between groups.In EAT, LPL and EL protein levels were not changed in CAD, although GPIHBP1 protein levels were higher. EAT would be a minor contributor to the circulating levels of the enzymes.

Background First description of a technique for left atrium transseptal puncture (TSP) with minimal radiation exposure by using the nonfluoroscopic MediGuide™ tracking system (MG; St. Jude Medical, St. Paul, MN, USA) without the assistance of intracardiac echocardiography. Methods This study included 31 consecutive patients with atrial fibrillation undergoing an MG-assisted percutaneous catheter ablation procedure. A Brockenbrough transseptal needle (BRK) is connected to a standard pressure transducer through a two-input valve. Then, an MG-enabled guidewire is inserted so that its tip exactly matches the BRK's distal tip. After the acquisition of two short radioscopic cine-loops we are able to trace the needle tip on the MG screen, performing the usual TSP maneuver but without fluoroscopy. Successful left atrium access is confirmed by noticing the change in the pressure curve and by advancing the guidewire into the left pulmonary veins. As a control group, 31 matched patients who underwent atrial fibrillation ablation with fluoroscopically guided, pressure-monitored TSP were included. Results Sixty-two MG-assisted TSP attempts were performed; all but two were successfully accomplished without changing to the conventional technique (96.7%). The mean total fluoroscopy time, until the double transseptal access was performed, was 26.65 ± 37.97 seconds in the MG group and 129.13 ± 37.77 seconds in the conventional-TSP group (P < 0.001). No major complications occurred during any of the procedures. Conclusion This new technique for TSP using MG is feasible and can be performed with minimal radiation exposure without the need for additional imaging techniques, achieving a significant reduction of fluoroscopy time.

Epicardial adipose tissue (EAT) is a visceral AT, surrounding myocardium and coronary arteries. Its volume is higher in Type 2 diabetic (DM2) patients, associated with cardiovascular disease risk. Lipoprotein lipase (LPL) hydrolyses triglycerides (TG) from circulating lipoproteins, supplying fatty acids to AT, contributing to its expansion. We aimed to evaluate LPL expression and activity in EAT from DM2 and no DM2 patients, and its regulators ANGPTL4, GPIHBP1 and PPARγ levels, together with VLDLR expression and EAT LPL association with VLDL characteristics.We studied patients undergoing coronary by-pass graft (CABG) divided into CABG-DM2 (n = 21) and CABG-noDM2 (n = 29), and patients without CABG (No CABG, n = 30). During surgery, EAT and subcutaneous AT (SAT) were obtained, in which LPL activity, gene and protein expression, its regulators and VLDLR protein levels were determined. Isolated circulating VLDLs were characterized.EAT LPL activity was higher in CABG-DM2 compared to CABG-noDM2 and No CABG (p=0.002 and p0.001) and in CABG-noDM2 compared to No CABG (p=0.02), without differences in its expression. ANGPTL4 levels were higher in EAT from No CABG compared to CABG-DM2 and CABG-noDM2 (p0.001). GPIHBP1 levels were higher in EAT from CABG-DM2 and CABG-noDM2 compared to No CABG (p= 0.04). EAT from CABG-DM2 presented higher PPARγ levels than CABG-noDM2 and No CABG (p=0.02 and p=0.03). No differences were observed in VLDL composition between groups, although EAT LPL activity was inversely associated with VLDL-TG and TG/protein index (p0.05).EAT LPL regulation would be mainly post-translational. The higher LPL activity in DM2 could be partly responsible for the increase in EAT volume.

Our aim was to analyze the effect of circulating triglyceride rich lipoprotein (TRL) on endothelial function in metabolic syndrome (MetS). Methods We studied 40 patients with MetS (ATPIII), divided into those presenting normal endothelial function (n = 19) and those with endothelial dysfunction (n = 21) by means of the evaluation of pulse wave velocity, before and after brachial artery ischemia. In fasting serum we measured lipid and lipoprotein profile, insulin and glucose (HOMA-IR). Moreover, isolated TRL (d

ResumenEn Argentina no se han realizado estudios destinados a establecer la prevalencia de disglucemias (glucemia alterada en ayunas [GAA], tolerancia alterada a la glucosa [TAG] y diabetes mellitus [DM]) en pacientes con enfermedad renal. Se decidió realizar un estudio observacional, evaluando la frecuencia con prueba de tolerancia oral a glucosa (PTOG) en pacientes con enfermedad renal crónica (ERC), sin registro de disglucemia en sus historias clínicas.Se realizó PTOG a 254 pacientes (60,62% masculinos), con ERC estadios 3, 4 y 5, en tratamiento conservador, hemodiálisis o trasplante.Los resultados mostraron pacientes con valores de DM: 10 pacientes según ayunas exclusivamente (3,94%; IC 95%: 1,35-6,53%); exclusivamente segunda hora, 11 pacientes (4,33%; IC 95%: 1,63-7,03%); por ambos criterios, 15 pacientes (5,91%; IC 95%: 2,81-9,00%); por al menos un criterio, 36 pacientes (14,17%; IC 95%: 9,69-18,66%). En análisis multivariado, la DM se asoció con valor de cintura (OR=1,033 por cm; IC 95%: 1,005-1,062; p=0,019) y con tratamiento sustitutivo vs. conservador (OR=0,41; IC 95%: 0,19-0,92; p=0,028). La GAA (criterio ADA) fue del 19,75% en tratamiento conservador vs. 9,24% en tratamiento sustitutivo, con diferencia estadísticamente significativa. No fue significativa la diferencia de TAG que evidenció 24,6 y 20,3% en tratamiento conservador y sustitutivo, respectivamente.Se propone la realización de PTOG en todo paciente con ERC, ya que permite la detección de todo el rango de disglucemias desconocidas, evitando el subdiagnóstico y favoreciendo la realización de tratamientos para evitar su progresión, en caso de estar ante la presencia de un grupo de riesgo para DM (GAA o TAG), así como la elección de la medicación más adecuada para el trasplante o el inicio del tratamiento de nuevos casos de DM no diagnosticada, para disminuir la morbimortalidad.AbstractIn Argentina, there have been no studies aimed at establishing the prevalence of dysglycaemia (impaired fasting glucose [IFG], impaired glucose tolerance [IGT] and diabetes mellitus [DM]) in patients with chronic kidney disease (CKD). Our group decided to conduct an observational study to evaluate the frequency with oral glucose tolerance test (OGTT) in CKD patients with no previous data for dysglycaemia in their medical records.OGTT was performed in 254 patients (60.62% male) with stage 3, 4 and 5 CKD under conservative treatment, haemodialysis or transplantation.Results for DM were found in 10 patients according to fasting glucose alone (3.94%; 95% CI: 1.35-6.53%), 11 patients with exclusively the second hour criterion (4.33%; 95% CI: 1.63-7.03%), 15 with both criteria (5.91%; 95% CI: 2.81-9.00%) and 36 patients with at least one criteria (14.17%; 95% CI: 9.69-18.66%). In a multivariate analysis, DM was associated with waist circumference (OR=1.033 per cm; 95% CI, 1.005 to 1.062; P=.019) and with conservative treatment vs. replacement therapy (OR=0.41; 95% CI: 0.19-0.92; P=.028). IGT was evident in 24.6% and 20.3 on conservative vs. replacement therapy, with no statistically significant difference. IFG (ADA criteria) was 19.75 vs. 9.24% in conservative vs. replacement therapy, with a statistically significant difference.OGTT is suggested for all CKD patients since it is able to detect the full range of unknown dysglycaemias, which avoids underdiagnoses and favours performing treatments to prevent progression in DM risk groups (IFG and/or IGT). It also aids in the selection of the most appropriate medication for transplantation or treatment initiation in new cases of undiagnosed DM to decrease morbidity and mortality.

Lipoprotein lipase (LPL) and endothelial lipase (EL) are involved in lipoprotein metabolism. In insulin-resistance, their behavior is altered. Peroxisome proliferator-activated receptors (PPAR) and apoproteins (apo)CII and CIII could be partly responsible for these alterations. To evaluate this response, we assessed Lpl and Lipg expression, protein levels, and enzyme activity in adipose tissue (AT) and heart in an obesity model. Besides, we assessed the role of PPAR and apoC. Male Wistar rats were fed with standard diet (Control, n = 14) or high-fat diet (HFD, n = 14) for 14 weeks. Glucose and lipoprotein profiles were measured. Histological studies were performed in heart and epididymal AT. Lpl and Lipg were assessed by reverse transcription polymerase chain reaction (RT-qPCR), protein levels by Western Blot, and activities by radiometric assays. Cardiac and AT PPAR expression were measured by Western Blot and hepatic Apoc2 and Apoc3 mRNA by RT-qPCR. In HFD, fat deposits were observed in hearts, whereas AT presented a higher adipocyte size. In heart and AT, no differences were found in Lipg mRNA between groups, while AT Lpl mRNA and LPL protein were decreased in HFD, without differences in heart. In both tissues, EL protein levels and activity were increased and inversely associated with decreased LPL activity, being partially responsible for the atherogenic lipoprotein profile in HFD. PPARγ expression in AT was decreased in HFD, without differences in cardiac PPARδ expression and hepatic apoC mRNA. The increase in EL activity could be an alternative pathway for fatty acid release from lipoproteins and uptake in tissues with decreased LPL activity. In AT, PPARγ could be involved in enzyme regulation. Fil: Barchuk, Magalí. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Miksztowicz, Verónica Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Zago, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Cevey, Ágata Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentina Fil: López, Graciela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Goren, Nora Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentina Fil: Friedman, Silvia. Universidad de Buenos Aires; Argentina Fil: Gelpi, Ricardo Jorge. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Morales, Maria Celina. Universidad de Buenos Aires; Argentina Fil: Fernandez Tomé, María del Carmen. Universidad de Buenos Aires; Argentina Fil: Schreier, Laura Ester. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Berg, Gabriela Alicia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Background and aims: Marked hypercholesterolemia, defined as low density lipoprotein cholesterol (LDL-C) levels ≥ 190 mg/dL, may be due to LDLR, APOB, and PCSK9 variants. In a recent analysis, only 1.7% of cases had such variants. Our goal was to identify other potential genetic causes of hypercholesterolemia. Methods: In a total of 51,253 subjects with lipid testing, 3.8% had elevated total cholesterol >300 mg/dL and/or LDL-C≥190 mg/dL. Of these, 246 were further studied, and 69 without kidney, liver, or thyroid disease and who met Dutch Lipid Clinic Network criteria of ≥6 points had DNA sequencing done at the LDLR, APOB, PCSK9, APOE, LDLRAP1, STAP1, ABCG5, ABCG8, CYP27A1, LIPA, LIPC, LIPG, LPL, and SCARB1 gene loci and also had 10 SNP analysis for a weighted high LDL-C genetic risk score. Results: In the 69 subjects with genetic analyses, the following variants were observed in 37 subjects (53.6%): LDLR (n = 20, 2 novel), ABCG5/8 (n = 7, 2 novel), APOB (n = 3, 1 novel), CYP27A1 (n = 3, 1 novel), LIPA (n = 2, 1 novel), APOE (n = 2), LIPC (n = 1, novel), LIPG (n = 1, novel), and SCARB1 (n = 1); 14 subjects (20.3%) had a high polygenic score, with 4 (5.8%) having no variants. Conclusions: Our data indicate that in addition to variants in LDLR, APOB, PCSK9, APOE, LDLRAP1, and STAP1, variants in ABCG5/8, CYP27A1, LIPA, LIPC, and LIPG may be associated with hypercholesterolemia and such information should be used to optimize therapy. Fil: Corral, Pablo. Universidad Fasta; Argentina Fil: Geller, Andrew S.. Boston Heart Diagnostics; Estados Unidos Fil: Polisecki, Eliana Y.. Boston Heart Diagnostics; Estados Unidos Fil: Lopez, Graciela Ines. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina Fil: Bañares, Virginia Gabriela. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán". Centro Nacional de Genética Médica; Argentina Fil: Cacciagiu, Leonardo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina Fil: Berg, Gabriela Alicia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Hegele, Robert A.. University Western Ontario; Canadá Fil: Schaefer, Ernst J.. Boston Heart Diagnostics; Estados Unidos Fil: Schreier, Laura Ester. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina

Evidences indicate the relationship between neurotensinergic and dopaminergic systems. Neurotensin inhibits synaptosomal membrane Na+, K+-ATPase activity, an effect blocked by SR 48692, antagonist for high affinity neurotensin receptor (NTS1) type. Assays of high affinity [3H]-ouabain binding (to analyze K+ site of Na+, K+-ATPase) show that in vitro addition of neurotensin decreases binding. Herein potential interaction between NTS1 receptor, dopaminergic D2 receptor and Na+, K+-ATPase was studied. To test the involvement of dopaminergic D2 receptors in [3H]-ouabain binding inhibition by neurotensin, Wistar rats were administered i.p.with antipsychotic drugs haloperidol (2 mg/kg) and clozapine (3, 10 and 30 mg/kg). Animals were sacrificed 18 h later, cerebral cortices harvested, membrane fractions prepared and high affinity [3H]-ouabain binding assayed in the absence or presence of neurotensin at a 10 micromolar concentration. No differences versus controls for basal binding or for binding inhibition by neurotensin were recorded, except after 10 mg/kg clozapine. Rats were administered with neurotensin (3, 10 y 30 μg, i.c.v.) and 60 min later, animals were sacrificed, cerebral cortices harvested and processed to obtain membrane fractions for high affinity [3H]-ouabain binding assays. Results showed a slight but statistically significant decrease in binding with the 30 μg neurotensin dose. To analyze the interaction between dopaminergic D2 and NTS1 receptors, [3H]-neurotensin binding to cortical membranes from rats injected with haloperidol (2 mg/kg, i.p.) or clozapine (10 mg/kg) was assayed. Saturation curves and Scatchard transformation showed that the only statistically significant change occurred in Bmax after haloperidol administration. Hill number was close to the unit in all cases. Results indicated that typical and atypical antipsychotic drugs differentially modulate the interaction between neurotensin and Na+, K+-ATPase. At the same time, support the notion of an interaction among dopaminergic and neurotensinergic systems and Na+, K+-ATPase at central synapses. Fil: Rosin, Carina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina Fil: López Ordieres, María Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina Fil: Rodriguez, Georgina Emma. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina

Highlights: - First description of familial hypercholesterolemia mutations in Argentina; - Identification of 7 patients with severe familial hypercholesterolemia; - Wide genetic heterogeneity with 1 relatively common allele, the Lebanese mutation; Description and deep bioinformatics characterization of 4 novel genetic variants; - Studying the exon 14 in a first step could be a low-cost approach for this population. Background: Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated low-density lipoprotein cholesterol and early cardiovascular disease. As cardiovascular disease is a leading cause of mortality in Argentina, early identification of patients with FH is of great public health importance. Objective: The aim of our study was to identify families with FH and to approximate to the characterization of the genetic spectrum mutations of FH in Argentina. Methods: Thirty-three not related index cases were selected with clinical diagnosis of FH. Genetic analysis was performed by sequencing, multiplex ligation-dependent probe amplification, and bioinformatics tools. Results: Twenty genetic variants were identified among 24 cases (73%), 95% on the low-density lipoprotein receptor gene. The only variant on APOB was the R3527Q. Four were novel variants: c.-135C>A, c.170A>C p.(Asp57Ala), c.684G>C p.(Glu228Asp), and c.1895A>T p.(Asn632Ile); the bioinformatics’ analysis revealed clear destabilizing effects for 2 of them. The exon 14 presented the highest number of variants (32%). Four variants were observed in more than 1 case and the c.2043C>A p.(Cys681*) was carried by 18% of index cases. Two true homozygotes, 3 compound heterozygotes, and 1 double heterozygote were identified. Conclusion: This study characterizes for the first time in Argentina genetic variants associated with FH and suggest that the allelic heterogeneity of the FH in the country could have 1 relative common low-density lipoprotein receptor mutation. This knowledge is important for the genotype–phenotype correlation and for optimizing both cholesterol-lowering therapies and mutational analysis protocols. In addition, these data contribute to the understanding of the molecular basis of FH in Argentina. The authors thank the support from University of Buenos Aires, Argentina, UBACyT-B093 and from the Centro Nacional de Genetica Medica, ANLIS ‘‘Dr. Carlos Malbram,’’ Argentina. info:eu-repo/semantics/publishedVersion

Type 2 diabetes (T2DM) and chronic renal disease constitute important risk factors of atherosclerotic cardiovascular disease, associated with lipid abnormalities, and proinflammatory states. Advances in renal replacement therapy such as hemodialysis (HD) have not reduced morbi-mortality. It has not been elucidated if the concomitant presence of T2DM or metabolic syndrome with end-stage renal disease further impairs the atherogenic profiles.We studied 122 HD patients, among which 44 presented with T2DM (HD-T2DM) and 30 with metabolic syndrome (HD-MS); 48 had neither T2DM nor metabolic syndrome (HD-C). Lipoprotein profile, including atherogenic remnant lipoproteins (RLP), and inflammation markers--high sensitivity C-reactive protein (hsCRP), adiponectin, and interleukin-6 (IL-6)--were measured.In all HD patients, triglycerides, free fatty acids, and RLP showed no differences between HD groups, whereas high-density lipoprotein cholesterol (HDL-C) was decreased, particularly in HD-T2DM and HD-MS, with respect to HD-C (P0.01). Regarding inflammatory parameters, both IL-6 and hsCRP were found to be similar between HD groups. Adiponectin paradoxically shows higher values in relation to those expected for insulin resistance situations showing no differences between HD groups.The presence of T2DM or metabolic syndrome did not worsen atherogenic lipoprotein levels, but did reduce HDL-C. Neither was the proinflammatory profile further altered in HD patients in the presence of insulin resistance conditions.

Neurotensin behaves as a neuromodulator or as a neurotransmitter interacting with NTS1 and NTS2 receptors. Neurotensin in vitro inhibits synaptosomal membrane Na+, K+-ATPase activity. This effect is prevented by administration of SR 48692 (antagonist for NTS1 receptor). The administration of levocabastine (antagonist for NTS2 receptor) does not prevent Na+, K+-ATPase inhibition by neurotensin when the enzyme is assayed with ATP as substrate. Herein levocabastine effect on Na+, K+-ATPase K+ site was explored. For this purpose, levocabastine was administered to rats and K+-p-nitrophenylphosphatase (K+-p-NPPase) activity in synaptosomal membranes and [3H]-ouabain binding to cerebral cortex membranes were assayed in the absence (basal) and in the presence of neurotensin. Male Wistar rats were administered with levocabastine (50 μg/kg, i.p., 30 min) or the vehicle (saline solution). Synaptosomal membranes were obtained from cerebral cortex by differential and gradient centrifugation. The activity of K+-p-NPPase was determined in media laking or containing ATP plus NaCl. In such phosphorylating condition enzyme behaviour resembles that observed when ATP hydrolyses is recorded. In the absence of ATP plus NaCl, K+-p-NPPase activity was similar for levocabastine or vehicle injected (roughly 11 μmole hydrolyzed substrate per mg protein per hour). Such value remained unaltered by the presence of 3.5 × 10−6 M neurotensin. In the phosphorylating medium, neurotensin decreased (32 %) the enzyme activity in membranes obtained from rats injected with the vehicle but failed to alter those obtained from rats injected with levocabastine. Levocabastine administration enhanced (50 %) basal [3H]-ouabain binding to cerebral cortex membranes but failed to modify neurotensin inhibitory effect on this ligand binding. It is concluded that NTS2 receptor blockade modifies the properties of neuronal Na+, K+-ATPase and that neurotensin effect on Na+, K+-ATPase involves NTS1 receptor and -at least partially- NTS2 receptor. Fil: Gutnisky, Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina Fil: López Ordieres, María Graciela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina Fil: Rodriguez, Georgina Emma. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina

Background: Epicardial adipose tissue (EAT) is a visceral adipose tissue (AT) surrounding and infiltrating myocardium and coronary arteries. Increased EAT may represent a chronic inflammatory injury and a link with coronary artery disease (CAD). Metalloproteinases (MMPs) are involved in expansion of AT. Objective: To evaluate MMP-2 and -9 behaviour in EAT from CAD patients. Methods: In EAT and subcutaneous AT (SAT) from patients undergoing coronary artery bypass graft (CABG, n=26) or valve replacement (No CABG, n=18), MMP-2 and -9 activity and localization, inflammatory cells and vascular endothelial growth factor (VEGF) levels were determined. Results: In EAT from CABG, MMP-2 and -9 activity was increased compared with No CABG (p=0.041 and p=0.027, respectively) and compared with SAT (p=0.005 and p=0.048, respectively). In CABG patients EAT showed higher infiltration of macrophages and T lymphocytes than SAT (p=0.01 and p=0.002, respectively). In No CABG patients no sign of cellular retention was observed in EAT or SAT. Vascular density was higher in EAT from CABG than No CABG (p=0.015) and it was directly correlated with MMP-2 (p=0.006) and MMP-9 (p=0.02). VEGF levels in EAT were directly associated with MMP-2 (p=0.016). Conclusion: In EAT from CABG patients the increase of MMP-2 and -9 activity and the presence of inflammatory cells would be partially responsible for extracellular matrix (ECM) remodeling and major vascular density necessary for EAT expansion. Improved knowledge of EAT behaviour may allow to identify new therapeutic targets for the treatment of CAD. Fil: Miksztowicz, Verónica Julieta. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Morales, Celina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina Fil: Barchuk, Magalí. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: López, Graciela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina Fil: Póveda, Ricardo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina Fil: Gelpi, Ricardo Jorge. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Schreier, Laura Ester. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina Fil: Rubio, Miguel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina Fil: Berg, Gabriela Alicia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Resumen En Argentina no se han realizado estudios destinados a establecer la prevalencia de disglucemias (glucemia alterada en ayunas [GAA], tolerancia alterada a la glucosa [TAG] y diabetes mellitus [DM]) en pacientes con enfermedad renal. Se decidió realizar un estudio observacional, evaluando la frecuencia con prueba de tolerancia oral a glucosa (PTOG) en pacientes con enfermedad renal crónica (ERC), sin registro de disglucemia en sus historias clínicas. Se realizó PTOG a 254 pacientes (60,62% masculinos), con ERC estadios 3, 4 y 5, en tratamiento conservador, hemodiálisis o trasplante. Los resultados mostraron pacientes con valores de DM: 10 pacientes según ayunas exclusivamente (3,94%; IC 95%: 1,35-6,53%); exclusivamente segunda hora, 11 pacientes (4,33%; IC 95%: 1,63-7,03%); por ambos criterios, 15 pacientes (5,91%; IC 95%: 2,81-9,00%); por al menos un criterio, 36 pacientes (14,17%; IC 95%: 9,69-18,66%). En análisis multivariado, la DM se asoció con valor de cintura (OR = 1,033 por cm; IC 95%: 1,005-1,062; p = 0,019) y con tratamiento sustitutivo vs. conservador (OR = 0,41; IC 95%: 0,19-0,92; p = 0,028). La GAA (criterio ADA) fue del 19,75% en tratamiento conservador vs. 9,24% en tratamiento sustitutivo, con diferencia estadísticamente significativa. No fue significativa la diferencia de TAG que evidenció 24,6 y 20,3% en tratamiento conservador y sustitutivo, respectivamente. Se propone la realización de PTOG en todo paciente con ERC, ya que permite la detección de todo el rango de disglucemias desconocidas, evitando el subdiagnóstico y favoreciendo la realización de tratamientos para evitar su progresión, en caso de estar ante la presencia de un grupo de riesgo para DM (GAA o TAG), así como la elección de la medicación más adecuada para el trasplante o el inicio del tratamiento de nuevos casos de DM no diagnosticada, para disminuir la morbimortalidad. Abstract In Argentina, there have been no studies aimed at establishing the prevalence of dysglycaemia (impaired fasting glucose [IFG], impaired glucose tolerance [IGT] and diabetes mellitus [DM]) in patients with chronic kidney disease (CKD). Our group decided to conduct an observational study to evaluate the frequency with oral glucose tolerance test (OGTT) in CKD patients with no previous data for dysglycaemia in their medical records. OGTT was performed in 254 patients (60.62% male) with stage 3, 4 and 5 CKD under conservative treatment, haemodialysis or transplantation. Results for DM were found in 10 patients according to fasting glucose alone (3.94%; 95% CI: 1.35-6.53%), 11 patients with exclusively the second hour criterion (4.33%; 95% CI: 1.63-7.03%), 15 with both criteria (5.91%; 95% CI: 2.81-9.00%) and 36 patients with at least one criteria (14.17%; 95% CI: 9.69-18.66%). In a multivariate analysis, DM was associated with waist circumference (OR = 1.033 per cm; 95% CI, 1.005 to 1.062; P = .019) and with conservative treatment vs. replacement therapy (OR = 0.41; 95% CI: 0.19-0.92; P = .028). IGT was evident in 24.6% and 20.3 on conservative vs. replacement therapy, with no statistically significant difference. IFG (ADA criteria) was 19.75 vs. 9.24% in conservative vs. replacement therapy, with a statistically significant difference. OGTT is suggested for all CKD patients since it is able to detect the full range of unknown dysglycaemias, which avoids underdiagnoses and favours performing treatments to prevent progression in DM risk groups (IFG and/or IGT). It also aids in the selection of the most appropriate medication for transplantation or treatment initiation in new cases of undiagnosed DM to decrease morbidity and mortality.

Background and objective Hepatic lipase is a lipolytic enzyme mostly synthesized and localized at the surface of liver sinusoidal capillaries, which hydrolyses triglycerides and phospholipids of intermediate density, large low density (LDL) and high density lipoproteins. Hepatic lipase activity is increased in insulin resistant states. Non-alcoholic fatty liver disease (NAFLD) is characterized by insulin resistance. However, at present, no data are available regarding the behaviour of hepatic lipase with regard to the degree of hepatic steatosis. Our aim was to evaluate hepatic lipase activity in NAFLD patients and its relationship to the severity of hepatic steatosis. Design and patients We studied 48 patients with NAFLD (diagnosed by ultrasonography and confirmed by liver biopsy) and 30 controls. Steatosis was semi-quantitatively assessed and considered as mild or grade 1, moderate or grade 2 and severe or grade 3. Measurements: hepatic lipase activity, lipid and lipoprotein profile (including intermediate density lipoproteins and dense LDL), adiponectin, insulin, glucose and high sensitivity C-reactive protein were measured. Homeostasis model assessment for insulin resistance (HOMA) index was calculated. Results Patients with hepatic steatosis presented with higher hepatic lipase activity, HOMA and dense LDL and lower levels of adiponectin, high density lipoproteins, cholesterol and apoA-I. Hepatic lipase activity positively correlated significantly with the severity of hepatic steatosis. Hepatic lipase correlated with a more atherogenic profile and persisted higher in patients even after corrected for age, gender, body mass index, HOMA and adiponectin. Conclusion The higher hepatic lipase activity in NAFLD patients contributes to a more atherogenic profile linked to increased cardiovascular risk, beyond the insulin resistance and the reduction in adiponectin. Copyright © 2012 John Wiley & Sons, Ltd.

Previous work from this laboratory showed the ability of neurotensin to inhibit synaptosomal membrane Na +, K +-ATPase activity, the effect being blocked by SR 48692, a non-peptidic antagonist for high affinity neurotensin receptor (NTS1) [López Ordieres and Rodríguez de Lores Arnaiz 2000; 2001]. To further study neurotensin interaction with Na +, K +-ATPase, peptide effect on high affinity [ 3H]-ouabain binding was studied in cerebral cortex membranes. It was observed that neurotensin modified binding in a dose-dependent manner, leading to 80% decrease with 1×10 4M concentration. On the other hand, the single addition of 1×10 -6M, 1×10 5M and 1×10 M SR 48692 (Sanofi-Aventis, U.S., Inc.) decreased [ 3H]-ouabain binding (in %) to 87±16; 74±16 and 34±17, respectively. Simultaneous addition of neurotensin and SR 48692 led to additive or synergic effects. Partial NTS2 agonist levocabastine inhibited [ 3H]-ouabain binding likewise. Saturation assays followed by Scatchard analyses showed that neurotensin increased K d value whereas failed to modify B max value, indicating a competitive type interaction of the peptide at Na +, K +-ATPase ouabain site. At variance, SR 48692 decreased B max value whereas it did not modify K d value. [ 3H]-ouabain binding was also studied in cerebral cortex membranes obtained from rats injected i. p. 30min earlier with 100μg and 250μg/kg SR 48692. It was observed that the 250μg/kg SR 48692 dose led to 19% decrease in basal [ 3H]-ouabain binding. After SR 48692 treatments, addition of 1×10 6M led to additive or synergic effect. Results suggested that [ 3H]-ouabain binding inhibition by neurotensin hardly involves NTS1 receptor. © 2010 Elsevier B.V. Fil: Rosin, Carina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacología; Argentina Fil: López Ordieres, María Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacología; Argentina Fil: Rodriguez, Georgina Emma. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacología; Argentina

We have previously showed that peptide neurotensin inhibits neuronal Na+, K+-ATPase activity, an effect which involves high affinity neurotensin receptor. Nitric oxide (NO) acts as a neurotransmitter or as a neuromodulator when it is synthesized by neuronal nitric oxide synthase. Neurotensin effect on Na+, K+-ATPase activity was evaluated in cortical synaptosomal membranes isolated from rats injected at 3, 4 and 5 postnatal days with saline (control) or N (ω)-nitro-l-arginine methyl esther (L-NAME), a nitric oxide synthase inhibitor. Assays were carried out at two stages: juvenile (35 days) and adult (56 days) ages. In an open field task, results recorded in juvenile rats markedly differed from those obtained in adult rats. The presence of neurotensin at 3.5 × 10-8-3.5 × 10-6M concentration decreased 16-34% Na+, K +-ATPase activity in membranes purified from control animals. At variance, the peptide failed to alter this enzyme activity in membranes obtained after L-NAME treatment. After administration of L-NAME, [3H]-ouabain binding to membranes isolated from adult male rats decreased 64% in the presence of 1.0 × 10-6M neurotensin, a peptide concentration which only slightly decreased binding to membranes isolated from juvenile rats. It is postulated that early postnatal NO dysfunction may exert a permanent change in neurotensin system that influence later Na+, K +-ATPase response to neurotensin. Fil: López Ordieres, María Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina Fil: Alvarez Juliá, Anabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina Fil: Kemmling, Alma Karen. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Rodriguez, Georgina Emma. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina

Background It is not elucidated if liver fat deposits associated to metabolic syndrome (MS) aggravate the atherogenic state. We evaluated, in MS patients, if the presence of non-alcoholic hepatic steatosis (HS) determines differences in inflammatory markers and VLDL characteristics. Methods Seventy-five patients with MS were divided into 2 groups depending on the presence or absence of HS, assessed by ultrasound. Lipid profile, free fatty acids (FFA), VLDL composition, adiponectin, tumor necrosis factor-alpha (TNF-α), high sensitivity C-reactive protein (hs-CRP), and soluble adhesion molecules (sVCAM-1 and sICAM-1) were measured. Results HS patients presented increased triglycerides levels, HOMA-IR and FFA. Patients with HS showed a reduction in adiponectin (p = 0.04) and increase in hs-CRP (p = 0.02), independently of insulin-resistance (IR). FFA correlated positively with TNF-α (p = 0.04) and inversely with adiponectin (p = 0.01). hs-CRP correlated with all inflammatory markers, independently of IR: TNF-α (r = 0.34, p = 0.02), sVCAM-1 (r = 0.29 p = 0.03), sICAM-1 (r = 0.56, p = 0.01), adiponectin (r = −0.34, p = 0.04). HS patients presented higher VLDL mass and number of particles. Adiponectin correlated with VLDL cholesterol content (r = −0.47, p = 0.04), independently of IR. VLDL, once secreted, would suffer from changes, becoming more atherogenic. Conclusions Simple HS would play an important role increasing cardiovascular risk, independently of IR. hs-CRP may represent a useful biomarker of this condition.

Na+, K+-ATPase is inhibited by neurotensin, an effect which involves the peptide high affinity receptor (NTS1). Neurotensin effect on cerebral cortex synaptosomal membrane Na+, K+-ATPase activity of rats injected i.p. with antipsychotic clozapine was studied. Whereas 3.5 x 10(-6) M neurotensin decreased 44% Na+, K+-ATPase activity in the controls, the peptide failed to modify enzyme activity 30 min after a single 3.0, 10.0 and 30.0 mg/kg clozapine dose. Neurotensin decreased Na+, K+-ATPase activity 40 or 20% 18 h after 3.0 or 5.6 mg/kg clozapine administration, respectively, and lacked inhibitory effect 18 h after 17.8 and 30.0 mg/kg clozapine doses. Results indicated that the clozapine treatment differentially modifies the further effect of neurotensin on synaptosomal membrane Na+, K+-ATPase activity according to time and dose conditions employed. Taken into account that clozapine blocks the dopaminergic D2 receptor, findings obtained favor the view of an interplay among neurotensinergic receptor, dopaminergic D2 receptor and Na+, K+-ATPase at synaptic membranes.

Background: Qualitative lipoprotein changes, such as an increase in fasting remnants, are reported in subclinical hypothyroidism (SCH). It was hypothesized that such changes are due to reduced hepatic lipase (HL) activity in SCH: HL is an enzyme regulated by thyroid hormones, and is involved in the degradation of triglyceride (TG)-rich remnants. This study aimed to quantify remnant-like lipoproteins (RLP), small dense LDL (sdLDL), and HL activity in women with SCH, and to assess these parameters after levothyroxine replacement therapy. Methods: This was an observational cross-sectional study with a subsequent longitudinal follow-up. Findings in women with thyrotropin levels >4.5 mIU/L (SH group) were compared with age- and body mass index (BMI)-matched euthyroid women (control group). In addition, a subgroup analysis was undertaken in SCH women who chose to receive levothyroxine treatment (0.9 μg/kg/day) for 6 months. RLP was quantified by measuring cholesterol (RLP-C) and triglycerides (RLP-TG) after immunoaffinity chromatography, and sdLDL by automated standardized methods; HL activity was measured in post-heparin plasma. Results: The SCH group included 37 women; 29 women were included in the control group. In addition, 22 women with SCH were included in the subgroup analysis (levothyroxine treatment). Significantly higher RLP values were observed in the SCH group than in the control group: RLP-C (median [range], mg/dL): 20.3 (5.8-66.8) versus 10.2 (2.7-36.3), p = 0.005; RLP-TG (mg/dL): 26.3 (3.2-123.3) versus 12.1 (2.5-61.6), p = 0.033. HL activity (mean ± standard deviation [SD], μmol free fatty acid/mL post-heparin plasma.h) - 9.83 ± 4.25 versus 9.92 ± 5.20, p = 0.707 - and sdLDL levels (mg/dL) - 23.1 ± 10.7 versus 22.6 ± 8.4, p = 0.83 - were similar. After levothyroxine, RLP-C decreased - 21.5 (5.8-66.8) versus 17.2 (4.1-45.6), p = 0.023 - and HL increased - 9.75 ± 4.04 versus 11.86 ± 4.58, p = 0.012 - in the subgroup of SCH women. No changes in sdLDL were observed. Conclusions: Women with SCH have higher RLP levels than matched controls do, but their RLP-C levels decrease significantly following levothyroxine therapy. Furthermore, HL activity also increases after levothyroxine therapy and can be interpreted as a possible explanation for the decrease in RLP-C. Fil: Brenta, Gabriela. Unidad Asistencial Doctor César Milstein; Argentina Fil: Berg, Gabriela Alicia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Miksztowicz, Verónica Julieta. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Lopez, Graciela Ines. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Lucero, Diego Martín. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Faingold, María Cristina. Unidad Asistencial Doctor César Milstein; Argentina Fil: Murakami, Masami. Gunma University Graduate School Of Medicine; Japón Fil: Machima, Tetsudo. Gunma University Graduate School Of Medicine; Japón Fil: Nakajima, Katsuyuki. Graduate School Of Health Sciences, Gunma University; Japón Fil: Schreier, Laura Ester. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Synaptosomal membrane Na + , K + -ATPase is inhibited by neurotensin, an effect which involves its high affinity receptor (NTS1) [Lopez Ordieres MG, Rodriguez de Lores Arnaiz, G. Peptides 2000; 21:571–576.]. Herein, the effect of neurotensin on synaptosomal membrane Na + , K + -ATPase of rats 18 h after i.p. administration of antipsychotic haloperidol (2 mg/kg) or clozapine (10 mg/kg) was studied. Basal enzyme activity after these treatments did not differ from that in vehicle-treated rats. It was observed that 3.5×10 −6 M neurotensin reduced roughly 40% cerebral cortex Na + , K + -ATPase from vehicle-injected rats, produced no effect on the enzyme from rats injected with haloperidol but enhanced 26% that from rats injected with clozapine. The peptide decreased 40% striatal Na + , K + -ATPase from vehicle-injected rats or from rats injected with clozapine, whereas it failed to alter this enzyme activity from rats injected with haloperidol. Haloperidol and clozapine (1×10 −6 M) added in vitro failed to alter Na + , K + -ATPase activity in cerebral cortex synaptosomal membranes. Results obtained after antipsychotic administration may well offer an alternative explanation for the particular side effects recorded in therapeutics by typical (haloperidol) versus atypical (clozapine) antipsychotic drugs.

Both renal failure and type 2 diabetes may contribute synergistically to the dyslipemia of diabetic renal failure with the development of atherosclerosis as the possible consequence. It has not yet been conclusively evaluated whether diabetic patients with end-stage renal failure under maintenance hemodialysis (HD) show accentuated alterations in plasma lipids and lipoproteins in comparison to nondiabetics under HD. These abnormalities would involve hepatic lipase activity and the regulation of triglyceride-rich lipoprotein metabolism. The purpose of the present study was to evaluate whether type 2 diabetic patients undergoing HD exhibited a lipid-lipoprotein profile different from that of nondiabetic hemodialyzed patients. We compared plasma lipids, apoprotein (apo) A-I and B, and lipoprotein parameters among 3 groups: 25 type 2 diabetics, 25 nondiabetics, both undergoing HD, and 20 healthy control subjects. Intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) were isolated by sequential ultracentrifugation. Hepatic lipase activity was measured in postheparin plasma. Both groups of HD patients showed higher triglyceride and IDL cholesterol (P.001), and lower high-density lipoprotein (HDL) cholesterol (P.01) and apo A-I (P.001) levels compared to the control group, even after adjustment for age and body mass index (BMI). However, no differences were found in lipid, lipoprotein, and apoprotein concentrations between diabetic and nondiabetic HD patients, except for high LDL triglyceride content of diabetic HD patients (P.01). Nondiabetics undergoing HD also presented higher LDL triglyceride levels than controls (P.05). LDL triglyceride correlated with plasma triglycerides (r = 0.51, P.001). A lower LDL cholesterol/apo B ratio was found in each group of HD patients in comparison to controls (P.02). Comparing the diabetic and nondiabetic patients, hepatic lipase activity remained unchanged, but significantly lower than control subjects (P.001). Hepatic lipase correlated with log-triglyceride (r = -0.31, P.01), IDL cholesterol (r = -0.41, P.001), and LDL triglyceride (r = -0.32, P.01). In conclusion, both diabetic and nondiabetic HD patients shared unfavorable alterations in lipid-lipoprotein profile not different between them but different from a healthy control group. The only difference between the groups of HD patients was a significant LDL triglyceride enrichment, which correlated negatively with hepatic lipase activity. Lipoprotein abnormalities in HD patients would enhance their risk for the development of atherosclerosis.

Background: Metabolic syndrome (MetS) is associated with changes in HDL levels, composition and sub-fraction profile. Whether these alterations affect HDL anti-atherogenic function, specifically measured as its capacity to perform cholesterol efflux, is not yet clearly known. Objective: To evaluate the relation between serum cholesterol efflux capacity and the changes in HDL composition and sub-fraction profile in MetS. Methods: In 35 non-treated MetS patients and 15 healthy controls, HDL mediated cholesterol efflux was measured as the ability of apoB-depleted serum to accept cholesterol from cholesterol-loaded BHK cells expressing either ABCA1 or ABCG1. Additionally we determined: lipid profile, HDL sub-fractions (NMR) and LCAT mass (ELISA). Isolated HDL (δ:1.063-1.210 g/mL) was chemically characterized. Pre-β1-HDL was determined by 2D-electrophoresis in a sub-group of MetS and controls (n = 6 each). Results: Surprisingly, MetS patients presented higher ABCA1 mediated cholesterol efflux (10.4 ± 1.8 vs. 8.7 ± 0.3%; p = 0.0001), without differences in ABCG1 efflux. In MetS, HDL showed reduction in particle size and number (p < 0.02) and lower large/small HDL ratio (p = 0.05), as well as triglyceride enrichment (p = 0.0001). Pre-β1-HDL was increased in MetS (p = 0.048) and correlated with ABCA1-cholesterol efflux (r = 0.64; p = 0.042). LCAT mass showed a tendency to reduction in MetS (p = 0.08), and inversely correlated with ABCA1-cholesterol efflux (r = -0.51; p = 0.001), independently of obesity and insulin-resistance (β = -0.40, p = 0.034). Conclusion: This is the first description of ABCA1 mediated cholesterol efflux in MetS. Regardless the reduced HDL-cholesterol, in vitro cholesterol efflux capacity by ABCA1 was enhanced, linked to increased pre-β1-HDL and slightly reduced in LCAT mass that would probably reflect a delay in reverse cholesterol transport occurring in MetS. Fil: Lucero, Diego Martín. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina Fil: Svidirov, Denis. National Institutes of Health; Estados Unidos Fil: Freeman, Lita. National Institutes of Health; Estados Unidos Fil: López, Graciela I.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; Argentina Fil: Fassio, Eduardo. Hospital Nacional Profesor Alejandro Posadas; Argentina Fil: Remaley, Alan T.. National Institutes of Health; Estados Unidos Fil: Schreier, Laura Ester. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; Argentina

SUMMARY Plasma lipid profile and abdominal obesity have been associated with breast cancer risk, however published resuits'have been inconsistent. To clarify these associations we studied lipid and lipoprotein alterations, obesity degree and body fat distribution, in 30 newly diagnosed breast cancer patients without treatment and 30 controls matched by age and menopausal status. Both pre and postmenopausal breast cancer patients presented higher body mass index, waist/hip ratio and insulin levels than their matched controls. An increase in triglycerides and a decrease in HDL-cholesterol, especially in the HDLz subfraction, were observed in patients with breast cancer. Besides, HDL particle from these patients showed increased apo AJHDL-cholesterol ratio. These alterations were correlated with waist/hip ratio. The association between lipoprotein alterations and abdominal obesity independent of menopausal status, in untreated newly diagnosed breast cancer patients is reported for the first time in this study.

The present investigation was undertaken to determine whether Ang-(1-7) is able to modify ATPase activities in membrane fractions prepared from several tissues. In the presence of 10(-6) M Ang-(1-7), total (Na , K+, Mg2+)-ATPase activity decreased 31% in rat atrium and 13% in sheep atrium but was unmodified in sheep liver, rat ventricle or crude brain membranes. In rat brain synaptosomal membranes, Ang-(1-7) at 10(-8) and 10(-7) M concentrations activated Na+, K+-ATPase 20 and 24%, respectively. Rat kidney Na+, K+-ATPase activity decreased roughly 40-70% with 10(-10)-10(-6) M Ang-(1-7)), but increased 22% with 10(-12) M peptide concentration, thus indicating a biphasic effect. Our findings showing that ATPase from several tissues responds differently to Ang-(1-7) are attributable to enzyme tissue specificity.

Objectives: To characterize low-density lipoprotein (LDL) chemical composition and oxidability in normolipidemic and dyslipidemic patients with atherosclerotic cardiovascular disease, as compared with matched control subjects. To evaluate LDL susceptibility to oxidation, we determined the cutoff points of thiobarbituric reactive substances (TBARS) in LDL after oxidative stress, as well as its resistance to oxidation. Design and methods: LDL (density 1.019–1.063 g/mL) of 24 men with atherosclerotic cardiovascular disease (12 normolipidemic and 12 dyslipidemic patients) and 18 age-matched healthy control men. LDL chemical composition was determined and apo B/cholesterol ratio was calculated. TBARS in native LDL and after 60 and 120 min of LDL oxidation with copper were measured. The conjugated diene production kinetics during LDL incubation with copper were also studied, lag time being an oxidation resistance marker. Cutoff points for the positivity criterion of apoB/cholesterol ratio in LDL and TBARS in native and oxidized LDL were evaluated using the receiver operator characteristic (ROC) graphic method. Results: LDL were triglyceride-enriched, the apoB/cholesterol ratio being higher in patients than in controls, without differences between normolipidemic and dyslipidemic subgroups. We have established the following cutoff values to differentiate between patients and controls: 0.43 mg/mg for the apo B/cholesterol ratio in LDL; 3.0 nmol malondialdehyde/mg protein for TBARS in native LDL; 22 and 80 nmol malondialdehyde/mg protein after 60- and 120-min postoxidative stress, respectively. We did not find differences in the conjugated diene production kinetics between patients and controls. Conclusions: The enrichment in triglycerides and the high apoB/cholesterol ratio suggest the presence of an abnormal LDL particle in normolipidemic and dyslipidemic patients. This LDL particle was more susceptible to oxidation. In the ROC analysis, the TBARS plot at 120 min exhibited greater accuracy and better performance than the other LDL oxidability markers.

Background: Hepatic steatosis (HS) is closely associated to metabolic syndrome (MS). Both, VLDL-triglyceride oversecretion and intrahepatic deposits, can take place. We evaluated VLDL characteristics, CETP, hepatic lipase (HL), IDL and small dense LDL (sdLDL), in patients with HS associated to MS. Methods: We studied 3 groups matched by age and sex: 25 MS patients with HS (diagnosed by ultrasonography), 25 MS patients without HS and 25 healthy controls. Main measurements were: lipid profile, free fatty acids, VLDL composition, VLDL size by HPLC, CETP and HL activities, IDL-cholesterol and sdLDL-cholesterol. Results: Patients with HS presented higher triglyceride levels, HOMA-IR and free fatty acids, VLDL mass and VLDL-apoB (p < 0.05). No differences in VLDL composition were observed. MS groups presented higher proportion of large VLDL than controls (p < 0.05). HS group showed higher CETP than controls (p = 0.01) and almost higher than MS without HS (p = 0.06). CETP correlated with VLDL-cholesterol content, r = 0.48, p < 0.005. The increase in sdLDL-cholesterol correlated with CETP (r = 0.47) and HL (r = 0.56), independent of insulin resistance (p < 0.003). Conclusion: Despite intrahepatic fat, patients with HS secreted higher number of VLDL particles. CETP would have a remodeling action on VLDL in circulation, enriching it in cholesterol and also favoring, together with HL, the formation of sdLDL. Fil: Lucero, Diego Martín. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina Fil: Zago, Valeria. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina Fil: López, Graciela I.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina Fil: Graffigna, Mabel Nora. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Agudos Carlos Durand; Argentina Fil: López, Gustavo. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Cátedra de Biología Molecular; Argentina Fil: Fainboim, Hugo. Hospital Muñiz; Argentina Fil: Miksztowicz, Verónica Julieta. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina Fil: Gomez Rosso, Leonardo Adrián. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina Fil: Belli, Susana Haydee. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Agudos Carlos Durand; Argentina Fil: Levalle, Oscar Alberto. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Agudos Carlos Durand; Argentina Fil: Berg, Gabriela Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina Fil: Brites, Fernando Daniel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina Fil: Wigdorovitz de Wikinski, Regina Luisa. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina Fil: Schreier, Laura Ester. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina

Adiponectin is an adipokine highly and specifically expressed by adipose cells with antiatherogenic and antiinflammatory activities. The aim of the present study was to evaluate plasma adiponectin concentration in patients with primary hypertriglyceridemia and its relationship with metabolic parameters.Male patients with primary hypertriglyceridemia and without the metabolic syndrome (n=22) were compared with normotriglyceridemic individuals (n=25). Plasma adiponectin concentration was measured by standardised enzyme-linked immunosorbent assay. Body mass index, waist circumference, glucose, insulin and non-esterified fatty acid levels, lipoprotein profile, and CETP activity were evaluated. Adiponectin levels were significantly decreased in hypertriglyceridemic patients in comparison with normotriglyceridemic subjects (4292+/-1717 vs. 6939+/-3249 ng/ml, p0.005, respectively). Adiponectin was negatively associated with glucose (r=-0.44, p0.01), insulin (r=-0.37, p0.01), HOMA (r=-0.40, p0.01), triglycerides (r=-0.36, p0.01), VLDL-C (r=-0.34, p0.05), and CETP (r=-0.47, p0.001). Positive and significant correlations were observed with QUICKI (r=0.49, p0.001) and HDL-C (r=0.33, p0.05). In the multiple linear regression analysis, considering waist circumference, QUICKI, Log-triglycerides, HDL-C, and CETP as independent variables, Log-adiponectin showed a positive correlation with QUICKI, with an r(2)=0.229 and p0.001. Therefore, the independent variable QUICKI explained the 23% of the variance in Log-adiponectin concentration.We found low adiponectin levels in a population of primary hypertriglyceridemic men without the metabolic syndrome and an independent relationship between adiponectin concentration and insulin resistance. A reduction in insulin sensitivity and its impact on adiponectin concentration could be linked to high non-esterified fatty acid levels, increased triglyceride synthesis in the liver and impaired catabolism of triglyceride-rich lipoproteins.

In postmenopausal women (PMW), an adverse lipoprotein pattern and high risk of coronary artery disease has been described. Studies of the mechanisms promoting the higher atherogenic risk observed in healthy PMW are relevant. We evaluated the interactions among several circulating factors involved in the endothelial injury and inflammation in relation to LDL characteristics, beyond LDL cholesterol.Lipoprotein profile, including apolipoproteins A-I and B, small dense LDL, hepatic lipase, cholesterol transfer protein (CETP), LDL composition and oxidability were assessed in PMW (n=30) in comparison to premenopausal (PreMW, n=28). The following emerging factors were measured: homocysteine, phospholipase A2, ferritin, hs-CRP and fibronectin from extracellular vascular matrix. Insulin-resistance was evaluated by waist circumference, HOMA and TG/HDL cholesterol ratios.The risk index apo B/apo A-I was significantly increased in PMW (p0.0001), PMW showed higher proportion of small dense LDL which correlated with the increase in hepatic lipase activity (p0.005) and with insulin-resistance markers (p0.05), but not with CETP. Phospholipase A2 (p0.05), homocysteine (p0.005), hs-CRP (p0.005), fibronectin (p0.05) and ferritin (p0.0001) were increased in PMW. LDL oxidability positively correlated with waist (p0.02), homocysteine (p0.05), fibronectin (p0.05), hs-CRP (p0.04), phospholipase A2 (p0.05), and small dense LDL (p0.01). After adjusting by menopausal condition, age and waist, LDL oxidability remained associated with waist (beta: 0.35, p=0.047), homocysteine (beta: 0,36 p0,038), fibronectin (beta: 0,41 p=0.05), and small dense LDL (beta: 0.36, p=0.027).Evaluation of classic and non-traditional circulating risk factors in hypoestrogenism reflected endothelial and subendothelial inflammation and subclinical atherogenic processes.

Objective Recently, the American Diabetes Association (ADA) proposed a new diagnostic entity for diabetes mellitus that has not been applied in renal failure patients so far. Our goal was to apply the new impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) criteria in a group of hemodialyzed patients to provide data on glucose alterations in chronic renal failure. Design and Patients We evaluated 74 hemodialyzed patients, (38 women, 36 men) without diagnosed diabetes. Blood was collected at fasting and at 120 minutes after a 75-g glucose intake, and insulin levels were determined. The weight, height, waist circumference, and hip circumference of each patient were measured, and the body mass index (BMI) and waist–hip ratio were calculated. Results and Conclusion Values of fasting plasma glycemia and 120-minute oral glucose tolerance test were (mean ± SD) 78 ± 9.4 mg/dL and 121 ± 39 mg/dL, respectively. Among the 74 subjects studied, 5 patients had IFG, none of them showing a glucose level above 110 mg/dL. If the ADA 1997 criteria were applied, these patients would be classified as normal. On the other hand, 15 of the 74 patients showed IGT, this prevalence being higher compared with that of the general population. Finally, in 5 of the 74 patients the presence of type 2 diabetes was shown by the second test. According to sex, no differences were observed in the prevalence of IFG, IGT, or diabetes. Glucose alterations are characteristics that need to be identified in chronic renal failure patients. Our results suggests that the glucose tolerance test might be evaluated during hemodialysis treatment to define its prevalence.

RodrIGuez de Lores Arnaiz, G. and M. G. LOPez Ordieres. A study of calcitonin effect on synaptosomal membrane enzymes. 18(4) 613–615, 1997.—Calcitonin is a hormone peptide produced by the thyroid gland, whose best described role is to prevent bone reabsorption. It also participates in other biological functions, even at central nervous system level. We studied the effect of added calcitonin on ATPase and acetylcholinesterase activities in synaptosomal membranes isolated from rat cerebral cortex. Calcitonin at 10 −7 − 10 −5 M concentration decreased 20–40% Na + , K + -ATPase and 15–25% K + - p -nitrophenylphosphatase activities, and at 10 −6 − 10 −5 M reduced 20–30% Mg 2+ - p -nitrophenylphosphatase activity. However, this peptide failed to modify Mg 2+ − and Ca 2+ − ATPase or acetylcholinesterase activities. Results suggest that the sodium pump may be a target for calcitonin effects at neuronal level. Thus, calcitonin inhibition of sodium/potassium transport through synaptic membranes supports a regulatory role of this peptide on neurotransmission.