Publications by authors named "Contreras G"

Aim: Cardiovascular complications are common in patients with chronic kidney disease in the general population. The study aims to investigate the prevalence and prognosis of CKD stages 3-5 in the veterans affairs (VA) population, which is sicker with more co-morbid conditions.

Methods: In this case-controlled study of 6,432 men the associations of risk factors with CKD and its risk of mortality were estimated using, primarily, logistic regression analysis.

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The aim of this study was the development of a panel constituted by well-defined HIV-1 strains of different genetic forms, with a particular focus on isolates from acute and recent infections. Fourteen HIV-1 isolates, including four from acute and five from recent infections, were expanded in peripheral blood mononuclear cells. SI phenotype, coreceptors use, and TCID(50)/ml were determined.

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After removal of the fast N-type inactivation gate, voltage-sensitive Shaker (Shaker IR) K channels are still able to inactivate, albeit slowly, upon sustained depolarization. The classical mechanism proposed for the slow inactivation observed in cell-free membrane patches--the so called C inactivation--is a constriction of the external mouth of the channel pore that prevents K(+) ion conduction. This constriction is antagonized by the external application of the pore blocker tetraethylammonium (TEA).

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Background/aims: The N-amino-terminal fragment of the prohormone B-type natriuretic peptide (NT-proBNP) is a marker of cardiac stress and elevated levels are indicative of heart failure. Few correlates of NT-proBNP levels have been identified in persons with moderate chronic kidney disease (CKD), and data from those without heart failure and from African Americans are especially limited.

Methods: The African American Study of Kidney Disease and Hypertension (AASK) enrolled nondiabetic African Americans with hypertensive kidney disease (glomerular filtration rate [GFR] = 20-65 ml/min/1.

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An unusual increase in infections caused by vancomycin-resistant Enterococcus gallinarum (VREG) was identified in May 2004, in a Colombian tertiary care teaching hospital. A case-control study was subsequently designed to identify risk factors associated with the development of infections due to these organisms. All VREG isolates were subjected to antimicrobial susceptibility testing, vancomycin resistance gene detection and pulsed-field gel electrophoresis (PFGE) typing.

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According to the "Fistula First Initiative" surgeon selection should be based on best outcomes, willingness, and ability to provide access services. This analysis presents arteriovenous access placement and outcomes in 75 patients when surgery was performed by one of two dedicated high-volume vascular access surgeons (community [surgeon I] and academic medical center [surgeon II]). Preoperative vascular mapping was performed in all the patients.

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Objective: To develop a measure of renal activity in systemic lupus erythematosus and use it to develop a renal response index.

Methods: Abstracted data from the medical records of 215 patients with lupus nephritis were sent to 8 nephrologists and 29 rheumatologists for rating. Seven nephrologists and 22 rheumatologists completed the ratings.

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Objective: To assess the degree to which physicians agree with each other and with ratings obtained with 3 existing responder indices, in rating the response to treatment of lupus nephritis.

Methods: Lupus nephritis patient medical records from 125 pairs of visits (6 months apart) were used to create renal response scenarios. Seven nephrologists and 22 rheumatologists rated each scenario as demonstrating complete response, partial response, same, or worsening.

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Background: Antihypertensive drugs that block the renin-angiotensin system (angiotensin-converting enzyme inhibitors [ACEIs] or angiotensin receptor blockers) are recommended for patients with chronic kidney disease (CKD). A low blood pressure (BP) goal (BP, <130/80 mm Hg) is also recommended. The objective of this study was to determine the long-term effects of currently recommended BP therapy in 1094 African Americans with hypertensive CKD.

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Background: Chronic kidney disease (CKD) is more likely to progress to kidney failure (end-stage renal disease) in African Americans, although the reasons for this are unclear. Metabolic syndrome is a risk factor for the development of diabetes and cardiovascular disease and recently was linked to incident CKD. The purpose of this study is to examine whether metabolic syndrome is associated with kidney disease progression in hypertensive African Americans.

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Background: Higher levels of N-terminal prohormone brain-type natriuretic peptide (NT-proBNP) predict cardiovascular disease (CVD) in several disease states, but few data are available in patients with chronic kidney disease or in blacks.

Methods And Results: The African American Study of Kidney Disease and Hypertension trial enrolled hypertensive blacks with a glomerular filtration rate of 20 to 65 mL x min(-1) x 1.73 m(-2) and no other identified cause of kidney disease.

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ABSTRACT The aim of this study was to characterize the HIV-1 intersubtype recombinant forms generated during the follow-up of a dual natural infection with subtypes B and G. Near full-length sequences from plasma and peripheral blood mononuclear cell (PBMC) compartments were analyzed and the biological characteristics of their derived primary isolates studied. Different mutations were detected in V1, V2, and V3 sequences from primary isolates but not in sequences from plasma RNA or PBMC DNA.

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The HIV-1 subtype A epidemic affecting injecting drug users (IDU) in former Soviet Union (FSU) countries started dramatically in Odessa, southern Ukraine, in 1995, and is caused by a variant of monophyletic origin, often designated IDU-A. We phylogenetically analyzed one near full-length genome and two partial sequences of three HIV-1 subtype A viruses collected in St. Petersburg, Russia, heterosexually transmitted in 1992-1994.

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African Americans with hypertensive renal disease represent a high-risk population for cardiovascular events. Although left ventricular hypertrophy is a strong predictor of adverse cardiac outcome, the prevalence and associated factors of left ventricular hypertrophy in this patient population are not well described. The African American Study of Kidney Disease Cohort Study is a prospective, observational study that is an extension of the African American Study of Kidney Disease randomized clinical trial that was conducted from 1994 to 2001 in African Americans with hypertension and mild-to-moderate renal dysfunction.

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Objective: It has yet to be determined whether genotyping at the angiotensin-converting enzyme (ACE) locus is predictive of blood pressure response to an ACE inhibitor.

Methods: Participants from the African American Study of Kidney Disease and Hypertension trial randomized to the ACE inhibitor ramipril (n = 347) were genotyped at three polymorphisms on ACE, just downstream from the ACE insertion/deletion polymorphism (Ins/Del): G12269A, C17888T, and G20037A. Time to reach target mean arterial pressure ( View Article and Find Full Text PDF

Understanding the complex interaction between human leukocyte antigen (HLA) and killer immunoglobulin-like receptor (KIR) requires study of both HLA and KIR diversity in the same population. The presence of KIR genes 2DL1, 2, 3, 4, 5, KIR3DL1, 3DL2, 3DL3, KIR2DS1, 2DS2, 2DS3, 2DS4, 2DS5, KIR3DS1, KIR3DP1, KIR2DP1 was determined in 54 unrelated Mexican Mestizo donors. The PCR sequence-specific oligonucleotide probe One Lambda kit (Luminex) kindly given by J.

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The main objective of this study is to evaluate the prevalence of resistance-associated mutations to reverse transcriptase (RT) and protease (PR) inhibitors (I) 2 years after the introduction of antiretroviral treatment in Cuba, analyzing the mutations corresponding to different HIV-1 genetic forms circulating in Cuba. A total of 425 plasma samples were collected in 2003, corresponding to 175 (41.2%) subtype B and 250 (58.

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Intra-access static pressure ratio (SPR) (intra-access pressure/mean arterial pressure) can be measured during angioplasty (PTA) to assess the functional importance of an arteriovenous graft (AVG) stenosis. We used SPR in 70 patients with AVGs who underwent 98 angioplasty procedures. SPR was measured during angioplasty by placing a catheter tip at mid-access.

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The biological characteristics of HIV-1 primary isolates of different recombinant forms (RFs) and non-B subtypes from Galicia, Spain, were investigated and the relationships between biological phenotype and evolution of infection were determined. Peripheral blood mononuclear cells (PBMCs) were obtained during the follow-up of 32 patients infected with HIV-1 non-subtype B genetic forms, characterized in partial sequences of pol (protease-reverse transcriptase) and env V3 region: 12 (37.5%) circulating RFs (CRFs), 9 (28.

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Whereas much research has investigated equations for obtaining estimated GFR (eGFR) from serum creatinine in cross-sectional settings, little attention has been given to validating these equations as outcomes in longitudinal studies of chronic kidney disease. A common objective of chronic kidney disease studies is to identify risk factors for progression, characterized by slope (rate of change over time) or time to event (time until a designated decline in kidney function or ESRD). The relationships of 35 baseline factors with eGFR-based outcomes were compared with the relationships of the same factors with iothalamate GFR (iGFR)-based outcomes in the African American Study of Kidney Disease and Hypertension (AASK; n = 1094).

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Systemic lupus erythematosus, which predominantly affects young women, frequently is complicated by renal involvement. The presence of acute glomerulonephritis significantly adds to morbidity and mortality. Based on currently published clinical trials, induction therapy with cyclophosphamide combined with pulse corticosteroids is an efficacious treatment option to preserve renal function, and long-term data are available to support this choice.

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Background: The African American Study of Kidney Disease and Hypertension was a multicenter trial of African Americans with hypertensive kidney disease randomized to an angiotensin-converting enzyme inhibitor (ramipril), a beta-blocker (metoprolol succinate), or a calcium channel blocker (amlodipine besylate). We compared the incidence of type 2 diabetes mellitus (DM) and the composite outcome of impaired fasting glucose or DM (IFG/DM) for the African American Study of Kidney Disease and Hypertension interventions.

Methods: Cox regression models were used to evaluate (post hoc) the association of the randomized interventions and the relative risk (RR) of DM and IFG/DM and to assess the RR of DM and IFG/DM by several prerandomization characteristics.

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Poor outcomes have been reported in African Americans and Hispanics compared to Caucasians with lupus nephritis. The purpose of this retrospective analysis was to identify independent predictors of outcomes in African Americans and Hispanics with lupus nephritis. In total, 93 African Americans, 100 Hispanics, and 20 Caucasians with a mean age of 28 +/- 13 years and an annual household income of 32.

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