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Biomedical subjects

J C Ruiz

Publications and source records attributed to J C Ruiz.

At least 37 records · Page 2Linked to original sources
PubMed2003

Pulse pressure is an independent risk factor of cardiovascular disease in renal transplant patients.

Elevated pulse pressure in the general population has been shown to be associated with cardiovascular disease, which is the main cause of death in renal transplant patients. We investigated the effects that a wide pulse pressure has on cardiovascular disease after renal transplantation in a cohort of 532 transplant patients with functioning grafts for more than one year. Patients were classified into two groups depending on whether the one-year pulse pressure was less than or greater than 65 mm Hg. We analyzed patient survival, posttransplant cardiovascular disease and principle causes of death. Five- and ten-year patient survival were lower among the group with higher pulse pressures. The main cause of death was vascular disease in both groups. The presence of posttransplant cardiovascular disease was higher among the group with higher pulse pressures (RR=1.73). In addition, the incidence of an elevated pulse pressure was directly associated with recipient age and posttransplant diabetes mellitus. In conclusion, pulse pressure represents an independent risk factor for increased cardiovascular morbidity and mortality in renal transplant patients.

Blood Pressure↗
PubMed2003

Early elimination of cyclosporine in kidney transplant recipients receiving sirolimus prevents progression of chronic pathologic allograft lesions.

Cyclosporine elimination in a regimen including sirolimus has been shown to be a safe and effective approach to improve graft function. Nevertheless, it is still unknown whether the functional benefit of CyA withdrawal coincides with a subsequent reduction in histologic lesions of chronic damage or development of chronic allograft nephropathy. This consideration would forecast a reduction in the rate of long-term graft loss. We analyzed 114 graft biopsies from a subgroup of 57 patients that had been included in a randomized study to eliminate CyA at 3 months posttransplant from a regimen including sirolimus either in group A CyA + SRL vs group B of SRL with CyA elimination at 3 months. Every patient had two biopsies, one at transplantation and another at 1 year. The biopsy reading was performed in a blinded manner by a central pathologist using the Banff 1997 and the CADI classifications. A significantly lower rate of progression of tubular and interstitial chronic lesions between basal and 1-year biopsies was observed for group B patients. In addition, the incidence of new cases of chronic allograft nephropathy during the first year was significantly lower in the group in which CyA had been eliminated at 3 months posttransplant. We conclude that early elimination of CyA in the first months posttransplant, when SRL is used as the main immunosuppressant, reduces the appearance or worsening of chronic histologic lesions, probably as a consequence of long-term CyA toxicity prevention.

Biopsy↗
PubMed2003

De novo hemolytic-uremic syndrome/thrombotic microangiopathy in renal transplant patients receiving calcineurin inhibitors: role of sirolimus.

The aim of this study was to evaluate the outcome of ten renal transplant recipients who developed de novo hemolytic uremic syndrome/thrombotic microangiopathy (DnHUS) after treatment with calcineurin inhibitors among 3,862 patients transplanted during the period 2000-2001 in Spain, and the results of switching to sirolimus for resolution of this pathologic condition. No patient had end-stage disease due to primary HUS. The criteria of diagnosis were decreased renal function, biopsy-proven thrombotic microangiopathy, and no signs of acute rejection. Calcineurin inhibitors were completely removed and immediate treatment with sirolimus started after diagnosis. The follow-up period was 19.0+/-4.3 months, at least 12 months after diagnosis. One patient died of sepsis shortly after starting sirolimus therapy. The serum creatinine level in the series decreased from 5.2+/-2.6 mg/dL at the time of biopsy to 2.15+/-1.9 mg/dL 1 month later (P=.011). All but one of the nine recipients, who lost his graft 3 months later (80% success) maintained function, with a serum creatinine of 2.1+/-1.4 mg/dL and Cockroft index of 61.3+/-34 mL/min at the end of follow up. During this time, none of the patients experienced an acute rejection episode and sirolimus was maintained without any remarkable secondary effect. Sirolimus seems to be a promising alternative for the treatment of renal transplant patients who develop calcineurin inhibitor-induced DnHUS.

Adult↗
PubMed2003

Effect of early graft function on patient survival in renal transplantation.

The influence of early graft function on long-term graft survival has been widely reported but its association with patient survival has received less attention. We investigated the effect of early renal function on patient survival and on cardiovascular disease after renal transplantation among 532 transplant patients who had grafts functioning for >1 year. Patients were classified into two groups, depending on the early creatinine clearance (< or >60 mL/min). We analyzed graft and patient survival, posttransplant cardiovascular disease, and the principal causes of death. Five- and 10-year graft and patient survival were lower among the group with worse early renal function. The main cause of death was vascular disease. Poorer early renal function increased the risk (RR) of patient death by 2.2-fold, and also the presence of posttransplant cardiovascular disease. In conclusion, patients with poor levels of early graft function are at an increased risk of death. These high-risk groups should be targeted for interventional studies to improve patient survival.

Creatinine↗
PubMed2003

Assessment of glomerular filtration rate in transplant recipients with severe renal insufficiency by Nankivell, Modification of Diet in Renal Disease (MDRD), and Cockroft-Gault equations.

Measurement of glomerular filtration rate (GFR) is time consuming and cumbersome. Several formulas have been developed to predict creatinine clearance (CrCl) or GFR using serum creatinine (Cr) concentrations and demographic characteristics. However, few studies have been performed to discern the best formula to estimate GFR in kidney transplantation. In this study, Cockroft-Gault (CG), Nankivell, and Levey (MDRD) formulas were tested to predict GFR in 125 cadaveric renal transplant patients with severe renal insufficiency (GFR less than 30 mL/min per 1.73 m2). The GFR was estimated as the average Cr and urea clearances. The mean GFR estimated by averaged Cr and urea clearances (22.18+/-5.23 mL/min per 1.73 m2) was significantly different from the mean values yielded by the MDRD formula (20.42+/-6.65 mL/min per 1.73 m2, P=.000), the Nankivell formula (30.14+/-11.98 mL/min per 1.73 m2, P=.000), and the CG formula (29.42+/-8.64 mL/min per 1.73 m2, P=.000). The MDRD formula showed a better correlation (R=0.741, P=.000) than the CG (R=0.698, P=.000) and the Nankivell formulas (R=0.685, P=.000). Analysis of differences using the Bland-Altmann method demonstrated that MDRD gave the lowest bias (MDRD: -1.65+/-4.4 mL/min per 1.73 m2; CG: 7.33+/-6.24 mL/min per 1.73 m2; Nankivell: 8.05+/-9.23 mL/min per 1.73 m2) and narrower limits of agreement (Nankivell: -10.41-26.51 mL/min per 1.73 m2; CG: -5.15-19.81 mL/min per 1.73 m2; MDRD: -10.61-7.31 mL/min per 1.73 m2). In transplant patients with severe renal insufficiency, the MDRD equation seems better than the other formulas to estimate GFR.

Creatinine↗
PubMed2003

Insulin-like growth factor I correlates with lean body mass in cystic fibrosis patients.

BACKGROUND: A major consequence of malnutrition in cystic fibrosis (CF) patients is the loss of lean body mass (LBM) and the subsequent impairment of respiratory muscle function. AIM: To determine whether insulin-like growth factor I (IGF-I) could be related to the LBM depletion and the evolution of respiratory disease in CF patients. METHODS: LBM was evaluated by dual energy x ray absorptiometry; serum concentrations of IGF-I were measured in 24 CF patients twice with a one year interval. Both values were expressed as SD score (SDS) calculated from normal data for age, sex, and pubertal stage and analysed with respect to anthropometric evaluation and disease related conditions. RESULTS: At the initial evaluation, IGF-I SDS had a mean value of -0.98 (range -3.6 to 3.2) and correlated with weight for age index, LBM SDS, and lung disease related conditions. Multiple regression analysis showed that only LBM remained independently related to IGF-I, suggesting that the relation of IGF-I to LBM was independent of weight and that the correlation between IGF-I and the respiratory conditions was related to the level of LBM. IGF-I SDS at the first evaluation was lower for the patients who lost > or =5% of weight for age index or > or =1 SD of LBM between the two evaluations. CONCLUSION: Low levels of IGF-I could be crucial for clinical outcome by impairing LBM and respiratory function. IGF-I could be a tool for nutritional evaluation by identifying the CF patients at risk of LBM depletion.

Absorptiometry, Photon↗
PubMed2002

Elongational flow of solutions of poly(ethylene oxide) and sulfonated surfactants.

In this work, the elongational flow behavior of aqueous solutions of poly(ethylene oxide) (PEO) was studied in the presence of sulfonated surfactants. The technique of opposed-jets flow was used to generate an elongational flow field in which pressure drops were measured as a function of strain rates. The surfactants used were sodium dodecyl benzene sulfonate (SDBS) and an alpha-olefin sulfonate (AOS). Solutions of PEO and other flexible polymers exhibit extension thickening in opposed-jets flow due to the formation of transient networks of entangled molecules. This effect is present at concentrations below the static coil overlap concentration, due to the changes in molecular conformation induced by the flow. When SDBS or AOS are added to PEO solutions at low concentrations, the extension thickening weakens due to an increase in PEO intramolecular interactions that lead to coil contraction. This occurs until the surfactant concentration is close to the critical aggregation concentration reported in the literature. Further addition of surfactant induces the formation of intermolecular interactions as the PEO molecules are expanded by the electrostatic repulsion between attached micellar aggregates, with an associated strengthening of extension thickening. Intramolecular effects were not seen beyond a specific PEO concentration.

Journal Article↗
PubMed2002

The risk of cardiovascular disease associated with proteinuria in renal transplant patients.

Proteinuria in the general population has been shown to be associated with cardiovascular disease, which is the main cause of death in renal transplantation. We investigated the effect of proteinuria on cardiovascular disease after renal transplantation in 532 renal transplant patients with functioning grafts for more than 1 year. Patients were classified into two groups depending on the presence of persistent proteinuria. We analyzed graft and patient survival, posttransplantation cardiovascular disease, and main causes of graft loss and death. Five- and 10-year graft and patient survival rates were lower in the group with proteinuria. The main cause of death was vascular disease in both groups. The presence of posttransplantation cardiovascular disease was higher in the group with proteinuria. Persistent proteinuria was associated with graft loss (RR=4.18), patient death (RR=1.92), and cardiovascular disease (RR=2.45). In conclusion, persistent proteinuria was an independent risk factor for increased cardiovascular morbidity and mortality in renal transplant patients.

Adult↗
PubMed2002

["Occult" renal insufficiency due to evaluating renal function using only serum creatinine].

Timely referral to nephrologists depends on identification of renal failure. Most primary care physicians and specialists rely on serum creatinine as the standard test for determination of renal function. Creatinine clearance requires 24 hours urine collection with many pitfalls and wrong results. We compare serum creatinine and the Cockcroft-Gault (C-G) equation as measure of glomerular filtration rate (GFR). The study included 1,053 outpatients with serum creatinine lower than 2.5 mg/dl referred to our nephrological laboratory for serum creatinine and GFR determination using the C-G formula. Patients were grouped into two groups: normal renal function (serum creatinine < 1.3 mg/dl) and "incipient" abnormal renal function (serum creatinine 1.3-2.5 mg/dl). In the group of females with normal creatinine 22% (60-70 y), 35% (70-80 y) and 57% (> 80 y) had GFR values below 50 ml/min. In the group of males 11.3% (70-80 y) and 33.3% (> 80 y) also had GFR reduction in spite of normal serum creatinine. A severe renal insufficiency with creatinine clearance lower than 30 ml/min was observed in the group with "incipient" renal failure based on serum creatinine: 22.7%, 40% and 82.9% for females and 6%, 22.7% and 57% for male (60-70 y; 70-80 y; and > 80 y respectively). In order to improve management and prevention of renal failure appropriate measurements of renal function other than serum creatinine should be emphasize.

Adult↗