Search PubMed⌕ Search

Biomedical subjects

V Navarro

Publications and source records attributed to V Navarro.

At least 289 records · Page 16Linked to original sources
PubMedDate not supplied

[Comparison of dialyzers in on-line hemodiafiltration].

UNLABELLED: At present we have a great variety of high-flux dialyzers whose characteristics in vitro seem similar. On-line HDF is a technique which combines diffusion with elevated convection and uses dialysate as replacement fluid. On-line HDF provides the highest clearances for small, medium-sized and large molecules and gives the best performance from the dialyzers. Conscious of this wide choice of dialyzers we evaluated the performance of different dialyzers in renowing small and medium-large molecules. Eleven patients were included in this study, 7 males and 4 females. Every patient received 11 on-line HDF sessions with Fresenius 4008B machine, Qi 100 ml/min or 6 L/h, QB 400 ml/min, QB 800 ml/min, UF 0.5 L/h and Td 60 min. Only the dialyzer was changed: 1.9 m2 cellulose triacetate (Tricea 190G), 2.1 m2 poly methyl methacrylate of PMMA (BK-2.1P), 1.8 m2 polyester-polymer Allol or PEPA (FLX-18GWS), 2.05 m2 acrylonitrile (Filtral 20), 2.1 m2 polyamide (Poliflux 2.1) and 1.8-2.4 m2 polysulfones (HF 80, BS-1.8S, APS-900, Arylane H9, Idemsa 2000, HdF 100). Arterial pressure, venous pressure and transmembrane pressure (TMP) were monitored. Plasma, urea, creatinine, phosphate, uric acid and beta 2m concentrations were measured at the beginning and at the end dialysis from arterial and venous blood lines, and arterial blood line with the slow flow method. Recirculation, dialyzer solutes clearance and solute reduction rates were calculated. No significant differences were found in arterial pressure, venous pressure and recirculation. Small molecule removal was similar except in BK-2.1P and HdF 100 dialyzers which were lower and higher respectively. There were differences in TMP and beta 2m removal among dialyzers employed. Mean TMP, beta 2m clearance and beta 2m reduction ratio were: Tricea 190G (TMP 336 mmHg, beta 2m K 79 ml/min and beta 2m reduction ratio 44.9%), BK-2.1P (TMP 485, beta 2m K 102 and beta 2mRR 48.3%), FLX-18 GWS (TMP 195, beta 2m K 140 and beta 2mRR 54.6%), Filtral 20 (TMP 245, beta 2m K 132 and beta 2mRR 54.1%), Poliflux 2.1 (TMP 209, beta 2m K 158 and beta 2mRR 56.0%), HF 80 (TMP 208, beta 2m K 160 and beta 2mRR 57.4%), BS-1.8S (TMP 186, beta 2m K 179 and beta 2mRR 59.6%), APS-900 (TMP 174, beta 2m K 176 and beta 2mRR 64.8%), Arylane H9 (TMP 206, beta 2m K 171 and beta 2mRR 59.9%), Idemsa 2000 (TMP 203, beta 2m K 169 and beta 2mRR 60.4%), HdF 100 (TMP 152, beta 2m K 186 and beta 2mRR 64.6%). CONCLUSIONS: Of the dialyzers evaluated in on-line HDF, cellulose triacetate and PMMA have a smaller beta 2m removal and their use is limited by an elevated TMP. The polysulfones provide greater beta 2m removal with lower TMP, particularly the APS-900 and HdF 100 dialyzers. The acrylonitrile, PEPA and polyamide are intermediate.

Equipment Design↗
PubMedDate not supplied

[Assessment of salt intake in hemodialysis].

One of the main goals of dialysis is to reach a correct sodium balance. Dietary sodium restriction facilitates control of thirst, water overload, hypertension and cardiac failure. Nowadays, it is possible to estimate sodium mass transfer and known interdialytic salt intake, by means of non-invasive methods. The use of dialysate sodium profiles improves dialysis tolerance but it has been reported that interdialytic thirst may increase because of an inappropriate sodium balance. The aim of this study was to evaluate the usual salt intake in hemodialysis patients, the effects on interdialytic gain weight, arterial pressure, blood volume preservation and dialysis tolerance of two different profiles of dialysate sodium and an additional session with salt restriction. Seventeen dialysis patients, 12 male and 5 females, were studied. Each patient underwent seven hemodialysis treatments: three consecutives sessions (a week) with constant sodium and ultrafiltration hemodialysis; three consecutive sessions with exponential decrease of conductivity (Initial 15.5-16.0, mid-session 14.3 and at the end 13.9-14 mS/cm) and ultrafiltration (1.6 l/h initial and 0.1 at the end) profiled hemodialysis; and an additional session which had a special dietary salt restriction. Dialysis parameters and dry weight were kept constant. Integra monitor with Diascan and Hemoscan biosensors (Hospal) were used in all sessions. We measured pre- and postdialytic plasma conductivity, sodium mass transfer, interdialytic weight gain, mean arterial pressure (MAP), percent reductions of blood volume (%R-BV) and hypotensive episodes during dialysis. Mean sodium mass transfer was 1,144 +/- 356 mmol (no profile week) vs 1,242 +/- 349 mmol (week with profiles), NS. It was equivalent to a salt ingestion of 9.6 +/- 3 and 10.4 +/- 3 g/day respectively. End plasma conductivity was 14.04 +/- 0.14 (no profile) versus 14.21 +/- 0.08 mS/cm (profiled), p < 0.001. Interdialytic weight gain was 2.49 +/- 0.76 (no profile) vs 2.32 +/- 0.56 kg (profiled), NS. MAP was 101 +/- 11 (no profile) vs 99 +/- 10 mmHg (profiled), NS. The %R-BV was -7.73 +/- 3 (no profile) vs -6.46 +/- 3% (profiled), p < 0.01. Hypotensive episodes/session were 0.66 +/- 0.75 (no profiles) vs 0.41 +/- 0.57 (profiled), NS. Mean sodium mass transfer was 356 +/- 125 mmol with usual salt intake and 240 +/- 81 mmol with salt restriction, p < 0.001. It was equivalent to a salt ingestion of 10.47 +/- 3 versus 7.06 +/- 2 g per day respectively, p < 0.001. Initial plasma conductivity was 14.31 +/- 0.21 (usually sodium intake) versus 14.16 +/- 0.17 mS/cm (salt restriction), p < 0.01. Predialysis blood pressures were decreased with dietary salt restriction, MAP was 99.1 +/- 11 vs 94.4 +/- 12 mmHg (p < 0.01). Interdialytic weight gain decreased with salt restriction, 2.32 +/- 0.76 vs 1.78 +/- 0.49 kg (p < 0.001). The %R-BV was -7.25 +/- 2 (usual sodium intake) vs -5.91 +/- 2% (salt restriction), p < 0.01. Hypotensive episodes/session were 0.71 +/- 0.8 (usual sodium intake) vs 0.18 +/- 0.5 (salt restriction), p < 0.05. In conclusion, automatic measurement of sodium mass transfer is a practical tool to follow dietary salt ingestion in hemodialysis patients. It allows us accurate, individualised and continual dietary interventions. The use of exponential decrease sodium profiles improve dialysis tolerance without changes in sodium balance, interdialytic weight gain or arterial pressure. A reduction of three g in salt intake observed in this study was beneficial in interdialytic weight gain, dialysis tolerance and blood pressure control.

Female↗
PubMedDate not supplied

[Behçet's syndrome with neurological involvement: value of magnetic resonance].

Behçet's syndrome is a rare inflammatory, multisystemic disease of unknown etiology and chronic relapsing course, manifested chiefly by ocular and mucocutaneous lesions. Among its neurologic complications, a cerebral vasculitis can occasionally been observed, upon which there is little information at present. A 31-year-old man presented with fever, weight loss, oral and genital ulcers, blurred vision and memory loss during the last two months. The cerebrospinal fluid contained 170 lymphocytes/microliters. Computed Tomography and cerebral angiography were normal. Magnetic resonance imaging (MRI) showed small hyperintense lesions in the corticomedullary and periventricular regions. The patient's condition improved with corticosteroids. We stress upon the importance of MRI to detect small-vessel vasculitis in Behçet's disease.

Adult↗
PubMedDate not supplied

[Evaluation of methods to calculate dialysis dose in daily hemodialysis].

UNLABELLED: Daily dialysis has shown excellent clinical results because a higher frequency of dialysis is more physiological. Different methods have been described to calculate dialysis dose which take into consideration change in frequency. The aim of this study was to calculate all dialysis dose possibilities and evaluate the better and practical options. Eight patients, 6 males and 2 females, on standard 4 to 5 hours thrice weekly on-line hemodiafiltration (S-OL-HDF) were switched to daily on-line hemodiafiltration (D-OL-HDF) 2 to 2.5 hours six times per week. Dialysis parameters were identical during both periods and only frequency and dialysis time of each session were changed. Time average concentration (TAC), time average deviation (TAD), normalized protein catabolic rate (nPCR), Kt/V, equilibrated Kt/V (eKt/V), equivalent renal urea clearance (EKR), standard Kt/V (stdKt/V), urea reduction ratio (URR), hemodialysis product and time off dialysis were measured. Daily on-line hemodiafiltration was well accepted and tolerated. Patients maintained the same TAC although TAD decreased from 9.7 +/- 2 in baseline to a 6.2 +/- 2 mg/dl after six months, p < 0.01. No significant changes were observed in weekly Kt/V and eKt/V throughout the study. However EKR, stdKt/V and weekly URR were increased during D-OL-HDF in 24-34%, 46% and 50%, respectively. Hemodialysis product was raised in a 95% and time off dialysis was reduced to half. CONCLUSION: Dialysis frequency is an important urea kinetic parameter which there are to take in consideration. It's necessary to use EKR, stdKt/V or weekly URR to calculate dialysis dose for an adequate comparison between different frequency dialysis schedules.

Aged↗
PubMedDate not supplied

[Von Willebrand factor as an intermediate between hemostasis and angiogenesis of tumor origin].

Cancer patients often show an imbalance condition between coagulation system and fibrinolysis which causes a prothrombotic state. Different molecular factors like von Willebrand factor (vWf), presenting higher plasmatic rates in these patients, play an important role in this situation. During active angiogenesis taking place in tumor growth, the vascular endothelial growth factor (VEGF) and the fibroblast growth factor (FGF-2) contribute to the proliferation and differentiation of endothelial tissue, the main vWf producer, promoting increased rates of vWf in the serum of neoplastic patients. Recently vWf's contribution to tumor cells and platelet adhesion has been described. In this process, the discovery of platelet, endothelial and tumor cell membrane integrins and their implication in cellular adhesion has represented a major step in demonstrating how blood clotting and platelet aggregation are mediated by tumor cell and platelet linkage. Migration properties acquired by tumor cells as a result of this binding have been also pointed out. Clinical trials show higher rates of plasmatic vWf in cancer patients the more advanced clinical and radiological stage they present (metastasic versus localized). Moreover, higher pre-surgical serum vWf rates in patients can be used to predict poorer survival after resection surgery. vWf high molecular weight multimers have been also related to a cleavage protease deficiency in the serum of the oncologic population. The promising results of antiaggregation/anticoagulation therapies in these patients permit us to envisage new therapeutic targets.

Hemostasis↗
PubMedDate not supplied

[Conjugated linoleic acid lowers hypercholesterolemia but increases the risk for biliary lithiasis].

The term conjugated linoleic acid (CLA) refers to a series of linoleic acid isomers present in meat and diary products from ruminants that have their double bonds in a conjugated position. The aim of the present work was to study the effects of a CLA isomer, trans-10,cis-12, on cholesterolemia and biliary lithiasis risk in an animal model of diet-induced hypercholesterolemia. For that, two groups of hamsters were fed with a hypercholesterolemic diet supplemented with 0.5% linoleic acid or with the trans-10,cis-12 CLA isomer, respectively. Daily food intake and weight were determined and, 6 weeks later, serum and bile samples were obtained, and livers and spleens were dissected and weighted. Cholesterolemia, hepatic and splenic cholesterol content, and biliary cholesterol phosnolipid and bileacid concentrations were determined; Biliary Lithogenic Index was calculated, and presence of gallstones was assessed. CLA did not modify energetic intake or final body weight, spleen size or spleen cholesterol content, but it did significantly reduce total serum cholesterol (-18%) at the expense of c-LDL (-66%), and it also significantly reduced hepatic content of free cholesterol (-26%), without changes in esterified cholesterol. Besides, CLA produced a 32% increase in biliary cholesterol concentration, a 28% increase in Lithogenic Index, and a higher incidence of biliary lithiasis. Therefore, the present study shows that the CLA trans-10,cis-12 isomer is hypercholesterolemic since it increases, at least in part, cholesterol secretion to the bile. As a consequence, this effect increases the risk for biliary lithiasis.

Animals↗
PubMedDate not supplied

Experimental evaluation of mimosa tenuiflora (willd.) poir. (Tepescohuite) I. Screening of the antimicrobial properties of bark extracts.

Mimosa tenuiflora (Willd.) Poir, is a tree from the south areas of Mexico. This bark is popularly used as remedy to treat different skin lesions. The present study demonstrates the in vitro antimicrobial properties of the water and ethanolic extracts prepared with the dried and powdered bark of this plant. A clear inhibition growth effect was observed in all the gram positive and gram negative organisms, yeasts and dermatophytes used.

Anti-Infective Agents↗