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Biomedical subjects

J Alsina

Publications and source records attributed to J Alsina.

At least 55 records · Page 3Linked to original sources
PubMed1996

Changes in renal hemodynamics and physiology after normothermic ischemia in animals supplemented with eicosapentaenoic acid.

In order to determine whether treatment of animals with an n-3 fatty acid, eicosapentaenoic acid (EPA), could modify renal hemodynamics and physiology after normothermic ischemia, we studied 42 Spraque Dawley rats orally supplemented with either olive oil or a purified lysine salt of EPA for 4 weeks. Four experimental groups were established. Three groups were treated with increasing doses of EPA: 20 mg/kg per day (EPA 20), 40 mg/kg per day (EPA 40) and 80 mg/kg per day (EPA 80), and one group was supplemented with isovolumetric olive oil (OLI). A control group that received neither EPA nor ischemia was also studied. On day 28, right nephrectomy was performed, followed by 30 min of left renal warm ischemia. Basal arterial pressure and renal blood flow (RBF) were monitored in two kidneys before arterial occlusion and continuously thereafter throughout the experiment in one kidney using an electronic transducer and a flowmeter. From 60 to 120 min after the end of ischemia, urine output (microliter/min), glomerular filtration rate (GFR, microliter/min), measured by inulin clearance, and fractional reabsortion of sodium (FRNa) were determined every 20 min. Renal plasma flow (RPF, ml/min) and renal vascular resistance (VR, mm Hg/ml per min) were calculated. RPF was estimated as RBF (1-hematocrit). Before ischemia, the mean RPF and RBF were higher in EPA-fed than in olive oil-fed animals and after ischemia showed a significantly greater increase in EPA-fed animals than in olive oil-fed animals. Mean VR was lower in EPA-fed animals than in olive oil-fed animals, both before arterial occlusion and after ischemia. Mean urine output was similar in the OLI and EPA 20 groups, and significantly higher in the EPA 40 and EPA 80 groups than in the control group. GFR was significantly lower in the OLI and EPA 20 groups than in the control group. Finally, the EPA 40 group showed a similar and the EPA 80 group a slightly higher GFR than the control group. We conclude that EPA supplementation provides protection from renal ischemic-reperfusion injury, and this effect is more evident at higher EPA doses.

Animals↗
PubMed1996

Longitudinal study of the frequency of cytotoxic T cell precursors in kidney allograft recipients.

Clonal deletion or inactivation of donor-specific alloreactive cells are important mechanisms that are believed to account for acquired immune tolerance in allograft recipients. Serial assessment of precursor cytotoxic T lymphocyte frequencies (CTLpf) by limiting dilution analysis (LDA) provides information at the clonal level on changes in the alloimmune response of graft recipients. We performed a longitudinal study of 15 cadaveric kidney recipients before and every 3 months throughout the first year after transplantation (Tx). Pre-Tx values of donor CTLpf showed high interindividual variability without a predictive value for the clinical outcome. All patients with well functioning kidneys had decreased CDLpf at 3 months post-Tx in comparison with pre-Tx values. This decrease was donor-specific in four patients and was permanent in two cases throughout the study. Most patients presented decreased anti-donor CTLpf values from 6 to 9 months, whereas a partial recovery of donor CTLpf was observed in three patients. Reversible acute rejection was diagnosed in three patients, and it was associated with a marked increase in anti-donor CTLpf, returning to pre-Tx values by 9 months post-Tx. In addition, one patient with chronic rejection displayed a transient increase in CDLpf 6 months after Tx. The results of this sequential study indicate the establishment of a state of either hyporesponsiveness or functional clonal inactivation, transient or permanent, which could facilitate allograft acceptance.

Adult↗
PubMed1996

Hepatitis C virus-associated membranoproliferative glomerulonephritis in renal allografts.

In renal transplantation, chronic allograft nephropathy is the leading cause of long-term graft losses, transplant glomerulopathy being its glomerular form. Differential diagnosis from recurrent or de novo membranoproliferative glomerulonephritis should be established. Whether hepatitis C virus is associated with cryoglobulinemia and glomerular damage in renal allograft recipients, as in native kidneys, is not known. We identified six hepatitis C virus-infected renal allograft recipients with proteinuria higher than 1.5 g/day, microhematuria, and membranoproliferative glomerulonephritis. Virologic and immunologic studies were conducted. Low serum levels of circulating immune complexes and cryoglobulins were observed, which were type II immunoglobulin G polyclonal-immunoglobulin Mk monoclonal in all six patients. Classical serum complement pathway activation and at least one type of autoantibodies were present in all of them. Hepatitis C virus RNA was found in higher concentrations in cryoprecipitate than in serum (percentage of enrichment ranged from 341 to 18,200%). Hepatitis C virus genotype was 1b in 4 of 6 patients, 1a in 1 of 6 patients, and 2a in 1 of 6 patients. In renal histology prominent parietal diffuse deposition of immunoglobulin M was the rule. Glomerular subendothelial electron-dense deposits with fibrillar appearance were observed in the two patients in which electron microscopy provided information about glomeruli. In renal allograft recipients hepatitis C virus infection may be associated with type II cryoglobulinemia which may lead to membranoproliferative glomerulonephritis. Immunologic and virologic studies may help to differentiate hepatitis C virus-associated membranoproliferative glomerulonephritis from transplant glomerulopathy.

Adult↗
PubMed1996

Automated classification of renal interstitium and tubules by local texture analysis and a neural network.

OBJECTIVE: To segment renal interstitial space in order to automatically quantify renal cortical interstitial volume fraction (Vvint/cortex) by means of image analysis techniques. STUDY DESIGN: The study group consisted of 35 renal biopsies with different degrees of chronic interstitial damage. Biopsies were stained with Sirius red and digitized under polarized light. Two methods were employed to segment interstitial space: (1) interstitial bright particles were thresholded, and afterwards interstitial space was reconstructed with a morphologic operation, and (2) the texture of the surroundings of each pixel was quantified by means of local granulometry, and this information was employed as the input of a neural network in order to classify interstitial and tubular pixels. RESULTS: The correlation between Vvint/cortex obtained manually and both methods was r = .92. The first method produced some deformation of tubular contours and underestimated Vvint/cortex (beta = .70) when compared to the second approach (beta = .95) (P < .05). CONCLUSION: Two different algorithms based on image analysis techniques allow the classification of renal interstitial and tubular structures and consequently allow the automated and precise estimation of renal Vvint/cortex.

Adult↗
PubMed1995

[Therapeutic immunoadsorption in Goodpasture disease].

The extraction of circulating antiglomerular basement membrane (GBM) antibodies by plasmapheresis (PP) has allowed the prognosis of Goodpasture's disease to markedly improve. Immunoabsorption (IA) may improve the results of PP upon allowing more effective immunoglobulin extraction. Two patients with Goodpasture disease were treated with IA. A rapid decrease was observed in the serum levels of anti GBM antibodies and improvement in respiratory failure. In one of the patients this regimen was administered following the observation of a lack of clinical response of pulmonary hemorrhage in three PP sessions (9 liters of treated plasma). In this patient, the IA processed 39 liters of plasma and the method was found to be equally effective on reinstatement (29 liters) on the occasion of a relapse in the pulmonary symptoms presented at three weeks after the first treatment. Both cases showed renal involvement. In one case this was incipient and the treatment was associated with non progression of the kidney disease, normalization of the urine sediment and preservation of renal function. In the second case treatment was initiated at an advanced disease state with no changes in dialysis needs. Immunoadsorption has shown to be effective in the treatment of pulmonary hemorrhage in Goodpasture's disease. Onset of treatment at an early stage of the kidney disease may avoid progression to renal failure.

Adult↗
PubMed1995

Interstitial nephritis in sarcoidosis: simultaneous multiorgan involvement.

Two cases of sarcoidosis with interstitial nephritis (lymphocytic and granulomatous) are described. In contrast to the majority of reported cases, patients simultaneously exhibited renal failure and multiple extrarenal manifestations, including bone marrow granulomas. Pretreatment gallium-67 gamma scan of the kidneys produced negative results. Patients were treated with steroids. Treatment resulted in a normal renal function after 1 year in the patient with lymphocytic interstitial nephritis. Renal function improved in the patient with granulomatous interstitial nephritis, and a second renal biopsy performed 13 months after diagnosis revealed granuloma disappearance and residual interstitial fibrosis. These cases provide evidence that interstitial nephritis in sarcoidosis may appear simultaneously with multiorgan involvement. The absence of gallium-67 renal intake does not guarantee that the disease is not active in the kidneys.

Female↗
PubMed1995

Evaluation of a preservation solution containing fructose-1,6-diphosphate and mannitol using the isolated perfused rat kidney. Comparison with Euro-Collins and University of Wisconsin solutions.

The renal preservation ability of a flushing solution (F-M) with fructose-1,6-diphosphate (1 g/dl) and mannitol (2 g/dl) during cold ischaemia was studied with the isolated perfused rat kidney model and compared with the Euro-Collins (EC) and University of Wisconsin (UW) solutions. Kidneys were stored in hypothermia for 4 and 18 h after initial flushing with the solution being tested, and then reperfused at 37 degrees C in an isolated perfusion circuit for 90 min with a Krebs-Henseleit solution containing 4.5% albumin. Forty-four kidneys were studied and divided in a control group and six study groups according to the cold ischaemia time and flushing solution used. Renal functional parameters of plasma flow rate (PFR), renal vascular resistance (RVR), urine flow rate (UFR) glomerular filtration rate (GFR), fractional (FRNa) and net (TNa) sodium reabsortion were assessed during reperfusion. Conventional histology and malondialdehyde tissue levels (MDA) were also evaluated. Our results show that PFR, RVR, and UFR were similar in all study groups. After 4 and 18 h of cold ischaemia, GFR, FRNa and TNa were better, and conventional histology worse in F-M than in EC flushed kidneys. After 4 and 18 h of cold ischaemia, GFR, FRNa and TNa, in fact, were not different between F-M and UW flushed kidneys. After 4 h of cold ischaemia, conventional histology was similar in F-M and UW flushed kidneys. Nevertheless, after 18 h of cold ischaemia, UW flushed kidneys showed worse histological parameters than F-M flushed kidneys. After 4 h of cold ischaemia, MDA was similar in kidneys flushed with three solutions. After 18 h of cold ischaemia MDA was higher in EC than in F-M or UW flushed kidneys. In summary, our newly developed cold storage solution shows promising results in renal preservation and its ability to preserve is at least as good as UW solution assessed in the isolated perfused rat kidney.

Adenosine↗
PubMed1995

Effect of ciclosporin on serum lipids and modification with LSL 90202, a lysine salt of eicosapentaenoic acid.

Ciclosporin (CS-A) has recently been considered a separate risk factor for the development of hyperlipidemia in transplant patients. In the present work, the effect of chronic CS-A administration on serum lipids and its modification using dietary supplementation with LSL 90202, a lysine salt of eicosapentaenoic acid, was studied. Thirty-one male Wistar rats were divided into four groups, receiving (1) 20 mg/kg CS-A in olive oil (CS-A group; n = 8); (2) isovolumetric olive oil (olive oil groups; n = 8); (3) 20 mg/kg CS-A in olive oil plus 20 mg/kg LSL 90202 (CS-A + LSL 20 group;) and (4) 20 mg/kg CS-A in olive oil plus 40 mg/kg LSL 90202 (CS-A+LSL 40 group; n = 8). Both, CS-A and LSL 90202 were given by daily gavage. On day 28, CS-A whole-blood levels and serum levels of total cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol fractions (HDL, HDL-2, HDL-3, non-HDL), and malondialdehyde were measured. On day 28, the rats given CS-A showed significantly higher cholesterol, triglyceride, and non-HDL cholesterol serum levels than rats given olive oil. Rats given CS-A and LSL 90202 (20 mg/kg) showed significantly lower triglyceride serum levels than rats given CS-A only. Rats given CS-A and LSL 90202 (40 mg/kg) showed significantly lower triglyceride, total cholesterol, and non-HDL cholesterol serum levels than rats given CS-A only. There were no differences in HDL, HDL-2, and HDL-3 cholesterol serum levels between the groups. The CS-A whole-blood levels were not different between groups of animals given CS-A.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗