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Biomedical subjects

A M Castelao

Publications and source records attributed to A M Castelao.

At least 19 recordsLinked to original sources
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↗
PubMed1994

Prevention of experimental cyclosporine nephrotoxicity by dietary supplementation with LSL 90202, a lysine salt of eicosapentaenoic acid. Role of thromboxane and prostacyclin in renal tissue.

Cyclosporine (CsA) nephrotoxicity is partially mediated by renal vasoconstriction due to an imbalance between vasodilator and vasoconstrictor eicosanoids. LSL 90202 is a purified lysine salt of eicosapentaenoic acid which is a known inhibitor of renal eicosanoid synthesis. The aim of the present work was to determine if chronic dietary supplementation with LSL 90202 prevented CsA nephrotoxicity and to establish the role of thromboxane and prostacyclin in renal tissue. Thirty-three male Sprague-Dawley rats were divided into 4 groups: group 1, CsA in olive oil (n = 10); group 2, isovolumetric olive oil (n = 7); group 3, CsA in olive oil plus LSL 90202 (n = 8); group 4, isovolumetric olive oil plus LSL 90202 (n = 8). CsA and LSL 90202 were given at 20 mg/kg/day. Weight and creatinine clearance (CrCl) were determined before and on days 14 and 30. On day 30 whole-blood CsA was determined and renal tissue processed for renal malondialdehyde, thromboxane B2 and 6-keto-PGF1 alpha measurement and for conventional histology. CrCl was severely reduced in the CsA in olive oil group compared to olive oil and LSL 90202 control groups. On day 30, CrCl in the CsA in olive oil plus LSL 90202 group showed a slight decrease, but the mean CrCl was significantly higher than in the CsA in olive oil group. Trough whole blood CsA levels were not significantly different in both groups given the drug. No morphological differences were found between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1994

[Malignant neoplasms and kidney transplantation].

In 661 renal transplantations, 2 potentially migrated tumours (0.38%), 5 preexisting neoplasias (0.76%), and 31 "de novo" tumours were seen in 29 patients (4.4&). Although of very low incidence, the likelihood of tumour migration from elderly donors, given the circumstances surrounding removal, offers a high risk. None of the preexisting neoplasias relapsed following transplant. The highest prevalence was seen in skin (40%), lung (13%), kidney (13%) and bladder (6.6%) "de novo" tumours. Incidence of lymphoma was low. Dominant etiological factors of the recipient were older age, effective and tolerated immunosuppression, viral infections, environmental agents and antigenic stimulation of the graft. Skin lesions have responded well to local treatment, without need to discontinue immunosuppression, a measure that is mandatory in other malignant tumours. Also, the conclusions of a round table during the 25th National Meeting of Urotransplantation of the Spanish Association of Urology held in 1994 on "Oncology and Renal Transplantation" are presented.

Adolescent↗
PubMed1993

Relationship between donor renal interstitial surface and post-transplant function.

Forty-three biopsies were performed between 30 and 60 min after reperfusion. Patients (22 males/21 females, mean age 41 +/- 12 years, mean donor age 32 +/- 14 years) were treated either with antilymphocytic globulin, cyclosporin, and prednisolone (24 cases), or OKT3, cyclosporin, and prednisolone (19 cases). Ten patients had delayed post-transplant renal function (DPRF), defined as haemodialysis requirements after surgery, and seven patients had acute rejection 11 +/- 16 days post-transplant. Kidneys were perfused with a hypertonic solution containing mannitol. All patients were followed up for at least 30 months. During follow-up, five patients lost their grafts due chronic rejection, two patients due to noncompliance and one due to recurrence of focal segmental glomerulosclerosis. One patient died from heart infarction. Biopsies were stained with H&E, Masson's trichrome, periodic acid-Schiff (PAS) and silver methenamine. Interstitial fibrosis, interstitial oedema, tubular vacuolization, and peritubular capillary oedema were measured using a semiquantitative scale. Five 400 x magnification micrographs of cortical interstitium from silver-methenamine-stained sections were used to measure percentage of interstitial surface with a morphometer. Interstitial surface was 18.7 +/- 6.2% (range 3.2-35.3%). A positive correlation was found between interstitial surface and donor age (r = 0.469, P = 0.0015). No relationship was found between warm and cold ischaemia times and tubular vacuolization or peritubular capillary oedema.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗