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Biomedical subjects

M Carrera

Publications and source records attributed to M Carrera.

At least 55 records · Page 3Linked to original sources
PubMed1997

Early protocol renal allograft biopsies and graft outcome.

To evaluate whether biopsies performed early after transplantation in stable grafts can predict graft failure due to chronic transplant nephropathy, a protocol biopsy was performed at three months in 98 patients treated with antilymphocytic antibodies, cyclosporine and prednisone. Patients were followed for 58 +/- 16 months. Histological diagnosis according to the Banff schema were: normal (N = 41), borderline changes (N = 12), chronic transplant nephropathy (CTN; N = 30), CTN associated to borderline changes (N = 11) and acute rejection (N = 4). Biopsies displaying acute rejection were not considered for statistical analysis. Since clinical characteristics of patients displaying CTN either with or without tubulitis were not different, biopsies were grouped as presence or absence of CTN. Patients displaying CTN had an increased incidence of acute rejection before performing biopsy (24.3 vs. 3.9%, P = 0.003), a higher mean cyclosporine level until biopsy (242 +/- 74 vs. 214 +/- 59 ng/ml, P = 0.049) and a lower actuarial graft survival (80.5% vs. 94.4%, P = 0.024). We conclude that early protocol biopsies are useful to detect patients at risk of losing their graft due to chronic transplant nephropathy.

Adult↗
PubMed1997

Early detection of reversed diastolic umbilical flow: should we offer karyotyping?

In normal pregnancy, end-diastolic flow appears in the umbilical artery around the 13th week of gestation, with a velocity which increases progressively with advancing gestation. The detection of reversed flow in the umbilical artery, the highest expression of an increase in placental vascular resistance, is extremely uncommon in the first half of gestation and, in three of the four cases reported in the literature, there were chromosomal abnormalities. We report a new case of reversed end-diastolic flow in the umbilical artery in a 13-week fetus with increased nuchal translucency thickness, megacystis and tachycardia. Cytogenetic analysis of chorionic villi and amniocytes revealed trisomy 13. The findings provide further evidence for a possible association between reversed end-diastolic flow in the umbilical artery and chromosomal abnormalities. However, the effectiveness of this potential marker in an unselected population requires further evaluation.

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↗
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

Clear cell ameloblastoma or odontogenic carcinoma. A case report.

An ameloblastoma of the right maxilla with a biphasic pattern of folicular ameloblastoma and clear cells, with an aggressive clinical behaviour in a 71-year-old male is reported. A literature review of clear cell ameloblastomas is made, focussing the discussion on the convenience of considering this type of ameloblastoma to be a low-grade odontogenic carcinoma.

Aged↗
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↗
PubMed1994

Renal protective effect of liposomed superoxide dismutase in an experimental warm ischemia model.

Superoxide dismutase (SOD) is a potent scavenger of superoxide radicals produced during normothermic ischemia-reperfusion. Since it has a short half-life, its optimal effect is achieved when it is given prior to reperfusion. The inclusion of SOD in liposomes (lipo-SOD) prolongs its half-life (free SOD: 6 min; lipo-SOD: 4 h). The protective effect of lipo-SOD in a 60-min bilateral renal warm ischemia model was studied. We divided 60 male Wistar rats between two control groups and five study groups according to the drug used (SOD or lipo-SOD) and to the time of SOD administration (prior to ischemia or prior to reperfusion). SOD and lipo-SOD were both given at 20 mg/kg endovenously. Weight, diuresis, creatinine per 100 g (Cr/100 g), and creatinine clearance per 100 g (CrCl/100 g) were studied. Conventional renal histology was performed after reperfusion and on day 7. Renal malondialdehyde, 6 keto PGF 1 alpha, and TxB2 tissue levels were studied after reperfusion. Results showed that the renal protective effect of free SOD on warm ischemic-reperfusion injury depended on the time of administration, being more effective when given before reperfusion. On the other hand, the renal protective effect of liposomed SOD did not depend on the time of administration since efficacy was similar when given before reperfusion or before ischemia. The functional protective effect of liposomed SOD was similar to that of free SOD when they were given prior to reperfusion. Nevertheless, since histological damage observed with liposomed SOD was less than with free SOD, it is suggested that the liposomed galenic form may offer better protection against renal warm ischemia. In addition, liposomed SOD was better at preventing tissue prostanoid generation after renal warm ischemic-reperfusion injury than free SOD. We concluded that liposomed SOD shows a higher renal protective effect against warm ischemia than free SOD.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

Mosaic uniparental disomy in Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth syndrome with variable expression. The major features are anterior abdominal wall defects, macroglossia, and gigantism and less commonly neonatal hypoglycaemia, organomegaly, congenital renal anomalies, hemihypertrophy and embryonal tumours occur. BWS is a genetically heterogeneous disorder; most cases are sporadic but approximately 15% are familial and a small number of BWS patients have cytogenetic abnormalities involving chromosome 11p15. Genomic imprinting effects have been implicated in familial and non-familial BWS, and uniparental disomy (UPD) for chromosome 11 has been reported in sporadic cases. We investigated the incidence, pathogenesis, and clinical associations of UPD in 49 patients with non-familial BWS and a normal karyotype. UPD for chromosome 11p15 was detected in nine of 32 (28%) informative patients. A further two patients appeared to be disomic at the WT1 locus in chromosome 11p13, but were uninformative at chromosome 11p15.5 loci tested. In all cases with UPD the affected person was mosaic for a paternal isodisomy and a normal cell line indicating that UPD had arisen as a postzygotic event. Compared to cases in which paternal isodisomy for chromosomes 11p15.5 had been excluded (n = 23), BWS patients with UPD was more likely to have hemihypertrophy (6/9 versus 1/23, p < 0.001) and less likely to have exomphalos (0/9 versus 13/23, p < 0.01), but there were no significant differences between disomic and non-disomic cases in the incidence of hypoglycaemia, nephromegaly, neoplasia, and developmental delay. The detection of UPD in BWS patients allows accurate genetic counselling to be provided and provides an insight into the molecular pathogenesis of BWS.

Adolescent↗
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↗
PubMed1993

Protective effect of the PAF antagonist BN 52021 in an experimental renal warm ischemia model.

Platelet activating factor is involved in warm ischemic damage. We studied the effect of the PAF receptor antagonist BN 52021 in an experimental model of 60 min of renal warm ischemia in which the left kidney was flushed with Euro-Collins solution and a right nephrectomy was performed. Eighty Wistar rats were divided into a sham-operated group, two control groups, and four study groups, according to the dosage and route of BN 52021 administration. BN 52021 was used in the flush solution at concentrations of 0.1 and 0.5 mg/ml, or intravenously prior to ischemia at 5 and 10 mg/kg body weight. Creatinine clearance per 100 g body weight, fractional sodium excretion, and conventional histology were studied. Rats that received BN 52021 intravenously showed a significantly higher creatinine clearance than controls. Intravenous BN 52021 produced a higher acceleration of renal function recovery at 10 mg/kg than at 5 mg/kg body weight. Conventional histology was better in animals that received BN 52021 at 10 mg/kg body weight than in controls. Addition of BN 52021 to Euro-Collins flushing solution showed no protective effect. We conclude that intravenous BN 52021 shows a renal protective effect against warm ischemia.

Animals↗
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↗
PubMed1993

Minimal-change glomerulopathy and carcinoma. Report of two cases and review of the literature.

We describe 2 patients with minimal-change glomerulopathy (MCG) associated with an undifferentiated carcinoma of unknown origin and urothelial carcinoma. Oliguric acute renal failure and histopathological changes consistent with acute tubular necrosis were also observed. Fourteen other cases of MCG complicating solid tumors reported in the literature are reviewed. MCG should be included in the nephropathies which cause nephrotic syndrome in adult patients with carcinoma.

Acute Kidney Injury↗
PubMed1992

[Renal vasculitis without hematuria in senile patients].

Systemic vasculitis is a disease whose prognosis has improved considerably with steroid and immunosuppressive treatment, which points up the importance of early diagnosis. In elderly, diagnosis is made more difficult because the frequent onset in the form of a febrile syndrome with non-specific disturbances in general condition. In these patients it is not uncommon that a kidney involvement is what leads to diagnosis of the disease. Hematuria is almost a constant in vasculitis nephropathy. In their absence, acute renal failure in elderly is usually attributed to hemodynamic causes and the frequent presence of iatrogenic tubular factors. This is a report on the case of three elderly patients who presented a febrile syndrome with asthenia, anorexia and weight loss. The three cases progressed to acute renal failure with no disorders in urinary sediment. In two cases was a history of administration of gentamycin, indomethacin and iodated contrast. The clinical diagnosis was toxic and ischemic tubulopathy and, when dialysis became necessary, a renal biopsy was done which showed granulomatous vasculitis, intersticial nephritis and in two cases, necrotizing glomerulitis and crescent formation. Treatment with steroids and cyclophosphamide was started which improved general condition and renal function in one case. Early renal biopsy is advisable in senile patients with non specific systemic symptoms and progressive acute renal failure of unclear origin, even when hematuria is lacking. In this setting, the appearance of underdiagnosed renal vasculitis is possible, and consequent immunosuppressive treatment is a factor for consideration.

Acute Kidney Injury↗
PubMed1992

Relationship between erythropoietic rate and iron donating capacity of the Fe/transferrin complex in mouse.

The transfer of iron from the Fe/transferrin complex to the erythroid cells was studied in in vitro system in mice in which a drastic and opposite change in their erythropoietic activity was produced by bleeding or actinomycin D administration. A reduction of iron donation in the serum of bled animals was found, whereas the aplastic condition induce in the donors of the serum by actinomycin D did not produce any change in the transfer process. It was also found that in spite of the normalization of the saturation in the serum of bled animals, the diminished donation remained unchanged. The possibility that conditions other than quantitative could produce this behavior is discussed.

Animals↗