Search PubMed⌕ Search

Biomedical subjects

U Valente

Publications and source records attributed to U Valente.

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

Plasma somatostatin response to an oral test meal in liver transplant patients.

Ten liver transplant patients were studied in basal conditions and after ingestion of a standard mixed test meal. Control groups included 10 normal subjects, 10 patients with nonalcoholic liver cirrhosis, and seven kidney transplant patients. Plasma somatostatin, blood glucose, and plasma insulin, C-peptide, and glucagon were determined before and 15, 30, 45, 60, 90, 120, and 180 minutes after the start of the meal. In liver transplant patients, basal somatostatin and insulin levels were significantly lower than in cirrhotics and were comparable to those recorded in controls and in kidney transplant patients. The time course of the somatostatin secretory response after the meal was similar in any group, but the increase, evaluated as the incremental area above baseline, was significantly higher in liver transplant patients than in controls and cirrhotics and comparable to that recorded in kidney transplant patients. Insulin incremental areas were also lower than in cirrhotics and comparable to those recorded in controls and kidney transplant patients. The data suggest that in liver transplant patients an increased somatostatin response to a meal may be related to a relative beta-cell secretory defect, which in turn seems consequent to immunosuppressive treatment.

Adult↗
PubMed1997

A randomized study comparing three cyclosporine-based regimens in cadaveric renal transplantation. Italian Multicentre Study Group for Renal Transplantation (SIMTRe).

Whether it is better to treat renal transplant patients with cyclosporine alone, combined with steroids, or combined with steroids and azathioprine is still unclear. After initial therapy with cyclosporine and steroids, 354 cadaver renal transplant recipients were randomly assigned at the post-transplant day 5 to cyclosporine alone (monotherapy), cyclosporine plus steroids (double therapy), or cyclosporine plus steroids plus azathioprine (triple therapy). Monotherapy patients, after a second acute rejection, were switched to either of the two alternative therapies. According to intention-to-treat (ITT) analysis, the 4-year patient survival was 97% in monotherapy, 91% in double therapy, and 96% in triple therapy; the graft survival including death was 84%, 77%, and 88%, respectively; and the pure graft survival was 87%, 85% and 91%, respectively (P = not significant). Acute rejections were diagnosed in 79 patients in monotherapy, 58 in double therapy, and 59 in triple therapy (P < 0.01). Of the patients on monotherapy, 52% were switched to double or triple therapy. In these patients, the 4-year graft survival including death was 68%, and the pure graft survival was 72%, in comparison with 93% and 94%, respectively, for patients who continued on cyclosporine alone. Patients with renal polycystic disease as a cause of renal failure and with low plasma creatinine at the time of randomization (5 days after transplant) had a higher probability of remaining on monotherapy, wherease those with glomerulonephritis or systemic lupus erythematosus (SLE) and with high plasma creatinine levels at randomization had a higher probability of being switched to double or triple therapy. According to ITT analysis, there were fewer ocular (P < 0.0001), osteomuscular (P < 0.002) and cardiovascular complications (P = 0.05) and fewer patients with hypercholesterolemia (P < 0.0028) in the monotherapy group, with no difference between double and triple therapy. Creatinine clearance at 3 years was lower in monotherapy, but no attrition of renal function was seen over the years in any of the groups. Cyclosporine, however used, provided good results in cadaveric renal transplantation. Triple therapy and monotherapy offered a nonsignificantly better patient and graft survival than double therapy. Patients on monotherapy had a higher risk of acute rejection but had fewer adverse events than those on double or triple therapy. Patients maintained on cyclosporine alone had the best graft survival, whereas those who were assigned to monotherapy and had to add steroids because of multiple rejections had the worst outcome. Therefore, it seems reasonable to limit the choice of monotherapy to patients without immune-mediated renal diseases and with good graft function in the early post-transplant period.

Adolescent↗
PubMed1997

[Renal transplantation in patients over 60 years of age. An increasing clinical reality].

The elevation of the uremic population age, the longer survival of dialysis, the increasing number of elderly donors, together with the safer surgical, anesthesiological and immunological procedures have led all over the word to an improvement of over 60s patients transplantation program, with very good results. The authors present their own experience of renal transplantation in elderly recipients and a review of what is reported in the literature on the question.

Age Factors↗
PubMed1997

[Vascular bench surgery in renal transplant].

The development in the number of patients for renal transplants has not been matched to the kidneys supplied. On this subject the authors think that this chronic deficit could be improved by making use of all the organs by using a series of technical means during bench surgery; which enable optimisation of use of kidneys with vascular abnormalities or those injured upon removal. The authors report their experience of 450 renal transplants operated between January 1981 and December 1985 and of the evolution vascular bench surgical techniques which enable use of a considerable number of kidneys which would otherwise have been discarded. Moreover, it helped the implant, shortened surgery time without prolonging hot ischemia, and did not increase the number of complications.

Humans↗
PubMed1997

[Severe infections after orthotopic hepatic transplant].

METHODS: The authors analysed severe infections in 43 consecutive patients undergoing orthotopic liver transplant. Prophylaxis and full anti-infection monitoring was performed in all cases. Immunosuppressive therapy was administered in the form of primary cyclosporine in 27 cases and primary OKT3 in 16 cases. RESULTS: Twenty-seven patients are still alive (median 8 months, range 2-40) and 16 died (median 22 days, range 10-92) of whom 4 without and 12 with infection, including two deaths owing to non-correlated causes with infection after recovery. Twenty-three patients underwent 33 episodes of severe infection (plus four with inconclusive positive cultures) without any case of protozoal or viral infection. All episodes occurred within two months of surgery and affected the lung (10), abdomen (7), lung + abdomen (1), urinary tract (1), lung + urinary tract (1), as well as two diffused cases and 7 cases of isolated bacteremia deriving from the donor (1), venous catheters (3), mild otorhinolaryngeal infection (1) and two unknown sources (2). Eighteen infective agents were identified in 45 cases. The bacteria involved in single-agent episodes were: 11 Gram+, 9 Gram- and five fungi. Polymicrobic and bacterial/fungal episodes were repeatedly observed in two and two cases. Postoperative renal insufficiency significantly influenced both the incidence of and mortality due to infection. Overall mortality was also influenced by early graft function, postoperative complications and reoperations, and the incidence of infections by the portal clamping stage, reject and prolonged coma. CONCLUSIONS: The absence of severe viral infections and the gradual reduction of mortality caused by infection appear to be parallel to the aggressive antiviral prophylaxis, the gradual improvement of intra- and postoperative management and primary immunosuppression with OKT3.

Adult↗
PubMed1996

HLA matching in pediatric recipients of a first kidney graft. A single center analysis.

We retrospectively examined the effect of HLA-A, -B, and -DR serological matching on graft survival in 88 pediatric end-stage renal disease patients who underwent primary renal transplantation. Actuarial graft survivals (GS) at 2 and 6 years in patients with zero DR mismatches (MM) (12 patients) or 1 DR MM (58 patients) were significantly higher than those in patients with 2 DR MM (18 patients) (2-year GS: 100% vs. 90% vs. 59%; 6-year GS: 100% vs. 79% vs. 59%, respectively). Because of the low number of patients in the zero DR MM group, only the GS difference between 1 DR MM and 2 DR MM had a significant result at 1 year (92% vs. 68%). No clear HLA matching effect was obtained in the HLA-A and -B loci. When DR were combined with A or B antigens (0-2 MM vs. 3-4 MM), significantly higher GS at 1, 2, and 6 years persisted for patients with 0-2 MM only in the A, DR group (96%, 94%, and 85% vs. 68%, 63%, and 56%, respectively). It is suggested that avoidance of mismatching for DR alleles at the serological level, in the selection of pediatric recipients of first cadaveric renal transplantation, leads to an improvement of both short- and longterm graft outcome.

Adolescent↗
PubMed1996

Complement-fixing islet cell antibodies in type-1 diabetes can trigger the assembly of the terminal complement complex on human islet cells and are potentially cytotoxic.

Forty-one sera of patients with IDDM (insulin-dependent diabetes mellitus) containing complement-fixing islet cell antibodies were analyzed for their ability to activate TCC (terminal complement complex). Eighteen sera were found to promote deposition of TCC on human islets of pancreatic cryostat sections with a nonhomogeneous pattern of distribution corresponding to that of insulin. Activation of TCC by IDDM serum and binding of this complex to islet cells was confirmed using purified islets. Flow cytometric analysis of islet cell treated with a TCC+ IDDM serum showed IgG binding to the cell surface. The same serum had a cytotoxic effect on islet cells in the presence of human C. These results obtained with a homologous system of C activation by IDDM sera suggest that TCC may contribute, at least in part, to the pancreatic beta cell damage.

Autoantibodies↗
PubMed1996

[Pregnancy in women undergoing a kidney transplant. Our experience and a review of the literature].

The chances of pregnancy for uremic women are usually very low, because of hormonal balance changes which determine a strong reduction in fertility. Epidemiological studies reveal that pregnancy in hemodialyzed women in fertile patients 4.6-6 months after a well functioning kidney transplant, one fertile transplanted woman over 50 can become pregnant. In the first transplant era, pregnancy after kidney transplant was considered "a big hazard", especially because of the possible side-effects of immunosuppression drugs on foetus development, and the risk of a worsening in the mother's renal function. Therefore, women were strongly recommended to avoid pregnancy. More recently, several reported papers have shown that pregnancy can be safely carried on also by transplanted women, under careful criteria and monitoring. Our experience too, even if limited in number (4 patients) reported in this article confirms this conviction.

Female↗
PubMed1995

Renal transplantation from living donor parents in two brothers with Alport syndrome. Can asymptomatic female carriers of the Alport gene be accepted as kidney donors?

Renal transplantation from living donor parents was performed in two brothers with end-stage renal failure due to Alport syndrome (AS). Two years later, the patient receiving the kidney graft from the mother, obligate carrier of AS, presented persistent microhematuria and proteinuria with normal renal function. The histological study demonstrated ultrastructural glomerular lesions consistent with AS. The authors conclude that: (1) Alport patients should not be deprived of renal transplantation from living donors, since anti-GBM nephritis is a rare complication; (2) an oligosymptomatic female carrier of the Alport gene may be considered as living renal donor, although a longer follow-up is needed in order to draw definitive conclusions.

Adult↗