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Biomedical subjects

O Salvatierra

Publications and source records attributed to O Salvatierra.

At least 19 recordsLinked to original sources
PubMed1991

Intraoperative radiation therapy for Wilms' tumor in situ or ex vivo.

Patients with bilateral Wilms' tumor who have local recurrence after undergoing maximum-dose multitechnique therapy are problematic. The role of surgery in the management of these patients is changing from ablation to preservation of renal tissue. Bilateral nephrectomy is reserved as a last resort. Intraoperative radiation therapy (IORT) is advantageous to conservative management, as illustrated by the current cases of two children with recurrent Wilms' tumors in their remaining kidneys. Both children underwent limited surgery and precisely directed IORT. In one patient the nephron-sparing surgery and IORT were performed in situ. In the other the kidney was removed, treated with ex vivo bench surgery and radiation surgery, and then reimplanted. The adjuvant use of IORT, either in situ or ex vivo, in nephron-sparing surgery permits complete obliteration of gross and microscopic disease while maximizing residual renal function.

Child↗
PubMed1991

Are blood transfusions beneficial in the cyclosporine era?

In patients treated with conventional immunosuppression (azathioprine and prednisone) after renal transplantation, there is a beneficial effect of pre-transplant blood transfusions on graft survival; in patients treated with cyclosporine, this effect may be lost. In 66 children who received living-related donor transplants after donor-specific transfusions (DST) and were treated with azathioprine-prednisone in our center, 1- and 5-year graft survival rates were 99% and 77% respectively. These rates were similar to those reported for children who did not receive DST but were treated with cyclosporine in other centers. There were 634 adult and pediatric recipients of cadaver transplants in our center who were treated with cyclosporine and prednisone (non-sequential therapy, n = 89) or antilymphoblast globulin, azathioprine preduisone, and cyclosporin (sequential therapy, n = 545). When all patients were considered, graft survival rates were higher in transfused than in non-transfused patients at 3-5 years, but in the sequential therapy group, there were no differences in graft survival rates between transfused and non-transfused patients. The results suggest that transfusions do not improve cadaver graft survival in patients receiving optimal cyclosporine therapy and that equally good related donor graft survival can be achieved with DST and conventional immunosuppression or no DST and cyclosporine.

Blood Transfusion↗
PubMed1991

Long-term results of renal transplantation in children.

The results of renal transplantation in 37 children, 3 through 16 years of age, who received transplants prior to June, 1970 in our center, were examined. Twenty-three received kidneys from living-related donors and 14 received kidneys from cadaver donors. Patient survival rates were 78% at 10 years and 68% at 20 to 26 years. Graft survival rates were 56% at 10 years, 31% at 20 years, and 23% at 22 to 26 years. Twenty children received on or more retransplants. At follow-up, 23 (62%) of the patients had functioning grafts and two (5%) were undergoing dialysis. Cataracts, hypertension, and aseptic necrosis of bone were the most common medical complications and most of the patients were more than two standard deviations below average height. Most enjoyed good rehabilitation, however: more than 70% were employed or performing full time housework, more than 50% were married, 24% had children, and all had normal activity at least part of the time. These results, achieved with immunosuppressive methods now considered obsolete, indicate that renal transplantation is a satisfactory long-term treatment for children with renal failure.

Adolescent↗
PubMed1991

Improved results with combined donor-specific transfusion (DST) and sequential therapy protocol.

A combined DST-sequential CyA therapy protocol has been described that results in optimum graft survival for 1- and 2-haplotype mismatched living related donor-recipient combinations. In addition to the excellent graft survival obtained through 4 years, lower prednisone and CyA dosage levels are achieved with significantly decreased infection rates during the posttransplant period.

Blood Transfusion↗
PubMed1990

Non-inherited maternal HLA antigens and protection against sensitisation.

To test the hypothesis that non-inherited maternal antigens (NIMAs), which reportedly afford protection against sensitisation by random transfusions, can provide protection against repetitive antigenic exposure of donor-specific transfusion (DST), 140 DST patients whose donors were mismatched for NIMAs and 71 whose donors were mismatched for non-inherited paternal antigens (NIPAs) were studied. The rate of sensitisation in the two groups of patients was similar (22.1% vs 15.5%). There was no difference in sensitisation to NIMAs and NIPAs between patients who received azathioprine and those who did not. The formation of donor specific HLA antibody was comparable in the two groups. After kidney transplantation there were no differences in 1-year graft survival or the incidence of rejection episodes. These findings suggest that NIMAs do not provide lifelong protection against subsequent repetitive antigen challenge and sensitisation.

Adult↗
PubMed1990

The association of cyclosporine with the 1-year costs of cadaver-donor kidney transplants.

Cyclosporine is associated with lower hospitalization costs for transplantation of cadaver kidneys. Whether this cost-lowering effect persists after discharge was assessed for 203 patients who received cadaver kidneys at the University of California, San Francisco, between July 1982 and June 1986. During the transplantation hospitalization period, cyclosporine was associated with significantly better graft survival (88.7% vs 71.0%) and lower (standardized) costs ($37,174 vs $52,983). Following discharge, however, there were no significant differences in graft survival, total charges ($29,716 vs $34,434), the number of readmissions, the total number of days hospitalized, or physician charges, although cyclosporine was associated with higher drug costs ($3885 vs $373). The results suggest that the initial association of cyclosporine with lower costs diminished substantially over time. For grafts that survive beyond several months, there may be little additional cost-reducing benefits of cyclosporine.

Adolescent↗
PubMed1990

Nephron-sparing approach to bilateral Wilms' tumor: in situ or ex vivo surgery and radiation therapy.

Bilateral Wilms' tumor patients, who experience local recurrence after maximal multimodality therapy, present a difficult surgical problem. The role of surgery in the management of these patients has changed from ablation to preservation of renal tissue, with bilateral nephrectomy as a last resort. Two children who had recurrent tumors in the remaining kidney underwent nephron-sparing surgery and focal intraoperative radiation therapy. In one case, this nephron-sparing surgery and intraoperative radiation therapy were performed in situ, in the other kidney was removed and reimplanted (ex vivo bench surgery and irradiation). These techniques may allow complete obliteration of gross and microscopic disease, while maximizing residual renal function.

Child↗
PubMed1989

The effect of cyclosporine on the use of hospital resources for kidney transplantation.

Over the past decade the clinical results of kidney transplantation have improved substantially, with much of the benefit being attributed to the introduction in late 1983 of the immunosuppressive drug cyclosporine. To assess the effect of cyclosporine on the use of hospital services, we studied 702 patients who received kidney transplants at the University of California, San Francisco, between July 1982 and June 1986. All services were priced in constant 1985 dollars, and multiple regression analysis was used to adjust for changing patient and hospital characteristics. The introduction of cyclosporine for patients receiving kidneys from cadavers was associated with a significantly shorter adjusted mean postoperative stay (26.4 days as compared with 37.0 for patients not taking the drug; P less than 0.0001) and lower adjusted mean hospital charges ($28,649 as compared with $37,895; P less than 0.0001), although cyclosporine was not associated with changes in the use of services by patients who received transplants from living related donors. Cyclosporine was also associated with a reduction in the use of certain ancillary services, such as laboratory tests and radiographic procedures. In patients without diabetes who received cadaver kidneys, a sequential cyclosporine regimen (in which a combination of antilymphoblast globulin, prednisone, and azathioprine was given before cyclosporine) reduced the use of hospital services even more than did a cyclosporine regimen in which the combination was not given. The results suggest that new medications, such as cyclosporine, that reduce the frequency of complications and improve outcomes may also reduce the use of hospital resources.

Adult↗
PubMed1989

"Anti-idiotypic" antibodies to HLA in transiently sensitized DST patients.

To test the hypothesis whether "anti-idiotypic" antibodies (Ab2) were involved in the loss of sensitization following donor-specific blood transfusions (DST), we investigated nine potential kidney graft recipients who became transiently sensitized after DST. Inhibiting "anti-idiotypic" activity of post-DST sera was determined using a complement-dependent cytotoxicity inhibition assay. The follow-up after DST ranged from 9 to 66 months. The nine patients developed 12 different anti-HLA antibodies (Ab1). Inhibiting post-DST serum activity was found in relation to four of them, while enhancement of cell killing caused by post-DST sera was observed in relation to six anti-HLA antibodies. In two patients presenting with more than one anti-HLA antibody inhibition was found with only one of the antibodies, indicating that the blocking of Ab1 was specific for the respective antibody. Enhancement was associated with a significantly prolonged sensitization of the patients. On the average, 5.7 +/- 5.0 months were necessary before "anti-idiotypic" activity was developed after the loss of sensitization, whereas enhancement was found immediately thereafter. Testing by flow cytometry indicated that enhancing sera still contained subthreshold levels of Ab1. Our results indicate that DST can induce the development of "anti-idiotypic" antibodies following a short period of sensitization. This finding provides further evidence that anti-idiotypic antibodies might be relevant factors in the eventual disappearance of sensitization to HLA antigens.

Adult↗
PubMed1989

Inability of cyclosporine to completely prevent the recurrence of focal glomerulosclerosis after kidney transplantation.

From January 1984 through July 1986, 15 patients with biopsy-proven focal glomerulosclerosis (FGS) underwent kidney transplantation. Following transplantation, all patients were immunosuppressed with cyclosporine and prednisone. There were 8 men and 7 women with a mean age of 33 years (range, 16-47 years). Five patients (33%) had recurrence of FGS. Two patients had received kidneys from HLA identical siblings, and 3 patients were transplanted with cadaveric kidneys. In 4 out of 5 patients, the recurrence of FGS occurred within 3 months of transplantation. Of the 2 graft losses in this group, one was from recurrence of FGS. Ten patients followed for a mean of 25 months did not develop recurrence of FGS. No graft loss occurred in this group. Three patients with end-stage renal disease of unknown etiology were found to have FGS in the renal allograft and were presumed to have recurrence of FGS. All 3 patients developed the nephrotic syndrome following transplantation, and 1 patient has had progressive renal failure. Cyclosporine did not prevent the recurrence or the clinical manifestations of FGS following kidney transplantation. Additional studies are needed to determine if cyclosporine is effective in certain subgroups of patients with FGS.

Adolescent↗
PubMed1989

Bilateral renal autotransplantation with pyelovesicostomy: a surgical treatment of refractory enteric hyperoxaluria.

A 38-year-old man, with only 3 feet of small bowel remaining after multiple resections because of chronic inflammatory bowel disease, had severe symptomatic calcium oxalate nephroureterolithiasis. Because of the refractory symptoms, he was successfully treated with bilateral autotransplantation of the kidneys, totally bypassing the ureters. Anatomically effective urinary tract continuity was reestablished by means of bilateral pyelovesicostomies with concomitant rectus muscle vesicofixation to create direct stone-dumping channels into the urinary bladder. The patient is now completely without symptoms 18 months after surgery. A description and rationale for this surgical treatment is provided. Bilateral autotransplantation of the kidneys with direct drainage into the urinary bladder may be an attractive and viable therapeutic option in complicated patients with short-gut syndrome and severe refractory calcium oxalate nephroureterolithiasis.

Abdominal Muscles↗