Search PubMed⌕ Search

Biomedical subjects

D Steinmuller

Publications and source records attributed to D Steinmuller.

At least 19 recordsLinked to original sources

Renal computed tomography with 3-dimensional angiography and simultaneous measurement of plasma contrast clearance reduce the invasiveness and cost of evaluating living renal donor candidates.

Renal computed tomography (CT), 3-dimensional CT angiography (3D-CTA), and simultaneous measurement of glomerular filtration rate (GFR) by x-ray fluorescence determination of plasma contrast clearance (PCC) are alternatives to intravenous urography (IVU), renal arteriography (RA), and 24-hr urine creatinine clearance (CrCl) for evaluation of renal structure and function in living renal donor (LRD) candidates. To determine if CT, 3D-CTA, and PCC provide data comparable to IVU, RA, and CrCl, both methods were used to evaluate 23 LRD candidates. Costs were also compared. Conventional RA identified 19 accessory arteries and one case of medial fibroplasia. Each of these anomalous vessels was recognized on 3D-CTA. Venous anatomy was more clearly delineated on 3D-CTA than the venous phase of conventional RA. CT demonstrated 3 benign cysts and a single, small intraparenchymal calcification in 3 renal units. GFRs measured by PCC and CrCl were 91 +/- 4 and 132 +/- 7 ml/min/1.73m2, respectively (r = 0.64, P < 0.05). Total cost for CT/3D-CTA/PCC was 46% less than that of IVU/RA/CrCl and 40% less than RA/CrCl. CT/3D-CTA/PCC provided reliable structural and functional data at substantially less cost, discomfort, and inconvenience to the living renal donor candidate. As such, CT/3D-CTA/PCC is superior to conventional methods for evaluation of the living renal donor candidate.

Adult↗

Long-term follow-up after partial removal of a solitary kidney.

BACKGROUND: The removal of more than one kidney in animals leads to proteinuria and progressive renal failure due to focal segmental glomerulosclerosis. This injury may be the result of chronic glomerular hyperfiltration. The purpose of this study was to determine the effect of a reduction in renal mass of more than 50 percent on residual renal function and morphology in humans. METHODS: We evaluated long-term renal function in 14 patients with a solitary kidney who had undergone partial nephrectomy for renal-cell or transitional-cell carcinoma. In 12, the first kidney had been removed 2 months to 21 years previously for the same type of cancer; in 2, the other kidney was congenitally atrophic. Before surgery, no patient had clinical or histopathological evidence of primary renal disease. All 14 patients underwent partial nephrectomy to remove a localized tumor, with 25 to 75 percent of the solitary kidney being excised. They were evaluated 5 to 17 years after surgery (mean, 7.7). RESULTS: Twelve patients had stable postoperative renal function, and end-stage renal failure developed in two. There were no changes in blood pressure in any patient during follow-up. Nine patients had proteinuria, which was mild (0.15 to 0.8 g of urinary protein per day) in five. The extent of proteinuria was inversely correlated with the amount of remaining renal tissue (P = 0.0065) and directly correlated with the duration of follow-up (P = 0.0005). Four patients with moderate-to-severe proteinuria had renal biopsies, which revealed focal segmental glomerulosclerosis in three patients and global glomerulosclerosis in one. CONCLUSIONS: Long-term renal function remains stable in most patients with a reduction in renal mass of more than 50 percent. These patients are, however, at increased risk for proteinuria, glomerulopathy, and progressive renal failure.

Adult↗

Evidence that epidermal alloantigen Epa-1 is an immunogen for murine heart as well as skin allograft rejection.

Epa-1 is a non-H-2 mouse alloantigen defined by MHC-restricted, CD8+ cytotoxic T cells. In vitro it is a strong determinant for the lysis of epidermal cells, fibroblasts, and macrophages but not lymphocytes, and in vivo it functions as a target for skin allograft rejection and cutaneous graft-versus-host reactions. Genetically, Epa-1 appears to be the nonpolymorphic manifestation of a loss mutation. The establishment of C3H.Epa-1 (Epa), an Epa-1+ congenic strain on the Epa-1- C3H/HeJ (C3H) inbred strain background, facilitated the investigation of the role of Epa-1 in skin and heart allograft rejection. C3H females and males rejected first-set Epa skin grafts with median survival times (MSTs) of 20 and 30 days, respectively. However, there was a strong factor of immunization, because all second-set skin allografts were rejected by hosts of both sexes within 10 days. In contrast, all Epa hosts of both sexes permanently accepted C3H skin allografts, consistent with Epa-1 arising from a loss mutation. C3H hosts of both sexes rejected primarily vascularized first-set Epa heart allografts in similar tempo to first-set Epa skin allografts, with MSTs of about 30 days. However, in contrast to the accelerated rejection of skin allografts, sensitized C3H hosts rejected Epa heart allografts in chronic fashion, with some transplants showing very prolonged survival. Thus, Epa-1 is a relatively strong determinant of skin allograft rejection but a weaker determinant of heart allograft rejection.

Animals↗

The outcome of renal transplantation in children without prolonged pre-transplant dialysis.

Controversy in the literature exists over whether or not it is beneficial to maintain a patient on dialysis for a prolonged time before transplantation. Because no data exist comparing children who have had prolonged dialysis before transplantation to those who have none, we reviewed the charts of all children transplanted at the Children's Hospital of the Cleveland Clinic Foundation. Of those, we selected three groups for analysis: group one (n = 12) consisted of patients who had had less than or equal to 10 weeks of dialysis before transplantation (6.8 +/- -2.2 weeks, +/- = SD); group two (n = 21) were patients who had had more than 10 weeks of dialysis (142 + +/- -148 weeks). Both groups had two years of follow-up data. Group three (n = 13) consisted of patients who had had less than two years of follow-up (18.7 +/-/-7 months) but no dialysis before transplantation. There were no differences in mode of dialysis between groups one and two nor in the type of transplant (living-related donor vs. cadaveric). Significantly, the patients in group three received more cyclosporine A and less anti-lymphocyte globulin than the other two groups (p less than 0.05). Patients in group two received more transfusions (11.9 +/- 14.3) than patients in group one (4.0 +/- 2.7) and group three (3.5 +/- 7.3). There were no differences in number of patients who experienced at least one rejection episode among the three groups. Although the mean serum creatinine concentration at two years of follow-up was higher in group two (3.6 +/- -3.9 mg/dl), this was not significantly different from group one (1.7 +/- -0.7 mg/dl) or group three (1.9 +/- -0.5, n = 7). Sixty-three percent of patients in group one, 60% of patients in group two and 91% in group three had functioning allografts at two years follow-up. Although there may be other considerations, our data do not indicate any increase in rejection or decrease in graft survival in children who do not receive prolonged dialysis.

Adolescent↗

Dissociation of tissue destruction induced by cytolytic T cells in vivo and cytotoxicity as measured in vitro.

Two forms of local cutaneous graft-versus-host reactions were used to examine the in vivo activity of cytolytic T cells in a large number of antigen systems and mouse strain combinations. In immune lymphocyte transfer reactions (TrRs), CTL were injected intradermally into allogeneic hosts to which they were sensitized; in bystander reactions (ByRs), CTL were mixed with target cells and the mixture injected into hosts syngeneic to the CTL. Both reactions frequently culminate in full-thickness skin destruction. However, CTL highly active in cell-mediated lympholysis assays in vitro sometimes failed to induce significant reactions in vivo, and CTL with negligible CML activity often induced severe, necrotizing lesions. In addition, Clone 58, a non-MHC-specific CD8+ clone that originated from cells extracted from a sponge matrix allograft, lost its CML activity but continued to induce necrotizing TrRs and ByRs. Insofar as these reactions may exemplify the specific (TrR) and nonspecific (ByR) tissue injury that occurs in the rejection process, these findings question the reliability of CML for predicting the ability of CTL to induce the tissue destruction seen in allograft rejection.

Animals↗

Recent results of cadaver kidney retransplantation.

The results of secondary cadaver renal transplantation in 42 patients treated from 1980 to 1986 have been reviewed. The initial graft was from a cadaver donor in all cases. All patients were managed with a maintenance immunosuppressive regimen, including either antilymphoblast globulin and/or cyclosporine. The over-all 1 and 2-year patient survival rates were 97 and 94 per cent, respectively. The over-all 1 and 2-year graft survival rates were 69 and 63 per cent, respectively. Graft success was not influenced by patient age greater than 50 years, diabetes, initial graft removal, interval between initial graft removal and retransplantation, duration of initial graft function, level of presensitization or HLA-Dr antigen matching. Currently, cadaver renal retransplantation can be performed safely and with an improved opportunity for graft success. Patients who return to dialysis after losing an allograft should be encouraged to consider another transplant for the same reasons that prompted initial transplantation.

Adolescent↗

Endoscopic correction of vesicoureteral reflux in the renal transplant candidate.

High grade vesicoureteral reflux is a well recognized risk factor for post-transplant infection that has been managed commonly with native nephrectomy. Recent reports have described the successful correction of vesicoureteral reflux by the subtrigonal injection of polytetrafluoroethylene (Teflon) paste. We treated 5 transplant candidates with vesicoureteral reflux with this technique. Ureteral reflux was corrected in 80 per cent of the treated ureters with 6 months of followup. Of the patients 3 have undergone successful renal transplantation without complication. This procedure is well suited to the end stage renal disease patient preparing for renal transplantation, since it avoids an open operation on the pre-transplant bladder and preserves the native kidney, thus, facilitating pretransplant dialysis.

Endoscopy↗

Two-color immunofluorescence flow cytometric analysis of lymphocytes in long-term renal allograft recipients.

We used 2-color immunofluorescence flow cytometry (FACS 440) and monoclonal antibodies (Becton-Dickinson) to study peripheral blood lymphocytes subsets from 26 patients with well functioning renal allografts for longer than 5 years. Comparisons were made to a group of 25 healthy volunteers and 25 dialysis patients awaiting renal transplantation. As anticipated, there was no significant difference with respect to the absolute number or percentage of activated (T11+ and HLA-DR+) and cytotoxic (Leu-2+ and Leu-15-)T lymphocytes among the 3 groups. However, there was a significantly decreased absolute number (p equals 0.0001) and percentage (p equals 0.0001) of suppressor cells (Leu-2+ and Leu-15+) in the transplant patients compared to the healthy control group. No significant differences existed between the transplant and dialysis groups. There also was an increase in the percentage (p equals 0.000) but not in the absolute number of T helper lymphocytes (Leu-3+ and Leu-8-) in the transplant population compared to healthy controls. No significant difference existed between the transplant and dialysis groups. These findings suggest that a normal value of cytotoxic (Leu-2+ and Leu-15-) and activated (T11+ and HLA-DR+) T lymphocytes may be a good prognostic indicator of long-term survival of renal allografts. Also, the highly significant decrease in the number of Leu-2+ and Leu-15+ cells in long-term, well functioning allografts indicates that additional functional characterization of this subset may be necessary.

Adult↗

Use of digital subtraction fluorography in screening for coronary artery disease in patients with chronic renal failure.

The diagnosis of coronary artery disease remains a major problem in patients with end-stage renal disease. Screening with conventional noninvasive techniques is limited by the poor exercise capacity of these patients. This study evaluated the accuracy of digital subtraction fluorography in detecting coronary calcification as a noninvasive, nonexercise screening test for coronary artery disease. Eighty-six patients under evaluation for renal transplantation and considered at increased risk of coronary artery disease were studied by coronary arteriography and digital subtraction fluorography for coronary calcification. Significant coronary disease (greater than or equal to 50% obstruction in at least one vessel) was present in 36 (42%) patients. The detection of coronary calcification by digital subtraction fluorography had a sensitivity of 78% and a specificity of 66%. The probability of disease being present in the absence of coronary calcification in this group was 18%. The detection of coronary calcification by digital subtraction fluorography appears to be a satisfactory and inexpensive screening test in this setting.

Calcinosis↗

Blocking of interleukin-2 production, but not the tissue destruction induced by cytotoxic T cells, by cyclosporine.

Cytotoxic T lymphocytes generated against epidermal alloantigen-1 (Epa-1), a tissue-restricted, non-H-2 alloantigen that is a target-cell determinant of both skin allograft rejection and cutaneous graft-versus-host reactions, directly produce full-thickness ulcerative skin lesions in Epa-1+ mice. Anti-Epa-1 CTL also indirectly cause extensive damage of "innocent bystander" tissue when injected admixed with Epa-1+ target cells into the skin of Epa-1- hosts. Unlike the direct destruction of host tissue by CTL in "immune lymphocyte transfer reactions" (TrR), "bystander reactions" (ByR) apparently are initiated by the release of lymphokines that recruit host inflammatory cells to the injection site. Treatment of CTL with cyclosporine in vitro prevents their production of lymphokines like interleukin 2 but has no effect on cell-mediated cytotoxicity. However, little is known about the function of CsA-treated CTL in vivo. We confirmed the differential effect of CsA on CTL function in vitro with bulk-culture anti-Epa-1 CTL-CsA pretreatment of CTL abrogated IL-2 production but did not affect CMC. Moreover, we found that CsA pretreatment did not affect the ability of CTL to evoke TrR, nor did it significantly impair their ability to mediate ByR. Therefore, when CTL are treated with CsA in such a way that they lose their capacity to produce IL-2, their cytotoxic activity in vitro as well as their ability to directly and indirectly mediate tissue destruction in vivo are left intact. These results suggest that the ability of CTL to mediate allograft rejection is not dependent on their ability to produce IL-2 and that CMC plays a role in the rejection process.

Animals↗