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Biomedical subjects

U Heemann

Publications and source records attributed to U Heemann.

At least 55 records · Page 3Linked to original sources
PubMed1998

Prevalence of diverticulosis and incidence of bowel perforation after kidney transplantation in patients with polycystic kidney disease.

Sigmoid perforation due to diverticulitis is a life-threatening complication in the postoperative course of allogenic kidney transplantation. The incidence of diverticulosis is especially high among patients with autosomal dominant polycystic kidney disease (ADPKD). Thus, those who undergo allogenic kidney transplantation represent a high-risk group. The aim of this study was to evaluate the prevalence of diverticulosis in ADPKD patients awaiting renal transplantation and the incidence of bowel perforation following allogenic kidney transplantation due to ADPKD. Within the group of 1128 patients who underwent transplantation between January 1974 and January 1990, there were 46 patients (4.07%) whose indication for transplantation was ADPKD. There was one patient who developed a sigmoid perforation under postoperative immunosuppression. Surgical treatment was a discontinuity resection of the sigmoid (Hartmann's procedure). The postoperative course was favorable, the bowel continuity has already been restored, and the graft is still functioning well. Fifteen of the 28 (53.5%) ADPKD patients awaiting transplantation had colon diverticulosis (12 male and 3 female patients). No case of bowel perforation has thus far been observed in 15 of these patients who have undergone transplantation. A sigmoid resection was necessary in one patient due to diverticulitis without perforation. We did not find a higher prevalence of diverticulosis in patients with ADPKD, nor did we see a higher incidence of sigmoid perforation during post-transplant immunosuppression in this study.

Adult↗
PubMed1998

Hypertension accelerates the pace of chronic graft dysfunction in the rat.

In this study we compared the effects of hypertension on chronic rejection in a rat model of renal transplantation utilizing genetically normotensive (BBOK) and spontaneously hypertensive rats (SHR). SHR received either a BBOK (BBOK-->SHR) or an SHR (SHR-->SHR) kidney; normotensive isografts served as controls. Before transplantation, SHR recipients were treated with hydralazine (50 mg/kg per day). To prevent acute rejection, an anti-CD4 antibody (3 mg/kg per day for 3 weeks) in combination with cyclosporin A (3 mg/kg per day for 1 week) was given to all groups. Six weeks after transplantation, blood pressure was measured, and the kidneys removed for histological and immunohistological analysis. SHR-->SHR developed a significantly higher blood pressure than BBOK-->SHR. Blood pressure in BBOK-->BBOK was significantly lower than in the other two groups. The degree of glomerulosclerosis was similarly increased in allografted (BBOK-->SHR) and SHR-->SHR kidneys as compared with the BBOK-->BBOK kidneys (P < 0.05). Infiltration of ED-1+ monocyte/macrophages and OX19 pan-T-cells was most pronounced in allografts (BBOK-->SHR) and was also increased in SHR-->SHR as compared with BBOK-->BBOK. Our results indicate that hypertension accelerates the morphological and immunohistological changes characteristic of grafts undergoing chronic rejection. However, our findings support the hypothesis that alloantigen-dependent factors are of greater important.

Animals↗
PubMed1998

Clinical efficacy of a new AT1 blocker.

The main goal of the treatment of hypertension is to decrease cardiovascular morbidity and mortality. Since this has been demonstrated for betablocker and diuretics only, other antihypertensive agents should be recommended for initial single-drug therapy only if they demonstrate that their antihypertensive potency, and their tolerability is at least comparable to that of the other established drug classes. From this latter perspective AT1 blockers should become one of the most favored anti-hypertensive drugs, since it can be shown that their efficacy is comparable to all other classes of antihypertensive drugs and their tolerability is undoubtedly better. Candesartan seems to be the most efficient AT1 blocker with regard to molar potency. Moreover, it has been shown that Candesartan achieves an impressively long duration of action presumably due to its special receptor binding properties with a peak trough ratio of more than 0.9. An other advantage of this special AT1 blocker may be its dose response curve which demonstrates a continuous increase of efficacy between 2 and 16 mg daily.

Angiotensin Receptor Antagonists↗
PubMed1998

Hepatitis G virus infection in children on dialysis and after renal transplantation.

The aim of the present study was to use a combination of the reverse transcription-polymerase chain reaction and a new diagnostic test for antibodies against the viral envelope protein E2 to assess the prevalence of hepatitis G virus (GBV-C/HGV) infection in sera of Hungarian children on hemodialysis (HD) or peritoneal dialysis (CAPD), as well as in sera of renal transplant patients (RTx). The GBV-C/HGV RNA prevalence was significantly higher in the whole group of children with renal failure (18.5%) than in the control group (children with urinary tract infection, 2.5%). The difference between the GBV-C/HGV RNA prevalence in the RTx group (33.3%) and in the control group (2.5%) was significant (P = 0.007). Anti-E2, which is considered an indicator of a past GBV-C/ HGV infection, was detected in 10% (1/10) of HD patients, in 33.3% (4/12) of RTx patients, but in none of the children on CAPD. These differences were not significant. Children receiving a renal graft are at an increased risk of developing GBV-C/HGV infection, which may be attributed to the immunosuppressive drugs necessary to maintain the grafts.

Adolescent↗
PubMed1998

Do urinary tract infections trigger chronic kidney transplant rejection in man?

PURPOSE: Urinary tract infections are frequent after kidney transplantation but little is known about the impact on long-term survival. As chronic rejection is the major cause of graft loss in the long term, we retrospectively analyzed the role of urinary tract infections in this process. MATERIALS AND METHODS: We included in the study all adult patients who received kidney transplants at our unit between 1972 and 1991, which ensured followup of at least 5 years, and we focused on the relationship between urinary tract infections and the incidence of chronic rejection episodes. To analyze the influence of urinary tract infections on chronic rejection patients were separated into those in whom biopsy proved chronic rejection developed within the first 5 years after transplantation (chronic rejection group 225) and those without apparent signs of chronic rejection during that period (control group 351). The correlation between urinary tract infections per year and the incidence of chronic rejection was analyzed. RESULTS: Patients with chronic rejection had more urinary tract infections per year than controls. In the first year after transplantation both groups had the highest incidence of urinary tract infections but thereafter the rate of urinary tract infections per year declined. However, the incidence consistently remained higher in the chronic rejection group. This difference reached significance by year 3 after transplantation. Furthermore, a high rate of urinary tract infections correlated with an early onset of chronic rejection. CONCLUSIONS: Urinary tract infections are an important risk factor for the onset of chronic rejection, and early and intense treatment is critical.

Adult↗
PubMed1998

Comparison between subcutaneous and intravenous interleukin-2 treatment in HIV disease.

OBJECTIVES: Therapy of HIV-infection using intravenous interleukin-2 (IL-2) is known to be effective in terms of increasing CD4-counts but is associated with significant side-effects and hospitalization. However, the combination with protease-inhibitor therapy has not been tested yet. The aim of the present study was to investigate the safety and efficacy of intravenous vs. subcutaneous IL-2 regimes using 9 Mio I.U. of IL-2, in combination with protease-inhibitor therapy. DESIGN: All patients were treated with a combination of two reverse transcriptase inhibitors and a protease-inhibitor prior to IL-2 administration for at least 6 weeks. Ten patients were assigned to the intravenous IL-2 group (group A). 10 to the subcutaneous group (group B). RESULTS: In both treatment groups, CD4 count significantly increased shortly after the end of therapy (group A: 223% over baseline [day 7]; group B: 264% over baseline [day 7]). During the follow-up CD4 counts slowly decreased thereafter but remained above baseline 3 months following IL-2 treatment. The CD8 lymphocytes showed a similar but less pronounced pattern with a maximum at day 7 (group A: 116% over baseline, group B: 158% over baseline) and reached baseline earlier in the follow-up-period. Altogether the CD4/CD8-ratio was elevated through long periods on follow-up. Throughout follow-up, there were no apparent changes in viral load during IL-2 therapy in either groups. IL-2 therapy was administered for a mean time of 4.2+/-0.1 days in the intravenous group and of 4.8+/-0.1 days in the subcutaneous group until therapy was terminated at day 5 or due to side-effects. Only 1/10 patients completed the 5-day course of intravenous therapy in contrast to 6/10 in the subcutaneous group. CONCLUSIONS: Subcutaneous interleukin-2 using 9 Mio IU day(-1) in combination with protease-inhibitors showed equal efficacy as intravenous therapy and was associated with less side-effects.

Adult↗
PubMed1998

Tacrolimus rescue therapy in patients with rejection and long-term dialysis after kidney transplantation.

Therapy with tacrolimus has been proven effective in patients with steroid-resistant rejection episodes. It was the objective of the present study to evaluate the efficacy of tacrolimus in patients with long-lasting primary or secondary non-function (defined as being on dialysis for at least 28 days) converted for biopsy proven acute rejection and to determine parameters of prognostic value. Eight patients with biopsy proven acute interstitial rejection unsuccessfully treated with steroids were converted from a cyclosporine based immunosuppressive regimen to tacrolimus. Three patients were additionally pretreated with OKT3 without success. The tacrolimus whole blood through level was 7.5 +/- 2.6 ng/ml at one week and 8.1 +/- 3.4 ng/ml at one month after conversion. The follow-up period after conversion to tacrolimus ranged from 12-18 months. In four patients hemodialysis was stopped after 78 +/- 49 days (range 36-145 days). One year thereafter, creatinine was 3.9 +/- 2.7 mg/dl. In conclusion, our observations, although obtained in a small number of patients, offer some hope in this selected group and may encourage further studies in patients with long-term dialysis after renal transplantation.

Adult↗
PubMed1997

Metabolic factors have a major impact on kidney allograft survival.

BACKGROUND: At the present time, late graft loss is the major cause of kidney failure after transplantation. However, the influence of metabolic factors on this process is ill-defined. METHODS: To identify the impact of lipid metabolism, glucose metabolism, and blood pressure and their prognostic value for graft survival, data for all recipients of a kidney allograft with a potential graft survival of >15 years and a minimum graft survival of 1 month were analyzed retrospectively. Recipients of kidney grafts functioning more than 15 years (n=32) were compared with those with a graft function of less than 10 years (n=152, controls) and evaluated in a multivariate analysis. RESULTS: Low levels of serum cholesterol, triglycerides, and glucose, before and after transplantation, were accompanied by a prolonged graft survival. Prognostic factors for early graft failure included serum triglycerides >300 mg/dl, cholesterol >250 mg/dl before transplantation, serum creatinine >4.0 mg/dl 1 month after transplantation, and donor age above 45 or less than 10 years. Additionally, systolic and, particularly, diastolic blood pressure was lower in the group with a prolonged graft function as compared with controls immediately before and after transplantation. In addition, the incidence of primary graft function was lower and the incidence of acute rejection episodes higher in controls. Cold and warm ischemic time, body mass index, recipient age, and gender did not differ significantly. CONCLUSIONS: Our data suggest that metabolic parameters play an important role in the process of late graft loss after kidney transplantation.

Adult↗
PubMed1997

Multicenter randomized trial comparing tacrolimus (FK506) and cyclosporine in the prevention of renal allograft rejection: a report of the European Tacrolimus Multicenter Renal Study Group.

BACKGROUND: To confirm the results of a number of studies conducted in Europe, the United States, and Japan, this multicenter, randomized trial compared the 12-month efficacy and safety of tacrolimus- and cyclosporine-based immunosuppressive regimens in the prevention of renal allograft rejection. METHODS: A total of 448 renal transplant recipients were recruited from 15 centers and assigned to receive triple-drug therapy consisting of tacrolimus (n=303) or cyclosporine (n=145) in conjunction with azathioprine and low-dose corticosteroids. RESULTS: At 12 months after transplantation, tacrolimus therapy was associated with a significant reduction in the frequency of both acute (tacrolimus 25.9% vs. cyclosporine 45.7%; P<0.001 [absolute difference: 19.8%, 95% confidence interval: 10.0-29.6%]) and corticosteroid-resistant rejection (11.3% vs. 21.6%; P=0.001 [absolute difference: 10.3%, 95% confidence interval: 2.5-18.2%]). Actuarial 1-year patient (tacrolimus 93.0% vs. cyclosporine 96.5%; P=0.140) and graft survival rates (82.5% vs. 86.2%; P=0.380) did not differ significantly between the two treatment groups. Overall, the safety profiles of the tacrolimus- and cyclosporine-based regimens were quite comparable. Infections, renal impairment, neurological complications, and gastrointestinal complaints were frequently reported but were mostly reversible in both groups. Higher incidences of elevated serum creatinine, tremor, diarrhea, hyperglycemia, diabetes mellitus, and angina pectoris were reported in the tacrolimus treatment group, whereas acne, arrhythmia, gingival hyperplasia, and hirsutism were more frequent with cyclosporine treatment. CONCLUSIONS: The significant reduction in the incidence of episodes of allograft rejection observed with tacrolimus therapy may have important long-term implications given the prognostic influence of rejection on graft survival.

Adolescent↗
PubMed1997

Factors contributing to the development of chronic rejection in heterotopic rat heart transplantation.

BACKGROUND: The present study was devised to elucidate the influence of immunogenicity, immunosuppression, and ischemia on the development of transplant vasculopathy (TVP) as well as to investigate myointimal proliferation in syngeneic transplantation. METHODS: Fischer 344 and Brown Norway rat heart allografts and Lewis isografts were treated with rapamycin or cyclosporine, exposed to 4 hr of cold ischemia, and observed for 100 to 300 days before the incidence and degree of TVP and perivascular infiltration were assessed. RESULTS: The incidence of TVP in Fischer 344-->Lewis allografts (rapamycin, 0.5 mg/kg for 14 days) rose steadily, with dense mononuclear infiltration present in coronary lesions at all times (from 10+/-2% at 50 days to 85+/-15% at 150 days). Increased immunogenicity (Brown Norway-->Lewis) intensified TVP (62+/-13%) as compared with its control (25+/-15%, P<0.005). Enhanced immunosuppression (rapamycin, 0.5 mg/kg daily) decreased the incidence of TVP (22+/-11%, P<0.005), and additional low-dose cyclosporine was ineffective (1.5 mg/kg daily, 40+/-14%, NS). Four hours of cold ischemia before transplantation failed to have any effect on allografts, but promoted TVP in isografts (0 vs. 11+/-8%). CONCLUSIONS: The antigenic stimulus has probably the most important impact on the development of TVP, but is not necessarily essential. In most allografts, TVP probably reflects ongoing sublethal acute rejection, whereas myointimal proliferation in isografts presumably results from a perioperative antigen-independent response-to-injury mechanism.

Animals↗
PubMed1997

Rescue therapy with tacrolimus in simultaneous pancreas/kidney transplantation.

Tacrolimus has been effective both in primary and rescue therapy following steroid and OKT3-resistant acute rejection in liver and kidney transplantation. Due to the effects of tacrolimus on glucose metabolism, there has been concern about its use in simultaneous pancreas/kidney transplantation. We report on the results of six patients (three female, three male, age 35.2 +/- 7.3 years) converted from cyclosporin A to tacrolimus following simultaneous pancreas/kidney transplantation in steroid-resistant acute rejection. Tacrolimus was induced 2.8 +/- 1.7 months (range 1-4.8 months) after transplantation; follow-up was 3-18 months. Following conversion, creatinine levels declined in all patients [3.5 +/- 1.2 mg/dl before conversion, 3.0 +/- 1.9 mg/dl (n = 6) at three months, 1.4 +/- 0.1 mg/ dl at 1 year (n = 3)]. Before conversion, fasting blood glucose levels averaged 154 +/- 33 mg/dl, with three patients receiving insulin. Three months later no patient required insulin, the mean glucose level being 107 +/- 23 mg/dl (n = 6); at 1 year it was 92 +/- 9 mg/dl (n = 3). One patient lost his pancreatic graft after 4 months due to a mycotic aneurysm. We conclude that conversion to tacrolimus is a safe and effective treatment in cases of steroid-resistant rejections following pancreas/ kidney transplantation.

Administration, Oral↗
PubMed1997

A comparison of EMIT and FPIA methods for the detection of cyclosporin A blood levels: does impaired liver function make a difference?

OBJECTIVE: Apparent cyclosporin A (CSA) blood levels, as determined by fluorescence polarization immunoassay (FPIA) and enzyme-multiplied immunoassay technique (EMIT), were compared in CSA-treated patients with various degrees of liver dysfunction. METHODS: FPIA and EMIT were performed in parallel according to test manufacturer instructions in blood from kidney (n = 82), liver (n = 96) and heart transplant (n = 20) patients. RESULTS: The precision of both techniques was greatest in patients with the highest blood levels, and at each blood level greater for the FPIA than for the EMIT. Apparent CSA blood levels, as determined by EMIT, were typically approximately 70% of those determined by FPIA, indicating greater cross-reaction of the antibody in the FPIA with CSA metabolites. However, the ratio of values determined with EMIT and FPIA was very similar in kidney, liver and heart transplant patients. Among liver transplant patients it was also very similar in those without major alterations of hepatic function and in those with impaired excretory (increased bilirubin and gamma GT) or synthetic (i.e., reduced thromboplastin time) function. Extended storage of blood samples for up to 10 days did not affect apparent CSA blood level estimates by EMIT in a clinically relevant manner. CONCLUSIONS: We conclude that the greater specificity of the antibody in the EMIT for the CSA parent compound does not translate into a clinically relevant advantage for CSA monitoring.

Cyclosporine↗
PubMed1997

GBV-C/HGV infection in renal dialysis and transplant patients.

BACKGROUND: Recently a new human virus (GBV-C/HGV) was identified. With the use of the polymerase chain reaction (PCR) the possibility of a high prevalence of the GBV-C/HGV infection in haemodialysis patients was demonstrated. The aim of the present study was to use a combination of the PCR and a new diagnostic test for antibodies to the viral envelope protein E2 to assess the prevalence of the GBV-C/HGV infection in German patients with renal failure. METHODS: RT-PCR and ELISA were used to detect GBV-C/HGV RNA and antiviral antibodies (anti-E2) in the sera of 31 patients on a maintenance haemodialysis (HD)), 25 patients on a perioneal dyalisis (CAPD), and 92 renal transplant patients (RT). RESULTS: A statistical trend was noted for a higher rate of the GBV-C/HGV RNA in the whole group of patients with renal failure (11.5%) than in the control group of organ donors (5.5%); The difference between GBV-C/HGV RNA prevalence in RT patients (15.2%) and in organ donors (5.5%) was found to be significant. Anti-E2, which are considered as an indicator of a past GBV-C/HGV infection, were detected in 12.9% of HD patients, in 20.0% of CAPD patients, in 10.9% of RT patients, in 11.1% of organ donors, and in 10.9% of blood donors. These differences were not significant. Time on haemodialysis was significantly longer in GBV-C/HGV infected patients compared to uninfected patients and all patients with the GBV-C/HGV RNA have a history of blood transfusions. CONCLUSIONS: Patients with renal failure treated with dialysis or subjected to renal transplantation are at increased risk of aquiring the GBV-C/HGV infection. Higher rates of the GBV-C/HGV RNA and a similar prevalence of anti-E2 in patients with renal failure as compared to donors suggest that the rate of GBV-C/HGV infection resolution in immunosuppressed patients with renal failure might be lower than in immunocompetent patients.

Adult↗