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M Behrend

Publications and source records attributed to M Behrend.

At least 37 records · Page 2Linked to original sources
PubMed1998

Peritoneal mononuclear cell differentiation and cytokine production in intermittent and continuous automated peritoneal dialysis.

The long period without dialysate exchanges in nightly intermittent peritoneal dialysis (NIPD; no peritoneal filling during the day) and continuous cyclic peritoneal dialysis (CCPD; peritoneal filling during the day) might lead to an improved repopulation and functional regeneration of peritoneal macrophages (PMOs). We investigated this issue in seven stable, noninfected CCPD patients and seven stable, noninfected NIPD patients. PMO differentiation and cytokine production were measured after automated peritoneal dialysis and after a 12- to 14-hour period without dialysate exchanges. PMO maturation was evaluated by antibody staining. The proportion of "young" monocytes (positive for 27E10 and RM3/1) was decreased, whereas the proportion of mature macrophages (positive for 25F9) was significantly increased after the exchange-free interval. No differences between NIPD and CCPD were observed. The cytokine response to lipopolysaccharide was significantly increased after the exchange-free interval in both NIPD and CCPD. The interleukin-1 receptor antagonist (IL-1Ra) content of PMO lysates significantly increased after the exchange-free interval in both groups, but no changes were found in dialysate and serum IL-1Ra. We conclude that the long daytime interval without dialysate exchanges allows for additional PMO differentiation. Furthermore, the potential for cytokine release, which is inhibited (possibly by dialysate effects) after automated peritoneal dialysis, is restored after a 12- to 14-hour interval without peritoneal dialysis exchanges. The "dry" day in NIPD seems to have no important additional positive effect compared with CCPD.

Adult↗
PubMed1998

Mycophenolate mofetil (Cellcept).

Mycophenolate mofetil (MMF) is a new immunosuppressive drug designed to inhibit inosine monophosphate dehydrogenase (IMPDH). IMPDH is a key enzyme in the purine synthesis pathway of lymphocytes. IMPDH is crucially important for the proliferative responses of human T- and B-lymphocytes. Therefore, inhibition of IMPDH leads to selective lymphocyte suppression. Following successful testing in different in vitro and animal models, MMF entered clinical trials, where it has been used in combination with cyclosporin and steroids. MMF has rapid and complete absorption following oral administration. Pilot studies suggested a significant reduction in the incidence of rejection at doses of 1-3 g/day. These data led to the initiation of 3 pivotal trials, in which MMF was compared against different standard immunosuppressive protocols. Nearly 1500 patients were enrolled in these 3 randomised, double-blind, multicentre studies of the addition of MMF to standard immunosuppressive protocols for the prevention of acute renal allograft rejection. After six months, the rate of biopsy-proven rejection was significantly reduced. The adverse event profile resembles that of triple therapy with azathioprine: primarily involving the gastrointestinal (GI) tract, the haematopoietic system and the occurrence of opportunistic infections. MMF affords improved immunosuppressive therapy following renal, and probably other solid organ, transplantation. It is licensed for the prevention of acute renal allograft rejection in most countries around the world.

Journal Article↗
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

Risk of renal cell carcinoma after kidney transplantation.

Between December 1968 and July 1995, 2372 renal transplant recipients were seen regularly in our outpatient clinic. 154 patients (6.5%) of these subsequently developed a malignant tumor. One of the most frequently observed malignancies was a renal cell carcinoma in the native kidneys, found in 12 patients (7.8%; i.e. 0.5% of the total population), two of them with analgesic nephropathy and one with adult polycystic kidney disease. So-called acquired cystic kidney disease of the native kidneys was found in 73% of the patients with renal cell carcinoma. In the patients with renal cell carcinoma the median age at transplantation was 43.9 (39-55) yr. The median time from onset of end-stage renal failure and from transplantation to the appearance of the tumor amounted to 117.3 (43-206) and 75.8 (5-164) months, respectively. Despite nephrectomy, four patients died of the cancer (6-57 months). As a consequence we suggest a regular sonographic screening of the native kidneys twice a year in all renal transplant patients. As in dialysis patients, the main risk factors for the development of renal cell carcinoma seem to be so-called acquired cystic disease of the native kidneys and the underlying renal disease, such as analgesic nephropathy, and obviously not the immunosuppressive regimen after transplantation.

Adult↗
PubMed1996

Incidence of Pneumocystis carinii pneumonia after renal transplantation. Impact of immunosuppression.

The incidence and potential risk factors of Pneumocystis carinii pneumonia (PCP) in our population of renal transplant recipients were analyzed retrospectively. Of 1427 patients who received transplants between January 1986 and June 1994, 1192 were evaluated. Four different immunosuppressive regimens were applied: (1) cyclosporine (CsA) + prednisolone (Pred), (2) CsA + azathioprine (Aza, 2 mg/kg/day) + Pred, (3) CsA + Aza + antithymocyte globulin, and (4) (after December 1, 1993, European multicenter trial) FK506 + Aza (1 mg/kg/day) + Pred. No prophylaxis against PCP was performed. Before December 1, 1993, three PCPs in 494 patients on protocol 2 or 3 occurred (0.6%). Afterward, seven PCPs in 77 patients occurred (9%): three in 38 patients on protocol 2 (7.8%) and four in 28 patients on protocol 4 (14.3%). Comparing patients with PCP on CsA and FK506, the mean Aza dose was 2.40 and 1.32 mg/kg/day, five and two patients received additional steroids, antibody treatment was used in three and no patients, and CMV infections occurred in five and two patients, respectively. The incidence of PCP with a moderate CsA-based immunosuppressive regimen is low and seems to occur only in cases of additional immunosuppressive cofactors. Despite a general increase of PCP, its incidence was highest in patients on FK506 with fewer immunosuppressive cofactors. Thus, prophylaxis against PCP after renal transplantation should be performed, if not in every renal transplant recipient, at least in case of treatment with additional steroids, antibodies, or FK506.

Adult↗
PubMed1996

High mortality from urothelial carcinoma despite regular tumor screening in patients with analgesic nephropathy after renal transplantation.

Patients with end-stage renal failure due to analgesic nephropathy have an increased risk of developing a urothelial carcinoma. To determine the impact of renal transplantation on the frequency of urothelial carcinomas, we analyzed 2072 patients who underwent 2371 renal transplantation between 1968 and 1993, including 78 (3.8%) with clinically proven analgesic nephropathy. Before and after transplantation a regular tumor screening was performed in patients with analgesic nephropathy by urine cytology and abdominal sonography. In 11 of the 78 patients with analgesic nephropathy (14.1%; age 51-66 years, 40-108 months after initiation of dialysis treatment, 5-77 months after transplantation), a urothelial carcinoma of the native urinary tract, especially the kidneys, was diagnosed. Therapy comprised nephroureterectomy (n = 6), transurethral resection (n = 6) and/or cystectomy (n = 2). Seven patients died due to tumor progression 16.3 (4-33) months postoperatively and one patient died due to a perioperative complication. Despite regular tumor screening after transplantation, the diagnosis of a urothelial carcinoma was made very late, leading to a high tumor-related mortality. As a consequence, we suggest that a bilateral nephroureterectomy should be performed prophylactically in patients with proven analgesic nephropathy. In addition, a cystoscopy with lavage cytology testing of the bladder should be performed twice a year.

Acetaminophen↗
PubMed1996

Targeted mutation of plakoglobin in mice reveals essential functions of desmosomes in the embryonic heart.

Plakoglobin (gamma-catenin), a member of the armadillo family of proteins, is a constituent of the cytoplasmic plaque of desmosomes as well as of other adhering cell junctions, and is involved in anchorage of cytoskeletal filaments to specific cadherins. We have generated a null mutation of the plakoglobin gene in mice. Homozygous -/- mutant animals die between days 12-16 of embryogenesis due to defects in heart function. Often, heart ventricles burst and blood floods the pericard. This tissue instability correlates with the absence of desmosomes in heart, but not in epithelia organs. Instead, extended adherens junctions are formed in the heart, which contain desmosomal proteins, i.e., desmoplakin. Thus, plakoglobin is an essential component of myocardiac desmosomes and seems to play a crucial role in the sorting out of desmosomal and adherens junction components, and consequently in the architecture of intercalated discs and the stabilization of heart tissue.

Animals↗
PubMed1996

A review of clinical experience with the novel immunosuppressive drug mycophenolate mofetil in renal transplantation.

This review gives a summary about the current knowledge on the novel immunosuppressive drug mycophenolate mofetil (RS61443) in renal transplantation. The results of the preclinical pilot trials and of the so far published pivotal study for the prevention of rejection are described. Mycophenolate mofetil (MMF), the 2-4-morpholino ethyl ester of mycophenolic acid, is an inhibitor of the Inosine Monophosphate Dehydrogenase, an enzyme in the de novo synthesis of purines. MMF showed no clinical significant interactions with a variety of medications used in renal transplantation. Following oral administration it is rapidly absorbed. Pilot studied suggested a significant reduction in the incidence of rejection at doses of 2 g/day. 491 patients were enrolled in a randomized, double blind, multicentre, placebo-controlled study of the addition of mycophenolate mofetil to cyclosporine and oral corticosteroids for the prevention of acute renal allograft rejection. After six month the rates for biopsy proven rejection were the following: placebo 46.4%, MMF 2 g 17.0% and MMF 3 g 13.8%. The adverse event profile resembles that of triple therapy with azathioprine. Most adverse events concerned the gastrointestinal tract, the hemic system and opportunistic infections. MMF offers an improved immunosuppressive therapy following renal transplantation.

Clinical Trials as Topic↗
PubMed1995

High glucose concentrations and protein kinase C isoforms in vascular smooth muscle cells.

High extracellular glucose activates protein kinase C (PKC), a family of kinases vital to intracellular signaling. However, which PKC isoforms are involved and where in the cell they operate is unclear. We tested the hypothesis that only those PKC isoforms binding to diacylglycerol (DAG) are activated by high glucose. We also reasoned that the isoforms would translocate to different parts of the cell, where they presumably serve different functions. The PKC isoforms alpha, beta, delta, epsilon, and zeta were studied. Twenty mM glucose caused an increase in total PKC activity at six hours, which was maintained at 24 hours. High glucose decreased the angiotensin II-induced calcium signal. This effect was reversed by preincubating the cells with the PKC inhibitor staurosporine. Glucose induced a translocation of all PKC isoforms except PKC zeta by Western blot. Confocal microscopy showed that PKC alpha, beta, and epsilon were translocated into the nucleus. PKC delta showed strong association with cytoskeletal structures. The effects were sustained at 24 hours for PKC isoform beta and to a lesser extent for PKC delta and epsilon, but not for PKC alpha. Thus, PKC isoforms differ in their propensity to be activated by high glucose. Those isoforms binding to DAG are activated. Both cytoskeletal and nuclear signaling may be involved.

Alkaloids↗
PubMed1995

Monocyte infiltration and c-fms expression in hearts of spontaneously hypertensive rats.

To elucidate mechanisms of myocardial hypertrophy in spontaneously hypertensive rats (SHR), we examined by Northern blotting the expression of the proto-oncogenes c-myc, c-fos, c-sis, and c-fms in the hearts of 4- and 14-week-old SHR and normotensive Wistar-Kyoto (WKY) rats. No difference in c-myc or c-fos expression could be found between SHR and WKY rats. In SHR, c-sis gave a weak and c-fms a very strong signal at 14 weeks, whereas no signal for these oncogenes was found in either WKY rats or Sprague-Dawley controls. Since c-fms codes for the receptor of monocyte colony-stimulating factor, we next used in situ hybridization to localize the presence of c-fms in hearts of SHR at 14 weeks. We found strong signals for c-fms around small blood vessels and between cardiac myocytes in 14-week-old SHR but none in WKY rats. Immunohistochemical staining corroborated the presence of clusters of monocyte infiltration at these same perivascular sites in significantly greater numbers in SHR than in WKY rats. We conclude that c-fms expression and macrophage infiltration are increased in the perivascular space of hypertrophied hearts from SHR. We suggest that mononuclear cell recruitment and induction of c-fms may play a role in the development of hypertension-associated myocardial hypertrophy.

Animals↗
PubMed1993

Intercellular immune adhesion molecules in human liver transplants: overview on expression patterns of leukocyte receptor and ligand molecules.

Recently it has become clear that the inflammatory response of immune cells to target cells and extracellular matrix is regulated by several receptor-ligand molecules. Three main classes of molecules mediating intercellular adhesion and activation processes have been identified: the integrin, immunoglobulin and selectin families. This study surveys the expression of adhesion molecules on resident and infiltrating cells in human liver grafts. The patterns of cellular expression and inducibility in different pathological conditions of the graft are described. Our results show organ-specific regulation of the different adhesion molecules during alloreactive reactions and other types of inflammatory reactions. No rejection-specific patterns were detected on comparison with reperfusion damage or infectious transplant inflammation. Major differences were noted in the composition of the portal tract and sinusoid with regard to endothelial and parenchymal cell expression of cell-cell and cell-matrix adhesion molecules. Intravascular and interstitial differences in the expression patterns of leukocyte adhesion receptors support a concept of stepwise expression. The implications for the appearance of inflammatory reactions in human liver in immunosuppressive and therapeutic interventions are discussed.

Cell Adhesion Molecules↗
PubMed1993

Expression patterns of leukocyte adhesion ligand molecules on human liver endothelia. Lack of ELAM-1 and CD62 inducibility on sinusoidal endothelia and distinct distribution of VCAM-1, ICAM-1, ICAM-2, and LFA-3.

Vascular expressed adhesion molecules mediate leukocyte reactivity and activation by receptor-ligand binding. A number of different ligand molecules have been identified to mediate the interaction between endothelial cells and leukocyte subpopulations. In this study, the tissue expression of ELAM-1, CD62 (PADGEM, GMP-140), VACM-1 (INCAM-110), ICAM-2, ICAM-1, and LFA-3 was analyzed on various liver endothelial cell types by immunohistology. The results reveal a differential expression of these molecules in normal liver and inflammation or rejection after liver transplantation. The selectins ELAM-1 and CD62 are basally expressed and inducible on portal tract endothelia (arterial and venous) and central vein endothelia with acute and chronic liver inflammation. Sinusoidal endothelia, however, lack this mechanism, even with severe inflammation, as in cases of irreversible rejection and sepsis. Portal and sinusoidal endothelia show a different expression and inducibility of VCAM-1, ICAM-1, ICAM-2, and LFA-3. The differences in expression of adhesion molecules on liver endothelial cell types may reflect their ability to regulate leukocyte trafficking and activation by means of the expression of specific ligand molecules. The inability of sinusoidal endothelia to express selectins may have implications for the pathophysiology of liver graft infiltration.

Cell Adhesion Molecules↗