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C D Heidecke

Publications and source records attributed to C D Heidecke.

At least 37 records · Page 2Linked to original sources
PubMed1997

Formation of DNA adducts by cyproterone acetate and some structural analogues in primary cultures of human hepatocytes.

Recently, we have shown that the therapeutically-used progestin and antiandrogen cyproterone acetate (CPA) causes the formation of high levels of DNA adducts in rat hepatocytes and rat liver [J. Topinka, U. Andrae, L.R. Schwarz, T. Wolff, Cyproterone acetate generates DNA adducts in rat liver and in primary rat hepatocyte cultures, Carcinogenesis 14 (1993) 423-427: J. Topinka, B. Binkova, L.R. Schwarz, T. Wolff, Cyproterone acetate is an integral part of hepatic DNA adducts induced by this steroidal drug, Carcinogenesis 17 (1996) 167-169; S. Werner, J. Topinka, T. Wolff, L.R. Schwarz, Accumulation and persistence of DNA adducts of the synthetic steroid cyproterone acetate in rat liver, Carcinogenesis 16 (1995) 2369-2372; J. Topinka, B. Binkova, H.K. Zhu, U. Andrae, I. Neumann, L.R. Schwarz, S. Werner, T. Wolff, DNA damaging activity of the cyproterone acetate analogues chlormadinone acetate and megestrol acetate in rat liver, Carcinogenesis 16 (1995) 1483-1487]. Its structural analogues, chlormadinone acetate (CMA) and megestrol acetate (MGA) were much less active in this respect [J. Topinka, B. Binkova, H.K. Zhu, U. Andrae, I. Neumann, L.R. Schwarz, S. Werner, T. Wolff, DNA damaging activity of the cyproterone acetate analogues chlormadinone acetate and megestrol acetate in rat liver, Carcinogenesis 16 (1995) 1483-1487]. In the present study we addressed the question whether these compounds and two further analogues, medroxyprogesterone acetate (MPA) and progesterone, induce the formation of DNA adducts in primary cultures of human hepatocytes. Incubation of CPA with human hepatocytes from two male and four female donors induced the formation of significant levels of CPA-DNA adducts detectable by 32P-postlabeling. The by far most prevalent DNA adduct is most likely identical with adduct A formed in CPA-treated rats. DNA binding was found even at 0.03 microM CPA, the lowest concentration used. The maximum effect occurred at about 10 microM in 5 of the 6 cell preparations. At this concentration 480 and 2690 adducts x 10(-9) nucleotides were detected in hepatocytes of the two male donors and 1072, 816, 613 and 659 adducts x 10(-9) nucleotides in the hepatocytes of the four female donors after an exposure of 6 h with CPA. Extending the incubation time to 20 h resulted in a roughly three-fold higher binding. CMA and MGA were assayed in two of the liver cell preparations from the female donors. At a concentration of 20 microM and an incubation time of 6 h, DNA adduct levels for CMA were 21 and 43% and for MGA 31 and 65% of the levels observed with 20 microM CPA. In contrast, DNA binding of MPA amounted to less than 1% of that observed with CPA and DNA binding of the natural occurring progestin progesterone was below the level of detection. The results point to a genotoxic risk associated with the therapeutic use of CPA and possibly of CMA and MGA. Furthermore, the findings suggest that the significant genotoxicity observed with CPA, MGA and CMA is associated with the presence of the double bond in position 6-7 of the steroid, which is absent in MPA and progesterone.

Adult↗
PubMed1997

[The role of liver transplantation in the treatment of acute liver failure following Amanita phalloides poisoning].

OBJECTIVE: To formulate the indications for liver transplantation in the treatment of acute liver failure after Amanita phalloides poisoning and to determine the results of this treatment. PATIENTS AND METHODS: In 1994 twelve patients with acute Amanita phalloides poisoning were treated in the intensive care unit of our hospital's toxicology department. Three of them developed irreversible signs of poisoning and were given orthotopic liver transplants. The findings and course of this group of patients were analysed retrospectively and prognostic criteria defined on the basis of this personal experience and published data. RESULTS: Amanita phalloides poisoning differs from other causes of acute liver failure in several respects. The following criteria make it possible reliably to distinguish a lethal from a non-lethal course: a Quick value < 20% over the course of several days, serum creatinine concentration > 1.4 mg%, even after correcting water and electrolyte abnormalities, serum bilirubin > 4.6 mg%, and progressive encephalopathy indicate a lethal course. Two of three patients survived severe poisoning by being given a liver transplant. Renal failure, pancreatitis and bone marrow suppression, in addition to liver failure, were signs relevant to treatment decisions. CONCLUSION: Liver transplantation is the procedure of choice in the treatment of acute Amanita phalloides poisoning, if the criteria for a probably lethal course under conservative treatment have been met. This should be taken into account when poisoned patients are to be transferred to a centre for treatment.

Adolescent↗
PubMed1997

Liver transplantation for the treatment of fulminant hepatic failure induced by the ingestion of ecstasy.

Methylenedimethoxymethamphetamine (MDMA), more commonly known as ecstasy, is a synthetic amphetamine derivative used by teenagers and young adults in the United States as well as in Western Europe as a "dance drug". Though a number of complications associated with this drug have been reported, there is little information pertaining to hepatoxity as a result of MDMA ingestion. This case report is about an 18-year-old female patient who regularly used ecstasy on weekends over a 2-month period. Within 2 days after accepting a "hit" of the substance at a party, she was admitted to the hospital because of lethargy, vomiting, abdominal pain, stool discoloration, icterus, and darkened urine. On day 7 she developed fulminant hepatic failure with reduced hepatic coagulation factors and grade IV encephalopathy. Orthotopic liver transplantation was carried out 10 days following the ingestion. The patient made a full recovery within 72 h and was released from the hospital 6 weeks later. Histopathological examination of the removed liver revealed a nutritive-toxic liver necrosis. This case demonstrates that the ingestion of ecstasy, even on an infrequent basis, can lead to acute fulminant liver necrosis, and that this life-threatening complication can be treated successfully by liver transplantation.

Adolescent↗
PubMed1997

Distinct mechanisms of immunosuppression as a consequence of major surgery.

Altered host defense mechanisms after major surgery or trauma are considered important for the development of infectious complications and sepsis. In the present study, we demonstrate that major surgery results in a severe defect of T-lymphocyte proliferation and cytokine secretion in response to coligation of the antigen receptor complex and CD28. During the early postoperative course, reduced cytokine secretion was observed for interleukin-2 (IL-2), gamma interferon, and tumor necrosis factor alpha, which are associated with the Th1 phenotype of helper T lymphocytes, and for IL-4, the index cytokine of Th2 cells. During the late postoperative course, T-cell cytokine secretion increased to normal levels. Production of the anti-inflammatory cytokine IL-10 was altered, with different kinetics being selectively elevated during the late postoperative course. In contrast, the capacity of peripheral blood monocytes to present bacterial superantigens and to stimulate T-cell proliferation was normal or enhanced after surgery despite a significant loss of cell surface HLA-DR molecules. Thus, the level of major histocompatibility complex class II protein expression does not appear to predict the antigen-presenting capacity of monocytes obtained from surgical patients with uneventful postoperative recovery. Secretion of IL-1beta and IL-10 by endotoxin-stimulated peripheral blood monocytes was increased at different time points after surgery. Major surgery therefore results in a distinct pattern of immune defects with a predominant defect in the T-cell response to T-cell receptor- and CD28 coreceptor-mediated signals rather than an impaired monocyte antigen-presenting capacity. Suppression of T-cell effector functions during the early phase of the postoperative course may define a state of impaired defense against pathogens and increased susceptibility to infection and septic complications.

Aged↗
PubMed1996

alpha/beta-T cell receptor-directed therapy in rat allograft recipients. Long-term survival of cardiac allografts after pretreatment with R73 mAb is associated with upregulation of Th2-type cytokines.

Rejection of vascularized allografts still poses the major problem in organ transplantation. Therefore, transplant rejection of cardiac allografts was investigated in a rat model (BN-to-LEW) under alpha/beta-TCR (R73) mAb-targeted therapy. Two protocols were studied: posttransplant ("immunosuppressive") and pretransplant conditioning therapy. In posttransplant therapy over a wide dose range, R73 mAb only marginally improved cardiac allograft survival (7.8 +/- 0.8 days vs. 12.5 +/- 0.8 days at 0.1 mg/kg for 7 days). In contrast, conditioning treatment with low-dose (0.1 mg/kg) anti-alpha/beta-TCR mAb given 3 to 7 days prior to organ transplantation was highly effective and resulted in 50% permanent acceptance of cardiac allografts. R73 mAb-treated rats were monitored with respect to peripheral lymphocyte populations and intragraft cytokine levels. A temporary, incomplete reduction (CD5+ cells) and partial modulation (alpha/beta-TCR/CD5 double+ cells) in the peripheral blood was observed. In contrast to untreated controls, intragraft production of IL-2 and IFN-gamma at the mRNA and protein level was abolished in both post- and pretreated recipients. Interestingly, pretransplant mAb application was associated with augmented in situ elaboration of the Th2-type cytokines, IL-4 and IL-10, together with up-regulated TGF-beta and PGE. Increased expression of IL-4 and IL-10 continued to be observed in long-term surviving allografts. In conclusion, the mechanism of conditioning therapy with alpha/beta-TCR mAb prior to alloantigen exposure appears to be a switch from Th1 to Th2 response allowing long-term acceptance of allogeneic grafts.

Animals↗
PubMed1996

Regionalization of donor organ procurement: first experiences in southern Bavaria and results of a regional donor hospital survey.

In order to improve organizational, qualitative, and economic aspects of organ procurement, a model of regionalization was established in the local area of southern Bavaria, as from September 1993, with the following characteristics. A collaborative 24 h-duty schedule with surgeons from all active regional transplant programs. Surgeons are grouped according to their operative qualification level: (1) Group I, capable of retrieving all abdominal organs (liver, pancreas, kidney), (2) Group II, capable of removing kidneys, and (3) Group III, surgical assistance in procurement procedures. All donor organs in the local region are explanted by the local team and foreign recipient centers are supplied with the organs removed by a standardized technique. Only three times during the first, and not once during the second year, did a foreign team insist on traveling to our region to perform a liver retrieval. A survey clearly documented univocal acceptance of this model by donor hospital executives. Simplified organization and less disturbance in operating theaters were among the most frequent arguments in favor, and the familiarity of explant teams in donor hospitals was considered advantageous. Most donor hospitals do not expect to profit in terms of financial savings. When asked for further possible measures to improve organ donation, a clearer legal situation, but also the need for more information and education programs, including better media representation of transplant issues, were cited most frequently. An improvement in financial reimbursements for the donor hospitals as an instrument to enhance willingness for organ donation was not considered essential. In conclusion, our model of regionalization of organ procurement proved to be effective in achieving a high quality of organ retrieval and a reduction in personnel requirements for the transplant centers. In addition, the response from donor hospitals was unequivocally positive and may, thus, positively influence donor activity. Relevant financial savings can result from reduced on-call duties and minimized traveling costs. Further attempts to rationalize organ procurement could possibly include heart(-/lung)surgeons in the regionalized teams.

Hospitals↗
PubMed1996

Interventional radiology in the treatment of blunt liver trauma: case report with review of literature.

Hepatic trauma remains one of the most serious problems in abdominal injury. Whenever possible a non-resectional approach is clearly preferred. Refinements of interventional radiology as an adjunct to surgery in blunt liver trauma may play an increasingly vital role in reducing mortality. The literature is reviewed with reference to the diagnostic procedure and the treatment strategy in blunt liver trauma.

Adult↗
PubMed1995

alpha/beta-T cell receptor-directed therapy in rat cardiac allograft recipients. Treatment prior to alloantigen exposure prevents sensitization and abrogates accelerated rejection.

An mAb directed to the alpha/beta-heterodimer of the rat T cell receptor was used to prevent rejection of cardiac allografts in sensitized (accelerated rejection) recipients. Over a wide dose range, alpha/beta-TCR-directed therapy abrogated accelerated rejection at 24-36 hr and extended cardiac allograft survival in a dose-dependent fashion, both when given after heart transplantation as well as during or before the sensitizing skin transplants (8.9 +/- 1.0 days, 12.7 +/- 0.6 days, or 8.7 +/- 1.5 days, respectively). Pretreatment with R73 completely abrogated host sensitization induced by skin grafting. As a result, post-heart transplant cyclosporine course (15 mg/kg for 7 day) has led to long-term graft acceptance (> 90 days vs. 15.2 +/- 1.6 days with postoperative CsA therapy alone). Administration of R73 mAb produced incomplete depletion (CD5+ cells) and partial modulation (alpha/beta-TCR/CD5 double-positive cells) in the peripheral blood. It suppressed in situ protein expression of many cytokines to background levels, in particular that of IL-2 and IFN-gamma, both when given after as well as before cardiac transplantation. However, only pretransplant mAb application was associated with augmented in situ elaboration of IL-4. alpha/beta-TCR-directed therapy induced strong host anti-idiotypic and, to a lesser degree, anti-isotypic antibody responses. Taken together, these results provide the rationale for a novel immunosuppressive strategy involving induction of hyporesponsiveness by alpha/beta-TCR-directed therapy before the alloantigenic exposure.

Animals↗
PubMed1995

Hepatocyte nitric oxide biosynthesis inhibits glucose output and competes with urea synthesis for L-arginine.

Inflammatory stimulation of the liver is known to induce nitric oxide (NO) biosynthesis. NO can interfere with the activity of a number of enzymes important to cellular metabolism. This study was carried out to investigate the influence of NO on rat hepatocyte glucose output and urea production. Induction of NO synthesis by incubation with a combination of cytokines and lipopolysaccharide led to a 48.8 +/- 2.4% inhibition of glucose output and to a 45.0 +/- 6.4% suppression of urea production. Inhibition of NO synthesis with NG-monomethyl-L-arginine was able to totally prevent these effects. High concentrations of L-arginine overcame the inhibition of urea production caused by endogenous NO synthesis. Exposure of HC to NO donors resulted in a concentration-dependent inhibition of glucose output, without having any effect on urea production. Hepatocellular glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity was also found to be inhibited by endogenously produced NO (33.5 +/- 5.2%), as well as by exogenously applied NO. However, an exact correlation between GAPDH activity and glucose output could not be established. These data indicate that NO biosynthesis may contribute to the development of hepatic dysfunction in chronic sepsis.

Animals↗
PubMed1995

[Immunosuppression and infection].

The course of prolonged sepsis is characterized by an initial activation of the immune system followed by the transition into a state of immunosuppression. Accordingly, a series of immunosuppressive substances can be detected in the serum of septic patients. On the cellular level many important functions of the unspecific as well as the specific defense systems of the organism are inhibited. As a consequence, immunosuppression may be contributing to the fact, that patients suffering from prolonged sepsis hardly recover with a high risk to end in multiple organ dysfunction. However, increasing efforts to investigate this problem may result in therapeutic approaches which may help to improve the bad prognosis of sepsis.

Humans↗
PubMed1992

[The effect of acute cellular rejection on liver function following orthoptic liver transplantation. Quantitative functional studies with the 14C-aminopyrine breath test].

To test the effect of acute cellular rejection on liver function as represented by cytochrome-P-450 enzyme activity, the 14C-aminopyrine breath test (ABT) was performed prospectively in 46 patients (31 men, 15 women; mean age 48 [15-66] years) who had undergone a total of 50 orthotopic liver transplantations. Routine biochemical tests were performed daily until the 30th postoperative day, while the ABT was done daily on days 1-10 and three times weekly on days 11-30, and liver puncture biopsies were obtained once weekly or more often if there was clinical suspicion of rejection. Histologically confirmed cellular rejection occurred within the stated period of observation in eight patients (five women, three men; median age 45 [18-59] years). Results of routine laboratory tests (transaminases, bilirubin, thromboplastin time), as well as bile-flow and body temperature, did not vary uniformly. On the other hand, results of ABT at the time of rejection showed a decrease in all patients by an average of 65% (P < 0.01). Changes in the ABT preceded those in other tests by 1-2 days in four patients, being the only measurable functional abnormality in one. All rejection episodes responded to glucocorticoid pulse-treatment (three times 1 g methyl-prednisolone). Using ABT results as criterion, liver function became normal after the glucocorticoid injection within 4-11 days. These data indicate that the ABT is suitable in the routine monitoring of transplant function, thus facilitating early diagnosis and controlled treatment of acute cellular rejection.

Acute Disease↗
PubMed1991

[Post-ischemia normal function of living related kidney transplants after preservation with HTK solution].

This study reports on the first clinical use of HTK preservation solution devised by Bretschneider in renal transplantation. Using this HTK solution, nine living related donor kidneys subjected to cold ischemia for up to 4 h were consecutively transplanted between 1987 and 1989. The postoperative function of the donor and recipient kidneys is analyzed. The endogenous creatinine clearance and the plasma creatinine level are used as function parameters. Within 24-48 h after transplantation a postischemic normal graft function occurred. With triple drug therapy the transplanted kidneys showed an increase in renal function identical with that in the donor's single remaining kidney. Within 7 postoperative days no perfusion damage and no HTK or CyA nephrotoxicity was observed.

Adult↗
PubMed1990

Direct evidence of a functional separation of alloreactive T lymphocytes from bystander cells infiltrating rat allografts. Interleukin 2 receptor-positive cells reacting with the monoclonal antibody ART 18 mediating second-set rejection.

In this study we examined the functional capacity of unseparated, IL-2R positive and IL-2R negative leukocytes infiltrating BN rat hearts or kidneys grafted into allogeneic LEW rats. Upon adoptive transfer into syngeneic LEW recipients, splenocytes or day-3 graft infiltrate cells of either cardiac or renal transplants were ineffective to alter BN cardiac test graft survival (controls 7.8 +/- 0.8 day). However, adoptive transfer of day-5 heart infiltrate cells resulted in a delay of test graft rejection (9.4 +/- 0.7 day, P less than 0.001), while day-5 kidney-graft-infiltrating cells produced second set rejection (6.2 +/- 0.5, P less than 0.001). Specificity controls of day-5 cells infiltrating DA heart or kidney grafts rejected at 7.8 +/- 0.8 or 7.7 +/- 0.5 days. Following separation into IL-2R positive and negative subpopulations by use of the mAB ART 18, IL-2R positive but not IL-2R negative cells caused second set rejection in both the renal and the cardiac model (6.2 +/- 0.4, respectively, 6.3 +/- 0.5 days, P less than 0.001 or P less than 0.005). Furthermore, in the kidney model IL-2R positive nylon-wool nonadherent cells also caused second set rejection (6.2 +/- 0.4, P less than 0.005) suggesting that IL-2R positive T cells present in the graft at maximal infiltration are the mediators of rejection. Thus, it appears that these cells can be phenotypically and functionally separated from bystander cells.

Animals↗