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M Messner

Publications and source records attributed to M Messner.

At least 37 records · Page 2Linked to original sources

Atherogenic properties of enzymatically degraded LDL: selective induction of MCP-1 and cytotoxic effects on human macrophages.

The mechanisms underlying the selective accumulation of macrophages in early atherosclerotic lesions are poorly understood but are likely to be related to specific properties of altered low density lipoprotein (LDL) deposited in the subendothelium. Enzymatic, nonoxidative degradation of LDL converts the lipoprotein to a potentially atherogenic moiety, enzymatically altered LDL (E-LDL), which activates complement and is rapidly taken up by human macrophages via a scavenger receptor-dependent pathway. Immunohistological evidence indicates that E-LDL is present in an extracellular location in the early lesion. We report that E-LDL causes massive release of monocyte chemotactic protein 1 (MCP-1) from macrophages and that expression of interleukin 8 or RANTES remains unchanged. Release of MCP-1 was preceded by a rapid expression of MCP-1 mRNA, which was detectable after 15 minutes, reached maximum levels after 1 hour, and remained detectable for 12 hours after exposure to concentrations as low as 10 microg/mL E-LDL. MCP-1 mRNA induction and protein release by E-LDL exceeded that evoked by oxidized LDL. Release of MCP-1 was dependent on de novo protein synthesis and on the activity of tyrosine kinases. At higher concentrations, E-LDL, but not oxidized LDL, exerted toxic effects on macrophages that in part appeared to be due to apoptosis. The results show that E-LDL possesses major properties of an atherogenic lipoprotein.

Arteriosclerosis↗

Evaluation of antiandrogen therapy in unresectable hepatocellular carcinoma: results of a European Organization for Research and Treatment of Cancer multicentric double-blind trial.

PURPOSE: The aim of the study was to evaluate the efficacy of antiandrogen therapy on overall survival and response in unresectable hepatocellular carcinoma (HCC). PATIENTS AND METHODS: A total of 244 patients with unresectable HCC were included in this multicentric double-blind trial. According to a two-by-two factorial design, patients were randomly assigned to receive one of the following treatments: pure antiandrogen plus placebo (A+P group, 60 patients); luteinizing hormone-releasing hormone (LHRH) agonist plus placebo (LHRH+P group, 62 patients); pure antiandrogen plus LHRH agonist (A+LHRH group, 62 patients); or placebo plus placebo (P+P group, 60 patients). Pure antiandrogen consisted of Anandron (Roussel-Uclaf Laboratory, Romainville, France) administered orally (300 mg daily for 1 month, then 150 mg daily). LHRH consisted of goseriline acetate (3.6 mg) or triptoreline (3.75 mg) administered monthly by subcutaneous injection. Treatment was given until death. Response was evaluated every 8 weeks according to World Health Organization (WHO) criteria. RESULTS: Six patients were considered ineligible. One patient had a complete response (A+P arm) and three had a partial response (two in the LHRH+P arm and one in the A+LHRH arm). An overall log-rank test did not demonstrate any significant difference in survival among the four arms. Taking the factorial design into account, comparison of survival showed no significant difference between Anandron-containing regimens and others, or between LHRH-containing regimens and others. No serious side effects occurred for any regimen. CONCLUSION: This controlled study shows clearly the lack of efficacy of androgen treatment in unresectable HCC.

Androgen Antagonists↗

Reduction of cyclosporine-induced gingival overgrowth following a change to tacrolimus. A case history involving a liver transplant patient.

During immunosuppression with cyclosporine, gingival overgrowth, a minor secondary effect, may appear in the first weeks of treatment. In certain cases it may affect the function and/or esthetic appearance in a manner intolerable to the patient. A new immunnosuppressive molecule, tacrolimus, presently used as a treatment of second choice to control acute corticoresistant rejection, may bring oral comfort to these patients, since it reduces gingival overgrowth to negligible levels.

Cyclosporine↗

[Epidemiology of hepatitis C virus infection in 1,304 HCV positive patients: variations according to the origin of transmission and year of diagnosis].

UNLABELLED: The evolution of epidemiological data on hepatitis C virus infection is poorly documented and thus the impact of screening is difficult to evaluate. AIM: To study epidemiological variations based on the origin of transmission and the year of diagnosis of hepatitis C virus infection. METHODS: The files of all 1304 patients seen in the hepatology unit of the Rennes University Hospital were analyzed (retrospectively before and prospectively after October 1995) in relation to epidemiological features. RESULTS: Despite widespread screening which is the source of 60% of the diagnoses, the total number of new cases of hepatitis C infection per year has not increased. Compared to patients diagnosed in the first years following the discovery of the virus, patients recently identified were younger (42 +/- 14 years) and frequently drug addicts (40%). Aminotransaminases were normal in 20% of cases. The frequency of cirrhosis has declined (17%). There has been a decrease in the proportion of patients who undergo liver biopsy (50%) and treatment with interferon (one third of patients). CONCLUSIONS: The impact of screening on the number of newly treated patients seems to be lower than previously predicted.

Adult↗

A reappraisal of hepatic siderosis in patients with end-stage cirrhosis: practical implications for the diagnosis of hemochromatosis.

The aim of this study was to describe the histologic pattern of iron distribution in end-stage cirrhosis due to various causes and to test the reliability of the hepatic iron index (equal to hepatic iron concentration divided by age) in excluding or confirming associated hemochromatosis in such a condition. Large slices of the resected livers of 30 patients transplanted for alcoholic and/or viral end-stage cirrhosis were assessed histologically for iron distribution and biochemically for hepatic iron concentration in the least and the most iron-overloaded nodules of each case. HLA-A3 was used as the marker for the hemochromatosis gene in the population studied. Intranodular parenchymal siderosis was found in 23 cases (12 spotty, 11 diffuse) with diffuse intrabiliary iron deposits apparent in only two cases. Although in 14 patients the hepatic iron index was significantly high (> 1.9) so as to suggest hemochromatosis, these cases did not correspond to homozygous hemochromatosis with respect to the prevalence of HLA-A3 antigen. End-stage cirrhosis arising from different causes is frequently complicated by parenchymal siderosis that may mimic hemochromatosis, including a hepatic iron index greater than 1.9. The diagnosis of hemochromatosis in patients with end-stage cirrhosis, even those with a hepatic iron index greater than 1.9, should rely mainly on clinical and histologic data.

Adult↗

Expression of active streptolysin O in Escherichia coli as a maltose-binding-protein--streptolysin-O fusion protein. The N-terminal 70 amino acids are not required for hemolytic activity.

Streptolysin 0 (SLO) is the prototype of a family of cytolysins that consists of proteins which bind to cholesterol and form very large transmembrane pores. Structure/function studies on the pore-forming cytolysin SLO have been complicated by the proteolytic inactivation of a substantial portion of recombinant SLO (rSLO) expressed in Escherichia coli. To overcome this problem, translational fusions between the E. coli maltose-binding protein (MBP) gene and SLO were constructed, using the vectors pMAL-p2 and pMAL-c2. MBP-SLO fusion proteins were degraded if secreted into the E. coli periplasm, but intact, soluble MBP-SLO fusion proteins were produced at high levels in the cytoplasm. Active SLO with the expected N-terminus was separated from the MBP carrier by cleavage with factor Xa. Cleavage with plasmin or trypsin also yielded active, but slightly smaller forms of SLO. Surprisingly, uncleaved MBP-SLO was also hemolytic and cytotoxic to human fibroblasts and keratinocytes. The MBP-SLO fusion protein displayed equal activities to SLO. Sucrose density gradient analyses showed that the fusion protein assembled into polymers, and no difference in structure was discerned compared with polymers formed by native SLO. These studies show that the N-terminal 70 residues of mature (secreted) SLO are not required for pore formation and that the N-terminus of the molecule is probably not inserted into the bilayer. In addition, they provide a simple means for producing mutants for structure/function studies and highly purified SLO for use as a permeabilising reagent in cell biology research.

ATP-Binding Cassette Transporters↗

[200 first hepatic transplantation at the Rennes University Hospital].

UNLABELLED: From 21st of april 1978 to 1st september 1994, 200 liver transplantations in 172 patients were performed in the Medical Center of University of Rennes. Three patients had a liver and kidney transplant. 26 patients received a second transplant (13%) and 2 patients a third transplant (1%). There were 110 males and 62 females with a mean age of 43.7 years (range 17 months-66 years). The indications of transplantations were the following: 22 fulminant hepatitis (12%), 104 cirrhosis (60.5%), including 41 alcoholic cirrhosis (24%), 21 post-hepatitis B cirrhosis (12.2%), 24 post-hepatitis C cirrhosis (14%), 6 autoimmune cirrhosis, 7 primary biliary cirrhosis (4%), 21 non A non B cirrhosis (12.9%), 3 undetermined cirrhosis. Thirty one patients had a liver transplantation for cancer. The other indications were 5 sclerosing cholangitis and 2 atresia of the biliary tract. 45% of the patients had an uneventful postoperative course. In hospital mortality rate is related to the indication and Child Pugh classification in cirrhotic patients. The vascular surgical complications were 8.5%, biliary complications 6.1%, intra-abdominal infection 9.2%, intra-abdominal bleeding 5.5%. The rate of reoperation was 18.5%. 23 re-transplantations were performed in emergency and 6 electively (one from outside). The overall survival of patients from 1978 to 1994, including the patients before cyclosporine era, the use of extracorporeal circulation, the preservation with Wisconsin solutions and with main indications for cancer was 69% at 1 year and 59% at 5 years. After 1988, the overall patient survival was 75% at 1 year and 70% at 5 years. The graft and patient survival is mainly related to the indications. In fulminant and subfulminant hepatitis, the quality of the graft was preferred as often as possible. The actuarial graft survival at 1 year, 3 years and 5 years was respectively 75%, 70.45% and 70.45%. The actuarial patient survival was 77.3%, 72.5% and 72.5%. In liver transplantation for cancer, the actuarial patient survival at 1 year, 3 years and 5 years is respectively 55%, 32% and 23.5%. 5 patients are alive and well at 5 years, including a patient who underwent a Cluster operation for Klatskin tumor. In post-hepatitis cirrhosis, the patient actuarial survival at 1 year, 3 years and 5 years was 79%, 76.5% and 76.5% and in alcoholic cirrhosis 75%, 72% and 72%. The actuarial survival is closely related to Child Pugh Classification (at one year Child A 87%, Child B 72.4%, Child C 58%). CONCLUSION: in this series of the first 200 liver transplants at the University of Rennes Medical Center, graft and patient survival depends on the evolution of the surgical technic but it is also closely related to the indication. In fulminant hepatitis, the quality of the graft (without incompatible graft, if possible) should permit to avoid retransplantation and to obtain results closely to the elective transplantation. Liver transplantation for cancer should be restricted. In cirrhosis, results are depending upon Child Pugh classification. The conclusions of Paris consensus conference should be followed. The limited number of donor livers call for the "priorization" (T.E. Starzl) favoring those patients who will benefit most, i.e., patients with the most serious conditions and the poorest short term vital prognosis.

Adolescent↗

["De novo" cancer after organ transplantation].

From March 1972 to 1st of January 1996, 804 kidney, liver and pancreas transplants were performed in 690 patients. 39 post transplant cancers occurred in 27 patients. 21 skin tumors (15 squamous cell carcinoma, 4 basocellular carcinomas, 1 squamous carcinoma, 1 melanoma), 4 squamous cancers (anus, esophagus, tongue, and parotid), 4 post-transplant lymphoproliferative disorders, 1 non-Hodgkin's lymphoma T, 4 gynecological tumors (breast, ovarian peritoneal carcinomatosis, 2 uterine cervix cancers), 4 miscellaneous tumors (larynx, right colon, brain, prostate, own kidney). 14 patients died (14/27: 52%). Post transplant de novo cancers are a major risk in transplant patients These cancers are mainly represented by skin tumors and lymphomas. Skin cancers are mainly spinocellular and occur in the areas which are exposed to the sun. Post transplant lymphoproliferative disorders are very close to Burkitt's lymphoma, they produced B lymphocyte proliferation due to the reduction of the control of T lymphocytes and induced by Epstein-Barr virus. They can disappear with the diminution of immunosuppression.

Adult↗

Different forms of streptolysin O produced by Streptococcus pyogenes and by Escherichia coli expressing recombinant toxin: cleavage by streptococcal cysteine protease.

To resolve apparent discrepancies in the literature, N-terminal sequences of the active high- and low-molecular-weight (high- and low-M(r)) forms of native streptolysin O (nSLO) purified from Streptococcus pyogenes culture supernatants and of the similar-size high- and low-M(r) forms of recombinant SLO (rSLO) found in the periplasm of Escherichia coli expressing a cloned slo gene were determined. The high-M(r) forms of nSLO and rSLO are identical, reflecting removal of a 31-residue signal peptide, but the similar-size low-M(r) forms are very different. Removal of C-terminal sequences by proteases in the E. coli periplasm produces an inactive low-M(r) form of rSLO. In contrast, an active low-M(r) form of nSLO is produced by proteolytic cleavage between the N-terminal residues Lys-77 and Leu-78, which was shown to correspond to an extremely sensitive cleavage site for the pyrogenic exotoxin B-derived streptococcal cysteine protease.

Amino Acid Sequence↗

Evaluation of efficacy of liver transplantation in alcoholic cirrhosis by a case-control study and simulated controls.

To assess the efficacy of liver transplantation in patients with alcoholic cirrhosis, we compared 2-year survival of 169 liver transplantation patients in 12 French centres with survival of two control groups treated conservatively. The matched group was 169 patients of similar age, cirrhosis severity, and bleeding history; the simulated group was 169 patients whose theoretical survival was determined in a cohort of 797 patients with alcoholic cirrhosis. The probability of survival to 2 years in transplanted patients was 73 (95% confidence interval 67-79%) versus 67% (59-75) in the matched and 67% (63-71) in simulated controls. When prognostic factors were taken into account, transplantation was associated with survival (r = 0.527; p = 0.069). Patients with severe liver disease (high-risk group) benefited most for 2-year survival: 64% (42-86) vs 41% (23-59) in the matched and 23% (19-27) in the simulated control groups (p < 0.01). There was no difference for patients at low and at medium risk. Liver transplantation increases the 2-year survival of patients with severe alcoholic cirrhosis. In patients with less severe disease, further studies should be done by non-randomised controlled studies with longer follow-up or by randomised trials.

Adult↗

Liver transplantation for severe Lepiota helveola poisoning.

Orthotopic liver transplantation in patients with fulminant hepatic failure secondary to Lepiota helveola poisoning has not, to our knowledge, been reported. Our recent experience with liver transplantation in a 27-year-old woman with acute hepatic failure secondary to this poisoning is described. The indications for orthotopic liver transplantation are discussed.

Adult↗

Altered pore-forming properties of proteolytically nicked staphylococcal alpha-toxin.

Staphylococcal alpha-toxin is a single-chain polypeptide with a molecular weight of 34,000 that hexamerizes in lipid bilayers to form pores of 1-1.5 nm effective diameter in membranes. We demonstrate that limited proteolysis of purified alpha-toxin with proteinase K generates a hemolytically active product that yields one major protein band of 17-18 kDa in SDS-polyacrylamide gel electrophoresis. The 17-18-kDa protein band harbors two major fragments of similar size representing the N- and C-terminal halves, which remain associated with each other in non-denaturing buffers but dissociate in 6 M urea. Dissociation in urea leads to loss of hemolytic activity. In contrast, unnicked alpha-toxin is not inactivated by urea. Nicked, hemolytically active alpha-toxin forms hexamers on erythrocyte membranes and on lymphocytes and monocytes. However, the nicked toxin can only lyse erythrocytes and fails to permeabilize nucleated cells. Osmotic protection experiments indicate that the size of pores generated by the nicked toxin is considerably smaller (0.6-0.9 nm effective diameter) than that generated by native toxin. The collective results do not support a previous proposal that different functions of alpha-toxin are contained in separate domains of the molecule.

Bacterial Toxins↗

Chemoembolization of hepatocellular carcinomas. A study of the biodistribution and pharmacokinetics of doxorubicin.

BACKGROUND: This study evaluated the effects of an association of ethiodized oil (Lipiodol Ultra Fluide, Laboratoires Guerbet, Aulnay-sous-Bois, France), with or without gelatin sponge, with doxorubicin (Adriamycin, Adria Laboratories, Columbus, OH) on the biodistribution and kinetics of doxorubicin during intraarterial injection. METHODS: Eighteen patients with hepatocellular carcinoma on cirrhotic liver received a therapeutic injection into the hepatic artery of 50 mg of doxorubicin alone (Group 1; n = 4), or emulsified in 10 ml of ethiodized oil and 2.5 ml of ioxaglate (Hexabrix, Laboratoires Guerbet) with (Group 2; n = 7) or without (Group 3; n = 7) gelatin sponge embolization. Before treatment, the absence of intrahepatic shunts was verified by an injection of technetium-labeled albumin macroaggregates. The biodistribution of doxorubicin was studied on two fronts: (1) pharmacokinetic--by measurement of the doxorubicin blood level during the 48 hours after injection; and (2) scintigraphic (2 mg of doxorubicin were labeled with 2 mCi of iodine 131)--by examination of the scintigrams and calculation of the following parameters: tumours liver/nontumorous liver binding ratio (T/NT ratio), liver/liver+lungs+abdomen binding ratio, and doxorubicin half-life in tumorous tissue. RESULTS: Pharmacokinetics results showed the following: the peak plasma concentration was significantly higher in Group 1 as compared with Groups 2 or 3 (Group 1: 2.1 +/- 0.9 mg/ml; Group 2: 0.9 +/- 0.3 mg/ml; Group 3: 0.5 +/- 0.2 mg/ml); the area under curve calculated from time zero to 1 hour was lower in Groups 2 and 3 compared with Group 1. Examination of the scintigrams showed the following: diffuse activity throughout the organism (Group 1), diffuse activity with strong hepatic and tumorous binding (Group 2), and mostly hepatic and tumoral binding (Group 3). The liver/liver+lungs+abdomen binding ratio was 28% +/- 1% in Group 1, 36% +/- 5% in Group 2, and 63% +/- 7% in Group 3. The T/NT ratios were 1.0 +/- 0 (Group 1), 1.5 +/- 0.1 (Group 2), and 4.7 +/- 0.5 (Group 3). The doxorubicin half-lives in tumourous tissue were 0.7 +/- 0.1 days (Group 1), 1.8 +/- 0.2 days (Group 2), and 2.6 days (n = 1; Group 3). CONCLUSIONS: This study shows (1) that the association of ethiodized oil with doxorubicin lowers the peak concentration of doxorubicin and increases the intratumoral concentration and half-life of doxorubicin, and (2) that these kinetic ameliorations are even more pronounced after embolization. Therefore, from a kinetic standpoint, the doxorubicin-ethiodized oil-gelatin sponge association is the best.

Aged↗

Magnetic resonance imaging and assessment of liver iron content in genetic hemochromatosis.

Computed tomography (CT) scanning is not highly sensitive in the assessment of liver iron content and magnetic resonance imaging (MRI) appears to be more efficient. The aim of this study was to determine the effectiveness of MRI in the evaluation of liver iron content using a standard spin-echo technique. The study included 23 patients with genetic hemochromatosis and 24 non-iron-overloaded patients as controls. A comparison was made of: (a) MRI signal intensity of liver, spleen, paravertebral muscles and subcutaneous adipose tissue using two different spin-echo sequences (SE 500/28; SE 2000/28,56); (b) liver attenuation determined by a single energy CT scan; and (c) a biochemical determination of hepatic iron. There was a significant decrease in liver signal intensity in the genetic hemochromatosis group (256 +/- 201, mean +/- S.D.) compared with the control group (801 +/- 413, p less than 0.001), but there was no correlation with liver iron concentration. However, such a correlation was found and was even more highly significant than in CT when the ratio between the liver and another organ was taken into account. For a lower limit of liver/spleen ratio calculated at 0.46 (mean 2 S.D. in the control group), the specificity (0.96) of MRI was satisfactory, but the sensitivity (0.78) remained insufficient (MRI being unable to detect an iron overload of up to 125 mumol/g). Hopefully, these results might be improved in the near future by using more sensitive sequences such as gradient echo sequences.

Adipose Tissue↗

Analysis of complement C3 activation products in human atherosclerotic lesions.

Cleavage of the complement C3 protein is essential for complement activation. Saline extracts of human atherosclerotic lesions were examined by various techniques for the presence of C3 cleavage fragments. Crossed intermediate gel immunoelectrophoresis revealed that native C3 was the predominate C3 protein in extracts and that the C3dg fragment was also detected. SDS-PAGE/Western blot analyses of lesion extracts employing monoclonal antibodies directed at C3c and C3dg fragment determinants demonstrated molecular weight bands corresponding to the known molecular weights of all the physiologic C3 cleavage fragments, except C3b which is known to have a short half-life. After C3, the two most common fragments observed were C3c and C3dg. No bands other than those corresponding to known C3 cleavage fragments were observed and control antibody stains were always negative. In some blots bands with a greater molecular mass than C3 were evident, indicating that some of the C3 in lesions may be covalently bound to an activator. We have previously identified a large (100-500 nm) nonapoprotein containing lipid particle (LCA) as a major complement activating structure in human atherosclerotic lesions. Fractionation of lesion extracts by molecular sieve chromatography and sucrose density gradient centrifugation failed to reveal a concordance between LCA and C3 antigens. The results indicate that complement activation, i.e. C3 convertase formation, takes place in human atherosclerotic lesions and that activated C3 is degraded according to normal complement regulatory mechanisms.

Arteries↗

Short-term prednisolone followed by recombinant human alpha-interferon alone or combined with adenine-arabinoside in chronic hepatitis B. A prospective and randomized trial.

Twenty-nine patients with chronic hepatitis B, presenting both hepatitis B surface antigen and hepatitis B virus deoxyribonucleic acid in serum, were studied in a randomized trial treatment consisting of oral prednisolone for 28 days followed 14 days after steroid withdrawal, by either a 55 s.c. injection course of 5 M unit recombinant human alpha-interferon (group 1, 14 patients) or by adenine-arabinoside (for 21 days) combined from the fourteenth day on with the same 55 s.c. injection schedule of interferon (IFN) (group 2, 15 cases). The two groups were well matched with respect to demographic, biochemical, virological and histologic features. Significant side-effects leading to premature discontinuation of interferon were observed in only four cases in group 2 and were always reversible. Efficacy was judged on a mean follow-up period of 17 months. For the whole population, 17 patients (59%) exhibited a sustained serum hepatitis B virus deoxyribonucleic acid disappearance which corresponded to a marked improvement in liver function as demonstrated by a quasi-normalization of their serum transaminase values (ALT with n less than 22 UI/l: 23 +/- 24 vs. 139 +/- 115 before treatment; P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗