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Biomedical subjects

M Messner

Publications and source records attributed to M Messner.

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

[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↗
PubMed1997

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↗
PubMed1996

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↗
PubMed1996

[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↗
PubMed1996

["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↗
PubMed1995

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↗
PubMed1994

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↗
PubMed1994

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↗
PubMed1993

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1991

[Indications and results of hepatic transplantation for cancer].

From April 1978 to 1st October 1990, 19 patients underwent liver transplantation for primary or secondary cancer of the liver. Eleven patients were transplanted for hepatocellular carcinoma secondary to cirrhosis, generally alcoholic (9 cases), hepatitis B (1 case) or secondary to haemochromatosis (1 cas). Three patients developed hepatocellular carcinoma in a normal liver, including one fibrolamellar cancer and three a proximal bile duct cancer. Lastly, two patients received a graft for secondary cancer from a colonic adenocarcinoma and a carcinoid tumour of the right colon. The operative mortality was nil for the transplantations for cancer in a normal liver, but there were 4 deaths out of the 11 cases of cancer secondary to cirrhosis. The actuarial survival of the overall series was 55% at 1 year and 31% at 2 years. The poorest survival was observed for cancers in a normal liver, with the exception of the fibrolamellar cancer in which recurrence was delayed. The longest survival was observed for cancers secondary to cirrhosis. At three years, the results of liver transplantation were equal to those of hepatic resections with a survival of 37%, despite the fact that the transplantation was generally performed for very large tumours.

Adult↗
PubMed1990

Traditional management of liver disorders.

Dietary measures have achieved mixed results in the management of liver disorders. Although a high energy diet may shorten the course of viral hepatitis by a relatively small amount, dietary restriction is usually of no benefit in compensated cirrhosis. Restriction of sodium intake to 22 to 60 mol/day leads to resolution of cirrhotic ascites in approximately 20% of patients, and reduces the requirement for diuretics in the remainder. In advanced liver disease, diet plays an important role in the avoidance of portal-systemic encephalopathy (PSE), with the tolerance of most nutrients, most importantly protein, being sharply reduced. Despite the frequent presence of carbohydrate intolerance in liver disease, carbohydrate supplementation may be required to ensure adequate utilisation of the reduced dietary protein intake. Zinc supplementation may also be required in liver cirrhosis to compensate for a deficiency. Bed rest is an important component of the management of acute and chronic liver disorders, together with the avoidance of fatigue. Abstinence from alcohol is required in alcoholic liver disease patients, who should receive parenteral thiamine 100 mg and other vitamin and mineral supplementation as required. Agents acting on the ascending loop of Henle [such as furosemide (frusemide)] or the distal tubule (such as spironolactone) are the diuretics most frequently employed to mobilise ascites in cirrhosis, the latter drug being the more effective in nonazotaemic patients. In the absence of oedema, the diuresis should be restricted to a maximum of 750 ml/day; however, patients with oedema may safely undergo a diuresis of less than or equal to 1.5 L/day. Diuretic therapy is often associated with renal complications, such as azotaemia (usually reversible) and severe hyponatraemia in cirrhotic patients with ascites; spironolactone may produce antiandrogenic adverse effects. Lactulose, used in the treatment of acute and chronic PSE, acts by inhibiting gastrointestinal absorption of ammonia and other toxic nitrogenous substances, and by reducing urea degradation. Other pharmacological treatments, such as branched-chain amino acids and benzodiazepine antagonists have a limited role in the management of PSE. Chronic cholestasis has been treated with cholestyramine and fat-soluble vitamins, whereas ursodeoxycholic acid appears to be a promising agent in the treatment of primary biliary cirrhosis. In chronic hepatitis, the prevention of development of cirrhosis is a primary treatment goal which has been attempted with variable success using antifibrotic drugs such as penicillamine and colchicine.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenal Cortex Hormones↗
PubMed1989

[Uncommon arterial and venous reconstruction in liver transplantation].

The aim of this work was to define the best technical options of reconstruction that we can proposed in front of an anatomical or parietal anomalies of venous or arterial system in hepatic transplantation. Through a retrospective study of 10 reconstructions performed between 1978 and 1989, we observed 5 cases of right hepatic artery from superior mesenteric artery of the donor. The two basic methods of reconstruction were either the "fold over" technic of Gordon or the realization of an end to end anastomosis between donor's right hepatic artery and donor's splenic artery. In 3 cases, the insufficiency of the hepatic arterial blood flow after classic anastomosis, led us to employ an arterial iliac graft between the recipient's aorta and the donor's coeliac patch. 2 patients with portocaval shunt or portal parietal defect underwent reconstruction by venous iliac graft. In conclusion, we emphasize the importance of a perfect reconstructed reconstruction as much on the anatomical level than functional.

Arteriovenous Malformations↗