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Biomedical subjects

M Chevallier

Publications and source records attributed to M Chevallier.

At least 91 records · Page 5Linked to original sources
PubMed1989

Morphometry of terminal hepatic veins. 1. Comparative study in man and baboon.

In the present study, hepatic venous distribution per unit of liver surface area on normal wedge biopsies from man (n = 11) and baboon (n = 8) were analysed and compared. Terminal hepatic veins (THV - man: n = 100; baboon: n = 200) morphometric size variables were obtained with a Leitz ASM 68K morphometric equipment. THV, defined as hepatic veins up to 150 microns in internal diameter (ID), in the centrolobular position and with sinusoidal openings, represented 84% and 74% of hepatic veins of man and baboon, respectively. Four or more THV were generally found on 8 mm2 of liver surface. Transversely sectioned THV selected by the ratio IDminimum/IDmaximum greater than 0.67, was found to be only 25% of the total THV. In baboon, THV merge with other terminal veins and the interlobular veins present sinusoidal inlets. The baboon THV wall surface (WS) and wall thickness (WT) values were higher than in man. Positive correlations between the number of mesenchymal cells (Mc) in the vein wall and wall surface of terminal hepatic veins (man: r = 0.79; baboon: r = 0.83) and between wall surface and internal surface (IS) (man: r = 0.80; baboon: r = 0.72) were found. Two ratios were selected as the most reliable parameters: (1) for the THV wall rim, wall surface/internal surface (WS/IS - man: 0.43 +/- 0.16; baboon: 0.63 +/- 0.23), regarding transversely sectioned THV; and (2) for the evaluation of wall cell density (WS/Mc-man: 550 +/- 231; baboon: 558 +/- 183 micron 2/cell) as they did not depend on THV caliber.

Adult↗
PubMed1989

Morphometry of terminal hepatic veins. 2. Follow up in chronically alcohol-fed baboons.

Alcohol induced perivenular fibrosis of terminal hepatic veins (THV) is claimed to be a precursor lesion leading to fibrosis development in man and baboon. The nature and significance of the THV lesions found in four baboons chronically fed with alcohol were studied in liver biopsies obtained during a three year period. The surface of THV wall and the number of mesenchymal cells were assessed with a semi-automatic image analyser. Histologically, THV were characterized as (a) phlebitic, in the presence of an inflammatory cell infiltrate involving the venous wall; (b) oedematous, when the connective tissue of the THV wall was disrupted or dissociated and (c) fibrotic, when perivenular scarring appeared as an increased rim. These lesions were present simultaneously and their intensity and distribution were independent of the duration of alcohol intoxication. Morphometric data obtained from these THV confirmed the thickening of the THV wall (WS/IS in: oedematous 1.05 +/- 0.36; phlebitic 1.65 +/- 1.04; fibrotic 1.47 +/- 0.36); and revealed an increased number of mesenchymal cells in fibrotic (439 microns 2/cell; p less than 0.01) and in phlebitic THV (510 microns 2/cell; p less than 0.05). A constant relationship was found between phlebitis and the presence of inflammatory infiltrate within the hepatic acini. Fibrotic THV was a less frequent finding and the lesion disappeared in the sequential biopsies of one of the baboons. In conclusion, THV lesions were heterogeneous and the collagen deposition in the THV wall was potentially reversible during the three year alcohol intoxication period, regardless the inflammatory reaction and, thus, did not indicate early irreversible hapatic fibrosis.

Alcoholic Intoxication↗
PubMed1988

Immunohistochemical micromethods for the measurement of specific collagen types in human liver biopsies.

Micromethods are needed for measuring the amount of collagen and other matricial proteins in human liver biopsies. Recently, a colorimetric method for the quantitative estimation of total collagen and protein has been developed. This method is sensitive, can be applied to fresh and fixed tissues and provides the absolute value of total collagen per section. Results are expressed as microgram of collagen per mg of proteins or per section. We now report two micromethods for the determination of specific collagen types in fresh frozen liver sections. The first method is a direct method utilizing the tissue section as an ELISA plate. Results are expressed as the amount of color reaction read at 450 nm per slide. After cleaving the antigen antibody complex with dilute acetic acid, the amount of total collagen can be measured by the colorimetric microchemical method and the amount of specific collagen type is expressed as the amount of color reaction per microgram of total collagen. The second method is an indirect method: the floating tissue section is incubated with an optimal amount of specific anti-collagen antibody and the residual amount of antibody present in the supernatant is measured in an ELISA plate coated with the specific collagen type. The amount of specific collagen type present in the tissue section is determined by comparing the optical deviation obtained with a standard curve prepared with known amounts of specific collagen, and values are expressed as microgram of collagen per tissue sections. As with the direct method, the amount of total collagen per section can be measured by the colorimetric method and then, the amount of specific collagen type can be expressed as microgram of specific collagen type per microgram of total collagen.

Biopsy, Needle↗
PubMed1987

Study of e+

Explore the source record for details and available documents.

Journal Article↗
PubMed1986

Therapeutic activity of vidarabine in symptomatic chronic active hepatitis related to HBV.

The potential inhibitory effects of nucleoside analogues such as ARA-A and acyclovir on HBV-DNA-polymerase were first demonstrated in vitro and then confirmed in vivo in open dose finding studies. The therapeutic efficacy of both ARA-A and ARA-AMP which appeared the most potent drugs was then confirmed by various studies in symptomatic HBeAg-positive patients. These studies demonstrated a similar benefit of therapy with 38 and 40% of treated patients given ARA-A and ARA-AMP, respectively, who permanently cleared HBV replication after a single course, and 67-80% who did so after two courses. Significant improvement in transaminases and histologic activity was also documented (P less than 0.001). Myalgias were observed in 10 and 30% of the patients, respectively. Patients who failed to respond to nucleosides, and those coinfected with HDV, were treated with interferons. Out of 8 cases of HDV/CAH given 5 MU thrice weekly of fibroblast beta-interferon (UPSA) for 3 months, DNA-p activity fell transiently in all 6 initially elevated cases. A parallel decrease in anti-HD titers (P less than or equal to 0.05), inflammation (P less than or equal to 0.001) and necrosis (P less than or equal to 0.05) were observed. alpha-Recombinant interferon was given i.m. for 4 months (2-7 MU/m2 X 2/7 days) to 10 CAH with high DNA-p values. HBV replication was permanently inhibited in 4 cases and dramatically reduced in 3 additional patients. Three failed to respond. Careful monitoring of DNA-p values appeared to be the single most important factor in assessing activity.

Clinical Trials as Topic↗
PubMed1986

Human extrahepatic biliary atresia: portal connective tissue activation related to ductular proliferation.

Surgical bile flow restoration in extrahepatic biliary atresia (EHBA) does not prevent the development of ongoing hepatic fibrosis and cirrhosis. Portal connective matrix was studied on liver biopsies obtained from seven children submitted to portoenterostomy. Electron microscopy and immunohistochemical techniques (using specific antibodies directed against collagen isotypes and associated glycoproteins) were performed. The study of extracellular and cellular components of connective matrix demonstrated the existence of two distinct areas according to their situation with regard to ductular proliferation: loose connective matrix--mainly composed of fibronectin, type III collagen, type IV collagen and laminin--associated with microvessels and myofibroblasts proliferation characterized periportal zones adjacent to bile ductules; in areas distant from ductular proliferation, connective matrix appeared dense, composed of type I and type III collagen associated with fibroblasts. The connective matrix pattern observed in periductular areas can be compared to that described in cicatricial and hypertrophic processes where the myofibroblastic cell population is known to play an important role in fibrosis development. Although the connective matrix activation process remains unclear in EHBA, it may be suggested that activation of a connective tissue cellular clone might be responsible for this portal fibromatosis.

Bile Ducts↗
PubMed1979

[Study of a new case of male pseudohermaphroditism due to 17-ketosteroid reductase deficiency (author's transl)].

We studied a 17 year old patient with primary amenorrhea, hirsutixm, clitoral enlargment, poor breast development and 46, XY karyotype. The results shown in table clearly indicate a 17-ketosteroid reductase deficiency. In the view of previously described patients we can conclude that: 1) intensity of virilisation depends on both plasma testosterone and androstenedione levels; 2) importance of gynecomastia depends on plasma E2 but not E1 levels; 3) FSH levels are not correlated with circulating androgens or estrogens but presumably depends on importance of seminiferous tubules' lesions.

17-Hydroxysteroid Dehydrogenases↗
PubMed1979

[Ultrastructural pathology of the liver in shock].

Ultrastructural findings in shock liver are in general very similar to data in the literature concerning experimental ischaemia in the animal. It is firstly a cellular disease which leads to a tissue disease, reflected morphologically by definitive and irreversible signs in the absence of hepatocellular regeneration. Assessment on the cellular scale of lesions of ischaemia may be used to define the potentially reversible nature of certain signs and should be adpated to the study of the cellular effects of therapeutic measures. By contrast, in practical terms it cannot be used for the quantitative assessment of the spatial extent of lesions within the hepatic acinus.

Humans↗
PubMedDate not supplied

Clinical consequences of hepatitis C virus infection.

Hepatitis C virus (HCV) is a positive strand RNA virus that belongs to the Hepacivirinae genus within the Flaviviridae family. HCV infection has a wide spectrum of cellular tropism and clinical presentations. This has major impacts in terms of pathogenesis and diagnosis. Consequently, a wide range of clinical consequences characterises this viral infection, including asymptomatic chronic carriage, acute hepatitis, chronic hepatitis, cirrhosis, hepatocellular carcinoma and extrahepatic manifestations. The latter are commonly observed and may represent the first sign of the disease. A better knowledge of the pathobiology of HCV and its clinical consequences will be important for developing better treatment strategies to cure HCV infection and extrahepatic manifestations.

Genetic Variation↗
PubMedDate not supplied

Small nodule detection in cirrhotic livers: evaluation with US, spiral CT, and MRI and correlation with pathologic examination of explanted liver.

PURPOSE: The purpose of this work was to evaluate the detection and characterization of nodules > or = 8 mm and small hepatocellular carcinomas (HCCs) in liver cirrhosis. METHOD: Pathologic examination and results of US, helical CT, and dynamic MRI with gadolinium were compared after orthotopic liver transplantation (OLT) of 43 cirrhotic patients. Nodules were classified as macroregenerative nodules (MRNs), borderline nodules (BNs), and HCC. RESULTS: Pathologic examination classified 69 nodules: 50 MRNs, 6 BNs, and 13 HCCs. Sensitivities of MRN, BN, and HCC detection were, respectively, for US imaging 2% (1/50), 33.3% (2/6), and 46.2% (6/13); for helical CT 2% (1/50), 50% (3/6), and 53.8% (7/13); and for MRI 42% (21/50), 50% (3/6), and 76.9% (10/13). MRI detected 21 MRNs. They presented on T1/T2-weighted images as hyperintense/hypointense (n = 8), hyperintense/isointense (n = 7), hypointense/hypointense (n = 4), hypointense/isointense (n = 1), and hypointense depicted only on echo planar imaging (n = 1). The three detected BNs were hyperintense/hypointense nodules. The 10 detected HCCs appeared hyperintense/isointense (n = 7), hyperintense/hypointense (n = 2), and hypointense/isointense (n = 1). None of the MRNs but eight HCCs and one BN were enhanced after gadolinium injection. CONCLUSION: Contrast-enhanced MRI is the most sensitive technique for detecting liver nodules. No MR signal intensity pattern characteristic of small HCCs enables differentiation from benign nodules, however. Gadolinium enhancement is the most sensitive and specific characteristic of HCC.

Adult↗
PubMedDate not supplied

Hepatic cytolytic and cholestatic changes related to a change of lipid emulsions in four long-term parenteral nutrition patients with short bowel.

Long-term parenteral nutrition hepatic-related impairment is commonly reported and diversely explained. However, with a low cyclic caloric intake (100% to 130% of basal metabolism calculated with the Harris-Benedict formula) consisting of two-thirds glucose, one-third lipid, and 0.20 to 0.25 g of nitrogen per kilogram per day, these complications were infrequent in a clinical practice of home long-term parenteral nutrition. Retrospectively, it was noticed that the switch from Intralipid 20% to Ivelip 20% at the same amount was followed within 2 months by four cases of jaundice in a population of four home long-term parenteral nutrition patients with short bowel disease. Hepatic disturbances were characterized by cytolysis and cholestasis and were reversible after switching from Ivelip 20% back to Intralipid 20%. Neither viral, nor biliary, nor septic etiologies were detected. The exact pathological mechanism remains unknown. The basal composition of both lipid emulsions seems to be identical: soy oil emulsion emulsified by egg phospholipids. However, some differences exist such as the size of particles, the presence of sodium oleate in Ivelip 20%, and the purification process of lecithin. These may explain the difference in hepatic tolerance during long-term parenteral nutrition.

Adult↗
PubMedDate not supplied

[Vidarabine treatment of chronic active hepatitis associated with hepatitis B virus multiplication. A randomized multicenter study].

A randomized controlled study of one course of vidarabin was carried out in 30 patients with HBs Ag, HBe Ag, DNAp, positive chronic active hepatitis: 15 patients were treated with vidarabin given intravenously (15 mg/kg/day for 7 days then 7.5 mg/kg/day for 14 days); the other 15 patients received a placebo for 21 days. During treatment, DNA polymerase activity fell dramatically in 13 treated patients and in no controls (p less than 0.001). Six months after inclusion, ALT normalization was observed in 40 p. 100 of the treated patients and 6 p. 100 of the controls (p less than 0.05), a decrease in inflammatory activity on liver biopsies was observed in 70 p. 100 of the treated patients and 20 p. 100 of the controls (p less than 0.05), a permanent lost of DNA polymerase and of HBe Ag occurred in 33 p. 100 and 13 p. 100 of the treated patients and 20 p. 100 and 7 p. 100 of the controls, respectively. In addition, a second course of vidarabin was administered to the 12 patients who were still HBe Ag positive 6 months after the first course. During the next 6 months, 8 patients lost DNA polymerase and 4 lost HBe Ag. Altogether, the final score of durable inhibition of HBV replication was 11/15 (73 p. 100) within one year. The above results demonstrate that one course of vidarabin can significantly improve ALT and liver inflammatory activity but the effect upon HBV replication is only transient. A second course does however increase efficacy on HBV replication without additional side effects.

Adult↗