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Biomedical subjects

C Balabaud

Publications and source records attributed to C Balabaud.

At least 109 records · Page 6Linked to original sources
PubMed1986

The sinusoidal barrier in alcoholic patients without liver fibrosis. A morphometric study.

Alcohol induces morphological changes in the endothelial and perisinusoidal cells at the fibrotic stage of alcoholic liver diseases. Directly or indirectly, through hemodynamic disturbances linked to the enlargement of steatotic hepatocytes, alcohol may modify this barrier before the onset of fibrosis. Liver biopsies were obtained from control and from alcoholic patients and perfusion-fixed. Volume and surface densities of endothelial cells, perisinusoidal cells and their processes were measured. Liver histology was normal in the 2 groups except for steatosis in the alcoholics. Volume densities represented 8.2%, 4.7% and 3.2% of the sinusoid in controls for endothelial cells, perisinusoidal cells and their processes whereas surface densities represented respectively 0.5, 0.23, 0.21 m2/cm3 of sinusoid. Morphometric values were not significantly different in the alcoholic patients. In none of the alcoholic patients did fine morphological studies of sinusoidal cells give any indication of the possible evolution of the alcoholic disease towards fibrosis. These results indicate that in the group of patients studied, alcohol, before the fibrotic stage, did not significantly alter the sinusoidal barrier.

Adult↗
PubMed1986

Perisinusoidal cells in patients with normal liver histology. A morphometric study.

We measured the number and the morphometric characteristics of perisinusoidal cells in perfusion-fixed biopsy samples from 7 control patients with normal liver histology. On 1-micron section, the number of cells was 18 +/- 1.5/0.1 mm2; 25% of cells did not apparently contain lipids. There were no significant zonal differences. The volume density of the cells represented 1 +/- 0.2% of the hepatic parenchyma. On ultrathin sections, the volume and surface densities of processes were 3.2 +/- 0.7% of sinusoid and 0.21 +/- 0.04 m2/cm3 of sinusoid respectively which represented 70% and 90% of total PSC volume and surface densities. Lipid volume density was 20.5 +/- 7.3% of the nucleated cell. More than 30% of cells contained less than 10% of lipids. There was no correlation between lipid volume density and RER surface density.

Adult↗
PubMed1986

Ultrastructure of sinusoidal cells in a benign liver cell adenoma.

A typical benign liver cell adenoma was removed from a 25-year-old female taking an oral contraceptive. The biopsy was perfusion-fixed, allowing good visualization of sinusoids and sinusoidal cells. Kupffer cells were seldom seen. Endothelial cells were of irregular thickness; most of them had few fenestrae and were attached to each other by well visible junctions. Normal perisinusoidal cells (PSC) were not seen but were replaced by myofibroblast-like cells with thick subendothelial processes. A basement membrane often underlaid endothelial cells and the processes of PSC. The enlarged Disse space with a flattened sinusoidal hepatocyte membrane contained occasional red blood cells and an abundant extracellular matrix but few collagen fibers. These sinusoidal abnormalities leading to the capillarization of sinusoids, either the cause or the consequence of the disease, indicated a loss of normal hepatocyte homeostasis.

Adenoma↗
PubMed1986

Sinusoids ultrastructure of human hepatocellular carcinoma.

Sinusoids ultrastructure was studied in a case of hepatocellular carcinoma developed in the non cirrhotic liver of a 40-year-old man. The surgical biopsy was perfusion-fixed with 1.5% glutaraldehyde. The number of Kupffer cells was very low. Endothelial cells with signs of hyperactivity were very irregular; digitations were often attached by numerous well identified junctional complexes to their own cell processes or to adjacent cell processes. Perisinusoidal cells without lipids resembled fibro-myofibroblasts. Discontinuous basement membranes underlaid endothelial cells and perisinusoidal cells. In addition numerous strands of short basement membranes segments were seen in the Disse space. Well organized bundles of collagen were not seen. The sinusoidal membranes of hepatocytes were flattened. The perfusion-fixation revealed to be a very useful technique in the identification of all these changes which have also been reported to some degree in benign liver cell adenoma and in cirrhosis; these two conditions are known to be associated with hepatocellular carcinoma.

Adult↗
PubMed1986

Ultrastructure of sinusoids in patients with agnogenic myeloid metaplasia.

Four patients with agnogenic myeloid metaplasia underwent liver biopsies. Under light microscopy, sinusoidal infiltration was very mild or moderate, liver architecture was normal with sinusoids slightly dilated and the perisinusoidal collagen network was increased. Under electron microscopy, in perfusion-fixed sinusoids, the following abnormalities were noticed. a) Presence of hemopoietic cells (erythroid, megakaryocytic, lymphoid, myeloid) at different stages of maturation. More frequently observed in the lumen than in the Disse space, they were usually isolated and never exceeded 2 or 3 cells. In the Disse space, hepatocytes in contact with hemopoietic cells were devoid of microvilli. In the lumen they were close to endothelial cells and Kupffer cells. Kupffer cells were numerous with intense phagocytic activity. b) Numerous collagen bundles encircling sinusoids. c) Transformation of perisinusoidal cells into transitional cells with few lipids, prominent RER, long and thick processes containing filaments sometimes condensed below the plasma membrane. Although only one patient showed clinical evidence of portal hypertension of sinusoidal origin, these results suggest that hepatic vascular resistance might be raised in agnogenic myeloid metaplasia.

Cell Adhesion↗
PubMed1985

The sinusoidal barrier in rats with portacaval anastomosis: a morphometric study.

Shunting of portal blood in the rat leads to liver atrophy and to an increase in arterial blood flow with microcirculatory disturbances. The aim of this study was to investigate the effects of these disturbances on the liver sinusoidal barrier (endothelial and perisinusoidal cells) using morphometric techniques. Rats with portacaval anastomosis (PCA) and sham operated pair-fed controls were studied 3 months after the shunt. Sinusoidal volume density in PCA increased but not significantly and the volume density (Vv) of total endothelial (EC) and perisinusoidal cells (PSC) increased by 104.54% compared to sham operated pair-fed rats. The increase of EC Vv was not associated with an increase in surface density (Sv) suggesting a fall in the number of small fenestrations and an increase in cell thickness. This interpretation supports the morphological observations. The increase of PSC Vv was mainly related to the increase in their subendothelial processes Vv and not to that of the cell body Vv. Lipids Vv and RER Sv expressed per sinusoidal cells remained unchanged suggesting that the balance between the 2 hypothetical functions of the PSC, namely fibrogenesis and storage of vitamin A, was maintained. In conclusion, changes of EC and PSC after PCA result mainly in thickening of the sinusoidal barrier. This increase may impair exchanges between the sinusoidal lumen and Disse space and contribute to functional abnormalities.

Animals↗
PubMed1985

Hyperplastic foci in the atrophic liver of rats after portacaval anastomosis.

Hyperplastic focal areas were investigated in livers of male rats 1 and 9 months after portacaval anastomosis (PCA) by light and electron microscopy. These alterations, predominantly found in periportal areas, were characterized by light microscopy as clusters of enlarged hepatocytes along narrowed sinusoids, contrasting in the remaining liver acinus with smaller hepatocytes along widened sinusoids. No differences were observed between 1 and 9 months PCA except for glycogen content, which was homogeneously distributed in the liver at 1 month but completely lacking in foci at 9 months. The most striking ultrastructural alterations were the sinusoids delimited in these hyperplastic areas by a thickened barrier consisting of thick endothelial cells encircled by numerous subendothelial processes of the perisinusoidal fat-storing cells. Deep and widened recesses of the sinusoidal lumen separated the two-cell-thick plates of the hyperplastic cells. Hepatocytes in foci, thought to represent regenerative areas, tend to increase their exchange surface. Their progressive loss in glycogen and their two-cell-thick plates architecture should be in favour of a potential malignancy. However, the spontaneous evolution of these foci which do not necessarily give rise to nodules, as well as the lack of other features of transformation, do not support this possibility.

Animals↗
PubMed1985

Hepatic blood flow in rats with portal branch ligation.

Hepatic arterial blood flow (HABF) in the liver lobes and splanchnic nonhepatic arterial blood flow were measured in rats with and without right portal branch ligation for 1 month using 57Co microspheres. Portal branch ligation led to 60% atrophy of the ligated lobe and to hypertrophy of the nonligated lobe. In nonligated lobes of the portal branch ligation model and in the lobes of controls, HABF expressed per gram liver was comparable. In both models splanchnic non-HABF was also comparable. In the atrophic lobe, HABF remained constant; expressed per gram liver, it increased. In this lobe the net result was a significant decrease in total hepatic blood flow (ml/min/g liver).

Animals↗
PubMed1985

Sinusoids in human cirrhotic nodules: better identification with the perfusion fixation technique.

Liver biopsies of two alcoholic patients with nodular cirrhosis were fixed by perfusion. Sinusoids, sinusoidal cells and the Disse space were well identified in the nodules. Compared to a 'normal' liver biopsy, the following abnormalities were found: a larger Disse space containing fibrillar material and numerous collagen bundles, the extension of the lateral recesses between hepatocytes, the presence of a basement membrane-like material beneath thick and irregular endothelial cells, the transformation of perisinusoidal cells into transitional cells and myofibroblasts-like cells. In addition perisinusoidal processes were clearly identified; they were thick, often containing numerous filaments, and displayed in two or more layers underlined by a discontinuous basement membrane-like material.

Fixatives↗
PubMed1984

Acute hepatotoxicity of carbon tetrachloride. Different liver lobes response in rats with portal branch ligation.

Portal branch ligation (PBL) leads to atrophy of the corresponding lobe (AL) and hypertrophy of the non ligated lobes (HL). Liver architecture of AL is preserved. In this model we assessed in rats, one month after PBL, the acute hepatotoxicity of carbon tetrachloride (CCl4) given i.p. or i.v. Grading of necrosis, steatosis and ballooning demonstrated that at 24 and 48 h, AL were less severely damaged than HL and lobes of sham operated rats. Changes in hepatic blood flow, drug metabolism and/or in sinusoidal cells may represent causes involved in the partial hepato-protection.

Acute Disease↗
PubMed1984

Neoplastic surface changes in urothelium of rats after portacaval anastomosis. A combined light and scanning electron microscopic study.

The development of preneoplastic and neoplastic alterations in the urinary tract was investigated by light and scanning electron microscopy in rats after portacaval anastomosis. The changes consisted of slight hyperplasia to papillary hyperplasia after 24 weeks. Carcinomas were present in all animals after 52 weeks. Surface characteristics can be correlated with the sequence of changes in urothelial cells. Short uniform microvilli appear in moderate hyperplasia and a cobblestone formation of the cells is typical of papillary hyperplasia. In transitional cell carcinomas the cells varied in shape and size and they were densely covered with pleomorphic microvilli. Although the cause of tumour induction after portacaval anastomosis is not clearly understood, possible mechanisms are discussed.

Animals↗
PubMed1984

Splanchnic arterial blood flow in rats with portacaval shunts.

With indirect methods, it was shown in rats with portacaval shunts (PCS) that total hepatic blood flow (THBF) remained constant when expressed per gram of liver. These results implied an absolute increase in hepatic arterial blood flow (HABF). The aim of this study was to investigate HABF and splanchnic nonhepatic arterial blood flow (SNHABF) with a direct method (57Co microspheres) in PCS rats. One month after surgery, the following results were obtained in PCS rats compared with pair-fed, sham-operated rats: 1) liver mass atrophy was 42.3 +/- 10.9%, 2) HABF (ml X min-1 X g liver-1) was increased by a factor of 2.7, 3) SNHABF (ml X min-1 X 100 g body wt-1) was higher (9.8 +/- 3.3 vs. 5.6 +/- 2.7) (P less than 0.05) and 4) THBF (ml X min-1 X g liver-1) was decreased (1.36 +/- 0.34 vs. 1.85 +/- 0.86) but not significantly. Increases in HABF and SNHABF were not the direct consequence of an increase in cardiac output as attested by a normal cerebral blood flow (ml X min-1 X g organ-1) in PCS rats. In PCS rats, an increase in HABF may prevent the further spread of liver necrosis. The cause and the reason for an increase in SNHABF remain unknown.

Animals↗
PubMed1984

Hypertrophy of the rat Golgi complex during enhancement of cholesterol and bile acids synthesis.

There are some evidences that the Golgi apparatus could be involved in bile salts transport. In this study we investigate the morphology of the Golgi apparatus in rats with a chronic bile fistula or treated with 4% cholestyramine, a bile salts chelating agent. In both models liver histology was normal by light microscopy. With electron microscopy--compared to sham groups--the only obvious change was the enlargement of the Golgi complex. Morphometric data confirmed that the Golgi rich area volume density was almost doubled after chronic bile fistula or cholestyramine treatment. These data give another support for the participation of the Golgi complex in bile salts transport.

Animals↗
PubMed1984

Hepatocyte ultrastructure in the rat after long term portacaval anastomosis: a morphometric study.

Hepatocyte ultrastructure was studied in rats after long term portacaval anastomosis (PCS). Compared to controls rats of the same age, in one year PCS rats, the liver atrophy was 24% of the mass. Hepatocytes area was decreased (-16%) but their architecture was grossly normal. The rough endoplasmic reticulum appeared well developed. The morphometric study revealed that: the rough endoplasmic surface density was significantly increased in the two zones of the liver acinus, the smooth endoplasmic reticulum surface density was significantly decreased in zone 1 only and the peroxisomes volume density was increased 2.5 times. These findings differ from data obtained shortly after surgery and probably indicate an adaptation to important functions such as protein synthesis, drug metabolism etc. Increased number of peroxisomes could be possibly linked to the abnormal uric acid metabolism observed in rats with portacaval shunts.

Animals↗