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Biomedical subjects

P Bioulac

Publications and source records attributed to P Bioulac.

At least 37 records · Page 2Linked to original sources

[Arterial manifestations of the Ehlers' Danlos syndrome].

The Ehlers-Danlos syndrome, or rather syndromes includes a heterogeneous group of diseases secondary to abnormalities of collagen fibres, for certain of which the specific biochemical defect has been identified. The preponderance of collagen fibers in the body explains the diversity of clinical manifestations which can occur as part of this form of hereditary connective tissue dysplasia. The involvement of the arteries is the most serious manifestation and determine the prognosis of the disease. The rupture of arteries, true vascular catastrophy occurring in young patients, is most characteristic of the type IV Ehlers-Danlos syndrome due to a deficiency in type III collagen. Aneurysms, and less frequently stenoses are also manifestations of the structural abnormality of the arterial walls. After a brief review of the other clinical manifestations of the Ehlers-Danlos syndrome, the authors analyse the Literature regarding the signs of arterial involvement in view of such a degree of arterial fragility, the authors underline the difficulties involved with surgery and the dangers of arteriography.

Aneurysm↗

Hepatocyte ultrastructure in rats with portacaval shunt. A morphometric study of acinar zones.

The principal reported morphological consequence of portacaval shunt in the rat is liver atrophy. The present study was designed to investigate ultrastructural changes in hepatocytes using electron microscopy morphometry. Two weeks following portacaval shunt, rat livers were fixed by perfusion and hepatocyte organelles from the two opposite zones of the acinus (zones 1 and 3) were quantified. Liver weight/body weight decreased by 50%, hepatocyte-specific volume decreased by 30% (28% in zone 1 nd 35% in zone 3). Estimated sinusoidal space increased, and estimated number of hepatocytes decreased by 50%. Hepatocytes had a normal ultrastructure except for mitochondria. Smooth endoplasmic reticulum-specific surface area was reduced by 65% (zone 3), and rough endoplasmic reticulum surface density was increased in zone 1 only. Mitochondria-specific volume was unchanged but decreased inner and outer membrane-specific surface area in zone 3 suggests in this zone a change in their conformation and possibly their number. Golgi-rich area surface density increased but not significantly. Hepatocyte loss and atrophy and rearrangement of organelles represent a new ultrastructural steady state following portacaval shunt that may help explain the new functional steady state.

Animals↗

Early patchy hepatic necrosis. Its appearance after bile-duct ligation in rats with a portacaval shunt.

We incidentally observed that rats with portacaval shunts (PCS) had patchy hepatic necrosis after bile-duct ligation (BDL). Rats with two weeks of PCS underwent BDL, then were killed after 0,5 or 20 hours, or two or four days; rats undergoing sham PCS were used as controls. Patchy hepatic necrosis distributed at random within the acinus was mainly lytic after five and 20 hours, then displayed inflammatory features after two days. The inflammation tends to disappear by four days, with a differentiation of new hepatocytes into neo-bile ducts. These necrotic areas were 60 times more severe after five hours, and 20 times more severe after 20 hours in rats undergoing PCS than in those undergoing sham PCS. In the former group, necrosis after five hours represented 1.92% of the total area examined. Histological characteristics and the high incidence with PCA suggest that necroses have vascular origin.

Animals↗

Liver arterialization improves hepatocytes ultrastructure in rats with portacaval shunts.

The effect of arterialization (ART) of the distal stump of the portal vein after portacaval shunt (PCS) on bile formation and liver ultrastructure was assessed. ART using the left gastric artery was performed in male Wistar rats. Animals were sacrificed 3 weeks later. ART prevented body and liver atrophy. However, the liver weight to body weight ratio was significantly decreased when compared to sham PCS (2.5 +/- 0.36 vs 3.22 +/- 0.15). Reduction in total bile secretion (microliter/min) seen following PCS is reversed by ART. ART partly corrected hepatocyte size atrophy and the major ultrastructural abnormalities, namely the irregularity of the nucleus and dilation of the nuclear envelope and of the rough endoplasmic reticulum appearing after PCS. However, mitochondria remained swollen, deformed and enlarged with scission figures. No lesions in connection with ART were seen. This result confirms, at the ultrastructural level, the beneficial effect of ART in PCS.

Animals↗

Chronic biliary drainage corrects liver atrophy induced by portacaval shunt in the rat.

Portacaval shunt induces a severe liver atrophy. The relative liver hypertrophy induced by chronic biliary drainage was studied by electron microscopy. Rats with either portacaval or sham portacaval shunt had a 4-day chronic bile fistula. Compared with rats not submitted to chronic bile fistula, liver weight/body weight ratio increased from 1.84 to +/- 0.12 to 3.54 +/- 0.48 (p less than 0.05) in portacaval shunt and from 3.52 +/- 0.15 to 3.64 +/- 0.40 (p less than 0.05) in sham portacaval shunt (controls). Chronic bile fistula stimulated bile acid synthesis in the two groups. Furthermore, the initial low bile flow observed in portacaval shunt (rats) reached control values after chronic bile fistula. Ultrastructural abnormalities observed in portacaval shunt: atrophy of the hepatocyte mainly related to the atrophy of the rough and smooth endoplasmic reticulum, irregularity of the nucleus, dilatation of the nuclear envelope and of the rough endoplasmic reticulum, and swelling of mitochondria, were greatly modified by chronic bile fistula. The hepatocyte size increased, mitochondria appeared smaller than normal, the nuclear envelope and the rough endoplasmic reticulum were not dilated, and the rough and smooth endoplasmic reticulum were expanded. Chronic bile fistula had no noticeable effect on the liver in sham portacaval shunt. Either stimulation of bile salts synthesis or removal of bile salts, which could be toxic for the atrophic liver, are possible explanations for the relative hypertrophy of the liver.

Animals↗

Decreased acute hepatotoxicity of carbon tetrachloride and bromobenzene by cholestyramine in the rat.

Numerous factors are known to increase or decrease drug-induced liver injury. The aim of this study was to test the effect of cholestyramine. Cholestyramine, and anion exchange resin binding in the gut substances taken up and metabolized by the liver such as bile salts, vitamins, endotoxins, etc., could indirectly modify drug-induced toxicity. Two groups of animals were studied: cholestyramine-fed and pair-fed controls. Five days after feeding, carbon tetrachloride or corn oil was injected intraperitoneally. Liver function and histology were normal after corn oil injection in both groups. One day after carbon tetrachloride injection liver weight/body weight ratio was lower in the cholestyramine-fed than in the pair-fed group (4.0 +/- 0.4 mean +/- SD vs. 4.4 +/- 0.3, p less than 0.05). Alanine and aspartate aminotransferases were lower (618 +/- 782 IU and 242 +/- 147 IU vs. 8245 +/- 8189 and 1966 +/- 1524 IU, p less than 0.001), as was necrosis (p less than 0.05). Steatosis and inflammatory reaction were similar in both groups. Two and four days later there were no significant differences between the two groups, because necrosis was no longer a major feature in the pair-fed group. Similar experiments were performed with bromobenzene. Here too cholestyramine prevents necrosis but to a much lesser extent. These results confirm that steatosis and necrosis are independent toxic effects of carbon tetrachloride. Cholestyramine, a widely used drug in cholestasis, could provide a potentially clinically important hepatocellular resistance to toxicity from environmental agents.

Alanine Transaminase↗

[Hereditary porphyria cutanea in children. Enzymatic studies (author's transl)].

A girl of 7 years presenting porphyria cutanea tarda was found to have a very low level of erythrocytary uroporphyrinogen decarboxylase. Tests on her brother, parents and maternal grand-parents, who were all free of the disease revealed the same level of enzyme in the mother and grandmother, through whom the hereditary factor was obviously transmitted. This supports evidence provided by juvenile cases and familial forms in the literature that heredity plays an important part in a disease which is often considered to be acquired or symptomatic. Despite clinical and biological resemblances, two types of porphyria cutanea can be distinguished: a sporadic form in which enzyme deficiency occurs only in the liver and is revealed by exogenous toxic factors such as alcohol or oestrogens and an hereditary form where the deficiency transmitted by a dominant autosomal mode is found in all hemasynthetising cells.

Child↗

[Familial Mediterranean fever and fatty liver. effect of a long time colchicine treatment on triglyceride storage (author's transl)].

A 35-year-old man, sephardic jew, complains for the last eleven years of typical and frequent attacks of FMF. His liver is hypertrophic. Needle-biopsy reveals an extensive macrovacuolar triglyceride storage (60 per cent) and an active vascular congestion with erythrodiapedesis in the mild and centrolobular zone, without any necrosis, cellular infiltration nor fibrosis. Electron microscopy shows lipofuschin deposits and mild lesions of mitochondrias, endoplasmic reticulum. Blood triglycerides and apo B are rather low. After six weeks of colchicine treatment, needle biopsy shows no more active congestion nor erythrodiapedesis. Triglyceride storage lowers to 40 per cent. After seven months of colchicine treatment, triglyceride storage falls down to 12 per cent. FMF may be considered as a cause of fatty liver when there is not any cause else and only after deep decrease or disparition of triglyceride deposit by a long time colchicine treatment.

Adult↗

Unscheduled DNA synthesis in psoriatic skin after ultraviolet irradiation and the effects of a combined treatment with 8-methoxypsoralen and longwave ultraviolet radiation: a clinical study.

Biopsies were taken from psoriatic patients undergoing photochemotherapy and then studied by autoradiography to investigate possible unscheduled DNA synthesis (UDS) following 8-MOP photodamage in epidermal cels. No sparse labelling was found in seventy samples taken from twenty-four different patients during PUVA therapy, indicating a lack of UDS. In contrast, UDS was observed in three patients irradiated with an all-spectrum UV lamp, as a test for DNA damage and excision repair activity. The incorporation of 3HTdR in these keratinocytes which were not undergoing S-phase was not affected by the dose of UV-A received during different stages of PUVA treatment. The results are discussed in terms of repair of the induced photodamage at the level of DNA, and in relation to a possible risk of this treatment when it is given over a long period of time.

Adolescent↗

[Ultrastructural study in the diagnosis of various neurolipidoses].

We have studied the sphingolipidosis, principally, ceroid-lipofuscinosis and other complex lipid storage diseases. We examined biopsy tissue of fourteen patients with diseases of the various types given above. The biopsy tissue was usually skin, muscle or peripheral nerve, and occassionally brain or various visceral tissue.

Biopsy↗

[Degos' malignant atrophic papulosis. Ultrastructural study of a new case].

The authors report a case of Degos' malignant atrophic papulosis (MAP) with typical skin lesions from a clinical and histological standpoint. They stress in particular the ultrastructural study of skin biopsies which revealed numerous "paramyxovirus-like" tubulo-reticular structures in the endothelial cells, lymphocytes of the perivascular infiltrate, fibroblasts and keratinocytes. Although the significance of these inclusions remains open to discussion and is probably non-specific, their frequency in MAP is worthy of emphasis.

Adolescent↗