Biomedical subjects

A Tabarin

Publications and source records attributed to A Tabarin.

76 records · Page 5Linked to original sources

PubMed1987

Hepatocellular carcinoma developed on noncirrhotic livers. Sinusoids in hepatocellular carcinoma.

In hepatocellular carcinoma, there is modification of cell-to-cell and cell-to-extracellular matrix interactions. Two cases of well-differentiated hepatocellular carcinoma that developed in noncirrhotic livers were explored by light and electron microscopy on perfusion-fixed liver biopsy specimens. In addition, immunocytolocalization of collagen types I, III, and IV, laminin, and fibronectin was assessed. The main features included the following: absence of collagen staining inside the tumor with Sirius red; decrease of collagen types I and III and the increase of collagen type IV, laminin, and fibronectin; widening of Disse's spaces containing numerous, discontinuous, and thick fragments of basement membrane-like material piled up beneath endothelial cells and around perisinusoidal cells; transformation of perisinusoidal cells into cells with the characteristics of fibroblasts and myofibroblasts; decreased numbers of fenestrae for endothelial cells with processes often overlapping and attached with tight junctions; and rarefaction of Kupffer's cells. Expression of cellular and extracellular material abnormalities are related to the tumor differentiation. The study of these abnormalities may have implications in prognosis.

Capillaries↗

PubMed1987

[Value of angioscanography in the morphologic exploration of hypophyseal adenomas].

Considerable progress has been made in the morphologic study of pituitary due to the availability of angioscan programs. An exceptional case is presented of a persistent intrasellar trigeminal artery associated with prolactinoma. Based on technological progress in CT scan imaging the place of angiographic explorations in the investigation of pituitary adenoma is reconsidered.

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↗

PubMedDate not supplied

[Cushing's syndrome: diagnostic exploration].

The diagnosis of Cushing's syndrome is one of the most perplexing and controversial problems in endocrinology. However, significant advances in the diagnosis procedures have been made in the past decade. The diagnostic studies involved in the evaluation of patients with suspected Cushing's syndrome fall into two categories: confirming the presence of true hypercortisolism and establishing the precise aetiology. Diagnosis of Cushing's syndrome: ambulatory screening relies on the overnight 1 mg dexamethasone test. Negative tests are confirmed by measuring cortisol in two 24-hour urine samples. If cortisol excretion is slightly above normal, a 48-hour low-dose dexamethasone suppression test or an intravenous infusion dexamethasone suppression test are required. Diagnosis of the aetiology of Cushing's syndrome: the first step is to establish if the hypercortisolism is ACTH-dependent or not. This step is solved by measuring plasma ACTH and cortisol in the late afternoon. Computed tomography scanning of the adrenal glands is required in ACTH-independent Cushing's syndrome. A unilateral tumour will be demonstrated in most of cases. If bilateral lesions are found, dynamic testing using cortisol releasing factor and/or metyrapone must be performed to confirm the ACTH-independency of the syndrome. In ACTH-dependent Cushing's syndrome, the major difficulty is to distinguish between a pituitary source and an ectopic source of ACTH secretion. Magnetic resonance imaging of the pituitary with gadolinium enhancement must be preferred to computed tomography scanning but its sensitivity is not better than 70-80% and false positives can occur. When no macroscopic pituitary lesion can be detected, bilateral inferior petrosal sinus sampling coupled to CRH injection for ACTH measurement will indicate the source of ACTH secretion. If this test indicates the patient has Cushing's disease, pituitary trans-sphenoidal surgery can be performed. If the test indicates the patient has ectopic ACTH-secretion, a cervico-thoraco-abdominal scanning is necessary to identify the tumour. In the case of occult tumour the hypercortisolism must be controlled by pharmacological agents and the imaging investigations must be repeated at appropriate intervals.

Adrenocortical Hyperfunction↗