Search PubMed⌕ Search

Biomedical subjects

T Ducastelle

Publications and source records attributed to T Ducastelle.

At least 37 records · Page 2Linked to original sources
PubMed1985

[Benign sub-periosteal osteoblastoma of the nasal cavity. histological and ultrastructural study of a case].

A case of periosteal benign osteoblastoma arising in the left nasal cavity is presented. The tumor develops on the surface of the middle turbinate without evidence of bone destruction. It has been locally excised and has not recurred in 3 1/2 years. The histological aspect is identical to that of the other cases of genuine osteoblastoma. The ultrastructure (the first of a periosteal osteoblastoma) is described. The osteoblasts resemble normal osteoblasts with a few exceptions: irregular nuclei, abundance of well-developed rough-surfaced endoplasmic reticulum and numerous fine filaments. The osteocytes and osteoclasts basically resemble their normal counterparts. The final diagnosis of benign osteoblastoma rests at the light microscopy level. The differential diagnosis are reviewed. Distinguishing histologic and ultrastructural characteristics between this tumor and other benign osteoblastic tumors are discussed.

Cell Nucleus↗
PubMed1985

[Glomerulonephritis secondary to ventriculo-atrial shunts].

The authors report the case of a 45 year old man who had undergone a ventriculo-atrial CSF shunt procedure 5 years previously for normal pressure hydrocephalus and who had several unexplained episodes of infection over a 12 months period and has now developed a mixed nephrotic syndrome associated with a septicaemia. Corynebacterium commensale and Staphylococcus epidermis were isolated from the valve culture. Ablation of the valve resulted in clinical cure with minimal functional renal sequellae. The initial renal biopsy showed type I proliferative glomerulonephritis with subendothelial deposits of complement and immunoglobulins, which did not completely regress after 3 months' evolution. The serum complement fractions suggested activation of the alternate pathway and the possible pathogenic role of circulating immune complexes.

Antigen-Antibody Complex↗
PubMed1984

Simultaneous occurrence of a T-cell lymphoma and a chronic myelogenous leukemia with an unusual karyotype.

The simultaneous occurrence of malignant T-cell lymphoma and chronic myelogenous leukemia is reported. The lymph nodes contained E rosette forming cells. Blood and bone marrow cell morphology were consistent with the diagnosis of chronic myelogenous leukemia. Lymph nodes, bone marrow and blood mitosis showed a t(6;8) (6pter----6q27 ::8p12----8pter;6qter----6q27 ::8p12----8qter) translocation. So far a number of recent reports have shown simultaneous B lymphoid and myeloid proliferations in some malignancies, this is apparently the first reported case of simultaneous T lymphoid and myeloid proliferations.

Adolescent↗
PubMed1982

Coupling defect of thyrotropin receptor and adenylate cyclase in a pseudohypoparathyroid patient.

A patient with type I pseudohypoparathyroidism was found to have mild hypothyroidism. The patient had an elevated basal TSH level and an exaggerated TSH response to TRH. There was no goiter despite increased TSH levels, and the 131I thyroidal uptake was low before and after exogenous TSH administration. These studies suggested that the patient might have partial resistance to TSH. The binding of radioiodinated TSH to thyroid membranes obtained by biopsy was next studied. The displacement of iodinated TSH by unlabeled TSH was found to be identical to that in normal control membranes. The adenylate cyclase stimulation by a supramaximal dose of TSH, however, was blunted (120.1 +/- 11.5 vs. 387.2 +/- 40.3 pmol cAMP/min/mg protein), while basal and NaF-stimulated activities were quite similar to the activities in normal membranes. These findings suggested a lack of signal transmission between the TSH receptor and the catalytic unit. Incubation of control membranes with TSH and GTP resulted in a synergistic effect on the adenylate cyclase activity. This was not found with the patient's membranes and suggested that the coupling failure was due to a defective guanine nucleotide regulatory protein. We conclude that in this case of type I pseudohypoparathyroidism, the associated mild primary hypothyroidism was due to a partial TSH refractoriness caused by a coupling defect between the TSH receptor and adenylate cyclase. This observation suggests that a common pathogenetic mechanism might underly type I pseudohypoparathyroidism and its associated hypothyroidism.

Adenosine Triphosphate↗
PubMed1982

[Amyloidosis: recent advances (author's transl)].

Recently acquired data have increased our knowledge of the structure of amyloid substance, and clarified its biochemical nature which leads to its progressive breakdown. Amyloid proteins differ greatly in their chemical composition, but amyloid substance itself is unique in that it possesses a characteristic spatial configuration in the form of folded layers. Current pathogenic hypotheses suggest a probable major role for the phagocytic cells, or even the total immunity system.

Amyloid↗
PubMed1981

[Non lymphoid cells of the peripheral lymphoid organs. Recent morphological progress and current understanding (author's transl)].

Peripheral lymphoid organs have two groups of non lymphoid cells : that of macrophages which belongs to R. van Furth's system of mononuclear phagocytes and the one made of elements for long labelled "reticular cells". The use of electron microscopy has permitted a good understanding of these elements and a recognition of ubiquitary cells (fibroblasts, endothelial cells) and specific cells to the lymph node which seem to play a very important role in the immune reactions (interdigitated cells, reticulum cells, dendritic cells). We describe their light and electron microscopical features and histoenzymatic characters, and present the actual concept of their origin and function. The latest discoveries on their classification are reviewed and have permitted to distinguish three categories of non lymphoid cells : first the group of reticulum cells (reticulum cells and dendritic cells), second that of mononuclear phagocytes (macrophages and interdigitated cells) and third that of endothelial cells. Other elements of questionable existence or insufficiently known do not appear in this classification : dark cells, Steinman and Cohn's dendritic cells and cells containing Birbeck's granules.

Humans↗
PubMed1981

[Mandibular condyle tumors (author's transl)].

The must frequently observed mandibular condyle tumors are benign in nature, followed by metastases; primary malignant tumors are very rarely encountered, following a review of the clinical and radiographic characteristics of all types of tumors that occur, three cases of condylar metastases are described. Treatment of primary tumors is exclusively surgical, that of secondary lesions being palliative because of the often poor prognosis related to the primary tumor.

Diagnosis, Differential↗
PubMed1980

Sarcoidosis. Retroperitoneal fibrosis, renal arterial involvement, and unilateral focal glomerulosclerosis.

In one patient with pulmonary sarcoidosis, hypertension occurred during the course of the disease. Aortography showed extensive narrowing of the right renal artery. Surgical exploration disclosed extensive periaortic and perirenal fibrosis. This fibrosis encircled the right renal artery and caused extrinsic compression. Pathological examination disclosed a large amount of histiocyte epithelioid infiltration in various samples of the fibrosis and particularly in the adventitia of the renal artery, highly suggestive of sarcoidal angiitis. Surgical biopsy was performed on both kidneys. The right kidney, protected by arterial stenosis, was little altered, while the left kidney showed extensive interstitial, tubular, and glomerular lesions. The glomerular lesions were focal and segmental hyalinosis.

Adult↗
PubMed1980

Calcitonin-producing pancreatic somatostatinoma.

A pancreatic somatostatinoma metastatized to the liver was detected in a 70-yr-old woman presenting with chronic diarrhea, steatorrhea, pancreatic insufficiency, diabetes mellitus, and achlorhydria. At immunocytochemistry, most tumor cells stored both somatostatin and calcitoninlike substances. Chromatography of acid extracts of the tumor on G50 Sephadex gave two distinct peaks coeluting with cyclic ovine somatostatin and human calcitonin, respectively, thus ruling out the hypothesis of a single cross-reacting molecule synthetized by the neoplastic cells. When the tumor was extracted at neutral pH, larger molecular forms of the above components were found, which accounted for less than 20% of the total immunoreactivity. Gel permeation of plasma showed that the circulating calcitonin- and somatostatinlike components consisted of three and four different forms, respectively, including components of molecular weights similar to those of the reference peptides. Inhibition curves and immunoadsorption experiments indicated that the large forms were immunologically similar, if not identical, to the corresponding standard preparations. The present case illustrates the occasional ability of neoplastic somatostatin cells of pancreas to synthetize simultaneously components immunologically related to somatostatin and calcitonin. These two inappropriate secretions could account for the symptoms displayed by this patient.

Adenoma, Islet Cell↗