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Biomedical subjects

M Patey

Publications and source records attributed to M Patey.

10 recordsLinked to original sources

Modification of the amounts of G proteins and of the activity of adenylyl cyclase in human benign thyroid tumours.

The possibility that a TSH post-receptor-binding defect is responsible for the pathogenesis of benign thyroid tumours was studied. Thus, we attempted to determine in hyperfunctioning (hot) nodules and non-functioning (cold) nodules whether the functional activity or the amount of G proteins were modified in comparison with surrounding normal tissues. The adenylyl cyclase response to agonists that bypass the TSH-receptor complex (forskolin, guanosine 5'- (beta.gamma-imido)triphosphate (Gpp(NH)p) or [AIF4]-) was studied on membranes from tumorous and adjacent normal thyroid tissues. We also examined the ability of G proteins to be ADP-ribosylated by cholera toxin (CT) or pertussis toxin (PT), and quantified G proteins by Western blot analysis with specific antisera directed against Gs alpha and Gi alpha subunits. Basal adenylyl cyclase activity was unchanged in hot tumours compared with normal tissue whereas the stimulation of adenylyl cyclase by Gpp(NH)p or [A1F4]- (which act directly on Gs) as well as by forskolin (which acts on the catalyst) was significantly (P less than 0.05) decreased in five of seven nodules studied. Two types of response were found in cold nodules, depending upon whether they were microfollicular or macrofollicular tumours. Basal as well as stimulated adenylyl cyclase activity was increased (0.02 less than P less than 0.05) in microfollicular tumours. In contrast, in macrofollicular tumours basal adenylyl cyclase was unchanged whereas stimulated adenylyl cyclase activity was decreased (0.02 less than P less than 0.05). The ability of Gs or Gi to be ADP-ribosylated by CT or PT respectively was maintained in tumorous tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma

[Acute malignant myelofibrosis. Report of 3 cases].

This report describes three cases of acute malignant myelofibrosis characterized by pancytopenia, absence of splenomegaly, bone marrow fibrosis with an immature cell proliferation and rapidly fatal outcome. The authors investigated the origin of blast cells with the use of immunohistochemical markers on paraffin embedded material with anti-factor VIII, BNH9 and anti-lysozyme. They studied the expression of megakaryoblastic, erythroblastic and myeloblastic differentiation in these cells. They demonstrated the heterogeneity of blast cells which are capable of differentiating along the three hematologic cell lines. The morphometric study showed the mutilating or systematized character of myelofibrosis. The increase in reticulin fiber density compared with normal bone marrow was not significantly different from two other types of myelofibrosis. It would be interesting to correlate a quantitative parameter with the course of this disease in order to evaluate the prognosis and the treatment.

Acute Disease

Chromosomal changes in thyroid tumors. Relation with DNA content, karyotypic features, and clinical data.

A cytogenetic study was performed in 63 thyroid tumors after a monolayer short-term culture. Clonal chromosomal changes were found in 47% of carcinomas and 31% of adenomas. Chromosome 7 was altered in 40% of cytogenetically abnormal tumors. The modal DNA index measured in 26 tumors was consistent with the chromosomal mode in 88% of cases. A quantitative morphometric analysis of nuclear features differentiated between diploid thyroid adenomas with or without a single translocation, which suggests that they have different biological properties. Clonal chromosomal changes were observed in 78% of carcinomas with an aggressive behavior, but only 28% of those had no risk factors. The two patients who died early had abnormalities of chromosome 7.

Adenoma

[Imprint cytology in the diagnosis of tumors of the thyroid].

We have correlated imprint cytology findings in thyroid tumors to the results of preoperative fine needle aspiration and operative specimen histology. Specificity of imprint cytology proved greater than that of fine needle aspiration cytology and topographic correlations were particularly helpful. Imprint cytology can improve the intraoperative histologic diagnosis. Because abundant cells are available, imprint thyroid cytology is ideal for teaching and training cytologists. Imprint cytology provides enough cells to perform special techniques, such as quantitative cytology, that are useful for the diagnosis of some tumor varieties (e.g. follicular tumors).

Cytodiagnosis

Chromosomal changes in a documented case of malignant histiocytosis: significance of polyploidy.

A case of malignant histiocytosis was studied by cytology, cytochemistry, electron microscopy, and cytogenetics. It was shown that the malignant cells expressed a fully differentiated histiocytic pattern with high macrophagic activity. This correlated with the presence of polyploid metaphases. The significance of polyploid cells in the definition of malignant histiocytosis is discussed.

Aged

[Immunohistochemical study of plasmocytes and T-lymphocyte subpopulations in Hashimoto's thyroiditis].

In Hashimoto's thyroiditis, there is a diffuse interfollicular infiltration of lymphocytes and plasmocytes and lymphoid collections with germinal centers. Eleven cases of Hashimoto's disease were studied with immunocytochemical methods for characterization of intracytoplasmic immunoglobulins (IgA, IgG, IgM, Kappa and lambda light chains). Most of the cells are plasmocytes stained positively for intracytoplasmic IgG; IgA positive cells were less frequent and IgM positive cells are rare. Kappa positive plasma cells are more numerous than lambda positive cells in the germinal centers and the interfollicular infiltration. By an indirect immunofluorescence technique in frozen tissue, we have studied with four monoclonal antibodies (OKT3, OKT4, OKT8, B1) the T cells subsets populations in two cases.

Female