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M N Walters

Publications and source records attributed to M N Walters.

60 records · Page 4Linked to original sources
PubMed1963

Iron storage in human disease: Fractionation of hepatic and splenic iron into ferritin and haemosiderin with histochemical correlations.

The hepatic and splenic storage iron, including the relative distribution between ferritin and haemosiderin, was estimated in 130 necropsies including normal accident cases and cases with a variety of diseases. The storage iron was also examined histochemically. It was found that in the normal subjects, on the average, approximately 400 mg. of iron was stored in these two organs, somewhat more than half being present as ferritin iron. Increased storage iron was found in some cases of infection, malignancy, and in blood and hepatic diseases, while low stores were present in other cases with malignancy and in polycythaemia vera. Although there was a slight tendency in infections and malignant diseases for more of the storage iron to be present as haemosiderin than normally, the most important factor affecting the distribution of iron between ferritin and haemosiderin was the total storage iron concentration. With total storage iron less than 500 mug. per gram of tissue, more iron was stored as ferritin than haemosiderin, and with values above 1,000 mug. per gram more was stored as haemosiderin. The behaviour of storage iron in this respect was very similar both in the liver and in the spleen. Although the histological and chemical estimates of the storage iron showed a general agreement there was much variation and histological examination of the tissues gave only a very approximate idea of the storage iron levels.

Journal Article↗
PubMedDate not supplied

Fine needle aspiration cytology of malignant mesothelioma.

The results of fine needle aspiration (FNA) cytology in 19 cases of malignant mesothelioma are presented. Adequate material for a diagnosis of malignancy was obtained in 17 cases, and in 8 cases a specific diagnosis of mesothelioma could be made. In four other cases, the findings were either consistent with or suggestive of mesothelioma; in four, accurate distinction from other neoplasms was not possible, and in two cases, adenocarcinoma was suggested. The spectrum of cytologic findings ranged from neoplasms of purely epithelial appearance through more pleomorphic biphasic neoplasms to anaplastic tumors. A combination of epithelial-like cell clusters, pavement-like sheets of epithelial cells with well-defined cell borders and prominent cell separation, dispersed angular cells with dense cytoplasm and some spindle-cell forms was the most specific cytologic pattern for mesothelioma. In four neoplasms, ultrastructural examination of aspirated material provided the additional evidence for a definitive diagnosis. The identification of hyaluronic acid within intracytoplasmic vacuoles, either in smears or in cell blocks, confirmed the diagnosis in three tumors. Only in one case, with a strong clinical background suggesting mesothelioma, was the cytologic preparation sufficient for diagnosis without ancillary diagnostic methods. FNA is of particular value in the diagnosis of pleural mesothelioma in patients who do not present with a pleural effusion. Obtaining material for cell block preparations, cytochemistry or ultrastructural study is generally necessary for definitive tumor typing.

Adult↗
PubMedDate not supplied

Cytologic and tissue culture characteristics of asbestos-induced mesothelioma in rats.

Mesotheliomas were induced in rats by the intrapleural injection of Western Australia crocidolite asbestos. Over a two-year period, 10 of 18 animals in which implants were established developed mesotheliomas, for a 56% success rate. Histologically, most mesotheliomas were biphasic although predominantly spindle celled. Pleural fluid was examined in five of these malignant cases: three had a papillary epithelial picture, one had mainly anaplastic cells, and one contained predominantly spindle-shaped cells. Three types of cell aggregates occurred: classical collagen-containing papillary clusters, spindle-cell aggregates and cystlike spheres. These last structures corresponded to microcystic or adenomatoid growth present in four mesotheliomas. Two of the effusions were cultured successfully; the growth pattern was typically mesothelial, with in vitro production of collagen. Ultrastructurally, long, slender microvilli, cell junctions and intermediate filaments confirmed the mesothelial nature of these asbestos-induced rat malignancies.

Animals↗