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Biomedical subjects

S M Lewis

Publications and source records attributed to S M Lewis.

At least 289 records · Page 16Linked to original sources

Value of surface counting in predicting response to splenectomy in haemolytic anaemia.

The value of surface counting with (51)Cr-labelled red cells in predicting response to splenectomy in haemolytic anaemia has been analysed in 18 cases. The cases included six patients with congenital haemolytic anaemias, four with primary autoimmune haemolytic anaemias, and eight patients with secondary haemolytic anaemias (four with a positive antiglobulin test). All patients showed evidence of splenic accumulation of labelled cells and in 16 of the cases this was confined to the spleen. Improvement followed splenectomy in 17 of the cases although there was no close correlation between the magnitude of accumulation of radioactivity as measured by excess counts and the degree of response. The reasons for these discrepancies are discussed, The only patient who completely failed to respond to splenectomy had a sideroblastic element to the anaemia. It has been concluded that surface counting is of value in selecting patients for splenectomy but should not be depended upon without reference to other clinical and haematological factors, which are likely to influence the prognosis.

Adolescent↗

Electron microscope study of PNH red cells and AET-treated normal red cells (PNH-like cells).

The morphology of red cells damaged by 2-aminoethylisothiouronium bromide (AET) has been compared to that of PNH cells by transmission and scanning electron microscopy. The main features of the effect of AET as demonstrated by the scanning electron microscope were spherical and deformed cells, with surface craters and relatively large pits. The transmission electron microscope revealed loss of surface structure, an unusual amount of irregularly shaped electrondense material and fine pits in the cell membranes. The paroxysmal nocturnal haemoglobinuria cells showed, by transmission electron microscope, electron-dense material scattered over the cell and fine pitting; by scanning electron microscope, larger craters were seen and swellings protruded from the cell surface. Although the AET changes were not identical with the natural abnormality of paroxysmal nocturnal haemoglobinuria, the two types of cells were sufficiently similar to each other to support the proposition that AET cells have many of the characteristics of paroxysmal nocturnal haemoglobinuria.

Cell Membrane↗

An evaluation of photoelectric haemoglobinometers.

A number of photoelectric haemoglobinometers have been evaluated as to their suitability for haemoglobinometry in the routine clinical laboratory. They have been tested for accuracy, precision, linearity of response, instrument comparability and, where relevant, for carry-over. The advantages and defects of each are described.

Colorimetry↗