Serum and urinary lysozyme (muramidase) in monocytic and monomyelocytic leukemia

Serum and urinary proteins, lysozyme (muramidase), and renal dysfunction in mono- and myelomonocytic leukemia

Serum levels, urinary excretion, and clearances of several proteins of different molecular weights were studied in 18 patients with mono- and myelomonocytic leukemia. Nine patients had normal renal function (group A) and nine had impaired renal function with azotemia (group B). The majority of patients in both groups had increased concentration of immunoglobulins, particularly IgG, IgA, and IgM; IgD level was normal. Serum transferrin and alpha(2)-macroglobulin were frequently reduced while the level of ceruloplasmin was often increased, especially in patients with azotemia. The activity of lysozyme in the serum was high in all patients, but was considerably higher in group B. Proteinuria was found in most patients but was more prominent in group B. Almost invariably albumin constituted less than 25% of the total protein excreted. Qualitative analysis of various urinary proteins by immunochemical techniques and clearance studies suggested the presence of glomerular as well as tubular dysfunction. Determination of urinary lysozyme frequently showed no direct correlation between the serum level of the enzyme and its concentration in the urine or its clearance by the kidney. In addition to glomerular filtration, impaired tubular reabsorption may account for the high level of lysozyme in the urine. It is postulated that the very high level of lysozyme in the glomerular filtrate and possibly hypergammaglobulinemia may play a role in the induction of tubular damage. Renal impairment has been correlated with histological changes in the kidneys. From a comparative study of various leukemias, it seems that the combined glomerular-tubular dysfunction is a manifestation unique to mono- and myelomonocytic leukemia.

Mouse lysozyme production by a monocytoma: isolation and comparison with other lysozymes

A transplantable mouse tumor, GPC-11, produces large amounts of lysozyme. The tumor is a reticulum cell sarcoma, type A, and is a neoplasm of monocytes. The lysozyme was purified from mouse urine in quantities sufficient for structural analysis. Comparison of mouse lysozyme with lysozymes from; chicken egg white and patients with monocytic leukemia reveals similarities in size and electrophoretic mobility and, with human lysozyme, in functional properties; but considerable differences are found in antigenic characteristics and amino acid composition.

IgD plasma cell neoplasia: clinical manifestations and characteristic features

Three patients, one with plasma cell leukemia and clinically asymptomatic hypernephroma and meningioma, and two others with multiple myeloma, had M-components of IgD/lambda type. In the first case, IgD globulin was found in the serum, ascitic and pleural fluids. Including our patients, 50 cases of IgD myeloma have been reported in the literature. A review of this group showed some significant differences from the other classes of multiple myeloma. IgD myeloma seems to involve a larger proportion of younger people, 66% being less than 59 years of age. The involvement of internal organs and renal damage were more frequent in IgD myeloma than in other classes. Serum total protein was frequently not increased, the relative concentration of M-component was often low and in 12% there was no spike in electrophoresis. The diagnosis therefore was sometimes difficult. In a quarter of the cases Bence Jones proteinemia was found and in 15% there were multiple spikes, both these manifestations being rare in IgG or IgA classes of myeloma. In 89%, IgD globulin had lambda type light chain, clearly contrasting with the figure of approximately 30% in other classes. Bence Jones protein was found in the urine in 91%. The survival time seemed to be shorter than in other myelomas.

Proportion of human colostral immunoglobulin-A molecules containing the secretory determinant

Concentrations of total colostral IgA were compared with concentrations remaining after precipitation with antibodies to secretory piece (SP). The anti-SP was obtained by filtering anti-colostral IgA through an immunosorbent column with firmly attached human serum globulins. IgA concentrations were measured by radial immunodiffusion with anti-α-chain serum.

The proportions of SP-containing IgA molecules were: in whole (defatted) colostrum, at least 68 per cent; in the polymeric IgA fraction, at least 88 per cent; in the monomeric IgA fraction, 43 per cent. Free SP was also detected in colostrum. The non-identity of SP with several known components of colostrum was ascertained by blocking experiments.

Lysozyme in epiphyseal cartilage. II. The effect of egg white lysozyme on mouse embryonic femurs in organ cultures

Embryonic mouse femoral cartilage, like the epiphyseal cartilage of the calf scapula, contains large amounts of lysozyme. The addition of egg white lysozyme to organ cultures of embryonic mouse femurs induces unique alterations in the gross and microscopic morphology of the femurs. The sites of these alterations are precisely related to the natural distribution of lysozyme in calf scapula. If the exogenous lysozyme is withdrawn from the culture, the morphological changes disappear, accompanied by a resumption or derepression of growth. The effect on growth is evident only in 17-day embryos. These observations support the idea that lysozyme has a physiological role in cartilage, perhaps related to a regulatory mechanism in bone formation.

Crystallization of human lysozyme

Lysozyme, isolated from the urine of patients with monocytic leu kemia, has been crystallized as the chlo ride at pH 4.5 and at pH 10.5. The crystal forms of the human enzyme show certain similarities as well as dis tinct dissimilarities compared with the crystal forms of lysozyme chloride from hen's egg white.