An immunohistochemical analysis of human aortic fatty streaks.

Recent studies have shown both macrophages and lymphocytes in very early intimal lesions of experimental aortic atherosclerosis. The authors obtained fresh samples of human aortic wall, which had been removed in the course of aortocoronary bypass graft surgery. Intimal fatty streaks were identified macroscopically and six were studied immunohistochemically. The fatty streaks contained foam cells that were virtually all labeled by antibodies directed against members of the mononuclear phagocyte series (RFD-2 and RFD-7). Macrophages demonstrated acid phosphatase activity and marked expression of HLA-DR, suggesting activation. Other monoclonal antibodies (UCHT-1, OKT-4, and RFT-8) identified T lymphocytes, of both helper and suppressor phenotypes, within the fatty streaks. T lymphocytes of suppressor phenotype appeared to predominate over helper cells. B lymphocytes were not detected. The presence of activated macrophages and T lymphocytes in the fatty streaks indicates that components of a cell-mediated immune response are present. Such an immune process may be important in the pathogenesis of human atherosclerosis.

Immunohistochemical analysis of mononuclear cell subsets in inflammatory and non-inflammatory myopathies.

Immunohistochemical procedures were used to analyse the subpopulations of mononuclear cells in muscle biopsies from 24 patients with polymyositis. The character of the cellular infiltrate was similar at the perivascular, perimysial, and endomysial sites, with cytotoxic-suppressor T lymphocytes (T8+) and macrophages being the dominant elements. Helper T lymphocytes (T4+) and B lymphocytes were present in smaller numbers. A control series of 17 muscle biopsies from normal subjects and patients with non-inflammatory myopathies and neurogenic conditions was also studied: the numbers of mononuclear cells present were much smaller than in polymyositis, but the ratio of T4:T8 lymphocytes was similar to that found in biopsies affected by polymyositis. We conclude that both cytotoxic-suppressor T lymphocytes and macrophages are important in the pathogenesis of inflammatory myopathy.

Hexokinase from maize endosperm and scutellum.

Hexokinase (EC 2.7.1.1) was isolated from endosperm and scutellum of developing and germinating maize (Zea mays) seeds. With fructose as the variable substate, Michaelis constant values for the scutellum enzyme were about onethird those of the endosperm enzyme (0.05 versus 0.15 mm), and no developmental differences were observed. With glucose as the variable substrate, Michaelis constant values were all in the range 0.1 to 0.2 mm. The enzyme preparation from germinating scutellum was studied further; when glucose was varied over a wide range, a Michaelis constant of 3.4 mm was observed in addition to the much lower Michaelis constant noted above. This low affinity binding of glucose may have regulatory significance and may indicate the presence of a glucokinase in addition to hexokinase.

A comparison of cytoplasmic immunoglobulins in retroperitoneal fibrosis and abdominal aortic aneurysms.

Retroperitoneal fibrosis is associated with Riedel's thyroiditis, in which an unexpectedly high proportion of the plasma cells have been reported to contain IgA and lambda light chains. It has been suggested that retroperitoneal fibrosis and the inflammation and fibrosis in thick-walled abdominal aortic aneurysms are caused by a hypersensitivity reaction to antigens leaked from aortic atheroma. We examined cases of retroperitoneal fibrosis and aortic aneurysms in order to quantify the types of heavy and light chains in the plasma cells. A mean of 44% of the plasma cells contained IgA and 52% contained lambda light chain. These results provide further evidence of the pathological relationship between retroperitoneal fibrosis and Riedel's thyroiditis. It is suggested that a cross-reaction between antigens in mucosal surfaces and in the thyroid or retroperitoneum may be implicated, possibly involving vessel walls. Of the total plasma cells in the wall of the aortic aneurysms 24% contained IgA and 40% lambda, although there was a significant trend towards a higher proportion of IgA with increasing thickness of the wall. No definite support for a relationship between atheroma and retroperitoneal fibrosis is provided by this study.

The pattern of involvement of adult-onset acid maltase deficiency at autopsy.

The autopsy findings in a clinically and biochemically documented case of adult-onset acid maltase deficiency presenting with limb girdle myopathy are presented. The skeletal muscles, tongue, extraocular and smooth muscles of gut and arterioles showed a vacuolar myopathy, most severely affecting proximal skeletal muscles. Muscle spindles were severely affected in all muscles. The heart showed basophilic degeneration and a vacuolar myopathy. The visceral organs and nervous system were morphologically normal. Possible mechanisms for this differential involvement of muscles and tissues are discussed.

Polysaccharide storage myopathy.

In a woman with a slowly progressive adult onset proximal myopathy, muscle biopsy showed storage of PAS positive material in type 1 fibers. This material consisted of a branched chain polysaccharide associated with a mucoprotein. No abnormality of glycogen-pathway enzymes was detected. This suggested that this polysaccharide accumulation occurred because the polysaccharide was laid down in a non-bioavailable form. The clinical and histochemical features in this patient and in the few similar reported cases indicate that polysaccharide storage myopathy is a distinct entity that is allied to the glycogen storage myopathies.

The immunocytochemical demonstration of basement membrane deposition in transitional cell carcinoma of bladder.

We assessed the staining characteristics of the basement membrane of transitional cell carcinoma of bladder using a monoclonal antibody to type IV collagen. Basement membranes were clearly stained at the stromal/carcinoma interface. As transitional cell carcinoma became less well differentiated and the depth of invasion increased interruptions to basement membrane staining became more extensive and these findings are comparable to those described in similar series of transitional cell carcinoma using polyclonal antibodies to type IV collagen. The defects in basement membrane staining may be related to the degree and direction of tumour cell differentiation or may be explained by increased degradation compared to synthesis of basement membrane components. Demonstration of the basement membrane may be of value in diagnostic histopathology as a marker of the biological behaviour of transitional cell carcinoma of bladder.

Myopathy of internal anal sphincter with polyglucosan inclusions.

In two members of an affected family with a hereditary syndrome of proctalgia fugax and constipation, a hypertrophied internal anal sphincter was found with histological features suggesting a myopathy of this muscle. In these two patients, and in an unrelated patient with a similar clinical syndrome, smooth muscle fibres of the internal anal sphincter showed numerous vacuoles, many of which contained ovoid inclusion bodies. The structural features and histochemical reactions of the inclusion bodies were consistent with a polyglucosan composition. Histological examination of the internal anal sphincter may reveal smooth muscle abnormalities in functional bowel disorders.