Simultaneous occurrence of angiomyolipoma and renal cell carcinoma. Clinical and pathologic (including ultrastructural) features.

The clinicopathologic features of an angiomyolipoma and a renal cell carcinoma occurring in the same patient are reported. A seventy-four-year-old woman was thought clinically and radiographically to have renal cell carcinoma of the left kidney with a metastasis to the right kidney. At surgery, however, she was found to have an angiomyolipoma in the right kidney and a renal cell carcinoma confined to the left kidney, both of which were resected with a good prognosis for survival. Light microscopy of the angiomyolipoma showed the characteristic admixture of adipose tissue, spindle cells, and hyalinized blood vessels. By electron microscopy, the spindle cells had cytoplasmic myofilaments and pinocytotic vesicles, and were surrounded by a basal lamina, consistent with a smooth muscle cell origin. This case is of interest in light of genetic influences in both of these neoplasms, and from the point of view of patient management.

Autoantigens in human sweat: purification and characterization of the D-group antigens.

We have found several heteropolysaccharides in human thermal sweat which are both autoantigenic and isoantigenic for a majority of healthy adults. They are present in trace amounts and are difficult to isolate. We have facilitated extraction through the use of a DEAE-Sephadex batch technique. One of the major antigenic fractions, the D group, has been purified and characterized. It contains 88.5 per cent carbohydrate as uronic acid, hexosamine, methyl pentose, and glucose. The protein content was 12.5 per cent.

The thermodynamics of interaction between Sephadex and penetrating solutes.

1. We have measured the partition coefficients of bovine serum albumin with Sephadex grades G-100, G-150 and G-200, and of a dextran ([unk](n) 19700) and a polyethylene glycol ([unk](n) 8000) with Sephadex G-200. We have also measured the effects of these solutes on the inner volumes of the grades of Sephadex. 2. The results can be described with fair consistency by means of a simple thermodynamic treatment that makes use of the virial coefficients of Sephadex and of the solute, and of a coefficient that expresses their interaction. This coefficient is related to the ;exclusion volume' of Sephadex for the solutes. 3. The Sephadex G-200-polyethylene glycol system shows anomalies of behaviour that are ascribed to the occurrence of ;incompatible' phase separation within the Sephadex beads.

Fractionation of ahyaluronic acid preparation in a density gradient. Some properties of the hyaluronic acid.

1. Hyaluronic acid was isolated from ox synovial fluid by sedimentation equilibrium in a caesium chloride density gradient (Silpananta, Dunstone & Ogston, 1967). The product was almost free from chondroitin sulphate and from protein. 2. Its composition did not differ significantly from that of the carbohydrate part of the protein-containing material isolated by filtration. Its physicochemical properties and molecular configuration were similar, except for its viscosity, which showed markedly reduced concentration-dependence and shear-dependence. This suggests that the associated protein tends to form links between molecules of hyaluronic acid. 3. The accurate measurement of viscosity at very low velocity gradient, by use of the damping of oscillations in a Couette viscometer, is described. 4. A method is described for measuring, approximately, the thermodynamic non-ideality of a solute from the shape of its schlieren curve at sedimentation equilibrium in a density gradient. 5. A value for the partial specific volume of hyaluronic acid in dilute salt solution was calculated from its isopycnic density in a caesium chloride gradient.

Fractionation of a hyaluronic acid preparation in a density gradient. The isolation and identification of a chondroitin sulphate.

1. Following the suggestion of Nichol, Ogston & Preston (1967) that hyaluronic acid, prepared by filtration from ox synovial fluid, contains a component of high density, such material has been detected and isolated by equilibrium sedimentation in a density gradient of caesium chloride. 2. This material (fraction III) has been characterized as a chondroitin sulphate-protein complex of average molecular weight about 250000. Its amino acid pattern is characteristic of such complexes present in cartilage. It contains a proportion of glucosamine (as well as galactosamine); this is not due to contamination with hyaluronic acid. 3. Preliminary findings on fraction I (low density) and fraction II (intermediate density) suggest that these consist chiefly of protein and hyaluronic acid respectively.