A case of sarcomatoid carcinoma of the skin

We describe the histological and immunocytochemical findings of an exophytic cutaneous tumour with mixed features of atypical fibroxanthoma (AFX) and basal cell carcinoma (BCC). A 73-year-old woman presented with a rapidly growing tumour measuring 35 mm in diameter and 10 mm in height on the left forearm. The tumour was excised and histology revealed a biphasic tumour with a pleomorphic spindle cell component and an associated tumour composed of discrete islands of atypical basaloid cells with peripheral palisading consistent with BCC. The two tumours merged into each other at one point. The spindle cell tumour showed a positive immunocytochemical reaction to fibrohistiocytic marker of KP-1 (CD68) and a negative immunocytochemical reaction to AE1/AE3, CAM5.2, S-100 and HMB-45, features consistent with AFX. Immunocytochemistry of the basaloid tumour showed a positive reaction to epithelial markers AE1/AE3 and CAM5.2, and a negative reaction to S-100, HMB-45 and KP-1 (CD68). To date, 15 cases of primary cutaneous carcinosarcoma have been reported in the literature. It has been postulated that these tumours may originate from undifferentiated progenitor cells capable of producing multiple cell lines.     

The effect of the plasticizer di(2-ethylhexyl)phthalate on red cell deformability

Red cell concentrates (RCC) are stored for 35 to 42 days in plastic containers manufactured with the liquid plasticizer di(2- ethylhexyl)phthalate (DEHP). DEHP leaches from the polyvinylchloride (PVC) plastic bag, then binds to and stabilizes the RC membrane. This study was undertaken to determine the deformability of the RC membrane using an osmotic gradient ektacytometer and to relate these measurements to the concentration of DEHP in the stored RCC. Pooled RCC was aliquoted into PL146 (PVC), PL732 (polyolefin), and PL732 (with added DEHP) bags with samples removed weekly for analysis of osmotic fragility, deformability, and DEHP concentration. The adenosine triphosphate (ATP) content was also measured. The increase in osmotic fragility during storage was greater when RCC was stored without DEHP. In addition, there was a decrease in the maximum elongation index (El max) when there was decreased DEHP in the storage bag. The osmolarity (Omax) at which El max occurred, as well as the Omin, the osmolarity at which minimum elongation (El min) occurred was higher in the PL732 container than in the PL146 or in the PL732 to which DEHP had been added. These changes could be reversed by addition of DEHP at the beginning of the storage period, showing a direct correlation between DEHP concentration during storage and RC membrane flexibility. By a better understanding of the mechanism of DEHP protection, it might be possible to substitute a less toxic stabilizing compound.     

Diet, plasma lipoproteins and experimental atherosclerosis in baboons (Papio sp.)

Diet-induced hyperlipidaemia in baboons is similar to that inhumans. As in humans, the ratio between low density lipoprotein(LDL) and high density lipoprotein (HDL) cholesterol is a majordeterminant of atherosclerosis. Baboons, like humans and othernon-human primates, vary in their lipaemic responses to dietarylipids. By selective breeding based on variability in plasmaand lipoprotein cholesterol response to diet, lines of baboonswith high and low responses of various lipoproteins have beendeveloped. Genetic analyses suggest that lipoprotein patternsin responses to dietary cholesterol and fat are heritable. Metabolicand molecular studies of high and low LDL and HDL cholesterolresponses to dietary lipids have suggested that different mechanismsregulate plasma LDL cholesterol on the chow and on the highcholesterol-high fat (HCHF) diet. On the chow diet, plasma LDLcholesterol levels are positively associated with cholesterolabsorption and negatively associated with hepatic LDL receptorlevels and, thus, cholesterol absorption and LDL receptors seemto regulate plasma LDL cholesterol levels. However, when theanimals consume a human-like fat- and cholesterol-enriched diet,plasma LDL cholesterol levels are not associated with eithercholesterol absorption or hepatic LDL receptor mRNA levels,but are negatively associated with plasma 27-hydroxycholesterolconcentrations, hepatic sterol 27-hydroxylase activity, andmRNA levels. Hepatic sterol 27-hydroxylase activity and mRNAlevels are induced by dietary cholesterol and fat in low respondingbaboons more than in high responding baboons. Thus, the abilityto induce sterol 27-hydroxylase determines the LDL cholesterolresponse in baboons. High HDL response baboons often have highlevels of HDL₁ in their plasma. Our studies suggest that theN-terminal fragment of apo C-I with 38 amino acids and a molecularweight of 4 kDa acts as a cholesteryl ester transfer inhibitorpeptide in high HDL₁ baboons. The inhibitor peptide associateswith apo A-1 in HDL to produce a modified apo A-1 protein witha molecular weight of 31 kDa. The inhibitor peptide is a geneproduct and the presence of this peptide produces an antiatherogenichigh HDL₁ phenotype.