Intrabronchial schwannoma. A case report.

A 17-year-old male presented with clinical features of left lung collapse. The diagnosis of isolated intrabronchial schwannoma was obtained by endoscopic biopsy and confirmed after pneumonectomy.

Experimental haematogenous pyelonephritis in mice with uropathogenic, enteropathogenic and enterotoxigenic Escherichia coli.

Acute haematogenous pyelonephritis was produced with known uropathogenic (075), enteropathogenic (0111) and enterotoxigenic (H10407) Escherichia coli in mice. The enterotoxigenic E. coli showed the highest bacterial counts in kidney and urine and was found to have the same potential for causing pyelonephritis as a known pyelonephritogenic strain both in untreated and corticosteroid treated mice.

Biochemical markers in colon tumorigenesis: retinoic acid and dihydrotestosterone-binding proteins.

A specific retinoic acid-binding protein (RABP) and a dihydrotestosterone-binding protein (DHTBP) appeared in colon tumors as well as in tissues surrounding the the tumors, but the proteins were nondetectable in normal adult human colon tissues. We have analyzed a total of 105 human colon tumors and related specimens for the presence of RABP and DHTBP as possible biochemical markers in colon tumorigenesis. The tissue or tumor extracts after incubation with (3H) retinoic acid or (3H) dihydrotestosterone were sedimented on sucrose gradients, and the binding proteins were detected from the 2S (RABP) or 6-7S (DHTBP) radioactive peaks.

The presence of binding proteins for retinoic acid and dihydrotestosterone in murine and human colon tumors.

Retinoic acid-binding protein (RABP), which is distinctly present in embryonic colon and lung, is below the limits of detection in adult mouse colon and lung. The binding protein is present in malignant murine colon tumors as well as in lungs of animals bearing subcutaneously implanted tumors. Primary cell cultures from 1 g of colon tumor 26 gave rise to about 10(7) tumor cells and yielded 30 mg of extractable protein.

Cellular uptake of retinoic acid in vitro.

Incubation of chick embryo skin and mouse colon tumour 26 with [3H]retinoic acid resulted in the formation of a complex of retinoic acid and its cellular binding protein both in cytosol and in nuclei. Formation of the ligand--protein complex was temperature-dependent and increased with increases in retinoic acid concentration in the incubation medium. About 3--8% of the ligand present in the cytosol was associated with the nuclei.

Purification and properties of retinol- and retinoic acid-binding proteins from a transplantable mouse colon tumor.

Cellular retinol-binding protein and retinoic acid-binding protein, the possible mediators of the action of retinoids in epithelial differentiation and control of tumorigenesis, have been reproducibly purified from mouse colon tumor 26, and some of their properties were studied. The main steps of purification involved acid-precipitation, DEAE-Sephadex, CM-cellulose and Sephadex G-100 chromatography. About 2 mg of the binding proteins were isolated from 60 g tumor.

Purification and properties of retinoic acid-binding protein from chick-embryo skin.

Retinoic acid-binding protein, which is considered to mediate the biological function of retinoic acid in epithelial differentiation and in the possible control of tumorigenesis, was reproducibly purified from chick-embryo skin by using DEAE-Sephadex and Sephadex G-100 column chromatography and isoelectric focusing. About 1mg of protein was isolated from 60g of skin. The purified protein-ligand complex was found to be homogeneous by electrophoresis on polyacrylamide gels.

Determination of binding affinities of retinoids to retinoic acid-binding protein and serum albumin.

Binding affinities of retinoic acid and its synthetic analogues to intracellular retinoic acid-binding protein, which is a possible candidate for mediating their biological function, and to serum albumin, the plasma transport protein, were evaluated. A quantitative method involving elimination of interfering serum albumin by immunoprecipitation was developed to measure the binding efficiency of these retinoids, some of which are active in modifying epithelial differentiation and preventing tumorigenesis. Two cyclopentenyl analogues of retinoic acid and 13-cis-retinoic acid showed, like retinoic acid, a binding efficiency of 100% for the cellular binding protein.

Fatal proliferative glomerulonephritis in lepromatous leprosy.

A patient of lepromatous leprosy with recurrent erythema nodosum leprosum developing acute renal failure proving fatal within 8 weeks is reported. The renal lesion demonstrated acute proliferative glomerulonephritis. Its pathogenesis in relation to ENL is discussed.