Biomedical subjects

B U Holecek

Publications and source records attributed to B U Holecek.

4 recordsLinked to original sources

PubMed1995

A tumour derived from Ebner's glands: microcystic adnexal carcinoma of the tongue.

Microcystic adnexal carcinoma (MAC) is known as an infiltrating but non-metastasizing tumour of the skin, that derives from sweat glands or follicular epithelium. We report on a rare case of MAC of the tongue. The patient had noticed the tumour for two years with slowly increasing dysphagia but no other symptoms of an oropharynx carcinoma. Histological and immunohistochemical analyses showed a similarity between the tumour derived from Ebner's glands of the tongue and MAC of the sweat glands.

Aged↗

PubMed1993

Bulge-activation hypothesis: is it valid?

This essay is a critique of a revolutionary hypothesis, and of the language used to frame it, that offers a novel interpretation for the dynamics of the follicular cycle by distinguishing, distinctly, germinative cells in the bulge from matrical cells in the bulb. Curiously, this intriguing "bulge-activation hypothesis" elicited practically no response in the scientific literature, and our critique is designed to rectify that.

Animals↗

PubMed1992

Expression of stromelysin 3 in the stromal elements of human basal cell carcinoma.

In basal cell carcinoma, release of proteolytic activity is implicated in extracellular matrix degradation and tumor infiltration. The stromelysin metalloproteinase family is a major candidate for the matrix proteolytic activity in infiltrative tumors. However, in murine models of basal cell carcinoma, neither stromelysin 1 nor 2 appears to play a role in tumor infiltration. We have analyzed the expression of the newly described stromelysin 3 in human basal cell carcinoma using Northern blot analysis and in situ hybridization. In 12 of 14 cases, levels of stromelysin 3 expression were more than tenfold above those observed in normal skin. In one of five cases of squamous cell carcinoma, stromelysin 3 expression was tenfold above levels seen in normal skin. Stromelysin 3 expression was either undetectable or extremely weak in all five cases of infiltrative malignant melanoma. In basal cell carcinoma, stromelysin 3 transcripts were localized by in situ hybridization to the stromal tissue immediately adjacent to basal cell carcinoma, the tumor cells themselves being negative. Therefore, expression of stromelysin 3 in stromal cells may be expected to play a significant role in destruction of the basal membrane zone and extracellular matrix in basal cell carcinoma invasion.

Blotting, Northern↗

PubMed1989

Chromosomal analysis of a diethylnitrosamine-induced tumorigenic and a nontumorigenic rat liver cell line.

A chromosomal analysis was performed on two cell lines which were derived from the liver of two rats exposed to diethylnitrosamine in vivo. The cells were obtained by collagenase perfusion of the liver at an early stage of development of ATPase-deficient putative preneoplastic populations, and propagated from foci of epithelial cells which started growth in vitro. Cell line CL 38 proved to be tumorigenic after transplantation into nude mice, giving rise to hepatocellular carcinomas and metastases. Cell line CL 44 was nontumorigenic after transplantation into nude mice and was therefore considered preneoplastic. The diploid nontumorigenic line CL 44, with a modal number of 42 chromosomes, showed a deletion of chromosome 1 and a translocation of chromosomes 3 and 14 [t(3q12;14q21)]. The hyperdiploid neoplastic cell line CL 38 has a modal chromosome number of 52 and showed tri- or tetrasomy of chromosomes 3, 7, 9, 11, and 12 and a marker chromosome that might have originated from aberrant chromosome 1. One or two homologues of chromosome 3 showed terminal deletions (q42, q41, or q35). In both cell lines rearrangements of chromosome 11 were observed [rob(11q;?) or +11 or -11 or del(11)(q12)]. Some of these karyotype abnormalities are located on the same chromosome as described for transplantable hepatomas and for other chemically induced tumors of the rat.

Animals↗