Ultrastructural changes and viral morphogenesis during the growth of the mouse preputial gland tumor ESR 586.

A study was undertaken to observe morphological changes and viral morphogenesis during the growth of the mouse preputial gland tumor ESR 586. The acinar cells of the normal preputial gland have an extensive agranular endoplasmic reticulum and Golgi apparatus and large lipid droplets. No viral particles are present. During tumor growth, and numerous lipid droplets never attain the size of those found in the normal gland. There is a decrease in the Golgi apparatus and agranular endoplasmic reticulum and an increase in the rough endoplasmic reticulum which could reflect a change in composition of tumor secretory product from the normal gland. Indeed, there is a decrease in triglycerides as the tumor ages and an increase in the sterol esters and waxes. In addition, intracisternal A-particles are observed budding from thickened endoplasmic reticulum membranes. Thickening of these membranes occur early in A-particle formation. One side of the membrane is first thickened while the opposing membrane appears is first thickened while the opposing membrane appears morphologically unaffected. The thickening of the affected membrane is initially confined to the outer (cytoplasmic) face of the membrane. In the older tumor, both opposing membranes of the reticulum are thickened and can assume an elongated whorled pattern.

Tissue connections in a transplantable virus-producing sebaceous adenoma of the mouse.

In this study a transplantable sebaceous adenoma is presented, which maintained its histological structure with similarities to normal sebaceous glands over a long series of transplantations. From the periphery toward the center a basal lamina, an outer layer of undifferenciated stem cells, loosely connected secreting tissue, a tightly packed zone of close cell attachment, and finally a central sebaceous zone can be distinguished. Special reference is made to the belt-like region around the zone of cell lysis and sebum accumulation, which forms a barrier to the surrounding tissue by means of numerous cell adhesions in the form of desmosomes. Relatively few virus particles of the retrovirus group, particularly type A particles, were found in any of the examined tumors.

Demodex-associated dermatologic conditions--A coincidence or an etiological correlate. Review with a report of a rare case of sebaceous adenoma.

Demodex folliculorum is a saprophytic mite of the human pilosebaceous unit with a prelidiction for facial skin and eyelashes. Infestation occurs frequently without symptoms; however, suppurative or granulomatous inflammation may be seen with high mite density. Skin lesions, such as rosacea, pityriasis, and blepharitis, have been attributed to Demodex; however, its role in sebaceous adenoma (SA) has not been reported in extensively searched medical literature. We report this rare case and review the skin lesions associated with Demodex folliculorum.

[Transplantable sebaceous adenoma of the mouse with virus particles studied by electron microscopy (author's transl)]. / Transplantables Talgdrüsenadenom der Maus mit elektronenmikroskopischem Virusnachweis

Histology and ultrastructure of a sebaceous adenoma of the mouse -- derived from i.p.-injection of 0.1 ml DNA, isolated from cells of a transplantable mouse-leukemia -- were studied. The original tumour and all transplanted tumours display the same tissular differentiation. In all tumours virus particles were found. Structure and behaviour of the intracytoplasmic A-particles resemble those of the mouse mammary tumour virus while the C-particles found extracellular were identical with the leukemia viruses of the mouse. It might be suspected that mammary tumour virus and leukemia viruses are either non specific or that a new virus is present in the sebaceous adenoma.

Papillomas and carcinomas associated with a papillomavirus in European harvest mice (Micromys minutus).

Papillomaviruses, group-specific papillomavirus antigens, or extrachromosomal papillomavirus DNA were detected in cutaneous, mucocutaneous, and pulmonary tumors affecting a colony of European harvest mice (Micromys minutus). Skin lesions were classified as acanthomatous hyperplasia, epidermal inclusion cysts, squamous papillomas, inverted papillomas, trichoepitheliomas, and sebaceous carcinomas. Cutaneous horns (hyperkeratotic papillomas) were on mucocutaneous junctions of one animal. One mouse, with a cutaneous sebaceous carcinoma, had multiple pulmonary keratinaceous cysts. Papillomavirus antigens, detected by the avidin-biotin technique, were in 20 of 31 lesions tested. In contrast, by Southern blot hybridization all 28 lesions tested contained papillomavirus DNA. Papillomavirus DNA was demonstrated in two of ten benign cutaneous lesions by in situ hybridization.