Myoepithelial cells in lobular carcinoma in situ of the breast: a parallel immunocytochemical and ultrastructural study.

The distribution and morphology of myoepithelial cells in one case of normal breast and in 4 cases of lobular carcinoma in situ (LCIS) were studed by immunoperoxidase and immunofluorescence with anti-actin antisera and by electron microscopy. The actin-rich cells appeared to lay flattened on the basement membrane, or perpendicular to it, or appeared dislodged toward the center of the neoplastic ductules in the different cases. It is proposed that the presence of actin-rich cells inside the neoplastic aggregates represents a process of colonization of lobular carcinoma by myoepithelial cells dislodged from the basement membrane; a differentiation of some neoplastic cells toward myoepithelial elements might also be taken into consideration.

Effect of Rush pins on the distal femoral growth plate of young dogs.

Rush pins were placed in the distal portion of the left femur in 15 young (4 months old) mongrel dogs. Microscopic evaluation of the growth plate showed closure beginning 1 month after the pins were implanted and complete closure occurring a month earlier than in the control (right) femur. The left femurs had a mean decrease in length of 22 mm compared with the length of the control femurs at the time of growth plate closure.

Tubular carcinoma: a variant of secretory breast carcinoma.

Fifteen cases of tubular carcinoma of the breast have been studied using histochemical methods for mucosubstances, immunocytochemical methods for casein and actin and conventional electron microscopy. Mucosubstances and casein were demonstrated lying freely in the lumina of the tubules. Occasionally, mucosubstances and casein assumed the form of target-like intracytoplasmic 'inclusions' like those characteristically seen in lobular carcinoma.

Selective lesions of acinar pancreatic cells in rats poisoned with abrin. A morphological and biochemical study.

Rats poisoned with abrin (2.5 micrograms/100 g body weight) died within 36 h with severe necrosis of acinar pancreatic cells. Incorporation in vivo of labelled amino acids into pancreatic protein was greatly impaired 6 h after poisoning.

Endocrine differentiation in basal cell carcinoma.

Argyrophilic cells have been found in 2 different basal cell carcinomas (BCC), and membrane-bound endocrine-like granules, in the carcinoid range, have been observed in 4 consecutive cases of such tumors. It is postulated that BCC can occasionally display cells showing an endocrine differentiation.

Primary oat-cell carcinoma of the larynx.

A primary oat-cell carcinoma of the larynx in a 63-year-old man is reported. The oat-cell pattern appeared intermingled at one edge with a squamous carcinoma. The origin of this mixed tumour is considered together with the literature of extrapulmonary carcinomas having an oat-cell pattern.

Ultrastructural changes in beta-cells of pancreatic islets in alpha-amanitin-poisoned mice.

In mice poisoned by alpha-amanitin nuclear changes typical of this toxin were observed in beta-cells of pancreatic islets. The lesions became progressively more severe and at 48 h after toxin injection some cells were necrotic. The damage to these cells could have implications in the changes in glycogen metabolism which occur after alpha-aminitin poisoning.

Zygomatic salivary mucoceles in the dog.

Zygomatic salivary mucoceles were diagnosed in 2 dogs. Ophthalmologic signs differed in both cases and reflected the position of the mucocele in relation to the orbit. Cytology of aspirated material and sialography were performed in both cases, but his enabled confirmation of the diagnosis in only one.

Oat-cell carcinoma of the oesophagus: a recently recognized entity.

A primary oat-cell carcinoma of the oesophagus is described with an adjacent squamous carcinoma, both parts having characteristic ultrastructure. The origin of this mixed tumour is discussed together with the literature on oesophageal carcinomas having an oat-cell pattern.