Vasopressin and its carrier protein, vasopressin-associated neurophysin, are co-packaged together with an opioid peptide, dynorphin, into 160 nm diameter neurosecretory vesicles in the normal rat hypothalamo-neurohypophysial system. The homozygous Brattleboro rat lacks vasopressin and vasopressin-associated neurophysin, but contains substantial amounts of dynorphin in the vasopressin-deficient neurosecretory cells. We used post-embedding electron microscopic immunocytochemistry to determine the subcellular location of dynorphin in Brattleboro rats. The results show that dynorphin is present within 100 nm neurosecretory vesicles in homozygous Brattleboro cell bodies and axons, and within 160 nm vesicles in heterozygous (control) neurosecretory cell bodies and axons. Oxytocin-associated neurophysin is present in a separate population of magnocellular neurons in both homozygous and heterozygous rats, and is contained within 160 nm vesicles in both cases. Therefore, the absence of synthesis of the vasopressin prohormone results in a dramatic reduction of neurosecretory vesicle size, despite the continued synthesis and packaging of dynorphin peptides.

Animals↗

PubMedDate not supplied

Microsporidian infection in the cyst wall of Trematode metacercariae encysted in fish.

Microsporidian infection is reported in Liza ramada (Risso), Mugilidae, from Bardawil Lagoon, Mediterranean coast of Sinai, in the fibroblasts of the metacercarial capsule of Heterophyes heterophyes (Siebold). Infection of the metacercarial cyst resulted in an hypertrophy of the cyst wall and degeneration and eventual death of the encapsulated metacercaria.

Animals↗

PubMedDate not supplied

[Environment of invasive breast carcinoma. Morphological and epidemiological study].

In a retrospective study, the authors have observed different types among 180 breast invasive carcinomas, their environment and their epidemiology. Tumors consisted in 158 invasive ductal carcinomas, 11 invasive lobular carcinomas and 11 special forms. The benign environment was divided in 3 groups: no epithelial lesion (1/5 cases), "mastosis simple" (3/5) (elementary lesions more or less associated, exceptionally isolated, diffuse or focal), the last, 1/5, corresponded to a "mastosis complex" defined as the significant association of the same elementary lesions (minimum 3 to 4), diffuse, with some degree of dysplasia and always an intraductal hyperplasia, of any type. The confrontation of these environments with carcinoma types and grades and with some epidemiological data allowed: 1) To opposite intraductal hyperplasias, mainly "mastosis complex", to other environments; 2) to discuss a) "mastosis complex" position in relation to cancer, b) an eventual lobular origin for precancerous lesions and c) individualization of epidemiological factors in relation to development of malignant tumors.

Adenocarcinoma↗