Immunohistochemical detection of laminin in various breast lesions

The distribution of laminin, a structural glycoprotein specific for basement membranes, was studied in 52 breast lesions with antilaminin and the avidin-biotin peroxidase complex method. Laminin was observed within vascular and epithelial basement membranes. It displayed a continuous linear pattern in normal breast tissue, fibrocystic disease and in benign tumors. In malignant tumors, laminin was heterogeneously distributed, with a discontinuous linear pattern. No intracellular laminin staining was detected. Laminin may be a valuable aid in the differentiation between benign and malignant breast lesions. Absence of basement membrane and lack of the linear pattern of laminin at the boundaries of malignant ducts may be of value in exclusion of carcinoma in situ

Immunohistochemical studies on patterns of fibronectin and collagen type IV in normal human liver and hepatocellular carcinoma

The distribution of fibronectin [FN] and collagen type IV [coll IV] which are two main components of the basement membrane [BM], was investigated in normal human liver and hepatocellular carcinoma [HCC]. The peroxidase antiperoxidase [PAP] method was applied on paraffin embedded pepsin treated tissue, and the pattern of distribution of the two antigens was compared with the grade of differentiation of the tumor. Fibronectin was observed both extracellularly and intracellularly. It was either increased or decreased. In the more differentiated tumors, fibronectin was increased and it consisted of thin or thick stands. It was either periglandular, pericellular, sinusoidal or stromal-vascular. Decreased fibronectin was seen in undifferentiated HCC. Collagen type IV was localized only extracellularly. It exhibited two patterns of distribution in HCC, peritrabecular or periacinar and stromal-vascular. The finding that FN can be located pericellularly or within the acini supports the concept that FN is synthesized, at least in part by hepatoma cells. The peritrabecular and periacinar location of coll IV suggested a sinusoidal cell derivation of this antigen. The immunohistochemical staining pattern for BM in HCC reflects the differentiation of the tumor, with differentiated tumors showing a relatively intact BM and poorly differentiated tumors revealing a sharply defective BM

Histopathological studies on the effect of the anticoagulant rodenticide brodifacoum on the testis of rat

In the present work, histopathological changes in the testis of rat were studied following oral administration of doses equal to 1/20 and 1/10 LD50 of the anticoagulant rodenticide brodifacoum for one, 2, 3 and 4 weeks. The pathological alterations of the testes of brodifacoum treated rats included disorganization of the seminiferous tubules, maturation arrest, germ cell hypoplasia, necrosis and the appearance of multinucleated giant cells. In the interstitial tissue, the most marked changes were the hemorrhage and congestion of some blood vessels. In cases of rats treated with either the low or the high dose for 4 weeks, besides the previously listed alterations, most of the seminiferous tubules appeared devoid of spermatozoa

Effect of the pyrethroid insecticide permethrin on the total protein contents of the mammalian testis

In the seminiferous tubules of adult normal rat testis, the total proteins were demonstrated in the form of fine granules scattered at random in both the cytoplasm and the nuclei of germ cells and Sertoli cells. The chromatinic proteins in the nuclei of spermatogonia, spermatocytes and old spermatids, as well as the acrosomes and spermatozoa, gave a strong reaction with the mercuric bromophenol blue, whereas the nuclei of young spermatids appeared weakly stained. Moreover, the boundary tissue of the tubules and the interstitial cells were significantly rich in proteins. Oral administration of the pyrethroid insecticide [permethrin] in a dose equal to 1/20 LD50 for one week produced no remarkable changes in the total protein contents of the germinal epithelium. On the other hand, treatment of rats with the same dose of the insecticide for longer periods resulted in a marked loss of the cytoplasmic and chromatinic proteins of spermatogonia and spermatocytes. The Sertoli cells appeared to be not affected by insecticidal treatment