The heart of metamorphosing Mexican axolotl but not that of the cardiac mutant is associated with the upregulation of Hox A5.

The Mexican axolotl (Ambystoma mexicanum) is a facultative neotene which rarely undergoes metamorphosis in the wild. We now report for the first time a dramatic increase in the expression of HoxA5 in axolotl hearts as determined by RT-PCR and in situ hybridization analyses during spontaneous metamorphosis. The Mexican axolotl has a naturally occurring mutation called gene c which allows hearts in homozygous (c/c) embryos to form but never to beat. RT-PCR analysis has not shown any significant differences of HoxA5 expression in normal and mutant hearts. The predicted open reading frame of our already published partial cDNA clone of HoxA5 was confirmed by expressing it as a fusion protein with Glutathione transferase (GST fusion protein). Phylogenetic analysis with the deduced amino acid sequence of the isolated cDNA of the axolotl homolog of the murine HoxA5 shows that the axolotl sequence clusters more closely with the human and mouse HoxA5 homologs than with axolotl sequence. Western blot analysis revealed that anti-mouse HoxA5 antibody recognizes the axolotl HoxA5 protein.

Immunocytochemical localization of insulin- and somatostatin-like material in human breast tumors.

Four types of human breast lesions and C3H mouse mammary adenocarcinomas (type A) were examined for the immunocytochemical localization of cells containing hormone-like substances. Insulin- or somatostatin-like immunoreactive material was observed in scattered single cells and nests of tumor cells in seven of eight infiltrating duct carcinomas, and in the majority of tumor cells from an anaplastic carcinoma. A few somatostatin-immunoreactive cells were observed in only one of seven fibroadenomas studied. No immunoreactive cells were observed in mouse adenocarcinomas or in human breast dysplasias. These results suggest that cells with hormone-like immunoreactivity may be a common feature in two types of malignant human breast tumors.

Fine structure analysis and surface characteristics of mouse mammary gland adenocarcinomas.

Mammary adenocarcinomas from C3H/HeJ mice carrying the mammary tumor virus were studied by means of light, transmission, and scanning electron microscopy. The histological appearance of the tumors was variable; however, 60% were classified as type B adenocarcinomas, while 20% were type A and 20% were composed of equal regions characteristic of both types. Four populations of tumor cells were observed with the TEM. The most abundant of these, primitive glandular cells, were characterized by large, regular, euchromatic nuclei and cytoplasm containing numerous free ribosomes, little rough endoplasmic reticulum, few mitochondria, small Golgi complex and a variable number of type A virus particles. Specialized glandular cells contained highly pleomorphic nuclei, many lysosomes, lipid droplets, multivesicular bodies, profiles of rough endoplasmic reticulum and granules resembling secretory proteins. Myoepithelial cells and dark glandular cells with abundant organelles, large Golgi complexes, dense cytoplasmic matrix and very heterochromatic nuclei were observed infrequently. The SEM revealed tumor cells to be variable in size, shape and surface characteristics. Most cells were rough in texture, displaying irregular ridges, small blebs and a few short microvilli. The contours of some cells were smooth, and a few cells had short, irregular microvilli on limited regions of their surfaces. Cells lining ducts within the tumor had microvilli on their apical surface, but the number, size, shape and distribution of microvilli varied considerably. Cells lining ducts from non-tumor-bearing animals displayed less variation in size, shape and surface morphology.

Changes in uterine morphology which accompany the development of preneoplastic and neoplastic mammary lesions in old mice.

Because of the accumulating evidence that anatomical and physiological changes occur in sites and systems removed from primary tumors, uterine morphology during the development of mammary tumors in C3H/HeJ mice was investigated. C3H/HeJ mice contain the mouse mammary tumor (MTV) virus in their milk and have a high incidence of mammary tumorigenesis. The C3HeB/FeJ mice, used as one set of controls, do not contain the mouse MTV virus in their milk and have a low incidence of mammary tumorigenesis. In young cycling animals without mammary lesions, no differences in uterine morphology were detected between the two strains. However, there were striking differences between the uteri of animals with mammary lesions (C3H/HeJ mice) and the uteri of animals with no mammary lesions. The age-matched control uteri ( 3HeB /FeJ) contained involuted uterine glands and quiescent endometrial stromal and epithelial tissue. The C3H/HeJ mice with mammary tumors contained cystic uterine glands, a stimulated endometrium, and extremely variable endometrial epithelial cells with pleomorphic microvilli. The uterine endometrium from C3H/HeJ mice with preneoplastic lesions also had a stimulated appearance. Some of the uteri of mice with preneoplastic lesions contained cells with cilia or stereocilia. The altered uterine morphology was correlated with preneoplastic and neoplastic mammary lesions and was not related to age or strain differences.

Immunoreactive hormones in human breast tissues.

Samples of breast tissue obtained at biopsy or mastectomy from women with benign breast disease and infiltrating duct or anaplastic carcinoma were maintained for 2 weeks in organ culture synthetic medium 199 without additional serum or hormones. Media were changed every 48 hours. Media withdrawn from the tissues were assayed for insulin, prolactin (Prl), and parathyroid hormone (PTH). In addition, tissue explants were extracted in acid-alcohol and assayed for insulin by standard radioimmunoassay (RIA) procedures. At day 0 portions of breast tissue from patients with malignant or benign disease were fixed in Bouin solution; they were then embedded in paraffin; and serial sections were obtained for histologic and immunocytochemical examination. The dissection media assayed for insulin and PTH by RIA showed that the hormones were present in media from patients with benign as well as malignant disease. However, there was no significant difference between the two groups of women. Only traces of Prl were detected in media. The amount of insulin present in certain tissue explants appeared to increase with time in culture. Immunocytochemical studies showed that insulin-like or PTH-like immunostaining appeared most often in malignant tumor tissue and was observed infrequently or not at all in patients with benign disease. Prl-positive cells were rare. These data suggest that breast tissues contain and may synthesize significant amounts of certain hormones that may influence the growth and proliferation of breast cells.

Male mouse accessory sex glands in organ culture.

Explants of epididymis, vas deferens, seminal vesicle, and coagulating gland from 10-12-week-old and 7-8-month-old male Swiss Webster mice were maintained in synthetic media without serum or hormones for up to 28 days. Differences were observed in the survival and responses of each gland and the behavior of the principal and basal cells. Epithelial cell migration was pronounced in the vas, moderate in the epididymis, and low in the seminal and coagulating gland. The incidence of basal cell proliferation, hyperplasia, and squamous metaplasia usually was positively related to the frequency of basal cells in the zero-time explants. Few differences were observed between the survival or responses of explants from young and old animals; however, explant culture appears useful for exploring fundamental properties of each accessory sex gland, especially the properties of basal cells.

Effects of perphenazine and bromocriptine on male accessory sex glands. III. The prostate gland.

The in vivo morphologic effects of androgen, perphenazine (a prolactin release stimulator), and bromocriptine (a prolactin release inhibitor) on the ventral prostate glands of immature intact and castrate C3H/HeJ mice were studied. Normal prostatic stromal and epithelial development was controlled by testicular androgens. Stromal proliferation and epithelial degeneration followed prepubertal castration at 21 d of age. These changes were reversed after 17-19 or 35-37 d of testosterone administration for 2 wk. In castrate mice, perphenazine administration produced near normal epithelial morphology, whereas bromocriptine stimulated principal cell hyperplasia with basal cell enlargement and increased mitotic activity. In the absence of testicular androgens, prolactin may partially control epithelial proliferation.

Effects of bromocriptine and perphenazine on male accessory sex glands II. Ultrastructure of the seminal vesicles.

The effects of prolactin (PRL) and androgen on the seminal vesicles of immature C3H/HeJ mice were studied. Glands from controls exhibited secretory activity and full differentiation. Glands from castrates were small, markedly atrophic with some stromal hyperplasia and moderate leukocytic infiltration. Testosterone-treated castrates were similar to intact controls. Perphenazine appeared to stimulate the rough endoplasmic reticulum (RER), Golgi, and secretory activity of the epithelium in the intact and castrated mice. Normal secretory granules were not made in the perphenazine-treated castrates, but a flocculent material usually was present in the RER, Golgi, and secretory vacuoles. Bromocriptine reduced cell height and secretory activity in intact mice and promoted anaplasia and epithelial proliferation in castrates. PRL seems to be required for the seminal vesicles to complete and maintain cytological development, but the effect of PRL may be different in the presence or absence of testicular androgens.

Effects of bromocriptine and perphenazine on male accessory sex glands. I. The seminal vesicles.

The effects of bromocriptine and perphenazine on C3H/HeJ mouse seminal vesicles were studied. The response of the stroma and parenchyma of the glands to the hormones differed. Testosterone repressed stromal proliferation. Prolactin had no observable stromal effect but influenced the response of the parenchyma. In castrated mice, low levels of prolactin were associated with abnormal epithelial mitotic activity and atypical cytology while elevated prolactin levels resulted in a nonatrophic epithelium similar to that from the seminal vesicles of intact individuals. In the absence of testicular testosterone, prolactin may exert an inhibitory influence on glandular proliferation.

Morphological changes in the mammalian vas deferens during aging. I. The occurrence of binuclear cells in the mouse.

The number of nuclei per principal cell was determined in the vas deferens of sexually immature, young sexually mature and old male mice. The incidence of binucleation increased with age. In 21-day-old mice approximately 99% of the principal cells were mononucleated and 9%-20% of the principal cells were binucleated. In the oldest animals, the ampulla and testis end of the vas usually had more binuclear cells than the middle segment. The biological significance and the mechanism of this phenomenon are not known; however, binucleation may prove to be a useful indicator of aging in the vas of this species. In addition, the mouse vas may provide a useful model for studies of binucleation and mitosis.

The effect of oxandrolone on low and high density lipoprotein profiles in retired breeder rats.

The retired breeder rat, an animal known to undergo premature aging and to develop hypercholesterolemia, was studied to determine the effect of oxandrolone, a synthetic hypolipidemic steroid, on serum lipoprotein subfractions. The methods utilized for this study included density ultracentrifugation, electron microscopic lipoprotein particle sizing, and disc gel electrophoresis. The data confirmed the cholesterol-lowering ability of oxandrolone and demonstrated that its effect on total serum cholesterol was limited to the low and high density lipoprotein subclasses. The drug-treated group had 50% less LDL cholesterol and 25% less HDL cholesterol. Though there was an absolute decrease in total serum cholesterol in both these fractions, there was a re-distribution of cholesterol, such that post-treatment LDL carried less cholesterol and HDL more cholesterol on a percentage basis than found in pre-treatment values. In the light of current concepts of atherogenicity these alterations are of interest and potentially of considerable value.

Cell surface differences in ducts from cancerous and noncancerous human breasts.

The scanning electron microscope reveals structural differences between the apical microvilli of duct cells from cancerous and noncancerous human breasts. The alterations in the microvilli from carcinomatous breasts appear to be highly specific, to extend throughout the affected breast, and may be pathognomonic for this condition.