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Biomedical subjects

P Marroni

Publications and source records attributed to P Marroni.

30 records · Page 2Linked to original sources
PubMed1984

Histochemical research into the facial caruncle of the Muscovy duck (Cairina moschata domestica L.) and its relationship with the adrenal glands and gonads.

Histochemical studies carried out on prepuberal and adult, males and females, Muscovy ducks (the Black ancestral variety) showed that the beginning of the facial caruncle is caused mainly by local androgenic activities. In adult males, support for this organ comes from the steroid hormones originating from the adrenal gland and testis. In adult females, caruncular androgenic activity also seems to be necessary for the support of this organ.

3-Hydroxysteroid Dehydrogenases↗
PubMed1983

Mechanism of action of the sodium pump in vertebrate photoreceptors.

Membrane potential and photoresponse of rods in the isolated toad retina was recorded while changing the ionic composition of the extracellular medium. In the presence of 10 mM external Cs+ the bright flash response consisted of an initial fast component of about 35 mV followed by a much slower component as large as 50 mV. The slow component of the photoresponse was blocked by micromolar amounts of both ouabain and strophanthidin. The effects induced by the latter were almost completely irreversible. The effects induced by changing the external concentrations of Na+, K+ and Ca2+ were analysed assuming that the amplitude of the slow component of voltage photoresponse reflects the activity of Na+--K+ pump. It is shown that external Na+, K+ and Ca2+ have the same effect on the amplitude of the slow component as on the Na+-K+ pump activity of other tissues.

Animals↗
PubMed1981

Diurnal changes in the pigeon electroretinogram.

The spectral sensitivity of the pigeon Electroretinogram was determined at different times during the 24-hour cycle. These measures show that diurnal changes occur in the relative sensitivity of the electroretino-graphic responses to light stimuli of different wavelength. Diurnal variations occur despite the absence of rhythmic photoperiodic stimulation. It is suggested that a spontaneous shift occurs in the functional dominance of cones and rods with a period near to 24 hours.

Animals↗
PubMedDate not supplied

Genotypic, phenotypic and biological characterization of a novel human lung adenocarcinoma cell line (LC 89)

A cell line termed LC 89 was established from a peritracheal lymph node metastasis removed from a 54-year-old patient who underwent surgery for pulmonary adenocarcinoma. Chromosomal analyses demonstrated structural and numerical aberrations, with a mode of 54 chromosomes per cell and several nonrandom abnormalities. The localization of intermediate filament antigens, low-molecular-weight (LMW) cytokeratins and vimentin, demonstrated a switch from LMW cytokeratins, predominantly expressed in primary tumor cells, to vimentin detected in LC 89 cells that were grown in vitro or transplanted into nude mice. In view of the phenotypic and chromosomal features, LC 89 should provide a useful addition to the cell lines currently available for in vitro and in vivo studies of lung cancer.

Adenocarcinoma↗
PubMedDate not supplied

Evaluation of cathepsin D as prognostic predictor in breast cancer.

Cathepsin D is an acidic lysosomal protease expressed in all cells. Some studies have shown correlations between high levels of tissue cathepsin D and poor prognosis. This paper deals with 158 cases of breast cancer in which tissue concentrations in cathepsin D, age, estrogen and progesterone receptor content, and pathological characteristics of the tumor were investigated. Tumors were considered to be cathepsin D+ when a concentration > 40 pmol/mg protein (median value in our samples) was determined. The expression of cathepsin D appears to be related to grading (p = 0.04) and lymph node status (p = 0.05). We found no significant associations among cathepsin D levels, patient age, steroid receptors and histological type. Moreover, the levels of cathepsin D have been evaluated in 9 samples of recurring or metastatic neoplasia and 11 cases of benign breast lesions. We conclude that cathepsin D may be a useful prognostic predictor in breast cancer. Further investigations are required to improve and extend the applications of this assay.

Biomarkers, Tumor↗
PubMedDate not supplied

The spinal cord development in guinea pig: a morphometric study on an image analysis system.

Using an image analysis system, the Authors carried out a morphometric study on guinea pig spinal cord in order to determine volumetric changes of white and gray matter during development. White and gray matter volumes were determined by measuring the area occupied by these matters in 10 micrograms sections of spinal cord in 1 day and 90 days old subjects. Several topographic correspondences in the localisation of the lowest and highest volumetric values were observed in the two groups of subjects. Such correspondences were more marked for white than gray matter. Moreover, during growth white matter volume showed an increase double that observed in gray matter.

Animals↗
PubMedDate not supplied

On the presence and ultrastructure of valves in the lymphatic vessels of the canine ovary.

The origin and course of the intraovarian lymphatic vessels were examined by means of histologic studies of the gonads of pubertal female dogs. The small vessels that were present in the cortex near the follicles and corpora lutea flowed into an anastomotic network located at the margins of the medulla. Vessels of larger caliber were found to originate from the medulla and to reach the hilum by an approximately rectilinear pathway. In concordance with their previous findings in other species, the authors identified numerous semilunar valves in the lymphatic vessels of the cortex. Their ultrastructure is described.

Animals↗
PubMedDate not supplied

Effects of stress on adrenal steroidogenesis blockade by aminoglutethimide.

After one week of AG-treatment, the adrenal cortex reveals a marked storage of lipids and cholesterol, as well as a decrease in haematic corticosterone and progesterone levels. On the contrary, when AG-treatment is associated with stress, an increase in plasma corticosterone and progesterone levels occurs, together with a less evident lipidic storage in the adrenal cortex. These results seem to indicate the possibility that, during stress, hypothalamo-hypophysis axis activation is able to remove, at least partially, the adrenal biosynthesis blockade operated by AG-administration.

Adrenal Cortex↗