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Biomedical subjects

A Mauriello

Publications and source records attributed to A Mauriello.

15 recordsLinked to original sources
PubMed1992

Densitometric and morphometric study of immunocytochemical estrogen receptors detection in breast carcinomas.

Immunohistochemical quantitative evaluation of estrogen receptors (ER) detected in tissue sections from 30 breast tumors by monoclonal antibody was performed using a densitometric method. In particular, ER concentration was calculated by nuclear mean optical density (nMOD), while heterogeneity in ER content was calculated by the coefficient of variation (CV) of the nuclear optical density histogram. Tumors which showed more than 60% of positive cells had a mean value of ER-nMOD of 0.116 +/- 0.002 a.u. and of ER-CV of 33.74 +/- 0.68. Tumors which showed 30% to 60% of positive cells had a mean value of ER-nMOD of 0.082 +/- 0.006 a.u. (arbitrary units) and of ER-CV of 36.25 +/- 3.44. Tumors showing less than 30% of positive cells had ER-nMOD of 0.052 +/- 0.009 a.u. and ER-CV of 48.49 +/- 5.61. These results indicate that the greater the concentration the lower the ER heterogeneity within the tumor sample. No significant differences between ER-ICA results, nuclear size and form factors were found.

Breast Neoplasms↗
PubMed1992

Age-related modification of average volume and anisotropy of vascular smooth muscle cells.

The aim of this study was to determine what changes in the arterial wall are related to age. In two groups of rabbits, one young and one adult, the aorta and carotid were studied using a morphometric approach based on stereological axioms and planimetric morphometry. The problem of anisotropy of smooth muscle cells is discussed in detail. Two forms of anisotropy must be distinguished, that of single cell and that due to the histological pattern of the smooth muscle cells in the arterial wall. Our results show in adult animals, as compared to the young ones, statistically significant decrease in anisotropy of the cell pattern which tends to become more regular. Moreover, in aorta and carotid of young and adult animals there is an increment of 95.39% and 80% of the absolute cell volume, respectively. We suggest that there may be a direct relationship between aging and phenotypical modulation of the smooth muscle cells and that the modification of the architectural cell pattern with age may represent an adaptive event related to the change in forces acting upon the arterial wall.

Aging↗
PubMed1992

Age-dependent increase of rabbit aortic atherosclerosis. A morphometric approach.

Aging has been indicated as one of the major risk factors for development of atherosclerotic lesions, although the role aging plays, lacks accurate evaluation. Our study was aimed at quantitatively defining such a role by using morphometric analysis. Aged (median age 3 years and 8 months) and young (4 months) white New Zealand rabbits received a hyperlipemic diet enriched with a low dose of cholesterol for 16 months. At regular intervals, levels of serum lipemic parameters were checked. A Quantimet 920 image analyzer was used on paraffin-embedded sections of the entire aortas to measure the volume density of the tunica intima, the volume density of atheroma, the ratio intima/media and the surface area of the tunica intima. Our results indicated for aged hyperlipemic rabbits a statistically significant increase in all morphometric parameters examined as compared to young hyperlipemic animals, and no statistically significant differences in serum cholesterol, triglycerides and phospholipids.

Aging↗
PubMed1991

Platelet-activating factor (PAF) stimulates the lysoPAF acetyltransferase in leukocyte-rich plasma: use in PAF antagonist studies.

Addition of platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) to leukocyte-rich plasma from several species resulted in the rapid and pronounced activation of the PAF biosynthetic enzyme acetyl-CoA:1-O-alkyl-sn-glycero-3-phosphocholine acetyltransferase (EC 2.3.1.67). Activation of acetyltransferase by PAF occurred in leukocyte-rich plasma from human, chimpanzee, rhesus monkey, and dog. The neutrophil was indicated to be the major cellular source of the activatable acetyltransferase in leukocyte-rich plasma. The induction of acetyltransferase was substantial with 10 nM PAF, and maximal at 10-30 seconds. Measurable acetyltransferase activation was significantly greater when the PAF-activated cells were separated from the plasma by centrifugation before the acetyltransferase assay. This may be due in part to the removal of the PAF-specific acetylhydrolase present in plasma which can cleave the acetyl group from PAF. Measuring PAF activation of acetyltransferase in leukocyte-rich plasma can be useful to determine the potency of PAF antagonists with neutrophils in plasma compared to isolated neutrophils in aqueous buffer, and as an ex vivo assay to determine the efficacy and plasma concentration equivalents of antagonists administered to whole animals. The PAF antagonist L-659,989 was shown to be 3-5 times more potent in inhibiting PAF induction of acetyltransferase in isolated human neutrophils than in human leukocyte-rich plasma, with IC50 values of 10 nM and 40 nM, respectively. In the ex vivo assay, oral administration of the PAF antagonist L-667,131 to dogs resulted in very substantial inhibition of PAF induction of acetyltransferase in the leukocyte-rich plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetyltransferases↗
PubMed1991

Aging and atherosclerosis in the rabbit. 1. Distribution, prevalence and morphology of atherosclerotic lesions.

Aging is considered a risk factor in the pathogenesis of atherosclerosis. It is not clear, however, whether the relationship between aging and atherosclerosis is the result of increased susceptibility of the arterial wall related to intrinsic alterations or the expression of the increase in intensity or duration of exposure to risk factors. In this study, we used aged (median age 46 months) and young (4 months old) New Zealand white rabbits. Nine aged and 11 young rabbits received a hyperlipemic diet enriched with a low dose of cholesterol for 18 months. Eleven aged and 8 young rabbits, fed standard chow for the same period, were used as controls. Using morphologic and morphometric methods, we detected in aged hyperlipemic rabbits (a) a marked prevalence of fibroatheromatous plaques (as opposed to fatty streaks in young hyperlipemic rabbits); (b) aortic lesions more extensive and of greater dimensions than in young hyperlipemic rabbits; (c) fibroatheromatous plaques in carotids and raised fatty streaks in the large subepicardial coronary branches. Our results show an increased susceptibility of the aged arterial wall to hypercholesterolemia.

Aging↗
PubMed1990

High-dose synthetic progestogens inhibit foam and smooth muscle cell proliferation and atherosclerotic plaque formation in aortas of rabbits fed a hypercholesterolemic diet.

Female rabbits on a hypercholesterolemic atherogenic diet were treated with high doses of the synthetic progestogens norethisterone and medroxyprogesterone acetate in order to clarify the effect and possibly some of the mechanism of action of these hormones on diet-induced atherogenesis. We employed morphometric studies to determine the surface area of the rabbit aorta occupied by and the maximum thickness of lipid plaques. Autoradiography with tritiated thymidine was performed to demonstrate the effect of the progestogens on cell proliferation, which plays a key role in atherogenesis. Medroxyprogesterone acetate-treated and, above all, norethisterone-treated animals exhibit a more marked reduction of atherosclerosis than control rabbits fed the same diet. Our results suggest that both progestogens we used inhibit the development of atherosclerosis mainly by blocking the proliferation of smooth muscle cells in the tunica media and the cell population of the plaque.

Animals↗
PubMed1990

Morphometric evidence of the trophic effect of L-carnitine on human skeletal muscle.

We investigated the effect of long-term i.v. administration of L-carnitine on human muscle fibers using morphometric parameters. We administered 2g/day L-carnitine to patients undergoing hemodialysis for at least 12 months. At the end of this period a marked increase in serum and muscle carnitine levels was observed in all patients, together with hypertrophy and predominance of type 1 fibers. L-carnitine was withheld for 4 months, during which time serum and muscle levels gradually decreased and no changes were observed in muscle fibers. Subsequent addition of L-carnitine to dialysis fluid for another 4 months stabilized lower levels. At the end of this period reduction of diameter of type 1 fibers was observed. Type 2 fibers remained unchanged. Moreover, type 1 fibers remained predominant in all cases. Hence, we suggest that carnitine has a specific trophic effect on type 1 fibers which are characterized by an oxidative metabolism.

Aged↗
PubMed1989

Proliferative response of foetal liver peroxisomes to clofibrate treatment of pregnant rats. A quantitative evaluation.

Liver peroxisomes during prenatal development were studied by means of morphological and morphometric analysis in foetuses growing both in untreated and in clofibrate-treated rats. Pregnant rats were fed a standard diet (25 g/d) containing or not 0.8% clofibrate during the week preceding sacrifice and livers were excised from 13, 15, 17, 19 and 21-day old foetuses and newborn rats. The morphometric analysis of hepatocyte peroxisomes, performed by a semiautomatic method in specimens incubated with 3,3' diaminobenzidine, shows that the peroxisome volume density and average diameter in test animals were significantly increased over the control values. While the increase in the average diameter was roughly the same (X 1.4) at all examined stages, the volume density increased over the control values particularly in foetuses over 19d-old and in newborn rats; over the same period the peroxisome numerical density also significantly increased over the control values. Finally, the average diameters of peroxisome profiles in test rats showed a more dispersed distribution (SD 40%) than in control animals (SD 30%). These results demonstrate that clofibrate, given to rats during pregnancy, induces peroxisomal proliferation in the livers of their foetuses. Data are discussed in view of the models proposed for peroxisomal biogenesis.

Animals↗
PubMed1985

Age-related modulation of vascular smooth muscle cells proliferation following arterial wall damage.

The proliferative response of vascular smooth muscle cells (SMC) to an arterial wall injury has been investigated in young (3-6 months) and old (30-52 months) rabbits, employing two different experimental models. In the first model the lesion was produced by passing an inflated balloon catheter along the abdominal and descending thoracic aorta, while in the second, the endothelium was removed from a segment of the right carotid artery by air-drying. Both experimental models produced very heterogeneous lesions in which the de-endothelialization of the arteries was often accompanied by foci of cellular necrosis of variable extension throughout the vascular wall. The autoradiographic evaluation of the proliferative response of arterial SMCs following in vivo administration of 3H-thymidine revealed different patterns of labeling according to the type of lesion produced. A significant negative correlation (p less than 0.001) was found between the proliferative response and the cellular density of the vascular district. An age-related decrease in the proliferative response of SMCs was observed only in the thoracic aorta where the damage to the tunica media was less extensive as compared to the other vascular districts.

Aging↗
PubMedDate not supplied

[Latent pathology of the thyroid: an epidemiological and statistical study of thyroids sampled during 507 consecutive autopsies].

In order to highlight the occult pathology of the thyroid in the aged, the authors examined all the glands withdrawn from 507 consecutive autopsies on subjects of 67.10 years of median age. In 10 tables there are weight and measurements of the thyroids, macro and microscopic details and pathologic appearances. Adenomas were found in 17.1% of cases and histologically besides the known cases referred also to the Hürtle cells type, 4 clear cells adenomas and 5 adenolipomas were found. In 27.42% the subjects were affected or were dead for a malignant extrathyroidal neoplasm, and in 26% of these there was a metastasis in the thyroid. Never a primitive thyroid carcinoma, macroscopically and clinically evident, but in 53 thyroid glands, 54 occult carcinomas (OC) were found, particularly 37 papillary and 17 medullary. IN 57% of 165 histologically treated thyroids, to evidence C-cells, hyperplasia of these cells was found associated with various pathologic conditions, more in aged subjects. In 147 glands were found 170 nodules of various number of cells, at times positive for calcitonin. These solid cellular nodes (SCN) were evaluated as nodular C-cells hyperplasia. Besides isolated cases of acute thyroiditis (also the mycotic type), of tubercular thyroiditis and Hashimoto's, in 12% of the glands a lymphocytic chronic thyroiditis was found, frequently with Hürtle cells. Others observations were: basophilic thickening of colloid also with calcium oxalate crystals, lipoid degeneration of follicular cells and fat interfollicular and interlobular infiltration, thyroid amyloidosis, inner and media elastic calcification of thyroid arteries, presence of cysts with squamous cells coating, parathyroid glands and cartilage intrathyroidal plaques.

Adolescent↗
PubMedDate not supplied

Echodensitometry: a methodologic approach to the non-invasive diagnosis of carotid atherosclerotic plaques.

The ultrasound image of the fibroatheromatous plaque has to date been unable to reveal the presence or absence of complications as shown by histology, such as thrombosis and intraplaque hemorrhage. We propose a novel densitometric method for determining the composition of the plaque at the echotomography, along with a new classification based on mathematical models drawn from the optical density distribution curve. This approach avails of an extremely high sensitivity. Percent areas occupied by thrombosis, intraplaque hemorrhage and atheroma in histologic sections have been shown to correspond to hyporeflecting areas in echotomographic images, whereas those occupied by calcium and fibrous tissue correspond to reflecting areas with or without acoustic shadow, respectively. This method may prove to have an important role in the non-invasive monitoring of even slight changes during progression or regression of the fibroatheromatous plaque.

Arteriosclerosis↗
PubMedDate not supplied

Histopathological characterization of carotid plaques echotomography.

The positive correlation between cerebral ischemia and carotid atherosclerosis of extracranial tract has been well established. The reliability of echotomography as diagnostic and prognostic tool in the evaluation of the carotid atherosclerotic lesions is now intensively investigated. Most of the attention has been payed to the accuracy in the determination of the carotid stenosis. A percentage of cerebrovascular accidents do not correlate to the vascular stenosis but to the other modifications induced by the atherosclerotic plaque, such as the release of emboli, acute stenosis for intraplaque haemorrhage or thrombosis. Thus the evaluation of the composition of the plaque may represent a good prognostic tool. In the present study, fifty-two carotid obtained at surgery from patients, who preoperatively underwent ultrasonographic scanning of both carotid arteries, were examined by histological methods. In calcified tissues a significant correlation between findings obtained with both techniques was observed. In the complicated plaques atheromasic gruel, intraplaque haemorrhages and thrombosis could not be discriminated by echotomography.

Carotid Arteries↗