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N Arena

Publications and source records attributed to N Arena.

49 records · Page 3Linked to original sources
PubMed1983

[Embryo-toxic effects of nickel sulfate in Paracentrotus lividus: preliminary observations].

A primary objective of the work described here was to determine the embryo-toxic effects induced by Nickel Sulfate upon the development of the Paracentrotus Lividus. Different concentrations of Nickel Sulfate have been dissolved in containers with not foul sea-water. The fecundation took place in the containers and verified by constant observations with a light microscope. The development of the Paracentrotus 1. was totally blocked at a concentration of 0.5 M.10(-2) of Nickel Sulfate, while an enormous development was observed at concentrations of 0.5 M.10(-3) and 0.5 M.10(-4). Finally, a concentration of 0.5 M.10(-5) caused a slow development. A normal development was observed only at a concentration of 0.5 M.10(-6). Our results support various hypotheses on the mechanism of action of the Nickel Sulfate as an inhibitor of the normal development.

Animals↗
PubMed1982

[Immunohistochemical observations on tubulin and alpha actinin during mitosis of cultured fibroblasts].

In this work we studied alpha-actinin and tubulin sites in rabbit fibroblasts in culture. Antibodies anti-alpha-actinin were used for indirect PAP-reaction while antibodies anti-tubulin were used for indirect immunofluorescence method. The observations were carried out by light microscopy, phase-contrast and interference-contrast microscopy, with regard to actinin, and by fluorescence microscopy, with regard to tubulin. During the early mitotic phase, alpha-actinin is localized all over the cell membrane of the fibroblasts, forming a sort strong protective cap, while during diacinesis it forms only rings, localizing below the cell membrane and the philopodia. Thus tubulin forms the bundle fibres during mitotic phases.

Actinin↗
PubMed1982

[Alpha-actinin sites on microvilli of the rabbit small intestine demonstrated by immunoperoxidase].

When Mooseker and Tilney showed the microvilli system must be ascribed among non-muscle contractile systems, they have proposed a contractile scheme formed by actin, miosin and probably alpha-actinin. The scheme proposed by these AA. consists of actin filaments oriented and running from the border to the base, bound to the border by a plate of dense substance formed by -actinin and, to the base, other perpendicular miosin filaments. In our opinion, Mooseker and Tilney research lacks a demonstration regarding alpha-actinin and that is reason why we have decided to display this protein in the microvilli by immunoperoxidase techniques. Considering our results we can definitively confirm the full validity of the contractile scheme of Mooseker and Tilney.

Actinin↗
PubMed1982

[Morphological changes alpha-actinin in skeletal striated muscle in the rabbit in experimental ischemia].

In this work we studied the alteration of Z-line alpha-actinin in striated skeletal muscle, under conditions of experimental ischemia, by immunohistochemical techniques. alpha-Actinin was extracted and purified from rabbit striated skeletal muscle and used, as an antigen, for the production of antibodies, in sheep. Electrophoresis was performed on PAA sla-gel and the Ag-Ab reaction test on agarose slab-gel (immunodiffusion). Antibodies were used for the indirect immunoperoxidase technique on semithin sections of rabbit striated skeletal muscle, included in in Araldehyde, and observed with phase-contrast microscopy. alpha-Actinin from ischemic muscle because of stenosis of the iliac artery, undergoes a progressive alteration, from the third hour of ischemia, going out of its usual sites. From the fifth to the eighth hour it gradually disappears until it leaves rare and residual points of positive reaction only in correspondence to the Z-lines.

Actinin↗
PubMed1982

[Dynamic aspects of alpha-actinin in cultured rabbit fibroblasts studied with immunofluorescence].

In this work we study alpha-actinin sites in rabbit fibroblasts in culture. For this purpose we extracted alpha-actinin from rabbit striated skeletal muscle and produced the relative antibodies in sheep. Electrophoresis was performed, on PAA slab-gel and the immunodiffusion test on agarose slab-gel. Antibodies were used for direct and indirect immunofluorescence techniques by TRIC and FITC. We noticed that in young fibroblasts alpha-actinin is concentrated in perinuclear regions, while in adult fibroblasts it is scattered, more or less evenly in the cytoplasm and above all on the plates which link the cell membrane to the substractum. Both the direct immunofluorescence method with antibodies anti-alpha-actinin, marked by TRITC, and the indirect one with sheep IgG, marked by FITC, gave identical results.

Actinin↗
PubMed1982

[Structural and ultrastructural changes in the rabbit myocardium exposed to dimethylformamide vapors].

The aim of this research is to show the alterations of alpha-actinin in rabbit myocardium after DMF treatment administered by forced inhalation. Z-lines observed with light and phase-contrast microscopy, appeared to be intact and they were clearly displayed by the indirect PAP-reaction. But if you consider that in normal muscle Z lines do not get coloured by the PAP-reaction without a previous light treatment with trypsin. It may be inferred that, in this case, The DMF has had the same effect as the trypsin, causing alteration to the protein structure. Besides the sarcomeric structure is undoubtedly altered by the DMF, causing alterations, in our opinion, similar to those found in rabbit skeletal muscle, under conditions of acute experimental ischemia.

Actinin↗
PubMed1980

[Myofibrils and autophagic vacuoles during atherosclerotic ischemia in man].

The various cases of ultrastructural changed in human skeletal muscles in an ischemic state have been examined. From the examination of the material used, it results that in these muscles, certain myelinic figures and autophagic vacuoles are present. These figures are at times linear and in order, whereas in other regions the lamellar components reveal to be disorganized. In many cases, the larger myelinic figure is near the nucleus, almost next to it. Even electron-dense membranes that surround crystalline inclusion placed between the myelinic figures have been observed. The presence of autophagic vacuoles and myelinic figures is important. The cause of this presence is probably due to a different state of degeneration of the different regions in which these vacuoles are or are not present. Both the autophagic vacuoles and the myelinic figures are found associated with the proteolysis of the tissues. Because of these observations, it has been hypothesized that these changes are a consequence of degeneration. Nonetheless, these changes could be caused by both ischemia and atrophy caused by denervation contemporarily, when the above happens in subjects forced to a long-term immobile state, or in an advanced state of gangrene, or during contemporary and associate phlogistic processes with deficient peripheral nervous structures.

Aged↗
PubMedDate not supplied

[Argyrophilic nucleoproteins of the cervical epithelium in HPV infection and intraepithelial neoplasia].

50 colposcopic biopsies of cervical epithelium were studied, using a silver colloid technique. These comprised 28 cases of human papillomavirus infection of the cervix, 8 cases of cervical intraepithelial neoplasia (CIN) I, 8 cases of CIN II, 6 cases of CIN III. The AgNOR mean number of the basal and parabasal cells of the cervical epithelium was significantly different in virus infected cells and in CIN. Different patterns of AgNOR distribution were observed: they were single and compact in virus infection without dysplasia whereas they appeared small and often loosely arranged in dysplastic lesions. Our data suggest that this simple technique is diagnostically useful in the evaluation of borderline lesions.

Carcinoma in Situ↗
PubMedDate not supplied

Toxic megacolon complicating ulcerative colitis and Crohn's disease.

The clinical, laboratory and radiological data of 17 cases of toxic megacolon (TM) complicating either ulcerative colitis (UC) or Crohn's disease (CD), referred to the Department of Clinica Chirurgica II of the University of Bologna in a twenty year-period, are reviewed. The surgical strategies and results are compared and discussed, and the mortality and morbidity considered along with the important advances in resuscitative medicine and the employment of total parenteral nutrition (TPN).

Adolescent↗
PubMedDate not supplied

Renal cell (Grawitz) carcinoma: an immunohistochemical study in correlation with nuclear grade, histological pattern and proliferative activity of tumor cells.

Since morphological features of renal cell carcinomas may not always predict their clinical behaviour, other biological parameters are more and more searched for, as prognostic indicators. Among those, the Authors evaluate the cytokeratin-vimentin intermediate-sized filaments co-expression in a series of 32 renal carcinomas and analyze this feature in correlation with both traditional criteria and proliferative activity of tumor cells, studied by means of the proliferation cellular nuclear antigen (PCNA) expression as well as of the nucleolar organizer regions (NORs) count, within tumor cells. From this study, nuclear grade stands out as the best parameter which, furthermore, shows a significant relationship with the cytokeratin-vimentin co-expression and the mean NORs count in tumor cell populations. Further investigations about relationships between these parameters and survival of the patients, who, at present, are almost all alive, will be performed afterwards.

Adult↗
PubMedDate not supplied

[Collagenous colitis. Morphologic and immunohistochemical study].

Collagenous colitis is a clinico-pathological entity characterized by chronic diarrhoeas and deposition of collagen beneath the epithelium surface of large bowel. We revised 265 endoscopy biopsy specimens of the large bowel from 198 consecutive patients with "aspecific chronic colitis". Morphometric study showed that were not significant differences among various tracts in the same patients regarding to the thickness of basament membrane. It was more than 11.9 +/- 0.49 mu only in 13 pts (6.6%), while it was 3.96 +/- 1.4 mu in the others. Immunohistochemistry study confirmed the normality of subepithelial basement membrane and the below deposition of the large quantity of collagen IV.

Aged↗