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Biomedical subjects

L Vitale

Publications and source records attributed to L Vitale.

At least 73 records · Page 4Linked to original sources
PubMed1981

Properties and distribution of aminopeptidase and dipeptidyl aminopeptidase III of human erythrocytes.

The catalytic properties of depeptidyl aminopeptidase and aminopeptidase isolated from human erythrocytes, and the distribution of their activities in different blood cells were determined. Dipeptidyl aminopeptidase was shown to be of the dipeptidyl aminopeptidase III type, activated by Co2+ and inhibited by EDTA, pCMB and partially by DFP and leupeptin. Aminopeptidase preferred Lys-, Phe-, ARg-, and Met-2-naphthylamides as substrates. It was activated by Co2+ and inhibited by EDTA amastatin, bestatin and leupeptin. Dipeptidyl aminopeptidase III activity and aminopeptidase activity on arginine-2-naphthylamide was higher in the population of younger red blood cells. The same activities were also found in thrombocytes, mononuclear and polymorphonuclear leukocytes in concentrations higher than those in erythrocytes.

Aminopeptidases↗
PubMed1977

Use of 131I-19-cholesterol in functional dynamic studies of the adrenals in vivo. II. Clinical application.

Functional dynamic studies of the adrenal in vivo employing 131I-19-cholesterol were carried out as a further screening test, according to the method previously described (Pavonia and Magrini, 1977), on seven patients in whom hyperadrenocorticism was suspected on the basis of clinical symptoms. The data obtained in basal conditions, under ACTH stimulation, and under dexamethasone suppression, compared with each other and supported by the results of conventional examinations, demonstrate that the quantitative information provided by this radioisotope test is correlated with the functional state of each adrenal, thus confirming the potential value of the method for diagnostic purposes. The functional dynamic test proposed does not require a higher dose of tracer than morphologic studies and the radiation risk (approximately 2.5 rad to the ovaries or gonads) seems acceptable in adult subjects.

Adenoma↗
PubMedDate not supplied

Lapstatin, a new aminopeptidase inhibitor produced by Streptomyces rimosus, inhibits autogenous aminopeptidases.

Lapstatin, a low-molecular-weight aminopeptidase inhibitor, was purified to homogeneity from Streptomyces rimosus culture filtrates. The purification procedure included extraction with methanol, followed by chromatography on Dowex 50WX4, AG50WX4, and HPLC RP C18 columns. By amino acid analysis, mass spectrometry, and NMR spectroscopy, the structure of lapstatin was shown to be 3-amino-2-hydroxy-4-methylpentanoylvaline. Lapstatin inhibited the extracellular leucine aminopeptidases from Streptomyces rimosus, Streptomyces griseus, and Aeromonas proteolytica with an IC50 in the range of 0.3-2.4 microM. IC50 values for other enzymes tested were at least tenfold higher. Leucine aminopeptidase from Streptomyces griseus was inhibited in a competitive manner, with an inhibition constant of 5 x 10(-7) M. Lapstatin is the first low-molecular-weight compound isolated from streptomycetes shown to inhibit an autogenous aminopeptidase.

Bacterial Proteins↗
PubMedDate not supplied

Immunotoxic effects of mercuric compounds on human lymphocytes and monocytes. IV. Alterations in cellular glutathione content.

The major goal of this investigation was to determine if the sensitivity of lymphocytes and monocytes to mercury (Hg++) was related to intracellular glutathione (GSH) levels and the thiol redox status [GSH/glutathione disulfide (GSSG)]. To isolate cells based upon their GSH content, T and B-cells were stained with monochlorobimane (MCB) and separated into high and low fluorescent groups by FACS analysis. Cells with high GSH fluorescence were found to be resistant to both the cytotoxic and immunotoxic effects of HgCl2 as evidenced by cell viability and their responsiveness to mitogen, respectively. In contrast, cells with low levels of GSH were extremely sensitive to mercury. To further examine the relationship between GSH level and mercury exposure, T-cells, B-cells and monocytes were treated with different doses of HgCl2 for 12 hrs. All cells exhibited a dose-dependent decrease in GSH content with a concomitant reduction in GSSG levels. However, the GSH/GSSG ratio in these cells remained constant, or increased following exposure to mercury. GSH levels were also reduced in monocytes following exposure to HgCl2; in this case, GSSG levels remained constant and a decline in the GSH/GSSG ratio was observed. For all cell types, mercury did not inhibit the activities of GSH reductase and GSH peroxidase, enzymes responsible for oxidation/reduction of GSH and GSSG, respectively. Results of the study clearly show that susceptibility to the immunotoxic effects of HgCl2 is, in part, dependent upon GSH levels and further that mercury inhibits GSH generation by lymphocytes and monocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

B-Lymphocytes↗
PubMedDate not supplied

[Clinical investigation of hyaluronidase and nerve growth factor (NGF) at the ocular level: detailed review of the international literature].

In this paper the authors analyse the international bibliography about clinic tests on hyaluronic acid and Nerve Growth Factor at ocular level. This study was performed on request of a private oculistic clinic in the centre of Rome about the clinic test of the drugs mentioned above. Therefore, this paper is a joint work of Public Health physicians and oculists.

Corneal Diseases↗
PubMedDate not supplied

Different responsiveness of normal and leukemic hemopoietic cells to esorubicin.

The effect of different Esorubicin concentrations (10(-7) M to 10(-10) M) has been tested on the in vitro growth of human normal hemopoietic progenitor cells and of three leukemic cell lines (K562, U 937, HL60). The highest drug concentration completely abolished both normal and leukemic proliferation. Lower doses of Esorubicin failed to induce any morphological or phenotypic differentiation of leukemic cell lines. A 24h pretreatment of the cells with 10(-9) M Esorubicin enhanced the in vitro proliferation of normal early myeloid progenitor cells, whereas it did not affect leukemic, myelomonocytic cell proliferation.

Antibiotics, Antineoplastic↗