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Biomedical subjects

P Ferraro

Publications and source records attributed to P Ferraro.

65 records · Page 4Linked to original sources
PubMed1989

DNA repair and replication in lymphocytes from smokers exposed in vitro to UV light.

In a sample of healthy subjects (23-59 years old), comprising 49 non-smokers and 23 smokers, we studied the effects of smoking on DNA repair synthesis (UDS) in peripheral lymphocytes. DNA repair after UV-irradiation was measured by [3H]TdR incorporation into DNA (semi-conservative synthesis was inhibited by hydroxyurea). Compared to lymphocytes from non-smokers, lymphocytes from smokers showed significantly higher levels of UDS and higher incorporation of [3H]TdR in non-irradiated cells. We also determined the rate of DNA replication after 60 h in the presence of phytohaemoagglutinin (PHA) by measuring the incorporation of [3H]TdR during the last 20 h of culture. By irradiating the lymphocytes with UV light before setting up the cultures, we measured the inhibition of DNA replication due to damage induced by UV light. This inhibition, determined by the ratio of DNA replication in irradiated over non-irradiated lymphocytes, was less marked in smokers than in non-smokers. In lymphocytes from a portion of the donors (18 non-smokers and 19 smokers) we also determined the rate of the [3H]TdR incorporation in the absence of PHA and compared the distribution of the radioactivity between the two groups. In unstimulated lymphocytes, more radioactivity was incorporated by smokers compared to non-smokers in both conditions (UV-irradiated or mock-irradiated), while in stimulated lymphocytes the distribution of radioactivity was significantly different only after UV-irradiation.

Adult↗
PubMed1988

Regional coronary hemodynamic effects of diltiazem in man.

We evaluated the changes in regional coronary hemodynamics induced by diltiazem, 0.25 mg/kg intravenously, in nine patients with 75% to 90% diameter stenosis of the left anterior descending coronary artery (LAD) (group 1) and in 10 patients with 100% occlusion of the LAD and collaterals to the distal LAD (group 2). Although diltiazem induced similar changes in systemic hemodynamics in the two groups, a decrease in anterior coronary vascular resistance (ACVR) and an increase in great cardiac vein flow (GCVF) were observed after administration of diltiazem in all patients in group 1 but in only 6 of 10 patients in group 2 (subgroup 2B). ACVR increased and GCVF decreased after administration of diltiazem in 4 of 10 patients in group 2 (subgroup 2A). Clinico-angiographic characteristics, origin of collaterals, and diltiazem-induced changes in systemic hemodynamics were similar in subgroups 2A and 2B. Thus diltiazem increases coronary flow distal to a stenotic coronary artery but can decrease regional coronary flow and increase regional coronary resistance in a minority of patients with an occluded coronary artery supplied by collaterals, probably through a steal mechanism.

Coronary Circulation↗
PubMed1986

[Beneficial effects of diltiazem in exertion stable angina. Evaluation of coronary hemodynamics during cardiac pacing].

We evaluated the protective effect of Diltiazem from pacing-induced myocardial ischemia in 9 patients (pts) with coronary heart disease (CAD) and stable effort angina by studying the changes in systemic and coronary hemodynamics during pacing. Hemodynamic parameters were evaluated at baseline and at peak pacing before and after Diltiazem, 25 mg i.v. Diltiazem prevented angina in 6 of 7 pts who presented angina in the control pacing. This beneficial effect was accompanied at peak pacing rate by a significant fall in ST depression, arterial pressure, rate-pressure product and left ventricular (LV) end-diastolic pressure, while no significant changes were observed in LV dp/dt max, coronary blood flow and coronary vascular resistance. Therefore, Diltiazem exerts a protective effect from pacing-induced myocardial ischemia in pts with CAD and stable effort angina, without impairing LV function. This beneficial effect is due to a reduction in myocardial metabolic requirements, rather than to an improvement of blood supply to the ischemic myocardium.

Aged↗
PubMed1983

Plasma cell leukemia: a report on three patients.

Three patients with plasma cell leukemia are reported. Two of them has a previous history of myeloma; the third one started with a plasma cell leukemia. Diagnosis was made from the required presence of 20% plasma cells in the peripheral blood. In all 3 cases, bone marrow aspiration and peripheral blood showed plasma cells strongly positive for acid phosphatase and alpha-naphthyl acetate esterase, and negative for periodic acid-Schiff. The first patient was treated with a polychemotherapy regimen that included vincristine, cyclophosphamide, chlorambucil and prednisone, and the second patient with melphalan and prednisone; the third one, who started with plasma cell leukemia, received total body irradiation at the dose of 600 rad. The results of the therapy and survival time, which was never more than 3 months, are in accord with other reports in the literature.

Aged↗
PubMed1976

Interaction between marihuana and altitude on a complex behavioral task in baboons.

Marihuana, or its principal active ingredient, delta-9-tetra-hydrocannabinal (delta9-THC), impairs performance on complex behavioral tasks in animals and man. Although there exists some evidence that altitude-induced hypoxia potentiates the physiological effects of marihuana, the interaction between altitude and marihuana on behavioral tasks has not been established. In the absence of evidence that use of marihuana is less frequent among members of the aviation community than among the general population, it was necessary to evaluate the effects on performance of any interaction between hypoxia and marihuana. Two baboons were trained to perform on a delayed matching-to-sample task at ground level and altitudes of 2438 and 3658 m (8000 and 12000 ft). The animals were orally administered doses of delta9-THC, ranging from 0.25 to 2.0 mg/kg, 2 h prior to experimental sessions at each altitude. No effects on accuracy of matching performance were observed for any of the drug doses or altitudes used. Amount of work output, as measured by number of trials completed and speed of responding, was not affected by delta9-THC at ground level but was markedly reduced by the higher drug doses at the 2438- and 3658-m altitudes. This interaction suggests that the behavioral impairment produced by marihuana can be potentiated by hypoxia.

Aerospace Medicine↗
PubMedDate not supplied

DNA damage and repair induced in vitro by nitrilotriacetic acid (NTA) in human lymphocytes.

In cultured human lymphocytes we determined the ability of nitrilotriacetic acid (NTA) to inhibit DNA replication and to stimulate DNA repair synthesis (UDS), as well as to influence the UDS induced by UV irradiation. In phytohemagglutinin-stimulated lymphocytes a strong inhibition of DNA replication was induced by NTA concentrations above 10(-3) M, which was accompanied by a marked cell lethality, whereas at lower doses the incorporation of tritiated thymidine (3H-TdR) into DNA or treated cells was slightly increased in comparison to untreated cells. When, after NTA pretreatment, UDS was determined by scintillation spectrometry or autoradiography in unstimulated G0 lymphocytes, UV-irradiated or unirradiated, an increased incorporation of 3H-TdR was observed, positively correlated with the NTA doses. This effect was only partially due to the expansion of the intracellular TdR pool as a consequence of the stimulation of 3H-TdR uptake by NTA. Even after normalization of the scintillometric data by the radioactivities of the soluble nucleotide fraction, significant increase of DNA repair synthesis was detected after treatment with 7.5 x 10(-3)-10(-2) M NTA.

Acetates↗
PubMedDate not supplied

Transient exposure to cytarabine increases peptide growth factor receptor expression and tumorigenicity of melanoma cells.

We have demonstrated that anticancer drugs at cytostatic concentrations enhance the expression and function of epidermal growth factor (EGF-R) and transferrin (TRF-R) receptors on human tumor cells. We hypothesized that these effects could represent a protective response of tumor cells to sublethal antiproliferative stimuli which could lead to enhanced growth potential. 72 hours exposure of human melanoma GLL-19 cells to 1,000 nM ara-C induced growth inhibition and increased the number of EGF-R, TRF-R and nerve growth factor receptor (NGF-R) on cell surface. Enhanced expression of beta 3 integrins CD49a, CD49c and CD49e, av integrin CD51, beta 3 integrin CD61, CD58/LFA3 and collagen IV and laminin was also detected in ara-C-treated GLL-19 cells. These changes at the tumor cell surface were paralleled by increased in vitro adhesion, invasive potential and clonogenic growth in soft agar and in vivo tumor formation. A more aggressive tumor cell phenotype is induced in human melanoma cells after transient exposure to cytostatic concentrations of ara-C.

Animals↗