Biomedical subjects

C Urani

Publications and source records attributed to C Urani.

24 records · Page 2Linked to original sources

PubMed1992

[Modification of the sympatho-vagal interaction in mitral valve prolapse syndrome. Evaluation of heart rate variability by spectrum analysis].

To determine whether clinical manifestations in patients with mitral valve prolapse (MVP) are associated with altered sympatho-vagal tone, 46 patients (mean age 27 +/- 6, range 20-45 years; 18 males and 28 females) were studied by power spectrum analysis of RR variability. Patients were divided in 2 groups, according to echocardiographic criteria: Group A: 11 patients with classical MVP; Group B: 35 patients with non classical MVP. These patients were compared with 30 healthy subjects (Group C) well matched for age, body surface area and heart rate. Our findings indicate that at rest there is a significant difference in the high-frequency component between Group A and Group C. Similarly, during the increase in sympathetic activity induced by 70 degrees head-up tilt all groups showed an increase in the low-frequency component, that was more evident in Group A. The data generated from our laboratory suggest that mitral regurgitation (Group A) is a probable cause of vagal tone increase and that there is an adaptive long-term mechanism towards sympathetic conditions. In addition, probably the normalization, demonstrable by the effect of sympathetic activity in tilt, can mask a dysfunction that may be differently evoked.

Adult↗

PubMed1991

Effect of stress on cardiovascular regulation in neurological diseases with dysautonomia.

Ten patients with Multiple Sclerosis (MS) and ten with Myotonic Dystrophy (MD) underwent an evaluation of cardiovascular reflexes by classic tests, tilt table test and mental stressors. Sympathetic and parasympathetic changes were detected by classical tests in MS patients. Mental stressors appeared able to reveal blood pressure control impairment in MD patients. Lower differential blood pressure was observed during mental stressors administration in MS with brainstem lesions at MRI.

Adult↗

PubMedDate not supplied

Copper and zinc uptake and hsp70 expression in HepG2 cells.

The aim of this work is to study the accumulation in HepG2 cells of two essential metals with toxic potency and to analyse the induction of the heat shock protein 70 kDa (hsp70) consequent to metal exposure. Cu and Zn were the metals considered and were analysed both as single compounds and in combination in order to evidence synergic effects of the mixture. The use of HepG2 cells provided an in vitro system that retains morphological and metabolic properties and the expression of specific genes typical of liver parenchymal cells. Moreover, the hepatic cells represent a suitable model for their susceptibility to metal toxicity since liver, gastrointestinal tract and renal tubular cells are involved in the uptake, transport, detoxification and secretion of these compounds. The uptake of Cu and Zn followed a time-dependent accumulation when they were used separate. The combination of the two metals produced a higher accumulation of Zn. The stress protein hsp70 was expressed before the metals accumulated within the cells, as shown by the measures obtained with the ICP-AES technique. Moreover, the accumulation of hsp70 by a sublethal shock provided a protective mechanism against metal cytotoxicity.

Cell Survival↗

PubMedDate not supplied

Overexpression of HSP70 is induced by ionizing radiation in C3H 10T1/2 cells and protects from DNA damage.

Various kinds of stress such as heat, UV, gamma-rays and chemicals that cause DNA damage induce heat shock proteins (Hsps), and in particular Hsp70. The Hsps cytoprotective function is not fully understood, although these proteins act as molecular chaperones or modulators of intracellular levels of reactive oxygen species (ROS). Recently, Hsps have been proposed to play a significant role in DNA repair after UV or gamma-ray irradiation. Ionizing radiation targets DNA molecules either via direct interaction or via production of free radicals and ROS. When exposed to gamma-rays C3H 10T1/2 cells are radiosensitive, therefore we decided to use them to investigate Hsp induction after ionizing radiation and their protective role against DNA damage. Here we demonstrate the induction of Hsps by gamma-rays, and investigate the kinetics of expression after irradiation at different doses. We also show that Hsp70 overexpression acts as a radioprotective mechanism towards the first event of DNA damage and increases long term viability. A preliminary investigation on the cell cycle does not evidence a significant protective action of inducible Hsp70 on it.

Animals↗

PubMedDate not supplied

Different induction of metallothioneins and Hsp70 and presence of the membrane transporter ZnT-1 in HepG2 cells exposed to copper and zinc.

Eukaryotic cells respond to stressful environmental stimuli, such as toxic concentrations of heavy metals, by rapidly synthesising defence proteins: the metallothioneins (MT) and the heat shock protein 70 (Hsp70). In this study we have analysed how the human hepatoblastoma cell line HepG2 responds to exposure to excess copper (30 microg/ml) and zinc (50 microg/ml) for long exposure times (48 and 72 h). Accumulation of the two metals, as measured by ICP-AES, was time-dependent reaching a plateau after 72 h. HepG2 cells responded by dramatically increasing levels of MT during stress, mostly during zinc exposure. A time lag in Hsp70 induction was observed as the levels of this protein increased only after removal of the stress from culture medium (recovery) for 24 h, thus suggesting that the two defence mechanisms are not coordinated in a metal-induced stress response. Moreover in HepG2 cells, immunochemical and fluorescence techniques showed the presence and the localisation of the zinc membrane exporter ZnT-1 as a further mechanism of defence/homeostasis against zinc toxicity.

Cell Line, Tumor↗

PubMedDate not supplied

Prevalence of valvular regurgitation in structurally normal hearts: a colour-Doppler study.

AIM: To evaluate, by colour-Doppler echocardiography, the effects of ageing on the continence of the heart valves in patients with normal hearts. METHODS: We reviewed all the consecutive echocardiographic examinations performed in our laboratory from 1988 to 1994. From a total of 4592 records, 1654 (977 from females and 677 from males) were selected as normal-that is, not having excluded any kind of valvular, chamber or wall pathology of the heart. These records alone were considered in the study. RESULTS: One or more valve regurgitations were evident on 286 of the records (17.3%; 202 from females and 84 from males); regurgitation was always mild and was more frequent in females (20.7% compared with 12.4% of males; P < 0.001). Mitral regurgitation was the most frequent (49.3% of all regurgitant valves), followed by tricuspid, aortic and pulmonary. In age groups 0-17 years and > or = 60 years there was no sex difference in regurgitation. With ageing, there was an increasing trend in prevalence of regurgitation of the mitral, aortic and tricuspid valves in females (P < 0.001, P < 0.001 and P < 0.05, respectively), and of aortic and mitral valves in males (P < 0.001 for both). Multiple regurgitation (two or three valves) was not sex-dependent, but showed an increasing trend with ageing (from 13% to 27.5% of records showing regurgitation; positive trend, P < 0.005). CONCLUSIONS: Prevalence of mild valvular regurgitation is age-dependent, but is more common in women than in men aged 18-59 years; there is no sex-related difference in patients aged 60 years or more.

Adolescent↗