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C Urani

Publications and source records attributed to C Urani.

At least 19 recordsLinked to original sources
PubMed2006

Metallothionein and hsp70 expression in HepG2 cells after prolonged cadmium exposure.

Cadmium is a widely distributed industrial and environmental pollutant. Principle target organs are soft tissues such as the liver, where cadmium accumulates with a biological half-life of approximately 20-30 years causing a variety of toxic responses. In HepG2, CdCl(2) exposure for short periods (from 1 to 24h) induces differential expression of stress proteins, including MT and hsp70. However, less is known about the stress response during a prolonged exposure to this metal. MTT assay showed a low cytotoxicity of CdCl(2) (0.1, 0.5, 1, 2, 5, 10microM), over a period of 72h. Cadmium uptake by ICP-AES technique and the corresponding expression of stress proteins (MT, hsp70) during the same prolonged time were also analysed. Results show that Cd was continuously and increasingly accumulated, at the highest of the concentrations tested. Metallothionein expression was up-regulated with a saturation curve at 48 as well as 72h after CdCl(2) exposure. High levels of MT probably confer an acquired tolerance to the stress and protection against cell injury as demonstrated by low cytotoxicity values. On the contrary, the unchanged pattern of hsp70 expression suggests that this protective mechanism, unlike other members of the family, is less involved during CdCl(2) prolonged exposure.

Cadmium Chloride↗
PubMed2005

Cytotoxicity and induction of protective mechanisms in HepG2 cells exposed to cadmium.

Cadmium is a widespread industrial pollutant. The primary route of exposure occurs via contaminated drinking water or food supplies, and tobacco. Its chronic introduction and ingestion lead to bio-magnification in target organs, as the liver. The aim of this paper is to determine Cd cytotoxic concentrations in the human hepatoma cell line HepG2. Further aims are the study of the activation and involvement of protection mechanisms against Cd hepatotoxicity. Cd was accumulated within the cells, as measured by ICP-AES. Metallothioneins (MT-1 and -2), a family of metal-binding proteins, were induced in a dose-dependent way after treatment with concentrations below the IC(50) value (mean value 22 microM). The over-expression of MT by Zn pre-treatment was able to defend against Cd cytotoxicity. Heat shock protein 70 kDa (hsp70) was induced at high non-cytotoxic concentrations (5, 10 microM) probably as a consequence of proteotoxicity, but its over-expression by a sub-lethal heat shock was not able to protect the cells from Cd cytotoxic concentrations (20, 50, 100 microM).

Cadmium↗
PubMed2005

Quantitative kinetics of damage and recovery of cytoskeletal structure by means of image analysis.

The cytoskeleton is a network of proteins which structurally and dynamically organise the cytoplasm of living cells. Microtubules are among its constituents. Morphological alterations of microtubules are related to functional impairment. Therefore cytoskeletal morphology is a valuable indicator of cell injury and functionality. This paper focuses on the comparison between normal and altered cytoskeletal microtubules by means of image analysis and classification with the aim of replacing visual assessment. Morphology has been quantified by the extraction of some descriptors yielded by spatial differentiation, fractal analysis and Fourier analysis followed by non-linear filtering. The principal component analysis of these descriptors has led to image recognition and has been applied to hepatocytes and fibroblasts exposed to some xenobiotics. In the case of hepatocytes, images have been ranked according to the severity of cytoskeletal damage, a dose-response relation has been derived from the regression of the first principal component and the percentage of structural recovery after exposure has been estimated.

Algorithms↗
PubMed2002

Comet assay evaluation of DNA single- and double-strand breaks induction and repair in C3H10T1/2 cells.

Ionizing radiation is a potent inducer of DNA damage because it causes single- and double-strand breaks, alkali-labile sites, base damage, and crosslinks. The interest in ionizing radiation is due to its environmental and clinical implications. Single-strand breaks, which are the initial damage induced by a genotoxic agent, can be used as a biomarker of exposure, whereas the more biologically relevant double-strand breaks can be analyzed to quantify the extent of damage. In the present study the effects of 137CS gamma-radiation at doses of 1, 5, and 10 Gray on DNA and subsequent repair by C3H10T1/2 cells (mouse embryo fibroblasts) were investigated. Two versions of the comet assay, a sensitive method for evaluating DNA damage, were implemented: the alkaline one to detect single-strand breaks, and the neutral one to identify double-strand breaks. The results show a good linear relation between DNA damage and radiation dose, for both single-strand and double-strand breaks. A statistically significant difference with respect to controls was found at the lowest dose of 1 Gy. Heterogeneity in DNA damage within the cell population was observed as a function of radiation dose. Repair kinetics showed that most of the damage was repaired within 2 h after irradiation, and that the highest rejoining rate occurred with the highest dose (10 Gy). Single-strand breaks were completely repaired 24 h after irradiation, whereas residual double-strand breaks were still present. This finding needs further investigation.

Animals↗
PubMed2000

Patent foramen ovale and its embolic implications.

This study investigates the usefulness of the echocardiographic characteristics of patent foramen ovale (PFO) in the stratification of stroke recurrence risk in patients with acute ischemic cerebral disease. Shunting at rest and a highly mobile fossa ovalis membrane are more frequently detected in stroke patients with PFO as the only identifiable cause of embolism. For PFO patients with both rest patency and membrane mobility > 6.5 mm, the risk of stroke/transient ischemic attack recurrence was 7.6% (95% CI, 0-18.0) at 12 months and 12.5% (95% CI, 0-26.1) at 24 months (p = 0.05). The association of both rest patency and high membrane mobility seems to identify those stroke patients with PFO at higher risk for further brain embolism.

Case-Control Studies↗
PubMed1998

Molecular approaches to evaluate pollutants.

Many organisms are in use to test pollutants and their extensive variability clearly emerges from reviews since researchers in the world are involved in continuous effort to set up new assays and to improve those already in use. In the present paper we focus the attention on the mixed function oxidase system and the DNA adduct formation which are two biomarkers widely used and extensively studied in mammals and fish by different Authors. We compare their results with the ones we obtained in amphibians, which result to be a good model. Moreover we present some significative results obtained by the use of cultured cell lines to test the herbicide MCPA. The results obtained demonstrate that the amphibian Xenopus is a suitable indicator for induction of cytochrome P-450 by B[a]P as well as for production of DNA adducts. Cultured cells evidenced that cytoskeletal array and thiol proteins are molecular targets of the herbicide used, demonstrating that risk assessment can be properly analysed in in vitro systems.

2-Methyl-4-chlorophenoxyacetic Acid↗
PubMed1998

Human-derived cell lines to study xenobiotic metabolism.

In vitro systems make for rapid identification of xenobiotic effects and can be used to study cellular and subcellular toxicity mechanisms. In this report the metabolic competence of two human-derived cell lines, a hepatic (Hep G2) and a pulmonary one (A549) was tested. In the two cell systems the capability to activate Benzo[a]Pyrene through the cytochrome P450 enzyme system and to form reactive metabolites was analysed. 3H-BaP and the scintillation counting analysis were used to show the differences of the metabolic activity in Hep G2 and A549. A similar time course of 3H-BaP uptake was observed in the cell systems. Nevertheless, in the two cell lines the distribution of radioactive metabolites seemed to reflect a specific tissue response to toxicity.

Benzo(a)pyrene↗
PubMed1998

Cellular targets in response to dioxin exposure.

Dioxins are contaminants present in a variety of environmental media. The 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) is biologically reactive at very low concentrations. This research is based on the use of innovative bioindicators able to evidence the exposure to TCDD by evaluating the biological effects on the embryonic development of the amphibious Xenopus laevis. TCDD exposure effects analyzed found that an Lc 50 value of 342 ng/l, TCDD concentrations up to 400 ng/l caused significative developmental delays. No significative teratogenic effects were found. X. laevis proved to be sensitive to the P-450 induction and alteration of glutathione levels at TCDD low doses (0.1-0.5 ng/l).

Animals↗
PubMed1997

[Primary non-Hodgkin's lymphoma of the intestine associated with asymptomatic celiac disease in adults].

Celiac disease (CD), a gluten-induced enteropathy, is characterized by typical intestinal involvement with classical clinic features in childhood and less frequent features in adult patients. Recognizing pauci- and asymptomatic patients is a critical point in the clinical management of CD because of the high mortality associated with the onset of complications. Among these, malignant diseases are the most severe, particularly squamous cell carcinoma and lymphoma, the latter accounting for 50% of all malignancies occurring in CD patients. The authors describe a 57 years old patient with CD and Enteropathy-Associated-T-Cell Lymphoma, who had no intestinal symptoms but only severe pruritus and hypereosinophilia.

Celiac Disease↗
PubMed1996

Power spectrum analysis contribution to the detection of cardiovascular dysautonomia in multiple sclerosis.

In multiple sclerosis (MS) autonomic cardiovascular dysfunction is an uncommon, but potentially dangerous event, to which studies of spectral analysis of heart rate variability have not been applied, yet. MATERIAL AND METHODS--We studied 16 patients with definite MS (11 women and 5 men, mean age 30.3 +/- 7.4 yrs., mean EDSS 2.06 +/- 1.42) and 16 sex- and age-matched healthy controls. Besides cardiovascular reflex tests (valsalva manoeuvre, deep breathing, lying to standing, Blood Pressure response to standing and sustained handgrip), each underwent spectral analysis of the R-R interval short-term variability at rest and after tilting, to detect three components: very low frequency (VLF), low frequency (LF) and high frequency (HF). A recent brain MRI was obtained from patients, to compare plaque characteristics with spectral parameters. RESULTS--At cardiovascular reflexes, only four patients (25%) showed an impairment, mostly of a mild degree. VLF and LF at rest were lower in MS subjects than in controls (p < 0.01). No significant correlation was found between spectral parameters and lesion area or localization as detected on MRI. CONCLUSIONS--Spectral analysis could usefully flank reflex tests to detect autonomic subclinical cardiovascular abnormalities.

Adult↗
PubMed1996

Cardiac autonomic dysfunction in relapsing-remitting multiple sclerosis during a stable phase.

The autonomic cardiovascular system was studied by means of autonomic tests and heart rate variability related to body movements during sleep, in 20 patients with relapsing-remitting multiple sclerosis in a stable phase and in 9 normal subjects. Responses to autonomic tests in multiple sclerosis and control subjects were similar. Heart rate variability, instead, showed a lower degree of adaptability in patients with multiple sclerosis than in controls during sleep, because of sympathetic system dysfunction. No significant correlation between magnetic resonance lesions and cardiovascular sleep indexes was found.

Adult↗
PubMed1995

Benomyl affects the microtubule cytoskeleton and the glutathione level of mammalian primary cultured hepatocytes.

Rat primary hepatocyte cultures have been used to study the effect of Benomyl alone or in combination with Pirimiphos-methyl. The results presented demonstrate that Benomyl alone is responsible for the microtubular disorganization in both a time- and dose-dependent manner, that the effect is reversible after the agent is removed, and that Benomyl is a potent glutathione-depleting agent. Pirimiphos-methyl, alone or combined with Benomyl had no effect on microtubule organization, but reinforced the decrease in glutathione.

Animals↗
PubMed1995

Sympathetic-parasympathetic activation during spontaneous attacks of cluster headache: evaluation by spectral analysis of heart-rate fluctuations.

Twenty-four hour ECG Holter and blood-pressure monitorings were performed in eight patients suffering from cluster headache. Spectral analysis of heart-rate fluctuation was used to assess the autonomic balance under basal conditions, after head-up tilt, and during a spontaneous attack. Normal autonomic balance was found at rest and during sympathetic activation obtained with head-up tilt in the interparoxysmal period. Before the onset of headache, an increase in the low-frequency (LF) component of the power spectrum was apparent in all patients. This sign of sympathetic activation was followed by an increase in the high-frequency (HF) component that developed about 2000 beats after the onset of headache and rapidly overcame the LF component until the end of pain. Significant differences were found when comparing the spectral parameters [total spectral values (TP), power of the LF and HF components and LF/HF ratio] obtained before, during and after headache. During the attack, blood pressure increased and heart rate decreased in all subjects. There appears to be a primary activation of both sympathetic and parasympathetic functions in cluster headache attacks. The sympathetic component seems to be involved mostly in the development of the attack, whereas the parasympathetic activation seems to occur, following the onset of the attack, independently of the pain.

Adult↗
PubMed1994

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) affects the actin cytoskeleton and calcium level of Swiss 3T3 mouse fibroblasts.

Organization of the actin cytoskeleton, the cytosolic free-calcium concentrations and ATP levels were analyzed in 3T3 mouse fibroblasts treated with 0.75 or 1.5 mM MPTP. In the presence of the drug actin filaments were time- and dose-dependently disorganized, ATP level was unaffected and intracellular calcium increased within 5 s. The correlation between MPTP cytotoxicity and [Ca2+]i level emerging from these results, suggests that the primary effect of the molecule itself is on the plasma membrane's integrity for calcium ion regulation.

Actins↗