Biomedical subjects

R De Salvia

Publications and source records attributed to R De Salvia.

At least 19 recordsLinked to original sources

PubMed2001

Prevalence of primary blepharospasm in a community of Puglia region, Southern Italy.

The authors ascertained the prevalence of primary blepharospasm (BSP) in a community located in Puglia, a region in Southern Italy, by focusing on neurologists and ophthalmologists. The crude prevalence rates were 133 per million (95% CI, 61--153) for both focal and segmental BSP, 74 per million (95% CI, 24--173) for focal BSP, and 59 per million (95% CI, 16--151) for segmental BSP. Prevalence rate increased with age. Apraxia of eyelid opening and BSP coexisted in one third of cases.

Adult↗

PubMed2001

Proton MR spectroscopy in idiopathic spasmodic torticollis.

Single-voxel proton magnetic resonance spectroscopy (1H-MRS), localised to the basal ganglia, was used to determine changes in metabolite levels in idiopathic spasmodic torticollis (IST). We examined nine patients and 13 healthy subjects. The mean values (+/- SD) of peak area ratios were: IST: N-acetyl-aspartate (NAA)/choline-containing compounds (Cho) 1.79 +/- 0.39, NAA/creatine and phosphocreatine compounds (Cr) 1.61 +/- 0.38, Cho/Cr 0.91 +/- 0.19; controls: NAA/Cho 2.07 +/- 0.35, NAA/ Cr 1.82 +/- 0.31, Cho/Cr 0.89 +/- 0.12. Statistical analysis showed that NAA/Cho and NAA/Cr were significantly lower in patients than in controls (P = 0.0304 and 0.0431, respectively). These results indicate a reduction in NAA, and suggest striatal involvement in the pathogenesis IST.

Adolescent↗

PubMed2000

Primary hemifacial spasm and arterial hypertension: a multicenter case-control study.

In a case-control study, the authors found that arterial hypertension occurred more frequently among 115 patients with primary hemifacial spasm than among 115 neurologic controls matched for age (+/-5 years), sex, and referral center. The association was not confounded by education level, smoking history, diabetes, or other diseases (adjusted OR 2.64; 95% CI 1.3 to 5.33, p = 0.007). Hypertension was significantly associated with the outcome in the left-sided group (OR 4.0; 95% CI 1.4 to 11.5), but data concerning patients with right-sided spasm were inconclusive (OR 1.05; 95% CI 0.36 to 3.1). In our sample, hypertension either preceded or followed the onset of hemifacial spasm.

Aged↗

PubMed2000

Evaluation of genotoxic and cytotoxic properties of pesticides employed in Italian agricultural practices.

In a program coordinated by the Italian Ministry of Works, we tested in vitro four pesticides widely employed in a developed agricultural region of central Italy. The four commercial agents were chosen on the basis of their diffusion in agricultural practice, knowledge of their active principle(s), and scant availability of data concerning their toxic and genotoxic activity. The agents were Cirtoxin, Decis, Tramat Combi (TC), and Lasso Micromix (LM). All substances were tested in three in vitro systems: Chinese hamster ovary (CHO) cells, a metabolically competent hamster cell line (Chinese hamster epithelial liver; CHEL), and root tips of Vicia faba (VF). The cytotoxic and genotoxic end points challenged were micronuclei and root tip length (RTL) in VF and mitotic index (MI), proliferation index (PI), cell survival (CS), cell growth (CG), cell cycle length (CCL), sister chromatid exchanges, chromosomal aberrations, and single-cell gel electrophoresis, or comet assay, in CHEL and CHO cells. Tested doses ranged from the field dose up to 200x the field dose to take into account accumulation effects. On the whole, tested agents appear to induce genotoxic damage only at subtoxic or toxic doses, indicating a low clastogenic risk. MI, PI, CS, CG, RTL, and CCL appear to be the less sensitive end points, showing no effects in the presence of a clear positive response in some or all of the other tests. Using cytogenetic tests, we obtained positive results for TC and LM treatments in CHO but not in CHEL cells. These data could be accounted for by postulating a detoxifying activity exerted by this cell line. However, cytogenetic end points appear to be more sensitive than those referring to cytotoxicity.

Agriculture↗

PubMed1999

Phyllanthus orbicularis aqueous extract: cytotoxic, genotoxic, and antimutagenic effects in the CHO cell line.

The present work evaluates the cytotoxic, genotoxic, and antimutagenic effects of Phyllanthus orbicularis (plant of genus Phyllantus) aqueous extract in Chinese hamster ovary (CHO) cells. P. orbicularis aqueous extracts are used in Cuban traditional medicine for their antiviral activity against Hepatitis B virus and A and B flu virus. The cytotoxicity of the extract was tested by means of colony-forming ability and growth-inhibition assays as well as by measuring the mitotic index. Apoptosis induction and cell-cycle kinetics were analyzed by cytofluorimetric methods. Chromosome aberration assays were performed to study the genotoxic and antimutagenic activity of the extract. Results show that doses of up to 100 microg/ml of the extract did not induce any cytotoxic effects. Cell survival and mitotic index decreased significantly at doses higher than 100 microg/ml as a function of dose as well as of treatment time. Moreover, continuous treatments of up to 18 h induced the appearance of a significant number of apoptotic cells. Following a 3-h exposure to a dose of 750 microg/ml, cells accumulated significantly in G(2)-M phase and remained blocked in G(1-) and G(2)-M phases after several posttreatments in fresh growth medium. The aqueous extract alone did not induce chromosome aberrations but, in combined treatment with H(2)O(2), significantly reduced H(2)O(2)-induced chromosome aberrations. Flow cytometric analysis of DCFH intracellular oxidation showed that the extract decreased the oxidizing power of H(2)O(2.) This ability could possibly explain the extract's antigenotoxic activity. Absence of cytotoxicity at the lower tested doses and the antimutagenic properties of the extract stimulate the interest in studying possible new pharmaceutical uses of P. orbicularis.

Animals↗

PubMed1999

Inhibitory action of melatonin on H2O2- and cyclophosphamide-induced DNA damage.

Melatonin, the pineal gland hormone known for its ability to modulate circadian rhythm, has recently been studied in its several functions. It is believed to inhibit cancer growth, to stimulate the immune system and to act as an antioxidant. In particular, this latter activity is ascribed to two different mechanisms: stimulation of radical detoxifying enzymes and scavenging of free radicals. We used this compound in mammalian cells in vitro to investigate its mechanism of action in modulating DNA damage. Cytogenetic and cytofluorimetric analyses were performed. We show that melatonin is able to modulate chromosome damage (chromosomal aberrations and sister chromatid exchanges) induced by cyclophosphamide. Conversely, its involvement in modulating oxidative processes, thereby reducing DNA damage, is less clear. In particular, melatonin is able to decrease H2O2-induced chromosomal aberrations but not sister chromatid exchanges and has been found to induce oxygen species in a cytofluorimetric test (DCFH assay).

Animals↗

PubMed1998

ICAM 1 expression and fluid phase endocytosis of cultured brain microvascular endothelial cells following exposure to interferon beta-1a and TNFalpha.

We have studied the effect of interferon (IF) beta-1a on the basal and TNFalpha-induced intercellular adhesion molecule 1 (ICAM 1) expression and fluid phase endocytosis (FPE) of horseradish peroxidase in cultured rat brain microvascular endothelial cells. Neither basal ICAM 1 expression nor basal FPE were significantly affected by 24-72 h exposure to 1000 U/ml IFbeta-1a. ICAM 1 induction and FPE enhancement caused by 100 U/ml TNFalpha for 24 h was not influenced by simultaneous administration of 1000 U/ml IFbeta-1a. Treatment of cultures with IFbeta-1a for 48 h followed by 24-h coincubation with TNFalpha (100 U/ml) and IFbeta-1a (1000 U/ml) resulted in significant downregulation of TNFalpha-induced ICAM 1 expression and FPE. Downregulation of TNFalpha-induced ICAM 1 expression was not observed when combined treatment with TNFalpha (100 U/ml) and IFbeta-1a (1000 U/ml) for 24 h was followed by 48 h exposure to IFbeta-1a. We concluded that the blood-brain barrier endothelium may be a target of IFbeta-1a. Further, these in vitro findings may correlate with the results of recent clinical trials indicating that chronic treatment of relapsing remitting multiple sclerosis with IFbeta-1a prevents both clinical exacerbations and the appearance on Magnetic Resonance Imaging of new lesions enhanced by gadolinium which is taken up by increased transendothelial fluid phase vesicular transport.

Animals↗

PubMed1998

DNA damage and cytotoxicity induced by beta-lapachone: relation to poly(ADP-ribose) polymerase inhibition.

beta-Lapachone (3,4-dihydro-2,2-dimethyl-2H-naphtho[1,2-b]pyran-5, 6-dione) was previously shown to enhance the lethality of X-rays and radiomimetic agents and its radiosensitizing role in mammalian cells was attributed to a possible interference with topoisomerase I activity. Furthermore, beta-lapachone alone was found to induce chromosomal damage in Chinese hamster ovary (CHO) cells. The aim of the present study was to further elucidate the possible mechanisms by which beta-lapachone exerts its genotoxic action in cultured mammalian cells. Flow cytometry analysis of beta-lapachone-treated CHO cells indicated a selective cytotoxic effect upon S phase of the cell cycle. beta-lapachone produced DNA strand breaks as determined by alkaline elution assay; alkaline elution profiles from treated cells showed a bimodal dose-response pattern, with a threshold dose above which a massive dose-independent DNA degradation was observed. Furthermore, beta-lapachone increased the capacity of crude CHO cellular extracts to unwind supercoiled plasmid DNA, while significantly inhibiting in vitro poly(ADP-ribose) polymerase (PARP). These results suggest that damage induction is probably mediated by the interaction between beta-lapachone and cellular enzymatic function(s), rather than reflecting a direct action on the DNA. We suggest that the inhibition of PARP plays a central role in the complex biological effects induced by beta-lapachone in CHO cells.

Animals↗

PubMed1998

Isolated so-called apraxia of eyelid opening: report of 10 cases and a review of the literature.

So-called apraxia of eyelid opening (scAEO) has been described chiefly in the context of extrapyramidal disorders. We described 10 new patients with scAEO developing in the absence of any other CNS sign and reviewed the 11 cases with isolated scAEO reported in the literature. Combining our patients and those from the literature, peak age at onset was in the 6th decade and there was a female preponderance of 2:1. The characteristic inability to initiate lid elevation was frequently associated with failure to sustain lid elevation, thus suggesting that eyelid motor control may be abnormal in isolated scAEO. Antecedent events included ocular signs and symptoms consistent with diseases of eyes or face (4 cases in our series and 2 in the literature), chronic treatment with flunarizine (1 case), and family history of dystonia (1 case). Flunarizine discontinuation led to sustained remission of the eyelid disturbance. Overall, these clues suggest the involvement of the extrapyramidal system in the pathophysiology of isolated scAEO. Familial clustering of isolated scAEO in one of our patients may be in favor of a genetic contribution. In our series, botulinum toxin administration close to the pretarsal part of the orbicularis oculi muscle significantly improved scAEO in 8/10 cases, whereas orbital/preseptal injection had no effect. We conclude that the term 'apraxia' may not be the correct descriptive term even when the eyelid disturbance occurs without any other CNS disease.

Apraxias↗

PubMed1998

Proton magnetic resonance spectroscopy in primary blepharospasm.

Single-volume proton magnetic resonance spectroscopy, localized to basal ganglia, was carried out in 10 patients with primary blepharospasm (PB) to assess the levels of N-acetyl aspartate (NAA), creatine-phosphocreatine, and choline-containing compounds. NAA was reduced significantly in patients compared with control subjects. This result suggests a striatal neuronal loss in PB.

Aged↗

PubMed1997

Endocytosis of horseradish peroxidase by brain microvascular and umbilical vein endothelial cells in culture: an ultrastructural and morphometric study.

The ability to form tight junctions and the paucity of fluid phase endocytosis showed by brain microvacular endothelial cells (BMECs) make up the structural basis of the blood-brain barrier (BBB). Most studies on cultured BMECs focused on intercellular junctions, whereas endocytosis received lesser attention. We studied endocytosis of horseradish peroxidase in primary and passage 1 and 2 BMEC cultures from rat brain as well as in human umbilical vein endothelial cell (HUVEC) culture. Endocytic activity was also analyzed in passage 1 BMECs treated with lipopolysaccharide (LPS, 1 microg/ml for 4 h), which mimics BBB disruption in bacterial meningoencephalitis. The percent of cytoplasmic area occupied by endocytic profiles (vesicles <70 nm and vacuoles >70 nm) and their mean number per cell were significantly lower in primary and passaged BMEC than in HUVEC cultures. The area and number of endocytic profiles significantly increased in BMECs after exposure to LPS. BMECs cultured under standard conditions may be a suitable model for studying the mechanism of increased fluid phase endocytosis in certain diseases and injury states.

Animals↗

PubMed1997

Ascorbic acid and beta-carotene as modulators of oxidative damage.

Naturally occurring antioxidants are extensively studied for their capacity to protect organisms and cells from damage induced by oxygen reactive species. In fact, oxidative stress is considered a cause of aging, degenerative disease and cancer. We have focused our attention on two agents, ascorbic acid and beta-carotene, commonly considered to be antioxidants, but whose protective activity against cancer is insufficiently known. This paper reports on the ability of these agents to act against damage induced by H2O2 and bleomycin, in Chinese hamster ovary cells cultivated in vitro. Cytogenetic and cytofluorimetric analyses were performed. Both vitamins proved effective in reducing H2O2-induced sister chromatid exchanges, but increased H2O2- and bleomycin-induced chromosomal aberrations. Cytofluorimetric data, in contrast, showed that ascorbic acid and beta-carotene act as scavengers of endogeneous and H2O2-induced oxygen species.

Animals↗

PubMed1996

Serum IgG to brain microvascular endothelial cells in multiple sclerosis.

Serum IgG to brain microvascular endothelial cells (BMECs) were assessed in the sera from 50 patients with definite multiple sclerosis, 24 patients with other inflammatory and non-inflammatory neurological diseases and 30 healthy individuals. Standard indirect immunofluorescence on BMEC culture was used as the bioassay system. Positive immunostaining was found in the sera (1:5 to 1:50 dilution) from 0/15 inactive relapsing remitting (RR), 12/16 active RR (p = 0.0001), 1/8 relapsing progressive (RP) and 0/11 primary progressive (PP) patients. No specific binding was detected when sera from neurologic and healthy controls were used. The specificity of the immune reaction for brain endothelium was established by the absence of staining on human umbilical vein endothelial cell and brain pericyte cultures. Gadolinium (Gd)-enhanced magnetic resonance imaging of the brain and spinal cord was performed in 36 MS patients within a 10-day interval from serum collection. Anti-brain endothelium antibodies were found in 9/12 patients with, and in 1/24 patients without Gd-enhanced lesions (p = 0.00002). Regardless of a pathogenetic role in the blood-brain barrier breakdown, serum IgG to BMECs may be a marker of disease activity in RR and RP MS and a factor differentiating RR/RP and PP MS.

Adult↗

PubMed1996

Topoisomerase I activity and cellular response to radiation in Chinese hamster cells.

The aim of the present study was to investigate the synergistic potential of the combination of camptothecin, a specific inhibitor of topoisomerase I, and radiation in the the induction of chromosome aberrations and cell cycle delay in actively proliferating mammalian cells. Synergistic effects of the combined treatments were obtained for induced frequencies of aberrations in exponentially growing Chinese hamster ovary cells. The potentiating effects were more pronounced for aberrations of the exchange type, suggesting that interaction of unrepaired radiation- and camptothecin-induced lesions during replication may be involved in the observed drug-radiation synergism. Cytofluorimetric analysis of cell cycle progression in cells receiving the combined treatments displayed enhanced responses of CHO cells to S- and G2 phase delay induced by the single treatments. To investigate the determinants of the synergistic response, the influence of radiation exposure on the catalytic activity of topoisomerase I was assayed. A decreased plasmid supercoiled DNA relaxation capacity of crude extracts derived from irradiated CHO cells was found which suggests a decrease in the topoisomerase I catalytic activity following irradiation. In addition, a lower sensitivity of the enzyme from irradiated cells to inhibition of topoisomerase I activity by camptothecin was also observed using the same DNA relaxation test.

Animals↗

PubMed1995

Taurine and ellagic acid: two differently-acting natural antioxidants.

Naturally occurring antimutagenic compounds are extensively analyzed for their capacity to protect cells from induced damage. We selected two agents, taurine and ellagic acid, treated in the literature as antioxidants, but whose activity is insufficiently known. This paper reports on the ability of these agents to act against damage induced by mitomycin-C and hydrogen peroxide in Chinese hamster ovary cells cultivated in vitro. Cytogenetic and cytofluorimetric analyses were performed. Ellagic acid proved to have more than one mechanism of action, probably as a scavenger of oxygen species produced by H2O2 treatment, and as a protector of the DNA double helix from alkylating agent injury. In our experimental conditions, taurine seems able to scavenge oxygen species.

Animals↗

PubMed1993

The production of chromosomal alterations by beta-lapachone, an activator of topoisomerase I.

The frequencies of chromosomal aberrations and sister-chromatid exchanges (SCE) after exposure to beta-lapachone, an activator of mammalian topoisomerase I, were studied in Chinese hamster cells. A dose-dependent increase in the frequencies of SCE was observed in continuous treatments with beta-lapachone. Chromatid-type aberrations were obtained in cells exposed to beta-lapachone for one cell cycle but also in cells exposed during the G2 phase of the cell cycle, with a marked induction of exchange-type aberrations for both treatment schedules. We therefore propose that activation of topoisomerase I by beta-lapachone results in the production of chromosomal alterations. The cell cycle dependence of beta-lapachone clastogenic effects strongly suggests a mechanism for the formation of chromosomal aberrations after this drug closely resembling the one observed for the topoisomerase I inhibitor, camptothecin.

Animals↗

PubMed1993

Hypersensitivity of lymphoblastoid lines derived from ataxia telangiectasia patients to the induction of chromosomal aberrations by etoposide (VP-16).

Mammalian DNA topoisomerase II represents the cellular target of many antitumor drugs, such as epipodophyllotoxin VP-16 (etoposide). The mechanism by which VP-16 exerts its cytotoxic and antineoplastic actions has not yet been firmly established, although the unique correlation between sensitivity to ionizing radiation and to topoisomerase II inhibitors suggest the involvement of DNA double-strand breaks. In the present study we analyzed the chromosomal sensitivity of lymphoblastoid cell lines derived from ataxia telangiectasia (AT) patients to low concentrations of the drug. Our results indicate that AT derived cells are hypersensitive to the clastogenic activity of VP-16 either when the drug is present for the whole duration of the cell cycle or specifically in the G2 phase, confirming that the induction of DNA double strand breaks, to which AT cells seem typically sensitive, could have an important role in the biological activity of VP-16.

Ataxia Telangiectasia↗

PubMed1993

Desmutagenic activity of natural humic acids: inhibition of mitomycin C and maleic hydrazide mutagenicity.

Humic acids are natural components of organic matter widespread in the environment. In spite of the incomplete knowledge about their composition, increasing interest in humic acid activity is justified by their ubiquity. Four different humic acids have been tested in Chinese hamster ovary cells in vitro, both alone and in combination with two well-known mutagens (mitomycin C and maleic hydrazide). Data about sister-chromatid exchanges, mitotic and proliferation indices were collected. Our results, on the whole, indicate: (i) a slight mutagenicity and toxicity of tested humic acids, probably due to chlorination during sample preparation; (ii) a desmutagenic rather than antimutagenic activity of the tested humic acids.

Animals↗