32 results on '"Valenti K"'
Search Results
2. “THAT’S MY PLAN. LET’S HOPE THAT’S WHAT HAPPENS:” LGBTQ OLDER WOMEN’S EXPECTATIONS AND DESIRES FOR END-OF-LIFE CARE
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Valenti, K, primary
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- 2018
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3. THE IMPACT OF FAMILY SATISFACTION: INFORMED CHOICES FOR CONSUMERS AND IMPROVEMENT OPPORTUNITIES FOR NURSING HOMES
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Valenti, K, primary, Dikhtyar, O, additional, and Straker, J, additional
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- 2018
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4. Antimutagenic, antigenotoxic and antioxidant activities of\textit Acacia salicina extracts (ASE) and modulation of cell gene expression by H_\textrm2\O_\textrm2\ and ASE treatment
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Bouhlel, I., Valenti, K., Kilani, S., Skandrani, I., Ben Sghaier, M., Mariotte, A. M., Dijoux-Franca, Marie. G., Ghedira, K., Hininger-Favier, I., Laporte, F., Chekir-Ghedira, L., Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire de Lyon (ENVL)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)
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[SDV]Life Sciences [q-bio] - Published
- 2008
5. Study of antimutagenic and antioxydant activities of gallic acid and 1,2,3,4,6-pentagalloylglucose from Pistacia lentiscus. Confirmation by microarray expression profiling
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Abdelwahed, A., Chekir-Ghedira, L., Dijoux-Franca, M.-G., Ghedira, K., Mariotte, A.-M., Bouhled, I., Skandrani, I., Valenti, K., Kadri, M., Guiraud, P., Steiman, R., Laporte, F., Unité de Pharmacognosie/Biologie Moléculaire, Faculté de Pharmacie/Médecine Dentaire de Monastir, Département de biologie intégrée, CHU Grenoble-Hôpital Michallon, Laboratoire ORSOX, Université Joseph Fourier - Grenoble 1 (UJF), Département de pharmacochimie moléculaire (DPM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), and Decout, Jean Luc
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[SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology ,[SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2007
6. Hyperhomocystéinémie sévère révélant une homocystinurie chez deux jeunes adultes présentant un phénotype peu marqué
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Ducros, V., primary, Rousset, J., additional, Garambois, K., additional, Boujet, C., additional, Rolland, M.O., additional, Valenti, K., additional, Bouillet, L., additional, Jaillard, A., additional, and Favier, A., additional
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- 2006
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7. A Simple Electrophoretic Method for Phenotyping Apo(a): Phenotype Frequency in Healthy Subjects from Paris, France
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Couderc, R, primary, Peoc’h, K, primary, Valenti, K, primary, Diop, M-E, primary, Bailleul, S, primary, Kiénou, L, primary, Ferrière, F, primary, and Etienne, J, primary
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- 1998
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8. ApoE polymorphism and albuminuria in diabetes mellitus: a role for LDL in the development of nephropathy in NIDDM?
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Boize, R., primary, Benhamou, P.-Y., additional, Corticelli, P., additional, Valenti, K., additional, Bosson, J.-L., additional, and Halimi, S., additional
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- 1998
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9. 2.P.99 A novel kringle-4 number-based recombinant apo(a) standard for human Lp(a) phenotyping
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Anglés-Cano, E., primary, Loyau, S., additional, Kang, C., additional, Couderc, R., additional, Valenti, K., additional, and Müller, J.H., additional
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- 1997
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10. Identification of a mutation, N543H, in exon 11 of the low-density lipoprotein receptor gene in a French family with familial hypercholesterolemia
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Tricot-Guerber, F., primary, Saint-Jore, B., additional, Valenti, K., additional, Foulon, T., additional, Bost, M., additional, and Hadjian, A. J., additional
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- 1995
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11. Mechanisms for vagal modulation of ventricular repolarization and of coronary occlusion-induced lethal arrhythmias in cats.
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Rosenshtraukh, L, primary, Danilo, P, additional, Anyukhovsky, E P, additional, Steinberg, S F, additional, Rybin, V, additional, Brittain-Valenti, K, additional, Molina-Viamonte, V, additional, and Rosen, M R, additional
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- 1994
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12. Contribution of apolipoprotein(a) size, pentanucleotide TTTTA repeat and C/T(+93) polymorphisms of the apo(a) gene to regulation of lipoprotein(a) plasma levels in a population of young European Caucasians
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Valenti, K., Aveynier, E., Leaute, S., Laporte, F., and Hadjian, A.J.
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- 1999
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13. ApoE polymorphism and albuminuria in diabetes mellitus: a role for LDL in the development of nephropathy in NIDDM?
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Boizel, R, Benhamou, P Y, Corticelli, P, Valenti, K, Bosson, J L, and Halimi, S
- Abstract
Chronic hyperglycaemia stands with diabetes duration as the main predicting factor for the development of nephropathy in insulin dependent diabetes mellitus (IDDM). In contrast, nephropathy in non-insulin-dependent diabetes mellitus (NIDDM) presents with a different natural history and, as well as atherosclerosis, can precede diabetes diagnosis and even the onset of patent hyperglycaemia. The role of lipid abnormalities in this matter remains debated.
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- 1998
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14. Evaluation of the genotyping and phenotyping approaches in the investigation of apolipoprotein (a) size polymorphism
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Valenti, K., Aveynier, E., Laporte, F., and Hadjian, A. J.
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- 1997
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15. Case Report: Percutaneous Peripheral Nerve Stimulation for the Treatment of Occipital Neuralgia.
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Valenti K, Robinson CL, Orhurhu V, Mahmood S, and Hasoon J
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Headaches are among the most prevalent medical complaints globally. Occipital neuralgia is a chronic headache disorder characterized by unilateral or bilateral severe pain originating in the neck or skull base and radiating up along the occipital nerve distribution. Effective treatment options for occipital neuralgia can be challenging and some patients may prove to be refractory to conventional medical and interventional therapies. We present a case report on a patient with severe occipital neuralgia that was refectory to conventional therapies that responded to percutaneous peripheral nerve stimulation., Competing Interests: JH is a consultant for SPR Therapeutics and Nevro. VO is a consultant for Medtronic
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- 2025
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16. Cervical Epidural Steroid Injection for Cervical Radicular Pain in a Patient with Fractured Cervical Hardware.
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Chu K, Chu W, Valenti K, Robinson CL, Kaye AD, and Hasoon J
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Cervical radicular pain following anterior cervical discectomy and fusion (ACDF) is a challenging condition, particularly in the presence of hardware complications. This case report discusses the successful use of a cervical interlaminar steroid injection to alleviate radicular pain in a patient who presented with a fractured screw following C6/7 ACDF. The patient's symptoms, treatment plan, and outcome are reviewed, highlighting the success of an interlaminar steroid injection in managing radicular pain until the patient could receive corrective surgery.
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- 2024
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17. My Partner Is My Family: Engaging and Advocating for Lesbian, Gay, Bisexual, Transgender, Queer+ Patients in Goals of Care Conversations.
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Valenti K, Doyon K, Morgan B, Quinn G, and Bekelman D
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- Humans, Female, Communication, Patient Care Planning, Decision Making, Male, Middle Aged, Patient Advocacy psychology, Patient Advocacy trends, Sexual and Gender Minorities psychology
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In goals of care conversations and through the care trajectory, to avoid insensitive or discriminatory care, it is vital clinicians recognize lesbian, gay, bisexual, transgender, queer+ patients' values and wishes. In clinical settings, implicit bias operating within unconscious awareness may challenge the commitment to equitable care, negatively affecting patient outcomes. In this composite case, during a conversation with a social worker/nurse team, a cisgender woman repeatedly expressed her wishes for her female partner to be her decision maker instead of her biological family. The conversation stalled during the patient's attempts to identify her partner as her most valued and trusted person. Interviewer follow-up responses based on motivational interviewing techniques, which do not include strategies for lesbian, gay, bisexual, transgender, queer+ interactions, inaccurately reflected the patient's needs. Two ethical issues emerged, (1) autonomy and (2) beneficence. Clinicians should approach all patients using nongendered language, and allow patients to self-identify and decide which people are in their support system. Lack of inclusivity training has significant potential to affect the patient experience and decrease clinician/patient trust. Clinicians should not assume the decision maker is a cisgender, heterosexual partner or a biological family member. When patients speak about their partners, it is imperative clinicians use the patient's language and not avoid or redirect responses., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 by The Hospice and Palliative Nurses Association. All rights reserved.)
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- 2024
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18. Palliative Care Professionals' Perceptions of Communication With Sexual and Gender Minority Patients.
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Valenti K, Bybee S, Nwakasi C, Kano M, and Coats H
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- Humans, Male, Female, Middle Aged, Adult, Colorado, Qualitative Research, Professional-Patient Relations, Health Personnel psychology, Aged, Perception, Healthcare Disparities, Sexual and Gender Minorities psychology, Palliative Care psychology, Palliative Care organization & administration, Communication, Attitude of Health Personnel
- Abstract
Purpose: For sexual and gender minority (SGM) individuals who identify as lesbian, gay, bisexual, transgender, queer, or any other sexual orientation or gender identity (LGBTQ+), the quality of palliative care can depend upon how clinicians view and communicate with this historically minoritized group. Prior literature has demonstrated that SGM patients access care at lower rates, and palliative care clinicians have suggested that SGM patients are more likely to experience discrimination than heterosexual patients. This study examined palliative care clinicians' perspectives and experiences regarding patient communication, care settings, the built environment, and inclusive care for SGM older adults with serious illness., Methods: The health disparities research framework informed a descriptive qualitative analysis of interview data with palliative care professionals (N = 20) across diverse healthcare settings within Colorado regarding their experiences and beliefs about communication and the care of SGM patients., Results: Three main themes emerged: (1) Limited sexual orientation and gender identity (SOGI) data collection; (2) Organizational and environmental inclusivity, and the "neutral" space viewed as safe; (3) Missing training platforms regarding SGM patients and a lack of opportunity to identify and discuss SGM patient needs., Conclusion: Study findings illuminated the following barriers to providing SGM-inclusive care: perspectives around (1) limitations and preferences regarding collection of SOGI data, (2) organizational and environmental inclusivity, and (3) education and training regarding cultural humility and communication with SGM patients. Findings indicate the need for multidimensional research to better understand and address SGM health disparities and promote equitable care., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
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- 2024
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19. Liver transplant outcomes using late allocation grafts.
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Jadlowiec CC, Brooks A, Pont K, Macdonough E, Buckner Petty S, Valenti K, Lizaola-Mayo B, Frasco P, Aqel B, Mathur AK, Moss A, and Reddy KS
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- Humans, Adult, Severity of Illness Index, Tissue Donors, Graft Survival, Retrospective Studies, Liver Transplantation adverse effects, End Stage Liver Disease surgery, End Stage Liver Disease etiology, Carcinoma, Hepatocellular etiology, Liver Neoplasms etiology, Tissue and Organ Procurement
- Abstract
Post-cross clamp late allocation (LA) liver allografts are at increased risk for discard for many reasons including logistical complexity. Nearest neighbor propensity score matching was used to match 2 standard allocation (SA) offers to every 1 LA liver offer performed at our center between 2015 and 2021. Propensity scores were based on a logistic regression model including recipient age, recipient sex, graft type (donation after circulatory death vs. donation after brain death), Model for End-stage Liver Disease (MELD), and DRI score. During this time, 101 liver transplants (LT) were performed at our center using LA offers. In comparing LA and SA offers, there were no differences in recipient characteristics including indication for transplant ( p = 0.29), presence of PVT ( p = 0.19), TIPS ( p = 0.83), and HCC status ( p = 0.24). LA grafts came from younger donors (mean age 43.6 vs. 48.9 y, p = 0.009) and were more likely to come from regional or national Organ Procurement Organizations (OPOs) ( p < 0.001). Cold ischemia time was longer for LA grafts (median 8.5 vs 6.3 h, p < 0.001). Following LT, there were no differences between the 2 groups in intensive care unit ( p = 0.22) and hospital ( p = 0.49) lengths of stay, need for endoscopic interventions ( p = 0.55), or biliary strictures ( p = 0.21). Patient (HR 1.0, 95% CI, 0.47-2.15, p = 0.99) and graft (HR 1.23, 95% CI, 0.43-3.50, p = 0.70) survival did not vary between the LA and SA cohorts. One-year LA and SA patient survival was 95.1% and 95.0%; 1-year graft survival was 93.1% and 92.1%, respectively. Despite the additional logistical complexity and longer cold ischemia time, LT outcomes utilizing LA grafts are similar to those allocated by means of SA. Improving allocation policies specific to LA offers, as well as the sharing of best practices between transplant centers and OPOs, are opportunities to further help minimize unnecessary discards., (Copyright © 2023 American Association for the Study of Liver Diseases.)
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- 2023
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20. LGBT+-specific experiences of partner bereavement suggest avoiding assumptions, promoting agency in disclosure and using inclusive communication as key to safe, accessible, supportive care.
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Valenti K
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- Humans, Disclosure, Palliative Care, Hospice Care, Bereavement, Sexual and Gender Minorities
- Abstract
Competing Interests: Competing interests: None declared.
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- 2023
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21. Donation after circulatory death transplant outcomes using livers recovered by local surgeons.
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Jadlowiec CC, Macdonough E, Pont K, Valenti K, Lizaola-Mayo B, Brooks A, Das D, Heilman R, Mathur AK, Hewitt W, Moss A, Aqel B, and Reddy KS
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- Death, Graft Survival, Humans, Ischemia, Retrospective Studies, Severity of Illness Index, Tissue Donors, United States, End Stage Liver Disease surgery, Liver Transplantation adverse effects, Liver Transplantation methods, Surgeons, Tissue and Organ Procurement
- Abstract
Donation after circulatory death (DCD) liver transplantation (LT) outcomes have been attributed to multiple variables, including procurement surgeon recovery techniques. Outcomes of 196 DCD LTs at Mayo Clinic Arizona were analyzed based on graft recovery by a surgeon from our center (transplant procurement team [TPT]) versus a local procurement surgeon (non-TPT [NTPT]). A standard recovery technique was used for all TPT livers. The recovery technique used by the NTPT was left to the discretion of that surgeon. A total of 129 (65.8%) grafts were recovered by our TPT, 67 (34.2%) by the NTPT. Recipient age (p = 0.43), Model for End-Stage Liver Disease score (median 17 vs. 18; p = 0.22), and donor warm ischemia time (median 21.0 vs. 21.5; p = 0.86) were similar between the TPT and NTPT groups. NTPT livers had longer cold ischemia times (6.5 vs. 5.0 median hours; p < 0.001). Early allograft dysfunction (80.6% vs. 76.1%; p = 0.42) and primary nonfunction (0.8% vs. 0.0%; p = 0.47) were similar. Ischemic cholangiopathy (IC) treated with endoscopy occurred in 18.6% and 11.9% of TPT and NTPT grafts (p = 0.23). At last follow-up, approximately half of those requiring endoscopy were undergoing a stent-free trial (58.3% TPT; 50.0% NTPT; p = 0.68). IC requiring re-LT in the first year occurred in 0.8% (n = 1) of TPT and 3.0% (n = 2) of NTPT grafts (p = 0.23). There were no differences in patient (hazard ratio [HR], 1.95; 95% confidence interval [CI], 0.76-5.03; p = 0.23) or graft (HR, 1.99; 95% CI, 0.98-4.09; p = 0.10) survival rates. Graft survival at 1 year was 91.5% for TPT grafts and 95.5% for NTPT grafts. Excellent outcomes can be achieved using NTPT for the recovery of DCD livers. There may be an opportunity to expand the use of DCD livers in the United States by increasing the use of NTPT., (© 2022 The Authors. Liver Transplantation published by Wiley Periodicals LLC on behalf of American Association for the Study of Liver Diseases.)
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- 2022
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22. Containment efficiency and control strategies for the corona pandemic costs.
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Gros C, Valenti R, Schneider L, Valenti K, and Gros D
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- Basic Reproduction Number, COVID-19 epidemiology, COVID-19 transmission, COVID-19 virology, Disease Outbreaks, Humans, Models, Statistical, Physical Distancing, COVID-19 prevention & control, Cost Control, Health Care Costs, Pandemics economics, SARS-CoV-2 isolation & purification
- Abstract
The rapid spread of the Coronavirus (COVID-19) confronts policy makers with the problem of measuring the effectiveness of containment strategies, balancing public health considerations with the economic costs of social distancing measures. We introduce a modified epidemic model that we name the controlled-SIR model, in which the disease reproduction rate evolves dynamically in response to political and societal reactions. An analytic solution is presented. The model reproduces official COVID-19 cases counts of a large number of regions and countries that surpassed the first peak of the outbreak. A single unbiased feedback parameter is extracted from field data and used to formulate an index that measures the efficiency of containment strategies (the CEI index). CEI values for a range of countries are given. For two variants of the controlled-SIR model, detailed estimates of the total medical and socio-economic costs are evaluated over the entire course of the epidemic. Costs comprise medical care cost, the economic cost of social distancing, as well as the economic value of lives saved. Under plausible parameters, strict measures fare better than a hands-off policy. Strategies based on current case numbers lead to substantially higher total costs than strategies based on the overall history of the epidemic.
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- 2021
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23. Chromium III histidinate exposure modulates gene expression in HaCaT human keratinocytes exposed to oxidative stress.
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Hazane-Puch F, Benaraba R, Valenti K, Osman M, Laporte F, Favier A, Anderson RA, Roussel AM, and Hininger-Favier I
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- DNA Repair, Expressed Sequence Tags, Glutathione Synthase genetics, Glutathione Synthase metabolism, Heme Oxygenase (Decyclizing) genetics, Heme Oxygenase (Decyclizing) metabolism, Histidine toxicity, Humans, Hydrogen Peroxide pharmacology, Keratinocytes drug effects, Peroxiredoxins genetics, Peroxiredoxins metabolism, Gene Expression Regulation, Histidine analogs & derivatives, Keratinocytes metabolism, Organometallic Compounds toxicity, Oxidative Stress
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While the toxicity of hexavalent chromium is well established, trivalent chromium is an essential nutrient involved in insulin and glucose homeostasis. To study the antioxidant effects of Cr(III)His, cDNA arrays were used to investigate the modulation of gene expression by trivalent chromium histidinate (Cr(III)His) in HaCaT human keratinocytes submitted to hydrogen peroxide (H2O2). Array was composed by a set of 81 expressed sequences tags (ESTs) essentially represented by antioxidant and DNA repair genes. HaCaT were preincubated for 24 h with 50 microM Cr(III)His and were treated with 50 muM H2O2. Total RNAs were isolated immediately or 6 h after the stress. In Cr(III)His preincubated cells, transcripts related to antioxidant family were upregulated (glutathione synthetase, heme oxygenase 2, peroxiredoxin 4). In Cr(III)His preincubated cells and exposed to H2O2, increased expressions of polymerase delta 2 and antioxidant transcripts were observed. Biochemical methods performed in parallel to measure oxidative stress in cells showed that Cr(III)His supplementation before H2O2 stress protected HaCaT from thiol groups decrease and thiobarbituric acid reactive substances increase. In summary, these results give evidence of antioxidant gene expression and antioxidant protection in HaCaT preincubated with Cr(III)His and help to explain the lack of toxicity reported for Cr(III)His.
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- 2010
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24. Study of fibroblast gene expression in response to oxidative stress induced by hydrogen peroxide or UVA with skin aging.
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Hazane-Puch F, Bonnet M, Valenti K, Schnebert S, Kurfurst R, Favier A, and Sauvaigo S
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- Adolescent, Adult, Aged, Cells, Cultured, DNA Repair, Female, Fibroblasts pathology, Humans, Middle Aged, Oligonucleotide Array Sequence Analysis, Oxidants adverse effects, Young Adult, Fibroblasts metabolism, Gene Expression Regulation drug effects, Gene Expression Regulation genetics, Gene Expression Regulation radiation effects, Hydrogen Peroxide adverse effects, Oxidative Stress, RNA genetics, Skin Aging, Ultraviolet Rays adverse effects
- Abstract
The skin aging process, implying oxidative stress, is associated with specific gene expression. Ultraviolet A (UVA) and hydrogen peroxide (H(2)O(2)) both generate reactive oxygen species (ROS) making them relevant in the study of skin cell responses to oxidative stresses. To investigate transcript expression associated with chronological skin aging and its modulation by two oxidative stresses, cDNA micro-arrays, composed of a set of 81 expressed sequence tag (EST) clones, were used to probe the patterns of transcript expression in human fibroblasts of five young (< 21 years-old) and five older (> 50 years-old) healthy females at basal levels and 24 h after exposure to UVA (7 J/cm2) and H(2)O(2) (20 mM). At the basal state, 22% of total genes were up-regulated in the older group. Although both stresses led to the same cell mortality, H(2)O(2) induced a stronger modulation of gene expression than UVA, with 19.5% of transcripts up-regulated versus 4%. The aging process affected the response to H(2)O(2) and even though cells from old donors presented higher basal levels of transcripts they were not able to regulate them in response to the stress. Interestingly, UVA had a specific strong inhibitory effect on the expression of chemokine (C-C) motif ligand 2 (CCL2) transcript, suggesting a possible mechanism for its anti-inflammatory and immunoregulatory roles.
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- 2010
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25. Antigenotoxic and antioxidant activities of isorhamnetin 3-O neohesperidoside from Acacia salicina.
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Bouhlel I, Skandrani I, Nefatti A, Valenti K, Ghedira K, Mariotte AM, Hininger-Favier I, Laporte F, Dijoux-Franca MG, and Chekir-Ghedira L
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- Cell Line, Tumor, Comet Assay, DNA Damage, DNA Repair drug effects, DNA Repair genetics, Flavonols pharmacology, Gene Expression drug effects, Humans, Hydrogen Peroxide toxicity, Hydroxyl Radical toxicity, Lipid Peroxidation drug effects, Oligonucleotide Array Sequence Analysis, Oxidants toxicity, Oxidative Stress genetics, Plant Leaves chemistry, Plasmids drug effects, Plasmids genetics, Up-Regulation drug effects, Acacia chemistry, Antimutagenic Agents pharmacology, Antioxidants pharmacology, Oxidative Stress drug effects
- Abstract
Antioxidant activity of isorhamnetin 3-O neohesperidoside (I3ON), isolated from the leaves of Acacia salicina, was determined by the ability of this compound to inhibit lipid peroxidation and to protect against hydroxyl radical-induced DNA damage in pKS plasmid DNA and Escherichia coli cultures. Antigenotoxic activity was assessed by using the comet assay. The IC(50) value of the inhibitory activity toward lipid peroxidation by I3ON is 0.6 mM. This compound was also able to protect against hydroxyl radical-induced DNA damage in pKS plasmid DNA. Moreover, this compound induced an inhibitory activity toward H2O2-induced genotoxicity. The protective effect exhibited by this molecule was also determined by analysis of gene expression as a response to an oxidative stress, using a cDNA microarray. Transcription of several genes related to the antioxidant system (HMOX2 and TXNL) and to the DNA repair pathway (XPC, POLD1, POLD2, PCNA, DDIT3, APEX, and LIG4) were upregulated after incubation with I3ON. Taken together, these observations provide evidence that the I3ON, isolated from the leaves of A. salicina, is able to protect cells against oxidative stress.
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- 2009
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26. The mycotoxin Zearalenone induces apoptosis in human hepatocytes (HepG2) via p53-dependent mitochondrial signaling pathway.
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Ayed-Boussema I, Bouaziz C, Rjiba K, Valenti K, Laporte F, Bacha H, and Hassen W
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- Caspase 3 drug effects, Caspase 3 metabolism, Caspase 9 drug effects, Caspase 9 metabolism, Cell Line, Tumor, Cell Proliferation drug effects, Cytochromes c drug effects, Cytochromes c metabolism, DNA Breaks, Double-Stranded drug effects, Dose-Response Relationship, Drug, Gene Expression Regulation drug effects, Hepatocytes metabolism, Humans, Membrane Potential, Mitochondrial drug effects, Mitochondria drug effects, Mitochondria metabolism, Oligonucleotide Array Sequence Analysis, Signal Transduction drug effects, Tumor Suppressor Protein p53 metabolism, Zearalenone administration & dosage, Apoptosis drug effects, Hepatocytes drug effects, Tumor Suppressor Protein p53 drug effects, Zearalenone toxicity
- Abstract
Zearalenone (Zen) is a fusarial mycotoxin commonly found in several food commodities worldwide. It is frequently implicated in reproductive disorders and exerts several genotoxic effects in vivo and in vitro. In response to DNA damage, cells may undergo an intricate network of different pathways including apoptosis. Meanwhile, data regarding the induction of apoptosis after Zen exposure are limited. Thus, the aim of this study was to demonstrate whether Zen-induced DNA damage can lead to apoptosis as a stress response and which pathways are undertaken. Our results clearly show that Zen reduces cell proliferation in HepG2 cells in a dose-dependent manner as attested by the MTT assay (IC50%, 100microM). The analysis of propidum iodide uptake has shown that the amount of necrotic cells was about 6% among 55% of dead cells (at 120microM of Zen). The involvement of apoptosis as a major cause of Zen-induced cell death was further confirmed but results of caspase-3 activity showed a Zen-dose dependant increase. Furthermore, results of microarrays analysis have shown that Zen induced an upregulation of ATM and p53 genes family. ATM pathway responds primarily to DNA double-strand breaks and has been involved in the activation and stabilization of p53. The activation of p53 was accompanied by an upregulation of GADD45 to arrest the cell cycle and to allow the repair mechanisms to take place. In addition, results of genes profiling as well as western-blotting analysis showed that Zen increased the ratio of pro-apoptotic factors/anti-apoptotic factors which led to the loss of mitochondrial potential, Bax translocation and cytochrome c release. Once released, cytochome c activates caspase 9 which in turn activates caspase-3 and enhances apoptosis. In summary, these data suggested that Zen induced apoptosis in a dose-dependent manner in HepG2 cells via a p53-dependent mitochondrial pathway.
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- 2008
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27. Antimutagenic, antigenotoxic and antioxidant activities of Acacia salicina extracts (ASE) and modulation of cell gene expression by H2O2 and ASE treatment.
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Bouhlel I, Valenti K, Kilani S, Skandrani I, Ben Sghaier M, Mariotte AM, Dijoux-Franca MG, Ghedira K, Hininger-Favier I, Laporte F, and Chekir-Ghedira L
- Subjects
- Animals, Cell Line, Tumor, Comet Assay, DNA drug effects, Drug Combinations, Flavonoids chemistry, Formazans metabolism, Gene Expression Profiling, Genes, Bacterial drug effects, Humans, K562 Cells drug effects, K562 Cells metabolism, Oligonucleotide Array Sequence Analysis, Plant Extracts pharmacology, Rats, Ribosomal Protein S9, Ribosomal Proteins drug effects, Ribosomal Proteins metabolism, Salmonella typhimurium drug effects, Salmonella typhimurium genetics, Tetrazolium Salts metabolism, Acacia chemistry, Antimutagenic Agents pharmacology, Antioxidants pharmacology, Flavonoids pharmacology, Gene Expression Regulation drug effects, Hydrogen Peroxide pharmacology, Medicine, Traditional, Oxidants pharmacology
- Abstract
The total oligomers flavonoids (TOF), chloroform, petroleum ether and aqueous extracts from Acacia salicina, were investigated for the antioxidative, cytotoxic, antimutagenic and antigenotoxic activities. The viability of K562 cells were affected by all extracts after 48 h exposure. Our results showed that A. salicina extracts have antigenotoxic and/or antimutagenic activities. TOF and chloroform extracts exhibit antioxidant properties, expressed by the capacity of these extracts to inhibit xanthine oxidase activity. To further explore the mechanism of action of A. salicina extracts, we characterized expression profiles of genes involved in antioxidant protection and DNA repair in the human lymphoblastic cell line K562 exposed to H2O2. Transcription of several genes related to the thioredoxin antioxidant system and to the DNA base-excision repair pathway was up-regulated after incubation with chloroform, TOF and petroleum ether extracts. Moreover genes involved in the nucleotide-excision repair pathway and genes coding for catalase and Mn-superoxide-dismutase, two important antioxidant enzymes, were induced after incubation with the chloroform extract. Taken together, these observations provide evidence that the chloroform and TOF extracts of A. salicina leaves contain bioactive compounds that are able to protect cells against the consequences of an oxidative stress.
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- 2008
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28. Transcriptional response of genes involved in cell defense system in human cells stressed by H2O2 and pre-treated with (Tunisian) Rhamnus alaternus extracts: combination with polyphenolic compounds and classic in vitro assays.
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Ammar RB, Bouhlel I, Valenti K, Sghaier MB, Kilani S, Mariotte AM, Dijoux-Franca MG, Laporte F, Ghedira K, and Chekir-Ghedira L
- Subjects
- Cell Line, Tumor, Dose-Response Relationship, Drug, Flavonoids chemistry, Free Radical Scavengers metabolism, Gene Expression Profiling, Gene Expression Regulation genetics, Humans, Mutagenicity Tests, Oligonucleotide Array Sequence Analysis, Phenols chemistry, Plant Extracts chemistry, Plant Extracts pharmacology, Polyphenols, Precursor Cell Lymphoblastic Leukemia-Lymphoma metabolism, RNA genetics, RNA metabolism, Superoxides metabolism, Xanthine Oxidase antagonists & inhibitors, Xanthine Oxidase metabolism, Flavonoids pharmacology, Gene Expression Regulation drug effects, Hydrogen Peroxide toxicity, Phenols pharmacology, Rhamnus chemistry
- Abstract
The ability of three Rhamnus alaternus leaves extracts on antigenotoxic and gene expression level effects was respectively investigated in a bacterial assay system, i.e. the SOS chromotest with Escherichia coli PQ37 and in human K562 lymphoblast cell line. Total oligomers flavonoids (TOF) enriched, methanol and ethyl acetate extracts were prepared from powdered R. alaternus leaves and characterized quantitatively for the presence of polyphenolic compounds. We explored the response to oxidative stress using the transcriptional profile of genes in K562 cells stressed with H2O2 after incubation with plant extracts. For this purpose, we used a cDNA microarrays containing 82 genes related to cell defense, essentially represented by antioxidant and DNA repair genes. Analysis revealed that SOD1, AOE 372, TXN genes involved in the antioxidant defense system and XPC, LIG4, POLD2, PCNA genes implied in the DNA repair system were among the most expressed ones in the presence of the tested extracts. These results were in accordance with those obtained when we tested the antigenotoxic and antioxidant effects of the same extracts with, respectively the SOS chromotest and the xanthine/xanthine oxidase enzymatic assay system. The effect of the tested extracts on SOS response induced by both Aflatoxin B1 (AFB1: 10 microg/assay) and nifuroxazide (20 microg/assay) showed that the TOF extract exhibited the highest antimutagenic level towards the indirect mutagen AFB1. Whereas ethyl acetate extract showed the highest antimutagenic effect towards the direct mutagen, nifuroxazide. None of the tested extracts induced mutagenic activity. However all the tested extracts exhibited xanthine oxidase inhibiting and superoxide anions scavenging effects. R. alaternus extracts contain compounds with significant antioxidant and antigenotoxic activities. These compounds modulate gene expression as detected by using cDNA arrays.
- Published
- 2007
- Full Text
- View/download PDF
29. Study of antimutagenic and antioxidant activities of gallic acid and 1,2,3,4,6-pentagalloylglucose from Pistacia lentiscus. Confirmation by microarray expression profiling.
- Author
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Abdelwahed A, Bouhlel I, Skandrani I, Valenti K, Kadri M, Guiraud P, Steiman R, Mariotte AM, Ghedira K, Laporte F, Dijoux-Franca MG, and Chekir-Ghedira L
- Subjects
- Aflatoxin B1 antagonists & inhibitors, Comet Assay, Dose-Response Relationship, Drug, Escherichia coli genetics, Free Radical Scavengers metabolism, Gene Expression Profiling methods, Humans, Hydroxybenzoates antagonists & inhibitors, K562 Cells, Mutagenicity Tests, Nitrofurans antagonists & inhibitors, Oligonucleotide Array Sequence Analysis methods, Xanthine Oxidase antagonists & inhibitors, Antimutagenic Agents pharmacology, Antioxidants pharmacology, Enzyme Inhibitors pharmacology, Gallic Acid pharmacology, Hydrolyzable Tannins pharmacology, Lipid Peroxidation drug effects, Pistacia chemistry
- Abstract
In vitro antioxidant and antimutagenic activities of two polyphenols isolated from the fruits of Pistacia lentiscus was assessed. Antioxidant activity was determined by the ability of each compound to scavenge the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH*), to inhibit xanthine oxidase and to inhibit the lipid peroxidation induced by H(2)O(2) in K562 cell line. Antimutagenic activity was assayed with SOS chromotest using Escherichia coli PQ37 as tester strain and Comet assay using K562 cell line. 1,2,3,4,6-Pentagalloylglucose was found to be more effective to scavenge DPPH* radical and protect against lipid peroxidation. Moreover, these two compounds induced an inhibitory activity against nifuroxazide and aflatoxin B1 mutagenicity. The protective effect exhibited by these molecules was also determined by analysis of gene expression as response to an oxidative stress. For this purpose, we used a cDNA-microarray containing 82 genes related to cell defense, essentially represented by antioxidant and DNA repair proteins. We found that 1,2,3,4,6-pentagalloylglucose induced a decrease in the expression of 11 transcripts related to antioxidant enzymes family (GPX1, TXN, AOE372, SHC1 and SEPW1) and DNA repair (POLD1, APEX, POLD2, MPG, PARP and XRCC5). The use of Gallic acid, induced expression of TXN, TXNRD1, AOE372, GSS (antioxidant enzymes) and LIG4, POLD2, MPG, GADD45A, PCNA, RPA2, DDIT3, HMOX2, XPA, TDG, ERCC1 and GTF2H1 (DNA repair) as well as the repression of GPX1, SEPW1, POLD1 and SHC1 gene expression.
- Published
- 2007
- Full Text
- View/download PDF
30. Ageing effects on the expression of cell defence genes after UVA irradiation in human male cutaneous fibroblasts using cDNA arrays.
- Author
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Hazane F, Valenti K, Sauvaigo S, Peinnequin A, Mouret C, Favier A, and Beani JC
- Subjects
- Adult, Aged, Aged, 80 and over, Cells, Cultured, Child, Preschool, Fibroblasts, Gene Expression Regulation genetics, Humans, Internet, Male, Oxidative Stress genetics, Skin Aging pathology, Transcription, Genetic genetics, Transcription, Genetic radiation effects, Cytoprotection genetics, Cytoprotection radiation effects, Gene Expression Regulation radiation effects, Oligonucleotide Array Sequence Analysis, Skin Aging genetics, Skin Aging radiation effects, Ultraviolet Rays adverse effects
- Abstract
Ageing is a multifactorial process in which reactive oxygen species (ROS) are thought to be implicated. ROS cause oxidative alterations on cell constituents, and damage accumulation can lead to mutations in DNA. Modulation of gene expression during ageing is now quite documented but results are often controversial and/or incomplete. As ultraviolet A is one of the exogenous factors involved in skin ageing, by the production of ROS, we further document the modifications in gene expression during ageing process and response to an oxidative stress. For this purpose, we used a cDNA macroarray containing 82 genes related to cell defence, essentially represented by antioxidant and DNA repair proteins. Ageing-associated gene expression was assessed in normal skin human fibroblasts from three age groups: children (n=4), adults (n=4) and olders (n=3), at the basal state and after a 5J/cm2 UVA irradiation. Analysis revealed that 22 genes were never detected, whereas certain were always expressed such as those related to antioxidant defence, extracellular matrix (ECM) regulator and XPC. Transcripts related to ECM, MMP1 and MMP3 were increased with age and after UVA irradiation, independently of age. It appeared that transcripts involved in the redox status control (TXN and APEX) decreased as a function of age, at the basal state and after irradiation, respectively. Most of transcripts involved in DNA repair were not detected but repression of POLD1 in the adult group and induction of XRCC5 and LIG4 were observed after UVA irradiation, as a function of age. In the basal state, the transcript of GAS1, regulator of cell cycle arrest in G1 phase was found to be decreased with age. HMOX1 increased after UVA irradiation. In conclusion, the decrease in expression of some antioxidant system, cell cycle control gene and extracellular matrix enzymes, particularly after UV exposure can explain the occurrence of photoaging.
- Published
- 2005
- Full Text
- View/download PDF
31. [Apolipoprotein (a) isoform size determination. Value and limits of high resolution phenotyping by agarose gel electrophoresis].
- Author
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Aveynier E, Peronnon C, Valenti K, and Laporte F
- Subjects
- Adolescent, Adult, Artifacts, Bias, Female, Genotype, Humans, Immunophenotyping, Male, Middle Aged, Reproducibility of Results, Sensitivity and Specificity, Terminology as Topic, Apolipoproteins A chemistry, Electrophoresis, Agar Gel methods, Immunoblotting methods, Isomerism
- Abstract
High-resolution methods using agarose gel electrophoresis followed by immunoblotting have been recently developed for the measurement of the apolipoprotein (a) size isoforms. Despite the high sensitivity of these methods, a variable proportion of isoforms remain undetected. Four primary antibodies were compared for their ability to detect a large number of isoforms, and were found to express equal reactivity irrespective of the apo (a) size. Comparison of the data obtained both by phenotyping and by genotyping led to the identification of 15 artefactual bands. All these nonspecific bands were of low intensity and occurred when more than 50 ng of Lp (a) were loaded on the gel. The visualization of the isoforms was performed by labelling apo (a) with a peroxidase conjugated antibody coupled to a luminescent substrate, thereby allowing quantification of the relative expression of each isoform by densitometry. There is currently no standardized nomenclature for the apo (a) isoforms: a procedure is proposed using a commercially available standard to express the results in kringle number.
- Published
- 1998
32. [Contribution of molecular biology to the diagnosis of familial hypercholesterolemias in children].
- Author
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Tricot-Guerber F, Valenti K, Lafeuillade B, Pradines S, Foulon T, Bost M, and Hadjian AJ
- Subjects
- Adolescent, Age Factors, Child, Child, Preschool, Humans, Hyperlipoproteinemia Type II genetics, Molecular Biology methods, Pedigree, Polymorphism, Restriction Fragment Length, Hyperlipoproteinemia Type II diagnosis
- Abstract
The detection of children at high risk in families with a genetic form of hypercholesterolemia is important for acceptance of prevention under medical control. However, usual lipidic parameters are difficult to interpret during infancy. So we studied by a molecular biology approach 11 families presenting with syndrome of pure hypercholesterolemia where a defect of the LDL receptor (LDL-R) gene was suspected (Familial Hypercholesterolemia: FH IIa). Markers of the LDL-R gene (Restriction Fragment Length Polymorphism RFLP) were studied with intragenic probes. The segregation of the abnormal gene was studied in each family. Our results illustrate the limits of such an approach (its heaviness and the fact that, in 2 families, the analysis was not informative), but also its advantages: indeed, in 8 families, the diagnosis was established (particularly in one case at birth). Moreover in 2 families the LDL-R abnormality was excluded. In such case, as an alternative, the hypothesis of an apo B abnormality was envisaged. This differential diagnosis is interesting since it permits the choice of an adequate treatment.
- Published
- 1992
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