154 results on '"C. Viau"'
Search Results
2. The FlowVizMenu and Parallel Scatterplot Matrix: Hybrid Multidimensional Visualizations for Network Exploration
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Igor Jurisica, Michael J. McGuffin, C Viau, and Yves Chiricota
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Theoretical computer science ,Computer science ,business.industry ,Diagram ,computer.software_genre ,Computer Graphics and Computer-Aided Design ,Visualization ,Matrix (mathematics) ,Data visualization ,Signal Processing ,Principal component analysis ,Graph (abstract data type) ,Computer Vision and Pattern Recognition ,Multidimensional scaling ,Data mining ,business ,computer ,Software ,Parallel coordinates - Abstract
A standard approach for visualizing multivariate networks is to use one or more multidimensional views (for example, scatterplots) for selecting nodes by various metrics, possibly coordinated with a node-link view of the network. In this paper, we present three novel approaches for achieving a tighter integration of these views through hybrid techniques for multidimensional visualization, graph selection and layout. First, we present the FlowVizMenu, a radial menu containing a scatterplot that can be popped up transiently and manipulated with rapid, fluid gestures to select and modify the axes of its scatterplot. Second, the FlowVizMenu can be used to steer an attribute-driven layout of the network, causing certain nodes of a node-link diagram to move toward their corresponding positions in a scatterplot while others can be positioned manually or by force-directed layout. Third, we describe a novel hybrid approach that combines a scatterplot matrix (SPLOM) and parallel coordinates called the Parallel Scatterplot Matrix (P-SPLOM), which can be used to visualize and select features within the network. We also describe a novel arrangement of scatterplots called the Scatterplot Staircase (SPLOS) that requires less space than a traditional scatterplot matrix. Initial user feedback is reported.
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- 2010
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3. Impact of Graft Type on Outcome in Pediatric Liver Transplantation
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T. Shisler, Jeffrey H. Fair, Glenn A. Halff, Kathy Orban-Eller, J. Mayo, Frederick M. Karrer, Cindy Mack, Susan Gilmour, A. Santiago, Ajai Khanna, J. Kraus, E. Phillips, C. Viau, Katie Neighbors, Leslie L. Studenski, Jean Pearson, Jody A. Weckwerth, L. Ferrer, Linda S. Book, Michelle Nadler, M. Christoff, Michelle Felix, M. K. Alford, W. Berquest, Louise Flynn, A. Bula, Jean Greseth, S. Fiest, L. Krawczuk, Fred Ryckman, John A. Goss, Munci Kalayoglu, Valorie Buchholz, Ross W. Shepherd, J. Eshun, K. Maseda, Dev M. Desai, Benjamin L. Shneider, George V. Mazariegos, Kathleen B. Schwarz, Tomoaki Kato, Joel E. Lavine, B. Dodd, J M Millis, Saul J. Karpen, Marcia Hodik, Douglas S. Fishman, C. Mark, John C. Bucuvalas, Deborah K. Freese, James D. Eason, D. Garner, Cynthia K. Kawai, Andre Hawkins, Peter L. Abt, Steven J. Lobritto, E. Spaith, Alan Norman Langnas, Debra L. Sudan, Humberto Soriano, Dean L. Antonson, Thomas G. Heffron, Robert Kane, M. Akyeampong, Vicky L. Ng, Elizabeth B. Rand, A. Fecteau, John C. Magee, Sukru Emre, K. Anderer, S. Wallace, Vicki Fioravanti, Robert Jurao, Nanda Kerkar, Molly O'Gorman, Stuart J. Knechtle, Andreas G. Tzakis, Deborah Weppler, Estella M. Alonso, Joseph Tector, Nissa I Erickson, Nydia Chien, Simon Horslen, Maureen M. Jonas, J. Prinzhorn, Melissa Young, J. DePaolo, Regino P. Gonzalez-Peralta, D. Filipowski, G. Arya, Ronald J. Sokol, Andreanne Benidir, S. V. McDiarmid, Norman M. Kneteman, Patricia Harren, P. Atkinson, L. Cutright, Robert A. Fisher, Thomas A. Aloia, Beth A. Carter, Alan W. Hemming, S. Lerrett, Pamela Boone, Beverly Fleckten, Jay S. Roden, J. Menendez, Jean F. Botha, James Lopez, J. Michael Millis, Angelo D'Alessandro, V. Shieck, Todd Pillen, Christine A. O'Mahony, Ravinder Anand, S. L. Powell, Jean P. Molleston, S. Cuellar, Fernando Alvarez, Jeffrey A. Lowell, Paul M. Colombani, Abhi Humar, Grzegorz Telega, M. de Angelis, Joan Lokar, James F. Daniel, S. McCracken, Kathleen Falkenstein, Ivan Diamond, Julian E. Losanoff, Michael R. Narkewicz, Lynn Seward, Naveen K. Mittal, J. Lim, Kenneth A. Andreoni, A. Tendick, Deborah A. Andersen, L. Cooper, P. Rosenthal, M. Castillo, Wendy J. Grant, R. Judo, Samuel So, Annie Fecteau, V. Ng, Stephen P. Dunn, Brenda Durand, Walter S. Andrews, Steven N. Lichtman, R. Clawson, L. Bruschke, L. Young, V. McLin, K.R. Seipel, L. Smith, Changhong Song, M. Gonzalez, Susan Kelly, L. Davis, Steven R. Martin, and S. Jarvis
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Male ,Canada ,medicine.medical_specialty ,Time Factors ,Waiting Lists ,medicine.medical_treatment ,Liver transplantation ,Living Donors ,medicine ,Humans ,Prospective Studies ,Child ,Prospective cohort study ,Graft Type ,business.industry ,Extramural ,Liver Diseases ,Graft Survival ,Follow up studies ,Infant ,Original Articles ,Prognosis ,United States ,Liver Transplantation ,Surgery ,Survival Rate ,Transplantation ,surgical procedures, operative ,Multicenter study ,Child, Preschool ,Tissue and Organ Harvesting ,Female ,Graft survival ,Morbidity ,business ,Follow-Up Studies - Abstract
To examine the outcome of technical variant liver transplant techniques relative to whole organ liver transplantation in pediatric liver transplant recipients.Technical variant liver transplant techniques comprising split, reduced, and live-donor liver transplantation evolved to address the need for timely and size appropriate grafts for pediatric recipients.Analysis of data from the Studies of Pediatric Liver Transplantation (SPLIT) registry, a multicenter database of 44 North American pediatric liver transplant programs. The outcome (morbidity and mortality) of each of the technical variants were compared with that of whole organ recipients.Data were available on 2192 transplant recipients (1183 whole, 261 split, 388 reduced, and 360 live donor). Recipients of all technical variant graft type were significantly younger than whole organ recipients, but on average spent 2.3 months less on the waiting list. Thirty-day post-transplant morbidity was increased for each type of technical variant relative to whole organ (45.1% whole, 66.7% split, 65.5% reduced, 51.9% live-donor). Biliary complications (30 day: 7.5% whole, 18.8% split, 16% reduced, 17.5% live-donor) and portal vein thrombosis (30 day: 3.6% whole, 8% split, 8% reduced, 7.5% live-donor) were more common in all technical variant types. Graft type was an independent predictor of graft loss (death or retransplantation) in a multivariate analysis. Split and reduced (relative risk = 1.74 and 1.77, respectively) grafts had a worse outcome when compared with whole organ recipients.Technical variant techniques expand the pediatric donor pool and reduce time from listing to transplant, but they are associated with increased morbidity and mortality.
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- 2007
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4. STUDIES OF PEDIATRIC LIVER TRANSPLANTATION (SPLIT): YEAR 2000 OUTCOMES
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R. Novak, Amy Jones, C. Klekamp, M. K. Alford, Robert A. Fisher, Deborah K. Freese, William F. Balistreri, Fernando Alvarez, Simon Horslen, Andreas G. Tzakis, Paul M. Colombani, H. Shokouh-Amiri, B. Friedman, K. Brock, Regino P. Gonzalez-Peralta, E. S. Maller, Peter F. Whitington, Prabhakar K. Baliga, Saul J. Karpen, Kathy Orban-Eller, E. Spaith, V. Fioravante, John A. Goss, John C. Bucuvalas, Munci Kalayoglu, Kenneth L. Cox, P. Atkinson, B. Wise, P. Rosenthal, Timothy E. Bunchman, Luis Mieles, Joan Lokar, Estella M. Alonso, Fred Ryckman, J. DePaulo, N. Higuchi, Walter S. Andrews, Steven N. Lichtman, K. Hall, E. DeLuca, Q. Mekki, M Jr Langham, L. D'Amico, Victoria Shieck, Ronald D. Holmes, George V. Mazariegos, M. Behnke, L. Covington, P. Inman, Hani P. Grewal, Deborah L. Brown, Amy Erica Smith, S. Doster, James F. Daniel, S. Stritzel, Angelo D'Alessandro, Harvey Solomon, Jean Greseth, A. Scheiman, Robert Kane, M. Akyeampong, Ravinder Anand, S. L. Powell, J M Millis, Samuel So, Michelle Nadler, Frederick M. Karrer, Theodore M. Johnson, S. V. McDiarmid, Annie Fecteau, Deborah Weppler, J. Irish-Feltner, B. Miller, Ronald J. Sokol, H. Phillips, Lesley J. Smith, Norman M. Kneteman, Sarah L. Kelly, C. Viau, Steven R. Martin, E. Mackay, Michael R. Narkewicz, B. W. Shaw, Sukru Emre, P. Mladucky, Deborah A. Andersen, Ross W. Shepherd, Thomas G. Heffron, Stuart J. Knechtle, Benjamin L. Shneider, B. Kassmann, Ruben E. Quiros, Joel E. Lavine, A. S. Lindblad, L. Bush, Rene Romero, Jay S. Roden, and Riccardo A. Superina
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Graft Rejection ,Male ,Reoperation ,medicine.medical_specialty ,Future studies ,Adolescent ,Cooperative research ,medicine.medical_treatment ,Population ,Liver transplantation ,Infections ,Child Development ,Postoperative Complications ,Internal medicine ,medicine ,Humans ,Child ,education ,Immunosuppression Therapy ,Transplantation ,education.field_of_study ,business.industry ,Incidence ,Infant, Newborn ,Infant ,Antibiotic Prophylaxis ,medicine.disease ,Survival Analysis ,Thrombosis ,Tacrolimus ,Liver Transplantation ,Surgery ,Hospitalization ,Treatment Outcome ,Child, Preschool ,Relative risk ,Female ,business - Abstract
Background. Initiated in 1995, the Studies of Pediatric Liver Transplantation (SPLIT) registry database is a cooperative research network of pediatric transplantation centers in the United States and Canada. The primary objectives are to characterize and follow trends in transplant indications, transplantation techniques, and outcomes (e.g., patient/graft survival, rejection, growth parameters, and immunosuppressive therapy.) Methods. As of June 15, 2000, 29 centers registered 1144 patients, 640 of whom received their first liver-only transplant while registered in SPLIT. Patients are followed every 6 months for 2 years and yearly thereafter. Data are submitted to a central coordinating center. Results. One/two-year patient survival and graft loss estimates are 0.85/0.82 and 0.77/0.72, respectively. Risk factors for death include: in ICU at transplant (relative risk (RR) = 2.63, P
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- 2001
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5. Urinary excretion of benzo[a]pyrene metabolites following intravenous, oral, and cutaneous benzo[a]pyrene administration
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M Bouchard and C Viau
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Pharmacology ,Physiology ,Physiology (medical) ,General Medicine - Published
- 1997
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6. Reversibility of renal tubular dysfunction in streptozotocin-induced diabetes in the rat
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C. Viau and S. Chouinard
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medicine.medical_specialty ,Physiology ,medicine.medical_treatment ,Drinking ,Diabetes Mellitus, Experimental ,Rats, Sprague-Dawley ,Excretion ,Renal tubular dysfunction ,Polyuria ,Glycosuria ,Physiology (medical) ,Internal medicine ,Diabetes mellitus ,Animals ,Insulin ,Medicine ,Diabetic Nephropathies ,Pharmacology ,Proteinuria ,business.industry ,Body Weight ,General Medicine ,medicine.disease ,Streptozotocin ,Enzymes ,Rats ,Molecular Weight ,Urodynamics ,Kidney Tubules ,Endocrinology ,Female ,Alanine aminopeptidase ,medicine.symptom ,beta 2-Microglobulin ,business ,medicine.drug - Abstract
Enzymuria and specific proteinuria were examined over a period of 19 days in 4 groups of 5 rats: a control group, a non-diabetic polyuric group, a group of streptozotocin-induced diabetic rats treated with insulin as of the 10th day after the injection of the drug, and a similar group of untreated diabetic rats. Increased urinary excretion of β-N-acetyl-D-glucosaminidase, lactate dehydrogenase, and alanine aminopeptidase was observed shortly after the induction of diabetes. It was partly or totally reversible following insulin treatment. Nondiabetic polyuria had a slight effect on the excretion of alanine aminopeptidase only. The urinary excretion of β2-microglobulin also rapidly increased after the onset of diabetes to a level approximately 50 times the control values. This effect was largely reversible with insulin treatment and was absent in the nondiabetic polyuric group. A small but significant 3-fold increase in albumin excretion was also noted but was not affected by insulin treatment. We conclude that streptozotocin-induced diabetes causes an early tubular dysfunction that is unrelated to polyuria and is reversible upon insulin treatment. This tubular dysfunction is best revealed by the urinary excretion of the low molecular weight protein β2-microglobulin. Our results suggest that it would be of interest to further examine the usefulness of sensitive markers of tubular dysfunction, especially low molecular weight proteinuria, in the detection of early stages of diabetic nephropathy.Key words: diabetic nephropathy, enzyme, urine, proteinuria, β2-microglobulin, streptozotocin, insulin, rat.
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- 1992
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7. Biological monitoring of environmental exposure to PAHs in the vicinity of a Soderberg aluminium reduction plant
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C Viau and N L Gilbert
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Adult ,Male ,Non occupational ,Pilot Projects ,Urine ,High-performance liquid chromatography ,Excretion ,chemistry.chemical_compound ,Animal science ,Humans ,Polycyclic Compounds ,Chromatography, High Pressure Liquid ,Creatinine ,Pyrenes ,Chemistry ,Quebec ,Public Health, Environmental and Occupational Health ,Environmental exposure ,Middle Aged ,Industrial town ,Metallurgical industry ,Case-Control Studies ,Epidemiological Monitoring ,Metallurgy ,Female ,Biomarkers ,Research Article ,Aluminum ,Environmental Monitoring - Abstract
OBJECTIVES: To assess environmental exposure to polycyclic aromatic hydrocarbons (PAHs) in the vicinity of a Söderberg aluminium reduction plant in Shawinigan, Canada with urinary 1-hydroxypyrene (1-OHP) as a biomarker. METHODS: Urine samples were collected from 20 non-occupationally exposed subjects living less than 500 m from the plant and from 20 controls living in Trois-Rivières, another industrial town 40 km from Shawinigan. Concentrations of 1-OHP were measured by high performance liquid chromatography (HPLC). RESULTS: Among controls, geometric mean (range) 1-OHP concentrations were 0.046 (0.012-0.116) mumol/mol creatinine in non-smokers and 0.125 (0.051-0.282) mumol/mol creatinine in smokers. Among exposed subjects, values were 0.103 (0.056-0.196) mumol/mol creatinine in non-smokers and 0.250 (0.112-0.448) mumol/mol creatinine in smokers. Excretion of 1-OHP was significantly higher in exposed subjects than in controls among non-smokers and smokers (P < 0.05). CONCLUSION: Based on urinary 1-OHP as a biomarker, it seems that living near an industrial point source of PAHs is associated with higher exposure. The health significance of this finding will require further investigation.
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- 1997
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8. Effects of peak concentrations on the neurotoxicity of styrene in volunteers
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B, Ska, A, Vyskocil, R, Tardif, G, Carrier, R, Thuot, K, Muray, and C, Viau
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Adult ,Male ,Dose-Response Relationship, Drug ,Brain ,Air Pollutants, Occupational ,Middle Aged ,Neuropsychological Tests ,Smell ,Affect ,Sensory Thresholds ,Administration, Inhalation ,Reaction Time ,Toxicity Tests, Acute ,Humans ,Color Perception ,Styrene ,Vision, Ocular - Abstract
The manufacture of fibreglass reinforced plastic products may give rise to substantial peak exposures to styrene. Such exposure patterns need further consideration in terms of styrene neurotoxicity. The aim of this study was to evaluate the neurotoxic effects of short-term peak exposures in volunteers, at levels respecting the Quebec occupational exposure limits (8 hours time weighed average of 213 mg/m3 and 15 min average of 426 mg/ m3). The volunteers had not been previously exposed to styrene and they had no documented exposure to known neurotoxicants during the study. Twenty-four volunteers were exposed to five exposure scenarios during 6 hours: a, stable exposure to 106 mg/m3; b, variable exposure with a mean concentration of 106 mg/m3 with four 15 min peaks mounting up to 213 mg/m3; c, stable exposure to 213 mg/m3; d, variable exposure with a mean concentration of 213 mg/m3 and four peaks of 426 mg/m3 and e, two stable exposures to 5 mg/m3 (control). Before and after each exposure scenario, volunteers were submitted to a battery of sensory tests (visual and olfactory), neuropsychological tests (reaction time, attention, memory, psychomotor function), and self-evaluation questionnaires (mood and symptoms) in a test-retest design. The results show that the different exposure scenarios involving peak exposures did not influence either the performance to any test or subjective signs and symptoms. However, due caution must be exercised in extrapolation of the current results to occupational exposure since only acute exposures were tested and volunteers were at rest during exposure, which resulted in lower doses than those experienced by physically active workers.
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- 2003
9. Preface
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Maurizio Manno and C Viau
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Political science ,Environmental monitoring ,MEDLINE ,Engineering ethics ,General Medicine ,Environmental exposure ,Toxicology ,Occupational safety and health ,Introductory Journal Article - Published
- 2010
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10. Assessment of molybdenum toxicity in humans
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A, Vyskocil and C, Viau
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Molybdenum ,No-Observed-Adverse-Effect Level ,Dose-Response Relationship, Drug ,Toxicity Tests ,Animals ,Humans ,Tissue Distribution ,Absorption ,Half-Life - Abstract
In an attempt to define a tolerable daily intake (TDI) for molybdenum based on a toxicological risk analysis approach, a large literature survey was conducted. In man, absorption of molybdenum after oral intake is in the range of 28-77% and urinary excretion is 17-80% of the total dose. A low order of toxicity of molybdenum compounds has been observed in humans. However, with the available data, it is not possible to calculate any dose-response or dose-effect relationships. Because molybdenum toxicity is associated with copper intake or depleted copper stores in the body, humans who have an inadequate intake of dietary copper or some dysfunction in their copper metabolism that makes them copper-deficient could be at greater risk of molybdenum toxicity. In the absence of relevant human studies, animal studies were evaluated for the derivation of the TDI. Effects of Mo on reproduction and foetal development were found to be critical effects observed in rats and mice. A dose-response relationship was observed in a study by Fungwe et al., with a 'no observed adverse effect' level (NOAEL) and a 'lowest observed adverse effect' level (LOAEL) of 0.9 and 1.6 mg Mo kg(-1) day(-1), respectively. Applying uncertainty factors of 10 for intraspecies and 10 for interspecies differences to the NOAEL, a TDI of 0.009 mg Mo kg(-1) day(-1) was calculated. The TDI is given a medium confidence rating. This TDI is more than double the upper limit of adequate intake for adolescents and adults that was derived from the Mo content of the average diet in the USA.
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- 1999
11. Inhibition of the renal tubular reabsorption of rat beta-2-microglobulin by lysozyme in perfused rat
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C, Viau, J R, Wouters, and S, Chouinard
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Perfusion ,Kidney Tubules ,Animals ,Female ,Muramidase ,Rats, Inbred Strains ,beta 2-Microglobulin ,Absorption ,Rats - Published
- 1990
12. Determination of rat β2-microglobulin in urine and in serum. II. Application of its urinary measurement to selected nephrotoxicity models
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Robert Lauwerys, A. Ouled, C. Viau, and Alfred Bernard
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Aging ,medicine.medical_specialty ,Nephrosis ,Urine ,Kidney ,Toxicology ,Nephrotoxicity ,Excretion ,Internal medicine ,Acetylglucosaminidase ,Chromates ,medicine ,Albuminuria ,Animals ,Chemistry ,Albumin ,Kidney metabolism ,Rats, Inbred Strains ,medicine.disease ,Sodium Compounds ,Rats ,Endocrinology ,medicine.anatomical_structure ,Female ,Gentamicins ,medicine.symptom ,beta 2-Microglobulin ,Cadmium - Abstract
beta 2-microglobulin (beta 2-m) was measured in the urine of rats by a specific immunoassay based on latex particles agglutination. The excretion of this protein was compared to the excretion of the enzyme beta-N-acetyl-D-glucosaminidase (NAG), albumin and amino acids in rats treated with either a single dose of sodium chromate (5 and 10 mg kg-1), repeated doses of gentamicin (5 and 20 mg kg-1), or cadmium (1 mg kg-1), and in aging rats (from 2 to 20 months). All treatments resulted in an early increased excretion of beta 2-m indicative of functional alterations of the proximal tubular cells. An increased NAG excretion was observed only at the highest dose of chromate and in the cadmium model but the relative increases of beta 2-m were much larger (up to 200 times the control values against four times the control values for NAG). From 2 to 20 months of age, urinary beta 2-m increases by a factor of four. Aminoacids excretion showed little sensitivity in the various models. Albumin showed little variations in purely tubular or in the tubular phase of renal injury but the chronic progressive nephrosis of aging rats caused a 40-fold increase in its excretion between 2 and 20 months of age. Therefore urinary beta 2-m, albumin and albumin/beta 2-m ratio provide useful tools in the assessment of nephrotoxicity and of its mechanisms in various experimental models.
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- 1986
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13. Evaluation of the nephrotoxic potential of styrene in man and in rat
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Alfred Bernard, R de Russis, A. Ouled, Robert Lauwerys, C. Viau, and Pierre Maldague
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Adult ,Male ,medicine.medical_specialty ,Urine ,Toxicology ,Styrenes ,Styrene ,Nephrotoxicity ,Excretion ,chemistry.chemical_compound ,Species Specificity ,Internal medicine ,medicine ,Animals ,Humans ,Kidney ,Proteinuria ,Chemistry ,Albumin ,Rats, Inbred Strains ,Middle Aged ,Rats ,Retinol-Binding Proteins ,medicine.anatomical_structure ,Endocrinology ,Toxicity ,Female ,Kidney Diseases ,medicine.symptom ,beta 2-Microglobulin - Abstract
The urinary excretion of beta 2-microglobulin, retinol-binding protein and albumin was measured in 65 workers exposed to styrene at levels averaging 50 percent of the current threshold limit value (215 mg/m2) for 1-13 years (mean: 6 years). By comparison with a control group matched for age and socioeconomic status, no significant difference was observed in the urinary excretion of proteins. In rats, styrene was weakly nephrotoxic. No functional or morphological renal change could be disclosed in rats exposed to 565 mg of styrene/m3, 5 days/week for 13 weeks. The repeated i.p. injection of 1 g styrene/kg (1/5 of oral LD50) for 10 days induced only a slight tubular dysfunction as evidenced by a 5-fold increase in beta 2-microglobulinuria. Altogether, these epidemiological and experimental data suggest that the current threshold limit value for styrene (215 mg/m3) proposed by the American Conference of Governmental and Industrial Hygienists does not entail any risk of renal toxicity.
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- 1987
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14. Detection of anti-laminin antibodies in sera by latex agglutination
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Am. Bernard, J. B. Foidart, Robert Lauwerys, P. R. Mahieu, and C. Viau
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Pathology ,medicine.medical_specialty ,biology ,medicine.diagnostic_test ,Renal glomerulus ,Biochemistry (medical) ,Clinical Biochemistry ,Antibody titer ,Autoantibody ,Radioimmunoassay ,Immunofluorescence ,Molecular biology ,Latex fixation test ,Agglutination (biology) ,medicine ,biology.protein ,Antibody - Abstract
We describe a latex particle agglutination assay for detecting circulating antibodies against laminin, a noncollagenous glycoprotein of basement membranes. Polystyrene latex particles on which laminin has been adsorbed are incubated with serum for about 25 min at 42-45 degrees C. The agglutination is then measured by counting residual unagglutinated particles. Polyethylene glycol 6000 enhances the agglutination. The assay is fully automated, yielding results in about 45 min, for 50 samples per hour. Addition of purified laminin abolishes the agglutination of laminin-coated particles in practically all positive sera. The anti-laminin antibody titers obtained by this latex immunoassay and by radioimmunoassay correlated well in 161 sera from patients with suspected or established renal diseases. The agglutination assay more frequently gave positive results for cases of glomerulonephritis with linear deposits (20/22 cases) than for glomerulonephritis with granular deposits (7/68) or glomerulonephritis with no glomerular deposits (2/13). The finding of low anti-laminin antibody titers in sera from about 15% (34/230) of the healthy subjects suggests that these autoantibodies are pathogenic only in certain circumstances.
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- 1986
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15. Distal tubular dysfunction in rats chronically exposed to a ‘white spirit’ solvent
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Alfred Bernard, Robert Lauwerys, and C. Viau
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Male ,medicine.medical_specialty ,Urinary system ,Dehydrogenase ,Toxicology ,Nephrotoxicity ,Kidney Concentrating Ability ,chemistry.chemical_compound ,Internal medicine ,Acetylglucosaminidase ,medicine ,Animals ,Kidney Tubules, Distal ,White spirit ,Inhalation exposure ,Chromatography ,L-Lactate Dehydrogenase ,Chemistry ,Rats, Inbred Strains ,General Medicine ,Hydrocarbons ,Rats ,Solvent ,Kidney Tubules ,Endocrinology ,Solvents ,Kidney Diseases ,Ammonium chloride ,Net acid excretion - Abstract
Inhalation exposure of male Sprague-Dawley rats to an industrial white-spirit solvent composed of a C10–C12 mixture of branched-chain unsubstituted satured aliphatic hydrocarbons at 6500 mg/m3 for over 9 months resulted in decreased urinary concentrating ability, decreased net acid excretion following a mild ammonium chloride load and increased urinary lactate dehydrogenase (LDH) activity, whereas urinary s-N- acetyl- d -glycosaminidase (NAG) activity remained normal. These observations suggest the existence of distal tubular alteration in the rat kidney.
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- 1984
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16. Effects of gentamicin on the renal uptake of endogenous and exogenous proteins in conscious rats
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A. Ouled, Alfred Bernard, C. Viau, Robert Lauwerys, and Paul M. Tulkens
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medicine.medical_specialty ,Endogeny ,Urine ,Kidney ,Toxicology ,Endocytosis ,Excretion ,chemistry.chemical_compound ,Internal medicine ,medicine ,Animals ,Humans ,Pharmacology ,Chemistry ,Reabsorption ,Albumin ,Rats, Inbred Strains ,Rats ,Retinol-Binding Proteins ,Endocrinology ,Biochemistry ,Immunoglobulin G ,Injections, Intravenous ,Female ,Gentamicin ,Gentamicins ,Lysozyme ,beta 2-Microglobulin ,medicine.drug - Abstract
To study the effect of gentamicin on the renal uptake of proteins, Sprague-Dawley female rats were intravenously injected with solutions containing unlabeled human beta 2-microglobulin (beta 2-m), retinol-binding protein, and increasing amounts of gentamicin (from 0.063 up to 31.5 mg/kg). The concentrations of human proteins and that of endogenous beta 2-m, albumin, and IgG in the urine collected during the 2 hr following the injection were determined by immunoassays. Gentamicin transiently increased the urinary excretion of rat and human beta 2-m in a dose-dependent manner. The mean relative increase of rat beta 2-m excretion ranged from 2 at a gentamicin dose of 0.06 mg/kg up to 500 at a gentamicin dose of 31.5 mg/kg. By contrast, the urinary excretion of other proteins was only increased by a factor of 2 to 5 at the highest dose of gentamicin. The relative increase of the urinary excretion of proteins was positively correlated with the fractional reabsorption of the proteins by the rat kidney. The inhibitory effect of gentamicin on the renal uptake of protein was very similar to that observed in rats injected with polycationic proteins like lysozyme and cytochrome C. These observations, combined with the fact that gentamicin, like proteins, enters the tubular cell by adsorptive endocytosis, strongly suggest that this drug competes with proteins for common binding sites on the apical tubular membrane and for subsequent endocytosis. Furthermore, the iv injection of large amounts of gentamicin and polycationic proteins induces a lysosomal enzymuria which very likely is a manifestation of an increased exocytosis.
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- 1986
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17. The renal uptake of proteins: A nonselective process in conscious rats
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Alfred Bernard, Ali Ouled Amor, Robert Lauwerys, and C. Viau
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Anions ,Protamine sulfate ,Ion Channels ,Absorption ,chemistry.chemical_compound ,Cations ,medicine ,Animals ,Metallothionein ,Stochastic Processes ,biology ,Chemistry ,Reabsorption ,Cytochrome c ,Albumin ,Proteins ,Renal Reabsorption ,Rats, Inbred Strains ,Enzymes ,Rats ,Molecular Weight ,Kidney Tubules ,Biochemistry ,Nephrology ,Renal physiology ,biology.protein ,Female ,Lysozyme ,medicine.drug - Abstract
The renal uptake of proteins: A nonselective process in conscious rats. The selectivity of the renal reabsorption of proteins has been investigated by competition experiments in conscious rats. The animals were intravenously injected with increasing doses of proteins over a wide range of net charge and size, including lysozyme, cytochrome C, metallothionein, β2-microglobulin, retinol-binding protein, albumin and IgG. The urinary excretion of exogenous proteins injected concomitantly (humanβ2-microglobulin, retinol-binding protein, albumin and/or egg white lysozyme depending on the experiment) and of rat β2-microglobulin, albumin and IgG was determined with specific immunoassays. The results show that low molecular weight cationic proteins and low or high molecular weight anionic proteins can increase each other's urinary excretion. Several observations strongly suggest that these effects result from a competitive inhibition of renal uptake. The phenomenon is dose-related in most cases and, as evidenced by cytochrome C injection, transient, reproducible and saturable. In addition, the injected proteins induce a tubular type proteinuria irrespective of their net charge and size. In the case of cationic proteins, this finding excludes the possibility of an enhanced glomerular permeability due to a partial neutralization of the glomerular polyanion which, as demonstrated with protamine sulfate, entails a glomerular type proteinuria. These quantitative data on the mutual inhibition of renal uptake of a wide spectrum of specific proteins lead us to challenge the concept of charge- and size-selective tubular reabsorption of proteins, and to postulate that proteins filtered through the glomeruli are taken up by common tubular endocytotic sites irrespectively of their physicochemical features. As demonstrated by the ability of β2-microglobulin and IgG to inhibit the uptake of lysozyme, the affinity of a protein for reabsorption sites is not simply related to its size and net positive charge. Evidence is also presented that proteins, when administered intravenously at high doses, induce a lysosomal enzymuria most likely reflecting a stimulated exocytosis.
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- 1988
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18. Gentamicin nephrotoxicity in cadmium, lead and mercury pretreated rats
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Guy Laurent, C. Viau, P. Maldague, Paul M. Tulkens, Alfred Bernard, and Robert Lauwerys
- Subjects
Chronic exposure ,Cadmium Poisoning ,Kidney Cortex ,medicine.drug_class ,Antibiotics ,chemistry.chemical_element ,Urine ,Pharmacology ,Toxicology ,Nephrotoxicity ,medicine ,Animals ,Drug Interactions ,Amino Acids ,Phospholipids ,Kidney ,Cadmium ,Osmolar Concentration ,Rats, Inbred Strains ,beta-Galactosidase ,Rats ,Mercury (element) ,Lead Poisoning ,Proteinuria ,medicine.anatomical_structure ,chemistry ,Mercury Poisoning ,Female ,Kidney Diseases ,Gentamicin ,Gentamicins ,medicine.drug - Abstract
The effect of a previous chronic exposure to cadmium, lead or inorganic mercury on the nephrotoxic potential of gentamicin was investigated in female Sprague-Dawley rats. A daily dose of 10 mg gentamicin/kg body weight/day was administered for 21 days to rats having a renal load of 168 micrograms Cd, 35 micrograms Pb or 129 micrograms Hg/g whole kidney. Urine analysis suggests an attenuation of the nephrotoxic potential of gentamicin while a microscopical examination of kidneys indicates a superimposition of the effects of the metals and the antibiotics. The only clear interaction observed consists in a reduction of gentamicin accumulation in the cortex of cadmium-treated animals. It is concluded that none of the metal pretreatments potentiates the nephrotoxic effects of gentamicin.
- Published
- 1983
- Full Text
- View/download PDF
19. Ultrasonic extraction of polychlorinated dibenzo-p-dioxins and other organic compounds from fly ash from municipal incinerators
- Author
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Francis W. Karasek, Gary A. Eiceman, and A. C. Viau
- Subjects
Solvent ,chemistry.chemical_compound ,Chemistry ,Environmental chemistry ,Fly ash ,Extraction (chemistry) ,Selected ion monitoring ,Gas chromatography ,Benzene ,Rotary evaporator ,Mass spectrometry ,Analytical Chemistry - Abstract
Polychlorinated dibenzo-p-dioxins (PCDDs) and other organic compounds are solvent extracted from 10- to 20-g samples of fly ash from municipal incinerators with 200 mL of benzene using ultrasonic agitation for 1 h. A convenient filtering device is used to separate fly ash and solvent which is then concentrated to 100 ..mu..L using a rotary evaporator. Extracts are analyzed directly by gas chromatography/mass spectrometry, including selected ion monitoring for PCDDs. Results from five replicate analyses of a fly ash sample yielded averages and standard deviations (ng/g) for the tetra-to octachlorinated dibenzo-p-dioxins of 8.6 +- 2.2, 15.0 +- 4.0, 13.0 +- 3.4, 3.2 +- 1.0, and 0.4 +- 0.1, respectively. 2 tables, 3 figures.
- Published
- 1980
- Full Text
- View/download PDF
20. Comparative analysis of hazardous compounds on fly-ash from municipal waste incineration by gas chromatography/mass spectrometry
- Author
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F. W. Karasek, S. M. Studak, and A. C. Viau
- Subjects
Chromatography ,Municipal solid waste ,Chemistry ,Organic Chemistry ,General Chemistry ,Fractionation ,Mass spectrometry ,Catalysis ,Incineration ,Hazardous waste ,Fly ash ,Environmental chemistry ,heterocyclic compounds ,Gas chromatography ,Gas chromatography–mass spectrometry - Abstract
Fly-ash samples from municipal incinerators in Canada and Norway were analyzed for polychlorinated dibenzo-p-dioxins using gas chromatography/mass spectrometry preceded by fractionation on column chromatography. Qualitative and quantitative differences in the organic compounds identified were found between the two samples. Many of the same dioxin congeners were present in both samples; however, tetrachlorodibenzo-p-dioxins were only detected in the Canadian sample.
- Published
- 1984
- Full Text
- View/download PDF
21. Isoparaffinic solvent-induced nephrotoxicity in the rat
- Author
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P. Maldague, Alfred Bernard, C. Viau, F. Gueret, Robert Lauwerys, and P. Gengoux
- Subjects
Male ,medicine.medical_specialty ,Urinary system ,Renal function ,Kidney ,Kidney Function Tests ,Toxicology ,Nephrotoxicity ,Excretion ,chemistry.chemical_compound ,Sex Factors ,Internal medicine ,Lactate dehydrogenase ,Acetylglucosaminidase ,Alpha-Globulins ,medicine ,Albuminuria ,Animals ,Castration ,Inhalation exposure ,L-Lactate Dehydrogenase ,Chemistry ,Albumin ,Rats ,Endocrinology ,medicine.anatomical_structure ,Paraffin ,Solvents ,Female ,beta 2-Microglobulin - Abstract
Prolonged inhalation exposure to 6.5 mg/l of an isoparaffinic solvent consisting of saturated aliphatic hydrocarbons (SAHC) resulted in both functional and morphological renal changes in male rats to the exclusion of female or castrated rats. Functionally, the increased excretion of lactate dehydrogenase in the absence of an increased beta-N-acetyl-D-glucosaminidase excretion together with a decreased urinary concentrating ability upon water deprivation and slower antinatriuretic response when the sodium intake is abruptly reduced, suggest a distal tubular alteration. beta 2-Microglobulin excretion is unchanged indicating good proximal tubular cell function. The increased excretion of albumin and slightly lowered glomerular filtration rate suggest a moderate glomerular impairment. Light microscopy shows prominent hyaline droplet accumulation in proximal tubular cells and a few scattered foci of regenerative epithelia in both proximal and distal cells of the deep cortex. The urinary clearance of the major male rat urinary protein, alpha 2u-globulin, is similar in control and exposed rats but the latter have a 10-fold greater renal accumulation of this protein while the hepatic levels are identical in both groups. It is concluded that SAHC exposure causes moderate and reversible tubular and also glomerular changes in the male rat kidney.
- Published
- 1986
- Full Text
- View/download PDF
22. Characterization of cadmium proteinuria in man and rat
- Author
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Alfred Bernard, Harry Roels, Robert Lauwerys, Jean-Pierre Buchet, and C. Viau
- Subjects
inorganic chemicals ,Adult ,medicine.medical_specialty ,Health, Toxicology and Mutagenesis ,chemistry.chemical_element ,Urine ,Excretion ,Internal medicine ,medicine ,Metallothionein ,Animals ,Humans ,Aged ,Cadmium ,Proteinuria ,Public Health, Environmental and Occupational Health ,Environmental exposure ,Environmental Exposure ,Middle Aged ,Blood proteins ,Rats ,Retinol-Binding Proteins ,Retinol binding protein ,Endocrinology ,chemistry ,medicine.symptom ,beta 2-Microglobulin ,Retinol-Binding Proteins, Plasma ,Research Article - Abstract
In workers chronically exposed to cadmium and without signs of renal insufficiency, plasma proteins with molecular weight ranging from 11,800 to 450,000 are excreted in greater amount in urine. Increased urinary excretion of low and high molecular weight proteins can occur independently. Because of its greater stability in urine and provided a sensitive immunological technique is used, the determination of retinol-binding protein is a more practical and reliable test of proximal tubular function than beta 2-microglobulin. The evaluation of renal function of workers removed from cadmium exposure indicates that cadmium-induced renal lesions, albeit of slow progression, are not reversible when exposures ceases. In workers chronically exposed to cadmium or removed from cadmium exposure, metallothionein in urine is directly correlated with cadmium in urine but not with cadmium in blood or years of cadmium exposure. The association between cadmium in urine and metallothionein in urine is independent of the status of renal function and the intensity of current exposure to cadmium. Whereas the repeated IP injection of high doses of cadmium to rat gives rise to a mixed or tubular type proteinuria, the prolonged oral administration of cadmium results mainly in the development of a glomerular type proteinuria. The former is usually reversible after cessation of treatment whereas the latter is not. Circulating antiglomerular basement membrane antibodies have been found in man and in rat chronically exposed to cadmium. The pathogenic significance of this finding deserves further investigation. Images FIGURE 5.
- Published
- 1984
23. Determination of IgE Complexes and of Total IgE by Latex Immunoassay
- Author
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Alfred Bernard, C. Viau, Jp. Dieryckx, Robert Lauwerys, and Hervé Bazin
- Subjects
Globulin ,education ,Clinical Biochemistry ,Radioimmunoassay ,Antigen-Antibody Complex ,Immunoglobulin E ,Nephelometry and Turbidimetry ,medicine ,Humans ,Immunoassay ,Chromatography ,biology ,medicine.diagnostic_test ,Chemistry ,Biochemistry (medical) ,General Medicine ,Molecular biology ,Pepsin A ,Latex fixation test ,Agglutination (biology) ,Chromatography, Gel ,biology.protein ,Turbidimetry ,Antibody ,Latex Fixation Tests - Abstract
j Summary: A sensitive immunoassay based on latex particle agglutination for the measurement of circulating j IgE-containing complexes is described. In this method, the anti-IgE-coated particles are incubated with !' diluted serum and the resulting agglutination is quantified by turbidimetry or particle counting. In the latter \ Version, the assay is fully automated in a continuous flow System. IgE-containing complexes were detected i in all tested sera. Increased concentrations were observed in about 80% of the subjects with elevated serum j IgE. However, high levels of IgE-complexes may also be found in subjects with a normal or even a very low j serum concentration of IgE. The same latex immunoassay can be used for the determination of total IgE, after pepsin digestion of the -globulin fraction of the serum. The results obtained correlate well with those found with a sandwich radioimmunoassay (r = 0.91, n = 83). The present method, however, yields a greater number of significantly positive results than the radioimmunoassay, probably because of its ability to detect IgE entrapped in circulating complexes.
- Published
- 1987
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- View/download PDF
24. Detection of anti-laminin antibodies in sera by latex agglutination
- Author
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A M, Bernard, J M, Foidart, P, Mahieu, C, Viau, and R R, Lauwerys
- Subjects
Glomerulonephritis ,Immunoglobulin G ,Kidney Glomerulus ,Radioimmunoassay ,Animals ,Fluorescent Antibody Technique ,Humans ,Laminin ,Rabbits ,Basement Membrane ,Latex Fixation Tests ,Autoantibodies - Abstract
We describe a latex particle agglutination assay for detecting circulating antibodies against laminin, a noncollagenous glycoprotein of basement membranes. Polystyrene latex particles on which laminin has been adsorbed are incubated with serum for about 25 min at 42-45 degrees C. The agglutination is then measured by counting residual unagglutinated particles. Polyethylene glycol 6000 enhances the agglutination. The assay is fully automated, yielding results in about 45 min, for 50 samples per hour. Addition of purified laminin abolishes the agglutination of laminin-coated particles in practically all positive sera. The anti-laminin antibody titers obtained by this latex immunoassay and by radioimmunoassay correlated well in 161 sera from patients with suspected or established renal diseases. The agglutination assay more frequently gave positive results for cases of glomerulonephritis with linear deposits (20/22 cases) than for glomerulonephritis with granular deposits (7/68) or glomerulonephritis with no glomerular deposits (2/13). The finding of low anti-laminin antibody titers in sera from about 15% (34/230) of the healthy subjects suggests that these autoantibodies are pathogenic only in certain circumstances.
- Published
- 1986
25. Renal handling of human beta 2-microglobulin in normal and cadmium-poisoned rats
- Author
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Alfred Bernard, Robert Lauwerys, and C. Viau
- Subjects
Oral treatment ,medicine.medical_specialty ,Cadmium Poisoning ,Health, Toxicology and Mutagenesis ,Beta-Globulins ,chemistry.chemical_element ,Toxicology ,Kidney ,Urinary excretion ,Internal medicine ,medicine ,Animals ,Cadmium ,medicine.diagnostic_test ,Beta-2 microglobulin ,Half-life ,Rats, Inbred Strains ,General Medicine ,Rats ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Tubular proteinuria ,Immunoassay ,Female ,beta 2-Microglobulin ,Half-Life - Abstract
The renal handling of human beta 2-microglobulin (beta 2-m) was investigated in normal rat and in rat with cadmium-induced renal damage. Cadmium was administered either in drinking water at a concentration of 100 ppm for up to 16 months or by i.p. injection of 1 mg Cd/kg, five times a week for up to 4 months. When renal dysfunction has developed, namely after 2 and 10 months of the i.p. and oral treatment respectively, unlabelled human beta 2-m was injected intravenously and its disappearance in serum and its urinary excretion were studied by means of a sensitive immunoassay. In serum, the level of beta 2-m drops by about 90% during the 10 first min, then declines more slowly with a half life around 20 min. Serum disappearance curves of beta 2-m in normal and cadmium-treated rats did not differ markedly. The amount of beta 2-m recovered in urine during the 4 h following the injection averaged 0.03% of the injected dose in normal rats. It increased on the average to 10% in rats treated i.p. with 1 mg Cd/kg for 3 months. However, in rats given 100 ppm Cd per os for 10 months, this amount averaged only 0.14%. A similar value was observed 5 months later, although at that stage, the critical level of cadmium in kidney cortex had been reached for 6-7 months. These data which were in accordance with the disturbances of the other renal parameters measured in cadmium-treated rats indicate that: 1) human beta 2-m is reabsorbed by rat kidney at a similar rate as by human kidney; 2) if the occurrence of cadmium tubulopathy is concomitant with the saturation of cadmium-binding sites in kidney, its severity depends greatly on the rate at which cadmium reaches the saturated kidneys.
- Published
- 1983
26. Competition between low- and high-molecular-weight proteins for renal tubular uptake
- Author
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Alfred Bernard, Robert Lauwerys, A. Ouled, and C. Viau
- Subjects
medicine.medical_specialty ,Protein Conformation ,Urinary system ,Cytochrome c Group ,urologic and male genital diseases ,Excretion ,Internal medicine ,Medicine ,Animals ,In patient ,Serum Albumin ,Kidney ,Proteinuria ,urogenital system ,business.industry ,Beta-2 microglobulin ,Glomerular proteinuria ,Albumin ,Rats, Inbred Strains ,Serum Albumin, Bovine ,Blood Proteins ,female genital diseases and pregnancy complications ,Rats ,Molecular Weight ,medicine.anatomical_structure ,Endocrinology ,Kidney Tubules ,Female ,medicine.symptom ,business ,beta 2-Microglobulin - Abstract
To explain the occurrence of tubular and glomerular proteinuria in patients with primarily tubular or glomerular dysfunction, it is usually assumed that the mechanisms responsible for the renal tubular transport of small and large proteins are different. The present in vivo study does not support this hypothesis since it clearly shows that small and large proteins (e.g., beta 2-microglobulin and albumin) can compete for renal uptake. Our results lead us to postulate the existence of common tubular reabsorption sites for which proteins exhibit different affinities depending on their charge, size and conformation.
- Published
- 1987
27. Determination of rat beta 2-microglobulin in urine and in serum. I. Development of an immunoassay based on latex particles agglutination
- Author
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C. Viau, Alfred Bernard, and Robert Lauwerys
- Subjects
Male ,Urine ,Toxicology ,Gel permeation chromatography ,chemistry.chemical_compound ,medicine ,Animals ,Antiserum ,Immunoassay ,Chromatography ,medicine.diagnostic_test ,Beta-2 microglobulin ,Chemistry ,Immune Sera ,Sodium chromate ,Rats, Inbred Strains ,Hydrogen-Ion Concentration ,Latex fixation test ,Rats ,Molecular Weight ,Agglutination (biology) ,Chromatography, Gel ,Female ,beta 2-Microglobulin ,Latex Fixation Tests - Abstract
Rat beta 2-microglobulin has been isolated from the urine of rats pretreated with sodium chromate. The purified protein was used to raise antisera in two rabbits. Treatment of the antisera with ammonium sulphate followed by gel chromatography led to an immunoglobulin fraction which was used to coat latex particles by physical adsorption. The latex suspension was used in an automated system including an optical particle counter to analyse the protein in serum, urine and cerebrospinal fluid. Serum contains 5.8 mg of beta 2-microglobulin/l, of which 33% is found as a 55000 dalton complex while 66% is present as the 'free' protein. The daily urinary excretion of beta 2-microglobulin in females is about 2 micrograms of which 7% is found to be a 65000-dalton complex while 92% is the free protein. From this, it can be calculated that the fractional urinary excretion of beta 2-microglobulin is about 0.03%. The cerebrospinal fluid contains about 1 mg of beta 2-microglobulin/l. Preliminary tests also suggest that the method can be adapted for non-automated turbidimetric detection. In the automated assay, the within- and between-assay coefficients of variation are less than 10% for the three biological fluids tested. The analytical recovery in the urine is 93%. In urine, beta 2-microglobulin undergoes proteolytic degradation at pH below 6. This does not represent a serious drawback to its use as a sensitive index of tubular function since in most experimental circumstances, rats excrete urine with a pH above this value.
- Published
- 1986
28. Kidney disorders and hematotoxicity from organic solvent exposure
- Author
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R, Lauwerys, A, Bernard, C, Viau, and J P, Buchet
- Subjects
Adult ,Male ,Anti-Glomerular Basement Membrane Disease ,Benzene ,Kidney Tubular Necrosis, Acute ,Hematologic Diseases ,Styrenes ,Europe ,Occupational Diseases ,Solvents ,Humans ,Female ,Kidney Diseases ,Epidemiologic Methods ,Styrene ,Ethers - Abstract
Short-term exposure to certain solvents, such as several halogenated hydrocarbons, petroleum distillates, ethylene glycol, ethylene glycol ethers, and diethylene glycol, may cause renal tubular necrosis. Tubular lesions with metabolic acidosis have been reported in addicts inhaling solvent vapor (eg, toluene). A Goodpasture's syndrome may be induced by acute or subacute exposure to solvents, but its incidence is rare. No adequate proof is yet available that repeated exposure to nonsubstituted organic solvents may lead to the development of different types of chronic glomerulonephritis, but the available epidemiologic data are suggestive of the existence of such an association. Only a few solvents have been reported to act on the hematopoietic system of humans. The hematotoxicity (aplastic anemia, leukemia) of benzene is well established. Some ethylene glycol ethers are also toxic to bone marrow.
- Published
- 1985
29. Cadmium, analgesics, and the chronic progressive nephrosis in the female Sprague-Dawley rat
- Author
-
Robert Lauwerys, C. Viau, Alfred Bernard, and P. Maldague
- Subjects
medicine.medical_specialty ,Health, Toxicology and Mutagenesis ,Nephrosis ,Renal function ,Toxicology ,Kidney ,Excretion ,Internal medicine ,Acetylglucosaminidase ,medicine ,Animals ,Aspirin ,Analgesics ,Chemistry ,Beta-2 microglobulin ,Phenacetin ,Rats, Inbred Strains ,General Medicine ,medicine.disease ,Rats ,Endocrinology ,medicine.anatomical_structure ,Chronic Disease ,Urine osmolality ,Female ,medicine.drug ,Cadmium - Abstract
Female Sprague-Dawley rats received phenacetin or aspirin at average daily doses of 135 and 27 mg/kg respectively in the diet and either demineralized water (DMW) or a 100 ppm cadmium (Cd) solution as their drinking water for 12 months. This dose of Cd produced borderline tubular toxicity, as measured by the excretion of IV-injected human beta 2-microglobulin. The kidney accumulation of Cd just reached the critical level of 200 ppm in all groups at the end of the study. The various treatments did not significantly affect growth, creatinine clearance, urine osmolality and the urinary excretion of beta-N-acetyl-D-glucosaminidase and aminoacids. No interaction resulted from the concomitant administration of analgesics and Cd. Both aspirin subgroups (receiving DMW or Cd) showed an attenuation of the age-related decline of the renal function as revealed by a lower urinary excretion of albumin and total protein. The accentuation of the mesangial matrix seen upon aging was also partly inhibited in the aspirin rats.
- Published
- 1984
30. Increased Urinary Excretion of Ferritin in Subjects with Moderate Proteinuria
- Author
-
Harry Roels, Robert Lauwerys, Alfred Bernard, and C. Viau
- Subjects
medicine.medical_specialty ,Kidney ,Cadmium ,Proteinuria ,biology ,business.industry ,Albumin ,chemistry.chemical_element ,Urine ,Nephrotoxicity ,Ferritin ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Internal medicine ,biology.protein ,medicine ,Moderate proteinuria ,medicine.symptom ,business - Abstract
The relationships between the urinary excretion of ferritin and that of albumin, β2-microglobulin and retinol-binding protein were studied in 60 healthy subjects and in 34 subjects exposed to a nephrotoxic agent (cadmium). The results suggest that the ferritin present in urine originates mainly from the kidney and its concentration depends on both the renal store of ferritin and the importance of tubular cell damage.
- Published
- 1984
- Full Text
- View/download PDF
31. A cross-sectional survey of kidney function in refinery employees
- Author
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Jean-Pierre Buchet, Antonio Mutti, L. Quaeghebeur, Alfred Bernard, C. Viau, Robert Lauwerys, Me. Cornu, S. Lucertini, Innocente Franchini, and Sc. Phillips
- Subjects
Adult ,Male ,Pathology ,medicine.medical_specialty ,Urinary system ,Occupational disease ,Physiology ,Renal function ,Urine ,Kidney ,Nephrotoxicity ,Excretion ,Medicine ,Albuminuria ,Humans ,Antigens ,business.industry ,Public Health, Environmental and Occupational Health ,Middle Aged ,medicine.disease ,Hydrocarbons ,Occupational Diseases ,Cross-Sectional Studies ,Petroleum ,Chemical Industry ,Kidney Diseases ,medicine.symptom ,business ,Energy source - Abstract
We examined sensitive biochemical and immunological markers of kidney function and damage in 53 male oil refinery workers exposed to hydrocarbons and compared their results with those of a control group of 61 age-matched nonexposed males. The mean duration of employment of exposed males was 11 years. The current levels of exposure to a variety of aliphatic and aromatic hydrocarbons, as determined by personal monitoring, were well below the current threshold limit values. No difference was found in the urinary tubular parameters beta-N-acetyl-D-glucosaminidase, beta 2-microglobulin (beta 2-m) and retinol-binding protein. Similar serum beta 2-m levels indicated no impairment of the glomerular filtration rate in the exposed workers. The levels of circulating immune complexes were also identical in both groups. The mean albuminuria was slightly higher (p less than .005) in the exposed group in a quantitative assay but was not dipstick-detectable. The mean urinary excretion of a renal antigen was also higher (p less than .05) in the exposed group and correlated with the excretion of albumin. Finally, slightly higher titers of anti-laminin antibodies were found in five exposed employees, but this was not accompanied by an increased albuminuria. We conclude that chronic low-level hydrocarbon exposure in these refinery workers does not lead to clinically significant renal abnormalities. Nevertheless, some findings are consistent with the possible role of hydrocarbon exposure in the induction of renal disturbances.
- Published
- 1987
32. A modern GS/MS/data system
- Author
-
Francis W. Karasek and Alan C. Viau
- Subjects
Chemistry ,Analytical chemistry ,General Chemistry ,Gas chromatography ,Mass spectrometry ,Education - Abstract
Describes the design, use, and advantages of a gas chromatography / mass spectrometer / computerized data system.
- Published
- 1984
- Full Text
- View/download PDF
33. Biomonitoring for occupational health risk assessment (BOHRA)
- Author
-
Claude Viau, Antonio Mutti, Sheng Wang, Larry Lowry, John Cocker, Maurizio Manno, Monica Nordberg, Claudio Colosio, Manno, Maurizio, and C., Viau
- Subjects
medicine.medical_specialty ,Medical education ,business.industry ,Rural health ,Public health ,MEDLINE ,General Medicine ,Commission ,Risk factor (computing) ,Toxicology ,Ecotoxicology ,Risk Assessment ,Occupational safety and health ,Occupational medicine ,Biological monitoring ,Data Interpretation, Statistical ,Occupational Exposure ,medicine ,Humans ,Public Health ,Risk assessment ,business ,Occupational Health ,Environmental Monitoring - Abstract
Biological monitoring (BM or biomonitoring) deals with the assessment of individual human exposure, effect and susceptibility to occupational risk factors. It is a fundamental tool in occupational health risk assessment (OHRA) and occupational health practice (OHP) and it has become one of the most, if not the most active area in occupational health (OH) research today. From the few hundred BM papers published in the 80s, there are now several tens of thousand papers published in the peer review literature each year, and the trend is still rising exponentially. As a result, BM has become a priority for the Scientific Committee on Occupational Toxicology (SCOT) of the International Commission on Occupational Health (ICOH). Moreover, there has been a long-term interest in biological monitoring by other SCs of ICOH such as the Scientific Committees on Toxicology of Metals (SCTM) and on Rural Health (SCRH). Despite its current popularity, though, BM is not always correctly used or interpreted by those involved in OHRA or OHP. The present review has been prepared to fill this gap and to help preventing misuse and misinterpretation of data. Although the document is meant to be a reference primarily for those involved in OH research and/or practice, it might become of interest for a wider audience within and outside ICOH, including scientists, occupational physicians, industrial hygienists and occupational or public health professionals in general, involved in chemical risk assessment for occupational health. The mission of SCOT and also of other SCs of ICOH, such as SCTM and SCRH, is indeed to promote the advancement and diffusion of knowledge on biological monitoring and other relevant occupational toxicology aspects and to make them available and useful to the entire OH scientific community. All articles retrieved as of 3 January, 2007 as "Review" with the combined key words "biological monitoring" in PubMed from 2000 to 2007 have been scanned individually. This yielded a total of 1400 articles from a grand total of 2486 (excluding limitation on year of publication). When the title was related to human occupational biological monitoring, the abstract was read and its content was included. Articles outside the 2000-2007 time frame or that are not classified as "Review" in PubMed have also been included, when relevant. The review is in four parts: (a) the introduction, containing the basic principles and definitions of BM and the different types of biomarkers (BMK), their toxicological significance, practical use and limitations, (b) the methodological and analytical aspects of BM in exposed workers, (c) the interpretation and management of BM data, including a number of recommendations to be considered when planning, performing and interpreting BM results and, finally, (d) the ethical aspects of BM. A list of key references to relevant papers or documents has been included. The BM of specific chemicals or groups of chemicals is outside the purpose of the review. The document is aimed to represent the state of the art on biological monitoring in occupational risk assessment. We expect that reference to its content will be made, whenever appropriate, by those involved in occupational health practice and research when dealing with BM issues. The document is not meant, though, to represent a rigid nor a permanent set of rules and it will be periodically updated according to new developments and any significant advance in BM science. Any part of the document, therefore, is open to suggestions by scientifically qualified persons or institutions officially involved in BM and comments should be sent directly to the authors. A preliminary draft of the document has been presented at the 7th International Symposium on Biological Monitoring, Beijing, 10-12 September, 2007.
- Published
- 2009
34. ISBM-7: Biological Monitoring in a Globalized World. Preface
- Author
-
Maurizio Manno, Viau, C., Manno, Maurizio, and C., Viau
35. Comprehensive Blood Metabolome and Exposome Analysis, Annotation, and Interpretation in E-Waste Workers.
- Author
-
Pang Z, Viau C, Fobil JN, Basu N, and Xia J
- Abstract
Background: Electronic and electrical waste (e-waste) production has emerged to be of global environmental public health concern. E-waste workers, who are frequently exposed to hazardous chemicals through occupational activities, face considerable health risks. Methods: To investigate the metabolic and exposomic changes in these workers, we analyzed whole blood samples from 100 male e-waste workers and 49 controls from the GEOHealth II project (2017-2018 in Accra, Ghana) using LC-MS/MS. A specialized computational workflow was established for exposomics data analysis, incorporating two curated reference libraries for metabolome and exposome profiling. Two feature detection algorithms, asari and centWave , were applied. Results: In comparison to centWave , asari showed better sensitivity in detecting MS features, particularly at trace levels. Principal component analysis demonstrated distinct metabolic profiles between e-waste workers and controls, revealing significant disruptions in key metabolic pathways, including steroid hormone biosynthesis, drug metabolism, bile acid biosynthesis, vitamin metabolism, and prostaglandin biosynthesis. Correlation analyses linked metal exposures to alterations in hundreds to thousands of metabolic features. Functional enrichment analysis highlighted significant perturbations in pathways related to liver function, vitamin metabolism, linoleate metabolism, and dynorphin signaling, with the latter being observed for the first time in e-waste workers. Conclusions: This study provides new insights into the biological impact of prolonged metal exposure in e-waste workers.
- Published
- 2024
- Full Text
- View/download PDF
36. Use of Caenorhabditis elegans to Unravel the Tripartite Interaction of Kynurenine Pathway, UPR mt and Microbiome in Parkinson's Disease.
- Author
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Viau C, Nouar A, and Xia J
- Subjects
- Animals, Humans, Disease Models, Animal, Mitochondria metabolism, Caenorhabditis elegans Proteins metabolism, Caenorhabditis elegans microbiology, Caenorhabditis elegans metabolism, Kynurenine metabolism, Parkinson Disease microbiology, Parkinson Disease metabolism, Gastrointestinal Microbiome, Unfolded Protein Response
- Abstract
The model organism Caenorhabditis elegans and its relationship with the gut microbiome are gaining traction, especially for the study of neurodegenerative diseases such as Parkinson's Disease (PD). Gut microbes are known to be able to alter kynurenine metabolites in the host, directly influencing innate immunity in C. elegans . While the mitochondrial unfolded protein response (UPR
mt ) was first characterized in C. elegans in 2007, its relevance in host-microbiome interactions has only become apparent in recent years. In this review, we provide novel insights into the current understanding of the microbiome-gut-brain axis with a focus on tripartite interactions between the UPRmt , kynurenine pathway, and microbiome in C. elegans , and explore their relationships for PD remediations.- Published
- 2024
- Full Text
- View/download PDF
37. MetaboAnalyst 6.0: towards a unified platform for metabolomics data processing, analysis and interpretation.
- Author
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Pang Z, Lu Y, Zhou G, Hui F, Xu L, Viau C, Spigelman AF, MacDonald PE, Wishart DS, Li S, and Xia J
- Subjects
- Chromatography, Liquid, Humans, Databases, Factual, Metabolomics methods, Software, Algorithms, Tandem Mass Spectrometry
- Abstract
We introduce MetaboAnalyst version 6.0 as a unified platform for processing, analyzing, and interpreting data from targeted as well as untargeted metabolomics studies using liquid chromatography - mass spectrometry (LC-MS). The two main objectives in developing version 6.0 are to support tandem MS (MS2) data processing and annotation, as well as to support the analysis of data from exposomics studies and related experiments. Key features of MetaboAnalyst 6.0 include: (i) a significantly enhanced Spectra Processing module with support for MS2 data and the asari algorithm; (ii) a MS2 Peak Annotation module based on comprehensive MS2 reference databases with fragment-level annotation; (iii) a new Statistical Analysis module dedicated for handling complex study design with multiple factors or phenotypic descriptors; (iv) a Causal Analysis module for estimating metabolite - phenotype causal relations based on two-sample Mendelian randomization, and (v) a Dose-Response Analysis module for benchmark dose calculations. In addition, we have also improved MetaboAnalyst's visualization functions, updated its compound database and metabolite sets, and significantly expanded its pathway analysis support to around 130 species. MetaboAnalyst 6.0 is freely available at https://www.metaboanalyst.ca., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)
- Published
- 2024
- Full Text
- View/download PDF
38. Suicidal Ideation among Older Family Caregivers for a Person with Dementia.
- Author
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Teasdale-Dubé A and Viau-Quesnel C
- Subjects
- Humans, Female, Male, Aged, Middle Aged, Pilot Projects, Aged, 80 and over, Loneliness psychology, Stress, Psychological psychology, Suicidal Ideation, Caregivers psychology, Dementia psychology, Dementia nursing, Qualitative Research
- Abstract
Objectives: This pilot study aimed to describe the phenomenon of suicidal ideation among caregivers who were aged 60 and over and who provided care for a person with dementia., Methods: A qualitative study was conducted, using a descriptive method. Semi-structured interviews were administered to caregivers who had or were having suicidal thoughts whilst caring for a relative with dementia., Results: Six caregivers were interviewed. Four caregivers reported experiencing active suicidal ideation whilst caregiving. Two subjects mentioned wishing for the death of their care recipient. While saturation criteria were not all met themes regarding suicidal ideation types and developmental contexts emerged. Findings suggest that family conflicts, placement difficulties, exhaustion, feelings of injustice, and loneliness contributed to the development of suicidal ideation., Conclusions: Suicidal distress can emerge from the dementia caregiving context and these findings highlight a complex phenomenon among caregivers. The understanding of caregivers' suicidal distress is of great importance to guide screening and intervention efforts. Research is needed to keep the implication and well-being of older caregivers., Clinical Implications: Screening efforts should consider the caregiving context as a conducive environment for suicidal distress and clinicians could use this knowledge to provide specific interventions to distressed carers.
- Published
- 2024
- Full Text
- View/download PDF
39. Impact of Cannabidiol and Exercise on Clinical Outcomes and Gut Microbiota for Chemotherapy-Induced Peripheral Neuropathy in Cancer Survivors: A Case Report.
- Author
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Vigano M, Kubal S, Lu Y, Habib S, Samarani S, Cama G, Viau C, Farzin H, Koudieh N, Xia J, Ahmad A, Vigano A, and Costiniuk CT
- Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) remains a clinical challenge for up to 80% of breast cancer survivors. In an open-label study, participants underwent three interventions: standard care (duloxetine) for 1 month (Phase 1), oral cannabidiol (CBD) for 2 months (Phase 2), and CBD plus multi-modal exercise (MME) for another 2 months (Phase 3). Clinical outcomes and gut microbiota composition were assessed at baseline and after each phase. We present the case of a 52-year-old female with a history of triple-negative breast cancer in remission for over five years presenting with CIPN. She showed decreased monocyte counts, c-reactive protein, and systemic inflammatory index after each phase. Duloxetine provided moderate benefits and intolerable side effects (hyperhidrosis). She experienced the best improvement and least side effects with the combined (CBD plus MME) phase. Noteworthy were clinically meaningful improvements in CIPN symptoms, quality of life (QoL), and perceived physical function, as well as improvements in pain, mobility, hand/finger dexterity, and upper and lower body strength. CBD and MME altered gut microbiota, showing enrichment of genera that produce short-chain fatty acids. CBD and MME may improve CIPN symptoms, QoL, and physical function through anti-inflammatory and neuroprotective effects in cancer survivors suffering from long-standing CIPN.
- Published
- 2024
- Full Text
- View/download PDF
40. MetaboAnalystR 4.0: a unified LC-MS workflow for global metabolomics.
- Author
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Pang Z, Xu L, Viau C, Lu Y, Salavati R, Basu N, and Xia J
- Subjects
- Algorithms, Chromatography, Liquid methods, Liquid Chromatography-Mass Spectrometry, Software, Mass Spectrometry methods, Metabolomics methods, Workflow
- Abstract
The wide applications of liquid chromatography - mass spectrometry (LC-MS) in untargeted metabolomics demand an easy-to-use, comprehensive computational workflow to support efficient and reproducible data analysis. However, current tools were primarily developed to perform specific tasks in LC-MS based metabolomics data analysis. Here we introduce MetaboAnalystR 4.0 as a streamlined pipeline covering raw spectra processing, compound identification, statistical analysis, and functional interpretation. The key features of MetaboAnalystR 4.0 includes an auto-optimized feature detection and quantification algorithm for LC-MS1 spectra processing, efficient MS2 spectra deconvolution and compound identification for data-dependent or data-independent acquisition, and more accurate functional interpretation through integrated spectral annotation. Comprehensive validation studies using LC-MS1 and MS2 spectra obtained from standards mixtures, dilution series and clinical metabolomics samples have shown its excellent performance across a wide range of common tasks such as peak picking, spectral deconvolution, and compound identification with good computing efficiency. Together with its existing statistical analysis utilities, MetaboAnalystR 4.0 represents a significant step toward a unified, end-to-end workflow for LC-MS based global metabolomics in the open-source R environment., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
41. Suicidal Ideation in Canadian Family Caregivers for a Person with Dementia: A Portrait of the Situation.
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Teasdale-Dubé A, Viau-Quesnel C, and Lapierre S
- Abstract
This study aimed to explore the prevalence of suicidal thoughts and potential associations (i.e., strength and direction) with caregiver characteristics or factors. A targeted survey was distributed to dementia caregivers aged 55+ years. Questions concerning psychological distress, suicidal thoughts while caregiving and antecedents of suicidal behaviours were administered. A sample of 71 French-speaking Canadian caregivers completed the survey between May and October 2019. Among them, 52.1 per cent ( n = 37) reported suicidal ideation while providing care to a relative or a friend living with dementia. Caregivers who presented suicidal ideation reported more abusive behaviour toward the care recipient. Caregivers who reported suicidal thoughts were significantly more distressed than caregivers without them on measures of burden, depression, and anxiety. Suicidal thoughts in caregivers are important evaluation targets, primarily for the prevention of suicide, but also because caregivers who report suicidal thoughts also present a heightened risk for abusing the care recipient.
- Published
- 2024
- Full Text
- View/download PDF
42. Letter to the editor: Negative feasibility for 1-bromopropane and call for additional data.
- Author
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Lowry LK, Hopf NB, Bader M, Blum LM, Grassman J, Jones K, Kaefferlein HU, Nylander-French LA, Spies GJ, Talaska G, and Viau C
- Subjects
- Feasibility Studies, Hydrocarbons, Brominated
- Published
- 2023
- Full Text
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43. The Native Microbiome Member Chryseobacterium sp. CHNTR56 MYb120 Induces Trehalose Production via a Shift in Central Carbon Metabolism during Early Life in C. elegans .
- Author
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Shiri TJ, Viau C, Gu X, Xu L, Lu Y, and Xia J
- Abstract
Aging is the system-wide loss of homeostasis, eventually leading to death. There is growing evidence that the microbiome not only evolves with its aging host, but also directly affects aging via the modulation of metabolites involved in important cellular functions. The widely used model organism C. elegans exhibits high selectivity towards its native microbiome members which confer a range of differential phenotypes and possess varying functional capacities. The ability of one such native microbiome species, Chryseobacterium sp. CHNTR56 MYb120, to improve the lifespan of C. elegans and to promote the production of Vitamin B6 in the co-colonizing member Comamonas sp. 12022 MYb131 are some of its beneficial effects on the worm host. We hypothesize that studying its metabolic influence on the different life stages of the worm could provide further insights into mutualistic interactions. The present work applied LC-MS untargeted metabolomics and isotope labeling to study the impact of the native microbiome member Chryseobacterium sp. CHNTR56 MYb120 on the metabolism of C. elegans . In addition to the upregulation of biosynthesis and detoxification pathway intermediates, we found that Chryseobacterium sp. CHNTR56 MYb120 upregulates the glyoxylate shunt in mid-adult worms which is linked to the upregulation of trehalose, an important metabolite for desiccation tolerance in older worms.
- Published
- 2023
- Full Text
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44. Genomic and phenotypic profiling of Staphylococcus aureus isolates from bovine mastitis for antibiotic resistance and intestinal infectivity.
- Author
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Majumder S, Sackey T, Viau C, Park S, Xia J, Ronholm J, and George S
- Subjects
- Animals, Cattle, Female, Anti-Bacterial Agents pharmacology, Caco-2 Cells, Caenorhabditis elegans, Canada, Drug Resistance, Microbial, Genomics, Microbial Sensitivity Tests, Staphylococcus aureus, Mastitis, Bovine microbiology, Staphylococcal Infections veterinary, Staphylococcal Infections microbiology
- Abstract
Background: Staphylococcus aureus is one of the prevalent etiological agents of contagious bovine mastitis, causing a significant economic burden on the global dairy industry. Given the emergence of antibiotic resistance (ABR) and possible zoonotic spillovers, S aureus from mastitic cattle pose threat to both veterinary and public health. Therefore, assessment of their ABR status and pathogenic translation in human infection models is crucial., Results: In this study, 43 S. aureus isolates associated with bovine mastitis obtained from four different Canadian provinces (Alberta, Ontario, Quebec, and Atlantic provinces) were tested for ABR and virulence through phenotypic and genotypic profiling. All 43 isolates exhibited crucial virulence characteristics such as hemolysis, and biofilm formation, and six isolates from ST151, ST352, and ST8 categories showed ABR. Genes associated with ABR (tetK, tetM, aac6', norA, norB, lmrS, blaR, blaZ, etc.), toxin production (hla, hlab, lukD, etc.), adherence (fmbA, fnbB, clfA, clfB, icaABCD, etc.), and host immune invasion (spa, sbi, cap, adsA, etc.) were identified by analyzing whole-genome sequences. Although none of the isolates possessed human adaptation genes, both groups of ABR and antibiotic-susceptible isolates demonstrated intracellular invasion, colonization, infection, and death of human intestinal epithelial cells (Caco-2), and Caenorhabditis elegans. Notably, the susceptibilities of S. aureus towards antibiotics such as streptomycin, kanamycin, and ampicillin were altered when the bacteria were internalized in Caco-2 cells and C. elegans. Meanwhile, tetracycline, chloramphenicol, and ceftiofur were comparatively more effective with ≤ 2.5 log
10 reductions of intracellular S. aureus., Conclusions: This study demonstrated the potential of S. aureus isolated from mastitis cows to possess virulence characteristics enabling invasion of intestinal cells thus calling for developing therapeutics capable of targeting drug-resistant intracellular pathogens for effective disease management., (© 2023. The Author(s).)- Published
- 2023
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- View/download PDF
45. Reported non-compliance with pre-donation screening among blood donors in Québec, Canada: A focus on the 3-month deferral for men who have sex with men.
- Author
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Lewin A, Grégoire Y, Delage G, Thibeault C, Viau C, Milot C, Parent É, and Renaud C
- Subjects
- Blood Donors, Canada, Donor Selection methods, Female, Homosexuality, Male, Humans, Male, Quebec, HIV Infections diagnosis, HIV Infections prevention & control, Sexual and Gender Minorities
- Abstract
Background and Objectives: In Québec (Canada), the donation deferral for men who have sex with men (MSM) has recently been shortened to 3 months. Whether this change impacted compliance with pre-donation screening is unknown. We assessed compliance with the disclosure of male-to-male sex and other behavioural risk factors for HIV amid this change., Materials and Methods: Québec residents who donated from 14 July 2020 to 30 November 2020 were invited to participate in an online survey. Donors were informed that the survey was optional and anonymous. Survey questions were those used for routine pre-donation screening. Rates of reported non-compliance were weighted based on several characteristics., Results: Of 21,918 contacted donors, 7113 (32.45%) participated. Among male participants (N = 3347), six (0.27% [95% confidence interval (CI) = 0.09%-0.44%]) were not compliant with a 3-month MSM deferral. Among female participants (N = 3766), two (0.06% [95% CI = 0.00%-0.13%]) were not compliant with a 3-month deferral for sex with a man who had male-to-male sex ≤12 months. Other risk factors exhibited similar or lower rates of reported non-compliance., Conclusion: Reported non-compliance with a 3-month MSM deferral and the disclosure of other HIV behavioural risk factors was low. These results warrant the investigation of behavioural donor risk assessment approaches to further improve the inclusiveness of blood donation., (© 2022 International Society of Blood Transfusion.)
- Published
- 2022
- Full Text
- View/download PDF
46. Native Microbiome Members of C. elegans Act Synergistically in Biosynthesis of Pyridoxal 5'-Phosphate.
- Author
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Haçariz O, Viau C, Gu X, and Xia J
- Abstract
The roles of the healthy microbiome on the host and the relationships between members of the microbiome remain to be fully characterized. Due to the complexity of the interactions between the mammalian microbiome and its host, the use of model organisms such as the nematode worm Caenorhabditis elegans is a promising strategy to study host-microbiome interactions in vivo, as well as bacterial crosstalk within the host. Previously it was found that native bacterial isolates of the worm, Chryseobacterium sp. CHNTR56 MYb120 and Comamonas sp. 12022 MYb131, possess genomic diversity in the biosynthesis of the active form of vitamin B6, pyridoxal 5'-phosphate (PLP), and contribute to host fitness and lifespan extension. However, the relative contribution of PLP from each isolate, as well as the existence of interbacterial relationships within the worm gut remain to be characterized. In the present work, we investigated the presence and measured the abundance of PLP in the isolates and in the worms grown with the isolates using ultraperformance liquid chromatography tandem-mass spectrometry (UPLC-MS/MS). Our analyses confirmed the presence of PLP in vitro and in vivo. The elevated abundance of PLP in the isolates (which reached statistically significant levels when the two isolates were combined), and within worms grown with the combination of bacterial isolates, compared to control, indicated synergism between the isolates in the production of PLP. Isotope labeling revealed that Comamonas sp. 12022 MYb131 was the main provider of PLP in worms grown with the combination of bacterial isolates. The dominance of this isolate inside the worm was further confirmed by a colonization assay. An untargeted metabolomics analysis of the bacteria showed that the pathways related to cell growth, protein synthesis and lipid synthesis/energy production were regulated in the combination group in comparison with Comamonas sp. 12022 MYb131 alone. Furthermore, glutamine, involved in the de novo synthesis of purine and pyrimidines, was specifically abundant in this group, indicating the potential role of this metabolite in initiating and sustaining bacterial growth. This bacterial crosstalk is suggested to promote the growth of Comamonas sp. 12022 MYb131 in vivo, and synthesis of bacterial metabolites such as PLP in the worm gut.
- Published
- 2022
- Full Text
- View/download PDF
47. Ascaris suum Informs Extrasynaptic Volume Transmission in Nematodes.
- Author
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Atkinson LE, Liu Y, McKay F, Vandewyer E, Viau C, Irvine A, Rosa BA, Li Z, Liang Q, Marks NJ, Maule AG, Mitreva M, Beets I, Li L, and Mousley A
- Subjects
- Animals, Caenorhabditis elegans, FMRFamide, Female, Ascaris suum, Nematoda, Neuropeptides
- Abstract
Neural circuit synaptic connectivities (the connectome) provide the anatomical foundation for our understanding of nematode nervous system function. However, other nonsynaptic routes of communication are known in invertebrates including extrasynaptic volume transmission (EVT), which enables short- and/or long-range communication in the absence of synaptic connections. Although EVT has been highlighted as a facet of Caenorhabditis elegans neurosignaling, no experimental evidence identifies body cavity fluid (pseudocoelomic fluid; PCF) as a vehicle for either neuropeptide or biogenic amine transmission. In the parasitic nematode Ascaris suum , FMRFamide-like peptides encoded on flp-18 potently stimulate female reproductive organs but are expressed in cells that are anatomically distant from the reproductive organ, with no known synaptic connections to this tissue. Here we investigate nonsynaptic neuropeptide signaling in nematodes mediated by the body cavity fluid. Our data show that (i) A. suum PCF (As-PCF) contains a catalog of neuropeptides including FMRFamide-like peptides and neuropeptide-like proteins, (ii) the A. suum FMRFamide-like peptide As-FLP-18A dominates the As-PCF peptidome, (iii) As-PCF potently modulates nematode reproductive muscle function ex vivo , mirroring the effects of synthetic FLP-18 peptides, (iv) As-PCF activates the C. elegans FLP-18 receptors NPR-4 and -5, (v) As-PCF alters C. elegans behavior, and (vi) FLP-18 and FLP-18 receptors display pan-phylum distribution in nematodes. This study provides the first direct experimental evidence to support an extrasynaptic volume route for neuropeptide transmission in nematodes. These data indicate nonsynaptic signaling within the nematode functional connectome and are particularly pertinent to receptor deorphanization approaches underpinning drug discovery programs for nematode pathogens.
- Published
- 2021
- Full Text
- View/download PDF
48. "It was a nightmare until I saw my wife": the importance of family presence for patients with COVID-19 hospitalized in the ICU.
- Author
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Kentish-Barnes N, Degos P, Viau C, Pochard F, and Azoulay E
- Subjects
- Dreams, Humans, Intensive Care Units, SARS-CoV-2, Spouses, COVID-19
- Published
- 2021
- Full Text
- View/download PDF
49. The symbiotic relationship between Caenorhabditis elegans and members of its microbiome contributes to worm fitness and lifespan extension.
- Author
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Haçariz O, Viau C, Karimian F, and Xia J
- Subjects
- Animals, Caenorhabditis elegans genetics, Caenorhabditis elegans metabolism, Longevity, Oxidative Stress, Silicon Dioxide, Caenorhabditis elegans Proteins genetics, Caenorhabditis elegans Proteins metabolism, Microbiota
- Abstract
Background: A healthy microbiome influences host physiology through a mutualistic relationship, which can be important for the host to cope with cellular stress by promoting fitness and survival. The mammalian microbiome is highly complex and attributing host phenotypes to a specific member of the microbiome can be difficult. The model organism Caenorhabditis elegans and its native microbiome, discovered recently, can serve as a more tractable, experimental model system to study host-microbiome interactions. In this study, we investigated whether certain members of C. elegans native microbiome would offer a benefit to their host and putative molecular mechanisms using a combination of phenotype screening, omics profiling and functional validation., Results: A total of 16 members of C. elegans microbiome were screened under chemically-induced toxicity. Worms grown with Chryseobacterium sp. CHNTR56 MYb120 or Comamonas sp. 12022 MYb131, were most resistant to oxidative chemical stress (SiO
2 nanoparticles and juglone), as measured by progeny output. Further investigation showed that Chryseobacterium sp. CHNTR56 positively influenced the worm's lifespan, whereas the combination of both isolates had a synergistic effect. RNAseq analysis of young adult worms, grown with either isolate, revealed the enrichment of cellular detoxification mechanisms (glutathione metabolism, drug metabolism and metabolism of xenobiotics) and signaling pathways (TGF-beta and Wnt signaling pathways). Upregulation of cysteine synthases (cysl genes) in the worms, associated with glutathione metabolism, was also observed. Nanopore sequencing uncovered that the genomes of the two isolates have evolved to favor the specific route of the de novo synthesis pathway of vitamin B6 (cofactor of cysl enzymes) through serC or pdxA2 homologs. Finally, co-culture with vitamin B6 extended worm lifespan., Conclusions: In summary, our study indicates that certain colonizing members of C. elegans have genomic diversity in vitamin B6 synthesis and promote host fitness and lifespan extension. The regulation of host cellular detoxification genes (i.e. gst) along with cysl genes at the transcriptome level and the bacterium-specific vitamin B6 synthesis mechanism at the genome level are in an agreement with enhanced host glutathione-based cellular detoxification due to this interspecies relationship. C. elegans is therefore a promising alternative model to study host-microbiome interactions in host fitness and lifespan.- Published
- 2021
- Full Text
- View/download PDF
50. Human biomonitoring initiative (HBM4EU): Human biomonitoring guidance values (HBM-GVs) derived for cadmium and its compounds.
- Author
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Lamkarkach F, Ougier E, Garnier R, Viau C, Kolossa-Gehring M, Lange R, and Apel P
- Subjects
- Adult, Biological Monitoring, Biomarkers, Humans, Kidney, Cadmium toxicity, Kidney Diseases
- Abstract
Aims: The methodology agreed within the framework of the HBM4EU project is used in this work to derive HBM-GVs for the general population (HBM-GV
GenPop ) and for workers (HBM-GVWorker ) exposed to cadmium (Cd) and its compounds., Methods: For Cd, a significant number of epidemiological studies with dose-response relationships are available, in particular for kidney effects. These effects are described in terms of a relation between urinary Cd (U-Cd) or blood Cd (B-Cd) levels and low molecular weight proteinuria (LMWP) markers like beta-2-microglobulin (β2M) and retinol-binding protein (RBP). In order to derive HBM-GVs for the general population and workers, an assessment of data from evaluations conducted by national or international organisations was undertaken. In this work, it appeared relevant to select renal effects as the critical effect for the both groups, however, differences between general population (including sensitive people) and workers (considered as an homogenous population of adults who should not be exposed to Cd if they suffer from renal diseases) required the selection of different key studies (i.e. conducted in general population for HBM-GVGenPop and at workplace for HBM-GVWorker )., Results and Conclusions: For U-Cd, a HBM-GVGenPop of 1 µg/g creatinine (creat) is recommended for adults older than 50 years, based on a robust meta-analysis performed by EFSA (EFSA, 2009a). To take into account the accumulation of Cd in the human body throughout life, threshold or 'alert' values according to age were estimated for U-Cd. At workplace, a HBM-GVWorker of 2 μg/g creat is derived from the study of Chaumont et al., (2011) for U-Cd, and in addition to this recommendation a HBM-GVworker for B-Cd of 5 µg/L is also proposed. The HBM-GVWorker for U-Cd is similar to the biological limit value (BLV) set by the new amendment of the European Carcinogens and Mutagens Directive in June 2019 (2 µg/g creat for U-Cd)., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
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