Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 326
Filter
1.
Vox Sang ; 113(4): 339-344, 2018 May.
Article in English | MEDLINE | ID: mdl-29508402

ABSTRACT

BACKGROUND AND OBJECTIVES: Since 25 May 2010, all donors at our blood centre who tested false-positive for HIV, HBV, HCV or syphilis are eligible for re-entry after further testing. Donors who have a second false-positive screening test, either during qualification for or after re-entry, are deferred for life. This study reports on factors associated with the occurrence of such deferrals. MATERIALS AND METHODS: Rates of second false-positive results were compared by year of deferral, transmissible disease marker, gender, age, donor status (new or repeat) and testing platform (same or different) both at qualification for re-entry and afterwards. Chi-square tests were used to compare proportions. Cox regression was used for multivariate analyses. RESULTS: Participation rates in the re-entry programme were 42·1%: 25·6% failed to qualify for re-entry [different platform: 2·7%; same platform: 42·9% (P < 0·0001)]. After re-entry, rates of deferral for second false-positive results were 8·4% after 3 years [different platform: 1·8%; same platform: 21·4% (P < 0·0001)]. Deferral rates were higher for HIV and HCV than for HBV at qualification when tested on the same platform. The risk, when analysed by multivariate analyses, of a second deferral for a false-positive result, both at qualification and 3 years after re-entry, was lower for donors deferred on a different platform; this risk was higher for HIV, HCV and syphilis than for HBV and for new donors if tested on the same platform. CONCLUSION: Re-entry is more often successful when donors are tested on a testing platform different from the one on which they obtained their first false-positive result.


Subject(s)
Blood Donors/statistics & numerical data , Donor Selection/standards , HIV Infections/blood , Hepatitis C/blood , Syphilis/blood , Adult , Biomarkers/blood , Donor Selection/methods , False Positive Reactions , Female , Humans , Male , Middle Aged , Serologic Tests/standards
2.
Scand J Med Sci Sports ; 28(5): 1532-1540, 2018 May.
Article in English | MEDLINE | ID: mdl-29356101

ABSTRACT

We compared the effects of cycling and running exercise on hemorheological and hematological properties, as well as eryptosis markers. Seven endurance-trained subjects randomly performed a progressive and maximal exercise test on a cycle ergometer and a treadmill. Blood was sampled at rest and at the end of the exercise to analyze hematological and blood rheological parameters including hematocrit (Hct), red blood cell (RBC) deformability, aggregation, and blood viscosity. Hemoglobin saturation (SpO2), blood lactate, and glucose levels were also monitored. Red blood cell oxidative stress, calcium content, and phosphatidylserine exposure were determined by flow cytometry to assess eryptosis level. Cycling exercise increased blood viscosity and RBC aggregation whereas it had no significant effect on RBC deformability. In contrast, blood viscosity remained unchanged and RBC deformability increased with running. The increase in Hct, lactate, and glucose concentrations and the loss of weight at the end of exercise were not different between running and cycling. Eryptosis markers were not affected by exercise. A significant drop in SpO2 was noted during running but not during cycling. Our study showed that a progressive and maximal exercise test conducted on a cycle ergometer increased blood viscosity while the same test conducted on a treadmill did not change this parameter because of different RBC rheological behavior between the 2 tests. We also demonstrated that a short maximal exercise does not alter RBC physiology in trained athletes. We suspect that exercise-induced hypoxemia occurring during running could be at the origin of the RBC rheological behavior differences with cycling.


Subject(s)
Bicycling/psychology , Eryptosis , Erythrocyte Deformability , Running/physiology , Adult , Blood Glucose , Blood Viscosity , Calcium/blood , Female , Hematocrit , Humans , Hypoxia , Lactic Acid/blood , Male , Oxygen Consumption , Phosphatidylserines/blood , Reactive Oxygen Species/blood
3.
Vox Sang ; 112(4): 318-325, 2017 May.
Article in English | MEDLINE | ID: mdl-28337765

ABSTRACT

BACKGROUND AND OBJECTIVES: Blood operators routinely monitor the pH of apheresis platelets as a marker of the so-called storage lesion, which can result from manufacturing problems. It is also suspected that some donor characteristics can increase the risk of poor platelet storage. To explore this hypothesis, we analysed a large, multinational data set of quality control (QC) pH test results on apheresis platelets. MATERIALS AND METHODS: For the period between September 2011 and August 2014, seven blood operators in Canada, the USA, the Netherlands, the United Kingdom, France and Australia provided pH QC test results and donor characteristics on a total of 21,671 apheresis platelets. RESULTS: Some variations in pH distribution between blood operators were in part explained by differences in collection, processing and testing methods. Younger age and female gender were significantly associated with a pH value below the 10th percentile. Among donors who had two or more pH measurements (n = 3672), there was a strong correlation between pH results (r = 0·726; P < 0·0001). CONCLUSION: The strong intradonor correlation of pH measurements and the association between donor characteristics and pH results suggest that donor factors play a role in the quality of platelets.


Subject(s)
Donor Selection , Plateletpheresis/standards , Quality Control , Adolescent , Adult , Age Factors , Aged , Female , Humans , Hydrogen-Ion Concentration , Male , Middle Aged , Plateletpheresis/methods , Sex Factors , Tissue Preservation/standards , Young Adult
4.
Vox Sang ; 110(3): 278-81, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26198382

ABSTRACT

The aim of the study was to test the relative efficacy of telephone and email reminders to trigger blood donation. A sample of 3454 donors was randomized to one of three conditions: phone only (n = 1176), email only (n = 1091) and phone + email (n = 1187). There was a higher proportion of donors who registered to give blood in the phone + email condition (18·45%) compared to the other two conditions (phone: 15·73%, P < 0·05; email: 13·20%; P < 0·001); this effect was apparent only in men. The phone and email conditions did not differ significantly (P = 0·16), suggesting equivalent efficacy.


Subject(s)
Blood Donors/psychology , Reminder Systems , Adolescent , Adult , Aged , Demography , Electronic Mail , Female , Humans , Male , Middle Aged , Registries , Sex Factors , Telephone , Young Adult
5.
Cell Tissue Bank ; 17(4): 593-601, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27522194

ABSTRACT

Cardiovascular allografts are usually disinfected using antibiotics, but protocols vary significantly between tissue banks. It is likely that different disinfection protocols will not have the same level of efficacy; they may also have varying effects on the structural integrity of the tissue, which could lead to significant differences in terms of clinical outcome in recipients. Ideally, a disinfection protocol should achieve the greatest bioburden reduction with the lowest possible impact on tissue integrity. We conducted a systematic review of methods applied to disinfect cardiovascular tissues. The use of multiple broad spectrum antibiotics in conjunction with an antifungal agent resulted in the greatest reduction in bioburden. Antibiotic incubation periods were limited to less than 24 h, and most protocols incubated tissues at 4 °C, however one study demonstrated a greater reduction of microbial load at 37 °C. None of the reviewed studies looked at the impact of these disinfection protocols on the risk of infection or any other clinical outcome in recipients.


Subject(s)
Allografts/microbiology , Disinfection/methods , Heart Valves/microbiology , Heart Valves/transplantation , Sterilization/methods , Tissue Banks , Anti-Bacterial Agents/pharmacology , Bacteria/isolation & purification , Bacterial Infections/prevention & control , Cell Culture Techniques/methods , Fungi/isolation & purification , Humans , Mycoses/prevention & control , Transplantation, Homologous
6.
Cell Tissue Bank ; 17(4): 573-584, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27665294

ABSTRACT

Musculoskeletal allografts are typically disinfected using antibiotics, irradiation or chemical methods but protocols vary significantly between tissue banks. It is likely that different disinfection protocols will not have the same level of microorganism kill; they may also have varying effects on the structural integrity of the tissue, which could lead to significant differences in terms of clinical outcome in recipients. Ideally, a disinfection protocol should achieve the greatest bioburden reduction with the lowest possible impact on tissue integrity. A systematic review of three databases found 68 laboratory and clinical studies that analyzed the microbial bioburden or contamination rates of musculoskeletal allografts. The use of peracetic acid-ethanol or ionizing radiation was found to be most effective for disinfection of tissues. The use of irradiation is the most frequently published method for the terminal sterilization of musculoskeletal allografts; it is widely used and its efficacy is well documented in the literature. However, effective disinfection results were still observed using the BioCleanse™ Tissue Sterilization process, pulsatile lavage with antibiotics, ethylene oxide, and chlorhexidine. The variety of effective methods to reduce contamination rate or bioburden, in conjunction with limited high quality evidence provides little support for the recommendation of a single bioburden reduction method.


Subject(s)
Allografts/microbiology , Allografts/virology , Bone Transplantation , Disinfection/methods , Muscles/transplantation , Sterilization/methods , Bone Transplantation/adverse effects , Bone and Bones/microbiology , Bone and Bones/virology , Cell Culture Techniques/methods , Humans , Muscles/microbiology , Muscles/virology , Tissue Banks , Transplantation, Homologous
7.
Vox Sang ; 106(4): 372-5, 2014 May.
Article in English | MEDLINE | ID: mdl-24877223

ABSTRACT

Canada now allows donations from men who had sex with men (MSM) if their last sexual contact with a man was more than 5 years ago. We modelled the impact of this policy on supply and safety. Approximately 4500 new donors will be added and assuming compliance to the new policy remains unchanged, the worst-case scenario predicts the introduction of one HIV-contaminated unit in the inventory every 1072 years. This change will entail negligible additional HIV risk to recipients. A five-year deferral will also protect recipients against the theoretical concern that MSM may represent a group at higher risk of sexually transmitted, emerging blood borne pathogens.


Subject(s)
Blood Donors/legislation & jurisprudence , Blood Safety , Sexual Behavior , Adult , Blood Donors/ethics , Blood Transfusion , Canada , HIV Infections/prevention & control , Homosexuality, Male , Humans , Male , Risk
8.
Vox Sang ; 104(4): 309-16, 2013 May.
Article in English | MEDLINE | ID: mdl-23134533

ABSTRACT

BACKGROUND AND OBJECTIVES: In many jurisdictions, blood donors who have an atypical pulse rate are temporarily deferred. This practice is not supported by evidence. We evaluated whether accepting donors with an atypical pulse rate increases their risk of cardiac ischaemic events. METHODS: We measured the cumulative incidence of hospitalizations and deaths for coronary heart disease within 1 year of follow-up among donors who, between 2002 and 2006, were temporarily deferred because of an atypical pulse (<50 beats/min, >100 beats/min, or irregular). We compared this incidence to that observed among donors who also had an atypical pulse but who were allowed to donate, following a change in our deferral policy in 2007. The occurrence of cardiac events was determined through hospital discharge and death registries. RESULTS: Among 6076 donors who were temporarily deferred for an atypical pulse, the 1-year rate of hospitalization or death for cardiac ischaemic events was 3.5/1000, compared to 2.4 in donors who had an atypical pulse but who were allowed to donate (n =10,671), for an adjusted odds ratio of 1.7 (95% CI, 0.9-3.0, P=0.08). CONCLUSION: Regardless of the clinical significance of an atypical pulse rate, our data show that accepting donors with this condition does not increase the occurrence of serious cardiac ischaemic events. We conclude that pulse rate measurement in prospective donors is not warranted.


Subject(s)
Blood Donors/statistics & numerical data , Coronary Disease/epidemiology , Heart Rate , Myocardial Ischemia/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Coronary Disease/blood , Coronary Disease/etiology , Female , Humans , Incidence , Male , Middle Aged , Myocardial Ischemia/blood , Myocardial Ischemia/etiology , Quebec/epidemiology , Risk Factors , Young Adult
9.
Trop Med Infect Dis ; 8(9)2023 Sep 12.
Article in English | MEDLINE | ID: mdl-37755906

ABSTRACT

WHO and endemic countries target elimination of transmission of Onchocerca volvulus, the parasite causing onchocerciasis. Population genetic analysis of O. volvulus may provide data to improve the evidence base for decisions on when, where, and for how long to deploy which interventions and post-intervention surveillance to achieve elimination. Development of necessary methods and tools requires parasites suitable for genetic analysis. Based on our experience with microfilariae obtained from different collaborators, we developed a microfilariae transfer procedure for large-scale studies in the Democratic Republic of Congo (DRC) comparing safety and efficacy of ivermectin, the mainstay of current onchocerciasis elimination strategies, and moxidectin, a new drug. This procedure is designed to increase the percentage of microfilariae in skin snips suitable for genetic analysis, improve assignment to metadata, and minimize time and materials needed by the researchers collecting the microfilariae. Among 664 microfilariae from South Sudan, 35.7% and 39.5% failed the mitochondrial and nuclear qPCR assay. Among the 576 microfilariae from DRC, 16.0% and 16.7% failed these assays, respectively. This difference may not only be related to the microfilariae transfer procedure but also to other factors, notably the ethanol concentration in the tubes in which microfilariae were stored (64% vs. ≥75%).

12.
Transfus Med ; 22(6): 395-403, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22998470

ABSTRACT

OBJECTIVES: Using population prevalence data for deferrable diseases/conditions we estimated the Canadian population eligible to donate according to three upper-age limit scenarios. BACKGROUND: The donor selection criteria limit the number of potential blood donors but relaxing the upper age criteria could mitigate this. METHODS AND MATERIALS: Forty deferral criteria were identified and their corresponding prevalence data obtained to estimate the number of people excluded by the criteria. The eligible blood donor population was estimated from national census data taking the age limits, deferral criteria and deferral time-period into account. As more than one disease/condition may co-exist, the estimate was adjusted to avoid over-representation. RESULTS: Of about 33 million Canadians aged 17 (18 in Québec) to 65, 15·1 million (45·8%) are eligible to donate blood. This number increases to 15·7 million when including people up to 71 years and to 17·1 million in the absence of an upper age limit. CONCLUSION: As about 1·2 million units are collected from 600,000 donors annually, there are more than enough eligible people to meet the need. However, recruitment of donors is challenging and the absence of an upper age limit allows an additional 2 million people to donate. Other countries may wish to consider modification of the upper age criterion to address the effect of an aging population on the blood supply.


Subject(s)
Blood Donors/supply & distribution , Donor Selection , Adolescent , Adult , Age Factors , Aged , Blood Donors/ethics , Blood Donors/psychology , Canada , Female , Humans , Male , Middle Aged
13.
Ann Chir Plast Esthet ; 57(1): 16-24, 2012 Feb.
Article in French | MEDLINE | ID: mdl-21908090

ABSTRACT

OBJECTIVE OF THE STUDY: Immediate failure in breast surgery with implant is a serious medical complication with negative ramifications for both the patient and the health care system. The classical treatment is removal of the breast implant and delay reconstruction. Our objective is to show that this standard treatment is not the good one in many cases, and abundant irrigation with implant salvage is a sure and effective alternative. PATIENTS AND METHODS: Between January 2001 and December 2009, among the 680 patients who had a breast reconstruction, 18 were operated using the same protocol treatment by the same surgeon: implant removal, irrigation, implant replacement, antibiotic treatment. RESULTS: After a median month follow-up period of 30 months, definitive conservation of the breast implant was obtained in all of the cases. CONCLUSION: This preliminary study provides encouraging results in a selected patient population improving the possibility of a conservative treatment according to a precise and rigourous protocol.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Breast Implantation/adverse effects , Breast Implants/microbiology , Mammaplasty , Prosthesis-Related Infections/therapy , Therapeutic Irrigation , Adult , Aged , Device Removal , Female , Follow-Up Studies , Humans , Mammaplasty/adverse effects , Mammaplasty/methods , Middle Aged , Patient Satisfaction , Prospective Studies , Prosthesis-Related Infections/microbiology , Surgical Flaps/adverse effects , Therapeutic Irrigation/methods , Treatment Outcome
14.
J Cell Biol ; 172(6): 847-60, 2006 Mar 13.
Article in English | MEDLINE | ID: mdl-16533945

ABSTRACT

Separase is a protease whose liberation from its inhibitory chaperone Securin triggers sister chromatid disjunction at anaphase onset in yeast by cleaving cohesin's kleisin subunit. We have created conditional knockout alleles of the mouse Separase and Securin genes. Deletion of both copies of Separase but not Securin causes embryonic lethality. Loss of Securin reduces Separase activity because deletion of just one copy of the Separase gene is lethal to embryos lacking Securin. In embryonic fibroblasts, Separase depletion blocks sister chromatid separation but does not prevent other aspects of mitosis, cytokinesis, or chromosome replication. Thus, fibroblasts lacking Separase become highly polyploid. Hepatocytes stimulated to proliferate in vivo by hepatectomy also become unusually large and polyploid in the absence of Separase but are able to regenerate functional livers. Separase depletion in bone marrow causes aplasia and the presumed death of hematopoietic cells other than erythrocytes. Destruction of sister chromatid cohesion by Separase may be a universal feature of mitosis in eukaryotic cells.


Subject(s)
Cell Cycle Proteins/genetics , Cell Cycle/genetics , Chromosome Segregation/genetics , DNA Replication Timing/genetics , Endopeptidases/genetics , Mitosis/genetics , Anaphase/genetics , Animals , Carrier Proteins/genetics , Cell Line , Chromosomal Proteins, Non-Histone/genetics , Embryonic Development/genetics , Female , Fibroblasts , Genes, Lethal/genetics , Hematopoietic Stem Cells/metabolism , Hepatocytes , Liver Regeneration/genetics , Male , Mice , Mice, Knockout , Nuclear Proteins/genetics , Polyploidy , Securin , Separase , Cohesins
16.
Pathogens ; 9(3)2020 Mar 05.
Article in English | MEDLINE | ID: mdl-32151038

ABSTRACT

We investigated urinary N-acetyltyramine-O,ß-glucuronide (NATOG) levels as a biomarker for active Onchocerca volvulus infection in an onchocerciasis-endemic area in the Democratic Republic of Congo with a high epilepsy prevalence. Urinary NATOG was measured in non-epileptic men with and without O. volvulus infection, and in O. volvulus-infected persons with epilepsy (PWE). Urinary NATOG concentration was positively associated with microfilarial density (p < 0.001). The median urinary NATOG concentration was higher in PWE (3.67 µM) compared to men without epilepsy (1.74 µM), p = 0.017; and was higher in persons with severe (7.62 µM) compared to mild epilepsy (2.16 µM); p = 0.008. Non-epileptic participants with and without O. volvulus infection had similar NATOG levels (2.23 µM and 0.71 µM, p = 0.426). In a receiver operating characteristic curve analysis to investigate the diagnostic value of urinary NATOG, the area under the curve was 0.721 (95% CI: 0.633-0.797). Using the previously proposed cut-off value of 13 µM to distinguish between an active O. volvulus infection and an uninfected state, the sensitivity was 15.9% and the specificity 95.9%. In conclusion, an O. volvulus infection is associated with an increased urinary NATOG concentration, which correlates with the individual parasitic load. However, the NATOG concentration has a low discriminating power to differentiate between infected and uninfected individuals.

19.
Environ Entomol ; 38(3): 797-802, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19508789

ABSTRACT

We examined landing patterns of phloeophagous and xylophagous Coleoptera among trees and snags of different physiological and decay states in a pure open-canopy black spruce stand in boreal Canada to study prelanding host selection mechanisms in the absence of nonhost volatiles. Sticky traps were used to capture insects landing on high- and low-density natural snags (i.e., wood density), girdled trees, living trees, and stovepipe controls. Patterns were generally weak, with high within-group variability in species composition and landing rates. Within-group variability differed between groups, with highest variations in living trees and recent snags. Despite this evidence of frequent landing on suboptimal or inappropriate hosts, affinities were detected in most common taxa. Cerambycidae showed preferences for girdled trees. Common species of Scolytinae showed divergent preferences, because Crypturgus borealis Swaine and Dryocoetes autographus (Ratzeburg) were captured more often on high-density natural snags, Polygraphus rufipennis (Kirby) on girdled trees, and Orthotomicus latidens (LeConte) on living trees. These observed landing patterns are broadly consistent with current knowledge on the ecology of these species. Although preferences, and thus prelanding assessment of hosts based on volatiles, were detected in several species, the numerous landings observed on inappropriate hosts suggest that random landing at close range may be as common in pure stands as what was previously observed in mixed stands.


Subject(s)
Appetitive Behavior , Coleoptera , Ecosystem , Feeding Behavior , Picea/physiology , Animals , Phloem , Quebec , Wood
20.
Sci Rep ; 9(1): 3750, 2019 03 06.
Article in English | MEDLINE | ID: mdl-30842582

ABSTRACT

Factor V serves an important role in the regulation of blood coagulation. The rs6025 (R534Q) and rs4524 (K858R) polymorphisms in the F5 gene, are known to influence the risk of venous thrombosis. While the rare Q534 (factor V Leiden) allele is associated with an increased risk of venous thrombosis, the minor R858 allele is associated with a lower risk of disease. However, no study has deeply examined the cumulative impact of these two variations on venous thrombosis risk. We study the association of these polymorphisms with the risk of venous thrombosis in 4 French case-control populations comprising 3719 patients and 4086 controls. We demonstrate that the Q534 allele has a dominant effect over R858. Besides, we show that in individuals not carrying the Q534 allele, the protective effect of the R858 allele acts in a dominant mode. Thrombin generation-based normalized activated protein C sensitivity ratio was lower in the 858R/R homozygotes than in the 858K/K homozygotes (1.92 ± 1.61 vs 2.81 ± 1.57, p = 0.025). We demonstrate that the R858 allele of the F5 rs4524 variant protects from venous thrombosis only in non-carriers of the Q534 allele of the F5 rs6025. Its protective effect is mediated by reduced factor VIII levels and reduced activated protein C resistance.


Subject(s)
Amino Acid Substitution , Factor V/genetics , Venous Thrombosis/genetics , Alleles , Case-Control Studies , Female , France , Genetic Association Studies , Heterozygote , Humans , Male , Protein C/metabolism , Venous Thrombosis/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL