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1.
BJOG ; 129(2): 291-299, 2022 01.
Article in English | MEDLINE | ID: mdl-34726316

ABSTRACT

OBJECTIVE: Evaluation of relevance and feasibility of universal newborn congenital cytomegalovirus infection (cCMVI) screening in saliva. DESIGN: Retrospective, population-based cohort study. SETTING: Clamart, France, 2016-2020. POPULATION: All neonates born consecutively in our level III maternity unit. METHODS: CMV PCR in saliva for all neonates at birth, and, if positive, CMV PCR in urine to confirm or exclude cCMVI. Prospective and retrospective characterisation of maternal infections. ROC curve analysis to assess saliva PCR performances. Acceptability of screening among staff members evaluated by a survey. MAIN OUTCOME MEASURES: Number of cCMVI neonates; number of expected and unexpected cCMVI. RESULTS: Among 15 341 tested neonates, 63 had cCMVI (birth prevalence of 0.4%, 95% CI 0.3-0.5). In 50% of cases, maternal infection was a non-primary infection (NPI) during pregnancy. cCMVI was expected or suspected (maternal primary infection [PI], antenatal or neonatal signs) in 24/63 neonates (38%), and unexpected in 39/63 neonates (62%). The best CMV saliva threshold to predict cCMVI was 356 (2.55 log) copies/ml [95% CI 2.52 log-3.18 log], with an area under the ROC curve of 0.97. Over 90% of the 72 surveyed staff members reported that the screening was easy and quick. No parent refused the screening. CONCLUSIONS: Universal screening for cCMVI with CMV PCR on saliva samples is feasible and highly acceptable to parents and healthcare providers. Over half (62%) of the cases had no prenatal/neonatal signs of cCMVI or a maternal history of CMV infection during pregnancy and would probably not have been diagnosed without universal screening. TWEETABLE ABSTRACT: In 62% of congenital cytomegalovirus infection cases, only universal neonatal screening in saliva can detect infection.


Subject(s)
Cytomegalovirus Infections/diagnosis , Neonatal Screening , Adult , Cohort Studies , Cytomegalovirus/isolation & purification , Cytomegalovirus Infections/congenital , Cytomegalovirus Infections/prevention & control , Feasibility Studies , Female , France , Humans , Infant, Newborn , Predictive Value of Tests , Pregnancy , Prenatal Care , ROC Curve , Retrospective Studies , Saliva/virology
2.
Epidemiol Infect ; 147: e234, 2019 01.
Article in English | MEDLINE | ID: mdl-31364570

ABSTRACT

Treatment options for Hepatitis C infection have greatly improved with direct-acting antiviral (DAA) combinations achieving high cure rates. Nevertheless, the cost of this treatment is still high and access to treatment in many countries has been preferentially reserved for patients with more severe fibrosis (F3 and F4). In this French nationwide study, we investigated the epidemiological characteristics and genotype distribution of hepatitis C virus (HCV) in treatment-naive patients with METAVIR fibrosis stages between F0 and F2 in order to identify patient profiles that became eligible for unrestricted treatment in a second period. Between 2015 and 2016 we collected data from nine French university hospitals on a total of 584 HCV positive patients with absent, mild or moderate liver fibrosis. The most represented genotypes were genotype 1b (159/584; 27.2%), followed by genotype 1a (150/584; 25.7%); genotype 3 (87/584: 14.9%); genotype 4 (80/584; 13.7%). Among genotype 4: 4a was predominantly encountered with 22 patients (27.5% of genotype 4). Genotypes 1b and 1a are currently the most frequent virus types present in treatment-naive patients with mild fibrosis in France. They can be readily cured using the available DAA. Nevertheless, non-a/non-d genotype 4 is also frequent in this population and clinical data on the efficacy of DAA on these subtypes is missing. The GEMHEP is the French group for study and evaluation of viral hepatitis on a national scale. Data collection on epidemiological and molecular aspects of viral hepatitis is performed on a regular basis in all main French teaching hospitals and serves as a basis for surveillance of these infections. Analysis and trends are regularly published on behalf of the GEMHEP group. Data collection was performed retrospectively over the 2015-2016 period, covering nine main university hospitals in France. A total of 584 hepatitis C positive patients were included in this study. Genotyping of the circulating viruses showed a high prevalence of genotypes 1b and 1a in our population. The epidemiology of hepatitis C is slowly changing in France, particularly as a consequence of the rise of 'non-a non-d' genotype 4 viruses mainly originating from African populations. More data concerning treatment efficacy of these genotypes is needed in order to guide clinical care.


Subject(s)
Hepacivirus/isolation & purification , Hepatitis C, Chronic/epidemiology , Hepatitis C, Chronic/genetics , Liver Cirrhosis/epidemiology , Viral Proteins/genetics , Adult , Databases, Factual , Female , France/epidemiology , Genotype , Hepacivirus/genetics , Hepatitis C, Chronic/diagnosis , Humans , Liver Cirrhosis/pathology , Liver Cirrhosis/virology , Logistic Models , Male , Multivariate Analysis , Prevalence , RNA, Viral/genetics , Retrospective Studies , Severity of Illness Index , Statistics, Nonparametric , Tertiary Care Centers
3.
J Comp Pathol ; 154(2-3): 165-8, 2016.
Article in English | MEDLINE | ID: mdl-26922858

ABSTRACT

Mycoplasma hyopneumoniae (Mh) is a bacterium that specifically infects the surface of bronchi and bronchioles of pigs without invading the host cells, and it is considered to be the primary agent of porcine enzootic pneumonia (PEN). The present study investigates the morphological and immunohistological changes induced in bronchiolar epithelium by Mh infection. Lungs from 20 pigs with naturally occurring Mh pneumonia were compared with those from 10 uninfected controls. Bronchiolar epithelial height, inflammatory infiltration, hyperplasia of bronchus-associated lymphoid tissue (BALT) and mucin subtype MUC5AC-producing cells significantly increased in all infected animals. Mh antigen was detected in association with the cilia of the bronchial and bronchiolar epithelium. Interleukin (IL)-5 and IL-13 were expressed consistently by epithelial and mononuclear cells of the airways of infected animals. The expression of these cytokines in the bronchial and bronchiolar tissues is related to the histological changes of PEN.


Subject(s)
Interleukin-13/biosynthesis , Interleukin-5/biosynthesis , Pneumonia of Swine, Mycoplasmal/metabolism , Pneumonia of Swine, Mycoplasmal/pathology , Respiratory Mucosa/metabolism , Animals , Bronchioles/metabolism , Bronchioles/pathology , Immunohistochemistry , Mycoplasma hyopneumoniae , Respiratory Mucosa/pathology , Sus scrofa , Swine
4.
Int Endod J ; 49(6): 511-8, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26100850

ABSTRACT

AIM: To evaluate the response of the apical and periapical tissues of dog teeth with apical periodontitis after one-session root canal treatment with and without antimicrobial photodynamic therapy (aPDT) compared with the use of an intracanal dressing. METHODOLOGY: Sixty root canals with an induced periapical lesion were instrumented and assigned to three groups: I, two-session root canal treatment using antibacterial dressing with calcium hydroxide-based paste; II, one-session root canal treatment using aPDT; and III, one-session root canal treatment in which the root canals were filled immediately after biomechanical preparation. The animals were euthanized after a 90-day experimental period. The maxillas and mandibles with teeth were submitted to histotechnical processing and haematoxylin-eosin staining. Descriptive microscopic analysis of the apical and periapical region characteristics was performed, as well as morphometric assessment of the periapical lesion areas in fluorescence microscopy. Quantitative data were analysed statistically by the nonparametric Kruskal-Wallis test and Dunn's post-test (α = 0.05). RESULTS: Group I was characterized by progressive repair, with the presence of fibres, cells and blood vessels. Group II had periodontal ligaments with the presence of collagen fibres and residual inflammatory cells. Group III had a dense inflammatory infiltrate with extensive oedematous areas and fibrillar dissociation, suggesting a persistent inflammatory and resorptive condition. Regarding periapical lesion size, group I had significantly smaller lesions (P < 0.05) than groups II and III, which did not differ significantly from each other. CONCLUSION: Two-session root canal treatment using a calcium hydroxide-based dressing was associated with significantly smaller periapical lesions at 90 days and characterized by progressive repair.


Subject(s)
Anti-Infective Agents/therapeutic use , Periapical Periodontitis/drug therapy , Photochemotherapy/methods , Root Canal Therapy/methods , Animals , Dogs , Microscopy, Fluorescence , Periapical Periodontitis/therapy
5.
Euro Surveill ; 20(29): 21192, 2015 Jul 23.
Article in English | MEDLINE | ID: mdl-26227370

ABSTRACT

In May 2013, Italy declared a national outbreak of hepatitis A, which also affected several foreign tourists who had recently visited the country. Molecular investigations identified some cases as infected with an identical strain of hepatitis A virus subgenotype IA. After additional European Union/European Economic Area (EU/EEA) countries reported locally acquired and travel-related cases associated with the same outbreak, an international outbreak investigation team was convened, a European outbreak case definition was issued and harmonisation of the national epidemiological and microbiological investigations was encouraged. From January 2013 to August 2014, 1,589 hepatitis A cases were reported associated with the multistate outbreak; 1,102 (70%) of the cases were hospitalised for a median time of six days; two related deaths were reported. Epidemiological and microbiological investigations implicated mixed frozen berries as the vehicle of infection of the outbreak. In order to control the spread of the outbreak, suspected or contaminated food batches were recalled, the public was recommended to heat-treat berries, and post-exposure prophylaxis of contacts was performed. The outbreak highlighted how large food-borne hepatitis A outbreaks may affect the increasingly susceptible EU/EEA general population and how, with the growing international food trade, frozen berries are a potential high-risk food.


Subject(s)
Disease Outbreaks , Food Contamination , Foodborne Diseases/epidemiology , Fruit/poisoning , Hepatitis A virus/genetics , Hepatitis A/epidemiology , Adolescent , Adult , Child, Preschool , Contact Tracing , Epidemiologic Studies , Europe/epidemiology , European Union , Female , Foodborne Diseases/diagnosis , Foodborne Diseases/virology , Frozen Foods/poisoning , Frozen Foods/virology , Fruit/virology , Hepatitis A/virology , Hepatitis A virus/isolation & purification , Humans , Male , Middle Aged , Surveys and Questionnaires
6.
Transpl Infect Dis ; 17(5): 662-70, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26192379

ABSTRACT

BACKGROUND: Few studies have investigated infections in human immunodeficiency virus (HIV)-infected liver transplant patients. The aim of this study was to describe the prevalence, time of onset, mortality of infectious complications, other than hepatitis C virus (HCV), and to identify risk factors for their development in a large single-center cohort of HIV-infected liver transplant patients. METHODS: We studied 109 consecutive HIV-infected patients who underwent liver transplantation (LT) between 1999 and 2010 and followed until December 2012. RESULTS: The median age was 44 years (interquartile range [IQR] 41-49), 82.6% were male, and the median follow-up was 45.7 months (IQR 14-65). The major indications for LT were HCV cirrhosis (61%) and hepatocellular carcinoma (19%). Forty patients (37%) developed at least 1 infection during the first year after LT. Twenty-eight (26%) patients had an episode of bacteremia. Five (4.6%) patients developed a cytomegalovirus infection. Fungal infections occurred in 5 (4.5%) patients. Four (3.6%) patients developed an HIV-related opportunistic infection. A total of 43 (39.4%) patients died during follow-up. Mortality related to infection occurred in 9 (7%) cases, and 20 (42.5%) patients died because of HCV recurrence. No patients died from opportunistic infections. Model for end-stage liver disease (MELD) score >17 was associated with a 2-fold higher risk (hazard ratio 1.96; 95% confidence interval 1.01-3.80) of developing infectious complications. CONCLUSIONS: Infections are not a major cause of mortality after LT in HIV patients and opportunistic infections of acquired immunodeficiency syndrome are infrequent. A MELD score >17 increased the risk of developing post-LT infectious complications. Recurrence of HCV infection remains a major cause of mortality.


Subject(s)
AIDS-Related Opportunistic Infections/etiology , Immunocompromised Host , Liver Transplantation , Postoperative Complications/etiology , AIDS-Related Opportunistic Infections/epidemiology , AIDS-Related Opportunistic Infections/immunology , Adult , Female , Follow-Up Studies , Humans , Male , Middle Aged , Postoperative Complications/epidemiology , Postoperative Complications/immunology , Prevalence , Risk Factors , Survival Analysis
7.
J Comp Pathol ; 152(2-3): 243-7, 2015.
Article in English | MEDLINE | ID: mdl-25731984

ABSTRACT

To gain further insight into the pathogenesis of Mycoplasma bovis-associated pneumonia, cytokine expression in different pulmonary compartments was examined. The expression of tumour necrosis factor (TNF)-α, interleukin (IL)-4 and interferon (IFN)-γ was examined immunohistochemically in the lung of 10 calves infected experimentally with M. bovis. M. bovis antigen was located in respiratory epithelial cells and within inflammatory cells in the airway lumina. Immunolabelling for TNF-α, IL-4 and IFN-γ was usually associated with inflammation, particularly in macrophages and lymphocytes in hyperplastic bronchus-associated lymphoid tissue (BALT), in thickened alveolar septa and in the bronchoalveolar exudate of infected animals. In M. bovis infection, macrophage and lymphocyte activation results in expression of a number of cytokines capable of inducing lung lesions and hyperplasia of the BALT. The cytokines examined likely play a role in pulmonary defence against M. bovis infection.


Subject(s)
Cytokines/biosynthesis , Pneumonia, Mycoplasma/pathology , Animals , Cattle , Immunohistochemistry , Mycoplasma bovis , Pneumonia, Mycoplasma/immunology
8.
J Colloid Interface Sci ; 420: 152-7, 2014 Apr 15.
Article in English | MEDLINE | ID: mdl-24559713

ABSTRACT

In this work we present semi-analytical solutions for the electro-osmotic annular flow of viscoelastic fluids modeled by the Linear and Exponential PTT models. The viscoelastic fluid flows in the axial direction between two concentric cylinders under the combined influences of electrokinetic and pressure forcings. The analysis invokes the Debye-Hückel approximation and includes the limit case of pure electro-osmotic flow. The solution is valid for both no slip and slip velocity at the walls and the chosen slip boundary condition is the linear Navier slip velocity model. The combined effects of fluid rheology, electro-osmotic and pressure gradient forcings on the fluid velocity distribution are also discussed.

10.
J Colloid Interface Sci ; 395: 277-86, 2013 Apr 01.
Article in English | MEDLINE | ID: mdl-23394805

ABSTRACT

This paper presents an analytical model that describes a two-fluid electro-osmotic flow of stratified fluids with Newtonian or viscoelastic rheological behavior. This is the principle of operation of an electro-osmotic two-fluid pump as proposed by Brask et al. [Tech. Proc. Nanotech., 1, 190-193, 2003], in which an electrically non-conducting fluid is transported by the interfacial dragging viscous force of a conducting fluid that is driven by electro-osmosis. The electric potential in the conducting fluid and the analytical steady flow solution of the two-fluid electro-osmotic stratified flow in a planar microchannel are presented by assuming a planar interface between the two immiscible fluids with Newtonian or viscoelastic rheological behavior. The effects of fluid rheology, shear viscosity ratio, holdup and interfacial zeta potential are analyzed to show the viability of this technique, where an enhancement of the flow rate is observed as the shear-thinning effects are increased.

11.
J Med Virol ; 84(11): 1831-8, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22997088

ABSTRACT

Rubella virus (RV) infection during the early stages of pregnancy can lead to serious birth defects, known as the congenital rubella syndrome (CRS). In 2003, the Pan American Health Organization (PAHO) adopted a resolution calling for the elimination of rubella and the congenital rubella syndrome (CRS) in the Americas by the year 2010. Brazil will have implemented the recommended PAHO strategy for elimination and interruption of endemic rubella virus transmission. The characterization of genotypes during the final stages of rubella elimination is important for determining whether new rubella isolates represent endemic transmission or importations. Samples (blood, urine, cerebrospinal fluid, and throat swabs) collected from patients with symptoms suggestive of rubella infection in 1997-2004 were isolated in cell culture and genotyped. Twenty-eight sequences were analyzed and two genotypes were identified: 1a and 1G. The information reported in this paper will contribute to understanding the molecular epidemiology of RV in São Paulo, Brazil.


Subject(s)
Rubella virus/classification , Rubella virus/genetics , Rubella/epidemiology , Rubella/virology , Adolescent , Adult , Brazil/epidemiology , Child , Child, Preschool , Cluster Analysis , Female , Genotype , Humans , Infant , Infant, Newborn , Male , Molecular Sequence Data , Phylogeny , Pregnancy , RNA, Viral/genetics , Retrospective Studies , Rubella virus/isolation & purification , Sequence Analysis, DNA , Virus Cultivation , Young Adult
12.
J Med Virol ; 84(10): 1666-71, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22930516

ABSTRACT

Rubella virus (RV) is an important human pathogen that causes rubella, an acute contagious disease. It also causes severe birth defects collectively known as congenital rubella syndrome when infection occurs during the first trimester of pregnancy. Here, we present the phylogenetic analysis of RV that circulated in São Paulo during the 2007-2008 outbreak. Samples collected from patients diagnosed with rubella were isolated in cell culture and sequenced. RV RNA was obtained from samples or RV-infected cell cultures and amplified by reverse transcriptase-polymerase chain reaction. Sequences were assigned to genotypes by phylogenetic analysis using RV reference sequences. Seventeen sequences were analyzed, and three genotypes were identified: 1a, 1G, and 2B. Genotypes 1a and 1G, which were isolated in 2007, were responsible for sporadic rubella cases in São Paulo. Thereafter, in late 2007, the epidemiological conditions changed, resulting in a large RV outbreak with the clear dominance of genotype 2B. The results of this study provide new approaches for monitoring the progress of elimination of rubella from São Paulo, Brazil.


Subject(s)
Phylogeny , Rubella virus/classification , Rubella virus/genetics , Rubella/epidemiology , Rubella/virology , Adolescent , Adult , Brazil/epidemiology , Child, Preschool , Cluster Analysis , Female , Genotype , Humans , Infant, Newborn , Male , Middle Aged , Molecular Epidemiology , Molecular Sequence Data , Rubella virus/isolation & purification , Sequence Analysis, DNA , Virus Cultivation , Young Adult
13.
J Oral Rehabil ; 39(11): 830-7, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22889084

ABSTRACT

The etiologic factors associated with crestal bone loss have not been comprehensively clarified. Several theories exist as to the reason for the observed changes in crestal bone height following implant restoration. In the 1990s, the wide-diameter implants were commercially introduced. Initially, the implants were restored with standard-diameter abutments because of lack of matching prosthetic components. Long-term radiographic follow-up of these 'platform-switched' restored wide-diameter dental implants has demonstrated a smaller-than-expected vertical change in the crestal bone height around these implants that is typically observed around implants restored conventionally with prosthetic components of matching diameters. The aim of this randomised controlled study was to assess radiographically marginal bone level alterations in implants restored according to the platform-switching concept compared with traditionally restored implants. Fifty-four subjects to participate in this randomised controlled study were selected. Two groups were assigned at random: control group (56 implants were restored with standard matching-diameter abutments) and test group (58 implants were restored with medialised abutments). X-ray explorations were taken for peri-implant bone level at the minute the last cementing of the prosthesis and at 1-year follow-up. NHI Image was used to digitally process and manipulate the radiographic images and perform the measurements. Mean of bone loss with platform-switching implants was -0·01 mm, and the mean of bone loss with standard platform implant was 0·42 mm. Outcomes of this study indicated that the platform-switching design could preserve the crestal bone levels to 1-year follow-up. There was a statistically significant difference in marginal bone loss.


Subject(s)
Alveolar Process/diagnostic imaging , Dental Implant-Abutment Design , Dental Implants, Single-Tooth , Adult , Aged , Alveolar Bone Loss/diagnostic imaging , Bone Density/physiology , Cementation , Cephalometry/methods , Dental Abutments , Female , Follow-Up Studies , Humans , Image Processing, Computer-Assisted/methods , Male , Middle Aged , Radiography, Bitewing/methods , Single-Blind Method
14.
Am J Transplant ; 11(8): 1686-95, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21749638

ABSTRACT

We characterized fibrosing cholestatic hepatitis (FCH) in a large cohort of HIV/HCV co-infected patients. Between 1999 and 2008, 59 HIV infected patients were transplanted for end-stage liver disease due to HCV. Eleven patients (19%) developed FCH within a mean period of 7 months [2-27] after liver transplantation (LT). At Week 1 post-LT, the mean HCV viral load was higher in the FCH group: 6.13 log(10) IU/mL ± 1.30 versus 4.9 log(10) IU/mL ± 1.78 in the non-FCH group, p = 0.05. At the onset of acute hepatitis after LT, activity was moderate to severe in 8/11 HIV+/HCV+ patients with FCH (73%) versus 13/28 (46%) HIV+/HCV+ non-FCH (p = 0.007) patients. A complete virological response to anti-HCV therapy was observed in 2/11 (18%) patients. Survival differed significantly between the two groups (at 3 years, 67% in non-FCH patients versus 15% in FCH patients, p = 0.004). An early diagnosis of FCH may be suggested by the presence of marked disease activity when acute hepatitis is diagnosed and when a high viral load is present. The initiation of anti-HCV therapy should be considered at this point.


Subject(s)
Biomarkers/blood , HIV Infections/blood , Hepatitis C/surgery , Liver Transplantation , Adult , Aged , Cholestasis, Intrahepatic , Cohort Studies , Female , HIV Infections/complications , Hepatitis C/blood , Hepatitis C/complications , Humans , Immunosuppressive Agents/therapeutic use , Male , Middle Aged , Viral Load
15.
Clin Vaccine Immunol ; 18(8): 1391-4, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21653739

ABSTRACT

A multicentric clinical study was conducted on representative sera from 1,738 European and U.S. subjects for the evaluation of new anti-hepatitis A virus enzyme immunoassays from Bio-Rad Laboratories. Comparison with reference DiaSorin S.p.A. tests confirmed the good performance of Bio-Rad assays (99.85% and 99.47% overall agreement in detecting total antibodies and IgM, respectively).


Subject(s)
Clinical Laboratory Techniques/methods , Hepatitis A Antibodies/blood , Hepatitis A virus/immunology , Hepatitis A/diagnosis , Immunoglobulin M/blood , Humans , Immunoenzyme Techniques/methods
17.
Pathol Biol (Paris) ; 59(1): 57-65, 2011 Feb.
Article in French | MEDLINE | ID: mdl-20822864

ABSTRACT

PURPOSE OF THE STUDY: Very few is known on genotype II hepatitis A virus (HAV) since it is rarely isolated. From 2002 to 2007, the French observatory of HAV identified six sub-genotype IIA strains of which one from a patient having travelled to West Africa. To investigate the possible African origin of sub-genotype IIA, we determined its prevalence among French travellers in 2008 and characterised its genetic variability. PATIENTS AND METHODS: The 2008 mandatory notification records were screened for travel to Africa. Viral genotype was determined on the nucleotide sequencing of the VP1/2A junction region. The P1 region coding for capsid proteins was used to compare the genetic diversity of IIA isolates to those of other genotypes. RESULTS: In 2008, five out of 54 patients returning from West Africa were infected by IIA strains and an additional "autochthonous" case was identified. Two more African cases were identified in 2009. A total of 14 IIA isolates (eight African and six "autochthonous") were analysed. Nucleotide and amino-acid variability of IIA sequences was lower than that of the other genotypes. Phylogenetic analysis revealed the clustering of two "autochthonous" cases with African isolates whereas the other ones belonged to a different lineage. CONCLUSION: Most IIA strains isolated in France are imported by travellers returning from West Africa. However, the unexplained contamination mode of some "autochthonous" cases suggests another geographical origin to discover or a French reservoir to explore.


Subject(s)
Hepatitis A virus/genetics , Hepatitis A/virology , RNA, Viral/genetics , Adolescent , Adult , Africa, Western , Amino Acid Sequence , Child , Female , France , Genetic Variation , Genotype , Hepatitis A virus/classification , Humans , Male , Middle Aged , Molecular Sequence Data , Phylogeny , Sequence Alignment , Sequence Homology, Amino Acid , Travel , Viral Structural Proteins/genetics , Young Adult
19.
J Colloid Interface Sci ; 344(2): 513-20, 2010 Apr 15.
Article in English | MEDLINE | ID: mdl-20153862

ABSTRACT

The electro-osmotic flow of a viscoelastic fluid between parallel plates is investigated analytically. The rheology of the fluid is described by the Phan-Thien-Tanner model. This model uses the Gordon-Schowalter convected derivative, which leads to a non-zero second normal stress difference in pure shear flow. A nonlinear Poisson-Boltzmann equation governing the electrical double-layer field and a body force generated by the applied electrical potential field are included in the analysis. Results are presented for the velocity and stress component profiles in the microchannel for different parametric values that characterize this flow. Equations for the critical shear rates and maximum electrical potential that can be applied to maintain a steady fully developed flow are derived and discussed.

20.
Pathol Biol (Paris) ; 58(2): 175-8, 2010 Apr.
Article in French | MEDLINE | ID: mdl-19942365

ABSTRACT

PURPOSE OF THE STUDY: Hepatitis C virus genotyping is needed for treatment decision and monitoring. The results of a genotyping assay based on real-time PCR and TaqMan chemistry were compared with the results of NS5B region sequencing. MATERIALS AND METHODS: One hundred and two sera (genotypes 1-6) were tested. Amplification and detection of viral RNA were performed with the Abbott RealTime HCV Genotype II assay targeting 5'non-coded region (5'NC) for the identification of genotypes 1 to 6 and NS5B, for 1a and 1b subtypes detection. Sequencing of 5'NC fragment was used to resolve discrepant results. RESULTS: No indeterminate results were obtained. Concordance with NS5B sequencing was 93% (95 on 102), 96% at the genotype level (98 on 102) and 93% for genotype 1 subtyping (40 on 43). Discordant genotyping results were a 2f subtype identified as 5, a 6a typed as 1, a 3a identified as a 1-3 co-infection and a 4r identified as a 1-4 co-infection. Discordant subtyping results were 2 1b subtypes only typed as 1 and a 1e identified as 1a. CONCLUSION: Abbott RealTime HCV Genotype II assay is a rapid, automated and simple to interpret method for HCV genotyping. It allows the detection of possible mixed infections which might have a negative impact on therapeutic response. However, the discrepant results found in this small series underline the need for assay optimization.


Subject(s)
Computer Systems , Genotype , Hepacivirus/genetics , Polymerase Chain Reaction/methods , RNA, Viral/genetics , Reagent Kits, Diagnostic , Sequence Analysis, RNA/methods , Hepacivirus/classification , Hepacivirus/isolation & purification , Hepatitis C, Chronic/blood , Hepatitis C, Chronic/virology , Humans , Prospective Studies , RNA, Viral/blood , RNA, Viral/isolation & purification , Taq Polymerase , Time Factors , Viremia/virology
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