60 results on '"BOYER, S."'
Search Results
2. GloPID-R report on chikungunya, o'nyong-nyong and Mayaro virus, part 5: Entomological aspects
- Author
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Pezzi, L., Diallo, M., Rosa-Freitas, M. G., Vega-Rua, A., Ng, L. F. P., Boyer, S., Drexler, J. F., Vasilakis, N., Lourenco-de-Oliveira, R., Weaver, S. C., Kohl, A., de Lamballerie, X., Failloux, A-B, Brasil, P., Busch, M., Diamond, M. S., Drebot, M. A., Gallian, P., Jaenisch, T., LaBeaud, A. D., Lecui, M., Neyts, J., Reusken, C. B., Ribeiro, G. S., Rios, M., Rodriguez-Morales, A. J., Sall, A., Simmons, G., Simon, F., Siqueira, A. M., Pezzi, L., Diallo, M., Rosa-Freitas, M. G., Vega-Rua, A., Ng, L. F. P., Boyer, S., Drexler, J. F., Vasilakis, N., Lourenco-de-Oliveira, R., Weaver, S. C., Kohl, A., de Lamballerie, X., Failloux, A-B, Brasil, P., Busch, M., Diamond, M. S., Drebot, M. A., Gallian, P., Jaenisch, T., LaBeaud, A. D., Lecui, M., Neyts, J., Reusken, C. B., Ribeiro, G. S., Rios, M., Rodriguez-Morales, A. J., Sall, A., Simmons, G., Simon, F., and Siqueira, A. M.
- Abstract
The GloPID-R (Global Research Collaboration for Infectious Disease Preparedness) chikungunya (CHIKV), o'nyong-nyong (ONNV) and Mayaro virus (MAYV) Working Group has been established to investigate natural history, epidemiology and clinical aspects of infection by these viruses. Here, we present a report dedicated to entomological aspects of CHIKV, ONNV and MAYV. Recent global expansion of chikungunya virus has been possible because CHIKV established a transmission cycle in urban settings using anthropophilic vectors such as Aedes albopictus and Aedes aegypti. MAYV and ONNV have a more limited geographic distribution, being confined to Africa (ONNV) and central-southern America (MAYV). ONNV is probably maintained through an enzootic cycle that has not been characterized yet, with Anopheles species as main vectors and humans as amplification hosts during epidemics. MAYV is transmitted by Haemagogus species in an enzootic cycle using non-human primates as the main amplification and maintenance hosts, and humans becoming sporadically infected when venturing in or nearby forest habitats. Here, we focused on the transmission cycle and natural vectors that sustain circulation of these viruses in their respective locations. The knowledge of the natural ecology of transmission and the capacity of different vectors to transmit these viruses is crucial to understand CHIKV emergence, and to assess the risk that MAYV and ONNV will expand on wide scale using anthropophilic mosquito species not normally considered primary vectors. Finally, the experts identified knowledge gaps and provided adapted recommendations, in order to address future entomological investigations in the right direction.
- Published
- 2020
3. Dehn Surgery on Knots
- Author
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BOYER, S, primary
- Published
- 2001
- Full Text
- View/download PDF
4. GloPID-R report on chikungunya, o'nyong-nyong and Mayaro virus, part 3: Epidemiological distribution of Mayaro virus
- Author
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Pezzi, L., Rodriguez-Morales, A. J., Reusken, C. B., Ribeiro, G. S., LaBeaud, A. D., Lourenco-de-Oliveira, R., Brasil, P., Lecuit, M., Failloux, A. B., Gallian, P., Jaenisch, T., Simon, F., Siqueira, A. M., Rosa-Freitas, M. G., Rua, A. Vega, Weaver, S. C., Drexler, J. F., Vasilakis, N., de Lamballerie, X., Boyer, S., Busch, M., Diallo, M., Diamond, M. S., Drebot, M. A., Kohl, A., Neyts, J., Ng, L. F. P., Rios, M., Sall, A., Simmons, G., Pezzi, L., Rodriguez-Morales, A. J., Reusken, C. B., Ribeiro, G. S., LaBeaud, A. D., Lourenco-de-Oliveira, R., Brasil, P., Lecuit, M., Failloux, A. B., Gallian, P., Jaenisch, T., Simon, F., Siqueira, A. M., Rosa-Freitas, M. G., Rua, A. Vega, Weaver, S. C., Drexler, J. F., Vasilakis, N., de Lamballerie, X., Boyer, S., Busch, M., Diallo, M., Diamond, M. S., Drebot, M. A., Kohl, A., Neyts, J., Ng, L. F. P., Rios, M., Sall, A., and Simmons, G.
- Published
- 2019
5. MULTI-DIMENSIONAL EMR OF AMERICAN COALS
- Author
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Clarkson, R.B., primary, Boyer, S., additional, Nilges, M.J., additional, Wang, W., additional, and Belford, R.L., additional
- Published
- 1991
- Full Text
- View/download PDF
6. Measurement of (n,$\gamma$) neutron capture cross-sections with liquid scintillator detectors
- Author
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Wilson, J.N., Haas, B., Boyer, S., Dassie, D., Barreau, G., Aiche, M., Czajkowski, S., Grosjean, C., Guiral, A., Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), and Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] - Published
- 2003
7. A comparison of functionality, rumination, and distraction tasks on women's state body image and mood after idealised media exposure.
- Author
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Mulgrew KE and Boyer S
- Abstract
Writing tasks that encourage an appreciation of body functionality can improve women's body image and may buffer against negative effects of idealised media exposure. However, no research has examined whether these tasks can serve as a coping strategy after idealised exposure. To this end, young adult women (N = 217, M
age = 21.63) recruited from an Australian university and general community completed a writing task after idealised media exposure, with state body image measures taken at baseline, post-exposure, and post-task. Women were randomly allocated to one of three writing tasks and asked to appreciate their body functionality, to focus on the previously viewed images (rumination), or to describe a frequently travelled route (distraction). Improvements on outcome measures were equally found across both the functionality and distraction condition. Only body appreciation uniquely improved in the functionality condition. The functionality task was rated more helpful but also more challenging. These findings add to the evidence base regarding the usefulness of functionality-based writing tasks for improving women's body image. They can offer immediate benefits when experiencing body image distress, as can distraction, and future research should explore their utility in driving more sustained and deeper ways of engaging with one's body long-term., Competing Interests: Declaration of Competing Interest None., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2024
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8. Performance evaluation of UF-4000 body fluid mode for detection of bacteria in body fluids.
- Author
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Siatkowski M, Dahyot S, Pestel-Caron M, and Boyer S
- Subjects
- Humans, Bacteria, ROC Curve, Leukocyte Count, Mass Screening, Flow Cytometry methods, Body Fluids
- Abstract
Background: Microbiological analysis of body fluids (BF) provides important information for diagnosis of infection. We evaluated the analytical performance of bacterial count by UF-4000 BF mode for ascitic, cerebrospinal, pleural, synovial and continuous ambulatory peritoneal dialysis fluids compared to classical microbiological procedure (direct Gram staining and culture)., Materials and Methods: For the 1,734 BF analyzed, distribution of UF-4000 bacterial count was analyzed according to the level of growth culture and results were compared using Mann-Whitney test. ROC curves analysis allowed to define the best cut-off value to predict or exclude positive culture for each type of BF., Results: UF-4000 bacterial counts were significantly lower in sterile than in infected BFs (p < 0.00001) and correlated with the level of growth on culture. The ROC curves of bacteria/μL and culture positivity yielded area under the curve >0.80 for each type of BF. Optimal cut-offs were chosen with excellent statistical parameters (sensitivity ranging from 0.70 to 0.86, specificity from 0.78 to 0.98, negative predictive value >0.95 and Youden index >0.55)., Conclusion: For BF, UF-4000 bacterial count correlate with culture results and is a discriminative method enhancing detection of microbiological etiology. It could be used as a screening method based on the cut-off values proposed in this study., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)
- Published
- 2023
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9. Performance evaluation of UF-4000 body fluid mode for automated body fluid cell counting.
- Author
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Siatkowski M, Dahyot S, Pestel-Caron M, and Boyer S
- Subjects
- Erythrocyte Count methods, Erythrocytes, Humans, Leukocyte Count, Microscopy methods, Reproducibility of Results, Body Fluids
- Abstract
Background: Cytological analysis of body fluids (BF) provides important information for diagnosis in various medical conditions. We evaluated the analytical performance of the UF-4000 BF mode for ascitic, cerebrospinal, pleural, synovial and continuous ambulatory peritoneal dialysis fluids compared to light microscopy counting (LM)., Materials and Methods: 223 consecutive BF were analyzed by UF-4000 and results were compared using Pearson's correlation, Bland-Altman analysis, and contingence tests at relevant cut-off values. This study also included the evaluation of precision, linearity, and carryover., Results: For white and red blood cells (WBC, RBC) counts in all BF, correlation was excellent with Pearson's coefficients R
2 > 0,98. Bland-Altman analysis didn't reveal significant differences with limited bias for WBC ranging from -10 to -1 WBC/µL and bias ranging from -43 to -6/µL for RBC. At specific cut-off values for WBC, Se and Spe were 100% except for ascites (Spe = 98%) due to two false positive. Precision evaluated at three concentration levels was good for each parameter (WBC < 10%). Linearity was excellent for WBC (R2 > 0,99) and carryover negligible (<0,004%)., Conclusion: UF-4000 BF mode is a good alternative to manual LM for BF cell counting. This automated method gives rapid and accurate results which is important for therapeutic decisions., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2022
- Full Text
- View/download PDF
10. Area of technical uncertainty for susceptibility testing of amoxicillin/clavulanate against Escherichia coli: analysis of automated system, Etest and disk diffusion methods compared to the broth microdilution reference.
- Author
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Soares A, Pestel-Caron M, Leysour de Rohello F, Bourgoin G, Boyer S, and Caron F
- Subjects
- Escherichia coli Infections microbiology, Humans, Reproducibility of Results, Amoxicillin-Potassium Clavulanate Combination pharmacology, Disk Diffusion Antimicrobial Tests methods, Disk Diffusion Antimicrobial Tests standards, Escherichia coli drug effects
- Abstract
Objectives: The European Committee on Antimicrobial Susceptibility Testing (EUCAST) recently warned about an area of technical uncertainty (ATU) of amoxicillin/clavulanate (AMX/C) disk susceptibility testing against members of the Enterobacterales. Thus, we aimed to compare the reliability of three routine methods and to evaluate the impact of the ATU., Methods: 286 Escherichia coli strains (including 159 AMX-resistant strains) were categorized for the two EUCAST AMX/C breakpoints by disk diffusion (Bio-Rad), the Phoenix automated system (Becton Dickinson) and the Etest (AES) compared to the broth microdilution reference method., Results: By microdilution, 84.2% of strains were AMX/C-susceptible using the urinary breakpoint (MIC ≤32 mg/L) and 62.2% using the systemic breakpoint (MIC ≤8 mg/L), with 63.6% of MICs between 4 and 16 mg/L. For the systemic breakpoint, category agreement (CA) and very major error (VME) were unacceptable for the Etest (71.7% and 27.3%), disk (73.1% and 23.4% at 19-mm cut-off) and to a lesser extent for the Phoenix system (83.6% and 10.5%). For disks, an unacceptable VME rate was observed for diameters up to 22 mm, probably due to overcharged disks. For the Etest, VMEs were high at 6 mg/L (46/63) and 8 mg/L (22/29). For the urinary breakpoint, CA was more acceptable for disk (88.9%) and Etest (84.3%) but was unevaluable for Phoenix., Conclusion: AMX/C susceptibility testing of E. coli for systemic breakpoint was unreliable with the three routine methods, explained mainly by the high prevalence (~60%) of strains with microdilution MICs around the breakpoint (8 mg/L). Our data confirmed the EUCAST 19-20-mm ATU for disk and suggest introducing ATU for Etest MIC values of 6 and 8 mg/L., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
11. Viral clearance capacity by continuous Protein A chromatography step using Sequential MultiColumn Chromatography.
- Author
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Goussen C, Goldstein L, Brèque C, You B, Boyer S, Bataille D, and Burlot L
- Subjects
- Adsorption, Animals, Cell Culture Techniques, Chromatography, Affinity methods, Mice, Parvovirinae growth & development, Antibodies, Monoclonal isolation & purification, Chromatography methods, Chromatography, Affinity instrumentation, Parvovirinae chemistry, Staphylococcal Protein A chemistry
- Abstract
In response to the strong demand of biological protein therapeutics, such as monoclonal antibodies (MAbs), continuous downstream process was developed to deliver these molecules while maintaining desired product consistency and quality attributes, and providing manufacturing efficiency and flexibility. Viral safety is a critical quality attribute for biopharmaceuticals, such as MAbs. Evaluation of the viral clearance by the downstream process is a key component of risk mitigation. Protein A chromatography is typically used as an initial capture step for MAbs and efficient for the removal of process-related impurities like Host Cell Proteins (HCP). This step can also contribute to the clearance of potential viral contaminants. Murine Minute Virus (MMV)-spiking experiments were performed at small scale to investigate the impact on the viral clearance efficiency of the way the Protein A chromatography step is carried out, whether in batch or multicolumn mode. Protein A chromatography step using Novasep Sequential MultiColumn Chromatography (SMCC) technology demonstrated no statistical difference in the viral reduction with reduction factor (RF) of 3.7 log
10 (vs. RF of 3.8 log10 for batch). The experiments showed also similar viral distribution over the purification cycles and columns. Data confirmed that the viral clearance capacity by the continuous Protein A chromatography step using SMCC technology is maintained and efficient., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2020
- Full Text
- View/download PDF
12. GloPID-R report on chikungunya, o'nyong-nyong and Mayaro virus, part 5: Entomological aspects.
- Author
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Pezzi L, Diallo M, Rosa-Freitas MG, Vega-Rua A, Ng LFP, Boyer S, Drexler JF, Vasilakis N, Lourenco-de-Oliveira R, Weaver SC, Kohl A, de Lamballerie X, and Failloux AB
- Subjects
- Aedes virology, Africa, Animals, Anopheles virology, Central America, Chikungunya virus pathogenicity, Humans, O'nyong-nyong Virus pathogenicity, Primates virology, Research Report, Alphavirus Infections transmission, Chikungunya Fever transmission, Mosquito Vectors virology
- Abstract
The GloPID-R (Global Research Collaboration for Infectious Disease Preparedness) chikungunya (CHIKV), o'nyong-nyong (ONNV) and Mayaro virus (MAYV) Working Group has been established to investigate natural history, epidemiology and clinical aspects of infection by these viruses. Here, we present a report dedicated to entomological aspects of CHIKV, ONNV and MAYV. Recent global expansion of chikungunya virus has been possible because CHIKV established a transmission cycle in urban settings using anthropophilic vectors such as Aedes albopictus and Aedes aegypti. MAYV and ONNV have a more limited geographic distribution, being confined to Africa (ONNV) and central-southern America (MAYV). ONNV is probably maintained through an enzootic cycle that has not been characterized yet, with Anopheles species as main vectors and humans as amplification hosts during epidemics. MAYV is transmitted by Haemagogus species in an enzootic cycle using non-human primates as the main amplification and maintenance hosts, and humans becoming sporadically infected when venturing in or nearby forest habitats. Here, we focused on the transmission cycle and natural vectors that sustain circulation of these viruses in their respective locations. The knowledge of the natural ecology of transmission and the capacity of different vectors to transmit these viruses is crucial to understand CHIKV emergence, and to assess the risk that MAYV and ONNV will expand on wide scale using anthropophilic mosquito species not normally considered primary vectors. Finally, the experts identified knowledge gaps and provided adapted recommendations, in order to address future entomological investigations in the right direction., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
13. Lack of effect of a poster-based intervention to reduce the number of blood culture samples collected.
- Author
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Boulet L, Vermeulin T, Vasiliu A, Gillibert A, Lottin M, Frébourg N, Boyer S, and Merle V
- Subjects
- Humans, Blood Culture, Blood Specimen Collection statistics & numerical data, Posters as Topic
- Abstract
Objective: To reduce the number of blood culture samples collected., Patients and Method: We performed a cluster randomized controlled trial in adult acute care, and subacute care and rehabilitation wards in a university hospital in France. A poster associating an image of eyes looking at the reader with a summary of blood culture sampling guidelines was displayed in hospital wards in the intervention group. The incidence rate of blood cultures per 1000 days during pre- and post-intervention periods was calculated., Results: Thirty-one wards participated in the study. The median difference in blood cultures/1000 days between periods was -1.863 [-11.941; 1.007] in the intervention group and -5.824 [-14.763; -2.217] in the control group (P=0.27)., Conclusion: The intervention did not show the expected effect, possibly due to the choice of blood cultures as a target of good practice, but also to confounding factors such as the stringent policy of decreasing unnecessary costly testing., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
14. An overview of mosquito vectors of Zika virus.
- Author
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Boyer S, Calvez E, Chouin-Carneiro T, Diallo D, and Failloux AB
- Subjects
- Aedes classification, Aedes physiology, Aedes virology, Animals, Communicable Diseases, Emerging epidemiology, Communicable Diseases, Emerging transmission, Communicable Diseases, Emerging virology, Disease Outbreaks, Geography, Humans, Mosquito Vectors classification, Zika Virus pathogenicity, Zika Virus Infection virology, Mosquito Vectors physiology, Mosquito Vectors virology, Zika Virus isolation & purification, Zika Virus Infection epidemiology, Zika Virus Infection transmission
- Abstract
The mosquito-borne arbovirus Zika virus (ZIKV, Flavivirus, Flaviviridae), has caused an outbreak impressive by its magnitude and rapid spread. First detected in Uganda in Africa in 1947, from where it spread to Asia in the 1960s, it emerged in 2007 on the Yap Island in Micronesia and hit most islands in the Pacific region in 2013. Subsequently, ZIKV was detected in the Caribbean, and Central and South America in 2015, and reached North America in 2016. Although ZIKV infections are in general asymptomatic or causing mild self-limiting illness, severe symptoms have been described including neurological disorders and microcephaly in newborns. To face such an alarming health situation, WHO has declared Zika as an emerging global health threat. This review summarizes the literature on the main vectors of ZIKV (sylvatic and urban) across all the five continents with special focus on vector competence studies., (Copyright © 2018 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)
- Published
- 2018
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15. Risk of maritime introduction of plague from Madagascar to Mayotte.
- Author
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Rahelinirina S, Harimalala M, Margueron T, Ramihangihajason T, Mansotte F, Rajerison M, Pagès F, and Boyer S
- Subjects
- Animals, Comoros epidemiology, Humans, Madagascar epidemiology, Rats, Rodentia parasitology, Disease Vectors, Insect Vectors microbiology, Plague epidemiology, Plague transmission, Rodent Diseases epidemiology, Siphonaptera microbiology, Yersinia pestis isolation & purification
- Abstract
Plague is a rodent-borne disease caused by Yersinia pestis. Most human infections are bubonic plague, as a result of being bitten by infected rodent fleas. Madagascar, Democratic Republic of Congo and Peru are the three most affected countries. Plague was introduced into eastern Madagascar in 1898 by boat from India. It is estimated that the risk of introduction of plague from Madagascar to neighboring islands is very high due to the maritime links. We conducted a study of plague reservoirs and vectors in Longoni Port in Mayotte and Mahajanga Port in Madagascar during two seasons to highlight a non-negligible risk of introduction of Y. pestis to Mayotte. The results showed that two main reservoirs of plague in Madagascar Suncus murinus and Rattus rattus and the main flea vector Xenopsylla cheopis exists in and surrounding the port of Longoni. Y. pestis was isolated from Rattus norvegicus captured close to the port of Mahajanga during this study. Plague bacteria circulate within populations of rodent without causing rodent die-off in Mahajanga. The risk of introduction of plague from Madagascar to Mayotte exists due to the regular exchanges. Continuous surveillance of rat, shrew and flea populations is therefore necessary in all the surrounding countries that have regular exchanges with Madagascar to prevent the spread of the plague., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
16. Beta-lactam resistance among Enterobacteriaceae in Cambodia: The four-year itch.
- Author
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Caron Y, Chheang R, Puthea N, Soda M, Boyer S, Tarantola A, and Kerléguer A
- Subjects
- Adult, Cambodia, Disk Diffusion Antimicrobial Tests, Enterobacteriaceae enzymology, Enterobacteriaceae Infections microbiology, Escherichia coli enzymology, Escherichia coli isolation & purification, Escherichia coli Infections microbiology, Humans, Klebsiella pneumoniae enzymology, Klebsiella pneumoniae isolation & purification, Microbial Sensitivity Tests, Retrospective Studies, beta-Lactamases genetics, beta-Lactamases metabolism, Anti-Bacterial Agents pharmacology, Enterobacteriaceae drug effects, beta-Lactam Resistance, beta-Lactams pharmacology
- Abstract
Although antibiotics are too often used inappropriately in Cambodia, published data on antimicrobial resistance in this country are scarce. Epidemic dissemination and the transfer of resistance genes to other bacterial species put the population at risk. The aim of this study was to evaluate the frequency and characteristics of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) isolated in consecutive samples tested at Institut Pasteur du Cambodge over a 4-year period (2012-2015). Antimicrobial susceptibility testing was performed by disk diffusion on agar technique and the results were read automatically using an OSIRIS system. The Etest was used to determine minimum inhibitory concentrations (MIC) for some resistance phenotypes. The strain most commonly identified was Escherichia coli (63.9%). The proportion of ESBL-E increased gradually over the study period, from 23.8% to 38.4%. ESBL was detected in 42.7% of the E. coli strains and 33.7% of all Klebsiella pneumoniae isolated. The proportion of ESBL-producing E. coli increased significantly from 28.9% in 2012 to 48.2% in 2015, while the increase for K. pneumoniae remained non-significant. Multidrug resistance was high in this Cambodian series, with some strains displaying resistance to all antibiotics available in the country. There is currently no established system for the surveillance of antimicrobial resistance in Cambodia. Collecting samples from clinical settings throughout the country is critical to assess the impact of antimicrobial drug use in patients in Cambodia and in the Mekong Region., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
17. Identifying the drivers of abundance and size of the invasive ctenophore Mnemiopsis leidyi in Northwestern Mediterranean lagoons.
- Author
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Delpy F, Albouy-Boyer S, Pagano M, Thibault D, Blanchot J, Guilhaumon F, Molinero JC, and Bonnet D
- Subjects
- Animals, Chlorophyll analysis, Chlorophyll A, Mediterranean Sea, Salinity, Ctenophora physiology, Environmental Monitoring, Introduced Species
- Abstract
Acknowledged as among the worst invasive marine species, Mnemiopsis leidyi has spread through European Seas since the mid-1980's. Here we report a bimonthly survey conducted in 2010-11 in three lagoons (Bages-Sigean, Thau and Berre) and at two adjacent coastal stations (Sète and SOMLIT-Marseille) along the French Mediterranean coast. M. leidyi was present only in Berre and Bages-Sigean with maximum abundances observed in late summer. M. leidyi adults were present year round in Berre with the largest organisms (∼6 cm) observed in April. In Bages-Sigean, they occurred in sufficient abundance to be recorded by fishermen between August and November. Multiple linear regressions highlighted that abundance in both lagoons was mainly influenced by direct effects of salinity and chlorophyll-a, and temperature to a lesser extent. While M. leidyi has not yet been recorded in Thau, the lagoon is continually monitored to detect the potential establishment of M. leidyi., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
18. A penicillin- and metronidazole-resistant Clostridium botulinum strain responsible for an infant botulism case.
- Author
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Mazuet C, Yoon EJ, Boyer S, Pignier S, Blanc T, Doehring I, Meziane-Cherif D, Dumant-Forest C, Sautereau J, Legeay C, Bouvet P, Bouchier C, Quijano-Roy S, Pestel-Caron M, Courvalin P, and Popoff MR
- Subjects
- Botulinum Toxins analysis, Botulism drug therapy, Botulism pathology, Feces chemistry, Feces microbiology, Female, Genes, Regulator, Genome, Bacterial, Humans, Infant, Membrane Transport Proteins genetics, Microbial Sensitivity Tests, Multigene Family, Penicillinase genetics, Penicillinase isolation & purification, Penicillinase metabolism, Sequence Analysis, DNA, Anti-Bacterial Agents pharmacology, Botulism diagnosis, Botulism microbiology, Clostridium botulinum drug effects, Clostridium botulinum isolation & purification, Drug Resistance, Bacterial, Metronidazole pharmacology, Penicillins pharmacology
- Abstract
The clinical course of a case of infant botulism was characterized by several relapses despite therapy with amoxicillin and metronidazole. Botulism was confirmed by identification of botulinum toxin and Clostridium botulinum in stools. A C. botulinum A2 strain resistant to penicillins and with heterogeneous resistance to metronidazole was isolated from stool samples up to 110 days after onset. Antibiotic susceptibility was tested by disc agar diffusion and MICs were determined by Etest. Whole genome sequencing allowed detection of a gene cluster composed of blaCBP for a novel penicillinase, blaI for a regulator, and blaR1 for a membrane-bound penicillin receptor in the chromosome of the C. botulinum isolate. The purified recombinant penicillinase was assayed. Resistance to β-lactams was in agreement with the kinetic parameters of the enzyme. In addition, the β-lactamase gene cluster was found in three C. botulinum genomes in databanks and in two of 62 genomes of our collection, all the strains belonging to group I C. botulinum. This is the first report of a C. botulinum isolate resistant to penicillins. This stresses the importance of antibiotic susceptibility testing for adequate therapy of botulism., (Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
19. Seasonal variation in size estimates of Aedes albopictus population based on standard mark-release-recapture experiments in an urban area on Reunion Island.
- Author
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Gouagna LC, Dehecq JS, Fontenille D, Dumont Y, and Boyer S
- Subjects
- Animals, Environment, Female, Male, Models, Theoretical, Reunion, Aedes physiology, Population Density, Seasons
- Abstract
The implementation of the sterile insect technique for area-wide vector control requires that natural population density be accurately estimated to determine both the appropriate time to treat and the adequate number of sterile males for release. Herein, we used mark-release-recapture (MRR) to derive seasonal abundance estimates of Aedes albopictus population sizes within a delimited geographical area in Reunion Island. Population size of Ae. albopictus was estimated through four mark-release-recapture experiments carried out separately in different seasons. Marked males and females were released each time, and recaptured using BG sentinel traps for six consecutive days. Data were used to estimate the population size using a conceptual model that incorporates the variation in daily mortality rates. The likely influence of environmental factors on the magnitude of catches and on population fluctuation was analyzed. A total of 2827 mosquitoes (1914 males and 913 females) were marked and released on four occasions during dry and wet seasons. After release, 138 males (7.21%) and 86 females (9.41%) of the marked specimens were recaptured in subsequent samplings. The effectiveness of the daily captures of wild and released mosquitoes was significantly influenced by meteorological conditions such as temperature, rainfall, wind speed and light intensity. The estimates of Ae. albopictus population size obtained with our model estimator ranged from 298 to 1238 males and 604 to 2208 females per ha, with seasonal variability - higher population size in the humid season. The presented results will be essential in designing more effective sterile male release strategies for long-term suppression of wild Ae. albopictus populations., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
20. Introducing conformal prediction in predictive modeling for regulatory purposes. A transparent and flexible alternative to applicability domain determination.
- Author
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Norinder U, Carlsson L, Boyer S, and Eklund M
- Subjects
- Drug and Narcotic Control methods, Forecasting, Quantitative Structure-Activity Relationship, Databases, Factual, Drug and Narcotic Control legislation & jurisprudence, Models, Theoretical, Molecular Conformation
- Abstract
Conformal prediction is presented as a framework which fulfills the OECD principles on (Q)SAR. It offers an intuitive extension to the application of machine-learning methods to structure-activity data where focus is on predictions with pre-defined confidence levels. A conformal predictor will make correct predictions on new compounds corresponding to a user defined confidence level. The confidence level can be altered depending on the situation the predictor is being used in, which allows for flexibility and adaption to risks that the user is willing to take. We demonstrate the usefulness of conformal prediction by applying it to 2 publicly available CAESAR binary classification datasets., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
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21. When mothers anticipate: effects of the prediapause stage on embryo development time and of maternal photoperiod on eggs of a temperate and a tropical strains of Aedes albopictus (Diptera: Culicidae).
- Author
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Lacour G, Vernichon F, Cadilhac N, Boyer S, Lagneau C, and Hance T
- Subjects
- Aedes physiology, Animals, Embryo, Nonmammalian physiology, Embryonic Development, Female, Ovum growth & development, Ovum physiology, Aedes embryology, Diapause, Insect, Photoperiod
- Abstract
Background: The diapause of Aedes albopictus is maternally induced by photoperiod and initiates at the pharate larvae stage in eggs. This pre-diapause results in enhanced survival eggs during the winter. This study aims to disentangle the effects of photoperiod and diapause on embryonic developmental time and egg size in A. albopictus. A temperate strain capable to perform diapause and a tropical strain unable of diapause were reared at 21°C with long-(LD) and short-day (SD) lengths. Four distinct traits were studied on embryos and eggs were measured at the end of embryogenesis., Results: The chronologies of embryo development for both strains were influenced by maternal photoperiod, especially in the temperate strain in which the development of SD eggs took longer than LD eggs. The delay increased gradually in the temperate strain, and reached up to 38 h at the end of embryogenesis. The kinetics of embryogenesis differed among the temperate and the tropical strains, each one of the 4 studied traits showing differences. For example the serosal cuticle was secreted precociously in the tropical strain. Egg width and volume are influenced by the maternal photoperiod and the strain×photoperiod interaction. For both strains, larger eggs were laid by female reared under SD when compared to LD., Conclusions: The influence of several maternal effects was demonstrated in this study. The diapause process modifies greatly the length of embryogenesis in the temperate strain, whereas the maternal photoperiod has a direct influence on egg size and embryogenesis regardless of the strain considered. These findings provide useful data on chronology of embryonic development for integrative biology studies of egg pre-diapause stages., (Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2014
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- View/download PDF
22. Sugar-source preference, sugar intake and relative nutritional benefits in Anopheles arabiensis males.
- Author
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Gouagna LC, Kerampran R, Lebon C, Brengues C, Toty C, Wilkinson DA, Boyer S, and Fontenille D
- Subjects
- Animals, Male, Anopheles physiology, Carbohydrates, Feeding Behavior
- Abstract
Plant-derived sugar is the only source of dietary carbohydrate for males of most mosquito species. Male resource acquisition and utilization remain an under-researched area of behavior in vectors of human diseases. However, the renewed interest in the use of sterile males against disease vector mosquitoes reinforces the urgent need for studies on the behavioral and ecological processes that underpin male fitness and reproductive success. Here an attempt was made first to characterize the conditions and modes of resource acquisition (plant derived sugar meals) early in the life of An. arabiensis males, and second to test the hypothesis that the plants chosen for their sugar meals are those which maximize their fitness in terms of energy gains (i.e. amount of lipids, proteins, glycogen and glucose). Olfactometry assays demonstrated the ability of An. arabiensis males to discriminate among a sample of ten abundant flowering plants present in their natural habitats. In further experiments, we observed significant variations in the sugar intake rates that matched their olfactory preferences, with the most attractive plants eliciting significantly higher sugar intake rates. Consistent with our expectations, analyses of the whole-body free sugars, lipids and glycogen unequivocally showed that the energy reserve accumulated post-feeding is dependent on the diet of the adult males, with the preferred plants providing more energy reserves than the less preferred ones, despite mosquitoes actively feeding on both. Taken together, these results show that An. Arabiensis males are able to discern between food sources, preferentially feeding on those species of plant that provide the highest metabolic payoff. Ensuring or somehow heightening the ability to detect and obtain rewarding sugar meals by male mosquitoes reared for field release could enhance their competitive ability in the field., (Copyright © 2013 International Atomic Energy Agency 2013. Published by Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
23. Urinary tract infections in hospital pediatrics: many previous antibiotherapy and antibiotics resistance, including fluoroquinolones.
- Author
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Garraffo A, Marguet C, Checoury A, Boyer S, Gardrat A, Houivet E, and Caron F
- Subjects
- Adolescent, Child, Child, Preschool, Female, Hospitals, Humans, Infant, Infant, Newborn, Male, Prospective Studies, Anti-Bacterial Agents therapeutic use, Drug Resistance, Bacterial, Fluoroquinolones therapeutic use, Urinary Tract Infections drug therapy, Urinary Tract Infections microbiology
- Abstract
Objective: We studied antibiotic resistance in pediatric UTIs and we evaluated the impact of antibiotic exposure in the previous 12 months, very little French data being available for this population., Methods: We conducted a multicenter prospective study including children consulting for, or admitted in 2 hospitals. Prior antibiotic exposure was documented from their health record., Results: One hundred and ten patients (73 girls), 11 days to 12 years of age, were included in 10 months. Ninety-six percent presented with pyelonephritis, associated to uropathy for 25%. Escherichia coli was predominant (78%), followed by Proteus spp. and Enterococcus spp. The antibiotic resistance rate of E. coli was high and close to that reported for adults with complicated UTIs: amoxicillin 60%, amoxicillin-clavulanate 35%, cefotaxim 5%, trimethoprim-sulfametoxazole 26%, nalidixic acid 9%, ciprofloxacin 7%, gentamycin 1%, nitrofurantoin and fosfomycin 0%. The antibiotic exposure in the previous 12 months involved 62 children (56%) most frequently with β-lactams (89%) for a respiratory tract infection (56%). A clear relationship between exposure and resistance was observed for amoxicillin (71% vs. 46%), first generation (65% vs. 46%) and third generation (9% vs. 3%) cephalosporins, or trimethoprim-sulfamethoxazole (36% vs. 15%). However, antibiotic exposure could not account alone for the results, as suggested by the 7% of ciprofloxacin resistance, observed without any identified previous treatment., Conclusion: Bacterial species and antibiotic resistance level in children are similar to those reported for adults. Antibiotic exposure in the previous 12 months increases the risk of resistance but other factors are involved (previous antibiotic therapies and fecal-oral or mother-to-child transmission)., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
24. Use of in silico systems and expert knowledge for structure-based assessment of potentially mutagenic impurities.
- Author
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Sutter A, Amberg A, Boyer S, Brigo A, Contrera JF, Custer LL, Dobo KL, Gervais V, Glowienke S, van Gompel J, Greene N, Muster W, Nicolette J, Reddy MV, Thybaud V, Vock E, White AT, and Müller L
- Subjects
- Computer Simulation, DNA Damage, Drug Contamination, Drug Industry methods, Quantitative Structure-Activity Relationship, Mutagenicity Tests methods, Mutagens chemistry, Mutagens toxicity
- Abstract
Genotoxicity hazard identification is part of the impurity qualification process for drug substances and products, the first step of which being the prediction of their potential DNA reactivity using in silico (quantitative) structure-activity relationship (Q)SAR models/systems. This white paper provides information relevant to the development of the draft harmonized tripartite guideline ICH M7 on potentially DNA-reactive/mutagenic impurities in pharmaceuticals and their application in practice. It explains relevant (Q)SAR methodologies as well as the added value of expert knowledge. Moreover, the predictive value of the different methodologies analyzed in two surveys conveyed in the US and European pharmaceutical industry is compared: most pharmaceutical companies used a rule-based expert system as their primary methodology, yielding negative predictivity values of ⩾78% in all participating companies. A further increase (>90%) was often achieved by an additional expert review and/or a second QSAR methodology. Also in the latter case, an expert review was mandatory, especially when conflicting results were obtained. Based on the available data, we concluded that a rule-based expert system complemented by either expert knowledge or a second (Q)SAR model is appropriate. A maximal transparency of the assessment process (e.g. methods, results, arguments of weight-of-evidence approach) achieved by e.g. data sharing initiatives and the use of standards for reporting will enable regulators to fully understand the results of the analysis. Overall, the procedures presented here for structure-based assessment are considered appropriate for regulatory submissions in the scope of ICH M7., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
25. Effects of irradiation, presence of females, and sugar supply on the longevity of sterile males Aedes albopictus (Skuse) under semi-field conditions on Reunion Island.
- Author
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Oliva CF, Maier MJ, Gilles J, Jacquet M, Lemperiere G, Quilici S, Vreysen MJ, Schooneman F, Chadee DD, and Boyer S
- Subjects
- Aedes physiology, Animals, Feeding Behavior radiation effects, Female, Longevity radiation effects, Male, Reunion, Sexual Behavior, Animal radiation effects, Aedes radiation effects, Carbohydrates supply & distribution
- Abstract
Background: The development of the sterile insect technique (SIT) for reducing populations of Aedes albopictus (Skuse), (the vector of Chikungunya and Dengue fever), was studied in Reunion Island. For some mosquito species the sterilization process and mating activity may alter male survival. Most previous studies were carried out in the laboratory and may inadequately reflect the field situation. We conducted a semi-field experiment to evaluate the impact of sugar supply and mating activity under natural climatic conditions on wild and sterile male Ae. albopictus longevity, using large cages set up in an open clearing between trees and shrubs in Reunion Island., Results: Wild males had a mean longevity of 15.5 days in the absence of females and with an immediate sugar supply; longevity in sterile males was similar. The presence of females greatly reduced both wild and especially sterile male lifespan; however, an immediate sugar supply could counteract this effect and allow sterile males to live an average of 11.6 days., Conclusion: The outcomes indicate that sugar feeding could compensate for sterilization-induced damage, and that mating activity is not deleterious for well-fed males. This study stresses the critical importance of providing suitable sugar sources prior to release during SIT programmes., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
26. Use of benchtop exactive high resolution and high mass accuracy orbitrap mass spectrometer for screening in horse doping control.
- Author
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Moulard Y, Bailly-Chouriberry L, Boyer S, Garcia P, Popot MA, and Bonnaire Y
- Subjects
- Animals, Horses, Hydrocortisone isolation & purification, Software, Chromatography, High Pressure Liquid methods, Doping in Sports, Hydrocortisone urine, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
Liquid chromatography-mass spectrometry (LC-MS) has been widely used in doping control laboratories over the last two decades. Currently, simple quadrupole, triple quadrupole and ion trap are the most commonly employed analyzers in toxicological analysis. Nevertheless, the main lack of these technologies is the restricted number of target compounds simultaneously screened without loss of sensitivity. In this article we present an innovative screening approach routinely applied in the French horse doping control laboratory based on high resolution (50000) and high mass accuracy (<5 ppm) in full scan MS mode for more than 235 target analytes screened from an initial volume of 5 mL of urine. The sample preparation was classically founded on solid phase extraction by means of reverse phase C18 cartridges. LC-MS analyses were carried out on a Shimadzu binary HPLC pumps linked to a C18 Sunfire column associated with the high resolution exactive benchtop orbitrap mass spectrometer. This screening was performed alternatively in positive-negative ionization mode during the same run. Thus, the identification of compounds of interest was made using their exact mass in positive-negative ionization mode at their expected retention time. All data obtained were processed by ToxID software (ThermoFisherScientific) which is able to identify a molecule by theoretical mass and retention time. In order to illustrate this innovative technology applied in our laboratory, sample preparation, validation data performed on 20 target compounds from 16 different horse urine samples, chromatograms and spectra will be discussed in this paper., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2011
- Full Text
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27. [Incidence and microbiology of infectious complications with the use of artificial skin Integra in burns].
- Author
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Bargues L, Boyer S, Leclerc T, Duhamel P, and Bey E
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Emergency Service, Hospital, France epidemiology, Humans, Incidence, Infant, Pneumonia, Bacterial epidemiology, Pneumonia, Bacterial microbiology, Pseudomonas aeruginosa isolation & purification, Retrospective Studies, Risk Factors, Staphylococcus aureus isolation & purification, Surgical Wound Infection prevention & control, Burns complications, Burns surgery, Chondroitin Sulfates adverse effects, Collagen adverse effects, Plastic Surgery Procedures methods, Surgical Wound Infection epidemiology, Surgical Wound Infection microbiology
- Abstract
Integra dermal substitute is used as biomaterial after thermal injury. This artificial skin allows temporary coverage after burns excision, transformation of matrix in neo dermis and definitive engraftment. Infections are the most common complication of this technique. The objectives were to evaluate incidence of sepsis, to analyse microbiology and risk factors of developing Integra infections. Patients with acute burns and indications of Integra during five years were retrospectively enrolled. Demographic data, surgical procedures and microbiologic biopsies were collected. Fifty patients (40 + or - 15 years) were studied and 71 surgical procedures using Integra were performed. Burns were extended 45 + or - 21% total body surface area. Placement of Integra was made 15 + or - 11 days after burns and autografts 31 + or - 9 days after placement of Integra. Twenty-one patients had infected Integra (42% of population). A total of 23 Integra infected sites were observed (15 local and eight invasive). Diagnosis of infection was made after 13 + or - 5 days using quantitative cultures. Other sites of infection were respiratory tract (46 pneumonias) and others burned wounds (17 infections outside of Integra. Any risk factor was identified between burns who developed Integra infections and the others. Incidence of infected Integra was higher than in previous studies. Delayed application of Integra after burns could explain higher incidence of infection. Pseudomonas aeruginosa and Staphylococcus aureus were more frequently isolated than other pathogens. Standardized technique for wounds coverage with Integra is necessary to reduce incidence of infections and improve functional results in burns patients.
- Published
- 2009
- Full Text
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28. [Pregnancy and lung cancer: a case report and review of the literature].
- Author
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Montilla F, Le Caer H, Boyer S, Diquelou JY, Amar P, and Le Saux S
- Subjects
- Adult, Cesarean Section, Fatal Outcome, Female, Humans, Infant, Newborn, Lung Neoplasms pathology, Pancoast Syndrome pathology, Pregnancy, Pregnancy Complications, Neoplastic pathology, Prognosis, Risk Factors, Lung Neoplasms complications, Pancoast Syndrome complications, Pregnancy Complications, Neoplastic etiology, Pregnancy Outcome
- Abstract
Lung cancer is a frequent pathology among women, as a result of tobacco increase. Lung cancer among pregnant women is especially rare when revealed by Pancoast-Tobias syndrome. Foetal injury is possible. The approach is multidisciplinary. Prognosis is bad.
- Published
- 2008
- Full Text
- View/download PDF
29. [Emergence of extended-spectrum beta-lactamases in Pseudomonas aeruginosa: about 24 cases at Rouen University Hospital].
- Author
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David M, Lemeland JF, and Boyer S
- Subjects
- Bacterial Proteins genetics, Cefepime, Ceftazidime pharmacology, Cephalosporins pharmacology, Cross Infection epidemiology, DNA, Bacterial genetics, France epidemiology, Hospital Departments statistics & numerical data, Humans, Polymerase Chain Reaction, Pseudomonas Infections epidemiology, Pseudomonas aeruginosa drug effects, Pseudomonas aeruginosa genetics, Pseudomonas aeruginosa isolation & purification, Random Amplified Polymorphic DNA Technique, Retrospective Studies, Substrate Specificity, beta-Lactamases genetics, Bacterial Proteins analysis, Cross Infection microbiology, Hospitals, University statistics & numerical data, Pseudomonas Infections microbiology, Pseudomonas aeruginosa enzymology, beta-Lactam Resistance genetics, beta-Lactamases analysis
- Abstract
Aim of the Study: This retrospective study was conducted in order to characterize mechanisms of resistance to beta-lactams and clonality of 24 isolates of Pseudomonas aeruginosa. These strains were isolated from patients hospitalized in Rouen University Hospital between August 2004 and December 2006 and were resistant to cefepime and/or ceftazidime (PMR) by a mechanism not only related to overproduction of the cephalosporinase., Patients and Methods: Clinical strains of PMR were characterized by conventional biochemical methods, antibiotic susceptibility testing by disk diffusion in agar with or without cloxacillin and RAPD for genetic comparison. Identification of beta-lactamase was performed by PCR amplification followed by sequencing of bla genes., Results: All strains produced the extended-spectrum beta-lactamase (ESBL) TEM-116. Epidemiological study identified eight unrelated strains, eight related strains originating from a single unit, three related strains isolated in different wards and five related strains coproducing TEM-116 and SHV-2a but isolated in different units. Detection of ESBL in these strains was difficult due to a low level of ESBL production., Conclusion: This is the first report of TEM-116 in France in 24 strains of P. aeruginosa and its association with SHV-2a in five cases. SHV-2a has been described in P. aeruginosa in France but not TEM-116 which was recently reported in this species, in China and in Netherlands (in a strain coproducing SHV-12). ESBL detection in PMR remains indispensable since these strains can cause therapeutic failures.
- Published
- 2008
- Full Text
- View/download PDF
30. [Clinical and psychological disorders of pregnant women induced by abuse].
- Author
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Diquelou JY, Amar P, Boyer S, Montilla F, and Karoubi R
- Subjects
- Adult, Anorexia epidemiology, Educational Status, Female, France epidemiology, Humans, Menstruation Disturbances epidemiology, Mental Disorders epidemiology, Occupations, Pregnancy, Pregnancy Complications epidemiology, Sexual Dysfunction, Physiological epidemiology, Sexual Dysfunctions, Psychological epidemiology, Surveys and Questionnaires, Domestic Violence psychology, Domestic Violence statistics & numerical data
- Abstract
This study is performed on a population of pregnant women during the second trimester of their pregnancy. The aim of this study is to demonstrate that clinical symptoms noticeable by the obstétricians during their consultations. Eight hundred and fifty-three patients have been involved in this study by responding to an anonymous questionnary. Hundred and seventy-five patients(groupI) have been abuse either physically or psychologically or sexually. The study shows that there is a strong difference between the groupI and the group without abuse in their medical past history (678 patients) about the occurracy of several disorders. The most frequently observed troubles are sexuals disorders, school failures, deficients relationship with others persons, anxiety and troubles of humor. We can concluded, about those clinical manifestations, that they do exist during pregnancy and probably thoses symptoms are linked to traumatism occured during their past history. Obstetricians must look after thoses symptoms very seriously to propose a good management of the pregnancy either about their psychological problems or about the social environnement in which they live.
- Published
- 2008
- Full Text
- View/download PDF
31. [Primary breast lymphoma during pregnancy: a case report].
- Author
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Montilla F, Grolier F, Gholam D, Diquelou JY, Amar P, Boyer S, and Karoubi R
- Subjects
- Adult, Breast Neoplasms drug therapy, Breast Neoplasms radiotherapy, Diagnosis, Differential, Female, Humans, Lymphoma drug therapy, Lymphoma radiotherapy, Pregnancy, Pregnancy Complications, Neoplastic drug therapy, Pregnancy Complications, Neoplastic radiotherapy, Prognosis, Antineoplastic Agents therapeutic use, Breast Neoplasms diagnosis, Lymphoma diagnosis, Pregnancy Complications, Neoplastic diagnosis
- Abstract
Primary breast lymphoma is a difficult diagnosis because it is very rare. It can be found during pregnancy. Its diagnosis is often delayed. Treatment combines radiotherapy and chemotherapy. Prognosis is generally bad. Therefore, it is most important to examine breasts during pregnancy.
- Published
- 2007
- Full Text
- View/download PDF
32. Detection of testosterone propionate administration in horse hair samples.
- Author
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Boyer S, Garcia P, Popot MA, Steiner V, and Lesieur M
- Subjects
- Animals, Horses, Testosterone Propionate administration & dosage, Doping in Sports, Gas Chromatography-Mass Spectrometry methods, Hair chemistry, Substance Abuse Detection methods, Testosterone Propionate analysis
- Abstract
A sensitive and specific method has been developed to detect semi-quantitatively testosterone in horse hair samples. The method involved a washing step with sodium dodecylsulfate aqueous solution. The mane and tail hair samples (100mg) were dissolved in 1 mL of sodium hydroxide for 15 min at 95 degrees C in the presence of d3-boldenone used as internal standard. The next three steps involved diethyl ether extraction and a solid phase extraction on Isolute C18 (EC) cartridges eluted with methanol. The residue was derivatized by adding 100 microL of acetonitrile and 30 microL of PFPA then incubating for 15 min at 60 degrees C. After evaporation, 30 microL of hexane was added and 2.5 microL was injected into the column (a bonded phase fused silica capillary column DB5MS, 30 m x 0.25 mm i.d. x 0.25 microm film thickness) of a Trace GC chromatograph. In order to improve the sensitivity of the method, damping gas flow has been optimized. Testosterone was identified in MS(2) full scan mode on the Polaris Q instrument. The assay was capable of detecting less than 1 pg mg(-1). The recovery was close to 90%. The analysis of tail and mane samples collected from a gelding horse having received a single dose of testosterone propionate (1 mg kg(-1)) showed the presence of testosterone in the range of 1-6 pg mg(-1) in hair collected during 5 months after administration.
- Published
- 2007
- Full Text
- View/download PDF
33. [Heterotopic pregnancy: a case report with a rare symptomatology].
- Author
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Montilla F, Amar P, Boyer S, Karoubi R, and Diquelou JY
- Subjects
- Adult, Female, Humans, Laparoscopy, Pregnancy, Pregnancy, Ectopic epidemiology, Pregnancy, Ectopic etiology, Pregnancy, Ectopic surgery, Prognosis, Fallopian Tubes surgery, Pregnancy, Ectopic diagnosis, Reproductive Techniques, Assisted adverse effects
- Abstract
Heterotopic pregnancy was a rare pathology many years ago, but its survey is more frequently observed during last years with Assisted Reproduction Technics. We report a case of a heterotopic pregnancy with a rare symptomatology, with in the front plan a miscarriage. It's diagnostic is difficult and occurred very late. The main treatment consists to perform a salpingotomy under laparoscopy. However laparotomy treatment is frequently performed in relation to the late time of diagnosis.
- Published
- 2007
- Full Text
- View/download PDF
34. Differential expression patterns of type I interferon subtypes in mouse embryo fibroblasts: influence of genotype and viral inducer.
- Author
-
Lai MC, Yeow WS, Boyer SJ, and Beilharz MW
- Subjects
- Animals, Base Sequence, Chick Embryo, Cytomegalovirus growth & development, Drug Stability, Embryo, Mammalian, Female, Fibroblasts physiology, Genotype, Hydrogen-Ion Concentration, Interferon Type I genetics, Interferon-beta biosynthesis, Interferon-beta classification, Interferon-beta genetics, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Mice, Inbred CBA, Molecular Sequence Data, Newcastle disease virus growth & development, Polymerase Chain Reaction, RNA-Directed DNA Polymerase, Virus Activation, Fibroblasts metabolism, Fibroblasts virology, Interferon Type I biosynthesis, Interferon Type I classification
- Abstract
Primary mouse embryo fibroblasts from 4 strains of mice (BALB/c, C57Bl/6, B6.C-H-28c and CBA) were infected with either Newcastle disease virus or murine cytomegalovirus. The time course of the total type I interferon response was assessed and the presence of individual subtypes determined. The total type I interferon produced was titrated using the cytopathic effect reduction assay and the relative levels of type I interferon subtypes expressed (alpha 1, alpha 4, alpha 5, alpha 6 and beta) were evaluated using a reverse transcription-polymerase chain reaction-based technique. In general, the patterns of type I interferon subtypes expressed appeared to be determined by the strain of mouse cells used rather than the inducing virus. However, the overall titre of type I interferons produced in response to a given virus was quite uniform across the strains of mice from which the mouse embryo fibroblasts were derived regardless of the subtype expression pattern. The latter observation fits the proposition that "cross-talk" or feedback between the type I interferon genes and their products is is occurring and that the inducer determines the level of response.
- Published
- 1994
- Full Text
- View/download PDF
35. Molecular detection and identification of type I interferon mRNAs.
- Author
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Lai MC, Boyer SJ, and Beilharz MW
- Subjects
- Animals, Base Sequence, Interferon Type I genetics, L Cells, Mice, Molecular Sequence Data, Newcastle disease virus physiology, Nucleic Acid Hybridization, Polydeoxyribonucleotides chemical synthesis, RNA, Messenger genetics, RNA-Directed DNA Polymerase, Sensitivity and Specificity, Interferon Type I biosynthesis, Polymerase Chain Reaction methods, RNA, Messenger isolation & purification
- Abstract
The development of a technique for identifying murine type I interferon messenger RNAs is described that involves the following essential steps: (a) the reverse transcription of total RNA extracts using oligo(dT)12-18 as a primer, (b) the amplification of any type I interferon cDNAs produced by polymerase chain reaction, and (c) the identification of interferon subtypes by hybridization of the polymerase chain reaction products to specific oligonucleotides. The technique was used to characterize the expression of the mouse interferon subtypes alpha 1, alpha 4, alpha 5, alpha 6, and beta in murine L929 cells that had been infected with Newcastle disease virus. The data derived from this study are in excellent agreement with earlier RNA protection experiments performed in the same system to characterize expression of the same genes. The present technique has advantages over those used previously, including superior sensitivity, speed, and far smaller input RNA requirements. The technique is not only applicable to other in vitro systems, but is appropriate for use in vivo.
- Published
- 1994
- Full Text
- View/download PDF
36. Diagnosis of mucopolysaccharidoses in a clinically selected population by urinary glycosaminoglycan analysis: a study of 2,000 urine samples.
- Author
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Piraud M, Boyer S, Mathieu M, and Maire I
- Subjects
- Adolescent, Adult, Aging urine, Child, Child, Preschool, Dermatan Sulfate urine, Electrophoresis, Female, Heparitin Sulfate urine, Humans, Infant, Infant, Newborn, Male, Mucopolysaccharidosis IV diagnosis, Mucopolysaccharidosis IV urine, Oligosaccharides urine, Reference Values, Glycosaminoglycans urine, Mucopolysaccharidoses diagnosis, Mucopolysaccharidoses urine
- Abstract
Two thousand urine samples (from patients presenting with clinical features suggestive of a mucopolysaccharidosis, MPS) were analysed by a procedure that included a quantitative measurement of glycosaminoglycan (GAG) hexuronic acids (harmine reagent), a qualitative GAG analysis (cellulose acetate electrophoresis) and a study of urinary oligosaccharide patterns. One hundred and seventy MPS and 29 oligosaccharidosis-affected patients were found, but 23 MPS patients among the 170 would have been missed by use of a quantitative procedure only. Fourteen of these (mainly MPS IV A) were detected on the basis of abnormal electrophoresis and the 9 others on the basis of abnormal urinary oligosaccharide patterns (MPS IV B patients). Our results emphasize that normal quantitative GAG excretion alone cannot rule out a diagnosis of MPS; qualitative analysis is also required, as well as oligosaccharide screening.
- Published
- 1993
- Full Text
- View/download PDF
37. Roles of erythropoietin, insulin-like growth factor 1, and unidentified serum factors in promoting maturation of purified murine erythroid colony-forming units.
- Author
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Boyer SH, Bishop TR, Rogers OC, Noyes AN, Frelin LP, and Hobbs S
- Subjects
- Animals, Blood, Cell Count, Cell Division, DNA metabolism, Erythroid Precursor Cells metabolism, Heme biosynthesis, Humans, Mice, Recombinant Proteins pharmacology, Erythroid Precursor Cells cytology, Erythropoietin pharmacology, Growth Substances pharmacology, Insulin-Like Growth Factor I pharmacology
- Abstract
We have used 75% to 90% pure murine erythroid colony-forming units (CFU-E) to delineate the processes and factors underlying their maturation. These CFU-E form 32 cell colonies and are drawn from what we term generation I of a six-generation long maturation sequence (Landschulz et al, Blood 79:2749, 1992). Applying assays of 59Fe-heme biosynthesis and colony numbers as measures of maturation and analyses of DNA degradation as an index of programmed cell death, we find that (1) erythropoietin (Epo) enhances maturation throughout most of its course; (2) Epo first seems able to forestall DNA degradation when CFU-E reach generation II; (3) the processes that Epo elicits thereafter start to persist when Epo is withdrawn; (4) insulin-like growth factor I (IGF-I) also forestalls DNA breakdown, but later loses effectiveness; (5) IGF-I adds little to maturation when Epo levels are high, but when Epo levels are low, enhances it substantially; and (6) for maturation to be entirely optimal, an unidentified serum factor(s) is probably required when Epo levels are high and is certainly needed when Epo levels are like those in normal animals. Quantitatively, about 40% of optimal in vitro erythropoiesis at normal Epo levels depends on Epo alone, another 30% or less on the addition of IGF-I, and the remaining 30% or more on the addition of unidentified serum factor(s). Applied together, these three or more factors lead to two-thirds of the maximum maturation realized with saturating Epo levels. Because we also find that heme accumulated in CFU-E culture can closely approach levels in red blood cells, we suppose that our conclusions apply as well to CFU-E maturation in vivo.
- Published
- 1992
38. Biological activities of recombinant murine interferons alpha 1 and alpha 4: large difference in antiproliferative effect.
- Author
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Swaminathan N, Lai CM, Beilharz MW, Boyer SJ, and Klinken SP
- Subjects
- Animals, Cell Division drug effects, Encephalomyocarditis virus drug effects, Interferon Type I classification, Killer Cells, Natural drug effects, L Cells drug effects, Leukemia, Erythroblastic, Acute drug therapy, Leukemia, Erythroblastic, Acute pathology, Mice, Mice, Inbred C3H, Recombinant Proteins, Tumor Cells, Cultured, Virus Replication drug effects, Growth Inhibitors pharmacology, Interferon Type I pharmacology
- Abstract
The mature forms of two recombinant murine interferons alpha, alpha 1 and alpha 4, have been expressed in vitro using an established transcription and translation system. The relative specific antiviral activity, antiproliferative activity and the natural killer cell stimulating activity of both subtypes were compared in vitro. While the antiviral and natural killer cell stimulating activities of the 2 subtypes were similar, the relative antiproliferative activities varied markedly. On the basis of equal molar inputs, MuIFN-alpha 1 had less than 8% of the antiproliferative activity of MuIFN-alpha 4. This data shows that a large functional difference exists between these two subtypes which are known to be expressed at different levels in mouse L-cells in vitro.
- Published
- 1992
- Full Text
- View/download PDF
39. Onset of erythropoietin response in murine erythroid colony-forming units: assignment to early S-phase in a specific cell generation.
- Author
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Landschulz KT, Boyer SH, Noyes AN, Rogers OC, and Frelin LP
- Subjects
- Animals, Cell Separation, Cells, Cultured, Colony-Forming Units Assay, Erythroid Precursor Cells drug effects, Erythropoietin metabolism, Kinetics, Mice, Receptors, Cell Surface metabolism, Receptors, Erythropoietin, Recombinant Proteins metabolism, Recombinant Proteins pharmacology, S Phase drug effects, Time Factors, Cell Cycle drug effects, Erythroid Precursor Cells cytology, Erythropoietin pharmacology
- Abstract
Murine erythroid colony-forming units (CFU-E) representing successive cell generations in a six-generation long in vitro maturation sequence were tested for their response to erythropoietin (Epo) by measurement of Epo-exposure times necessary to stimulate heme biosynthesis. Generation I CFU-E, which produce mainly 32-cell erythroid colonies, were isolated in 82% average purity from spleens of thiamphenicol-treated anemic animals via differential centrifugation. Generation II CFU-E, which produce mainly 16-cell colonies, were similarly isolated in 51% average purity. Although both types of CFU-E had equivalent dose sensitivity to and affinity for Epo, generation II CFU-E responded to shorter pulses of Epo than did generation I. Correlations between DNA cell-cycle profiles and 59Fe-heme biosynthesis resulting from pulsed exposures established that appreciable Epo response only begins when CFU-E attain early S-phase of generation II. Because CFU-E did not require Epo or other serum factors to pass from generation I to II and because the onset of Epo responsiveness coincided with the beginning of DNA replication in generation II, we suppose that differentiation has reprogrammed one or more of the events associated with generation II S-phase in CFU-E and that these alterations allow Epo to act. Further comparisons between CFU-E from generation I and II may allow us to identify the alterations in question and the nature of their interaction with Epo.
- Published
- 1992
40. Structure/function studies of murine interferon-alpha 1 using site-directed mutagenesis followed by in vitro synthesis.
- Author
-
Lai MC, Beilharz MW, Scalzo AA, Garrett KL, Cannon JF, Boyer SJ, and Swaminathan N
- Subjects
- Animals, Base Sequence, Cell Line, Cloning, Molecular, Interferon-alpha biosynthesis, Interferon-alpha chemistry, Interferon-alpha genetics, Lymphocyte Activation, Mice, Mice, Inbred C3H, Molecular Sequence Data, Mutagenesis, Site-Directed, Structure-Activity Relationship, Encephalomyocarditis virus physiology, Interferon-alpha pharmacology, Killer Cells, Natural immunology
- Abstract
Site-directed in vitro mutagenesis followed by in vitro transcription and translation has been used to study structure/function relationships for murine interferon-alpha 1 (MuIFN-alpha 1). The mature form of the MuIFN-alpha 1 protein was expressed as well as analogue forms with amino acid substitutions at positions 33, 71, 72, 123 and 133. These positions were chosen on the basis of known human interferon-alpha structure/function relationships. Biological assays for antiviral activity on murine cells and natural killer cell activation have been performed for each of the proteins produced. The data obtained have been interpreted in the light of previous human and murine interferon-alpha structure/function work and the recently published three-dimensional structure of murine type I interferon.
- Published
- 1992
- Full Text
- View/download PDF
41. Erythropoietin receptors on murine erythroid colony-forming units: natural history.
- Author
-
Landschulz KT, Noyes AN, Rogers O, and Boyer SH
- Subjects
- Animals, Cells, Cultured, Endocytosis, In Vitro Techniques, Membrane Proteins physiology, Mice, Mice, Inbred BALB C, Molecular Weight, Receptors, Erythropoietin, Temperature, Erythropoiesis, Erythropoietin physiology, Hematopoietic Stem Cells physiology, Receptors, Cell Surface physiology
- Abstract
Erythropoietin (Epo) response and binding was assessed in purified murine CFU-E and their descendants. Several features emerged. First, Epo on CFU-E is in rapid flux: Half-time for 125I-Epo internalization is approximately four to five minutes. Second, computer-aided Scatchard analyses indicate that greater than 70 high-affinity Epo-receptor sites on anemic animal CFU-E are sometimes already occupied by Epo acquired in vivo. When this is removed, 40% of greater than or equal to 370 sites per CFU-E belong to a high-affinity class (dissociation constant, kd: 73 pmol/L +/- 15 [SE]) and 60% belong to a low-affinity class (kd: 813 pmol/L +/- 246). Third, the few small colonies that develop from CFU-E in the absence of Epo are shown, by serial assay of 59Fe-heme biosynthesis, to stem from contaminating erythroblasts: a result consistent with our finding that, after eight-hour CFU-E culture, most erythroblasts no longer require appreciable Epo for growth. Thus, although the early need for Epo by CFU-E is nearly absolute, this need is not met by the often substantial Epo already on board. The inference is that repeated occupancy of the rapidly turning over Epo receptors is required. Fourth, Epo bound and/or internalized by CFU-E descendants decreases to 40% of zero-time levels after 14 hours in Epo-supplemented culture and disappears after 28 hours. Scatchard analyses indicate that 73 pmol/L kd receptor sites become undetectable at seven to eight hours, whereas 813 pmol/L kd sites are undiminished and only one-third less by 16 hours. This apparent disappearance of high-affinity sites and persistence of low-affinity sites suggests that (a) at least two gene products mediate Epo binding, eg, two different receptor polypeptides or one receptor and one cofactor which modulates affinity; (b) high-affinity sites mediate the growth function of Epo during the first eight hours of culture; and (c) lingering low-affinity receptors may mediate some unrecognized Epo function. Fifth, the efficiency with which 106- and 91-Kd CFU-E membrane polypeptides can be cross-linked to 125I-Epo is two- to threefold higher for cells labeled at high Epo concentrations than at low ones, which suggests that these polypeptides largely reflect low-affinity site reactions.
- Published
- 1989
42. 5-Azacytidine increases HbF production and reduces anemia in sickle cell disease: dose-response analysis of subcutaneous and oral dosage regimens.
- Author
-
Dover GJ, Charache S, Boyer SH, Vogelsang G, and Moyer M
- Subjects
- Administration, Oral, Adult, Anemia, Sickle Cell drug therapy, Anemia, Sickle Cell physiopathology, Drug Administration Schedule, Erythrocyte Count drug effects, Erythrocyte Indices, Erythropoiesis, Hemoglobins metabolism, Humans, Injections, Subcutaneous, Middle Aged, Pain drug therapy, Pain physiopathology, Reticulocytes classification, Reticulocytes metabolism, Anemia, Sickle Cell blood, Azacitidine administration & dosage, Fetal Hemoglobin biosynthesis
- Abstract
Varying doses of 5-azacytidine (5-aza) were given to four sickle cell individuals for 500, 200, 100, and 30 days. The percentage of fetal hemoglobin (HbF) containing reticulocytes (F reticulocytes) increased two- to five-fold within five days of 5-aza therapy in all patients, with a two- to three-fold rapid response (less than 48 hours after initial dose) in three patients. Reticulocyte suppression was not observed prior to, during, or after therapy in those patients who responded within 48 hours. Subcutaneous 5-aza was given in 35-day courses consisting of every day, every other day, or three consecutive days a week. No marrow toxicity was observed on any of the regimens. For three patients, the highest average F reticulocyte level was observed on the three consecutive day a week regimen. Oral 5-aza, given with tetrahydrouridine, produced comparable F reticulocyte response. In the two patients treated for more than 100 days, Hb levels increased to 11 to 12 and 9 g/dL, MCV and MCH increased by 25%, and lysate HbF levels peaked at 12% and 20%. Fetal erythroid characteristics (i-antigen, galactokinase activity, and G gamma/A gamma ratios) did not correlate with maximal HbF production. The frequency of vasoocclusive crises appeared to decrease in both patients followed for more than 100 days.
- Published
- 1985
43. Enrichment of erythrocytes of fetal origin from adult-fetal blood mixtures via selective hemolysis of adult blood cells: an aid to antenatal diagnosis of hemoglobinopathies.
- Author
-
Boyer SH, Noyes AN, and Boyer ML
- Subjects
- Acetazolamide pharmacology, Age Factors, Amniotic Fluid physiology, Bicarbonates pharmacology, Blood Preservation, Carbonic Anhydrases pharmacology, Female, Humans, Immunodiffusion, Infant, Newborn, Kinetics, Maternal-Fetal Exchange, Pregnancy, Erythrocytes physiology, Fetal Blood physiology, Hemoglobinopathies diagnosis, Hemolysis drug effects, Pregnancy Complications, Hematologic diagnosis
- Abstract
Red cell lysis in isotonic solutions containing NH4Cl, NH4HCO3, and a carbonic anhydrase enzyme inhibitor (acetazolamide) is a function of erythrocyte enzyme activity and permeability of cells to the inhibitor. Erythrocyte carbonic anhydrase activity is at least fivefold greater and acetazolamide permeability about tenfold less for adults than for newborns. In this setting, greater than 99.9% of red cells from adults can be hemolyzed at a time when greater than 25% of those from newborns remain intact. This easily applied method may be useful when antenatal diagnosis of hemoglobinopathies is otherwise precluded by contaimination with maternal erythrocytes. The feasibility of differential hemolysis via NH4Cl--HCO3-mediated, acetazolamide-modulated reactions is shown by the successful isolation of the few fetal-origin erythrocytes present in grossly nonbloody amniotic fluids and, in one instance, by approximately 3300-fold enrichment of apparently authentic fetal-origin red cells from the arm blood of a woman in her 18th wk of pregnancy.
- Published
- 1976
44. Developmental changes in human erythrocyte carbonic anhydrase levels: coordinate expression with adult hemoglobin.
- Author
-
Boyer SH, Siegel S, and Noyes AN
- Subjects
- Aging, Carbonic Anhydrases genetics, Hemolysis, Humans, Carbonic Anhydrases blood, Erythrocytes enzymology, Fetal Blood enzymology, Gene Expression Regulation, Hemoglobin A genetics
- Abstract
In order to bolster the argument that parallel developmental changes in erythrocyte adult hemoglobin (HbA) and carbonic anhydrase (CA) content provide a potentially suitable model for the dissection of coordinate gene expression, the magnitude of fetal vs adult differences in CA I and CA II levels was examined in human red cell subpopulations obtained after varying periods of exposure to CA-dependent, NH4Cl-HCO-3-mediated, acetazolamide-modulated hemolysis. When content of CA I and CA II was immunologically assessed in cohorts surviving successively longer periods of hemolysis, cord blood red cells were divisible into two populations. Fifteen to thirty percent are rapidly disrupted and have CA I and CA II concentrations similar to those in adult blood erythrocytes. The remaining 70 to 85% have CA I concentrations which are 100-fold less and CA II concentrations which are 5- to 20-fold less than those found in adults. Thus, contrary to past reports, the magnitude of the developmental change in CA I concentration closely resembles the magnitude of change in HbA levels.
- Published
- 1983
- Full Text
- View/download PDF
45. Quantitation of hemoglobins within individual red cells: asynchronous biosynthesis of fetal and adult hemoglobin during erythroid maturation in normal subjects.
- Author
-
Dover GJ and Boyer SH
- Subjects
- Animals, Antibody Affinity, Antibody Specificity, Erythrocytes, Fetal Hemoglobin immunology, Fluorescent Antibody Technique, Goats, Humans, Reticulocytes, Erythropoiesis, Fetal Hemoglobin biosynthesis, Hemoglobin A biosynthesis, Hemoglobins
- Abstract
We outline a method for estimating either HbF or HbA content in single erythrocytes and their precursors. Our method depends on microphotometric assay of darkfield reflectance arising from individual pericellular immunoprecipitates developed with anti-HbF or anti-HbA. When uniform-diameter latex microspheres were used to normalize comparisons between preparations, mean coefficient of variation for HbF reflectance among separate preparations of the same sample was < 3%. Reflectance is a faithful (r = 0.99) linear function of the logarithm of picograms per cell in samples with known HbF or HbA content. The following features emerged from such analyses. First, despite the use of antigenically-specific antihemoglobins from different sources, the least detectable quantity of HbF (3.2 pg) and HbA (14.8 pg) remained invariant. Second, these detection thresholds depends on antihemoglobin affinity constants but are little influenced by antibody concentration. Third, our procedure is equally valid for persons with normal HbF constant (mean +/- SD = 4.4 +/- 0.3 pg per cell, 15 subjects) and for those with much higher levels. Fourth, like the percentage of HbF-bearing cells, HbF content is usually unchanging in serial samples. Fifth, the utility of the method is evidenced in bone marrow analyses of five hematologically normal persons in whom HbF content, unlike HbA content, remained constant throughout maturation from erythroblasts to erythrocytes. In vivo HbF biosynthesis is thus normally completed long before HbA production.
- Published
- 1980
46. Fetal hemoglobin-containing cells have the same mean corpuscular hemoglobin as cells without fetal hemoglobin: a reciprocal relationship between gamma- and beta-globin gene expression in normal subjects and in those with high fetal hemoglobin production.
- Author
-
Dover GJ and Boyer SH
- Subjects
- Anemia blood, Anemia, Sickle Cell blood, Antibodies, Monoclonal, Fanconi Anemia blood, Gene Expression Regulation, Humans, Thalassemia blood, Erythrocytes analysis, Fetal Hemoglobin genetics, Globins genetics, Hemoglobinopathies blood
- Abstract
We have developed methodology that allows comparison of the mean corpuscular hemoglobin (MCH) of fetal hemoglobin (HbF)-containing red cells (F cells) with the MCH of non-F cells from the same individual. To do this, suspensions of peripheral blood erythrocytes and their internal contents are fixed with an imidodiester, dimethyl-3,3'-dithiobispropionimidate dihydrochloride (DTBP). Thereafter fixed cells are made permeable to antisera by treatment with Triton X-100 and isopropanol, reacted with a mouse monoclonal antibody (MoAb) against HbF, and then with fluorescein-conjugated antimouse IgG. No appreciable hemoglobin is lost during such manipulation. Red cells from a diversity of subjects were thus treated and examined microscopically, first by transmitted light and then by epifluorescence. A direct correlation between Coulter-derived MCH and mean absorbance of 415 nm transmitted light was found for 100 unfixed (r = 0.96) and for 100 antibody-treated fixed-permeabilized red cells (r = 0.99) among individuals selected so as to provide a range of Coulter MCH values between 20 and 35. Comparisons of microscopically derived MCH of F cells and non-F cells were statistically nondistinguishable (P greater than 0.05) in all subjects. Such comparisons included normal individuals (less than 1% F cells), SS patients (7% to 48% F cells), subjects with congenital anemia (22% to 65% F cells), individuals with heterocellular hereditary persistence of HbF (HPFH) (12% to 21% F cells), and heterozygotes for beta + thalassemia (11% to 31% F cells). We conclude that gamma- and beta-globin production within F cells is regulated in a reciprocal fashion both among normal individuals and among individuals with elevated HbF production.
- Published
- 1987
47. Microscopic method for assaying F cell production: illustrative changes during infancy and in aplastic anemia.
- Author
-
Dover GJ, Boyer SH, and Bell WR
- Subjects
- Adult, Blood Cell Count methods, Gels, Humans, Immunodiffusion, Infant, Sepharose, Anemia, Aplastic blood, Reticulocytes
- Abstract
Fetal hemoglobin (HbF)-bearing reticulocytes (F reticulocytes) can be detected in peripheral blood by a modification of the microscopic single-cell radial immunodiffusion method. Thereby otherwise inappreciable changes in HbF production can readily be recognized. F reticulocyte frequencies are reporducibly measurable whenever the product of whole blood HbF-bearing red cell (F cell) frequency and reticulocyte frequency is approximately 5 X 10(-4) or greater. Serial analyses of F reticulocytes and nonreticulocyte F cells (F erythrocytes) illustrate that (1) levels of F reticulocytes and F erythrocytes are persistently similar in normal adults with more than 6% F cells and thus cell survival times of F and non-F cells must be essentially the same, (2) changing levels of F reticulocytes can be sensitive predictors of later changes in mature F cell frequencies during infancy and in adults recovering from aplastic anemia, and (3) alterations in F reticulocyte frequency and the amount of HbF per F reticulocyte are discordant in some settings but concordant in others.
- Published
- 1978
48. Changing erythrocyte populations in juvenile chronic myelocytic leukemia: evidence for disordered regulation.
- Author
-
Dover GJ, Boyer SH, Zinkham WH, Kazazian HH Jr, Pinney DJ, and Sigler A
- Subjects
- Child, Preschool, Erythrocytes enzymology, Female, Fetal Hemoglobin analysis, Hemoglobin A analysis, Hemoglobins analysis, Hemolysis, Humans, I Blood-Group System, Erythrocytes analysis, Leukemia, Myeloid blood
- Abstract
Fetal and adult erythrocyte characteristics were studied serially in a 30-mo-old female with juvenile chronic myelocytic leukemia. On presentation the erythrocytes exhibited predominantly fetal characteristics as indicated by 69% hemoglobin F (HbF), 1.1% hemoglobin A2 (HbA2), absent I antigen, and fetal levels of the erythrocyte enzymes, carbonic anhydrase I and II, glucose-6-phosphate dehydrogenase, hexokinase, pyruvate kinase, and lactate dehydrogenase; 100% of the erythrocytes present contained HbF. However, Orskov-Jacobs-Stewart hemolysis demonstrated that at least one adult characteristic was present. Seven months later HbF was 17%; I antigen and carbonic anhydrase I had increased to adult levels. The number of cells containing HbF had decreased to 30%. Further studies indicated that at least three new populations of red cells were present after 7 mo which had not previously been detected. Two of these populations exhibited a mixture of both fetal and adult characteristics. Such findings suggested that an ongoing disturbance of regulatory mechanisms was responsible for the variable expression of fetal versus adult erythrocyte characteristics.
- Published
- 1977
49. [The role of Chlamydia trachomatis in the infectious etiology of extra-uterine pregnancy].
- Author
-
Diquelou JY, Pia P, Tesquier L, Henry-Suchet J, Gicquel JM, and Boyer S
- Subjects
- Abortion, Spontaneous complications, Adult, Antibodies, Bacterial analysis, Chlamydia Infections immunology, Chlamydia trachomatis immunology, Chlamydia trachomatis isolation & purification, Fallopian Tubes surgery, Female, Humans, Pelvis, Pregnancy, Salpingitis complications, Chlamydia Infections complications, Pregnancy, Ectopic etiology
- Abstract
The study was carried out in two different hospital centres on a series of 55 women who had ectopic pregnancies compared with 2 control groups. The study concerned taking samples from cells in the pelvis to culture for Chlamydia trachomatis and to estimate the levels of anti-Chlamydia antibodies. The cultures were positive in 30% of the cases and the serology was positive in 52% of the cases. This difference is significant when compared with the control groups (p less than 0.001). There was no significant statistical difference as far as positive cultures were concerned between the groups of women who had or had not had previous tubal infertility or a history of salpingitis. It seems that Chlamydia trachomatis can itself therefore be a direct cause for the development of an ectopic pregnancy.
- Published
- 1988
50. Production of F cells in sickle cell anemia: regulation by a genetic locus or loci separate from the beta-globin gene cluster.
- Author
-
Boyer SH, Dover GJ, Serjeant GR, Smith KD, Antonarakis SE, Embury SH, Margolet L, Noyes AN, Boyer ML, and Bias WB
- Subjects
- Adolescent, Adult, Alleles, Anemia, Sickle Cell blood, Child, Family, Humans, Reticulocytes analysis, Anemia, Sickle Cell genetics, Fetal Hemoglobin analysis, Gene Expression Regulation
- Abstract
Levels of fetal hemoglobin (HbF) bearing reticulocytes (F reticulocytes) range from 2% to 50% in patients with sickle cell (SS) anemia. To learn whether any portion of such variation in F cell production is regulated by loci genetically separable from the beta-globin gene cluster, percentages of F reticulocytes were compared in 59 sib pairs composed solely of SS members, including 40 pairs from Jamaica and 19 from the United States. We reasoned that differences in F reticulocyte levels might arise (1) from any of several kinds of artifact, (2) via half-sib status, or (3) because one or more genes regulating F cell production segregate separately from beta S. We minimized the role of artifact by assay of fresh samples from 84 SS individuals, including both members of 38 sib pairs. In 78 of the 84 subjects, serial values for percent F reticulocytes fell within 99.9% confidence limits or were alike by t test (P greater than or equal to .05). This left 32 sib pairs for which F reticulocyte levels in each member were reproducible. When sib-sib comparisons were limited to these 32 pairs, percentages of F reticulocytes were grossly dissimilar within 12 Jamaican and 3 American sibships. Within them, the probability that sibs were alike was always less than or equal to .005 and usually less than or equal to 10(-4). We next minimized the contribution of half-sibs among Jamaicans by a combination of paternity testing and sib-sib comparison of beta-globin region DNA restriction fragment length polymorphisms, especially among discordant pairs. We thereafter concluded that at least seven to eight Jamaican pairs were composed of reproducibly discordant full sibs. There is thus little doubt that there are genes regulating between-patient differences in F cell production that are separate from the beta-globin gene cluster. Still unanswered is (1) whether or not these genes are actually linked to beta S, (2) why F reticulocyte levels in Americans tend to be lower than in Jamaicans, and (3) whether or not differences in F cell production among SS patients are regulated by several major loci or by only one.
- Published
- 1984
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