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2.
Respir Med Res ; 79: 100828, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34023794

RESUMEN

OBJECTIVES: In March 2020, the World Health Organization declared the coronavirus disease 2019 (COVID-19) a pandemic. In absence of official recommendations, implementing daily multidisciplinary team (MDT) COVID-19 meetings was urgently needed. Our aim was to describe our initial institutional standard operating procedures for implementing these meetings, and their impact on daily practice. METHODS: All consecutive patients who were hospitalized in our institution due to COVID 19, from March 31 to April 15, 2020, were included. Criteria to be presented at MDT meetings were defined as a proven COVID-19 by PCR or strongly suspected on CT scan, requiring hospitalization and treatment not included in the standard of care. Three investigators identified the patients who met the predefined criteria and compared the treatment and outcomes of patients with predefined criteria that were presented during MDT meeting with those not presented during MDT meeting. COVID-19 MDT meeting implementation and adhesion were also assessed by a hospital medical staff survey. RESULTS: In all, 318 patients with confirmed or suspected COVID-19 were examined in our hospital. Of these, 230 (87%) were hospitalized in a COVID-19 unit, 91 (40%) of whom met predefined MDT meeting criteria. Fifty (55%) patients were presented at a MDT meeting versus 41 (45%) were not. Complementary exploration and inclusion in the CorImmuno cohort were higher in MDT meeting group (respectively 35 vs. 15%, P=0.03 and 80 versus 49%, P=0.0007). Prescription of hydrocortisone hemisuccinate was higher in group of patients not presented during MDT meeting (24 vs. 51%, P=0.007). Almost half of the patients fulfilling the inclusion criteria were not presented at MDT meeting, which can be partly explained by technical software issues. CONCLUSIONS: Multidisciplinary COVID-19 meetings helped implementing a single standard of care, avoided using treatments that were untested or currently being tested, and facilitated the inclusion of patients in prospective cohorts and therapeutic trials.


Asunto(s)
COVID-19/terapia , Procesos de Grupo , Cuerpo Médico de Hospitales , Nivel de Atención , Anciano , Anciano de 80 o más Años , Toma de Decisiones Clínicas , Femenino , Francia , Hospitales Universitarios , Humanos , Masculino , Persona de Mediana Edad
3.
J Colloid Interface Sci ; 582(Pt A): 149-158, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-32814221

RESUMEN

HYPOTHESIS: Dispersions of Laponite in water may form gels, the rheological properties of which being possibly tuned by the addition of polymer chains. Laponite-based hydrogels with poly(ethylene oxide) (PEO) were the most widely investigated systems and the PEO chains were then found to reduce the elastic modulus. EXPERIMENTS: Here, hydrogels based on Laponite and poly(2-methyl-2-oxazoline) (POXA) were considered. The adsorption behavior and the local structures within these nanocomposite gels were investigated by small-angle neutron scattering and NMR. The same materials were macroscopically characterized using rheology. FINDINGS: An original evolution of the storage modulus G' with the POXA concentration is evidenced compared to Laponite/PEO hydrogels. At low POXA concentrations, a continuous reduction of G' is observed upon increasing the polymer content, as with PEO, due to the screening of electrostatic interactions between the clay platelets. However, above a critical value of the POXA concentration, G' increases with the polymer content. This difference with PEO-based hydrogels is correlated to the stronger affinity of POXA chains for the clay surfaces, which results in the reduction of the inhomogeneities for the Laponite disks within the gels. Steric repulsions would then counterbalance the effect of electrostatic repulsions and lead to the strengthening of the POXA-based hydrogels.

4.
J Antimicrob Chemother ; 73(8): 2147-2151, 2018 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-29718247

RESUMEN

Background: Atazanavir is a PI widely used as a third agent in combination ART. We aimed to determine the prevalence and the patterns of resistance in PI-naive patients failing on an atazanavir-based regimen. Methods: We analysed patients failing on an atazanavir-containing regimen used as a first line of PI therapy. We compared the sequences of reverse transcriptase and protease before the introduction of atazanavir and at failure [two consecutive viral loads (VLs) >50 copies/mL]. Resistance was defined according to the 2014 Agence Nationale de Recherche sur le SIDA et les Hépatites Virales (ANRS) algorithm. Results: Among the 113 patients, atazanavir was used in the first regimen in 71 (62.8%) patients and in the first line of a PI-based regimen in 42 (37.2%). Atazanavir was boosted with ritonavir in 95 (84.1%) patients and combined with tenofovir/emtricitabine or lamivudine (n = 81) and abacavir/lamivudine or emtricitabine (n = 22). At failure, median VL was 3.05 log10 copies/mL and the median CD4+ T cell count was 436 cells/mm3. The median time on atazanavir was 21.2 months. At failure, viruses were considered resistant to atazanavir in four patients (3.5%) with the selection of the following major atazanavir-associated mutations: I50L (n = 1), I84V (n = 2) and N88S (n = 1). Other emergent PI mutations were L10V, G16E, K20I/R, L33F, M36I/L, M46I/L, G48V, F53L, I54L, D60E, I62V, A71T/V, V82I/T, L90M and I93L/M. Emergent NRTI substitutions were detected in 21 patients: M41L (n = 2), D67N (n = 3), K70R (n = 1), L74I/V (n = 3), M184V/I (n = 16), L210W (n = 1), T215Y/F (n = 3) and K219Q/E (n = 2). Conclusions: Resistance to atazanavir is rare in patients failing the first line of an atazanavir-based regimen according to the ANRS. Emergent NRTI resistance-associated mutations were reported in 18% of patients.


Asunto(s)
Sulfato de Atazanavir/uso terapéutico , Farmacorresistencia Viral/genética , Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/uso terapéutico , VIH-1/genética , Adulto , Didesoxinucleósidos , Combinación de Medicamentos , Emtricitabina/uso terapéutico , VIH-1/efectos de los fármacos , Humanos , Lamivudine , Masculino , Persona de Mediana Edad , Mutación , Estudios Retrospectivos , Tenofovir/uso terapéutico , Insuficiencia del Tratamiento , Carga Viral
5.
J Clin Virol ; 99-100: 57-60, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29331843

RESUMEN

OBJECTIVES: There is no consensus about the performances of genotypic rules for predicting HIV-1 non-B subtype tropism. Three genotypic methods were compared for CRF01_AE HIV-1 tropism determination. METHODS: The V3 env region of 207 HIV-1 CRF01_AE and 178 B subtypes from 17 centers in France and 1 center in Switzerland was sequenced. Tropism was determined by Geno2Pheno algorithm with false positive rate (FPR) 5% or 10%, the 11/25 rule or the combined criteria of the 11/25, net charge rule and NXT/S mutations. RESULTS: Overall, 72.5%, 59.4%, 86.0%, 90.8% of the 207 HIV-1 CRF01_AE were R5-tropic viruses determined by Geno2pheno FPR5%, Geno2pheno FPR10%, the combined criteria and the 11/25 rule, respectively. A concordance of 82.6% was observed between Geno2pheno FPR5% and the combined criteria for CRF01_AE. The results were nearly similar for the comparison between Geno2pheno FPR5% and the 11/25 rule. More mismatches were observed when Geno2pheno was used with the FPR10%. Neither HIV viral load, nor current or nadir CD4 was associated with the discordance rate between the different algorithms. CONCLUSION: Geno2pheno predicted more X4-tropic viruses for this set of CRF01_AE sequences than the combined criteria or the 11/25 rule alone. For a conservative approach, Geno2pheno FPR5% seems to be a good compromise to predict CRF01_AE tropism.


Asunto(s)
Algoritmos , Técnicas de Genotipaje/métodos , Infecciones por VIH/virología , VIH-1/fisiología , Tropismo Viral , Recuento de Linfocito CD4 , Reacciones Falso Positivas , Francia , Genotipo , Proteína gp120 de Envoltorio del VIH/genética , VIH-1/clasificación , VIH-1/genética , Humanos , ARN Viral/sangre , Suiza , Carga Viral
6.
J Antimicrob Chemother ; 72(6): 1769-1773, 2017 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-28333232

RESUMEN

Background: Surveillance of HIV-1 resistance in treated patients with a detectable viral load (VL) is important to monitor, in order to assess the risk of spread of resistant viruses and to determine the proportion of patients who need new antiretroviral drugs with minimal cross-resistance. Methods: The HIV-1 protease and reverse transcriptase (RT) and integrase genes were sequenced in plasma samples from 782 consecutive patients on failing antiretroviral regimens, seen in 37 specialized centres in 2014. The genotyping results were interpreted using the ANRS v24 algorithm. Prevalence rates were compared with those obtained during a similar survey conducted in 2009. Results: The protease and RT sequences were obtained in 566 patients, and the integrase sequence in 382 patients. Sequencing was successful in 60%, 78%, 78% and 87% of patients with VLs of 51-200, 201-500, 501-1000 and >1000 copies/mL, respectively. Resistance to at least one antiretroviral drug was detected in 56.3% of samples. Respectively, 3.9%, 8.7%, 1.5% and 3.4% of patients harboured viruses that were resistant to any NRTI, NNRTI, PI and integrase inhibitor (INI). Resistance rates were lower in 2014 than in 2009. Resistance was detected in 48.5% of samples from patients with a VL between 51 and 200 copies/mL. Conclusion: In France in 2014, 90.0% of patients in AIDS care centres were receiving antiretroviral drugs and 12.0% of them had VLs >50 copies/mL. Therefore, this study suggests that 6.7% of treated patients in France might transmit resistant strains. Resistance testing may be warranted in all treated patients with VL > 50 copies/mL.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Farmacorresistencia Viral Múltiple , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , Carga Viral , Adulto , Terapia Antirretroviral Altamente Activa , Femenino , Francia , Genes Virales , Genotipo , Infecciones por VIH/sangre , Integrasa de VIH/sangre , Integrasa de VIH/genética , Proteasa del VIH/sangre , Proteasa del VIH/genética , Transcriptasa Inversa del VIH/sangre , Transcriptasa Inversa del VIH/genética , VIH-1/genética , Humanos , Masculino , Persona de Mediana Edad , ARN Viral/sangre , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Análisis de Secuencia de ADN , Insuficiencia del Tratamiento
7.
FEMS Microbiol Lett ; 364(3)2017 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-28087614

RESUMEN

In this study, the potential of Fourier transform infrared (FTIR) spectroscopy for assessing putative biochemical and structural differences between the two variants, rough (R) and smooth (S), of Lactobacillus farciminis CNCM-I-3699, a pleomorphic strain, was investigated. The main differences observed were localized in the polysaccharide (1200-900 cm-1) and protein (1700-1500 cm-1) regions. Based on spectral information in these two spectral ranges, clustering resulted in a dendrogram that showed a clear discrimination between both morphotypes. Significant increases in favor of morphotype S compared to R at specific wavenumbers for polysaccharides (22.18% vs. 5.24% at 1068 cm-1) and capsular polysaccharides (16% vs. 13.17% at 1048 cm-1) were recorded. Compared to S, the morphotype R exhibits a 1.27-fold higher signal at the wavenumber of 1637 cm-1 assigned to the amide I ß-sheet and a 2.71-fold higher signal at the wavenumber of 1513 cm-1 assigned to the tyrosine involved in the ß-sheet arrangement of proteins. The FTIR analysis is efficient to separate and give data on mainly surface component differences observed previously between S colony morphotype (ropy and exopolysaccharide positive) and the R colony morphotype (non-ropy but highly autoaggregative).


Asunto(s)
Proteínas Bacterianas/análisis , Lactobacillus/química , Polisacáridos Bacterianos/análisis , Espectroscopía Infrarroja por Transformada de Fourier , Lactobacillus/citología
8.
Gene Ther ; 23(2): 144-50, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26488891

RESUMEN

Targeting viral entry is the most likely gene therapy strategy to succeed in protecting the immune system from pathogenic HIV-1 infection. Here, we evaluated the efficacy of a gene transfer lentiviral vector expressing a combination of viral entry inhibitors, the C46 peptide (an inhibitor of viral fusion) and the P2-CCL5 intrakine (a modulator of CCR5 expression), to prevent CD4⁺ T-cell infection in vivo. For this, we used two different models of HIV-1-infected mice, one in which ex vivo genetically modified human T cells were grafted into immunodeficient NOD.SCID.γc⁻/⁻mice before infection and one in which genetically modified T cells were derived from CD34⁺ hematopoietic progenitors grafted few days after birth. Expression of the transgenes conferred a major selective advantage to genetically modified CD4⁺ T cells, the frequency of which could increase from 10 to 90% in the blood following HIV-1 infection. Moreover, these cells resisted HIV-1-induced depletion, contrary to non-modified cells that were depleted in the same mice. Finally, we report lower normalized viral loads in mice having received genetically modified progenitors. Altogether, our study documents that targeting viral entry in vivo is a promising avenue for the future of HIV-1 gene therapy in humans.


Asunto(s)
Linfocitos T CD4-Positivos/virología , Quimiocina CCL5/genética , Técnicas de Transferencia de Gen , Infecciones por VIH/prevención & control , VIH-1 , Proteínas Recombinantes de Fusión/genética , Internalización del Virus , Animales , Antígenos CD34 , Antagonistas de los Receptores CCR5/uso terapéutico , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/trasplante , Femenino , Vectores Genéticos , Humanos , Lentivirus/genética , Ratones , Ratones Endogámicos NOD , Ratones SCID , Receptores CCR5/metabolismo
9.
Antimicrob Agents Chemother ; 59(6): 3660-2, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25845873

RESUMEN

We describe the pharmacokinetics of dolutegravir (DTG) in a premature neonate after maternal intensification of an antiretroviral (ARV) regimen by adding DTG. During the last 2 weeks of pregnancy, the ARV was tenofovir-emtricitabine, atazanavir-ritonavir, and DTG (50 mg once daily). From the interaction between atazanavir and DTG via CYP3A4 and UGT1A1 and placental efflux transporter inhibition and considering the infant's probable enzymatic immaturity, the DTG elimination half-life was estimated to be 4-fold longer in neonates than in adults.


Asunto(s)
Fármacos Anti-VIH/farmacocinética , Fármacos Anti-VIH/uso terapéutico , Compuestos Heterocíclicos con 3 Anillos/farmacocinética , Compuestos Heterocíclicos con 3 Anillos/uso terapéutico , Adulto , Sulfato de Atazanavir/farmacocinética , Sulfato de Atazanavir/uso terapéutico , Citocromo P-450 CYP3A/metabolismo , Emtricitabina/farmacocinética , Emtricitabina/uso terapéutico , Femenino , Glucuronosiltransferasa/metabolismo , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/metabolismo , Humanos , Recién Nacido , Masculino , Oxazinas , Piperazinas , Embarazo , Piridonas , Ritonavir/farmacocinética , Ritonavir/uso terapéutico , Tenofovir/farmacocinética , Tenofovir/uso terapéutico
10.
Emerg Med J ; 31(e1): e71-5, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24421348

RESUMEN

INTRODUCTION: The demand for urgent care is increasing, and the pressure on emergency departments is of significant concern. General practitioner (GP)-led urgent care centres are a new model of care developed to divert patients to more appropriate primary care environments. This study explores why patients with minor illness choose to attend an urban urgent care centre for their healthcare needs. METHODS: A self-completed questionnaire among patients aged 18 years or over (N=649) who were triaged with a 'minor illness' on arrival to an urgent care centre, colocated with an emergency department in London. RESULTS: Median participant age was 29 years. 58% (649/1112) of patients attending the centre with minor illness during the study period took part. 72% participants were registered with a GP; more women (59%) attended than men; and the majority of participants rated themselves as healthy (81%). Access to care (58%) was a key reason for using the service as was expectation of receiving prescription medication (69%). GP dissatisfaction influenced 10% of participants in their decision to attend. 68% did not contact their GP in the previous 24 h before attending. CONCLUSIONS: We found that the GP-led urgent care centre was similar to walk in centres in attracting healthy young adults, who were mostly registered with a GP and used services because of convenience and ease of access rather than satisfaction levels with their GP. This group may benefit from being seen as part of routine general practice care to provide opportunities for education and promotion of self-management.


Asunto(s)
Instituciones de Atención Ambulatoria/estadística & datos numéricos , Servicio de Urgencia en Hospital/estadística & datos numéricos , Accesibilidad a los Servicios de Salud , Aceptación de la Atención de Salud , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Medicina General , Humanos , Masculino , Persona de Mediana Edad , Factores Socioeconómicos , Encuestas y Cuestionarios , Triaje , Reino Unido , Adulto Joven
11.
Med Mal Infect ; 43(5): 202-7, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23701923

RESUMEN

OBJECTIVE: The authors had for aim to assess the prevalence of hepatitis B co-infection in a cohort of HIV-infected patients, routinely followed-up at the Day Care Unit of the Bobo Dioulasso Sanou Souro University Hospital, Burkina Faso. PATIENTS AND METHODS: The Elisa technique was used to dose HBs antigen (AgHBs), antibodies anti-HBs and anti-HBc in all the patients followed by the biological laboratory, from October to December 2008. RESULTS: The AgHBs prevalence was 12.7% [CI at 95%: 10.7-15.0%] and men were slightly more likely to be positive for AgHBs than women (16.5% [12.0-21.9%] versus 11.6% [9.4-14.1%]; P=0.047); 83.3% of the patients [80.8-85.6%] were positive for hepatitis B core antibody, and 32.6% [29.7-35.6%] for hepatitis B surface antibody; 29.9% of the patients [27.1-32.8%] had a complete profile of former hepatitis B infection, 41.3% [38.2-44.4%] expressed core antibodies only; 13.8% [11.7-16.0%] had a negative serological test, and 2.3% [1.5-3.4%] presented a vaccinal immunity. CONCLUSION: These results stress the usefulness of screening for hepatitis B in all HIV-infected patients, along with the initial biological tests. This would help adapt HIV treatment to co-infected patients and to build an expanded program of vaccination for non-immune patients.


Asunto(s)
Centros de Día/estadística & datos numéricos , Infecciones por VIH/epidemiología , Anticuerpos contra la Hepatitis B/sangre , Hepatitis B/epidemiología , Servicio Ambulatorio en Hospital/estadística & datos numéricos , Adulto , Anciano , Alanina Transaminasa/sangre , Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa , Antivirales/uso terapéutico , Burkina Faso/epidemiología , Portador Sano/epidemiología , Coinfección , Ensayo de Inmunoadsorción Enzimática , Femenino , Infecciones por VIH/tratamiento farmacológico , Hepatitis B/tratamiento farmacológico , Antígenos de la Hepatitis B/inmunología , Vacunas contra Hepatitis B/inmunología , Hospitales Universitarios , Humanos , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Estudios Seroepidemiológicos , Adulto Joven
12.
Animal ; 7(2): 322-9, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23031842

RESUMEN

Integrated Multi-Trophic Aquaculture takes advantage of the mutualism between some detritivorous fish and phytoplankton. The fish recycle nutrients by consuming live (and dead) algae and provide the inorganic carbon to fuel the growth of live algae. In the meanwhile, algae purify the water and generate the oxygen required by fishes. Such mechanism stabilizes the functioning of an artificially recycling ecosystem, as exemplified by combining the euryhaline tilapia Sarotherodon melanotheron heudelotii and the unicellular alga Chlorella sp. Feed addition in this ecosystem results in faster fish growth but also in an increase in phytoplankton biomass, which must be limited. In the prototype described here, the algal population control is exerted by herbivorous zooplankton growing in a separate pond connected in parallel to the fish-algae ecosystem. The zooplankton production is then consumed by tilapia, particularly by the fry and juveniles, when water is returned to the main circuit. Chlorella sp. and Brachionus plicatilis are two planktonic species that have spontaneously colonized the brackish water of the prototype, which was set-up in Senegal along the Atlantic Ocean shoreline. In our system, water was entirely recycled and only evaporation was compensated (1.5% volume/day). Sediment, which accumulated in the zooplankton pond, was the only trophic cul-de-sac. The system was temporarily destabilized following an accidental rotifer invasion in the main circuit. This caused Chlorella disappearance and replacement by opportunist algae, not consumed by Brachionus. Following the entire consumption of the Brachionus population by tilapias, Chlorella predominated again. Our artificial ecosystem combining S. m. heudelotii, Chlorella and B. plicatilis thus appeared to be resilient. This farming system was operated over one year with a fish productivity of 1.85 kg/m2 per year during the cold season (January to April).


Asunto(s)
Acuicultura/métodos , Chlorella/fisiología , Cíclidos/fisiología , Rotíferos/fisiología , Animales , Acuicultura/normas , Biomasa , Chlorella/crecimiento & desarrollo , Cíclidos/crecimiento & desarrollo , Ecosistema , Fitoplancton/crecimiento & desarrollo , Estanques , Dinámica Poblacional , Rotíferos/crecimiento & desarrollo , Salinidad , Estaciones del Año , Senegal , Zooplancton/crecimiento & desarrollo
14.
HIV Med ; 12(3): 138-44, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20722751

RESUMEN

OBJECTIVES: Amino acid insertions in the protease gene have been reported rarely, and mainly in patients receiving protease inhibitors (PIs). The aim of the study was to assess the long-term viro-immunological follow-up of HIV-infected patients harbouring virus with protease insertions. METHODS: Cases of virus exhibiting protease insertions were identified in routine resistance genotyping tests. Therapeutic, immunological and virological data were retrospectively collected. RESULTS: Eleven patients harbouring virus with a protease gene insertion were detected (prevalence 0.24%), including three PI-naïve patients. The insertions were mainly located between codons 33 and 39 and associated with surrounding mutations (M36I/L and R41K). The three PI-naïve patients were infected with an HIV-1 non-B subtype. Follow-up of these PI-naïve patients showed that the insert-containing virus persisted for several years, was archived in HIV DNA, and displayed a reduced viral replicative capacity with no impact on resistance level. Of the eight PI-experienced patients, 63% were infected with HIV-1 subtype B; one had been antiretroviral-free for 5 years and seven were heavily PI-experienced (median duration of follow-up 24 months; range 10-62 months). The protease insertion was selected under lopinavir in four patients and under darunavir in one, in the context of major PI-resistance mutations, and following long-term exposure to PIs. The insert-containing virus persisted for a median of 32 months (range 12-62 months) and displayed no specific impact on phenotypic resistance level or viral replicative capacity. CONCLUSION: Our data, obtained during long-term follow-up, show that insertions in the protease gene do not seem to have an impact on resistance level. This finding supports the recommendation of PI-based regimens, although further work is required to confirm it.


Asunto(s)
Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/uso terapéutico , VIH-1/genética , Mutagénesis Insercional/genética , Péptido Hidrolasas/genética , Codón , Resistencia a Medicamentos/genética , Genes Virales , Genotipo , Infecciones por VIH/genética , Humanos , Fenotipo
15.
J Appl Microbiol ; 109(1): 166-79, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20059620

RESUMEN

AIMS: A polyphasic approach was used to study the biodiversity bacteria associated with biocorrosion processes, in particular sulfate-reducing bacteria (SRB) and thiosulfate-reducing bacteria (TRB) which are described to be particularly aggressive towards metallic materials, notably via hydrogen sulfide release. METHODS AND RESULTS: To study this particular flora, an infrared spectra library of 22 SRB and TRB collection strains were created using a Common Minimum Medium (CMM) developed during this study and standardized culture conditions. The CMM proved its ability to allow for growth of both SRB and TRB strains. These sulfurogen collection strains were clearly discriminated and differentiated at the genus level by fourier transform infrared (FT-IR) spectroscopy. In a second step, infrared spectra of isolates, recovered from biofilms formed on carbon steel coupons immersed for 1 year in three different French harbour areas, were compared to the infrared reference spectra library. In parallel, molecular methods (M13-PCR and 16S rRNA gene sequencing) were used to qualitatively evaluate the intra- and inter-species genetic diversity of biofilm isolates. The biodiversity study indicated that strains belonging to the Vibrio genus were the dominant population; strains belonging to the Desulfovibrio genus (SRB) and Peptostreptococcaceae were also identified. CONCLUSION: Overall, the combination of the FT-IR spectroscopy and molecular approaches allowed for the taxonomic and ecological study of a bacterial flora, cultivated on CMM, associated with microbiology-induced corrosion (MIC) processes. SIGNIFICANCE AND IMPACT OF THE STUDY: Via the use of the CMM medium, the culture of marine bacteria (including both SRB and TRB bacteria) was allowed, and the implication of nonsulforogen bacteria in MIC was observed. Their involvement in the biocorrosion phenomena will have to be studied and taken into account in the future.


Asunto(s)
Biodiversidad , Bacterias Reductoras del Azufre/clasificación , Microbiología del Agua , Biopelículas , Corrosión , Medios de Cultivo , ADN Bacteriano/genética , Genes Bacterianos , Genes de ARNr , Filogenia , Análisis de Secuencia de ADN , Espectroscopía Infrarroja por Transformada de Fourier , Acero , Sulfatos/metabolismo , Bacterias Reductoras del Azufre/genética , Bacterias Reductoras del Azufre/aislamiento & purificación
17.
J Biomed Mater Res A ; 86(3): 736-48, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18041727

RESUMEN

This study aims to investigate the rheological properties of self-assembling gels containing cyclodextrins with potential application as injectable matrix for the sustained delivery of poorly soluble drugs. The ability of these gels to entrap two hydrophobic molecules, benzophenone (BZ) and tamoxifen (TM), and to allow their in vitro sustained release was evaluated. In view of their future pharmaceutical use, gels were sterilized by high hydrostatic pressures (HHP) and tested for their biocompatibility. The gels formed instantaneously at room temperature, by mixing the aqueous solutions of two polymers: a beta-cyclodextrin polymer (pbetaCD) and a hydrophobically modified dextran by grafting alkyl side chains (MD). MD-pbetaCD gels presented a viscoelastic behavior under low shear, characterized by constant values of the loss modulus G'' and the storage modulus G'. The most stable gels were obtained for a total polymer concentration C(p) of 6.6% and 7.5% (w/w), and a polymer ratio MD/pbetaCD of 50/50 and 33/67 (w/w). BZ and TM were successfully incorporated into MD-pbetaCD gels with loading efficiencies as high as 90%. In vitro, TM and BZ were released gradually from the gel matrix with less than 25% and 75% release, respectively, after 6 days incubation. HHP treatment did not modify the rheological characteristics of MD-pbetaCD gels. Moreover, the low toxicity of these gels after intramuscular administration in rabbits makes them promising injectable devices for local delivery of drugs.


Asunto(s)
Benzofenonas/farmacología , Sistemas de Liberación de Medicamentos , Hidrogeles/química , Tamoxifeno/farmacología , beta-Ciclodextrinas/química , Animales , Materiales Biocompatibles/metabolismo , Fenómenos Biomecánicos , Dextranos/química , Interacciones Hidrofóbicas e Hidrofílicas , Presión Hidrostática , Ensayo de Materiales , Microscopía Electrónica de Transmisión , Proteínas/farmacología , Conejos , Reología , Sales (Química)/farmacología , Piel/citología
18.
J Viral Hepat ; 14(11): 806-11, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17927617

RESUMEN

In HIV/hepatitis C virus (HCV)-coinfected patients, it is recommended to repeat liver biopsy every 3 years when anti-HCV treatment is not indicated. We studied fibrosis progression in HIV/HCV-coinfected patients, who were not receiving anti-HCV treatment, on the basis of two successive liver biopsies. Thirty-two patients were retrospectively included. Twenty-six patients (79%) were on antiretroviral treatment at the first biopsy. The mean CD4 cell count was 470 +/- 283/mm(3). Three patients were staged F2 and the remainder F0/F1. The median interval between the two biopsies was 49 (24-80) months. At the second biopsy, the stage distribution was F0 0%, F1 41% (n = 13), F2 34% (n = 11), F3 19% (n = 6) and F4 6% (n = 2). The mean fibrosis progression rate (FPR) was 0.25 points/year. Nine patients (28%) were considered as rapid fibrosis progressors (progression by more than two points) and their FPR was 0.5 point/year; comparison of these subjects with the other 23 patients showed no relation between FPR and age, alcohol consumption, CD4+ cell count, HIV viral load, HCV genotype, aspartate aminotransferase or alanine aminotransferase. Analysis of the treatment received between the two liver biopsies did not find any correlation between liver FPR and a specific compound. Fifteen patients started anti-HCV therapy based on the second biopsy. Liver fibrosis in HIV/HCV-coinfected patients should be evaluated at least every 3 years, as nine of 32 (28%) of our patients progressed by at least two fibrosis points despite a high CD4+ cell count. The second biopsy showed that 15 patients (45%) qualified for anti-HCV therapy. Development of noninvasive methods of fibrosis evaluation should permit more frequent monitoring.


Asunto(s)
Infecciones por VIH/virología , VIH/crecimiento & desarrollo , Hepacivirus/crecimiento & desarrollo , Hepatitis C Crónica/virología , Cirrosis Hepática/virología , Adulto , Alanina Transaminasa/sangre , Fosfatasa Alcalina/sangre , Aspartato Aminotransferasas/sangre , Bilirrubina/sangre , Biopsia con Aguja Fina , Recuento de Linfocito CD4 , Femenino , Infecciones por VIH/sangre , Infecciones por VIH/inmunología , Infecciones por VIH/patología , Hepatitis C Crónica/sangre , Hepatitis C Crónica/inmunología , Hepatitis C Crónica/patología , Histocitoquímica , Humanos , Cirrosis Hepática/inmunología , Cirrosis Hepática/patología , Masculino , Persona de Mediana Edad , Tiempo de Protrombina , Estudios Retrospectivos , Estadísticas no Paramétricas , Carga Viral , gamma-Glutamiltransferasa/sangre
19.
J Phys Chem B ; 111(20): 5587-95, 2007 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-17469868

RESUMEN

In aqueous solutions, beta-cyclodextrin (CD) and cyclodextrin-containing polymers (PolCD) associate with azobenzene-modified polyacrylate (AMP). Inclusion complexes in solution of CD (or PolCD) and AMP, and the viscosity of these mixtures, have been studied as a function of the composition of AMP and concentrations of samples. AMPs are random copolymers containing a low fraction of a light-responsive hydrophobic moieties (<10 mol % of 6-[4-alkylamido]phenylazobenzene acrylamide), and a charged hydrophilic unit, sodium acrylate. PolCDs are beta-cyclodextrin randomly conjugated with epichlorohydrin and fractionated to yield copolymers of average number of CD per chain equal to 50. In dilute solutions, the composition of complexes has been investigated by capillary electrophoresis and UV-vis spectrometry. Association between PolCD and AMP appears more complex than the conventional Benesi-Hildebrand scheme. We identified a tight (quantitative) binding regime followed by a gradual increase of the density of AMP-bound PolCD upon increasing the concentration of PolCD. At higher concentrations, the formation of large clusters has been characterized by the increase of viscosity by several decades. Light-triggered trans-conformation of the azobenzene moieties of AMPs leads to a marked photoswitch of viscosity. Reversible viscosity swings by up to 6-fold were achieved by alternative exposure to UV and visible lights. In contrast, the composition of PolCD/AMP complexes in dilute regime does not respond to light, though subtle modifications of the structures of complexes are reflected by variation of electrophoretic mobilities and UV spectra. The properties of interpolymer clusters and photoviscosity are accordingly the result of modification of the dynamics of association. In practice, the low concentration of photochrome makes it possible to obtain rapid responses in samples having a thickness of the order of cm. The data reported provide guidelines for the formulations of CD/polymer systems, specifically, viscosity enhancers, which should show promising developments in pharmaceuticals or cosmetics.


Asunto(s)
Resinas Acrílicas/química , Compuestos Azo/química , Ciclodextrinas/química , Modelos Moleculares , Estructura Molecular , Fotoquímica , Viscosidad , Agua/química
20.
J Colloid Interface Sci ; 307(1): 83-93, 2007 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-17126360

RESUMEN

New nanoassemblies were instantaneously prepared by mixing two aqueous solutions, one containing a beta-cyclodextrin polymer (pbetaCD), and the other a hydrophobically modified by alkyl chains dextran (MD). The formation mechanism and the inner structure of these nanoassemblies were analysed using surface tension measurements and (1)H NMR spectroscopy. The effect of a hydrophobic guest molecule, such as benzophenone (BZ), on the formation and stability of the nanoassemblies was also evaluated. MD exhibited the typical behaviour of a soluble amphiphilic molecule and adsorbed at the air/water interface. Whereas the injection of native beta-CDs in the solution beneath the adsorbed MD monolayer did not produce any change in the surface tension, that of the pbetaCD resulted in an increase in the surface tension, indicating the desorption of the polymer from the interface. This result accounts for a cooperative effect of beta-CDs linked together in the pbetaCD polymer on dextran desorption. The presence of benzophenone in the system hindered the sequestration of dextran alkyl moieties by beta-CD in the polymer without impeding the formation of associative nanoassemblies of 100-200 nm. (1)H NMR investigations demonstrated that, in the BZ-loaded nanoassemblies, the hydrophobic molecule was mainly located into the cyclodextrin cavities.


Asunto(s)
Benzofenonas/química , Dextranos/química , Nanopartículas/química , Glicoles de Propileno/química , beta-Ciclodextrinas/química , Interacciones Hidrofóbicas e Hidrofílicas , Espectroscopía de Resonancia Magnética
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