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1.
Actas Dermosifiliogr ; 113(2): 183-186, 2022 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-34545255

RESUMO

The aim of this study was to describe oral lesions in a group of patients with COVID-19. We recruited 55 patients, 25 women (45.5%) and 30 men (54.5%), aged between 1 and 89 years with confirmed COVID-19 at different stages of severity. After obtaining informed consent, we examined their mouths and recorded clinical findings. Forty percent of the patients had at least 1 oral lesion. The most common lesions were candidiasis and ulcers (7 patients each); 2 patients had enanthems. Geographic tongue and caviar tongue were also observed. Altered taste, dry mouth, and painful/burning mouth were noted in 60%, 27.3%, and 36.4% of patients, respectively. Oral mucosal alterations and lesions were prevalent in this series of COVID-19 patients. Altered taste and a painful/burning mouth were common symptoms.

2.
Actas Dermosifiliogr ; 2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34848890

RESUMO

The aim of this study was to describe oral lesions in a group of patients with COVID-19. We recruited 55 patients, 25 women (45.5%) and 30 men (54.5%), aged between 1 and 89 years with confirmed COVID-19 at different stages of severity. After obtaining informed consent, we examined their mouths and recorded clinical findings. Forty percent of the patients had at least 1 oral lesion. The most common lesions were candidiasis and ulcers (7 patients each); 2 patients had enanthems. Geographic tongue and caviar tongue were also observed. Altered taste, dry mouth, and painful/burning mouth were noted in 60%, 27.3%, and 36.4% of patients, respectively. Oral mucosal alterations and lesions were prevalent in this series of COVID-19 patients. Altered taste and a painful/burning mouth were common symptoms.


El propósito de este trabajo fue caracterizar las alteraciones orales en un grupo de pacientes COVID-19. Para ello se evaluaron 55 pacientes hospitalizados, confirmados COVID-19 en distintos estadios de severidad. Previo consentimiento informado, se examinó la cavidad oral y se registraron los hallazgos clínicos. El grupo de estudio estuvo conformado por 25 mujeres (45,5%) y 30 hombres (54,5%), con edades comprendidas entre 1 y 89 años. Un 40% de los pacientes mostraron alguna lesión bucal. Las lesiones más comunes fueron candidiasis y ulceraciones (7 pacientes cada uno) y en dos pacientes se observó enantema. También se encontraron alteraciones de la normalidad como glositis migratoria y varicosidades linguales. Asimismo, se registraron alteraciones del gusto, xerostomía y dolor/ardor bucal en el 60%, 27,3% y 36,4% respectivamente. En los pacientes COVID-19 se observaron con frecuencia alteraciones y lesiones en la mucosa bucal. Finalmente, la disgeusia y el dolor y/o el ardor oral fueron síntomas comunes en estos pacientes.

3.
Phys Rev Lett ; 122(3): 035001, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30735406

RESUMO

Fuel-ion species dynamics in hydrodynamiclike shock-driven DT^{3}He-filled inertial confinement fusion implosion is quantitatively assessed for the first time using simultaneously measured D^{3}He and DT reaction histories. These reaction histories are measured with the particle x-ray temporal diagnostic, which captures the relative timing between different nuclear burns with unprecedented precision (∼10 ps). The observed 50±10 ps earlier D^{3}He reaction history timing (relative to DT) cannot be explained by average-ion hydrodynamic simulations and is attributed to fuel-ion species separation between the D, T, and ^{3}He ions during shock convergence and rebound. At the onset of the shock burn, inferred ^{3}He/T fuel ratio in the burn region using the measured reaction histories is much higher as compared to the initial gas-filled ratio. As T and ^{3}He have the same mass but different charge, these results indicate that the charge-to-mass ratio plays an important role in driving fuel-ion species separation during strong shock propagation even for these hydrodynamiclike plasmas.

4.
Phys Rev Lett ; 115(17): 175004, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26551121

RESUMO

To explain many natural magnetized plasma phenomena, it is crucial to understand how rates of collisionless magnetic reconnection scale in large magnetohydrodynamic (MHD) scale systems. Simulations of isolated current sheets conclude such rates are independent of system size and can be reproduced by the Hall-MHD model, but neglect sheet formation and coupling to MHD scales. Here, it is shown for the problem of flux-rope merging, which includes this formation and coupling, that the Hall-MHD model fails to reproduce the kinetic results. The minimum sufficient model must retain ion kinetic effects, which set the ion diffusion region geometry and give time-averaged rates that reduce significantly with system size, leading to different global evolution in large systems.

5.
Neurologia ; 30(2): 90-6, 2015 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-25440067

RESUMO

INTRODUCTION: Corpora amylacea (CoA) are present in about 60% of atrophic hippocampi resected from patients with drug resistant temporal lobe epilepsy (DRTLE). They have also been described in the lateral temporal neocortex, although less frequently. OBJECTIVE: The objective is to measure the presence, distribution and density of CoA in the lateral temporal lobes of patients with DRTLE and focal cortical dysplasia (FCD), also examining how CoA density may be linked to demographic and clinical traits. METHODS: Resected tissue from 35 patients was analysed. CoA density was assessed with a semi-quantitative scale according to the criteria established by Cherian et al. RESULTS: Presence of CoA in the neocortex of 9 patients was associated with hippocampal sclerosis (FCD type iiia, 7 cases), disembryoplastic neuroepithelial tumour (FCD type iiib, 1 case), and cavernous angioma (FCD type iiic, 1 case). The meningeal surface (MS) was involved in all cases, and 8 cases displayed CoA in the cerebral parenchyma (white matter) and around blood vessels. CoA density on the MS showed a negative correlation with age at seizure onset (r = -0.828, P<.05) and a positive correlation with disease duration (r = 0.678, P<.05) but not with postoperative clinical outcome. CONCLUSIONS: Patients with DRTLE and a primary lesion (hippocampal sclerosis, tumour, vascular malformation) associated with mild FCD were shown to have CoA deposits in the neocortex. No association was found between presence of CoA and clinical outcome one year after surgery.


Assuntos
Epilepsia do Lobo Temporal/patologia , Malformações do Desenvolvimento Cortical/patologia , Neocórtex/patologia , Adulto , Epilepsia Resistente a Medicamentos , Feminino , Hipocampo/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Lobo Temporal/patologia , Adulto Jovem
6.
PLOS Glob Public Health ; 4(1): e0002736, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38232105

RESUMO

There is ongoing scientific and policy debate about the role e-cigarettes play in tobacco control, with concerns centring around unknown long-term effects, and the potential industry co-option of harm reduction efforts, including marketing to youths. There is substantial evidence of the influence of conventional cigarette promotion on smoking behaviours in Anglophone countries, and the popularity of social networking sites, as well as the lack of marketing regulations on the commercial promotion of electronic cigarettes online, suggest an urgent need to explore this topic further. This scoping review aims to map the existing evidence related to the influence of e-cigarette commercial promotion on social media on positive perceptions of vaping and vaping behaviours in core Anglophone countries. Searches were conducted in CENTRAL, Cochrane Database of Systematic Reviews (CDSR), Embase, Epistemonikos, MEDLINE, PsycINFO and Science Citation Index, on the 21st of July 2022. From 1,385 studies, 11 articles were included in the final review, using diverse study designs, including focus groups, content analysis, cross-sectional studies, and experiments. The studies were primarily based in the U.S. and evidenced the association between the commercial promotion of e-cigarettes on social media with positive perceptions of vaping and vaping behaviours, particularly among young people, addressing diverse themes including celebrities' sponsorship, e-liquid appeal (including flavours and nicotine levels), users' engagement with ads, and other marketing strategies. Further, social networking sites commercially promoting e-cigarettes might increase positive attitudes towards vaping and vaping behaviours, particularly among youths. Future research should be conducted in broader settings, incorporate larger and diverse sample sizes, ensure research transparency, cover multiple social networking sites, emphasize ecological validity, and foment longitudinal studies.

7.
Phys Rev Lett ; 111(8): 085002, 2013 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-24010447

RESUMO

We report the first nonlinear three-dimensional magnetohydrodynamic (MHD) numerical simulations of the reversed-field pinch (RFP) that exhibit a systematic repetition of quasisingle helicity states with the same dominant mode in between reconnection events. This distinctive feature of experimental self-organized helical RFP plasmas is reproduced in MHD simulations at low dissipation by allowing a helical modulation of the plasma magnetic boundary similar to the experimental one. Realistic mode amplitudes and magnetic topology are also found.

8.
Phys Rev Lett ; 106(19): 195004, 2011 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-21668169

RESUMO

A novel approach for the study of parallel transport in magnetized plasmas is presented. The method avoids numerical pollution issues of grid-based formulations and applies to integrable and chaotic magnetic fields with local or nonlocal parallel closures. In weakly chaotic fields, the method gives the fractal structure of the devil's staircase radial temperature profile. In fully chaotic fields, the temperature exhibits self-similar spatiotemporal evolution with a stretched-exponential scaling function for local closures and an algebraically decaying one for nonlocal closures. It is shown that, for both closures, the effective radial heat transport is incompatible with the quasilinear diffusion model.

9.
Phys Rev Lett ; 107(2): 025002, 2011 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-21797613

RESUMO

Using fully kinetic simulations of the island coalescence problem for a range of system sizes greatly exceeding kinetic scales, the phenomenon of flux pileup in the collisionless regime is demonstrated. While small islands on the scale of λ ≤ 5 ion inertial length (d(i)) coalesce rapidly and do not support significant flux pileup, coalescence of larger islands is characterized by large flux pileup and a weaker time averaged reconnection rate that scales as √(d(i)/λ) while the peak rate remains nearly independent of island size. For the largest islands (λ = 100d(i)), reconnection is bursty and nearly shuts off after the first bounce, reconnecting ~20% of the available flux.

10.
Phys Rev E ; 104(5-2): 055205, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34942772

RESUMO

We report on simulations of strong, steady-state collisional planar plasma shocks with fully kinetic ions and electrons, independently confirmed by two fully kinetic codes (an Eulerian continuum and a Lagrangian particle-in-cell). While kinetic electrons do not fundamentally change the shock structure as compared with fluid electrons, we find an appreciable rearrangement of the preheat layer, associated with nonlocal electron heat transport effects. The electron heat-flux profile qualitatively agrees between kinetic- and fluid-electron models, suggesting a certain level of "stiffness," though substantial nonlocality is observed in the kinetic heat flux. We also find good agreement with nonlocal electron heat-flux closures proposed in the literature. Finally, in contrast to the classical hydrodynamic picture, we find a significant collapse in the "precursor" electric-field shock at the preheat layer leading edge, which correlates with the electron-temperature gradient relaxation.

11.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33177012

RESUMO

INTRODUCTION: The loss of bone mass, as a consequence of bone remodelling, in the proximal third of the femur, is a factor that contributes to the failure of hip prostheses in the medium to long term. This periprosthetic remodelling occurs mainly during the first 12 months after the operation. The aim is to evaluate the behaviour at one year of a new anatomical stem, the ANATO® stem (2015-Stryker®), which is a redesign of its predecessor (ABG-ii®-Stryker stem) by means of bone densitometry. METHOD: Prospective, controlled study in which the changes in bone mineral density (BMD) observed around the seven areas of Gruen in a group of 61 patients affected by primary coxarthrosis, in whom an ANATO® stem was implanted, are analysed densitometrically. The healthy hip was taken as the control group. The existence of differences in the remodelling pattern according to sex, age and body mass index (BMI) was compared. The follow-up was during the first year after the intervention. RESULTS: After one year of follow-up, decreases of bone mineral density in zone seven of -5.9% were observed, being this decrease statistically significant. No differences were found in the remodelling pattern according to age, sex and body mass index. CONCLUSION: The ANATO® stem allows an efficient transmission of loads from the stem to the proximal femur. Only in zone seven significant bone atrophy is observed. Differences in age, BMI and sex do not seem to influence the bone remodelling around this new stem.

12.
Int J Tuberc Lung Dis ; 13(1): 62-7, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19105880

RESUMO

SETTING: Nicaragua, a country where the DOTS strategy has been successfully implemented since 1984. OBJECTIVE: To estimate the prevalence and trends of Mycobacterium tuberculosis resistance to first-line anti-tuberculosis drugs. DESIGN: A prospective national survey carried out in 2004 according to the standardised model developed by the World Health Organisation and the International Union Against Tuberculosis and Lung Disease. RESULTS: A total of 423 M. tuberculosis strains were studied. Among the 320 strains evaluated for initial resistance, 13.1% displayed resistance to any drug, lower than the 1998 figure of 15.6%. Overall initial resistance to isoniazid (INH), rifampicin (RMP) and multidrug resistance (MDR) was respectively 6.6%, 0.9% and 0.6%. Initial resistance was higher in older age groups. Overall acquired resistance was 35.9% (n = 103); resistance to INH was 29.3% and to RMP 8.9%, while MDR was 7.9%. The acquired MDR rate was clearly higher in Category I failures (44.4%) than in relapses (3.8%) and retrieved defaulters (2.7%). All resistance rates found in this study were lower than those detected in 1998. CONCLUSION: This study shows low rates of resistance and MDR and a downward trend in all rates, undoubtedly related to the proper implementation of the National Tuberculosis Programme.


Assuntos
Antituberculosos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Pulmonar/epidemiologia , Resistência Microbiana a Medicamentos , Inquéritos Epidemiológicos , Humanos , Isoniazida/farmacologia , Nicarágua/epidemiologia , Prevalência , Estreptomicina/farmacologia , Tuberculose Resistente a Múltiplos Medicamentos/prevenção & controle , Tuberculose Pulmonar/prevenção & controle
13.
Phys Rev E ; 99(4-1): 041201, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31108601

RESUMO

This Rapid Communication identifies the physical mechanism for the quench of turbulent resistivity in two-dimensional magnetohydrodynamics. Without an imposed, ordered magnetic field, a multiscale, blob-and-barrier structure of magnetic potential forms spontaneously. Magnetic energy is concentrated in thin, linear barriers, located at the interstices between blobs. The barriers quench the transport and kinematic decay of magnetic energy. The local transport bifurcation underlying barrier formation is linked to the inverse cascade of 〈A^{2}〉 and negative resistivity, which induce local bistability. For small-scale forcing, spontaneous layering of the magnetic potential occurs, with barriers located at the interstices between layers. This structure is effectively a magnetic staircase.

14.
Rev Neurol ; 67(2): 41-49, 2018 Jul 15.
Artigo em Espanhol | MEDLINE | ID: mdl-29971757

RESUMO

AIM: To know the differences in the patterns of functional connectivity, the topological characteristics of the network and the relationship between these latter and the interictal epileptiform anomalies in children with primary and secondary autism spectrum disorder (ASD). PATIENTS AND METHODS: A retrospective study was conducted with 27 children aged between 3 and 13 years diagnosed with ASD. Subjects were submitted to an electroencephalogram in a functional state of spontaneous sleep. Functional connectivity and the properties of the network were analysed using data obtained from the electroencephalogram during the N2 stage of non-REM sleep. The frequency of discharge of the interictal epileptiform activity (FDIEA) was determined and was correlated with the topological properties of the network. RESULTS: Synchronisation was diminished in patients with secondary ASD for the alpha frequency and increased for the theta and delta frequency compared with patients with primary ASD. Local alpha efficiency was higher in patients who presented interictal epileptiform activity. Additionally, in patients with secondary ASD there was a statistically significant positive and negative correlation between FDIEA and the topological properties of the network. CONCLUSIONS: Patients with secondary ASD display patterns of functional connectivity that are weaker for the alpha frequency and stronger for theta and delta than patients with primary ASD. In patients with secondary ASD, the interictal epileptiform activity is related to local and global connectivity of the network for the alpha and beta bands during non-REM sleep.


TITLE: Conectividad funcional derivada del electroencefalograma durante el sueño no REM en los trastornos del espectro autista.Objetivo. Conocer las diferencias en los patrones de conectividad funcional, las caracteristicas topologicas de la red y la relacion de estas con las anomalias epileptiformes interictales en niños con trastorno del espectro autista (TEA) primario y secundario. Pacientes y metodos. Se realizo un estudio retrospectivo con 27 niños de 3-13 años diagnosticados con TEA, a los que se les realizo un electroencefalograma en estado funcional de sueño espontaneo. Se analizo la conectividad funcional y las propiedades de la red a partir de los datos obtenidos del electroencefalograma durante la etapa N2 del sueño no REM. Se determino la frecuencia de descarga de la actividad epileptiforme interictal (FDAEI) y se correlaciono con las propiedades topologicas de la red. Resultados. Los pacientes con TEA secundario tenian una disminucion de la sincronizacion para la frecuencia alfa y un incremento para la frecuencia theta y delta en comparacion con los pacientes con TEA primario. La eficiencia local alfa fue mayor en los pacientes que presentaban actividad epileptiforme interictal. Ademas, en los pacientes con TEA secundario, existia una correlacion positiva y negativa estadisticamente significativa entre la FDAEI y las propiedades topologicas de red. Conclusiones. Los pacientes con TEA secundario muestran patrones de conectividad funcional mas debiles para la frecuencia alfa y mas fuerte para la theta y delta que los pacientes con TEA primario. En pacientes con TEA secundario, la actividad epileptiforme interictal se relaciona con la conectividad local y global de la red para las bandas de frecuencia alfa y beta durante el sueño no REM.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Sincronização de Fases em Eletroencefalografia/fisiologia , Eletroencefalografia , Fases do Sono/fisiologia , Adolescente , Ondas Encefálicas/fisiologia , Criança , Pré-Escolar , Conectoma , Feminino , Humanos , Masculino , Estudos Retrospectivos
15.
Rev Neurol ; 44(3): 139-45, 2007.
Artigo em Espanhol | MEDLINE | ID: mdl-17285517

RESUMO

AIM: To evaluate the value of prolonged video-electroencephalographic (video-EEG) monitoring complemented with spectral and EEG source analysis in identifying the epileptogenic area in patients with medial temporal lobe epilepsy who are candidates for non-lesional resective surgery. PATIENTS AND METHODS: The electrographic patterns during the onset of seizures were evaluated in over 667 seizures from 41 patients with a clinical diagnosis of medication-resistant partial epilepsy. Analyses were performed using Harmonie software and variable resolution electrical tomography (VARETA). RESULTS: Video-EEG was used to determine that 53.6% of the patients evaluated suffered complex partial seizures of a temporal origin; these were characterised by having an average frequency of 5.56 +/- 1.56 Hz, while the non-temporal seizures displayed a frequency within the range 9.17 +/- 3.32 Hz. The topographic location of the dominant ictal frequency during the period of maximum spectral energy in patients with temporal lobe epilepsy enabled us to draw a distinction between a group of patients with mesial seizures and those with non-mesial seizures that exceeded the number that was determined by visual inspection of the EEG, that is, 78.9 versus 47.3%, respectively. There was a 100% coincidence between the area where the seizures began as defined by surface EEG complemented with spectral analysis, the generator of this activity as defined by VARETA and the epileptogenic region. CONCLUSIONS: The localising information provided by video-EEG complemented with spectral and EEG source analysis allows for non-invasive location of the epileptogenic region in patients with medial temporal lobe epilepsy even when structural imaging studies show an absence or bilaterality of abnormalities.


Assuntos
Eletroencefalografia , Epilepsia do Lobo Temporal/fisiopatologia , Gravação em Vídeo , Eletroencefalografia/métodos , Epilepsia do Lobo Temporal/classificação , Epilepsia do Lobo Temporal/diagnóstico , Epilepsia do Lobo Temporal/terapia , Humanos , Monitorização Fisiológica/métodos
16.
Phys Rev E ; 96(4-1): 041101, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29347565

RESUMO

We study the evolution of the concentration field in a single eddy in the two-dimensional (2D) Cahn-Hilliard system to better understand scalar mixing processes in that system. This study extends investigations of the classic studies of flux expulsion in 2D magnetohydrodynamics and homogenization of potential vorticity in 2D fluids. Simulation results show that there are three stages in the evolution: (A) formation of a "jelly roll" pattern, for which the concentration field is constant along spirals; (B) a change in isoconcentration contour topology; and (C) formation of a target pattern, for which the isoconcentration contours follow concentric annuli. In the final target pattern stage, the isoconcentration bands align with stream lines. The results indicate that the target pattern is a metastable state. The band merger process continues on a time scale exponentially long relative to the eddy turnover time. The band merger process resembles step merger in drift-ZF staircases; this is characteristic of the long-time evolution of phase-separated patterns described by the Cahn-Hilliard equation.

17.
Int J Tuberc Lung Dis ; 10(6): 613-9, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16776447

RESUMO

SETTINGS: Tuberculosis (TB) diagnostic laboratories in Latin America. OBJECTIVES: Evaluation of thin-layer agar (TLA) compared to Löwenstein-Jensen (LJ) culture for the diagnosis of TB. DESIGN: Phase II prospective study in six laboratories. Samples included sputum and extra-pulmonary specimens from patients with a clinical diagnosis of TB. Respiratory samples were decontaminated using NaOH/ NALC; all samples were centrifuged, stained with Ziehl-Neelsen for acid-fast bacilli (AFB), cultured on LJ and TLA and identified according to recommended procedures. Sensitivity and likelihood ratios (LR), growth detection time and contamination rate were calculated for both media. RESULTS: A total of 1118 clinical specimens were studied. Cultures detected Mycobacterium tuberculosis in all AFB-positive samples, whereas for AFB-negative specimens LJ detected 3.2% and TLA 4.4%. Sensitivity was 92.6% (95%CI 87.9-95.9) and 84.7% (95%CI 78.8-89.0) for TLA and LJ, respectively. Positive and negative LRs were similar. Contamination was 5.1% for TLA and 3.0% for LJ. Median time to detection of a positive culture was 11.5 days (95%CI 9.3-15.0) for TLA and 30.5 days (95%CI 26.9-39.0) for LJ (P < 0.0001). CONCLUSION: Difference in the characteristics of the participating laboratories, the disease prevalence and the number and type of specimens processed did not affect the overall performance of TLA as compared to LJ, supporting the robustness of the method and its feasibility in different laboratory settings.


Assuntos
Mycobacterium tuberculosis/isolamento & purificação , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia , Ágar , Técnicas Bacteriológicas/métodos , Humanos , América Latina , Estudos Prospectivos , Fatores de Tempo
18.
Rev Sci Instrum ; 87(11): 11D701, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27910508

RESUMO

A Particle X-ray Temporal Diagnostic (PXTD) has been implemented on OMEGA for simultaneous time-resolved measurements of several nuclear products as well as the x-ray continuum produced in High Energy Density Plasmas and Inertial Confinement Fusion implosions. The PXTD removes systematic timing uncertainties typically introduced by using multiple instruments, and it has been used to measure DD, DT, D3He, and T3He reaction histories and the emission history of the x-ray core continuum with relative timing uncertainties within ±10-20 ps. This enables, for the first time, accurate and simultaneous measurements of the x-ray emission histories, nuclear reaction histories, their time differences, and measurements of Ti(t) and Te(t) from which an assessment of multiple-ion-fluid effects, kinetic effects during the shock-burn phase, and ion-electron equilibration rates can be made.

19.
Int J Tuberc Lung Dis ; 9(8): 901-6, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16104638

RESUMO

OBJECTIVE: A multicentre evaluation was performed to assess two rapid low-cost methods, MTT (3-[4.5-dimethylthiazol-2-yl]-2.5-diphenyltetrazolium bromide) and resazurin assays, for testing the susceptibility of Mycobacterium tuberculosis to the first-line anti-tuberculosis drugs rifampicin (RMP), isoniazid (INH), ethambutol (EMB) and streptomycin (SM). METHODS: Thirty coded M. tuberculosis strains were sent to seven laboratories located in Latin America, representing six countries. Each site performed the colorimetric assays, MTT and resazurin, blind for the first-line drugs RMP, INH, EMB and SM. The minimum inhibitory concentration results obtained were compared to the conventional proportion method on Lowenstein-Jensen medium. RESULTS: After establishing the breakpoint concentrations, excellent results were obtained for RMP, INH and EMB, with levels of specificity and sensitivity of between 96% and 99%. CONCLUSION: MTT and resazurin assays are promising, accessible new alternative methods for middle- and low-resource countries that need low-cost methods to perform rapid susceptibility testing of M. tuberculosis to key anti-tuberculosis drugs.


Assuntos
Antituberculosos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Corantes , Farmacorresistência Bacteriana , Humanos , Indicadores e Reagentes , América Latina , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/patogenicidade , Oxazinas , Valores de Referência , Reprodutibilidade dos Testes , Sais de Tetrazólio , Tiazóis , Tuberculose Pulmonar/tratamento farmacológico , Xantenos
20.
Int J Tuberc Lung Dis ; 5(2): 129-36, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11258506

RESUMO

SETTING: IUATLD collaborative programme, Nicaragua. OBJECTIVE: To analyse reported trends in the retreatment failure rate (2SRHZE/1RHZE/5R3H3E3), and assess demographic characteristics, drug resistance and survival in patients who fail retreatment. DESIGN: A retrospective, descriptive study. Reports from 1988-1996 were analysed and records of 69 patients who failed retreatment were reviewed. RESULTS: The treatment success rate in new cases improved from 71% in 1988-1991 to 79% in 1992-1996, the default rate decreased from 16% to 10%, and the failure rate remained stable at 2-3%. The proportion of previously treated patients among all smear-positives decreased from 20% to 15%. In retreatment patients the failure rate declined from 6.6% to 4.3% and the average annual number of failures from 24 to 13. In 1992-1996, 64 patients, 0.8% of new smear-positive cases treated during this period, failed retreatment; the corresponding figures for 1988-1991 are 95 and 1.6%. Among 69 retreatment failure cases reviewed, there was male predominance and increasing age during the study period. Drug susceptibility results were available for 38, of whom 89% were resistant to isoniazid and rifampicin. The median survival of patients after failure was 3.9 years. CONCLUSION: Treatment results improved over the study period. The proportion of patients on retreatment out of all smear positives treated decreased, as did the absolute number of failures and the retreatment failure rate. Development of multidrug resistance has been largely prevented in Nicaragua; the low failure rate justifies the continued use of the standardised retreatment regimen.


Assuntos
Antituberculosos/uso terapêutico , Avaliação de Resultados em Cuidados de Saúde , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose/prevenção & controle , Adulto , Antituberculosos/farmacologia , Feminino , Humanos , Masculino , Nicarágua/epidemiologia , Vigilância da População , Prevalência , Estudos Retrospectivos , Estatísticas não Paramétricas , Taxa de Sobrevida , Falha de Tratamento , Tuberculose/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/mortalidade
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