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1.
Ann Intern Med ; 176(5): 632-641, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37094349

RESUMO

BACKGROUND: A growing number of older persons in developing countries live entirely alone and are physically, mentally, and financially vulnerable. OBJECTIVE: To determine whether phone-based cognitive behavioral therapy (CBT) or a cash transfer reduce functional impairment, depression, or food insecurity in this population. DESIGN: Randomized controlled trial. (ClinicalTrials.gov: NCT04225845; American Economic Association RCT Registry: AEARCTR-0007582). SETTING: Tamil Nadu, India, 2021. PARTICIPANTS: 1120 people aged 55 years and older and living alone. INTERVENTIONS: A 6-week, phone-based CBT and a 1-time cash transfer of 1000 rupees (U.S. $12 at market exchange rates) were evaluated in a factorial design. MEASUREMENTS: The World Health Organization Disability Assessment Schedule (WHODAS), the Geriatric Depression Scale, and food security, all measured 3 weeks after CBT for 977 people and 3 months after for 932. Surveyors were blind to treatment assignment. RESULTS: The WHODAS score (scale 0 to 48, greater values representing more impairment) decreased between baseline and the 3-week follow-up by 2.92 more (95% CI, -5.60 to -0.23) in the group assigned cash only than in the control group, and the depression score (ranging from 0 to 15, higher score indicating more depressive symptoms) decreased by 1.01 more (CI, -2.07 to 0.06). These effects did not persist to the 3-month follow-up, and CBT alone and the 2 together had no significant effects. There were no effects on food security. LIMITATIONS: The study cannot say whether more sustained or in-person therapy would have been effective, how results would translate outside of the COVID-19 period, or whether results in the consented sample differ from those in a larger population. Primary outcomes were self-reported. CONCLUSION: Among older people living alone, a small cash transfer was effective in alleviating short-term (3 weeks) functional impairment, produced a small but not clinically or statistically significant reduction in depression, and had no effect on food security. There were no short-term effects from CBT or the 2 interventions together. None of the interventions showed any effect at 3 months. PRIMARY FUNDING SOURCE: National Institute on Aging (NIA).


Assuntos
COVID-19 , Terapia Cognitivo-Comportamental , Humanos , Idoso , Idoso de 80 Anos ou mais , Índia , Ambiente Domiciliar , Autorrelato
2.
Ann Intern Med ; 174(4): 484-492, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33347320

RESUMO

BACKGROUND: The paucity of public health messages that directly address communities of color might contribute to racial and ethnic disparities in knowledge and behavior related to coronavirus disease 2019 (COVID-19). OBJECTIVE: To determine whether physician-delivered prevention messages affect knowledge and information-seeking behavior of Black and Latinx individuals and whether this differs according to the race/ethnicity of the physician and tailored content. DESIGN: Randomized controlled trial. (Registration: ClinicalTrials.gov, NCT04371419; American Economic Association RCT Registry, AEARCTR-0005789). SETTING: United States, 13 May 2020 to 26 May 2020. PARTICIPANTS: 14 267 self-identified Black or Latinx adults recruited via Lucid survey platform. INTERVENTION: Participants viewed 3 video messages regarding COVID-19 that varied by physician race/ethnicity, acknowledgment of racism/inequality, and community perceptions of mask wearing. MEASUREMENTS: Knowledge gaps (number of errors on 7 facts on COVID-19 symptoms and prevention) and information-seeking behavior (number of web links demanded out of 10 proposed). RESULTS: 7174 Black (61.3%) and 4520 Latinx (38.7%) participants were included in the analysis. The intervention reduced the knowledge gap incidence from 0.085 to 0.065 (incidence rate ratio [IRR], 0.737 [95% CI, 0.600 to 0.874]) but did not significantly change information-seeking incidence. For Black participants, messages from race/ethnicity-concordant physicians increased information-seeking incidence from 0.329 (for discordant physicians) to 0.357 (IRR, 1.085 [CI, 1.026 to 1.145]). LIMITATIONS: Participants' behavior was not directly observed, outcomes were measured immediately postintervention in May 2020, and online recruitment may not be representative. CONCLUSION: Physician-delivered messages increased knowledge of COVID-19 symptoms and prevention methods for Black and Latinx respondents. The desire for additional information increased with race-concordant messages for Black but not Latinx respondents. Other tailoring of the content did not make a significant difference. PRIMARY FUNDING SOURCE: National Science Foundation; Massachusetts General Hospital; and National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases.


Assuntos
Negro ou Afro-Americano , COVID-19/etnologia , COVID-19/prevenção & controle , Informação de Saúde ao Consumidor , Hispânico ou Latino , Comportamento de Busca de Informação , Saúde Pública/métodos , Adulto , COVID-19/epidemiologia , Feminino , Humanos , Incidência , Masculino , Máscaras , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Pneumonia Viral/virologia , SARS-CoV-2 , Inquéritos e Questionários , Gravação em Vídeo
3.
Proc Natl Acad Sci U S A ; 108(5): 1821-6, 2011 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21245314

RESUMO

Does completing a household survey change the later behavior of those surveyed? In three field studies of health and two of microlending, we randomly assigned subjects to be surveyed about health and/or household finances and then measured subsequent use of a related product with data that does not rely on subjects' self-reports. In the three health experiments, we find that being surveyed increases use of water treatment products and take-up of medical insurance. Frequent surveys on reported diarrhea also led to biased estimates of the impact of improved source water quality. In two microlending studies, we do not find an effect of being surveyed on borrowing behavior. The results suggest that limited attention could play an important but context-dependent role in consumer choice, with the implication that researchers should reconsider whether, how, and how much to survey their subjects.


Assuntos
Comportamento , Coleta de Dados , Humanos
4.
J Labelled Comp Radiopharm ; 57(2): 78-81, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24307484

RESUMO

The epothilones, including epothilones B and D, are macrocyclic lactones, which have potent cytotoxicities and promote the polymerization of tubulin to mictotubules by binding to and stabilizing the tubulin polymer. They have a very similar mechanism of action to paclitaxel (Taxol®). The determination of the microtubule-binding conformation of the epothilones is an important piece of information in designing improved analogs for possible clinical use, and internuclear distance information that will assist the determination of this conformation can be obtained by rotational echo double resonance (REDOR) NMR studies of microtubule-bound epothilones with appropriate stable isotope labels. Analogs of epothilone B and epothilone D with [(2) H3 ] and [(19) F] labels were prepared from an advanced precursor for potential use in REDOR NMR studies to determine internuclear distances in tubulin-bound ligand.


Assuntos
Deutério/química , Epotilonas/síntese química , Marcação por Isótopo , Moduladores de Tubulina/síntese química , Linhagem Celular Tumoral , Epotilonas/química , Epotilonas/farmacologia , Humanos , Ligação Proteica , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia
5.
Sci Rep ; 14(1): 4332, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38383539

RESUMO

Complex envelope and reduced phase simulation models describing the dynamical behaviour of an optoelectronic oscillator (OEO) under injection by an external source are described. The models build on the foundations of a previously reported delay integral/differential equation (DDE) theory of injection locking of time delay oscillators (TDO) such as the OEO. The DDE formulation is particularly amenable to high precision simulation using the Simulink™ block diagram environment. The correspondence between the blocks and the oscillator components offers intuition and considerable freedom to explore different circuit architectures and design variations with minimal coding effort. The simulations facilitate the study of the profound effect the multimode nature of a TDO has on its dynamical behavior. The reduced phase models that make use of the Leeson approximation are generally successful in reproducing the results of complex envelope models for established oscillations except for spiking phenomena for which the Leeson approximation fails. Simulation results demonstrating phenomena not captured by classical injection theory are presented, including multimode oscillation, the appearance of sidemodes in the RF and phase noise spectrum, and persistent spike trains redolent of recent experimental observations of [Formula: see text] phase pulse trains in a broadband OEO under injection.

7.
Am Econ Rev ; 102(4): 1206-1240, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25197099

RESUMO

This paper reports an experiment in 640 Indonesian villages on three approaches to target the poor: proxy-means tests (PMT), where assets are used to predict consumption; community targeting, where villagers rank everyone from richest to poorest; and a hybrid. Defining poverty based on PPP$2 per-capita consumption, community targeting and the hybrid perform somewhat worse in identifying the poor than PMT, though not by enough to significantly affect poverty outcomes for a typical program. Elite capture does not explain these results. Instead, communities appear to apply a different concept of poverty. Consistent with this finding, community targeting results in higher satisfaction.

8.
JAMA Netw Open ; 4(7): e2117115, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34259846

RESUMO

Importance: Social distancing is critical to the control of COVID-19, which has disproportionately affected the Black community. Physician-delivered messages may increase adherence to these behaviors. Objectives: To determine whether messages delivered by physicians improve COVID-19 knowledge and preventive behaviors and to assess the differential effectiveness of messages tailored to the Black community. Design, Setting, and Participants: This randomized clinical trial of self-identified White and Black adults with less than a college education was conducted from August 7 to September 6, 2020. Of 44 743 volunteers screened, 30 174 were eligible, 5534 did not consent or failed attention checks, and 4163 left the survey before randomization. The final sample had 20 460 individuals (participation rate, 68%). Participants were randomly assigned to receive video messages on COVID-19 or other health topics. Interventions: Participants saw video messages delivered either by a Black or a White study physician. In the control groups, participants saw 3 placebo videos with generic health topics. In the treatment group, they saw 3 videos on COVID-19, recorded by several physicians of varied age, gender, and race. Video 1 discussed common symptoms. Video 2 highlighted case numbers; in one group, the unequal burden of the disease by race was discussed. Video 3 described US Centers for Disease Control and Prevention social distancing guidelines. Participants in both the control and intervention groups were also randomly assigned to see 1 of 2 American Medical Association statements, one on structural racism and the other on drug price transparency. Main Outcomes and Measures: Knowledge, beliefs, and practices related to COVID-19, demand for information, willingness to pay for masks, and self-reported behavior. Results: Overall, 18 223 participants (9168 Black; 9055 White) completed the survey (9980 [55.9%] women, mean [SD] age, 40.2 [17.8] years). Overall, 6303 Black participants (34.6%) and 7842 White participants (43.0%) were assigned to the intervention group, and 1576 Black participants (8.6%) and 1968 White participants (10.8%) were assigned to the control group. Compared with the control group, the intervention group had smaller gaps in COVID-19 knowledge (incidence rate ratio [IRR], 0.89 [95% CI, 0.87-0.91]) and greater demand for COVID-19 information (IRR, 1.05 [95% CI, 1.01-1.11]), willingness to pay for a mask (difference, $0.50 [95% CI, $0.15-$0.85]). Self-reported safety behavior improved, although the difference was not statistically significant (IRR, 0.96 [95% CI, 0.92-1.01]; P = .08). Effects did not differ by race (F = 0.0112; P > .99) or in different intervention groups (F = 0.324; P > .99). Conclusions and Relevance: In this study, a physician messaging campaign was effective in increasing COVID-19 knowledge, information-seeking, and self-reported protective behaviors among diverse groups. Studies implemented at scale are needed to confirm clinical importance. Trial Registration: ClinicalTrials.gov Identifier: NCT04502056.


Assuntos
Negro ou Afro-Americano , COVID-19/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Promoção da Saúde , Médicos , Racismo , População Branca , Adulto , Comunicação , Competência Cultural , Escolaridade , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Distanciamento Físico , Saúde Pública , SARS-CoV-2 , Marketing Social , Inquéritos e Questionários , Adulto Jovem
9.
Nat Med ; 27(9): 1622-1628, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34413518

RESUMO

During the Coronavirus Disease 2019 (COVID-19) epidemic, many health professionals used social media to promote preventative health behaviors. We conducted a randomized controlled trial of the effect of a Facebook advertising campaign consisting of short videos recorded by doctors and nurses to encourage users to stay at home for the Thanksgiving and Christmas holidays ( NCT04644328 and AEARCTR-0006821 ). We randomly assigned counties to high intensity (n = 410 (386) at Thanksgiving (Christmas)) or low intensity (n = 410 (381)). The intervention was delivered to a large fraction of Facebook subscribers in 75% and 25% of randomly assigned zip codes in high- and low-intensity counties, respectively. In total, 6,998 (6,716) zip codes were included, and 11,954,109 (23,302,290) users were reached at Thanksgiving (Christmas). The first two primary outcomes were holiday travel and fraction leaving home, both measured using mobile phone location data of Facebook users. Average distance traveled in high-intensity counties decreased by -0.993 percentage points (95% confidence interval (CI): -1.616, -0.371; P = 0.002) for the 3 days before each holiday compared to low-intensity counties. The fraction of people who left home on the holiday was not significantly affected (adjusted difference: 0.030; 95% CI: -0.361, 0.420; P = 0.881). The third primary outcome was COVID-19 infections recorded at the zip code level in the 2-week period starting 5 days after the holiday. Infections declined by 3.5% (adjusted 95% CI: -6.2%, -0.7%; P = 0.013) in intervention compared to control zip codes. Social media messages recorded by health professionals before the winter holidays in the United States led to a significant reduction in holiday travel and subsequent COVID-19 infections.

10.
ArXiv ; 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34159223

RESUMO

During the COVID-19 epidemic, many health professionals started using mass communication on social media to relay critical information and persuade individuals to adopt preventative health behaviors. Our group of clinicians and nurses developed and recorded short video messages to encourage viewers to stay home for the Thanksgiving and Christmas Holidays. We then conducted a two-stage clustered randomized controlled trial in 820 counties (covering 13 States) in the United States of a large-scale Facebook ad campaign disseminating these messages. In the first level of randomization, we randomly divided the counties into two groups: high intensity and low intensity. In the second level, we randomly assigned zip codes to either treatment or control such that 75% of zip codes in high intensity counties received the treatment, while 25% of zip codes in low intensity counties received the treatment. In each treated zip code, we sent the ad to as many Facebook subscribers as possible (11,954,109 users received at least one ad at Thanksgiving and 23,302,290 users received at least one ad at Christmas). The first primary outcome was aggregate holiday travel, measured using mobile phone location data, available at the county level: we find that average distance travelled in high-intensity counties decreased by -0.993 percentage points (95% CI -1.616, -0.371, p-value 0.002) the three days before each holiday. The second primary outcome was COVID-19 infection at the zip-code level: COVID-19 infections recorded in the two-week period starting five days post-holiday declined by 3.5 percent (adjusted 95% CI [-6.2 percent, -0.7 percent], p-value 0.013) in intervention zip codes compared to control zip codes.

11.
medRxiv ; 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34230932

RESUMO

During the COVID-19 epidemic, many health professionals started using mass communication on social media to relay critical information and persuade individuals to adopt preventative health behaviors. Our group of clinicians and nurses developed and recorded short video messages to encourage viewers to stay home for the Thanksgiving and Christmas Holidays. We then conducted a two-stage clustered randomized controlled trial in 820 counties (covering 13 States) in the United States of a large-scale Facebook ad campaign disseminating these messages. In the first level of randomization, we randomly divided the counties into two groups: high intensity and low intensity. In the second level, we randomly assigned zip codes to either treatment or control such that 75% of zip codes in high intensity counties received the treatment, while 25% of zip codes in low intensity counties received the treatment. In each treated zip code, we sent the ad to as many Facebook subscribers as possible (11,954,109 users received at least one ad at Thanksgiving and 23,302,290 users received at least one ad at Christmas). The first primary outcome was aggregate holiday travel, measured using mobile phone location data, available at the county level: we find that average distance travelled in high-intensity counties decreased by -0.993 percentage points (95% CI -1.616, -0.371, p -value 0.002) the three days before each holiday. The second primary outcome was COVID-19 infection at the zip-code level: COVID-19 infections recorded in the two-week period starting five days post-holiday declined by 3.5 percent (adjusted 95% CI [-6.2 percent, -0.7 percent], p -value 0.013) in intervention zip codes compared to control zip codes. ONE SENTENCE SUMMARY: In a large scale clustered randomized controlled trial, short messages recorded by health professionals before the winter holidays in the United States and sent as ads to social media users led to a significant reduction in holiday travel, and to a decrease in subsequent COVID-19 infection at the population level.

12.
Anal Biochem ; 402(2): 194-6, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20361920

RESUMO

High-resolution separation of alpha- and beta-tubulin by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) on minigels can be performed rapidly using simple modifications of the standard Laemmli procedure. Separation of the subunits can be observed even in high-protein loads (up to 40microg of protein).


Assuntos
Eletroforese em Gel de Poliacrilamida/métodos , Tubulina (Proteína)/isolamento & purificação , Animais , Bovinos , Eletroforese em Gel de Poliacrilamida/economia , Subunidades Proteicas/isolamento & purificação , Dodecilsulfato de Sódio
13.
Bioorg Med Chem Lett ; 19(10): 2884-7, 2009 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-19359169

RESUMO

A knowledge of the bioactive tubulin-binding conformation of paclitaxel (Taxol()) is crucial to a full understanding of the bioactivity of this important anticancer drug, and potentially also to the design of simplified analogs. The bioactive conformation has been shown to be best approximated by the T-Taxol conformation. As a further test of this conclusion, the paclitaxel analog 4 was designed as a compound which has all the chemical functionality necessary for activity, but which cannot adopt the T-Taxol conformation. The synthesis and bioassay of 4 confirmed its lack of activity, and thus provided further support for the T-Taxol conformation as the bioactive tubulin-binding conformation.


Assuntos
Antineoplásicos Fitogênicos/síntese química , Carbamatos/síntese química , Paclitaxel/análogos & derivados , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Carbamatos/química , Carbamatos/farmacologia , Linhagem Celular Tumoral , Humanos , Paclitaxel/síntese química , Paclitaxel/farmacologia , Tubulina (Proteína)/química
15.
Ann N Y Acad Sci ; 1136: 333-41, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18579890

RESUMO

The current trend in antipoverty policy emphasizes mandated empowerment: the poor are being handed the responsibility for making things better for themselves, largely without being asked whether this is what they want. Beneficiary control is now being built into public service delivery, while microcredit and small business promotion are seen as better ways to help the poor. The clear presumption is that the poor are both able and happy to exercise these new powers. This essay uses two examples to raise questions about these strategies. The first example is about entrepreneurship among the poor. Using data from a number of countries, we argue that there is no evidence that the median poor entrepreneur is trying his best to expand his existing businesses, even if we take into account the many constraints he faces. While many poor people own businesses, this seems to be more a survival strategy than something they want to do. The second example comes from an evaluation of a program in India that aims to involve poor rural parents in improving local public schools. The data suggest that despite being informed that they now have both the right to intervene in the school and access to funds for that purpose, and despite being made aware of how little the children were learning, parents opt to not get involved. Both examples raise concerns about committing ourselves entirely to antipoverty strategies that rely on the poor doing a lot of the work.


Assuntos
Participação da Comunidade , Formulação de Políticas , Pobreza/prevenção & controle , Autoeficácia , Educação , Empreendedorismo , Humanos , Índia
16.
Org Biomol Chem ; 6(24): 4542-52, 2008 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-19039362

RESUMO

Six epothilone D analogues with a bridge between the C4-methyl and the C12-methyl carbons were prepared in an attempt to constrain epothilone D to its proposed tubulin-binding conformation. Ring-closing metathesis (RCM) was employed as the key step to build the C4-C26 bridge. In antiproliferative assays in the human ovarian cancer (A2780) and prostate cancer (PC3) cell lines, and also in tubulin assembly assay, all these compounds proved to be less active than epothilone D.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Desenho de Fármacos , Epotilonas/síntese química , Epotilonas/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Epotilonas/química , Humanos , Modelos Moleculares , Conformação Molecular , Ligação Proteica/efeitos dos fármacos , Tubulina (Proteína)/metabolismo
17.
Economica ; 85(340): 671-700, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30374489

RESUMO

Randomized controlled trials have found only modest effects of microfinance, but these studies focus on new clients. Existing estimates may thus understate ongoing gains for more experienced borrowers and the longer-run potential of microfinance. We estimate impacts of microfinance on experienced borrowers, using an episode when a microfinance institution modestly increased existing clients' fees in randomly selected villages (in exchange for a mandatory health insurance policy that turned out to be useless). This increase in fees led to a 22 percentage point decline in loan renewal in treatment villages (95% confidence interval: 16 to 27), compared to control villages where the policy was not introduced. Using this randomly generated variation in microfinance participation among experienced borrowers, we find impacts of microfinance that are strikingly similar to previous estimates for new clients: neither business outcomes nor household consumption were affected, on average. Also, consistent with prior studies, we find significant impacts on business outcomes among clients who had started their businesses before microfinance entered the village (0.06 standard deviation decline in an index of business outcomes from the loss of microfinance, 95% confidence interval: -0.002 to -0.12). However, despite these measured losses, these clients were just as willing to give up microfinance.

19.
J Med Chem ; 50(4): 713-25, 2007 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-17263521

RESUMO

The important anticancer drug paclitaxel binds to the beta-subunit of the alphabeta-tubulin dimer in the microtubule in a stoichiometric ratio, promoting microtubule polymerization and stability. The conformation of microtubule-bound drug has been the subject of intense study, and various suggestions have been proposed. In previous work we presented experimental and theoretical evidence that paclitaxel adopts a T-shaped conformation when it is bound to tubulin. In this study we report additional experimental data and calculations that delineate the allowable parameters for effective paclitaxel-tubulin interactions.


Assuntos
Antineoplásicos/síntese química , Paclitaxel/análogos & derivados , Paclitaxel/síntese química , Tubulina (Proteína)/química , Antineoplásicos/farmacologia , Hidrocarbonetos Aromáticos com Pontes/síntese química , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Lactamas Macrocíclicas/síntese química , Lactamas Macrocíclicas/farmacologia , Modelos Moleculares , Conformação Molecular , Paclitaxel/farmacologia , Soluções , Estereoisomerismo , Relação Estrutura-Atividade
20.
J Med Microbiol ; 66(6): 762-769, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28598307

RESUMO

PURPOSE: The role of antibiotics below their MIC in the development of bacterial drug resistance is becoming increasingly important. We investigated the effect of sub-MICs of bactericidal antibiotics on the susceptibility pattern of Staphylococcus aureus and evaluated the role of free radicals. METHODOLOGY: A total of 12 S. aureus strains were recovered from pus samples and their antibiograms determined. The test isolates were treated with sub-MIC levels of tetracycline, gentamicin, ciprofloxacin and cefotaxime. Alterations in their respective breakpoints were observed along with measurements of free radical generation by nitro blue tetrazolium test.Results/Key findings. Gentamicin, ciprofloxacin and cefotaxime exposure significantly altered the breakpoints of exposed isolates against several tested antibiotics and higher levels of free radicals were generated after antibiotic exposure. CONCLUSIONS: Our study demonstrates that sub-MIC levels of antimicrobials can lead to resistance and cross-resistance across several classes of antibiotics in wild strains of S. aureus, possibly by free radical production. The molecular mechanisms behind the acquisition of drug resistance at low antibiotic concentrations and the specific target genes of reactive oxygen speciesneed to be explored further.


Assuntos
Antibacterianos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Cefotaxima/farmacologia , Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana Múltipla , Gentamicinas/farmacologia , Humanos , Meticilina/farmacologia , Testes de Sensibilidade Microbiana , Staphylococcus aureus/metabolismo
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