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1.
Nature ; 586(7830): 589-593, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32785213

RESUMO

In March 2020, the World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)1, a pandemic. With rapidly accumulating numbers of cases and deaths reported globally2, a vaccine is urgently needed. Here we report the available safety, tolerability and immunogenicity data from an ongoing placebo-controlled, observer-blinded dose-escalation study (ClinicalTrials.gov identifier NCT04368728) among 45 healthy adults (18-55 years of age), who were randomized to receive 2 doses-separated by 21 days-of 10 µg, 30 µg or 100 µg of BNT162b1. BNT162b1 is a lipid-nanoparticle-formulated, nucleoside-modified mRNA vaccine that encodes the trimerized receptor-binding domain (RBD) of the spike glycoprotein of SARS-CoV-2. Local reactions and systemic events were dose-dependent, generally mild to moderate, and transient. A second vaccination with 100 µg was not administered because of the increased reactogenicity and a lack of meaningfully increased immunogenicity after a single dose compared with the 30-µg dose. RBD-binding IgG concentrations and SARS-CoV-2 neutralizing titres in sera increased with dose level and after a second dose. Geometric mean neutralizing titres reached 1.9-4.6-fold that of a panel of COVID-19 convalescent human sera, which were obtained at least 14 days after a positive SARS-CoV-2 PCR. These results support further evaluation of this mRNA vaccine candidate.


Assuntos
Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Vacinas Virais/imunologia , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19 , Vacinas contra COVID-19 , Infecções por Coronavirus/genética , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/terapia , Feminino , Humanos , Imunização Passiva , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Pandemias , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Fatores de Tempo , Vacinas Virais/administração & dosagem , Vacinas Virais/efeitos adversos , Vacinas Virais/genética , Adulto Jovem , Soroterapia para COVID-19
2.
N Engl J Med ; 385(3): 239-250, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34043894

RESUMO

BACKGROUND: Until very recently, vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had not been authorized for emergency use in persons younger than 16 years of age. Safe, effective vaccines are needed to protect this population, facilitate in-person learning and socialization, and contribute to herd immunity. METHODS: In this ongoing multinational, placebo-controlled, observer-blinded trial, we randomly assigned participants in a 1:1 ratio to receive two injections, 21 days apart, of 30 µg of BNT162b2 or placebo. Noninferiority of the immune response to BNT162b2 in 12-to-15-year-old participants as compared with that in 16-to-25-year-old participants was an immunogenicity objective. Safety (reactogenicity and adverse events) and efficacy against confirmed coronavirus disease 2019 (Covid-19; onset, ≥7 days after dose 2) in the 12-to-15-year-old cohort were assessed. RESULTS: Overall, 2260 adolescents 12 to 15 years of age received injections; 1131 received BNT162b2, and 1129 received placebo. As has been found in other age groups, BNT162b2 had a favorable safety and side-effect profile, with mainly transient mild-to-moderate reactogenicity (predominantly injection-site pain [in 79 to 86% of participants], fatigue [in 60 to 66%], and headache [in 55 to 65%]); there were no vaccine-related serious adverse events and few overall severe adverse events. The geometric mean ratio of SARS-CoV-2 50% neutralizing titers after dose 2 in 12-to-15-year-old participants relative to 16-to-25-year-old participants was 1.76 (95% confidence interval [CI], 1.47 to 2.10), which met the noninferiority criterion of a lower boundary of the two-sided 95% confidence interval greater than 0.67 and indicated a greater response in the 12-to-15-year-old cohort. Among participants without evidence of previous SARS-CoV-2 infection, no Covid-19 cases with an onset of 7 or more days after dose 2 were noted among BNT162b2 recipients, and 16 cases occurred among placebo recipients. The observed vaccine efficacy was 100% (95% CI, 75.3 to 100). CONCLUSIONS: The BNT162b2 vaccine in 12-to-15-year-old recipients had a favorable safety profile, produced a greater immune response than in young adults, and was highly effective against Covid-19. (Funded by BioNTech and Pfizer; C4591001 ClinicalTrials.gov number, NCT04368728.).


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Imunogenicidade da Vacina , Adolescente , Adulto , Fatores Etários , Vacina BNT162 , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/efeitos adversos , Criança , Feminino , Humanos , Imunoglobulina G/sangue , Injeções Intramusculares/efeitos adversos , Masculino , Dor/etiologia , Resultado do Tratamento , Adulto Jovem
3.
N Engl J Med ; 385(19): 1761-1773, 2021 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-34525277

RESUMO

BACKGROUND: BNT162b2 is a lipid nanoparticle-formulated, nucleoside-modified RNA vaccine encoding a prefusion-stabilized, membrane-anchored severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) full-length spike protein. BNT162b2 is highly efficacious against coronavirus disease 2019 (Covid-19) and is currently approved, conditionally approved, or authorized for emergency use worldwide. At the time of initial authorization, data beyond 2 months after vaccination were unavailable. METHODS: In an ongoing, placebo-controlled, observer-blinded, multinational, pivotal efficacy trial, we randomly assigned 44,165 participants 16 years of age or older and 2264 participants 12 to 15 years of age to receive two 30-µg doses, at 21 days apart, of BNT162b2 or placebo. The trial end points were vaccine efficacy against laboratory-confirmed Covid-19 and safety, which were both evaluated through 6 months after vaccination. RESULTS: BNT162b2 continued to be safe and have an acceptable adverse-event profile. Few participants had adverse events leading to withdrawal from the trial. Vaccine efficacy against Covid-19 was 91.3% (95% confidence interval [CI], 89.0 to 93.2) through 6 months of follow-up among the participants without evidence of previous SARS-CoV-2 infection who could be evaluated. There was a gradual decline in vaccine efficacy. Vaccine efficacy of 86 to 100% was seen across countries and in populations with diverse ages, sexes, race or ethnic groups, and risk factors for Covid-19 among participants without evidence of previous infection with SARS-CoV-2. Vaccine efficacy against severe disease was 96.7% (95% CI, 80.3 to 99.9). In South Africa, where the SARS-CoV-2 variant of concern B.1.351 (or beta) was predominant, a vaccine efficacy of 100% (95% CI, 53.5 to 100) was observed. CONCLUSIONS: Through 6 months of follow-up and despite a gradual decline in vaccine efficacy, BNT162b2 had a favorable safety profile and was highly efficacious in preventing Covid-19. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04368728.).


Assuntos
Vacinas contra COVID-19 , COVID-19/prevenção & controle , Imunogenicidade da Vacina , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/análise , Vacina BNT162 , COVID-19/epidemiologia , Vacinas contra COVID-19/efeitos adversos , Vacinas contra COVID-19/imunologia , Criança , Feminino , Seguimentos , Humanos , Imunização Secundária , Incidência , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , Método Simples-Cego , Resultado do Tratamento , Adulto Jovem
4.
N Engl J Med ; 383(27): 2603-2615, 2020 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-33301246

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (Covid-19) have afflicted tens of millions of people in a worldwide pandemic. Safe and effective vaccines are needed urgently. METHODS: In an ongoing multinational, placebo-controlled, observer-blinded, pivotal efficacy trial, we randomly assigned persons 16 years of age or older in a 1:1 ratio to receive two doses, 21 days apart, of either placebo or the BNT162b2 vaccine candidate (30 µg per dose). BNT162b2 is a lipid nanoparticle-formulated, nucleoside-modified RNA vaccine that encodes a prefusion stabilized, membrane-anchored SARS-CoV-2 full-length spike protein. The primary end points were efficacy of the vaccine against laboratory-confirmed Covid-19 and safety. RESULTS: A total of 43,548 participants underwent randomization, of whom 43,448 received injections: 21,720 with BNT162b2 and 21,728 with placebo. There were 8 cases of Covid-19 with onset at least 7 days after the second dose among participants assigned to receive BNT162b2 and 162 cases among those assigned to placebo; BNT162b2 was 95% effective in preventing Covid-19 (95% credible interval, 90.3 to 97.6). Similar vaccine efficacy (generally 90 to 100%) was observed across subgroups defined by age, sex, race, ethnicity, baseline body-mass index, and the presence of coexisting conditions. Among 10 cases of severe Covid-19 with onset after the first dose, 9 occurred in placebo recipients and 1 in a BNT162b2 recipient. The safety profile of BNT162b2 was characterized by short-term, mild-to-moderate pain at the injection site, fatigue, and headache. The incidence of serious adverse events was low and was similar in the vaccine and placebo groups. CONCLUSIONS: A two-dose regimen of BNT162b2 conferred 95% protection against Covid-19 in persons 16 years of age or older. Safety over a median of 2 months was similar to that of other viral vaccines. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04368728.).


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2 , Adolescente , Adulto , Idoso , Vacina BNT162 , COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/efeitos adversos , Fadiga/etiologia , Feminino , Cefaleia/etiologia , Humanos , Imunização Secundária , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/genética , Método Simples-Cego , Resultado do Tratamento , Vacinas Sintéticas , Adulto Jovem , Vacinas de mRNA
5.
N Engl J Med ; 383(25): 2439-2450, 2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-33053279

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and the resulting disease, coronavirus disease 2019 (Covid-19), have spread to millions of persons worldwide. Multiple vaccine candidates are under development, but no vaccine is currently available. Interim safety and immunogenicity data about the vaccine candidate BNT162b1 in younger adults have been reported previously from trials in Germany and the United States. METHODS: In an ongoing, placebo-controlled, observer-blinded, dose-escalation, phase 1 trial conducted in the United States, we randomly assigned healthy adults 18 to 55 years of age and those 65 to 85 years of age to receive either placebo or one of two lipid nanoparticle-formulated, nucleoside-modified RNA vaccine candidates: BNT162b1, which encodes a secreted trimerized SARS-CoV-2 receptor-binding domain; or BNT162b2, which encodes a membrane-anchored SARS-CoV-2 full-length spike, stabilized in the prefusion conformation. The primary outcome was safety (e.g., local and systemic reactions and adverse events); immunogenicity was a secondary outcome. Trial groups were defined according to vaccine candidate, age of the participants, and vaccine dose level (10 µg, 20 µg, 30 µg, and 100 µg). In all groups but one, participants received two doses, with a 21-day interval between doses; in one group (100 µg of BNT162b1), participants received one dose. RESULTS: A total of 195 participants underwent randomization. In each of 13 groups of 15 participants, 12 participants received vaccine and 3 received placebo. BNT162b2 was associated with a lower incidence and severity of systemic reactions than BNT162b1, particularly in older adults. In both younger and older adults, the two vaccine candidates elicited similar dose-dependent SARS-CoV-2-neutralizing geometric mean titers, which were similar to or higher than the geometric mean titer of a panel of SARS-CoV-2 convalescent serum samples. CONCLUSIONS: The safety and immunogenicity data from this U.S. phase 1 trial of two vaccine candidates in younger and older adults, added to earlier interim safety and immunogenicity data regarding BNT162b1 in younger adults from trials in Germany and the United States, support the selection of BNT162b2 for advancement to a pivotal phase 2-3 safety and efficacy evaluation. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04368728.).


Assuntos
Vacinas contra COVID-19/efeitos adversos , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Vacina BNT162 , COVID-19/imunologia , Feminino , Humanos , Injeções Intramusculares/efeitos adversos , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Método Simples-Cego , Glicoproteína da Espícula de Coronavírus , Adulto Jovem
8.
Disabil Rehabil ; : 1-9, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38994847

RESUMO

PURPOSE: To explore the cause, influences and consequences of falling for adults with cerebral palsy (CP) across their life course, and how this is managed. MATERIALS AND METHODS: We used interview data from a multimethod UK study exploring the effects of ageing with CP and healthcare across the life course. Twenty-six participants were recruited and interviewed using various digital platforms to maximise inclusive participation in the UK. Follow-up email semi-structured interviews were conducted to further explore experiences of falls. Transcribed interviews were analysed thematically. RESULTS: Falling and fear of falling (FoF) is problematic for over half of the participants in the sample. They perceived falls and FoF as limiting their participation, autonomy and independence in employment, social and cultural activities. Participants used their own management strategies, due to limited specialist interventions or practitioner knowledge to manage or prevent falls. Practices, such as the use of a wheelchair or avoiding activities prompted changes to relationships and identity. CONCLUSIONS: Falling for adults with CP happens earlier in life compared to the general population. Adults with CP may benefit from specialist falls prevention services to help maintain muscle strength and balance. Research is needed to evaluate effective interventions for people with CP.


Falling negatively impacts on the lives and identities of people with cerebral palsy, including younger adults.In other areas such as services for older people, or those who have experienced stroke, rehabilitation services have helped people reduce falls rates through maintaining strength and balance.Falls prevention rehabilitation services are needed for people with cerebral palsy and should include relevant mobility devices and assistive technologies while maintaining social participation and quality of life.

9.
Vaccine ; 40(10): 1483-1492, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35131133

RESUMO

INTRODUCTION: Individuals with an underlying malignancy have high risk of poor COVID-19 outcomes. In clinical trials, COVID-19 vaccines were safe and efficacious against infection, hospitalization, and death, but most trials excluded participants with cancer. We report results from participants with a history of past or active neoplasm (malignant or benign/unknown) and up to 6 months' follow-up post-dose 2 from the placebo-controlled, observer-blinded trial of the 2-dose BNT162b2 mRNA COVID-19 vaccine. PATIENTS AND METHODS: Between July 2020-January 2021, 46,429 participants aged ≥ 12 years were randomized at 152 sites in 6 countries. Healthy participants with pre-existing stable neoplasm could participate; those receiving immunosuppressive therapy were excluded. Data are reported for participants, aged ≥ 16 years for safety and ≥ 12 years for efficacy, who had any history of neoplasm at baseline (data cut-off: March 13, 2021). Adverse-event (AE) data are controlled for follow-up time before unblinding and reported as incidence rates (IRs) per 100 person-years follow-up. RESULTS: At baseline, 3813 participants had a history of neoplasm; most common malignancies were breast (n = 460), prostate (n = 362), and melanoma (n = 223). Four BNT162b2 and 71 placebo recipients developed COVID-19 from 7 days post-dose 2; vaccine efficacy was 94.4% (95% CI: 85.2, 98.5) after up to 6 months' follow-up post-dose 2. This compares favorably with vaccine efficacy of 91.1% in the overall trial population after the same follow-up. AEs were reported at IRs of 95.4(BNT162b2) and 48.3 (placebo) per 100 person-years. Most common AEs were reactogenicity events (injection-site pain, fatigue, pyrexia). Three BNT162b2 and 1 placebo recipients withdrew because of vaccine-related AEs. No vaccine-related deaths were reported. CONCLUSION: In participants with past or active neoplasms, BNT162b2 vaccine has a similar efficacy and safety profile as in the overall trial population. These results can inform BNT162b2 use during the COVID-19 pandemic and future trials in participants with cancer. Clinical trial number: NCT04368728.


Assuntos
COVID-19 , Neoplasias , Adolescente , Vacina BNT162 , Vacinas contra COVID-19 , Criança , Humanos , Masculino , Pandemias , RNA Mensageiro , SARS-CoV-2
10.
Health (London) ; 24(5): 535-551, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-30606063

RESUMO

Taking a social model of disability approach, this article explores how disabled people negotiate barriers in the large, modern hospital settings typically found in complex healthcare systems. While there is evidence of intractable barriers in the United Kingdom's National Health Service, little is known about the actions disabled people take in the face of barriers and the immediate effects of doing so. Analysis of data from a qualitative study of disabled people's healthcare encounters is presented. This draws on the concept of threats to embodied well-being to understand how disabled people perceive barriers and the influence this perception has on barrier negotiation. It demonstrates that some barriers are unique to healthcare and that these place disabled people in situations where their well-being is threatened. Despite these situations being inherently disempowering, disabled people are forced to take whatever action they can to protect the embodied self. We theorise that barriers are created inadvertently by the design, organisation and healthcare practices characteristics of modern hospital settings. Effective barrier removal requires understanding not only their impact on disabled people's embodied well-being, but also the political, policy and social relations implicated in their creation.


Assuntos
Pessoas com Deficiência/psicologia , Acessibilidade aos Serviços de Saúde , Hospitais , Negociação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Medicina Estatal , Reino Unido
11.
medRxiv ; 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32839784

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and the resulting disease, coronavirus disease 2019 (COVID-19), have spread to millions of people globally. Multiple vaccine candidates are under development, but no vaccine is currently available. METHODS: Healthy adults 18-55 and 65-85 years of age were randomized in an ongoing, placebo-controlled, observer-blinded dose-escalation study to receive 2 doses at 21-day intervals of placebo or either of 2 lipid nanoparticle-formulated, nucleoside-modified RNA vaccine candidates: BNT162b1, which encodes a secreted trimerized SARS-CoV-2 receptor-binding domain, or BNT162b2, which encodes a prefusion stabilized membrane-anchored SARS-CoV-2 full-length spike. In each of 13 groups of 15 participants, 12 received vaccine and 3 received placebo. Groups were distinguished by vaccine candidate, age of participant, and vaccine dose level. Interim safety and immunogenicity data of BNT162b1 in younger adults have been reported previously from US and German trials. We now present additional safety and immunogenicity data from the US Phase 1 trial that supported selection of the vaccine candidate advanced to a pivotal Phase 2/3 safety and efficacy evaluation. RESULTS: In both younger and older adults, the 2 vaccine candidates elicited similar dose-dependent SARS-CoV-2-neutralizing geometric mean titers (GMTs), comparable to or higher than the GMT of a panel of SARS-CoV-2 convalescent sera. BNT162b2 was associated with less systemic reactogenicity, particularly in older adults. CONCLUSION: These results support selection of the BNT162b2 vaccine candidate for Phase 2/3 large-scale safety and efficacy evaluation, currently underway.

12.
Crit Care Med ; 37(10): 2775-81, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19581803

RESUMO

OBJECTIVE: To determine a) if a checklist covering a diverse group of intensive care unit protocols and objectives would improve clinician consideration of these domains and b) if improved consideration would change practice patterns. DESIGN: Pre- and post observational study. SETTING: A 24-bed surgical/burn/trauma intensive care unit in a teaching hospital. PATIENTS: A total of 1399 patients admitted between June 2006 and May 2007. INTERVENTIONS: The first component of the study evaluated whether mandating verbal review of a checklist covering 14 intensive care unit best practices altered verbal consideration of these domains. Evaluation was performed using real-time bedside audits on morning rounds. The second component evaluated whether the checklist altered implementation of these domains by changing practice patterns. Evaluation was performed by analyzing data from the Project IMPACT database after patients left the intensive care unit. MEASUREMENTS AND MAIN RESULTS: Verbal consideration of evaluable domains improved from 90.9% (530/583) to 99.7% (669/671, p < .0001) after verbal review of the checklist was mandated. Bedside consideration improved on the use of deep venous thrombosis prophylaxis (p < .05), stress ulcer prophylaxis (p < .01), oral care for ventilated patients (p < 0.01), electrolyte repletion (p < .01), initiation of physical therapy (p < .05), and documentation of restraint orders (p < .0001). Mandatory verbal review of the checklist resulted in a greater than two-fold increase in transferring patients out of the intensive care unit on telemetry (16% vs. 35%, p < .0001) and initiation of physical therapy (28% vs. 42%, p < .0001) compared with baseline practice. CONCLUSIONS: A mandatory verbal review of a checklist covering a wide range of objectives and goals at each patient's bedside is an effective method to improve both consideration and implementation of intensive care unit best practices. A bedside checklist is a simple, cost-effective method to prevent errors of omission in basic domains of intensive care unit management that might otherwise be forgotten in the setting of more urgent care requirements.


Assuntos
Cuidados Críticos/normas , Medicina Baseada em Evidências/normas , Fidelidade a Diretrizes/normas , Implementação de Plano de Saúde , Programas Obrigatórios , Análise Custo-Benefício/normas , Cuidados Críticos/economia , Medicina Baseada em Evidências/economia , Feminino , Fidelidade a Diretrizes/economia , Implementação de Plano de Saúde/economia , Mortalidade Hospitalar , Hospitais de Ensino/economia , Hospitais Universitários , Humanos , Unidades de Terapia Intensiva/economia , Unidades de Terapia Intensiva/estatística & dados numéricos , Tempo de Internação/economia , Masculino , Programas Obrigatórios/economia , Programas Obrigatórios/estatística & dados numéricos , Erros Médicos/prevenção & controle , Pessoa de Meia-Idade , Avaliação de Processos e Resultados em Cuidados de Saúde/estatística & dados numéricos , Transferência de Pacientes/economia , Transferência de Pacientes/normas , Garantia da Qualidade dos Cuidados de Saúde/economia , Garantia da Qualidade dos Cuidados de Saúde/normas , Resultado do Tratamento , Washington
14.
Nurs Manag (Harrow) ; 13(1): 16-9, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16602558

RESUMO

The implementation of two key policies highlighted the need to support nurses and midwives to challenge colleagues effectively. To overcome the difficulties this presented, an innovative training package using drama provided participants with practical tips and a safe environment to practise newly developed skills. The programme was well evaluated but further work needs to be undertaken to evaluate its impact upon practice.


Assuntos
Drama , Capacitação em Serviço/métodos , Recursos Humanos de Enfermagem Hospitalar/educação , Qualidade da Assistência à Saúde/normas , Humanos , Controle de Infecções/normas , Cultura Organizacional , Reino Unido
15.
Toxicol Sci ; 81(2): 332-43, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15254333

RESUMO

Allergic contact dermatitis resulting from skin sensitization is a common occupational and environmental health problem. In recent years, the local lymph node assay (LLNA) has emerged as a practical option for assessing the skin sensitization potential of chemicals. In addition to accurate identification of skin sensitizers, the LLNA can also provide a reliable measure of relative sensitization potency; information that is pivotal in successful management of human health risks. However, even with the significant animal welfare benefits provided by the LLNA, there is still interest in the development of nonanimal test methods for skin sensitization testing. One characteristic of a chemical allergen is its ability to react with proteins prior to the induction of skin sensitization. The majority of chemical allergens is electrophilic and as such reacts with nucleophilic amino acids like cysteine or lysine. In order to determine if reactivity correlates with sensitization potential, 38 chemicals representing allergens of different potencies (weak to extreme) and nonsensitizers were evaluated for their ability to react with glutathione or three synthetic peptides containing either cysteine, lysine, or histidine. Following a 15-min reaction time for glutathione or a 24 h reaction period for the three synthetic peptides, the samples were analyzed by HPLC. UV detection was used to monitor the depletion of glutathione or the peptide following reaction. The results demonstrate that a significant correlation (Spearman correlation) exists between allergen potency and the depletion of glutathione (p = 0.001), lysine (p = 0.025), and cysteine (p = 0.020), but not histidine. The peptide with the highest sensitivity was cysteine (80.8%) whereas histidine was the least sensitive (11.5%). The data presented show that measuring peptide reactivity has utility for screening chemicals for their skin sensitization potency and thus potential for reducing our reliance on animal test methods.


Assuntos
Alérgenos/toxicidade , Dermatite Alérgica de Contato/diagnóstico , Peptídeos/toxicidade , Algoritmos , Aminoácidos/química , Animais , Calibragem , Cromatografia Líquida de Alta Pressão , Cisteína/química , Cisteína/toxicidade , Feminino , Glutationa/metabolismo , Histidina/química , Histidina/toxicidade , Cinética , Ensaio Local de Linfonodo , Lisina/química , Lisina/toxicidade , Camundongos , Camundongos Endogâmicos CBA , Peptídeos/química , Testes Cutâneos , Espectrofotometria Ultravioleta , Relação Estrutura-Atividade
17.
Nurs Manag (Harrow) ; 13(1): 16-19, 2006 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27718952
20.
Toxicol Lett ; 188(2): 119-29, 2009 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-19446244

RESUMO

To address the provision of the 7th Amendment to the EU Cosmetics Directive banning the use of in vivo genotoxicity assays for testing cosmetic ingredients in 2009, the 3D EpiDerm reconstructed human skin micronucleus assay has been developed. To further characterise the EpiDerm tissue for potential use in genotoxicity testing, we have evaluated the dermal penetration and metabolism of two hair dye ingredients, p-aminophenol (PAP) and p-phenylenediamine (PPD) in this reconstructed epidermis model. When EpiDerm tissue was topically exposed to PAP or PPD for 30 min (typical for a hair dye exposure), the majority (80->90%) of PAP or PPD was excluded from skin tissue and removed by rinsing. After a 23.5h recovery period, the PAP fraction that did penetrate was completely N-acetylated to acetaminophen (APAP). Similarly, 30 min topical application of PPD resulted in the formation of the N-mono- and N,N'-diacetylated metabolites of PPD. These results are consistent with published data on the dermal metabolism of these compounds from other in vitro systems as well as from in vivo studies. When tissue was exposed topically (PAP) or via the culture media (PPD) for 24h, there was good batch-to-batch and donor-to-donor reproducibility in the penetration and metabolism of PAP and PPD. Overall, the results demonstrate that these two aromatic amines are biotransformed in 3D EpiDerm tissue via N-acetylation. Characterising the metabolic capability of EpiDerm tissue is important for the evaluation of this model for use in genotoxicity testing.


Assuntos
Aminofenóis/metabolismo , Epiderme/metabolismo , Modelos Biológicos , Fenilenodiaminas/metabolismo , Absorção Cutânea , Aminofenóis/farmacocinética , Biotransformação , Calibragem , Cromatografia Líquida de Alta Pressão , Qualidade de Produtos para o Consumidor , Tinturas para Cabelo/química , Tinturas para Cabelo/farmacocinética , Tinturas para Cabelo/toxicidade , Humanos , Espectrometria de Massas , Técnicas de Cultura de Órgãos , Fenilenodiaminas/farmacocinética , Soluções
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