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1.
Int J Obstet Anesth ; 57: 103935, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37925355

RESUMO

BACKGROUND: Caesarean section (CS) is a major abdominal surgery performed usually on a young and healthy population under neuraxial anesthesia with little to no sedation. This creates a distinct surgical experience whereby patients are aware of the surgical process, physical sensations, and their environment. This study aimed to provide an in-depth descriptive assessment of subjective surgical experience during CS under regional anaesthesia. We expected the information gained would enhance our current understanding and better alleviate patient anxiety through informed counselling. METHODS: This qualitative descriptive study was conducted at a Canadian academic centre. Twenty patients participated in semi-structured interviews within a week of CS, using an interview guide developed for this study. Patient medical records were reviewed to collect demographic and surgical information. Thematic analysis was conducted using an inductive approach to determine common themes. RESULTS: Nine themes were identified. Five themes were identified in the category of surgical sensation and four themes were identified in the category of peri-operative education. CONCLUSIONS: Patients commonly experienced pressure and movement sensations at varying intensity, and most did not experience pain. Environmental factors, including sounds and distraction by the newborn, affected perception of surgical sensation. Patients wish to receive pre-operative counselling regarding potential surgical sensations, as well as ongoing communication from their anaesthesiologist. These results can be used to guide informed discussions with patients and direct further investigation in this area.


Assuntos
Anestesia por Condução , Cesárea , Recém-Nascido , Humanos , Feminino , Gravidez , Canadá , Pesquisa Qualitativa , Sensação
2.
J Infect Dis ; 228(Suppl 6): S355-S358, 2023 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-37849398

RESUMO

Given the increased risk of pandemics driven by emerging and reemerging infectious diseases, it is imperative that the United States and global scientific community be better prepared for future threats by prioritizing and launching key research programs and strategies. In December 2021, the National Institute of Allergy and Infectious Diseases (NIAID) published its pandemic preparedness plan, which focuses on the prototype pathogen approach for medical countermeasure development. The plan was introduced before its release at a NIAID-hosted workshop in November 2021 that featured scientific experts from the extramural community, government, and the private sector and focused on selection of prototype pathogens from 10 viral families with pandemic risk and moderate resources. This article will serve as an introduction to this special issue and will briefly define the prototype pathogen approach, describe the workshop goals and process for outcomes, and provide an outline of the viral working group articles to follow and future directions for NIAID.


Assuntos
Doenças Transmissíveis Emergentes , Vacinas , Estados Unidos , Humanos , National Institute of Allergy and Infectious Diseases (U.S.) , Pandemias/prevenção & controle
3.
J Public Health (Oxf) ; 45(4): 935-946, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-37496202

RESUMO

BACKGROUND: The prevalence of childhood obesity has been increasing for several decades. Active video games (AVG) may be an effective intervention to help manage this rising health crisis. The aim of this review is to evaluate whether AVG are effective at reducing weight or improving body composition in overweight youths. METHOD: Medline, Embase, SportDiscus, ASSIA, CINAHL Plus, CENTRAL, CDSR and PsychINFO databases were searched for studies assessing quantitative or qualitative impact of AVG in overweight adolescents published in English. Three authors screened the results using inclusion/exclusion criteria. RESULTS: A total of 12 studies met the inclusion criteria; 11 reported a significant decrease in at least one weight outcome. Results from seven randomized controlled trials were pooled by meta-analysis, which compared with controls subjects in AVG groups demonstrated greater body mass index (BMI) Z-score reduction (mean difference: -0.09 (-0.12, -0.05) I2 = 34%, P < 0.0001). The mean weight reduction (-2.66 Kg (-5.67, +0.35) I2 = 0%, P = 0.08) and BMI (-2.29 (-4.81, +0.22) I2 = 49%, P = 0.07) were greater in AVG groups but results did not reach statistical significance. CONCLUSIONS: BMI Z-score was significantly reduced in the AVG group and the majority of included studies reported significant results in at least one weight outcome, suggesting AVG can be used to reduce weight or improve body composition in overweight youths. Further studies investigating the long-term sustainability of this change in body composition are needed.


Assuntos
Obesidade Infantil , Jogos de Vídeo , Criança , Humanos , Adolescente , Obesidade Infantil/prevenção & controle , Sobrepeso/prevenção & controle , Índice de Massa Corporal
4.
J Infect Dis ; 227(12): 1433-1441, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35876700

RESUMO

Severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) emerged 20 years ago, presaging a series of subsequent infectious disease epidemics of international concern. The recent emergence of SARS-CoV-2 has underscored the importance of targeted preparedness research to enable rapid countermeasure development during a crisis. In December 2021 the National Institute of Allergy and Infectious Diseases (NIAID), building upon the successful strategies developed during the SARS-CoV-2 response and to prepare for future pandemics, published a pandemic preparedness plan that outlined a research strategy focused on priority pathogens, technology platforms, and prototype pathogens. To accelerate the discovery, development, and evaluation of medical countermeasures against new or previously unknown pathogens of pandemic potential, we present here a strategy of research directed at select prototype pathogens. In this manner, leveraging a prototype pathogen approach may serve as a powerful cornerstone in biomedical research preparedness to protect public health from newly emerging and reemerging infectious diseases.


Assuntos
Pandemias , Vacinas , Surtos de Doenças , National Institute of Allergy and Infectious Diseases (U.S.) , Pandemias/prevenção & controle , Desenvolvimento de Vacinas , Doenças Transmissíveis/epidemiologia
6.
Epidemiol Infect ; 149: e36, 2021 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33509318

RESUMO

This paper describes the epidemiology of coronavirus disease 2019 (COVID-19) in Northern Ireland (NI) between 26 February 2020 and 26 April 2020, and analyses enhanced surveillance and contact tracing data collected between 26 February 2020 and 13 March 2020 to estimate secondary attack rates (SAR) and relative risk of infection among different categories of contacts of individuals with laboratory confirmed severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Our results show that during the study period COVID-19 cumulative incidence and mortality was lower in NI than the rest of the UK. Incidence and mortality were also lower than in the Republic of Ireland (ROI), although these observed differences are difficult to interpret given considerable differences in testing and surveillance between the two nations. SAR among household contacts was 15.9% (95% CI 6.6%-30.1%), over 6 times higher than the SAR among 'high-risk' contacts at 2.5% (95% CI 0.9%-5.4%). The results from logistic regression analysis of testing data on contacts of laboratory-confirmed cases show that household contacts had 11.0 times higher odds (aOR: 11.0, 95% CI 1.7-70.03, P-value: 0.011) of testing positive for SARS-CoV-2 compared to other categories of contacts. These results demonstrate the importance of the household as a locus of SARS-CoV-2 transmission, and the urgency of identifying effective interventions to reduce household transmission.


Assuntos
COVID-19/epidemiologia , SARS-CoV-2 , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Busca de Comunicante , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Irlanda do Norte/epidemiologia , Vigilância da População , Adulto Jovem
7.
Epidemiol Infect ; 147: e321, 2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31826785

RESUMO

Diversified farms are operations that raise a variety of crops and/or multiple species of livestock, with the goal of utilising the products of one for the growth of the other, thus fostering a sustainable cycle. This type of farming reflects consumers' increasing demand for sustainably produced, naturally raised or pasture-raised animal products that are commonly produced on diversified farms. The specific objectives of this study were to characterise diversified small-scale farms (DSSF) in California, estimate the prevalence of Salmonella enterica and Campylobacter spp. in livestock and poultry, and evaluate the association between farm- and sample-level risk factors and the prevalence of Campylobacter spp. on DSSF in California using a multilevel logistic model. Most participating farms were organic and raised more than one animal species. Overall Salmonella prevalence was 1.19% (95% confidence interval (CI95) 0.6-2), and overall Campylobacter spp. prevalence was 10.8% (CI95 = 9-12.9). Significant risk factors associated with Campylobacter spp. were farm size (odds ratio (OR)10-50 acres: less than 10 acres = 6, CI95 = 2.11-29.8), ownership of swine (OR = 9.3, CI95 = 3.4-38.8) and season (ORSpring: Coastal summer = 3.5, CI95 = 1.1-10.9; ORWinter: Coastal summer = 3.23, CI95 = 1.4-7.4). As the number of DSSF continues to grow, evaluating risk factors and management practices that are unique to these operations will help identify risk mitigation strategies and develop outreach materials to improve the food safety of animal and vegetable products produced on DSSF.


Assuntos
Infecções por Campylobacter/veterinária , Gado , Doenças das Aves Domésticas/epidemiologia , Salmonelose Animal/epidemiologia , Salmonella enterica/isolamento & purificação , Animais , California/epidemiologia , Infecções por Campylobacter/diagnóstico , Infecções por Campylobacter/epidemiologia , Estudos Transversais , Modelos Logísticos , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/microbiologia , Prevalência , Fatores de Risco , Salmonelose Animal/diagnóstico
8.
Neurosci Lett ; 711: 134437, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31422098

RESUMO

Parkinson's disease (PD) is characterised pathologically by degeneration of the dopaminergic (DA) neurones of the substantia nigra pars compacta (SNpc) and the presence of α-synuclein containing Lewy body inclusions. Trichloroethylene (TCE) has been suggested as a potential environmental chemical that may contribute to the development of PD, via conversion to the neurotoxin, 1-Trichloromethyl-1,2,3,4-tetrahydro-ß-carboline (TaClo). We investigated the effect of an 8 week exposure to TCE or TaClo on wild type and, as an experimental model of PD, A30P mutant α-synuclein overexpressing mice using a combination of behaviour and pathology. TCE or TaClo exposure caused significant DA neuronal loss within the SNpc in both wild type and transgenic mice. Cell numbers were lower in A30P animals than wild type, however, no additive effect of TCE or TaClo exposure and A30P overexpression was found. TCE or TaClo did not appear to lead to acceleration of motor or cognitive deficits in either wild type or A30P mutant mice, potentially because of the modest reductions of DA neuronal number in the SNpc. Our results do however suggest that TCE exposure could be a possible factor in development of PD like changes following exposure.


Assuntos
Neurônios Dopaminérgicos/efeitos dos fármacos , Degeneração Neural/patologia , Neurotoxinas/toxicidade , Transtornos Parkinsonianos/patologia , Tricloroetileno/toxicidade , Animais , Neurônios Dopaminérgicos/patologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação , Neurotoxinas/metabolismo , Substância Negra/efeitos dos fármacos , Substância Negra/patologia , Tricloroetileno/metabolismo , alfa-Sinucleína/genética
9.
Epidemiol Infect ; 147: e141, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30869054

RESUMO

The burden of community-associated Clostridium difficile infection (CA-CDI) has increased. We aimed to describe the epidemiology of CA-CDI to inform future interventions. We used population-based linked surveillance data from 2012 to 2016 to describe socio-demographic factors, ribotype and mortality for all CA (n = 1303) and hospital-associated (HA, n = 1356) CDI. For 483 community-onset (CO) CA-CDI and 287 COHA-CDI cases, a questionnaire on risk factors was completed and we conducted a case-case study using logistic regression models for univariate and multivariable analysis. CA-CDI cases had lower odds of being male (adjusted odds ratio (AOR) 0.71, 95% confidence interval (CI) 0.58-0.87; P < 0.001), and higher odds of living in rural rather than urban settlement (AOR 1.5, 95% CI 1.1-2.1; P = 0.05) compared with HA-CDI cases. The distribution of ribotypes was similar in both groups with RT078 being most prevalent. CDI-specific death was lower in CA-CDI than HA-CDI (7% vs. 11%, P < 0.001). COCA-CDI had lower odds of having had an outpatient appointment in the previous 4 weeks compared with COHA-CDI (AOR 0.61; 95% CI 0.41-0.9, P = 0.01) and lower odds of being in a care home or hospice when compared with their own home, than COHA-CDI (AOR 0.66; 95% CI 0.45-0.98 and AOR 0.35; 95% CI 0.13-0.92, P = 0.02). Exposure to gastric acid suppressants (50% in COCA-CDI and 55% in COHA-CDI) and antimicrobial therapy (18% in COCA-CDI and 20% in COHA-CDI) prior to CDI was similar. Our analysis of community-onset cases suggests that other risk factors for COHA-CDI may be equally important for COCA-CDI. Opportunities to safely reduce antibiotic and gastric acid suppressants use should be investigated in all healthcare settings.


Assuntos
Infecções por Clostridium/epidemiologia , Infecções Comunitárias Adquiridas/epidemiologia , Infecção Hospitalar/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Irlanda do Norte/epidemiologia , Fatores de Risco , Adulto Jovem
10.
Med Mycol ; 57(1): 23-29, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29390156

RESUMO

In Northern Ireland there are concerns about candidaemia, with rates higher than those reported in England and Wales. Our aim was to explore the epidemiology of candidaemia during a 10 year period and the clinical management upon suspicion of cases during a one year enhanced investigation in Northern Ireland.Candidaemia reports to the Public Health Agency were validated during 2002-2011 and used to examine incidence and antifungal sensitivity trends (during 2007-2011). A clinical proforma was used to collate information for all patients with candidaemia in 2011.The majority (96%) of isolates were captured through voluntary laboratory reporting. There was a year-on-year increase in candidaemia from 2002-2011, from 80 to 131 episodes (incidence rate ratio 1.09 95% CI 1.05-1.13). Rates were highest in males under 1 year and over 75 years. 83/98 (85%) of case notes were available from candidaemia patients during 2011. The most prevalent risk factors were patients on total parenteral nutrition (26 people, 31.3%), surgery in the two months prior to the candidaemia (25 people, 30.1%), significant steroid use in the previous 3 months (24 people, 28.9%) and active neoplastic disease (23 people, 27.7%),This study confirmed an increase in candidaemia rates over time, with the observed incidence in 2011 higher than England and Wales. We identified areas for improvement around the clinical management of candidaemia. We recommend raising the awareness of guidelines for fundoscopy, echocardiography and central venous catheter removal.


Assuntos
Antifúngicos/uso terapêutico , Candidemia/tratamento farmacológico , Candidemia/epidemiologia , Antifúngicos/farmacologia , Candida/classificação , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Candidemia/prevenção & controle , Bases de Dados Factuais , Feminino , Humanos , Incidência , Masculino , Testes de Sensibilidade Microbiana/estatística & dados numéricos , Testes de Sensibilidade Microbiana/tendências , Irlanda do Norte/epidemiologia , Estudos Retrospectivos , Fatores de Risco
11.
J Therm Biol ; 70(Pt B): 86-96, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29108562

RESUMO

The thermal coadaptation hypothesis posits that ectotherms thermoregulate behaviorally to maintain body temperatures (Tb) that maximize performance, such as net energy gain. Huey's (1982) energetics model describes how food availability and Tb interact to affect net energy gain. We tested the thermal coadaptation hypothesis and Huey's energetics model with growth rates of juvenile Yarrow's spiny lizards (Sceloporus jarrovii). We compared the preferred (selected) Tb range (Tsel) of lizards in high and low energy states to their optimal temperature (To) for growth over nine weeks, and determined whether the To for growth depended on food availability. We also measured the same lizards' resting metabolic rate at five Tbs to test the energetics model assumptions that metabolic cost increases exponentially with Tb and does not differ between energy states. The Tsel of lizards on both diets overlapped with the To for growth. The assumptions of the energetics model were verified, but the To for net energy gain did not depend on food availability. Therefore, we found support for the thermal coadaptation hypothesis. We did not find support for the energetics model, but this may have been due to low statistical power.


Assuntos
Regulação da Temperatura Corporal , Lagartos/crescimento & desenvolvimento , Lagartos/fisiologia , Animais , Temperatura Corporal , Ingestão de Alimentos , Metabolismo Energético , Feminino , Masculino , Temperatura
12.
Eur J Public Health ; 27(suppl_2): 62-67, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28431085

RESUMO

Background: : In Europe, over 70% of the population live in urban areas (UAs). Most international comparative health research is done using national level data, as reliable and comparable urban data are often unavailable or difficult to access. This study aims to investigate whether population health is different in UAs compared with their corresponding countries. : Routinely available health-related data were collected by the EURO-URHIS 2 project, for 10 European countries and for 24 UAs within those countries. National and UA level data for 11 health indicators were compared through the calculation of relative difference, and geographical patterns within Europe were investigated using the Mann Whitney U test. Linear regression modelling was used to adjust for population density, gross domestic product and urbanicity. : In general, the urban population in Eastern Europe is less healthy than the Western European urban population. However, people in Eastern Europe have significantly better broad health outcomes in UAs as compared with the corresponding country as a whole, whereas people in Western Europe have generally worse broader health outcomes in UAs. : For most European countries and UAs that were investigated, the national level health status data does not correspond with the health status at UA level. In order to identify health problems in UAs and to provide information for local health policy, health monitoring and international benchmarking should also be conducted at the local level.


Assuntos
Nível de Saúde , Saúde da População Urbana/estatística & dados numéricos , Europa (Continente)/epidemiologia , Europa Oriental/epidemiologia , Feminino , Política de Saúde , Indicadores Básicos de Saúde , Humanos , Expectativa de Vida , Masculino , População Urbana/estatística & dados numéricos
13.
Int J Obes (Lond) ; 40(6): 921-8, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26984418

RESUMO

BACKGROUND/OBJECTIVE: Obesity and metabolic diseases are at an alarming level globally and increasingly affect children and adolescents. Gastric bypass and other bariatric surgeries have proven remarkably successful and are increasingly performed worldwide. Reduced desire to eat and changes in eating behavior and food choice account for most of the initial weight loss and diabetes remission after surgery, but the underlying mechanisms of altered gut-brain communication are unknown. SUBJECTS/METHODS: To explore the potential involvement of a powerful brainstem anorexia pathway centered around the lateral parabrachial nucleus (lPBN), we measured meal-induced neuronal activation by means of c-Fos immunohistochemistry in a new high-fat diet-induced obese mouse model of Roux-en-Y gastric bypass (RYGB) at 10 and 40 days after RYGB or sham surgery. RESULTS: Voluntary ingestion of a meal 10 days after RYGB, but not after sham surgery, strongly and selectively activates calcitonin gene-related peptide neurons in the external lPBN as well as neurons in the nucleus tractus solitarius, area postrema and medial amygdala. At 40 days after surgery, meal-induced activation in all these areas was greatly diminished and did not reach statistical significance. CONCLUSIONS: The neural activation pattern and dynamics suggest a role of the brainstem anorexia pathway in the early effects of RYGB on meal size and food intake that may lead to adaptive neural and behavioral changes involved in the control of food intake and body weight at a lower level. However, selective inhibition of this pathway will be required for a more causal implication.


Assuntos
Anorexia/fisiopatologia , Modelos Animais de Doenças , Ingestão de Alimentos , Comportamento Alimentar , Derivação Gástrica , Núcleos Parabraquiais/fisiopatologia , Animais , Dieta Hiperlipídica , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/patologia , Obesidade/cirurgia , Resposta de Saciedade
14.
Euro Surveill ; 20(21)2015 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-26062559

RESUMO

We report an outbreak of four confirmed cases of invasive pneumococcal disease (IPD) in individuals occupationally exposed to welding fumes, at a Belfast shipyard (Northern Ireland). All cases were hospitalised. A high-risk sub-group of 679 workers has been targeted for antibiotic prophylaxis and pneumococcal vaccination. Physicians and public health institutions outside Northern Ireland should be alert to individuals presenting with pneumonia or IPD and recent links to the shipyard, to facilitate early assessment and treatment.


Assuntos
Surtos de Doenças/prevenção & controle , Indústrias , Exposição por Inalação/efeitos adversos , Exposição Ocupacional/efeitos adversos , Pneumonia Pneumocócica/epidemiologia , Soldagem , Adulto , Amoxicilina/administração & dosagem , Antibioticoprofilaxia/métodos , Azitromicina/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Irlanda do Norte/epidemiologia , Vacinas Pneumocócicas/administração & dosagem , Pneumonia Pneumocócica/prevenção & controle , Estudos Retrospectivos , Vacinação
15.
Anim Genet ; 46(2): 213-5, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25690906

RESUMO

The Mangalarga Marchador (MM) is a Brazilian horse breed known for a uniquely smooth gait. A recent publication described a mutation in the DMRT3 gene that the authors claim controls the ability to perform lateral patterned gaits (Andersson et al. 2012). We tested 81 MM samples for the DMRT3 mutation using extracted DNA from hair bulbs using a novel RFLP. Horses were phenotypically categorized by their gait type (batida or picada), as recorded by the Brazilian Mangalarga Marchador Breeders Association (ABCCMM). Statistical analysis using the plink toolset (Purcell, 2007) revealed significant association between gait type and the DMRT3 mutation (P = 2.3e-22). Deviation from Hardy-Weinberg equilibrium suggests that selective pressure for gait type is altering allele frequencies in this breed (P = 1.00e-5). These results indicate that this polymorphism may be useful for genotype-assisted selection for gait type within this breed. As both batida and picada MM horses can perform lateral gaits, the DMRT3 mutation is not the only locus responsible for the lateral gait pattern.


Assuntos
Marcha/genética , Cavalos/genética , Fatores de Transcrição/genética , Animais , Brasil , Cruzamento , Frequência do Gene , Genótipo , Mutação , Polimorfismo de Fragmento de Restrição
16.
Clin Immunol ; 155(1): 91-107, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25229164

RESUMO

To identify the most promising vaccine candidates for combinatorial strategies, we compared five SIV vaccine platforms including recombinant canary pox virus ALVAC, replication-competent adenovirus type 5 host range mutant RepAd, DNA, modified vaccinia Ankara (MVA), peptides and protein in distinct combinations. Three regimens used viral vectors (prime or boost) and two regimens used plasmid DNA. Analysis at necropsy showed that the DNA-based vaccine regimens elicited significantly higher cellular responses against Gag and Env than any of the other vaccine platforms. The T cell responses induced by most vaccine regimens disseminated systemically into secondary lymphoid tissues (lymph nodes, spleen) and effector anatomical sites (including liver, vaginal tissue), indicative of their role in viral containment at the portal of entry. The cellular and reported humoral immune response data suggest that combination of DNA and viral vectors elicits a balanced immunity with strong and durable responses able to disseminate into relevant mucosal sites.


Assuntos
Imunidade Celular , Vírus da Imunodeficiência Símia/imunologia , Vacinas Virais/imunologia , Animais , Antígenos Virais/imunologia , Linfócitos T CD8-Positivos , Células Cultivadas , Feminino , Macaca mulatta
17.
Biochim Biophys Acta ; 1840(10): 3190-7, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25018004

RESUMO

BACKGROUND: Excess 5-aminolevulinic acid (ALA) and α-aminoacetone (AA) are implicated in ketosis, porphyrinpathies and diabetes. Pathologic manifestations involve O2⁻, H2O2, OH, enoyl radicals (ALA and AA) and their oxidation end products. METHODS: To characterize enoyl radicals resulting from reaction of OH radicals with ALA and AA, micromolar OH concentrations were produced by pulse radiolysis of ALA and AA in aqueous solutions. RESULTS: ALA and AA react with OH at k=1.5 × 109 M⁻¹s⁻¹. At pH7.4, the ALA absorbance spectrum has a maximum at 330 nm (ε=750 M⁻¹cm⁻¹). This band appears as a shoulder at pH8.3 where two ALA species are present: (NH3)⁺-CH2-CO-CH2-CH2-COO⁻ and NH2-CH2-CO-CH2-CH2-COO⁻ (pKa=8.3). At pH8.3, ALA reacts with oxygen (k=1.4 × 108 M⁻¹s⁻¹) but not with O2⁻. At pH8.3, AA oxidation produces two AA species characterized by an absorbance spectrum with maxima at 330 and 450 nm. ALA and AA are repaired by antioxidants (quercetin (QH), catechin, trolox, ascorbate) which are semi-oxidized (k>10(8)M⁻¹s⁻¹). QH bound to HSA or to apoferritin and ferritin repairs ALA and AA. In O2-saturated apoferritin solutions, Q, O2⁻, AA and reaction product(s) react with QH. CONCLUSIONS: The optical absorption properties and the time evolution of ALA and AA were established for the first time. These radicals and their reaction products may be neutralized by antioxidants free in solution or bound to proteins. GENERAL SIGNIFICANCE: Adjuvant antioxidant administration may be of interest in pathologies related to excess ALA or AA production.


Assuntos
Acetona/análogos & derivados , Ácido Aminolevulínico/química , Radicais Livres/química , Acetona/química , Oxirredução , Análise Espectral
18.
Clin Immunol ; 153(2): 308-22, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24907411

RESUMO

Combinatorial HIV/SIV vaccine approaches targeting multiple arms of the immune system might improve protective efficacy. We compared SIV-specific humoral immunity induced in rhesus macaques by five vaccine regimens. Systemic regimens included ALVAC-SIVenv priming and Env boosting (ALVAC/Env); DNA immunization; and DNA plus Env co-immunization (DNA&Env). RepAd/Env combined mucosal replication-competent Ad-env priming with systemic Env boosting. A Peptide/Env regimen, given solely intrarectally, included HIV/SIV peptides followed by MVA-env and Env boosts. Serum antibodies mediating neutralizing, phagocytic and ADCC activities were induced by ALVAC/Env, RepAd/Env and DNA&Env vaccines. Memory B cells and plasma cells were maintained in the bone marrow. RepAd/Env vaccination induced early SIV-specific IgA in rectal secretions before Env boosting, although mucosal IgA and IgG responses were readily detected at necropsy in ALVAC/Env, RepAd/Env, DNA&Env and DNA vaccinated animals. Our results suggest that combined RepAd priming with ALVAC/Env or DNA&Env regimen boosting might induce potent, functional, long-lasting systemic and mucosal SIV-specific antibodies.


Assuntos
Imunidade nas Mucosas/imunologia , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Vacinação/métodos , Vacinas contra a AIDS/administração & dosagem , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Quimioterapia Combinada , ELISPOT , Produtos do Gene env/imunologia , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Macaca mulatta , Vacinas contra a SAIDS/administração & dosagem , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/fisiologia , Fatores de Tempo , Vacinas de DNA/administração & dosagem , Vacinas de DNA/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia
19.
PLoS One ; 8(11): e82111, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24260588

RESUMO

A novel methodology is described for the efficient and divergent synthesis of pseudodisaccharides, molecules comprising of amino carbasugar analogues linked to natural sugars. The methodology is general and enables the introduction of diversity both at the carbasugar and the natural sugar components of the pseudodisaccharides. Using this approach, a series of pseudodisaccharides are synthesised that mimic the repeating backbone unit of heparan sulfate, and are tested for inhibition of heparanase, a disease-relevant enzyme that hydrolyses heparan sulfate. A new homology model of human heparanase is described based on a family 79 ß-glucuronidase. This model is used to postulate a computational rationale for the observed activity of the different pseudodisaccharides and provide valuable information that informs the design of potential inhibitors of this enzyme.


Assuntos
Dissacarídeos/síntese química , Inibidores Enzimáticos/síntese química , Glucuronidase/química , Heparitina Sulfato/química , Domínio Catalítico , Dissacarídeos/química , Desenho de Fármacos , Inibidores Enzimáticos/química , Glucuronidase/antagonistas & inibidores , Humanos , Conformação Molecular , Simulação de Acoplamento Molecular , Mimetismo Molecular , Bibliotecas de Moléculas Pequenas
20.
Free Radic Res ; 47(6-7): 463-73, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23560676

RESUMO

Ferritin (Ft) impairment through (•)O2(-), H2O2, and (•)OH production occurs in the cases of ketoses, diabetes mellitus, acute intermittent porphyria and tyrosinemia. In addition to (•)Trp and TyrO(•) radical production, ferrous iron liberation and Ft synthesis stimulation, site-specific oxidation reactions are induced leading to toxic iron accumulation in organs with high Ft content, for example, liver and brain. To elucidate the potential pathways to Ft recovery, repair of oxidative damage to horse spleen apoferritin (apoFt) and Ft by quercetin (QH) or rutin (RH) was studied in the presence and absence of oxygen. (•)Trp and TyrO(•) radicals were produced in pulse radiolysis through apoFt oxidation by (•)Br2(-) radicals. QH and RH bind to apoFt on eight sites with binding constants of ˜80,000 and ˜32,000 M(-1), respectively. In deaerated solutions, a repair of apoFt radicals is observed involving both bound and free flavonoids. This repair occurs by a fast intra- and a slow inter-molecular electron transfer from bound and free flavonoids, respectively. With QH, the rate constants are 10(4) s(-1) and 3.5 × 10(7) M(-1) s(-1) for the intra- and intermolecular repair reactions, respectively. Oxygen does not interfere with repair of apoFt or Ft by bound QH but inhibits 90% of Ft repair by RH. These results taken together indicate that flavonoid antioxidants may help alleviate Ft impairment in diseases involving an oxidative stress.


Assuntos
Antioxidantes/farmacologia , Apoferritinas/metabolismo , Modelos Biológicos , Estresse Oxidativo/efeitos dos fármacos , Quercetina/farmacologia , Rutina/farmacologia , Ar , Animais , Antioxidantes/química , Apoferritinas/química , Radicais Livres/química , Radicais Livres/metabolismo , Cavalos , Quercetina/química , Rutina/química , Soluções , Baço/química
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