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1.
BMJ Glob Health ; 8(5)2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37147016

RESUMO

BACKGROUND: Seasonal vaccination with the RTS,S/AS01E malaria vaccine given alongside seasonal malaria chemoprevention (SMC) substantially reduces malaria in young children. The WHO has recommended the use of RTS,S/AS01E, including seasonal vaccination, in areas with seasonal malaria transmission. This study aimed to identify potential strategies to deliver RTS,S/AS01E, and assess the considerations and recommendations for delivery of seasonal malaria vaccination in Mali, a country with highly seasonal malaria. METHODS: Potential delivery strategies for RTS,S/AS01E in areas with seasonal malaria were identified through a series of high level discussions with the RTS,S/AS01E plus SMC trial investigators, international and national immunisation and malaria experts, and through the development of a theory of change. These were explored through qualitative in-depth interviews with 108 participants, including national-level, regional-level and district-level malaria and immunisation programme managers, health workers, caregivers of children under 5 years of age, and community stakeholders. A national-level workshop was held to confirm the qualitative findings and work towards consensus on an appropriate strategy. RESULTS: Four delivery strategies were identified: age-based vaccination delivered via the Essential Programme on Immunisation (EPI); seasonal vaccination via EPI mass vaccination campaigns (MVCs); a combination of age-based priming vaccination doses delivered via the EPI clinics and seasonal booster doses delivered via MVCs; and a combination of age-based priming vaccination doses and seasonal booster doses, all delivered via the EPI clinics, which was the preferred strategy for delivery of RTS,S/AS01E in Mali identified during the national workshop. Participants recommended that supportive interventions, including communications and mobilisation, would be needed for this strategy to achieve required coverage. CONCLUSIONS: Four delivery strategies were identified for administration of RTS,S/AS01E alongside SMC in countries with seasonal malaria transmission. Components of these delivery strategies were defined as the vaccination schedule, and the delivery system(s) plus the supportive interventions needed for the strategies to be effective. Further implementation research and evaluation is needed to explore how, where, when and what effective coverage is achievable via these new strategies and their supportive interventions.


Assuntos
Vacinas Antimaláricas , Malária Falciparum , Malária , Criança , Humanos , Pré-Escolar , Vacinas Antimaláricas/uso terapêutico , Malária Falciparum/prevenção & controle , Estações do Ano , Malária/prevenção & controle , Vacinação
2.
Antibiotics (Basel) ; 11(10)2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36290000

RESUMO

Antibiotic use in animal agriculture contributes significantly to antibiotic use globally and is a key driver of the rising threat of antibiotic resistance. It is becoming increasingly important to better understand antibiotic use in livestock in low-and-middle income countries where antibiotic use is predicted to increase considerably as a consequence of the growing demand for animal-derived products. Antibiotic crossover-use refers to the practice of using antibiotic formulations licensed for humans in animals and vice versa. This practice has the potential to cause adverse drug reactions and contribute to the development and spread of antibiotic resistance between humans and animals. We performed secondary data analysis of in-depth interview and focus-group discussion transcripts from independent studies investigating antibiotic use in agricultural communities in Uganda, Tanzania and India to understand the practice of antibiotic crossover-use by medicine-providers and livestock-keepers in these settings. Thematic analysis was conducted to explore driving factors of reported antibiotic crossover-use in the three countries. Similarities were found between countries regarding both the accounts of antibiotic crossover-use and its drivers. In all three countries, chickens and goats were treated with human antibiotics, and among the total range of human antibiotics reported, amoxicillin, tetracycline and penicillin were stated as used in animals in all three countries. The key themes identified to be driving crossover-use were: (1) medicine-providers' and livestock-keepers' perceptions of the effectiveness and safety of antibiotics, (2) livestock-keepers' sources of information, (3) differences in availability of human and veterinary services and antibiotics, (4) economic incentives and pressures. Antibiotic crossover-use occurs in low-intensity production agricultural settings in geographically distinct low-and-middle income countries, influenced by a similar set of interconnected contextual drivers. Improving accessibility and affordability of veterinary medicines to both livestock-keepers and medicine-providers is required alongside interventions to address understanding of the differences between human and animal antibiotics, and potential dangers of antibiotic crossover-use in order to reduce the practice. A One Health approach to studying antibiotic use is necessary to understand the implications of antibiotic accessibility and use in one sector upon antibiotic use in other sectors.

3.
Elife ; 112022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34985413

RESUMO

Excitation-contraction coupling (ECC) is the process by which electrical excitation of muscle is converted into force generation. Depolarization of skeletal muscle resting potential contributes to failure of ECC in diseases such as periodic paralysis, intensive care unit acquired weakness and possibly fatigue of muscle during vigorous exercise. When extracellular K+ is raised to depolarize the resting potential, failure of ECC occurs suddenly, over a narrow range of resting potentials. Simultaneous imaging of Ca2+ transients and recording of action potentials (APs) demonstrated failure to generate Ca2+ transients when APs peaked at potentials more negative than -30mV. An AP property that closely correlated with failure of the Ca2+ transient was the integral of AP voltage with respect to time. Simultaneous recording of Ca2+ transients and APs with electrodes separated by 1.6mm revealed AP conduction fails when APs peak below -21mV. We hypothesize propagation of APs and generation of Ca2+ transients are governed by distinct AP properties: AP conduction is governed by AP peak, whereas Ca2+ release from the sarcoplasmic reticulum is governed by AP integral. The reason distinct AP properties may govern distinct steps of ECC is the kinetics of the ion channels involved. Na channels, which govern propagation, have rapid kinetics and are insensitive to AP width (and thus AP integral) whereas Ca2+ release is governed by gating charge movement of Cav1.1 channels, which have slower kinetics such that Ca2+ release is sensitive to AP integral. The quantitative relationships established between resting potential, AP properties, AP conduction and Ca2+ transients provide the foundation for future studies of failure of ECC induced by depolarization of the resting potential.


Assuntos
Potenciais de Ação/fisiologia , Acoplamento Excitação-Contração , Potenciais da Membrana , Músculo Esquelético/fisiologia , Animais , Camundongos
4.
Elife ; 102021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33904400

RESUMO

In addition to the hallmark muscle stiffness, patients with recessive myotonia congenita (Becker disease) experience debilitating bouts of transient weakness that remain poorly understood despite years of study. We performed intracellular recordings from muscle of both genetic and pharmacologic mouse models of Becker disease to identify the mechanism underlying transient weakness. Our recordings reveal transient depolarizations (plateau potentials) of the membrane potential to -25 to -35 mV in the genetic and pharmacologic models of Becker disease. Both Na+ and Ca2+ currents contribute to plateau potentials. Na+ persistent inward current (NaPIC) through NaV1.4 channels is the key trigger of plateau potentials and current through CaV1.1 Ca2+ channels contributes to the duration of the plateau. Inhibiting NaPIC with ranolazine prevents the development of plateau potentials and eliminates transient weakness in vivo. These data suggest that targeting NaPIC may be an effective treatment to prevent transient weakness in myotonia congenita.


Myotonia is a neuromuscular condition that causes problems with the relaxation of muscles following voluntary movements. One type of myotonia is Becker disease, also called recessive myotonia congenita. This is a genetic condition that causes muscle stiffness as a result of involuntary muscle activity. Patients may also suffer transient weakness for a few seconds or as long as several minutes after initiating a movement. The cause of these bouts of temporary weakness is still unclear, but there are hints that it could be linked to the muscle losing its excitability, the ability to respond to the stimuli that make it contract. However, this is at odds with findings that show that muscles in Becker disease are hyperexcitable. Muscle excitability depends on the presence of different concentrations of charged ions (positively charged sodium, calcium and potassium ions and negatively charged chloride ions) inside and outside of each muscle cells. These different concentrations of ions create an electric potential across the cell membrane, also called the 'membrane potential'. When a muscle cell gets stimulated, proteins on the cell membrane known as ion channels open. This allows the flow of ions between the inside and the outside of the cell, which causes an electrical current that triggers muscle contraction. To better understand the causes behind this muscle weakness, Myers et al. used mice that had either been genetically manipulated or given drugs to mimic Becker disease. By measuring both muscle force and the electrical currents that drive contraction, Myers et al. found that the mechanism underlying post-movement weakness involved a transient change in the concentrations of positively charged ions inside and outside the cells. Further experiments showed that proteins that regulate the passage of both sodium and calcium in and out of the cell ­ called sodium and calcium channels ­ contributed to this change in concentration. In addition, Myers et al. discovered that using a drug called ranolazine to stop sodium ions from entering the cell eliminated transient weakness in live mice. These findings suggest that in Becker disease, muscles cycle rapidly between being hyperexcited or not able to be excited, and that targeting the flow of sodium ions into the cell could be an effective treatment to prevent transient weakness in myotonia congenita. This study paves the way towards the development of new therapies to treat Becker disease as well as other muscle ion channel diseases with transient weakness such as periodic paralysis.


Assuntos
Potenciais da Membrana/fisiologia , Miotonia Congênita/fisiopatologia , Animais , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Miotonia Congênita/diagnóstico , Miotonia Congênita/genética , Sódio/fisiologia
5.
Ann Neurol ; 88(2): 297-308, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32418267

RESUMO

OBJECTIVE: Myotonia is caused by involuntary firing of skeletal muscle action potentials and causes debilitating stiffness. Current treatments are insufficiently efficacious and associated with side effects. Myotonia can be triggered by voluntary movement (electrically induced myotonia) or percussion (mechanically induced myotonia). Whether distinct molecular mechanisms underlie these triggers is unknown. Our goal was to identify ion channels involved in mechanically induced myotonia and to evaluate block of the channels involved as a novel approach to therapy. METHODS: We developed a novel system to enable study of mechanically induced myotonia using both genetic and pharmacologic mouse models of myotonia congenita. We extended ex vivo studies of excitability to in vivo studies of muscle stiffness. RESULTS: As previous work suggests activation of transient receptor potential vanilloid 4 (TRPV4) channels by mechanical stimuli in muscle, we examined the role of this cation channel. Mechanically induced myotonia was markedly suppressed in TRPV4-null muscles and in muscles treated with TRPV4 small molecule antagonists. The suppression of mechanically induced myotonia occurred without altering intrinsic muscle excitability, such that myotonia triggered by firing of action potentials (electrically induced myotonia) was unaffected. When injected intraperitoneally, TRPV4 antagonists lessened the severity of myotonia in vivo by approximately 80%. INTERPRETATION: These data demonstrate that there are distinct molecular mechanisms triggering electrically induced and mechanically induced myotonia. Our data indicates that activation of TRPV4 during muscle contraction plays an important role in triggering myotonia in vivo. Elimination of mechanically induced myotonia by TRPV4 inhibition offers a new approach to treating myotonia. ANN NEUROL 2020;88:297-308.


Assuntos
Contração Isométrica/fisiologia , Morfolinas/farmacologia , Miotonia Congênita/genética , Miotonia Congênita/metabolismo , Pirróis/farmacologia , Canais de Cátion TRPV/antagonistas & inibidores , Canais de Cátion TRPV/deficiência , Animais , Antracenos/farmacologia , Contração Isométrica/efeitos dos fármacos , Camundongos , Camundongos Knockout , Morfolinas/uso terapêutico , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Miotonia Congênita/prevenção & controle , Pirróis/uso terapêutico
7.
eNeuro ; 6(4)2019.
Artigo em Inglês | MEDLINE | ID: mdl-31311802

RESUMO

We investigated the calcium dynamics of dorsal root ganglion (DRG) neurons using transgenic mice to target expression of the genetically encoded calcium indicator (GECI), GCaMP6s, to a subset of neurons containing parvalbumin (PV), a calcium-binding protein present in proprioceptors and low-threshold mechanoreceptors. This study provides the first analysis of GECI calcium transient parameters from large-diameter DRG neurons. Our approach generated calcium transients of consistent shape and time-course, with quantifiable characteristics. Four parameters of calcium transients were determined to vary independently from each other and thus are likely influenced by different calcium-regulating mechanisms: peak amplitude, rise time (RT), decay time, and recovery time. Pooled analysis of 188 neurons demonstrated unimodal distributions, providing evidence that PV+ DRG neurons regulate calcium similarly as a population despite their differences in size, electrical properties, and functional sensitivities. Calcium transients increased in size with elevated extracellular calcium, longer trains of action potentials, and higher stimulation frequencies. RT and decay time increased with the addition of the selective sarco/endoplasmic reticulum calcium ATPases (SERCA) blocker, thapsigargin (TG), while peak amplitude and recovery time remained the same. When elevating bath pH to 8.8 to block plasma-membrane calcium ATPases (PMCA), all measured parameters significantly increased. These results illustrate that GECI calcium transients provide sufficient resolution to detect changes in electrical activity and intracellular calcium concentration, as well as discern information about the activity of specific subclasses of calcium regulatory mechanisms.


Assuntos
Sinalização do Cálcio/fisiologia , Gânglios Espinais/fisiologia , Neurônios/fisiologia , Parvalbuminas/fisiologia , Animais , Cálcio/análise , Feminino , Masculino , Camundongos Transgênicos , Imagem Óptica/métodos
8.
Regul Toxicol Pharmacol ; 91: 124-141, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29080853

RESUMO

The Texas Commission on Environmental Quality (TCEQ) developed guidance on conducting systematic reviews during the development of chemical-specific toxicity factors. Using elements from publicly available frameworks, the TCEQ systematic review process was developed in order to supplement the existing TCEQ Guidelines for developing toxicity factors (TCEQ Regulatory Guidance 442). The TCEQ systematic review process includes six steps: 1) Problem Formulation; 2) Systematic Literature Review and Study Selection; 3) Data Extraction; 4) Study Quality and Risk of Bias Assessment; 5) Evidence Integration and Endpoint Determination; and 6) Confidence Rating. This document provides guidance on conducting a systematic literature review and integrating evidence from different data streams when developing chemical-specific reference values (ReVs) and unit risk factors (URFs). However, this process can also be modified or expanded to address other questions that would benefit from systematic review practices. The systematic review and evidence integration framework can improve regulatory decision-making processes, increase transparency, minimize bias, improve consistency between different risk assessments, and further improve confidence in toxicity factor development.


Assuntos
Projetos de Pesquisa/normas , Medição de Risco/normas , Animais , Viés , Tomada de Decisões , Humanos , Fatores de Risco , Texas
9.
Inhal Toxicol ; 29(7): 304-309, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28891353

RESUMO

The Texas Commission on Environmental Quality (TCEQ) follows standard scientific methods to develop up-to-date toxicity factors for chemicals emitted in the state of Texas. An inhalation unit risk factor (URF) was developed for ethylene dibromide (EDB, CAS 106-93-4) based on an increased incidence of nasal cavity adenocarcinomas observed in female rats in a 2-year inhalation cancer bioassay conducted by the National Toxicology Program (NTP). The NTP study provided evidence of several EDB-induced tumors in male and female rats and in female mice. Tumor incidences that were statistically increased at the low dose and that showed a statistically significant increasing trend were considered in identifying the critical effect. Following benchmark concentration (BMC) modeling and animal-to-human dosimetric adjustments, the increased incidence of nasal cavity adenocarcinomas observed in female rats was determined to be the most sensitive tumorigenic effect in the most sensitive species and sex and was utilized as the carcinogenic endpoint for the development of the URF. The 95% lower confidence limit of the BMC at the 10% excess risk level (BMCL10 of 292.8 ppb) was determined for calculation of the URF. The resulting URF based on increased nasal cavity adenocarcinomas observed in female rats is 3.4E-04 per ppb (4.4E-05 per µg/m3). The lifetime air concentration corresponding to a no significant excess risk level of one in 100,000 is 0.029 ppb (0.22 µg/m3), which is considered sufficiently health-protective for use in protecting the general public against the potential carcinogenic effects of chronic exposure to EDB in ambient air.


Assuntos
Carcinógenos/normas , Exposição Ambiental/normas , Dibrometo de Etileno/normas , Neoplasias/prevenção & controle , Administração por Inalação , Animais , Carcinógenos/toxicidade , Relação Dose-Resposta a Droga , Dibrometo de Etileno/toxicidade , Feminino , Humanos , Masculino , Camundongos , Neoplasias/induzido quimicamente , Ratos , Medição de Risco
10.
J Pediatr Urol ; 13(5): 481.e1-481.e6, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28434634

RESUMO

INTRODUCTION: Hypospadias surgery has progressed steadily over recent years. There remains considerable variation in the operative management of boys with hypospadias in the UK, and it is therefore difficult to identify acceptable standards with regards to reoperation rates. OBJECTIVE: To determine the frequency of reoperations and complications from all centres performing hypospadias surgery in England and to identify variables that influence outcome. METHODS: All children undergoing NHS hypospadias surgery in England between 1999 and 2009 were identified using the Hospital Episode Statistics database. Patient demographics, centre type, and associated diagnostic (ICD-10) and treatment codes (OPCS4.6) were collected for both primary repairs and postoperative complications. Centres were classed as high volume if they performed an average of 20 or more operations a year. Operative complications were split into revisions (repeat repairs), repairs of urethral fistulae, repairs of meatal stenosis, or urethral stricture repairs. Statistical analysis included logistic regression, Spearman's correlation, and Mann-Whitney U for non-parametric data, with p < 0.05 taken as significant. Data are presented as median (interquartile range) unless otherwise stated. RESULTS: children underwent a total of 23,962 operations at 75 centres in England during the study period. The median age at primary repair was 21 (15-38) months. The overall complication rate was 18.1%. The median complication rate for individual centres was 20.0% (13.9-27.4%) overall; 10.8% (4.7-15.9%) for revision procedures, 8.1% (5.5-11.7%) for urethral fistulae, 2.3% (1.1-3.7%) for meatal stenosis repairs, and 1.8% (0-2.8%) for urethral strictures. High volume centres had significantly lower complication rates than low volume centres (17.5% vs. 25%, p = 0.01) (Figure), and this was proven to be an independent predictor of outcomes (p = 0.01). Staged repairs were associated with more complications (p < 0.001); however, patient age and centre type were not. Median time to repair of complication was 13 (8-22) months. DISCUSSION: This national population-based study used hospital episode statistics data. While accuracy is high and it has been validated for use in research, it has intrinsic limitations which affect our study. We are unable to fully account for the severity of hypospadias or the number of operating surgeons within institutions. CONCLUSIONS: This study has found a clear relationship between caseload volume and complications following hypospadias surgery. Furthermore, there is significant variability between centres in terms of their surgical outcomes. Taken together these results suggest that surgeons, particularly those in centres with small caseloads should assess their results against such benchmarks when evaluating the service they provide.


Assuntos
Hospitais com Alto Volume de Atendimentos , Hipospadia/cirurgia , Complicações Pós-Operatórias/epidemiologia , Pré-Escolar , Inglaterra , Humanos , Lactente , Masculino , Reoperação/estatística & dados numéricos , Estudos Retrospectivos
11.
Inhal Toxicol ; 28(9): 403-9, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27308968

RESUMO

The Texas Commission on Environmental Quality (TCEQ) conducts up-to-date carcinogenic assessments for chemicals emitted in Texas. An inhalation unit risk factor (URF) was developed for ethylene dichloride (EDC, CAS 107-06-2) based on tumorigenicity results observed in a 2-year animal inhalation study conducted by Nagano et al. More specifically, the incidence of combined mammary gland tumors (adenomas, fibroadenomas, adenocarcinomas) in female rats demonstrated a statistically significant dose-response relationship, was amenable to benchmark concentration (BMC) modeling, was ultimately determined to be the most sensitive tumorigenic effect in the most sensitive species and sex, and was utilized as the carcinogenic endpoint for the development of the URF. The 95% lower confidence limit of the BMC at the 10% excess risk level (BMCL10 of 40.1 ppm) was determined for calculation of the URF. The resulting URF based on increased incidence of combined mammary gland tumors in female rats is 1.4E-02 per ppm (3.4E-03 per mg/m(3)). The lifetime air concentration corresponding to a no significant excess risk level of 1 in 100 000 is 0.71 ppb (2.9 µg/m(3)), which is considered sufficiently health-protective for use in protecting the general public against the potential carcinogenic effects of chronic exposure to EDC in ambient air.


Assuntos
Testes de Carcinogenicidade/métodos , Carcinógenos/toxicidade , Dicloretos de Etileno/toxicidade , Guias como Assunto , Exposição por Inalação/efeitos adversos , Neoplasias Experimentais/induzido quimicamente , Animais , Relação Dose-Resposta a Droga , Feminino , Incidência , Masculino , Camundongos , Ratos , Medição de Risco , Fatores de Risco , Fatores Sexuais , Especificidade da Espécie
12.
Exp Biol Med (Maywood) ; 241(4): 367-74, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26515141

RESUMO

Major progress in deciphering the role of the E3 ligase, ITCH, in animal physiology has come from the generation and identification of Itch loss-of-function mutant mice (itchy). Mutant mice display an autoimmune-like phenotype characterized by chronic dermatitis, which has been attributed to increased levels of ITCH target proteins (e.g. transcription factors JUNB and CJUN) in T cells. Autoimmune disorders also exist in humans with Itch frameshift mutations resulting in loss of functional ITCH protein. Recent phenotypic analysis of male itchy mice revealed reduced sperm production, although cross breeding experiments showed no difference in litter size when male itchy mice were bred to wild type females. However, a reduction in litter sizes did occur when itchy females were bred to wild type males. Based on these results, characterization of female reproductive function in itchy mice was performed. Developmental analysis of fetuses at gestational day 18.5, cytological evaluation of estrous cyclicity, histopathological analysis of ovaries, and protein analysis were used to investigate the itchy reproductive phenotype. Gross skeletal and soft tissue analysis of gestational day 18.5 itchy fetuses indicated no gross developmental deformities. Itchy females had reduced implantation sites, decreased corpora lutea, and increased estrous cycle length due to increased number of days in estrus compared to controls. Alterations in the expression of prototypical ITCH targets in the ovaries were not indicated, suggesting that an alteration in an as yet defined ovary-specific ITCH substrate or interaction with the altered immune system likely accounts for the disruption of female reproduction. This report indicates the importance of the E3 ligase, ITCH, in female reproduction.


Assuntos
Ciclo Estral , Reprodução , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/metabolismo , Animais , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL
13.
Inhal Toxicol ; 27(9): 440-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26213288

RESUMO

The Texas Commission on Environmental Quality has developed a chronic inhalation Reference Value (ReV) for hexamethylenediamine (HMDA, CAS 124-09-4) based on respiratory effects identified in an animal study. HMDA is used in the fiber and plastics industry as an intermediate in the production of nylon, high-strength resins and polyamide adhesives. As a toxicant, HMDA acts primarily as a respiratory irritant with effects occurring in the upper respiratory tract, although systemic effects have been noted at higher concentrations. ReVs are chemical-specific air concentrations derived to protect human health. Acute and chronic ReVs were developed for HDMA based on an inhalation study conducted by the National Toxicology Program (NTP), which used the salt of HMDA, hexamethylenediamine dihydrochloride (HDDC, CAS 6055-52-3). For the chronic evaluation, rats and mice were exposed to 0, 1.6, 5, 16, 50 and 160 mg HDDC/m(3) for 13 weeks. The critical effect identified for the most sensitive species was hyaline degeneration in the olfactory epithelium in mice. The data provided in this study were suitable to benchmark concentration (BMC) modeling. Dosimetric adjustments using the rat and mouse Multiple-Path Particle Dosimetry Model (version 3.0) were made to the 95% lower limit of the BMC(10) to determine the human equivalent point of departure. Uncertainty factors were applied to account for variation in sensitivity within the human population, toxicodynamic differences between mice and humans, and use of a subchronic study. The ReV was initially calculated for HDDC and then adjusted for HMDA. The chronic ReV is 1.8 µg/m(3) for respirable HMDA ≤ 10 µm in diameter.


Assuntos
Poluentes Atmosféricos/toxicidade , Diaminas/toxicidade , Guias como Assunto , Exposição por Inalação , Irritantes/toxicidade , Modelos Biológicos , Administração por Inalação , Animais , Feminino , Humanos , Hialina/efeitos dos fármacos , Masculino , Camundongos , Ratos , Mucosa Respiratória/efeitos dos fármacos , Sistema Respiratório/efeitos dos fármacos , Medição de Risco , Especificidade da Espécie , Texas , Testes de Toxicidade
14.
Chem Biol Interact ; 241: 2-9, 2015 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-25727265

RESUMO

Texas has the largest ambient air monitoring network in the country with approximately 83 monitoring sites that measure ambient air concentrations of volatile organic compounds (VOCs). The lower olefins, including 1,3-butadiene, ethylene, isoprene, and propylene, are a group of VOCs that can be measured in both 24h/every sixth-day canister samples and continuous 1-h Automated Gas Chromatography (AutoGC) samples. Based on 2012 Toxics Release Inventory data, the total reported industrial air emissions in Texas for these olefins, as compared to total national reported air emissions, were 79% for 1,3-butadiene, 62% for ethylene, 76% for isoprene, and 54% for propylene, illustrating that Texas industries are some of the major emitters for these olefins. The purpose of this study was to look at the patterns of annual average air monitoring data from 2002 to 2012 using Texas Commission on Environmental Quality (TCEQ) data for these four lower olefins. It should be emphasized that monitors may not be located close to or downwind of the highest emitters of these lower olefins. In addition, air monitors only provide a snapshot in time of air concentrations for their respective locations, and may not be able to discriminate emissions between specific sources. In 2012, the highest annual average air concentration for 1,3-butadiene was 1.28 ppb by volume (ppbv), which was measured at the Port Neches monitoring site in Region 10-Beaumont. For ethylene, the highest 2012 annual average air concentration was 5.77 ppbv, which was measured at the Dona Park monitoring site in TCEQ Region 14-Corpus Christi. Although reported industrial emissions of isoprene are predominantly from the Houston and Beaumont regions, trees are natural emitters of isoprene, and the highest ambient air concentrations tend to be from regions with large areas of coniferous and hardwood forests. This was observed with TCEQ Region 5-Tyler, which had the two highest isoprene annual average air concentrations for 2012: 0.56 ppbv at the Karnack monitoring site and 0.47 ppbv at the Longview monitoring site. For propylene, the highest 2012 annual average air concentration was recorded at the HRM 7 monitoring site in TCEQ Region 12-Houston, which was 7.9 ppbv. A significant portion of the total 2012 industrial propylene emissions were also reported in TCEQ Region 12-Houston. Although some individual monitors showed increased annual averages from 2002 to 2012, there was a general decreasing trend present across the state for all four lower olefins examined. The annual average air concentrations of the four lower olefins were well below their respective Air Monitoring Comparison Values (AMCVs) and are not expected to cause long-term or chronic adverse health effects.


Assuntos
Poluentes Atmosféricos/análise , Alcenos/análise , Emissões de Veículos/análise , Alcenos/química , Animais , Butadienos/química , Monitoramento Ambiental/métodos , Hemiterpenos/química , Humanos , Pentanos/química , Texas , Compostos Orgânicos Voláteis/análise
15.
Semin Cell Dev Biol ; 30: 27-35, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24632385

RESUMO

The ubiquitination of proteins is a post-translational modification that was first described as a means to target misfolded or unwanted proteins for degradation by the proteasome. It is now appreciated that the ubiquitination of proteins also serves as a mechanism to modify protein function and cellular functions such as protein trafficking, cell signaling, DNA repair, chromatin modifications, cell-cycle progression and cell death. The ubiquitination of proteins occurs through the hierarchal transfer of ubiquitin from an E1 ubiquitin-activating enzyme to an E2 ubiquitin-conjugating enzyme and finally to an E3 ubiquitin ligase that transfers the ubiquitin to its target protein. It is the final E3 ubiquitin ligase that confers the substrate specificity for ubiquitination and is the focus of this review. Spermatogenesis is a complex and highly regulated process by which spermatogonial stem cells undergo mitotic proliferation and expansion of the diploid spermatogonial population, differentiate into spermatocytes and progress through two meiotic divisions to produce haploid spermatids that proceed through a final morphogenesis to generate mature spermatozoa. The ubiquitination of proteins in the cells of the testis occurs in many of the processes required for the progression of mature spermatozoa. Since it is the E3 ubiquitin ligase that recognizes the target protein and provides the specificity and selectivity for ubiquitination, this review highlights known examples of E3 ligases in the testis and the differing roles that they play in maintaining functional spermatogenesis.


Assuntos
Espermatogênese , Ubiquitina-Proteína Ligases/fisiologia , Ubiquitinação , Animais , Humanos , Junções Intercelulares/metabolismo , Masculino , Proteólise , Transdução de Sinais , Testículo/citologia , Testículo/fisiologia
16.
Clin Infect Dis ; 56(1): 27-35, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23042972

RESUMO

BACKGROUND: Admission to a room previously occupied by a patient with certain multidrug-resistant organisms (MDROs) increases the risk of acquisition. Traditional cleaning strategies do not remove all environmental MDROs. We evaluated the environmental and clinical impact of hydrogen peroxide vapor (HPV) room disinfection. METHODS: We performed a 30-month prospective cohort intervention study on 6 high-risk units in a 994-bed tertiary care hospital. Following a 12-month preintervention phase, HPV was implemented on 3 units to decontaminate the rooms of patients known to be infected or colonized with epidemiologically important MDROs, following their discharge. Monthly environmental samples for MDROs were collected on all study units for 3 preintervention and 6 intervention months. The risk of MDRO acquisition in patients admitted to rooms decontaminated using HPV was compared with rooms disinfected using standard methods. RESULTS: The prior room occupant was known to be infected or colonized with an MDRO in 22% of 6350 admissions. Patients admitted to rooms decontaminated using HPV were 64% less likely to acquire any MDRO (incidence rate ratio [IRR], 0.36; 95% confidence interval [CI], .19-.70; P < .001) and 80% less likely to acquire VRE (IRR, 0.20; 95% CI, .08-.52; P < .001) after adjusting for other factors. The risk of acquiring Clostridium difficile, methicillin-resistant Staphylococcus aureus, and multidrug-resistant gram-negative rods individually was reduced, but not significantly. The proportion of rooms environmentally contaminated with MDROs was reduced significantly on the HPV units (relative risk, 0.65, P = .03), but not on non-HPV units. CONCLUSIONS: HPV decontamination reduced environmental contamination and the risk of acquiring MDROs compared with standard cleaning protocols.


Assuntos
Infecções Bacterianas/prevenção & controle , Infecção Hospitalar/prevenção & controle , Desinfecção/métodos , Farmacorresistência Bacteriana Múltipla , Peróxido de Hidrogênio , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Infecções Bacterianas/microbiologia , Estudos de Coortes , Infecção Hospitalar/microbiologia , Monitoramento Ambiental , Feminino , Gases , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Centros de Atenção Terciária
17.
Transfusion ; 53(10): 2152-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23241141

RESUMO

BACKGROUND: The Gerbich (Ge) blood group system consists of 11 antigens carried on red blood cell (RBC) membrane glycophorins C and D; of these, Ge:3 antigen is of high prevalence, and the anti-Ge3 is found to be clinically significant. CASE REPORT: A 34-week neonate born to a Hispanic mother with anti-Ge3 developed late-onset hemolysis with hyperbilirubinemia and was successfully treated with transfusions from her mother. Relevant clinical findings and laboratory results for this case are summarized and compared to three other previously reported cases; all babies were born from a mother of Hispanic ethnicity. CONCLUSION: Hemolytic disease of the fetus and new born associated with anti-Ge3 is rare but should be considered when working up a broadly reactive RBC antibody screen in women of Hispanic ethnicity. Early identification of pregnant women with anti-Ge3 is recommended for prenatal transfusion planning and close monitoring of the newborn infant for evidence of late-onset anemia.


Assuntos
Antígenos de Grupos Sanguíneos/imunologia , Eritroblastose Fetal/etiologia , Adulto , Eritropoetina/uso terapêutico , Feminino , Humanos , Recém-Nascido
18.
BMC Med Res Methodol ; 12: 180, 2012 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-23181419

RESUMO

BACKGROUND: Adjusting for laboratory test results may result in better confounding control when added to administrative claims data in the study of treatment effects. However, missing values can arise through several mechanisms. METHODS: We studied the relationship between availability of outpatient lab test results, lab values, and patient and system characteristics in a large healthcare database using LDL, HDL, and HbA1c in a cohort of initiators of statins or Vytorin (ezetimibe & simvastatin) as examples. RESULTS: Among 703,484 patients 68% had at least one lab test performed in the 6 months before treatment. Performing an LDL test was negatively associated with several patient characteristics, including recent hospitalization (OR = 0.32, 95% CI: 0.29-0.34), MI (OR = 0.77, 95% CI: 0.69-0.85), or carotid revascularization (OR = 0.37, 95% CI: 0.25-0.53). Patient demographics, diagnoses, and procedures predicted well who would have a lab test performed (AUC = 0.89 to 0.93). Among those with test results available claims data explained only 14% of variation. CONCLUSIONS: In a claims database linked with outpatient lab test results, we found that lab tests are performed selectively corresponding to current treatment guidelines. Poor ability to predict lab values and the high proportion of missingness reduces the added value of lab tests for effectiveness research in this setting.


Assuntos
Azetidinas/uso terapêutico , Revisão da Utilização de Seguros , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Sinvastatina/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Testes Diagnósticos de Rotina , Combinação de Medicamentos , Combinação Ezetimiba e Simvastatina , Feminino , Hemoglobinas Glicadas/efeitos dos fármacos , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipolipemiantes , Lipídeos/sangue , Lipoproteínas HDL/efeitos dos fármacos , Lipoproteínas LDL/efeitos dos fármacos , Masculino , Medicare Part B , Medicare Part C , Pessoa de Meia-Idade , Estados Unidos , Adulto Jovem
19.
N Engl J Med ; 367(12): 1119-27, 2012 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-22992075

RESUMO

BACKGROUND: The effects of clinical-trial funding on the interpretation of trial results are poorly understood. We examined how such support affects physicians' reactions to trials with a high, medium, or low level of methodologic rigor. METHODS: We presented 503 board-certified internists with abstracts that we designed describing clinical trials of three hypothetical drugs. The trials had high, medium, or low methodologic rigor, and each report included one of three support disclosures: funding from a pharmaceutical company, NIH funding, or none. For both factors studied (rigor and funding), one of the three possible variations was randomly selected for inclusion in the abstracts. Follow-up questions assessed the physicians' impressions of the trials' rigor, their confidence in the results, and their willingness to prescribe the drugs. RESULTS: The 269 respondents (53.5% response rate) perceived the level of study rigor accurately. Physicians reported that they would be less willing to prescribe drugs tested in low-rigor trials than those tested in medium-rigor trials (odds ratio, 0.64; 95% confidence interval [CI], 0.46 to 0.89; P=0.008) and would be more willing to prescribe drugs tested in high-rigor trials than those tested in medium-rigor trials (odds ratio, 3.07; 95% CI, 2.18 to 4.32; P<0.001). Disclosure of industry funding, as compared with no disclosure of funding, led physicians to downgrade the rigor of a trial (odds ratio, 0.63; 95% CI, 0.46 to 0.87; P=0.006), their confidence in the results (odds ratio, 0.71; 95% CI, 0.51 to 0.98; P=0.04), and their willingness to prescribe the hypothetical drugs (odds ratio, 0.68; 95% CI, 0.49 to 0.94; P=0.02). Physicians were half as willing to prescribe drugs studied in industry-funded trials as they were to prescribe drugs studied in NIH-funded trials (odds ratio, 0.52; 95% CI, 0.37 to 0.71; P<0.001). These effects were consistent across all levels of methodologic rigor. CONCLUSIONS: Physicians discriminate among trials of varying degrees of rigor, but industry sponsorship negatively influences their perception of methodologic quality and reduces their willingness to believe and act on trial findings, independently of the trial's quality. These effects may influence the translation of clinical research into practice.


Assuntos
Avaliação de Medicamentos/normas , Projetos de Pesquisa/normas , Apoio à Pesquisa como Assunto , Coleta de Dados , Indústria Farmacêutica , Humanos , Medicina Interna , National Institutes of Health (U.S.) , Médicos , Análise de Regressão , Estados Unidos
20.
Arthritis Rheum ; 64(10): 3076-82, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22782529

RESUMO

OBJECTIVE: Previous study findings have suggested that patients with chronic diseases such as rheumatoid arthritis (RA) do not receive optimal preventive medical services, including cancer screening tests. This study was undertaken to evaluate cancer screening rates in RA patients compared to non-RA control populations. METHODS: Using data from a large US commercial insurance plan, we examined rates of screening tests for cervical, breast, and colon cancer in patients with RA compared to control subjects without RA (non-RA controls) or control subjects with hypertension. Individuals were included in the RA cohort if they had at least 2 visits coded for a diagnosis of RA and had received at least 1 prescription for a disease-modifying antirheumatic drug during the study period. Multivariable Cox proportional hazards models were used to compare the rates of different cancer screening tests between RA patients and non-RA controls. RESULTS: RA patients (n = 13,314) and control subjects (non-RA and hypertension controls) (n = 212,324) were screened, on average, once every 3 years for cervical cancer and once every 2 years for breast cancer during the followup period (mean 2.3 years of followup). In the age-adjusted Cox regression model, women with RA were more likely to receive ≥ 1 Papanicolaou smear (hazard ratio [HR] 1.21, 95% confidence interval [95% CI] 1.17-1.24), ≥ 1 mammogram (HR 1.49, 95% CI 1.45-1.53), and ≥ 1 colonoscopy (HR 1.69, 95% CI 1.61-1.77) compared to female non-RA control subjects. Men with RA were also more likely to receive at least 1 colonoscopy (HR 1.52, 95% CI 1.40-1.64) than were male non-RA control subjects. These results were robust in multivariable analyses adjusted for age, number of physician visits, percentage of visits made to primary care physicians, and the Charlson Comorbidity Index. CONCLUSION: Patients with RA did not appear to be at risk for receiving fewer cancer screening tests when compared to individuals without RA. The majority of both RA patients and non-RA control subjects were screened regularly for cervical, breast, and colon cancer, in accordance with current recommendations.


Assuntos
Artrite Reumatoide/complicações , Neoplasias da Mama/diagnóstico , Neoplasias do Colo/diagnóstico , Detecção Precoce de Câncer/estatística & dados numéricos , Neoplasias do Colo do Útero/diagnóstico , Adolescente , Adulto , Idoso , Neoplasias da Mama/complicações , Neoplasias do Colo/complicações , Feminino , Humanos , Masculino , Mamografia , Pessoa de Meia-Idade , Teste de Papanicolaou , Fatores de Risco , Neoplasias do Colo do Útero/complicações , Esfregaço Vaginal
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