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1.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35110411

RESUMO

In persons living with HIV-1 (PLWH) who start antiretroviral therapy (ART), plasma virus decays in a biphasic fashion to below the detection limit. The first phase reflects the short half-life (<1 d) of cells that produce most of the plasma virus. The second phase represents the slower turnover (t1/2 = 14 d) of another infected cell population, whose identity is unclear. Using the intact proviral DNA assay (IPDA) to distinguish intact and defective proviruses, we analyzed viral decay in 17 PLWH initiating ART. Circulating CD4+ T cells with intact proviruses include few of the rapidly decaying first-phase cells. Instead, this population initially decays more slowly (t1/2 = 12.9 d) in a process that largely represents death or exit from the circulation rather than transition to latency. This more protracted decay potentially allows for immune selection. After ∼3 mo, the decay slope changes, and CD4+ T cells with intact proviruses decay with a half-life of 19 mo, which is still shorter than that of the latently infected cells that persist on long-term ART. Two-long-terminal repeat (2LTR) circles decay with fast and slow phases paralleling intact proviruses, a finding that precludes their use as a simple marker of ongoing viral replication. Proviruses with defects at the 5' or 3' end of the genome show equivalent monophasic decay at rates that vary among individuals. Understanding these complex early decay processes is important for correct use of reservoir assays and may provide insights into properties of surviving cells that can constitute the stable latent reservoir.


Assuntos
Antirretrovirais/farmacologia , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Provírus/efeitos dos fármacos , Vírion/efeitos dos fármacos , Linfócitos T CD4-Positivos/efeitos dos fármacos , Células Cultivadas , DNA Viral/efeitos dos fármacos , Humanos , Estudos Longitudinais , Carga Viral/efeitos dos fármacos , Latência Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
2.
J Biol Chem ; 299(4): 103028, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36805339

RESUMO

The emergence of SARS-CoV-2, which is responsible for the COVID-19 pandemic, has highlighted the need for rapid characterization of viral mechanisms associated with cellular pathogenesis. Viral UTRs represent conserved genomic elements that contribute to such mechanisms. Structural details of most CoV UTRs are not available, however. Experimental approaches are needed to allow for the facile generation of high-quality viral RNA tertiary structural models, which can facilitate comparative mechanistic efforts. By integrating experimental and computational techniques, we herein report the efficient characterization of conserved RNA structures within the 5'UTR of the HCoV-OC43 genome, a lab-tractable model coronavirus. We provide evidence that the 5'UTR folds into a structure with well-defined stem-loops (SLs) as determined by chemical probing and direct detection of hydrogen bonds by NMR. We combine experimental base-pair restraints with global structural information from SAXS to generate a 3D model that reveals that SL1-4 adopts a topologically constrained structure wherein SLs 3 and 4 coaxially stack. Coaxial stacking is mediated by short linker nucleotides and allows SLs 1 to 2 to sample different cojoint orientations by pivoting about the SL3,4 helical axis. To evaluate the functional relevance of the SL3,4 coaxial helix, we engineered luciferase reporter constructs harboring the HCoV-OC43 5'UTR with mutations designed to abrogate coaxial stacking. Our results reveal that the SL3,4 helix intrinsically represses translation efficiency since the destabilizing mutations correlate with increased luciferase expression relative to wildtype without affecting reporter mRNA levels, thus highlighting how the 5'UTR structure contributes to the viral mechanism.


Assuntos
Regiões 5' não Traduzidas , Coronavirus Humano OC43 , RNA Viral , Coronavirus Humano OC43/genética , Luciferases/genética , Espalhamento a Baixo Ângulo , Difração de Raios X , RNA Viral/genética
3.
J Neuroophthalmol ; 42(1): 97-100, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35500237

RESUMO

BACKGROUND: To evaluate the change in intraocular pressure (IOP) in patients with idiopathic intracranial hypertension (IIH) who underwent optic nerve sheath fenestration (ONSF) and to determine if radiographic evidence of posterior scleral or globe indentation influenced IOP. METHODS: This is a retrospective analysis of IOP in IIH patients who underwent ONSF. The study included all patients from September 2010 to March 2018 operated on by a single surgeon (R.M.). IOPs preoperatively and postoperatively were recorded along with the acetazolamide dosage and whether there was evidence of posterior scleral or globe indentation on preoperative MRI. RESULTS: A total of 29 patients (35 eyes) with IIH underwent ONSF. The average reduction in IOP among all patients was 1.24 mm Hg (P = 0.0218), but this increased to 2.69 mm Hg (P = 0.004) in patients who were maintained on the same dosage of acetazolamide in the preoperative and postoperative period. Furthermore, the reduction in IOP in those with posterior scleral or globe indentation was 2.5 mm Hg (P = 0.0095). When the perioperative period was evaluated, the mean decrease in IOP was 1.83 mm Hg (P = 0.0217). CONCLUSIONS: Reducing the cerebral spinal fluid pressure (CSFP) at the level of the intraorbital optic nerve through an ONSF can slightly reduce the IOP. In those with evidence of posterior globe or scleral indentation/flattening, the reduction in IOP was higher, which supports the theory that CSF pressure indents the globe and leads to an increase in IOP. Although these changes in IOP are small, this study provides further evidence for a connection between IOP and CSFP.


Assuntos
Oftalmopatias , Pseudotumor Cerebral , Acetazolamida/uso terapêutico , Humanos , Pressão Intraocular , Nervo Óptico/cirurgia , Pseudotumor Cerebral/complicações , Pseudotumor Cerebral/diagnóstico , Pseudotumor Cerebral/cirurgia , Estudos Retrospectivos
4.
J Pharmacol Exp Ther ; 376(1): 51-63, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33115824

RESUMO

Asthma is still an incurable disease, and there is a recognized need for novel small-molecule therapies for people with asthma, especially those poorly controlled by current treatments. We previously demonstrated that calcium-sensing receptor (CaSR) negative allosteric modulators (NAMs), calcilytics, uniquely suppress both airway hyperresponsiveness (AHR) and inflammation in human cells and murine asthma surrogates. Here we assess the feasibility of repurposing four CaSR NAMs, which were originally developed for oral therapy for osteoporosis and previously tested in the clinic as a novel, single, and comprehensive topical antiasthma therapy. We address the hypotheses, using murine asthma surrogates, that topically delivered CaSR NAMs 1) abolish AHR; 2) are unlikely to cause unwanted systemic effects; 3) are suitable for topical application; and 4) inhibit airway inflammation to the same degree as the current standard of care, inhaled corticosteroids, and, furthermore, inhibit airway remodeling. All four CaSR NAMs inhibited poly-L-arginine-induced AHR in naïve mice and suppressed both AHR and airway inflammation in a murine surrogate of acute asthma, confirming class specificity. Repeated exposure to inhaled CaSR NAMs did not alter blood pressure, heart rate, or serum calcium concentrations. Optimal candidates for repurposing were identified based on anti-AHR/inflammatory activities, pharmacokinetics/pharmacodynamics, formulation, and micronization studies. Whereas both inhaled CaSR NAMs and inhaled corticosteroids reduced airways inflammation, only the former prevented goblet cell hyperplasia in a chronic asthma model. We conclude that inhaled CaSR NAMs are likely a single, safe, and effective topical therapy for human asthma, abolishing AHR, suppressing airways inflammation, and abrogating some features of airway remodeling. SIGNIFICANCE STATEMENT: Calcium-sensing receptor (CaSR) negative allosteric modulators (NAMs) reduce airway smooth muscle hyperresponsiveness, reverse airway inflammation as efficiently as topical corticosteroids, and suppress airway remodeling in asthma surrogates. CaSR NAMs, which were initially developed for oral therapy of osteoporosis proved inefficacious for this indication despite being safe and well tolerated. Here we show that structurally unrelated CaSR NAMs are suitable for inhaled delivery and represent a one-stop, steroid-free approach to asthma control and prophylaxis.


Assuntos
Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Indanos/uso terapêutico , Naftalenos/uso terapêutico , Fenilpropionatos/uso terapêutico , Quinazolinonas/uso terapêutico , Receptores de Detecção de Cálcio/agonistas , Regulação Alostérica , Animais , Antiasmáticos/efeitos adversos , Antiasmáticos/farmacologia , Brônquios/efeitos dos fármacos , Brônquios/metabolismo , Reposicionamento de Medicamentos , Células HEK293 , Humanos , Indanos/efeitos adversos , Indanos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Naftalenos/efeitos adversos , Naftalenos/farmacologia , Fenilpropionatos/efeitos adversos , Fenilpropionatos/farmacologia , Quinazolinonas/efeitos adversos , Quinazolinonas/farmacologia , Receptores de Detecção de Cálcio/metabolismo
5.
J Intensive Care Med ; 36(7): 793-797, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32319348

RESUMO

BACKGROUND: Knowledge of patient weight is required to guide initial intravenous fluid therapy for patients with sepsis-associated hypotension or elevated lactate. Previous studies have shown patients are better estimators of their weight than medical providers are; critically ill patients, however, may be unable to provide this information. OBJECTIVES: This study compares the accuracy of physician-estimated and patient self-reported weights to subsequent inpatient bed/stretcher scale weights for guiding initial protocol-based intravenous fluid therapy in the treatment of emergency department patients with suspected sepsis. METHODS: Adult patients presenting with a suspected diagnosis of severe sepsis to a large, urban, academic emergency department had either physician-estimated or patient self-reported weights recorded on presentation. All patients had subsequent inpatient bed/stretcher scale weights recorded on the first day of hospitalization. RESULTS: Physician-estimated and patient self-reported weights linearly correlated (P < .001) with inpatient bed/stretcher scale weights. Median accuracy error for physicians (5.4% [2.0-10.1]) and patients (3.9% [1.6-6.4]) was not significantly different (P = .28). Physician-estimated and patient self-reported weights accuracy was determined at multiple levels: within 5% (46%, 57%, respectively), 10% (75%, 90%), 15% (90%, 95%), and 20% (100%, 95%) error tolerances, as well accurate estimates within 5 kg (69.2%, 70.0%). CONCLUSIONS: Both physician-estimated and patient self-reported weights are reliable when calculating initial protocol-based intravenous fluid resuscitation for emergency department patients with sepsis.


Assuntos
Médicos , Sepse , Adulto , Serviço Hospitalar de Emergência , Hidratação , Humanos , Ressuscitação , Autorrelato , Sepse/tratamento farmacológico
6.
Am J Emerg Med ; 46: 539-544, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33191044

RESUMO

BACKGROUND: Difficult intravenous access (DIVA) is a common problem in Emergency Departments (EDs), yet the prevalence and clinical impact of this condition is poorly understood. Ultrasound-guided peripheral intravenous catheter (USGPIV) insertion is a successful modality for obtaining intravenous (IV) access in patients with DIVA. OBJECTIVES: We aimed to describe the prevalence of DIVA, explore how DIVA affects delivery of care, and determine if nurse insertion of USGPIV improves care delays among patients with DIVA. METHODS: We retrospectively queried the electronic medical record for all ED patients who had a peripheral IV (PIV) inserted at a tertiary academic medical center from 2015 to 2017. We categorized patients as having DIVA if they required ≥3 PIV attempts or an USGPIV. We compared metrics for care delivery including time-to-IV-access, time-to-laboratory-results, time-to-IV-analgesia, and ED length of stay (LOS) between patients with and without DIVA. We also compared these metrics in patients with DIVA with a physician-inserted USGPIV versus those with a nurse-inserted USGPIV. RESULTS: A total of 147,260 patients were evaluated during the study period. Of these, 13,192 (8.9%) met criteria for DIVA. Patients with DIVA encountered statistically significant delays in time-to-IV-access, time-to-laboratory-results, time-to-IV-analgesia, and ED LOS compared to patients without DIVA (all p < 0.001). Patients with nurse-inserted USGPIVs also had statistically significant improvements in time-to-IV-access, time-to-laboratory-results, time-to-IV-analgesia, and ED LOS compared to patients with physician-inserted USGPIVs (all p < 0.001). CONCLUSION: DIVA affects many ED patients and leads to delays in PIV access-related care. Nurse insertion of USGPIVs improves care in patients with DIVA.


Assuntos
Cateterismo Periférico/métodos , Enfermeiras e Enfermeiros , Ultrassonografia de Intervenção/métodos , Adolescente , Adulto , Idoso , Analgésicos/administração & dosagem , Serviço Hospitalar de Emergência , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Flebotomia/métodos , Médicos , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Tempo para o Tratamento/estatística & dados numéricos , Ultrassonografia , Adulto Jovem
7.
Clin Sci (Lond) ; 134(11): 1219-1242, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32501497

RESUMO

Research using animal models of asthma is currently dominated by mouse models. This has been driven by the comprehensive knowledge on inflammatory and immune reactions in mice, as well as tools to produce genetically modified mice. Many of the identified therapeutic targets influencing airway hyper-responsiveness and inflammation in mouse models, have however been disappointing when tested clinically in asthma. It is therefore a great need for new animal models that more closely resemble human asthma. The guinea pig has for decades been used in asthma research and a comprehensive table of different protocols for asthma models is presented. The studies have primarily been focused on the pharmacological aspects of the disease, where the guinea pig undoubtedly is superior to mice. Further reasons are the anatomical and physiological similarities between human and guinea pig airways compared with that of the mouse, especially with respect to airway branching, neurophysiology, pulmonary circulation and smooth muscle distribution, as well as mast cell localization and mediator secretion. Lack of reagents and specific molecular tools to study inflammatory and immunological reactions in the guinea pig has however greatly diminished its use in asthma research. The aim in this position paper is to review and summarize what we know about different aspects of the use of guinea pig in vivo models for asthma research. The associated aim is to highlight the unmet needs that have to be addressed in the future.


Assuntos
Asma/patologia , Modelos Animais de Doenças , Cobaias/fisiologia , Animais , Desenvolvimento de Medicamentos , Edição de Genes , Cobaias/genética , Pulmão/patologia , Pulmão/fisiopatologia
8.
Am J Emerg Med ; 38(12): 2607-2613, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-31982224

RESUMO

INTRODUCTION: This study evaluates the utility of heart rate variability (HRV) for assessment of severity of illness and poor outcome in Emergency Department (ED) patients with sepsis. HRV measures evaluated included low frequency (LF) signal, high frequency (HF) signal, and deviations in LF and HF signal from age-adjusted reference values. METHODS: This was a prospective, observational study. Seventy-two adult ED patients were assessed within 6 h of arrival. RESULTS: Severity of illness as defined by sepsis subtype correlated with decreased LF signal (sepsis: 70.68 ± 22.95, severe sepsis: 54.00 ± 28.41, septic shock: 45.54 ± 23.31, p = 0.02), increased HF signal (sepsis: 27.87 ± 19.42, severe sepsis: 44.63 ± 27.29, septic shock: 47.66 ± 20.98, p = 0.01), increasingly negative deviations in LF signal (sepsis: 0.41 ± 24.53, severe sepsis: -21.43 ± 30.09, septic shock -30.39 ± 26.09, p = 0.005) and increasingly positive deviations in HF signal (sepsis: -1.86 ± 21.09, severe sepsis: 20.07 ± 29.03, septic shock: 23.6 ± 24.17, p = 0.004). Composite poor outcome correlated with decreased LF signal (p = 0.008), increased HF signal (p = 0.03), large negative deviations in LF signal (p = 0.004) and large positive deviations in HF signal (p = 0.02). Deviations in LF and HF signal from age-adjusted reference values correlated with individual measures of poor outcome with greater consistency than LF or HF signal. DISCUSSION: Accounting for the influence of age on baseline HRV signal improves the predictive value of HRV measures in ED patients with sepsis.


Assuntos
Frequência Cardíaca/fisiologia , Unidades de Terapia Intensiva/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Sepse/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Serviço Hospitalar de Emergência , Feminino , Humanos , Intubação Intratraqueal/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Mortalidade , Prognóstico , Estudos Prospectivos , Respiração Artificial/estatística & dados numéricos , Índice de Gravidade de Doença , Choque Séptico/fisiopatologia
9.
J Pharmacol Exp Ther ; 362(2): 327-337, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28576975

RESUMO

Lipopolysaccharide (LPS) contributes to asthma exacerbations and development of inhaled corticosteroid insensitivity. Complete resistance to systemic corticosteroids is rare, and most patients lie on a continuum of steroid responsiveness. This study aimed to examine the sensitivity of combined ovalbumin- (Ova) and LPS-induced functional and inflammatory responses to inhaled and systemic corticosteroid in conscious guinea pigs to test the hypothesis that the route of administration affects sensitivity. Guinea pigs were sensitized to Ova and challenged with inhaled Ova alone or combined with LPS. Airway function was determined by measuring specific airway conductance via whole-body plethysmography. Airway hyper-responsiveness to histamine was determined before and 24 hours post-Ova challenge. Airway inflammation and underlying mechanisms were determined from bronchoalveolar lavage cell counts and lung tissue cytokines. Vehicle or dexamethasone was administered by once-daily i.p. injection (5, 10, or 20 mg/kg) or twice-daily inhalation (4 or 20 mg/ml) for 6 days before Ova challenge or Ova with LPS. LPS exacerbated Ova-induced responses, elongating early asthmatic responses (EAR), prolonging histamine bronchoconstriction, and further elevating airway inflammation. Intraperitoneal dexamethasone (20 mg/kg) significantly reduced the elongated EAR and airway inflammation but not the increased bronchoconstriction to histamine. In contrast, inhaled dexamethasone (20 mg/ml), which inhibited responses to Ova alone, did not significantly reduce functional and inflammatory responses to combined Ova and LPS. Combined Ova and LPS-induced functional and inflammatory responses are insensitive to inhaled, but they are only partially sensitive to systemic, dexamethasone. This finding suggests that the route of corticosteroid administration may be important in determining corticosteroid sensitivity of asthmatic responses.


Assuntos
Corticosteroides/administração & dosagem , Asma/induzido quimicamente , Asma/tratamento farmacológico , Lipopolissacarídeos/toxicidade , Ovalbumina/toxicidade , Administração por Inalação , Animais , Asma/metabolismo , Hiper-Reatividade Brônquica/induzido quimicamente , Hiper-Reatividade Brônquica/tratamento farmacológico , Hiper-Reatividade Brônquica/metabolismo , Vias de Administração de Medicamentos , Combinação de Medicamentos , Cobaias , Injeções Intraperitoneais , Lipopolissacarídeos/administração & dosagem , Masculino , Ovalbumina/administração & dosagem , Hipersensibilidade Respiratória/induzido quimicamente , Hipersensibilidade Respiratória/tratamento farmacológico , Hipersensibilidade Respiratória/metabolismo
10.
J Environ Qual ; 46(6): 1413-1423, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29293822

RESUMO

The contribution of macropore flow to phosphorus (P) loadings in tile-drained agricultural landscapes remains poorly understood at the field scale, despite the recognized deleterious impacts of contaminant transport via macropore pathways. A new subroutine that couples existing matrix-excess and matrix-desiccation macropore flow theory and a modified P routine is implemented in the Agricultural Policy Environmental eXtender (APEX) model. The original and modified formulation were applied and evaluated for a case study in a poorly drained field in Western Ohio with 31 months of surface and subsurface monitoring data. Results highlighted that a macropore subroutine in APEX improved edge-of-field discharge calibration and validation for both tile and total discharge from satisfactory and good, respectively, to very good and improved dissolved reactive P load calibration and validation statistics for tile P loads from unsatisfactory to very good. Output from the calibrated macropore simulations suggested median annual matrix-desiccation macropore flow contributions of 48% and P load contributions of 43%, with the majority of loading occurring in winter and spring. While somewhat counterintuitive, the prominence of matrix-desiccation macropore flow during seasons with less cracking reflects the importance of coupled development of macropore pathways and adequate supply of the macropore flow source. The innovative features of the model allow for assessments of annual macropore P contributions to tile drainage and has the potential to inform P site assessment tools.


Assuntos
Agricultura , Modelos Teóricos , Fósforo/análise , Poluentes da Água/análise , Monitoramento Ambiental , Ohio , Movimentos da Água
11.
Analyst ; 141(4): 1472-82, 2016 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-26818563

RESUMO

We hereby report the design and implementation of an Autonomous Microbial Cell Culture and Classification (AMC(3)) system for rapid detection of food pathogens. Traditional food testing methods require multistep procedures and long incubation period, and are thus prone to human error. AMC(3) introduces a "one click approach" to the detection and classification of pathogenic bacteria. Once the cultured materials are prepared, all operations are automatic. AMC(3) is an integrated sensor array platform in a microbial fuel cell system composed of a multi-potentiostat, an automated data collection system (Python program, Yocto Maxi-coupler electromechanical relay module) and a powerful classification program. The classification scheme consists of Probabilistic Neural Network (PNN), Support Vector Machines (SVM) and General Regression Neural Network (GRNN) oracle-based system. Differential Pulse Voltammetry (DPV) is performed on standard samples or unknown samples. Then, using preset feature extractions and quality control, accepted data are analyzed by the intelligent classification system. In a typical use, thirty-two extracted features were analyzed to correctly classify the following pathogens: Escherichia coli ATCC#25922, Escherichia coli ATCC#11775, and Staphylococcus epidermidis ATCC#12228. 85.4% accuracy range was recorded for unknown samples, and within a shorter time period than the industry standard of 24 hours.


Assuntos
Inteligência Artificial , Técnicas de Cultura de Células/métodos , Escherichia coli/citologia , Escherichia coli/isolamento & purificação , Microbiologia de Alimentos , Staphylococcus epidermidis/citologia , Staphylococcus epidermidis/isolamento & purificação , Automação , Eletroquímica , Humanos , Redes Neurais de Computação , Controle de Qualidade , Máquina de Vetores de Suporte
12.
Proc Natl Acad Sci U S A ; 110(5): 1606-10, 2013 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-23319660

RESUMO

We have investigated the folding dynamics of Thermus thermophilus cytochrome c(552) by time-resolved fluorescence energy transfer between the heme and each of seven site-specific fluorescent probes. We have found both an equilibrium unfolding intermediate and a distinct refolding intermediate from kinetics studies. Depending on the protein region monitored, we observed either two-state or three-state denaturation transitions. The unfolding intermediate associated with three-state folding exhibited native contacts in ß-sheet and C-terminal helix regions. We probed the formation of a refolding intermediate by time-resolved fluorescence energy transfer between residue 110 and the heme using a continuous flow mixer. The intermediate ensemble, a heterogeneous mixture of compact and extended polypeptides, forms in a millisecond, substantially slower than the ∼100-µs formation of a burst-phase intermediate in cytochrome c. The surprising finding is that, unlike for cytochrome c, there is an observable folding intermediate, but no microsecond burst phase in the folding kinetics of the structurally related thermostable protein.


Assuntos
Proteínas de Bactérias/química , Grupo dos Citocromos c/química , Heme/química , Dobramento de Proteína , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Dicroísmo Circular , Cristalografia por Raios X , Cisteína/química , Cisteína/genética , Cisteína/metabolismo , Grupo dos Citocromos c/genética , Grupo dos Citocromos c/metabolismo , Heme/metabolismo , Cinética , Modelos Moleculares , Estrutura Molecular , Mutação , Desnaturação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Desdobramento de Proteína , Espectrometria de Fluorescência , Thermus thermophilus/genética , Thermus thermophilus/metabolismo , Fatores de Tempo
13.
Exp Lung Res ; 41(4): 189-98, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25844692

RESUMO

PURPOSE: Asthma is associated with reversible airway obstruction, leucocyte infiltration, airways hyperresponsiveness (AHR), and airways remodeling. Fluid accumulation causes pulmonary edema contributing to airways obstruction. We examined the temporal relationship between the late asthmatic response (LAR) following allergen challenge of sensitized guinea-pigs and pulmonary edema measured by magnetic resonance imaging (MRI). MATERIALS AND METHODS: Ovalbumin (OVA) sensitized guinea-pigs received either a single OVA inhalation (acute) or nine OVA inhalations at 48 h intervals (chronic). Airways obstruction was measured as specific airways conductance (sG(aw)) by whole body plethysmography. AHR to inhaled histamine and bronchoalveolar lavage for leucocyte counts were measured 24 h after a single or the final chronic ovalbumin challenges. MRI was performed at intervals after OVA challenge and high-intensity edemic signals were quantified. RESULTS: Ovalbumin caused early bronchoconstriction, followed at 7 h by an LAR and at 24 h AHR and leucocyte influx. The bright-intensity MRI edema signal, peaking at 7 h, was significantly (P < .05) greater after chronic (9.0 ± 0.7 × 10(3) mm(3)) than acute OVA (7.6 ± 0.2 × 10(3) mm(3)). Dexamethasone treatment before acute OVA abolished the AHR and LAR and significantly reduced eosinophils and the bright-intensity MRI edema from 9.1 ± 1.0 to 6.4 ± 0.3 × 10(3) mm(3). CONCLUSION: We show a temporal relationship between edema and the LAR and their parallel reduction, along with eosinophils and AHR, by dexamethasone. This suggests a close causative association between pulmonary edema and impaired airways function.


Assuntos
Alérgenos , Asma/patologia , Pulmão/patologia , Imageamento por Ressonância Magnética , Ovalbumina , Edema Pulmonar/patologia , Animais , Antiasmáticos/farmacologia , Asma/induzido quimicamente , Asma/imunologia , Asma/fisiopatologia , Asma/prevenção & controle , Líquido da Lavagem Broncoalveolar/imunologia , Broncoconstrição , Quimiotaxia de Leucócito , Dexametasona/farmacologia , Modelos Animais de Doenças , Cobaias , Pulmão/efeitos dos fármacos , Pulmão/fisiopatologia , Masculino , Valor Preditivo dos Testes , Edema Pulmonar/induzido quimicamente , Edema Pulmonar/imunologia , Edema Pulmonar/prevenção & controle , Eosinofilia Pulmonar/induzido quimicamente , Eosinofilia Pulmonar/imunologia , Eosinofilia Pulmonar/patologia , Eosinofilia Pulmonar/prevenção & controle , Fatores de Tempo
14.
J Emerg Med ; 48(4): 508-19, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25605319

RESUMO

BACKGROUND: Acute bacterial skin and skin structure infections (ABSSSI), formally referred to as complicated skin and soft tissue infections, include infections with resistance to previously effective antimicrobials. Increasing dramatically in incidence, they have become a challenging medical problem associated with high direct and indirect costs to both the medical system and society. OBJECTIVES: To describe the burden of ABSSSI and to explore multidisciplinary approaches to its management and new treatments that can be initiated in the emergency department. DISCUSSION: We offer a best practice model aimed at providing risk-stratified and convenient care for ABSSSI at the lowest possible cost, while minimizing complications, readmissions, and inappropriate antibiotic use. In doing so, we focus on the care provided by emergency physicians and hospitalists and the transition of management between them for inpatient care, as well as the facilitation of observation or direct-to-outpatient care for suitable patients. CONCLUSIONS: A standard, consistent, and multidisciplinary approach to ABSSSI can streamline care, reduce admissions, support antimicrobial stewardship, and improve clinical and resource consumption outcomes.


Assuntos
Antibacterianos/uso terapêutico , Serviço Hospitalar de Emergência , Guias de Prática Clínica como Assunto , Dermatopatias Bacterianas/tratamento farmacológico , Doença Aguda , Continuidade da Assistência ao Paciente , Efeitos Psicossociais da Doença , Gerenciamento Clínico , Humanos
16.
bioRxiv ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38915549

RESUMO

Short-interfering RNA (siRNA) has gained significant interest for treatment of neurological diseases by providing the capacity to achieve sustained inhibition of nearly any gene target. Yet, achieving efficacious drug delivery throughout deep brain structures of the CNS remains a considerable hurdle. We herein describe a lipid-siRNA conjugate that, following delivery into the cerebrospinal fluid (CSF), is transported effectively through perivascular spaces, enabling broad dispersion within CSF compartments and through the CNS parenchyma. We provide a detailed examination of the temporal kinetics of gene silencing, highlighting potent knockdown for up to five months from a single injection without detectable toxicity. Single-cell RNA sequencing further demonstrates gene silencing activity across diverse cell populations in the parenchyma and at brain borders, which may provide new avenues for neurological disease-modifying therapies.

17.
Clin Sci (Lond) ; 125(10): 471-82, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23678868

RESUMO

Viral exacerbations of allergen-induced pulmonary inflammation in pre-clinical models reportedly reduce the efficacy of glucocorticoids to limit pulmonary inflammation and airways hyper-responsiveness to inhaled spasmogens. However, exacerbations of airway obstruction induced by allergen challenge have not yet been studied. hPIV-3 (human parainfluenza type 3 virus) inoculation of guinea-pigs increased inflammatory cell counts in BAL (bronchoalveolar lavage) fluid and caused hyper-responsiveness to inhaled histamine. Both responses were abolished by treatment with either dexamethasone (20 mg/kg of body weight, subcutaneous, once a day) or fluticasone propionate (a 0.5 mg/ml solution aerosolized and inhaled over 15 min, twice a day). In ovalbumin-sensitized guinea-pigs, allergen (ovalbumin) challenge caused two phases of airway obstruction [measured as changes in sGaw (specific airways conductance) using whole body plethysmography]: an immediate phase lasting between 4 and 6 h and a late phase at about 7 h. The late phase, airway hyper-responsiveness to histamine and inflammatory cell counts in BAL were all significantly reduced by either glucocorticoid. Inoculation of guinea-pigs sensitized to ovalbumin with hPIV-3 transformed the allergen-induced airway obstruction from two transient phases into a single sustained response lasting up to 12 h. This exacerbated airway obstruction and airway hyper-responsiveness to histamine were unaffected by treatment with either glucocorticoid whereas inflammatory cell counts in BAL were only partially inhibited. Virus- or allergen-induced pulmonary inflammation, individually, are glucocorticoid-sensitive, but in combination generate a phenotype where glucocorticoid efficacy is impaired. This suggests that during respiratory virus infection, glucocorticoids might be less effective in limiting pulmonary inflammation associated with asthma.


Assuntos
Glucocorticoides/uso terapêutico , Vírus da Parainfluenza 3 Humana , Pneumonia/virologia , Hipersensibilidade Respiratória/virologia , Infecções por Respirovirus/complicações , Administração por Inalação , Alérgenos/imunologia , Androstadienos/administração & dosagem , Androstadienos/uso terapêutico , Animais , Hiper-Reatividade Brônquica/tratamento farmacológico , Hiper-Reatividade Brônquica/virologia , Líquido da Lavagem Broncoalveolar/citologia , Dexametasona/uso terapêutico , Resistência a Medicamentos , Fluticasona , Glucocorticoides/administração & dosagem , Cobaias , Histamina , Humanos , Masculino , Ovalbumina/imunologia , Pneumonia/tratamento farmacológico , Hipersensibilidade Respiratória/tratamento farmacológico
18.
Healthcare (Basel) ; 11(8)2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37107959

RESUMO

A high percentage of asthma patients have symptoms that are not well controlled, despite effective drugs being available. One potential reason for this may be that poor inhaler technique limits the dose delivered to the lungs, thereby reducing the therapeutic efficacy. The aim of this study was to assess the prevalence of poor inhaler technique in an asthma patient population and to probe the impact of various demographic parameters on technique quality. This study was conducted at community pharmacies across Wales, UK. Patients diagnosed with asthma and 12 years or older were invited to participate. An aerosol inhalation monitor (AIM, Vitalograph®) was used to measure the quality of patient inhaler technique. A total of 295 AIM assessments were carried out. There were significant differences in the quality of inhaler technique across the different inhaler types (p < 0.001, Chi squared). The best technique was associated with dry-powder inhalers (DPI devices, 58% of 72 having good technique), compared with pressurized metered-dose inhalers (pMDI) or pMDIs with a spacer device (18% of 174 and 47% of 49 AIM assessments, respectively). There were some significant associations between gender, age, and quality of inhaler technique, as determined with adjusted odds ratios. It seems that the majority of asthmatic patients were not using their inhalers appropriately. We recommend that healthcare professionals place more emphasis on assessing and correcting inhaler technique, as poor inhaler technique might be responsible for the observed lack of symptom control in the asthma patient population.

19.
Pulm Pharmacol Ther ; 25(6): 453-64, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23046662

RESUMO

Pre-clinical evaluation of asthma therapies requires animal models of chronic airways inflammation, airway hyperresponsiveness (AHR) and lung remodelling that accurately predict drug effectiveness in human asthma. However, most animal models focus on acute allergen challenges where chronic inflammation and airway remodelling are absent. Chronic allergen challenge models have been developed in mice but few studies use guinea-pigs which may be more relevant to humans. We tested the hypothesis that a chronic rather than acute pulmonary inflammation model would best predict clinical outcome for asthma treatments. Guinea-pigs sensitized with ovalbumin (OVA) received single (acute) or nine OVA inhalation challenges at 48 h intervals (chronic). Airways function was recorded as specific airways conductance (sG(aw)) in conscious animals for 12 h after OVA challenge. AHR to inhaled histamine, inflammatory cell influx and lung histology were determined 24 h after the single or 9th OVA exposure. The inhaled corticosteroid, fluticasone propionate (FP), the phosphodiesterase 4 inhibitor, roflumilast, and the inducible nitric oxide synthase (iNOS) inhibitor, GW274150, orally, were administered 24 and 0.5 h before and 6 h after the single or final chronic OVA exposure. Both models displayed early (EAR) and late (LAR) asthmatic responses to OVA challenge, as falls in sG(aw), AHR, as increased histamine-induced bronchoconstriction, and inflammatory cell influx. Tissue remodelling, seen as increased collagen and goblet cell hyperplasia, occurred after multiple OVA challenge. Treatment with FP and roflumilast inhibited the LAR, cell influx and AHR in both models, and the remodelling in the chronic model. GW274150 also inhibited the LAR, AHR and eosinophil influx in the acute model, but not, together with the remodelling, in the chronic model. In the clinical setting, inhaled corticosteroids and phosphodiesterase 4 inhibitors are relatively effective against most features of asthma whereas the iNOS inhibitor GW274150 was ineffective. Thus, while there remain certain differences between our data and clinical effectiveness of these antiasthma drugs, a chronic pulmonary inflammation guinea-pig model does appear to be a better pre-clinical predictor of potential asthma therapeutics than an acute model.


Assuntos
Antiasmáticos/farmacologia , Asma/tratamento farmacológico , Hiper-Reatividade Brônquica/tratamento farmacológico , Inflamação/tratamento farmacológico , Doença Aguda , Administração por Inalação , Administração Oral , Aminopiridinas/farmacologia , Androstadienos/farmacologia , Animais , Asma/fisiopatologia , Benzamidas/farmacologia , Hiper-Reatividade Brônquica/fisiopatologia , Doença Crônica , Ciclopropanos/farmacologia , Modelos Animais de Doenças , Fluticasona , Cobaias , Histamina/imunologia , Inflamação/fisiopatologia , Masculino , Ovalbumina , Sulfetos/farmacologia , Fatores de Tempo
20.
Pharmacy (Basel) ; 10(3)2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35736774

RESUMO

The role of the community pharmacist has evolved to include the provision of more clinical services for patients. Those people who have stable chronic conditions will be managed in community pharmacies. This qualitative study used semi-structured in-depth interviews to understand the potential of providing additional patient-centred care for patients with stable chronic conditions in community pharmacies and identify potential limitations of this approach. Participants were recruited from Welsh Government, Local Health Boards (LHBS), Community Pharmacy Wales (CPW) and the Royal Pharmaceutical Society Wales (RPSW). The interviews were audio-recorded, transcribed verbatim, and analysed thematically. Eight interviews were conducted. The identified themes were as follows: (1) inconsistency and bureaucracy in commissioning pharmacy services; (2) availability of funding and resources; (3) disagreement and uncertainty about the contribution of the community pharmacy sector; (4) continuity of patient medical information and fragmented care; (5) accessibility, capacity and facilities in community pharmacy; (6) pharmacy education and clinical expertise, and (7) patient acceptability. It was clear that the potential benefit of managing stable chronic diseases in community pharmacies was recognised; however, several limitations expressed by stakeholders of pharmacy services need to be considered prior to moving forward.

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