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1.
Biomech Model Mechanobiol ; 21(6): 1803-1823, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36287315

RESUMO

Certain assemblies of fibers, called fiber bundles, play a crucial role in the statistical macroscale properties of fibrous structures like natural or artificial materials. Based on the concept of using idealized statistical fiber bundle cells (FBCs) as model elements, the software named FiberSpace was developed by us earlier for the phenomenological modeling of the tensile test process of real fibrous structures. The model fibers of these FBCs had been considered linear elastic, which was suitable for modeling certain textiles and composites. However, the biological tissues are multilevel structures with fiber-like building elements on every structural level where the fiber elements on the dominant level are statistical bundles of elementary fibers. Hence, their modeling required us to introduce model fibers of nonlinear mechanical behavior and derive the proper mathematical formulas for the calculation of the expected tensile force processes of the FBCs. Accordingly, we developed a new version of FiberSpace. The proposed nonlinear FBCs-based modeling method is essentially phenomenological that decomposes the measured and averaged stress-strain curve into the weighted sum of the responses of different idealized nonlinear FBCs. However, this decomposition can give certain information about the fibrous structure and some details of its damage and failure sub-processes. A special application of nonlinear E-bundles, where the measured stress-strain curve is expanded into a product-function series, may give another type of description for the failure process and can be applied to single measurements of structured failure process containing significant peaks and drops as well. The fitted phenomenological FBC models provide a decomposition of the measured force-strain curve, which enables to construct informative damage and failure maps. The applicability of the phenomenological modeling method and the fitting procedure is demonstrated with the tensile test data of some human and animal tissues, such as facial nerves and tendons.


Assuntos
Dinâmica não Linear , Tendões , Animais , Humanos , Tendões/fisiologia , Estresse Mecânico
2.
Equine Vet J ; 54(3): 457-466, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34428330

RESUMO

BACKGROUND: Accuracy of baseline ACTH for the diagnosis of PPID in horses varies between studies. OBJECTIVES: To estimate the diagnostic accuracy of ACTH as a biomarker for PPID in adult horses and appraise potential causes of heterogeneity. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A literature review identified studies reporting diagnostic accuracy data for extraction. Risk of bias was evaluated using QUADAS-2. Two random-effects models, the hierarchical summary receiver operating curve (HSROC) and the bivariate binomial normal model (BBN) were used to pool accuracy measurements. We performed meta-regression using study-level variables. The impact of diagnostic test accuracy on the frequency of false-positive and false-negative results at various pretest probabilities was calculated using the BBN model's accuracy results. RESULTS: Patient selection and index test evaluation demonstrated significant risk of bias. Mean and 95% confidence intervals for sensitivity and specificity for all studies (n = 11) based upon the HSROC model were (0.72, 95% CI: 0.62 to 0.82) and (0.88, 95% CI: 0.79 to 0.93), respectively. When studies with a common positivity threshold of 35 pg/mL ACTH were evaluated (n = 6), sensitivity and specificity were (0.66, 95% CI:0.54 to 0.77) and (0.87, 95% CI: 0.74 to 0.94). In a hypothetical group of one thousand horses with PPID prevalence of 2%, 20%, and 90%, the frequency of resulting false-positive and false-negatives would be (127 and 7), (104 and 68) and (13 and 306), respectively. Factors leading to increased accuracy were case-control design, clinical reference standard and data-driven choice of ACTH threshold. MAIN LIMITATIONS: A small number of primary studies (n = 11) were available, demonstrating significant biases. CONCLUSIONS: Less biased studies examining diagnostic accuracy of ACTH are needed. In horses with a high pretest probability of PPID, ACTH may be a functional "rule-in" test. Baseline ACTH is not recommended for screening purposes or use in horses without clinical signs of PPID.


Assuntos
Doenças dos Cavalos , Doenças da Hipófise , Adeno-Hipófise Parte Intermédia , Hormônio Adrenocorticotrópico , Animais , Biomarcadores , Doenças dos Cavalos/diagnóstico , Cavalos , Doenças da Hipófise/diagnóstico , Doenças da Hipófise/veterinária , Prevalência
3.
Expert Rev Clin Pharmacol ; 14(6): 671-675, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33861675

RESUMO

INTRODUCTION: The pooled worldwide prevalence of low-back pain-related presentations in primary care varies between 6.8% and 28.4% in the high-income countries rendering it a major healthcare/economy problem. To best manage this complex bio-psycho-social condition a 360-degree approach is needed, as the psycho-social components are often more important than the scant pathophysiology. Pattern analysis of cannabis users suggested that attempts to alleviate musculo-skeletal pain is often seen as a major drive to use cannabinoids. AREAS COVERED: Unlike NSAIDs/opioids, cannabidiol might directly affect more than one modality of pain signaling/perception. The 2019 guideline of the National Institute for Clinical Excellence recommended further studies with cannabidiol in pain medicine because of its excellent safety profile and presumed therapeutic potential. Therefore, we have researched relevant databases for pharmaco-physiological papers published between 2000 and 2021 to collate evidence in a narrative fashion to determine the clinical rationale for this cannabinoid in low-back pain. EXPERT OPINION: Observational research reported good results with CBD in pain and fear reduction, which are both key factors in low-back pain. Given the paucity of high-quality evidence, further research is needed to determine the efficacy/non-inferiority of CBD in primary/emergency care setting, using multimodal assessment of various patient-reported outcomes.


Assuntos
Analgésicos/administração & dosagem , Canabidiol/administração & dosagem , Dor Lombar/tratamento farmacológico , Analgésicos/efeitos adversos , Analgésicos/farmacologia , Animais , Canabidiol/efeitos adversos , Canabidiol/farmacologia , Canabinoides/administração & dosagem , Canabinoides/efeitos adversos , Canabinoides/farmacologia , Medo/efeitos dos fármacos , Humanos , Dor Lombar/fisiopatologia
4.
Res Vet Sci ; 132: 338-341, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32738730

RESUMO

Exercise-induced pulmonary hemorrhage (EIPH) and asthma in barrel racing horses is a common disease across the United States. Limited information is available on non-infectious respiratory diseases in this population, the interaction between these two diseases, and the occurrence of both EIPH and asthma in the horse. The purpose of this study was to evaluate the bronchoalveolar lavage (BAL) fluid cytological results of barrel racing horses with EIPH, asthma, or both. A retrospective study was conducted using the medical records of horses that presented with cough and decreased athletic performance and BAL results that met the criteria for inclusion. Data from 95 horses were included from a private practice referral hospital in Texas. No statistical difference was found in the frequency of neutrophilia, eosinophilia, or mastocytosis between diagnoses of EIPH, asthma, or concurrent diagnoses of EIPH and asthma. Bronchoalveolar lavage of horses suspected of EIPH is warranted to fully characterize the noninfectious respiratory disease of barrel racing horses.


Assuntos
Asma/veterinária , Líquido da Lavagem Broncoalveolar/química , Hemorragia/veterinária , Doenças dos Cavalos/diagnóstico , Pneumopatias/veterinária , Animais , Asma/diagnóstico , Líquido da Lavagem Broncoalveolar/citologia , Hemorragia/diagnóstico , Cavalos , Pneumopatias/diagnóstico , Masculino , Condicionamento Físico Animal , Estudos Retrospectivos , Texas
5.
Curr Pharm Des ; 26(25): 3026-3038, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32503401

RESUMO

Herpes zoster (HZ) causes considerable pain and distress, and γ-Aminobutyric acid (GABA) and its derivatives are assumed to control this, but the available data are inconsistent. This meta-analysis and systematic review aimed to assess the effectiveness of GABA derivatives in the prevention of acute herpetic pain. The metaanalysis was conducted following the PRISMA guidelines using PICO format, registered in PROSPERO number CRD42018095758. PubMed, Web of Science, Ovid, Scopus, and EMBASE databases were searched. Records were included if they were randomized controlled trials of patients undergoing HZ infection, investigating the effect of GABA derivatives versus placebo in the treatment of HZ pain. Eligible trials were evaluated for the risk of bias. Then data were extracted and analysed. The number of patients with observed presence of pain after treatment was used to calculate odds ratio in a random effect model with the DerSimonian-Laird estimator. The I2 statistic was analysed for heterogeneity. The potential risk of bias was measured using Egger's regression test. The meta-analysis included three randomized controlled trials with a total of 297 patients. The incidence of acute HZ pain events for GABA group was significantly lower compared to placebo group,18/148 vs 44/149, respectively (OR = 0.36; 95% CI = 0.14 to 0.93; Z = 2.11; P = 0.035), Egger's test yielded P = 0.308. In conclusion, the present meta-analysis demonstrates that GABA derivatives reduce the incidence of acute herpetic pain. However, additional, well-designed randomized clinical trials are needed to determine their dose- and time-dependency regarding this symptom.


Assuntos
Dor Aguda , Herpes Zoster , Dor Aguda/tratamento farmacológico , Herpes Zoster/complicações , Herpes Zoster/tratamento farmacológico , Herpes Zoster/epidemiologia , Humanos , Incidência , Ácido gama-Aminobutírico
6.
Curr Pharm Des ; 26(25): 3015-3025, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32410557

RESUMO

BACKGROUND: Effective and selective oral rinses are required in the daily medical and dental practice. Currently mouthwashes used have substantial side effects. OBJECTIVES: Our aim was to evaluate the efficacy of chlorine dioxide-containing mouthwashes in comparison with other previously established mouth rinses in healthy adults using oral hygiene indices. METHODS: This work was registered in PROSPERO (CRD42018099059) and carried out using multiple databases and reported according to the PRISMA statement. The search terms used were "chlorine dioxide" AND "oral", and only randomised controlled trials (RCTs) were included. The primary outcome was the alteration of the plaque index (PI), while the secondary outcomes were the gingival index (GI) and bacterial counts. For the risk of bias assessment, the Cochrane Risk of Bias Tool was used. Statistical analysis for data heterogeneity was performed by Q-value and I2-tests. RESULTS: 364 articles were found in the databases. After the selection process, only five RCTs were eligible for meta-analysis. Data heterogeneity was low. There were no statistical differences in effectiveness between chlorine dioxide and other effective mouth rinses in PI (0.720±0.119 vs 0.745±0.131; 95%; confidence intervals (CIs): 0.487-0.952 vs 0.489-1.001, respectively) and GI (0.712±0.130 vs 0.745±0.131; 95% CIs: 0.457-0.967 vs 0.489- 1.001, respectively) and also in bacterial counts. CONCLUSION: Chlorine dioxide reduces both plaque and gingival indices and bacterial counts in the oral cavity similar to other routinely used oral rinses, however, the evidence supporting this outcome is very limited. Therefore, further large scale RCTs are needed to decrease the risk of bias.


Assuntos
Compostos Clorados , Higiene Bucal , Adulto , Compostos Clorados/farmacologia , Humanos , Antissépticos Bucais/farmacologia , Óxidos/farmacologia
7.
Genome Med ; 12(1): 18, 2020 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-32075696

RESUMO

The European Union (EU) initiative on the Digital Transformation of Health and Care (Digicare) aims to provide the conditions necessary for building a secure, flexible, and decentralized digital health infrastructure. Creating a European Health Research and Innovation Cloud (HRIC) within this environment should enable data sharing and analysis for health research across the EU, in compliance with data protection legislation while preserving the full trust of the participants. Such a HRIC should learn from and build on existing data infrastructures, integrate best practices, and focus on the concrete needs of the community in terms of technologies, governance, management, regulation, and ethics requirements. Here, we describe the vision and expected benefits of digital data sharing in health research activities and present a roadmap that fosters the opportunities while answering the challenges of implementing a HRIC. For this, we put forward five specific recommendations and action points to ensure that a European HRIC: i) is built on established standards and guidelines, providing cloud technologies through an open and decentralized infrastructure; ii) is developed and certified to the highest standards of interoperability and data security that can be trusted by all stakeholders; iii) is supported by a robust ethical and legal framework that is compliant with the EU General Data Protection Regulation (GDPR); iv) establishes a proper environment for the training of new generations of data and medical scientists; and v) stimulates research and innovation in transnational collaborations through public and private initiatives and partnerships funded by the EU through Horizon 2020 and Horizon Europe.


Assuntos
Pesquisa Biomédica/organização & administração , Computação em Nuvem , Difusão de Inovações , Guias de Prática Clínica como Assunto , Pesquisa Biomédica/métodos , União Europeia , Disseminação de Informação/legislação & jurisprudência , Disseminação de Informação/métodos
8.
Bull Emerg Trauma ; 4(4): 244-247, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27878132

RESUMO

The majority of blunt trauma is secondary to motor vehicle crashes,especially in those wearing seatbelts or sitting in the front or passenger seat location.Hollow viscus gastrointestinal injuries occur more frequently in small bowel, followed by colorectal, duodenum, stomach and appendix. A 25-year-old male presents after being involved in a motor vehicle accident. Initialworkup was significant for moderate amount of pelvic free fluid and curvilinear,cysticlike structures in the pelvis. He subsequently developed peritonitis and underwentdiagnostic laparoscopy, which revealed multiple cystic nodules arising from theperitoneum. Pathology demonstrated benign cystic mesothelioma (BCM). BCM is a very rarecondition of mesotheliallined, variably sized, fluidfilled cysts that arises from theserous, pericardial or peritoneal lining. Due to the scarcity of cases, its management and prognosis are not fully established. This singular case highlights the necessity for a clinician to have a widedifferential forunusual causes of free pelvic fluid after blunt abdominaltrauma.

9.
Exp Clin Endocrinol Diabetes ; 122(10): 575-81, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25054312

RESUMO

The extracellular ion milieu determines the exocytosis mechanism that is coupled to spontaneous electrical activity. The K(+) ion plays crucial role in this mechanism: as the potassium current is associated with membrane hyperpolarization and hormone release through protein cascade activation. The primary aim of this study was to investigate the response mechanisms of normal adenohypophysis and adenohypophyseal prolactinoma cell populations at different extracellular K(+) levels with an otherwise isoionic milieu of all other essential ions. We focused on prolactin (PRL) and adrenocorticotrophic hormone (ACTH) release.In our experimental study, female Wistar rats (n=20) were treated with estrone-acetate (150 µg/kg b.w./week) for 6 months to induce prolactinomas in the adenohypophysis. Primary, monolayer cell cultures were prepared by enzymatic and mechanical digestion. PRL and ACTH hormone presence was measured by radioimmunoassay or immuno-chemiluminescence assay. Immunocytochemistry was used to assess the apoptotic cells.Differences between the effects of hypokalaemia on normal adenohypophysis cultures and prolactinoma cell populations were investigated. Significant alteration (p<0.001, n=10) in hormone exocytosis was detected in K(+) treated adenohypophyseal and prolactinoma cell cultures compared to untreated groups. Immunocyto-chemistry showed that Bcl-2 expression was reduced under hypokalaemic conditions.The decrease in hormone exocytosis was tightly correlated to the extracellular K(+) in both cell types, leading to the conclusion that external K(+) may be the major factor for the inhibition of hormone release. The significant increase in hormone content in supernatant media suggests that hypokalaemia may play important role in apoptosis.


Assuntos
Hormônio Adrenocorticotrópico/metabolismo , Exocitose/efeitos dos fármacos , Hipopotassemia/metabolismo , Adeno-Hipófise/efeitos dos fármacos , Neoplasias Hipofisárias/metabolismo , Potássio/farmacologia , Prolactina/metabolismo , Prolactinoma/metabolismo , Animais , Células Cultivadas , Estrona/análogos & derivados , Feminino , Adeno-Hipófise/metabolismo , Neoplasias Hipofisárias/induzido quimicamente , Neoplasias Hipofisárias/patologia , Prolactinoma/induzido quimicamente , Prolactinoma/patologia , Ratos , Ratos Wistar
10.
J Phys Chem Lett ; 4(20): 3392-6, 2013 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-26705582

RESUMO

The narrow bulk band gap and large exciton Bohr radius of germanium (Ge) make it an attractive material for optoelectronics utilizing band-gap-tunable photoluminescence (PL). However, realization of PL due to quantum confinement remains scarcely reported. Instead, PL is often observed from surface trap states and is independent of nanocrystal (NC) size. Here, we demonstrate tunable band gap PL by chemically passivating the Ge NC surface. The exchange of native Ge-Cl surface groups with alkyl groups using Grignard reagents leads to the first instance of tunable band gap emission from free-standing Ge NCs synthesized in the gas phase. Ge NCs between 4.8 and 10.2 nm in diameter exhibit near-infrared emission featuring spectral line widths that are at least a factor of 2 narrower than any previous report.

11.
Neurotoxicol Teratol ; 34(1): 9-19, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22024238

RESUMO

Chlorobenzenes have often been applied to study persistent organic pollutants with endocrine disruptor effects (POP/EDCs), but with the focus mainly on physiological aspects. Few data exist on the effects of chlorobenzenes and most POP/EDCs on anxiety or other arginine-vasopressin (AVP)- and oxytocin (OXT)-mediated behavior, albeit exposure to POP/EDCs or their ambient mixtures, even in low doses, may pose health risks for subjects living in contaminated areas and/or consuming polluted food. Our primary aim was therefore to demonstrate behavioral effects of longterm exposure to a discrete dose of a chlorobenzene mixture, and to draw attention to the results of subtoxic oral exposure on anxiety-related elements and the possible underlying endocrine processes. Adult male Wistar rats were treated daily with a mixture (ClB) of 1 µg/kg each of hexachlorobenzene and 1,2,4-trichlorobenzene via a gastric tube for 30, 60 or 90 days. After exposure, anxiety-related behavioral elements were determined in open-field and elevated plus maze tests. At euthanasia, the plasma levels of AVP, OXT and adrenocorticotrophic hormone (ACTH) were measured. Simultaneously, pituicytes from subjects were cultured to study the levels of basal and serotonin- or norepinephrinestimulated AVP and OXT secretion. Various anxiety-related behavioral elements were observed to be increased in both tests. The plasma AVP, OXT and ACTH concentrations were increased, to extents depending on the duration of exposure. The basal and monoamine-stimulated levels of AVP and OXT secretion of pituicytes prepared from the ClB-exposed rats were also elevated. Thus, certain anxietyrelated behavioral and endocrine elements were modulated by long-term exposure to ClB. As adult subjects were involved, which are generally less susceptible to toxic agents, it may be concluded that discrete doses of POP/EDC chlorobenzenes that are low enough to fall below the range of legal regulation may exert anxiogenic effects, which suggests that certain anxiogenic disorders may be induced environmentally in exposed human populations.


Assuntos
Comportamento Animal/efeitos dos fármacos , Clorobenzenos/toxicidade , Exposição Ambiental/efeitos adversos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Animais , Transtornos de Ansiedade/sangue , Transtornos de Ansiedade/induzido quimicamente , Transtornos de Ansiedade/fisiopatologia , Doença Crônica , Técnicas de Cocultura , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipotálamo-Hipofisário/fisiopatologia , Masculino , Cultura Primária de Células , Ratos , Ratos Wistar
12.
Physiol Behav ; 103(5): 421-30, 2011 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-21419145

RESUMO

Many chemicals utilized by humans are present as environmental pollutants and may influence homeostasis from neurological, immunological, endocrinological and/or behavioral aspects. Such agents, acting alone or in ambient mixtures, may be biologically active even at extremely low doses, and it may be postulated that stable, bioaccumulative, reactive endocrine disruptors may affect central and/or peripheral secretion of arginine-vasopressin (AVP) and oxytocin (OXT) and thereby related physiological and behavioral functions, potentially leading to disorders in exposed subjects. The primary aim of this study was to demonstrate effects of chronic exposure to a low dose of an orally administered chlorobenzene mixture on anxiety-related and aggressive behavior mediated largely by AVP and OXT. Chlorobenzenes were applied to model ambient mixtures of endocrine disruptors. Adult, male Wistar rats were exposed daily to 0.1 µg/kg of 1,2,4-trichlorobenzene and hexachlorobenzene via a stomach tube for 30, 60 or 90 days, after which anxiety-related and aggressive behavioral elements were examined in open-field, elevated plus maze and resident-intruder tests. The plasma levels of AVP, OXT and adrenocorticotrophic hormone at the endpoints were measured by radioimmunoassay or immunochemiluminescence assay. The levels of basal and serotonin- or norepinephrine-stimulated AVP and OXT secretion in pituicyte cultures prepared from the posterior lobe of the pituitaries were also measured. The hormone levels proved to be increased to extents depending on the duration of exposure to the chlorobenzenes. Several anxiety-related and aggressive behavioral elements were also enhanced following chlorobenzene exposure, while certain explorative and locomotive elements of the animals were decreased. As both physiological and behavioral elements were modulated by chronic, subtoxic doses of chlorobenzenes, it is concluded that doses of such environmental pollutants low enough to fall outside the range of legal regulation may pose potential risks of anxiogenic and/or aggressive consequences in exposed subjects, including humans.


Assuntos
Agressão/efeitos dos fármacos , Ansiedade/induzido quimicamente , Arginina Vasopressina/metabolismo , Clorobenzenos/farmacologia , Ocitocina/metabolismo , Hormônio Adrenocorticotrópico/sangue , Agressão/fisiologia , Animais , Ansiedade/psicologia , Arginina Vasopressina/sangue , Células Cultivadas , Clorobenzenos/administração & dosagem , Modelos Animais de Doenças , Esquema de Medicação , Poluentes Ambientais/administração & dosagem , Poluentes Ambientais/farmacologia , Hexaclorobenzeno/administração & dosagem , Hexaclorobenzeno/farmacologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Norepinefrina/farmacologia , Ocitocina/sangue , Neuro-Hipófise/efeitos dos fármacos , Neuro-Hipófise/metabolismo , Ratos , Ratos Wistar , Serotonina/farmacologia
13.
J Surg Res ; 165(1): 128-35, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20085844

RESUMO

BACKGROUND: Burn injury is frequently complicated by bacterial infection. Following burn injury, exposure to endotoxin produces a measurable decrease in cardiomyocyte sarcomere contractile function. Lipopolysaccharide-binding protein (LBP) is an acute phase protein that potentiates the recognition of lipopolysaccharide (LPS) by binding to the lipid A moiety of LPS. In this study, we sought to determine the effect of recombinant rat LBP (rLBP) on cardiomyocyte sarcomere function after burn or sham injury in the presence or absence of bacterial endotoxin. METHODS: Rats underwent a full-thickness 30% total body surface area scald or sham burn. At 24 h post-injury, cardiomyocytes were isolated, plated at 50,000 cells/well, and incubated with 50 µg/mL LPS and rLBP or chloramphenicol acetyltransferase (BVCat, an irrelevant control protein produced using the same expression system as rLBP) at concentrations by volume of 1%, 5%, 10%, and 30%. Subsets of cardiomyocytes were incubated with 5% rat serum or 30% rLBP and blocking experiments were conducted using an LBP-like synthetic peptide (LBPK95A). In vitro sarcomere function was measured using a variable rate video camera system with length detection software. RESULTS: Co-culture of burn and sham injury derived cardiomyocytes with high-dose rLBP in the presence of LPS resulted in a significant reduction to the functional impairment observed in peak sarcomere shortening following exposure to LPS alone. LBP-like peptide LBPK95A at a concentration of 20 µg/mL, in the presence of LPS, abolished the ability of 30% rLBP and 5% rat serum to restore peak sarcomere shortening of cardiomyocytes isolated following burn injury to levels of function exhibited in the absence of endotoxin exposure. CONCLUSIONS: In the setting of LPS challenge following burn injury, rLBP at high concentrations restores cardiomyocyte sarcomere contractile function in vitro. Rather than potentiating the recognition of LPS by the cellular LPS receptor complex, rLBP at high concentrations likely results in an inhibitory binding effect that minimizes the impact of endotoxin exposure on cardiomyocyte function following thermal injury.


Assuntos
Proteínas de Fase Aguda/farmacologia , Queimaduras/complicações , Proteínas de Transporte/farmacologia , Insuficiência Cardíaca/etiologia , Glicoproteínas de Membrana/farmacologia , Contração Miocárdica/efeitos dos fármacos , Animais , Apoptose , Sequência de Bases , Queimaduras/fisiopatologia , Relação Dose-Resposta a Droga , Marcação In Situ das Extremidades Cortadas , Lipopolissacarídeos/farmacologia , Masculino , Dados de Sequência Molecular , Miócitos Cardíacos/patologia , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Sarcômeros/efeitos dos fármacos , Sarcômeros/fisiologia
14.
Surgery ; 146(4): 775-85; discussion 785-6, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19789038

RESUMO

BACKGROUND: Topical inhibition of activated p38 MAPK within burn wounds attenuates the local and systemic inflammatory response. In this study, we investigated the effects of local activated p38 MAPK inhibition on burn-induced cardiac dysfunction. METHODS: Using a standardized rat model of scald burn injury, rats were given a 30% total body surface area partial thickness burn or sham injury, and the wounds were treated with an activated p38 MAPK inhibitor (SB) or vehicle. Systemic blood pressure measurements were recorded in vivo followed by in vitro assessment of sarcomere contraction in single-cell suspensions of isolated cardiomyocytes. RESULTS: Systolic blood pressure or maximum left ventricular pressures in vivo and peak cardiomyocyte sarcomere contractility in vitro were significantly reduced after burn injury. These functional deficits were abolished 24 h after burn injury following local p38 MAPK inhibition. In vitro incubation of normal cardiomyocytes with homogenate from burned skin or burn serum resulted in a similar pattern of impaired cardiomyocyte contractility. These effects were reversed in normal cardiomyocytes exposed to burn skin homogenates treated topically with a p38 MAPK inhibitor. A Western blot analysis showed that cardiac p38 MAPK activation was not affected by dermal blockade of activated p38 MAPK, arguing against systemic absorption of the inhibitor and indicating the involvement of systemic cytokine signaling. CONCLUSION: Topical activated p38 MAPK inhibition within burned skin attenuates the release of proinflammatory mediators and prevents burn-induced cardiac dysfunction after thermal injury. These results support the inhibition of burn-wound inflammatory signaling as a new therapeutic approach to prevent potential postthermal injury multiorgan dysfunction syndrome.


Assuntos
Queimaduras/fisiopatologia , Imidazóis/farmacologia , Contração Miocárdica/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Função Ventricular Esquerda/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Masculino , Ratos , Ratos Sprague-Dawley , Sarcômeros/efeitos dos fármacos
15.
J Immunol ; 180(11): 7664-72, 2008 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-18490769

RESUMO

Although acute lung injury (ALI) is an important problem in humans, its pathogenesis is poorly understood. Airway instillation of bacterial LPS, a known complement activator, represents a frequently used model of ALI. In the present study, pathways in the immunopathogenesis of ALI were evaluated. ALI was induced in wild-type, C3(-/-), and C5(-/-) mice by airway deposition of LPS. To assess the relevant inflammatory mediators, bronchoalveolar lavage fluids were evaluated by ELISA analyses and various neutralizing Abs and receptor antagonists were administered in vivo. LPS-induced ALI was neutrophil-dependent, but it was not associated with generation of C5a in the lung and was independent of C3, C5, or C5a. Instead, LPS injury was associated with robust generation of macrophage migration inhibitory factor (MIF), leukotriene B(4) (LTB4), and high mobility group box 1 protein (HMGB1) and required engagement of receptors for both MIF and LTB4. Neutralization of MIF or blockade of the MIF receptor and/or LTB4 receptor resulted in protection from LPS-induced ALI. These findings indicate that the MIF and LTB4 mediator pathways are involved in the immunopathogenesis of LPS-induced experimental ALI. Most strikingly, complement activation does not contribute to the development of ALI in the LPS model.


Assuntos
Ativação do Complemento , Proteínas do Sistema Complemento/metabolismo , Proteína HMGB1/metabolismo , Leucotrieno B4/metabolismo , Lipopolissacarídeos/imunologia , Fatores Inibidores da Migração de Macrófagos/metabolismo , Síndrome do Desconforto Respiratório/imunologia , Animais , Líquido da Lavagem Broncoalveolar/imunologia , Proteínas do Sistema Complemento/imunologia , Modelos Animais de Doenças , Proteína HMGB1/imunologia , Mediadores da Inflamação/metabolismo , Leucotrieno B4/imunologia , Pulmão/imunologia , Pulmão/metabolismo , Fatores Inibidores da Migração de Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Síndrome do Desconforto Respiratório/metabolismo
16.
Antioxid Redox Signal ; 10(5): 973-81, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18257742

RESUMO

We recently showed that acute oxidant-related lung injury (ALI) in rats after application of 2-chloroethyl ethyl sulfide (CEES) is attenuated by the airway instillation of antioxidants. We investigated whether intratracheal administration of antioxidant-containing liposomes immediately after instillation of CEES would attenuate short-term as well as long-term (fibrotic) effects of CEES-induced lung injury. In the acute injury model (4 h after injury), N-acetylcysteine (NAC)-containing liposomes were protective and reduced to baseline levels both the lung permeability index and the appearance of proinflammatory mediators in bronchoalveolar lavage fluids from CEES-exposed lungs. Similar results were obtained when rat alveolar macrophages were incubated in vitro with either CEES or lipopolysaccharide in the presence of NAC-liposomes. When lung fibrosis 3 weeks after CEES was quantitated by using hydroxyproline content, liposomes containing NAC or NAC + glutathione had no effects, but liposomes containing alpha/gamma-tocopherol alone or with NAC significantly suppressed the increase in lung hydroxyproline. The data demonstrate that delivery of antioxidants via liposomes to CEES-injured lungs is, depending on liposomal content, protective against ALI, prevents the appearance of proinflammatory mediators in bronchoalveolar fluids, and suppresses progressive fibrosis. Accordingly, the liposomal strategy may be therapeutically useful in CEES-induced lung injury in humans.


Assuntos
Antioxidantes , Lipossomos , Síndrome do Desconforto Respiratório/tratamento farmacológico , Síndrome do Desconforto Respiratório/prevenção & controle , Acetilcisteína/administração & dosagem , Acetilcisteína/metabolismo , Acetilcisteína/uso terapêutico , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/uso terapêutico , Líquido da Lavagem Broncoalveolar/química , Quimiocinas/metabolismo , Citocinas/metabolismo , Sequestradores de Radicais Livres/administração & dosagem , Sequestradores de Radicais Livres/metabolismo , Sequestradores de Radicais Livres/uso terapêutico , Humanos , Lipossomos/administração & dosagem , Lipossomos/química , Lipossomos/metabolismo , Lipossomos/uso terapêutico , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Macrófagos Alveolares/metabolismo , Masculino , Gás de Mostarda/análogos & derivados , Gás de Mostarda/farmacologia , Ratos , Ratos Long-Evans , Síndrome do Desconforto Respiratório/induzido quimicamente , Síndrome do Desconforto Respiratório/patologia , Tocoferóis/administração & dosagem , Tocoferóis/metabolismo , Tocoferóis/uso terapêutico
17.
Med Sci Monit ; 14(3): HY1-8, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18301363

RESUMO

BACKGROUND: Previous studies demonstrated a correlation between bone density, stability of fracture fixation, and outcome. Because current fracture classifications do not take osteoporosis into account, a prospective radiological analysis was conducted of patients with hip and wrist fracture to evaluate the impact of osteoporosis on fracture classification. MATERIAL/METHODS: Altogether, 77 consecutive patients with either hip or wrist fracture were prospectively recruited within 24 hours of sustaining the fracture. The patients were assigned to subgroups according to gender, fracture site, fracture type, and bone mineral density (BMD). Using widely accepted classification systems for hip and wrist fractures, the impact of osteoporosis on fracture classification was assessed. RESULTS: Osteoporosis dominated in both fracture types and bone mineral density showed a significant negative correlation with age. Pertrochanteric fractures were more frequent, showing an equal distribution among severity grades, while less frequent femoral neck fractures were mainly unstable fractures. Postmenopausal patients sustained more severe intraarticular comminuted wrist fractures, which were not found using the Fernandez classification. CONCLUSIONS: The contradiction between the higher incidence but lower severity of pertrochanteric fractures compared with femoral neck fractures in osteoporotic bone and inconsistencies between the classifications of wrist fractures may indicate incomplete fracture classification in osteoporosis. Given the high incidence of osteoporotic fractures, incorporating bone mineral status into fracture classification systems may improve preoperative assessment, implant stability, and outcome.


Assuntos
Fraturas do Quadril/classificação , Osteoporose , Traumatismos do Punho/classificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa , Estudos Prospectivos
18.
FASEB J ; 22(7): 2198-205, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18299333

RESUMO

IL-17A is a proinflammatory cytokine produced by a variety of cells. In the current study, we examined the role of IL-17A in sepsis induced in mice by cecal ligation and puncture (CLP). IL-17A levels, which rose time-dependently in plasma after CLP, were not affected in the absence of alphabeta T cells or neutrophils. In sharp contrast, gammadelta T cell-knockout or gammadelta T cell-depleted mice displayed baseline IL-17A plasma levels after CLP. Neutralization of IL-17A by two different antibodies improved sepsis (survival from approximately 10% to nearly 60%). Unexpectedly, antibody treatment was protective, even when administration of anti-IL-17A was delayed for up to 12 h after CLP. These protective effects of IL-17A blockade were associated with substantially reduced levels of bacteremia together with significant reductions of systemic proinflammatory cytokines and chemokines in plasma. In vitro incubation of mouse peritoneal macrophages with lipopolysaccharide (LPS) in the copresence of IL-17A substantially increased the production of TNF-alpha, IL-1beta, and IL-6 by these cells. These data suggest that, during experimental sepsis, gammadelta T cell-derived IL-17A promotes high levels of proinflammatory mediators and bacteremia, resulting in enhanced lethality. IL-17A may be a potential therapeutic target in sepsis.


Assuntos
Interleucina-17/toxicidade , Sepse/fisiopatologia , Animais , Bacteriemia , Ceco/patologia , Quimiocinas/sangue , Citocinas/sangue , Modelos Animais de Doenças , Inflamação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Punções , Sepse/etiologia , Linfócitos T/patologia
19.
Crit Care Med ; 35(9): 2139-44, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17855827

RESUMO

OBJECTIVE: We previously showed that topical inhibition of inflammatory signaling in burn wounds reduced systemic inflammatory response and burn-induced pulmonary inflammation. We hypothesized that this topical intervention would attenuate burn-induced lung injury, improve pulmonary function, protect lungs from bacterial invasion, and reduce mortality. DESIGN: Controlled, in vivo, laboratory study. SETTING: University laboratory. SUBJECTS: Female mice, 8-10 wks old. INTERVENTIONS: Animals received 30% total body surface area burn followed by topical application of a specific inhibitor of p38 mitogen-activated protein kinase, a key inflammatory signaling pathway, or vehicle to the wound. Twenty-four hours after injury, pulmonary collagen deposition and pulmonary function were assessed. One day postburn, some of the animals received intratracheal instillation of Klebsiella pneumoniae and were subsequently monitored for 7 days. MEASUREMENTS AND MAIN RESULTS: Topical inhibition of p38 mitogen-activated protein kinase significantly decreased pulmonary collagen deposition and prevented a decline in pulmonary function at 1 day after burn injury. Compared with sham controls, animals with burn injury had a significantly higher mortality in response to intratracheal bacterial challenge. Application of p38 mitogen-activated protein kinase inhibitor to the burn wound attenuated pulmonary neutrophil infiltration and reduced the mortality rate to a level experienced by sham controls. CONCLUSIONS: Inflammatory source control in burn wounds with topical p38 mitogen-activated protein kinase inhibition attenuates acute lung injury, avoids pulmonary dysfunction, protects lungs from bacterial challenge, and improves survival.


Assuntos
Queimaduras/tratamento farmacológico , Queimaduras/fisiopatologia , Pneumonia/prevenção & controle , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Colágeno/metabolismo , Modelos Animais de Doenças , Feminino , Infecções por Klebsiella/prevenção & controle , Klebsiella pneumoniae , Pulmão/metabolismo , Camundongos , Transdução de Sinais/efeitos dos fármacos
20.
Surgery ; 142(1): 86-93, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17630004

RESUMO

BACKGROUND: Although the inflammatory response is a prerequisite for wound healing, excessive activation of the innate immune system can induce epithelial cell damage and apoptosis, which may further compromise dermal integrity. In a noninfectious burn wound model, we previously demonstrated that topical inhibition of p38 MAPK, an important inflammatory signaling pathway, attenuated epithelial cell damage and apoptosis. We now question whether attenuating local inflammation would weaken bacterial wound resistance and compromise host defense. METHODS: Rats received 30% total body surface area burn, and the wound was treated with topical application of a p38 MAPK inhibitor or vehicle. At 24 hours after injury, burn wounds were inoculated with Pseudomonas aeruginosa. At 48 hours postinjury, animals were sacrificed, and the burn wound was analyzed. RESULTS: Inoculating burn wounds induced significant bacterial growth. Dermal inflammatory changes were markedly accentuated in the inoculated animals. Topical p38 MAPK inhibition reduced the proinflammatory cytokine expression in the burn wounds and neutrophil sequestration with or without bacterial inoculation. Interestingly, the bacterial wound growth was significantly attenuated in animals treated with topical p38 MAPK inhibitor. CONCLUSIONS: Topical p38 MAPK inhibition attenuated wound inflammation without interfering with bacterial host defense. Attenuation of excessive burn wound inflammatory signaling may prevent secondary damage of the dermal barrier and reduce the growth of opportunistic pathogens.


Assuntos
Queimaduras/microbiologia , Inibidores Enzimáticos/administração & dosagem , Imidazóis/administração & dosagem , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Piridinas/administração & dosagem , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Administração Tópica , Animais , Queimaduras/complicações , Queimaduras/metabolismo , Queimaduras/patologia , Quimiocina CXCL2 , Quimiocinas CXC/antagonistas & inibidores , Quimiocinas CXC/metabolismo , Ensaio de Unidades Formadoras de Colônias , Citocinas/antagonistas & inibidores , Dermatite/etiologia , Dermatite/microbiologia , Dermatite/patologia , Inibidores Enzimáticos/farmacologia , Imidazóis/farmacologia , Mediadores da Inflamação/antagonistas & inibidores , Masculino , Infiltração de Neutrófilos/efeitos dos fármacos , Óxido Nítrico/antagonistas & inibidores , Infecções por Pseudomonas , Piridinas/farmacologia , Ratos , Ratos Sprague-Dawley , Pele/metabolismo
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