RESUMEN
Baricitinib is approved for the treatment of rheumatoid arthritis (RA) in more than 70 countries, and juvenile idiopathic arthritis (JIA) in the European Union. Population pharmacokinetic (PK) models were developed in a phase 3 trial to characterize PK in pediatric patients with JIA and identify weight-based dosing regimens. The phase 3, randomized, double-blind, placebo-controlled withdrawal, efficacy and safety trial, JUVE-BASIS, enrolled patients (aged 2 to <18 years) with polyarticular course JIA. During a safety/PK period, baricitinib concentration data from age-based dose cohorts were compared to concentrations from adult patients receiving 4-mg QD. PK data were used to develop a population PK model with allometric scaling to determine a weight-based posology in pediatric patients with JIA that matched the adult 4-mg exposure. Baricitinib plasma concentrations from 217 pediatric patients were used to characterize PK. Based on the adult model, pediatric PK was best described using a 2-compartment model with allometric scaling on clearance and volume of distribution and renal function (estimated with glomerular filtration rate [GFR], a known covariate affecting PK of baricitinib) on clearance. The PK modeling suggested the optimal dosing regimen based on weight for pediatric patients as: 2-mg QD for patients 10 to <30 kg and 4-mg QD for patients ≥30 kg. The use of a population PK model of baricitinib treatment in adult patients with RA, with the addition of allometric scaling for weight on clearance and volume terms, was useful to predict exposures and identify weight-based dosing in pediatric patients with JIA.
Asunto(s)
Artritis Juvenil , Azetidinas , Modelos Biológicos , Purinas , Pirazoles , Sulfonamidas , Humanos , Purinas/farmacocinética , Purinas/administración & dosificación , Azetidinas/farmacocinética , Azetidinas/administración & dosificación , Niño , Sulfonamidas/farmacocinética , Sulfonamidas/administración & dosificación , Pirazoles/farmacocinética , Pirazoles/administración & dosificación , Artritis Juvenil/tratamiento farmacológico , Preescolar , Adolescente , Masculino , Femenino , Método Doble Ciego , Adulto , Peso Corporal , Relación Dosis-Respuesta a Droga , Antirreumáticos/farmacocinética , Antirreumáticos/administración & dosificación , Antirreumáticos/uso terapéuticoRESUMEN
Manually documented trauma flow sheets contain critical information regarding trauma resuscitations in the emergency department (ED). The American College of Surgeons (ACS) has enforced certain thresholds on trauma surgeons' arrival time to the trauma bay. Due to the complex and fast-paced ED environment, this information can be easily overlooked or erroneously recorded, affecting compliance with ACS standards. This paper is a retrospective study conducted at a Level I trauma center equipped with an RFID system to investigate an automated solution to evaluate and improve the accuracy of measuring trauma surgeons' response time to the highest level (red) trauma activations.Clinical Relevance- Demonstration of timely response to trauma activations is required for ACS verification. As real-time location systems become more prevalent, they may improve a hospital's ability to report accurate response times for trauma team activations.
Asunto(s)
Dispositivo de Identificación por Radiofrecuencia , Servicio de Urgencia en Hospital , Resucitación , Estudios Retrospectivos , Centros TraumatológicosRESUMEN
BACKGROUND: Scribes are unlicensed professionals trained in medical data entry. Limited data exist on the impact of scribes on provider time management in the emergency department (ED). Time-motion analysis is a tool utilized in business to capture detailed movements and durations to task completion. It offers a means to categorize how providers allocate their time during a clinical shift. OBJECTIVE: Evaluate the impact of scribes on how ED providers spend their time. METHODS: A prospective observational study was conducted to assess scribe impact on provider time utilization. Four research assistants (RAs) observed attending providers on 24 8-h control shifts (without a scribe), and 24 scribed shifts. RAs observed and categorized provider activity. Providers self-reported after-hours documentation times. Two-sample t-tests were used for normally distributed data, and Wilcoxon rank-sum tests were used for skewed data. All tests were two-sided, and p-values < 0.05 were considered statistically significant. RESULTS: Scribes decreased total documentation time both on shift (mean 55.3 vs. 36.4 min, p < 0.001) and post shift (mean 42.5 vs. 23.3 min, p = 0.038). They did not significantly decrease the amount of time spent reviewing the medical records or placing orders, nor did they have an impact on provider time spent at patients' bedside or time spent discussing patient care with team members. CONCLUSION: The presence of scribes decreased provider documentation time but did not change the amount of time spent at the bedside or communicating with other team members. Scribes may be a potential strategy to decrease the clerical burden.
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Personal Administrativo/estadística & datos numéricos , Personal Administrativo/normas , Personal de Salud/estadística & datos numéricos , Administración del Tiempo/métodos , Documentación/métodos , Registros Electrónicos de Salud/instrumentación , Registros Electrónicos de Salud/estadística & datos numéricos , Servicio de Urgencia en Hospital/organización & administración , Servicio de Urgencia en Hospital/estadística & datos numéricos , Humanos , Tiempo de Internación/estadística & datos numéricos , Satisfacción del Paciente , Estudios Prospectivos , Estudios de Tiempo y MovimientoRESUMEN
OBJECTIVE: Most anti-angiogenic preeclampsia models in rodents utilized the overexpression of a truncated soluble fms-like tyrosine kinase-1 (sFlt-1) not expressed in any species. Other limitations of mouse preeclampsia models included stressful blood pressure measurements and the lack of postpartum monitoring. We aimed to 1) develop a mouse model of preeclampsia by administering the most abundant human placental sFlt-1 isoform (hsFlt-1-e15a) in preeclampsia; 2) determine blood pressures in non-stressed conditions; and 3) develop a survival surgery that enables the collection of fetuses and placentas and postpartum (PP) monitoring. METHODS: Pregnancy status of CD-1 mice was evaluated with high-frequency ultrasound on gestational days (GD) 6 and 7. Telemetry catheters were implanted in the carotid artery on GD7, and their positions were verified by ultrasound on GD13. Mice were injected through tail-vein with adenoviruses expressing hsFlt-1-e15a (n = 11) or green fluorescent protein (GFP; n = 9) on GD8/GD11. Placentas and pups were delivered by cesarean section on GD18 allowing PP monitoring. Urine samples were collected with cystocentesis on GD6/GD7, GD13, GD18, and PPD8, and albumin/creatinine ratios were determined. GFP and hsFlt-1-e15a expression profiles were determined by qRT-PCR. Aortic ring assays were performed to assess the effect of hsFlt-1-e15a on endothelia. RESULTS: Ultrasound predicted pregnancy on GD7 in 97% of cases. Cesarean section survival rate was 100%. Mean arterial blood pressure was higher in hsFlt-1-e15a-treated than in GFP-treated mice (∆MAP = 13.2 mmHg, p = 0.00107; GD18). Focal glomerular changes were found in hsFlt-1-e15a -treated mice, which had higher urine albumin/creatinine ratios than controls (109.3 ± 51.7 µg/mg vs. 19.3 ± 5.6 µg/mg, p = 4.4 x 10(-2); GD18). Aortic ring assays showed a 46% lesser microvessel outgrowth in hsFlt-1-e15a-treated than in GFP-treated mice (p = 1.2 x 10(-2)). Placental and fetal weights did not differ between the groups. One mouse with liver disease developed early-onset preeclampsia-like symptoms with intrauterine growth restriction (IUGR). CONCLUSIONS: A mouse model of late-onset preeclampsia was developed with the overexpression of hsFlt-1-e15a, verifying the in vivo pathologic effects of this primate-specific, predominant placental sFlt-1 isoform. HsFlt-1-e15a induced early-onset preeclampsia-like symptoms associated with IUGR in a mouse with a liver disease. Our findings support that hsFlt-1-e15a is central to the terminal pathway of preeclampsia, and it can induce the full spectrum of symptoms in this obstetrical syndrome.
Asunto(s)
Preeclampsia/etiología , Receptor 1 de Factores de Crecimiento Endotelial Vascular/fisiología , Secuencia de Aminoácidos , Animales , Presión Sanguínea , Monitores de Presión Sanguínea , Modelos Animales de Enfermedad , Femenino , Perfilación de la Expresión Génica , Edad Gestacional , Proteínas Fluorescentes Verdes/genética , Humanos , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular , Fenotipo , Placenta/diagnóstico por imagen , Placenta/patología , Placenta/fisiopatología , Preeclampsia/patología , Preeclampsia/fisiopatología , Embarazo , Isoformas de Proteínas/administración & dosificación , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/genética , Homología de Secuencia de Aminoácido , Especificidad de la Especie , Telemetría , Ultrasonografía , Receptor 1 de Factores de Crecimiento Endotelial Vascular/administración & dosificación , Receptor 1 de Factores de Crecimiento Endotelial Vascular/genéticaRESUMEN
Cigarette smoke-induced lung disease presents a morphologic contradiction in that the small airways become fibrotic but the parenchyma becomes emphysematous over time. To examine the mechanisms behind these phenomena, we exposed mice to cigarette smoke for up to 6 months and isolated small airways from histologic sections by laser capture microdissection. We then removed residual airway tissue and vessels, and collected the remaining parenchymal tissue. Gene expression of 13 fibrogenic growth/signaling factors (particularly TGF-beta-related genes), matrix proteins, or enzymes involved in matrix production was examined by real-time RT-PCR. Combining present and previously published data from our laboratory, in the airways over the long term there was a sustained and marked increase in expression of almost all of these genes. By contrast, in the parenchyma, expression of most genes was elevated at 2 and 24 hours after initial exposure, and all were elevated at 1 month; but by 6 months, when emphysema was present, most genes (9/13) were either at control values or down-regulated below control. At 3 months, several genes that were considerably elevated at 1 month were back to control levels, suggesting that loss of the parenchymal response precedes the development of emphysema. We conclude that with smoke exposure the airways demonstrate an ongoing profibrotic/proelastogenic response and the parenchyma a generally anti-fibrotic/anti-elastogenic response, but one that develops only with long-term exposure to smoke. These observations support the idea that the parenchyma largely fails to repair smoke-induced matrix damage, but this phenomenon is a relatively late event.
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Bronquiolos/fisiología , Regulación de la Expresión Génica/efectos de los fármacos , Pulmón/anatomía & histología , Pulmón/efectos de los fármacos , Nicotiana/efectos adversos , Fibrosis Pulmonar/fisiopatología , Humo/efectos adversos , Animales , Bronquiolos/patología , Colágeno/genética , Colágeno/metabolismo , Enfisema/patología , Enfisema/fisiopatología , Perfilación de la Expresión Génica , Humanos , Rayos Láser , Pulmón/patología , Pulmón/fisiología , Ratones , Ratones Endogámicos C57BL , Microdisección , Fibrosis Pulmonar/genética , Transducción de Señal/genética , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
Interleukin-1beta (IL-1beta), a proinflammatory cytokine, is elevated in cigarette smokers. To determine whether IL-1beta plays a role in the pathogenesis of cigarette smoke-induced emphysema and small airway remodeling, IL-1 receptor knockout (IL1RKO), TNF-alpha receptor knockout (TNFRKO), or C57Bl/6 (control) mice were exposed to cigarette smoke acutely or for up to 6 months. With a single acute exposure, smoke elevated IL-1beta in C57Bl/6 mice. IL1RKO mice were protected against acute smoke-mediated increases in lavage inflammatory cells and matrix breakdown. In C57Bl/6 mice, acute smoke-mediated increases in inflammatory cells, serum IL-1beta, and serum TNF-alpha were blocked by z-VAD-fmk, a pan-caspase inhibitor, or z-WEHD-fmk, a caspase-1 (IL-1-converting enzyme, [ICE]) inhibitor. With 6 months of exposure, IL-1beta was no longer increased, but IL-18 was elevated. After 6 months of exposure, IL1RKO mice were 65% protected against emphysema, whereas TNFRKO mice were 83% protected. Both strains were completely protected against small airway remodeling. Lavage desmosine, hydroxyproline, and hyaluronan, matrix breakdown markers, were elevated in C57 but not IL1RKO mice. We conclude that IL-1beta plays a significant role in induction of murine emphysema and small airway remodeling, and is comparable to TNF-alpha in its effects. The protective effects of caspase inhibitors appear to be related to inhibition of ICE and raise the question of whether models that ameliorate emphysema with caspase inhibitors are really blocking IL-1beta (and IL-18) activation rather than blocking apoptosis.
Asunto(s)
Interleucina-1beta/metabolismo , Pulmón/patología , Enfisema Pulmonar/patología , Fumar/efectos adversos , Animales , Biomarcadores/metabolismo , Líquido del Lavado Bronquioalveolar , Desmosina/metabolismo , Matriz Extracelular/metabolismo , Matriz Extracelular/patología , Ácido Hialurónico/metabolismo , Mediadores de Inflamación/metabolismo , Interleucina-18/metabolismo , Interleucina-1beta/sangre , Pulmón/metabolismo , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Neutrófilos/metabolismo , Tamaño de los Órganos , Enfisema Pulmonar/sangreRESUMEN
BACKGROUND: Matrix metalloproteases (MMPs) are believed to be important in the pathogenesis of cigarette smoke-induced emphysema, but this hypothesis has only been proved in the mouse and its applicability to other species, particularly humans, is uncertain. The role of MMPs in smoke-induced small airway remodelling is unknown. METHODS: The effects of a dual MMP-9/MMP-12 inhibitor, AZ11557272, on the development of anatomical and functional changes of chronic obstructive pulmonary disease (COPD) in guinea pigs exposed daily to cigarette smoke for up to 6 months were examined. RESULTS: At all times, smoke-induced increases in lavage inflammatory cells, lavage desmosine (a marker of elastin breakdown) and serum tumour necrosis factor alpha (TNFalpha) were completely abolished by AZ11557272. At 6 months there was an increase in lung volumes and airspace size. AZ11557272 returned the pressure- volume curve to control levels, decreased smoke-induced increases in total lung capacity, residual volume and vital capacity by about 70%, and also reversed smoke-induced airspace enlargement by about 70%. There was a very strong correlation between surface to volume ratio and both lavage desmosine and serum TNFalpha levels. AZ11557272 protected against smoke-mediated increases in small airway wall thickness but did not prevent smoke-induced increases in mean pulmonary artery pressure. CONCLUSIONS: An MMP-9/MMP-12 inhibitor can substantially ameliorate morphological emphysema, small airway remodelling and the functional consequences of these lesions in a non-murine species. These findings strengthen the idea that MMPs are important mediators of the anatomical changes behind COPD in humans, and suggest that MMP-9 and MMP-12 may be potential intervention targets.
Asunto(s)
Enfermedades Bronquiales/etiología , Inhibidores de la Metaloproteinasa de la Matriz , Enfermedad Pulmonar Obstructiva Crónica/etiología , Enfisema Pulmonar/etiología , Fumar/metabolismo , Animales , Bronquios/patología , Enfermedades Bronquiales/metabolismo , Enfermedades Bronquiales/patología , Líquido del Lavado Bronquioalveolar/química , Desmosina/metabolismo , Inhibidores Enzimáticos/farmacología , Femenino , Cobayas , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/patología , Enfisema Pulmonar/metabolismo , Fumar/efectos adversos , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
BACKGROUND: Small airway remodeling (SAR) is an important cause of airflow obstruction in cigarette smokers with chronic obstructive pulmonary disease, but the pathogenesis of SAR is not understood. OBJECTIVE: To determine whether smoke causes production of profibrotic growth factors in the airway wall. METHODS: We exposed C57Bl/6 mice to cigarette smoke for up to 6 mo and examined growth factor/procollagen gene expression in laser-capture microdissected small airways by real-time reverse transcription-polymerase chain reaction. RESULTS: With a single smoke exposure, increases in procollagen, connective tissue growth factor (CTGF), transforming growth factor (TGF)-beta(1), platelet-derived growth factor (PDGF)-A and -B expression were seen 2 h after the start of smoking and declined to baseline by 24 h. With repeated exposures and at killing of animals 24 h after the last exposure, increases in procollagen, CTGF, PDGF-B, and (minimally) PDGF-A expression persisted through 1 wk, 1 mo, and 6 mo. TGF-beta(1) gene expression declined over time; however, increased immunochemical staining for phopho-Smad 2 was present at all time points, indicating continuing TGF-beta downstream signaling. Morphometric analysis showed that the small airways in smoke-exposed mice had more collagen at 6 mo. CONCLUSIONS: These findings suggest that smoke can induce growth factor and procollagen production in small airways in a time frame that initially is too short for a significant inflammatory response and that profibrotic growth factor and procollagen gene expression become self-sustaining with repeated smoke exposures. These results imply that the pathogenesis of and possible treatment approaches to emphysema and small airway remodeling might be quite different.
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Bronquios/efectos de los fármacos , Péptidos y Proteínas de Señalización Intercelular/biosíntesis , Procolágeno/biosíntesis , Alveolos Pulmonares/efectos de los fármacos , Fumar/fisiopatología , Animales , Factor de Crecimiento del Tejido Conjuntivo , Expresión Génica , Proteínas Inmediatas-Precoces/genética , Péptidos y Proteínas de Señalización Intercelular/genética , Ratones , Ratones Endogámicos C57BL , Factor de Crecimiento Derivado de Plaquetas/genética , Procolágeno/genética , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/fisiologíaRESUMEN
OBJECTIVE: As part of our ongoing studies to understand the biologic mechanisms of wound repair that lead to postoperative adhesions, we have identified characteristics of an adhesion phenotype that differs between fibroblasts that are obtained from human normal peritoneum and adhesions. In this study, we sought to examine whether stimulation of aerobic metabolism would alter differential expression of tissue plasminogen activator and plasminogen activator inhibitor-1, thereby creating a milieu likely to be less favorable to postoperative adhesion development. To examine this issue, we used a compound, dichloroacetic acid, that stimulates the pyruvate dehydrogenase complex, which causes pyruvate to be metabolized in the Kreb's cycle rather than being converted into lactate, thereby switching anaerobic to aerobic metabolism. STUDY DESIGN: Human fibroblasts from normal peritoneum and adhesions were cultured in the absence or presence of dichloroacetic acid (100 microg/mL) for 24 hours, under normal and hypoxic (2% O(2)) conditions. Real-time reverse transcriptase-polymerase chain reaction of tissue plasminogen activator, plasminogen activator inhibitor-1, and a housekeeping gene beta-actin was performed with messenger RNA that was extracted from all treatment points. RESULTS: Dichloroacetic acid stimulated normal peritoneal fibroblast tissue plasminogen activator messenger RNA expression under hypoxic conditions. In adhesion fibroblasts, dichloroacetic acid treatment enhanced tissue plasminogen activator messenger RNA expression under both normoxic and hypoxic conditions. Plasminogen activator inhibitor-1 messenger RNA expression was unaltered by dichloroacetic acid in normoxic normal peritoneal fibroblasts; but during culture under hypoxic conditions, dichloroacetic acid reduced plasminogen activator inhibitor-1 messenger RNA expression. Similarly, in adhesion fibroblasts, dichloroacetic acid reduced plasminogen activator inhibitor-1 messenger RNA expression under both normoxic and hypoxic conditions. As a result, in normal peritoneal fibroblasts under hypoxic conditions and in adhesion fibroblasts under normoxic and hypoxic conditions, dichloroacetic acid greatly increased the tissue plasminogen activator/plasminogen activator inhibitor-1 ratios. CONCLUSION: These findings confirm that fibroblasts from adhesions are characterized by reduced tissue plasminogen activator and increased plasminogen activator inhibitor-1 production. These observations are extended to show the stimulation of oxidative metabolism by dichloroacetic acid increases tissue plasminogen activator expression under hypoxic conditions. Dichloroacetic acid reduces plasminogen activator inhibitor-1 production by hypoxic normal peritoneal fibroblasts and adhesion fibroblasts under hypoxic conditions. The resultant increases in the tissue plasminogen activator/plasminogen activator inhibitor-1 ratios would favor the development of a fibrinolytic milieu, which would be expected potentially to limit postoperative adhesion development. Thus, regulation of metabolic activity of peritoneal cells may provide a target for future interventions for the reduction of the development of postoperative adhesions, particularly as intervention relates to the healing of peritoneal sites that previously had adhesions. (eg, sites of potential adhesion reformation).
Asunto(s)
Ácido Dicloroacético/farmacología , Fibroblastos/efectos de los fármacos , Enfermedades Peritoneales/metabolismo , Inhibidor 1 de Activador Plasminogénico/metabolismo , Adherencias Tisulares/metabolismo , Activador de Tejido Plasminógeno/efectos de los fármacos , Hipoxia de la Célula , Cartilla de ADN , Femenino , Fibroblastos/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Peritoneo/citología , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Activador de Tejido Plasminógeno/metabolismoRESUMEN
OBJECTIVE: To examine the role of stimulation of aerobic metabolism on the differential expression of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), which are differentially regulated in fibroblasts isolated from normal human peritoneum and adhesions. DESIGN: Tissue culture study. SETTING: University research laboratory. PATIENT(S): Human fibroblasts cultures from normal peritoneum and adhesions that were exposed to dichloroacetic acid (DCA; 0 and 100 microg/mL) for 24 hours under normal and hypoxic conditions. MAIN OUTCOME MEASURE(S): Real-time reverse-transcription polymerase chain reaction of MMP-1, TIMP-1, and beta-actin. RESULT(S): Dichloroacetic acid stimulated peritoneal fibroblast MMP-1 mRNA expression under normoxic conditions; this stimulation was lost during hypoxia. In adhesion fibroblasts, DCA increased MMP-1 mRNA expression; this effect was reversed by hypoxia. Expression of TIMP-1 mRNA was insignificantly increased by DCA in normal peritoneal and adhesion fibroblasts under normoxic conditions; however under hypoxic conditions, DCA reduced TIMP-1 mRNA expression from both. CONCLUSION(S): Regulation of metabolic activity of peritoneal cells may provide a target for future interventions for reduction of development of postoperative adhesions, particularly as it relates to healing of peritoneal sites that did not previously have adhesions as opposed to sites that underwent lysis of preexistent adhesions.
Asunto(s)
Ácido Dicloroacético/farmacología , Metaloproteinasa 1 de la Matriz/metabolismo , Peritoneo/efectos de los fármacos , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Hipoxia de la Célula , Células Cultivadas , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/patología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Metaloproteinasa 1 de la Matriz/efectos de los fármacos , Metaloproteinasa 1 de la Matriz/genética , Peritoneo/citología , Peritoneo/fisiología , ARN Mensajero/efectos de los fármacos , ARN Mensajero/metabolismo , Adherencias Tisulares/patología , Inhibidor Tisular de Metaloproteinasa-1/efectos de los fármacos , Inhibidor Tisular de Metaloproteinasa-1/genéticaRESUMEN
OBJECTIVE: To examine the role of aerobic metabolism in fibroblasts from normal peritoneum and adhesions in the differential expression of extracellular matrix (ECM) and transforming growth factor-beta (TGF-beta), an inflammatory cytokine that regulates ECM expression. DESIGN: Cell culture under normoxic and hypoxic conditions. SETTING: University research laboratory. PATIENT(S): Human fibroblasts cultures from normal peritoneum and adhesions. INTERVENTION(S): Exposure to dichloroacetic acid (DCA), which activates pyruvate dehydrogenase, for 24 hours under normal and hypoxic (2% O(2)) conditions. MAIN OUTCOME MEASURE(S): Multiplex reverse transcriptase polymerase chain reaction (RT/PCR) of type III collagen, fibronectin, TGF-beta1, and beta-actin was performed, with analysis of PCR-amplified products performed by densimetric analysis of gel bands using the National Institutes of Health Image analysis program. RESULT(S): DCA inhibited human peritoneal fibroblast and adhesion fibroblast TGF-beta1 mRNA expression under normoxic and hypoxic conditions. DCA also markedly reduced fibronectin and type III collagen expression under hypoxic conditions in fibroblasts from normal peritoneum and adhesions. CONCLUSION(S): These observations provide further support for the suggestion that regulation of metabolic activity of peritoneal cells may provide a target for interventions designed to reduce postoperative adhesions.
Asunto(s)
Colágeno Tipo III/genética , Ácido Dicloroacético/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Peritoneo/metabolismo , Adherencias Tisulares/metabolismo , Factor de Crecimiento Transformador beta/genética , Hipoxia de la Célula , Células Cultivadas , Fibroblastos/metabolismo , Fibronectinas , Humanos , Peritoneo/citología , Complicaciones Posoperatorias/prevención & control , ARN Mensajero/análisis , Adherencias Tisulares/patología , Adherencias Tisulares/prevención & control , Factor de Crecimiento Transformador beta1RESUMEN
OBJECTIVE: The purpose of this study was to evaluate the potential biologic effects of oxidized regenerated cellulose, which has been shown in multiple human in vivo studies to reduce postoperative adhesion development, on the messenger RNA levels of transforming growth factor-beta1, type I collagen, type III collagen, and fibronectin. STUDY DESIGN: The oxidized regenerated cellulose was dissolved in saline solution and added to confluent, monolayer cultures of human normal fibroblasts and mesothelial cells. Control cells were maintained in media alone at the same pH. After 24 hours of treatment, total RNA was extracted from all cells. Real-time reverse transcription-polymerase chain reaction was performed to determine the relative change in messenger RNA levels of type I, type HI collagen, fibronectin, transforming growth factor-beta1, and beta-actin (housekeeping gene) in response to the oxidized regenerated cellulose treatment (n=4 cultures). Student t tests were performed for each cell type, which compared oxidized regenerated cellulose-treated cells to control cells. Calculated power for the statistically significant findings ranged from 65% to 100%. RESULTS: Transforming growth factor-beta1 messenger RNA was elevated by the oxidized regenerated cellulose treatment in the mesothelial cells by 13% (control cells, 0.562+/-0.022; oxidized regenerated cellulose-treated cells, 0.636+/-0.014; P=.03). In normal fibroblasts, transforming growth factor-beta1 messenger RNA was slightly, but not significantly, decreased in oxidized regenerated cellulose-exposed normal fibroblasts compared with controls (control cells, 0.622+/-0.062; oxidized regenerated cellulose-treated cells, 0.609+/-0.006; P=.85). Type I collagen was found to be increased by exposure to oxidized regenerated cellulose in both mesothelial cells and normal peritoneal fibroblasts. Type I collagen was increased by 23% in mesothelial cells (control cells [0.587+/-0.018] vs oxidized regenerated cellulose-treated cells [0.722+/-0.010], P=.002), and 27% in normal fibroblasts (control cells, 0.522+/-0.018, oxidized regenerated cellulose-treated cells, 0.665+/-0.009; P=.001). However, messenger RNA levels of type III collagen and fibronectin (other representative molecules of the extracellular matrix) were not altered significantly by oxidized regenerated cellulose application in vitro. CONCLUSION: Oxidized regenerated cellulose influences the expression of factors that are accepted commonly to be associated with adhesiogenesis. Oxidized regenerated cellulose increased the expression of transforming growth factor-beta1 in mesothelial cells and type I collagen in mesothelial cells and normal peritoneal fibroblasts. Minimization of these oxidized regenerated cellulose-induced molecular changes, if they occur in vivo, may improve the ability of oxidized regenerated cellulose to reduce postoperative adhesion development.
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Celulosa Oxidada/farmacología , Matriz Extracelular/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Células Cultivadas , ADN Complementario/análisis , Células Epiteliales/efectos de los fármacos , Células Epiteliales/fisiología , Matriz Extracelular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Fibroblastos/fisiología , Humanos , Peritoneo/citología , Probabilidad , ARN Mensajero/análisis , Valores de Referencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sensibilidad y Especificidad , Factor de Crecimiento Transformador beta/efectos de los fármacos , Factor de Crecimiento Transformador beta1RESUMEN
OBJECTIVE: We have previously demonstrated that collagen I, a major component of postoperative adhesions, is differentially regulated in fibroblasts isolated from normal human peritoneum and adhesions. Collagen I messenger RNA (mRNA) levels are significantly lower in fibroblasts from normal peritoneum compared with levels from adhesion fibroblasts. This variation is further accentuated by hypoxia. Because adhesions provide a means of supplying oxygen and nutrients to postsurgical ischemic tissue, we sought to examine the role of aerobic metabolism in the differential expression of collagen I. To examine this issue, we used a compound, dichloroacetic acid (DCA), that stimulates pyruvate dehydrogenase, causing pyruvate to be metabolized in the Kreb's cycle rather than converted into lactate, thereby switching anaerobic to aerobic metabolism. Specifically, we have exposed human fibroblast cultures from normal peritoneum and adhesions to DCA (0, 50, and 100 microg/mL) for 24 hours under normal and hypoxic (2% oxygen) conditions. STUDY DESIGN: Multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) of collagen I and beta-actin was performed by using mRNA extracted from all treatment points. Analysis of PCR-amplified products was performed by fractionation over a 2% agarose gel, followed by ethidium bromide staining of DNA bands. A scanning densimeter was used to determine the ratio of intensity of each band relative to beta-actin. Densimetric analysis of gel bands was performed by using the National Institutes of Health image analysis program. RESULTS: Although DCA stimulated peritoneal fibroblast collagen I mRNA expression under normoxic conditions, its expression was reduced during hypoxia. In adhesion fibroblasts, DCA treatment consistently lowered collagen I mRNA expression; this effect was manifested to a greater extent under hypoxic conditions. CONCLUSION: In summary, these findings confirm that fibroblasts from adhesions are characterized by excessive collagen I production, which is further accentuated by hypoxia. These observations are extended to show the stimulation of oxidative metabolism by DCA increases collagen I production; in contrast DCA inhibits collagen I production by normoxic adhesion fibroblasts as well as under hypoxic conditions in both types of fibroblasts. Thus, regulation of metabolic activity of peritoneal cells may provide a target for future interventions for reduction of postoperative adhesions.