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Mechanically ventilated patients suffering from acute respiratory distress syndrome (ARDS) frequently receive aerosolized iloprost. Because of prostacyclin's short half-life, prolonged inhalative administration might improve its clinical efficacy. But, this is technically challenging. A solution might be the use of inspiration-synchronized vibrating mesh nebulizers (VMNsyn), which achieve high drug deposition rates while showing prolonged nebulization times. However, there are no data comparing prolonged to bolus iloprost nebulization using a continuous vibrating mesh nebulizer (VMNcont) and investigating the effects of different ventilation modes on inspiration-synchronized nebulization. Therefore, in an in vitro model of mechanically ventilated adults, a VMNsyn and a VMNcont were compared in volume-controlled (VC-CMV) and pressure-controlled continuous mandatory ventilation (PC-CMV) regarding iloprost deposition rate and nebulization time. During VC-CMV, the deposition rate of the VMNsyn was comparable to the rate obtained with the VMNcont, but 10.9% lower during PC-CMV. The aerosol output of the VMNsyn during both ventilation modes was significantly lower compared to the VMNcont, leading to a 7.5 times longer nebulization time during VC-CMV and only to a 4.2 times longer nebulization time during PC-CMV. Inspiration-synchronized nebulization during VC-CMV mode therefore seems to be the most suitable for prolonged inhalative iloprost administration in mechanically ventilated patients.
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Fluorinated compounds have been used in clinical and biomedical applications for years. The newer class of semifluorinated alkanes (SFAs) has very interesting physicochemical properties including high gas solubility (e.g., for oxygen) and low surface tensions, such as the well-known perfluorocarbons (PFC). Due to their high propensity to assemble to interfaces, they can be used to formulate a variety of multiphase colloidal systems, including direct and reverse fluorocarbon emulsions, microbubbles and nanoemulsions, gels, dispersions, suspensions and aerosols. In addition, SFAs can dissolve lipophilic drugs and thus be used as new drug carriers or in new formulations. In vitreoretinal surgery and as eye drops, SFAs have become part of daily clinical practice. This review provides brief background information on the fluorinated compounds used in medicine and discusses the physicochemical properties and biocompatibility of SFAs. The clinically established use in vitreoretinal surgery and new developments in drug delivery as eye drops are described. The potential clinical applications for oxygen transport by SFAs as pure fluids into the lungs or as intravenous applications of SFA emulsions are presented. Finally, aspects of drug delivery with SFAs as topical, oral, intravenous (systemic) and pulmonary applications as well as protein delivery are covered. This manuscript provides an overview of the (potential) medical applications of semifluorinated alkanes. The databases of PubMed and Medline were searched until January 2023.
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Aerosol therapy in patients suffering from acute respiratory distress syndrome (ARDS) has so far failed in improving patients' outcomes. This might be because dependent lung areas cannot be reached by conventional aerosols. Due to their physicochemical properties, semifluorinated alkanes (SFAs) could address this problem. After induction of ARDS, 26 pigs were randomized into three groups: (1) control (Sham), (2) perfluorohexyloctane (F6H8), and (3) F6H8-ibuprofen. Using a nebulization catheter, (2) received 1 mL/kg F6H8 while (3) received 1 mL/kg F6H8 with 6 mg/mL ibuprofen. Ibuprofen plasma and lung tissue concentration, bronchoalveolar lavage (BAL) fluid concentration of TNF-α, IL-8, and IL-6, and lung mechanics were measured. The ibuprofen concentration was equally distributed to the dependent parts of the right lungs. Pharmacokinetic data demonstrated systemic absorption of ibuprofen proofing a transport across the alveolo-capillary membrane. A significantly lower TNF-α concentration was observed in (2) and (3) when compared to the control group (1). There were no significant differences in IL-8 and IL-6 concentrations and lung mechanics. F6H8 aerosol seemed to be a suitable carrier for pulmonary drug delivery to dependent ARDS lung regions without having negative effects on lung mechanics.
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BACKGROUND: Emulsions on the basis of Perfluorohexyloctane (F6H8), a semifluorinated alkane (SFA), have shown to dissolve and transport highly lipophilic compounds. It is unknown how F6H8-containing emulsions (F6H8-cEM) interact with compartment blood, the reticuloendothelial system (RES), or influence injured organs in vivo. The current study was conducted to investigate the in vitro biocompatibility of F6H8-cEM and their drug delivery properties. Afterward, an in vivo study was performed as a proof-of-concept study in a rat model of acute kidney injury (AKI), which focused on the potential influence of F6H8-cEM on inflammation in an injured organ. METHODS: Two different F6H8-cEM were stabilized by the emulsifying agents Poloxamer 188 (Pluronic® F68) or lecithin (S75). The two resulting emulsions F6H8-Pluronic or F6H8-lecithin were tested in vitro for the potential modulation of acute inflammation via whole blood assay, FACS, and ELISA. Antioxidant capacity and drug delivery properties were measured with an oxidation assay. Secondly, AKI was induced in the rats, which were treated with the F6H8-lecithin emulsion. Renal function and inflammation were assessed. RESULTS: Both F6H8-cEM were phagocytized by monocytes and both dose-dependently affected apoptosis (Annexin V binding) in monocytes. TNF-α expression increased dose-dependency for F6H8-Pluronic emulsion but not for F6H8-lecithin in a whole blood assay. Both F6H8-cEM were able to carry α-tocopherol as a model drug. Animals with AKI treated with the F6H8-lecithin emulsion showed a significantly better renal function and less infiltration of inflammatory cells in renal tissue compared to the control, while inflammatory markers in renal tissue, except HO-1, were not affected by F6H8-lecithin. CONCLUSIONS: Pluronic® F68 does not seem suitable as a biocompatible surfactant for F6H8-cEM. The injured kidney was not negatively influenced by the F6H8-lecithin emulsion. Lecithin-stabilized F6H8-cEM could be tested for preclinical studies as a carrier system for lipophilic agents.
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Lesión Renal Aguda/tratamiento farmacológico , Antiinflamatorios no Esteroideos/farmacología , Antioxidantes/farmacología , Materiales Biocompatibles/farmacología , Sistemas de Liberación de Medicamentos , Fluorocarburos/farmacología , Inflamación/tratamiento farmacológico , Lesión Renal Aguda/metabolismo , Lesión Renal Aguda/patología , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/química , Antioxidantes/administración & dosificación , Antioxidantes/química , Materiales Biocompatibles/administración & dosificación , Materiales Biocompatibles/química , Modelos Animales de Enfermedad , Emulsiones/administración & dosificación , Emulsiones/química , Emulsiones/farmacología , Fluorocarburos/administración & dosificación , Fluorocarburos/química , Voluntarios Sanos , Humanos , Concentración de Iones de Hidrógeno , Inflamación/metabolismo , Inflamación/patología , Inyecciones Intravenosas , Riñón/efectos de los fármacos , Riñón/metabolismo , Riñón/patología , Masculino , Concentración Osmolar , Tamaño de la Partícula , Ratas , Ratas Endogámicas LewRESUMEN
BACKGROUND: Cell-based therapies with bone marrow-derived progenitor cells (BMDPC) lead to an improved clinical outcome in animal sepsis models. In the present study we evaluated the ability of granulocyte macrophage-colony stimulating factor (GM-CSF) to mobilize BMDPC in a lipopolysaccharide (LPS)-induced sepsis model and thereby its potential as a novel treatment strategy. METHODS: Male Wistar rats received LPS (25µg/kg/h for 4 days) intravenously and were subsequently treated with GM-CSF 12.5µg/kg (0h,24h,48h,72h). As control groups, rats were infused with sodium chloride or GM-CSF only. Clinical and laboratory parameters, proinflammatory plasma cytokines as well as BMDPC counts were analyzed. Cytokine release by isolated peripheral blood mononuclear cells from rat spleen upon incubation with LPS, GM-CSF and a combination of both were investigated in vitro. RESULTS: In vivo, rats receiving both LPS and GM-CSF, showed a reduced weight loss and increased mobilization of BMDPC. At the same time, this regime resulted in an increased release of proinflammatory cytokines (IL-6, IL-8) and a significantly increased mortality. In vitro, the combination of LPS and GM-CSF showed a significantly increased IL-6 release upon incubation compared to incubation with LPS or GM-CSF alone. CONCLUSIONS: GM-CSF did not have a beneficial effect on the clinical course in our LPS-induced sepsis model. It synergistically promoted inflammation with LPS and probably thereby impaired survival.
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Factor Estimulante de Colonias de Granulocitos y Macrófagos/uso terapéutico , Sepsis/tratamiento farmacológico , Animales , Células Cultivadas , Citocinas/sangre , Factor Estimulante de Colonias de Granulocitos y Macrófagos/administración & dosificación , Factor Estimulante de Colonias de Granulocitos y Macrófagos/efectos adversos , Lipopolisacáridos/toxicidad , Masculino , Monocitos/efectos de los fármacos , Ratas , Ratas Wistar , Sepsis/etiología , Bazo/citología , Bazo/efectos de los fármacosRESUMEN
PURPOSE: To evaluate changes in hemodynamic effects of intramyometrial epinephrine injection for blood loss reduction in laparoscopic myomectomy. METHODS: A total of 185 women with symptomatic uterine fibroids who underwent laparoscopic myomectomy were enrolled in this study. Eighty-six women (study collective) received an intramyometrial injection of epinephrine and were compared to ninety-nine women (control collective) who underwent laparoscopic myomectomy without an intramyometrial epinephrine injection. Demographic parameters, change of hemodynamic parameters during surgery as well as hemoglobin drop after surgery were analyzed. RESULTS: In the study collective maximum systolic blood pressure (p < 0.001), maximum increase of the systolic blood pressure within 5 min (p = 0.003), duration of hypertension (p = 0.012), maximal (p < 0.001) and mean heart rate (p = 0.005), maximal increase of heart rate within 5 min (p = 0.003) and difference of mean to maximal heart rate (p < 0.001) were higher compared to the control collective. There was no difference in pre- and postoperative hemoglobin levels in both collectives and no intraoperative clinically relevant complication occurred due to intramyometrial epinephrine injection. CONCLUSION: The intramyometrial application of epinephrine seems to be safe but leads to significant alterations of hemodynamic parameters without a significant change in postoperative hemoglobin levels.
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Pérdida de Sangre Quirúrgica/prevención & control , Epinefrina/administración & dosificación , Hemodinámica/efectos de los fármacos , Laparoscopía/efectos adversos , Miomectomía Uterina/efectos adversos , Adulto , Femenino , Humanos , Inyecciones Intramusculares , Leiomioma/cirugía , Miometrio/efectos de los fármacos , Neoplasias Uterinas/cirugíaRESUMEN
Pathophysiological changes of brain death (BD) are impairing distal organ function and harming potential renal allografts. Whether ventilation strategies influence the quality of renal allografts from BD donors has not been thoroughly studied. 28 adult male Wistar rats were randomly assigned to four groups: 1) no brain death (NBD) with low tidal volume/low positive endexpiratory pressure (PEEP) titrated to minimal static elastance of the respiratory system (LVT/OLPEEP); 2) NBD with high tidal volume/low PEEP (HVT/LPEEP); 3) brain death (BD) with LVT/OLPEEP; and 4) BD with HVT/LPEEP. We hypothesized that HVT/LPEEP in BD leads to increased interleukin 6 (IL-6) gene expression and impairs potential renal allografts after six hours of mechanical ventilation. We assessed inflammatory cytokines in serum, genome wide gene expression profiles and quantitative PCR (qPCR) in kidney tissue. The influence of BD on renal gene-expression profiles was greater than the influence of the ventilation strategy. In BD, LVT ventilation did not influence the inflammatory parameters or kidney function in our experimental model.
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Muerte Encefálica/metabolismo , Trasplante de Riñón/métodos , Respiración Artificial/métodos , Transcriptoma/fisiología , Análisis de Varianza , Animales , Análisis de los Gases de la Sangre , Muerte Encefálica/sangre , Muerte Encefálica/orina , Creatinina/sangre , Creatinina/orina , Citocinas/sangre , Citocinas/orina , Modelos Animales de Enfermedad , Masculino , Infiltración Neutrófila/fisiología , Respiración con Presión Positiva , ARN Mensajero/metabolismo , Distribución Aleatoria , Ratas , Ratas Wistar , Volumen de Ventilación PulmonarRESUMEN
INTRODUCTION: Healing of airway anastomoses after preoperative irradiation can be a significant clinical problem. The augmentation of bronchial anastomoses with a fibroblast-seeded human acellular dermis (hAD) was shown to be beneficial, although the underlying mechanism remained unclear. Therefore, in this study we investigated the fate of the fibroblasts transplanted to the scaffold covering the anastomosis. MATERIAL AND METHODS: 32 Fisher rats underwent surgical anastomosis of the left main bronchus. In a 2 × 2 factorial design, they were randomized to receive preoperative irradiation of 20 Gy and augmentation of the anastomosis with a fibroblast-seeded transplant. Fibroblasts from subcutaneous fat of Fischer-344 rat were transduced retrovirally with tdTomato for cell tracking. After 7 and 14 days, animals were sacrificed and cell concentration of transplanted and nontransplanted fibroblasts in the hAD as well as in the bronchial tissue was measured using RT-PCR. RESULTS: Migration of transplanted fibroblasts from dermis to bronchus were demonstrated in both groups, irradiated and nonirradiated. In the irradiated groups, there was a cell count of 7 × 104 ± 1 × 104 tomato+-fibroblasts in the bronchial tissue at day 7, rising to 1 × 105 ± 1 × 104 on day 14 (p <0.0001). Tomato+-cell concentration in hAD increased from 6 × 103 ± 1 × 103 at day 7 to 6 × 104 ± 1 × 104 at day 14 (p <0.0001). In the nonirradiated groups, tomato+-cell concentration in bronchus was 4 × 103 ± 1 × 103 on day 7 and 4 × 103 ± 1 × 103 at day 14. In the hAD tomato+ cell concentration rising from 1 × 104 ± 1 × 103 at day 7 to 2 × 104 ± 3 × 103 cells at day 14 (p = 0.0028). CONCLUSIONS: Transplanted fibroblasts in the irradiated groups proliferate and migrate into the irradiated host bronchial tissue, but not in the nonirradiated groups.
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Anastomosis Quirúrgica , Bronquios/citología , Fibroblastos/efectos de la radiación , Fibroblastos/trasplante , Cicatrización de Heridas , Dermis Acelular/efectos de la radiación , Animales , Bronquios/cirugía , Movimiento Celular , Proliferación Celular , Fibroblastos/citología , Modelos Animales , Dosis de Radiación , Ratas Endogámicas F344RESUMEN
OBJECTIVES: Minimally invasive resection of small, deep intrapulmonary lesions can be challenging due to the difficulty of localizing them during video-assisted thoracoscopic surgery (VATS). We report our preliminary results evaluating the feasibility of an image-guided, minimally invasive, 1-stop-shop approach for the resection of small, deep intrapulmonary lesions in a hybrid operating room (OR). MATERIALS AND METHODS: Fifteen patients (5 men, 10 women; mean age, 63 years) with a total of 16 solitary, deep intrapulmonary nodules of unknown malignant status were identified for intraoperative wire marking. Patients were placed on the operating table for resection by VATS. A marking wire was placed within the lesion under 3D laser and fluoroscopic guidance using a cone beam computed tomography system. Then, wedge resection by VATS was performed in the same setting without repositioning the patient. RESULTS: Complete resection with adequate safety margins was confirmed for all lesions. Marking wire placement facilitated resection in 15 of 16 lesions. Eleven lesions proved to be malignant, either primary or secondary; 5 were benign. Mean lesion size was 7.7 mm; mean distance to the pleural surface was 15.1 mm (mean lesion depth-diameter ratio, 2.2). Mean procedural time for marking wire placement was 35 minutes; mean VATS duration was 36 minutes. CONCLUSIONS: Computed tomography-assisted thoracoscopic surgery is a new, safe, and effective procedure for minimally invasive resection of small, deeply localized intrapulmonary lesions. The benefits of computed tomography-assisted thoracoscopic surgery are 1. One-stop-shop procedure, 2. Lower risk for the patient (no patient relocation, no marking wire loss), and 3. No need to coordinate scheduling between the CT room and OR.
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Tomografía Computarizada de Haz Cónico/métodos , Neoplasias Pulmonares/cirugía , Cirugía Torácica Asistida por Video/métodos , Estudios de Factibilidad , Femenino , Humanos , Pulmón/diagnóstico por imagen , Pulmón/cirugía , Neoplasias Pulmonares/diagnóstico por imagen , Masculino , Persona de Mediana EdadRESUMEN
This work examines the variation of longitudinal relaxation rate R1(= 1/T1) of the 19F-CF3-resonance of semifluorinated alkanes (SFAs) with oxygen tension (pO2), temperature (T) and pH in vitro. Contrary to their related perfluorocarbons (PFCs), SFA are amphiphilic and facilitate stable emulsions, a prerequisite for clinical use. A linear relationship between R1 and pO2 was confirmed for the observed SFAs at different temperatures. Using a standard saturation recovery sequence, T1 has been successfully measured using fluorine 19F-MRI with a self-constructed birdcage resonator at 9.4 T. A calibration curve to calculate pO2 depending on T and R1 was found for each SFA used. In contrast to the commonly used PFC, SFAs are less sensitive to changes in pO2, but more sensitive to changes in temperature. The influence of pH to R1 was found to be negligible.
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Imagen por Resonancia Magnética con Fluor-19/métodos , Fluorocarburos/química , Oximetría/métodos , Animales , HumanosRESUMEN
BACKGROUND: N-octanoyl dopamine (NOD) treatment improves renal function when applied to brain dead donors and in the setting of warm ischaemia-induced acute kidney injury (AKI). Because it also activates transient receptor potential vanilloid type 1 (TRPV1) channels, we first assessed if NOD conveys its renoprotective properties in warm ischaemia-induced AKI via TRPV1 and secondly, if renal transplant recipients also benefit from NOD treatment. METHODS: We induced warm renal ischaemia in Lewis, wild-type (WT) and TRPV1(-/-) Sprague-Dawley (sd) rats by clamping the left renal artery for 45 min. Transplantations were performed in allogeneic and syngeneic donor-recipient combinations (Fisher to Lewis and Lewis to Lewis) with a cold ischaemia time of 20 h. Treatment was instituted directly after restoration of organ perfusion. Renal function, histology and perfusion were assessed by serum creatinine, microscopy and magnetic resonance imaging (MRI) using arterial spin labelling (ASL). RESULTS: NOD treatment significantly improved renal function in Lewis rats after warm ischaemia-induced AKI. It was, however, not effective after prolonged cold ischaemia. The renoprotective properties of NOD were only observed in Lewis or WT, but not in TRPV1(-/-) sd rats. Renal inflammation was significantly abrogated by NOD. MRI-ASL showed a significantly lower cortical perfusion in ischaemic when compared with non-ischaemic kidneys. No overall differences were observed in renal perfusion between NOD- and NaCl-treated rats. CONCLUSIONS: NOD treatment reduces renal injury in warm ischaemia, but is not effective in renal transplant in our experimental animal models. The salutary effect of NOD appears to be TPRV1-dependent, not involving large changes in renal perfusion.
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Lesión Renal Aguda/tratamiento farmacológico , Dopamina/análogos & derivados , Trasplante de Riñón/efectos adversos , Riñón/fisiopatología , Animales , Dopamina/uso terapéutico , Riñón/efectos de los fármacos , Riñón/cirugía , Masculino , Ratas , Ratas Endogámicas Lew , Ratas Sprague-Dawley , Donantes de Tejidos , Trasplante Homólogo , Isquemia TibiaRESUMEN
This study aimed to assess the impact of pulmonary inflammation on early fibrotic response in rats challenged with increasing doses of lipopolysaccharide (LPS). Twenty-four rats were randomized and infused with three different increasing doses of continuous LPS infusion (n=8/group) while being ventilated with low tidal volumes and open-lung positive end-expiratory pressure. Another eight animals served as uninjured control group. Hemodynamics, gas exchange, respiratory system mechanics, lung histology, α-smooth muscle actin, plasma cytokines, and mRNA expression of cytokines and type I and III procollagen in lung tissue were assessed. We found impaired hemodynamics and gas exchange as well as higher histological lung injury scores and α-smooth muscle actin expressions in the medium LPS dose compared to control and the lower LPS dose. The highest LPS dose did not cause further aggravation of these findings. In all LPS groups type I and III procollagen decreased compared to controls and there was a negative correlation between type III procollagen-RNA expression and proinflammatory mediators.
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Lipopolisacáridos/toxicidad , Pulmón/patología , Neumonía/inducido químicamente , Neumonía/terapia , Respiración Artificial/efectos adversos , Animales , Citocinas/genética , Citocinas/metabolismo , Relación Dosis-Respuesta a Droga , Ensayo de Inmunoadsorción Enzimática , Fibrosis/etiología , Hemodinámica/efectos de los fármacos , Hemodinámica/fisiología , Masculino , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Respiración/efectos de los fármacos , Estadísticas no ParamétricasRESUMEN
Propofol (2,6-diisopropylphenol) is a safe and widely used anaesthetic, but due to low water solubility and high lipophilicity a difficult compound to formulate. The solubility of propofol in the semifluorinated alkane perfluorohexyloctane (F6H8) is very high (>300 mg/ml). In the present work we investigate if a F6H8-based emulsion could be used as a new intravenous drug delivery system for propofol from a pharmacokinetic, pharmacodynamic and safety point of view. The pharmacokinetic parameters were evaluated after an intravenous bolus injection of either Disoprivan(®) or a F6H8-based propofol emulsion in Wistar rats. The onset and end of sedation after multiple dosings (5, 10 and 15 mg/kg bw) were examined. Clinical chemistry and histology were assessed. No significant difference was found for any of the pharmacokinetic parameters. No differences in the onset nor the end of sedation in the tested dosages could be detected. Histology scores revealed no differences. A slightly increased alanine aminotransferase (ALT) was measured after multiple application of the F6H8-propofol emulsion. In conclusion, the F6H8-propofol emulsion showed no significant different pharmacokinetics and sedation properties, compared to a commercial soy-based propofol emulsion. Further, no toxic effects could be detected on the F6H8 emulsion indicating it was a safe excipient in rats.
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Anestésicos Intravenosos , Fluorocarburos/química , Propofol , Anestésicos Intravenosos/administración & dosificación , Anestésicos Intravenosos/sangre , Anestésicos Intravenosos/química , Anestésicos Intravenosos/farmacocinética , Animales , Emulsiones , Glucosa/química , Lecitinas/química , Masculino , Propofol/administración & dosificación , Propofol/sangre , Propofol/química , Propofol/farmacocinética , Ratas WistarRESUMEN
BACKGROUND: This study investigated the potential use of N-octanoyl dopamine (NOD) in donor management to ameliorate the damage caused by brain death and ischemia-reperfusion injury in a rat model of kidney and heart transplantation. METHODS: Brain-dead Fisher rats were treated for 6 hours with either saline or saline plus NOD. Orthotopic kidney and heterotopic heart transplantation were performed in different Lewis recipient rats. The right donor kidneys were stored for biochemical analysis. Blood samples were taken from the donor and on several days after transplantation from the recipient. All grafts were harvested after 7 days. RESULTS: There was no effect on donor heart rate and blood pressure under NOD treatment. The release of lactate dehydrogenase (LDH) during brain death was reduced in the NOD group. The right kidneys from NOD-preconditioned animals revealed diminished expression of the proinflammatory cell adhesion molecules intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1). Nevertheless, there was no difference in renal infiltration with ED1 (CD68) or major histocompatibility complex (MHC) class II-positive cells. Recipients receiving a renal allograft from NOD-treated donors had a significantly better renal function at day 1 after transplantation. Banff-grading after 7 days showed significantly reduced scores for tubulitis and vasculitis in the grafts of these recipients. In the heart allograft recipients, lower plasma LDH levels were observed. CONCLUSIONS: Donor preconditioning with NOD leads to better graft function and reduced acute rejection in untreated renal allograft recipients without displaying adverse effects on heart allografts.
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Muerte Encefálica , Dopamina/análogos & derivados , Trasplante de Corazón , Trasplante de Riñón , Donantes de Tejidos , Animales , Dopamina/farmacología , Riñón/patología , Masculino , Miocardio/patología , Ratas , Ratas Endogámicas F344 , Ratas Endogámicas Lew , Canales Catiónicos TRPV/fisiologíaRESUMEN
Annulus fibrosus repair techniques for the intervertebral disc (IVD) address the unsolved problem of reherniation after IVD herniation and might facilitate the development of nucleus pulposus replacement techniques for IVD diseases. This study investigates the suitability of a bio-integrative annulus implant.Standardized box defects were applied to the annulus L3/4 and L4/5 of 16 sheep, followed by randomized insertion of the textile polyglycolic acid/polyvinylidene fluoride annulus implant in one of the defects. Explantation was conducted after 2, 6 and 12 weeks, followed by provocative pressure testing and histological analysis. At 2 weeks' follow-up, all specimens of the control defect group demonstrated uncontained herniated nucleus pulposus tissue in the annulus defects. For the treated specimens, the annulus implant consistently provided an effective barrier for herniating nucleus pulposus tissue, with no implant dislocation at all time-points. After 2 weeks, a homogeneous cell infiltration of the annulus implant was observed, leading to a progressive directional matrix build-up. Repair tissue thickness was significantly stronger with the annulus implant at all follow-ups (p < 0.01). No pronounced foreign body reaction and no difference in the amount of supra-annular scar tissue over the defect sites were observed. The implantation procedure inflicted annulus damage adjacent to the defect. At later time-points, however, no difference in comparison with the control defect group was evident. The investigated biointegrative annulus implant showed promising results with regard to biointegration, enhancement of repair tissue and function as a mechanical barrier in an ovine model.
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Implantes Absorbibles , Desplazamiento del Disco Intervertebral/cirugía , Disco Intervertebral/lesiones , Ácido Poliglicólico/farmacología , Polivinilos/farmacología , Animales , OvinosRESUMEN
Recently, we developed a nonhemodynamic dopamine derivative, NOD, which has profound anti-inflammatory effects in vitro. As NOD also protects rats from ischemic AKI, the present study tested whether NOD is able to modulate cellular immunity for potential use as a T cell-suppressive agent. To this end, T cells were stimulated by anti-CD3/CD28 or PMA/ionomycin in the presence or absence of different concentrations of NOD. T cell proliferation, activation markers, intracellular cytokine expression, and activation of transcription factors were assessed. Whereas T cell proliferation was inhibited significantly by NOD at Day 3, proliferation was restored at Day 7 or later depending on the NOD concentration used. Inhibition of proliferation was reflected by a diminished CD25 expression and switch from naive to memory T cells. Early TCR activation events were unaffected, yet NF-κB and AP-1 were strongly inhibited by NOD. The inhibitory effect of NOD seemed to be dependent on its redox activity, as NOT, a redox-inactive NOD derivate, did not influence proliferation. NOD displayed synergistic effects with CNIs on T cell proliferation. Our data demonstrate that NOD displays T cell-suppressive activity. In keeping with its anti-inflammatory action and its beneficial effect on ischemia-induced AKI, NOD may be an interesting drug candidate to prevent CNI-related side-effects.
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Dopamina/análogos & derivados , Fase G1/efectos de los fármacos , Inmunosupresores/farmacología , Activación de Linfocitos/efectos de los fármacos , Linfocitos T/efectos de los fármacos , Factores de Transcripción/antagonistas & inhibidores , Inhibidores de la Calcineurina/farmacología , División Celular/efectos de los fármacos , Dopamina/farmacología , Evaluación Preclínica de Medicamentos , Sinergismo Farmacológico , Humanos , Memoria Inmunológica , Proteína Tirosina Quinasa p56(lck) Específica de Linfocito/metabolismo , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Oxidación-Reducción , Estrés Oxidativo , Fosforilación/efectos de los fármacos , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Complejo Receptor-CD3 del Antígeno de Linfocito T/efectos de los fármacos , Complejo Receptor-CD3 del Antígeno de Linfocito T/inmunología , Linfocitos T/citología , Factor de Transcripción AP-1/antagonistas & inhibidores , Factor de Transcripción AP-1/metabolismo , Factores de Transcripción/metabolismo , Proteína Tirosina Quinasa ZAP-70/metabolismoRESUMEN
INTRODUCTION: The ideal ventilation strategy for patients with massive brain damage requires better elucidation. We hypothesized that in the presence of massive brain injury, a ventilation strategy using low (6 milliliters per kilogram ideal body weight) tidal volume (V(T)) ventilation with open lung positive end-expiratory pressure (LV(T)/OLPEEP) set according to the minimal static elastance of the respiratory system, attenuates the impact of massive brain damage on gas-exchange, respiratory mechanics, lung histology and whole genome alterations compared with high (12 milliliters per kilogram ideal body weight) V(T) and low positive end-expiratory pressure ventilation (HV(T)/LPEEP). METHODS: In total, 28 adult male Wistar rats were randomly assigned to one of four groups: 1) no brain damage (NBD) with LV(T)/OLPEEP; 2) NBD with HV(T)/LPEEP; 3) brain damage (BD) with LV(T)/OLPEEP; and 4) BD with HV9T)/LPEEP. All animals were mechanically ventilated for six hours. Brain damage was induced by an inflated balloon catheter into the epidural space. Hemodynamics was recorded and blood gas analysis was performed hourly. At the end of the experiment, respiratory system mechanics and lung histology were analyzed. Genome wide gene expression profiling and subsequent confirmatory quantitative polymerase chain reaction (qPCR) for selected genes were performed. RESULTS: In NBD, both LV(T)/OLPEEP and HV(T)/LPEEP did not affect arterial blood gases, as well as whole genome expression changes and real-time qPCR. In BD, LVT/OLPEEP, compared to HV(T)/LPEEP, improved oxygenation, reduced lung damage according to histology, genome analysis and real-time qPCR with decreased interleukin 6 (IL-6), cytokine-induced neutrophil chemoattractant 1 (CINC)-1 and angiopoietin-4 expressions. LV(T)/OLPEEP compared to HV(T)/LPEEP improved overall survival. CONCLUSIONS: In BD, LV(T)/OLPEEP minimizes lung morpho-functional changes and inflammation compared to HV(T)/LPEEP.
Asunto(s)
Lesiones Encefálicas/terapia , Lesión Pulmonar/prevención & control , Respiración con Presión Positiva/métodos , Volumen de Ventilación Pulmonar/fisiología , Animales , Lesiones Encefálicas/patología , Lesiones Encefálicas/fisiopatología , Lesión Pulmonar/fisiopatología , Masculino , Distribución Aleatoria , Ratas , Ratas Wistar , Respiración Artificial/métodos , Mecánica Respiratoria/fisiologíaRESUMEN
Donor heart allografts are extremely susceptible to prolonged static cold storage. Because donor treatment with low-dose dopamine improves clinical outcome after heart transplantation, we tested the hypothesis that dopamine and its lipophilic derivate, N-octanoyl dopamine (NOD), protect cardiomyocytes from cold storage injury. Neonatal rat cardiomyocytes were treated with dopamine or NOD or left untreated and subsequently subjected to static cold storage (8-12 hours). Dopamine- and NOD-treated cardiomyocytes displayed a better viability compared with untreated cells after hypothermia. In untreated cardiomyocytes, cell damage was reflected by lactate dehydrogenase (LDH) release and a decrease in intracellular ATP. NOD was approximately 20-fold more potent than dopamine. Similarly to cardiomyocytes in vitro, rat hearts perfused with NOD before explantation showed significantly lower LDH release after static cold storage. ATP regeneration and spontaneous contractions after cold storage and rewarming only occurred in treated cardiomyocytes. Hypothermia severely attenuated isoprenaline-induced cAMP formation in control but not in dopamine- or NOD-treated cells. Esterified derivates of NOD with redox potential and lipophilic side chains reduced cell damage during cold storage similarly to NOD. In contrast to dopamine, neither NOD nor its derivates induced a significant ß-adrenoceptor-mediated elevation of cellular cAMP levels. The ß1-adrenoceptor antagonist atenolol and D1/D2 receptor antagonist fluphenazine had no impact on the protective effect of NOD or dopamine. We conclude that dopamine as well as NOD treatment mitigates cold preservation injury to cardiomyocytes. The beneficial effects are independent of ß-adrenoceptor or dopaminergic receptor stimulation but correlate with redox potential and lipophilic properties.
Asunto(s)
Cardiotónicos/farmacología , Criopreservación , Dopamina/análogos & derivados , Dopamina/farmacología , Miocitos Cardíacos/efectos de los fármacos , Preservación de Órganos/efectos adversos , Animales , Células Cultivadas , Frío/efectos adversos , Criopreservación/métodos , Femenino , Masculino , Miocitos Cardíacos/patología , Preservación de Órganos/métodos , Ratas , Ratas Endogámicas Lew , Ratas WistarRESUMEN
BACKGROUND AND PURPOSE: Catechol containing compounds have anti-inflammatory properties, yet for catecholamines these properties are modest. Since we have previously demonstrated that the synthetic dopamine derivative N-octanoyl dopamine (NOD) has superior anti-inflammatory properties compared to dopamine, we tested NOD in more detail and sought to elucidate the molecular entities and underlying mechanism by which NOD down-regulates inflammation. EXPERIMENTAL APPROACH: Genome wide gene expression profiling of human umbilical vein endothelial cells (HUVECs) was performed after stimulation with TNF-α or in the combination with NOD. Confirmation of these differences, NFκB activation and the molecular entities that were required for the anti-inflammatory properties were assessed in subsequent experiments. KEY RESULTS: Down regulation of inflammatory genes by NOD occurred predominantly for κB regulated genes, however not all κB regulated genes were affected. These findings were explained by inhibition of RelA phosphorylation at Ser276. Leukocyte adherence to TNF-α stimulated HUVECs was inhibited by NOD and was reflected by a diminished expression of adhesion molecules on HUVECs. NOD induced HO-1 expression, but this was not required for inhibition of NFκB. The anti-inflammatory effect of NOD seems to involve the redox active catechol structure, although the redox active para-dihydroxy benzene containing compounds also displayed anti-inflammatory effects, provided that they were sufficiently hydrophobic. CONCLUSIONS AND IMPLICATIONS: The present study highlighted important mechanisms and molecular entities by which dihydroxy benzene compounds exert their potential anti-inflammatory action. Since NOD does not have hemodynamic properties, NOD seems to be a promising candidate drug for the treatment of inflammatory diseases.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Dopamina/análogos & derivados , Regulación de la Expresión Génica/efectos de los fármacos , Serina/metabolismo , Factor de Transcripción ReIA/química , Factor de Transcripción ReIA/metabolismo , Antiinflamatorios no Esteroideos/química , Adhesión Celular/efectos de los fármacos , Dopamina/química , Dopamina/farmacología , Regulación hacia Abajo/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/citología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/efectos de los fármacos , Fosforilación/efectos de los fármacos , Factor de Necrosis Tumoral alfa/farmacología , Molécula 1 de Adhesión Celular Vascular/metabolismoRESUMEN
BACKGROUND: The combination of neoadjuvant radiochemotherapy and parenchyma-preserving sleeve resection for lung cancer remains controversial because of potentially increased rate of anastomotic breakdown. We analyzed the effects of applying a decellularized human dermis transplant seeded with autologous fibroblasts in a rodent sleeve resection model with neoadjuvant radiotherapy. MATERIALS AND METHODS: A total of 64 male Fisher rats underwent a transsection and surgical anastomosis of the left main bronchus and were randomized to receive plus/minus radiation treatment and plus/minus augmentation of the anastomosis with a fibroblast-seeded dermis transplant (2 × 2 factorial design). A µCT scan was performed at postoperative days 7 and 14, and the animals were sacrificed on day 14. Anastomotic bursting pressure and hydroxyproline concentration were measured. RESULTS: In the irradiated groups, the anastomotic bursting pressure was significantly higher in the augmented group at day 7 (100.9 ± 18.3 vs 141.3 ± 18.0 kPa, p = 0.0005) but not at day 14. Hydroxyproline levels showed a similar pattern in the irradiated group with significant differences at day 7 (7 days postoperative 158 ± 11.6 vs 198.2 ± 10.9 nmol/mg, p < 0.0001) but not at day 14 postoperatively. CONCLUSIONS: Augmentation of a bronchial anastomosis by a dermal matrix, seeded with autologous, viable fibroblasts improves early wound breaking strength. Fibroblast-enhanced dermal matrices provide a new and easily usable tool to prevent early anastomotic leakage after neoadjuvant chemoradiation in locally advanced lung cancer.