RESUMEN
Background. Previous studies showed significant interaction between the local and systemic inflammatory response after severe trauma in small animal models. The purpose of this study was to establish a new combined trauma model in pigs to investigate fracture-associated local inflammation and gain information about the early inflammatory stages after polytrauma. Material and Methods. Combined trauma consisted of tibial fracture, lung contusion, liver laceration, and controlled hemorrhage. Animals were mechanically ventilated and under ICU-monitoring for 48 h. Blood and fracture hematoma samples were collected during the time course of the study. Local and systemic levels of serum cytokines and diverse alarmins were measured by ELISA kit. Results. A statistical significant difference in the systemic serum values of IL-6 and HMGB1 was observed when compared to the sham. Moreover, there was a statistical significant difference in the serum values of the fracture hematoma of IL-6, IL-8, IL-10, and HMGB1 when compared to the systemic inflammatory response. However a decrease of local proinflammatory concentrations was observed while anti-inflammatory mediators increased. Conclusion. Our data showed a time-dependent activation of the local and systemic inflammatory response. Indeed it is the first study focusing on the local and systemic inflammatory response to multiple-trauma in a large animal model.
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Hematoma/sangre , Hematoma/inmunología , Inflamación/sangre , Traumatismo Múltiple/sangre , Traumatismo Múltiple/inmunología , Animales , Ensayo de Inmunoadsorción Enzimática , Inflamación/inmunología , Interleucina-10/sangre , Interleucina-6/sangre , Interleucina-8/sangre , Masculino , PorcinosRESUMEN
BACKGROUND: We investigated the brain-derived proteins neuron-specific enolase (NSE) and protein S-100b (S-100b) in survivors of cardiac arrest who had either received therapeutic hypothermia (TH) or had not. METHODS: In a retrospective cohort study, we analysed serum levels of these two proteins over 5 days in 201 adult cardiac arrest survivors admitted to our intensive care unit between 2003 and 2010. These were all survivors that remained comatose and survived at least 48 h. Of these, 140 received therapeutic hypothermia (hypothermia group). The remainder received only standard therapy without hypothermia (normothermia group). RESULTS: There was no difference in survival between the hypothermia and normothermia groups. At 4 weeks after arrest, 61 (43.6%) patients of the hypothermia group and 26 (42.6%) patients of the normothermia group were still alive with favourable to moderate neurological outcome (Cerebral Performance Category Scale 1-3). We observed no change in the mean serum levels of either protein between the two groups. Within each group, we found significantly higher serum levels of NSE and S-100b in patients with unfavourable neurological outcome (Cerebral Performance Category Scale 4 and 5) than in those with moderate to favourable outcome. Cut-off levels 3 days after cardiac arrest predicting an unfavourable outcome were >40 ng/ml for NSE [specificity 95.2%, Sensitivity 74.1%, areas under the curve (AUC):0.889], false positive rate 4 [confidence interval (CI): 0.0131-0.1175] and >1.03 µg/1 for S-100b (specificity 95.6%, Sensitivity 57.8%, AUC: 0.875) false positive rate 3 (CI: 0.0091-01218). CONCLUSIONS: Additional application of TH was not associated with significant changes in serum levels of NSE and S-100b in comatose survivors of cardiac arrest, compared to those treated without TH.
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Paro Cardíaco/sangre , Hipotermia Inducida/métodos , Fosfopiruvato Hidratasa/sangre , Proteínas S100/sangre , Anciano , Área Bajo la Curva , Biomarcadores/sangre , Encéfalo/metabolismo , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
BACKGROUND: Trauma represents one of the leading causes of death in children. Beside an injury pattern that differs from adult trauma patients, children seem to develop multiple organ dysfunction syndrome (MODS) less frequently. Compared to adult MODS, pediatric MODS has also been described to occur earlier in the posttraumatic course. METHOD: Biomarkers for early identification of patients at high-risk for posttraumatic complications are of high clinical relevance. However, little is known from clinical studies about the relevance of biomarkers during the posttraumatic course. AIM: Therefore, the purpose of this review is to summarize current knowledge on this topic in order to investigate the prognostic significance of different parameters.
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Citocinas/inmunología , Traumatismo Múltiple/diagnóstico , Traumatismo Múltiple/inmunología , Síndrome de Respuesta Inflamatoria Sistémica/diagnóstico , Síndrome de Respuesta Inflamatoria Sistémica/inmunología , Adolescente , Biomarcadores/análisis , Niño , Preescolar , Medicina Basada en la Evidencia , Femenino , Humanos , Lactante , Recién Nacido , MasculinoRESUMEN
The quality of recorded peripheral nerve signals is decisive for their application in therapies. The electroneurogram can be recorded via implantable circumeural electrodes that are wrapped around the peripheral nerve. The shape and amplitude of the signal recorded by the electrode are influenced by the design and contact configuration of the electrode. In this paper, the impact of the number of contacts, contact size and electrical insulation to the outside is investigated to predict the single fiber action potential based on the measured impedance data.
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Nervios Periféricos , Nervios Periféricos/fisiología , Electrodos Implantados , Potenciales de Acción/fisiología , Impedancia EléctricaRESUMEN
INTRODUCTION: Occult hypoperfusion (OH) entails inadequate tissue oxygenation in the presence of normal vital signs. Numerous studies have demonstrated that this phenomenon is associated with impaired outcome and increased mortality, however definitions of OH differ between studies. The aim of the current study was to identify and evaluate the published definitions of the term `occult hypoperfusion` in trauma (tOH). MATERIAL & METHODS: A review of literature was performed using the Medline database. The following MeSH terms have been used: occult hypoperfusion, severe trauma, polytrauma, resuscitation. Clinical studies on OH were included and utilized definitions have been compared. A predefined data-interpretation process was applied to create an integrative definition for tOH. RESULTS: A total of 43 publications used the term OH. A definition of OH was provided in 16 manuscripts. A pooled mean number of participants of 729 (SD: 1158) was found per study. The majority of manuscripts combine multiple parameters for inadequate tissue oxygenation and normal vital signs to define OH in trauma. In 12 manuscripts, specific cut-off values for hemodynamic parameters (SBP/PR/UP) and in 11/16 papers exact metabolic thresholds (lactate/B.E) were defined. The following definition best integrates definitions in current literature: Lactate > 2 mmol/l or BE <-3 mmol/l (to define inadequate oxygenation) plus SBP > 90 mmHg and PR < 120 bpm (to define normal macroperfusion). CONCLUSIONS: The current systematic review demonstrates that definitions of occult hypoperfusion in trauma differ in the literature. The following comprehensive definition for (tOH) is proposed: Lactate > 2 mmol/l or BE <-3 mmol/l plus SBP > 90 mmHg and PR < 120 bpm. This recommendation appears to represent current literature on tOH and may improve the identification of trauma patients at risk for OH and related complicated courses. Further validation studies are required to demonstrate the clinical role of tOH and the proposed definition.
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Traumatismo Múltiple , Humanos , Ácido Láctico , Signos Vitales , Hemodinámica , Puntaje de Gravedad del TraumatismoRESUMEN
This review focuses on the presentation of the diagnostic and therapeutic principles for treatment of chronic osteomyelitis of long bones in adults. Early detection of the offending bacteria is a crucial step which has to be performed with tissue and fluids from the depth of the wound. Superficial samples and swaps from fistulas should be avoided and are not considered to be representative. Chronic osteomyelitis is characterized by necrotic and nonvascularized bony tissue which represents one of the most relevant sources for recurrence infection. Appropriate therapy includes radical excision of the diseased bone and infected scar tissue, closure of the wound with well-vascularized (muscle) flaps, stabilization, and administration of adequate antibiotics.
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Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/prevención & control , Osteomielitis/diagnóstico , Osteomielitis/terapia , Osteotomía/métodos , Adulto , Infecciones Bacterianas/diagnóstico , Terapia Combinada/métodos , HumanosRESUMEN
The indications, technical principals, and results after vertebroplasty and kyphoplasty are presented in detail. We focus on the complications of both procedures. The benefit of vertebroplasty has been fundamentally questioned by two papers which have recently been published in the New England Journal of Medicine. Our paper discusses the present knowledge and policy about indication. The contradictory results from different studies are presented. In general, there is a lack of randomized clinical trials. Therefore, a final judgement of these two techniques is not possible. New procedures like stent-kyphoplasty or lordoplasty are briefly described. However, at present an assessment of these new techniques is impossible. A similar situation is give for the application of resorbable bone cements.
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Ensayos Clínicos Controlados Aleatorios como Asunto , Enfermedades de la Columna Vertebral/etiología , Fracturas de la Columna Vertebral/cirugía , Vertebroplastia/efectos adversos , Vertebroplastia/métodos , Humanos , Enfermedades de la Columna Vertebral/prevención & control , Fracturas de la Columna Vertebral/complicaciones , Resultado del Tratamiento , Vertebroplastia/instrumentaciónRESUMEN
BACKGROUND: Salter innominate osteotomy of the pelvis is widely used to improve the coverage of the femoral head in developmental dysplasia of the hip, but the biomechanical and geometric changes after this osteotomy are not well understood. METHODS: A CT dataset of an 8-year-old child with severe dysplasia of both hips was used to create a polyamide model of the left hemipelvis and proximal femur. The hemipelvis was mounted to a holding device and the proximal femur attached to a sensor guided industrial robot. The robot was programmed to apply joint forces and torques based on single-leg stance. Two major muscles were represented by wires connected to hydraulic cylinders; muscle forces were adjusted to balance the joint moments. Resulting joint forces were measured using a pressure measuring sensor before and after Salter osteotomy of the hip. Geometric changes were recorded using a three-dimensional ultrasound measurement system. FINDINGS: The preoperative hip joint resultant force was 583N (270% body weight), while after the operation a mean force of 266N (120% body weight) was measured. Postoperative muscle forces were roughly half the preoperative values. The hip joint was translated medially and caudally. Postoperatively, the length of gluteus medius and maximus muscles increased. INTERPRETATION: The preoperative value of the resultant hip joint force is comparable to values reported in the literature. The results suggest that Salter innominate osteotomy leads to a reduction of hip joint and muscle forces in addition to increasing joint contact area.
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Luxación Congénita de la Cadera/fisiopatología , Luxación Congénita de la Cadera/cirugía , Articulación de la Cadera/fisiopatología , Articulación de la Cadera/cirugía , Modelos Biológicos , Músculo Esquelético/fisiopatología , Osteotomía/métodos , Fenómenos Biomecánicos , Niño , Simulación por Computador , Elasticidad , Femenino , Luxación Congénita de la Cadera/diagnóstico , Humanos , Contracción Muscular , Estrés Mecánico , Resultado del Tratamiento , Soporte de PesoRESUMEN
PURPOSE: This review gives an overview of physiological processes, mainly regarding vascular endothelial cells and their important role in hemostasis, information processing, and communication during trauma. An insight is given into molecules and cells involved in the first innate immune response through to the behavior of endothelial cells in developing trauma. The goal of this review is to show the overlap of crucial factors related to the endothelium and the development of trauma. METHODS: A systemic literature search was performed using Google scholar and PubMed. RESULTS: The results of the literature search showed that the endothelium, especially the vascular endothelium, is involved in various cellular and subcellular pathways of activation, suppression, and transfer of information. A variety of molecules and cells are orchestrated, subsequently the endothelium gets in contact with a traumatizing event. CONCLUSION: The endothelium is one of the first barriers that comes into contact with exo- and endogenous trauma-related signals and is a pivotal point in activating subsequent pathways and cascades by transfer of information.
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Células Endoteliales/fisiología , Endotelio Vascular/fisiología , Inmunidad Innata/fisiología , Heridas y Lesiones/inmunología , Heridas y Lesiones/fisiopatología , Plaquetas/fisiología , Hemostasis/fisiología , Humanos , Inflamación/fisiopatología , Leucocitos/fisiología , Lipopolisacáridos , Fenotipo , Transducción de Señal/fisiología , Vasodilatación/fisiologíaRESUMEN
Neuroleptic malignant syndrome (NMS) is a rare disorder caused by drug-induced dopamine-receptor-blockage or low dopamine concentration in the brain. It is a severe reaction to neuroleptic drugs in antipsychotic therapy. Symptoms in NMS typically consist of fever, muscle rigidity and cognitive changes; laboratory findings include elevated infectious disease markers and creatine kinase as well as signs of rhabdomyolysis. To differentiate NMS from other malignant hyperthermia syndromes identifying the offending drug and clinical history are essential. Therapy in NMS includes withdrawal of the causative medication and intensive care treatment possibly with administration of dantrolene.In this case report, we describe the clinical course of a 48 year old man who developed typical clinical symptoms and laboratory parameters of malignant hyperthermia syndrome after injection of haloperidol.
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Antipsicóticos , Haloperidol , Síndrome Neuroléptico Maligno , Antipsicóticos/efectos adversos , Dantroleno , Haloperidol/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Síndrome Neuroléptico Maligno/etiología , Rabdomiólisis/inducido químicamenteRESUMEN
BACKGROUND: Pelvic fractures contribute to morbidity and mortality following injury. We sought to study the impact of pelvic fractures on the clinical course and outcomes of trauma patients with a pelvic fracture in comparison to patients with similar injury severity without pelvic fracture to identify potential parameters to track patients' clinical course post-injury. METHODS: A cohort of 206 consecutive blunt trauma survivors, studied over a 5-year period in a level I trauma center of which 75 patients (36.4%) had a pelvic fracture, was included in the study. To perform a retrospective cohort study with matched controls, 60 patients of the pelvic fracture group [(PF), 41 males and 19 females; age: 40 ± 17; injury severity score (ISS): 26.6 ± 9.3] were compared to 60 patients without pelvic fracture (non-PF) trauma as controls (41 males and 19 females; age: 40 ± 13; ISS: 26.9 ± 7.7), both with matching age (±5 years), sex, and ISS (±5 points). RESULTS: Statistically significant differences were observed in Intensive Care Unit (ICU) length of stay (LOS), total LOS, and Marshall MOD score between PF and non-PF groups, respectively. Acid-base markers such as pH, lactate, LDH, and base deficit were all significantly altered in PF compared to non-PF cohort upon admission. Moreover, our analysis showed significant differences in inflammatory biomarkers (Prolactin, CRP, and IL-6), and clinical parameters (CPK, Hgb, Platelets count, and WBC) over the 7-day clinical course in patients with PF when compared to non-PF cohort. CONCLUSION: In this matched cohort, patients with pelvic fractures exhibited biochemical and physiological alterations upon admission. Furthermore, our results suggest that pelvic fracture affects the clinical outcomes in severely injured patients, independently of injury severity, mechanism of injury, age or gender.
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Fracturas Óseas/mortalidad , Traumatismo Múltiple/mortalidad , Huesos Pélvicos/lesiones , Adulto , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Alemania , Humanos , Puntaje de Gravedad del Traumatismo , Tiempo de Internación , Masculino , Estudios RetrospectivosRESUMEN
The purpose of this study was to define the relationship between cardiac depression and morphological and immunological alterations in cardiac tissue after multiple trauma. However, the mechanistic basis of depressed cardiac function after trauma is still elusive. In a porcine polytrauma model including blunt chest trauma, liver laceration, femur fracture and haemorrhage serial trans-thoracic echocardiography was performed and correlated with cellular cardiac injury as well as with the occurrence of extracellular histones in serum. Postmortem analysis of heart tissue was performed 72 h after trauma. Ejection fraction and shortening fraction of the left ventricle were significantly impaired between 4 and 27 h after trauma. H-FABP, troponin I and extracellular histones were elevated early after trauma and returned to baseline after 24 and 48 h, respectively. Furthermore, increased nitrotyrosine and Il-1ß generation and apoptosis were identified in cardiac tissue after trauma. Main structural findings revealed alteration of connexin 43 (Cx43) and co-translocation of Cx43 and zonula occludens 1 to the cytosol, reduction of α-actinin and increase of desmin in cardiomyocytes after trauma. The cellular and subcellular events demonstrated in this report may for the first time explain molecular mechanisms associated with cardiac dysfunction after multiple trauma.
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Lesiones Cardíacas/patología , Lesiones Cardíacas/fisiopatología , Ventrículos Cardíacos/patología , Traumatismo Múltiple/patología , Actinina/metabolismo , Animales , Apoptosis/fisiología , Conexina 43/metabolismo , Citosol/metabolismo , Citosol/fisiología , Desmina/metabolismo , Ecocardiografía/métodos , Proteína 3 de Unión a Ácidos Grasos/metabolismo , Lesiones Cardíacas/metabolismo , Ventrículos Cardíacos/metabolismo , Histonas/metabolismo , Interleucina-1beta/metabolismo , Masculino , Traumatismo Múltiple/metabolismo , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Porcinos , Troponina I/metabolismo , Proteína de la Zonula Occludens-1/metabolismoRESUMEN
Severe trauma is still one of the leading causes of death worldwide. The initial treatment and diagnostics are of immense importance in polytraumatized patients. The initial approach mainly focuses on the advanced trauma life support (ATLS) concept. This includes the identification of life-threatening conditions and application of life-saving interventions. Depending on the physiological condition of the patient, the surgical treatment strategies of early total care (ETC) or damage control orthopedics (DCO) can be chosen. Appropriate surgical management can reduce the incidence of associated delayed systemic complications. This review summarizes the most commonly used definitions of polytrauma (including the Berlin polytrauma definition) and classification systems of severely injured patients. Moreover, the recently introduced treatment strategy of the safe definitive surgery concept for severely injured patients is also discussed in this article.
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Traumatismo Múltiple/diagnóstico , Traumatismo Múltiple/cirugía , Atención de Apoyo Vital Avanzado en Trauma , Alemania , Adhesión a Directriz , Humanos , Traumatismo Múltiple/clasificación , Traumatismo Múltiple/fisiopatología , Procedimientos Ortopédicos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Prevención SecundariaRESUMEN
PURPOSE: Traumatic insults result in an altered inflammatory response, in which alarmins release has a central role. The impact of haemorrhagic shock intensity on the long-term kinetics of alarmins is not yet fully elucidated. We investigated these aspects in a combined trauma (chest, abdominal, and extremities injury) porcine model with different severities and durations of haemorrhagic shock. METHODS: After induction of combined trauma (tibia fracture, lung contusion, and liver laceration), haemorrhagic shock was induced at different intensities: moderate haemorrhage (MH; n = 15): mean arterial pressure (MAP) <30 ± 5 mmHg [maximum loss of total blood volume (TBVmax): 45 %] for 90 min, and severe haemorrhage (SH; n = 10): MAP <25 ± 5 mmHg (TBVmax 50 %) for 120 min. Resuscitation was performed using a standardized crystalloid infusion protocol. Animals were mechanically ventilated and underwent ICU-monitoring for 48 h (MH) and 48.5 h (SH). Blood samples were collected over the clinical time course, and systemic levels of serum alarmins [High-Mobility Group Protein B-1 (HMGB-1) and Heat Shock Protein 70 (HSP70)] were measured using an ELISA kit. RESULTS: Heart rate, systemic blood pressure, lactate, and base excess were significantly altered as a function of haemorrhagic shock in both trauma groups (MH and SH). Systemic HMGB-1 levels were significantly elevated in both trauma groups when compared to the sham group. Haemorrhagic shock severity and duration were positively correlated with HMGB-1 levels and compared to baseline values, concentrations remained significantly increased in SH when compared to MH. On the other hand, we observed a significant decrease in the systemic HSP70 levels of trauma groups (MH, and SH) when compared to the sham group, which was significantly decreased compared to baseline values in SH over the entire time course. CONCLUSION: Our data show that haemorrhagic shock duration and severity affect the systemic levels of HMGB-1 and HSP70. This early alarmins release after trauma can be used to guide the treatment strategies (e.g. surgical procedures) of polytrauma patients.
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Proteína HMGB1/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Traumatismo Múltiple/metabolismo , Choque Hemorrágico/metabolismo , Alarminas/metabolismo , Animales , Contusiones , Soluciones Cristaloides , Modelos Animales de Enfermedad , Fluidoterapia , Soluciones Isotónicas , Laceraciones , Hígado/lesiones , Lesión Pulmonar , Masculino , Traumatismo Múltiple/complicaciones , Respiración Artificial , Resucitación , Índice de Severidad de la Enfermedad , Choque Hemorrágico/etiología , Sus scrofa , Porcinos , Fracturas de la TibiaRESUMEN
BACKGROUND: Hypothermia has been discussed as playing a role in improving the early phase of systemic inflammation. However, information on the impact of hypothermia on the local inflammatory response is sparse. We therefore investigated the kinetics of local and systemic inflammation in the late posttraumatic phase after induction of hypothermia in an established porcine long-term model of combined trauma. MATERIALS & METHODS: Male pigs (35 ± 5kg) were mechanically ventilated and monitored over the study period of 48 h. Combined trauma included tibia fracture, lung contusion, liver laceration and pressure-controlled hemorrhagic shock (MAP < 30 ± 5 mmHg for 90 min). After resuscitation, hypothermia (33°C) was induced for a period of 12 h (HT-T group) with subsequent re-warming over a period of 10 h. The NT-T group was kept normothermic. Systemic and local (fracture hematoma) cytokine levels (IL-6, -8, -10) and alarmins (HMGB1, HSP70) were measured via ELISA. RESULTS: Severe signs of shock as well as systemic and local increases of pro-inflammatory mediators were observed in both trauma groups. In general the local increase of pro- and anti-inflammatory mediator levels was significantly higher and prolonged compared to systemic concentrations. Induction of hypothermia resulted in a significantly prolonged elevation of both systemic and local HMGB1 levels at 48 h compared to the NT-T group. Correspondingly, local IL-6 levels demonstrated a significantly prolonged increase in the HT-T group at 48 h. CONCLUSION: A prolonged inflammatory response might reduce the well-described protective effects on organ and immune function observed in the early phase after hypothermia induction. Furthermore, local immune response also seems to be affected. Future studies should aim to investigate the use of therapeutic hypothermia at different degrees and duration of application.
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Hipotermia Inducida/métodos , Inflamación/patología , Traumatismo Múltiple/patología , Animales , Citocinas/metabolismo , Modelos Animales de Enfermedad , Hematoma/metabolismo , Hematoma/patología , Inflamación/metabolismo , Laceraciones/metabolismo , Laceraciones/patología , Hígado/metabolismo , Hígado/patología , Lesión Pulmonar/metabolismo , Lesión Pulmonar/patología , Masculino , Traumatismo Múltiple/metabolismo , Resucitación/métodos , Choque Hemorrágico/metabolismo , Choque Hemorrágico/patología , Sus scrofa , PorcinosRESUMEN
Chest trauma has a significant relevance on outcome after severe trauma. Clinically, impaired lung function typically occurs within 72 hours after trauma. However, the underlying pathophysiological mechanisms are still not fully elucidated. Therefore, we aimed to establish an experimental long-term model to investigate physiological, morphologic and inflammatory changes, after severe trauma. Male pigs (sus scrofa) sustained severe trauma (including unilateral chest trauma, femur fracture, liver laceration and hemorrhagic shock). Additionally, non-injured animals served as sham controls. Chest trauma resulted in severe lung damage on both CT and histological analyses. Furthermore, severe inflammation with a systemic increase of IL-6 (p = 0.0305) and a local increase of IL-8 in BAL (p = 0.0009) was observed. The pO2/FiO2 ratio in trauma animals decreased over the observation period (p < 0.0001) but not in the sham group (p = 0.2967). Electrical Impedance Tomography (EIT) revealed differences between the traumatized and healthy lung (p < 0.0001). In conclusion, a clinically relevant, long-term model of blunt chest trauma with concomitant injuries has been developed. This reproducible model allows to examine local and systemic consequences of trauma and is valid for investigation of potential diagnostic or therapeutic options. In this context, EIT might represent a radiation-free method for bedside diagnostics.
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Traumatismos Torácicos/diagnóstico por imagen , Heridas no Penetrantes/diagnóstico por imagen , Animales , Líquido del Lavado Bronquioalveolar , Modelos Animales de Enfermedad , Impedancia Eléctrica , Hemodinámica , Inflamación/patología , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Pulmón/fisiopatología , Lesión Pulmonar/fisiopatología , Masculino , Traumatismo Múltiple/fisiopatología , Choque Hemorrágico/patología , Porcinos , Traumatismos Torácicos/fisiopatología , Tomografía , Tomografía Computarizada por Rayos X , Heridas no Penetrantes/fisiopatologíaAsunto(s)
Cianuro de Hidrógeno/toxicidad , Hipoxia Encefálica/diagnóstico , Imagen por Resonancia Magnética , Tomografía Computarizada por Rayos X , Adulto , Contaminantes Ocupacionales del Aire/farmacocinética , Contaminantes Ocupacionales del Aire/toxicidad , Asfixia/sangre , Asfixia/diagnóstico , Diagnóstico Diferencial , Femenino , Humanos , Cianuro de Hidrógeno/farmacocinética , Hipoxia Encefálica/sangre , Ácido Láctico/sangre , Masculino , Persona de Mediana Edad , Enfermedades Profesionales/sangre , Enfermedades Profesionales/inducido químicamente , Enfermedades Profesionales/diagnóstico , Emisiones de Vehículos/toxicidad , SoldaduraRESUMEN
Thecocodium quadratum (Werner, Jber. Biol. Anst. Helgoland, 1965) is a colonial hydroid which produces 2 different types of polyps: gastrogonozooids and dactylozooids. The mouthless dactylozooids bear tentacles and catch the prey, which is then taken over and swallowed by the gastrogonozooids which have no tentacles. It is obvious that for a colony to survive both polyps must exist simultaneously arranged in a certain spatial pattern. Our experiments indicate that the formation of polyps in a growing culture is governed by at least 3 principles: (1) short range inhibition between polyps irrespective of their differentiation; (2) long range specific inhibition between gastrogonozooids; and (3) long range supporting influence (lateral help, Meinhardt, H., Models of Biological Pattern Formation, 1982) between gastrogonozooids and dactylozooids.
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Hydra/crecimiento & desarrollo , Animales , Técnica del Anticuerpo Fluorescente , Hydra/anatomía & histología , Sistema Nervioso/química , Neuropéptidos/análisisRESUMEN
Soft robots can exhibit diverse behaviors with simple types of actuation by partially outsourcing control to the morphological and material properties of their soft bodies, which is made possible by the tight coupling between control, body, and environment. In this paper, we present a method that will quantitatively characterize these diverse spatiotemporal dynamics of a soft body based on the information-theoretic approach. In particular, soft bodies have the ability to propagate the effect of actuation through the entire body, with a certain time delay, due to their elasticity. Our goal is to capture this delayed interaction in a quantitative manner based on a measure called momentary information transfer. We extend this measure to soft robotic applications and demonstrate its power using a physical soft robotic platform inspired by the octopus. Our approach is illustrated in two ways. First, we statistically characterize the delayed actuation propagation through the body as a strength of information transfer. Second, we capture this information propagation directly as local information dynamics. As a result, we show that our approach can successfully characterize the spatiotemporal dynamics of the soft robotic platform, explicitly visualizing how information transfers through the entire body with delays. Further extension scenarios of our approach are discussed for soft robotic applications in general.
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Biomimética/métodos , Extremidades/fisiología , Almacenamiento y Recuperación de la Información/métodos , Octopodiformes/fisiología , Robótica/instrumentación , Robótica/métodos , Animales , Simulación por Computador , Módulo de Elasticidad , Modelos BiológicosRESUMEN
PURPOSE: External fixators are easy to apply and maximize soft tissue preservation. However, frames need providing an adequate stiffness in order to avoid excessive interfragmentary movement during the healing period. We characterized the stiffness of four different configurations of the newly developed Hoffmann 3 external fixation system. METHODS: A synthetic fracture gap model was stabilized using four different frame configurations: a double-∅ 11 mm rod configuration (group DR), a hybrid double-∅ 8 mm rod configuration (group H), a single ∅ 11 mm rod direct link configuration (group DL) and a single ∅ 11 mm rod side arm configuration (group SA). The stiffness of each configuration was measured under anterior-posterior bending, medial-lateral bending and axial torsion loading directions and the results statistically compared. RESULTS: The basic frame construct (group DR) showed the highest bending and torsional stiffness properties while the single rod side arm configuration (group SA) the lowest. CONCLUSIONS: The diameter and the amount of used connecting rods as well as the adequate placement of these rods towards the main loading directions determine the construct stiffness. These results could help the surgeons estimating how different frames can potentially affect the interfragmentary motion. This information might help in choosing specific configuration when treating different fracture types on given patients.