Lynx eats cat: disease risk assessment during an Iberian lynx intraguild predation.

Lethal interactions between members of the carnivore guild are well represented in literature. In the Iberian lynx, interspecific killing (without prey consumption) of some mesocarnivores, such as the Egyptian mongoose, genet, and red fox, has been reported. Although vaguely documented, evidence suggests feral cats fall victim to interactions with this apex predator. Here, we describe the first documented case of interspecific killing and partial consumption of a feral cat by an adult male Iberian lynx reintroduced in Southwestern Spain. Ulterior analyses demonstrated that the victim was viremic to feline leukemia virus. To prevent the dissemination of the virus and a potential outbreak in the Iberian lynx population, control measures, including the clinical evaluation of the male Iberian lynx, and intensive monitoring were implemented in order to detect intraspecific interactions. After 3 weeks, the lynx was evaluated, presented good condition and resulted negative to both ELISA and RT-PCR. Thanks to the long-term monitoring, this case could be detected and measures to prevent an outbreak could be implemented.

Differentiation of mesenchymal stem cells for cartilage tissue engineering: Individual and synergetic effects of three-dimensional environment and mechanical loading.

Chondrogenesis of dedifferentiated chondrocytes and mesenchymal stem cells is influenced not only by soluble molecules like growth factors, but also by the cell environment itself. The latter is achieved through both mechanical cues - which act as stimulation factor and influences nutrient transport - and adhesion to extracellular matrix cues - which determine cell shape. Although the effects of soluble molecules and cell environment have been intensively addressed, few observations and conclusions about the interaction between the two have been achieved. In this work, we review the state of the art on the single effects between mechanical and biochemical cues, as well as on the combination of the two. Furthermore, we provide a discussion on the techniques currently used to determine the mechanical properties of materials and tissues generated in vitro, their limitations and the future research needs to properly address the identified problems. STATEMENT OF SIGNIFICANCE: The importance of biomechanical cues in chondrogenesis is well known. This paper reviews the existing literature on the effect of mechanical stimulation on chondrogenic differentiation of mesenchymal stem cells in order to regenerate hyaline cartilage. Contradictory results found with respect to the effect of different modes of external loading can be explained by the different properties of the scaffolding system that holds the cells, which determine cell adhesion and morphology and spatial distribution of cells, as well as the stress transmission to the cells. Thus, this review seeks to provide an insight into the interplay between external loading program and scaffold properties during chondrogenic differentiation. The review of the literature reveals an important gap in the knowledge in this field and encourages new experimental studies. The main issue is that in each of the few cases in which the interplay is investigated, just two groups of scaffolds are compared, leaving intermediate adhesion conditions out of study. The authors propose broader studies implementing new high-throughput techniques for mechanical characterization of tissue engineering constructs and the inclusion of fatigue analysis as support methodology to more exhaustive mechanical characterization.

Design and validation of a biomechanical bioreactor for cartilage tissue culture.

Specific tissues, such as cartilage, undergo mechanical solicitation under their normal performance in human body. In this sense, it seems necessary that proper tissue engineering strategies of these tissues should incorporate mechanical solicitations during cell culture, in order to properly evaluate the influence of the mechanical stimulus. This work reports on a user-friendly bioreactor suitable for applying controlled mechanical stimulation--amplitude and frequency--to three-dimensional scaffolds. Its design and main components are described, as well as its operation characteristics. The modular design allows easy cleaning and operating under laminar hood. Different protocols for the sterilization of the hermetic enclosure are tested and ensure lack of observable contaminations, complying with the requirements to be used for cell culture. The cell viability study was performed with KUM5 cells.

In vitro mechanical fatigue behavior of poly-ɛ-caprolactone macroporous scaffolds for cartilage tissue engineering: Influence of pore filling by a poly(vinyl alcohol) gel.

Polymeric scaffolds used in regenerative therapies are implanted in the damaged tissue and submitted to repeated loading cycles. In the case of articular cartilage engineering, an implanted scaffold is typically subjected to long-term dynamic compression. The evolution of the mechanical properties of the scaffold during bioresorption has been deeply studied in the past, but the possibility of failure due to mechanical fatigue has not been properly addressed. Nevertheless, the macroporous scaffold is susceptible to failure after repeated loading-unloading cycles. In this work fatigue studies of polycaprolactone scaffolds were carried by subjecting the scaffold to repeated compression cycles in conditions simulating the scaffold implanted in the articular cartilage. The behavior of the polycaprolactone sponge with the pores filled with a poly(vinyl alcohol) gel simulating the new formed tissue within the pores was compared with that of the material immersed in water. Results were analyzed with Morrow's criteria for failure and accurate fittings are obtained just up to 200 loading cycles. It is also shown that the presence of poly(vinyl alcohol) increases the elastic modulus of the scaffolds, the effect being more pronounced with increasing the number of freeze/thawing cycles.

Fatigue prediction in fibrin poly-ε-caprolactone macroporous scaffolds.

Tissue engineering applications rely on scaffolds that during its service life, either for in-vivo or in vitro applications, are under loading. The variation of the mechanical condition of the scaffold is strongly relevant for cell culture and has scarcely been addressed. The fatigue life cycle of poly-ε-caprolactone, PCL, scaffolds with and without fibrin as filler of the pore structure were characterized both dry and immersed in liquid water. It is observed that the there is a strong increase from 100 to 500 in the number of loading cycles before collapse in the samples tested in immersed conditions due to the more uniform stress distributions within the samples, the fibrin loading playing a minor role in the mechanical performance of the scaffolds.

Fibronectin adsorption and cell response on electroactive poly(vinylidene fluoride) films.

Due to the large potential of electroactive materials in novel tissue engineering strategies, the aim of this work is to determine if the crystalline phase and/or the surface electrical charge of electroactive poly(vinylidene fluoride), PVDF, have influence on the biological response in monolayer cell culture. Non-polar α-PVDF and electroactive ß-PVDF were prepared. The ß-PVDF films were poled by corona discharge to show negative or positive electrical surface charge density. It has been concluded that hydrophilicity of the PVDF substrates depends significantly on crystalline phase and polarity. Furthermore, by means of atomic force microscopy and an enzyme-linked immunosorbent assay test, it has been shown that positive or negative poling strongly influences the behavior of ß-PVDF supports with respect to fibronectin (FN) adsorption, varying the exhibition of adhesion ligands of adsorbed FN. Culture of MC3T3-E1 pre-osteoeblasts proved that cell proliferation depends on surface polarity as well. These results open the viability of cell culture stimulation by mechanical deformation of a piezoelectric substrate that results in varying electrical charge densities on the substrate surface.

Catéteres tunelizados. Complicaciones en su inserción / No disponible

Introducción: La creación de accesos vasculares para hemodiálisis en pacientes afectos de insuficiencia renal terminal, se presenta periódicamente como un problema. Por ello, la disponibilidad de alternativas a la fístula arteriovenosa es algo necesario; distintos tipos de catéteres tunelizados se vienen desarrollando, entre los cuales el catéter de Tesio es el mejor conocido y utilizado. Frecuentemente es implantado por cirujanos vasculares o radiólogos, lo que conlleva una dependencia para los servicios de nefrología que puede retrasar la obtención del nuevo acceso vascular y el inicio o reinicio de tratamiento. Material y métodos: Se realizó un estudio descriptivo con el objetivo de analizar las complicaciones inmediatas durante la inserción de catéteres centrales tunelizados para hemodiálisis y evaluar la posibilidad de su consecución por nefrólogos y personal especialista en diálisis. Entre enero de 2003 y diciembre de 2005 se implantaron 175 catéteres centrales tunelizados de Tesio en nuestra unidad de hemodiálisis. Se registró edad y sexo del paciente, tiempo en diálisis, diagnóstico de hipertensión, diabetes mellitus o cardiopatía previa, antecedentes de tratamiento anticoagulante o antiagregante, dificultad percibida por el nefrólogo para el desarrollo de la técnica, sangrado, presión arterial sistólica y diastólica, frecuencia cardíaca, saturación de oxígeno y cambios en la monitorización de ECG, al inicio de la intervención, durante la canalización de la vena, inserción del dilatador y catéter, y al final de la misma. Resultados: Los pacientes fueron 88 hombres y 82 mujeres, con media de edad de 64 años. El 21% de los pacientes llevaban habitualmente tratamiento con antiagregante o anticoagulante, que había sido retirado en los días previos. El tamaño ecográfico de la vena era mayor de 1 cm en el 79% de los casos. De 175 inserciones sólo 3 pacientes (2%) presentaron signos de inestabilidad hemodinámica, dos de ellos por descenso de tensión arterial y uno por descenso de saturación de oxígeno; ninguno de ellos requirió soporte asistido, no apareció hemorragia ni otras complicaciones. Conclusiones: La implantación de catéteres tunelizados, bajo anestesia local, presenta mínimas complicaciones e incidencias durante su inserción. Puede llevarse a cabo por un nefrólogo y personal especializado, en hospitales con el respaldo de unidades que permitan abordar las posibles complicaciones (AU)

Introduction: The creation of vascular accesses for hemodialysis in patients affected with terminal kidney failure affections, is presented periodically as a problem. Because of it, the availability of alternatives to the arteriovein fistula is something necessary; different types of tunnelled dialysis catheters are being developed, among which the Tesio catheter is the most well known and most widely utilized. Often it is implanted by vascular surgeons or radiologists; this creates dependence for the nephrology services that can delay obtaining the new vascular access and initiating or reinitiating the treatment. Material and methods: A descriptive study with the objective of analyzing the immediate complications during the insertion of tunnelled central catheters for hemodialysis and to evaluate the possibility of its attainment was carried out by nephrologists and personnel specialized in dialysis. Between january of 2003 and december of 2005, 175 Tesio tunnelled central catheters were implanted in our hemodialysis unit. Age and sex of the patient was registered, time in dialysis, diagnosis of hypertension, diabetes mellitus or prior heart disease, previous anticoagulant or platelet antiaggregate treatment, difficulty perceived by the nephrologist for the development of the technique, bleeding, systolic and diastolic arterial pressure, cardiac frequency, oxygen saturation and changes in the monitoring of electrocardiogram, at the beginning of the intervention, during the channelling of the vein, insertion of the dilatators and catheter, and at the end of it. Results: The patients were 88 men and 82 women, with an average of age of 64. 21% of the patients habitually followed a treatment with platelet antiaggregate or anticoagulant, which had been withdrawn in the prior days. The ultrasound size of the vein was greater than one cm in 79% of the cases. Of 175 insertions only three patients (2%) presented signs of hemodynamic instability, two of them due to a descent of arterial tension and one by oxygen saturation descent; none of them required assisted backup, neither hemorrhage nor other complications appeared. Conclusions: The implant of tunnelled catheters, under local anesthesia, presents minimal complications and incidents during its insertion. It can be carried out by a nephrologist and specialized personnel, in hospitals with backup units that can undertake any possible complications (AU)

[Tunneled catheters. Complications during insertion]. / Catéteres tunelizados. Complicaciones en su inserción.

INTRODUCTION: The creation of vascular accesses for hemodialysis in patients affected with terminal kidney failure affections, is presented periodically as a problem. Because of it, the availability of alternatives to the arteriovein fistula is something necessary; different types of tunnelled dialysis catheters are being developed, among which the Tesio catheter is the most well known and most widely utilized. Often it is implanted by vascular surgeons or radiologists; this creates dependence for the nephrology services that can delay obtaining the new vascular access and initiating or reinitiating the treatment. MATERIAL AND METHODS: A descriptive study with the objective of analyzing the immediate complications during the insertion of tunnelled central catheters for hemodialysis and to evaluate the possibility of its attainment was carried out by nephrologists and personnel specialized in dialysis. Between January of 2003 and December of 2005, 175 Tesio tunnelled central catheters were implanted in our hemodialysis unit. Age and sex of the patient was registered, time in dialysis, diagnosis of hypertension, diabetes mellitus or prior heart disease, previous anticoagulant or platelet antiaggregate treatment, difficulty perceived by the nephrologist for the development of the technique, bleeding, systolic and diastolic arterial pressure, cardiac frequency, oxygen saturation and changes in the monitoring of electrocardiogram, at the beginning of the intervention, during the channelling of the vein, insertion of the dilatators and catheter, and at the end of it. RESULTS: The patients were 88 men and 82 women, with an average of age of 64. 21% of the patients habitually followed a treatment with platelet antiaggregate or anticoagulant, which had been withdrawn in the prior days. The ultrasound size of the vein was greater than one cm in 79% of the cases. Of 175 insertions only three patients (2%) presented signs of hemodynamic instability, two of them due to a descent of arterial tension and one by oxygen saturation descent; none of them required assisted backup, neither hemorrhage nor other complications appeared. CONCLUSIONS: The implant of tunnelled catheters, under local anesthesia, presents minimal complications and incidents during its insertion. It can be carried out by a nephrologist and specialized personnel, in hospitals with backup units that can undertake any possible complications.

Radiografía de tórax

No disponible

Ventilación mecánica no invasiva. Utilidad clínica enurgencias y emergencias / Non-invasive mechanical ventilation. Clinical utility in urgencias and emergencias

La ventilación mecánica no invasiva (VMNI) es una modalidad ventilatoria en la cual la interfase entre el ventilador y el paciente es una máscara nasal o facial. Esto evita muchas de las complicaciones de la ventilación mecánica convencional ligadas fundamentalmente a la intubación endotraqueal y la sedorrelajación del enfermo. Con VMNI el paciente mantiene intactos los mecanismos de defensa de la vía aérea, el habla y la deglución. La forma de administrar VMNI suele ser mediante presión de soporte durante la inspiración y presión positiva (PEEP) en la espiración (ésta es la modalidad conocida con las siglas BIPAP), o mediante presión positiva continua en la vía aérea (CPAP).Otras formas, como la ventilación con presión positiva intermitente con máscara facial o nasal se puede también emplear, aunque se utiliza menos. La principal indicación la constituye la insuficiencia respiratoria aguda con hipercapnia, aunque también puede ser utilizada en el fracaso respiratorio hipoxémico. En los pacientes con autoPEEP proporciona descanso a la musculatura respiratoria y mejora notablemente el intercambio de gases. Esta forma de ventilación mecánica se está empezando a utilizar en los servicios de urgencia y emergencia, evitando en muchos casos el ingreso del paciente en la unidad de cuidados intensivos y acortando la estancia en el hospital. El médico de urgencias debe conocer esta técnica de terapia respiratoria y administrarla precozmente al paciente en insuficiencia respiratoria, y no esperar a una situación de preintubación (AU)

[Association of metabolic risk factors and blood pressure in a natural population (Mora de Toledo)]. / Asociación de los factores de riesgo metabólico y presiones arteriales en una población natural (Mora de Toledo).

OBJECTIVE: Evaluate relationships between the next variables in an adult natural population: total cholesterol, LDL-cholesterol, HDL-cholesterol, triglicerides, total cholesterol/HDL-cholesterol and glucose blood levels with blood pressure (systolic and diastolic). DESIGN: A crossover observation study with descriptive and analytic components. PATIENTS: Random sample of 251 individuals taken from census and representative of the adult general population from Mora de Toledo (with 10,000 inhabitants approximately). SETTING: A medical station in a health centre. MEASUREMENTS AND MAIN RESULTS: Blood pressure measurements and lipids and glucose blood levels were got in the selected patients. Some positive and significant relationships were got in the adult population from Mora de Toledo between systolic and diastolic blood pressure with the next variables: total cholesterol, LDL-cholesterol, total cholesterol/HDL-cholesterol, triglicerides and glucose blood levels. These associations are stronger in young people from 21-40 years-old. When we consider the relationship with HDL-cholesterol, we can see it is mildly positive but not significant. CONCLUSION: These results agree with others encountered in different countries and support the hypothesis that there is an association between blood pressure and the cardiovascular metabolic risk factors.

Renal insufficiency and fosfomycin.

After the parenteral injection of 1 g sodium salt of fosfomycin the serum levels of the antibiotic are detected in a series of eight adult patients with different degrees of chronic renal insufficiencies four of them submitted to periodical dialysis. The results obtained reveal that the levels as well as the time of elimination of fosfomycin maintain an obvious relation to the degree of renal insufficiency in the patients.