Microplastics do not increase bioaccumulation of petroleum hydrocarbons in Arctic zooplankton but trigger feeding suppression under co-exposure conditions.

Arctic sea ice has alarmingly high concentrations of microplastics (MPs). Additionally, sea ice reduction in the Arctic is opening new opportunities for the oil and maritime industries, which could increase oil pollution in the region. Yet knowledge of the effects of co-exposure to MPs and crude oil on Arctic zooplankton is lacking. We tested the influence of MPs (polyethylene, 20.7 µm) on polycyclic aromatic hydrocarbon (PAH) bioaccumulation and oil toxicity in the key arctic copepod Calanus hyperboreus after exposure to oil with and without dispersant. Up to 30% of the copepods stopped feeding and fecal pellet production rates were reduced after co-exposure to oil (1 µL L-1) and MPs (20 MPs mL-1). The PAH body burden was ~3 times higher in feeding than in non-feeding copepods. Copepods ingested both MPs and crude oil droplets. MPs did not influence bioaccumulation of PAHs in copepods or their fecal pellets, but chemical dispersant increased bioaccumulation, especially of ≥4 ring-PAHs. Our results suggest that MPs do not act as vectors of PAHs in Arctic marine food webs after oil spills, but, at high concentrations (20 MPs mL-1), MPs can trigger behavioral stress responses (e.g., feeding suppression) to oil pollution in zooplankton.

[External fixation with reconstruction rail system as a treatment for pseudoarthrosis of the distal femur]. / Fijación externa con sistema de riel de reconstrucción como tratamiento para seudoartrosis del fémur distal.

Distal femur pseudoarthrosis also called «distal femur non-union¼ (DFNU) represents a rare complication associated with a fracture caused by high-energy trauma; its treatment is controversial, as there is a wide variety of surgical techniques that can be implemented, from open reduction plus internal fixation with plates, to the use of fixed angle plates combined with bone autograft. We expose the case of a 24-year-old man who shows up for consultation with the history of having presented a left femoral supracondylar fracture with a year of evolution, treated by osteosynthesis of the distal femur with dynamic condylar screws (DCS plate); developed a torpid evolution with severe pain in the distal third of the left thigh and functional limitation, developed a progressive varus deformity of the left thigh that caused a shortening of 3.8 cm of the limb. A focus of pseudoarthrosis was identified, which was surgically removed, the intramedullary canal was recanalized, and a lateral closed wedge osteotomy was performed to correct the angulation and allow reduction. 5.5 mm (three proximal and three distal) hydroxyapatite screws and an external fixator were placed. In addition, a review of the literature focused on the use of external fixation was carried out as a treatment for the pseudoarthrosis of the distal femur.

La seudoartrosis del fémur distal, también llamada «no unión del fémur distal¼ (NUFD), representa una complicación poco frecuente asociada a una fractura causada por un traumatismo de alta energía; su tratamiento es controversial, ya que existe una gran variedad técnicas quirúrgicas que pueden ser implementadas desde la reducción abierta más la fijación interna con placas hasta el uso de placas de ángulo fijo combinadas con autoinjerto óseo. Exponemos el caso de un hombre de 24 años de edad, el cual se presenta a la consulta con el antecedente de haber sufrido una fractura supracondílea femoral izquierda con un año de evolución, tratada mediante una osteosíntesis del fémur distal con tornillos condilares dinámicos (placa DCS); mostró una evolución tórpida con dolor severo en el tercio distal del muslo izquierdo y limitación funcional, desarrolló una deformidad en varo progresiva del muslo izquierdo que causó un acortamiento de 3.8 cm de la extremidad. Se identificó un foco de seudoartrosis, el cual se retiró quirúrgicamente, se recanalizó el canal intramedular y se realizó una osteotomía de cuña cerrada lateral para corregir la angulación y permitir la reducción. Se colocaron tornillos de hidroxiapatita de 5.5 mm (tres proximales y tres distales) y un fijador externo. Además se hizo una revisión de la literatura enfocada en el uso de la fijación externa como tratamiento de la seudoartrosis del fémur distal.

Total and regional bone mineral content in healthy Spanish subjects by dual-energy X-ray absorptiometry.

DESIGN: This is an observational cross-sectional study. OBJECTIVE: The aim of the present study was to describe and analyze patterns of change in total and regional bone mineral content in relation to age and gender in a sedentary Spanish sample population (from the Community of Madrid). The age range of the sample population was from birth to 80 years. MATERIALS AND METHODS: One thousand one hundred twenty healthy subjects were recruited and divided into 16 groups according to age. Each subject underwent whole-body densitometry using dual-energy X-ray absorptiometry. An analysis was made of the amount of bone mineral content (BMC) in the whole body and in different regions: the head, trunk, upper limbs, and lower limbs. RESULTS: Gender differences in mean values for upper limbs and lower limbs are statistically significant between 16 and 70 years of age. For the head and trunk, the mean BMC values show the most significant gender differences between 16 and 25 years of age (p

Pediatric cardiac resuscitation team: a 6 year study.

A cardiopulmonary resuscitation team based in the pediatric intensive care unit responded to 239 cardiac arrests over a 6 year period. Patients with respiratory problems and infectious diseases requiring isolation composed the largest groups in whom unexpected arrests occurred. There was a 78 per cent rate of initial response to therapy and a 47 per cent survival rate. This is almost twice the survival rate of the best previously reported study and five times the average.

Changes in walking pattern between five and six years of age.

A study was carried out of the parameters of the ground reaction forces and temporal and spatial walking parameters of 62 children aged between five and six years. The children were evaluated barefoot, walking freely at normal speed over the surface of two platforms. The aims were to establish normal parameters for children of this age and to identify any differences existing between these ages. Differences were noticeable in the kinetic and temporal and spatial walking parameters, indicating that maturation has not yet been completed at these ages.

Densitometric analysis of the human calcaneus.

A densitometric study was performed on 50 dry calcanei to assess bone mineral density (BMD) in the constituent regions of the bone. In the lateral projection, the area with the highest BMD was the anterosuperior region, where the greatest concentration of trabeculae occurs. The areas with the least BMD were the intermediate or retrothalamic and the anteroinferior regions, where the neutral triangle is situated. In the dorsoplantar projection, a greater BMD was observed in the intermediate and middle regions, whereas the anterior region showed the lowest BMD. These results conform to the arrangement previously described for the trabecular system. It is concluded that bone densitometry, measured by dual x-ray absorptiometry, is useful for assessing trabecular architecture of the calcaneus.