Magnetic and elemental characterization of the particulate matter deposited on leaves of urban trees in Santiago, Chile.

Airborne particulate matter is a serious threat to human health, especially in fast-growing cities. In this study, we carried out a magnetic and elemental study on tree leaves used as passive captors and urban dust from various sites in the city of Santiago, Chile, to assess the reliability of magnetic and elemental measurements to characterize particulate matter pollution from vehicular origin. We found that the magnetic susceptibility and saturation isothermal remanent magnetization measured on urban tree leaves is a good proxy for tracing anthropogenic metallic particles and allow controlling the exposure time for particulate matter collection, in agreement with other studies carried out in large cities. Similar measurements on urban soil can be influenced by particles of detritic (natural) origin, and therefore, magnetic measurements on tree leaves can help to identify hotspots where fine particles are more abundant. Elemental particle-induced X-ray emission analysis of tree leaves showed the presence of a number of elements associated with vehicular emissions, in particular Cu, Zn, Fe, K and S which are present at every site, and As, Se, V, Ni, Sr, Zr, Mo and Pb identified at some sites. We observed a correlation between magnetic parameters and the concentrations of S and Br as well as Cu to a smaller extent. Moreover, this study shows the importance of selecting carefully the tree species as well as the location of trees in order to optimize phytoremediation.

Barking up the Right Tree: Using Tree Bark to Track Airborne Particles in School Environment and Link Science to Society.

Children's exposure to air pollution affects both their health and learning skills. Fine and ultrafine particulate matter (PM2.5, PM1), notably issued from traffic sources in urban centers, belong to the most potential harmful health hazards. However their monitoring and the society's awareness on their dangers need to be consolidated. In this study, raising teacher and pupil involvement for air quality improvement in their schools environment is reached through developing a passive monitoring technique (bio-sensors made of tree bark). The experiment was implemented in two urban elementary schools situated close to a main traffic road of the city of Toulouse (South of France). Magnetic properties, carbonaceous fraction measurements, and scanning electronic microscopy (SEM-EDX) investigations were realized both on passive bio-sensors and filters issued from active sampling. We find that traffic is the main PM1 source for both outdoors and indoors at schools. Higher levels of outdoor PM in the school's environments compared to urban background are reached especially in the cold period. The schools proximity to a main traffic source and lack of ventilation are the main causes for observed PM1 accumulation in classrooms. The co-working experiment with educational teams and pupils shows that the use of bio-sensors is a driver for children empowerment to air pollution and therefore represents a potential key tool for the teachers though limiting eco-anxiety. As PM accumulation is observed in many scholar environments across Europe, the proposed methodology is a step toward a better assessment of PM impact on pupil's health and learning skills.

Methylphenidate amplifies long-term potentiation in rat hippocampus CA1 area involving the insertion of AMPA receptors by activation of ß-adrenergic and D1/D5 receptors.

Methylphenidate (MPH, Ritalin©) is widely used in the treatment of Attention Deficit Hyperactivity Disorder and recently as a drug of abuse. Although the effect of MPH has been studied in brain regions such as striatum and prefrontal cortex (PFC), the hippocampus has received relatively little attention. It is known that MPH increases the TBS-dependent Long Term Potentiation (LTP) in the CA1 area. However, the cellular and molecular mechanisms involved in this process are still unknown. Using field potential recordings and western blot analysis in rat hippocampal slices of young rats, we found that acute application of MPH enhances LTP in CA3-CA1 synapses in a dose-dependent manner with an EC50 of 73.44±6.32 nM. Using specific antagonists and paired-pulse facilitation protocols, we observed that the MPH-dependent increase of LTP involves not only ß-adrenergic receptors activation but also post-synaptic D1/D5 dopamine receptors. The inhibition of PKA with PKI, suppressed the facilitation of LTP induced by MPH consistent with an involvement of the adenyl cyclase-cAMP-PKA dependent cascade downstream of the activation of D1/D5 receptors. In addition, samples of CA1 areas taken from slices potentiated with MPH presented an increase in the phosphorylation of the Ser845 residue of the GluA1 subunit of AMPA receptors compared to control slices. This effect was reverted by SCH23390, antagonist of D1/D5 receptors, and PKI. Moreover, we found an increase of surface-associated functional AMPA receptors. We propose that MPH increases TBS-dependent LTP in CA3-CA1 synapses through a polysynaptic mechanism involving activation of ß-adrenergic and D1/D5 dopaminergic receptors and promoting the trafficking and insertion of functional AMPA receptors to the plasma membrane.

Improved survival in steroid-refractory acute graft versus host disease after non-myeloablative allogeneic transplantation using a daclizumab-based strategy with comprehensive infection prophylaxis.

Approximately 15% of patients undergoing non-myeloablative allogeneic haematopoietical cell transplantation (NMHCT) develop steroid-refractory acute-graft versus host disease (aGVHD), a usually fatal complication. We encountered 18 cases of steroid-refractory aGVHD in 146 patients, undergoing NMHCT from a related human leucocyte antigen-compatible donor following cyclophosphamide/fludarabine-based conditioning. Our initial cohort of steroid-refractory aGVHD patients treated with antithymocyte globulin (ATG) and mycophenolate mofetil (regimen-1: n = 6) had high GVHD-related mortality. Therefore, we investigated an alternative strategy for subsequent patients developing this complication (regimen-2: n = 12), consisting of daclizumab (alone or combined with infliximab/ATG) and targeted broad spectrum antibacterial and aspergillus prophylaxis in conjunction with rapid tapering of steroids to minimize opportunistic infections. In a retrospective analysis, patients receiving regimen-2 were significantly more likely to have complete resolution of GVHD compared with those receiving regimen-1 [12/12 (100%) vs. 1/6 (17%); P < 0.001]. When compared with those receiving regimen-1, regimen-2 patients also had a higher probability of survival at day 100 (100% vs. 50%) and day 200 (73% vs. 17%) post-transplant, and improved overall survival (median 453 d vs. 42 d from aGVHD onset; P < 0.0001). GVHD-related mortality was 89% for regimen-1 patients vs. 17% for regimen-2 patients (P < 0.0001). These data suggest that a co-ordinated approach using immunoregulatory monoclonal antibodies, pre-emptive antimicrobial therapy and judicious steroid withdrawal can dramatically improve outcome in steroid-refractory aGVHD.

[Patients with acute adult respiratory distress syndrome: effects of inhaled nitric oxide on gas exchange and hemodynamics]. / Pacientes con síndrome de distress respiratorio agudo del adulto: efectos del óxido nítrico inhalado sobre el intercambio gaseoso y la hemodinamia.

BACKGROUND: Adult respiratory distress syndrome is highly prevalent in intensive care units and has a high mortality. Lately, nitric oxide has been used as adjuvant therapy. AIM: To study the effects of nitric oxide inhalation in patients with adult respiratory distress syndrome. PATIENTS AND METHODS: Twelve patients with adult respiratory distress syndrome, were subjected to nitric oxide inhalation at a concentration of 10 parts per million, during 30 minutes. RESULTS: At the end of the nitric oxide inhalation period, there was an improvement of PaO2/FIO2 ratio from 89 +/- 32 to 111 +/- 43 mm Hg and a 16% reduction of lung shunting (Qs/Qt). CONCLUSIONS: Nitric oxide inhalation at a concentration of 10 parts per million improved arterial oxygenation and reduced pulmonary shunting in patients with adult respiratory distress syndrome.

[Prolonged inhalation of nitric oxide in adult respiratory distress syndrome in a case]. / Inhalación prolongada de óxido nítrico en el distress respiratorio agudo del adulto en un caso.

Inhalation therapy with nitric oxide has been suggested as beneficial in the adult respiratory distress syndrome, however there are few reports of its prolonged use. We report a patient with a chronic lymphocytic leukemia that developed an adult respiratory distress syndrome with severe hypoxemia, refractory to conventional therapeutic measures, during the course of a septic shock. The patient received nitric oxide (19 ppm) improving arterial oxygen saturation and allowing the reduction of FiO2 to 40%. The patient died five days later due to a multiple organ failure.

Cirugía conservadora en cáncer renal / Conservative surgery in renal cancer

El incremento de los cánceres incidentales del riñón podría significar un aumento de la cirugía conservadora en el tratamiento del cáncer renal. Se analiza una serie constituida por 15 casos de la cirugía conservadora en el tratamiento de cánceres renales durante 11 años. Corresponde a alrededor del 8 por ciento del total de operaciones por cáncer renal en ese período. En once oportunidades debió realizarse este tipo de intervenciones por tumores bilaterales sincrónicos (9 casos) o monorrenos reales o funcionales (2 casos). Solo 4 pacientes fueron sometidos a cirugía conservador por tumor unilateral pequeño. Del total de tumores renales incidentales Grado I de Robson (18 casos), candidatos a cirugía parcial, solo se realizó ésta en el 22 por ciento dadas las características de localización y tamaño del tumor. El tiempo de seguimiento para los 15 pacientes varió entre 4 y 119 meses. La sobrevida actuarial es del 93 por ciento. Se discuten las indicaciones, ventajas e inconvenientes de este tipo de tratamiento de los cánceres renales a la luz del claro incremento de los tumores incidentales renales