Redistribution of Cs 137 introduced into montmorillonite in association with organic matter coming from biomass composting.

The adsorption and later bioavailability of 137Cs from the system humic acid (HA)/humic acid like compounds (HALC) and montmorillonite was investigated. The setup of the experiments should approach as much as possible natural conditions when 137Cs is introduced into soil with HALC from decomposed biomass. The significant differences were found in the trials containing various HA/HALC and also pure montmorillonite. The 137Cs was more available when it reached soil in association with HALC originated from compost than when it was adsorbed on stable humic acids. Moreover, the long term interaction of 137Cs with HALC led to decrease of 137Cs adsorbed on montmorillonite and increase of its bioavailable fraction. UV-Vis spectrometry and infrared spectroscopy showed the clear difference between HA, fresh HALC and old HALC which could partially explain the different results.

Infección sistémica por citomegalovirus: influencia del tratamiento con foscarnet en los niveles plasmáticos de calcio y magnesio / Systemic cytomegalovirus infection: Changes in serum calcium and magnesium levels with foscarnet treatment

La infección por citomegalovirus es frecuente en pacientes trasplantados cardiacos. Foscarnet se utiliza, con evidencia limitada, como tratamiento de segunda línea tras el fracaso de ganciclovir en estos pacientes. Presentamos un caso de alteraciones electrolíticas por foscarnet administrado para el tratamiento de infección por citomegalovirus en un paciente pediátrico trasplantado cardiaco. La infección se resolvió tras 6 semanas de tratamiento, apareciendo niveles de calcio iónico bajos durante la infusión del fármaco e hipomagnesemia mantenida tratada con suplementos, que revirtieron al retirar el fármaco

Cytomegalovirus infection is common in cardiac transplant patients. Foscarnet is used, with limited evidence, as second-line treatment after ganciclovir failure in these patients. We describe the case of a paediatric cardiac transplant patient who developed electrolyte disturbances during foscarnet treatment for cytomegalovirus infection. The infection resolved after 6 weeks of treatment. Low ionized calcium and magnesium levels were observed during the drug infusion, which were treated with supplements. The serum levels reverted to normal after drug withdrawal

[Systemic cytomegalovirus infection: changes in serum calcium and magnesium levels with foscarnet treatment]. / Infección sistémica por citomegalovirus: influencia del tratamiento con foscarnet en los niveles plasmáticos de calcio y magnesio.

Cytomegalovirus infection is common in cardiac transplant patients. Foscarnet is used, with limited evidence, as second-line treatment after ganciclovir failure in these patients. We describe the case of a paediatric cardiac transplant patient who developed electrolyte disturbances during foscarnet treatment for cytomegalovirus infection. The infection resolved after 6 weeks of treatment. Low ionized calcium and magnesium levels were observed during the drug infusion, which were treated with supplements. The serum levels reverted to normal after drug withdrawal.

Morbimortalidad asociada al daño renal agudo en pacientes ingresados en unidades de cuidados intensivos pediátricos / Morbimortality associated to acute kidney injury in patients admitted to pediatric intensive care units

OBJETIVO: Analizar la morbimortalidad asociada a daño renal agudo (DRA) definido por los criterios RIFLE adaptados a Pediatría en los niños que ingresan en la Unidad de Cuidados Intensivos Pediátricos (UCIP). DISEÑO: Estudio retrospectivo de cohorte. Ámbito: UCIP de un hospital terciario. Pacientes o participantes: Trescientos veinte niños ingresados en la UCIP en el año 2011. Se excluyeron los neonatos y los trasplantados renales. Variables principales El DRA fue definido con los criterios RIFLE adaptados a Pediatría. Para la valoración de la morbimortalidad se utilizó la duración de las estancias en la UCIP y en el hospital, la necesidad de ventilación mecánica y la mortalidad. RESULTADOS: Se estudiaron 315 niños, con una mediana de edad de 19 meses (6-72). Presentaron DRA 128 niños (40,6%) (73 en la categoría de Risk [riesgo] y 55 en las categorías Injury [daño] y Failure [fallo]). Los niños con DRA presentaron mayor mortalidad (11,7%) que el resto de pacientes (0,5%), una estancia más prolongada en UCIP (6,0 [4,0-12,5] frente a 3,5 [2,0-7,0] días) y en el hospital (17 (10-32) frente a 10 (7-15] días) y más niños precisaron ventilación mecánica (61,7 frente a 36,9%). El desarrollo de DRA fue un factor independiente de morbilidad, asociado a una mayor estancia en UCIP y hospitalaria y a una ventilación mecánica más prolongada, incrementándose esta morbilidad de forma paralela a la gravedad del daño renal. CONCLUSIÓN: El desarrollo de DRA en niños en estado crítico se asocia a un incremento en la morbimortalidad, que es directamente proporcional a la magnitud de la gravedad del daño renal

AIM: To describe the morbimortality associated to the development of acute kidney injury (AKI) defined by the pediatric adaptation of the RIFLE criteria in a Pediatric Intensive Care Unit (PICU). DESIGN: A retrospective cohort study was carried out. SETTING: Children admitted to a PICU in a tertiary care hospital. Patients or participants A total of 320 children admitted to a tertiary care hospital PICU during the year 2011. Neonates and renal transplant patients were excluded. Primary endpoints AKI was defined and classified according to the pediatric adaptation to the RIFLE criteria. PICU and hospital stays, use of mechanical ventilation and mortality were used to evaluate morbimortality. RESULTS: A total of 315 children met the inclusion criteria, with a median age of 19 months (range 6-72). Of these patients, 128 presented AKI (73 reached the Risk category and 55 reached the Injury and Failure categories). Children with AKI presented a longer PICU stay (6.0 [4.0-12.5] vs. 3.5 [2.0-7.0] days) and hospital stay (17 [10-32] vs. 10 [7-15] days), and a greater need for mechanical ventilation (61.7 vs. 36.9%). The development of AKI was an independent factor of morbidity, associated with a longer PICU and hospital stay, and with a need for longer mechanical ventilation, with a proportional relationship between increasing morbidity and the severity of AKI. CONCLUSION: The development of AKI in critically ill children is associated with increased morbimortality, which is proportional to the severity of renal injury

Morbimortality associated to acute kidney injury in patients admitted to pediatric intensive care units.

AIM: To describe the morbimortality associated to the development of acute kidney injury (AKI) defined by the pediatric adaptation of the RIFLE criteria in a Pediatric Intensive Care Unit (PICU). DESIGN: A retrospective cohort study was carried out. SETTING: Children admitted to a PICU in a tertiary care hospital. Patients or participants A total of 320 children admitted to a tertiary care hospital PICU during the year 2011. Neonates and renal transplant patients were excluded. Primary endpoints AKI was defined and classified according to the pediatric adaptation to the RIFLE criteria. PICU and hospital stays, use of mechanical ventilation and mortality were used to evaluate morbimortality. RESULTS: A total of 315 children met the inclusion criteria, with a median age of 19 months (range 6-72). Of these patients, 128 presented AKI (73 reached the Risk category and 55 reached the Injury and Failure categories). Children with AKI presented a longer PICU stay (6.0 [4.0-12.5] vs. 3.5 [2.0-7.0] days) and hospital stay (17 [10-32] vs. 10 [7-15] days), and a greater need for mechanical ventilation (61.7 vs. 36.9%). The development of AKI was an independent factor of morbidity, associated with a longer PICU and hospital stay, and with a need for longer mechanical ventilation, with a proportional relationship between increasing morbidity and the severity of AKI. CONCLUSION: The development of AKI in critically ill children is associated with increased morbimortality, which is proportional to the severity of renal injury.

Final analysis and results of the Phase II SIMPLE dark matter search.

We report the final results of the Phase II SIMPLE measurements, comprising two run stages of 15 superheated droplet detectors each, with the second stage including an improved neutron shielding. The analyses include a refined signal analysis, and revised nucleation efficiency based on a reanalysis of previously reported monochromatic neutron irradiations. The combined results yield a contour minimum of σp=5.7×10(-3) pb at 35 GeV/c2 in the spin-dependent sector of weakly interacting massive particle (WIMP) proton interactions, the most restrictive to date for MW}≤60 GeV/c2 from a direct search experiment and overlapping, for the first time, with results previously obtained only indirectly. In the spin-independent sector, a minimum of 4.7×10(-6) pb at 35 GeV/c2 is achieved, with the exclusion contour challenging a significant part of the light mass WIMP region of current interest.

Comparison of protocols for walking and running kinematics based on skin surface markers and rigid clusters of markers.

The purpose of this study was to compare the two main types of marker sets for human body representation based on rigid clusters of markers and skin surface markers for measuring kinematics during walking and running. Velocity, body segment, and joint angle were considered in the comparison of both protocols. Six male athletes were studied during treadmill gait at 1.4 and 5.5 m/s and recorded with 8 high speed video cameras. The subjects used simultaneously both protocols in the same walking and running cycles, in order to compare the variability in the determination of the joint centers' positions and the joint angles calculated from each protocol. The three-way ANOVA results showed that the variability of the inter-markers distance in the skin surface protocol was higher than that in the rigid clusters of markers, as reported in the literature. However, no statistical differences between the protocols were found in the variability of the determination of the joint centers' positions. Therefore no advantage was verified to rigid cluster protocols even for the upper body segments. Another conclusion is that increases in velocity produced increases in variability of the joint centers' distances and increases in the maximum differences between the joint angles.

Engraftment syndrome in children undergoing autologous peripheral blood progenitor cell transplantation.

There is limited experience on engraftment syndrome (ES) in children. The present study analyzes the characteristics of ES in pediatric patients undergoing autologous peripheral blood progenitor cells transplantation (PBPCT). From 1993 to 2001, 30 of 156 patients (19.2%) who underwent PBPCT developed ES (skin rash which involved more than 27% of the body surface and temperature >38.3 degrees C with no compatible infectious disease etiology, during neutrophil recovery). Of the 30 patients who developed ES, 20 (66%) developed hypoxia and/or pulmonary infiltrates, seven (23%) had hepatic dysfunction, six (20%) developed renal insufficiency, 16 (53%) showed weight gain and three (10%) experienced transient encephalopathy. Multivariate analysis showed that the only positive predictive factor for developing ES was mobilization with high-dose G-CSF (12 microg/kg twice daily) (RR 3.88, CI 95% 1.73-8.67; P < 0.0005). The overall transplant-related mortality (TRM) was 8.33% and this was significantly higher in the patients who developed ES than in those who did not (23% vs 4.76%; P < 0.0001). We also found a higher morbidity in patients who developed ES, expressed as a statistically significant increase in supportive care (transfusion requirement, parenteral nutrition) and increase in the length of hospital stay. In summary, we have found ES to be the most important cause of morbidity and mortality in children undergoing autologous PBPCT.

X-ray structure of a blue copper nitrite reductase at high pH and in copper-free form at 1.9 A resolution.

Copper-containing nitrite reductases possess a trimeric structure where the catalytic Cu site, located at the monomer-monomer interface, resembles the catalytic sites of a number of Zn enzymes. Nitrite reductase from Alcaligenes xylosoxidans has optimum activity at pH 5.2 which decreases to a negligible level at pH 8. The structure of this nitrite reductase has previously been determined at pH 4.6. It has now been crystallized under new conditions at pH 8.5. Its crystallographic structure provides a structural explanation for the greatly reduced activity of the enzyme at high pH. Characterization of overexpressed protein in solution by EXAFS suggested that the protein lacked Cu in the catalytic type 2 Cu site and that the site was most probably occupied by Zn. Using the anomalous signals from Cu and Zn, the crystal structure revealed that the expressed protein was devoid of Cu in the catalytic site and that only a trace amount (<10%) of Zn was present at this site in the crystal. Despite the close structural similarity of the catalytic site to a number of Zn enzymes, these data suggest that Zn, if it binds at the catalytic copper site, binds weakly in nitrite reductase.

Catalytic and spectroscopic analysis of blue copper-containing nitrite reductase mutants altered in the environment of the type 2 copper centre: implications for substrate interaction.

The blue dissimilatory nitrite reductase (NiR) from Alcaligenes xylosoxidans is a trimer containing two types of Cu centre, three type 1 electron transfer centres and three type 2 centres. The latter have been implicated in the binding and reduction of nitrite. The Cu ion of the type 2 centre of the oxidized enzyme is ligated by three His residues, and additionally has a co-ordinated water molecule that is also hydrogen-bonded to the carboxyl of Asp(92) [Dodd, Van Beeumen, Eady and Hasnain (1998), J. Mol. Biol. 282, 369-382]. Two mutations of this residue have been made, one to a glutamic acid residue and a second to an asparagine residue; the effects of both mutations on the spectroscopic and catalytic properties of the enzyme have been analysed. EPR spectroscopy revealed that both mutants retained intact type 1 Cu centres with g( parallel)=2.12 (A( parallel)=0 mT) and g( perpendicular)=2.30 (A( perpendicular)=6.4 mT), which was consistent with their blue colour, but differed in their activities and in the spectroscopic properties of the type 2 centres. The D92E mutant had an altered geometry of its type 2 centre such that nitrite was no longer capable of binding to elicit changes in the EPR parameters of this centre. Accordingly, this mutation resulted in a form of NiR that had very low enzyme activity with the artificial electron donors reduced Methyl Viologen and sodium dithionite. As isolated, the EPR spectrum of the Asp(92)-->Asn (D92N) mutant showed no characteristic type 2 hyperfine lines. However, oxidation with iridium hexachloride partly restored a type 2 EPR signal, suggesting that type 2 copper is present in the enzyme but in a reduced, EPR-silent form. Like the Asp(92)-->Glu mutant, D92N had very low enzyme activities with either Methyl Viologen or dithionite. Remarkably, when the physiological electron donor reduced azurin I was used, both mutant proteins exhibited restoration of enzyme activity. The degree of restoration differed for the two mutants, with the D92N derivative exhibiting approx. 60% of the activity seen for the wild-type NiR. These findings suggest that on formation of an electron transfer complex with azurin, a conformational change in NiR occurs that returns the catalytic Cu centre to a functionally active state capable of binding and reducing nitrite.

Purification, characterization, and preliminary crystallographic study of copper-containing nitrous oxide reductase from Pseudomonas nautica 617.

The aerobic purification of Pseudomonas nautica 617 nitrous oxide reductase yielded two forms of the enzyme exhibiting different chromatographic behaviors. The protein contains six copper atoms per monomer, arranged in two centers named Cu(A) and Cu(Z). Cu(Z) could be neither oxidized nor further reduced under our experimental conditions, and exhibits a 4-line EPR spectrum (g(x)=2.015, A(x)=1.5 mT, g(y)=2.071, A(y)=2 mT, g(z)=2.138, A(z)=7 mT) and a strong absorption at approximately 640 nm. Cu(A) can be stabilized in a reduced EPR-silent state and in an oxidized state with a typical 7-line EPR spectrum (g(x)=g(y)= 2.021, A(x) = A(y)=0 mT, g(z) = 2.178, A(z)= 4 mT) and absorption bands at 480, 540, and approximately 800 nm. The difference between the two purified forms of nitrous oxide reductase is interpreted as a difference in the oxidation state of the Cu(A) center. In form A, Cu(A) is predominantly oxidized (S = (1)/(2), Cu(1.5+)-Cu(1.5+)), while in form B it is mostly in the one-electron reduced state (S = 0, Cu(1+)-Cu(1+)). In both forms, Cu(Z) remains reduced (S = 1/2). Complete crystallographic data at 2.4 A indicate that Cu(A) is a binuclear site (similar to the site found in cytochrome c oxidase) and Cu(Z) is a novel tetracopper cluster [Brown, K., et al. (2000) Nat. Struct. Biol. (in press)]. The complete amino acid sequence of the enzyme was determined and comparisons made with sequences of other nitrous oxide reductases, emphasizing the coordination of the centers. A 10.3 kDa peptide copurified with both forms of nitrous oxide reductase shows strong homology with proteins of the heat-shock GroES chaperonin family.

A novel type of catalytic copper cluster in nitrous oxide reductase.

Nitrous oxide (N20) is a greenhouse gas, the third most significant contributor to global warming. As a key process for N20 elimination from the biosphere, N20 reductases catalyze the two-electron reduction of N20 to N2. These 2 x 65 kDa copper enzymes are thought to contain a CuA electron entry site, similar to that of cytochrome c oxidase, and a CuZ catalytic center. The copper anomalous signal was used to solve the crystal structure of N20 reductase from Pseudomonas nautica by multiwavelength anomalous dispersion, to a resolution of 2.4 A. The structure reveals that the CuZ center belongs to a new type of metal cluster, in which four copper ions are liganded by seven histidine residues. N20 binds to this center via a single copper ion. The remaining copper ions might act as an electron reservoir, assuring a fast electron transfer and avoiding the formation of dead-end products.

Tabaquismo pasivo y bronquitis asmatiforme en niños ingresados en pediatría / Passive smoking and asthmatic bronchitis in children hospitalized in the pediatric service

Objetivos: investigar la posible relación entre diversas patologías y la exposición al humo del tabaco en los niños ingresados en nuestra Sección.Material y métodos: hemos investigado a 553 niños con edades comprendidas entre los 2 6/12 y 7 años ingresados en la Sección de Preescolares de un Hospital Pediátrico, mediante una encuesta sobre los antecedentes de tabaquismo en el hogar y los antecedentes personales de diversas patologías.Resultados: el 71,42 por ciento de los niños estudiados están expuestos al humo del tabaco en su hogar. En la mayoría de los hogares estudiados existen dos o tres fumadores (58,73 por ciento). Respecto a las patologías asociadas al humo del tabaco en el hogar, el diagnóstico de bronquitis asmática al ingreso fue significativamente mayor en niños con antecedentes de tabaquismo positivo que en niños con antecedentes de tabaquismo negativo (24,81 por ciento vs 12,65 por ciento, con una p = 0,00038). También hemos constatado diferencias estadísticamente significativas entre los niños expuestos al humo del tabaco en el hogar y los no expuestos con respecto a sus antecedentes personales de bronquitis asmática (31,64 por ciento vs 14,64 por ciento, con p < 0,00001) e ingresos anteriores por este motivo (16,41 por ciento vs 7,35 por ciento, con p = 0,004) y foco ORL (53,67 por ciento vs 40,56 por ciento, con p = 0,004). Nuestro estudio también pone de manifiesto la existencia de una relación significativa entre el número de cigarrillos consumidos al día por la madre (r = 0,364; p < 0,01) o conviviente habitual en el hogar (r = 0,415; p < 0,05) y el número de episodios de foco ORL en los niños.Conclusiones: los niños que conviven con fumadores tienen más episodios de foco ORL, bronquitis asmática e ingresos más frecuentes por este último motivo, que los que habitan en un ambiente libre de humo de tabaco. Es esencial la prevención del tabaquismo pasivo en los niños de nuestro medio (AU)

The blue copper-containing nitrite reductase from Alcaligenes xylosoxidans: cloning of the nirA gene and characterization of the recombinant enzyme.

The nirA gene encoding the blue dissimilatory nitrite reductase from Alcaligenes xylosoxidans has been cloned and sequenced. To our knowledge, this is the first report of the characterization of a gene encoding a blue copper-containing nitrite reductase. The deduced amino acid sequence exhibits a high degree of similarity to other copper-containing nitrite reductases from various bacterial sources. The full-length protein included a 24-amino-acid leader peptide. The nirA gene was overexpressed in Escherichia coli and was shown to be exported to the periplasm. Purification was achieved in a single step, and analysis of the recombinant Nir enzyme revealed that cleavage of the signal peptide occurred at a position identical to that for the native enzyme isolated from A. xylosoxidans. The recombinant Nir isolated directly was blue and trimeric and, on the basis of electron paramagnetic resonance spectroscopy and metal analysis, possessed only type 1 copper centers. This type 2-depleted enzyme preparation also had a low nitrite reductase enzyme activity. Incubation of the periplasmic fraction with copper sulfate prior to purification resulted in the isolation of an enzyme with a full complement of type 1 and type 2 copper centers and a high specific activity. The kinetic properties of the recombinant enzyme were indistinguishable from those of the native nitrite reductase isolated from A. xylosoxidans. This rapid isolation procedure will greatly facilitate genetic and biochemical characterization of both wild-type and mutant derivatives of this protein.

[The effect of the chronic administration of acetylsalicylic acid and acetaminophen on feeding efficiency in rats]. / Influencia de la administratión crónica de ácido acetilsalicílico y de acetaminofeno sobre la eficacia alimentaria en ratas.

The influence was studied of the administration of acetylsalicylic acid and acetaminophen in doses of 450 mg/kg body weight/day, and 600 mg/kg/day respectively on the alimentary efficacy coefficient (AEC), on growth and on the hepatosomatic index in rats on a diet sufficient in all nutrients required to meet the animal's needs. The AEC was studied both for the whole experimental period and at values taken weekly. The results show that both aspirin and paracetamol significantly reduce overall alimentary efficacy (p < 0.05) and increase the hepatosomatic index. Partial AEC values showed that the analgesics studied significantly affect the figures (p < 0.05) for the intermediate periods (aspirin, 0.27 +/- 0.01, vs 0.38 +/- 0.03), and that these are more affected than those of the final treatment period (aspirin, 0.33 +/- 0.14, vs 0.36 +/- 0.07).

Factor for correcting the ruthenium interference in instrumental neutron activation analysis of barium in uraniferous samples.

The fission spectral interference of ruthenium on the instrumental neutron activation analysis of barium in samples containing uranium is extensively discussed. In particular the dependence of the correction factor on the phi epi/phi th ratio is studied. An excellent agreement between experimental and calculated values is achieved. A procedure is suggested for the resolution of multiple interferences in the general case where uranium, barium and/or ruthenium are present in samples to be analysed.