Processing and immobilization of chondroitin-4-sulphate by UV laser radiation.

Chondroitin-4-sulphate (ChS A) was immobilized by matrix assisted pulsed laser evaporation (MAPLE) with the aid of a UV KrF* excimer laser source. Distilled water was used as solvent for the preparation of the frozen composite MAPLE targets. The surface morphology, chemical structure and functional properties of laser transferred ChS A were investigated as a function of laser processing conditions. The results indicate that the amount of laser immobilized material, structure, and functional properties can be controlled by the laser fluence value used for the irradiation of the MAPLE targets. Under selected irradiation conditions besides the molecular structure, the functional properties of the laser processed ChS A molecules can be maintained.

Incidencia de bacteriemia asociada a catéter venoso central en una unidad de cuidados intensivos / Incidence of central line-associated bloodstream infection in an intensive care unit

Introducción: La bacteriemia asociada a catéter venoso central (BACVC) es una infección nosocomial frecuente. Su incidencia es mayor en los pacientes pediátricos que en los adultos y en aquellos ingresados en unidades de cuidados intensivos (UCI). La morbimortalidad asociada a esta entidad hace de la BACVC un problema de salud importante frente al que es imprescindible desarrollar estrategias de prevención. Pacientes y métodos: Se ha realizado un estudio de intervención en una UCI pediátrica (UCIP) para valorar el impacto de la implantación, en diciembre de 2007, del programa «Bacteriemiazero», que tiene como objetivo la prevención de la BACVC. Se han recogido datos demográficos y variables relacionadas con la hospitalización y la infección de los pacientes desde enero a diciembre de 2007 (antes de la intervención) y desde enero a diciembre de 2008 (después de la intervención), estudiándose 497 pacientes en el primer periodo y 495 en el segundo, y se han comparado los resultados entre ambos periodos. Resultados: Se ha observado una reducción del 30,4% en la tasa de incidencia de BACVC (p = 0,49) en el segundo año de estudio (de 5,5 a 3,8 episodios por 1.000 catéter-días). La ratio de utilización de CVC ha sido de 0,59 y de 0,64, respectivamente. El microorganismo más frecuentemente aislado ha sido Staphylococcus spp. coagulasa negativo. Conclusiones: La implantación de un programa de «bacteriemia 0» que implica tanto a los profesionales de la UCIP como a los de control de la infección nosocomial consigue reducir la incidencia de BACV (AU)

Background: Central line-associated bloodstream infection (CLABSI) is one of the most common nosocomial infections. The incidence is higher in paediatric patients than in adults, especially in those admitted to Intensive Care Units (ICU). CLABSI-related morbidity makes it a majo rhealth problem; therefore it is necessary to develop prevention strategies against it. Patients and methods: An intervention study in a paediatric ICU (PICU) was performed, in order to assess the impact of the introduction of the program «Bacteraemia zero» in December 2007. This program aims to prevent CLABSI. Demographic data and variables related to hospitalization and infection were collected from January to December 2007 (before the intervention) and from January to December 2008 (after the intervention), and were compared. In the first period, 497patients were studied, and 495 in the second. Results: A reduction of 30.4% in the incidence of CLABSI (P = 0.49) in the second year was observed (5.5 to 3.8 episodes per 1000 catheter-days). The CVC use ratio was 0.59 and 0.64, respectively. The most frequently isolated organism was coagulase-negative Staphylococcusspp. Conclusions: The implementation of a «no bacteraemia» program, involving all staff in the PICU as well as the professionals in infection control, reduces the incidence of CLABSI (AU)

Effects of pulsed laser radiation on epitaxial self-assembled Ge quantum dots grown on Si substrates.

Laser irradiation of Ge quantum dots (QDs) grown on Si(100) substrates by solid-source molecular beam epitaxy has been performed using a Nd:YAG laser (532 nm wavelength, 5 ns pulse duration) in a vacuum. The evolution of the Ge QD morphology, strain and composition with the number of laser pulses incident on the same part of the surface, have been studied using atomic force microscopy, scanning electron microscopy and Raman spectroscopy. The observed changes in the topographical and structural properties of the QDs are discussed in terms of Ge-Si diffusion processes. Numerical simulations have been developed for the investigation of the temperature evolution of the QDs during laser irradiation. The obtained results indicate that the thermal behaviour and structural variation of the nanostructures differ from conventional thermal annealing treatments and can be controlled by the laser parameters. Moreover, an unusual island motion has been observed under the action of subsequent laser pulses.

[Incidence of central line-associated bloodstream infection in an intensive care unit]. / Incidencia de bacteriemia asociada a catéter venoso central en una unidad de cuidados intensivos.

BACKGROUND: Central line-associated bloodstream infection (CLABSI) is one of the most common nosocomial infections. The incidence is higher in paediatric patients than in adults, especially in those admitted to Intensive Care Units (ICU). CLABSI-related morbidity makes it a major health problem; therefore it is necessary to develop prevention strategies against it. PATIENTS AND METHODS: An intervention study in a paediatric ICU (PICU) was performed, in order to assess the impact of the introduction of the program «Bacteraemia zero¼ in December 2007. This program aims to prevent CLABSI. Demographic data and variables related to hospitalisation and infection were collected from January to December 2007 (before the intervention) and from January to December 2008 (after the intervention), and were compared. In the first period, 497 patients were studied, and 495 in the second. RESULTS: A reduction of 30.4% in the incidence of CLABSI (P=0.49) in the second year was observed (5.5 to 3.8 episodes per 1000 catheter-days). The CVC use ratio was 0.59 and 0.64, respectively. The most frequently isolated organism was coagulase-negative Staphylococcus spp. CONCLUSIONS: The implementation of a «no bacteraemia¼ program, involving all staff in the PICU as well as the professionals in infection control, reduces the incidence of CLABSI.

Lung transplantation in young infants with interstitial pneumonia.

OBJECTIVES: We describe our experience with infants suffering from interstitial pneumonia referred for lung transplantation. METHODS: From April 1998 to December 2000, three infants were admitted to our lung transplantation program: a 9-month-old girl (patient 1) suffering from surfactant protein C deficiency who had high oxygen requirements (fraction of inspired oxygen: 70% to 90%), and two boys, ages 2 (patient 2) and 9 months (patient 3), who were ventilator-dependent due to chronic pneumonitis of infancy. RESULTS: Patients were transplanted at the age of 5 months (patient 2) and 13 months (patients 1 and 3) at 87 to 105 days after being accepted for lung transplantation. All cases underwent a sequential double lung transplant on cardiopulmonary bypass. The immunosuppressive regime included tacrolimus, prednisone, and azathioprine. Patients 2 and 3 also received basiliximab. Two cases suffered a mild rejection episode that responded to high-dose steroids. Patient 2 was ventilator-dependent for 8 months after transplant, owing to severe bronchomalacia and left main bronchus stenosis. Bronchial stenosis resolved after pneumatic dilatation and endobronchial stenting. This patient also presented with a pulmonary artery anastomosis stricture that required percutaneous balloon dilatation. All three patients are at home, carrying out normal activities for their age, with no respiratory symptoms after a period of 8 to 29 months of follow-up. CONCLUSIONS: Interstitial pneumonia of infancy is a rare disease with a bad prognosis and no specific treatment; therefore, lung transplantation represents a good therapeutic option for these infants.

Growth hormone/insulin-like growth factors axis in children undergoing cardiac surgery.

OBJECTIVES: To describe the sequential changes in the growth hormone (GH)/insulin-like growth factors axis and their relationship with nitrogen balance in children following cardiac surgery. DESIGN: Prospective, descriptive study. SETTING: Pediatric intensive care unit of a university hospital. PATIENTS: Twenty three postoperative cardiac surgical patients after bypass. INTERVENTIONS: Blood and urine samples were taken on days 1, 2, and 7 of pediatric intensive care unit admission. An intraanesthesia, presurgery sample was also obtained. MEASUREMENTS AND MAIN RESULTS: Serum concentrations of insulin, insulin growth factor-I (IGF-I), insulin growth factor binding proteins 1 and 3 (IGFBP-1 and IGFBP-3), growth hormone binding protein (GHBP), and urinary concentrations of GH and free cortisol (UFC) were measured on days 1, 2, and 7 of the study period. C-reactive protein and prealbumin, were also measured in blood samples as conventional markers of inflammatory or nutritional status. Pediatric Risk of Mortality II score and UFC were used as indicators of acute stress. The nitrogen balance and urinary nitrogen urea excretion were used as markers of catabolic state. Urinary concentrations of GH were high from days 1 to 7. Plasma concentrations of IGF-I and GHBP were low and remained low throughout the study period. IGFBP-3 levels were below normal but without reaching statistical significance. The IGFBP-1 levels were initially high but descended progressively toward normal values. Urinary nitrogen urea production was persistently elevated and was associated with a negative nitrogen balance. No relationship was found between nitrogen balance and IGF-I, prealbumin, or C-reactive protein. CONCLUSIONS: A GH-resistant state is observed in postoperative children following cardiac surgery. Stress response is characterized by an elevation of growth hormone secretion that is not followed by the corresponding increment in IGF-I and IGFBP-3 concentrations. These hormonal changes may be permissive for the catabolic state of these patients. IGF-I and IGFBP-1 and -3 are not related to either nitrogen balance or urinary nitrogen urea excretion.