Terahertz-slicing - an all-optical synchronization for 4th generation light sources.

A conceptually new approach to synchronizing accelerator-based light sources and external laser systems is presented. The concept is based on utilizing a sufficiently intense accelerator-based single-cycle terahertz pulse to slice a thereby intrinsically synchronized femtosecond-level part of a longer picosecond laser pulse in an electro-optic crystal. A precise synchronization of the order of 10 fs is demonstrated, allowing for real-time lock-in amplifier signal demodulation. We demonstrate successful operation of the concept with three benchmark experiments using a 4th generation accelerator-based terahertz light source, i.e. (i) far-field terahertz time-domain spectroscopy, (ii) terahertz high harmonic generation spectroscopy, and (iii) terahertz scattering-type scanning near-field optical microscopy.

Antiglioma activity of GoPI-sugar, a novel gold(I)-phosphole inhibitor: chemical synthesis, mechanistic studies, and effectiveness in vivo.

Glioblastoma, an aggressive brain tumor, has a poor prognosis and a high risk of recurrence. An improved chemotherapeutic approach is required to complement radiation therapy. Gold(I) complexes bearing phosphole ligands are promising agents in the treatment of cancer and disturb the redox balance and proliferation of cancer cells by inhibiting disulfide reductases. Here, we report on the antitumor properties of the gold(I) complex 1-phenyl-bis(2-pyridyl)phosphole gold chloride thio-ß-d-glucose tetraacetate (GoPI-sugar), which exhibits antiproliferative effects on human (NCH82, NCH89) and rat (C6) glioma cell lines. Compared to carmustine (BCNU), an established nitrosourea compound for the treatment of glioblastomas that inhibits the proliferation of these glioma cell lines with an IC50 of 430µM, GoPI-sugar is more effective by two orders of magnitude. Moreover, GoPI-sugar inhibits malignant glioma growth in vivo in a C6 glioma rat model and significantly reduces tumor volume while being well tolerated. Both the gold(I) chloro- and thiosugar-substituted phospholes interact with DNA albeit more weakly for the latter. Furthermore, GoPI-sugar irreversibly and potently inhibits thioredoxin reductase (IC50 4.3nM) and human glutathione reductase (IC50 88.5nM). However, treatment with GoPI-sugar did not significantly alter redox parameters in the brain tissue of treated animals. This might be due to compensatory upregulation of redox-related enzymes but might also indicate that the antiproliferative effects of GoPI-sugar in vivo are rather based on DNA interaction and inhibition of topoisomerase I than on the disturbance of redox equilibrium. Since GoPI-sugar is highly effective against glioblastomas and well tolerated, it represents a most promising lead for drug development. This article is part of a Special Issue entitled: Thiol-Based Redox Processes.

Negative-frequency resonant radiation.

Optical solitons or solitonlike states shed light to blueshifted frequencies through a resonant emission process. We predict a mechanism by which a second propagating mode is generated. This mode, called negative resonant radiation, originates from the coupling of the soliton mode to the negative-frequency branch of the dispersion relation. Measurements in both bulk media and photonic-crystal fibers confirm our predictions.

Optical nanoscopy of transient states in condensed matter.

Recently, the fundamental and nanoscale understanding of complex phenomena in materials research and the life sciences, witnessed considerable progress. However, elucidating the underlying mechanisms, governed by entangled degrees of freedom such as lattice, spin, orbit, and charge for solids or conformation, electric potentials, and ligands for proteins, has remained challenging. Techniques that allow for distinguishing between different contributions to these processes are hence urgently required. In this paper we demonstrate the application of scattering-type scanning near-field optical microscopy (s-SNOM) as a novel type of nano-probe for tracking transient states of matter. We introduce a sideband-demodulation technique that allows for probing exclusively the stimuli-induced change of near-field optical properties. We exemplify this development by inspecting the decay of an electron-hole plasma generated in SiGe thin films through near-infrared laser pulses. Our approach can universally be applied to optically track ultrafast/-slow processes over the whole spectral range from UV to THz frequencies.

Infantile intranuclear rod myopathy.

This report concerns three unrelated floppy infants, two girls and one boy, each biopsied at the age of 1 month. They were hypotonic since birth and required artificial ventilation. The two girls died at the ages of 4 and 3 1/2 months, respectively, the boy is still alive at the age of 2 years, but requires assisted ventilation. Each of the three infants showed, by muscle biopsy, abundant intranuclear rods, the boy and one girl also had sarcoplasmic rods, which were not present in the other girl's muscle. Absence of sarcoplasmic rods, but the presence of intranuclear rods could also be documented in her autopsied muscle. Using an antibody against alpha-actinin, immunoelectron microscopy showed reaction of the sarcoplasmic and intranuclear rods demonstrating their Z-band origin. To our knowledge, this is the first report on rod myopathy with intranuclear rods only and of an immunoelectron microscopic demonstration of alpha-actinin in intranuclear rods. The presence of intranuclear rods in infants with nemaline myopathy also appears to indicate a grave prognosis of their rod myopathy.

Near-field examination of perovskite-based superlenses and superlens-enhanced probe-object coupling.

A planar slab of negative-index material works as a superlens with sub-diffraction-limited resolution, as propagating waves are focused and, moreover, evanescent waves are reconstructed in the image plane. Here we demonstrate a superlens for electric evanescent fields with low losses using perovskites in the mid-infrared regime. The combination of near-field microscopy with a tunable free-electron laser allows us to address precisely the polariton modes, which are critical for super-resolution imaging. We spectrally study the lateral and vertical distributions of evanescent waves around the image plane of such a lens, and achieve imaging resolution of λ/14 at the superlensing wavelength. Interestingly, at certain distances between the probe and sample surface, we observe a maximum of these evanescent fields. Comparisons with numerical simulations indicate that this maximum originates from an enhanced coupling between probe and object, which might be applicable for multifunctional circuits, infrared spectroscopy and thermal sensors.

Anisotropy contrast in phonon-enhanced apertureless near-field microscopy using a free-electron laser.

We demonstrate the imaging of ferroelectric domains in BaTiO3, using an infrared-emitting free-electron laser as a tunable optical source for scattering scanning near-field optical microscopy and spectroscopy. When the laser is tuned into the spectral vicinity of a phonon resonance, ferroelectric domains can be resolved due to the anisotropy of the dielectric properties of the material. Slight detuning of the wavelength gives rise to a contrast reversal clearly evidencing the resonant character of the excitation. The near-field domain contrast shows that the orientation of the dielectric tensor with respect to the sample surface has a clear influence on the near-field signal.

[Periarteriitis nodosa in children and mucocutaneous lymph node syndrome as causes of multifocal convulsions (propulsive petit-mal) (author's transl)]. / Infantile Periarteriitis nodosa/mukokutanes Lymphknotensyndrom--Ursache für BNS-Krämpfe?

On an infant with the classical signs of Kawasaki-disease (MLNS), in whom after a few days began to show distal demarcations on all four extremities due to arterial malperfusion. Parts of these extremities had to be resected. Histologic evaluation showed an infantile type of periarteriitis nodosa. Later on the child developed multifocal convulsions. The similarities of MLNS and IPN are discussed as well as cerebral vasculitis.

[Congenital pilocytic astrocytoma of the brain]. / Angeborenes pilozytisches Astrozytom des Grosshirns.

Case report about a 9 months old female infant, that died of an exorbitant large astrocytoma of the base of both hemispheres. The tumor was apparent 10 weeks after birth and considered to be connatal. It has been classified as a pilocytic form, which is very rare in this age. The origin has been discussed as dysontogenic.

[Diabetes mellitus type I, thyroid gland autoimmunity, thyroid gland function and HLA status]. / Diabetes mellitus Typ I, Schilddrüsenautoimmunität, Schilddrüsenfunktion und HLA-Status.

In a cross-sectional study sera of 130 children and adolescents with insulin dependent (type I) diabetes were tested for the presence of cytoplasmatic islet cell antibodies (ICA), thyroid microsomal antibodies (TMA) as well as thyroid function (T3, T4, thyrotrophin). 102 of the patients were examined for thyroid enlargement, all patients with TMA were within this group. TMA were found in 15.4%, ICA in 38.5%, the latter decreasing with duration of diabetes. Of the TMA positive sera, 45% were also ICA positive, but only one child out of these was diabetic for more than 5 years. Thyroid enlargement occurred in 33.3%, however in TMA positive patients in 70%, of which one girl suffered from hypothyroidism due to biopsy-proven Hashimoto's thyroiditis, all the other diabetics being euthyroid. There was no sex predisposition. By HLA-typing 40% of TMA positive patients expressed the HLA-DR3 antigen which is said to be responsible for "autoimmune" diabetes, whereas only some of these were ICA positive as well. In our study, no significant association was found between presence or even persistence of ICA and TMA, nor between thyroid autoimmunity and HLA-DR3. Since type I diabetic patients with thyroid autoimmunity are predisposed to develop hypothyroidism with time, less likely also Addison's disease, screening of type I diabetics for thyroid microsomal antibodies should be considered especially in those with thyroid enlargement.

[Nuclear magnetic resonance tomography in the differential diagnosis of adrenal gland hemorrhage and neuroblastoma in a newborn infant]. / Kernspintomographie in der Differentialdiagnose Nebennierenblutung und Neuroblastom bei einem Neugeborenen.

Adrenal hemorrhages in newborns are usually diagnosed by sonography. Magnetic resonance imaging is indicated when morphological change, clinical appearance and follow-up do not allow differentiation of adrenal hemorrhage and neuroblastoma. Using artefact-suppressing sequences, the adrenal gland can be examined with modern MRI systems. The adrenal gland hemorrhage is characterized by a typical signal behaviour. If a haematoma persists over a longer period, a circular methemoglobin zone can be observed. An additional contrast application (Gadolinium-DTPA) can aid in demonstrating vascular tumors.

Comparación entre nutrición enteral precoz y nutrición enteral tardía en el estado nutricional de pacientes gastrectomizados / Comparison between early enteral nutrition and late enteral nutrition in the nutritional status of patients with gastrectomy

Enteral nutrition (EN) is an effective method to meet the nutritional requirements in patients who have a deteriorated nutritional status. Objectives: To compare clinical and nutritional performance of two groups: Early Enteral Nutrition (EEN) versus Late Enteral Nutrition (LEN) of patients undergoing to total gastrectomy for gastric cancer. Material and Methods: 18 patients with resectable gastric cancer were studied with anthropometric, functional and biochemical parameters to assess nutritional status in the preoperative and postoperative period. They received a polimeric enteral formula (1 kcal/ml) in the postoperative period. They were randomly assigned to the type of nutrition (early or late). Results: The group with EEN had a significant improvement in the bicipital fold adequacy percentage and dynamometry. The LEN group had a significant decrease of albumin. The bloating was more frequent in the group with EEN. Conclusion: Early enteral nutrition is a safe nutritional support, effective and that brings nutritional benefits compared with late enteral nutrition in patients undergoing to total gastrectomy for gastric cancer.

La nutrición enteral (NE) es un método efectivo para cubrir los requerimientos nutricionales en pacientes que presentan un estado nutricional deteriorado. Objetivos: Comparar la Nutrición Enteral Precoz (NEP) versus Nutrición Enteral Tardía (NET) en la evolución clínica y nutricional de pacientes sometidos a gastrectomía total por Cáncer Gástrico. Material y Método: 18 pacientes con cáncer gástrico resecable, fueron estudiados con parámetros antropométricos, funcionales y bioquímicos que evalúan el estado nutricional, en el período preoperatorio y postoperatorio. Recibieron una fórmula enteral polimérica (1 kcal/ml) en el período postoperatorio. De manera aleatoria fueron asignados al tipo de nutrición (precoz o tardía). Resultados: El grupo con NEP presentó mejoría significativa del porcentaje de adecuación del pliegue bicipital y dinamometría. El grupo con NET presentó disminución significativa de la albuminemia. La distensión abdominal fue más frecuente en grupo con NEP. Conclusión: La Nutrición Enteral Precoz es un soporte nutricional seguro, eficaz y que trae consigo ventajas nutricionales en comparación con la Nutrición Enteral Tardía en el grupo de pacientes gastrectomizados totales por presentar cáncer gástrico.

Aplicación de un sistema de análisis de peligros y control de puntos críticos en la nutrición enteral administrada en la unidad de cuidados intensivos / Application of a hazard analysis control of critical points on the enteral feeding administered at the intensive care unit

Se aplicó un sistema de Análisis de Peligros y Control de Puntos Críticos (HACCP) en la administración de la nutrición enteral (NE) en la Unidad de Cuidados Intensivos (UCI) de un Hospital de alta complejidad, con la colaboración del personal que trabaja en la UCI, para garantizar la seguridad de la calidad en la preparación, almacenamiento y entrega de la nutrición enteral a pacientes hospitalizados. Se estudiaron los métodos de rutina de preparación de la nutrición enteral, su almacenamiento y entrega a pacientes y se realizó un diagrama de flujo del proceso de administración de la fórmula de NE, luego, se identificaron los peligros y se evaluó su gravedad. Se determinaron los Puntos Críticos de Control (PCC) y se establecieron los criterios de control. La abertura del envase de la Fórmula Enteral (FE) y la introducción del equipo de infusión a la FE constituyen los únicos PCC cuando se manipula una FE lista para colgar. Se monitorearon y se aplicaron límites críticos y medidas correctivas para cada uno de los PCC del proceso. Además, se tomaron muestras para realizar un análisis para medir la calidad microbiológica del producto en cada PCC del proceso y se controló su temperatura ambiental. El análisis estadístico del recuento bacteriano de Aerobios Mesófilos (RAM) y Coliformes totales (CT) al tiempo 0 y 48 horas señala que no existen diferencias estadísticamente significativas en el nivel RAM y CT (p<0,05) en esos tiempos de estudio. La aplicación del sistema HACCP en la manipulación de la FE listas para usar en pacientes hospitalizados en la UCI, demuestra que es un sistema eficaz que permite garantizar en forma efectiva y segura el empleo de NE en pacientes hospitalizados.

A Hazard Analysis and Control of Critical Points (HACCP) was applied to enteral nutrition (EN) at the Intensive Care Unit (ICU) in a highly complex Hospital, with the collaboration of personnel working at the ICU to guarantee the certainty of the quality in the preparation, storage and delivery of enteral feeding solutions to hospitalized patients. Routine methods of food preparation, storage and delivery to patients were studied and a flux diagram of the process of the administration of the EN formula was draw; later, hazards were identified and their seriousness was evaluated. Critical Controls Points (CCP) were determined, and control criteria were established. The opening of the EN container and the introduction of infusion equipment are the only Critical Control Points (CCP) when a ready-to-hang EN preparation is manipulated. Critical limits and correction measures were monitored and applied for each of the CCP of the process. Moreover, samples were taken to analyze and measure the microbiologic quality of the product at each CCP of the process and room temperature was controlled. The statistical analysis of bacteria recount on enteral food shows that there are no statistically significant differences at RMA and TC levels (p<0.05).

Calidad microbiológica de una fórmula enteral lista para usar / Microbiological quality of an enteral formula ready to use

El objetivo de este estudio fue determinar y comparar en dos periodos de tiempo la calidad microbiológica de una fórmula enteral (FE) lista para usar: ADN lÝquido½. En central de FE, se recolectaron 40 muestras, de 50 ml cada una, al tiempo 0 y 24 horas, a temperatura ambiente, y se realizaron los siguientes estudios en el laboratorio de microbiologÝa del CESMEC: Recuento de bacterias mesófilas (Me), coliformes totales (CT) y coliformes fecales (CF). Los estßndares de calidad microbiológica (ECM) utilizados al tiempo 0 fueron < 102 ufc/ml de Me y, ausencia de CT y CF; y a las 24 horas < 103 ufc/ml de Me; < 10 ufc/ml de CT y ausencia de CF. El anßlisis estadÝstico se realizó en programa Stata. Los resultados fueron analizados mediante prueba Z para proporciones. Se consideró significativo un nivel p < 0,05. Los porcentajes de cumplimiento de ECM al tiempo 0 fueron: 100 por ciento para Me, CT y CF y a las 24 horas: 95 por ciento para Me y 100 por ciento para CT y CF (p = 0,3). Se concluye que las FE de ADN lÝquido½ pueden estar colgadas hasta por 24 horas a temperatura ambiente.

Contaminación microbiana de fórmulas enterales de uso hospitalario / Microbiological contamination of enteral formulas used in hospitals

Objetivo: determinar la calidad microbiológica de dos fórmulas enterales (FE): ADN polvo (P) y ADN líquido (L) listo para utilizar. Método: en 4 hospitales de Santiago se realizó recuento de mesófilas (Me), coliformes totales (CT) y coliformes fecales (CF) en un total de 144 muestras de FE, obtenidas a los tiempos 0, 2, 4, 6, 10, 24 y 48 horas. Los estándares de calidad microbiológica (ECM) utilizados al tiempo cero fueron: <10² UFC/ml de Me y ausencia de CF. Resultados: Los porcentajes de cumplimiento de los ECM de ADN -P para Me fueron: 42 por ciento, 75 por ciento, 50 por ciento, 33 por ciento y 25 por ciento, y para CT fueron: 83 por ciento, 91,5 por ciento, 83 por ciento, 75 por ciento y 42 por ciento al tiempo 0, 2, 4, 6 y 10 horas respectivamente. El cumplimiento de los ECM de ADN -L para Me fue 100 por ciento al tiempo 0, 2, 4 y 6 horas, 92 por ciento a las 10 horas; para CT fue de 100 por ciento en todos los tiempos evaluados. El recuento de CT fue significativamente superior en las muestras de ADN -P desde las cuatro horas en adelante. El ADN -L abierto y refrigerado a 4ºC cumplió con los ECM hasta las 48 horas de estudio. Conclusiones: la mayor adhesión de las FE de ADN -L a los ECM sugieren privilegiar su uso. Las FE de ADN -P y de ADN -L pueden estar colgadas a temperatura ambiente hasta por 4 y 10 horas respectivamente. La conservación de cajas Tetra Pak de ADN -L abiertas y refrigeradas a 4ºC permite su uso hasta las 48 horas

Actualización de las normas de nutrición enteral en la unidad de cuidados intensivos / Updating enteral nutrition standards in intensive care units

La aplicación de protocolos de nutrición enteral que enfatizan el empleo de sondas nasoyeyunales ubicadas distal al ligamento de Treitz ha demostrado ser exitosas en pacientes con alto riesgo de aspiración. La nutrición enteral gástrica puede ser utilizada en pacientes con bajo riesgo de aspiración pero requiere de la evaluación periódica del residuo gástrico, aplicando determinadas conductas terapéuticas en relación a los valores obtenidos.

Uso de fibra dietaria en nutrición enteral / Use of dietary fiber in enteral nutrition

Numerosas investigaciones han demostrado que la fibra dietaria tiene diversas funciones a nivel de tubo digestivo, así como también diversas indicaciones terapeúticas. Entre éstas destacan constipación, la diarrea, las enfermedades inflamatorias intestinales y el síndrome de intestino corto. El trabajo clasifica las fibras dietarias en polisacáridos estructurales; no estructurales y componentes no carbohidratos y las divide también en solubles e insolubles. Se comentan los efectos fisiológicos de las fibras dietarias sobre el tubo digestivo

Sepsis relacionada a catéter en nutrición parenteral central / Catheter related sepsis and parenteral nutrition

The pathogenesis, clinical and microbiological definitions of catheter related sepsis (CRS) are summarized. Pirfalls for diagnosis, treatment and prevention of CRS are included

Quilotórax postoperatorio en resección esofágica: tratamiento conservador / Post-surgery chylothorax in esophageal resection: conservative treatment

Se presenta el caso de un quilotórax en una enferma de 56 años, luego de una esofagectomía de Lewis-Tanner realizada debido a un tumor del tercio medio del cuerpo esofágico. Al séptimo día del postoperatorio se detecta la existencia de un quilotórax (líquido opalescente con alto contenido de triglicéridos). Se instituye tratamiento médico conservador suprimiendo la alimentación oral, iniciando la alimentación parenteral total central y manteniendo los drenajes pleurales. A los 10 días del postoperatorio se reinicia la alimentación oral, manteniéndose la parenteral hasta el vigésimo tercer día, momento en que se retiran los drenajes. En suma, el tratamiento médico descrito es una buena alternativa terapéutica para los quilotórax postoperatorios con fístulas que drenan menos de 1.000 ml diarios. Sus éxitos oscilan entre 25 y 50%