Evidence of nonthermal particles in coronal loops heated impulsively by nanoflares.

The physical processes causing energy exchange between the Sun's hot corona and its cool lower atmosphere remain poorly understood. The chromosphere and transition region (TR) form an interface region between the surface and the corona that is highly sensitive to the coronal heating mechanism. High-resolution observations with the Interface Region Imaging Spectrograph (IRIS) reveal rapid variability (~20 to 60 seconds) of intensity and velocity on small spatial scales (≲500 kilometers) at the footpoints of hot and dynamic coronal loops. The observations are consistent with numerical simulations of heating by beams of nonthermal electrons, which are generated in small impulsive (≲30 seconds) heating events called "coronal nanoflares." The accelerated electrons deposit a sizable fraction of their energy (≲10(25) erg) in the chromosphere and TR. Our analysis provides tight constraints on the properties of such electron beams and new diagnostics for their presence in the nonflaring corona.

Prevalence of small-scale jets from the networks of the solar transition region and chromosphere.

As the interface between the Sun's photosphere and corona, the chromosphere and transition region play a key role in the formation and acceleration of the solar wind. Observations from the Interface Region Imaging Spectrograph reveal the prevalence of intermittent small-scale jets with speeds of 80 to 250 kilometers per second from the narrow bright network lanes of this interface region. These jets have lifetimes of 20 to 80 seconds and widths of ≤300 kilometers. They originate from small-scale bright regions, often preceded by footpoint brightenings and accompanied by transverse waves with amplitudes of ~20 kilometers per second. Many jets reach temperatures of at least ~10(5) kelvin and constitute an important element of the transition region structures. They are likely an intermittent but persistent source of mass and energy for the solar wind.

Evidence for Alfvén waves in solar x-ray jets.

Coronal magnetic fields are dynamic, and field lines may misalign, reassemble, and release energy by means of magnetic reconnection. Giant releases may generate solar flares and coronal mass ejections and, on a smaller scale, produce x-ray jets. Hinode observations of polar coronal holes reveal that x-ray jets have two distinct velocities: one near the Alfvén speed ( approximately 800 kilometers per second) and another near the sound speed (200 kilometers per second). Many more jets were seen than have been reported previously; we detected an average of 10 events per hour up to these speeds, whereas previous observations documented only a handful per day with lower average speeds of 200 kilometers per second. The x-ray jets are about 2 x 10(3) to 2 x 10(4) kilometers wide and 1 x 10(5) kilometers long and last from 100 to 2500 seconds. The large number of events, coupled with the high velocities of the apparent outflows, indicates that the jets may contribute to the high-speed solar wind.

Quistes de ovario en la urgencia: ¿un dilema terapéutico para el cirujano general? / Ovarian cysts in the urgency: a therapeutic dilemma for the general surgeon?

Ovarian cysts occur in women of all ages. In young women, the majority are benign, and the incidence of malignancy is maximal in the fifth to seventh decades. An ovaian cyst may present to the emergency surgeon as a pelvic or abdominal mass. it may also be discovered as an incidental finding on pelvic examination. An ultrasound scan yields valuable information about the nature of an ovaian cyst. The aim of this report was to present an experience with this pathology with laparoscopic management and with a revision of the literature(AU)

Quistes de ovario en la urgencia: ¿un dilema terapéutico para el cirujano general? / Ovarian cysts in the urgency: a therapeutic dilemma for the general surgeon?

Ovarian cysts occur in women of all ages. In young women, the majority are benign, and the incidence of malignancy is maximal in the fifth to seventh decades. An ovaian cyst may present to the emergency surgeon as a pelvic or abdominal mass. it may also be discovered as an incidental finding on pelvic examination. An ultrasound scan yields valuable information about the nature of an ovaian cyst. The aim of this report was to present an experience with this pathology with laparoscopic management and with a revision of the literature

Demandas por responsabilidad profesional: etiologías / Professional responsability demands: real causes

Antecedentes: En los últimos años las demandas por mala práctica médica han tenido un crecimiento vertiginosos y se han constituido en una preocupación constante para todos los galenos. Objetivos: Detectar las causas que originaron juicios de mala práctica en contra de cirujanos y analizar sus motivos. Lugar de aplicación: Colegio de Médicos Distrito VIII de la provincia de Buenos Aires. Población: 116 demandas entre enero de 1993 y mayo de 2003, de las cuales 29 involucran a 30 médicos con actividad quirúrgica. Resultados: 30 cirujanos fueron demandados, 20 (66-6 por ciento) son especialistas, 9 (30 por ciento) no poseen dicho título, y 1 (3,3 por ciento) es residente. A su vez el 35 por ciento de los especialistas debieran recertificar hallándose el 65 por ciento restante encuadrados en la ley vigente. Las historias clínicas estudiadas revelaron que el consentimiento informado faltó en el 96,5 por ciento y estaban incompletas el 56,6 por ciento. La negligencia se halló en el 51,7 por ciento, la impericia en el 34,4 por ciento e imprudencia 20,6 por ciento, asociadas en algunos casos. Hubo 14 profesionales demandados con eximentes de responsabilidad profesional. Conclusiones: Están minimizadas las medidas de prevención y se observó escasa coincidencia en relación a la responsabilidad profesional. Hubo insuficiente esfuerzo individual respecto a la Educación Médica Continua y se hallaron faltas graves a la ética profesional (AU)

Demandas por responsabilidad profesional: etiologías / Professional responsability demands: real causes

Antecedentes: En los últimos años las demandas por mala práctica médica han tenido un crecimiento vertiginosos y se han constituido en una preocupación constante para todos los galenos. Objetivos: Detectar las causas que originaron juicios de mala práctica en contra de cirujanos y analizar sus motivos. Lugar de aplicación: Colegio de Médicos Distrito VIII de la provincia de Buenos Aires. Población: 116 demandas entre enero de 1993 y mayo de 2003, de las cuales 29 involucran a 30 médicos con actividad quirúrgica. Resultados: 30 cirujanos fueron demandados, 20 (66-6 por ciento) son especialistas, 9 (30 por ciento) no poseen dicho título, y 1 (3,3 por ciento) es residente. A su vez el 35 por ciento de los especialistas debieran recertificar hallándose el 65 por ciento restante encuadrados en la ley vigente. Las historias clínicas estudiadas revelaron que el consentimiento informado faltó en el 96,5 por ciento y estaban incompletas el 56,6 por ciento. La negligencia se halló en el 51,7 por ciento, la impericia en el 34,4 por ciento e imprudencia 20,6 por ciento, asociadas en algunos casos. Hubo 14 profesionales demandados con eximentes de responsabilidad profesional. Conclusiones: Están minimizadas las medidas de prevención y se observó escasa coincidencia en relación a la responsabilidad profesional. Hubo insuficiente esfuerzo individual respecto a la Educación Médica Continua y se hallaron faltas graves a la ética profesional

Growth in children following liver transplantation.

Although liver transplantation (OLT) has become standard therapy for end-stage liver disease in children, growth after OLT remains an area of concern. We reviewed our experience with growth after OLT at the Hospital for Sick Children in 83 patients who survived at least 1 yr post-transplant. Our aims were to describe the success rate in steroid cessation in patients after transplantation, to examine the effect of transplantation on subsequent growth, to see if steroid reduction had a beneficial effect on growth, and to quantify the risk of stopping steroids on rejection. Patients below age 5 yr were weaned off steroids more easily than those over age 5: 19.2% vs. 0% (p<0.05), 65.9% vs. 50%, and 79.5% vs. 37.5% (p<0.05) at post-transplant years 1, 2, and 3, respectively. Pre-transplant, 30% of patients were below the third percentiles for height and weight. Post-transplant, there was a steady improvement in the distribution of patients above the 3rd percentile, so that by post-transplant year 6, only 5% were below the 3rd percentile. Height and height velocity percentiles were found to correlate inversely with total yearly steroid dose (mg/kg) at post-transplant years 2, 3 and 6 (p<0.05). In 60% of patients, steroids were successfully discontinued. In these patients, height and height velocity percentiles have achieved a near normal distribution with 40% and 46% of patients above the 50th percentile for height and height velocity percentiles, respectively. No grafts were lost to rejection in those off steroids, and all rejection episodes were easily reversed. We conclude that the majority of children can be weaned off steroids successfully after OLT and that growth in those children in the presence of good graft function is near normal.

Broad inter-individual variations in circulating progenitor cell numbers induced by granulocyte colony-stimulating factor therapy.

The elevated white cell counts (WCC) and myeloid progenitor cell levels in the blood induced by granulocyte colony-stimulating factor (G-CSF) treatment were studied in three settings: cancer patients previously treated with chemo/radiotherapy (n = 13), untreated cancer patients (n = 5) and normal volunteers (n = 9). The inter-individual variations in progenitor cell mobilization responses to G-CSF and the impact of previous chemo/radiotherapy were investigated. The absolute levels of circulating progenitor cells, but not total white cells, were reduced significantly in the pretreated cancer patients (median 961, range 289-3355 per ml blood) as compared to untreated cancer patients (median 9891, range 2219-16625 per ml blood). In each setting, wide ranges of circulating progenitor cell numbers were observed, and the variation in progenitor cell numbers was considerably greater than observed for the WCC. However, progenitor cell numbers in normal volunteers (942-25296 per ml blood) demonstrated as much variance as observed in pretreated cancer patients. This broad physiological variation in progenitor cell levels induced by G-CSF needs to be considered when designing strategies for allogeneic peripheral blood stem cell transplantation.

Reconsidering rituals: a vehicle for educational change.

Rituals continue to be a component of nursing practice. Their origins may be related to the historical antecedents of physician domination, the experience of sacred events such as birth and death, and an unconscious need of nurses not purely explained by logic. Educators will be most able to promote changes in practice by incorporating the meaning of ritual in educational programs through discussing issues and interacting with nurses on an individual basis as they master new practice techniques. It is essential that educators become one with the environments of nurses so an understanding of context and values can impact educational strategy and reform nursing practice.

No evidence for GM-CSF receptor alpha chain gene mutation in AML-M2 leukemias which have lost a sex chromosome.

Sixty-five percent of acute myeloid leukemias subtype M2 (AML-M2), displaying a translocation between chromosomes 8 and 21 (t8;21) have also lost one or other copy of the sex chromosomes (XO). This finding has led to the hypothesis that a recessive oncogene may be present in the DNA common to both sex chromosomes, that is the pseudoautosomal region. The alpha chain of the receptor for the hemopoietic growth factor GM-CSF has recently been mapped to the human pseudoautosomal region and, given the role of this molecule in the control of normal hemopoiesis, it is thought to be a good candidate gene. This paper examines the structure, expression, and sequence of the GM-CSF receptor alpha chain gene (GMR alpha) in three primary AML-M2,XO samples and one AML-M2,XO cell line. Results of this work show no gross rearrangement or loss of the remaining allele of GMR alpha, detectable expression of its transcript and protein, and no changes at the nucleotide sequence level. Thus, we find no evidence to support a role for the GM-CSF receptor alpha chain molecule in the development of AML-M2,XO leukemias.

The SCL gene product is regulated by and differentially regulates cytokine responses during myeloid leukemic cell differentiation.

Differentiation induction in murine M1 leukemia cells by interleukin 6 (IL-6), leukemia inhibitory factor (LIF), and oncostatin M (OSM) is postulated to occur via a common receptor chain, gp130. In this study, growth factor-induced differentiation of M1 cells was accompanied by a late and persistent decrease in levels of mRNA and protein for a helix-loop-helix transcription factor, the SCL gene product. To evaluate whether reduced SCL expression was instrumental in monocyte differentiation, an SCL cDNA expression vector was introduced into M1 cells to obtain cell lines in which overexpression of SCL mRNA and protein was enforced. This resulted in a reduction in cells differentiating in response to LIF and OSM but not in response to IL-6. Scatchard analysis indicated that both parental and SCL-transfected cell lines exhibited similar receptor numbers and receptor affinities for LIF, OSM, and IL-6, suggesting that the differential responsiveness was not due to selective receptor down-modulation. Thus, these data implicate SCL in monocytic differentiation and provide evidence for differential receptor signaling pathways despite utilization of a common gp130 subunit by all three receptors.

Induced myeloid differentiation of K562 cells with downregulation of erythroid and megakaryocytic transcription factors: a novel experimental model for hemopoietic lineage restriction.

The human erythroleukemia cell line K562 can be induced to differentiate along the erythroid and megakaryocytic lineages. Here we demonstrate that hexamethylene bisacetamide (HMBA) induced K562 cells to differentiate along a third pathway. This was accompanied by downregulation of two transcription factors normally expressed in erythroid, mast and megakaryocyte lineages. Northern analysis demonstrated coordinate downregulation of alpha globin and gamma globin in addition to the two lineage-restricted transcription factors, SCL and GATA-1. Proliferation of the K562 cells was also suppressed. Clonal assay showed that the suppression was irreversible and appeared analogous to the commitment of murine erythroleukemia (MEL) cells to terminal differentiation. In contrast to MEL cells, however, K562 cells acquired a macrophage-like morphology and exhibited a complete failure to generate benzidine-positive cells. Electron microscopy revealed a marked increase in granules resembling those specific for eosinophils. Surface marker analysis showed that HMBA-induced cells expressed reduced levels of glycophorin A, CD5, CD7 and CD11b. No upregulation of megakaryocyte or lymphoid markers occurred. Thus the response of K562 cells to HMBA may provide a useful experimental system for studying the molecular mechanisms responsible for downmodulation of lineage-restricted transcription factors during hemopoietic lineage commitment.

Physical health promotion in psychiatric day treatment.

Physiological and self-care needs are often neglected in the treatment of chronic psychiatric patients. In an attempt to treat the whole person, a stress and health management program was implemented in the partial hospitalization program of a large, urban medical center, with the goal of improving client capabilities and self-esteem. The Psychiatric Day Treatment Center was a nurse-coordinated program held Monday through Friday from 9 to 4 in an office separate from the hospital. Most patients attended from 2 weeks to 6 months, at first on a daily basis, and then tapered off to a part-time schedule as they neared discharge. The population was varied with regard to age, educational, and socioeconomic background. Clients ranged in age from 16 to 85; some participants were professionals, while others had not completed high school. When they left the program, some clients were able to manage part-time jobs, while others opted for volunteer work or for longer term day treatment. All clients had been previously hospitalized for treatment of psychiatric illness. Some clients attended the program to avoid another hospitalization, as it offered more intensive treatment and medication management than the weekly outpatient treatment did. Some clients used the program to ease the transition between hospital and community. Clients who needed more stimulation and interaction than they were receiving also participated.

Prior chemotherapy does not prevent effective mobilisation by G-CSF of peripheral blood progenitor cells.

In this study we demonstrate that the hemopoietic growth factor, G-CSF successfully mobilised progenitor cell populations into the peripheral blood in a population of patients despite intensive pretreatment with chemotherapy. Administration of G-CSF increased the numbers of peripheral blood progenitor cells (PBPC) by a median of 76-fold above basal levels. Maximal levels of PBPC were observed on days 5 and 6 after G-CSF treatment. In two patients a second cycle of G-CSF mobilised PBPC to levels comparable with those seen after the first cycle of G-CSF treatment. An earlier hemopoietic cell population (pre-CFC's) was also mobilised with levels increased up to 50-fold above basal levels. Using a standard mononuclear cell leukapheresis technique the PBPC were collected extremely efficiently (essentially 100%) and could be further successfully enriched by separation using a Ficoll gradient. For patients who underwent the optimal collection protocol (i.e. leukapheresis on days 5, 6 and 7) a total of 32 +/- 6 x 10(4) GM-CFC kg-1 were collected. The ability to mobilise PBPC using G-CSF alone and to successfully and efficiently harvest these cells has important implications for the future of transplantation and high dose chemotherapy procedures.

G-CSF mobilised progenitor cells in autologous transplantation: in vitro and in vivo aspects.

G-CSF administration leads to significant elevation in the levels of circulating progenitor cells. Infusion of these cells after high-dose chemotherapy is associated with accelerated platelet engraftment that has a considerable impact in shortening thrombocytopenia and reducing need for platelet transfusions.