Prone positioning before extracorporeal membrane oxygenation for severe acute respiratory distress syndrome: A retrospective multicenter study / Decúbito prono previo a la oxigenación de membrana extracorpórea para el síndrome de dificultad respiratoria aguda: un estudio retrospectivo multicéntrico

Objective: To evaluate the clinical outcomes of patients with severe acute respiratory distress syndrome (ARDS) subjected to prone positioning before extracorporeal membrane oxygenation (ECMO). Design: A retrospective analysis of a multicenter cohort was carried out. Setting: Patients admitted to the Intensive Care Units of 11 hospitals in Korea. Patients: Patients were divided into those who underwent prone positioning before ECMO (n=28) and those who did not (n=34). Interventions: None. Variables of interest: Thirty-day mortality, ECMO weaning failure rate, mechanical ventilation weaning success rate, mechanical ventilation-free days at day 60. Results: The prone group had lower median peak inspiratory pressure and lower median dynamic driving pressure before ECMO. Thirty-day mortality was 21% in the prone group and 41% in the non-prone group (p=0.098). The prone group also showed a lower ECMO weaning failure rate, and a higher mechanical ventilation weaning success rate and more mechanical ventilation-free days at day 60. In the non-prone group, median dynamic compliance marginally decreased shortly after ECMO, but no significant change was observed in the prone group. Conclusions: Prone positioning before ECMO was not associated to increased mortality and tended to exert a protective effect

Objetivo: Evaluar los resultados clínicos de pacientes con síndrome de dificultad respiratoria aguda (SDRA) quienes fueron colocados en decúbito prono previo a la oxigenación con membrana extracorpórea (ECMO). Diseño: Análisis retrospectivo de una cohorte multicéntrico. Escenario: Pacientes admitidos en las unidades de cuidado intensivo de 11 hospitales en Corea. Pacientes: Los pacientes fueron divididos en aquellos que fueron colocados en decúbito prono antes de la ECMO (n=28) y aquellos que no fueron colocados en decúbito prono antes de la ECMO (n=34). Intervenciones: Ninguna. Variables de interés principales: Mortalidad a los 30 días, tasa de fracaso de retirada gradual de la ECMO, tasa de éxito de retirada gradual de la ventilación mecánica, días sin ventilación mecánica a los 60 días. Resultados: El grupo prono tuvo una mediana más baja de la presión inspiratoria máxima y una mediana más baja de la presión de conducción dinámica antes de la ECMO. La mortalidad a los 30 días fue 21% en el grupo prono y 41% en el grupo no prono (P = 0.098). El grupo prono también mostró un valor numérico menor de tasa de fracaso de retirada progresiva de la ECMO, y valores más altos de tasa de éxito de destete de la ventilación mecánica y días sin ventilación mecánica a los 60 días. En el grupo no prono, la mediana del cumplimiento dinámico descendió marginalmente, poco después de ECMO, pero no se observó un cambio significativo en el grupo prono. Conclusiones: La colocación en decúbito prono antes de la ECMO no se asoció con un incremento en mortalidad y tendió a ser de protección

Prone positioning before extracorporeal membrane oxygenation for severe acute respiratory distress syndrome: A retrospective multicenter study.

OBJECTIVE: To evaluate the clinical outcomes of patients with severe acute respiratory distress syndrome (ARDS) subjected to prone positioning before extracorporeal membrane oxygenation (ECMO). DESIGN: A retrospective analysis of a multicenter cohort was carried out. SETTING: Patients admitted to the Intensive Care Units of 11 hospitals in Korea. PATIENTS: Patients were divided into those who underwent prone positioning before ECMO (n=28) and those who did not (n=34). INTERVENTIONS: None. VARIABLES OF INTEREST: Thirty-day mortality, ECMO weaning failure rate, mechanical ventilation weaning success rate, mechanical ventilation-free days at day 60. RESULTS: The prone group had lower median peak inspiratory pressure and lower median dynamic driving pressure before ECMO. Thirty-day mortality was 21% in the prone group and 41% in the non-prone group (p=0.098). The prone group also showed a lower ECMO weaning failure rate, and a higher mechanical ventilation weaning success rate and more mechanical ventilation-free days at day 60. In the non-prone group, median dynamic compliance marginally decreased shortly after ECMO, but no significant change was observed in the prone group. CONCLUSIONS: Prone positioning before ECMO was not associated to increased mortality and tended to exert a protective effect.

Molecular Interactions Between Flowering Time and Abiotic Stress Pathways.

Plants have adapted to environmental changes and stresses over generations. The decision of transition from the vegetative to reproductive stage is critical, particularly under unfavorable conditions. Thus, plants appear to have developed mechanisms by which environmental factors or inputs are transmitted to stress response signaling pathways to confer tolerance and are simultaneously integrated into flowering regulation pathways (photoperiod, vernalization, autonomous, and gibberellic acid signaling) to propagate the next generation. In this review, we summarize how abiotic stresses influence, induce, or delay flowering time, particularly in the long-day plant Arabidopsis. Four major modes including FLOWERING LOCUS C (FLC), CONSTANS (CO), DELLA, and GIGANTEA (GI), which serve as hubs that integrate stress signals for regulating flowering time, are introduced. GI, a mediator of the photoperiod floral pathway and circadian clock, is involved in various biological processes and thus controls stress response directly through interaction with stress-responsive components and indirectly through association with circadian clock components.

Proposed mechanism in the change of cellular composition in the outer medullary collecting duct during potassium homeostasis.

Potassium depletion (K⁺-D) induces hypertrophy and hyperplasia of collecting duct cells, and potassium repletion (K⁺-R) induces regression of these changes. The purpose of this study was to examine the time courses of the changes in cellular composition, the origin of intercalated cells (ICs) and the mechanism responsible for these changes. SD rats received K⁺-depleted diets for 1, 7, or 14 days. After K⁺-D for 14 days some of the rats received normal diets for 1, 3, 5, or 7 days. In the inner stripe of the outer medulla, K⁺-D increased significantly the number and proportion of H⁺-ATPase-positive ICs, but decreased the proportion of H⁺-ATPase-negative principal cells (PCs). However, proliferation was limited to H⁺-ATPase-negative PCs. During K⁺-R, the cellular composition was recovered to control level. Apoptosis increased during K⁺-R and exclusively limited in H⁺-ATPase-negative PCs. Double immunolabeling with antibodies to PC and IC markers identified both cells negative or positive for all markers during both K⁺-D and K⁺-R. Electron microscopic observation showed that ultrastructure of AE1-positive some cells were similar to AE1-negative some cells during K⁺-R. LC3 protein expression increased significantly and autophagic vacuoles appeared particularly in PCs on days 14 of K⁺-D and in ICs on days 3 of K⁺-R. These results suggest that PCs and ICs may interconvert in response to changes in dietary K+ availability and that autophagic pathways may be involved in the interconversion.

The effects of midazolam on the bispectral index after fetal expulsion in caesarean section under general anaesthesia with sevoflurane.

The effects of midazolam used with low concentration inhaled anaesthetics on the bispectral index (BIS) was investigated after fetal expulsion during caesarean section. Forty-five patients undergoing caesarean section received either normal saline (control, n = 15), or an intravenous bolus of 0.03 mg/kg (n = 15) or 0.05 mg/kg (n = 15) midazolam. Changes in BIS and maternal haemodynamics were monitored before induction, on intubation, at uterine incision, on delivery, at 3, 5 and 10 min after fetal expulsion, at subcutaneous tissue closure, at skin closure, on eye opening and at extubation. BIS values in the group that received 0.05 mg/kg midazolam were significantly lower than in the other two groups at 3, 5 and 10 min after fetal expulsion, and at subcutaneous tissue closure and skin closure. Values of BIS < 60 could only be maintained with 0.05 mg/kg midazolam and there was no delay in maternal emergence or recovery.

Seismic identification of along-axis hydrothermal flow on the East Pacific Rise.

Hydrothermal circulation at the axis of mid-ocean ridges affects the chemistry of the lithosphere and overlying ocean, supports chemosynthetic biological communities and is responsible for significant heat transfer from the lithosphere to the ocean. It is commonly thought that flow in these systems is oriented across the ridge axis, with recharge occurring along off-axis faults, but the structure and scale of hydrothermal systems are usually inferred from thermal and geochemical models constrained by the geophysical setting, rather than direct observations. The presence of microearthquakes may shed light on hydrothermal pathways by revealing zones of thermal cracking where cold sea water extracts heat from hot crustal rocks, as well as regions where magmatic and tectonic stresses create fractures that increase porosity and permeability. Here we show that hypocentres beneath a well-studied hydrothermal vent field on the East Pacific Rise cluster in a vertical pipe-like zone near a small axial discontinuity, and in a band that lies directly above the axial magma chamber. The location of the shallow pipe-like cluster relative to the distribution and temperature of hydrothermal vents along this section of the ridge suggests that hydrothermal recharge may be concentrated there as a consequence of the permeability generated by tectonic fracturing. Furthermore, we interpret the band of seismicity above the magma chamber as a zone of hydrothermal cracking, which suggests that hydrothermal circulation may be strongly aligned along the ridge axis. We conclude that models that suggest that hydrothermal cells are oriented across-axis, with diffuse off-axis recharge zones, may not apply to the fast-spreading East Pacific Rise.

Posttranslational photomodulation of circadian amplitude.

The transcription-translation feedback loops that form our current view of how the core mechanism of the clock operates is being challenged, as more and more posttranslational events are seen as essential to a full understanding of oscillator function. But in addition to phosphorylation, other processes may be involved. Here, a novel mechanism of posttranslational photomodulation of circadian amplitude is described that uniquely ties together light perception, protein stabilization, and proteolysis. In the process, the waveform of a core clock component is sharpened or "sculpted," resulting in appropriately high amplitude and proper phasing to obtain normal clock function.

Effect of fresh gas flow on isoflurane concentrations during low-flow anaesthesia.

The effect of fresh gas flow (FGF) on isoflurane concentrations at given vaporizer settings during low-flow anaesthesia was investigated. Ninety patients (American Society of Anaesthesiologists physical status I or II) were randomly allocated to three groups (FGF 1 l/min, FGF 2 l/min and FGF 4 l/min). Anaesthesia was maintained for 10 min with vaporizer setting isoflurane 2 vol% and FGF 4 l/min for full-tissue anaesthetic uptake in a semi-closed circle system. Low-flow anaesthesia was maintained for 20 min with end-tidal isoflurane 1.5 vol% and FGF 2 l/min. FGF was then changed to FGF 1 l/min, FGF 2 l/min or FGF 4 l/min. Measurements during the 20-min period showed that inspired and end-tidal isoflurane concentrations decreased in the FGF 1-l/min group but increased in the FGF 4-l/min group compared with baseline values. No haemodynamic changes were observed. Monitoring of anaesthetic concentrations and appropriate control of vaporizer settings are necessary during low-flow anaesthesia.

Measurements of GnE/GnM from the 2H(e-->,en-->)1H Reaction to Q2=1.45 (GeV/c)2.

We report new measurements of the ratio of the electric form factor to the magnetic form factor of the neutron, G(n)(E)/G(n)(M), obtained via recoil polarimetry from the quasielastic 2H(e-->,e(')n-->)1H reaction at Q2 values of 0.45, 1.13, and 1.45 (GeV/c)(2) with relative statistical uncertainties of 7.6% and 8.4% at the two higher Q2 points, which points have never been achieved in polarization measurements.