In Vivo Study of HIV-1 Tat Arginine-rich Motif Unveils Its Transport Properties

Tat-derived peptides have attracted much interest as molecular carriers for intracellular delivery as they incorporate specific attributes required for efficient cargo delivery to sub-cellular domains. Little is known, however, about intracellular trafficking and interactions of Tat peptide–tagged cargoes, although some in vitro studies have suggested the relevance of active processes in Tat peptide–driven nuclear translocation. These issues are addressed by comparing Tat peptide–induced transport properties with well-established passive diffusion and active import benchmarks in living cells. Specifically, we examine several constructs of increasing molecular weight (MW) both below and above the threshold for passive diffusion through the nuclear pore. The resulting sub-cellular localization is analyzed by confocal imaging, and construct intracellular dynamics is investigated by fluorescence recovery after photobleaching (FRAP) real-time imaging. Our experiments yield the characteristic transport parameters of Tat peptide intra-cytoplasm dynamics and nucleus/cytoplasm shuttling. These results allow us to elucidate the mechanism of Tat peptide–driven nuclear permeation, demonstrating that it crosses the nuclear envelope (NE) by passive diffusion. Finally, we discuss the limitations of this route in terms of acceptable cargo size

Datos de evaluación preanestésica no influyen en el tiempo de intubación traqueal con el videolaringoscopio Airtraq® en pacientes obesos

ResumenObjetivoel objetivo de este estudio fue evaluar la influencia de los predictores anatómicos en la laringoscopia e intubación orotraqueal difíciles en pacientes obesos comparando el laringoscopio Macintosh y el videolaringoscopio Airtraq®.Métodosen 132 pacientes sometidos a cirugía bariátrica (índice de masa corporal≥35kg/m2), se registraron los valores de perímetro cervical, distancia mentoesternal, distancia interincisivos y puntuación de Mallampati. Los pacientes fueron aleatorizados en 2 grupos de acuerdo con el uso de los laringoscopios Macintosh (n=64) o Airtraq® (n=68) para intubación traqueal. El resultado primario fue el tiempo necesario para la intubación. Se registraron la puntuación de Cormack-Lehane, el número de intentos de intubación, el uso de lámina Macintosh y cualquier necesidad de compresión traqueal externa o la utilización de introductor del tubo traqueal. Las estrategias de intubación adoptadas y los fallos de las intubaciones también fueron recogidos en el informe.Resultadosen el grupo Macintosh, 2 pacientes presentaron fallo en la intubación y fueron incluidos como los peores casos de intubación. Los tiempos de intubación fueron 36,9±22,8s y 13,7±3,1s para los grupos Macintosh y Airtraq® (p<0,01), respectivamente. Las puntuaciones de Cormack-Lehane también fueron menores para el grupo Airtraq®. Un paciente del grupo Macintosh con fallo de intubación fue rápidamente intubado con el Airtraq®. La circunferencia cervical (p<0,01) y la distancia interincisivos (p<0,05) influyeron en el tiempo necesario para la intubación en el grupo Macintosh, pero no en el grupo Airtraq®.Conclusiónen los pacientes obesos, a pesar del aumento de la circunferencia del cuello y de la abertura limitada de la boca, el laringoscopio Airtraq® ofrece una intubación traqueal más rápida que el laringoscopio Macintosh, pudiendo servir como una alternativa cuando la laringoscopia convencional falle

Two dimensional patterning of fluorescent proteins in hydrogels.

This work describes the successful micropatterning of hybrid systems consisting of hydrogel-dispersed optically active and controllable proteins on solid surfaces without degradation of the photophysical properties of the light-emitting biomolecules. It demonstrates the preservation of the luminescence properties of proteins entrapped into isolated microstructures of poly(acrylamide) gel. This way we can exploit both the structural and function-preserving properties of the hydrogels and the functionality of light-emitting proteins. We believe that this approach can open the way to the realization of nanopatterned optical memories based on photochromic biomolecules

Intracortical and interhemispheric excitability changes in arm amputees: A TMS study

Objective: To evaluate cortical circuits and excitability of the motor cortex in the hemisphere contralateral to the affected (AH) and to the unaffected arm (UH), in upper limb amputees. Methods: Motor evoked potentials (MEP) were recorded in 17 subjects who had upper limb amputation: 11 trans-radial (TR) and 6 trans-humeral (TH). Motor thresholds (MT), short interval intracortical inhibition (SICI), and interhemispheric inhibition (IHI) in the available arm muscles of the stump were evaluated. Results: There was no significant difference in MT between hemispheres. SICI was preserved in TR but not in TH group. Additionally, in the TR group, the MEP amplitudes in AH were higher than in UH. A significant IHI was observed in the whole sample but not in each hemisphere or patient group. Conclusions: In our population of TR amputees, we found increased corticospinal excitability in the AH with preserved intracortical inhibition. This finding was not observed in the TH population. Significance: Understanding the changes in intracortical excitability in amputees may enhance knowledge of the functional reorganization of the brain in the post-amputation phase, bringing useful information for prosthetic rehabilitation

Molecular Mechanisms of AKI in the Elderly: From Animal Models to Therapeutic Intervention

Acute kidney injury (AKI), a critical syndrome characterized by a sudden reduction of renal function, is a common disorder among elderly patients particularly in Intensive Care Unit (ICU). AKI is closely associated with both short- and long-term mortality and length of hospital stay and is considered a predictor of chronic kidney disease (CKD). Specific hemodynamic, metabolic, and molecular changes lead to increased susceptibility to injury in the aged kidney; therefore, certain causes of AKI such as the prerenal reduction in renal perfusion or vascular obstructive conditions are more common in the elderly; moreover, AKI is often multifactorial and iatrogenic. Older patients present several comorbidities (diabetes, hypertension, heart failure) and are exposed to multiple medical interventions such as the use of nephrotoxic contrasts media and medications, which can also trigger AKI. Considering the emerging relevance of this condition, prevention and treatment of AKI in the elderly should be crucial in the internist and emergency setting. This review article summarizes the incidence, the risk factors, the pathophysiology, the molecular mechanisms and the strategies of prevention and treatment of AKI in elderly patients

Biorefinery of olive leaves to produce dry oleuropein aglycone:use of homemade ceramic capillary biocatalytic membranes in a multiphase system

Oleuropein aglycone is an important antioxidant compound produced during oleuropein hydrolysis, not yet commercially available. Its production from renewable material by green processes is a challenge because it permits waste re-use and low environmental impact. In this work, homemade asymmetric capillary ceramic membranes were used to develop biocatalytic membranes, which were further used to produce oleuropein aglycone from olive leaves and/or commercial oleuropein. Results indicated that the biocatalytic system (containing covalently immobilized β-glucosidase) promotes the hydrolysis of oleuropein in both monophase and multiphase processes. Furthermore, the multiphase biocatalytic system enables the extraction of the hydrophobic oleuropein aglycone in an organic phase, before its rearrangement in water. This was achieved by the production, of an unstable water-in-oil emulsion (permeate side), on the basis of membrane emulsification process. The intensified biocatalytic/extractor system allowed taking shelter the hydrophobic compound in the organic phase with good efficiency (90%), protecting it from rearrangement

Static compliance and driving pressure are associated with ICU mortality in intubated COVID-19 ARDS

Background Pathophysiological features of coronavirus disease 2019-associated acute respiratory distress syndrome (COVID-19 ARDS) were indicated to be somewhat different from those described in nonCOVID-19 ARDS, because of relatively preserved compliance of the respiratory system despite marked hypoxemia. We aim ascertaining whether respiratory system static compliance (Crs), driving pressure (DP), and tidal volume normalized for ideal body weight (VT/kg IBW) at the 1st day of controlled mechanical ventilation are associated with intensive care unit (ICU) mortality in COVID-19 ARDS. Methods Observational multicenter cohort study. All consecutive COVID-19 adult patients admitted to 25 ICUs belonging to the COVID-19 VENETO ICU network (February 28th-April 28th, 2020), who received controlled mechanical ventilation, were screened. Only patients fulfilling ARDS criteria and with complete records of Crs, DP and VT/kg IBW within the 1st day of controlled mechanical ventilation were included. Crs, DP and VT/kg IBW were collected in sedated, paralyzed and supine patients. Results A total of 704 COVID-19 patients were screened and 241 enrolled. Seventy-one patients (29%) died in ICU. The logistic regression analysis showed that: (1) Crs was not linearly associated with ICU mortality (p value for nonlinearity = 0.01), with a greater risk of death for values &lt; 48 ml/cmH(2)O; (2) the association between DP and ICU mortality was linear (p value for nonlinearity = 0.68), and increasing DP from 10 to 14 cmH(2)O caused significant higher odds of in-ICU death (OR 1.45, 95% CI 1.06-1.99); (3) VT/kg IBW was not associated with a significant increase of the risk of death (OR 0.92, 95% CI 0.55-1.52). Multivariable analysis confirmed these findings. Conclusions Crs &lt; 48 ml/cmH(2)O was associated with ICU mortality, while DP was linearly associated with mortality. DP should be kept as low as possible, even in the case of relatively preserved Crs, irrespective of VT/kg IBW, to reduce the risk of death