Yeast as a Tool to Study Signaling Pathways in Mitochondrial Stress Response and Cytoprotection

Cell homeostasis results from the balance between cell capability to adapt or succumb to environmental stress. Mitochondria, in addition to supplying cellular energy, are involved in a range of processes deciding about cellular life or death. The crucial role of mitochondria in cell death is well recognized. Mitochondrial dysfunction has been associated with the death process and the onset of numerous diseases. Yet, mitochondrial involvement in cellular adaptation to stress is still largely unexplored. Strong interest exists in pharmacological manipulation of mitochondrial metabolism and signaling. The yeast Saccharomyces cerevisiae has proven a valuable model organism in which several intracellular processes have been characterized in great detail, including the retrograde response to mitochondrial dysfunction and, more recently, programmed cell death. In this paper we review experimental evidences of mitochondrial involvement in cytoprotection and propose yeast as a model system to investigate the role of mitochondria in the cross-talk between prosurvival and prodeath pathways

Spatial summation in the glaucomatous macula: a link with retinal ganglion cell damage

Purpose: to test whether functional loss in the glaucomatous macula is characterised by an enlargement of Ricco’s area (RA) through the application of a computational model linking retinal ganglion cell (RGC) damage to perimetric sensitivity Methods: one eye from each of 29 visually-healthy subjects <40 years old, 30 glaucoma patients and 20 age-similar controls was tested with a 10-2 grid with stimuli of five different area sizes. Structural estimates of point-wise RGC density were obtained from Optical Coherence Tomography scans. Structural and functional data from the young healthy cohort were used to estimate the parameters of a computational spatial summation model to generate a template. The template was fitted with a Bayesian hierarchical model to estimate the latent RGC density in glaucoma patients and agematched controls. We tested two alternative hypotheses: fitting the data by translating the template horizontally (H1: change in RA) or vertically (H2: loss of sensitivity without change in RA). Root Mean Squared Error (RMSE) of the model fits to perimetric sensitivity were compared. 95%-Confidence Intervals were bootstrapped. The dynamic range of the functional and structural RGC density estimates was denoted by their 1st and the 99th percentile. Results: the RMSE was 2.09 [1.92-2.26] under H1 and 2.49 [2.24-2.72] under H2 (p < 0.001). The average dynamic range for the structural RGC density estimates was only 11% that of the functional estimates. Conclusions: macular sensitivity loss in glaucoma is better described by a model in which RA changes with RGC loss. Structural measurements have limited dynamic range

Induction of autophagy by spermidine promotes longevity.

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Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study

Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak. Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study. Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM. Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide

Predictive simulation of mechanical behavior from 3D laser scans of violin plates

In this paper we present a methodology for the predictive simulation of the vibrometric behaviour of a violin plate. The 3D outer shape of the plate is acquired by means of a 3D laser scanner and then smoothed in order to remove artefacts and details that are unnecessary for the acoustics simulation. The thickness of the plate is incorporated into the model through a technique that receives as input the thickness sampled at some points of the plate and interpolates it over the entire surface. We validate this 3D reconstruction technique by comparing the vibrometric behaviour of the 3D model with data measured on the reference plate, and with simulations on a model with uniform thicknes