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Resolution (global and local) is one of the most reported metrics of quality measurement in Single Particle Analysis (SPA). However, in electron tomography, the situation is different and its computation is not straightforward. Typically, resolution estimation is global and, therefore, reduces the assessment of a whole tomogram to a single number. However, it is known that tomogram quality is spatially variant. Still, up to our knowledge, a method to estimate local quality metrics in tomography is lacking. This work introduces MonoTomo, a method developed to estimate locally in a tomogram the highest reliable frequency component, expressed as a form of local resolution. The fundamentals lie in a local analysis of the density map via monogenic signals, which, in analogy to MonoRes, allows for local estimations. Results with experimental data show that the local resolution range that MonoTomo casts agrees with reported resolution values for experimental data sets, with the advantage of providing a local estimation. A range of applications of MonoTomo are suggested for further exploration.

Parkinson disease (PD) is the second-most common age-related neurodegenerative disease and is characterized by the selective destruction of dopaminergic neurons. Increasing evidence indicates that oxidative stress plays a crucial role in the pathogenesis of idiopathic PD. Anti-oxidant agents including catalase, manganese porphyrin and pyruvate confer cytoprotection to different cell cultures when challenged with 6-hydroxydopamine (6-OHDA). Herein we used rat cerebellar granular cell cultures to ascertain the plausible cellular pathways involved in pyruvate-induced cytoprotection against 0.1 mM 6-OHDA. Pyruvate provided cytoprotection in a concentration-dependent manner (2–10 mM). Consistent with its well-established anti-oxidant capacity, pyruvate (10 mM) prevented 6-OHDA-induced lipid peroxidation by blocking the rise in intracellular peroxides and maintaining the intracellular reduced glutathione (GSH) levels. Further experiments revealed that pyruvate increased Akt, but not extracellular signal-regulated kinase phosphorylation. Moreover, phosphatidylinositol 3-kinase (PI3K) inhibitors attenuated pyruvate-induced cytoprotection indicating that PI3K-mediated Akt activation is necessary for pyruvate to induce cytoprotection. On the other hand, pyruvate also up-regulated glutathione peroxidase mRNA levels, but not those of the anti-oxidant enzymes superoxide dismutase-1 and -2, catalase or the anti-apoptotic oncogenes Bcl-2 or Bcl-xL. In summary, our results strongly suggest that pyruvate, besides the anti-oxidant properties related to its structure, exerts cytoprotective actions by activating different anti-apoptotic routes that include gene regulation and Akt pathway activation.

Background and Objectives: Acute kidney injury (AKI) is common among hospitalized patients with COVID-19 and associated with worse prognosis. The Spanish Society of Nephrology created the AKI-COVID Registry to characterize the population admitted for COVID-19 that developed AKI in Spanish hospitals. The need of renal replacement therapy (RRT) therapeutic modalities, and mortality in these patients were assessed., Material and Method: In a retrospective study, we analyzed data from the AKI-COVID Registry, which included patients hospitalized in 30 Spanish hospitals from May 2020 to November 2021. Clinical and demographic variables, factors related to the severity of COVID-19 and AKI, and survival data were recorded. A multivariate regression analysis was performed to study factors related to RRT and mortality., Results: Data from 730 patients were recorded. A total of 71.9% were men, with a mean age of 70 years (60-78), 70.1% were hypertensive, 32.9% diabetic, 33.3% with cardiovascular disease and 23.9% had some degree of chronic kidney disease (CKD). Pneumonia was diagnosed in 94.6%, requiring ventilatory support in 54.2% and admission to the ICU in 44.1% of cases.The median time from the onset of COVID-19 symptoms to the appearance of AKI (37.1% KDIGO I, 18.3% KDIGO II, 44.6% KDIGO III) was 6 days (4-10). A total of 235 (33.9%) patients required RRT: 155 patients with continuous renal replacement therapy, 89 alternate-day dialysis, 36 daily dialysis, 24 extended hemodialysis and 17 patients with hemodiafiltration. Smoking habit (OR 3.41), ventilatory support (OR 20.2), maximum creatinine value (OR 2.41) and time to AKI onset (OR 1.13) were predictors of the need for RRT; age was a protective factor (0.95). The group without RRT was characterized by older age, less severe AKI, shorter kidney injury onset and recovery time ( p  < 0.05). 38.6% of patients died during hospitalization; serious AKI and RRT were more frequent in the death group. In the multivariate analysis, age (OR 1.03), previous chronic kidney disease (OR 2.21), development of pneumonia (OR 2.89), ventilatory support (OR 3.34) and RRT (OR 2.28) were predictors of mortality while chronic treatment with ARBs was identified as a protective factor (OR 0.55)., Conclusions: Patients with AKI during hospitalization for COVID-19 had a high mean age, comorbidities and severe infection. We defined two different clinical patterns: an AKI of early onset, in older patients that resolves in a few days without the need for RRT; and another more severe pattern, with greater need for RRT, and late onset, which was related to greater severity of the infectious disease. The severity of the infection, age and the presence of CKD prior to admission were identified as risk factors for mortality in these patients. In addition chronic treatment with ARBs was identified as a protective factor for mortality., (© 2023 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U.)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia emerged in Wuhan, China in December 2019. Unfortunately, there is a lack of evidence about the optimal management of novel coronavirus disease 2019 (COVID-19), and even less is available in patients on maintenance hemodialysis therapy than in the general population. In this retrospective, observational, single-center study, we analyzed the clinical course and outcomes of all maintenance hemodialysis patients hospitalized with COVID-19 from March 12th to April 10th, 2020 as confirmed by real-time polymerase chain reaction. Baseline features, clinical course, laboratory data, and different therapies were compared between survivors and nonsurvivors to identify risk factors associated with mortality. Among the 36 patients, 11 (30.5%) died, and 7 were able to be discharged within the observation period. Clinical and radiological evolution during the first week of admission were predictive of mortality. Among the 36 patients, 18 had worsening of their clinical status, as defined by severe hypoxia with oxygen therapy requirements greater than 4 L/min and radiological worsening. Significantly, 11 of those 18 patients (61.1%) died. None of the classical cardiovascular risk factors in the general population were associated with higher mortality. Compared to survivors, nonsurvivors had significantly longer dialysis vintage, increased lactate dehydrogenase (490 U/l ± 120 U/l vs. 281 U/l ± 151 U/l, P = 0.008) and C-reactive protein levels (18.3 mg/dl ± 13.7 mg/dl vs. 8.1 mg/dl ± 8.1 mg/dl, P = 0.021), and a lower lymphocyte count (0.38 ×10 3 /µl ± 0.14 ×10 3 /µl vs. 0.76 ×10 3 /µl ± 0.48 ×10 3 /µl, P = 0.04) 1 week after clinical onset. Thus, the mortality among hospitalized hemodialysis patients diagnosed with COVID-19 is high. Certain laboratory tests can be used to predict a worsening clinical course., (Copyright © 2020 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

The cellulosome is a highly elaborate cell-bound multienzyme complex that efficiently orchestrates the deconstruction of cellulose and hemicellulose, two of the nature's most abundant polymers. Understanding the intricacy of these nanomachines evolved by anaerobic microbes could sustain the development of an effective process for the conversion of lignocellulosic biomass to bio-ethanol. In Clostridium thermocellum, cellulosome assembly is mediated by high-affinity protein:protein interactions (>10(9) M(-1)) between dockerin modules found in the catalytic subunits and cohesin modules located in a non-catalytic protein scaffold termed CipA. Whereas the atomic structures of several cellulosomal components have been elucidated, the structural organization of the complete cellulosome remains elusive. Here, we reveal that a large fragment of the cellulosome presents a mostly compact conformation in solution, by solving the three-dimensional structure of a C. thermocellum mini-cellulosome comprising three consecutive cohesin modules, each bound to one Cel8A cellulase, at 35 Å resolution by cryo-electron microscopy. Interestingly, the three cellulosomal catalytic domains are found alternately projected outward from the CipA scaffold in opposite directions, in an arrangement that could expand the area of the substrate accessible to the catalytic domains. In addition, the cellulosome can transit from this compact conformation to a multitude of diverse and flexible structures, where the linkers between cohesin modules are extended and flexible. Thus, structural transitions controlled by changes in the degree of flexibility of linkers connecting consecutive cohesin modules could regulate the efficiency of substrate recognition and hydrolysis., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Vasculitis is diagnosed with increasing frequency in the elderly. We hereby present the case of an 84-year-old male, who had weight loss, low-degree fever, anemia and epigastric pain. After 14 days of study with the tentative diagnosis of digestive neoplasia, a progressive renal insufficiency was detected. This clinical picture was secondary to ANCA-positive vasculitis. The case poses the differential diagnosis of non-oliguric acute renal failure (FRA) in elder people and the systematics of the study of renal insufficiency in individuals with previously unknown renal function. Also, this patient's history emphasizes the importance of acute deterioration of renal function as a guiding symptom for orienting the interpretation of clinical data. In the present case, a diagnostic hypothesis based only in the pursue of an occult digestive tumor misguided the attention from the main cause of the disease.

Background: Sevelamer is a non-absorbable phosphorus chelator that is not a source of aluminium, calcium or base. The clinical experience with sevelamer in peritoneal dialysis and in daily clinical practice is scarce. The aim of this study is to evaluate the results of therapy of hyperphosphoremia with sevelamer on serum phosphorus and phosphorus chelators requirements, in a peritoneal dialysis clinical practice., Methods: Sevalamer 400 mg was prescribed to peritoneal dialysis patients with hyperphosphoremia who were treated with aluminium hydroxide or with calcium salts in the absence of hypocalcemia. Fourteen patients completed 12 months of therapy., Results: The initial sevelamer dose was 2,280 +/- 760 mg/day, and was increased to 2,760 +/- 1,160 mg/day at 12 months. At 12 months no patient was on aluminium salts and calcium salts had been significantly reduced. Phosphoremia (5.9 +/- 0.6 to 5.0 +/- 1.4 mg/dL, p = 0.049), calcium-phosphorus product (59.8 +/- 5.8 to 48.6 +/- 12.5 mg2/dL2, p = 0.01) and serum cholesterol (191 +/- 29 to 167 +/- 33 mg/dL, p = 0.02) decreased at 12 months. No significant changes were observed in serum triglycerides, total CO2 or PTH. Serum alkaline phosphatase increased at 6 months, but values returned to normal at 12 months. No changes were observed in serum gamma-glutamyl-transpeptidase. Five patients were started on 1.25 (OH)2 vitamin D therapy., Conclusion: In peritoneal dialysis patients, sevelamer allows a satisfactory control of serum phosphorus levels and calcium-phosphorus product, while decreasing the amount of aluminium and calcium salts prescribed.