The lung ultrasound in children with SARS-COV-2 infection: a national multicenter prospective study.

Coronavirus disease-19 (COVID-19) caused hospitalizations, severe disease, and deaths in any age, including in the youngest children. The aim of this multicenter national study is to characterize the clinical and the prognostic role of lung ultrasound (LU) in children with COVID-19. We enrolled children between 1 month and 18 years of age with severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection who underwent a LU within 6 h from the first medical evaluation. A total of 213 children were enrolled, 51.6% were male, median age was 2 years and 5 months (interquartile range (IQR) 4 months -11 years and 4 months). One hundred and forty-eight (69.4%) children were admitted in hospital, 9 (6.1%) in pediatric intensive care unit. We found an inverse correlation between the lung ultrasound score (LUS) and the oxygen saturation at the first clinical evaluation (r = -0.16; p = 0.019). Moreover, LUS was significantly higher in patients requiring oxygen supplementation (8 (IQR 3-19) vs 2 (IQR 0-4); p = 0.001). Among LU pathological findings, irregular pleural lines, subpleural consolidations, and pleural effusions were significantly more frequent in patients needing oxygen supplementation (p = 0.007, p = 0.006, and p = 0.001, respectively).  Conclusion: This multicenter study showed that LU in children with COVID-19 can highlight pleural line irregularities, vertical artifacts, and subpleural consolidation. Notably, children with higher LUS have a higher risk of hospitalization and need for oxygen supplementation, supporting LU as a valid and safe point-of-care first level tool for the clinical evaluation of children with COVID-19. What is Known: • Few children infected with SARS-CoV-2 develop a severe disease and need oxygen therapy. • Lung ultrasound can easily detect low respiratory tract infection during SARS-CoV-2. What is New: • Children with higher lung ultrasound score have a higher risk of need for oxygen supplementation. • Irregular pleural line, sub-pleural consolidations and pleural effusions were significantly more frequent in patients needing oxygen supplementation.

The Finely Coordinated Action of SSB and NurA/HerA Complex Strictly Regulates the DNA End Resection Process in Saccharolobus solfataricus.

Generation of the 3' overhang is a critical step during homologous recombination (HR) and replication fork rescue processes. This event is usually performed by a series of DNA nucleases and/or helicases. The nuclease NurA and the ATPase HerA, together with the highly conserved MRE11/RAD50 proteins, play an important role in generating 3' single-stranded DNA during archaeal HR. Little is known, however, about HerA-NurA function and activation of this fundamental and complicated DNA repair process. Herein, we analyze the functional relationship among NurA, HerA and the single-strand binding protein SSB from Saccharolubus solfataricus. We demonstrate that SSB clearly inhibits NurA endonuclease activity and its exonuclease activities also when in combination with HerA. Moreover, we show that SSB binding to DNA is greatly stimulated by the presence of either NurA or NurA/HerA. In addition, if on the one hand NurA binding is not influenced, on the other hand, HerA binding is reduced when SSB is present in the reaction. In accordance with what has been observed, we have shown that HerA helicase activity is not stimulated by SSB. These data suggest that, in archaea, the DNA end resection process is governed by the strictly combined action of NurA, HerA and SSB.

Silica Meets Tannic Acid: Designing Green Nanoplatforms for Environment Preservation.

Hybrid tannic acid-silica-based porous nanoparticles, TA-SiO2 NPs, have been synthesized under mild conditions in the presence of green and renewable tannic acid biopolymer, a glycoside polymer of gallic acid present in a large part of plants. Tannic acid (TA) was exploited as both a structuring directing agent and green chelating site for heavy metal ions recovery from aqueous solutions. Particles morphologies and porosity were easily tuned by varying the TA initial amount. The sample produced with the largest TA amount showed a specific surface area an order of magnitude larger than silica nanoparticles. The adsorption performance was investigated by using TA-SiO2 NPs as adsorbents for copper (II) ions from an aqueous solution. The effects of the initial Cu2+ ions concentration and the pH values on the adsorption capability were also investigated. The resulting TA-SiO2 NPs exhibited a different adsorption behaviour towards Cu2+, which was demonstrated through different tests. The largest adsorption (i.e., ~50 wt% of the initial Cu2+ amount) was obtained with the more porous nanoplatforms bearing a higher final TA content. The TA-nanoplatforms, stable in pH value around neutral conditions, can be easily produced and their use would well comply with a green strategy to reduce wastewater pollution.

Chromogenic Properties of p-Pyridinium- and p-Viologen-Calixarenes and Their Cation-Sensing Abilities.

The synthesis of calix[4]- and -[6]arene derivatives P6(H)22+·(Cl-)2, V4(H)24+·(Cl-)2·(I-)2, and V6(H)24+·(Cl-)2·(I-)2 bearing N-linked pyridinium (P) and viologen (V) units at the upper rim is described here. A rare example of an anionic conformational template is reported for p-pyridiniumcalix[6]arene P6(H)22+, which adopts a 1,3,5-alternate conformation in the presence of chloride anions. Derivatives P6(H)22+·(Cl-)2, V6(H)24+·(Cl-)2·(I-)2, and V4(H)24+·(Cl-)2·(I-)2 show a negative solvatochromism, while their UV-vis acid-base titration evidenced that upon addition of a base, new bands appear at 487, 583, and 686 nm, respectively, due to the formation of betainic monodeprotonated species P6(H)1+, V6(H)13+, and V4(H)13+. These new bands were attributable to the intramolecular charge-transfer (CT) transition from the phenoxide to the pyridinium or viologen moiety and were responsive to the presence of cations. In fact, the band at 487 nm of P6(H)1+ was quenched in the presence of a hard Li+ cation, and the color of its acetonitrile solution was changed from pink to colorless upon addition of LiI. Consequently, this derivative can be considered as a useful host for the recognition and sensing of lithium cations.

Interdomain interactions rearrangements control the reaction steps of a thermostable DNA alkyltransferase.

BACKGROUND: Alkylated DNA-protein alkyltransferases (AGTs) are conserved proteins that repair alkylation damage in DNA by using a single-step mechanism leading to irreversible alkylation of the catalytic cysteine in the active site. Trans-alkylation induces inactivation and destabilization of the protein, both in vitro and in vivo, likely triggering conformational changes. A complete picture of structural rearrangements occurring during the reaction cycle is missing, despite considerable interest raised by the peculiarity of AGT reaction, and the contribution of a functional AGT in limiting the efficacy of chemotherapy with alkylating drugs. METHODS: As a model for AGTs we have used a thermostable ortholog from the archaeon Sulfolobus solfataricus (SsOGT), performing biochemical, structural, molecular dynamics and in silico analysis of ligand-free, DNA-bound and mutated versions of the protein. RESULTS: Conformational changes occurring during lesion recognition and after the reaction, allowed us to identify a novel interaction network contributing to SsOGT stability, which is perturbed when a bulky adduct between the catalytic cysteine and the alkyl group is formed, a mandatory step toward the permanent protein alkylation. CONCLUSIONS: Our data highlighted conformational changes and perturbation of intramolecular interaction occurring during lesion recognition and catalysis, confirming our previous hypothesis that coordination between the N- and C-terminal domains of SsOGT is important for protein activity and stability. GENERAL SIGNIFICANCE: A general model of structural rearrangements occurring during the reaction cycle of AGTs is proposed. If confirmed, this model might be a starting point to design strategies to modulate AGT activity in therapeutic settings.

The BH4 domain of anti-apoptotic Bcl-XL, but not that of the related Bcl-2, limits the voltage-dependent anion channel 1 (VDAC1)-mediated transfer of pro-apoptotic Ca2+ signals to mitochondria.

Excessive Ca(2+) fluxes from the endoplasmic reticulum to the mitochondria result in apoptotic cell death. Bcl-2 and Bcl-XL proteins exert part of their anti-apoptotic function by directly targeting Ca(2+)-transport systems, like the endoplasmic reticulum-localized inositol 1,4,5-trisphosphate receptors (IP3Rs) and the voltage-dependent anion channel 1 (VDAC1) at the outer mitochondrial membranes. We previously demonstrated that the Bcl-2 homology 4 (BH4) domain of Bcl-2 protects against Ca(2+)-dependent apoptosis by binding and inhibiting IP3Rs, although the BH4 domain of Bcl-XL was protective independently of binding IP3Rs. Here, we report that in contrast to the BH4 domain of Bcl-2, the BH4 domain of Bcl-XL binds and inhibits VDAC1. In intact cells, delivery of the BH4-Bcl-XL peptide via electroporation limits agonist-induced mitochondrial Ca(2+) uptake and protects against staurosporine-induced apoptosis, in line with the results obtained with VDAC1(-/-) cells. Moreover, the delivery of the N-terminal domain of VDAC1 as a synthetic peptide (VDAC1-NP) abolishes the ability of BH4-Bcl-XL to suppress mitochondrial Ca(2+) uptake and to protect against apoptosis. Importantly, VDAC1-NP did not affect the ability of BH4-Bcl-2 to suppress agonist-induced Ca(2+) release in the cytosol or to prevent apoptosis, as done instead by an IP3R-derived peptide. In conclusion, our data indicate that the BH4 domain of Bcl-XL, but not that of Bcl-2, selectively targets VDAC1 and inhibits apoptosis by decreasing VDAC1-mediated Ca(2+) uptake into the mitochondria.

A novel thermostable protein-tag: optimization of the Sulfolobus solfataricus DNA- alkyl-transferase by protein engineering.

In the last decade, a powerful biotechnological tool for the in vivo and in vitro specific labeling of proteins (SNAP-tag™ technology) was proposed as a valid alternative to classical protein-tags (green fluorescent proteins, GFPs). This was made possible by the discovery of the irreversible reaction of the human alkylguanine-DNA-alkyl-transferase (hAGT) in the presence of benzyl-guanine derivatives. However, the mild reaction conditions and the general instability of the mesophilic SNAP-tag™ make this new approach not fully applicable to (hyper-)thermophilic and, in general, extremophilic organisms. Here, we introduce an engineered variant of the thermostable alkylguanine-DNA-alkyl-transferase from the Archaea Sulfolobus solfataricus (SsOGT-H5), which displays a catalytic efficiency comparable to the SNAP-tag™ protein, but showing high intrinsic stability typical of proteins from this organism. The successful heterologous expression obtained in a thermophilic model organism makes SsOGT-H5 a valid candidate as protein-tag for organisms living in extreme environments.

Properties of an alkali-thermo stable xylanase from Geobacillus thermodenitrificans A333 and applicability in xylooligosaccharides generation.

An extracellular thermo-alkali-stable and cellulase-free xylanase from Geobacillus thermodenitrificans A333 was purified to homogeneity by ion exchange and size exclusion chromatography. Its molecular mass was 44 kDa as estimated in native and denaturing conditions by gel filtration and SDS-PAGE analysis, respectively. The xylanase (GtXyn) exhibited maximum activity at 70 °C and pH 7.5. It was stable over broad ranges of temperature and pH retaining 88 % of activity at 60 °C and up to 97 % in the pH range 7.5-10.0 after 24 h. Moreover, the enzyme was active up to 3.0 M sodium chloride concentration, exhibiting at that value 70 % residual activity after 1 h. The presence of other metal ions did not affect the activity with the sole exceptions of K(+) that showed a stimulating effect, and Fe(2+), Co(2+) and Hg(2+), which inhibited the enzyme. The xylanase was activated by non-ionic surfactants and was stable in organic solvents remaining fully active over 24 h of incubation in 40 % ethanol at 25 °C. Furthermore, the enzyme was resistant to most of the neutral and alkaline proteases tested. The enzyme was active only on xylan, showing no marked preference towards xylans from different origins. The hydrolysis of beechwood xylan and agriculture-based biomass materials yielded xylooligosaccharides with a polymerization degree ranging from 2 to 6 units and xylobiose and xylotriose as main products. These properties indicate G. thermodenitrificans A333 xylanase as a promising candidate for several biotechnological applications, such as xylooligosaccharides preparation.

The selective BH4-domain biology of Bcl-2-family members: IP3Rs and beyond.

Anti-apoptotic Bcl-2-family members not only neutralize pro-apoptotic proteins but also directly regulate intracellular Ca(2+) signaling from the endoplasmic reticulum (ER), critically controlling cellular health, survival, and death initiation. Furthermore, distinct Bcl-2-family members may selectively regulate inositol 1,4,5-trisphosphate receptor (IP3R): Bcl-2 likely acts as an endogenous inhibitor of the IP3R, preventing pro-apoptotic Ca(2+) transients, while Bcl-XL likely acts as an endogenous IP3R-sensitizing protein promoting pro-survival Ca(2+) oscillations. Furthermore, distinct functional domains in Bcl-2 and Bcl-XL may underlie the divergence in IP3R regulation. The Bcl-2 homology (BH) 4 domain, which targets the central modulatory domain of the IP3R, is likely to be Bcl-2's determining factor. In contrast, the hydrophobic cleft targets the C-terminal Ca(2+)-channel tail and might be more crucial for Bcl-XL's function. Furthermore, one amino acid critically different in the sequence of Bcl-2's and Bcl-XL's BH4 domains underpins their selective effect on Ca(2+) signaling and distinct biological properties of Bcl-2 versus Bcl-XL. This difference is evolutionary conserved across five classes of vertebrates and may represent a fundamental divergence in their biological function. Moreover, these insights open novel avenues to selectively suppress malignant Bcl-2 function in cancer cells by targeting its BH4 domain, while maintaining essential Bcl-XL functions in normal cells. Thus, IP3R-derived molecules that mimic the BH4 domain's binding site on the IP3R may function synergistically with BH3-mimetic molecules selectivity suppressing Bcl-2's proto-oncogenic activity. Finally, a more general role for the BH4 domain on IP3Rs, rather than solely anti-apoptotic, may not be excluded as part of a complex network of molecular interactions.

Autoimmune Polyendocrine Syndromes in Adult Italian Celiac Disease Patients.

Celiac disease (CD) is frequently associated with other autoimmune disorders. Different studies have explored the association between CD and single autoimmune endocrine disease (AED), especially autoimmune thyroiditis (AIT) and type-1 diabetes mellitus (T1DM). Data about CD as a component of autoimmune polyendocrine syndrome (APS) are scant. We analyzed a large dataset including prospectively collected data from 920 consecutive adult CD patients diagnosed in a third-level Italian institution in the 2013-2023 period, The prevalence of isolated autoimmune endocrine diseases and APS were collected. A total of 262 (28.5%) CD patients had at least one associated AED, with AIT (n = 223, 24.2%) and T1DM (n = 27, 2.9%) being the most frequent conditions. In most cases (n = 173, 66%), AEDs were diagnosed after CD. Thirteen patients (1.4%) had at least two of the requested three endocrinopathies, satisfying the diagnosis of type 2 APS. APS-2 is a rare but not exceptional occurrence among Italian CD patients, underscoring the intricate and multifaceted nature of autoimmune disorders. Periodic evaluations of thyroid function and glycaemia should be recommended after the diagnosis of CD together with testing for autoantibodies that may be helpful in assessing disease risk before disease onset. Likewise, implementation of a systematic screening for CD amongst T1DM and other autoimmune endocrine diseases are paramount.

Induction of Ca²+-driven apoptosis in chronic lymphocytic leukemia cells by peptide-mediated disruption of Bcl-2-IP3 receptor interaction.

Bcl-2 contributes to the pathophysiology and therapeutic resistance of chronic lymphocytic leukemia (CLL). Therefore, developing inhibitors of this protein based on a thorough understanding of its mechanism of action is an active and promising area of inquiry. One approach centers on agents (eg, ABT-737) that compete with proapoptotic members of the Bcl-2 protein family for binding in the hydrophobic groove formed by the BH1-BH3 domains of Bcl-2. Another region of Bcl-2, the BH4 domain, also contributes to the antiapoptotic activity of Bcl-2 by binding to the inositol 1,4,5-trisphosphate receptor (IP3R) Ca²(+) channel, inhibiting IP(3)-dependent Ca²(+) release from the endoplasmic reticulum. We report that a novel synthetic peptide, modeled after the Bcl-2-interacting site on the IP3R, binds to the BH4 domain of Bcl-2 and functions as a competitive inhibitor of the Bcl-2-IP3R interaction. By disrupting the Bcl-2-IP3R interaction, this peptide induces an IP3R-dependent Ca²(+) elevation in lymphoma and leukemia cell lines and in primary CLL cells. The Ca²(+) elevation evoked by this peptide induces apoptosis in CLL cells, but not in normal peripheral blood lymphocytes, suggesting the involvement of the Bcl-2-IP3R interaction in the molecular mechanism of CLL and indicating the potential merit of targeting this interaction therapeutically.

Direct oral anticoagulants for the treatment of splanchnic vein thrombosis: A state of art.

Splanchnic vein thrombosis (SVT) is a manifestation of venous thromboembolism in an unusual site. Portal, mesenteric, and splenic veins are the most common vessels involved in SVT which occurs mainly in patients with liver cirrhosis, although non-cirrhotic patients could be affected as well. Thrombosis of hepatic veins, also known as Budd-Chiari syndrome, is another manifestation of SVT. Prompt diagnosis and intervention are mandatory in order to increase the recalization rate and reduce the risk of thrombus progression and hypertensive complications. Traditional anticoagulation with heparin and vitamin-K antagonists is the treatment of choice in these cases. However, recent studies have shown promising results on the efficacy and safety of direct oral anticoagulants (DOACs) in this setting. Available results are mainly based on retrospective studies with small sample size, but first clinical trials have been published in the last years. This manuscript aims to provide an updated overview of the current evidence regarding the role of DOACs for SVT in both cirrhotic and non-cirrhotic patients.

The IP(3) receptor-mitochondria connection in apoptosis and autophagy.

The amount of Ca(2+) taken up in the mitochondrial matrix is a crucial determinant of cell fate; it plays a decisive role in the choice of the cell between life and death. The Ca(2+) ions mainly originate from the inositol 1,4,5-trisphosphate (IP(3))-sensitive Ca(2+) stores of the endoplasmic reticulum (ER). The uptake of these Ca(2+) ions in the mitochondria depends on the functional properties and the subcellular localization of the IP(3) receptor (IP(3)R) in discrete domains near the mitochondria. To allow for an efficient transfer of the Ca(2+) ions from the ER to the mitochondria, structural interactions between IP(3)Rs and mitochondria are needed. This review will focus on the key proteins involved in these interactions, how they are regulated, and what are their physiological roles in apoptosis, necrosis and autophagy. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.

Profiling of the Bcl-2/Bcl-X(L)-binding sites on type 1 IP(3) receptor.

Several members of the anti-apoptotic Bcl-2-protein family, including Bcl-2, Bcl-X(L) and Mcl-1, directly bind and regulate the inositol 1,4,5-trisphosphate receptor (IP(3)R), one of the two main intracellular Ca(2+)-release channel types present in the endoplasmic reticulum. However, the molecular determinants underlying their binding to the IP(3)R remained a matter of debate. One interaction site for Bcl-2 was proposed in the central part of the modulatory domain [Y.P. Rong, A.S. Aromolaran, G. Bultynck, F. Zhong, X. Li, K. McColl, S. Matsuyama, S. Herlitze, H.L. Roderick, M.D. Bootman, G.A. Mignery, J.B. Parys, H. De Smedt, C.W. Distelhorst, Targeting Bcl-2-IP3 receptor interaction to reverse Bcl-2's inhibition of apoptotic calcium signals, Mol. Cell 31 (2008) 255-265] and another site in the C-terminal domain of the IP(3)R encompassing the sixth transmembrane domain, to which Bcl-2, Bcl-X(L) and Mcl-1 can bind [E.F. Eckenrode, J. Yang, G.V. Velmurugan, J.K. Foskett, C. White, Apoptosis protection by Mcl-1 and Bcl-2 modulation of inositol 1,4,5-trisphosphate receptor-dependent Ca(2+) signaling, J. Biol. Chem. 285 (2010) 13678-13684]. Here, we investigated and compared the binding of Bcl-2 and Bcl-X(L) to both sites. Two different IP(3)R domains were used for the C-terminal site: one lacking and one containing the sixth transmembrane domain. Our results show that elements preceding the C-terminal cytosolic tail located at the sixth transmembrane domain of IP(3)R1 were critical for recruiting both Bcl-2 and Bcl-X(L) to the C-terminal part of the IP(3)R. Furthermore, consistent with our previous observations, Bcl-X(L) bound with higher efficiency to the C-terminal part of the IP(3)R and to a much lesser extent to the central, modulatory domain, while Bcl-2 targeted both sites with similar efficiencies. In conclusion, IP(3)R harbors two different binding sites for anti-apoptotic Bcl-2 proteins, one in the central, modulatory domain and one in the C-terminal domain near the Ca(2+)-channel pore.

Odorant receptors at the growth cone are coupled to localized cAMP and Ca2+ increases.

A distinctive feature in the topographic organization of the olfactory system in mammals is the dual function of the odorant receptor (OR): it detects odors in the nasal epithelium and plays an instructive role in the axonal convergence of olfactory sensory neurons (OSN) into the olfactory bulb (OB). The latter function is supported by genetic experiments and by the expression of the OR not only on the cilia, but also on the axon termini of the OSN. The signaling pathway coupled to the OR on the cilia is well known and is recognized to involve cAMP and Ca(2+), whereas, until now, nothing was known on the functional characteristics of the OR on the axon termini-growth cone. Here, by analyzing the spatiotemporal dynamics of cAMP and Ca(2+) in living OSN in vitro and in situ, we found that the OR at the growth cone is capable of binding odors and is coupled to cAMP synthesis and Ca(2+) influx through cyclic nucleotide gated (CNG) channels. Furthermore we found that selective odor activation of the OR on the growth cone is followed by nuclear translocation of protein kinase A catalytic subunit. These results define the functional properties of the OR on the growth cone and suggest a potential role of OR activation in axonal convergence and sensory map formation.

Budgeting at the Ca2+ store: a PIP(2)eline to starve LSCs?

The oxysterol-binding protein-related proteins (ORPs) have emerged as orchestrators of phosphatidylinositol-4,5-bisphosphate (PIP2) and cholesterol trafficking to the plasma membrane (PM). In this scenario, recent studies raised the prospect of ORPs cooperative behavior in sustaining leukemia stem cells (LSCs) survival by remotely enhancing ER-mitochondria Ca2+ communication. At the apex of the signaling cascade, the aberrantly upregulated LSC-ORP4L fosters PM-PIP2 extraction & cleavage, endoplasmic reticulum (ER)-Ca2+ release and mitochondrial energetics. The theoretical ember of draining fuel from the chemoresistant LSCs by restraining endoplasmic reticulum (ER)-mitochondria Ca2+ fluxes in a lipid-contingent fashion ensues. In light of relevant literature, this review briefly and critically discusses some key molecular ins & outs underlying such therapeutic opportunity in acute myeloid leukemia (AML).

Critical Temperatures for Vibrations and Buckling of Magneto-Electro-Elastic Nonlocal Strain Gradient Plates.

An analytical method is presented in this work for the linear vibrations and buckling of nano-plates in a hygro-thermal environment. Nonlinear von Kármán terms are included in the plate kinematics in order to consider the instability phenomena. Strain gradient nonlocal theory is considered for its simplicity and applicability with respect to other nonlocal formulations which require more parameters in their analysis. Present nano-plates have a coupled magneto-electro-elastic constitutive equation in a hygro-thermal environment. Nano-scale effects on the vibrations and buckling behavior of magneto-electro-elastic plates is presented and hygro-thermal load outcomes are considered as well. In addition, critical temperatures for vibrations and buckling problems are analyzed and given for several nano-plate configurations.

Corrigendum to "Superoxide Anion Production and Bioenergetic Profile in Young and Elderly Human Primary Myoblasts".

[This corrects the article DOI: 10.1155/2018/2615372.].

Small molecule 3PO inhibits glycolysis but does not bind to 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3).

6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase isoform 3 (PFKFB3) is a key enzyme of the glycolytic pathway, and it plays an essential role in angiogenesis. 3-(3-Pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO) is frequently used as a glycolysis inhibitor and is thought to inhibit PFKFB3. However, this latter effect of 3PO has never been investigated in detail and was the aim of the present study. To demonstrate binding of 3PO to PFKFB3, we used isothermal titration calorimetry. However, 3PO did not bind to PFKFB3, even up to 750 µm, in contrast to 3 µm of AZ67, which is a potent and specific PFKFB3 inhibitor. Instead, 3PO accumulated lactic acid inside the cells, leading to a decrease in the intracellular pH and an inhibition of enzymatic reactions of the glycolytic pathway.