Infrared spectra of SinH4n-1+ ions (n = 2-8): inorganic H-(Si-H)n-1 hydride wires of penta-coordinated Si in 3c-2e and charge-inverted hydrogen bonds.

SinHm+ cations are important constituents in silane plasmas and astrochemical environments. Protonated disilane (Si2H7+) was shown to have a symmetric three-centre two-electron (3c-2e) Si-H-Si bond that can also be considered as a strong ionic charge-inverted hydrogen bond with polarity Siδ+-Hδ--Siδ+. Herein, we extend our previous work to larger SinH4n-1+ cations, formally resulting from adding SiH4 molecules to a SiH3+ core. Infrared spectra of size-selected SinH4n-1+ ions (n = 2-8) produced in a cold SiH4/H2/He plasma expansion are analysed in the SiH stretch range by complementary dispersion-corrected density functional theory calculations (B3LYP-D3/aug-cc-pVTZ) to reveal their bonding characteristics and cluster growth. The ions with n = 2-4 form a linear inorganic H-(Si-H)n hydride wire with adjacent Si-H-Si 3c-2e bridges, whose strength decreases with n, as evident from their characteristic and strongly IR active SiH stretch fundamentals in the range 1850-2100 cm-1. These 3c-2e bonds result from the lowest-energy valence orbitals, and their high stability arises from their delocalization along the whole hydride wire. For SinH4n-1+ with n ≥ 5, the added SiH4 ligands form weak van der Waals bonds to the Si4H19+ chain. Significantly, because the SinH4n-1+ hydride wires are based on penta-coordinated Si atoms leading to supersaturated hydrosilane ions, analogous wires cannot be formed by isovalent carbon.

The N1 domain of the peroxisomal AAA-ATPase Pex6 is required for Pex15 binding and proper assembly with Pex1.

The heterohexameric ATPases associated with diverse cellular activities (AAA)-ATPase Pex1/Pex6 is essential for the formation and maintenance of peroxisomes. Pex1/Pex6, similar to other AAA-ATPases, uses the energy from ATP hydrolysis to mechanically thread substrate proteins through its central pore, thereby unfolding them. In related AAA-ATPase motors, substrates are recruited through binding to the motor's N-terminal domains or N terminally bound cofactors. Here, we use structural and biochemical techniques to characterize the function of the N1 domain in Pex6 from budding yeast, Saccharomyces cerevisiae. We found that although Pex1/ΔN1-Pex6 is an active ATPase in vitro, it does not support Pex1/Pex6 function at the peroxisome in vivo. An X-ray crystal structure of the isolated Pex6 N1 domain shows that the Pex6 N1 domain shares the same fold as the N-terminal domains of PEX1, CDC48, and NSF, despite poor sequence conservation. Integrating this structure with a cryo-EM reconstruction of Pex1/Pex6, AlphaFold2 predictions, and biochemical assays shows that Pex6 N1 mediates binding to both the peroxisomal membrane tether Pex15 and an extended loop from the D2 ATPase domain of Pex1 that influences Pex1/Pex6 heterohexamer stability. Given the direct interactions with both Pex15 and the D2 ATPase domains, the Pex6 N1 domain is poised to coordinate binding of cofactors and substrates with Pex1/Pex6 ATPase activity.

Association between platelet lymphocyte ratio and neutrophil lymphocyte ratio and clinical outcomes following carotid endarterectomy.

Background: Approximately 30% of stroke cases result from carotid disease. Although several risk factors for complications after carotid endarterectomy have been identified, the existence of a biomarker that can estimate postoperative risk in these patients has not yet been proven. Objectives: This study aimed to investigate correlations between the platelet-lymphocyte ratio (PLR) and the neutrophil-lymphocyte ratio (NLR) and postoperative clinical outcomes in patients undergoing carotid endarterectomy. Methods: A retrospective study was conducted, including 374 patients who underwent carotid endarterectomy between 2002 and 2019 due to moderate to high extracranial internal carotid artery stenosis. Their platelet-lymphocyte ratio and neutrophil-lymphocyte ratios were obtained from the same blood samples. Results: There was a statistically significant correlation between the PLR and the occurrence of restenosis (p < 0.01) and acute myocardial infarction (AMI) after endarterectomy (p = 0.03). Additionally, there was a statistically significant correlation between the PLR and the combined outcomes stroke and/or AMI and/or death (p = 0.03) and stroke and/or AMI and/or death and/or restenosis (p < 0.01). However, there were no significant correlations between NLR and these outcomes (p = 0.05, p = 0.16). Conclusions: The platelet-lymphocyte ratio proved to be a useful test for predicting occurrence of strokes, acute myocardial infarctions, and deaths during the postoperative period after carotid endarterectomy. It was also associated with the risk of postoperative restenosis.

Contexto: Aproximadamente 30% dos casos de acidente vascular cerebral (AVC) resultam de doença carotídea. Embora vários fatores de risco para complicações pós-endarterectomia carotídea tenham sido identificados, ainda não foi comprovada a existência de um biomarcador que possa estimar o risco pós-operatório nesses pacientes. Objetivos: Correlacionar o índice plaqueta-linfócito (IPL) e o índice neutrófilo-linfócito (INL) com os desfechos clínicos pós-operatórios em pacientes submetidos a endarterectomia carotídea. Métodos: Estudo retrospectivo que incluiu 374 pacientes submetidos a endarterectomia carotídea, entre 2009 e 2019, por estenose extracraniana da artéria carótida interna. O IPL e o INL foram calculados, tendo sido obtidos das mesmas amostras de sangue. Resultados: Houve correlação estatisticamente significativa entre IPL e presença de reestenose (p<0,01) e infarto agudo do miocárdio (IAM) após endarterectomia (p=0,03). Os desfechos combinados AVC e/ou IAM e/ou óbito e AVC e/ou IAM e/ou óbito e/ou reestenose apresentaram, respectivamente, correlação estatisticamente significativa com o IPL (p=0,03; p<0,01) e não significativa com o INL (p=0,05; p=0,16). Conclusões: O IPL mostrou-se um teste útil, capaz de predizer os desfechos de AVC e/ou IAM e/ou óbito em pacientes no pós-operatório de endarterectomia carotídea, relacionando-se também com risco de reestenose pós-operatória.

Preparation of site-specifically fluorophore-labeled polyubiquitin chains for FRET studies of Cdc48 substrate processing.

A critical step in the removal of polyubiquitinated proteins from macromolecular complexes and membranes for subsequent proteasomal degradation is the unfolding of an ubiquitin moiety by the cofactor Ufd1/Npl4 (UN) and its insertion into the Cdc48 ATPase for mechanical translocation. Here, we present a stepwise protocol for the assembly and purification of Lys48-linked ubiquitin chains that are fluorophore labeled at specific ubiquitin moieties and allow monitoring polyubiquitin engagement by the Cdc48-UN complex in a FRET-based assay. For complete details on the use and execution of this protocol, please refer to Williams et al. (2023).1.

The Pex6 N1 domain is required for Pex15 binding and proper assembly with Pex1.

The heterohexameric AAA-ATPase Pex1/Pex6 is essential for the formation and maintenance of peroxisomes. Pex1/Pex6, similar to other AAA-ATPases, uses the energy from ATP hydrolysis to mechanically thread substrate proteins through its central pore, thereby unfolding them. In related AAA-ATPase motors, substrates are recruited through binding to the motor's N-terminal domains or N-terminally bound co-factors. Here we use structural and biochemical techniques to characterize the function of the N1 domain in Pex6 from budding yeast, S. cerevisiae. We found that although Pex1/ΔN1-Pex6 is an active ATPase in vitro, it does not support Pex1/Pex6 function at the peroxisome in vivo. An X-ray crystal structure of the isolated Pex6 N1 domain shows that the Pex6 N1 domain shares the same fold as the N terminal domains of PEX1, CDC48, or NSF, despite poor sequence conservation. Integrating this structure with a cryo-EM reconstruction of Pex1/Pex6, AlphaFold2 predictions, and biochemical assays shows that Pex6 N1 mediates binding to both the peroxisomal membrane tether Pex15 and an extended loop from the D2 ATPase domain of Pex1 that influences Pex1/Pex6 heterohexamer stability. Given the direct interactions with both Pex15 and the D2 ATPase domains, the Pex6 N1 domain is poised to coordinate binding of co-factors and substrates with Pex1/Pex6 ATPase activity.

Successful one-stage resection of intracardiac intravenous leiomyomatosis: A case report.

This case report is about a 47-year-old patient, who was diagnosed with intracardiac intravenous leiomyomatosis and received treatment at our institution. Intravenous leiomyomatosis is a rare, histologically benign, uterine neoplasm, which is characterized by non-invasive intravascular proliferation of smooth muscle cells. Intravenous leiomyomatosis arises from the myometrium and, in its most extensive form, can reach the heart via the pelvic veins and the inferior vena cava, causing hemodynamic complications. Treatment of choice is the complete resection of the tumor, even though there is no consensus on the optimal surgical approach. In this case, complete resection of the tumor was accomplished in a one-stage procedure. The patient recovered well and CT scan did not show any signs of recurrence after five months.

A basidomycetous hydroxynaphthalene-prenylating enzyme exhibits promiscuity toward prenyl donors.

The fungal prenyltransferase ShPT from Stereum hirsutum was believed to prenylate 4-hydroxybenzyl alcohol and thereby be involved in the vibralactone biosynthesis. In this study, we demonstrate that hydroxynaphthalenes instead of benzyl alcohol or aldehyde were accepted by ShPT for regular C-prenylation in the presence of both dimethylallyl and geranyl diphosphate. Although the natural substrate of ShPT remains unknown, our results provide one additional prenyltransferase from basidiomycetes, which are less studied, in comparison to those from other sources. Furthermore, this study expands the chemical toolbox for regioselective production of prenylated naphthalene derivatives. KEY POINTS: •Basidiomycetous prenyltransferase •Biochemical characterization •A DMATS prenyltransferase prenylating hydroxynaphthalene derivatives.

Microhydration of the adamantane cation: intracluster proton transfer to solvent in [Ad(H2O)n=1-5]+ for n ≥ 3.

Radical cations of diamondoids are important intermediates in their functionalization reactions in polar solvents. To explore the role of the solvent at the molecular level, we characterize herein microhydrated radical cation clusters of the parent molecule of the diamondoid family, adamantane (C10H16, Ad), by infrared photodissociation (IRPD) spectroscopy of mass-selected [Ad(H2O)n=1-5]+ clusters. IRPD spectra of the cation ground electronic state recorded in the CH/OH stretch and fingerprint ranges reveal the first steps of this fundamental H-substitution reaction at the molecular level. Analysis of size-dependent frequency shifts with dispersion-corrected density functional theory calculations (B3LYP-D3/cc-pVTZ) provides detailed information about the acidity of the proton of Ad+ as a function of the degree of hydration, the structure of the hydration shell, and the strengths of the CH⋯O and OH⋯O hydrogen bonds (H-bonds) of the hydration network. For n = 1, H2O strongly activates the acidic C-H bond of Ad+ by acting as a proton acceptor in a strong CH⋯O ionic H-bond with cation-dipole configuration. For n = 2, the proton is almost equally shared between the adamantyl radical (C10H15, Ady) and the (H2O)2 dimer in a strong C⋯H⋯O ionic H-bond. For n ≥ 3, the proton is completely transferred to the H-bonded hydration network. The threshold for this size-dependent intracluster proton transfer to solvent is consistent with the proton affinities of Ady and (H2O)n and confirmed by collision-induced dissociation experiments. Comparison with other related microhydrated cations reveals that the acidity of the CH proton of Ad+ is in the range of strongly acidic phenol+ but lower than for cationic linear alkanes such as pentane+. Significantly, the presented IRPD spectra of microhydrated Ad+ provide the first spectroscopic molecular-level insight of the chemical reactivity and reaction mechanism of the important class of transient diamondoid radical cations in aqueous solution.

Microhydrated clusters of a pharmaceutical drug: infrared spectra and structures of amantadineH+(H2O)n.

Solvation of pharmaceutical drugs has an important effect on their structure and function. Analysis of infrared photodissociation spectra of amantadineH+(H2O)n=1-4 clusters in the sensitive OH, NH, and CH stretch range by quantum chemical calculations (B3LYP-D3/cc-pVTZ) provides a first impression of the interaction of this pharmaceutically active cation with water at the molecular level. The size-dependent frequency shifts reveal detailed information about the acidity of the protons of the NH3+ group of N-protonated amantadineH+ (AmaH+) and the strength of the NH⋯O and OH⋯O hydrogen bonds (H-bonds) of the hydration network. The preferred cluster growth begins with sequential hydration of the NH3+ group by NH⋯O ionic H-bonds (n = 1-3), followed by the extension of the solvent network through OH⋯O H-bonds. However, smaller populations of cluster isomers with an H-bonded solvent network and free N-H bonds are already observed for n ≥ 2, indicating the subtle competition between noncooperative ion hydration and cooperative H-bonding. Interestingly, cyclic water ring structures are identified for n ≥ 3, each with two NH⋯O and two OH⋯O H-bonds. Despite the increasing destabilization of the N-H proton donor bonds upon gradual hydration, no proton transfer to the (H2O)n solvent cluster is observed up to n = 4. In addition to ammonium cluster ions, a small population of microhydrated iminium isomers is also detected, which is substantially lower for the hydrophilic H2O than for the hydrophobic Ar environment.

The Ufd1 cofactor determines the linkage specificity of polyubiquitin chain engagement by the AAA+ ATPase Cdc48.

The AAA+ ATPase Cdc48 utilizes the cofactor Ufd1/Npl4 to bind and thread polyubiquitinated substrates for their extraction from complexes or membranes and often for subsequent proteasomal degradation. Previous studies indicated that Cdc48 engages polyubiquitin chains through the Npl4-mediated unfolding of an initiator ubiquitin; yet, the underlying principles remain largely unknown. Using FRET-based assays, we revealed the mechanisms and kinetics of ubiquitin unfolding, insertion into the ATPase, and unfolding of the ubiquitin-attached substrate. We found that Cdc48 uses Ufd1's UT3 domain to bind a K48-linked ubiquitin on the initiator's proximal side of the chain, thereby directing the initiator toward rapid unfolding by Npl4 and engagement by Cdc48. Ubiquitins on the initiator's distal side increase substrate affinity and facilitate unfolding but impede substrate release from Cdc48-Ufd1/Npl4 in the absence of additional cofactors. Our findings explain how Cdc48-UN efficiently processes substrates with K48-linked chains of 4-6 ubiquitins, which represent most cellular polyubiquitinated proteins.

Robot-assisted laparoscopic radical cystectomy with intracorporeal ileal conduit diversion versus open radical cystectomy with ileal conduit for bladder cancer in an ERAS setup (BORARC): protocol for a single-centre, double-blinded, randomised feasibility study.

BACKGROUND: Radical cystectomy (RC) with urinary diversion is the recommended treatment for selected cases of non-metastatic high-risk non-muscle-invasive and muscle-invasive bladder cancer. It remains unknown whether robot-assisted laparoscopic cystectomy (RARC) offers any advantage in terms of safety compared to open cystectomy (ORC) in an Enhanced Recovery After Surgery (ERAS) setup. Blinded randomised controlled trials (RCTs) between RARC versus ORC have never been conducted in cystectomy patients. We will investigate the feasibility of conducting a double-blinded RCT comparing ORC with RARC with intra-corporal ileal conduit (iRARC) in an ERAS setup. METHODS: This is a single-centre, double-blinded, randomised (1:1) clinical feasibility study for patients with non-metastatic high-risk non-muscle-invasive or muscle-invasive bladder cancer scheduled for cystectomy. All participants are recruited from Rigshospitalet, Denmark. The planned sample size is 50 participants to investigate whether blinding of the surgical technique is feasible. Participants and postoperative caring physicians and nurses are blinded using a pre-study designed abdominal dressing and blinding of the patient's electronic health record. Study endpoints are assessed 90 days postoperatively. The primary aim is to study the frequency and pattern of unplanned unblinding after surgery and the number of participants who cannot guess the surgical technique at the day of discharge. Eleven secondary endpoints are assessed: length of stay, days alive and out of hospital, in-hospital complication rate, 30-day complication rate, 90-day complication rate, readmission rate, quality of life, blood loss, pain, rate of moderate/severe post-anaesthesia care unit (PACU) complications, and delirium. Participants are managed in an ERAS setup in both arms of the trial. DISCUSSION: We report on the design and objectives of a novel experimental feasibility study investigating whether blinding of the surgical technique in cystectomy patients is possible. This information is essential for the design of future blinded trials comparing ORC to RARC. There is a continued need to compare RARC and ORC in terms of both efficacy, safety, and oncological outcomes. Estimated end of study is March 2021. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03977831. Registered on the 6th of June 2019.

Direct determination of glyphosate, aminomethylphosphonic acid and glufosinate in food samples with ion chromatography coupled to electrospray ionization tandem mass spectrometry.

A fast and reliable method for the direct determination of the herbicide glyphosate, its major degradation product aminomethylphosphonic acid (AMPA) and glufosinate is presented for a variety of food matrices. The Quick Polar Pesticides in food of Plant Origin method (QuPPe-PO-Method) was used for extraction without further preconcentration or clean-up steps involving e.g. solid phase extraction (SPE). The method makes use of a commercially available high performance liquid chromatograph coupled to a tandem mass spectrometer with electrospray ionization (LC-ESI-MS/MS) - as present in many laboratories - equipped with an ion chromatography (IC)-column using an MS-compatible eluent made of 0.8% formic acid in water. Due to the absence of time-consuming clean-up procedures, strong matrix effects (ME) of up to 91% for AMPA in grapefruit can be observed, when comparing its sensitivity to that obtained for solvent-based standards. The limits of detection (LODs) were determined for the sample matrices apple, mushrooms, grapefruit, linseed, red lentils and wheat and they were found to be in the range of 0.09 to 0.8, 0.04 to 1 and 0.2 to 2 µg/kg for glyphosate, AMPA and glufosinate, respectively. For the same matrices the validation was carried out according to SANTE guidelines for different commodity groups by spiking them up prior to extraction to concentrations ranging from 10 to 400 µg/kg for matrices with high water content and from 10 to 800 µg/kg for matrices with low water content. When using solvent-based calibration under the use of isotopically labelled internal standards (ILIS) the recoveries were found to range from 84% to 120% and the relative standard deviations (RSD) range between 1% and 19% for glyphosate, AMPA and glufosinate at all fortification levels for all matrices investigated. Accordingly, the method was successfully introduced in our laboratory with limits of quantification (LOQs) of 10 µg/kg for glyphosate, AMPA and glufosinate in samples from SANTE commodity groups 1, 2, 4a and 5. The reliability and robustness of the method are demonstrated by showing a recovery control chart obtained for glyphosate in randomly selected samples from different commodity groups. Therefore, the samples were spiked up with 10 µg/kg of glyphosate during routine analysis, whereby all recoveries were found to be in the range between 70 and 120%.

High-Throughput Assay for Characterizing Rpn11 Deubiquitinase Activity.

Rpn11 is an essential metalloprotease responsible for the en bloc removal of ubiquitin chains from protein substrates that are targeted for degradation by the 26S proteasome. A unique feature of Rpn11 is that its deubiquitinase (DUB) activity is greatly stimulated by the mechanical translocation of the substrate into the proteasomal AAA+ (ATPase Associated with diverse cellular Activities) motor, which delivers the scissile isopeptide bond between a substrate lysine and the proximal moiety of an attached ubiquitin chain to the DUB catalytic active site. As a consequence, Rpn11 cleaves at the base of ubiquitin chains and lacks selectivity towards specific ubiquitin-chain linkage types, which is in contrast to other DUBs, including the related AMSH that selectively cleaves Lys63-linked chains. Prevention of Rpn11's deubiquitinase activity leads to inhibition of proteasomal degradation by stalling substrate translocation. With the proteasome as an approved anticancer target, Rpn11 is therefore an attractive point of attack for the development of new inhibitors, which requires robust biochemical assays to measure DUB activity. Here we describe a method for the purification of the Rpn8/Rpn11 heterodimer and ubiquitin-GC-TAMRA, a model substrate that can be used to characterize the DUB activity of Rpn11 in isolation without the need of purifying 26S proteasomes. This assay thus enables a high-throughput screening platform for Rpn11-targeted small-molecule discovery.

Exercise training to increase tumour natural killer-cell infiltration in men with localised prostate cancer: a randomised controlled trial.

OBJECTIVES: To explore the effects of preoperative high-intensity interval training (HIIT) compared to usual care on tumour natural killer (NK)-cell infiltration in men with localised prostate cancer (PCa), as NK-cell infiltration has been proposed as one of the key mechanisms whereby exercise can modulate human tumours. PATIENTS AND METHODS: A total of 30 patients with localised PCa undergoing radical prostatectomy (RP) were randomised (2:1) to either preoperative aerobic HIIT four-times weekly (EX; n = 20) or usual care (CON; n = 10) from time of inclusion until scheduled surgery. Tumour NK-cell infiltration was assessed by immunohistochemistry (CD56+ ) in diagnostic core needle biopsies and corresponding prostatic tissue from the RP. Changes in cardiorespiratory fitness, body composition, blood biochemistry, and health-related quality of life were also evaluated. RESULTS: The change in tumour NK-cell infiltration did not differ between the EX and CON groups (between-group difference: -0.09 cells/mm2 , 95% confidence interval [CI] -1.85 to 1.66; P = 0.913) in the intention-to-treat analysis. The total number of exercise sessions varied considerably from four to 30 sessions. The per-protocol analysis showed a significant increase in tumour NK-cell infiltration of 1.60 cells/mm2 (95% CI 0.59 to 2.62; P = 0.004) in the EX group. Further, the total number of training sessions was positively correlated with the change in NK-cell infiltration (r = 0.526, P = 0.021), peak oxygen uptake (r = 0.514, P = 0.035) and peak power output (r = 0.506, P = 0.038). CONCLUSION: Preoperative HIIT did not result in between-group differences in tumour NK-cell infiltration. Per-protocol and exploratory analyses demonstrate an enhanced NK-cell infiltration in PCa. Future studies are needed to test the capability of exercise to increase tumour immune cell infiltration.

A metabarcode based (species) inventory of the northern Adriatic phytoplankton.

Background: The northern Adriatic is characterised as the coldest and most productive marine area of the Mediterranean, which is due to high nutrient levels introduced by river discharges, the largest of which is the Italian Po River (at the same time also the largest freshwater input into the Mediterranean). The northern Adriatic is a very shallow marine ecosystem with ocean current patterns that result in long retention times of plankton in the area. The northern Adriatic phytoplankton biodiversity and abundance are well-studied, through many scientific and long-term monitoring reports. These datasets were based on phytoplankton morphological traits traditionally obtained with light microscopy. The most recent comprehensive eastern Adriatic phytoplankton checklist was published more than 20 years ago and is still valuable today. Since phytoplankton taxonomy and systematics are constantly being reviewed (partly also due to new molecular methods of species identification that complement classical methodologies), checklists need to be updated and complemented. Today, metabarcoding of molecular markers gains more and more importance in biodiversity research and monitoring. Here, we report the use of high throughput sequencing methods to re-examine taxonomic richness and provide updated knowledge of phytoplankton diversity in the eastern northern Adriatic to complement the standardised light microscopy method. New information: This study aimed to report an up-to-date list of the phytoplankton taxonomic richness and phylogenetic relationships in the eastern northern Adriatic, based on sequence variability of barcoding genes resolved with advanced molecular tools, namely metabarcoding. Here, metabarcoding is used to complement standardised light microscopy to advance conventional monitoring and research of phytoplankton communities for the purpose of assessing biodiversity and the status of the marine environments. Monthly two-year net sampling targeted six phytoplankton groups including Bacillariophyceae (diatoms) and Chrysophyceae (golden algae) belonging to Ochrophyta, Dinophyceae (dinoflagellates), Cryptophyceae (cryptophytes), Haptophyta (mostly coccolithophorids) and Chlorophyta with Prasinophyceae (prasinophytes) and Chlorophyceae (protist green algae). Generated sequence data were taxonomically assigned and redistributed in two kingdoms, five classes, 32 orders, 49 families and 67 genera. The most diverse group were dinoflagellates, comprising of 34 found genera (48.3%), following by diatoms with 23 (35.4%) and coccolithophorids with three genera (4.0%). In terms of genetic diversity, results were a bit different: a great majority of sequences with one nucleotide tolerance (ASVs, Amplicon sequence variants) assigned to species or genus level were dinoflagellates (83.8%), 13.7% diatoms and 1.6% Chlorophyta, respectively. Although many taxa have not been detected that have been considered as common in this area, metabarcoding revealed five diatoms and 20 dinoflagellate genera that were not reported in previous checklists, along with a few species from other targeted groups that have been reported previously. We here describe the first comprehensive 18S metabarcode inventory for the northern Adriatic Sea.

Association between platelet lymphocyte ratio and neutrophil lymphocyte ratio and clinical outcomes following carotid endarterectomy / Associação do índice plaqueta-linfócito e do índice neutrófilo-linfócito com desfechos clínicos após endarterectomia de carótida

Abstract Background Approximately 30% of stroke cases result from carotid disease. Although several risk factors for complications after carotid endarterectomy have been identified, the existence of a biomarker that can estimate postoperative risk in these patients has not yet been proven. Objectives This study aimed to investigate correlations between the platelet-lymphocyte ratio (PLR) and the neutrophil-lymphocyte ratio (NLR) and postoperative clinical outcomes in patients undergoing carotid endarterectomy. Methods A retrospective study was conducted, including 374 patients who underwent carotid endarterectomy between 2002 and 2019 due to moderate to high extracranial internal carotid artery stenosis. Their platelet-lymphocyte ratio and neutrophil-lymphocyte ratios were obtained from the same blood samples. Results There was a statistically significant correlation between the PLR and the occurrence of restenosis (p < 0.01) and acute myocardial infarction (AMI) after endarterectomy (p = 0.03). Additionally, there was a statistically significant correlation between the PLR and the combined outcomes stroke and/or AMI and/or death (p = 0.03) and stroke and/or AMI and/or death and/or restenosis (p < 0.01). However, there were no significant correlations between NLR and these outcomes (p = 0.05, p = 0.16). Conclusions The platelet-lymphocyte ratio proved to be a useful test for predicting occurrence of strokes, acute myocardial infarctions, and deaths during the postoperative period after carotid endarterectomy. It was also associated with the risk of postoperative restenosis.

Resumo Contexto Aproximadamente 30% dos casos de acidente vascular cerebral (AVC) resultam de doença carotídea. Embora vários fatores de risco para complicações pós-endarterectomia carotídea tenham sido identificados, ainda não foi comprovada a existência de um biomarcador que possa estimar o risco pós-operatório nesses pacientes. Objetivos Correlacionar o índice plaqueta-linfócito (IPL) e o índice neutrófilo-linfócito (INL) com os desfechos clínicos pós-operatórios em pacientes submetidos a endarterectomia carotídea. Métodos Estudo retrospectivo que incluiu 374 pacientes submetidos a endarterectomia carotídea, entre 2009 e 2019, por estenose extracraniana da artéria carótida interna. O IPL e o INL foram calculados, tendo sido obtidos das mesmas amostras de sangue. Resultados Houve correlação estatisticamente significativa entre IPL e presença de reestenose (p<0,01) e infarto agudo do miocárdio (IAM) após endarterectomia (p=0,03). Os desfechos combinados AVC e/ou IAM e/ou óbito e AVC e/ou IAM e/ou óbito e/ou reestenose apresentaram, respectivamente, correlação estatisticamente significativa com o IPL (p=0,03; p<0,01) e não significativa com o INL (p=0,05; p=0,16). Conclusões O IPL mostrou-se um teste útil, capaz de predizer os desfechos de AVC e/ou IAM e/ou óbito em pacientes no pós-operatório de endarterectomia carotídea, relacionando-se também com risco de reestenose pós-operatória.

Ubiquitin modulates 26S proteasome conformational dynamics and promotes substrate degradation.

The 26S proteasome recognizes thousands of appropriate protein substrates in eukaryotic cells through attached ubiquitin chains and uses its adenosine triphosphatase (ATPase) motor for mechanical unfolding and translocation into a proteolytic chamber. Here, we used single-molecule Förster resonance energy transfer measurements to monitor the conformational dynamics of the proteasome, observe individual substrates during their progression toward degradation, and elucidate how these processes are regulated by ubiquitin chains. Rapid transitions between engagement- and processing-competent proteasome conformations control substrate access to the ATPase motor. Ubiquitin chain binding functions as an allosteric regulator to slow these transitions, stabilize the engagement-competent state, and aid substrate capture to accelerate degradation initiation. Upon substrate engagement, the proteasome remains in processing-competent states for translocation and unfolding, except for apparent motor slips when encountering stably folded domains. Our studies revealed how ubiquitin chains allosterically regulate degradation initiation, which ensures substrate selectivity in a crowded cellular environment.

Critical Offset Magnetic PArticle SpectroScopy for rapid and highly sensitive medical point-of-care diagnostics.

Magnetic nanoparticles (MNPs) have been adapted for many applications, e.g., bioassays for the detection of biomarkers such as antibodies, by controlled engineering of specific surface properties. Specific measurement of such binding states is of high interest but currently limited to highly sensitive techniques such as ELISA or flow cytometry, which are relatively inflexible, difficult to handle, expensive and time-consuming. Here we report a method named COMPASS (Critical-Offset-Magnetic-Particle-SpectroScopy), which is based on a critical offset magnetic field, enabling sensitive detection to minimal changes in mobility of MNP ensembles, e.g., resulting from SARS-CoV-2 antibodies binding to the S antigen on the surface of functionalized MNPs. With a sensitivity of 0.33 fmole/50 µl (≙7 pM) for SARS-CoV-2-S1 antibodies, measured with a low-cost portable COMPASS device, the proposed technique is competitive with respect to sensitivity while providing flexibility, robustness, and a measurement time of seconds per sample. In addition, initial results with blood serum demonstrate high specificity.