Stable ubiquitin conjugation for biological interrogation of ubiquitinated tau repeat domain.

Protein semisynthesis approaches are key for gaining insights into the effects of post-translational modifications (PTMs) on the structure and function of modified proteins. Among PTMs, ubiquitination involves the conjugation of a small protein modifier to a substrate amino acid residue and is unique in controlling a variety of cellular processes. Interest has grown in understanding the role of ubiquitination in neurodegenerative conditions, including tauopathies. The latter are characterized by the accumulation of the intrinsically disordered protein tau in the form of neurofibrillary tangles in the brains of patients. The presence of ubiquitinated tau in the pathological aggregates suggests that ubiquitination might play a role in the formation of abnormal protein deposits. In this study, we developed a new strategy, based on dehydroalanine chemistry, to install wild type ubiquitin on a tau repeat domain construct with site-specificity. We optimized a three-step reaction which yielded a good amount of highly pure tau repeat domain ubiquitinated in position 353. The structural features of the conjugate were examined by circular dichroism and NMR spectroscopy. The ubiquitinated tau was challenged in a number of assays: fibrils formation under aggregating conditions in vitro, chemical stability upon exposure to a variety of biological media including cell extracts, and internalization into astrocytes. The results demonstrated the wide applicability of the new semisynthetic strategy for the investigation of ubiquitinated substrates in vitro or in cell, and in particular for studying if ubiquitination has a role in the molecular mechanisms that underlie the aberrant transition of tau into pathological aggregates.

Ultrasmall Gold Nanoparticles as Clients of Biomolecular Condensates.

Liquid-liquid phase separation (LLPS) of biopolymers to form condensates is a widespread phenomenon in living cells. Agents that target or alter condensation can help uncover elusive physiological and pathological mechanisms. Owing to their unique material properties and modes of interaction with biomolecules, nanoparticles represent attractive condensate-targeting agents. Our work focused on elucidating the interaction between ultrasmall gold nanoparticles (usGNPs) and diverse types of condensates of tau, a representative phase-separating protein associated with neurodegenerative disorders. usGNPs attract considerable interest in the biomedical community due to unique features, including emergent optical properties and good cell penetration. We explored the interaction of usGNPs with reconstituted self-condensates of tau, two-component tau/polyanion and three-component tau/RNA/alpha-synuclein coacervates. The usGNPs were found to concentrate into condensed liquid droplets, consistent with the formation of dynamic client (nanoparticle) - scaffold (tau) interactions, and were observable thanks to their intrinsic luminescence. Furthermore, usGNPs were capable to promote LLPS of a protein domain which is unable to phase separate on its own. Our study demonstrates the ability of usGNPs to interact with and illuminate protein condensates. We anticipate that nanoparticles will have broad applicability as nanotracers to interrogate phase separation, and as nanoactuators controlling the formation and dissolution of condensates.

New Paradigm for Nano-Bio Interactions: Multimolecular Assembly of a Prototypical Disordered Protein with Ultrasmall Nanoparticles.

Understanding the interactions between nanoparticles (NPs) and proteins is crucial for the successful application of NPs in biological contexts. Protein adsorption is dependent on particle size, and protein binding to ultrasmall (1-3 nm) NPs is considered to be generally weak. However, most studies have involved structured biomacromolecules, while the interactions of ultrasmall NPs with intrinsically disordered proteins (IDPs) have remained elusive. IDPs are abundant in eukaryotes and found to associate with NPs intracellularly. As a model system, we focused on ultrasmall gold nanoparticles (usGNPs) and tau, a cytosolic IDP associated with Alzheimer's disease. Using site-resolved NMR, steady-state fluorescence, calorimetry, and circular dichroism, we reveal that tau and usGNPs form stable multimolecular assemblies, representing a new type of nano-bio interaction. Specifically, the observed interaction hot spots explain the influence of usGNPs on tau conformational transitions, with implications for the intracellular targeting of aberrant IDP aggregation.

Recurrent stent thrombosis in a patient with acute coronary syndrome and ischemic colitis: between life-threatening thrombosis and life-threatening bleeding.

Complete blood count should always be considered to tailor diagnosis and appropriate management in patients with acute ischemic heart disease. We present a challenging case of recurrent acute coronary syndrome, in the context of very high thrombotic risk due to concomitant inflammatory disease. Although no general guidelines exist for the switch between antiplatelet agents, particularly in the acute setting, in specific cases, the availability of different orally- and i.v.-acting agents and platelet function tests may allow to discriminate among multiple possible mechanisms of drug failure or side effects in the individual patient.

Acute myocardial infarction complicating ischemic stroke: is there room for cangrelor?

Acute myocardial infarction (AMI) complicating ischemic stroke is a well known and undertreated event. A conservative management is not infrequent in these settings, due to the fear of hemorrhagic complications related to antithrombotic therapy. Notably, an invasive approach with a primary percutaneous coronary intervention (PCI) has been shown to be associated with a lower in-hospital mortality in patients with concomitant ischemic stroke and AMI. The optimal antiplatelet regimen in these cases has been not clearly defined, yet. We report two cases of patients with AMI complicating ischemic stroke, successfully treated with cangrelor infusion, which was started during PCI and maintained up to 48 h at bridge therapy dosage (0.75 mcg/kg/min). Both patients underwent successful PCI in the acute phase, and neither ischemic nor hemorrhagic complications occurred during in-hospital stay.

Protracted aortic valve closure during peripheral veno-arterial extracorporeal life support: is intra-aortic balloon pump an effective solution?

BACKGROUND: Left ventricular (LV) afterload increase with protracted aortic valve (AV) closure may represent a complication of veno-arterial extracorporeal membrane oxygenation (V-A ECMO). The aim of the present study was to assess the effects of an intra-aortic balloon pump (IABP) to overcome such a hemodynamic shortcoming in patients submitted to peripheral V-A ECMO. METHODS: Among 184 adult patients who were treated with peripheral V-A ECMO support at Medical University Center Maastricht Hospital between 2007 and 2018, patients submitted to IABP implant for protracted AV closure after V-A ECMO implant were retrospectively identified. All clinical and hemodynamic data, including echocardiographic monitoring, were collected and analyzed. RESULTS: During the study period, 10 subjects (mean age 60 years old, 80% males) underwent IABP implant after peripheral V-A ECMO positioning due to the diagnosis of protracted AV closure and inefficient LV unloading as assessed by echocardiography and an absence of pulsation in the arterial pressure wave. Recovery of blood pressure pulsatility and enhanced LV unloading were observed in 8 patients after IABP placement, with no significant differences in the main hemodynamic parameters, inotropic therapy or in the ECMO flow (p=0.48). The weaning rate in this patient subgroup (mean ECMO duration 8 days), however, was only 10%, with another patient finally transplanted, leading to a 20% survival-to-hospital discharge. CONCLUSION: IABP placement was an effective solution in order to reverse the protracted AV closure and impaired LV unloading observed during peripheral V-A ECMO support. However, the impact on the weaning rate and survival needs further investigations.

Ultrasound-Assisted, Catheter-Directed Thrombolysis for Acute Intermediate/High-Risk Pulmonary Embolism: Design of the Multicenter USAT IH-PE Registry and Preliminary Results.

Catheter-based revascularization procedures were developed as an alternative to systemic thrombolysis for patients with intermediate-high- and high-risk pulmonary embolisms. USAT IH-PE is a retrospective and prospective multicenter registry of such patients treated with ultrasound-facilitated, catheter-directed thrombolysis, whose preliminary results are presented in this study. The primary endpoint was the incidence of pulmonary hypertension (PH) at follow-up. Secondary endpoints were short- and mid-term changes in the echocardiographic parameters of right ventricle (RV) function, in-hospital and all-cause mortality, and procedure-related bleeding events. Between March 2018 and July 2023, 102 patients were included. The majority were at intermediate-high-risk PE (86%), were mostly female (57%), and had a mean age of 63.7 ± 14.5 years, and 28.4% had active cancer. Echocardiographic follow-up was available for 70 patients, and in only one, the diagnosis of PH was confirmed by right heart catheterization, resulting in an incidence of 1.43% (CI 95%, 0.036-7.7). RV echocardiographic parameters improved both at 24 h and at follow-up. In-hospital mortality was 3.9% (CI 95%, 1.08-9.74), while all-cause mortality was 11% (CI 95%, 5.4-19.2). Only 12% had bleeding complications, of whom 4.9% were BARC ≥ 3. Preliminary results from the USAT IH-PE registry showed a low incidence of PH, improvement in RV function, and a safe profile.

Espresso Coffee Mitigates the Aggregation and Condensation of Alzheimer's Associated Tau Protein.

Espresso coffee is among the most consumed beverages in the world. Recent studies report a protective activity of the coffee beverage against neurodegenerative disorders such as Alzheimer's disease. Alzheimer's disease belongs to a group of disorders, called tauopathies, which are characterized by the intraneuronal accumulation of the microtubule-associated protein tau in fibrillar aggregates. In this work, we characterized by NMR the molecular composition of the espresso coffee extract and identified its main components. We then demonstrated with in vitro and in cell experiments that the whole coffee extract, caffeine, and genistein have biological properties in preventing aggregation, condensation, and seeding activity of the repeat region of tau. We also identified a set of coffee compounds capable of binding to preformed tau fibrils. These results add insights into the neuroprotective potential of espresso coffee and suggest candidate molecular scaffolds for designing therapies targeting monomeric or fibrillized forms of tau.

Uric acid associated with acute heart failure presentation in Acute Coronary Syndrome patients.

We focused on the role of Uric Acid (UA) as a possible determinant of Heart Failure (HF) related issues in Acute Coronary Syndromes (ACS) patients. Main outcomes were acute HF and cardiogenic shock at admission, secondary outcomes were the use of Non Invasive Ventilation (NIV) and the admission Left Ventricular Ejection Fraction (LVEF). We consecutively enrolled 1269 ACS patients admitted to the cardiological Intensive Care Unit of the Niguarda and San Paolo hospitals (Milan, Italy) from June 2016 to June 2019. Median age was 68 (first-third quartile 59-77) years and males were 970 (76%). All the evaluated outcomes occurred more frequently in the hyperuricemic subjects (UA higher than 6 mg/dL for females and 7 mg/dL for males, n = 292): acute HF 35.8 vs 11.1% (p < 0.0001), cardiogenic shock 10 vs 3.1% (p < 0.0001), NIV 24.1 vs 5.1% (p < 0.0001) and lower admission LVEF (42.9±12.8 vs 49.6±9.9, p < 0.0001). By multivariable analyses, UA was confirmed to be significantly associated with all the outcomes with the following Odds Ratio (OR): acute HF OR = 1.119; 95% CI 1.019;1.229; cardiogenic shock OR = 1.157; 95% CI 1.001;1.337; NIV use OR = 1.208; 95% CI 1.078;1.354; LVEF ß = -0.999; 95% CI -1.413;-0.586. We found a significant association between UA and acute HF, cardiogenic shock, NIV use and LVEF. Due to the cross-sectional nature of our study no definite answer on the direction of these relationship can be drawn and further longitudinal study on UA changes over time during an ACS hospitalization are needed.

Predicting survival in patients with acute decompensated heart failure complicated by cardiogenic shock.

BACKGROUND: Acute decompensated heart failure (ADHF) complicated by cardiogenic shock (CS) has unique pathophysiological background requiring specific patient stratification, management and therapeutic targets. Accordingly, the aim of this study was to derive a simple stratification tool to predict survival in patients with ADHF complicated by CS. METHODS AND RESULTS: Using logistic regression, univariable testing was performed to identify the variables potentially associated with 28-day mortality. We propose a new logistic model (ALC-Shock score) based on three easy parameters (age, serum creatinine and serum lactate at the ICU admission) as a powerful predictor of survival or successful bridge to heart replacement therapy at 28-day follow-up in this specific population. A multivariable analysis (logistic model) was performed to evaluate the association between selected variables and outcome (overall death at 28-day follow up). The score was then validated in a different cohort of 93 ADHF-CS patients and compared to a previous developed score (the Cardshock score).Overall, 28-day mortality was 34%. The ALC-shock score showed better discrimination (Area Under the Curve-AUC- 0.82; 95% CI 0.73-0.91) as compared to the Cardshock score (AUC 0.67; 95% CI 0.55-0.79) (p = 0.009) to predict 28-days overall mortality. In the validation cohort the AUC for the ALC-shock score was 0.66. CONCLUSIONS: A simple score including age, lactates and creatinine on admission could be considered to predict short-term mortality in CS-ADHF patients in order to drive towards a treatment intensification.

[Relevance of complete blood count parameters in the assessment of acute coronary syndromes: a combined hematological and cardiological perspective]. / Alterazioni dell'emocromo nella sindrome coronarica acuta: ematologi e cardiologi a confronto.

The aim of this review is to explore the available evidence concerning the relationship between the different parameters of the complete blood count, its pathophysiological changes and cardiovascular disease, specifically focusing on the acute ischemic setting. Erythrocytes, leukocytes and platelets undergo significant and more or less durable changes over time in response to conditions of systemic inflammatory, infectious and neoplastic disease. This is the reason why blood cell count parameters can (and should) be implemented in the global assessment of the patient with acute coronary syndrome.From the literature review it emerges that anemia and thrombocytopenia have an independent negative prognostic role in the medium and long term, being markers of the overall frailty of patients with ischemic heart disease. On the other hand, essential thrombocythemia and polycythemia vera, two chronic myeloproliferative neoplasms, are characterized by an important increase in thrombotic risk. Both conditions are given a brief description for the particular importance of the close collaboration between cardiologists and hematologists in the diagnosis and treatment of these diseases in the context of ischemic heart disease.

Long-term survival and major outcomes in post-cardiotomy extracorporeal membrane oxygenation for adult patients in cardiogenic shock.

Extracorporeal membrane oxygenation (ECMO) in the veno-arterial (VA) configuration is an established method for the treatment of refractory cardiogenic shock. Such a condition characterizes the postoperative course of approximatively 1% of cardiac surgery patients. Although some studies have reported ECMO-related short-term results, little is known about the long-term outcomes of VA-ECMO therapy in the post-cardiotomy setting. Therefore, an extensive literature search was conducted regarding articles published after 1990 reporting postoperative ECMO use. PubMed, EMBASE and Web of Science were searched for sources. In-hospital mortality was high in post-cardiotomy VA-ECMO patients, ranging from 24.8% to 52%. Long-term results were poorly reported. However, based on the limited information available, hospital survivors showed a favorable outcome, with improvement in overall clinical condition, quality of life and limited hospital readmission for cardiac-related events. To conclude, in-hospital outcome in post-cardiotomy ECMO is often unfavorable, post-discharge results show satisfactory condition, with stable improvement of overall patient clinical status and low rate of hospital readmission and cardiac-related adverse events. Data reporting is, however, scarce and hence new and detailed studies are still warranted to investigate such aspects.

Use of PRECISE-DAPT Score and Admission Platelet Count to Predict Mortality Risk in Patients With Acute Coronary Syndrome.

The PREdicting bleeding Complications In patients undergoing Stent implantation and subsEquent Dual Antiplatelet Therapy (PRECISE-DAPT) score has been validated to predict bleeding complications in patients undergoing stent implantation and dual antiplatelet therapy. This score does not include the platelet count (PC), which has been shown to be an independent marker of mortality in patients with acute coronary syndrome (ACS). We assessed the role of the PRECISE-DAPT score calculated on admission for mortality risk prediction and evaluated whether the predictive accuracy of this score improved by adding the PC. In a retrospective cohort study of 1000 patients with ACS, after adjustment for relevant covariates, a PRECISE-DAPT score ≥25 was independently associated with mortality (hazard ratio [HR]: 7.91; 95% confidence interval [CI]: 4.37-14.30). When this score was combined with PC, compared to patients with PRECISE-DAPT <25 and PC ≥150 × 109/L, the adjusted HR was 7.2 (95% CI 2.4-21.6) for those with PRECISE-DAPT <25 and PC <150 × 109/L; 10.7 (95% CI: 5.2-21.9) for those with PRECISE-DAPT ≥25 and PC ≥150 × 109/L; and 17.9 (95% CI 7.0-45.4) for those with PRECISE-DAPT ≥25 and PC <150 × 109/L. Selecting thresholds for high-risk designation, the PRECISE-DAPT score integrated with PC had a higher prediction value, compared to the PRECISE-DAPT and Global Registry of Acute Coronary Events scores.

Lung function and serum concentrations of different cytokines in patients submitted to radiotherapy and intermediate/high dose chemotherapy for Hodgkin's disease.

The aim of the present investigation was to evaluate lung function and the time course of serum concentration of selected cytokines known to be involved in pulmonary fibrosis, in 39 patients with stages IIB, III and IV Hodgkin's disease submitted to intermediate-high dose chemotherapy, (epirubicin, vincristine, cyclophosphamide, etoposide, prednisone) followed by radiotherapy. Lung function tests were performed before, at the end of treatment and after a follow-up of more than 12 months from the end of the combined therapy. Tumor necrosis factor alpha, fibronectin and Interleukins 4, 6 and 8 were determined on serum samples collected at the same time intervals. In the patients, spirometric parameters apparently improved whereas diffusing capacity for CO (DLCO) decreased, TNF-alpha concentrations constantly decreased, fibronectin and IL-8 showed a tendency to increase, but Interleukins 4 and 6 did not show significant modifications. No significant correlations were observed between the changes of lung function tests and serum cytokine concentrations, probably because cytokine serum levels were not able to reflect events occurring in the alveolar phase.

Regression of urrets-zavalia syndrome after deep lamellar keratoplasty for keratoconus: a case study.

We report a case of pharmacologic regression of Urrets-Zavalia syndrome, following deep lamellar keratoplasty for severe keratoconus. Sympatholytic and parasympathomimetic drops were administered and a progressive reduction of mydriasis and restoring of pupillary kinetics were observed. Four years after surgery, it was resulting in only slight residual anisocoria.