Alkyl Cyclopropyl Ketones in Catalytic Formal [3 + 2] Cycloadditions: The Role of SmI2 Catalyst Stabilization.

Alkyl cyclopropyl ketones are introduced as versatile substrates for catalytic formal [3 + 2] cycloadditions with alkenes and alkynes and previously unexplored enyne partners, efficiently delivering complex, sp3-rich products. The key to effectively engaging this relatively unreactive new substrate class is the use of SmI2 as a catalyst in combination with substoichiometric amounts of Sm0; the latter likely acting to prevent catalyst deactivation by returning SmIII to the catalytic cycle. In the absence of Sm0, background degradation of the SmI2 catalyst can outrun product formation. For the most recalcitrant alkyl cyclopropyl ketones, catalysis is "switched-on" using these new robust conditions, and otherwise unattainable products are delivered. Combined experimental and computational studies have been used to identify and probe reactivity trends among alkyl cyclopropyl ketones, including more complex bicyclic alkyl cyclopropyl ketones, which react quickly with various partners to give complex products. In addition to establishing alkyl cyclopropyl ketones as a new substrate class in a burgeoning field of catalysis, our study provides vital mechanistic insight and robust, practical approaches for the nascent field of catalysis with SmI2.

Remdesivir Plus Dexamethasone Versus Dexamethasone Alone for the Treatment of Coronavirus Disease 2019 (COVID-19) Patients Requiring Supplemental O2 Therapy: A Prospective Controlled Nonrandomized Study.

BACKGROUND: Remdesivir is an antiviral used to treat coronavirus disease 2019 (COVID-19), which improves some clinical outcomes. Dexamethasone has been shown to be effective in reducing mortality. It has been hypothesized that combination of these two drugs can improve mortality. We evaluated the effect of combination on mortality of COVID-19 patients requiring O2 therapy. METHODS: A prospective quasi-experimental study, including two independent, sequential controlled cohorts, one received remdesivir-dexamethasone and the other dexamethasone alone, was designed. All COVID-19 patients requiring supplemental O2 therapy were enrolled consecutively. The sample size to power mortality was a priori calculated. The primary endpoints were 30-day mortality and viral clearance differences. Secondary endpoints were differences in hospitalization times, improvement in respiratory failure (PO2/FiO2) and inflammatory indices (fibrinogen, CRP, neutrophil/lymphocyte ratio, D-Dimer). Kaplan-Meier curves and the log-rank test were used to evaluate significant differences in mortality between groups. RESULTS: In total, 151 COVID-19 patients were enrolled (remdesivir/dexamethasone group, 76, and dexamethasone alone, 75). No differences in demographic, clinical, and laboratory characteristics were observed between the 2 groups at baseline. Faster viral clearance occurred in the remdesivir/dexamethasone group compared to dexamethasone alone (median 6 vs 16 days; P < .001). The 30-day mortality in the remdesivir/dexamethasone group was 1.3%, whereas in dexamethasone alone was 16% (P < .005). In the remdesivir/dexamethasone group compared to dexamethasone alone there was a reduction in hospitalization days (P < .0001) and a faster improvement in both respiratory function and inflammatory markers. CONCLUSIONS: Remdesivir/dexamethasone treatment is associated with significant reduction in mortality, length of hospitalization, and faster SARS-CoV-2 clearance, compared to dexamethasone alone.

Conformational Flexibility as a Tool for Enabling Site-Selective Functionalization of Unactivated sp3 C-O Bonds in Cyclic Acetals.

A dual catalytic manifold that enables site-selective functionalization of unactivated sp3 C-O bonds in cyclic acetals with aryl and alkyl halides is reported. The reaction is triggered by an appropriate σ*-p orbital overlap prior to sp3 C-O cleavage, thus highlighting the importance of conformational flexibility in both reactivity and site selectivity. The protocol is characterized by its excellent chemoselectivity profile, thus offering new vistas for activating strong σ sp3 C-O linkages.

Non-invasive respiratory support in SARS-CoV-2 related acute respiratory distress syndrome: when is it most appropriate to start treatment?

BACKGROUND: Acute respiratory distress syndrome (ARDS) is one of the most severe complications of SARS-CoV-2 infection. Non-Invasive Respiratory Support (NRS) as Continuous Positive Airway Pressure (CPAP) and/or Non-Invasive Ventilation (NIV) has been proven as effective in the management of SARS-CoV-2-related ARDS. However, the most appropriate timing for start NRS is unknown. METHODS: We conducted a prospective pilot study including all consecutive patients who developed moderate SARS-CoV-2-related ARDS during hospitalization. Patients were randomly divided into two intervention groups according to ARDS severity (assessed by PaO2/FiO2-P/F) at NRS beginning: group A started CPAP/NIV when P/F was ≤ 200 and group B started CPAP/NIV when P/F was ≤ 150. Eligible patients who did not give their consent to CPAP/NIV until the severe stage of ARDS and started non-invasive treatment when P/F ≤ 100 (group C) was added. The considered outcomes were in-hospital mortality, oro-tracheal intubation (OTI) and days of hospitalization. RESULTS: Among 146 eligible patients, 29 underwent CPAP/NIV when P/F was ≤ 200 (Group A), 68 when P/F was ≤ 150 (Group B) and 31 patients agreed to non-invasive treatment only when P/F was ≤ 100 (Group C). Starting NRS at P/F level between 151 and 200 did not results in significant differences in the outcomes as compared to treatment starting with P/F ranging 101-150. Conversely, patients undergone CPAP/NIV in a moderate stage (P/F 101-200) had a significantly lower in-hospital mortality rate (13.4 vs. 29.0%, p = 0.044) and hospitalization length (14 vs. 15 days, p = 0.038) than those in the severe stage (P/F ≤ 100). Age and need for continuous ventilation were independent predictors of CPAP/NIV failure. CONCLUSIONS: Starting CPAP/NIV in patients with SARS-CoV-2-related ARDS in moderate stage (100 > P/F ≤ 200) is associated to a reduction of both in-hospital mortality and hospitalization length compared to the severe stage (P/F ≤ 100). Starting CPAP/NIV with a P/F > 150 does not appear to be of clinical utility.

Remote Functionalization of α,ß-Unsaturated Carbonyls by Multimetallic Sequential Catalysis.

The remote functionalization of α,ß-unsaturated carbonyls by an array of multimetallic sequential catalytic systems is described. The reactions are triggered by hydrometalation using [Pd-H] or [Ru-H] isomerization catalysts and driven by the formation of thermodynamically more stable 1,2-vinyl arenes. The Pd-catalyzed deconjugative isomerization was combined with a Cu-catalyzed ß-borylation of the transiently generated styrenyl derivatives to deliver a range of products that would not be accessible with the use of a single catalyst. [Pd/Cu] catalytic systems were also identified for the highly enantioselective α-hydroboration and α-hydroamination of the styrenyl intermediates. Difunctionalization simultaneously at the benzylic and homobenzylic positions was achieved by combining the isomerization process with Sharpless asymmetric dihydroxylation (SAD) using [Pd/Os] or [Ru/Os] couples. Starting from a simple α,ß-unsaturated ester, an isomerization/dihydroxylation/lactonization sequence gave access to a naturally occurring γ-butyrolactone in good yield, with excellent diastereo- and enantioselectivity.

Site-Selective Catalytic Deaminative Alkylation of Unactivated Olefins.

A catalytic deaminative alkylation of unactivated olefins is described. The protocol is characterized by its mild conditions, wide scope, including the use of ethylene as substrate, and exquisite site-selectivity pattern for both α-olefins and internal olefins, thus unlocking a new catalytic platform to forge sp3-sp3 linkages, even in the context of late-stage functionalization.

Multicatalytic Stereoselective Synthesis of Highly Substituted Alkenes by Sequential Isomerization/Cross-Coupling Reactions.

Starting from readily available alkenyl methyl ethers, the stereoselective preparation of highly substituted alkenes by two complementary multicatalytic sequential isomerization/cross-coupling sequences is described. Both elementary steps of these sequences are challenging processes when considered independently. A cationic iridium catalyst was identified for the stereoselective isomerization of allyl methyl ethers and was found to be compatible with a nickel catalyst for the subsequent cross-coupling of the in situ generated methyl vinyl ethers with various Grignard reagents. The method is compatible with sensitive functional groups and a multitude of olefinic substitution patterns to deliver products with high control of the newly generated C═C bond. A highly enantioselective variant of this [Ir/Ni] sequence has been established using a chiral iridium precatalyst. A complementary [Pd/Ni] catalytic sequence has been optimized for alkenyl methyl ethers with a remote C═C bond. The final alkenes were isolated with a lower level of stereocontrol. Upon proper choice of the Grignard reagent, we demonstrated that C( sp2)-C( sp2) and C( sp2)-C( sp3) bonds can be constructed with both systems delivering products that would be difficult to access by conventional methods.

Palladium-Catalyzed Long-Range Deconjugative Isomerization of Highly Substituted α,ß-Unsaturated Carbonyl Compounds.

The long-range deconjugative isomerization of a broad range of α,ß-unsaturated amides, esters, and ketones by an in situ generated palladium hydride catalyst is described. This redox-economical process is triggered by a hydrometalation event and is thermodynamically driven by the refunctionalization of a primary or a secondary alcohol into an aldehyde or a ketone. Di-, tri-, and tetrasubstituted carbon-carbon double bonds react with similar efficiency; the system is tolerant toward a variety of functional groups, and olefin migration can be sustained over 30 carbon atoms. The refunctionalized products are usually isolated in good to excellent yield. Mechanistic investigations are in support of a chain-walking process consisting of repeated migratory insertions and ß-H eliminations. The bidirectionality of the isomerization reaction was established by isotopic labeling experiments using a substrate with a double bond isolated from both terminal functions. The palladium hydride was also found to be directly involved in the product-forming tautomerization step. The ambiphilic character of the in situ generated [Pd-H] was demonstrated using isomeric trisubstituted α,ß-unsaturated esters. Finally, the high levels of enantioselectivity obtained in the isomerization of a small set of α-substituted α,ß-unsaturated ketones augur well for the successful development of an enantioselective version of this unconventional isomerization.

Metal-free enantioselective electrophilic activation of allenamides: stereoselective dearomatization of indoles.

The effective and unprecedented chiral BINOL phosphoric acid catalyzed (1-10 mol%) dearomatization of indoles through electrophilic activation of allenamides (ee up to 94%), is documented. Besides the synthesis of 3,3-disubstituted indolenine cores, a dearomatization/hydrogen transfer cascade sequence is also presented as a new synthetic shortcut toward highly enantiomerically enriched indolines.

Non-Invasive Measurement of Hepatic Fibrosis by Transient Elastography: A Narrative Review.

Transient elastography by FibroScan® (Echosens, Paris, France) is a non-invasive method that can provide a reliable measurement of liver fibrosis through the evaluation of liver stiffness. Despite its limitations and risks, liver biopsy has thus far been the only procedure able to provide data to quantify fibrosis. Scientific evidence and clinical practice have made it possible to use FibroScan® in the diagnostic work-up of several liver diseases to monitor patients' long-term treatment response and for complication prevention. For these reasons, this procedure is widely used in clinical practice and is still being investigated for further applications. The aim of this narrative review is to provide a comprehensive overview of the main applications of transient elastography in the current clinical practice.

Long-Term Prognosis among COVID-19 Patients: The Predictive Role Played by Hyperinflammation and Arrhythmic Disorders in Fatal Outcome.

Limited data are available on outcomes among COVID-19 patients beyond the acute phase of the disease. All-cause mortality among our COVID-19 patients one year after hospital discharge and factors/conditions associated with death were evaluated. All patients discharged from our COVID center were periodically evaluated by clinical assessment and by digital healthcare registry consultation. All findings acquired on discharge day represented the baseline data and were utilized for statistics. Of the 208 patients admitted, 187 patients were discharged. Among these, 17 patients died within 12 months (non-survivors). Compared to survivors, non-survivor patients were significantly (p < 0.05) older, exhibited significantly greater comorbidities and prevalence of active malignancy, heart failure, and arrhythmias, and showed significantly higher circulating levels of B-type natriuretic peptide, troponin, C-reactive protein, and d-dimer, as well as a longer heart-rate-corrected QT interval and significantly lower values for the glomerular filtration rate. Following multivariate analysis, cancer, arrhythmias, and high C-reactive protein levels were found to be factors independently associated with death. At the one-year follow-up, about 9% of patients discharged from our COVID center had a fatal outcome. Ageing, myocardial injury, impaired renal function, and, in particular, cancer, hyperinflammation, and arrhythmias represented strong predictors of the worst long-term outcome among COVID-19 patients.

Liver Involvement in Patients with Systemic Sclerosis: Role of Transient Elastography in the Assessment of Hepatic Fibrosis and Steatosis.

Background Systemic sclerosis (SSc) is a rare, multisystemic disorder of connective tissue characterized by widespread inflammation, vascular abnormalities, and both skin and visceral organ fibrosis. Tissue fibrosis is the final phase of a complex biological process of immune activation and vascular damage. Objectives The aim of the study was to assess hepatic fibrosis and steatosis in SSc patients by transient elastography (TE). Methods Fifty-nine SSc patients fulfilling the 2013 ACR/EULAR classification criteria were recruited. Clinical and laboratory findings, modified Rodnan skin score (mRSS), activity index, videocapillaroscopy, echocardiography, and lung function data were analyzed. Liver stiffness (LS) was measured by transient elastography (TE), with 7 kPa used as the cut-off value for significant liver fibrosis. In addition, hepatic steatosis was evaluated by means of controlled attenuation parameter (CAP) findings. Specifically, CAP values ≥ 238 ≤ 259 dB/m were considered consistent with mild steatosis (S1), values ≥ 260 ≤ 290 dB/m were compatible with moderate steatosis (S2), and values ≥ 291 dB/m were indicative of severe steatosis (S3). Results The median age of patients was 51 years, with a median disease duration of 6 years. The median LS was 4.5 (2.9-8.3) kPa; 69.5% of patients had no evidence of fibrosis (F0); 27.1% displayed LS values between 5.2 and 7 kPa; and only 3.4% of patients had LS values > 7 kPa (F3). The median CAP value for liver steatosis was 223 dB/m (IQR: 164-343). Overall, 66.1% of patients did not show evidence of steatosis (CAP values < 238 dB/m); 15.2% showed values consistent with mild (S1) steatosis (CAP value ≥ 238 ≤ 259 dB/m); 13.5% had moderate (S2) steatosis (CAP value ≥ 260 ≤ 290 dB/m); and 5.1% were deemed to have severe steatosis (S3) due to CAP values ≥ 291 dB/m. Conclusions Although systemic sclerosis is associated with fibrosis of the skin and several organs, only 3.4% of our patient population showed evidence of marked liver fibrosis, which is the same prevalence as that expected in the general population. Therefore, fibrosis of the liver did not appear to be a significant concern in SSc patients, albeit moderate fibrosis could still be detected in a significant proportion of subjects. A prolonged follow-up may clarify whether liver fibrosis in SSc patients may still progress. Likewise, the prevalence of significant steatosis was low (5.1%) and depended on the same variables associated with fatty liver disease in the general population. TE was shown to be an easy and valuable method for detection and screening of hepatic fibrosis in SSc patients with no additional risk factors for liver disease and may be useful to assess the potential progression of liver fibrosis over time.

Liver Involvement during SARS-CoV-2 Infection Is Associated with a Worse Respiratory Outcome in COVID-19 Patients.

Coronavirus disease of 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), may be complicated by life-threatening interstitial pneumonia. SARS-CoV-2 infection may also damage several tissues and/or organs beyond the lungs, including the liver. However, controversy still exists as to whether SARS-CoV-2-induced liver alterations can have an impact on the outcome of COVID-19. The aim of this study was therefore to assess whether SARS-CoV-2-infected patients with liver abnormalities at the time of hospital referral had a worse outcome with respect to patients with no liver biochemistry alterations. To this end, the medical records of 123 patients admitted to our COVID center between the end of 2020 and spring 2021 were retrospectively reviewed. Patients were divided into two groups: those with normal liver biochemistries (group 1, 77 patients) and those with altered liver function tests (group 2, 46 patients). Serum levels of aminotransferases (AST and ALT) and bile duct cell injury markers (γ-GT and ALP) were used to dichotomize patients. A higher percentage of patients with liver enzyme alterations were found to develop COVID-19 pneumonia with respect to group 1 patients (74% vs. 65%); moreover, they needed more days of respiratory support and, more importantly, more intensive administration of supplemental oxygen. A statistically significant correlation was also found between aminotransferase levels and duration of respiratory support. The mortality rate was not superior in group 2 vs. group 1 patients. In conclusion, liver abnormalities on admission predisposed COVID-19 patients to development of more severe interstitial pneumonia, because of a longer requirement for supplemental oxygen and a more intensive respiratory support, indicative of a worse disease evolution in these patients.

Prevalence and Outcome of Serum Autoantibodies in Chronic Hepatitis C Patients Undergoing Direct-Acting Antiviral Treatment.

Background: Chronic immune stimulation by hepatitis C virus (HCV) may cause occurrence of several autoantibodies in infected patients, with or without features of clinically overt autoimmune diseases. The recent introduction of direct-acting antivirals (DAAs) has dramatically changed the natural history of chronic HCV infection. The aim of this study was to assess the effects of DAA therapy on serum autoantibodies in chronic hepatitis C (CHC) patients. Methods: The medical records of 113 CHC patients were reviewed to assess autoantibody behavior following DAA-directed HCV eradication. Statistical analysis was performed to assess correlations between DAA treatment and autoantibody titers, HCV genotypes, and viral loads. Results: Anti-nuclear (ANA), anti-smooth muscle cell (ASMA) and anti-mitochondrial (AMA) antibody testing was available in 77 patients; 31 out of 77 patients (40%) had one or more serum autoantibodies prior to treatment. Measurement of autoantibody titers before and after HCV eradication was performed in 20 of 31 patients. DAA treatment significantly affected ANA and ASMA titers, leading to disappearance or reduction of autoantibody titers; conversely, AMA were not influenced by DAA treatment. No correlations were observed between autoantibody specificity and both HCV genotypes and viral loads at baseline. Likewise, serum autoantibody titers were independent of HCV genotypes. Conclusions: DAA-directed HCV clearance may interrupt chronic immune stimulation by removing the drive for autoantibody induction. The isolated persistence of autoantibodies in the small fraction of patients who did not show clearance following DAA treatment may require long-term vigilance.

COVID-19 and arrhythmia: The factors associated and the role of myocardial electrical impulse propagation. An observational study based on cardiac telemetric monitoring.

Background: The heart is commonly involved in COVID-19, and rhythm disorders have been largely reported. Objective: To evaluate the association of some non-cardiac and cardiac comorbidities and QT dispersion with arrhythmias and their impact on outcomes in hospitalized patients with COVID-19. Methods: Each patient underwent cardiac telemetry monitoring through the entire hospitalization period, laboratory analyses, 12-lead ECG, and lung imaging examination. Patients with arrhythmia were divided into three groups (bradyarrhythmias, tachyarrhythmias, and tachy- and bradyarrhythmias). Results: Two-hundred patients completed the study (males, 123; mean age, 70.1 years); of these, 80 patients (40%) exhibited rhythm disorders on telemetry. Patients with arrhythmia were older (p < 0.0001), had a greater number of comorbidities (p < 0.0001), higher values of creatinine (p = 0.007), B-type natriuretic peptide (p < 0.0001), troponin (p < 0.0001), C-reactive protein (p = 0.01), ferritin (p = 0.001), D-dimer (p < 0.0001), procalcitonin (p = 0.0008), QT interval (p = 0.002), QTc interval (p = 0.04), and QTc dispersion (p = 0.01), and lower values of sodium (p = 0.03), magnesium (p = 0.04), glomerular filtration rate (p < 0.0001), and hemoglobin (p = 0.008) as compared to patients without arrhythmia. By comparing the three subgroups of patients, no significant differences were found. At multivariate analysis, age [odds ratio (OR) = 1.14 (95% CI: 1.07-1.22); p = 0.0004], coronary artery disease [OR = 12.7 (95% CI: 2.38-68.01); p = 0.005], and circulating troponin [OR = 1.05 (95% CI: 1.003-1.10); p = 0.04] represented risk factors independently associated with arrhythmia. All-cause in-hospital mortality was ∼40-fold higher among patients with arrhythmia [OR = 39.66 (95% CI: 5.20-302.51); p = 0.0004]. Conclusion: Arrhythmias are associated with aging, coronary artery disease, subtle myocardial injury, hyperinflammatory status, coagulative unbalance, and prolonged QTc dispersion in patients with COVID-19, and confer a worse in-hospital prognosis. Given its usefulness, routinary use of cardiac telemetry should be encouraged in COVID wards.