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1.
Semin Thromb Hemost ; 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38936417

RESUMO

Type 3 von Willebrand disease (VWD), the most severe form of VWD, is an inherited recessive bleeding disorder caused by the complete deficiency of von Willebrand factor (VWF). The reported prevalence is 1 per million but varies worldwide according to the frequency of consanguineous marriages. The clinical phenotype is characterized not only by mucocutaneous bleedings, but also by hemarthroses and muscle hematoma, as in patients with moderate hemophilia. Long-term prophylaxis with factor (F)VIII/VWF concentrates is recommended in patients with a history of severe and frequent bleeds. A rare complication of replacement therapy is the development of alloantibodies against VWF, with the consequences of an ineffective therapy and risk of anaphylactic reactions upon treatment. Emicizumab is the first bispecific monoclonal antibody that mimics FVIII coagulant activity and is approved for prophylaxis of bleeding in patients with inherited hemophilia A with or without inhibitors and recently also for acquired hemophilia. In this manuscript we report and discuss available data in the literature on the use of emicizumab in type 3 VWD and describe the case of a female patient with type 3 VWD with a history of alloantibodies against VWF and posttransfusion anaphylaxis, recently and successfully put on off-label prophylaxis with emicizumab.

2.
J Org Chem ; 88(19): 13995-14003, 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37747795

RESUMO

A new straightforward approach to 1-aryl-2-aminopropanes using easily accessible substrates has been developed. Simple allyl alcohol is shown to be an ideal synthetic equivalent of the C3 propane-1,2-diylium bis-cation synthon in three-component cascade reactions with arenes and sulfonamide nucleophiles to regioselectively afford 1-aryl-2-aminopropanes. The reaction is catalyzed by Cu(OTf)2 and is expected to involve a Friedel-Crafts-type allylation of the arene, followed by hydroamination.

3.
J Org Chem ; 87(7): 4640-4648, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35290058

RESUMO

A new Ru3(CO)12-catalyzed directed alkenylation of 2-carboxaldimine-heterocyclopentadienes has been accomplished. This process allows coupling of furan, pyrrole, indole, and thiophene 2-carboxaldimines with electron-poor alkenes such as acrylates, vinylsulfones, and styrenes. This regio- and chemoselective oxidative C-H coupling does not require the presence of an additional sacrificial oxidant. Density functional theory calculations allowed us to propose a mechanism and unveiled the nature of the H2 acceptor.

4.
J Org Chem ; 87(5): 2580-2589, 2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-35138099

RESUMO

The synthesis of a small library of NH-Boc- or NH-Fmoc-protected l-phenylalanines carrying methyl groups at positions 2 and 6 and diverse functionalities at position 4 has been achieved. The approach, which took advantage of a Pd-catalyzed directed C-H dimethylation of picolinamide derivatives, allowed the electronic and steric properties of the resulting amino acid derivatives to be altered by appending a variety of electron-withdrawing, electron-donating, or bulky groups.


Assuntos
Aminoácidos , Fenilalanina , Aminoácidos/química , Fenilalanina/química , Tirosina/análogos & derivados
5.
Sensors (Basel) ; 22(9)2022 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-35591156

RESUMO

With the advent of digital technologies, the computer has become a generalized tool for music production. Music can be seen as a creative form of human-human communication via a computer, and therefore, research on human-computer and computer-human interfaces is very important. This paper, for the Sensors Special Issue on 800 Years of Research at Padova University, presents a review of the research in the field of music technologies at Padova University by the Centro di Sonologia Computazionale (CSC), focusing on scientific, technological and musical aspects of interaction between musician and computer and between computer and audience. We discuss input devices for detecting information from gestures or audio signals and rendering systems for audience and user engagement. Moreover, we discuss a multilevel conceptual framework, which allows multimodal expressive content processing and coordination, which is important in art and music. Several paradigmatic musical works that stated new lines of both musical and scientific research are then presented in detail. The preservation of this heritage presents problems very different from those posed by traditional artworks. CSC is actively engaged in proposing new paradigms for the preservation of digital art.


Assuntos
Música , Computadores , Gestos , Humanos , Tecnologia , Universidades
6.
Beilstein J Org Chem ; 18: 1256-1263, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36158173

RESUMO

3-Silylated furfurals, readily prepared in three steps from biomass-derived furfural and 5-methylfurfural, are converted into 3-silylated 2-furyl carbinols upon condensation with organomagnesium or organolithium reagents. The hydroxy unit of the carbinol adducts can be exploited to promote C3(sp2)-Si bond functionalization through intramolecular activation. Two approaches were contemplated for this purpose. Activation by alkoxides of the C3-SiEt3 or C3-SiMe2 t-Bu bonds was ineffective. Conversely, treatment of the C3-benzyldimethylsilyl-appended derivatives with tetrabutylammonium fluoride led to cyclic siloxanes, which revealed to be competent donors for copper-catalyzed cross-coupling reactions, such as arylation reactions catalyzed by Pd2(dba)3/CuI, as well as allylation and methylation reactions catalyzed by CuI⋅PPh3. C3-Benzyldimethylsilyl-appended furfurals are thus introduced as versatile platforms, providing a modular access to 3-substituted 2-furyl carbinols from renewable feedstock.

7.
Arterioscler Thromb Vasc Biol ; 40(12): 2975-2989, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33052054

RESUMO

OBJECTIVE: Pulmonary thrombosis is observed in severe acute respiratory syndrome coronavirus 2 pneumonia. Aim was to investigate whether subpopulations of platelets were programmed to procoagulant and inflammatory activities in coronavirus disease 2019 (COVID-19) patients with pneumonia, without comorbidities predisposing to thromboembolism. Approach and Results: Overall, 37 patients and 28 healthy subjects were studied. Platelet-leukocyte aggregates, platelet-derived microvesicles, the expression of P-selectin, and active fibrinogen receptor on platelets were quantified by flow cytometry. The profile of 45 cytokines, chemokines, and growth factors released by platelets was defined by immunoassay. The contribution of platelets to coagulation factor activity was selectively measured. Numerous platelet-monocyte (mean±SE, 67.9±4.9%, n=17 versus 19.4±3.0%, n=22; P<0.0001) and platelet-granulocyte conjugates (34.2±4.04% versus 8.6±0.7%; P<0.0001) were detected in patients. Resting patient platelets had similar levels of P-selectin (10.9±2.6%, n=12) to collagen-activated control platelets (8.7±1.5%), which was not further increased by collagen activation on patient platelets (12.4±2.5%, P=nonsignificant). The agonist-stimulated expression of the active fibrinogen receptor was reduced by 60% in patients (P<0.0001 versus controls). Cytokines (IL [interleukin]-1α, IL-1ß, IL-1RA, IL-4, IL-10, IL-13, IL, 17, IL-27, IFN [interferon]-α, and IFN-γ), chemokines (MCP-1/CCL2 [monocyte chemoattractant protein 1]), and growth factors (VEGF [vascular endothelial growth factor]-A/D) were released in significantly larger amounts upon stimulation of COVID-19 platelets. Platelets contributed to increased fibrinogen, VWF (von Willebrand factor), and factor XII in COVID-19 patients. Patients (28.5±0.7 s, n=32), unlike controls (31.6±0.5 s, n=28; P<0.001), showed accelerated factor XII-dependent coagulation. CONCLUSIONS: Platelets in COVID-19 pneumonia are primed to spread proinflammatory and procoagulant activities in systemic circulation.


Assuntos
Plaquetas/metabolismo , COVID-19/sangue , Tromboembolia/etiologia , Idoso , Idoso de 80 Anos ou mais , COVID-19/complicações , Citocinas/metabolismo , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Prognóstico , Tromboembolia/sangue
8.
Semin Thromb Hemost ; 45(3): 308-314, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30699441

RESUMO

This study aimed to provide a preliminary evaluation of the analytical performance of the new Roche COBAS T 711: fully automated coagulation analyzer, which uses both liquid and lyophilized reagent cassettes. The analytical assessment included analysis of imprecision and linearity of prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen on COBAS T 711: analyzer. Test results of 120 routine plasma samples were also compared with those obtained using two other coagulation analyzers (Instrumentation Laboratory ACL TOP 700 and Stago STA-R MAX). The accuracy, imprecision, and comparability of manual and automatic lyophilized material resuspension were also evaluated using 200 routine plasma samples. Overall, automatic resuspension was found to be more precise than, and equally accurate as, manual reconstitution, with coefficient of variations (CV%) three- to sixfold lower compared with manual reconstitution. The analytical imprecision was found to be excellent, as attested by total CV% of 0.7% for PT, 1.7 to 1.8% for APTT, and 1.9 to 3.2% for fibrinogen. Linearity was excellent over a clinically significant range of PT, APTT, and fibrinogen values, displaying correlation coefficients comprised between 0.994 and 0.999. Methods comparison studies revealed that results of PT, APTT, and fibrinogen on COBAS T 711: are globally aligned with those obtained using identical plasma samples on IL ACL TOP 700 and Stago STA-R MAX, displaying correlation coefficients of 0.97 for PT, 0.81 and 0.88 for APTT, 0.90 and 0.94 for fibrinogen, respectively. In conclusion, the results of this preliminary evaluation demonstrate that PT, APTT, and fibrinogen on COBAS T 711: coagulation analyzer displays excellent performance for routine use in clinical laboratories.


Assuntos
Testes de Coagulação Sanguínea/métodos , Coagulação Sanguínea/imunologia , Hemostasia/imunologia , Humanos , Laboratórios
9.
Clin Chem Lab Med ; 57(11): 1784-1789, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30939111

RESUMO

Background Although accumulating evidence suggests that the hemostatic balance is impaired in patients with hypertriglyceridemia, hyperbilirubinemia or hemolytic anemias, little is known on the underlying biological mechanisms. This experimental study was aimed at exploring whether increasing values of triglycerides, bilirubin or cell-free hemoglobin promote thrombin generation in plasma. Methods Three different pools were prepared from three different sets of 20 normal routine plasma citrate samples. The native pools were spiked with increasing amounts of exogenous triglycerides (up to 8.8 mmol/L), bilirubin (up to 350 µmol/L) or autologous hemolyzed blood (up to 3.5 g/L cell-free hemoglobin). Using the fully-automated thrombin generation analyzer ST Genesia, we measured the following parameters: lag time (LT), time to peak (TP), peak height (PH) and endogenous thrombin potential (ETP). Results A sustained increase of PH and ETP was found in parallel with increasing triglyceride concentrations, peaking in the aliquot with 8.8 mmol/L. Conversely, LT and TP displayed an opposite trend, reaching a maximum decrease in the 8.8 mmol/L aliquot. Increasing bilirubin concentrations promoted remarkable increases of PH and ETP and decreases of TP and LT, up to 211 µmol/L. After this threshold, all parameters tended to return towards baseline values. A constant increase of PH and ETP was also noted in hemolyzed samples, peaking in the 3.5 g/L cell-free hemoglobin aliquot, whereas the TP and LT remained unchanged in all hemolyzed aliquots. Conclusions Our findings suggest that hypertriglyceridemia, hyperbilirubinemia and hemolysis may promote a hypercoagulable state in human plasma.


Assuntos
Hemólise/fisiologia , Hiperbilirrubinemia/sangue , Plasma/metabolismo , Trombina/efeitos adversos , Testes de Coagulação Sanguínea/métodos , Feminino , Humanos , Hiperbilirrubinemia/etiologia , Hipertrigliceridemia/sangue , Hipertrigliceridemia/etiologia , Masculino
10.
Beilstein J Org Chem ; 15: 1107-1115, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31164947

RESUMO

Two complementary [3 + 2] annulation protocols between 3-oxoglutarates and cyclic γ-oxy-2-cycloalkenones, simply differing on the reaction temperature, are disclosed. These domino transformations allow C-C/O-C or C-C/C-C [3 + 2] annulations at will, via an intermolecular Pd-catalyzed C-allylation/intramolecular O- or C-1,4-addition sequence, respectively. In particular, exploiting the reversibility of the O-1,4-addition step, in combination with the irreversible C-1,4-addition/decarboxylation path, the intramolecular conjugate addition step could be diverted from the kinetic (O-alkylation) to the thermodynamic path (C-alkylation) thanks to a simple temperature increase. Crucial for the success of this bis-nucleophile/bis-electrophile [3 + 2] annulation is its well-defined step chronology in combination with the total chemoselectivity of the former step. This [3 + 2] C-C/O-C bond forming annulation protocol could be also extended to 1,3,5-triketones as well as 1,3-bis-sulfonylpropan-2-one bis-nucleophiles.

11.
Chemistry ; 23(35): 8385-8389, 2017 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-28445630

RESUMO

Furfural and related compounds are industrially relevant building blocks obtained from lignocellulosic biomass. To enhance the added value of these renewable resources, a Ru-catalyzed hydrofurylation of alkenes, involving a directed C-H activation at C3 of the furan ring, was developed. A thorough experimental study revealed that a bidentate amino-imine directing group enabled the desired coupling. Removal of the directing group occurred during the purification step, directly releasing the C3-functionalized furfurals. Development of the reaction as well as optimization and scope of the method were described. A mechanism was proposed on the basis of DFT calculations.

12.
Clin Sci (Lond) ; 131(16): 2095-2107, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28634189

RESUMO

Loss-of-function mutations of the the ATP-binding cassette-1 (ABCA1) gene are the cause of Tangier disease (TD) in homozygous subjects and familial HDL deficiency (FHD) in heterozygous subjects. These disorders are characterized by reduced plasma HDL-cholesterol (HDL-C) and altered efflux of cholesterol from cells. Previous studies in TD patients and ABCA1-/- murine models reported defects in platelet count, morphology, and function, but the issue is still controversial. We analyzed three subjects with low to very low HDL-C levels due to the loss-of-function mutations of the ABCA1 gene. Two related patients with FHD were heterozygous carriers of two mutations on the same ABCA1 allele; one, with TD, was homozygous for a different mutation. Mild to moderate thrombocytopenia was observed in all the patients. No morphological platelet abnormalities were detected under optical or EM. History of moderate bleeding tendency was recorded only in one of the FHD patients. Only limited alterations in platelet aggregation and activation of the integrin αIIbß3 were observed in one FHD patient. While α-granule secretion (P-selectin), content, and secretion of platelet δ-granules (serotonin, ATP, and ADP) and thromboxane (TX) A2 synthesis were normal in all the patients, the expression of lysosomal CD63, in response to some agonists, was reduced in TD patients. In conclusion, three patients carrying ABCA1 genetic variants had low platelet count, with the lowest values observed in TD, not associated with major alterations in platelet morphology and response to agonists or bleeding.


Assuntos
Transportador 1 de Cassete de Ligação de ATP/genética , Plaquetas/fisiologia , Mutação , Trombocitopenia/genética , Idoso , Plaquetas/ultraestrutura , Coleta de Amostras Sanguíneas/métodos , Feminino , Humanos , Hipoalfalipoproteinemias/sangue , Hipoalfalipoproteinemias/genética , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Agregação Plaquetária/fisiologia , Contagem de Plaquetas , Testes de Função Plaquetária/métodos , Doença de Tangier/sangue , Doença de Tangier/genética , Trombocitopenia/sangue
13.
Chimia (Aarau) ; 70(1-2): 84-92, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26931222

RESUMO

The use of tert-butanesulfinamides as nitrogen nucleophiles in carbon-nitrogen bond forming reactions is reviewed. This field has grown in the shadow of the general interest in N-tert-butanesulfinyl imines for asymmetric synthesis and occupies now an important place in its own right in the chemistry of the chiral amine reagent tert-butanesulfinamide. This article provides an overview of the area and emphasizes recent contributions wherein the tert-butanesulfinamides act as chiral auxiliaries or perform as nitrogen donors in metal-catalyzed amination reactions.

14.
Acc Chem Res ; 47(12): 3439-47, 2014 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-25415844

RESUMO

CONSPECTUS: Lactones and lactams are a well-known class of natural products and can be used as building blocks in organic synthesis. In addition, they can be found in many natural sources and synthetic drugs and have a broad range of biological or odorant properties. Chemists can create these useful compounds through palladium catalysis, which is a highly efficient tool for organic synthesis and is conveniently functional group tolerant. In this Account, we describe our work over the past 15 years in intramolecular Pd-catalyzed allylations where we have tethered the nucleophile and the electrophile by either an amide or an ester moiety, to produce γ-lactams and γ-lactones. We discuss in detail how the nature of the heteroatom tether influences the regioselectivity of the reaction. For example, a ketone [-C(O)CH2-] tether leads to mixtures of 5-exo and 7-endo cyclization products, while ester or amide [-C(O)X-] tethers afford sole 5-exo products. However, in the case of X = O, we were required to overcome two issues in the synthesis of γ-lactones. First of all, the tethering ester function can compete with the allylic leaving group in the oxidative addition to the Pd(0) center. Second, in this case, the proportion of the conformers that have a suitable geometry for cyclization is very low. When we insert a juxtaposed silyl group on the allyl fragment, the molecule can undergo oxidative addition and functionalization of the lactone via Hiyama cross-coupling. We also performed DFT calculations on these systems, which allowed us to better understand the behavior of [-C(O)X-] and [-C(O)CH2-] tethers. Computations also let us rationalize the different reactivities that we observed as a function of the geometry (Z or E) of the starting substrates. In addition, we were able to synthesize natural products or analogs (α-kainic acid, isoretronecanol, and picropodophyllin). We could turn these allylation reactions into asymmetric transformations and incorporate them into domino sequences. Thus, an allylation/Mizoroki-Heck sequence allowed us to straightforwardly access an aza-analog of picropodophyllin, as well as reach the lysergic acid backbone. Finally, we found that through carbopalladation of allenes, we could efficiently synthesize the key η(3)-allylpalladium intermediates that were then ready for allylation reactions.


Assuntos
Compostos Alílicos/química , Simulação por Computador , Lactamas/síntese química , Lactonas/síntese química , Modelos Químicos , Paládio/química , Alquilação , Catálise , Lactamas/química , Lactonas/química , Estrutura Molecular
16.
Chemistry ; 20(6): 1539-46, 2014 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-24403244

RESUMO

Pd(II)-catalyzed alkene aminopalladation and allylic C-H activation are two competing reaction sequences sharing the same reaction conditions. This study aimed at understanding the factors that bias one or the other path in the intramolecular oxidative cyclization of two types of N-tosyl amidoalkenes. The results obtained are in accord with the initial generation of a high-energy cyclic (5- or 6-membered) aminopalladated intermediate. However, this latter species can evolve only if the following specific conditions are met: the availability of distocyclic ß-H elimination pathway, the presence of a strong terminal oxidant, or the availability of a carbopalladation pathway. Conversely, the cyclic alkylpalladium complex is only a latent species in equilibrium with the initial substrate and cannot evolve. Such a reactivity hurdle leaves the way open for alternative reactivities such as allylic C-H activation of the olefinic substrate to generate a η(3)-allyl complex followed by its interception by the nitrogen nucleophile, [3,3]-sigmatropic rearrangement, or decomposition. This study proposes a unifying mechanistic picture that connects these competing mechanisms.

17.
Int J Lab Hematol ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38716760

RESUMO

INTRODUCTION: This observational study conducted across seven emergency care units compares the efficacy of four D-dimer detection methods, namely HemosIL D-dimer HS (HS), HemosIL D-dimer HS-500 (HS-500), VIDAS D-dimer (VIDAS), and HemosIL AcuStar D-dimer (ACUSTAR). The primary focus is on patients with a clinical suspicion of deep venous thrombosis (DVT) or pulmonary embolism (PE). METHODS: A total of 149 samples were collected from patients with suspected DVT or PE. The confirmation of DVT/PE was based on calf ultrasound or computed tomography-Angiography. Direct comparisons were made between the different detection methods, considering both their analytical performance and clinical utility. Additionally, the impact of an age-adjusted cut-off on the diagnostic accuracy of each method was assessed. RESULTS: The results revealed comparable negative predictive value, sensitivity, and specificity across the methods, with a notable exception of increased specificity for HS compared with HS-500 (50.8% vs. 41.5%, p = 0.03). Further analysis incorporating an age-adjusted cut-off demonstrated a significant improvement in specificity for HS. When using the age-adjusted cut-off, HS exhibited a substantial increase in specificity compared with HS-500 (63.1% vs. 49.2%, p = 0.004) and demonstrated significantly higher specificity compared with VIDAS (63.1% vs. 53.8%, p = 0.04). CONCLUSION: The study emphasizes the nonuniversal effect of an age-adjusted cut-off and discusses the potential necessity for different cut-off values, particularly in the case of HS-500. These findings contribute to the understanding of D-dimer detection methods in the context of DVT and PE, providing insights into their relative performances and the potential optimization through age-adjusted cut-offs.

18.
Chemistry ; 19(38): 12607-12, 2013 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-23983072

RESUMO

Handy POMs: Several palladium-catalyzed coupling reactions have been applied to polyoxometalate post-functionalization. The feasibility of each reaction with one model substrate was investigated and each set of synthetic conditions was optimized to obtain full conversions and high purity hybrid compounds.

19.
Org Lett ; 25(40): 7380-7384, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37772494

RESUMO

A phosphine-catalyzed domino assembly of six units of 2-bromomethyl acrylates afforded polyalkenyl adducts containing two cyclohexenyl rings. This reaction occurs under mild conditions providing the final product by formation of seven carbon-carbon bonds and four stereocenters. Experimental and computational studies support an initial dimerization of the substrate, which in turn trimerizes involving two totally regio- and stereocontrolled Diels-Alder cycloadditions. The yield of the hexamerization of the 2-bromomethyl acrylates depends on the size of the ester function. The protocol has also proved to be practicable on a gram scale.

20.
Front Psychol ; 13: 828699, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35369229

RESUMO

This study sought to determine if hues overlayed on a video recording of a piano performance would systematically influence perception of its emotional arousal level. The hues were artificially added to a series of four short video excerpts of different performances using video editing software. Over two experiments 106 participants were sorted into 4 conditions, with each viewing different combinations of musical excerpts (two excerpts with nominally high arousal and two excerpts with nominally low arousal) and hue (red or blue) combinations. Participants rated the emotional arousal depicted by each excerpt. Results indicated that the overall arousal ratings were consistent with the nominal arousal of the selected excerpts. However, hues added to video produced no significant effect on arousal ratings, contrary to predictions. This could be due to the domination of the combined effects of other channels of information (e.g., the music and player movement) over the emotional effects of the hypothesized influence of hue on perceived performance (red expected to enhance and blue to reduce arousal of the performance). To our knowledge this is the first study to investigate the impact of these hues upon perceived arousal of music performance, and has implications for musical performers and stage lighting. Further research that investigates reactions during live performance and manipulation of a wider range of lighting hues, saturation and brightness levels, and editing techniques, is recommended to further scrutinize the veracity of the findings.

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