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1.
Ann Med Surg (Lond) ; 86(2): 930-942, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38333295

RESUMO

Lewy body dementia (LBD) is situated at the convergence of neurodegenerative disorders, posing an intricate and diverse clinical dilemma. The accumulation of abnormal protein in the brain, namely, the Lewy body causes disturbances in typical neural functioning, leading to a range of cognitive, motor, and mental symptoms that have a substantial influence on the overall well-being and quality of life of affected individuals. There is no definitive cure for the disease; however, several nonpharmacological and pharmacological modalities have been tried with questionable efficacies. The aim of this study is to figure out the role of different interventional strategies in the disease. Donepezil, rivastigmine, memantine, and galantamine were the commonly used drugs for LBD. Together with that, levodopa, antipsychotics, armodafinil, piracetam, and traditional medications like yokukansan were also used, when indicated. Talking about nonpharmacological measures, exercise, physical therapy, multicomponent therapy, occupational therapy, psychobehavioral modification, transcranial stimulation, and deep brain stimulation have been used with variable efficacies. Talking about recent advances in the treatment of LBD, various disease-modifying therapies like ambroxol, neflamapimod, irsenontrine, nilotinib, bosutinib, vodobatinib, clenbuterol, terazosin, elayta, fosgonimeton, and anle138b are emerging out. However, there drugs are still in the different phases of clinical trials and are not commonly used in clinical practice. With the different pharmacological and nonpharmacological modalities we have for treatment of LBD, all of them offer symptomatic relief only. Being a degenerative disease, definite cure of the disease can only be possible with regenerative measures.

2.
Medicine (Baltimore) ; 102(41): e35569, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37832119

RESUMO

cerebrovascular accident (CVA) has contributed to a significant increase in the morbidity and mortality rates in lower middle-income counties like Nepal. Despite being a common noncommunicable disease in Nepal, little attention has been paid to it, in terms of formulating national health plans and policies by the concerned authorities. This was a descriptive cross-sectional study in patients diagnosed with cerebrovascular accidents at a tertiary care hospital in Eastern Nepal. We analyzed 128 diagnosed cases of cerebrovascular accidents from February 26, 2023 to June 26, 2023 after taking ethical clearance from the Institutional Review Committee (Reference no. IRC-PA-283/2078-79). Data were analyzed by Statistical Package for the Social Sciences version 23. The objective of this study was to explore the age and sex distribution of CVA, its association with medical co-morbidities, and known risk factors like Type-2-Diabetes Mellitus, hypertension, thyroid disorders, smoking and alcohol. Together with calculating the distribution of ischemic CVA and hemorrhagic CVA we had also staged the disease based on the National Institute of Health Stroke Scale.


Assuntos
Acidente Vascular Cerebral , Humanos , Estudos Transversais , Nepal/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Comorbidade , Fatores de Risco , Centros de Atenção Terciária
3.
Medicine (Baltimore) ; 102(35): e34664, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37657009

RESUMO

BACKGROUND: The last few decades have witnessed an appalling rise in several emerging and re-emerging viral and zoonotic outbreaks. Amongst those emerging zoonosis, one of the diseases which is gaining popularity these days and has been declared as public health emergency of international concern by the world health organization, is human monkeypox virus (HMPX). Proper understanding of the clinical spectrum of the disease is of paramount importance for early diagnosis and treatment. In this review, we aimed to study and quantify the neurological manifestations of HMPX virus infection. METHODS: Any study, released prior to April 13, 2023, that reported neurological manifestations in patients infected by HMPX virus were reviewed systematically on PubMed, Scopus, Google Scholar, and Cochrane Library using the PRISMA (Preferred Reporting Items for Systematic review and Meta-Analysis) statement. RESULTS: Our systematic review included data from 22 eligible studies: 10 cohort studies, 3 cross sectional studies, one retrospective study, 5 case series, and 2 case reports. The most commonly reported neurological manifestations of HMPX were headache (48.84%), myalgia (27.50%), fatigue (17.73%), and photophobia (4.43%). Uncommonly, HMPX can also present with visual deficit (0.57%), seizure (0.34%), encephalitis (0.8%), dizziness (0.34%), encephalomyelitis (0.23%), coma (0.11%), and transverse myelitis (0.11%). DISCUSSIONS: Monkeypox virus usually presents with self-limiting painful rash, lymphadenitis, and fever, complications like secondary skin infection, eye problems and pneumonia can be life threatening, carrying a case fatality rate of 1% to 10%. Neurological manifestations are not uncommon and can further add-on to morbidity and mortality.


Assuntos
Coinfecção , Mpox , Humanos , Estudos Transversais , Mpox/epidemiologia , Monkeypox virus , Saúde Pública , Estudos Retrospectivos
6.
ACS Catal ; 6(1): 151-154, 2015 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-27980875

RESUMO

Stereoselective synthesis of two fluorine-bearing drug-like scaffolds, dihydroquinazolone and benzooxazinone, has been accomplished through asymmetric fluorocyclization reactions initiated by the fluorination process. The reaction employs double axially chiral anionic phase-transfer catalysts to achieve high diastereo- and enantioselectivities, and a wide range of fluorine-containing dihydroquinazolones were obtained (>20:1 dr, up to 98% ee).

7.
Br J Pharmacol ; 171(1): 92-106, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24102184

RESUMO

BACKGROUND AND PURPOSE: Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an increased risk for stroke, heart failure and cardiovascular-related mortality. Candidate targets for anti-AF drugs include a potassium channel K(v)1.5, and the ionic currents I(KACh) and late I(Na), along with increased oxidative stress and activation of NFAT-mediated gene transcription. As pharmacological management of AF is currently suboptimal, we have designed and characterized a multifunctional small molecule, compound 1 (C1), to target these ion channels and pathways. EXPERIMENTAL APPROACH: We made whole-cell patch-clamp recordings of recombinant ion channels, human atrial I(Kur), rat atrial I(KACh), cellular recordings of contractility and calcium transient measurements in tsA201 cells, human atrial samples and rat myocytes. We also used a model of inducible AF in dogs. KEY RESULTS: C1 inhibited human peak and late K(v)1.5 currents, frequency-dependently, with IC50 of 0.36 and 0.11 µmol·L(-1) respectively. C1 inhibited I(KACh)(IC50 of 1.9 µmol·L(-1)) and the Na(v)1.5 sodium channel current (IC50s of 3 and 1 µmol·L(-1) for peak and late components respectively). C1 (1 µmol·L(-1)) significantly delayed contractile and calcium dysfunction in rat ventricular myocytes treated with 3 nmol·L(-1) sea anemone toxin (ATX-II). C1 weakly inhibited the hERG channel and maintained antioxidant and NFAT-inhibitory properties comparable to the parent molecule, resveratrol. In a model of inducible AF in conscious dogs, C1 (1 mg·kg(-1)) reduced the average and total AF duration. CONCLUSION AND IMPLICATIONS: C1 behaved as a promising multifunctional small molecule targeting a number of key pathways involved in AF.


Assuntos
Antiarrítmicos/farmacologia , Fibrilação Atrial/tratamento farmacológico , Miócitos Cardíacos/efeitos dos fármacos , Estilbenos/farmacologia , Potenciais de Ação , Adulto , Idoso , Animais , Animais Recém-Nascidos , Antioxidantes/farmacologia , Fibrilação Atrial/metabolismo , Fibrilação Atrial/fisiopatologia , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Canal de Potássio ERG1 , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Canais de Potássio Éter-A-Go-Go/genética , Canais de Potássio Éter-A-Go-Go/metabolismo , Acoplamento Excitação-Contração/efeitos dos fármacos , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/antagonistas & inibidores , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/genética , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/metabolismo , Células HEK293 , Humanos , Canal de Potássio Kv1.5/antagonistas & inibidores , Canal de Potássio Kv1.5/genética , Canal de Potássio Kv1.5/metabolismo , Masculino , Pessoa de Meia-Idade , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.5/efeitos dos fármacos , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Fatores de Transcrição NFATC/antagonistas & inibidores , Fatores de Transcrição NFATC/metabolismo , Bloqueadores dos Canais de Potássio/farmacologia , Ratos , Ratos Sprague-Dawley , Resveratrol , Bloqueadores dos Canais de Sódio/farmacologia , Transfecção
8.
Proc Natl Acad Sci U S A ; 110(34): 13729-33, 2013 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-23922394

RESUMO

We report a catalytic enantioselective electrophilic fluorination of alkenes to form tertiary and quaternary C(sp3)-F bonds and generate ß-amino- and ß-aryl-allylic fluorides. The reaction takes advantage of the ability of chiral phosphate anions to serve as solid-liquid phase transfer catalysts and hydrogen bond with directing groups on the substrate. A variety of heterocyclic, carbocyclic, and acyclic alkenes react with good to excellent yields and high enantioselectivities. Further, we demonstrate a one-pot, tandem dihalogenation-cyclization reaction, using the same catalytic system twice in series, with an analogous electrophilic brominating reagent in the second step.


Assuntos
Alcenos/química , Fluoretos/síntese química , Halogenação , Modelos Químicos , Transição de Fase , Ânions/química , Catálise , Ligação de Hidrogênio , Estrutura Molecular , Fosfatos/química
9.
Angew Chem Int Ed Engl ; 52(30): 7724-7, 2013 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-23766145

RESUMO

Chiral-anion phase-transfer catalysis (PTC) has been applied towards the enantioselective fluorocyclization reactions of 1,3-dienes. The method affords unprecedented fluorinated benz[f]isoquinoline and octahydroisoquinoline products in high yields and up to 96 % ee. New fluorinated amine reagents outperformed Selectfluor in the desired transformation.

11.
J Am Chem Soc ; 134(31): 12928-31, 2012 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-22830953

RESUMO

A chiral anion phase-transfer system for enantioselective halogenation is described. Highly insoluble, ionic reagents were developed as electrophilic bromine and iodine sources, and application of this system to o-anilidostyrenes afforded halogenated 4H-3,1-benzoxazines with excellent yield and enantioselectivity.

12.
Science ; 334(6063): 1681-4, 2011 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-22194571

RESUMO

The discovery of distinct modes of asymmetric catalysis has the potential to rapidly advance chemists' ability to build enantioenriched molecules. As an example, the use of chiral cation salts as phase-transfer catalysts for anionic reagents has enabled a vast set of enantioselective transformations. Here, we present evidence that a largely overlooked analogous mechanism wherein a chiral anionic catalyst brings a cationic species into solution is itself a powerful method. The concept is applied to the enantioselective fluorocyclization of olefins with a cationic fluorinating agent and a chiral phosphate catalyst. The reactions proceed in high yield and stereoselectivity, especially considering the scarcity of alternative approaches. This technology can in principle be applied to the large portion of reaction space that uses positively charged reagents and reaction intermediates.

13.
J Am Chem Soc ; 133(33): 12972-5, 2011 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-21797265

RESUMO

A highly enantioselective transformation catalyzed by chiral (acyclic diaminocarbene)gold(I) complexes is reported. The enantioselective synthesis of 2-substituted chromenyl pivalates from racemic phenol-substituted propargyl pivalates was developed. Rearrangement of the substrates in the presence of cationic gold gave allene intermediates, whose cyclization resulted in formation of enantioenriched product through a dynamic kinetic asymmetric transformation.


Assuntos
Alcinos/síntese química , Ésteres/síntese química , Catálise , Ouro , Metano/análogos & derivados , Estereoisomerismo
14.
J Am Chem Soc ; 133(22): 8486-9, 2011 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-21561153

RESUMO

A catalytic enantioselective reaction based on a copper(II) catalyst strictly containing chiral anionic ligands is described. In the present work, copper(II)-phosphate catalyst promotes the intramolecular heterocyclization of 2-(1-alkynyl)-2-alkene-1-ones and facilitates high levels of enantioselectivity in the subsequent nucleophile attack. Mechanistic studies suggest that formation of a copper(II)-indole species is important for catalysis.

15.
Nature ; 470(7333): 245-9, 2011 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-21307938

RESUMO

Chiral Brønsted acids (proton donors) have been shown to facilitate a broad range of asymmetric chemical transformations under catalytic conditions without requiring additional toxic or expensive metals. Although the catalysts developed thus far are remarkably effective at activating polarized functional groups, it is not clear whether organic Brønsted acids can be used to catalyse highly enantioselective transformations of unactivated carbon-carbon multiple bonds. This deficiency persists despite the fact that racemic acid-catalysed 'Markovnikov' additions to alkenes are well known chemical transformations. Here we show that chiral dithiophosphoric acids can catalyse the intramolecular hydroamination and hydroarylation of dienes and allenes to generate heterocyclic products in exceptional yield and enantiomeric excess. We present a mechanistic hypothesis that involves the addition of the acid catalyst to the diene, followed by nucleophilic displacement of the resulting dithiophosphate intermediate; we also report mass spectroscopic and deuterium labelling studies in support of the proposed mechanism. The catalysts and concepts revealed in this study should prove applicable to other asymmetric functionalizations of unsaturated systems.


Assuntos
Alcenos/química , Fosfatos/química , Ácidos/química , Aminação , Catálise , Deutério , Indóis/química , Espectrometria de Massas , Modelos Químicos
16.
Auto Immun Highlights ; 2(2): 59-65, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26000120

RESUMO

MicroRNAs (miRNAs) are non-coding, single-stranded small RNAs, usually 18-25 nucleotides long, have ability to regulate gene expression post-transcriptionally. miRNAs are highly homologous, conserved and are found in various living organisms including plants and animals. Present studies show that these small RNAs anticipate and are directly involved in many important physiological and pathological processes including growth, proliferation, maturation, metabolism, and inflammation among others. Evidences are accumulating that miRNAs play active role in directing immune responses and, therefore, might be involved in pathogenesis of autoimmune diseases. Recent studies have found that miRNAs are critical in proliferation, maturation and differentiation of T cells, B cells and, therefore, may affect the outcome of an immune response. In light of such understanding, this review briefly introduces miRNAs and discusses its role in the pathogenesis of various autoimmune diseases, as well as its potential as a biomarker and therapeutic target in the management of autoimmune diseases.

17.
J Am Chem Soc ; 131(40): 14216-7, 2009 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-19764721

RESUMO

A catalytic enantioselective synthesis of the antimelanoma marine natural product (-)-palmerolide A was accomplished using a longest sequence of 21 steps and without resorting to stoichiometric chiral auxiliaries or the chiral pool. The right half was constructed with a new variant of the Claisen-Ireland rearrangement exploiting an alkenylboronate as a masked hydroxyl. The left half featured the first application of a diol.SnCl(4)-catalyzed enantioselective crotylboration in the context of a complex target. This distinct strategy could pave the way to the design of simplified analogues of palmerolide.


Assuntos
Compostos de Boro/química , Macrolídeos/síntese química , Catálise , Macrolídeos/química , Estereoisomerismo
18.
J Org Chem ; 74(11): 4236-41, 2009 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-19422213

RESUMO

One of the most useful reactions in organic synthesis, the stereocontrolled addition of allylic metal reagents to carbonyl compounds, provides access to enantiomerically enriched homoallylic alcohols related to the acetate, propionate, and other oxygen-containing functionalities present in a large number of biologically active natural products and pharmaceutical drugs. In the search for an ideal carbonyl allylation methodology, the catalytic enantioselective allylboration presents numerous advantages such as a high chemo-, diastereo-, and enantiocontrol with stable and nontoxic pinacol allylic boronates. This article reports a rationally improved diol x SnCl(4) complex as chiral protic acid catalyst, which provides unprecedented levels of enantioselectivity in the catalytic allylation, methallylation, crotylation, and 2-bromoallylation of aliphatic aldehydes. The new diol, p-F-Vivol (4b), enables a more active diol x SnCl(4) catalyst that can compete more effectively with the background uncatalyzed allylboration. The usefulness of this optimized catalytic allylboration methodology was demonstrated with an efficient synthesis of the naturally occurring pyranone (+)-dodoneine and to the preparation of biologically important exomethylene-gamma-lactones.


Assuntos
Aldeídos/química , Boratos/química , Produtos Biológicos/síntese química , Catálise , Indicadores e Reagentes , Lactonas/síntese química , Métodos , Estereoisomerismo
19.
J Am Chem Soc ; 130(26): 8481-90, 2008 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-18540580

RESUMO

We report a novel class of C2-symmetric chiral diols derived from the hydrobenzoin skeleton. The combination of these diols with SnCl4 under Yamamoto's concept of Lewis acid assisted Brønsted acidity (LBA catalysis) leads to high levels of asymmetric induction in the allylboration of aldehydes by commercially available allylboronic acid pinacol ester 1a. The corresponding homoallylic alcohol products of synthetically useful aliphatic aldehydes are obtained in excellent yields with up to 98:2 er. This combined acid manifold is also efficient in catalyzing the diastereo- and enantioselective crotylboration of aldehydes, thus providing the propionate units in >95:5 dr and up to 98:2 er. The X-ray crystal structure of the optimal diol x SnCl4 complex, Vivol (4m) x SnCl4, unambiguously shows the Brønsted acidic character of this LBA catalyst and its highly dissymmetrical environment. Further controls have ruled out a possible boron trans-esterification mechanism with the chiral diol and point to LBA catalyst-derived activation of the pinacol allylic boronates 1. Due to slow dissociation of the diol x SnCl4 complex, a small excess of diol is required in order to suppress a competing racemic cycle catalyzed by free SnCl4.


Assuntos
Aldeídos/química , Boranos/química , Catálise , Estereoisomerismo , Compostos de Estanho
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