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1.
N Engl J Med ; 387(9): 810-823, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-36053506

RESUMO

BACKGROUND: The bedaquiline-pretomanid-linezolid regimen has been reported to have 90% efficacy against highly drug-resistant tuberculosis, but the incidence of adverse events with 1200 mg of linezolid daily has been high. The appropriate dose of linezolid and duration of treatment with this agent to minimize toxic effects while maintaining efficacy against highly drug-resistant tuberculosis are unclear. METHODS: We enrolled participants with extensively drug-resistant (XDR) tuberculosis (i.e., resistant to rifampin, a fluoroquinolone, and an aminoglycoside), pre-XDR tuberculosis (i.e., resistant to rifampin and to either a fluoroquinolone or an aminoglycoside), or rifampin-resistant tuberculosis that was not responsive to treatment or for which a second-line regimen had been discontinued because of side effects. We randomly assigned the participants to receive bedaquiline for 26 weeks (200 mg daily for 8 weeks, then 100 mg daily for 18 weeks), pretomanid (200 mg daily for 26 weeks), and daily linezolid at a dose of 1200 mg for 26 weeks or 9 weeks or 600 mg for 26 weeks or 9 weeks. The primary end point in the modified intention-to-treat population was the incidence of an unfavorable outcome, defined as treatment failure or disease relapse (clinical or bacteriologic) at 26 weeks after completion of treatment. Safety was also evaluated. RESULTS: A total of 181 participants were enrolled, 88% of whom had XDR or pre-XDR tuberculosis. Among participants who received bedaquiline-pretomanid-linezolid with linezolid at a dose of 1200 mg for 26 weeks or 9 weeks or 600 mg for 26 weeks or 9 weeks, 93%, 89%, 91%, and 84%, respectively, had a favorable outcome; peripheral neuropathy occurred in 38%, 24%, 24%, and 13%, respectively; myelosuppression occurred in 22%, 15%, 2%, and 7%, respectively; and the linezolid dose was modified (i.e., interrupted, reduced, or discontinued) in 51%, 30%, 13%, and 13%, respectively. Optic neuropathy developed in 4 participants (9%) who had received linezolid at a dose of 1200 mg for 26 weeks; all the cases resolved. Six of the seven unfavorable microbiologic outcomes through 78 weeks of follow-up occurred in participants assigned to the 9-week linezolid groups. CONCLUSIONS: A total of 84 to 93% of the participants across all four bedaquiline-pretomanid-linezolid treatment groups had a favorable outcome. The overall risk-benefit ratio favored the group that received the three-drug regimen with linezolid at a dose of 600 mg for 26 weeks, with a lower incidence of adverse events reported and fewer linezolid dose modifications. (Funded by the TB Alliance and others; ZeNix ClinicalTrials.gov number, NCT03086486.).


Assuntos
Antituberculosos , Linezolida , Nitroimidazóis , Tuberculose Resistente a Múltiplos Medicamentos , Aminoglicosídeos/uso terapêutico , Antituberculosos/efeitos adversos , Antituberculosos/uso terapêutico , Diarilquinolinas/efeitos adversos , Fluoroquinolonas , Humanos , Linezolida/efeitos adversos , Linezolida/uso terapêutico , Nitroimidazóis/efeitos adversos , Nitroimidazóis/uso terapêutico , Rifampina/uso terapêutico , Medição de Risco , Resultado do Tratamento , Tuberculose/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
2.
Molecules ; 28(10)2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37241973

RESUMO

Diterpenoid alkaloids, originating from the amination of natural tetracyclic diterpenes, have long interested scientists due to their medicinal uses and infamous toxicity which has limited the clinical application of the native compound. Alkaloid lappaconitine extracted from various Aconitum and Delphinium species has displayed extensive bioactivities and active ongoing research to reduce its adverse effects. A convenient route to construct hybrid molecules containing diterpenoid alkaloid lappaconitine and 3H-1,5-benzodiazepine fragments was proposed. The key stage involved the formation of 5'-alkynone-lappaconitines in situ by acyl Sonogashira coupling of 5'-ethynyllappaconitine, followed by cyclocondensation with o-phenylenediamine. New hybrid compounds showed low toxicity and outstanding analgesic activity in experimental pain models, which depended on the nature of the substituent in the benzodiazepine nucleus. An analogous dependence was also shown for the antiarrhythmic activity in the epinephrine arrhythmia test in vivo. Studies on the isolated atrium have shown that the mechanism of action of the new compounds is included the blockade of beta-adrenergic receptors and potassium channels. Molecular docking analysis was conducted to determine the binding potential of target molecules with the voltage-gated sodium channel NaV1.5. All obtained results provide a basis for future rational modifications of lappaconitine, reducing side effects, while retaining its therapeutic effects.


Assuntos
Aconitina , Analgésicos não Narcóticos , Antiarrítmicos , Benzodiazepinas , Bloqueadores do Canal de Sódio Disparado por Voltagem , Aconitina/análogos & derivados , Aconitina/síntese química , Aconitina/farmacologia , Benzodiazepinas/síntese química , Benzodiazepinas/química , Benzodiazepinas/farmacologia , Modelos Moleculares , Analgésicos não Narcóticos/síntese química , Analgésicos não Narcóticos/química , Analgésicos não Narcóticos/farmacologia , Ligação Proteica , Animais , Ratos , Ratos Wistar , Antiarrítmicos/síntese química , Antiarrítmicos/química , Antiarrítmicos/farmacologia , Canal de Sódio Disparado por Voltagem NAV1.5 , Masculino , Camundongos , Camundongos Endogâmicos , Bloqueadores do Canal de Sódio Disparado por Voltagem/síntese química , Bloqueadores do Canal de Sódio Disparado por Voltagem/química , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacologia , Simulação de Acoplamento Molecular
3.
Chem Rev ; 120(22): 12357-12489, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33147405

RESUMO

This is the first comprehensive review on methods and materials for use in optical sensing of pH values and on applications of such sensors. The Review starts with an introduction that contains subsections on the definition of the pH value, a brief look back on optical methods for sensing of pH, on the effects of ionic strength on pH values and pKa values, on the selectivity, sensitivity, precision, dynamic ranges, and temperature dependence of such sensors. Commonly used optical sensing schemes are covered in a next main chapter, with subsections on methods based on absorptiometry, reflectometry, luminescence, refractive index, surface plasmon resonance, photonic crystals, turbidity, mechanical displacement, interferometry, and solvatochromism. This is followed by sections on absorptiometric and luminescent molecular probes for use pH in sensors. Further large sections cover polymeric hosts and supports, and methods for immobilization of indicator dyes. Further and more specific sections summarize the state of the art in materials with dual functionality (indicator and host), nanomaterials, sensors based on upconversion and 2-photon absorption, multiparameter sensors, imaging, and sensors for extreme pH values. A chapter on the many sensing formats has subsections on planar, fiber optic, evanescent wave, refractive index, surface plasmon resonance and holography based sensor designs, and on distributed sensing. Another section summarizes selected applications in areas, such as medicine, biology, oceanography, bioprocess monitoring, corrosion studies, on the use of pH sensors as transducers in biosensors and chemical sensors, and their integration into flow-injection analyzers, microfluidic devices, and lab-on-a-chip systems. An extra section is devoted to current challenges, with subsections on challenges of general nature and those of specific nature. A concluding section gives an outlook on potential future trends and perspectives.

4.
Environ Sci Technol ; 56(23): 17471-17480, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36414252

RESUMO

Bacterial metabolisms using electron acceptors other than oxygen (e.g., methanogenesis and fermentation) largely contribute to element cycling and natural contaminant attenuation/mobilization, even in well-oxygenated porous environments, such as shallow aquifers. This paradox is commonly explained by the occurrence of small-scale anoxic microenvironments generated by the coupling of bacterial respiration and dissolved oxygen (O2) transport by pore water. Such microenvironments allow facultative anaerobic bacteria to proliferate in oxic environments. Microenvironment dynamics are still poorly understood due to the challenge of directly observing biomass and O2 distributions at the microscale within an opaque sediment matrix. To overcome these limitations, we integrated a microfluidic device with transparent O2 planar optical sensors to measure the temporal behavior of dissolved O2 concentrations and biomass distributions with time-lapse videomicroscopy. Our results reveal that bacterial colony morphology, which is highly variable in flowing porous systems, controls the formation of anoxic microenvironments. We rationalize our observations through a colony-scale Damköhler number comparing dissolved O2 diffusion and a bacterial O2 uptake rate. Our Damköhler number enables us to predict the pore space fraction occupied by anoxic microenvironments in our system for a given bacterial organization.


Assuntos
Bactérias , Água Subterrânea , Porosidade , Bactérias/metabolismo , Oxigênio , Biomassa
5.
Int J Mol Sci ; 23(22)2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36430664

RESUMO

Novel 9-N-alkyltetrahydroberberine derivatives were synthesized, among which, based on the results of OGTT, one compound containing the longest aliphatic substituent was selected for study in mice C57BL/6Ay, which demonstrate obesity, impaired glucose tolerance, and concomitant liver non-alcoholic fatty disease. Administration of this substance at a dose of 15 mg/kg for four weeks improved the insulin sensitivity of mice, which resulted in a decrease in fasting glucose levels and improved the tolerance of mice to OGTT glucose loading. A decrease in the level of lactate in the blood and a decrease in the amount of glucokinase in the liver were also found. The introduction of compound 3c did not have a toxic effect on animals based on biochemical data, histological analysis, and measurements of general parameters such as body weight and feed intake. Thus, the 9-N-heptyltetrahydroberberine derivative showed prominent hypoglycemic effects, which makes it promising to obtain and study other derivatives with longer substituents.


Assuntos
Hipoglicemiantes , Insulina , Camundongos , Animais , Hipoglicemiantes/farmacologia , Camundongos Endogâmicos C57BL , Teste de Tolerância a Glucose , Glucose
6.
Molecules ; 27(24)2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36557798

RESUMO

Natural and synthetic coumarins are often considered privileged scaffolds for obtaining pharmacological agents with hypoglycemic activity. Chemical modification of coumarins often leads to antidiabetic agents with greater efficacy. In the present work, twenty monoterpene-substituted 7-hydroxycoumarins were synthesized. A new approach using the Mitsunobu reaction was shown to be effective for the synthesis of target compounds. All of the synthesized compounds were evaluated in an oral glucose tolerance test, and two of them containing geranyl and (-)-myrtenyl substituents showed in vivo hypoglycemic action. A possible mechanism of action of these compounds may include inhibition of DPP IV, which was proved in an in vitro test.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores da Dipeptidil Peptidase IV , Humanos , Hipoglicemiantes/química , Inibidores da Dipeptidil Peptidase IV/química , Teste de Tolerância a Glucose , Dipeptidil Peptidase 4/química , Glicemia
7.
Chemistry ; 27(41): 10685-10692, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-33950529

RESUMO

Three new aza-BODIPY dyes incorporating fused fluorene or carbazole moieties have been prepared. The dyes show significant enhancement of photophysical properties compared to the parent 1,3,5,7-tetraphenyl aza-BODIPY (TPAB): a bathochromic shift of the absorption maximum (up to 2700 cm-1 ) and emission maximum (up to 2270 cm-1 ); an almost threefold increase in molar absorption coefficients (to ca. 230 000 M-1 cm-1 ) and a significant increase in the fluorescence quantum yield to 49-66 %. Owing to the combination of these properties, the new aza-BODIPY dyes belong to the brightest NIR dyes reported. The dyes also show excellent photostability. Due to their outstanding properties, the new dyes represent a promising platform for further exploration in biomedical research. A pH indicator containing only one fused carbazole unit was also prepared and shows absorption and emission spectra that are bathochromically shifted by about 110 and 100 nm, respectively, compared to the indicator dye based on the TPAB chromophore.


Assuntos
Compostos de Boro , Corantes Fluorescentes , Carbazóis , Fluorenos
8.
Molecules ; 27(1)2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-35011399

RESUMO

Steroid sapogenin diosgenin is of significant interest due to its biological activity and synthetic application. A consecutive one-pot reaction of diosgenin, oxalyl chloride, arylacetylenes, and phenylhydrazine give rise to steroidal 1,3,5-trisubstituted pyrazoles (isolated yield 46-60%) when the Stephens-Castro reaction and heterocyclization steps were carried out by heating in benzene. When the cyclization step of alkyndione with phenylhydrazine was performed in 2-methoxyethanol at room temperature, steroidal α,ß-alkynyl (E)- and (Z)-hydrazones were isolated along with 1,3,5-trisubstituted pyrazole and the isomeric 2,3,5-trisubstituted pyrazole. The consecutive reaction of diosgenin, oxalyl chloride, phenylacetylene and benzoic acid hydrazides efficiently forms steroidal 1-benzoyl-5-hydroxy-3-phenylpyrazolines. The structure of new compounds was unambiguously corroborated by comprehensive NMR spectroscopy, mass-spectrometry, and X-ray structure analyses. Performing the heterocyclization step of ynedione with hydrazine monohydrate in 2-methoxyethanol allowed the synthesis of 5-phenyl substituted steroidal pyrazole, which was found to exhibit high anti-inflammatory activity, comparable to that of diclofenac sodium, a commercial pain reliever. It was shown by molecular docking that the new derivatives are incorporated into the binding site of the protein Keap1 Kelch-domain by their alkynylhydrazone or pyrazole substituent with the formation of more non-covalent bonds and have higher affinity than the initial spirostene core.


Assuntos
Anti-Inflamatórios/síntese química , Cloretos/química , Diosgenina/química , Hidrazinas/química , Hidrazonas/química , Oxalatos/química , Pirazóis/síntese química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Técnicas de Química Sintética , Técnicas de Química Combinatória , Modelos Animais de Doenças , Edema/tratamento farmacológico , Edema/etiologia , Camundongos , Modelos Moleculares , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Pirazóis/química , Pirazóis/farmacologia
9.
Molecules ; 26(6)2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33802031

RESUMO

Nimesulide (NIM, N-(4-nitro-2-phenoxyphenyl)methanesulfonamide) is a relatively new nonsteroidal anti-inflammatory analgesic drug. It is practically insoluble in water (<0.02 mg/mL). This very poor aqueous solubility of the drug may lead to low bioavailability. The objective of the present study was to investigate the possibility of improving the solubility and the bioavailability of NIM via complexation with polysaccharide arabinogalactan (AG), disodium salt of glycyrrhizic acid (Na2GA), hydroxypropyl-ß-cyclodextrin (HP-ß-CD) and MgCO3. Solid dispersions (SD) have been prepared using a mechanochemical technique. The physical properties of nimesulide SD in solid state were characterized by differential scanning calorimetry and X-ray diffraction studies. The characteristics of the water solutions which form from the obtained solid dispersions were analyzed by reverse phase and gel permeation HPLC. It was shown that solubility increases for all complexes under investigation. These phenomena are obliged by complexation with auxiliary substances, which was shown by 1H-NMR relaxation methods. The parallel artificial membrane permeability assay (PAMPA) was used for predicting passive intestinal absorption. Results showed that mechanochemically obtained complexes with polysaccharide AG, Na2GA, and HP-ß-CD enhanced permeation of NIM across an artificial membrane compared to that of the pure NIM. The complexes were examined for anti-inflammatory activity on a model of histamine edema. The substances were administered per os to CD-1 mice. As a result, it was found that all investigated complexes dose-dependently reduce the degree of inflammation. The best results were obtained for the complexes of NIM with Na2GA and HP-ß-CD. In noted case the inflammation can be diminished up to 2-fold at equal doses of NIM.


Assuntos
Galactanos/farmacologia , Sulfonamidas/química , Sulfonamidas/farmacologia , 2-Hidroxipropil-beta-Ciclodextrina/química , Animais , Anti-Inflamatórios não Esteroides/química , Disponibilidade Biológica , Varredura Diferencial de Calorimetria/métodos , Química Farmacêutica/métodos , Galactanos/química , Ácido Glicirrízico/química , Magnésio/química , Masculino , Camundongos , Permeabilidade , Preparações Farmacêuticas , Solubilidade , Difração de Raios X/métodos , beta-Ciclodextrinas/química
10.
Angew Chem Int Ed Engl ; 60(24): 13401-13404, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-33773004

RESUMO

Reaction of [NiCl2 (PnH)4 ] (1) (PnH=6-tert-butyl-pyridazine-3-thione) with NiCl2 affords the binuclear paddlewheel (PW) complex [Ni2 (Pn)4 ] (2). Diamagnetic complex 2 is the first example of a PW complex capable of reversibly binding and releasing NH3 . The NH3 ligand in [Ni2 (Pn)4 (NH3 )] (2⋅NH3 ) enforces major spectroscopic and magnetic susceptibility changes, thus displaying vapochromic properties (λmax (2)=532 nm, λmax (2⋅NH3 )=518 nm) and magnetochemical switching (2: S=0; 2⋅NH3 : S=1). Upon repeated adsorption/desorption cycles of NH3 the PW core remains intact. Compound 2 can be embedded into thin polyurethane films (2P ) under retention of its sensing abilities. Therefore, 2 qualifies as reversible optical probe for ammonia. The magnetochemical switching of 2 and 2⋅NH3 was studied in detail by SQUID measurements showing that in 2⋅NH3 , solely the Ni atom coordinated the NH3 molecule is responsible for the paramagnetic behavior.

11.
Emerg Infect Dis ; 26(11): 2709-2712, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917293

RESUMO

Coronavirus disease has disrupted tuberculosis services globally. Data from 33 centers in 16 countries on 5 continents showed that attendance at tuberculosis centers was lower during the first 4 months of the pandemic in 2020 than for the same period in 2019. Resources are needed to ensure tuberculosis care continuity during the pandemic.


Assuntos
Continuidade da Assistência ao Paciente/tendências , Infecções por Coronavirus/epidemiologia , Utilização de Instalações e Serviços/tendências , Saúde Global/tendências , Pneumonia Viral/epidemiologia , Tuberculose/terapia , Betacoronavirus , COVID-19 , Humanos , Pandemias , SARS-CoV-2 , Tuberculose/epidemiologia
12.
Photochem Photobiol Sci ; 19(12): 1677-1689, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33179701

RESUMO

The authors took an independent and closer look at the family of red-emitting rhodamine dyes known for a decade due to their excellent performance in STED microscopy. After the family was further extended, the true grounds of this performance became clear. Small-molecule protective agents and/or auxiliary groups were attached at two different sites of the dye's scaffold. Thus, a rhodamine core, which is already quite photostable as it is, and an intramolecular stabilizer - a 4-nitrobenzyl or a 4-nitrobenzylthio group were combined to give potentially "everlasting dyes". The fluorescence quantum yields (Φf) and the fluorescence lifetimes (τ) of the modified dyes were thoroughly measured with comparison to those of the parent dyes. The correlation of their STED performance with photostability and fluorescence color stability under illumination in water were explored. Unexpectedly, the anaerobic GSDIM (GOC) buffer proved unhelpful with respect to STED performance. It was demonstrated that, even dyes with a Φf of only 14-17% allow STED imaging with a sufficient photon budget and good signal-to-noise ratio. For the dyes with photostabilizing groups (PSG) the Φf values are 4-5 times lower than in the reference dyes, and lifetimes τ are also strongly reduced. Noteworthy are very high fluorescence color stability and constant or even increasing fluorescence signal under photobleaching in bulk aqueous solutions, which suggests a sacrificing role of the 4-nitrobenzyl-containing moieties. Straightforward and improved recipes for "last-minute" modifications and preparations of "self-healing" red-emitting fluorescent tags are described.

13.
Inorg Chem ; 59(9): 6382-6389, 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-32275406

RESUMO

Metallocorroles involving 5d transition metals are currently of interest as near-IR phosphors and as photosensitizers for oxygen sensing and photodynamic therapy. Their syntheses, however, are often bedeviled by capricious and low-yielding protocols. Against this backdrop, we describe rhenium-imido corroles, a new class of 5d metallocorroles, synthesized simply and in respectable (∼30%) yields via the interaction of a free-base corrole, Re2(CO)10, K2CO3, and aniline in 1,2,4-trichlorobenzene at ∼190 °C in a sealed vial under strict anaerobic conditions. The generality of the method was shown by the synthesis of six derivatives, including those derived from meso-tris(pentafluorophenyl)corrole, H3[TPFPC], and five different meso-tris(p-X-phenyl)corroles, H3[TpXPC], where X = CF3, F, H, CH3, OCH3. Single-crystal X-ray structures obtained for two of the complexes, Re[TpFPC](NPh) and Re[TpCF3PC](NPh), revealed relatively unstrained equatorial Re-N distances of ∼2.00 Å, a ∼ 0.7-Å displacement of the Re from the mean plane of the corrole nitrogens, and an Re-Nimido distance of ∼1.72 Å. Details of the corrole skeletal bond distances, diamagnetic 1H NMR spectra, relatively substituent-independent Soret maxima, and electrochemical HOMO-LUMO gaps of ∼2.2 V all indicated an innocent corrole macrocycle. Surprisingly, unlike several other classes of 5d metallocorroles, the Re-imido complexes proved nonemissive in solution at room temperature and also failed to sensitize singlet oxygen formation, indicating rapid radiationless deactivation of the triplet state, presumably via the rapidly rotating axial phenyl group. By analogy with other metal-oxo and -imido corroles, we remain hopeful that the Re-imido group will prove amenable to further elaboration and thereby contribute to the development of a somewhat challenging area of coordination chemistry.

14.
Macromol Rapid Commun ; 41(5): e1900581, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32031747

RESUMO

Emulsion templated norbornadiene is cured via ring-opening metathesis polymerization yielding macroporous poly(norbornadiene) foams of 76% porosity exhibiting appealing stiffness combined with considerable ductility. The foams are readily oxidized in the presence of air at room temperature exhibiting an oxygen uptake capacity of more than 300 mg O2 g-1 foam. In closed volumes of air, a final oxygen level of a maximum of 0.0005 vol%, that is, 5 ppm(v) can be achieved after several hours at room temperature. The synergism of the porous morphology and the chemical nature of the polymer allows for the first example of an organic oxygen scavenger material with properties distinctly surpassing the state-of-the art in the field.


Assuntos
Norbornanos/química , Oxigênio/química , Polímeros/química , Estirenos/química , Emulsões , Microscopia Eletrônica de Varredura , Polimerização , Porosidade
15.
Molecules ; 25(23)2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-33261161

RESUMO

Convenient and efficient routes to construct hybrid molecules containing diterpene alkaloid lappaconitine and pyrimidine fragments are reported. One route takes place via first converting of lappaconitine to 1-ethynyl-lappaconitine, followed by the Sonogashira cross-coupling-cyclocondensation sequences. The other involves the palladium-catalyzed carbonylative Sonogashira reaction of 5'-iodolappaconitine with aryl acetylene and Mo (CO)6 as the CO source in acetonitrile and subsequent cyclocondensation reaction of the generated alkynone with amidines. The reaction proceeded cleanly in the presence of the PdCl2-(1-Ad)2PBn∙HBr catalytic system. The protocol provides mild reaction conditions, high yields, and high atom and step-economy. Pharmacological screening of lappaconitine-pyrimidine hybrids for antinociceptive activity in vivo revealed that these compounds possessed high activity in experimental pain models, which was dependent on the nature of the substituent in the 2 and 6 positions of the pyrimidine nucleus. Docking studies were undertaken to gain insight into the possible binding mode of these compounds with the voltage-gated sodium channel 1.7. The moderate toxicity of the leading compound 12 (50% lethal dose (LD50) value was more than 600 mg/kg in vivo) and cytotoxicity to cancer cell lines in vitro encouraged the further design of therapeutically relevant analogues based on this novel type of lappaconitine-pyrimidine hybrids.


Assuntos
Aconitina/análogos & derivados , Analgésicos/síntese química , Analgésicos/farmacologia , Nociceptividade/efeitos dos fármacos , Dor/tratamento farmacológico , Pirimidinas/química , ortoaminobenzoatos/química , Aconitina/química , Animais , Masculino , Camundongos , Dor/induzido quimicamente
16.
BMC Oral Health ; 20(1): 230, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32825831

RESUMO

BACKGROUND: Dental plaque biofilms are the causative agents of caries, gingivitis and periodontitis. Both mechanical and chemical strategies are used in routine oral hygiene strategies to reduce plaque build-up. If allowed to mature biofilms can create anoxic microenvironments leading to communities which harbor pathogenic Gram-negative anaerobes. When subjected to high velocity fluid jets and sprays biofilms can be fluidized which disrupts the biofilm structure and allows the more efficient delivery of antimicrobial agents. METHODS: To investigate how such jets may disrupt anoxic niches in the biofilm, we used planar optodes to measure the dissolved oxygen (DO) concentration at the base of in-vitro biofilms grown from human saliva and dental plaque. These biofilms were subject to "shooting" treatments with a commercial high velocity microspray (HVM) device. RESULTS: HVM treatment resulted in removal of much of the biofilm and a concurrent rapid shift from anoxic to oxic conditions at the base of the surrounding biofilm. We also assessed the impact of HVM treatment on the microbial community by tracking 7 target species by qPCR. There was a general reduction in copy numbers of the universal 16S RNA by approximately 95%, and changes of individual species in the target region ranged from approximately 1 to 4 log reductions. CONCLUSION: We concluded that high velocity microsprays removed a sufficient amount of biofilm to disrupt the anoxic region at the biofilm-surface interface.


Assuntos
Placa Dentária , Microbiota , Biofilmes , Humanos , Oxigênio , Saliva
18.
Anal Chem ; 91(1): 808-816, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30518209

RESUMO

Novel fluorescent diazaoxatriangulenium (DAOTA) pH indicators for lifetime-based self-referenced pH sensing are reported. The DAOTA dyes were decorated with phenolic-receptor groups inducing fluorescence quenching via a photoinduced-electron-transfer mechanism. Electron-withdrawing chlorine substituents ensure response in the most relevant pH range (apparent p Ka' values of ∼5 and 7.5 for the p, p-dichlorophenol- and p-chlorophenol-substituted dyes, respectively). The dyes feature long fluorescence lifetimes (17-20 ns), high quantum yields (∼60%), and high photostabilities. Planar optodes are prepared upon immobilization of the dyes into polyurethane hydrogel D4. Apart from the response in the fluorescence intensity, the optodes show pH-dependent lifetime behavior, which makes them suitable for studying 2D pH distributions with the help of fluorescence-lifetime-imaging techniques. The lifetime response is particularly pronounced for the sensors with high dye concentrations (0.5-1 wt % with respect to the polymer) and is attributed to the efficient homo-FRET mechanism.

19.
Anal Chem ; 91(5): 3233-3238, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30758940

RESUMO

Luminescence lifetime based imaging is still the most reliable method for generating chemical images using chemical sensor technology. However, only few commercial systems are available that enable imaging lifetimes within the relevant nanosecond to microsecond range. In this technical note we compare the performance of an older time-domain (TD) based camera system with a frequency-domain (FD) based camera system regarding their measuring characteristics and applicability for O2 and pH imaging in environmental samples and with different indicator dye systems emitting in the visible and near-infrared part of the spectrum. We conclude that the newly introduced FD imaging system delivers comparable if not better results than its predecessor, now enabling robust and simple chemical imaging based on FD luminescence lifetime measurements.

20.
Eur Respir J ; 54(6)2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31601711

RESUMO

The World Health Organization (WHO) recommends that countries implement pharmacovigilance and collect information on active drug safety monitoring (aDSM) and management of adverse events.The aim of this prospective study was to evaluate the frequency and severity of adverse events to anti-tuberculosis (TB) drugs in a cohort of consecutive TB patients treated with new (i.e. bedaquiline, delamanid) and repurposed (i.e. clofazimine, linezolid) drugs, based on the WHO aDSM project. Adverse events were collected prospectively after attribution to a specific drug together with demographic, bacteriological, radiological and clinical information at diagnosis and during therapy. This interim analysis included patients who completed or were still on treatment at time of data collection.Globally, 45 centres from 26 countries/regions reported 658 patients (68.7% male, 4.4% HIV co-infected) treated as follows: 87.7% with bedaquiline, 18.4% with delamanid (6.1% with both), 81.5% with linezolid and 32.4% with clofazimine. Overall, 504 adverse event episodes were reported: 447 (88.7%) were classified as minor (grade 1-2) and 57 (11.3%) as serious (grade 3-5). The majority of the 57 serious adverse events reported by 55 patients (51 out of 57, 89.5%) ultimately resolved. Among patients reporting serious adverse events, some drugs held responsible were discontinued: bedaquiline in 0.35% (two out of 577), delamanid in 0.8% (one out of 121), linezolid in 1.9% (10 out of 536) and clofazimine in 1.4% (three out of 213) of patients. Serious adverse events were reported in 6.9% (nine out of 131) of patients treated with amikacin, 0.4% (one out of 221) with ethionamide/prothionamide, 2.8% (15 out of 536) with linezolid and 1.8% (eight out of 498) with cycloserine/terizidone.The aDSM study provided valuable information, but implementation needs scaling-up to support patient-centred care.


Assuntos
Antituberculosos/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/diagnóstico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Farmacovigilância , Estudos Prospectivos
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