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1.
Eur J Neurol ; 31(5): e16228, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38375947

RESUMO

BACKGROUND AND PURPOSE: Rituximab (RTX) is frequently used off-label in multiple sclerosis. However, studies on the risk-benefit profile of RTX in pediatric-onset multiple sclerosis are scarce. METHODS: In this multicenter retrospective cohort study, patients with pediatric-onset multiple sclerosis from Sweden, Austria and Germany, who received RTX treatment were identified by chart review. Annualized relapse rates, Expanded Disability Status Scale scores and magnetic resonance imaging parameters (new T2 lesions and contrast-enhancing lesions) were assessed before and during RTX treatment. The proportion of patients who remained free from clinical and disease activity (NEDA-3) during RTX treatment was calculated. Side effects such as infusion-related reactions, infections and laboratory abnormalities were assessed. RESULTS: Sixty-one patients received RTX during a median (interquartile range) follow-up period of 20.9 (35.6) months. The annualized relapse rate decreased from 0.6 (95% confidence interval [CI] 0.38-0.92) to 0.03 (95% CI 0.02-0.14). The annual rate of new T2 lesions decreased from 1.25 (95% CI 0.70-2.48) to 0.08 (95% CI 0.03-0.25) and annual rates of new contrast-enhancing lesions decreased from 0.86 (95% CI 0.30-3.96) to 0. Overall, 70% of patients displayed no evidence of disease activity (NEDA-3). Adverse events were observed in 67% of patients. Six patients discontinued treatment due to ongoing disease activity or adverse events. CONCLUSION: Our study provides class IV evidence that RTX reduces clinical and radiological activity in pediatric-onset multiple sclerosis.


Assuntos
Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Criança , Humanos , Rituximab/efeitos adversos , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/tratamento farmacológico , Fatores Imunológicos/efeitos adversos , Estudos Retrospectivos , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Recidiva
2.
J Org Chem ; 88(21): 15189-15197, 2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37823216

RESUMO

This study presents an improved synthetic route to ligand (S)-4-(tert-butyl)-2-(5-(trifluoromethyl)pyridin-2-yl)-4,5-dihydrooxazole and its application as a highly active and enantioselective catalyst in the addition of arylboronic acids to cyclic N-sulfonylketimines. Immobilization of such a ligand was achieved using a commercially available starting material and a PS-PEG TentaGel S NH2 support, resulting in a stable heterogeneous catalyst. Although the anchored catalyst exhibited a slight reduction in enantioselectivity and a 4-fold decrease in reaction rate, it displayed remarkable stability, enabling 10 consecutive reaction cycles. Furthermore, the successful transition to a continuous flow system demonstrated even higher turnover numbers compared to batch arrangements. These findings provide valuable insights into the development of efficient flow reactors for continuous synthesis of benzosultams, further advancing the field of asymmetric catalysis.

3.
Macromol Rapid Commun ; 44(17): e2300168, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37220400

RESUMO

This study presents a systematic comparison of the antifouling properties of water-soluble poly(2-oxazoline) (PAOx) and poly(2-oxazine) (PAOzi) brushes grafted to gold surfaces. PAOx and PAOzi are emerging polymer classes in biomedical sciences and are being considered superior alternatives to widely used polyethylene glycol (PEG). Four different polymers, poly(2-methyl-2-oxazoline) (PMeOx), poly(2-ethyl-2-oxazoline) (PEtOx), poly(2-methyl-2-oxazine) (PMeOzi), and poly(2-ethyl-2-oxazine) (PEtOzi), each of them in three different chain lengths, are synthesized and characterized for their antifouling properties. Results show that all polymer-modified surfaces display better antifouling properties than bare gold surfaces as well as analogous PEG coatings. The antifouling properties increase in the following order: PEtOx < PMeOx ≈ PMeOzi < PEtOzi. The study suggests that the resistance to protein fouling derives from both surface hydrophilicity and the molecular structural flexibility of the polymer brushes. PEtOzi brushes with moderate hydrophilicity show the best antifouling performance, possibly due to their highest chain flexibility. Overall, the research contributes to the understanding of antifouling properties in PAOx and PAOzi polymers, with potential applications in various biomaterials.


Assuntos
Incrustação Biológica , Polímeros , Polímeros/química , Incrustação Biológica/prevenção & controle , Polietilenoglicóis/química , Oxazinas/química
4.
Molecules ; 28(17)2023 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-37687092

RESUMO

In this study, we propose a promising photoprotective additive that combines the advantages of both organic UV absorbers and inorganic particles without compromising the properties of the paint material. This additive involves the intercalation of a well-known organic UV absorber, 2-phenylbenzimidazole-5-sulfonic acid (PBISA), into zinc-aluminum layered double hydroxide (ZnAl-LDH). Three ZnAl-LDH intercalates with PBISA were prepared using various methods based on either anion exchange or direct synthesis. The intercalates were characterized using powder X-ray diffraction, thermogravimetry, elemental analysis, and IR and UV-Vis spectroscopies. The composition and basal spacings of all three intercalates are very similar. An effective UV protection film was prepared when the ZnAl-PBISA-1 intercalate was incorporated into polyurethane-acrylate lacquer. The resultant UV protective film exhibited stability and uniform distribution of the intercalated fillers. Some minimal particle sedimentation and aggregation were observed on the cured film's underside, but did not compromise the films' UV protective properties. The prepared lacquers with intercalated fillers offer a viable solution for the surface modification of plastic products.

5.
Beilstein J Org Chem ; 19: 808-819, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37346496

RESUMO

Reactions of thiobenzamide or thioacetamide with 4-bromo-1,1-dimethyl-1,4-dihydroisoquinoline-3(2H)-one, 4-bromoisoquinoline-1,3(2H,4H)-dione and two α-bromo(phenyl)acetamides were examined under various conditions (base, solvent, thiophile, temperature) and structure/medium features that influence product distribution (Eschenmoser coupling reaction, Hantzsch thiazole synthesis and elimination to nitriles) were identified. The key factor that enables the successful Eschenmoser coupling reaction involves the optimum balance in acidity of nitrogen and carbon atoms of the intermediary α-thioiminium salts.

6.
Acta Paediatr ; 111(3): 566-575, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34665877

RESUMO

AIM: Little is known about the prevalence of discrete white matter abnormalities (WMA) beyond the first years in children born extremely preterm (EPT) and the relation to neurodevelopmental outcomes. Our aim was to investigate the prevalence of discrete WMA in children born EPT and the relationship to neonatal white matter injuries (WMI), white matter (WM) volume, WM diffusivity and neurodevelopment. METHODS: The study was a part of a longitudinal follow-up study of EPT neonates. All children were scanned at Karolinska University hospital 2004-2007 (neonates) and 2014-2015 (children at 8-11 years). WMA was qualitatively assessed by visual inspection. Developmental assessment was conducted at 12 years. RESULTS: In total, 112 children (median age 10.3 years, 56 girls) underwent MRI of the brain (68 EPT, 45 controls). In the EPT group, a subset had MRI around term equivalent age (n = 61). In the EPT group, the prevalence of discrete WMA at 8-11 years was 52%. There was a positive association between WMI at TEA and 8-11 years. There was no association between WMI and WM volumes or diffusivity at 8-11 years. Discrete WMA was not related to neurodevelopmental outcomes. CONCLUSION: Discrete WMA was prevalent in children born EPT at 8-11 years but were not related to neurodevelopmental outcomes.


Assuntos
Substância Branca , Encéfalo/diagnóstico por imagem , Criança , Cognição , Feminino , Seguimentos , Humanos , Lactente Extremamente Prematuro , Recém-Nascido , Imageamento por Ressonância Magnética , Substância Branca/diagnóstico por imagem
7.
Sensors (Basel) ; 22(7)2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35408397

RESUMO

The main task of the research is to acquire fundamental knowledge about the effect of polymer structure on the physicochemical properties of films. A novel meta-material that can be used in manufacturing sensor layers was developed as a model. At the first stage, poly(sodium 4-styrenesulfonate) (PNaSS) cross-linked microspheres are synthesized (which are based on strong polyelectrolytes containing sulfo groups in each monomer unit), and at the second stage, PNaSS@PEDOT microspheres are formed. The poly(3,4-ethylenedioxythiophene) (PEDOT) shell was obtained by the acid-assisted self-polymerization of the monomer; this process is biologically safe and thus suitable for biomedical applications. The suitability of electrochemical impedance spectroscopy for E. coli detection was tested; it was revealed that the attached bacterial wall was destroyed upon application of constant oxidation potential (higher than 0.5 V), which makes the PNaSS@PEDOT microsphere particles promising materials for the development of antifouling coatings. Furthermore, under open-circuit conditions, the walls of E. coli bacteria were not destroyed, which opens up the possibility of employing such meta-materials as sensor films. Scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle, and wide-angle X-ray diffraction methods were applied in order to characterize the PNaSS@PEDOT films.


Assuntos
Escherichia coli , Polímeros , Compostos Bicíclicos Heterocíclicos com Pontes/química , Microesferas , Polímeros/química
8.
Molecules ; 27(2)2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35056681

RESUMO

A family of oxazaborines, diazaborinones, triazaborines, and triazaborinones was prepared by reaction of polarized ethylenes, such as ß-enaminoamides, with 4-methylbenzenediazonium tetraphenylborates. The reaction conditions (stirring in CH2Cl2 at room temperature (Method A) or stirring with CH3COONa in CH2Cl2 at room temperature (Method B) or refluxing in the CH2Cl2/toluene mixture (Method C)) controlled the formation and relative content of these compounds in the reaction mixtures from one to three products. Substituted oxazaborines gradually rearranged into diazaborinones at 250 °C. The prepared compounds were characterized by 1H NMR, 13C NMR, IR, and UV-Vis spectroscopy, HRMS, or microanalysis. The structure of individual compounds was confirmed by 11B NMR, 15N NMR, 1D NOESY, and X-ray analysis. The mechanism of reaction of enaminoamides with 4-methylbenzenediazonium tetraphenylborate was proposed.

9.
Beilstein J Org Chem ; 18: 438-445, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35529894

RESUMO

The human drugs - the antibiotic linezolid (1) and the anticoagulant rivaroxaban (2) - belong among modern pharmaceutics, which contain an oxazolidine-2-one moiety bearing a stereogenic center. The chirality of these drugs is a fundamental attribute for their biological activity. Herein, one of the efficient asymmetric syntheses of these drugs was studied in detail. Highly enantioselective catalysts were tested in the key step of the synthetic procedure, i.e., the asymmetric Henry reaction, under different reaction conditions, using several starting aldehydes. The corresponding nitroaldols as chiral intermediates in the syntheses of these drugs were obtained in high yields and enantiomeric excesses of up to 91% ee.

10.
Neurobiol Learn Mem ; 183: 107477, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34116140

RESUMO

Neural components enabling flexible cognition and behavior are well-established, and depend mostly on proper intercommunication within the prefrontal cortex (PFC) and striatum. However, dense projections from the ventral hippocampus (vHPC) alter the functioning of the medial PFC (mPFC). Dysfunctional hippocampo-prefrontal connectivity negatively affects the integrity of flexible cognition, especially in patients with schizophrenia. In this study, we aimed to test the role of the vHPC and mPFC in a place avoidance task on a rotating arena using two spatial flexibility task variants - reversal learning and set-shifting. To achieve this, we inactivated each of these structures in adult male Long-Evans rats by performing bilateral local muscimol (a GABAA receptor agonist) injections. A significantly disrupted performance was observed in reversal learning in the vHPC-inactivated, but not in the mPFC-inactivated rats. These results confirm the notion that the vHPC participates in some forms of behavioral flexibility, especially when spatial cues are needed. It seems, rather unexpectedly, that the mPFC is not taxed in these flexibility tasks on a rotating arena.


Assuntos
Atenção/fisiologia , Hipocampo/fisiologia , Córtex Pré-Frontal/fisiologia , Reversão de Aprendizagem/fisiologia , Processamento Espacial/fisiologia , Animais , Atenção/efeitos dos fármacos , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Agonistas de Receptores de GABA-A/farmacologia , Hipocampo/efeitos dos fármacos , Masculino , Muscimol/farmacologia , Córtex Pré-Frontal/efeitos dos fármacos , Ratos , Reversão de Aprendizagem/efeitos dos fármacos , Processamento Espacial/efeitos dos fármacos
11.
Behav Brain Funct ; 17(1): 7, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34158061

RESUMO

Schizophrenia research arose in the twentieth century and is currently rapidly developing, focusing on many parallel research pathways and evaluating various concepts of disease etiology. Today, we have relatively good knowledge about the generation of positive and negative symptoms in patients with schizophrenia. However, the neural basis and pathophysiology of schizophrenia, especially cognitive symptoms, are still poorly understood. Finding new methods to uncover the physiological basis of the mental inabilities related to schizophrenia is an urgent task for modern neuroscience because of the lack of specific therapies for cognitive deficits in the disease. Researchers have begun investigating functional crosstalk between NMDARs and GABAergic neurons associated with schizophrenia at different resolutions. In another direction, the gut microbiota is getting increasing interest from neuroscientists. Recent findings have highlighted the role of a gut-brain axis, with the gut microbiota playing a crucial role in several psychopathologies, including schizophrenia and autism.There have also been investigations into potential therapies aimed at normalizing altered microbiota signaling to the enteric nervous system (ENS) and the central nervous system (CNS). Probiotics diets and fecal microbiota transplantation (FMT) are currently the most common therapies. Interestingly, in rodent models of binge feeding, optogenetic applications have been shown to affect gut colony sensitivity, thus increasing colonic transit. Here, we review recent findings on the gut microbiota-schizophrenia relationship using in vivo optogenetics. Moreover, we evaluate if manipulating actors in either the brain or the gut might improve potential treatment research. Such research and techniques will increase our knowledge of how the gut microbiota can manipulate GABA production, and therefore accompany changes in CNS GABAergic activity.


Assuntos
Microbioma Gastrointestinal , Probióticos , Esquizofrenia , Encéfalo , Eixo Encéfalo-Intestino , Humanos , Optogenética , Esquizofrenia/terapia
12.
J Org Chem ; 86(15): 10621-10629, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34269051

RESUMO

A novel synthetic approach involving an Eschenmoser coupling reaction of substituted 3-bromooxindoles (H, 6-Cl, 6-COOMe, 5-NO2) with two substituted thiobenzanilides in dimethylformamide or acetonitrile was used for the synthesis of eight kinase inhibitors including Nintedanib and Hesperadin in yields exceeding 76%. Starting compounds for the synthesis are also easily available in good yields. 3-Bromooxindoles were prepared either from corresponding isatins using a three-step synthesis in an average overall yield of 65% or by direct bromination of oxindoles (yield of 65-86%). Starting N-(4-piperidin-1-ylmethyl-phenyl)-thiobenzamide was prepared by thionation of the corresponding benzanilide in an 86% yield and N-methyl-N-(4-thiobenzoylaminophenyl)-2-(4-methylpiperazin-1-yl)acetamide was prepared by thioacylation of the corresponding aniline with methyl dithiobenzoate in an 86% yield.


Assuntos
Indóis , Sulfonamidas , Oxindóis
13.
Beilstein J Org Chem ; 17: 527-539, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33727976

RESUMO

A highly modular method for the synthesis of (Z)-3-[amino(phenyl/methyl)methylidene]-1,3-dihydro-2H-indol-2-ones starting from easily available 3-bromooxindoles or (2-oxoindolin-3-yl)triflate and thioacetamides or thiobenzamides is described. A series of 49 compounds, several of which have previously been shown to possess significant tyrosin kinase inhibiting activity, was prepared in yields varying mostly from 70 to 97% and always surpassing those obtained by other published methods. The method includes an Eschenmoser coupling reaction, which is very feasible (even without using a thiophile except tertiary amides) and scalable. The (Z)-configuration of all products was confirmed by NMR techniques.

14.
Beilstein J Org Chem ; 17: 1048-1085, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34093877

RESUMO

The transition metal (palladium)-catalysed asymmetric 1,4-addition of arylboronic acids to conjugated enones belong to the most important and emerging strategies for the construction of C-C bonds in an asymmetric fashion. This review covers known catalytic systems used for this transformation. For clarity, we are using the type of ligand as a sorting criterion. Finally, we attempted to create a flowchart facilitating the selection of a suitable ligand for a given combination of enone and arylboronic acid.

15.
Anal Chem ; 92(7): 4716-4720, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32129604

RESUMO

Polymer brush coatings are effective in preventing blood coagulation or bacterial attachment, but their chain conformation, while vital for this effect, was never characterized in high spatial resolution. Here, we report mid-infrared spectroscopic nanoscopy studies of few-nanometer-thin poly(ethylene oxide) (PEO) films which reveal marked spectral variations along the surface at a length scale smaller than 100 nm and originating only from the physical conformation of the chains. The conformation and average orientation of the polymer chains in the layer is extracted from the spectra with the aid of theoretic modeling, confirming the spontaneous formation of a crystalline phase. This result suggests spectroscopic nanoscopy as a powerful new tool to characterize polymer brush coatings.


Assuntos
Nanotecnologia , Polietilenoglicóis/química , Raios Infravermelhos , Conformação Molecular , Tamanho da Partícula , Propriedades de Superfície
16.
J Comput Aided Mol Des ; 34(6): 683-695, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32052351

RESUMO

Classical molecular simulation methods were used for a description of an arrangement of intercalated molecules N-(pyridin-4-yl)pyridin-4-amine (AH) and its derivatives, 3-methyl-N-(pyridin-4-yl)pyridin-4-amine (AMe), and 3-nitro-N-(pyridin-4-yl)pyridin-4-amine (ANO2) within a layered structure of zirconium 4-sulfophenylphosphonate. The intercalated molecules were placed between SO3H groups of the host layers. Their mutual positions and orientations were solved by molecular simulation methods and compared with the presented experimental results. Final calculated data showed differences of partially disordered arrangement of the intercalated molecules between zirconium 4-sulfophenylphosphonate layers. The calculation results revealed a dense net of hydrogen bonds connecting water molecules and the guests in the interlayer space and the sulfo groups of the host layers. We calculated the dipole moments of the AH, AMe and ANO2 guests in the final models in order to illustrate potential use of these materials in non-linear optics.


Assuntos
Aminas/química , Modelos Moleculares , Piridinas/química , Simulação por Computador , Ligação de Hidrogênio , Estrutura Molecular , Zircônio/química
17.
Proc Natl Acad Sci U S A ; 114(26): E5148-E5157, 2017 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-28607078

RESUMO

The extent of virus transmission among individuals and species is generally determined by the presence of specific membrane-embedded virus receptors required for virus entry. Interaction of the viral envelope glycoprotein (Env) with a specific cellular receptor is the first and crucial step in determining host specificity. Using a well-established retroviral model-avian Rous sarcoma virus (RSV)-we analyzed changes in an RSV variant that had repeatedly been able to infect rodents. By envelope gene (env) sequencing, we identified eight mutations that do not match the already described mutations influencing the host range. Two of these mutations-one at the beginning (D32G) of the surface Env subunit (SU) and the other at the end of the fusion peptide region (L378S)-were found to be of critical importance, ensuring transmission to rodent, human, and chicken cells lacking the appropriate receptor. Furthermore, we carried out assays to examine the virus entry mechanism and concluded that these two mutations cause conformational changes in the Env variant and that these changes lead to an activated, or primed, state of Env (normally induced after Env interaction with the receptor). In summary, our results indicate that retroviral host range extension is caused by spontaneous Env activation, which circumvents the need for original cell receptor. This activation is, in turn, caused by mutations in various env regions.


Assuntos
Produtos do Gene env , Vetores Genéticos , Mutação de Sentido Incorreto , Vírus do Sarcoma de Rous , Transdução Genética , Substituição de Aminoácidos , Animais , Linhagem Celular Tumoral , Galinhas , Produtos do Gene env/genética , Produtos do Gene env/metabolismo , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Humanos , Ratos , Vírus do Sarcoma de Rous/genética , Vírus do Sarcoma de Rous/metabolismo
18.
Int J Mol Sci ; 21(18)2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32947982

RESUMO

Antifouling polymer layers containing extracellular matrix-derived peptide motifs offer promising new options for biomimetic surface engineering. In this contribution, we report the design of antifouling vascular grafts bearing biofunctional peptide motifs for tissue regeneration applications based on hierarchical polymer brushes. Hierarchical diblock poly(methyl ether oligo(ethylene glycol) methacrylate-block-glycidyl methacrylate) brushes bearing azide groups (poly(MeOEGMA-block-GMA-N3)) were grown by surface-initiated atom transfer radical polymerization (SI-ATRP) and functionalized with biomimetic RGD peptide sequences. Varying the conditions of copper-catalyzed alkyne-azide "click" reaction allowed for the immobilization of RGD peptides in a wide surface concentration range. The synthesized hierarchical polymer brushes bearing peptide motifs were characterized in detail using various surface sensitive physicochemical methods. The hierarchical brushes presenting the RGD sequences provided excellent cell adhesion properties and at the same time remained resistant to fouling from blood plasma. The synthesis of anti-fouling hierarchical brushes bearing 1.2 × 103 nmol/cm2 RGD biomimetic sequences has been adapted for the surface modification of commercially available grafts of woven polyethylene terephthalate (PET) fibers. The fiber mesh was endowed with polymerization initiator groups via aminolysis and acylation reactions optimized for the material. The obtained bioactive antifouling vascular grafts promoted the specific adhesion and growth of endothelial cells, thus providing a potential avenue for endothelialization of artificial conduits.


Assuntos
Materiais Biomiméticos , Prótese Vascular , Materiais Revestidos Biocompatíveis , Regeneração Tecidual Guiada/instrumentação , Oligopeptídeos/química , Polietilenotereftalatos/química , Polimerização , Adsorção , Motivos de Aminoácidos , Azidas/química , Proteínas Sanguíneas , Adesão Celular , Divisão Celular , Química Click , Endotélio Vascular/fisiologia , Vidro , Ouro , Células Endoteliais da Veia Umbilical Humana , Humanos , Proteínas Imobilizadas , Teste de Materiais , Plasma , Silício , Propriedades de Superfície , Trombose/prevenção & controle
19.
Neurobiol Learn Mem ; 162: 59-66, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31085330

RESUMO

Memory is related to the function of N-methyl-D-aspartate (NMDA) receptors. Depending on the dose, NMDA receptor antagonists (such as memantine or MK-801) can impair memory and/or cognitive as well as procedural functions, while they also can prevent the long-term toxic effects of over-excitation of these receptors in pathophysiological processes. There is an unresolved question of whether memantine at low doses could exert an acute pro-cognitive activity. A therapeutic dose of memantine was found to improve short-term spatial memory tested in the alternation version of active place avoidance in a Carousel Maze, whereas no data are available on long-term memory in various versions of place avoidance. In an effort to reconcile this issue, rats were administered memantine (5 mg/kg) 30 min before a training session and trained in two different versions of place avoidance. A control group received saline injections. In an active place avoidance task (hereby referred to as Room+Arena-), this place was fixed to distal room cues, whereas cues from the arena were misleading. Performance thus demanded the on-going segregation of information that engages cognitive coordination. Following the Room+Arena- training, rats were trained in another place avoidance task (hereby referred to as Arena+), which requires focusing on substratal and idiothetic cues from the arena. In this version, a to-be-avoided sector rotated along with the arena in darkness that hid the extramaze cues. The rats given memantine avoided better than the control rats in the Room+Arena- task. In the Arena+ task, both groups had problems with acquiring the task. Subsequently, memantine was withdrawn and both groups relearned Room+Arena- avoidance with a new sector position. In this task, no effect of groups was seen. In conclusion, memantine at a therapeutic dose improved performance in a task that required the segregation of spatial stimuli into coherent subsets.


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Memantina/farmacologia , Memória Espacial/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Sinais (Psicologia) , Masculino , Ratos , Ratos Wistar , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores
20.
Biomacromolecules ; 20(9): 3453-3463, 2019 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-31329428

RESUMO

Poly(2-alkyl-2-oxazoline)s (PAOx) represent a class of emerging polymers that can substitute or even outperform poly(ethylene oxide) (PEO) standard in various applications. Despite the great advances in PAOx research, there is still a gap in the direct experimental comparison of antifouling properties between PAOx and the golden standard PEO when exposed to blood. Motivated by this, we developed a straightforward protocol for the one-pot PAOx polymerization and surface coating by a "grafting to-" approach. First, we synthesized a library of hydrophilic poly(2-methyl-2-oxazoline)s (PMeOx) and poly(2-ethyl-2-oxazoline)s (PEtOx) with molar mass ranging from 1.5 to 10 kg/mol (DP = 16-115). The PAOx living chains were directly terminated by amine and hydroxyl groups of polydopamine (PDA) anchor layer providing the highest so far reported grafting densities ranging from 0.2 to 2.1 chains/nm2. In parallel, PEO chains providing the same degree of polymerization (molar mass from 1.2 to 5 kg/mol, DP = 28-116) bearing thiol groups were grafted to PDA. The thickness, surface-related parameters, covalent structure, and antifouling properties of the resulting polymer brushes were determined via various surface sensitive techniques. The comparison of the synthesized PAOx and PEO brushes led us to the conclusion that at the same surface-related parameters, PMeOx brushes show significantly better antifouling character when challenged against human blood plasma.


Assuntos
Oxazóis/química , Poliaminas/química , Polímeros/química , Humanos , Interações Hidrofóbicas e Hidrofílicas/efeitos dos fármacos , Peso Molecular , Oxazóis/síntese química , Oxazóis/farmacologia , Plasma/efeitos dos fármacos , Poliaminas/síntese química , Poliaminas/farmacologia , Polietilenoglicóis/síntese química , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Polimerização , Polímeros/síntese química , Polímeros/farmacologia , Propriedades de Superfície/efeitos dos fármacos
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