RESUMO
A literature survey showed that different derivatives with the 9-phenyl-9H-carbazole or the dihydroindoline scaffold may be of biological activity including cytotoxic effect. Driven by this experience, P-functionalized derivatives of these N-heterocycles were synthesized. Three N-heterocycles, 9-(4-bromophenyl)-9H-carbazole, 3-bromo-9-phenyl-9H-carbazole and 1-(5-bromoindolin-1-yl)ethan-1-one, were coupled with dialkyl phosphites and diarylphosphine oxides using Pd(OAc)2 (10 %) as the catalyst precursor and triethylamine as the base in ethanol under microwave irradiation. The excess of the Y2 P(O)H reagent (Y=alkoxy, aryl) (30 %) served as the P-ligand in its trivalent tautomeric form (Y2 POH), hence there was no need for the usual P-ligands meaning cost and environmental burden. Hence, the presented method is a "green" approach that proved to be more efficient than the preparation by the traditional method. The products, dialkyl phosphonates and tertiary phosphine oxides obtained in 58-84 % yields were characterized, one of them also by single crystal X-ray analysis, and were subjected to inâ vitro biological activity evaluation. A (carbazol)yl-phenylphosphonate, an N-phenyl-(carbazol)yl-phosphonate, a (carbazol)yl-phenylphosphine oxide and an N-phenyl-(carbazol)ylphosphine oxide revealed a significant cytotoxic activity on A549 human non-small-cell lung carcinoma and MonoMac-6 acute monocytic leukemia cancer cells. The cytotoxic effect was significant as compared to that of the reference compounds.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Paládio/química , Micro-Ondas , Catálise , ÓxidosRESUMO
Diethyl α-benzylamino- and α-amino-benzylphosphonates obtained by the Kabachnik-Fields reaction were useful intermediates in the synthesis of other derivatives. Acylation of α-aminophosphonates with acyl chlorides led to the corresponding N-acyl species existing under a dynamic equilibrium of two conformers. Judging from the broad NMR signals, the sterically most crowded N-benzoyl-N-benzyl derivative suffered a hindered rotation around the N-C axis to the acyl carbon atom at 26 °C. Low temperature NMR measurements at -10 °C showed the presence of two distinct rotamers that were characterized. The other acylated α-amino-benzylphosphonates prepared revealed a less hindered rotation. Single crystal X-ray diffraction of the NH-propionyl species showed a dimer, in which the two molecules were held together by rare intermolecular PîOâ¯HN bonds. On the other hand, substituted α-benzylamino-benzylphosphonates prepared by phospha-Mannich reactions were employed, as a new approach, in a second Kabachnik-Fields condensation by reaction with formaldehyde and dialkyl phosphites or secondary phosphine oxides to afford novel N-phosphonoylmethyl- and N-phosphinoylmethyl-α-amino-benzylphosphonates. The structure of the new products was confirmed by two-dimensional NMR spectroscopy. A symmetrical bis derivative was prepared in a diastereoselective manner. A related tris(phosphonoylmethyl)amine species was also synthesized.
RESUMO
In the context of reporting a case of a patient with Aslanger pattern, the application of additional leads in the frontal plane is proposed to facilitate the recognition of this condition - indicating occlusive myocardial infarction - as eligible for the current ST-segment elevation myocardial infarction (STEMI) criteria and consequently for immediate reperfusion strategy recommendation.
Assuntos
Infarto do Miocárdio , Infarto do Miocárdio com Supradesnível do Segmento ST , Humanos , Eletrocardiografia , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnósticoRESUMO
BACKGROUND: The three-step Brugada group algorithm is the only published electrocardiographical (ECG) algorithm for differentiating ventricular tachycardia (VT) from pre-excited tachycardia (PXT) as a cause of regular wide QRS complex tachycardia (WCT). This study aimed to improve the diagnostic accuracy of the Brugada group algorithm. METHODS: This study modified the Brugada group algorithm by adding a new aVR lead criterion (initial positive deflection in lead aVR and the QRS complex area above the baseline is greater than the area below the baseline). The Brugada group algorithm and the new, modified four-step algorithm in 300 WCT ECGs (241 VTs, 59 PXTs) was applied. If any of the criteria were fulfilled, VT was diagnosed; if none were fulfilled, a diagnosis of PXT was established. RESULTS: The test accuracy, VT diagnosis sensitivity, and negative predictive value (NPV) of the new, modified algorithm were significantly greater than that of the Brugada group algorithm: test accuracy 220 of 300 (73%) vs 182 of 300 (61%); sensitivity 73% vs 55% (p<0.001 for both); NPV 40% vs 31% (p=0.0205). The VT diagnosis specificity of the Brugada group algorithm was greater than that of the new, modified algorithm (83% vs 75%; p=0.019). There was no significant difference between the new, modified and Brugada group algorithms in the positive predictive values (92% vs 93%, respectively) for a VT diagnosis, and positive and negative likelihood ratio values (2.87 vs 3.26; 0.36 vs 0.54, respectively). CONCLUSIONS: The new, modified algorithm proved to be more sensitive for the differentiation of VT from PXT than the Brugada group algorithm.
Assuntos
Taquicardia Supraventricular , Taquicardia Ventricular , Humanos , Taquicardia Supraventricular/diagnóstico , Diagnóstico Diferencial , Taquicardia Ventricular/diagnóstico , Ventrículos do Coração , Eletrocardiografia , AlgoritmosRESUMO
Salamanders have been hailed as champions of regeneration, exhibiting a remarkable ability to regrow tissues, organs and even whole body parts, e.g. their limbs. As such, salamanders have provided key insights into the mechanisms by which cells, tissues and organs sense and regenerate missing or damaged parts. In this Primer, we cover the evolutionary context in which salamanders emerged. We outline the varieties of mechanisms deployed during salamander regeneration, and discuss how these mechanisms are currently being explored and how they have advanced our understanding of animal regeneration. We also present arguments about why it is important to study closely related species in regeneration research.
Assuntos
Modelos Animais , Modelos Biológicos , Regeneração/fisiologia , Urodelos/fisiologia , Animais , Evolução Biológica , Pesquisa Biomédica/métodos , Pesquisa Biomédica/tendências , Humanos , Medicina Regenerativa/métodos , Medicina Regenerativa/tendênciasRESUMO
Identifying key molecules that launch regeneration has been a long-sought goal. Multiple regenerative animals show an initial wound-associated proliferative response that transits into sustained proliferation if a considerable portion of the body part has been removed. In the axolotl, appendage amputation initiates a round of wound-associated cell cycle induction followed by continued proliferation that is dependent on nerve-derived signals. A wound-associated molecule that triggers the initial proliferative response to launch regeneration has remained obscure. Here, using an expression cloning strategy followed by in vivo gain- and loss-of-function assays, we identified axolotl MARCKS-like protein (MLP) as an extracellularly released factor that induces the initial cell cycle response during axolotl appendage regeneration. The identification of a regeneration-initiating molecule opens the possibility of understanding how to elicit regeneration in other animals.
Assuntos
Ambystoma mexicanum/fisiologia , Extremidades/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Regeneração/fisiologia , Ambystoma mexicanum/lesões , Amputação Traumática/metabolismo , Animais , Ciclo Celular/genética , Proliferação de Células/genética , Clonagem Molecular , Extremidades/lesões , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , Camundongos , Dados de Sequência Molecular , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/fisiologia , Substrato Quinase C Rico em Alanina Miristoilada , Notophthalmus viridescens/genética , Notophthalmus viridescens/lesões , Notophthalmus viridescens/fisiologia , Cauda/citologia , Cauda/lesões , Cauda/fisiologia , Cicatrização/fisiologia , Xenopus , Peixe-ZebraRESUMO
Melanocytes are pigmented cells residing mostly in the skin and hair follicles of vertebrates, where they contribute to colouration and protection against UV-B radiation. However, the spectrum of their functions reaches far beyond that. For instance, these pigment-producing cells are found inside the inner ear, where they contribute to the hearing function, and in the heart, where they are involved in the electrical conductivity and support the stiffness of cardiac valves. The embryonic origin of such extracutaneous melanocytes is not clear. We took advantage of lineage-tracing experiments combined with 3D visualizations and gene knockout strategies to address this long-standing question. We revealed that Schwann cell precursors are recruited from the local innervation during embryonic development and give rise to extracutaneous melanocytes in the heart, brain meninges, inner ear, and other locations. In embryos with a knockout of the EdnrB receptor, a condition imitating Waardenburg syndrome, we observed only nerve-associated melanoblasts, which failed to detach from the nerves and to enter the inner ear. Finally, we looked into the evolutionary aspects of extracutaneous melanocytes and found that pigment cells are associated mainly with nerves and blood vessels in amphibians and fish. This new knowledge of the nerve-dependent origin of extracutaneous pigment cells might be directly relevant to the formation of extracutaneous melanoma in humans.
Assuntos
Encéfalo/fisiologia , Orelha Interna/fisiologia , Coração/fisiologia , Meninges/fisiologia , Sistema Nervoso/fisiopatologia , Células de Schwann/fisiologia , Anfíbios/metabolismo , Anfíbios/fisiologia , Animais , Encéfalo/metabolismo , Linhagem da Célula/fisiologia , Orelha Interna/metabolismo , Desenvolvimento Embrionário/fisiologia , Feminino , Peixes/metabolismo , Peixes/fisiologia , Melanócitos/metabolismo , Melanócitos/fisiologia , Meninges/metabolismo , Camundongos , Sistema Nervoso/metabolismo , Gravidez , Receptor de Endotelina B/metabolismo , Células de Schwann/metabolismoRESUMO
The overall bauplan of the tetrapod brain is highly conserved, yet significant variations exist among species in terms of brain size, structural composition and cellular diversity. Understanding processes underlying neural and behavioral development in a wide range of species is important both from an evolutionary developmental perspective as well as for the identification of cell sources with post-developmental neurogenic potential. Here, we characterize germinal processes in the brain of Notophthalmus viridescens and Pleurodeles waltl during both development and adulthood. Using a combination of cell tracking tools, including clonal analyses in new transgenic salamander lines, we examine the origin of neural stem and progenitor cells found in the adult brain, determine regional variability in cell cycle length of progenitor cells, and show spatiotemporally orchestrated neurogenesis. We analyze how maturation of different brain regions and neuronal subpopulations are linked to the acquisition of complex behaviors, and how these behaviors are altered upon chemical ablation of dopamine neurons. Our data analyzed from an evolutionary perspective reveal both common and species-specific processes in tetrapod brain formation and function.
Assuntos
Comportamento Animal/fisiologia , Encéfalo/embriologia , Neurogênese/fisiologia , Notophthalmus/embriologia , Células-Tronco/metabolismo , Animais , Encéfalo/citologia , Pleurodeles , Células-Tronco/citologiaRESUMO
This work presents the synthesis of six new phase-transfer organocatalysts in which the squaramide unit is directly linked to the nitrogen atom of an aza-crown ether. Four chiral skeletons, namely hydroquinine, quinine, cinchonine (cinchonas), and α-d-glucopyranoside were responsible for the asymmetric construction of an all-carbon quaternary stereogenic center in α-alkylation and Michael addition reactions of malonic esters. We investigated the effects of these different chiral units and that of crown ethers with different sizes on catalytic activity and enantioselectivity. During extensive parameter investigations, both conventional and emerging green solvents were screened, providing valuable α,α-disubstituted malonic ester derivatives with excellent yields (up to 98%).
RESUMO
We present the case of a patient with Takotsubo syndrome developing simultaneous inferior, anterior spiked helmet sign (SHS) and macroscopic T-wave alternans (TWA) leading to torsade de pointes ventricular tachycardia (TdP VT). Based on our observations we propose that the SHS is a type of manifestation of critically prolonged QT(U).
Assuntos
Síndrome do QT Longo , Torsades de Pointes , Arritmias Cardíacas , Eletrocardiografia , Humanos , Síndrome do QT Longo/diagnósticoRESUMO
Glioblastoma (GBM) is regarded as the most common malignant brain tumor but treatment options are limited. Thus, there is an unmet clinical need for compounds and corresponding targets that could inhibit GBM growth. We screened a library of 80 dopaminergic ligands with the aim of identifying compounds capable of inhibiting GBM cell line proliferation and survival. Out of 45 active compounds, 8 were further validated. We found that the dopamine receptor D2 antagonist trifluoperazine 2HCl inhibits growth and proliferation of GBM cells in a dose dependent manner. Trifluoperazine's inhibition of GBM cells is cell line dependent and correlates with variations in dopamine receptor expression profile. We conclude that components of the dopamine receptor signaling pathways are potential targets for pharmacological interventions of GBM growth.
Assuntos
Avaliação Pré-Clínica de Medicamentos , Glioblastoma/patologia , Trifluoperazina/farmacologia , Contagem de Células , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Dopamina/metabolismo , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/genética , Humanos , Ligantes , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Trifluoperazina/químicaRESUMO
Glioblastoma (GBM) is regarded as the most common malignant brain tumor but treatment options are limited. Thus, there is an unmet clinical need for compounds and corresponding targets that could inhibit GBM growth. We screened a library of 80 dopaminergic ligands with the aim of identifying compounds capable of inhibiting GBM cell line proliferation and survival. Out of 45 active compounds, 8 were further validated. We found that the dopamine receptor D2 antagonist trifluoperazine 2HCl inhibits growth and proliferation of GBM cells in a dose dependent manner. Trifluoperazine's inhibition of GBM cells is cell line dependent and correlates with variations in dopamine receptor expression profile. We conclude that components of the dopamine receptor signaling pathways are potential targets for pharmacological interventions of GBM growth.
Assuntos
Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Trifluoperazina/administração & dosagem , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Antagonistas de Dopamina/administração & dosagem , Relação Dose-Resposta a Droga , Descoberta de Drogas/métodos , Glioblastoma/metabolismo , Humanos , Receptores Dopaminérgicos/metabolismoRESUMO
A feasible and enantioselective total synthesis of (-)-trans-dihydronarciclasine [(-)-1], a highly biologically active alkaloid, was devised starting from vanillin (8). The key step of this new synthesis was an asymmetric, organocatalytic Michael addition, in which an optically active nitropentanone [(-)-13] was obtained from a butenone derivative (12). Excellent enantioselectivity (>99% ee) was achieved using the (8S,9S)-9-amino(9-deoxy)epiquinine (16) organocatalyst. The target molecule can be prepared in 13 steps from compound (-)-13. The total synthesis has provided a facile and first access to the ent-form of naturally occurring (+)-trans-dihydronarciclasine, a highly potent cytostatic alkaloid.
Assuntos
Alcaloides/síntese química , Alcaloides de Amaryllidaceae/síntese química , Alcaloides/química , Alcaloides de Amaryllidaceae/química , Catálise , Cristalografia por Raios X , Estrutura Molecular , EstereoisomerismoRESUMO
It was long thought that no new neurons are added to the adult brain. Similarly, neurotransmitter signaling was primarily associated with communication between differentiated neurons. Both of these ideas have been challenged, and a crosstalk between neurogenesis and neurotransmitter signaling is beginning to emerge. In this Review, we discuss neurotransmitter signaling as it functions at the intersection of stem cell research and regenerative medicine, exploring how it may regulate the formation of new functional neurons and outlining interactions with other signaling pathways. We consider evolutionary and cross-species comparative aspects, and integrate available results in the context of normal physiological versus pathological conditions. We also discuss the potential role of neurotransmitters in brain size regulation and implications for cell replacement therapies.
Assuntos
Encéfalo/metabolismo , Neurogênese , Transmissão Sináptica , Vertebrados/metabolismo , Animais , Evolução Biológica , Encéfalo/citologia , Encéfalo/fisiologia , Proliferação de Células , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neuropeptídeo Y/metabolismo , Óxido Nítrico/metabolismo , Tamanho do Órgão , Receptores de GABA-A/metabolismo , Regeneração , Vertebrados/fisiologiaRESUMO
Increasing the activation of protein kinase B (Akt) has been suggested as a key signaling step in the nonhormonal anabolic activity of the phytoecdysteroid 20-hydroxyecdysone (20E) in mammals. Base-catalyzed autoxidation of this compound was shown previously to yield interesting B-ring-modified analogues. Herein is reported a thorough study on this reaction, resulting in the preparation and complete NMR spectroscopic assignments of calonysterone (5) and its previously overlooked desmotropic pair (7), along with two new sensitive metabolites of 20E. The two isomers showed considerable stability in solution. Time dependency of the reaction for yield optimization is also presented; by means of analytical HPLC, the two desmotropes can reach a maximum combined yield of >90%. The activity of these compounds on Akt phosphorylation was tested in murine skeletal muscle cells. Compounds 2 and 5 showed more potent activity than 20E in increasing Akt activation, while compound 7 exerted an opposite effect. As such, the present study provides the first direct evidence for a pair of desmotropes exerting significantly different bioactivities.
Assuntos
Commelinaceae/química , Medicamentos de Ervas Chinesas/química , Ecdisterona/metabolismo , Músculo Esquelético/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Ecdisterona/isolamento & purificação , Camundongos , Estrutura Molecular , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/efeitos dos fármacos , Oxirredução , Fosforilação , Raízes de Plantas/química , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de SinaisRESUMO
Salamanders have a remarkable capacity to regenerate complex tissues, such as limbs and brain, and are therefore an important comparative model system for regenerative medicine. Despite these unique properties among adult vertebrates, the genomic information for amphibians in general, and salamanders in particular, is scarce. Here, we used massive parallel sequencing to reconstruct a de novo reference transcriptome of the red spotted newt (Notophthalmus viridescens) containing 118,893 transcripts with a N50 length of 2016 nts. Comparisons to other vertebrates revealed a newt transcriptome that is comparable in size and characteristics to well-annotated vertebrate transcriptomes. Identification of putative open reading frames (ORFs) enabled us to infer a comprehensive proteome, including the annotation of 19,903 newt proteins. We used the identified domain architectures (DAs) to assign ORFs phylogenetic positions, which also revealed putative salamander specific proteins. The reference transcriptome and inferred proteome of the red spotted newt will facilitate the use of systematic genomic technologies for regeneration studies in salamanders and enable evolutionary analyses of vertebrate regeneration at the molecular level.
Assuntos
Perfilação da Expressão Gênica/normas , Notophthalmus viridescens/genética , Notophthalmus viridescens/metabolismo , Proteoma/análise , Transcriptoma/fisiologia , Animais , Análise por Conglomerados , Biologia Computacional/métodos , Evolução Molecular , Anotação de Sequência Molecular , Notophthalmus viridescens/fisiologia , Fases de Leitura Aberta/genética , Proteoma/metabolismo , Proteômica/métodos , Padrões de Referência , Regeneração/genética , Urodelos/genética , Urodelos/metabolismo , Urodelos/fisiologia , Estudos de Validação como AssuntoRESUMO
OBJECTIVES: Although horticultural therapy has been used successfully to reduce neuropsychiatric symptoms in elderly people with cognitive impairment, we do not yet know how it affects balance. The aim of our study was to determine the acceptability and effect of a 12-week horticultural therapy on balance and walking speed among institutionalized older adults with cognitive impairment. METHODS: This mixed-methods controlled trial included 23 participants. Subjects in the experimental group (n=13) participated in a 60â¯min horticultural therapy programme twice a week for 12 weeks in addition to the institution's usual social activities. Subjects in the control group (n=10) participated in the institution's usual social activities. Static and dynamic balance were measured with the Performance Oriented Mobility Assessment scale. In addition, gait speed was measured. Qualitative data were collected through a semi-structured interview with participants of the experimental group. RESULTS: At the end of the intervention period, the experimental maintained their baseline performance on the static balance, while the control group showed a decline. The gait speed of the experimental improved, while that of the control group did not change. In dynamic balance, no changes were demonstrated. The results of our qualitative data analysis indicate that horticultural therapy increases the possibility of social interactions, encourages older people to engage in conversation. CONCLUSIONS: As a conclusion, horticultural therapy should be more widely included in programmes for older people with cognitive impairment.