Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Anat Histol Embryol ; 53(3): e13045, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38735038

RESUMO

This work extensively studied the vasculature of mice mammary fat pads (BALB/c and C57BL/6) with special reference to haematogenous drainage routes. Mammary fat pads were five pairs (first cervical, second and third thoracic, fourth abdominal and fifth inguinal), bilaterally symmetrical, extending laterally and continuously with the subcutaneous fascia. The superficial cervical artery and vein primarily accomplished the blood vasculature of the first mammary fat pad, while the lateral thoracic and external thoracic arteries and veins supplied the second and third mammary fat pads. The superficial cervical vein (found parallel to the superficial cervical artery) drained into the external jugular vein. The lateral thoracic artery and external thoracic artery branched almost at the same level as the axillary artery (branch of subclavian artery), the latter being more medial in position. However, in some specimens, the branching of both arteries appeared to be at the same level, and their origins were indistinguishable. The lateral thoracic vein that was parallel to the lateral thoracic artery drained to the axillary vein close to the drainage of the external thoracic vein. The lateral thoracic, superficial caudal epigastric, iliolumbar and external thoracic arteries and veins vascularized the fourth mammary fat pad and displayed anastomosis among themselves. The iliolumbar vein (found parallel to the iliolumbar artery) drained into the inferior vena cava. The superficial caudal epigastric vein (found parallel to the superficial caudal epigastric artery (SCaEA)) drained into the femoral vein. Unlike humans, the internal thoracic artery and vein did not participate in the vasculature of mammary fat pads. The SCaEA and vein supplied blood and drained the fifth mammary fat pad. The anatomical continuity of the fourth and fifth mammary fat pads provided common drainage for both mammary fat pads. The BALB/c and C57BL/6 mice strains studied did not differ in topography and size of mammary fat pads. The vascular supply and drainage of the mammary fat pads also did not differ in the strains studied. Only minor variations could be noted in the small veins draining into the lateral thoracic vein. Lateral tributaries seen in the terminal end of the lateral thoracic vein were absent in the C57BL/6 mice.


Assuntos
Tecido Adiposo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Animais , Camundongos/anatomia & histologia , Camundongos Endogâmicos C57BL/anatomia & histologia , Tecido Adiposo/anatomia & histologia , Tecido Adiposo/irrigação sanguínea , Feminino , Glândulas Mamárias Animais/irrigação sanguínea , Glândulas Mamárias Animais/anatomia & histologia , Artérias Torácicas/anatomia & histologia
2.
Biomed Pharmacother ; 109: 1339-1345, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30551384

RESUMO

Chronic inflammation of the myelin sheath is the crucial event behind the progression of multiple sclerosis (MS). Bacoside-A is one of the major constituents obtained from Bacopa monerii (L.) Wettst., and possess neuroprotective as well as anti-inflammatory actions. The current study explores the effect of Bacoside-A in acute and chronic models of Experimental Autoimmune Encephalomyelitis (EAE). The results indicate that the Bacoside-A treated mice produced a significant reduction in disease score compared to disease control in both models. The treatment with Bacoside-A downregulated the inflammatory cytokines (IL-6, IL-17a, and TNFα) and inflammatory chemokine CCL-5 in EAE mice. On the other hand, Bacoside-A treated mice showed a nonsignificant effect on promoting the expressions of NCAM, BDNF1, and FOXP3 in acute and chronic models of EAE. Histopathological analysis revealed that the Bacoside-A treated mice at a dose of 10 mg/kg exhibited a significant reduction in cellular infiltrations, cellular changes, and demyelination in cerebral tissues, but unable to protect at a higher dose in both models. In conclusion, Bacoside-A can able to inhibit the progression of EAE may be by the inhibition of inflammatory cytokines and chemokine evolved during active EAE.


Assuntos
Quimiocinas/antagonistas & inibidores , Citocinas/antagonistas & inibidores , Encefalomielite Autoimune Experimental/tratamento farmacológico , Inflamação/tratamento farmacológico , Saponinas/farmacologia , Triterpenos/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Encefalomielite Autoimune Experimental/metabolismo , Feminino , Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/metabolismo , Bainha de Mielina/efeitos dos fármacos , Bainha de Mielina/metabolismo
3.
Neurotoxicology ; 68: 1-12, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29981346

RESUMO

Quinolinic acid (QUIN) is a well-known neuroactive metabolite of tryptophan degradation pathway or kynurenine pathway. The QUIN is involved in the development of several toxic cascades which leads to the neuronal degeneration processes. The QUIN-induced toxicity is also responsible for the impairment of the motor function and motor learning ability. This study seeks to investigate the several mechanisms which are involved in the intrastriatal administration of QUIN-induced neurodegeneration and the neuroprotective effects of wedelolactone (WL) and gallic acid (GA) over QUIN-induced toxicity. The Wistar rats were used for the study and conducted behavioral model to evaluate the effects of WL (100 & 200 mg/kg) and GA (100 & 200 mg/kg) on impaired motor function and motor learning ability. We also assessed the effects of WL and GA on the antioxidant profile, cytotoxicity, apoptosis, excitotoxicity, inflammatory cascades, and on growth factors which helps in neurogenesis. The compounds effectively improved the motor function, motor learning memory in the rats. Similarly, enhanced the activity of Glutathione peroxidase, SOD, catalase, and declined the lipid peroxidation and nitrite production in the brain. The treatment with WL and GA lowered the activities of LDH, m-calpain, and caspase-3. The reports strongly support that both compounds are useful in the prevention of glutamate excitotoxicity induced by QUIN. The NAA, IGF-1, and VEGF levels in the brain were improved after treatment with WL and GA. The neuroprotective effects of WL and GA further proved through the anti-inflammatory effects. The compounds significantly down-regulated the expression of TNF-α, IL-6, and IL-ß in the brain. Immunohistochemical analysis shows that the WL and GA reduced the expression of NF-κB. The histopathological studies for cerebellum, hippocampus, striatum, and spinal cord confirms the toxic effects of QUIN and neuroprotective effects of WL and GA. The results suggest that WL and GA could ameliorate the toxic events triggered by QUIN and might be effective in the prevention and progression of several cascades which lead to the development of sALS.


Assuntos
Esclerose Lateral Amiotrófica/induzido quimicamente , Encéfalo/efeitos dos fármacos , Cumarínicos/administração & dosagem , Ácido Gálico/administração & dosagem , Aprendizagem/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Ácido Quinolínico/toxicidade , Esclerose Lateral Amiotrófica/metabolismo , Animais , Antioxidantes/administração & dosagem , Apoptose , Encéfalo/metabolismo , Modelos Animais de Doenças , Encefalite/induzido quimicamente , Encefalite/metabolismo , Masculino , Ratos Wistar
4.
J Chem Phys ; 138(9): 094113, 2013 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-23485283

RESUMO

We employed an explicit expression for the dispersion (D) energy in conjunction with Kohn-Sham (KS) density functional theory and frozen-density embedding (FDE) to calculate interaction energies between DNA base pairs and a selected set of amino acid pairs in the hydrophobic core of a small protein Rubredoxin. We use this data to assess the accuracy of an FDE-D approach for the calculation of intermolecular interactions. To better analyze the calculated interaction energies we furthermore propose a new energy decomposition scheme that is similar to the well-known KS bond formation analysis [F. M. Bickelhaupt and E. J. Baerends, Rev. Comput. Chem. 15, 1 (2000)], but differs in the electron densities used to define the bond energy. The individual subsystem electron densities of the FDE approach sum to the total electron density which makes it possible to define bond energies in terms of promotion energies and an explicit interaction energy. We show that for the systems considered only a few freeze-and-thaw cycles suffice to reach convergence in these individual bond energy components, illustrating the potential of FDE-D as an efficient method to calculate intermolecular interactions.


Assuntos
Aminoácidos/química , DNA/química , Teoria Quântica , Rubredoxinas/química , Interações Hidrofóbicas e Hidrofílicas
5.
J Comput Chem ; 32(10): 2328-38, 2011 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-21541961

RESUMO

Applications of quantum chemistry have evolved from single or a few calculations to more complicated workflows, in which a series of interrelated computational tasks is performed. In particular multiscale simulations, which combine different levels of accuracy, typically require a large number of individual calculations that depend on each other. Consequently, there is a need to automate such workflows. For this purpose we have developed PYADF, a scripting framework for quantum chemistry. PYADF handles all steps necessary in a typical workflow in quantum chemistry and is easily extensible due to its object-oriented implementation in the Python programming language. We give an overview of the capabilities of PYADF and illustrate its usefulness in quantum-chemical multiscale simulations with a number of examples taken from recent applications.

6.
J Phys Chem A ; 115(9): 1493-9, 2011 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-21323362

RESUMO

Isoflavones are known to show fluorescence with intensities that depend strongly on the solvent properties and exhibit Stokes' shifts as large as 1.4 eV. While some of this behavior can be explained by (excited state) deprotonation, this mechanism does not apply for all isoflavones. The aim of this study is to computationally and experimentally investigate the reasons for this anomalous behavior of neutral isoflavones, taking the daidzein molecule as a model compound. We find that the absence in fluorescence in aprotic solvents and the weak fluorescence in protic solvents can be explained by a change of order of the lowest singlet states in which a fluorescent charge-transfer state lies below the nonfluorescent locally excited state in water but not in acetonitrile. The large Stokes' shift is partly due to a significant rotation among the chromone-phenyl bond in the excited state.


Assuntos
Fluorescência , Isoflavonas/química , Teoria Quântica , Absorção , Simulação por Computador , Modelos Moleculares , Conformação Molecular , Solventes/química , Espectrometria de Fluorescência , Água/química
7.
J Chem Phys ; 132(4): 044114, 2010 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-20113026

RESUMO

We have assessed the accuracy of a representative set of currently available approximate kinetic-energy functionals used within the frozen-density embedding scheme for the NgAuF (Ng=Ar, Kr, Xe) molecules, which we partitioned into a Ng and a AuF subsystem. Although it is weak, there is a covalent interaction between these subsystems which represents a challenge for this subsystem density functional theory approach. We analyzed the effective-embedding potentials and resulting electron density distributions and provide a quantitative analysis of the latter from dipole moment differences and root-mean-square errors in the density with respect to the supermolecular Kohn-Sham density functional theory reference calculation. Our results lead to the conclusion that none of the tested approximate kinetic-energy functionals performs well enough to describe the bond between the noble gas and gold adequately. This observation contributes to the growing evidence that the current procedure to obtain approximate kinetic-energy functionals by reparametrizing functionals obtained via the "conjointness" hypothesis of Lee, Lee, and Parr [Phys. Rev. A 44, 768 (1991)] is insufficient to treat metal-ligand interactions with covalent character.


Assuntos
Flúor/química , Ouro/química , Gases Nobres/química , Teoria Quântica
8.
J Chem Theory Comput ; 5(12): 3161-74, 2009 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-26602501

RESUMO

We have tested the performance of a large set of kinetic energy density functionals of the local density approximation (LDA), the gradient expansion approximation (GEA), and the generalized gradient approximation (GGA) for the calculation of interaction energies within a subsystem approach to density functional theory. Our results have been obtained with a new implementation of interaction energies for frozen-density embedding into the Amsterdam Density Functional program. We present data for a representative sample of 39 intermolecular complexes and 15 transition metal coordination compounds with interaction energies spanning the range from -1 to -783 kcal/mol. This is the first time that kinetic energy functionals have been tested for such strong interaction energies as the ligand-metal bonds in the investigated coordination compounds. We confirm earlier work that GGA functionals offer an improvement over the LDA and are particularly well suited for weak interactions like hydrogen bonds. We do, however, not find a particular reason to prefer any of the GGA functionals over another. Functionals derived from the GEA in general perform worse for all of the weaker interactions and cannot be recommended. An unexpectedly good performance is found for the coordination compounds, in particular with the GEA-derived functionals. However, the presently available kinetic energy functionals cannot be applied in cases in which a density redistribution between the subsystems leads to strongly overlapping subsystem electron densities.

9.
J Chem Phys ; 126(23): 234116, 2007 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-17600413

RESUMO

We have investigated the functional derivative of the nonadditive kinetic-energy bifunctional, which appears in the embedding potential that is used in the frozen-density embedding formalism, in the limit that the separation of the subsystems is large. We have derived an exact expression for this kinetic-energy component of the embedding potential and have applied this expression to deduce its exact form in this limit. Comparing to the approximations currently in use, we find that while these approximations are correct at the nonfrozen subsystem, they fail completely at the frozen subsystem. Using test calculations on two model systems, a H2O...Li+ complex and a cluster of aminocoumarin C151 surrounded by 30 water molecules, we show that this failure leads to a wrong description of unoccupied orbitals, which can lead to convergence problems caused by too low-lying unoccupied orbitals and which can further have serious consequences for the calculation of response properties. Based on our results, a simple correction is proposed, and we show that this correction is able to fix the observed problems for the model systems studied.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA