RESUMO
Band structure and transition dipole moment play important roles in high-order harmonic generation from solid materials. In this work we provide a new all-optical technique to reconstruct the momentum-dependent transition dipole moment using the harmonic spectrum from MgO crystal driven by an ultrashort mid-infrared laser pulse. Under the influence of the ultrashort laser pulse, the emitted photon energy and the crystal momentum form a one-to-one match, in the same way between the intensity of the harmonic above the minimum bandgap and the square of the amplitude of the transition dipole moment, resulting in a realization of directly probing the transition dipole moment. Our all-optical method paves a way to image the two-dimensional transition dipole moment of crystals with the inversion symmetry.
RESUMO
Lactoferrin (LF) is a soluble glycoprotein of the transferring family found in most biological fluids, functioning as a major first line defense molecule against infection in mammals. It also shows certain anti-tumor activity, but its clinical application in tumor therapy is limited because high dosage is required. In this study, we demonstrate that M860, a monoclonal antibody against human LF (hLF), could significantly increase the anti-tumor potential of low dosage hLF by forming LF-containing immune complex (IC). Human monocytes primed with LF-IC, but not hLF or M860 alone, or control ICs, showed strong tumoricidal activity on leukemia cell lines Jurkat and Raji through induction of secreted Granzyme B (GzB). LF-IC is able to colligate membrane-bound CD14 (a TLR4 co-receptor) and FcγRIIa (a low affinity activating Fcγ receptor) on the surface of human monocytes, thereby triggering the Syk-PI3K-AKT-mTOR pathway leading to GzB production. Our work identifies a novel pathway for LF-mediated tumoricidal activity and may extend the clinical application of LF in tumor therapy.
Assuntos
Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Granzimas/biossíntese , Lactoferrina/antagonistas & inibidores , Biomarcadores , Sinergismo Farmacológico , Expressão Gênica , Granzimas/genética , Humanos , Lactoferrina/administração & dosagem , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Quinase Syk/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Fabrication of an outer membrane is crucial for an implantable biosensor to enhance the long-term stability and accuracy of sensors. Herein, an adaptable, controllable, porous outer membrane for an implantable biosensor was fabricated using a "top-down" method, allowing maximum retention of enzyme activity and fine control over membrane microstructure. Polysulfone hollow fibrous membranes with different pore sizes and porosities were used as a base membrane. Chitosan (CH) and sodium alginate (SA) were self-assembled on the inner surface of PSfHM to construct a biocompatible and conductive interface between PSfHM and the electrode. In vitro and in vivo experiments were used to evaluate the performance of implantable glucose biosensors with PSfHM and CH/SA modified PSfHM (PSfHM-CH/SA). The glucose biosensor with PSfHM-CH/SA exhibited a more stable output current than bare sensors and a quick response time (<50 s). The glucose biosensor with PSfHM-CH/SA linear sensing range was between 0 and 22 mM ( R2 = 0.9905), and relative sensitivity remained at >87% within 7 days and >76% within 15 days. Furthermore, response currents recorded by implanted sensors closely followed the blood glucose trend from the tail vein blood during in vivo experiments.
Assuntos
Técnicas Biossensoriais/métodos , Glicemia/análise , Membranas Artificiais , Polímeros/química , Sulfonas/química , Alginatos/química , Animais , Técnicas Biossensoriais/instrumentação , Glicemia/química , Quitosana/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Enzimas Imobilizadas/química , Glucose Oxidase/química , Masculino , Porosidade , Próteses e Implantes , Ratos Sprague-DawleyRESUMO
Chemical modification was performed for improving the antioxidant activity of lead compound glycyrrhetinic acid (Ib). Two conjugated diene derivatives were prepared by reduction and dehydration reactions. Their in vitro antioxidant activities were studied using a cytochrome P450/NADPH reductase system from rat liver microsomes. The generation of microsomal free radicals was followed by oxidation of the DCFH-DA probe, while evaluating the capacity to inhibit reactive oxygen species (ROS) formation. The initial result showed that the two homo- and heterocyclic diene derivatives--18beta-olean-11,13(18)-diene-3beta, 30-diol (IV) and 18beta-olean-9 (11), 12-diene-3beta, 30-diol (V) exhibited strong antioxidant activities, at a concentration of 1.0 mg x mL(-1), they inhibited free radical (ROS) formation by 45% and 41%, respectively. In the same conditions, the lead compound (Ib) and the reference vitamin E inhibited ROS activity by 31% and 32%. Our results suggest that the elimination of the 11-keto group and the chemical reduction of 30-carboxylic group into hydroxyl function can increase the antioxidant activity of Ib significantly.
Assuntos
Antioxidantes/síntese química , Ácido Glicirretínico/análogos & derivados , Microssomos Hepáticos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Triterpenos/síntese química , Animais , Antioxidantes/farmacologia , Masculino , Ratos , Triterpenos/farmacologiaRESUMO
OBJECTIVE: To compare antiproliferation effects of vinblastine nanopraticles and vinblastine water solution in human glioma cell lines BT325. METHOD: Vinblastine nanoparticles were prepared by emulsion polymerization process and using dextran as a stabilizing agent. It was characterized by means of morphology, size, drug entrapment efficiency and loading efficiency. Human glioma cell lines BT325 were treated with different concentrations of vinblastine nanoparticles and vinblastine water solution for 48 h, Antiproliferation effect was measured by MTT method. Morphological changes were observed by inverted microscope, transmission electron microscope and scanning electron microscope. RESULT: Mean diameter of VLB-PBCA-NP was about 74.4 nm, and drug entrapment efficiency and loading efficiency was 78.47% and 39.24%, respectively. Cell growth inhibition rate of vinblastine nanoparticles group and vinblastine water solution group in a concentration range (5-5 000 g x L(-1)) for 48 h was 41%, 49%, 73%, 83% and 28%, 33%, 54%, 60% respectively. Entrapment of VLB in NPS may distinctly degrade absorbency as compared to free drugs. Glioma cell BT325 which treated with VLB water solution were initial stage of apoptosis, and apoptosis body were forming. But VLB NPS-treated BT325 cells were intermediate or end stage, and missed structure integrality. CONCLUSION: VLB-PBCA-NP and VLB water solution could inhibit the growth of human glioma cell lines BT325, and VLB nanoparticles have stronger inhibition effect compared with VLB water solution in the same dose. PBCA may be effective as promising carrier for the transport of vinblastine into the glioma cells.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Nanopartículas , Vimblastina/farmacologia , Linhagem Celular Tumoral , Medicamentos de Ervas Chinesas/farmacologia , Humanos , Microscopia Eletrônica de TransmissãoRESUMO
Tofacitinib (CP-690550), an oral Janus kinase inhibitor, has shown significant efficacy in the treatment of rheumatoid arthritis through blocking the signaling pathways of pro-inflammatory cytokines. However, recent evidence suggests that long-term tofacitinib treatment is associated with increased risk of infection (e.g. tuberculosis) in patients. In the present study, we illustrate that tofacitinib administration significantly reduced the survival rate of mice given lethal or sub-lethal dose challenge with Candida albicans. This was related to the ability of tofacitinib to reverse TNFα- and IFNγ-enhanced candidacidal activity of murine polymorph nuclear cells (PMNs) and also to suppress chemokine CXCL5 expression and PMN infiltration in the infected tissues of mice. More importantly, tofacitinib significantly antagonized the ability of TNFα, IFNγ and GM-CSF to boost human PMNs in phagocytosis and direct killing of C. albicans in vitro. It also down-regulated reactive oxygen production and neutrophil extracellular trap formation by human PMNs stimulated with yeast-derived ß-glucans in the presence of TNFα, IFNγ or GM-CSF. Our data emphasizes a significantly increased risk for opportunistic fungal infection associated long-term tofacitinib treatment in humans, likely through antagonizing the PMN-boosting effect of pro-inflammatory cytokines.
Assuntos
Artrite Reumatoide/tratamento farmacológico , Candida albicans/fisiologia , Candidíase/etiologia , Piperidinas/efeitos adversos , Piperidinas/uso terapêutico , Pirimidinas/efeitos adversos , Pirimidinas/uso terapêutico , Pirróis/efeitos adversos , Pirróis/uso terapêutico , Administração Oral , Adulto , Animais , Artrite Reumatoide/patologia , Candida albicans/efeitos dos fármacos , Candidíase/microbiologia , Candidíase/patologia , Suscetibilidade a Doenças , Feminino , Humanos , Camundongos Endogâmicos BALB C , Ativação de Neutrófilo/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Fagocitose/efeitos dos fármacos , Piperidinas/administração & dosagem , Piperidinas/farmacologia , Pirimidinas/administração & dosagem , Pirimidinas/farmacologia , Pirróis/administração & dosagem , Pirróis/farmacologia , Fatores de RiscoRESUMO
BACKGROUND: The SLAM family recently has been reported to show an important biological role in lymphocyte development and immunological function, and it is efficient to highly purify hematopoietic stem cells using a simple combination of SLAM family members. To elucidate the presence of this family on acute lymphoblastic leukemia (ALL), as well as its relationship with the leukemia-initiating potential, we analyzed the expression pattern of this family members on human ALL progenitor cells, combined with serial xenotransplantation assay. METHODS: Expression analysis was carried out by flow cytometry. We combined the expression pattern of human CD(150), CD(244) and CD(48) with serial xenotransplantation of B-ALL progenitor cells to indicate their relationship. RESULTS: CD(48) and CD(244) were expressed on most B-ALL progenitor cells, the percentage being (93.08 ± 6.46)% and (63.37 ± 29.31)%, respectively. Interestingly, the proportion of CD(150)(+) cells declined obviously in engrafted cases ((24.94 ± 7.32)%) compared with non-engrafted cases ((77.54 ± 5.93)%, P < 0.01), which indicated that only blast cells with low percentage of CD(150)(+) population were able to reconstitute leukemia into primary, secondary and tertiary NOD/SCID mice. CONCLUSIONS: SLAM family members are present on B-ALL progenitor cells and the leukemia-initiating potential of leukemic blasts is correlated negatively with the proportion of CD(150)(+) cells, the percentage of which can serve as a useful predictor for engraftment success of B-ALL to immune deficient mice.