410 research outputs found
(4R*,5R*)-Diethyl 2-(4-nitrophenyl)-1,3-dioxolane-4,5-dicarboxylate
In the title compound, C15H17NO8, the nitro group is essentially coplanar with the aromatic ring [dihedral angle = 6.4 (3) Å]. The five-membered ring has a twist conformation. In the crystal, C—H⋯O interactions link the molecules into a helical chain propagating along [010]
Effects of total flavonoids from Drynariae Rhizoma prevent bone loss in vivo and in vitro
AbstractEstrogen deficiency is one of the major causes of osteoporosis in postmenopausal women. Drynariae Rhizoma is a widely used traditional Chinese medicine for the treatment of bone diseases. In this study, we investigated the therapeutic effects of the total Drynariae Rhizoma flavonoids (DRTF) on estrogen deficiency-induced bone loss using an ovariectomized rat model and osteoblast-like MC3T3-E1 cells. Our results indicated that DRTF produced osteo-protective effects on the ovariectomized rats in terms of bone loss reduction, including decreased levels of bone turnover markers, enhanced biomechanical femur strength and trabecular bone microarchitecture deterioration prevention. In vitro experiments revealed that the actions of DRTF on regulating osteoblastic activities were mediated by the estrogen receptor (ER) dependent pathway. Our data also demonstrated that DRTF inhibited osteoclastogenesis via up-regulating osteoprotegrin (OPG), as well as down-regulating receptor activator of NF–κB ligand (RANKL) expression. In conclusion, this study indicated that DRTF treatment effectively suppressed bone mass loss in an ovariectomized rat model, and in vitro evidence suggested that the effects were exerted through actions on both osteoblasts and osteoclasts
The expression of p63 is associated with the differential stage in nasopharyngeal carcinoma and EBV infection
BACKGROUND: Nasopharyngeal carcinoma (NPC) is common among Southern Chinese and the main histology is the undifferentiated carcinoma associated with Epstein-Barr virus (EBV) infection. p63 is a recently proved member of the p53 family based on the structural similarity to p53, but its function in NPC is still unknown. This study was aimed to investigate the association between p63 and NPC. RESULTS: p63 was expressed in 100%(202/202) of nasopharyngeal carcinoma (NPC) tissues but not in 29 nasopharynx inflammation and 17 non-cancerous nasopharyngeal epidermises on a tissue microarray by immunohistostaining. Further investigation suggested that the p63 expression was associated with the differential stage of NPC: p63 strong staining in Keratinizing squamous cell carcinoma, differentiated non-keratinizing NPC and undifferentiated non-keratinizing NPC presented the percentage of 5/8 (62.5%), 43/48 (92.5%) and 50/50 (100%), respectively. A significant difference (p = 0.001) existed between the keratinizing and non-keratinizing groups. No pathogenic mutations were detected in p63 gene in 12 primary NPC tissues and matched peripheral blood lymphocytes (PBL). Half-life measurement study revealed distinct stability of p63 protein in the different cell lines, especially between the carcinoma cell lines with EBV infection and the non-cancerous cell lines. The results of immunoprecipitation suggested a direct interaction between Epstein-Barr virus nuclear antigen 5 (EBNA-5) and p63 protein in NPC, and this binding would increase the stability of p63. CONCLUSION: Our data suggested p63 might be used as an adjunct diagnostic marker of NPC and contributed a new way to understand the contribution of the EBV in the pathogenesis of NPC
Demonstration of intermodal four-wave mixing by femtosecond pulses centered at 1550 nm in an air-silica photonic crystal fiber
In this paper, we demonstrated experimentally the intermodal four-wave mixing effect by launching femtosecond pulses centered at 1550 nm into deeply normal dispersion region in the fundamental guided-mode of an air-silica photonic crystal fiber with two zero dispersion wavelengths. When intermodal phase-matching condition is satisfied, the energy of the pump waves at 1550 nm in the fundamental guided-mode is converted to the anti-Stokes waves around 1258 nm and Stokes waves around 2018 nm both in the second-order guided-mode. When femtosecond pulses at input average power Pav of 90 mW are propagated inside 22 cm long photonic crystal fiber, the conversion efficiencies ηas and ηs of the anti-Stokes and Stokes waves generated are 8.5 and 6.8%, respectively. We also observed that the influences of the fiber bending and walk-off effect between the fundamental and second-order guided-modes on intermodal four-wave mixing-based frequency conversion process are very small
Ectopic lymphoid tissues support local immunoglobulin production in patients with chronic rhinosinusitis with nasal polyps
Background: The contribution of ectopic lymphoid tissues (eLTs) to local immunoglobulin hyperproduction in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) is unclear.
Objective: We sought to explore the cellular basis, formation mechanisms, and function of eLTs in patients with CRSwNP.
Methods: We graded lymphoid aggregations in sinonasal mucosa and histologically studied their structures. The expression of lymphorganogenic factors and molecules required for immunoglobulin production was measured by using real-time PCR, and their localization was analyzed by means of immunohistochemistry and immunofluorescence. The phenotype of follicular helper T cells was analyzed by performing flow cytometry. Immunoglobulin levels were quantified by using the Bio-Plex assay or ImmunoCAP system. Nasal tissue explants were challenged ex vivo with Dermatophagoides pteronyssinus group 1 (Der p 1), and the expression of I epsilon-C mu and I epsilon-C gamma circle transcripts was detected by using seminested PCR.
Results: Increased formation of eLTs with germinal center-like structures was discovered in patients with eosinophilic (20.69%) and noneosinophilic (17.31%) CRSwNP compared with that in patients with chronic rhinosinusitis without nasal polyps (5.66%) and control subjects (3.70%). The presence of eLTs was associated with increased expression of lymphorganogenic and inflammatory chemokines and cytokines, as well as their receptors. The expression of molecules required for immunoglobulin production, generation of follicular helper T cells, and production of IgE in eosinophilic polyps and IgG and IgA in both eosinophilic and noneosinophilic polyps were predominantly upregulated in patients with eLTs. After Der p 1 challenge ex vivo, I epsilon-C mu transcript was detected only in eosinophilic polyps with eLTs but not in polyps without eLTs and noneosinophilic polyps.
Conclusion: eLTs might support local immunoglobulin production and therefore significantly contribute to the development of CRSwNP
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