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81.
Aging‐associated declines in innate and adaptive immune responses are well documented and pose a risk for the growing aging population, which is predicted to comprise greater than 40 percent of the world''s population by 2050. Efforts have been made to improve immunity in aged populations; however, safe and effective protocols to accomplish this goal have not been universally established. Aging‐associated chronic inflammation is postulated to compromise immunity in aged mice and humans. Interleukin‐37 (IL‐37) is a potent anti‐inflammatory cytokine, and we present data demonstrating that IL‐37 gene expression levels in human monocytes significantly decline with age. Furthermore, we demonstrate that transgenic expression of interleukin‐37 (IL‐37) in aged mice reduces or prevents aging‐associated chronic inflammation, splenomegaly, and accumulation of myeloid cells (macrophages and dendritic cells) in the bone marrow and spleen. Additionally, we show that IL‐37 expression decreases the surface expression of programmed cell death protein 1 (PD‐1) and augments cytokine production from aged T‐cells. Improved T‐cell function coincided with a youthful restoration of Pdcd1, Lat, and Stat4 gene expression levels in CD4+ T‐cells and Lat in CD8+ T‐cells when aged mice were treated with recombinant IL‐37 (rIL‐37) but not control immunoglobin (Control Ig). Importantly, IL‐37‐mediated rejuvenation of aged endogenous T‐cells was also observed in aged chimeric antigen receptor (CAR) T‐cells, where improved function significantly extended the survival of mice transplanted with leukemia cells. Collectively, these data demonstrate the potency of IL‐37 in boosting the function of aged T‐cells and highlight its therapeutic potential to overcome aging‐associated immunosenescence.  相似文献   
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83.
Abstract

In recent papers [1–3] we reported molecular dynamics simulation studies of ions and water molecules adsorbed in a rigid zeolite-A framework using a simple Lennard-Jones potential plus Coulomb potential with Ewald summation to investigate the structure and dynamics of the adsorbates. In the present paper the same technique is applied to study the local structure and dynamics of NH4 + ions in a rigid dehydrated zeolite-A. During the preliminary equilibration, the unstable NH4(4) type ion (the 12th ion) is pushed down to near a more stable 6-ring position in the α-cage that is already associated with an NH4(1) type ion (the 1st) in the β-cage, which moves to another 6-ring position in the β-cage that is already associated with an NH4(2) type ion (the 7th) in the α-cage. Calculated x, y, and z coordinates of some NH4 + ions are in good agreement with those obtained from an X-ray diffraction experiment except that no NH4(4) type ion is found and there are six NH4(2) type ions instead of 0.5 and 5.5 occupancy. The analyses of calculated interatomic distances and time correlation functions of these ions indicate that the NH4(1 – 1) and NH4(3) type ions are associated loosely with only one O (3) atom of the 6-ring and with only one O (1) atom of the 8-ring windows, respectively, while the NH4(1–2) and NH4(2) type ions are associated strongly with two or three O (3) atoms of the 6-ring windows in the α- and β-cages, respectively. The analysis of hydrogen bond time correlation functions of these ions indicate that about one, two or three, three, and one hydrogen bond of each NH4(1–1), NH4(1–2), NH4(2) and NH4(3) type ion is kept for 1.4, 21, 75, and 1.4 ps, respectively, before breakup of the hydrogen bond occurs and significant exchange of O atom hydrogen-bonded to the ion.  相似文献   
84.
Amphitetranychus quercivorus (Ehara and Gotoh, 1990) was first identified in Mongolian oak tree Quercus mongolica in Daegu, Korea. In comparison to A. viennensis (Zacher), A. quercivorus was much shorter in the distal, dorsally directed portion of the male aedeagus, as well as smaller and less folded in the distal anastomosed portion of the female peritreme. Comparison of the nucleotide sequences of ITS2 and COI revealed 90% and 89% similarities, respectively, between the two species. In addition, species-specific primer sets for each species were designed using unique ITS2 sequences and then used to diagnose these two species under plant quarantine. We report the Korean name of this species as “Sin-gal-na-mu-eung-ae”.  相似文献   
85.
Ras-related small GTP-binding proteins execute many cellular functions, such as cell growth, differentiation, cytoskeletal reorganization, membrane trafficking, and membrane fusion. RalA belongs to the superfamily of Ras-related small GTP-binding proteins. Synaptic vesicles (SV) contain small GTP-binding proteins, where RalA, Rab3A, and Rab5A are the major GTP-binding proteins. It has been postulated that a cycling of these proteins between membrane-bound and soluble states is required for regulating cellular functions. Calmodulin (CaM) was found to dissociate Rab3A from SV membranes by forming a 1:1 complex with Ca2+/CaM. RalA was also found to be a Ca2+/CaM-binding protein. Therefore, we examined if Ca2+/CaM can also cause the RalA to dissociate from SV membranes. In this study, we identified that Ca2+/CaM dissociates RalA as well as Rab3A from synaptic vesicles.  相似文献   
86.
The high morphological resemblance between branching corals and trees, can lead to comparative studies on pattern formation traits, best exemplified in plants and in some cnidarians. Here, 81 branches of similar size of the hermatypic coral Stylophora pistillata were lopped of three different genets, their skeletons marked with alizarin red-S, and divided haphazardly into three morphometric treatment groups: (I) upright position; (II) horizontal position, intact tip; and (III) horizontal position, cut tip. After 1 y of in-situ growth, the 45 surviving ramets were brought to the laboratory, their tissues removed and their architectures analyzed by 22 morphological parameters (MPs). We found that within 1 y, isolated branches developed into small coral colonies by growing new branches from all branch termini, in all directions. No architectural dissimilarity was assigned among the three studied genets of treatment I colonies. However, a major architectural disparity between treatment I colonies and colonies of treatments II and III was documented as the development of mirror structures from both sides of treatments II and III settings as compared to tip-borne architectures in treatment I colonies. We did not observe apical dominance since fragments grew equally from all branch sides without documented dominant polarity along branch axis. In treatment II colonies, no MP for new branches originating either from tips or from branch bases differed significantly. In treatment III colonies, growth from the cut tip areas was significantly lower compared to the base, again, suggesting lack of apical dominance in this species. Changes in branch polarity revealed genet associated plasticity, which in one of the studied genets, led to enhanced growth. Different genets exhibited canalization flexibility of growth patterns towards either lateral growth, or branch axis extension (skeletal weight and not porosity was measured). This study revealed that colony astogeny in S. pistillata is a regulated process expressed through programmed events and not directly related to simple energy trade-off principles or to environmental conditions, and that branch polarity and apical dominance do not dictate colony astogeny. Therefore, plasticity and astogenic disparities encompass a diversity of genetic (fixed and flexible) induced responses.  相似文献   
87.
88.
89.
Comparison of bone marrow extracellular matrices.   总被引:1,自引:0,他引:1  
We have compared the structure and composition of adult and fetal bovine bone marrow extracellular matrices. In contrast to fetal bone marrow, adult bone marrow has more oval fenestration and accumulation of adipocytes as well as lower protein content. These differences could be due to remodeling of bone marrow tissue as it develops. Zymogram analysis of matrix metalloproteinase (MMP) and tissue inhibitor of MMP (TIMP) activities showed that fetal, but not adult bone marrow extract contained a 96-kDa MMP and TIMP-1 and -2. These activities may contribute to the structural differences between adult and fetal bone marrow tissues.  相似文献   
90.
Monocytes/macrophages play a critical role in the initiation and progression of a variety of glomerulonephritides. We sought to define the interactions between physiologically activated human monocytes and glomerular mesangial cells (MC) by employing a cell culture system that permits the accurate assessment of the contribution of soluble factors and cell-to-cell contact. Human peripheral blood monocytes, primed with IFN-gamma and GM-CSF, were activated with CD40 ligand (CD40L) or TNF-alpha and cocultured with MC. CD40L-activated monocytes induced higher levels of IL-6, monocyte chemoattractant protein-1 (MCP-1) and ICAM-1 synthesis by MC. Separation of CD40L-activated monocytes from MC by a porous membrane decreased the mesangial synthesis of IL-6 by 80% and ICAM-1 by 45%, but had no effect on MCP-1. Neutralizing Abs against the beta 2 integrins, LFA-1 and Mac-1, decreased IL-6 production by 40 and 50%, respectively. Ligation of mesangial surface ICAM-1 directly enhanced IL-6, but not MCP-1, production. Simultaneous neutralization of soluble TNF-alpha and IL-1 beta decreased MCP-1 production by 55% in membrane-separated cocultures of MC/CD40L-activated monocytes. Paraformaldehyde-fixed CD40L-activated monocytes (to preserve membrane integrity but prevent secretory activity), cocultured with MC at various ratios, induced IL-6, MCP-1, and ICAM-1 synthesis by MC. Plasma membrane preparations from activated monocytes also induced mesangial IL-6 and MCP-1 synthesis. The addition of plasma membrane enhanced TNF-alpha-induced mesangial IL-6 production by approximately 4-fold. Together, these data suggest that the CD40/CD40L is essential for optimal effector function of monocytes, that CD40L-activated monocytes stimulate MC through both soluble factors and cell-to-cell contact mediated pathways, and that both pathways are essential for maximum stimulation of MC.  相似文献   
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