Lp(a) is an LDL-like lipoprotein that is a major inherited risk factor for atherosclerosis. It is distinguished from Lp(a) by the addition of apolipoprotein(a). The gene structure of apolipoprotein(a) is homologous to plasminogen, and competition with plasminogen activity may account for some of the pathophysiology associated with Lp(a). Six highly related genes have now been identified, and at least four are found in close proximity in overlapping genomic clones. Studies have begun on the regulation of apolipoprotein (a) gene expression, and the human apolipoprotein(a) gene has been inserted into transgenic mice, where it leads to the development of arterial lesions. 相似文献
Summary: The wavelength‐dependent vacuum ultraviolet (VUV) photolysis of several polymers, low density polyethylene (LDPE), biaxially oriented poly(propylene) (BOPP), atactic polystyrene (PS), and poly(methyl methacrylate) (PMMA), was studied by irradiation in vacuum with the well‐characterized emissions from four different resonant or excimer VUV sources. These lamps comprise radiofrequency (r.f.) discharges in different noble gases, such as krypton, xenon (at low pressures, producing near‐monochromatic resonant line radiations), xenon excimer (at “high” pressure), and a deuterium/argon mixture (producing a broad‐band emission). VUV‐induced mass loss (ablation or etching) was monitored in situ by quartz crystal microbalance measurements. Following irradiation, samples were analysed by ATR‐FTIR and XPS, to evaluate near‐surface structural changes (e.g., creation of unsaturation, cross‐linking) resulting from the VUV‐initiated bond scissions and radical‐creation reactions. PMMA was the most readily ablatable polymer, whereas the mass loss of BOPP was higher than that of LDPE, regardless of the irradiation wavelength, λ. All polymers were found to form double bonds, with the exception of PS, which is rather stable, probably due to energy dissipation by fluorescence.
Formation of double bonds in a) vinyl‐, b) vinylidene‐, and c) vinylene‐like unsaturated groups, as a function of the radiation dose, D, for KrL (?), XeL (?), and D2Ar‐irradiated (?) PMMA. 相似文献
Human Immunodeficiency virus type 1 (HIV-1), as well as many other viruses that depend on nuclear entry for replication, has developed an evolutionary strategy to dock and translocate through the nuclear pore complex (NPC). In particular, the nuclear pore is not a static window but it is a dynamic structure involved in many vital cellular functions, as nuclear import/export, gene regulation, chromatin organization and genome stability. This review aims to shed light on viral mechanisms developed by HIV-1 to usurp cellular machinery to favor viral gene expression and their replication. In particular, it will be reviewed both what is known and what is speculated about the link between HIV translocation through the nuclear pore and the proviral integration in the host chromatin. 相似文献
Distribution of substance P-, [Leu]enkephalin-, cholecystokinin-8-, neurotensin-, avian pancreatic polypeptide- and gamma-melanocyte stimulating hormone-like immunoreactive structures were investigated in the nucleus tractus solitarii of the rat by means of the indirect immunofluorescence method. The density of the immunoreactive structures varied markedly according to neuropeptides or subnuclei, with the medial and commissural nuclei containing the highest density. This suggests that the peptides examined play a role in cardiovascular function. However, as seen in the substance P- and [Leu]enkephalin-like immunoreactive structures, these peptides were widely distributed in the nucleus tractus solitarii in addition to the commissural and medial nuclei; a high density of immunoreactive fibers in the ventral, dorsolateral and intermediate subnuclei. In addition to the immunoreactive fiber plexus, a group of immunoreactive cells was also identified in the subnuclei mentioned above. These findings strongly suggest that substance P- and [Leu]enkephalin-like immunoreactive structures are involved not only in cardiovascular function but also in other functions such as respiration, at least in the rat. Finally, the present study demonstrated that the area postrema, particularly its lateral portion, contains various neuropeptide-like structures, both neurons and fibers, substance P-, [Leu]enkephalin-, cholecystokinin-8- and neurotensin-like immunoreactive neurons and fibers, and avian pancreatic polypeptide- and gamma-melanocyte stimulating hormone-like immunoreactive fibers. 相似文献
Aim: AQP4 in the brain is involved in the occurrence and development of a variety of encephalopathy. AQPs family changes in kidney were accompanied by altered UTs family. The aim of this study was to observe AQP4 and UT-A3 expression in CNS and to explore their role in the pathogenesis of endotoxemia encephalopathy following peripheral LPS injection in mice. Methods: Endotoxemia was induced in C57Bl/6 mice by intraperitoneal injection of LPS. The expression of UT-A3 and AQP4 in brain were detected by Western blot and immunohistochemistry, the level of cytokines were detected by ELISA, and the content of LDH, AST/ALT, BUN and CREA were detected by colorimetric method. Results: As compared with the control group, in model group, the brain weight/ body weight ratio increased by 13%. Meanwhile, a 2.5 fold increase in LDH and a 1.2 fold increase in AST/ALT were found in peripheral serum (P < 0.05), and also, BUN and CREA increased 2.5 fold (P < 0.01). In addition to severe CNS injury in response to lipopolysaccharide, the contents of cytokines and the expression of AQP4 protein in hippocampal is increased (P < 0.05), while the expression of UT-A3 protein in the hippocampus and cortical astrocytes decreased (P < 0.05). And, in part, Dexa pretreatment attenuated those effects. Conclusions: In endotoxemia encephalopathy, AQPs and UTs which regulate the functions of cell membrane are both altered. We suggested that the molecular mechanisms of regulation in endotoxemia may provide a new strategy for clinical treatment of the disease and drug binding sites. 相似文献
Based on evidence from differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), and Fourier‐transform infrared (FTIR) spectroscopy, a new stereocomplex crystal (DSC Tm = 175 °C, with WAXD 2θ = 10.0° and 12.5°) is proven for the first time between structurally dissimilar chiral poly(L ‐lactic acid) (PLLA) and syndiotactic poly(methyl methacrylate) (sPMMA). There is a strong complexing capacity only between low molecular weight PLLA and sPMMA, in miscible state, at specific weight fractions (70:30). The complexing capacity is more significant when the mixtures are melt‐crystallized at Tc = 110 °C or lower, and the intensity of this complex can be further enhanced if it is annealed between 100 and 160 °C, below its Tm = 175 °C. The new complex crystal can be formed only between PLLA and sPMMA, but not with isotactic or atactic PMMA. 相似文献
