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Characterization of the adipose tissue atrophy induced by peroxisome proliferators in mice 总被引:4,自引:0,他引:4
In the present study, we characterized the effects of peroxisome proliferators (PP) on adipose tissue in mice. Treatment with
potent PP, such as perfluorooctanoic acid (PFOA), 2-methyl-2-(p(1,2,3,4-tetrahydroxy-naphthyl)-phenoxy)propionic acid, (4-chloro-6-(2,3-xylidino)2-pyrimidinylthio) acetic acid, and di(2-ethylhexyl)phthalate,
caused dramatic decreases in adipose tissue weight, whereas the moderately potent PP, acetylsalicylic acid, had a relatively
weak effect. This decrease in weight reflects a loss of fat from adipocytes rather than a loss of cells, as demonstrated by
constant DNA content. The dose-dependency and time-course experiments indicate that peroxisome proliferation occurs simultaneously
with or prior to adipose tissue atrophy. Thus, hepatic peroxisome proliferation might result in the increased mobilization
of lipids and lipid utilization in liver. The enhanced adipose tissue hormonesensitive lipase (HSL) activity and down-regulated
lipoprotein lipase (LPL) activity observed upon PP treatment might, at least in part, explain the loss of fat via increase FA release from adipocytes and/or decreased FA uptake from the circulation, respectively. In addition, the possible
involvement of the increased tumor necrosis factor α expression found upon PFOA treatment in reducing the insulin sensitivity
of adipose tissue and thereby altering LPL and HSL activities is discussed. 相似文献
5.
Garrett BC Dixon DA Camaioni DM Chipman DM Johnson MA Jonah CD Kimmel GA Miller JH Rescigno TN Rossky PJ Xantheas SS Colson SD Laufer AH Ray D Barbara PF Bartels DM Becker KH Bowen KH Bradforth SE Carmichael I Coe JV Corrales LR Cowin JP Dupuis M Eisenthal KB Franz JA Gutowski MS Jordan KD Kay BD Laverne JA Lymar SV Madey TE McCurdy CW Meisel D Mukamel S Nilsson AR Orlando TM Petrik NG Pimblott SM Rustad JR Schenter GK Singer SJ Tokmakoff A Wang LS Wettig C Zwier TS 《Chemical reviews》2005,105(1):355-390
6.
A novel optical interconnection is introduced for a multistage optical switching network that uses orthogonally polarized data and address information. The network is unique in that the data information is never regenerated and remains in optical form throughout (i.e., it is never converted into electrical information). This has two main consequences: (1) the bandwidth of the data is not restricted by electrical circuit considerations, and (2) the optical interconnections from one stage of the network to the next must be highly efficient. The interconnection meets several goals: high efficiency, preservation of cross polarization of data and address, low cross talk between polarizations, good manufacturability, resistance to misalignment caused by thermal expansion, and absence of significant aberrations. In addition, sychronization of the signals is maintained, as the optical path lengths for all routes through the system are equal. 相似文献
7.
Highly sensitive detection of neutral Kr atoms was accomplished by the use of laser-induced fluorescence. In one experiment, Kr at 40 parts per 10(12) in He was detected at a signal-to-noise ratio of 500 by time-resolved fluorescence measurements. The Kr metastable 1s(5) level was populated by cascade after two-photon excitation to the 2p(6) level by the frequency-tripled output of a pulsed single-longitudinalmode dye laser. After a delay, when scattered laser light and cascade resonance fluorescence became negligible, trace quantities of Kr were detected by the use of a pulsed-laser pumping scheme. In a related experiment, (78)Kr/(86)Kr isotope ratios ranging from 1 to 0.1 were measured with a resonant isotopic depletion technique first proposed by Makarov [Sov. J. Quantum Electron. 13, 722 (1983)]. The (86)Kr metastable population was selectively depleted by optical pumping to a higher-lying state that relaxed to the ground state by means of radiative cascade. After the (78)Kr/(86)Kr ratio of metastables had been enriched by a factor of 10, the (78)Kr population was probed by pulsed excitation. Premixed (78)Kr/(86)Kr ratios were measured to within an accuracy of 10%, even for unresolved, Doppler-broadened transitions. 相似文献
8.
The gradual reorientations in crystal geometry encountered during angle-multiplexed holographic recording with obliquely incident recording beams can create significant parametric exposure-time and recording-angle dependencies in both grating writing- and erasure-time constants. We present a parametric extension of the classically derived backward-recursion algorithm that compensates for the intermingling effects of recording geometry, writing-beam intensity variations, and unique crystal behavior. We present experimental data for a sequence of 301 holograms recorded with the goal of equal hologram strength and, separately, the same sequence recorded with the goal of equal hologram reconstruction intensity-which are different cases for a steeply incident readout beam. 相似文献
9.
Sheep shearers are known to work in sustained flexed postures and have a high prevalence of low back pain (LBP). As sustained posture and spinal movement asymmetry under substantial loads are known risk factors for back injury our aim was to describe the 3D spinal movement of shearers while working. We hypothesised that thoraco-lumbar and lumbo-sacral movement would be tri-axial, asymmetric, and task specific. Sufficient retro-reflective markers were placed on the trunk of 12 shearers to define thoraco-lumbar and lumbo-sacral 3D motion during three tasks. Thoraco-lumbar movement consistently involved flexion, left lateral flexion, and right rotation. Lumbo-sacral movement consistently involved right lateral flexion in flexion with minimal rotation. Shearers therefore work in sustained spinal flexion where concurrent, asymmetric spinal movements into both lateral flexion and rotation occur. These asymmetric movements combined with repetitive loading may be risk factors leading to the high incidence of LBP in this occupational group. 相似文献
10.