| 1. |
- De Pergola, G, et al.
(författare)
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Amount of G-protein alpha-subunit in rat white adipocytes: lack of difference between subcutaneous and visceral fat.
- 1993
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Ingår i: Acta endocrinologica. - 0001-5598. ; 129:4, s. 366-70
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Tidskriftsartikel (refereegranskat)abstract
- It has been the purpose of this study to examine possible differences in the amount of stimulatory (Gs) and inhibitory (Gi) G-protein alpha-subunits (measured with a quantitative enzyme-linked immunosorbent assay in fat cell membrane preparation) between subcutaneous and intra-abdominal regions in rats. The lipolytic response to isoproterenol and the number of beta-adrenergic binding sites were also examined. These parameters were all evaluated simultaneously in subcutaneous (inguinal), epididymal and perirenal fat samples collected from six male Sprague-Dawley rats. The membrane contents of the Gs and Gi alpha-subunits were similar in the three depots. Moreover, no difference was found among the different regions with regard to isoproterenol-stimulated glycerol release and beta-adrenoceptor number, expressed per cell number. In conclusion, the present study shows for the first time in rats that the abundance of inhibitory and stimulatory G-protein alpha-subunits is similar in subcutaneous and in visceral adipocytes. Moreover, the number of beta-adrenoceptors and the lipolytic response to isoproterenol do not show significant variations with the anatomical site. As the present results are apparently in contrast with those obtained previously in human adipocytes, there is a possibility that the different results observed in rat and in human fat cells could be explained by species differences.
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| 2. |
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| 3. |
- Kröll, Stefan, et al.
(författare)
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Influence of excited state Pr3+ on the relaxation of the Pr3+-YAlO3 3H4-1D2 transition
- 1991
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Ingår i: Physical Review B (Condensed Matter). - 0163-1829. ; 44:1, s. 30-34
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Tidskriftsartikel (refereegranskat)abstract
- Two-pulse photon-echo measurements on the 0.1 at. % Pr3+:YAlO3 H-3(4)-D-1(2) transition suggest that the relaxation time depends on the density of excited states created by the excitation pulses. The dependence of the relaxation time on the intensity of each excitation pulse shows that our results are inconsistent with instantaneous spectral diffusion, a model often invoked in this type of experiment, where excited states created by the second pulse chiefly influence the relaxation time. A homogeneous linewidth contribution, noted in previous work as being of unknown origin, is eliminated at low excitation fluences.
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| 4. |
- Kröll, Stefan, et al.
(författare)
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Intensity dependent photon echo relaxation in rare earth doped crystals
- 1990
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Ingår i: Physical Review B (Condensed Matter). - 0163-1829. ; 41:16, s. 11568-11571
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Tidskriftsartikel (refereegranskat)abstract
- Photon-echo-relaxation measurements made on the 3H4-3P0 transition of 0.01 at. % Pr3+:YAG (where YAG represents yttrium aluminum garnet), 3H4-1D2 transition in 0.1 at. % Pr3+:YAlO3, and 7F0-5D0 transition in 0.25 at. % Eu3+:YAlO3 show that the photon-echo relaxation rate increases when the intensities of the excitation pulses are increased. Although a part of the relaxation-rate increase in Pr3+:YAG may be attributed to an instantaneous spectral diffusion (ISD) in which the presence of excited neighboring Pr3+ ions change the local field and the absorption frequency of the rare-earth ions, our data deviate significantly from the ISD-model predictions. An additional intensity-dependent relaxation mechanism is required to explain the results.
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| 5. |
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| 6. |
- Xu, E. Y, et al.
(författare)
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Nanosecond image processing using stimulated photon echoes
- 1990
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Ingår i: Optics Letters. - 0146-9592. ; 15:10, s. 562-564
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Tidskriftsartikel (refereegranskat)abstract
- Processing of two-dimensional images on a nanosecond time scale is demonstrated using the stimulated photon echoes in a rare-earth-doped crystal (0.1 at. \% Pr3$+$:LaF3). Two spatially encoded laser pulses (pictures) resonant with the 3P0-3H4 transition of Pr3$+$ were stored by focusing the image pulses sequentially into the Pr3$+$:LaF3 crystal. The stored information is retrieved and processed by a third read pulse, generating the echo that is the spatial convolution or correlation of the input images. Application of this scheme to high-speed pattern recognition is discussed.
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| 7. |
- Xu, S Y, et al.
(författare)
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Purification and characterization of a human neutrophil lipocalin (HNL) from the secondary granules of human neutrophils
- 1994
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - 0036-5513 .- 1502-7686. ; 54:5, s. 365-376
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Tidskriftsartikel (refereegranskat)abstract
- A 45 kDa-protein was purified from the granules of human neutrophils. The protein consists of two apparently identical subunits. The isoelectric point was pH8.40, and the molecular weight 45kDa (unreduced) or 24kDa (reduced). Treatment of the protein with Endoglucosidase F resulted in a reduction in the molecular weight to 20 kDa, indicating the presence of N-linked carbohydrate. The extinction coefficient was E1%lcm = 13.76 at 280nm. The 60 amino acid sequence revealed up to 65% sequence homology with rat α2-microglobulin-related protein, which belongs to the lipocalin family. The protein co-sedimented with secondary (specific) granule marker proteins and correlated to the neutrophil content of Lactoferrin (r = 0.81,p<0.001) and was estimated to be 0.59 fig 10-6 cells. Release studies showed that the neutrophils released 51.4 ± 9.0% of the total cellular content of the protein when they were exposed to serum-opsonized particles, which was much higher than the release of Myeloperoxidase (12.7 ±3.5%) and Lactoferrin (22.9 ± 4.7%). The N-terminal and four tryptic fragment amino acid sequence of the protein was identical with an N-formyl peptide binding 24 kDa protein and gelatinase associated protein of human neutrophils. In conclusion, we have purified and characterized a protein, human neutrophil lipocalin (HNL), from the secondary granules of human neutrophils and shown that it is readily mobilized from the neutrophils upon stimulation.
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