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951.
RA Cusick H Lee K Sano JM Pollok H Utsunomiya PX Ma R Langer JP Vacanti 《Canadian Metallurgical Quarterly》1997,32(2):357-360
A novel treatment for end-stage liver disease using heterotopic hepatocyte transplantation on biodegradable polymers has been investigated. Survival and repopulation of adequate cell mass to replace hepatic function has been the principal difficulty of this method. Hence the authors have begun to investigate the role of donor and recipient age on the efficiency of hepatocyte transplantation. Lewis rats were used as donors and recipients. Hepatocytes were isolated with a collagenase digestion, both for the adult and fetal livers (17 days estimated gestational age). After digestion, the hepatocytes were seeded onto 95% porous poly-(L)-lactic acid matrices. The polymer-cell constructs with adult or fetal cells were then implanted between mesenteric leaves of three different recipient groups: adults (approximately 200 g), 2-week, and 4-week neonates (two to five animals per group, depending on litter size). The specimens were harvested at 4 weeks, stained with Hematoxylin and Eosin (H&E), and the cell area of each specimen (24 sections per group) was quantitated using morphometric analysis. Results were statistically analyzed using an unpaired, two-tailed Student's t test. At 4 weeks, all specimens showed survival of groups of hepatocytes, especially along the periphery of the polymers and near blood vessels. The hepatocyte cell area for the six groups was calculated in square micrometers: the adult cells transplanted into adult recipients, 0.16 x 10(5) microns2; fetal cells into adults, 0.47 x 10(5) microns2; adult into 4-week neonates, 1.17 x 10(5) microns2; fetal into 4-week neonates, 4.54 x 10(5) microns2; adult into 2-week neonates, 2.98 x 10(5) microns2, and fetal into 2-week neonates, 5.81 x 10(5) microns2. In all three recipient groups, the area of fetal hepatocytes was approximately two to three times the area of the adult hepatocytes (P < .05 for 2-week and 4-week neonatal recipients, P = .06 for adult recipients). Also, as the recipient age decreased, there was an increase in the hepatocyte cell area (P < .05 for fetal or adult groups). The authors conclude that fetal hepatocytes heterotopically transplanted have a significant survival advantage over adult hepatocytes, independent of recipient age. The authors further conclude that the neonatal environment is more favorable than the adult environment for implantation of hepatocytes. 相似文献
952.
953.
Thin films of BN were prepared by chemical vapour deposition onto fused silica and sapphire using the reaction of BCl3 with NH3. The temperature of the substrate was varied between 600 and 1100°C. Transparent and smooth films of BN were obtained on fused silica and sapphire at substrate temperatures of 1000–1100°C. The growth rate of the film on sapphire was about 1 μm h?1, and the growth rate on fused silica was about one-half that on sapphire. The films were chemically inert and adherent to the substrate. The absorption of the BN film was measured at room temperature. In the near-UV region, the main absorption peak was at about 6.2 eV and a sharp drop occurred near 5.8 eV. The sharp drop is attributed to the direct band gap. The photoluminescence of the films was measured at room temperature by excitation with light of wavelength 254 nm. A broad emission with a peak near 360 nm was observed. 相似文献
954.
955.
956.
In this paper the multiconriguration self-consistent field method with configuration interaction is first described. Then
this method is applied to YBa2Cu3O7 (YBCO7) compound, and the key features of the calculated electronic structure are discussed and compared with those of La2-xSrxCuO4 (LSCO) compounds previously calculated by Kamimura and Eto and also by Kamimura and Suwa. In LSCO the key feature of the
electronic state in the superconducting regime is a coherent state in a local antiferromagnetic (AF) order in which Zhan-Rice’s
spinsinglet state and the spin-triplet state due to Hund’s coupling appear alternately. In the present paper it is pointed
out that, in order to realize such coherent state in YBCO7, the charge of Cu ion in the Cu-0 chain must be in between 1.3 and 2.0. Finally, the important results of the effective one-electron-type
band structure, Fermi surfaces, the electron-phonon coupling constants, and the momentum-dependent spectral function calculated
for LSCO by Kamimura, Matsuno, Suwa, and Ushio are reviewed, and following them it is stated that even the phonon mechanism
gives rise tod-wave pairing when the AF local order exists. 相似文献
957.
958.
AIMS: The aim of the study was to obtain further information regarding the modes of action of doxazosin, naftopidil and nifedipine on platelet function. METHODS: We conducted an in vitro study of drug influences on adrenaline and collagen-induced mobilization of platelet calcium. RESULTS: In the presence of fibrinogen (300 micrograms ml-1) both collagen (5 micrograms ml-1) and adrenaline (16 microM) stimulated the aggregation of washed platelets. Collagen induced a transient rise (+4.97 +/- 0.63 microM) in platelet Ca2+ concentration, [Ca2+]i, as measured using the photoprotein aequorin, which coincided with the onset of aggregation. Adrenaline induced a smaller rise (+3.6 +/- 0.96 microM) which, however, occurred after the onset of aggregation. Naftopidil, an alpha 1-adrenoreceptor antagonist produced a concentration-dependent inhibition of collagen-induced Ca2+ mobilization, maximum inhibition (22.9 +/- 4%, P < 0.05) occurring with 40 microM naftopidil. The inhibition of Ca2+ mobilization was not reflected by a concentration-dependent inhibition of platelet aggregation, although 40 microM naftopidil produced statistically significant inhibition (23.3 +/- 11.7%, P < 0.05). The adrenaline-induced rise in [Ca2+]i was inhibited dose dependently by naftopidil (e.g. 40 microM naftopidil, 100 +/- 0%, P < 0.05), as was aggregation (40 microM naftopidil, 100 +/- 0%, P < 0.05). Doxazosin, another alpha 1-adrenoreceptor blocker, inhibited Ca2+ mobilization induced by collagen to similar extents as for naftopidil (30 microM doxazosin, 17.4 +/- 2.5%, P < 0.05), but did not inhibit platelet aggregation. It also inhibited the adrenaline-induced rise in [Ca2+]i in a concentration-dependent manner (30 microM doxazosin, 37.6 +/- 13.7%, P < 0.05), significant inhibitions of platelet aggregation also being produced (30 microM, 49.6 +/- 17.2%, P < 0.05). As expected, the calcium channel blocker nifedipine produced concentration-dependent inhibitions of both collagen-induced Ca2+ mobilization (e.g. 28 microM nifedipine, 47.8 +/- 2.7%, P < 0.05) and aggregation (28 microM, 55.1 +/- 9.2%, P < 0.05). CONCLUSIONS: These data indicate that the alpha 1-adrenoreceptor blockers, naftopidil and doxazosin, inhibit Ca2+ mobilization, this mechanism being possibly the means whereby these drugs inhibit platelet aggregation. 相似文献
959.
T Matsuzawa H Saitoh M Sano I Tomita M Ohkawa T Ikekawa 《Canadian Metallurgical Quarterly》1998,118(10):476-481
The in vivo effect of Hypsizigus marmoreus on the plasma antioxidant status of tumor-bearing mice was examined. Female DBA/2 mice treated with subcutaneous injection of 3-methylcholanthrene were fed on a basal diet (CE-2) or CE-2 containing 5% fruit bodies of the mushroom for 76 weeks. Antioxidant activities (AOA) of mice with tumor were significantly higher than those of mice without tumor. The high levels of AOA were attributable to the increase of high molecular weight AOA in the plasma. A similar increase in plasma AOA was also observed in sarcoma-180 solid tumor-bearing mice. The mushroom feeding exhibited a potent antitumor effect and caused a significant decrease in lipid peroxide levels (as thiobarbituric acid reactive substances; TBARS). These results suggest that the increase of AOA in the plasma of tumor-bearing mice is one of the mechanism of cancer preventive effects and also suggest that Hypsizigus marmoreus might play a role in decreasing TBARS by controlling AOA induction. 相似文献
960.
T Asano O Namikawa A Yamamoto T Sano J Mukai K Kawaji M Kobayashi 《Canadian Metallurgical Quarterly》1998,36(9):771-775
A 78-year-old man was admitted to hospital with heart failure and chronic bronchitis. A computed tomographic scan of the chest incidentally demonstrated bilateral abnormal vessels near the left atrium. Selective angiography showed that both internal mammary arteries and bronchial arteries communicated with the pulmonary arteries bilaterally. The patient refused surgery and was discharged on medical therapy. This is the first reported case of bilateral fistulas between the internal mammary arteries and bronchial arteries and the pulmonary arteries. 相似文献