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991.
The present study investigated the phototoxic effect of bergamot oil and its photosensitive component, bergapten, on sunburn cell (SBC) production in guinea pig skin. The back skin was pretreated with bergamot oil or bergapten and exposed to monochromatic light under various conditions. After irradiation, skin specimens were excised, and histological sections were prepared. The number of sunburn cells in the interfollicular epidermis was counted. The SBC formation by bergamot oil or bergapten plus UVB radiation was the same as that without pretreatment with any photosensitizer. In contrast, a significant number of SBCs were induced by bergamot oil or bergapten plus UVA radiation, but no SBCs were found after the treatment with UVA alone. The result indicates that bergamot oil or bergapten was photosensitized by UVA irradiation. The SBCs were linearly increased in a UV-dose dependent manner. On the basis of the regression lines, an action spectrum and spectral peak for the photosensitizers plus UVA were obtained. The action spectrum for bergamot oil- and bergapten-induced SBC formation was in the ranges of 325–365 nm and 325–350 nm, and their spectral peaks were at 335–345 nm and 335–350 nm, respectively. The data are in good accordance with those estimated from skin erythema reactions. Therefore, counting SBCs is a very useful parameter for quantitative evaluation of phototoxicity. 相似文献
992.
Masayoshi Johno Munashi Oishi Masahiro Kohmaru Kohji Yoshimura Tomomichi Ono 《The Journal of dermatology》1994,21(3):197-204
A boy with skin eruptions resembling varicella and specific for Langerhans cell histiocytosis (LCH) is reported. At his initial visit when he was four months old, vesiculopustular lesions were present over the entire body; these had first appeared on the third day post partus. Histopathological, immunohistochemical, and electron microscopical examination confirmed the Langerhans cell phenotype and Birbeck granules in the responsible cells. He also had hydronephrosis, recurrent fever, and cutaneous bacterial infections. His parents refused further medical treatment and he died of diarrhea with cachexia about two years later. LCH may present diagnostic difficulties by manifesting as a skin eruption which resembles varicella. 相似文献
993.
994.
In the analysis of 40 CEPH families, under the EUROGEM project, with a total of 29 microsatellites (26 CA-repeats, a TCTA-repeat within the vWFII-3 gene, a TTA-repeat within the PLA-2 gene, and an AAAT-repeat intragenic to the NF1 gene) from human chromosomes 12, 17, and 21, we have detected 21 cases of abnormal segregation of alleles in 16 pedigrees for a total of 14 markers (48%). In 11 cases, the abnormal transmissions were of somatic origin, 10 of which (91%) occurred in the lymphoblastoid cell lines. In 9 other cases, it was not possible to determine if the origin of the new alleles was somatic or germline, and in one case hemizygosity in several family members was observed, so its origin was germline. The 20 new mutations detected in the 22,852 meioses analysed represent a mutation frequency of 8.7 × 10?4 per locus per allele. The germline mutation rate could be as high as 3.9 × 10?4 per locus per gamete (from 0 to 3.9 × 10?4), but the rate of somatic mutations detected in the study was much higher (4.8 × 10?4 to 8.7 × 10?4 per locus per allele). Individual mutation rates ranged from 0 to 3.8 × 10?3. Among the markers analysed, all three that were tri- or tetranucleotide repeats showed one or two new alleles, compared to only 10 of the 26 (38%) CA-repeats showing mutations. Three CEPH families (102, 45 and 1333) each had several mutational events, and one individual (10210) had somatic mutations for two microsatellites from different chromosomes. The mutation rate at microsatellite loci within families, using DNA directly obtained from cells from the individual, is less than 1 × 10?4 (true germline mutation rate), which should not affect the use of these markers in diagnosis and linkage. However, these results and previous data suggest that for DNA obtained from cell lines, mutations are much more frequent (1 × 10?2?1 × 10?3). © 1994 Wiley-Liss, Inc. 相似文献
995.
Nodular hyperplasia surrounding fibrolamellar carcinoma 总被引:2,自引:0,他引:2
We report a case of acetaminophen-induced liver necrosis in a 14-year-old girl. At autopsy, a 9 cm subcapsular nodule was present in the right lobe of the liver which showed distinct zonation: a central greyish white area of fibrolamellar carcinoma with a peripheral fleshy, tan-coloured rim ranging from 1 to 2 cm in thickness. This peripheral zone consisted of nodular, hyperplastic parenchyma resembling the changes seen in focal nodular hyperplasia, and stood out from the adjacent necrotic parenchyma. The sparing of this zone from the deleterious effects of acetaminophen provides indirect evidence of a predominantly arterial rather than portal blood supply to this region. The arterial supply was most probably derived from the tumour vasculature and may explain the parenchymal hyperplasia sometimes reported adjacent to a fibrolamellar carcinoma. Awareness of this phenomenon is essential when evaluating a needle biopsy, as sampling of this region may lead to a false negative diagnosis. 相似文献
996.
997.
目的 以腺病毒介导gax基因转染血管平滑肌细胞 (VSMC) ,增强VSMC中gax基因的表达。方法 采用位置特异性重组方法构建携带大鼠 gax基因表达序列的复制缺陷型 5型腺病毒载体(AdCMV gax) ,经 2 93细胞扩增 ,纯化制备高滴度病毒转染液 ;以病毒转染液常规转染VSMC后 ,应用RT PCR、流式细胞仪和免疫细胞化学等方法分别检测VSMC中 gaxmRNA和蛋白质的表达。 结果 流式细胞仪检测和免疫细胞化学染色均显示AdCMV gax转染VSMC后 ,VSMC的Gax蛋白表达率明显增高 ,转染后 2 4小时即可达 80 %左右 ,高水平的表达可维持 5天以上 ;AdCMV gax转染前 ,PDGF BB对gax基因转录和翻译水平的表达均有下调作用 ,AdCMV gax转染后 ,无论有无PDGF BB刺激 ,VSMC中 gax基因的表达均比转染前显著增高。 结论 腺病毒载体可有效地介导 gax基因转染VSMC ,并且表达为蛋白质。这有利于进一步研究 gax基因对VSMC生物学行为的影响 相似文献
998.
Summary In this study the technique of labelling the cell membrane with DPH fluorescence polarization was used to observe the membrane
fluidity of B lymphocytic cell lines and tonsillar cells from healthy persons; the modulation effect on membrane-fluidity
induced by McAbs against isotypic and idiotypic determinants of IgM from patients with leukemia was studied as well. The expression
of the corresponding isotypic and idiotypic determinants of IgM on the cell membrane was determined. The results show that
the membrane fluidity of leukemic cell lines is remarkably higher than that of tonsillar cells from healthy persons, and McAbs
against isotypic determinants of leukemic IgM can enhance the membrane fluidity of all kinds of cells mentioned above. However,
the anti-idiotypic monoclonal antibody increased only the membrane fluidity of leukemic cell lines. These results indicated
that there was a close relationship between the effect of McAbs on cell membrane fluidity and the expression of corresponding
isotypic and idiotypic determinants of IgM on the cell membrane. 相似文献
999.
Clonal deletion and anergy are two major mechanisms of self-tolerance. However, the molecular mechanisms underlying clonal deletion and anergy, as well as the threshold of TCR affinity/avidity required for these processes, are not known. Expression of the V beta 8.1 TCR correlates with the reactivity of the T cells to the minor lymphocyte stimulating locus-1a (Mls-1a) and T cells expressing this TCR are deleted in the thymus of Mls-1a mice. Similarly, in TCR V beta 8.1 transgenic mice, the number of CD4+CD8-T cells is reduced in Mls-1a mice. However, small numbers of CD4+CD8-T cells remain in the periphery of adult Mls-1a transgenic mice. We have generated T cell clones from TCR V beta 8.1 transgenic mice by stimulation of lymph node T cells with C57BL/6 alloantigens. Interestingly, CD4+CD8-V beta 8.1+ clones isolated from the transgenic mice of Mls-1a background responded to the self-antigen Mls-1a, to which they did not respond in primary assay. Reactive patterns of the clones were compared with clones derived from Mls-1b mice. Proliferation and cytokine production of the clones from Mls-1a mice to the self-antigen Mls-1a were generally reduced when compared with clones from Mls-1b mice. More importantly, T cell clones from Mls-1a mice required more Mls-1a antigen for their activation, and were more susceptible to the inhibitory effects of anti-CD4 antibody on the proliferative responses to Mls-1a than those from Mls-1b mice. These results suggest that the T cell receptor on clones derived from Mls-1a mice have functional but reduced affinity/avidity for self-antigen Mls-1a. 相似文献
1000.