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1.
Bayrak S; Holmdahl R; Travers P; Lauster R; Hesse M; Dolling R; Mitchison NA 《International immunology》1997,9(11):1687-1699
Type II collagen (CII) is of immunological interest because of its
repetitive structure and properties as an autoantigen. The mouse gene has
recently been cloned, thus enabling T cell-defined epitopes to be
identified. Multiple novel epitopes on mouse CII are here detected in the
autoreactive T cell response. The major response is directed to an epitope
with residues 707-721 located on the CB10 fragment. Some 25 other epitopes
are also recognized, including the autologous homologue of the 256-270
epitope which dominates in the response to foreign collagen. The cells
reactive with mouse collagen peptides were of Th1 type, as judged by
release of IFN-gamma. No significant reactivity was detected to mouse CII
peptides during ongoing disease. Alignment of the mouse epitopes revealed a
sequence motif with characteristic side chains at residues P1, P4 and P7,
and to a lesser extent at P5, within a nonamer core sequence. Binding of
these epitopes was simulated in a computer model of the I-Aq molecule,
where peptides with anchor residues at P1, P4 and P7 were indeed found to
fit the binding groove best. The spacing of pockets and the fine structure
of the binding surface of the I-Aq molecule meshes with the repetitive
structure of the collagen (X-Y-Gly), thus providing a likely explanation
for the occurrence of multiple epitopes. Comparison with human DR binding
motifs showed that the I-Aq motif resembles most closely that of the DR4
subtypes which predispose for rheumatoid arthritis.
相似文献
2.
3.
Dal Zotto L; Quaderi NA; Elliott R; Lingerfelter PA; Carrel L; Valsecchi V; Montini E; Yen CH; Chapman V; Kalcheva I; Arrigo G; Zuffardi O; Thomas S; Willard HF; Ballabio A; Disteche CM; Rugarli EI 《Human molecular genetics》1998,7(3):489-499
We have recently reported isolation of the gene responsible for X- linked
Opitz G/BBB syndrome, a defect of midline development. MID1 is located on
the distal short arm of the human X chromosome (Xp22. 3) and encodes a
novel member of the B box family of zinc finger proteins. We have now
cloned the murine homolog of MID1 and performed preliminary expression
studies during development. Mid1 expression in undifferentiated cells in
the central nervous, gastrointestinal and urogenital systems suggests that
abnormal cell proliferation may underlie the defect in midline development
characteristic of Opitz syndrome. We have also found that Mid1 is located
within the mouse pseudoautosomal region (PAR) in Mus musculus , while it
seems to be X- specific in Mus spretus. Therefore, Mid1 is likely to be a
recent acquisition of the M. musculus PAR. Genetic and FISH analyses also
demonstrated a high frequency of unequal crossovers in the murine PAR,
creating spontaneous deletion/duplication events involving Mid1. These data
provide evidence for the first time that genetic instability of the PAR may
affect functionally important genes. In addition, we show that MID1 is the
first example of a gene subject to X-inactivation in man while escaping it
in mouse. These data contribute to a better understanding of the molecular
content and evolution of the rodent PAR.
相似文献
4.
Interchromosomal duplications of the adrenoleukodystrophy locus: a phenomenon of pericentromeric plasticity 总被引:13,自引:5,他引:13
Eichler EE; Budarf ML; Rocchi M; Deaven LL; Doggett NA; Baldini A; Nelson DL; Mohrenweiser HW 《Human molecular genetics》1997,6(7):991-1002
A 9.7 kb segment encompassing exons 7-10 of the adrenoleukodystrophy (ALD)
locus of the X chromosome has duplicated to specific locations near the
pericentromeric regions of human chromosomes 2p11,10p11, 16p11 and 22q11.
Comparative sequence analysis reveals 92-96% nucleotide identity,
indicating that the autosomal ALD paralogs arose relatively recently during
the course of higher primate evolution (5-10 million years ago). Analysis
of sequences flanking the duplication region identifies the presence of an
unusual GCTTTTTGC repeat which may be a sequence-specific integration site
for the process of pericentromeric- directed transposition. The breakpoint
sequence and phylogenetic analysis predict a two-step transposition model,
in which a duplication from Xq28 to pericentromeric 2p11 occurred once,
followed by a rapid distribution of a larger duplicon cassette among the
pericentromeric regions. In addition to facilitating more effective
mutation detection among ALD patients, these findings provide further
insight into the molecular basis underlying a pericentromeric-directed
mechanism for non- homologous interchromosomal exchange.
相似文献
5.
p53 immunoreactivity in hepatocellular adenoma, focal nodular hyperplasia, cirrhosis and hepatocellular carcinoma 总被引:2,自引:0,他引:2
I. OJANGUREN A. ARIZA E.M. CASTELLÀ A. FERNÁNDEZ-VASALO J.L. MATE J.J. NA VAS-PALACIOS 《Histopathology》1995,26(1):63-68
The prolonged half-life of mutant p53 makes feasible its immunocytochemical detection. In order to assess the pathogenetic role of mutant p53 in regenerative and neoplastc liver disease we studied its immunohistochemical expression in cases of hepatic cirrhosis, hepatocellular carcinoma (HCC), cirrhosis with areas of HCC, hepatocellular adenoma and focal nodular hyperplasia. The study included needle and wedge biopsies of 50 cirrhotic livers, 59 HCCs (36 of them with associated cirrhosis), six adenomas and two focal nodular hyperplasias. Sixty-five HCC fineneedle cytology specimens were also included in the study. There was no immunohistochemical evidence of mutant p53 expression in any of the cases of cirrhotic liver (except for one instance associated with HCC) adenoma or focal nodular hyperplasia. In contrast p53 was detected in 8.5% of HCC cases in the biopsy series and 24% of HCC cases in the fine needle aspiration series. In addition, mutant p53 expression in HCC was positively correlated with tumour grade. According to grade, the distribution of p53 positive immunoreactivity among HCCs was as follows: Grade I-II, 0% of cases in the biopsy series and 9% in the fine needle aspirates; Grade III, 18% in the biopsy series and 55% in the fine needle aspirates; and Grade IV, 40% in the biopsy series. Therefore, mutant p53 expression does not seem to be associated with benign liver lesions but seems to correlate with the progression of HCC through various grades of increasing malignancy. 相似文献
6.
7.
Three triploid infants, two male (69,XXY) and one female (69,XXX) all of which survived beyond 35 weeks' gestation are described. One was stillborn due to a difficult delivery, the other two survived for a few hours only. Two were of relatively low birth weight, the other was normal. There was no evidence of mosaicism in the tissue examined.
In keeping with previously reported triploid infants they showed a variety of abnormalities. From a total of 13 cases now reported the more frequent associated anomalies are low set ears, coloboma of the iris, syndactyly of the hands, a single palmar crease, abnormal male genitalia in XXY individuals, polycystic kidney, and congenital heart defect. The most common anomaly, however, is hydatidiform degeneration of a large placenta.
相似文献8.
An in vitro assay was used to determine the effects of conditioning nerve lesions on the regeneration of adult rat retinal ganglion cell (RGC) axons from retinal explants. Following the conditioning lesion (CL) of unilateral optic nerve transection, maximal regrowth was seen from RGC explanted from ipsilateral retinae 10 days post-CL. Explants from this group initiated axonal regrowth earlier and a greater percentage regrew axons when compared with explants from normal rats. Axonal regrowth from explants of retinae contralateral to CL was also seen earlier than normal. In further experiments, the effects of both exposure of the optic nerve sheath in the orbit and the incision of the dura without injury to optic nerve axons were studied. The conditioning effect of a dural incision was found to be the same as that of optic nerve transection, whilst exposure of the optic nerve sheath had no conditioning effect on RGC axonal regrowth in vitro. 相似文献
9.
目的 分析放射工作者外周血象、淋巴细胞微核及染色体畸变情况,为放射工作者职业防护和健康监测提供依据。方法 对2015年、2017年和2019年连续3次接受健康检查的127名放射工作者进行淋巴细胞微核、染色体及血象分析,将其设为放射组。另外选取133名无射线接触史的医务人员设为对照组;结果 放射组中淋巴细胞微核率和染色体畸变率高于对照组,白细胞和血小板计数低于对照组,均具有统计学意义(P < 0.05)。127名放射工作者外周血白细胞总数随着接触电离辐射时间的增长逐渐降低,染色体畸变率逐渐增加,均具有统计学意义(P < 0.05)。损害工龄大于20年的放射工作者染色体畸变率高于低工龄组,不同损害工龄之间比较无统计学意义(P > 0.05)。核医学与介入治疗工种染色体畸变率高于其他工种,具有统计学意义(P < 0.05)。结论 长时间接触低剂量电离辐射可使放射工作者白细胞总数降低和淋巴细胞染色体畸变率增加,应加强放射工作者防护措施以备降低电离辐射损伤程度,特别要加强核医学和介入治疗放射工作人员的职业防护。 相似文献
10.
彩色多普勒超声心动图诊断肺心病的临床价值 总被引:1,自引:1,他引:0
目的:阐述彩色多普勒超声心动图(CDE)诊断肺心病的临床价值。方法:通过CDE对临床上拟诊的肺心病患者进行肺动脉高压(PH)定性、定量的诊断、并观测由PH继发引起心脏在CDE上的异常改变。结果:CDE测定PH44例(88%),其肺动脉收缩压(SPAP)>36mmHg,6例(32mmHg≤SPAP<36mmHg,确诊CPM的临床符合率665(50/76)。结论作为无创性诊技术,CDE估测PH或诊断CPM准确简便,重复性强,对于指导临床治疗意义重大。 相似文献