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排序方式: 共有889条查询结果,搜索用时 15 毫秒
1.
Braffman BH; Coleman BG; Ramchandani P; Arger PH; Nodine CF; Dinsmore BJ; Louie A; Betsch SE 《Radiology》1994,190(3):797
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Rupture of the distal biceps tendon: evaluation with MR imaging 总被引:2,自引:0,他引:2
4.
B M Almeida S J Challacombe J W Eveson C G Smith I M Leigh 《The Journal of pathology》1992,166(3):243-253
The murine monoclonal antibody, LH39 was characterized in this study and appeared to bind to a novel basement membrane epitope. This antigen was expressed in the epithelial basement membrane of human tissue derived from all three germ cell layers and in basement membranes surrounding small blood vessels within the stroma of all organs examined. LH39 antigen could be first detected in fetal skin at the dermo-epidermal junction at 7 weeks estimated gestational age but was not present in the dermal vasculature until 16 weeks. When tested against tissue from a range of lower mammalian species, LH39 antigen appeared to be primate-specific. The epithelial basement membrane zone in organotypical cultures, where there is de novo synthesis of basement membrane components, contained abundant LH39 antigen in contrast to other basement membrane components, type IV collagen, laminin, and type VII collagen. Ultrastructural localization of LH39 epitope, using immunogold electron microscopy on unfixed freshly frozen tissue, was to the lamina lucida. No cross-reactivity could be detected between LH39 and laminin, fibronectin, and collagens I, III, IV, and V using the ELISA assay. In vitro studies with a range of proteolytic enzymes suggested that the antigen was non-collagenous in nature. LH39 precipitated a polypeptide with a molecular weight of 185 kD from extracts of metabolically labelled cultured keratinocytes, and polypeptides of 185 and 200 kD from the culture medium. The tissue distribution of LH39 antigen suggested that it may be an epitope within anchoring filaments. Potential applications of this antibody include the study of benign and malignant human vascular disorders, diseases and tumours associated with angiogenesis, epithelial neoplasms, and conditions of tissue regeneration and repair, such as wound healing. 相似文献
5.
Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献
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B D Williams S J Challacombe J M Slaney P J Lachmann T Lehner 《Clinical and experimental immunology》1975,19(3):423-423
High titres of immunoconglutinin activity (antibody to bound complement components) have been found in the parotid, sublingual and submandibular saliva of most healthy subjects. The immunoconglutinin (IK) titre in mixed saliva was substantially lower than in the other samples of saliva. C3 was detectable in only three of 164 samples of parotid, submandibular and sublingual saliva but was present in forty-seven of 117 mixed saliva samples. It is suggested that crevicular fluid is the major source of C3 in mixed saliva. A negative correlation was found in mixed saliva between the C3 concentration and the IK titre, and this suggested that C3 was the inhibitor of IK in mixed saliva. Binding of C3 to IK has been demonstrated in mixed saliva by using highly purified salivary IK and C3. Purified C3, C3i, C3c and C3d inhibited the activity of purified IK. It is suggested that salivary IK represents the secretion of a B-lymphocyte population which has evaded the mechanism responsible for inducing B-cell tolerance to autologous serum proteins. The reason for its persistence in the salivary glands, however, is not known at present. 相似文献
8.
Increased tissue concentrations of histamine in the duodenal mucosa of children with coeliac disease.
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Tissue concentrations of histamine have been estimated in peroral duodenal biopsy specimens from five children with coeliac disease while on a gluten-free diet and after a three-month gluten challenge. Histamine concentrations in the patients on a diet did not differ significantly from a group of control children. However after gluten challenge, histological relapse of the duodenal mucosa in each patient was associated with increased tissue concentrations of histamine. The findings suggest that histamine may be involved in the pathogenesis of the small intestinal mucosal changes in children with coeliac disease. 相似文献
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10.
It is well recognized that the ability to cryopreserve unfertilizedhuman oocytes would make a significant contribution to infertilitytreatment. However, despite considerable interest, very fewsuccessful pregnancies have arisen from cryopreserved oocytesafter thawing, insemination and transfer of the subsequent embryo.The reasons for this lack of progress may well result from adearth of information on how the various biophysical changesduring a cryopreservation regimen affect human oocyte function.Recently, fundamental studies on the effects of cooling, membranepermeability, cryoprotectant addition and ice formation havebeen performed on human oocytes by a number of groups, and theseform the basis of the current review. It is likely that successfulhuman oocyte cryopreservation will only follow once these factorsare fully understood, but the existing base of knowledge shouldprovide a platform for further improvements in the techniquescurrently employed. 相似文献