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1.
Abdominal Radiology - 相似文献
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Oscillatory motion of the normal cervical spinal cord 总被引:2,自引:0,他引:2
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Mutational analysis of the SOX9 gene in campomelic dysplasia and autosomal sex reversal: lack of genotype/phenotype correlations 总被引:9,自引:1,他引:9
Meyer J; Sudbeck P; Held M; Wagner T; Schmitz ML; Bricarelli FD; Eggermont E; Friedrich U; Haas OA; Kobelt A; Leroy JG; Van Maldergem L; Michel E; Mitulla B; Pfeiffer RA; Schinzel A; Schmidt H; Scherer G 《Human molecular genetics》1997,6(1):91-98
It has previously been shown that, in the heterozygous state, mutations in
the SOX9 gene cause campomelic dysplasia (CD) and the often associated
autosomal XY sex reversal. In 12 CD patients, 10 novel mutations and one
recurrent mutation were characterized in one SOX9 allele each, and in one
case, no mutation was found. Four missense mutations are all located within
the high mobility group (HMG) domain. They either reduce or abolish the
DNA-binding ability of the mutant SOX9 proteins. Among the five nonsense
and three frameshift mutations identified, two leave the C-terminal
transactivation (TA) domain encompassing residues 402-509 of SOX9 partly or
almost completely intact. When tested in cell transfection experiments, the
recurrent nonsense mutation Y440X, found in two patients who survived for
four and more than 9 years, respectively, exhibits some residual
transactivation ability. In contrast, a frameshift mutation extending the
protein by 70 residues at codon 507, found in a patient who died shortly
after birth, showed no transactivation. This is apparently due to
instability of the mutant SOX9 protein as demonstrated by Western blotting.
Amino acid substitutions and nonsense mutations are found in patients with
and without XY sex reversal, indicating that sex reversal in CD is subject
to variable penetrance. Finally, none of 18 female patients with XY gonadal
dysgenesis (Swyer syndrome) showed an altered SOX9 banding pattern in SSCP
assays, providing evidence that SOX9 mutations do not usually result in XY
sex reversal without skeletal malformations.
相似文献
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54 sporadic colorectal cancers were analyzed for aberrations in the K-ras oncogene. DNA was extracted from frozen tissues obtained from surgical resection and analyzed for mutations in codons 12, 13 and 61 of the K-ras oncogene using single strand conformation polymorphism analysis (SSCP) and direct sequencing. Point mutations in the K-ras oncogene were found in 26/54 (48%) cases, all of which resulted in amino acid substitutions. No other types of mutations (e.g. insertions or deletions) were found. 4 of the mutations were at codon 12, 22 in codon 13 and only 1 was a codon 61 mutant. G-->A transitions were found to be predominant. A remarkable finding was the high preponderance of (13)Gly-(13)Ser mutations (54%). No correlation was observed between K-ras mutations and tumor location, Dukes' stage, differentiation levels, age or sex of the patient. 相似文献
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Objectives. To compare the effects of density-gradient centrifugation and swim-up technique on sperm DNA integrity.Methods. Semen samples (n = 22) were obtained from consecutive nonazoospermic men presenting for infertility evaluation. Individual samples were divided into three aliquots (whole semen, density-gradient centrifugation, and swim-up) for subsequent analysis of sperm motility and DNA integrity. Sperm DNA integrity was evaluated by flow cytometry analysis of acridine orange-treated spermatozoa and expressed as the percentage of spermatozoa demonstrating denatured DNA.Results. Mean sperm motility (±SEM) improved significantly after processing with two-layer density-gradient and swim-up compared with whole semen (65.6% ± 4.0% and 73.0% ± 3.0% versus 52.0% ± 3.6%, respectively, P <0.005), with no significant difference in motility between Percoll-treated and swim-up-treated spermatozoa. In contrast, the percentage of spermatozoa with denatured DNA was reduced significantly in swim-up-treated but not in Percoll-treated spermatozoa compared with whole semen (4.8% ± 1.2% and 13.6% ± 3.6% versus 10.1% ± 2.3%, respectively, P <0.0001).Conclusions. Although density-gradient centrifugation is comparable to swim-up technique in recovering spermatozoa with enhanced motility, spermatozoa recovered after swim-up possess higher DNA integrity. These data urge us to reexamine our current sperm processing techniques in order to minimize sperm DNA damage. 相似文献
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Effect of genetic modification of acute inflammatory responsiveness on tumorigenesis in the mouse 总被引:1,自引:3,他引:1
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