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71.
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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The susceptibility of Mycobacterium tuberculosis to isoniazid and the Arg-->Leu mutation at codon 463 of katG are not associated 总被引:1,自引:0,他引:1 下载免费PDF全文
van Doorn HR Kuijper EJ van der Ende A Welten AG van Soolingen D de Haas PE Dankert J 《Journal of clinical microbiology》2001,39(4):1591-1594
A mutation (CCG-->CTG [Arg-->Leu]) in codon 463 of katG (catalase peroxidase) of Mycobacterium tuberculosis has been found in isoniazid (INH)-resistant strains. A PCR restriction endonuclease analysis to detect this mutation was applied to 395 M. tuberculosis isolates from patients in The Netherlands. The proportion of isolates with a detectable mutation was 32% (32 out of 100) and 29% (85 out of 295) among INH-susceptible isolates and INH-resistant or -intermediate isolates, respectively. Sequencing of five INH-susceptible isolates with such mutations showed that all five had the Arg463Leu mutation. We conclude that the Arg463Leu mutation of katG of M. tuberculosis is not a reliable indicator of INH resistance. 相似文献
76.
Odenbreit S Faller G Haas R 《International journal of medical microbiology : IJMM》2002,292(3-4):247-256
The attachment of the bacterial pathogen Helicobacter pylori (H. pylori) to gastric epithelial cells is commonly believed to be required for an efficient and persistent colonization of the human stomach as well as for host cell trans-membrane signaling. In the past, several putative adhesins were postulated, including the outer membrane proteins AlpAB and the bacterial lipopolysaccharide (LPS) presenting oligomeric Lewis x (Le(x)) sugar components. We investigated the AlpAB-mediated and the Le(x)-dependent binding by knockout mutagenesis in one distinct strain, H. pylori P1. We show here that the mutagenesis of either alpA and/or alpB dramatically reduced the adherence of H. pylori P1 to a given gastric biopsy section. None of these mutations influenced the surface exposure of the Le(x) antigen, suggesting that the assembly and/or presentation of LPS is independent of the AlpAB outer membrane proteins. However, a truncation of the LPS O-side chain by a galE mutation abolished the presentation of the Le(x) epitope. This Le(x)-negative strain did not show any significant reduction in its binding capacity to the gastric tissue, when compared with the corresponding wild-type strain. From these data we conclude that the AlpAB-specific adherence is independent of the composition of the LPS and that the oligomeric Le(x) structure does not confer binding to the gastric biopsy material used in this study. As the adhesion properties of our H. pylori strain P1 vary in dependence on the respective biopsy donor it is assumed that the surface-exposed Le(x) epitope recognizes a different host cell receptor than AlpAB, which was probably not present in the tissue sections used in this study. 相似文献
77.
Stereoselectivity of L-baclofen in hippocampal slices of the rat 总被引:2,自引:0,他引:2
Extra- and intracellular recording from hippocampal slices of the rat revealed the following effects when baclofen (BF) (0.1-10 microM) was added to the perfusion fluid: a block of synaptic potentials evoked by stimulation of stratum radiatum; a direct hyperpolarization and a conductance increase (for potassium ions) of CA1 pyramidal cells. All this activity was found in the L- none in the D-enantiomer. D-BF did not antagonize the action of L-BF. 相似文献
78.
G G Haas H Lambert J E Stern P Manganiello 《American journal of reproductive immunology (New York, N.Y. : 1989)》1990,22(3-4):130-132
Thirty-seven semen samples were assayed for sperm-associated IgG and IgA using the immunobead test. Portions of these sperm samples were sent for testing with a direct radiolabeled antiglobulin assay and the testing results were compared. If the results of the immunobead test when only tail-tip bead binding was noted are regarded as negative, there was close correlation between the two assay methodologies. 相似文献
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