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81.
Prevalence of the 281 (Gly→Glu) mutation in hepatoerythropoietic porphyria and porphyria cutanea tarda 总被引:4,自引:0,他引:4
Hubert de Verneuil Joanna Hansen Christiane Picat Bernard Grandchamp James Kushner Andrew Roberts George Elder Yves Nordmann 《Human genetics》1988,78(1):101-102
Summary The prevalence of the 281 (GlyGlu) mutation in hepatoerythropoietic porphyria (HEP) was investigated by the use of hybridization with a synthetic oligonucleotide probe. The mutation was found in HEP-affected members of two unrelated families from Spain, but was absent in two other patients from Italy and Portugal who also had HEP. Moreover, this mutation was not detected in 13 unrelated cases of familial (type II) porphyria cutanea tarda. 相似文献
82.
83.
Elisa Garcia Anja M. Hamers Hans E. N. Bergmans Bernard A. M. van der Zeijst Dr. Wim Gaastra 《Current microbiology》1988,17(6):333-337
Escherichia coli strains causing urinary tract infections in dogs produce fimbriae composed of fimbrial subunits closely related to the F12 and F13 fimbriae of human uropathogenic strains [4]. The adhesins carried by the fimbriae of human and canine isolates differ, however, as concluded from a different hemagglutination pattern and from the fact that the dog strains do not agglutinate latex beads coated with P-fimbriae receptor. This possible difference in adhesive specificity was confirmed by experiments in which the adhesion of human and dog isolates to dog kidney epithelial cells (MDCK cells) and human bladder epithelial cells (T24 cells) was compared. Dog uropathogenic strains, in contrast to human uropathogenicE. coli strains, adhere to MDCK cells but hardly to T24 cells. Adhesion to MDCK cells correlates with the presence of F12 or F13 fimbriae on the dog strains. These results suggest that homologous fimbrial subunits can carry different adhesin molecules and that these adhesin molecules can be responsible for species-specific adherence. On the contrary, adhesion of a number of dog uropathogenicProteus mirabilis strains to MDCK and T24 cells was not species specific; it depended on the mere presence of fimbriae. 相似文献
84.
Virulence of 10 human and 10 bovine isolates (5 type II and 5 type III of each origin) of group B streptococci (GBS) was measured in two experimental mouse models. In the first model, mice were intraperitoneally (i.p.) infected, and the 50% lethal doses (LD50) were significantly lower for human isolates than for bovine isolates. In the second model, abortion and lethality were recorded for mice infected intravenously (i.v.) on day 13 of pregnancy. All 10 human isolates induced abortions, whereas only 5 bovine isolates did so. There was no relationship between 50% abortive doses determined for 9 isolates (4 human and 5 bovine) and the LD50 values. Post-partum lethality was significantly correlated with LD50 values.Our studies suggested that the lethality test for nonpregnant mice and the abortion test for pregnant mice were not redundant and that the latter would be a useful additional model for identification of virulence factors of GBS. 相似文献
85.
Christine C. Berte Nobuyuki Tanigaki Roberto Tosi Jack Gorski Bernard Mach 《Immunogenetics》1988,27(3):167-173
HLA class 11 molecules were isolated from mouse L cells transfected with a DR
gene and an allele, 52a, of locus DR
III from an HLA-homozygous cell line, AVL, of the DR3 haplotype. The isolated molecules were found to possess a new allospecificity, named TR81. This specificity behaved allelic to the previously described DR
III locus. The TR81 specificity was also present on the DR
I gene product of the DR3 haplotype. The nucleotide sequence of the gene encoding TR81 differs from TR81-negative DR
genes of the DRw52 family in only two codons, both located in the regions known to be involved in a gene conversion event. Consequently, the following conclusions can be formulated. (a) TR81 is a bi-locus specificity and allelic to TR22 only in its DR
III locus localization. (b) The TR81 specificity is the phenotypic counterpart of the gene conversion event which led to the generation of the DR
I gene of the DR3 haplotype. (c) One or both individual amino acid substitutions in the first domain of the DR
chain are responsible for the TR81 allospecificity. (d) Since TR81 is expressed on the DR
I chain of the DR3 haplotype, it is possible that TR81 and DR3 represent the same serological specificity. 相似文献
86.
Summary The effects of a non-ionic surfactant, Pluronic F-68, on growth of microbial cell cultures have been studied. Growth ofSaccharomyces cerevisiae at 30°C or 37°C as measured by viable cell counts was unaffected by culture with pluronic. However, corresponding absorbance measurements forS. cerevisiae incubated with 5–10% pluronic were lower than controls at both temperatures. Absorbance ofE. coli cultures was also significantly reduced by incubation with 5.0–10.0% pluronic at both temperatures although viable counts again revealed no significant inhibition of growth. 相似文献
87.
Jürgen M. Schmitt Christine Michalowski Hans J. Bohnert 《Photosynthesis research》1988,17(1-2):159-171
Mesembryanthemum crystallinum responds to high salinity in the soil by shifting the mode of carbon assimilation from the C3 mode to Crassulacean acid metabolism (CAM). Several enzymes of carbon metabolism have increased apparent activities in the CAM mode, including phosphoenolpyruvate carboxylase (PEPcase) and pyruvate orthophosphate dikinase (PPDK). We have identified cDNA clones for PEPcase and PPDK by immunological screening of a cDNA library constructed in the protein expression vector lambda gt11. The clones were characterized by immunoblotting and RNA blotting techniques. RNA blotting showed that during CAM induction the steady-state level of mRNAs for both PEP case and PPDK increased.Abbreviations IPTG
isopropyl thiogalactoside
- PEP
phosphoenolpyruvate
- PEPcase
phosphoenolpyruvate carboxylase
- PPDK
pyruvate orthophosphate dikinase
- Xgal-5
bromo-4-chloro-3-indolyl-beta-D-galactopyranoside 相似文献
88.
Cytoplasmic Poly(ADP-Ribose) Polymerase Associated with Free Messenger Ribonucleoprotein Particles in Rat Brain 总被引:1,自引:0,他引:1
Poly(ADP-ribose) polymerase associated with free cytoplasmic messenger ribonucleoprotein particles (free mRNP particles) carrying messenger RNA has been characterized in rat brain. There were first-order kinetics for NAD with an apparent Km for NAD of 90.5 +/- 0.70 microM and Vmax of 19.7 +/- 2.8 pmol ADP-ribose incorporated min-1 mg protein-1. Five poly(ADP-ribose) protein acceptors were identified in the Mr 37,000-120,000 range. It is hypothesized that ADP-ribosylation of specific free mRNP proteins might play a role in the derepression and translation of the silent mRNAs of free mRNP particles. 相似文献
89.
Martin Cambray-Deakin Brian Pearce Christine Morrow Sean Murphy 《Journal of neurochemistry》1988,51(6):1846-1851
Astrocyte-enriched and meningeal cell cultures of the rat cerebral cortex were prepared, and their glycogen content was measured after 10-90 min under control (2.5 mM) concentrations of potassium after prefeeding with 20 mM glucose. No net change in glycogen level was noted in either culture over this period. Cell cultures were then exposed to increased concentrations of potassium (5, 10, and 15 mM), and their glycogen content was measured after 10-90 min. Both types of cell culture showed complex and variable changes in glycogen content. In general, increased potassium concentrations caused astrocyte glycogen stores to be reduced at physiological increases of potassium levels (from 2.5 to 5 mM and above), although a period of resynthesis was evident at all potassium concentrations. Meningeal cell glycogen levels were highly variable and only affected by high (10 and 15 mM) levels of potassium. These results are discussed with respect to the theory that changes in the external potassium concentration caused by neuronal activity might act as a signal controlling astrocyte glycogen stores. 相似文献
90.
Glutamate appears to be the neurotransmitter of granule cells, the major neuronal population of the cerebellar cortex. To determine the role of astroglial cells in the synthesis of glutamate, we have measured the specific activity of glutamate dehydrogenase (GDH) in clonal cell lines that might be the in vitro equivalents of the different cerebellum astroglial cell types. In conditions where GDH operates in the direction of glutamate synthesis, the specific activity of GDH measured in the "Golgi-Bergmann"-like clone was 4-6 times higher than in the "velate protoplasmic"- or "fibrous-like" astrocytic clones. These data correlate well with the intense immunoreactivity to GDH in Golgi-Bergmann astrocytes in vivo that has been recently reported. 相似文献