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1.
James McNaught Inglis 《BMJ (Clinical research ed.)》1950,2(4686):1003-1004
2.
Turnover of nascent proteins in HeLa-S3 cells and the quasi-linear incorporation kinetics of amino acids 总被引:1,自引:0,他引:1
The turnover of nascent proteins in HeLa S-3 cells was estimated simultaneously with synthesis by the difference between the expected accumulation of radioactivity, based on rate determinations from very short pulse treatments, from that observed by continuous exposure for 100 min. The results were similar to those from conventional pulse-chase analysis, but not identical for reasons which are discussed. They confirm that extensive protein turnover accompanies synthesis in the growing cell, and therefore net synthesis is much lower than gross synthesis. Cells retained all proteins synthesised during heat treatment at 45 degrees C, indicating the complete inhibition of protein degradation, cells retaining all proteins synthesised. This particular perturbation experimentally validated the deficit method, and its potential usefulness in future turnover studies. 相似文献
3.
Donald Spencer Peter M. Chandler Thomas J. V. Higgins Adam S. Inglis Michael Rubira 《Plant molecular biology》1983,2(5):259-267
Serological studies and comparison of N-terminal amino acid sequences with the amino acid sequence deduced from a cDNA clone have been used to establish the sequence relationships between the subunits of the pea seed storage protein, vicilin. Subunits smaller than Mr~50 000 (i.e., Mr 34 000, 30 000, 25 000, 18 000, 14 000, 13 000 and 12 000) show extensive homology with molecules within Mr~50 000 group. Both the sequencing and serological data confirm earlier evidence from studies on vicilin synthesisin vivo andin vitro which indicated that the vicilin subunits smaller than Mr~50 000 arose by endoproteolytic cleavage of parent molecules within the Mr~50 000 group. Cleavage in different Mr 50 000 parent molecules containing either one or both of two susceptible processing sites accounts for the formation of all the vicilin subunits smaller than Mr~50 000, with the possible exception of the Mr34 000 polypeptide. The position of these sites in the putative parents were defined by reference to a complete amino acid sequence deduced from the sequence of DNA complementary to mRNA for one member of the Mr~50 000 group. 相似文献
4.
Two patients with disseminated histoplasmosis are reported. One patient presented with severe thrombocytopenic purpura and splenomegaly. Histoplasmin skin test, blood and bone marrow cultures and smears, sputum cultures, and chest radiographs were negative for Histoplasma capsulatum. She died on the sixth hospital day from a massive intracerebral hemorrhage. Cardiorespiratory function was maintained until one kidney was removed for homotransplantation. The second patient, with chronic glomerulonephritis and uremia, received the renal homograft from the first patient. Initial signs of homograft rejection developed five days postoperatively. Diffuse thrombocytopenic purpura occurred shortly thereafter. Spores of Histoplasma capsulatum were observed in blood smears, in leukocyte concentrates, and in five-day leukocyte cultures from the blood obtained prior to death. Disseminated histoplasmosis was found in both patients at autopsy. The severe platelet deficit in both cases suggests that systemic histoplasmosis should be considered as a cause of thrombocytopenic purpura.To our knowledge, this is the first reported instance of direct transmission of Histoplasma capsulatum, and must be considered a hazard in homotransplantation.In vitro leukocyte cultures as a method for early diagnosis of certain disseminated fungous infections needs further investigation. 相似文献
5.
Induced deletions within a cluster of resistance genes in the mec region of the chromosome of Staphylococcus aureus 总被引:6,自引:0,他引:6
Variants of a methicillin-resistant Staphylococcus aureus showing loss of or reduced resistance to the antibiotic were isolated at frequencies of 0.1-100% from cultures which had been starved, grown at elevated temperature, or given small doses of UV radiation. Three types of variant were identified on the basis of population distribution of resistance to the antibiotic, and field-inversion gel electrophoresis of digests of the chromosome cut with the rare-cutting restriction endonuclease SmaI. Type I variants are methicillin-sensitive and have a deletion in the mec region of the chromosome. Type II variants have reduced methicillin resistance and rearranged DNA elsewhere in the chromosome. Type II variants show reduced methicillin resistance and no detectable change in the chromosome. Type I deletions were mapped using cloned fragments from the mec region. In 13 of the 16 independently isolated deletion mutants, one of the deletion endpoints appears to correlate with the positions of insertion sequences or transposons found in this region of the staphylococcal chromosome. 相似文献
6.
7.
Effects of chorda-lingual nerve injury and repair on human taste 总被引:1,自引:1,他引:0
Citric acid detection threshold and magnitude response weremeasured on the anterior tongue in 10 patients with unilateralchorda-lingual nerve transections before and after repair. Fungiformtaste buds were analysed by videomicroscopy. Preliminary datasuggests that humans can regenerate fungiform taste buds andrecover some taste sensitivity after repair. 相似文献
8.
Potential problems in the use of oligonucleotide probes for staphylococcal enterotoxin genes 总被引:2,自引:1,他引:1
Oligonucleotide probes unique to the five major enterotoxin genes of Staphylococcus aureus were synthesized and used to detect DNA sequences homologous to these genes in 27 non-clinical isolates of Staph. aureus isolated from nasal swabs of 74 healthy human volunteers. Genomic DNA from all 27 isolates reacted with at least one of the probes. In a phenotypic assay for toxin production by a reverse passive latex agglutination test however, only 15 of the 27 isolates produced enterotoxin in culture. The results raise the possibility that a number of Staph. aureus isolates harbour DNA sequences that are apparently silent or mutant copies of the enterotoxin genes. This complicates the identification of enterotoxin producers by tests which depend on oligonucleotide or DNA hybridization. 相似文献
9.
DNA sequences were determined for three to five alleles of the bride-of-
sevenless (boss) gene in each of four species of Drosophila. The product of
boss is a transmembrane receptor for a ligand coded by the sevenless gene
that triggers differentiation of the R7 photoreceptor cell in the compound
eye. Population parameters affecting the rate and pattern of molecular
evolution of boss were estimated from the multinomial configurations of
nucleotide polymorphisms of synonymous codons. The time of divergence
between D. melanogaster and D. simulans was estimated as approximately 1
Myr, that between D. teissieri and D. yakuba as approximately 0.75 Myr, and
that between the two pairs of sibling species as approximately 2 Myr. (The
boss genes themselves have estimated divergence times approximately 50%
greater than the species divergence times.) The effective size of the
species was estimated as approximately 5 x 10(6), and the average mutation
rate was estimated as 1-2 x 10(-9)/nucleotide/generation. The ratio of
amino acid polymorphisms within species to fixed differences between
species suggests that approximately 25% of all possible single-step amino
acid replacements in the boss gene product may be selectively neutral or
nearly neutral. The data also imply that random genetic drift has been
responsible for virtually all of the observed differences in the portion of
the boss gene analyzed among the four species.
相似文献
10.