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1.
Martin Knapp 《BMJ (Clinical research ed.)》1984,289(6437):107-108
2.
The microbial degradation of morpholine 总被引:5,自引:1,他引:4
Morpholine can be completely degraded microbiologically, and two organisms have been isolated, each capable of growth in a simple mineral salts medium with morpholine as the sole source of carbon, nitrogen and energy. Excess nitrogen is liberated as ammonia. The enzymes responsible for the oxidation of morpholine are inducible and, in organism Mor G, will also oxidize piperidine, piperazine and pyrrolidine, which are not growth substrates. Ethanolamine is a likely intermediate, though the metabolic steps in morpholine degradation do not give rise solely to acetyl-CoA. After a period of acclimation, a laboratory scale activated sludge plant effectively removed morpholine over the long period it was operated; the sludge was also capable of nitrification. The possible effects of other chemicals in trade wastes containing morpholine on nitrification and morpholine oxidation are described. 相似文献
3.
Georgia Vlahou Oxana Schmidt Bettina Wagner Handan Uenlue Petra Dersch Francisco Rivero Barbara A Weissenmayer 《BMC microbiology》2009,9(1):138-12
Background
All human pathogenic Yersinia species share a virulence-associated type III secretion system that translocates Yersinia effector proteins into host cells to counteract infection-induced signaling responses and prevent phagocytosis. Dictyostelium discoideum has been recently used to study the effects of bacterial virulence factors produced by internalized pathogens. In this study we explored the potential of Dictyostelium as model organism for analyzing the effects of ectopically expressed Yersinia outer proteins (Yops). 相似文献4.
Teresa Sadras Mickaël Martin Kohei Kume Mark E. Robinson Supraja Saravanakumar Gal Lenz Zhengshan Chen Joo Y. Song Tanya Siddiqi Laura Oksa Anne Marie Knapp Jevon Cutler Kadriye Nehir Cosgun Lars Klemm Veronika Ecker Janet Winchester Dana Ghergus Pauline Soulas-Sprauel Markus Müschen 《Molecular cell》2021,81(10):2094-2111.e9
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Oat (Avena sativa L.) mesophyll protoplasts were recently demonstrated to be capable of dedifferentiation, repeated divisions, and colony formation. Since the development of oat mesophyll protoplasts is decisively influenced by the nature of the used feeder culture (species, variety and concentration), we conducted a systematic study of this parameter. Generally, graminaceous feeders promoted protoplast proliferation, while dicot species repressed protoplast divisions. The beneficial effect of those feeders that promote divisions was counterbalanced by a factor that causes necrosis. The correct balance between promotion of divisions or necrosis depended on the nature of the feeder and its plating density. 相似文献
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8.
Leslie A. Knapp 《Evolutionary anthropology》2005,14(1):28-37
The major histocompatibility complex (MHC) contains the most diverse genes known in vertebrates. These genes encode cell‐surface molecules that play a central role in controlling immunological activity and, as a consequence, in tissue rejection, autoimmunity, and immune responses to infectious diseases. In vertebrates, there are many different MHC genes, most with many alleles. This is true for all primates studied thus far. Multiple loci and alleles allow for an increased peptide‐binding repertoire; their variety has a profound impact on an organism's ability to battle constantly evolving pathogens. The argument that infectious disease is a driving force for MHC variability is supported by observations that most of the allelic variation centers on the amino acid residues that directly interact with foreign peptides. However, while MHC diversity could be maintained through heterozygote advantage, frequency‐dependent selection, or both, the direct evidence that natural selection enhances diversity is limited. Indeed, it is not wholly clear whether selection operates only with respect to disease resistance or if behavioral and biological mechanisms also contribute to the extreme variation that has been observed for many species. Furthermore, reproductive behavior and biology may also help to maintain genetic variability at MHC loci. 相似文献
9.
J.D. Lane Bettina Schöne U. Langenbeck V. Neuhoff 《Biochimica et Biophysica Acta (BBA)/General Subjects》1980,627(2):144-156
Phenylalanine in conjuction with p-chlorophenylalanine or α-methylphenylalanine was administered to suckling rats to induce hyperphenylalaninemia reminiscent of untreated phenylketonuria, and developmental parameters were monitored. The experimental model utilizing p-chlorophenylalanine was found to be unsatisfactory, in that the drug had general deleterous effects on growth, numerous side effects including increased mortality, and affected brain levels of biogenic monoamine neurotransmitters. The model utilizing α-methylphenylalalanine was relatively free from nonspecific effects and thus, changes observed in the animals were attributable to expereimental phenylketonuria. The latter animals had slightly decreased body and brain weights, and exhibited grossly elevated serum phenylalanine and urinary excretion of phenylketone metabolites. Hyperphenylalaninemia produced greatly disrupted brain amino acids at 10 days of age (prior to the formalization of the blood-brain barrier and specific transport systems) which was limited by 30 days of age to changes in glycine, γ-aminobutyric acid and the aliphatic and aromatic amino acids which compete for uptake in t he brain by a common carrier. These animals also exhibited a myelin deficit and changes in proteins from isolated nerve cell preparations. Mature animals which had daily treatment up to 60 days of age results obtained with animal models and the clinical findings in untreated phenylketonuric patients. 相似文献
10.