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51.
In studies of T cell responses to synthetic peptides we have observed agonist and antagonist activities associated with contaminants identified within the parent synthesis. The synthesis of two candidate analogues implied by a peptide contaminant formed during the synthesis of La 51-58 (IMIKFNRL) has been carried out. The peptide contaminant was 17-18 Da smaller than the parent peptide consistent with a modified asparagine residue at position 6 and so we synthesised both an aspartimide and a nitrile analogue, representing cyclisation or dehydration of the asparagine residue. The candidate aspartimide and nitrile analogues both bound empty MHC class I molecules to form allo determinants recognised by monoclonal antibodies. These results demonstrate that altered synthetic peptides can bind class I MHC molecules and prompt caution in the use of synthetic peptides as a source of immunising antigen. 相似文献
52.
Six patients with classical transient ischemic attacks that were not directly related to extracranial carotid disease are presented. These cases were selected to include a variety of pathologic conditions: one case each of brain tumor, arteriovenous malformation, chronic subdural hematoma, cervical spondylosis, and two cases of giant intracranial aneurysms. These case histories are significant because they illustrate that without complete angiographic investigation, tragic results could have and did occur in some cases. Transient ischemic attacks should be considered as a symptom of various possible pathologic conditions, and a careful search for the cause must be pursued aggressively. 相似文献
53.
The application of alumino silicate alkali ion sources to the study of ion desorption of surface gas
Investigations are described which illustrate the compatibility of alumino silicate alkali ion sources with an UHV (~10?11 torr) vacuum environment. The application of the sources to the determination of ion desorption efficiency of surface gas is demonstrated, as well as their use as a basis for a technique of ion stimulated surface gas analysis. 相似文献
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Germfree mice were immunized orally or intraperitoneally for 6 weeks with heat-killed vaccines of indigenous Escherichia coli or nonindigenous E. coli O 127: B8 before colonization with these strains. The mice exhibited increases in specific serum antibodies and intestinal immunoglobulin A reacting with the E coli antigens. Prior immunization did not reduce the gastrointestinal population levels of the E. coli strains attained 3 and 7 days after colonization. Neither oral nor intraperitoneal immunization with the E. coli strains before colonization decreased the incidence of bacterial translocation to the mesenteric lymph nodes or reduced the number of viable E. coli cells per mesenteric lymph node. There also was no relation in individual mice between serum antibody titers and the numbers of viable E. coli cells translocating to the mesenteric lymph nodes. Thus, prior vaccination with E. coli in this study did not decrease the incidence or reduce the numbers of viable E. coli translocating to the mesenteric lymph nodes in gnotobiotic mice monoassociated with E. coli. 相似文献
56.
PM Johnson AO Ogbimi MJ Diver AW Thomson RD Bremner CH Horne 《Canadian Metallurgical Quarterly》1980,59(2):437-440
Placental protein 5 (PP5), pregnancy-specific glycoprotein (SP1), pregnancy-associated alpha 2-glycoprotein (SP3) and chorionic gonadotrophin could not be demonstrated in appreciable molar quantities in the soluble fraction from microvillous plasma membrane preparations isolated from the syncytiotrophoblast of full-term human placentae. However, progesterone, total oestriol and placental lactogen may have some association with this membrane. 相似文献
57.
An industry-wide survey of plasm fractionation facilities in the United States was conducted during 1973-74. Hepatitis was reported among the workers with varying degrees of plasma contact at all plant sites. For each of fourteen facilities in this investigation, field inspections disclosed: (1) numerous overt instances of employee-product contact: (2) inconsistent methodologic approaches at virtually all stages of the plasma fractionation process; (3) at low level of management and employee awareness regarding the potential bio-hazard identified; and (4) disparate examples of hepatitis surveillance and prophylaxis. Our data suggests that there is a high risk of hepatitis among plasma fractionation workers and, as such, much more attention needs to be focused on the reduction of health hazards within this industry. 相似文献
58.
Of 30 bile acids tested, none was mutagenic in the Salmonella-mammalian-microsome test with indicator strains G46, TA1530, TA1535, TA1536, TA1537, TA1538, TA98, or TA100. However, when lithocholic acid or one of its conjugates was tested with suboptimal amounts of 2-aminoanthracene and phenobarbital-stimulated rat liver homogenate, enhancement and co-mutagenesis were observed if TA1538 was the indicator strain. 相似文献
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