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901.
The presence of the t haplotypes in strains derived from the Japanese wild mice (Mus musculus molossinus) was investigated. Crosses between the T/+ heterozygous short tailed mice and five normal tailed molossinus strains (MOL-ANJ, MOA, MOL-NEM, MOM and Mns) produced no tailless mice, indicating that these strains possess no t haplotype. In contrast, tailless mice were produced by a cross between the T/+ heterozygotes and a MOL-NIS strain. Mating experiments showed that the tailless character was due to an interaction between the T gene and an autosomal recessive gene carried by the MOL-NIS strain that expresses the short tail character under the homozygous condition. We have tentatively named this gene brachyury-interacting tail length modifier (btm). It remains to be investigated whether the btm gene is located in the t complex region or in the other locus. 相似文献
902.
Bacillus thuringiensis serotype H-14 spores and crystals, produced in 51 fermenters, were centrifuged and resuspended in emulsified palm olein to give 3.2 x 10(11) colony forming units (cfu)/ml. The suspension was mixed with a cassava-molasses-palm olein-charcoal (CMPC-2) mixture which served as the carrier, adhesive, dispersant and protectant. The final concentration of the formulation was 3.2 x 10(9) cfu/ml. The lethal concentrations capable of killing 50% of the test population (LC50) of CMPC-2 during 0, 1 and 2 years of storage at 32 +/- 4 degrees C were 0.056, 0.058 and 0.058 mg/ml respectively as against 0.054, 0.051 and 0.054 mg/ml for the Institut Pasteur Standard-1978 (IPS-78) during the corresponding period. The chi 2 tests showed that the results were homogeneous at P = 0.05. The relative potencies of the preparations were 964.3, 879.3 and 931 International toxic units (ITU) Aedes aegypti as compared with the 1000 ITU assigned to IPS-78. At 95% confidence limits there was no significant difference between the potencies of CMPC-2 and IPS-78. Field tests showed that CMPC-2 provided between 87.5 and 100% control of natural populations of Aedes spp. and Cutex spp. Sedimentation tests showed that CMPC-2 settled markedly during storage. This, therefore, required that the product be thoroughly shaken before use. 相似文献
903.
A Saadawi A Ayad V N Maltsev 《Journal of hygiene, epidemiology, microbiology, and immunology》1991,35(3):241-249
In the course of research done it was concluded that circulation of pool water through the nuclear reactor core produces a bactericidal effect on microflora due to influence of radiation of various types. Contents of microbes returns to the initial level after 2-4 months after circulation was stopped. Microflora of pool water comprises big amount of coccus, G-positive rods and fungi and a lower content of G-negative rods if compared to water which had been used to fill reactor pool. There is an increased number of radioresistant forms with intensified production of catalase and nuclease. Supposedly, presence of these enzymes gives to the microbes certain advances to survive in high-radiation zones. 相似文献
904.
905.
906.
907.
908.
The products of mitochondrial protein synthesis have been investigated in Tetrahymena after labelling with [35S]methionine in the presence of cycloheximide. The labelled proteins were analyzed by sodium dodecyl sulfate slab polyacrylamide gel electrophoresis. We have identified 13 electrophoretically discrete bands as well as 4 other bands with a more variable occurrence. These proteins ranged in apparent molecular weight from 8100 to 57,500. The cycloheximide-resistant incorporation could be blocked with chloramphenicol. The mitochondrial proteins appeared to be in a disaggregated state and were stable to agents such as trichloroacetic acid (hot or cold) and chloroform-methanol. The pattern of proteins was similar following labelling times ranging from 30 min to 3 h. 相似文献
909.
910.
Retrovirus-mediated immunosuppression. II. FeLV-UV alters in vitro murine T lymphocyte behavior by reversibly impairing lymphokine secretion 总被引:5,自引:0,他引:5
C G Orosz N E Zinn R G Olsen L E Mathes 《Journal of immunology (Baltimore, Md. : 1950)》1985,135(1):583-590
Murine splenocytes and cloned murine T cells were used to study the in vitro immunosuppressive effects of UV-inactivated feline leukemia virus (FeLV-UV) on lymphokine secretion. FeLV-UV can significantly depress the accumulation of IL 2 in cultures of Con A-stimulated C57BL/6 splenocytes and in cultures containing the alloreactive helper T cell clone B6D/2-2m plus Con A. Inhibition of lymphokine accumulation in these cultures could not be attributed to absorption or inactivation of IL 2 by the FeLV-UV or to the FeLV-UV-induced production of substances which interfere with the IL 2 bioassay. Thus, FeLV-UV appears to block production and/or secretion of IL 2 by a direct inhibitory effect on IL 2-secreting murine T lymphocytes. Additional studies indicate that FeLV-UV impairs IL 2 production only if added very soon after lymphocyte contact with lymphokine-inducing agents and that IL 2 secretion resumes when FeLV-UV is removed from the culture. FeLV-UV also impairs accumulation of MAF (interferon-gamma?) in cultures of Con A-stimulated C57BL/6 splenocytes and in cultures containing the alloreactive cytotoxic T lymphocyte clone B6D/2-7c plus Con A. The latter observation again suggests that FeLV-UV impairs lymphokine secretion by a direct effect on lymphokine-producing T lymphocytes. Furthermore, it suggests that FeLV-UV does not selectively impair production of IL 2 nor does it have selective inhibitory effects on helper T cells. Rather, FeLV-UV appears to have a general inhibitory effect on lymphokine production by T lymphocytes. Finally, concentrations of FeLV-UV which suppress MAF production by the CTL clone have little influence on the cytolysis mediated by the same cloned T cell population. Thus, the immunosuppressive influence of FeLV-UV is selective for phenomena associated with induction of new T lymphocyte functions, such as lymphokine secretion, and spares other immune functions already expressed by the same cells. 相似文献