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Multipoint mapping studies of six loci on chromosome 11 总被引:1,自引:0,他引:1
D A Meyers T H Beaty N E Maestri S D Kittur S E Antonarakis H H Kazazian 《Human heredity》1987,37(2):94-101
The six loci, beta-globin (HBBC), parathyroid hormone (PTH), oncogene c-Ha-ras-1 (HRAS1), insulin (INS), calcitonin (CAL) and catalase (CAT) loci, have been mapped to 11p in the order: CAT-CAL-PTH-HBBC-(HRAS1-INS). The purpose of the current study was to examine the linkage relationships, especially the multipoint relationships of these loci in detail. In the 18 families studied, a significant sex difference in recombination was found for the HBBC: HRAS1 linkage with more recombination in the male parent than the female parent (22 vs. 2%). The results of the multipoint analyses provided further evidence for the order CAT-CAL-PTH-HBBC-(HRAS1-INS); however, the order of the last two tightly linked loci is still not clear. 相似文献
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A device to measure fluorescein in tissue has been constructed from standard photographic equipment--an electronic strobe and a flashmeter both covered with interference filters. The instrument works well in the light and need not touch the area being measured, an advantage over existing fluorometers. The instrument has been used to measure the amount of dye in flaps in rats, pigs, and three humans. The results revealed that the amount of dye in a freshly made flap was rarely as much as in normal skin, and skin with less than 20 percent of the dye of control areas usually sloughed, although there were exceptions. In the future the instrument will be improved, and its readings will be compared to those obtained from radioactive microspheres, the present "gold standard" of techniques to measure vascularity. The instrument can be used to estimate the blood supply to any tissue and seems to be as reliable as the dermofluorometers already on the market. 相似文献
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Assessing toxicity of Lake Diefenbaker (Saskatchewan,Canada) sediments using algal and nematode bioassays 总被引:1,自引:1,他引:0
Lake Diefenbaker, on the South Saskatchewan River, Saskatchewan, Canada, receives, on average, 90% of its inflow from snowmelt and rainfall in the Rocky Mountains. The inflowing rivers also receive irrigation return flows and municipal and industrial effluents which may result in the contamination of lake sediments. The sediments were assessed by nematode and algal bioassays.The toxicity of five chemical fractions of the sediment was determined using the nematode Panagrellus redivivus as the test organisms. The results suggest that the sediment chemical fractions frequently inhibit growth and maturation, while lethality was observed at 4 of 12 sites.Samples from 3 of these sites were further evaluated using conventional elutriate Algal Fractionation Bioassays (AFB) with both natural Lake Diefenbaker phytoplankton and a mixed laboratory grown algal culture. The natural phytoplankton showed inhibition at sediment: water ratios of 10: 1; whereas the algal cultures showed both enhancement and inhibition. Evidently, the sediments are frequently toxic to the species tested except for the algal culture. The AFB assesses the mitigative and synergistic effects of contaminants and nutrients and being a conventional elutriate, is more realistic and potentially more acceptable than the chemical fractionation/nematode bioassay technique which essentially considers potential trace organic contaminant effects. 相似文献
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A. K. Kononowicz K. Floryanowicz-Czekalska J. Clithero A. Meyers P. M. Hasegawa R. A. Bressan 《Plant cell reports》1990,8(11):672-675
Cultured tobacco (Nicotiana tabacum L. cv. Wisconsin 38) cells were found to have altered DNA contents and chromosome numbers after adaptation to NaCl. Cells adapted to 428 mM NaCl were predominately hexaploid compared to the normal tetraploid 2N(2C)=4X=48 chromosome number of unadapted cells. Enrichment of the cell population for hexaploid cells occurred only after exposure to higher NaCl (428 mM), not lower levels of NaCl (171 mM). The majority of adapted cells remain hexaploid for at least 25 cell generations after removal from NaCl exposure. Adapted cell populations were found to have fewer cells with highly polyploid (2N96) nuclei. Salt tolerance of hexaploid cells was not found to be significantly greater than that of tetraploid cells. Cells with higher ploidy levels were less salt tolerant. It is suggested that high levels of NaCl induce polyploidization and that exposure to NaCl selects against cells with very high ploidy levels. 相似文献
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Inhibition of glycoprotein oligosaccharide processing in vitro and in influenza-virus-infected cells by alpha-D-mannopyranosylmethyl-p-nitrophenyltriazene. 下载免费PDF全文
W McDowell A Tlusty R Rott J N BeMiller J A Bohn R W Meyers R T Schwarz 《The Biochemical journal》1988,255(3):991-998
The effects of alpha-D-mannopyranosylmethyl-p-nitrophenyltriazene (MMNT) on mannosidases involved in asparagine-linked oligosaccharide processing were investigated. MMNT was found to inhibit the activity of rat liver Golgi alpha-mannosidase I in a concentration-dependent manner (50% inhibition with 0.18 mM-MMNT), whereas rat liver endoplasmic-reticulum alpha-mannosidase appeared to be resistant (less than 5% inhibition at 1 mM-MMNT). Jack-bean alpha-mannosidase was also sensitive to inhibition by MMNT (50% inhibition with 0.32 mM-MMNT). Treatment of influenza-virus-infected chick-embryo cells with 1 mM-MMNT led to a decrease in the formation of complex-type asparagine-linked oligosaccharides and an accumulation of high-mannose-type oligosaccharides with the composition Man8(GlcNAc)2 and Man7(GlcNAc)2 on the viral glycoproteins. The biological activities of influenza-virus haemagglutinin and neuraminidase synthesized in the presence of 1 mM-MMNT remained unchanged, but the virus was less infectious than the control. 相似文献