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1.
Types,rates, origin and expressivity of chromosome mutations involving 13q14 in retinoblastoma patients 总被引:7,自引:2,他引:5
Summary A cytogenetic survey of 200 retinoblastoma (Rb) patients revealed that approximately 8.5% of the fresh germinal mutations were microscopically detectable chromosome mutations, either interstitial deletions or rearrangements, involving 13q14. They showed a strong bias toward paternal origin, indicating a significant contribution of errors in paternal meiotic processes. The incidence of patients with Rb due to such chromosome mutations was estimated to be 1.9 x 10-6 of live births. Age-specific incidence of Rb tumors suggested that the Rb mutations by such chromosomal mechanisms had a lower carcinogenic potential, as indicated by the later onset of disease, than other Rb mutations of germinal origin. 相似文献
2.
Chika Kawashima Koji Terayama Masayuki II Shogo Oka Toshisuke Kawasaki 《Glycoconjugate journal》1992,9(6):307-314
The properties of a rat brain glucuronyltransferase, which is presumed to be associated with the biosynthesis of the HNK-1 epitope on sulfoglucuronyl glycolipids, are described. The enzyme required divalent cations for reaction, with maximal activity at 10mm Mn2+, and exhibited a dual optimum at pH 4–5 and pH 6 depending upon the buffer used, with the highest activity at pH 4.5 in MES buffer. This enzyme strictly recognized the Gal1-4GlcNAc terminal structure, and was highly specific for neolacto (type 2) glycolipids as acceptor. The enzyme was localized specifically in the brain, and was barely detected in other issues, including the thymus, spleen, liver, kidney, lung, and sciatic nerve fibres. Phosphatidylinositol and phosphatidylserine increased the enzymatic reaction 4.4- and 2.3-fold, respectively, whereas phosphatidylcholine slightly decreased the rate.Abbreviations GlcA
glucuronic acid
- Lc-PA14
lactotetraose-phenyl-C14H29
- nLc-PA14
neolactotetraose-phenyl-C14H29
- nLcOse4-Cer
neolactotetraosylceramide
- NP-40
Nonidet P-40
- PC
phosphatidylcholine
- PE
phosphatidylethanolamine
- PI
phosphatidylinositol
- PS
phosphatidylserine
- SGGL
sulfoglucuronyl glycolipid 相似文献
3.
Determination of the chromosomal site for the human radiosensitive ataxia telangiectasia gene by chromosome transfer 总被引:3,自引:0,他引:3
The chromosomal localization of the gene which complements radiation hypersensitivity of AT cells was studied by microcell-mediated chromosome transfer. A 6-thioguanine-resistant derivative of an immortalized AT cell line, AT2KYSVTG, was used as a recipient for microcell-mediated chromosome transfer from 4 strains of mouse A9 cells, 3 of which carried a human X/11 recombinant chromosome containing various regions of chromosome 11, while the other carried an intact X chromosome. HAT-resistant microcell hybrids were isolated and examined for their radiosensitivity and chromosome constitution. The microcell hybrid clones obtained from the transfer of an intact X chromosome or an X/11 chromosome bearing the pter → q13 region of chromosome 11 did not show a difference in radiosensitivity from parental AT cells, while those obtained from the transfer of X/11 chromosomes bearing either the p11 → qter or the pter → q23 region of chromosome 11 exhibited a marked radioresistance which was comparable to normal human fibroblasts. A HAT-resistant but radiosensitive variant was further obtained from the microcell fusion with an A9 cell strain carrying an X/11 chromosome bearing the 11p11 → qter region, in which a deletion at the 11q23 region was found. The results indicate that the gene which complements a radiosensitive phenotype of AT is located at the q23 region of chromosome 11. 相似文献
4.
Y Namba K Yoshizawa A Ejima T Hayashi T Kaneda 《The Journal of biological chemistry》1969,244(16):4437-4447
5.
Kenji Abe Noboru Kagei Yoshiyuki Teramura Hiroyasu Ejima 《Journal of medical primatology》1993,22(4):237-239
Hepatocellular carcinoma associated with chronic Schistosoma mansoni infection in a chimpanzee, estimated to be a 12-year-old and born in West Africa, is reported. The hepatic tumor appeared as a solitary firm nodule, and histological examination revealed well-differentiated hepatocellular carcinoma with a trabecular pattern. Hepatitis B virus and hepatitis C virus infections were excluded by serological testing in that animal. This is the first report of hepatocellular carcinoma in the chimpanzee with schistosomiasis. 相似文献
6.
Seibu Mochizuki Shingo Seki Masa-aki Ejima Tatsuyuki Onodera Masayuki Taniguchi Shin-ichiro Ishikawa 《Molecular and cellular biochemistry》1993,119(1-2):151-157
The roles of the Na+/H+ exchange system in the development and cessation of reperfusion induced ventricular arrhythmias were studied in the isolated perfused rat heart. The hearts were perfused in the working heart mode with modified Krebs Henseleit bicarbonate (KHB) buffer and whole heart ischemia was induced by a one-way ball valve with 330 beat/min pacing. Ischemia was continued for 15 min followed by 20 min of aerobic reperfusion (control). Amiloride (1.0mM), an inhibitor of the Na+/H+ exchange system, was added to the KHB buffer only during reperfusion (group B) or only during ischemic periods (group C). Electrocardiographic and hemodynamic parameters were monitored throughout the perfusion. Coronary effluent was collected through pulmonary artery cannulation and PO2, PCO2, HCO
3
–
and pH were measured by blood-gas analyzer.The incidence of reperfusion induced ventricular arrhythmias was 100%, 100% and 0% in control, group B and group C, respectively. The mean onset time of termination of reperfusion arrhythmias was significantly shorter in group B than in control. PCO2 increased from 39.0±0.9 to 89.3±6.0 mmHg at the end of ischemia in control and from 40.6±0.4 to 60.5±5.8 in group C, the difference between groups was statistically significant. HCO
3
–
level decreased from 21.8±0.1 to 18.3±0.5 mmol/l in control, however, this decrease was significantly inhibited in group C (from 22.0±0.5 to 20.3±0.2). The increase in PCO2 and the decrease in HCO
3
–
in group B were similar over time to those observed in control. The decrease in pH produced by ischemia was marked in control (from 7.35±0.01 to 6.92±0.04) and group B (from 7.34±0.01 to 6.94±0.02), whereas a decrease in pH was significantly prevented in group C (from 7.34±0.01 to 7.15±0.04). There were no significant differences in PCO2, HCO
3
–
or pH among the three groups during reperfusion.These experiments provide evidence that amiloride significantly prevented the incidence of reperfusion arrhythmias when added only during ischemia and significantly terminated reperfusion arrhythmias when added only during reperfusion. Amiloride may prevent a decrease in pH, due to alterations in PCO2 and/or HCO
3
–
. These changes in PCO2 and HCO
3
–
might be indirectly influenced by inhibition of the Na+/H+ exchange system via Cl–/HCO
3
–
exchange. The mechanism by which amiloride terminates reperfusion arrhythmias seems to involve electrophysiological effects which were not directly addressed in this experiment. 相似文献
7.
Hiroshi Suemizu Chika Kito-Maruyama Yusuke Sotomaru Tomoyuki Ogura Kyoji Hioki Yasuyuki Ohnishi Norikazu Tamaoki 《Experimental Animals》2004,53(5):463-466
In short-term carcinogenicity testing using CB6F1-TgrasH2 mice, sibling nonTgrasH2 mice are used as a negative control. However, selection of TgrasH2 and nonTgrasH2 mice has been performed by PCR with only transgene specific primers by the conventional method. Therefore, the conventional method involves the risk of false negative results due to reaction failure, and contamination with TgrasH2 mice in the control mice group. Based on the nucleotide sequence information around the pre-integration site, we developed a genotyping method for distinguishing not only TgrasH2 mice (hemizygous for the Tg allele) but also nonTgrasH2 (homozygous for the nonTg allele) in a positive manner. 相似文献
8.
Proteins and Carbohydrates in Xylem Sap from Squash Root 总被引:8,自引:0,他引:8
Satoh Shinobu; Iizuka Chika; Kikuchi Akira; Nakamura Norio; Fujii Tadashi 《Plant & cell physiology》1992,33(7):841-847
The xylem sap from squash roots was collected from the cut surfaceof stems, and the proteins and carbohydrates in the sap wereanalyzed. The sap contained 18.6 µg ml1 proteinand the major polypeptides were as follows: 1) two polypeptides,of 75 and 40 kDa, with high-mannose glycans, the levels of whichincreased for about 24 h after cutting and then decreased; 2)a 32-kDa polypeptide, which appeared soon after cutting, disappearedand then reappeared again 4864 h after cutting; and 3)a 19-kDa and a 14-kDa polypeptide, which were present constitutively.The carbohydrates contained in the xylem sap were fractionatedinto 80% ethanol-soluble and -insoluble material, and whichwere analyzed by high-performance liquid chromatography, gaschromatography and enzymatic mathods. The former fraction containedconsiderable amounts of myo-inositol and fructose as free sugarsand oligosaccharides composed mainly of galactose, arabinoseand glucose. The latter contained polysaccharides composed mainlyof uronic acids, galactose and arabinose. The possible significanceof these substances, which may mediate the interactions betweenthe root and the aerial organs, is discussed. (Received April 20, 1992; Accepted July 4, 1992) 相似文献
9.
10.