Involvement of protein synthesis in the development of thermotolerance using a CHO temperature-sensitive mutant

A Chinese hamster ovary temperature-sensitive mutant (CHO-tsH1) with defective leucyl-tRNA synthetase at temperatures greater than 39 degrees C was used to examine the importance of protein synthesis in the development of thermotolerance. Its wild-type parent CHO-SC1 was used as the control. At temperatures of 41.5 degrees C, 42 degrees C and 42.5 degrees C, SC1 showed the classical biphasic thermotolerant response while tsH1 showed no thermotolerance. When both cell lines were heated for 15 min at 45 degrees C, then allowed to incubate at the permissive temperature of 35 degrees C and finally challenged with another 25 min treatment at 45 degrees C, tolerance was expressed in both cell lines. When the development incubation temperature was raised from 35 degrees C to the non-permissive temperature of 40 degrees C, tolerance was also observed. Although both cell lines expressed tolerance under these conditions, the magnitude and duration of response of the mutant cell line were reduced. Heat-shock protein analysis using one-dimensional gel electrophoresis showed that, under permissive conditions, the mutant cell was able to express the full spectrum of heat-shock proteins as seen in the wild-type cells. Under non-permissive conditions, little or no detectable proteins were synthesized in the mutant cell. We therefore postulate that the synthesis of new cytosol proteins is not required for the initial onset of thermotolerance but is necessary for the sustenance of tolerance.     

Surface of the brain: three-dimensional MR images created with volume rendering

Image processing and volume rendering have been applied to magnetic resonance (MR) images to produce three-dimensional views of the surface of the brain. Four healthy volunteers and 17 patients with a variety of disorders underwent MR imaging of the head, and these images were processed and subjected to volume rendering. The resulting three-dimensional views depict abnormalities of the brain surface, as well as important landmarks of normal brain surface anatomy such as precentral, postcentral, superior temporal, and inferior frontal gyri, which are difficult to identify on cross-sectional images.     

美国国家骨髓库无关供者造血干细胞移植20年回顾

自美国国家骨髓库(NMDP)开展第一例无关供者移植以来,至今已有20年.NMDP目前的库容量已逾700万,已为6大洲提供了30 000多份无关供者造血干细胞.这一辉煌成就是美国国家骨髓库600多名工作人员共同努力的结果,同时也得益于广泛的国际合作,包括171个移植中心,73个供者中心,24个脐血库,97个骨髓采集中心,91个血液净化中心,26个HLA分型实验室和26个合作供者登记处.本文回顾了美国国家骨髓库的历史,阐述了20年来移植病人、移植物来源和预处理方案几方面的主要变化趋势.     

美国国家骨髓库无关供者造血干细胞移植20年回顾

自美国国家骨髓库(NMDP)开展第一例无关供者移植以来,至今已有20年.NMDP目前的库容量已逾700万,已为6大洲提供了30 000多份无关供者造血干细胞.这一辉煌成就是美国国家骨髓库600多名工作人员共同努力的结果,同时也得益于广泛的国际合作,包括171个移植中心,73个供者中心,24个脐血库,97个骨髓采集中心,91个血液净化中心,26个HLA分型实验室和26个合作供者登记处.本文回顾了美国国家骨髓库的历史,阐述了20年来移植病人、移植物来源和预处理方案几方面的主要变化趋势.