From a subtracting cDNA library constructed from normal liver versus human primary hepatic cancer (PHC), a cDNA clone pG8 was isolated. Using it as a probe, RNA extracted from one human liver and 9 PHC samples were an...From a subtracting cDNA library constructed from normal liver versus human primary hepatic cancer (PHC), a cDNA clone pG8 was isolated. Using it as a probe, RNA extracted from one human liver and 9 PHC samples were analyzed by Northern hybridization. As expected, its mRNA was highly expressed in liver; however, the expression was strikingly suppressed in PHC. Only weak signal was observed in 2 out of 9 PHC, while no signal was detectable in the other 7 samples. Utilizing pG8 as a probe, DNA from the same PHC specimens was analyzed after MspI digestion and Southern hybridization. Deletion of DNA fragment was observed in 4 out of 9 samples. In further study of cancer and non-cancerous liver from other 7 PHC patients, similar deletion of DNA fragments in cancer was observed in 4 out of 7 samples. After sequencing of the clone of 572 bp, it was unexpectedly found that pG8 was completely homologous to the coding sequence of transthyretin, TTR gene, as TTR (or prealbumin) gene has been known to be linked to a hereditary disorder, familial amyloidosis (FAP), and related to thyroxine transport and binding to retinol-RBP (the retinol binding protein) complex. This is the first report of a study on TTR in human primary hepatic cancer. Since TTR gene was strikingly suppressed in mRNA expression and possibly defective in its gene structure, it was strongly implicated that TTR might be an important gene marker or a candidate of anti-oncogene for human PHC. The biological activity of TTR gene is under study.展开更多
The deep_sea floor images are acquired under non_uniform illumination,the effects of which bring up many difficulties for image segmentation.The paper compares three methods of removing non_uniform illumination effect...The deep_sea floor images are acquired under non_uniform illumination,the effects of which bring up many difficulties for image segmentation.The paper compares three methods of removing non_uniform illumination effects.The effectiveness and robustness are evaluated on three test images with high_,moderate_ and low_density grains,respectively.The results show that local filtering algorithm does not remove the non_uniform illumination effects completely.The image subtracting algorithm will lose some of the dynamic range of the original data.The enhanced image stretching algorithm is the most effective one.展开更多
文摘From a subtracting cDNA library constructed from normal liver versus human primary hepatic cancer (PHC), a cDNA clone pG8 was isolated. Using it as a probe, RNA extracted from one human liver and 9 PHC samples were analyzed by Northern hybridization. As expected, its mRNA was highly expressed in liver; however, the expression was strikingly suppressed in PHC. Only weak signal was observed in 2 out of 9 PHC, while no signal was detectable in the other 7 samples. Utilizing pG8 as a probe, DNA from the same PHC specimens was analyzed after MspI digestion and Southern hybridization. Deletion of DNA fragment was observed in 4 out of 9 samples. In further study of cancer and non-cancerous liver from other 7 PHC patients, similar deletion of DNA fragments in cancer was observed in 4 out of 7 samples. After sequencing of the clone of 572 bp, it was unexpectedly found that pG8 was completely homologous to the coding sequence of transthyretin, TTR gene, as TTR (or prealbumin) gene has been known to be linked to a hereditary disorder, familial amyloidosis (FAP), and related to thyroxine transport and binding to retinol-RBP (the retinol binding protein) complex. This is the first report of a study on TTR in human primary hepatic cancer. Since TTR gene was strikingly suppressed in mRNA expression and possibly defective in its gene structure, it was strongly implicated that TTR might be an important gene marker or a candidate of anti-oncogene for human PHC. The biological activity of TTR gene is under study.
文摘The deep_sea floor images are acquired under non_uniform illumination,the effects of which bring up many difficulties for image segmentation.The paper compares three methods of removing non_uniform illumination effects.The effectiveness and robustness are evaluated on three test images with high_,moderate_ and low_density grains,respectively.The results show that local filtering algorithm does not remove the non_uniform illumination effects completely.The image subtracting algorithm will lose some of the dynamic range of the original data.The enhanced image stretching algorithm is the most effective one.
