Colorectal cancer(CRC)is the third most commonly diagnosed cancer in the world.The incidence and mortality show wide geographical variations.Screening is recommended to reduce both incidence and mortality.However,ther...Colorectal cancer(CRC)is the third most commonly diagnosed cancer in the world.The incidence and mortality show wide geographical variations.Screening is recommended to reduce both incidence and mortality.However,there are significant differences among studies in implementation strategies and detection.This review aimed to present the results and strategies of different screening programs worldwide.We reviewed the literature on national and international screening programs published in Pub Med,on web pages,and in clinical guidelines.CRC Screening programs are currently underway in most European countries,Canada,specific regions in North and South America,Asia,and Oceania.The most extensive screening strategies were based on fecal occult blood testing,and more recently,the fecal immunochemical test(FIT).Participation in screening has varied greatly among different programs.The Netherlands showed the highest participation rate(68.2%)and some areas of Canada showed the lowest(16%).Participation rates were highest among women and in programs that used the FIT test.Men exhibited the greatest number of positive results.The FIT test has been the most widely used screening program worldwide.The advent of this test has increased participation rates and the detection of positive results.展开更多
Dear Editor, The PIWI proteins （originally P-element-induced wimpy testis in Drosophila） are predominantly present in the germ-line in diverse organisms and are involved in the processing of a class of small RNAs kn...Dear Editor, The PIWI proteins （originally P-element-induced wimpy testis in Drosophila） are predominantly present in the germ-line in diverse organisms and are involved in the processing of a class of small RNAs known as piRNAs （see Refs. for review）. The human PIWI protein family consists of four members： PIWIL1-4. Of these, PIWIL4 is known to have essential roles in the first phases ofspermatogenesis： its expression is restricted to gonocytes and it is required for transposon silencing. The lack of this gene in mice causes meiotic arrest in spermatogenesis.展开更多
文摘Colorectal cancer(CRC)is the third most commonly diagnosed cancer in the world.The incidence and mortality show wide geographical variations.Screening is recommended to reduce both incidence and mortality.However,there are significant differences among studies in implementation strategies and detection.This review aimed to present the results and strategies of different screening programs worldwide.We reviewed the literature on national and international screening programs published in Pub Med,on web pages,and in clinical guidelines.CRC Screening programs are currently underway in most European countries,Canada,specific regions in North and South America,Asia,and Oceania.The most extensive screening strategies were based on fecal occult blood testing,and more recently,the fecal immunochemical test(FIT).Participation in screening has varied greatly among different programs.The Netherlands showed the highest participation rate(68.2%)and some areas of Canada showed the lowest(16%).Participation rates were highest among women and in programs that used the FIT test.Men exhibited the greatest number of positive results.The FIT test has been the most widely used screening program worldwide.The advent of this test has increased participation rates and the detection of positive results.
文摘Dear Editor, The PIWI proteins （originally P-element-induced wimpy testis in Drosophila） are predominantly present in the germ-line in diverse organisms and are involved in the processing of a class of small RNAs known as piRNAs （see Refs. for review）. The human PIWI protein family consists of four members： PIWIL1-4. Of these, PIWIL4 is known to have essential roles in the first phases ofspermatogenesis： its expression is restricted to gonocytes and it is required for transposon silencing. The lack of this gene in mice causes meiotic arrest in spermatogenesis.
