Objective:To construct suitable vectors for the secretory expression of hirudin in Pichia pastoris.Methods:The α-facor-hirudin gene was amplified from pPIC9-hirudin by PCR and sub-cloned into PA0815.The multi-copy recombinant plasmid pA0815-(α-Hirudin)n was constructed.The recombinant was transformed into P.pastoris strain GS115 for induction expression and then the activity of secreted products was identified.Results:A new multi-copy vector pA0815-(αHirudin)n was successfully constructed and was capable of secreting recombinant hirudin efficiently,which was confirmed respectively by PCR and SDS-PAGE.The products possessed the activity of thrombin inhibitor.Conclusion:This result offers efficient P.pastoris stains for mass production of biological active hirudin.

Objective: To determine the screening and early detection reference age for individuals with family history of cancer in either one of the parents. Methods: We examined the family history of 33 200 subjects who visited the Department of Cancer Prevention, National Cancer Center and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College between January 2008 and March 2018 for cancer screening and early detection. The age differences between the subjects in the research population were analyzed using an independent t-test. All statistical analysis was performed using IBM SPSS Statistics for Windows version 24.0 (IBM Corp., Armonk, NY, USA). Results: We documented 480 families in which fathers and one or more of their children were diagnosed with malignancies, attributing to 614 father-child pairs. We also documented 476 families with mothers and one or more of their children diagnosed with malignancies, attributing to 614 mother-child pairs. In total, we included 956 families in our study with a total of 505 sons and 723 daughters diagnosed with cancer during the study period. In the father-child group the average age at diagnosis for fathers, sons, and daughters were 66.6±10.8, 56.6±11.7, and 51.7±11.7 years, respectively. Sons and daughters were diagnosed with malignancy 10.0 and 14.9 years earlier than their fathers, respectively (P<0.001). Daughters developed malignancies approximately 5 years earlier than sons in the father-child group (P<0.001). In the mother-child group, the average age at diagnosis for mothers, sons, and daughters were 65.8±12.2, 57.8±12.2, and 52.3±12.4 years, respectively. Mothers were diagnosed with malignant disease 8 years later than their sons (P<0.001) and 13.5 years later than their daughters (P<0.001). Interestingly, daughters developed malignant diseases 5.5 years earlier than sons even in this group (P<0.001). Average age at diagnosis for subjects whose fathers and mothers developed malignancy before 50 years was 4.8 years and 4.4 years earlier than those whose fathers and mothers developed malignancy after 50 years old (P<0.05, P<0.001). Sons and daughters were diagnosed with lung cancer 9.3 and 12.6 years earlier than the fathers, and 10.2 and 13.6 years earlier than the mothers, respectively (P<0.001).The daughters in the mother-children group and the father-daughter group were diagnosed with breast cancer 10.5 and 11.1 years earlier than the mothers in the mother-child group (P<0.001). Conclusions Children develop malignancy earlier than their parents in families with cancer in parents and children. Hence, individuals with a family history of cancer in either of their parents should undergo interventions for cancer screening and early detection at a relatively earlier age compared to the initial screening age recommended by conventional screening guidelines for certain cancers.

Objective To investigate the role and significance of opportunistic screening in cervical cancer screening for elderly women aged≥65 years old. Methods The screening data of 1 304 elderly women (≥65 years old) who underwent opportunistic screening for cervical cancer at the Cancer Hospital, Chinese Academy of Medical Sciences, between January 1, 2010, and December 31 st, 2018, were analyzed retrospectively. Women who underwent cervical cytology tests and human papillomavirus (HPV) testing were divided into two groups according to age as following 65-69 and ≥70 years old. Women with abnormal cytology or who were hrHPV-positive were followed up. The cervical cytological abnormalities and high-risk HPV infection rates in women aged≥65 years in opportunistic screening were analyzed. Results Of all cases, 175 had abnormal cytology or were hrHPV-positive. Among the 1 304 women, 69 were TCT-positive, with a positivity rate of 5.3%, including 17 cases (24.6%) of high-degree squamous intraepithelial neoplasia and 3 cases (4.4%) of squamous cell carcinoma. The total abnormality rate of TCT in the 65-to 69-year age group (6.7%, 43 cases) was significantly higher than that in the≥70 age group (3.9%, 26 cases), and the difference was statistically significant between the two groups (P=0.024). The overall prevalence of hrHPV infection was 10.7% (139/1 304). HPV58 (31/174, 17.9%) was identified as the most common high-risk HPV type, followed by HPV16, HPV52, HPV33, and HPV31. Follow-up showed that 50.3% of the women had never been screened in the past 10 years, and no statistically significant difference in TCT abnormality and hrHPV infection positivity rate were found between those who had been screened (80 cases) and those who had not been screened at least once in 5 years (87 cases) (P>0.05). Conclusion Attention should be paid to the screening for cervical cancer in elderly women aged ≥65 years old. Opportunistic screening is a supplement to the population-based organized cervical cancer screening. The termination age of cervical cancer screening for elderly women may be appropriately extended.