The concepts of two modes of government Procurement,invitation bidding and public bidding,are explained. Their characteristics are also analyzed and compared to each other. That is very propitious for us to choose the better mode and get the most benefit of the public bidding.

Listeriamonocytogenes is a facultative intracellular bacterium that enters professional antigen presenting cells , presents passenger antigens to the major histocompatibility complex class I and II pathways ,then elicits CD+4 and CD+8 T-cell-mediated immune responses .It was demonstrated that attenuated Listeriamonocytogenes as a novel live vaccine vector in deliv-ering tumor antigens of cervical cancer and melanoma etc .,could induce strong protective immune response ,and shows effec-tive antitumor immunotherapeutics .This review discussed the characteristics of immune responses elicited by Listeria monocy-togenes ,and the progress of its antitumor immunotherapeutics as delivery vaccine vector .

The prevalence of human and animal listeriosis for nearly 11 years in China was investigated in this study . The literature information about listeriosis in China from 2002 to 2012 was collected through retrieval system to make clinical and epidemiological statistical analysis of listeriosis .Cases of listeriosis were reported in 27 (79% ) provinces of China .The re-sult showed that animal listeriosis was reported for 123 times ,among these reports ,most were from pigs (39% ) ,and the sheep was in second place .Central nervous system infection was the main clinical manifestation of listeriosis in animals (72% ) . For human listeriosis ,84 clinical cases of listeriosis were reported ,including 35% cases in non-perinatal stage and 65% cases in perinatal stage .The main clinical manifestation of listeriosis was septicemia (51% ) .According to the result of investigation about listeriosis based on literatures information ,Listeriamonocytogenes caused humans and animals listeriosis annually ,which were reported in most provinces of China .The epidemic characteristics for listeriosis suggested that it was essential to strength-en the prevention and control of listeriosis .

Objective:To explore the prognostic value of PD-L1 expression level in patients with metastatic renal cell carcinoma (mRCC).Methods:The clinicopathological and survival data of patients with mRCC in our hospital from Jan 2014 to Apr 2016 were retrospectively analyzed including 46 males and 15 females. The median age of these patients was 56 years(range: 29-75 years), with 41 patients ≤60 years and 20 patients >60 years. The baseline data before the systemic therapy showed 36 patients(59.0%)had 1 metastatic organ and 25 patients (41.0%) had equal or more than 2 organs to be metastasized. Among them, 17 patients(27.9%)had lung metastasis and 54 patients(88.5%)had liver metastasis. Abnormal baseline LDH occurred in 4 patients and 52 patients had normal LDH. Favorite and intermediate risk patients categorized by MSKCC risk stratification accounted for 59.6%(34 patients)and 40.4%(23 patients), respectively. Six patients(9.8%)experienced distant metastasis at initial diagnosis, with 4 of them undergoing primary site resection, and the other 55 patients undergoing radical nephrectomy. PD-L1 expression was detected by the immunohistochemical staining method. PD-L1 staining rate ≥1% detected on the tumor cell membrane was defined as positive expression. The correlation between PD-L1 expression and clinicopathological characteristics were compared. Kaplan-Meier method and log-rank test were used to compare the differences about DFS and OS under different factors. Cox proportional hazards regression model is used for multivariable analysis of survival data.Results:The detailed pathological types of the 61 patients with renal cell carcinoma were classified as 53 clear cell carcinomas, 3 papillary carcinomas, 1 collecting duct carcinoma, 2 translocation renal cell carcinomas and 2 being unclassified. There were 4, 20, 19 and 9 patients categorized as WHO/ISUP nuclear grade 1, 2, 3 and 4, and 26, 12, 20 and 2 patients were categorized as T 1, T 2, T 3 and T 4 stage, respectively. Five patients had regional lymph node metastasis(N+), and the other 56 patients had no regional lymph node metastasis(N-). The numbers of patients categorized as stage Ⅰ, Ⅱ, Ⅲ and Ⅳ diseases according to TNM staging system were 20, 11, 21 and 8, respectively. The total PD-L1 positive rate was 24.6%(15/61). The corresponding PD-L1 expression rate of patients with WHO/ISUP nuclear grade 1-4 were 0(0 patient), 5.0%(1 patient), 31.6%(6 patients)and 44.4%(4 patients), respectively; With the increasing WHO/ISUP nuclear grade, the positive rate of PD-L1 gradually escalated with a linear correlation ( P=0.006). The PD-L1 expression of the normal and abnormal LDH group were 19.2%(10 patients)and 75.0%(3 patients), respectively, with significant difference( P=0.035). Univariate analysis of disease-free survival time(DFS)showed that the prognostic factors include PD-L1( P=0.045), age group( P=0.014), WHO/ISUP nuclear grade( P<0.001), T stage( P=0.015), N stage( P=0.026)and TNM stage( P=0.005). However multivariate analysis only suggested WHO/ISUP nuclear grade as the independent prognostic factors for DFS( HR=1.8, 95% CI 1.1-2.9, P=0.018). Either in univariate or multivariate analysis, PD-L1 was not a prognostic factor for overall survival (OS)of mRCC patients(univariate analysis: P=0.154; multivariate analysis: P=0.902). The independent prognostic factors of OS include WHO/ISUP nuclear grade( HR=3.0, 95% CI 1.1-8.0, P=0.033)and MSKCC risk stratification( HR=5.9, 95% CI 1.2-29.7, P=0.03). Conclusions:This study showed that the higher the WHO/ISUP nuclear grade of patients with mRCC, the higher the positive rate of PD-L1. PD-L1 expression was not the independent prognostic factor for DFS or OS of mRCC.

[Abstract] Objective: To explore the expression patterns of melanoma lineage antigens and nuclear antigen Ki-67 and their correlations with survival in melanoma patients. Methods: A retrospective analysis was conducted to analyze the pathological data of melanoma patients treated at the Department of Melanoma, Peking University Cancer Hospital from February 2008 to August 2020, mainly including the expression patterns of melanoma lineage antigens (S-100, HMB-45, Melan-A) and Ki-67, demographics, clinical features and survival. The correlation between expression patterns of melanoma lineage antigens, Ki-67 and melanoma-specific survival (MSS) was analyzed. Results: In total, 603 patients were included in this study. The median follow-up time was 47.4 months. The positive rates of S-100, HMB, and Melan-A were 92.8%, 92.1% and 90.0%, respectively. The percentages of patients with melanoma lineage antigen scores (S-100, HMB-45 and Melan-A was scored each, as 1 when positive and 0 when negative) of 0, 1, 2, and 3 were 0.5%, 5.0%, 15.6%, and 78.8%, respectively. The percentages of patients with Ki-67 scores of 0, 1, 2, and 3 were 43.0%, 36.3%, 16.3%, and 4.5%, respectively. Ki-67 was highly expressed in mucosal and progressive melanomas. In a multivariate analysis, Ki-67 expression was an independent prognostic factor for poorer MSS (HR=1.506, 95%CI: 1.248-1.818, P<0.001) as the incidence of MSS event increased by 50% per 25% increase in Ki-67 expression, whereas there was no statistical correlation between melanoma lineage antigen expression and MSS (HR=0.991, 95%CI: 0.759-1.293, P=0.94). Conclusion: High expressions melanoma lineage antigens are ubiquitous in melanoma tissues, and Ki-67 is an independent prognostic factor for MSS.