Objective:To construct and prepare recombinant virus strains chimeric with human metapneumovirus (HMPV) antigenic epitopes.Methods:Recombinant influenza virus vectors which chimeric with different HMPV antigenic epitopes were rescued by reverse genetics using eight-plasmid system. The recombinant influenza virus strain used the internal genes of A/PR/8/34 (PB1, PB2, PA, NP, NS, M, HA, and NA) as a backbone, with concomitant genetic modifications to insert the B-cell epitopes of HMPV into the HA gene, and the CTL+ Th cell epitopes of HMPV into the NA gene. Preparation of recombinant influenza virus strains using reverse genetics in a " 7+ 1" model. The recombinant virus strains were evaluated by measuring hemagglutinin (HA) titers, half tissue culture infectious dose (TCID 50) and growth curves. Sequencing analysis was conducted to verify whether the rescued viruses carried the chimeric HMPV epitopes. Results:The epitopes of HMPV were inserted into the influenza virus genome and two recombinant influenza virus strains were rescued successfully, named as FLU/HMPV/B and FLU/HMPV/CTL+ Th. HA titers of the recombinant strains were both 2 7, their TCID 50 were 10 5.2/ml and 10 5.0/ml, respectively. After cultured for three passages in chick embryo, these two recombinant strains could proliferate steadily. Whole genome sequencing verified that the FLU/HMPV/B carried the B-cell epitopes of HMPV, the FLU/HMPV/CTL+ Th carried the CTL and Th cell epitopes of HMPV. Growth curve tests also verified that the recombinant strains could proliferate steadily in eggs. Conclusions:Two recombinant influenza virus vector strains carrying the B cell, CTL and Th epitopes of HMPV were rescued successfully. The result of the recombinant virus strains in terms of growth characteristics as well as genetic stability indicate that they meet the requirements for proceeding to the next step of animal experiments. The immunogenicity and immunoprotective effect will be further evaluated by mouse experiments. Ultimately new ideas for the realization of " one vaccine for two uses" or " one vaccine formultiple uses", as well as a new strategy for the development of HMPV vaccine will be proposed.

Objective:To investigate the epidemiological and genetic characteristics of human metapneumovirus (hMPV) in Tianjin during two influenza epidemic seasons from October 2020 to March 2021 and from October 2021 to March 2022, and enrich the whole genome database of hMPV in China.Methods:A total of 1 040 pharyngeal swab samples collected from patients with influenza-like illness (ILI) were analyzed using microfluidic chip fluorescence quantitative PCR. RT-PCR was used to amplify the whole genome in hMPV-positive samples, and the second-generation sequencing was performed for complete genome sequencing. Bioinformatics software including CLC, DNAStar, and MEGA was used for sequence assembly, nucleotide and amino acid homology analysis, and phylogenetic tree mapping.Results:Among the 1 040 samples, 25 were positive for hMPV with a positive rate of 2.40%. The highest positive rate was observed in the age group of 3 to 5 years, reaching 3.71% (16/431). During the influenza epidemic seasons, the detection rate of hMPV peaked in December, reaching 6.67% (12/180). Twelve strains were successfully sequenced, and there were seven of type B2, four of type A2b, and one of type B1. More variations were detected in the G gene, with 111nt-dup sequence repeats observed in the G gene of three A2b strains.Conclusions:The prevalence of hMPV peaks in December during the influenza epidemic seasons in Tianjin, with Type B2 being the predominant type. Except for the G gene with more mutations, other genes remain stable.

Objective:To investigate the efficacy of different treatment modes for locoregional recurrence after nephrectomy in patients with renal cell carcinoma.Methods:A total of 106 patients with locoregional recurrence after nephrectomy without distant metastasis (77 males and 29 females) admitted to Sun Yat-sen University Cancer Center from October 2001 to July 2020 were retrospectively analyzed. The median age was 51 (40, 60) years old. Radical nephrectomy was performed in 90 patients with primary tumor and partial nephrectomy was performed in 16 patients. Pathological diagnosis showed that 54 cases were clear cell carcinoma and 52 cases were non-clear cell carcinoma. 53 cases were in stage T 1-2 and 53 cases in stage T 3-4. The median diameter of recurrent lesions was 3.2 (2.0, 6.3) cm, and the median number was 2 (1, 4). The recurrence sites were divided into renal fossa recurrence (33 cases), renal fossa±retroperitoneal lymph node recurrence (38 cases), and intra-abdominal spread (35 cases). The median duration from primary surgery to local recurrence was 14.8 (7.3, 35.8) months. Two treatment groups were identified as systemic therapy alone (Group A) and local therapy with or without systemic therapy (Group B). The Kaplan-Meier method was used to compare the progression free survival (PFS) and overall survival (OS) between Group A and Group B. The Cox model was used to perform univariate and multivariate analysis. Results:Of all the 106 patients, 33 patients were in Group A and 73 patients were in Group B. In Group A, 29 patients (87.9%) received targeted therapy, and 4 patients (12.1%) received targeted therapy combined with immunotherapy. In Group B, 34 patients (46.6%) received surgery or ablation and 39 patients (53.4%) received SBRT, of which 62 patients (84.9%) received concurrent systemic therapy. Among them, 58 patients (93.5%) received targeted therapy, and 4 patients (6.5%) received targeted therapy combined with immunotherapy. The median follow-up period was 29.0 (15.4, 45.9) months, 64 patients progressed on tumor including 28 patients died. The median PFS and OS were 15.6 (7.1, 35.2) months and 66.9 (37.8, not reached) months. The median PFS of Group A and Group B were 7.6(5.0, 17.2)months and 22.2(9.6, 63.9)months respectively ( P=0.001), median OS of Group A and Group B were 45.7 (23.4, 62.8)months and 71.0(50.6, not reached)months respectively, and the 2-year OS were 70.6% and 85.5% in Group A and Group B respectively ( P=0.023). The univariate analysis showed local therapy with or without systemic therapy was significantly reduced 56% risk of tumor progression ( HR=0.44, P=0.003) and reduced 60% risk of death ( HR=0.40, P=0.028). The multivariate analysis showed that the OS was associated with ECOG score( HR=10.20, 95% CI 4.13-25.30, P<0.001)and local therapy( HR=0.23, 95% CI 0.09-0.58, P=0.002). Conclusion:Compared with systemic therapy alone, local therapy with or without systemic therapy can effectively improve the PFS and OS of patients with locoregional recurrence after nephrectomy.

Objective:To analyze the clinically acceptable and reproducible bladder and rectum volumes of prostate cancer patients during radiotherapy under bladder and bowel preparation, aiming to provide quantitative indicators for bowel and bladder preparation before and after radiotherapy.Methods:Clinical data of 275 prostate cancer patients with strict bladder and bowel preparation and completion of whole course radical radiotherapy at Sun Yat-sen University Cancer Center from April 2015 to December 2020 were retrospectively analyzed. Patients were scanned with cone beam CT (CBCT) before each treatment and the setup error was recorded. Sixty-six patients were selected by simple random sampling and the bladder and rectum on daily CBCT was outlined using MIM software. The relationship between the ratio of daily bladder or rectum volume to the planned bladder or rectum volume (relative value of volume) and setup error was analyzed. Quantitative data were expressed as mean±SD. Normally distributed data were analyzed by paired t-test while non-normally distributed data were assessed by Kruskal-Wallis test.Results:The bladder and rectum volume on planning CT were (370.87±110.04) ml and (59.94±25.07) ml of 275 patients. The bladder and rectum volumes on planning CT were (357.51±107.38) ml and (65.28±35.37) ml respectively of the 66 selected patients with 1611 sets of CBCT images. And the bladder and rectum volumes on daily CBCT were (258.96±120.23) ml and (59.95 ± 30.40) ml. The bladder volume of patients was decreased by 3.59 ml per day on average during the treatment and 0.37 ml for the rectum volume. According to the bladder volume on planning CT, all patients were divided into three groups: <250 ml, 250-450 ml and >450 ml groups. The relative value of volume in the 250-450 ml group during the course of radiotherapy was the smallest. And the setup error in the superior and inferior (SI) direction was (0.28±0.24) cm and (0.19±0.17) cm in the left and right (LR) direction, significantly lower than those in the other two groups (both P≤0.027). According to the rectum volume on planning CT, all patients were divided into four groups: <50 ml, 50-<80 ml, 80-120 ml and >120 ml groups. The <50 ml group had the smallest relative value of volume during radiotherapy, and the setup error in the SI direction was (0.26±0.22) cm and (0.24±0.22) cm in the anterior and posterior (AP) direction, significantly smaller than those in the other groups (both P≤0.003). The setup errors in the SI, LR, AP directions of the enrolled 66 patients were (0.30±0.25) cm, (0.20±0.18) cm and (0.28±0.27) cm, respectively. Among them, the relative value of bladder volume in the AP direction was (0.73±0.37) in the setup error <0.3 cm group, which was statistically different from those in the setup error 0.3-0.5 cm and >0.5 cm groups (both P<0.05). Conclusion:Under the bladder and bowel preparation before planning CT, the appropriate bladder and rectum volumes are in the range of 250-450 ml and <50 ml, which yields higher reproducibility and smaller setup error.

Objective:To provide evidence for the selection of fixation devices and CTV to PTV margins (M ptv) in precision radiotherapy for pelvic tumors by analyzing three fixation devices in precision radiotherapy for prostate cancer. Methods:From April 2015 to December 2020, 133 prostate cancer patients treated with pelvic drainage area irradiation in our center were retrospectively analyzed. The patients were fixed with 1.2m vacuum bag (n=39), 1.8m vacuum bag (n=44) and personalized prone plate by our center (n=50). Each patient was asked to complete our bowel and bladder preparation process before positioning and radiotherapy. The registration of CBCT to planned CT before each treatment adopted the same registration box and algorithm. Setup errors in the SI, LR and AP directions under qualified bowel and bladder conditions were recorded. Setup errors in three directions under three fixation devices and corresponding M ptv values were analyzed. The correlation between setup errors with age and body mass index (BMI) was analyzed. Results:Analysis of 3333 setup errors data showed: in the SI and LR directions, the mean setup errors of 1.2m vacuum bag (3.26mm, 2.34mm) were greater than those of 1.8m vacuum bag (2.51mm, P<0.001; 1.90mm, P<0.001), and personalized prone plate (3.07mm, P=0.066; 2.10 mm, P=0.009). In the AP direction, the mean setup errors of 1.2m vacuum bag (supine)(2.20mm) were smaller than those of 1.8m vacuum bag (3.33mm, P<0.001) and personalized prone plate (3.61mm, P<0.001). The setup errors of 1.8m vacuum bag in all directions were smaller than those of personalized prone plate (P≤0.028). According to Van Herk's expansion formula, the M ptv of 1.2m vacuum bag in three directions was approximately 4 mm. The M ptv of 1.8m vacuum bag and personalized prone plate in the SI and LR directions was approximately 3 mm, and more than 5 mm in the AP direction. The setup errors were not correlated with age or BMI. Conclusions:From the setup errors results of three devices, 1.8m vacuum bag is the best, followed by personalized prone plate. And supine position is better than prone position in the AP direction.

Objective:To understand the epidemiological characteristics and pathogenic spectrum of influenza-like illnesses in Tianjin Children′s Hospital from October 2020 to March 2021, and to provide reference for the prevention, control and clinical diagnosis and treatment of influenza-like illnesses.Methods:A total of 520 throat swabs samples were collected from patients with influenza-like illnesses in sentinel hospitals. Thirty respiratory tract pathogens were detected by real-time fluorescence quantitative PCR. The results were statistically analyzed by descriptive epidemiological methods.Results:Among the 520 samples, 239 were positive for 16 respiratory pathogens with a positive rate of 45.96%. The top three pathogens were respiratory syncytial virus (9.62%, 50/520), rhinovirus (9.62%, 50/520) and cytomegalovirus (5.96%, 31/520). The positive rate of respiratory pathogens was 49.67% in males and 40.91% in females and the difference between males and females was statistically significant (χ 2=3.919, P<0.05). There were significant differences in the positive rates among three age groups (χ 2=6.182, P<0.05) with the highest positive rate in the <2 years old group (52.91%, 91/172) and the lowest rate in the >4 years old group (38.10%, 40/105). There were significant differences in the positive rates detected in different months (χ 2=15.358, P<0.05) and the highest detection rate was in December (58.00%, 58/100), followed by those in November (52.50%, 42/80) and January (47.50%, 38/80). The multiple infection rate was 21.76% (52/239) and most of the multiple infections were caused by rhinovirus and other pathogens (48.08%, 25/52). Conclusions:Respiratory syncytial virus, rhinovirus and cytomegalovirus were the predonimant pathogens responsible for influenza-like illnesses in Tianjin Children′s Hospital from October 2020 to March 2021. Multiple infections were common and children under 2 years old were more susceptible. The detection rate of respiratory pathogens varied in different months. It was necessary to strengthen the surveillance and research on those respiratory pathogens in order to provide scientific data for the prevention and control of respiratory diseases in children.

Objective To investigate and analysis the epidemiological characteristics of a cluster epidemic of COIVD-19 in a collective workplace in Tianjin, evduate the prevention and control measures based on limited evidence and experience in early period of COVID-19 epidemic. Methods Descriptive research method was used to describe the distribution and other epidemiological characteristics of the cluster cases of COVID-19. Results Since the onset of the first index case on January 15, ten confirmed COVID-19 cases had occurred in the workplace, and the epidemic had spread from the workplace to 4 families, infecting 7 family members. The median age of 17 cases was 55 (19-79) years. All the 10 employee cases were males, and in 7 family cases, 3 were males and 4 were females. Of the employee cases, 8 worked in CW workshop and 2 worked in administrative office building. The median exposure-onset interval of all the cases was 4 (0-12) days, and the median exposure-onset interval was 4.5 days in the employee cases and 4 days in the family cases. The median onset-medical care seeking interval was 4 days in the non-isolated cases, 2.5 days in the cases with home isolation after onset, and 0.5 day in the cases with home isolation before onset. Conclusion The clustering of COVID-19 cases was observed in this workplace in Tianjin, which affected 4 families. In the early stage of the epidemic, accurate and rapid blocking and control measures can completely prevent the large-scale spread of COVID-19.

Objective:To evaluate the efficacy and safety of Tyrosine Kinase Inhibitors (TKIs) combined with stereotactic body radiation therapy(SBRT) in the treatment of renal cell carcinoma (RCC) patients with bone metastasis.Methods:The clinical data of 80 RCC patients with bone metastasis in Sun Yat-sen University Cancer Center from April 2010 to April 2020 were analyzed retrospectively. Among them, 64 patients were medium or high risk according to the International Metastatic Renal Cell Carcinoma Database Consortium(IMDC) score. Twenty-four patients received TKI therapy alone(Group A), and the other 56 cases received TKIs combined with SBRT to bone metastastic lesions (Group B).Results:The median follow-up period was 20.7 months (4.8-115.6 months), 70 patients received second or third-line targeted drug therapy, and 4 patients in group A and 15 patients in group B received TKI plus immunotherapy. Fifty-four patients had symptoms of bone pain before radiotherapy, 46 patients were satisfied with the analgesic effect after SBRT treatment. Twelve patients got complete response (CR) after bone lesions, and 32 patients achieved partial response (PR). Forty patients died of disease progression during follow-up. The median OS was: 20.7 months vs not reached(Group A vs. Group B), and the 2-y OS and 5-y OS were 50% vs. 62%, and 19% vs. 56%, respectively ( P=0.006). There were only 2 patients (3.6%) had grade 3 SBRT related adverse events. Conclusions:SBRT combined with TKIs improved the quality of life and prolonged the overall survival of RCC patients with bone metastasis.

Objective:To investigate the efficacy and safety of daratumumab in relapsed and refractory multiple myeloma (RRMM).Methods:The efficacy and adverse events (AEs) of daratumumab based regimens were retrospectively analyzed in 37 patients with RRMM from Peking University People′s Hospital, Beijing Hospital and Fu Xing Hospital affiliated to Capital Medical University in China. The deadline for inclusion was December, 2019.Results:Among the 37 patients, 35 patients were available for response evaluation. The overall response rate (ORR) was 68.6%, which was better in patients receiving 16 mg/kg daratumumab than in those with fixed doses of 800 mg daratumumab [ORR: 78.3%(18/23) vs. 40.0%(4/10)]. The percentage of infusion related reactions of daratumumab was 27.0%(10/37). The most common hematological AEs were lymphocytopenia and thrombocytopenia, with the incidences of grade 3 or more severe 59.5%(22/37) and 43.2%(16/37) respectively. Pulmonary infections(37.8%, 14/37) were the most common non-hematological AEs. One patient with positive hepatitis B surface antigen (HBsAg) and two patients dependent on dialysis were safely treated with daratumumab.Conclusion:Daratumumab is highly effective in relapsed and refractory multiple myeloma. Adverse reactions are mild and well tolerable.

Objective:To study the characteristics and influence factors of laboratory test results of confirmed COVID-19 cases in Tianjin.Methods:Sample collection was conducted based on the standard operating procedure. Tianlong automatic magnetic bead nucleic acid extraction reagent was used for RNA extraction. Real-time RT-PCR was performed using four approved COVID-19 nucleic acid detection kits. Related epidemiological data of the cases were collected. One-way analysis of variance and non-parametric test for inter-group differences analysis were conducted using SPSS25.0 software.Results:A total of 162 PCR tests were completed for novel coronavirus nucleic acid detection in 123 confirmed COVID-19 cases. Eleven PCR results were positive for a single target gene and 10 of which were positive for nucleocapsid protein (N) gene. Nineteen cases were tested with two kinds of nucleic acid detection kits and the results of different detection kits were different. Different types of samples were collected form 13 cases for nucleic acid detection and the results showed that the Ct value of sputum sample was lower than that of throat swab sample. No significant difference in Ct values of throat swab samples was observed among patients with different clinical symptoms ( PCt-N=0.797, PCt-ORF1a/b=0.551). The 123 cases were divided into different groups according to the time interval between the onset date and the date of the first positive detection of viral nucleic acid. No significant difference in Ct values of throat swab samples was observed among different time interval groups ( PCt-N=0.373, PCt-ORF1a/b=0.058). Conclusions:Sputum samples were better than upper respiratory tract samples for viral nucleic acid detection. The sensitivity of N gene detection was higher, but re-sampling was needed when the result was positive for the single target N gene. Appropriate detection kits should be selected according to the actual needs, and samples should be collected at multiple time points, in multiple types and form multiple sites for detection.