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Objective:To investigate the protective effect of two doses of varicella vaccine in a population at high risk for varicella.Methods:The case group involved all varicella cases in classes with no less than three patients during varicella outbreaks in Tianjin schools from 2017 to 2019. A case-control study was carried out in a 1∶3 ratio. According to the seat position of each case, three nearby students who did not suffer from varicella were selected as controls. The protective effect of two doses of varicella vaccine was evaluated.Results:The total protective effect of varicella vaccine was 46.0% (95% CI: 42.7%-49.0%). The protective effect was 44.7% (95% CI: 41.2%-48.0%) for one-dose varicella vaccine and 80.0% (95% CI: 63.1%-89.2%) for two-dose varicella vaccine. For two doses of varicella vaccine, the protective effect was 87.6% (95% CI: 52.0%-96.8%) after 0-2 years and 76.6% (95% CI: 33.6%-91.5%) after 3-5 years.Conclusions:The protective effect of two doses of varicella vaccine is better than that of one dose. However, both one-dose and two-dose vaccines show decreased protective effect over time. A booster immunization could be considered in high-risk population with longer intervals since the last vaccination.
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Self-microemulsifying drug delivery systems (SMEDDSs) have recently returned to the limelight of academia and industry due to their enormous potential in oral delivery of biomacromolecules. However, information on gastrointestinal lipolysis and trans-epithelial transport of SMEDDS is rare. Aggregation-caused quenching (ACQ) fluorescent probes are utilized to visualize the
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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.
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Objective To investigate the clinical and epidemiological characteristics of 135 confirmed cases of COVID-19 in Tianjin. Methods The clinical and epidemiological data of 135 cases of COVID-19 in Tianjin were collected, and the data were analyzed with descriptive method. The factors influencing the severity of the illness were analyzed. Results Among the 135 COVID-19 cases, 72 were males and 63 were females, the age of the cases was (48.62±16.83) years, and the case fatality rate was 2.22%. Local transmission caused 74.81% of the cases. A total of 33 clusters occurred, involving 85.92% of all COVID-19 cases. The median of the incubation period of COVID-19 was 6.50 days, the average generation interval was 5 days, and the household secondary transmission rate was 20.46%. Fever was the main symptom (78.63%), followed by cough (56.48%). Multivariate regression analysis indicated that age ( OR =1.038, 95% CI : 1.010-1.167) and the number of chronic underlying diseases ( OR =1.709, 95% CI : 1.052-2.777) were the risk factors of severe illness. Conclusions Fever was the main symptom at the early phase of COVID-19 in Tianjin, and the local cluster cases accounted for high proportion in confirmed COVID-19 cases reported in Tianjin. Severe illness was prone to occur in people with old age and multi underlying diseases. Strict isolation of close contacts and intensive care of high-risk groups are the main measures to reduce the morbidity and case fatality of COVID-19.
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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.
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Objective To analyze the characteristics of antibiotic resistance in group A Streptococ-cus ( GAS) strains isolated from children with scarlet fever in Tianjin in order to provide reference for clinical drug administration. -ethods GAS strains were collected from 2011 to 2016. A total of 276 isolates were analyzed by antibiotic susceptibility test and emm typing. Results All of the isolates were susceptible to penicillin, cefazolin and vancomycin, while 98. 2％ were susceptible to both chloramphenicol and levofloxa-cin. The resistance rates to azithromycin, erythromycin, clarithromycin, clindamycin and tetracycline were 97. 8％, 97. 1％, 94. 2％, 94. 2％ and 79. 3％. The concomitant resistance to erythromycin, azithromycin, clarithromycin, clindamycin and tetracycline was 73. 2％. The resistance rates of GAS strains isolated from different years to tetracycline, clindamycin, clarithromycin, erythromycin and azithromycin were significantly different. A statistically significant difference was found between the percentages of emm12 and emm1 strains resistant to tetracycline (84. 0％ vs 59. 5％, χ2=13. 820, P=0. 000). Conclusions The isolated GAS strains are sensitive toβ-lactams and highly resistant to macrolide antibiotics, clindamycin and tetracycline. Penicillin remains the preferred treatment for GAS infection and cephalosporins may be used as a substitute if the patient is allergic to penicillin.
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Objective@#To investigate the etiological characteristics of Streptococcus pyogenes that caused scarlet fever from 2012 to 2016 in Tianjin.@*Methods@#The subjects were children diagnosed clinically as scarlet fever in Tianjin scarlet fever monitoring hospital from 2012 to 2016. The exclusion criteria were children with scarlet fever who were unable to cooperate with sampling. A total of 575 cases of children's swabs were collected. Biochemical methods were used to isolate and identify the bacteria of pharynx swab, and the PCR method was used to detect the emm genotyping and superantigen speA and speC, and the resistance of the strains to 10 antibiotics was measured by K-B paper method. We compared the carrying status of superantigen genes by different types of GAS and the resistance of all GAS to different antibiotics.@*Results@#There were 5 emm types (emm1/11/12/22/89). The dominant types were emm12 (52.9%, 100 strains) and emm1 (44.4%, 84 strains). The carrying rates of speA and speC genes were 21.7% (41 strains) and 76.7% (145 strains), respectively. The speA gene carrying rate of emm1 type GAS was 33.3% (28 strains), which were higher than that of emm12 (12% (12 strains)) (χ2=12.21, P<0.001). The speA and speC gene simultaneous carrying rate of emm1 type GAS was 27.4% (23 strains), which was higher than that of emm12 type (12% (12 strains)) (χ2=7.01, P=0.008). The percentages of the strains that were resistant to Azithromycin, Erythromycin, Clarithromycin, Clindamycin, Tetracyclin, Levofloxacin and Chloramphenicol were 96.8% (183 strains), 96.3% (182 strains), 92.1% (174 strains), 92.1% (174 strains), 73.0%(138 strains), 2.1% (4 strains) and 1.6% (3 strains), respectively. All isolates were susceptible to Penicillin, Cefazolin and Vancomycin, and there were statistical significance (χ2=953.28, P<0.001).@*Conclusion@#The dominant emm types causing scarlet fever are emm12 and emm1. The frequencies of speA and speC in emm1 and emm12 are different. S.pyrogenes in Tianjin were susceptible to penicillin, cefazolin and vancomycin, but highly resistant to the clindamycin, clarithromycin, erythromycin and azithromycin.
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Biomimetic nanocarriers are emerging as efficient vehicles to facilitate dietary absorption of biomacromolecules. In this study, two vitamins, thiamine and niacin, are employed to decorate liposomes loaded with insulin, thus facilitating oral absorption vitamin ligand-receptor interactions. Both vitamins are conjugated with stearamine, which works to anchor the ligands to the surface of liposomes. Liposomes prepared under optimum conditions have a mean particle size of 125-150 nm and an insulin entrapment efficiency of approximately 30%-36%. Encapsulation into liposomes helps to stabilize insulin due to improved resistance against enzymatic disruption, with 60% and 80% of the insulin left after 4 h when incubated in simulated gastric and intestinal fluids, respectively, whereas non-encapsulated insulin is broken down completely at 0.5 h. Preservation of insulin bioactivity against preparative stresses is validated by intra-peritoneal injection of insulin after release from various liposomes using the surfactant Triton X-100. In a diabetic rat model chemically induced by streptozotocin, both thiamine- and niacin-decorated liposomes showed a comparable and sustained mild hypoglycemic effect. The superiority of decorated liposomes over conventional liposomes highlights the contribution of vitamin ligands. It is concluded that decoration of liposomes with thiamine or niacin facilitates interactions with gastrointestinal vitamin receptors and thereby facilitates oral absorption of insulin-loaded liposomes.
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Objective To prepare methoxy polyethylene glycol (mPEG)-polycaprolactone (PCL) nanoparticles loading a water-quenching fluorescent probe and to evaluate its in vitro characteristics and stability.Methods PCL nanoparticles and mPEG-PCL nanoparticles with different mPEG chain lengths (mPEG5k,mPEG2k) loading the waterquenching fluorescent probe P2 were prepared by an emulsification/solvent evaporation method using PCL and mPEG-PCL as materials.In vitro characteristics such as morphology,particle size and distribution were evaluated.The P2 probe displayed fluorescent signals when encapsulated in the matrix of the nanoparticles,but quenched immediately when released into water.Based on this properties of P2 probe,the stability of various nanoparticles in different aqueous media was investigated.Results The prepared mPEG-PCL nanoparticles showed a particle size of about 200 nm,narrow size distribution,polydispersity index below 0.06 and near neutral surface potentials with spherical morphology and smooth surfaces.In buffers of different pHs and simulated bio-relevant media,all nanoparticles showed very good stability without significant change in particle size,polydispersity index and fluorescence intensity.Conclusion mPEG-PCL nanoparticles have promising in vitro characteristics and robust stability.It is fast and convenient to monitor the stability of nanoparticles by using the water-quenching probe.
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Objective To analyze the epidemiological characteristics of reported emergency public health events at schools from 2006 to 2013, and provide a scientific basis for better disposal of school-related events. Methods The reported emergency public health events at schools in Tianjin from 2006 to 2013 were collected, and descriptive epidemiological analysis was conducted on data. Results A total of 267 reported emergency public health events at school in Tianjin during 2006-2013, of which 257 infectious disease events, accounting for 96.25%. The incident occurred in primary schools and nurseries. The peak was from March to June and October to December for the incident. The top three species of disease onset were influenza (2 360 cases), chicken pox (2 032 cases) and mumps (1 813 cases). There was a correlation between the duration and interval from onset of the first case to report of emergency public health events(rs=0.522,P＜0.05). Conclusion In recent years, school public health emergency events are high momentum, mainly in rural areas, primary schools and nurseries. Timely detection and disposal of emergency public health events can reduce the harm generated by them.
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A series of noscapine analogues have been synthesized via 13-step reaction starting from 2-hydroxy-3-methoxybenzaldehyde. Anti-tumor activities of these compounds were evaluated against HL-60 cell lines in vitro by the standard MTT assay. It was found that most of these derivatives showed appreciable inhibitory activity against HL-60 and tubulin polymerization. The results also indicated that the potency of compound 31 is about three times more than that ofnoscapine against HL-60 cell line and tubulin polymerization. Moreover, it induced a massive accumulation of cells in G2/M phase. These results showed noscapine and its derivatives were worth to be intensively studied further.