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Objective:To understand the etiology and clinical characteristics of hospitalized severe community-acquired pneumonia(SCAP) in Changchun, and provide scientific basis for its etiology diagnosis and targeted treatment.Methods:The study subjects included 618 children with clinical diagnosis of SCAP who were hospitalized from January 2016 to December 2019.We collected pharyngeal swabs and alveolar lavage fluid from children.Virus isolation, bacterial culture, time-of-flight mass spectrometry, PCR/RT-PCR, colloidal gold method and Optochin test were used to detect the antigen, nucleic acid and protein profiles in the specimen.Results:There were more boys than girls in hospitalized children with SCAP.The peak age of onset was 7 to 12 months.Most cases occurred in winter and spring.The highest detection rate of SCAP virus was 56.15%(347/618); 73.49%(255/347) were positive for one virus, among which the top five were respiratory syncytial virus (27.8%), influenza A virus (23.9%), influenza B virus (16.1%), rhinovirus (12.2%) and metapneumovirus (10.2%). Two viruses were positive for 19.88%(69/347); three viruses were positive for 4.32%(15/347); four viruses were positive for 2.31%(8/347). Atypical microbial infections were 29.77%(184/618), of which Mycoplasma pneumoniae accounted for 95.65%(176/184). Bacterial infections were 17.31%(107/618), mainly Streptococcus pneumoniae(39.25%, 42/107) and Staphylococcus aureus(24.30%, 26/107). The mixed infection of multiple pathogens was 7.61%(47/618), among which the mixed infection rates of Mycoplasma pneumonia with Streptococcus pneumoniae, virus were 40.43% and 34.04%, respectively.High fever, faster breathing, and perioral cyanosis were risk factors for SCAP, with OR and 95% CI of 7.71 and 4.56-13.04, 2.43 and 2.02-2.93, 3.53 and 2.56-4.86, respectively.Viral co-infection occurred in 36.96%(34/92) of complications such as heart failure, toxic encephalopathy, and myocardial damage; Mycoplasma pneumoniae and other pathogens co-infected 35.29% of children with pleural effusion. Conclusion:The pathogens of SCAP in Changchun are mainly viruses notably, respiratory syncytial virus is the dominant pathogen, followed by Mycoplasma pneumoniae.The bacterial pathogen is mainly Streptococcus pneumoniae.High fever, faster breathing, and cyanosis around the mouth are risk factors for severe pneumonia.Multi-pathogen mixed infection is prone to serious complications.
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Objective:To clarify the infection and epidemic characteristics of the human metapneumovirus (HMPV) in Chinese patients with febrile respiratory syndrome (FRS), and to provide important baseline data for clinical diagnosis, treatment, prevention and control of HMPV-induced respiratory tract diseases in China.Methods:FRS cases from January 2009 to June 2021 in 9 provinces in China, including Beijing, Hebei, Jilin, Shandong, Shaanxi, Xinjiang, Anhui, Guangdong, Hunan were retrospectively analyzed for their respiratory samples, clinical and epidemic data.The respiratory samples were detected for HMPV by quantitative real-time PCR.Results:A total of 11 660 cases were tested for HMPV, involving 296 (2.54%) HMPV-positive cases.Among 296 HMPV-positive cases, 218 were single HMPV infection, and 78/296 (26.35%) were co-infected with one or more respiratory viruses.HMPV mainly affected children under 5 years of age (3.10%), and in this population, the proportion of pneumonia in HMPV co-infection cases was significantly higher than that of single HMPV infection.HMPV could be detected all year round, which was more popular in winter and spring, with the peak of HMPV epidemic in March.Conclusions:HMPV is one of the important pathogens causing acute respiratory infection in children, showing a clear seasonal epidemic.HMPV can be infected alone or in combination with other respiratory viruses, which may increase the risk of pneumonia in children.
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Objective To evaluate the inhibitory effect of fenretinide-loaded liposomes(4-HPR-L) on subcutaneous transplanted malignant melanomas in nude mice.Methods A film-ultrasonic dispersion method was used to prepare 4-HPR-L.BALB/c nude mice were subcutaneously inoculated with A375 melanoma cells in the right axillary fossae to establish malignant melanoma-bearing nude mouse models.Ten nude mouse models were randomly and equally divided into 2 groups to be injected with near-infrared fluorescent cell membrane label (DiR) solution or DiR liposomes (DiR-L)at the same concentration in the caudal vein,and a live imaging system was used to observe the distribution of DiR or DiR-L in nude mice at 6,12,24 hours after the injection.Another 30 nude mice were randomly and equally divided into 3 groups to be injected with 5％ (mass fraction) glucose solution at a single-dose of 0.2 ml (control group),25 mg/kg 4-HPR solution (4-HPR group)and 25 mg/kg 4-HPR-L solution (4-HPR-L group) respectively on days 8,10,12,14,16,18,20 and 22 after the inoculation with A375 cells.The mouse body weight and tumor volume were dynamically monitored in the above groups after the injection,and the survival situation was observed.The nude mice were sacrificed on day 2 after the final injection,and the heart,liver,spleen,lung,kidney and tumor tissues were resected.These tissues were subjected to hematoxylin-eosin staining and immunohistochemical staining to observe the metastasis of melanoma in mice,and terminal deoxyribonucleotidyl transferase-mediated nick end labelling was performed to detect the apoptosis in tumor cells.One-way analysis of variance and independent-sample t test were used to analyze measurement data.Results The live imaging system showed that DiR-L could be retained in melanoma for a long time,and strong fluorescence of DiR-L could be still observed in the tumors at 24 hours after injections.Quantitative fluorescence analysis revealed that the fluorescence intensity of DiR-L (22.85 ± 1.66) was significantly higher than that of DiR in tumor tissues (8.45 ± 0.97,t =12.957,P ＜ 0.01).Compared with the control group and 4-HPR group,the resected tumor weight on day 2 after the final injection was significantly decreased in the 4-HPR-L group (F =27.055,t =4.768,6.640,respectively,both P ＜ 0.05).Hematoxylineosin staining showed that liver metastasis occurred in 2 nude mice in the 4-HPR-L group,but in all the nude mice in the control group and 4-HPR group.All the nude mice in the 4-HPR-L group died within 76 days after inoculation,and the mice in the control group and 4-HPR group all died within 56 and 59 days respectively after inoculation.There were significant differences in the apoptotic index among the control group (12.14‰ ± 1.33‰),4-HPR group (67.17‰± 15.18‰) and 4-HPR-L group (152.73‰ ± 11.27‰;F =167.588,P ＜ 0.05),and the apoptotic index was significantly higher in the 4-HPR-L group than in the control group and 4-HPR group (t =18.162,11.075 respectively,both P ＜ 0.05).Conclusion 4-HPR-L can effectively inhibit the growth of subcutaneous melanoma in nude mice and metastasis of melanoma cells,and prolong the survival duration of nude mice.
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Objective To assess the effect of fenretinide (4-HPR) on proliferation,apoptosis and migration of B16F10 and A375 melanoma cells,and to evaluate the effect of liposomes and RGD peptidemodified liposomes on its uptake and therapeutic effects.Methods A film-hydration method was used to prepare 4-HPR liposomes (4-HPRL),which were modified with RGD peptide to prepare RGD-4-HPRL,and the concentration,particle size,electric potential,drug loading capacity and encapsulation efficiency were measured for 4-HPRL and RGD-4-HPRL.In vitro cultured B16F10 and A375 cells were divided into several groups:4-HPR group,4-HPRL group and RGD-4-HPRL group treated with Dulbecco's minimum essential medium (DMEM) containing 4-HPR bulk drug,4-HPRL and RGD-4-HPRL respectively at the same concentration of 4-HPR,and control group treated with culture solution at the same volume.After different durations of treatment,cell counting kit-8 (CCK8) assay was performed to evaluate cellular proliferative activity,annexin V/propidium iodide staining to detect apoptosis,and scratch wound healing assay to evaluate the effect of drug treatment on cell migration ability.Then,4-HPR was replaced by coumarin 6 (C6) to prepare C6 liposomes (C6L) and RGD-C6L,and flow cytometry was conducted to evaluate C6 uptake by B16F10 cells.Statistical analysis was carried out with SPSS22.0 software by one-way analysis of variance (ANOVA) for the comparison among several groups and t test for the comparison between two groups.Results The concentration of 4-HPR in the prepared 4-HPRL solution was over 1 300 mg/L.The encapsulation efficiency and drug loading capacity of 4-HPRL were (95.51 ± 1.22)％ and (7.27 ± 0.11)％ respectively,and those of RGD-4-HPRL were (95.82 ± 0.81)％ and (7.14 ± 0.13)％ respectively.The particle size distribution of 4-HPRL and RGD-4-HPRL was uniform,and their average particle size was below 100 nm.CCK8 assay showed that 4-HPR could markedly inhibit the proliferative activities of B16F10 and A375 cells.The cell proliferation inhibition rate of 4-HPRL was higher than that of 4-HPR at the same concentration of 4-HPR (P ＜ 0.01),and the inhibition rate of RGD-4-HPRL was higher than that of 4-HPRL (P ＜ 0.01 or P ＜ 0.05) and 4-HPR (P ＜ 0.01).As annexin V/propidium iodide apoptosis assay showed,when the concentration of 4-HPR was 10 mg/L,the total apoptosis rates of B16F10 cells in the control group,4-HPR group,4-HPRL group and RGD-HPRL group were (4.44 ± 0.35)％,(28.33 ± 0.66)％,(46.43 ± 0.77)％ and (51.33 ± 0.37)％ respectively.When the concentration of 4-HPR was 20 mg/L,the total apoptosis rates of A375 cells in the above 4 groups were (4.97 ± 0.62)％,(16.68 ± 3.81)％,(32.62 ± 1.24)％ and (44.85 ± 4.92)％ respectively.The apoptosis rates of B16F10 and A375 cells were significantly higher in the 4-HPRL group than in the 4-HPR group (both P ＜ 0.01),and higher in the RGD-4-HPRL group than in the 4-HPRL group (both P ＜ 0.01) and 4-HPR group (both P ＜0.01).Scratch wound healing assay showed that 4-HPR could inhibit scratch healing and migration of B16F10 and A375 cells,and the inhibitory effects of 4-HPRL and RGD-4-HPRL were distinctly superior to those of 4-HPR bulk drug.C6 uptake assay revealed that the fluorescence intensity of C6 in B16F10 cells in the control group,C6 group,C6L group and RGD-C6L group were 2.15 ± 0.28,8.56 ± 0.36,20.48 ± 0.13 and 22.55 ± 0.07 respectively,and there were significant differences between the 4 groups (F =67 194.186,P ＜ 0.01).Additionally,the fluorescence intensity of C6 was significantly higher in the C6L group and RGD-C6L group than in the C6 group (both P ＜ 0.01),and higher in the RGD-C6L group than in the C6L Group (P ＜ 0.01).Conclusions 4-HPR can inhibit the proliferation and migration of A375 and B16F10 cells,and induce their apoptosis.Liposomes and RGD-targeted liposomes can markedly enhance the effect of 4-HPR on melanoma cells.
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Objective To understand the clinical features and pathogenic spectrum of encephalitis and menin﹣gitis syndrome in children. Methods A total of 667 cases of children with encephalitis or meningitis diagnosed and documented at Changchun Children′s Hospital from May 2012 to July 2015 were enrolled. A variety of samples in diffe﹣rent types were collected and presented,including 335 cerebrospinal fluid specimens,530 blood samples,and 332 stool samples. All the samples were collected from the patients within 72 hours on admission. Moreover,these samples are analyzed and tested,including PCR for enterovirus(EV),herpesvirus(HSV),mycobacterium tuberculosis( TB)and My﹣coplasma pneumoniae(MP)nucleic acid in cerebrospinal fluid samples;fecal specimens were tested for EV,enterovirus 71(EV71),coxsackievirus A6(CA6),coxsackievirus A16(CVA16),coxsackievirus A10( CVA10)nucleic acids;degenerate primers to amplify Echovirus 30(Echo30). Clinical data of children were collected. Results The peak in﹣cidence of encephalitis and meningitis syndrome was from June to August,age distribution was from 0 to 15 years old, the proportion of children aged from 0－6 accounted for 81. 41﹪;the highest proportion was among 0－1 years old in﹣fants,occupying 32. 38﹪;408 males and 259 females;the main symptoms were fever(586 cases),apathy(337 ca﹣ses),vomiting(307 cases)and headache(203 cases). And clinical signs included drowsiness(103 cases),neck stiff﹣ness(71 cases),meningeal irritation(12 cases),and pathological reflex( 313 cases),etc. The clinical diagnosis included 272 cases of viral encephalitis,332 cases of severe hand,foot and mouth disease complicated by encephalitis, 30 cases of bacterial meningitis,and 33 other cases;the etiological detection included:the positive rates of EV,EBV and Echo30 in cerebrospinal fluid specimens were 59. 72﹪,3. 16﹪ and 70. 00﹪,respectively. And EV71,CVA16,CVA6, EV71+CA16 and EV71+CVA16+CVA6 nucleic acids were detected in fecal samples,in which the highest detection rate was EV71(98. 96﹪). Conclusions In Changchun Children′s Hospital,the children with encephalitis and menin﹣gitis are mainly viral encephalitis. The main symptoms were fever,apathetic,drowsiness,vomiting and headache. Signs included,neck stiffness,meningeal irritation,and pathological reflexes,etc. The main pathogen of the disease is EV71.
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Objective@#To understand the clinical features and pathogenic spectrum of encephalitis and meningitis syndrome in children.@*Methods@#A total of 667 cases of children with encephalitis or meningitis diagnosed and documented at Changchun Children′s Hospital from May 2012 to July 2015 were enrolled.A variety of samples in diffe-rent types were collected and presented, including 335 cerebrospinal fluid specimens, 530 blood samples, and 332 stool samples.All the samples were collected from the patients within 72 hours on admission.Moreover, these samples are analyzed and tested, including PCR for enterovirus(EV), herpesvirus(HSV), mycobacterium tuberculosis(TB) and Mycoplasma pneumoniae(MP) nucleic acid in cerebrospinal fluid samples; fecal specimens were tested for EV, enterovirus 71 (EV71), coxsackievirus A6 (CA6), coxsackievirus A16 (CVA16), coxsackievirus A10 (CVA10) nucleic acids; degenerate primers to amplify Echovirus 30 (Echo30). Clinical data of children were collected.@*Results@#The peak incidence of encephalitis and meningitis syndrome was from June to August, age distribution was from 0 to 15 years old, the proportion of children aged from 0-6 accounted for 81.41%; the highest proportion was among 0-1 years old infants, occupying 32.38%; 408 males and 259 females; the main symptoms were fever(586 cases), apathy(337 cases), vomiting (307 cases) and headache(203 cases). And clinical signs included drowsiness (103 cases), neck stiffness (71 cases), meningeal irritation (12 cases), and pathological reflex (313 cases), etc.The clinical diagnosis included 272 cases of viral encephalitis, 332 cases of severe hand, foot and mouth disease complicated by encephalitis, 30 cases of bacterial meningitis, and 33 other cases; the etiological detection included: the positive rates of EV, EBV and Echo30 in cerebrospinal fluid specimens were 59.72%, 3.16% and 70.00%, respectively.And EV71, CVA16, CVA6, EV71+ CA16 and EV71+ CVA16+ CVA6 nucleic acids were detected in fecal samples, in which the highest detection rate was EV71(98.96%).@*Conclusions@#In Changchun Children′s Hospital, the children with encephalitis and meningitis are mainly viral encephalitis.The main symptoms were fever, apathetic, drowsiness, vomiting and headache.Signs included, neck stiffness, meningeal irritation, and pathological reflexes, etc.The main pathogen of the disease is EV71.
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Objective To evaluate the effect of fenretinide (4-HPR)-loaded liposomes (4-HPR-L) on the proliferation,apoptosis and migration of A375 and B16F10 melanoma cells.Methods A film-ultrasonic dispersion method was used to prepare 4-HPR-L.In vitro cultured A375 cells,as well as B16F10 melanoma cells,were divided into the following groups:blank control group treated with fresh culture medium alone,4-HPR groups treated with 4-HPR at concentrations of 0.1,1,15,30,50 and 70 mg/L separately,and 4-HPR-L groups treated with 4-HPR-L at concentrations of 0.1,1,15,30,50 and 70 mg/L separately.Cell counting kit-8 (CCK8) assay was conducted to detect cell proliferation,Hoechst33258 staining and flow cytometry to detect cell apoptosis,wound healing assay to evaluate cell migration ability,and laser scanning confocal microscopy to observe endocytic uptake of the liposomes.Statistical analysis was done by one-way analysis of variance (ANOVA) for intergroup comparison,and a two-sample t-test for comparisons between 2 groups with SPSS 20.0 software.Results Both 4-HPR and 4-HPR-L showed inhibitory effects on the proliferation of A375 and B16F10 melanoma cells.After 48-hour treatment,the survival rates of A375 cells in the 0.1-,1-,15-,30-,50-and 70-mg/L 4-HPR groups were (94.3 ± 1.4)％,(91.7 ± 2.5)％,(84.4 ± 2.5％),(78.8 ± 2.1)％,(59.0 ± 1.1)％ and (42.8 ± 2.0)％ respectively,and those in the 0.1-,1-,15-,30-,50-and 70-mg/L 4-HPR-L groups were (86.0 ± 0.2)％,(76.5 ± 0.6)％,(60.9 ± 1.5)％,(49.0 ± 0.5)％,(32.9 ± 0.2)％ and (18.9 ± 0.5)％ respectively.After 48-hour treatment,the survival rates of B16F10 cells in 0.1-,1-,15-,30-,50-and 70-mg/L 4-HPR groups were (95.4 ± 1.9)％,(90.5 ± 2.6)％,(77.0 ± 0.8％),(64.4 ± 3.5)％,(59.1 ± 2.9)％ and (49.9 ± 1.9)％ respectively,and those in the 0.1-,1-,15-,30-,50-and 70-mg/L 4-HPR-L groups were (88.4 ± 2.0)％,(80.9 ± 3.4)％,(60.9 ± 2.2)％,(51.5 ± 2.9)％,(41.1 ± 1.2)％ and (33.5 ± 2.4)％ respectively.The survival rates of A375 and B16F10 cells were significantly higher in the 0.1-,1-,15-,30-,50-and 70-mg/L 4-HPR groups than in the 4-HPR-L groups at the same concentrations (A375 cells:t =8.019,8.298,11.455,19.978,33.672,16.314 respectively,all P ＜ 0.01;B16F10 cells:t =3.573,3.153,9.953,4.019,8.097,7.53 respectively,all P ＜ 0.05).Hoechst33258 staining showed that the morphology of the melanoma cells in the control group and 4-HPR groups did not change obviously,but the cells.in the 4-HPR-L groups became smaller,with the cytoplasm concentrated,nuclei dissociated into fragments,and apoptotic bodies formed.Flow cytometry showed that the apoptosis rates of A375 and B16F10 cells were significantly higher in the 4-HPR-L groups than in the 4-HPR groups (all P ＜ 0.01).Cell wound healing assay showed that the inhibitory effect of 4-HPR-L on the migration of cells was stronger than that of 4-HPR,and 4-HPR-L could markedly decrease the degree of wound healing.Laser scanning confocal microscopy showed that C6 liposomes could be rapidly and successfully internalized into both A375 and B16F10 cells.Conclusion The 4-HPR-L can be internalized into A375 and B16F10 cells better than 4-HPR,effectively inhibit the proliferation and migration of A375 and B16F10 cells,and induce the apoptosis of these cells.
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Objective@#To better understand the evolution and epidemiology of human adenovirus-55 (HAdV-55) and provide a scientific basis for the prevention and control of the epidemic of HAdV-55 in China.@*Methods@#HAdV-55 isolates from 5 provinces in China included Beijing, Hebei, Shandong, Hunan and Yunnan were collected during 2011-2014. The hexon, fiber and penton base gene were sequenced, and compared with other strains of HAdV-55 sequences downloaded from GenBank for homology and evolution analysis.@*Results@#During the past decade, HAdV-55 was found in 15 provinces throughout China. Genetic and phylogenetic analysis showed that the HAdV-55 virus is highly conservative in evolution due to aggregation in a branch in the evolutionary tree. However, bayesian phylogenetic tree shows a certain time evolution trend. The evolution rate of hexon and fiber gene of HAdV-55 are 5.228×10-5 and 1.238×10-4 substitutions/site/year respectively, and the latest coevolutionary ancestor tMRCA of hexon gene can be traced back to 1963.@*Conclusions@#HAdV-55 has been widely spread and continued circulating in China. Establishing effective monitoring system and conducting vaccine related research is very important for its control and prevention.