Analysis of the clinical features and the risk factors of severe human metapneu movirus-associated community acquired pneumonia in children / 中华儿科杂志

Objective: To investigate the clinical characteristics and the risk factors of severe human metapneumovirus (hMPV)-associated community acquired pneumonia (CAP) in children. Methods: A retrospective case summary was conducted. From December 2020 to March 2022, 721 children who were diagnosed with CAP and tested positive for hMPV nucleic acid by PCR-capillary electrophoresis fragment analysis of nasopharyngeal secretions at the Yuying Children's Hospital, the Second Affiliated Hospital of Wenzhou Medical University were selected as the research objects. The clinical characteristics, epidemiological characteristics and mixed pathogens of the two groups were analyzed. According to CAP diagnostic criteria, the children were divided into the severe group and the mild group. Chi-square test or Mann-Whitney rank and contrast analysis was used for comparison between groups, while multivariate Logistic regression was applied to analyze the risk factors of the severe hMPV-associated CAP. Results: A total of 721 children who were diagnosed with hMPV-associated CAP were included in this study, with 397 males and 324 females. There were 154 cases in the severe group. The age of onset was 1.0 (0.9, 3.0) years, <3 years old 104 cases (67.5%), and the length of hospital stay was 7 (6, 9) days. In the severe group, 67 children (43.5%) were complicated with underlying diseases. In the severe group, 154 cases (100.0%) had cough, 148 cases (96.1%) had shortness of breath and pulmonary moist rales, and 132 cases (85.7%) had fever, 23 cases (14.9%) were complicated with respiratory failure. C-reactive protein (CRP) was elevated in 86 children (55.8%), including CRP≥50 mg/L in 33 children (21.4%). Co-infection was detected in 77 cases (50.0%) and 102 strains of pathogen were detected, 25 strains of rhinovirus, 17 strains of Mycoplasma pneumoniae, 15 strains of Streptococcus pneumoniae, 12 strains of Haemophilus influenzae and 10 strains of respiratory syncytial virus were detected. Six cases (3.9%) received heated and humidified high flow nasal cannula oxygen therapy, 15 cases (9.7%) were admitted to intensive care unit, and 2 cases (1.3%) received mechanical ventilation. In the severe group, 108 children were cured, 42 children were improved, 4 chlidren were discharged automatically without recovery and no death occurred. There were 567 cases in the mild group. The age of onset was 2.7 (1.0, 4.0) years, and the length of hospital stay was 4 (4, 6) days.Compared with the mild group, the proportion of children who age of disease onset <6 months, CRP≥50 mg/L, the proportions of preterm birth, congenital heart disease, malnutrition, congenital airway malformation, neuromuscular disease, mixed respiratory syncytial viruses infection were higher (20 cases (13.0%) vs. 31 cases (5.5%), 32 cases (20.8%) vs. 64 cases (11.3%), 23 cases (14.9%) vs. 44 cases (7.8%), 11 cases (7.1%) vs. 18 cases (3.2%), 9 cases (5.8%) vs. 6 cases (1.1%), 11 cases (7.1%) vs. 12 cases (2.1%), 8 cases (5.2%) vs. 4 cases (0.7%), 10 cases (6.5%) vs. 13 cases (2.3%), χ2=0.42, 9.45, 7.40, 4.94, 11.40, 8.35, 3.52, 6.92, all P<0.05). Multivariate Logistic regression analysis showed that age<6 months (OR=2.51, 95%CI 1.29-4.89), CRP≥50 mg/L (OR=2.20, 95%CI 1.36-3.57), prematurity (OR=2.19, 95%CI 1.26-3.81), malnutrition (OR=6.05, 95%CI 1.89-19.39) were the independent risk factors for severe hMPV-associated CAP. Conclusions: Severe hMPV-associated CAP is most likely to occur in infants under 3 years old and has a higher proportion of underlying diseases and co-infection. The main clinical manifestations are cough, shortness of breath and pulmonary moist rales, fever. The overall prognosis is good. Age<6 months, CRP≥50 mg/L, preterm birth, malnutrition are the independent risk factors for severe hMPV-associated CAP.

Control study on antimicrobial resistance of invasive and non-invasive Streptococcus pneumoniae in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the antimicrobial resistance of invasive and non-invasive Streptococcus pneumoniae (SP) strains in children and to provide a basis for proper use of antimicrobial drugs in the treatment of SP infection.</p><p><b>METHODS</b>Seventy children who were diagnosed with invasive pneumococcal diseases (IPD) between January 2009 and December 2013 were enrolled, and 164 children with lower respiratory tract infection caused by SP were randomly selected as the control group. The samples from sterile sites (blood, cerebrospinal fluid, etc) of children with IPD, as well as the sputum samples of children in the control group, were collected for bacterial culture, and the drug susceptibility tests for isolated SP strains were conducted.</p><p><b>RESULTS</b>A total of 82 invasive strains of SP were isolated from sterile sites of 70 children with IPD; 49 strains (60%) were isolated from blood, and 19 strains (23%) from cerebrospinal fluid. The detection rate of invasive SP strains decreased from 2009 to 2013 (P<0.01). The total detection rates of penicillin-nonsusceptible SP from the invasive and non-invasive strains were 27% and 17% respectively (P>0.05). Among invasive strains, the penicillin-nonsusceptible SP strains had significantly higher rates of insusceptibility to cefotaxime, ceftriaxone, and cefepime than the penicillin-susceptible SP (P<0.01). There were significant differences in the rates of insusceptibility to cefotaxime, ceftriaxone, and meropenem between the sensitive and non-sensitive SP strains (P<0.05). The multidrug resistance rates of the invasive and non-invasive SP strains were 89% and 93% respectively (P>0.05).</p><p><b>CONCLUSIONS</b>Invasive SP can easily invade the blood in children, but the total detection rate has decreased year by year. The results of drug sensitivity tests have guiding significance for proper use of antimicrobial drugs for different SP infections.</p>

Role of c-Jun N-terminal kinase signal transduction pathway in the course of airway remodeling of asthma rat / 中华儿科杂志

<p><b>OBJECTIVE</b>To study the role of c-Jun N-terminal kinase (JNK) signal transduction pathway in the course of asthma airway remodeling, to explore whether IL-1beta participates in asthma airway remodeling mediated by JNK signal transduction pathway.</p><p><b>METHODS</b>Totally 72 male Sprague-Dawlay rats (6 - 8 weeks old, weighing about 120 g) were randomly divided into control groups (36 rats) and asthma groups (36 rats). The rats were sensitized for inducing asthma by intraperitoneal injection of ovalbumin and AL(OH)3 and were repeatedly exposed to aerosolized ovalbumin for 4, 8, 12 weeks (A4, A8, or A12 group), each had 12 rats, and correspondingly control rats were intraperitoneally injected with 0.9% NaCl, then were repeatedly exposed to 0.9% NaCl for 4, 8, 12 weeks (C4, C8, or C12 group), each had 12 rats. The ultrastructural changes of pulmonary tissues were observed by transmission electron microscope (TEM). The total bronchial wall thickness (Wat) and the airway smooth muscle thickness (Wam) were measured by an image analysis system. The concentrations of IL-1beta in serum and bronchoalveolar lavage fluid (BALF) were tested by a "sandwich" ELISA. The protein expressions of P-JNK and P-c-Jun were detected by immunohistochemical technique. Lung tissue extracts were analyzed for phosphorylation of JNK by Western blotting. Linear correlation analysis showed the correlation between Wat and P-JNK protein, Wam and P-JNK protein, levels of IL-1beta in serum and P-JNK protein, levels of IL-1beta in BALF and P-JNK protein.</p><p><b>RESULTS</b>In asthma groups, TEM showed alveolar septal proliferation and alveolus type II epithelial cells swelling. Wat and Wam in all asthma groups were significantly higher than those in corresponding control groups (P < 0.01, respectively), and compared with group A4 and group A8, Wat and Wam of group A12 significantly increased (P < 0.01). The concentrations of IL-1beta in serum and BALF of asthma groups were all significantly higher than those of the corresponding control groups (P < 0.01, respectively), and compared with group A4 and group A8, the concentrations of IL-1beta in BALF of group A12 significantly increased (P < 0.01 or P < 0.05), but the levels of IL-1beta in serum were not significantly different among them (P > 0.05). Mean absorbance values (by immunohistochemistry) of P-JNK and P-c-Jun in asthma groups were significantly higher than those in corresponding control groups (P < 0.01, respectively), and compared with group A4 and group A8, those of group A12 significantly increased (P < 0.01 or P < 0.05). The absorbance (by Western Blot) of P-JNK in A4, A8, A12 group was significantly higher than that in C4, C8, C12 groups (P < 0.01, respectively), and compared with group A4, that of P-JNK of A12 significantly increased (P < 0.01), and compared with group A8, there was no significant difference (P > 0.05). Strong positive correlations were found between Wat or Wam and P-JNK (r = 0.823 and r = 0.818, P < 0.01, respectively, n = 68) and between P-JNK and concentration of IL-1beta in serum or BALF (r = 0.717 and r = 0.803, P < 0.01, respectively, n = 68).</p><p><b>CONCLUSIONS</b>The expression of P-JNK and its downstream P-c-Jun in rats of asthma airway remodeling is increased, which implicates that JNK signal transduction pathway plays an important role in the course of asthma airway remodeling. IL-1beta participates in asthma airway remodeling possibly partly through activating JNK signal transduction pathway.</p>

Effect of Radix Astragali on signal transducer and activator of transcription activator-4 and its mRNA expression in a rat model of asthma / 中华儿科杂志

<p><b>OBJECTIVE</b>To study the effect of Radix Astragali (RA) on the expression of signal transducer and activator of transcription-4 (STAT4) and its mRNA in the bronchus of a rat model of asthma.</p><p><b>METHODS</b>Forty male SD rats were randomly divided into four groups: the control group, asthma group, high dosage of RA group and low dosage of RA group. In the experiment, the rat model of asthma was established by the ovalbumin (OVA) challenge methods. The lung tissue was gainedfrom the left lung, bronchoalveolar lavage fluid (BALF) was gained from the right lung. The eosinophils (EOS) numbers and differentiated cell numbers in BALF were counted by different counting fluids; the protein expressions of STAT4 were detected by immunohistochemistry; the mRNA expressions of STAT4 were detected by in situ hybridization.</p><p><b>RESULTS</b>(1) In the BALF of the asthma group, the absolute numbers of EOS, the ratios of EOS to the total cell numbers (EOS%) of asthma group [(35.81 +/- 7.30) x 10(7)/L, (8. 20 +/- 1.75)%] were all significantly higher than those of the control group [(1.51 +/- 1.04) x 10(7)/L, (0.70 +/- 0.48)%] (P < 0.01); the total cell numbers in BALF, the absolute numbers of EOS and EOS% of RA groups [(14.89 +/- 2.35) x 10(7)/L, (4.70 +/- 0.82)%; (10.98 +/- 1.81) x 10(7)/L, (3.56 +/- 0.53)%] were all significantly lower than those of asthma group (P < 0.01); (2) The concentration of IL-4 in BALF of asthma group (25.70 +/- 7.36) was significantly higher than that of the control group (8.55 +/- 2.97) (P < 0.01); the concentration of IL-4 of BALF of RA groups [(31.89 +/- 5.46), (35.26 +/- 6.03)] was significantly lower than that of asthma group (P < 0.01); the concentration of IL-12 of BALF of asthma group (16.10 +/- 3.38) was significantly lower than that of the control group (42.33 +/- 9.66) (P < 0.01); the concentration of IL-12 of BALF of the RA groups [(31.89 +/- 5.46), (35.26 +/- 6.03)] was significantly higher than that of the asthma group (P < 0.01); (3) Immunohistochemistry and in situ hybridization showed that the protein content of STAT4 and the STAT4 mRNA expression around the bronchus of asthma group [(0.096 +/- 0.012), (0.098 +/- 0.011)] were lower than those of the control group [(0.216 +/- 0.034), (0.228 +/- 0.032)], while those of RA groups [(0.176 +/- 0.012), (0.185 +/- 0.023); (0.183 +/- 0.011), (0.201 +/- 0.019)] were all significantly higher than that of the asthma group (P < 0.01), the airway smooth muscle cells, the pulmonary arterial smooth muscle cells and endothelial cells were the chief expression cells; (4) the STAT4 and the STAT4mRNA expression around the bronchus had positive correlation with the concentration of IL-12 in BALF while had negative correlation with the concentration of IL-4, absolute numbers of EOS in BALF.</p><p><b>CONCLUSIONS</b>RA has an inhibitory effect on airway inflammation cells infiltration such as EOS, it raises the STAT4 protein and its mRNA expression in the airway smooth muscle cells, the pulmonary arterial smooth muscle cells and endothelial cells, and the key mechanism may be that the IL-12 composition is increased.</p>

Regulative mechanism of dexamethasone on Toll-like receptor 4 signal transduction of infant asthma rat / 中华儿科杂志

<p><b>OBJECTIVE</b>Eosinophilic airway inflammation is one of the basic characteristics of allergic asthma. Toll-like receptor is one of the most important innate immunity pattern recognition receptors. Glucocorticoids (GCS) are still the most effective treatment for asthma. However, few reports of studies on regulatory mechanism of GCS on the innate immunity system are available. The mechanism of effects of GCS on TLR4 is unclear. The present study aimed at understanding the effect of dexamethasone (DXM) on change of TLR4 and mechanism of regulatory effect of TLR4 on eosinophil (EOS) apoptosis.</p><p><b>METHODS</b>Twenty-seven Sprague-Dawley (SD) rats (age 28 to 42 days, body weight 120 to 180 gram) were randomly divided into the control group, asthma group and DXM group with 9 in each. Asthma model rats were sensitized with the mixture of ovalbumin (OVA, 1 mg) and Al (OH)(3), 100 mg on day 1 and day 8, repeatedly exposed to aerosolized OVA after day 15, once a day for three days and continued for 30 minutes at every time. During the sensitization stage, 100 microg/ml DXM were prepared with DXM group for every other day, and the same doses DXM were prepared for every day on the stage of challenge. The histopathological changes of lung tissues were observed with light microscope (LM). EOS and other inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted; the concentrations of OVA-sIgE in serum were measured by using "sandwich" ELISA; The expressions of TLR4 mRNA were determined by in situ hybridization, the apoptosis of EOS was detected by TUNEL.</p><p><b>RESULTS</b>(1) LM showed many inflammatory cells infiltration around the bronchi and blood vessels, bronchus mucus increased, airway epithelium damage and desquamation, and airway mucous plugs in asthma group, whereas DXM group showed significantly milder changes. (2) Inflammationary cells count in BALF of asthma group was significantly higher as compared to control group (P < 0.01); compared with asthma group, the total cell count, EOS absolute count and EOS% were all significantly decreased in DXM group [(2.14 +/- 0.10) x 10(9)/L, (4.78 +/- 1.23) x 10(7)/L, (2.17 +/- 0.25)%]. (3) Levels of OVA-sIgE in serum of asthma group [(83.40 +/- 6.80) microg/ml] were significantly higher than those of the control group [(14.38 +/- 4.25) microg/ml] (P < 0.01), while those of DXM group [(45.02 +/- 7.47) microg/ml] were significantly lower than asthma group (P < 0.0 1). (4) There were no significant differences in TLR4 mRNA detected by in situ hybridization between control group (24.71 +/- 0.85) and asthma group (25.81 +/- 3.56) (P > 0.05); but it significantly increased in DXM group (29.86 +/- 3.92) as compared to asthma group. (5) The percentages of apoptotic EOS in asthma group [(7.39 +/- 1.93)%] were significantly lower than those in control group [(9.06 +/- 1.52)%] (P < 0.01); and significantly higher in DXM group [(13.33 +/- 1.09)%] than in asthma group (P < 0.01). There were significantly positive correlations between TLR4 mRNA and the percentage of apoptotic EOS (r = 0.612, P < 0.01).</p><p><b>CONCLUSION</b>DXM can decrease OVA-sIgE level, induce EOS apoptosis, which may correlate with the activation of TLR4 signal transduction.</p>

Effect of achyranthes bidentata polysaccharides on signal transducer and activator of transcription 6 and its mRNA expression in a rat model of asthma / 中国应用生理学杂志

<p><b>AIM</b>To study the effect of achyranthes bidentata polysaccharides(ABPS) on the expression of signal transducer and activator of transcription 6 and its mRNA in bronchus of a rat model of asthma.</p><p><b>METHODS</b>Thirty male SD rats were randomly divided into three groups: the control group, asthma group and ABPS group. The total cell numbers, eosinophils (EOS) numbers and differentiated cell numbers in bronchoalveolar lavage fluid (BALF) were counted by different count fluids. The concentrations of IL-4 in serum and BALF were measured by sandwich ELISA. The protein expressions of STAT6 were detected by immunohistochemistry techniques. The mRNA expressions of STAT6 were detected by hybridization in situ.</p><p><b>RESULTS</b>(1) The total cell numbers in BALF, the absolute numbers of EOS, the ratios of eosinophils to the total cell numbers (EOS%) of asthma group were all significantly higher than those of the control group (P < 0.01). The total cell numbers in BALF, the absolute numbers of EOS and EOS% of ABPS group were all significantly lower than those of asthma group (P < 0.01). (2) The concentrations of IL-4 in BALF and serum of asthma group were significantly higher than those of control group (P < 0.01), while the concentrations of IL-4 in BALF and serum of ABPS group were significantly lower than those of asthma group. (3) Immunohistochemistry showed that the protein content of STAT6 around the bronchus of asthma group was significantly higher than that of the control group (P < 0.01), while that of ABPS group was significantly lower than that of asthma group , the epithelial cells were the chief expression cells; hybridization in situ showed that the mRNA expression of STAT6 around the bronchus of asthma group was significantly higher than that of the control group (P < 0.01), while that of ABPS group was significantly lower than that of asthma group , the epithelial cells were the chief expression cells.</p><p><b>CONCLUSION</b>STAT6 protein and STAT6 mRNA were found strongly expressed in rat asthma model, the epithelial cells were the chief expression cells. ABPS had an inhibitory effect on airway inflammation cells infiltration such as EOS, it significantly depressed STAT6 and its mRNA expression, thus reduced the synthesis of IL-4 might be key in modulating mechanism of asthma.</p>