Changes in Spectrum of Respiratory Pathogen Infections and Disease Severity Among Children in Hohhot, China: Impact of COVID-19 Prevention Measures.

BACKGROUND This retrospective study evaluated the effects of specific COVID-19 preventive measures, including the use of medical masks, nucleic acid testing, and patient isolation, on respiratory infections, disease severity, and seasonal patterns among children in Hohhot, located in northern China. Understanding these alterations is pivotal in developing effective strategies to handle pediatric respiratory infections within the context of continuous public health initiatives. MATERIAL AND METHODS At the First Hospital of Hohhot, throat swabs were collected from 605 children with community-acquired respiratory between January 2022 and March 2023 for pathogen infection spectrum detection using microarray testing. RESULTS Among the patients, 56.03% were male, and their average age was 3.45 years. SARS-CoV-2 infections were highest between October 2022 and January 2023. Influenza A peaked in March 2023, and other pathogens such as respiratory syncytial virus and influenza B virus disappeared after December 2022. The proportion of mixed infections was 41.94% among SARS-CoV-2 patients, while other pathogens had mixed infection rates exceeding 57.14%. Before December 2022, the mean WBC count for Streptococcus pneumoniae and Haemophilus influenzae was 8.83×109/L, CRP was 18.36 mg/L, and PCT was 1.11 ng/ml. After December 2022, these values decreased significantly. Coughing, difficulty breathing, running nose, and lower respiratory tract infection diagnoses decreased in December 2022, except for SARS-CoV-2 infections. CONCLUSIONS SARS-CoV-2 peaked around November 2022, influenza A peaked in March 2023, and other pathogens like respiratory syncytial virus and influenza B virus were greatly reduced after December 2022. Inflammatory markers and respiratory symptoms decreased after December 2022, except for SARS-CoV-2.

Causes of Lower Respiratory Tract Infections and the Use of Diagnostic Biomarkers in Blood Samples from Children in Hohhot, Inner Mongolia, China, Between July 2019 and June 2020.

BACKGROUND Lower respiratory tract infection (LRTI) in children is due to various pathogens. Appropriate diagnosis and early treatment are important for reducing the mortality rate of LRTI. Data on the epidemiology profiles of LRTI are scarce in northern China. The aim of this study was to provide data on the pathogen pattern of LRTI in hospitalized children in Hohhot, Inner Mongolia, China. MATERIAL AND METHODS From July 2019 to June 2020, nasopharyngeal swabs were collected from 265 children in Hohhot with LRTI, and pathogens were detected with RT-PCR and PCR. The correlations among procalcitonin (PCT), C-reactive protein (CRP), and white blood cells (WBC) with acute respiratory infections were evaluated. RESULTS The highest prevalence of LRTI was detected in 2- to 6-year-old children (149, 56.2%) in winter. Eleven respiratory pathogens were evaluated, and respiratory syncytial virus, Streptococcus pneumoniae and Haemophilus influenza were the most common pathogens in this region. Single viruses, bacteria, mycoplasma, and multiple pathogens were identified in 24.2, 15.8, 5.3, and 54.7% of patients, respectively. The mean blood biomarker values of patients with LRTI were significantly different from those of healthy children. Furthermore, The AUCs were 0.90, 0.74, and 0.84 for bacteria, virus, and mycoplasma PCT values, which were significantly higher than that of WBC and CRP. CONCLUSIONS This evaluation of the regional pattern of pathogens in children with acute respiratory infections and the correlation with blood biomarkers provides valuable information for the prevention and treatment of LRTI in children.

Effect of micropore/microsphere topography and a silicon-incorporating modified titanium plate surface on the adhesion and osteogenic differentiation of BMSCs.

Good biological properties for titanium implants will shorten the treatment cycle and improve patient comfort, which are also the main goals of dentistry and orthopaedics. At present, the biological properties of titanium implants are mainly enhanced in two aspects: their surface chemistry and surface morphology. In this study, a surface modification strategy combining bioactive trace elements with surface micromorphology modification was used to enhance the biological properties of pure titanium. A new coating incorporating silicon micropore/microsphere topography was prepared on a titanium plate by micro-arc oxidation (MAO) technology. The properties of the coating and its effects on the adhesion and osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs) were further analyzed. The experimental results show that a coating doped with amorphous silicon with micropore/microsphere topography was incorporated onto the titanium surface and the surface roughness in the treated groups was obviously higher than that in the Ti group. In vitro, the presence of a silicon-incorporating coating with a micropore/microsphere topography on the titanium surface significantly enhanced the initial adhesion, proliferation and osteogenic differentiation of BMSCs. These results indicate that the silicon-incorporating coating with micropore/microsphere topography has potential applications in dentistry and orthopaedics.

Enhanced corrosion resistance and bioactivity of Mg alloy modified by Zn-doped nanowhisker hydroxyapatite coatings.

In this work, Zn is doped into a hydroxyapatite coating on the surface of ZK60 magnesium alloys using a one-pot hydrothermal method to obtain a corrosion-resistant implant with abilities of osteogenic differentiation and bacterial inhibition. With the addition of Zn, the morphology changes with a nanowhisker structure appearing on the coating. Electrochemical measurements show that the nanowhisker hydroxyapatite coating provides a high corrosion resistance. Compared with hydroxyapatite coating, the nanowhisker coating not only effectively inhibits bacteria, but also promotes the adhesion and differentiation of rat bone marrow mesenchymal stem cells at appropriate Zn concentrations. In conclusion, a novel nanowhisker structure prepared by a single variable Zn doping can significantly improve the corrosion resistance and biological activity of hydroxyapatite coatings.

Effect of titanium implants with coatings of different pore sizes on adhesion and osteogenic differentiation of BMSCs.

A variety of surface modification methods are applied to modify titanium implants to improve their biological activity. Micro-arc oxidation (MAO) can relatively simply and efficiently produce porous coatings with high bioactivity and bond strength on titanium surfaces. However, there is no conclusion about the effect of coatings with different pore sizes produced by MAO on bone marrow mesenchymal stem cells (BMSCs). To study the effect of different pore sizes on BMSCs, rat BMSCs were applied to detect the effect of different pore sizes prepared by MAO on cell adhesion and osteogenic differentiation. Three groups of coatings with different pore sizes were successfully prepared, and the pore size was within the range of 3-10 µm. Importantly, the expression of adhesion-related protein integrin ß1 and osteogenic-related proteins OSX and ALP increased along with the increase in pore size. This study showed that the porous coating prepared by MAO promotes BMSCs adhesion and osteogenic differentiation. It reveals that the pore size is in the range of 3-10 µm and the larger pores are more beneficial for BMSCs adhesion and osteogenic differentiation. This study is instructive for optimizing the design of biomedical implant surfaces.