Objective:In order to explore the impact of corona virus disease 2019(COVID-19)on the hospitalization of children with bronchiolitis and to improve clinicians′ understanding of the characteristics of bronchiolitis during the COVID-19 epidemic.Methods:This was a multicenter clinical study, and the data have been collected from 23 children′s medical centers in China.All the clinical data were retrospectively collected from children with bronchiolitis who were hospitalized at each study center from January 1, 2019 to December 31, 2021.The results included gender, age at hospitalization, length of stay, respiratory syncytial virus(RSV) test results, severity rating, ICU treatment, and the total number of children hospitalized with respiratory tract infection during the same period.The clinical data of children with bronchiolitis in 2019 before COVID-19 epidemic and in 2020、2021 during COVID-19 epidemic were statistically analyzed and compared.Results:According to a summary of data provided by 23 children′s medical centers, there were 4 909 cases of bronchiolitis in 2019, 2 654 cases in 2020, and 3 500 cases in 2021.Compared with 2019, the number of bronchiolitis cases decreased by 45.94% in 2020 and 28.70% in 2021.In 2019, 2020 and 2021, there were no significant differences in gender ratio, age, and duration of hospitalization.Compared with 2019, the ratio of bronchiolitis to the total number of hospitalizations for respiratory tract infection decreased significantly in 2020 and 2021( χ2=12.762, P<0.05; χ2=84.845, P<0.05).The proportion of moderate to severe bronchiolitis cases in both 2020 and 2021 was lower than that in 2019, and the difference was statistically significant ( χ2=4.054, P<0.05; χ2=8.109, P<0.05).There was no statistically significant difference in the proportion of bronchiolitis cases requiring ICU treatment between 2019, 2020, and 2021 ( χ2=1.914, P>0.05).In 2019, a total of 52.60%(2 582/4 909) of children with bronchiolitis underwent RSV pathogen testing, and among them, there were 708 cases with RSV positive, accounting for 28.00%.In 2020, 54.14%(1 437/2 654) of children with bronchiolitis underwent RSV pathogen testing, and there were 403 cases with RSV positive, accounting for 28.04%.In 2021, 66.80%(2 238/3 500) of children with bronchiolitis underwent RSV pathogen testing, and there were 935 cases with RSV positive, accounting for 41.78%.Compared with 2019 and 2020, the RSV positive rate in 2021 showed a significant increase( χ2=99.673, P<0.05; χ2=71.292, P<0.05). Conclusion:During the COVID-19 epidemic, the implementation of epidemic prevention and control measures reduced the hospitalization rate and severity of bronchiolitis, but did not reduce the positive rate of RSV detection.

Hypoxemia is a common complication of pneumonia, asthma, and bronchopulmonary dysplasia in children.Rapid identification of hypoxemia is of great significance for the disposal and management of critical children.Pulse oximetry is recognized by the World Health Organization as the best way to monitor hypoxemia in children, and it can monitor pulse oxygen saturation noninvasively and continuously.Based on the related literature at home and abroad, combined with the clinical needs of pediatrics, the " Expert consensus on clinical application of pulse oximetry in children" is formulated to improve the understanding of pediatricians and nurses on the application in pediatric clinical practice, principle, operation techniques, and limitations of pulse oximetry.

Objective:To investigate the knowledge, attitudes, and practices (KAP) of pulse oximetry among pediatric healthcare providers in China and analyze the factor influencing the KAP.Methods:A self-developed questionnaire was used for an online research on the KAP of 11 849 pediatric healthcare providers from 31 provinces, autonomous regions, and municipalities of China from March 11 to 14, 2022.The factors influencing the KAP of pulse oximetry among pediatric healthcare providers were examined by Logistic regression. Results:The scores of KAP, of pulse oximetry were 5.57±0.96, 11.24±1.25 and 11.19±4.54, respectively.The corresponding scoring rates were 69.61%, 74.95%, and 55.99%, respectively. Logistic regression results showed that the gender and working years of pediatric healthcare providers, the region they were located, and whether their medical institution was equipped with pulse oximeters were the main factors affecting the knowledge score (all P<0.05). Main factors influencing the attitude score of pediatric healthcare providers included their knowledge score, gender, educational background, working years, region, medical institution level, and whether the medical institution was equipped with pulse oximeters (all P<0.05). For the practice score, the main influencing factors were the knowledge score, gender, age, and whether the medi-cal institution was equipped with pulse oximeters (all P<0.05). Conclusions:Chinese pediatric healthcare providers need to further improve their knowledge about and attitudes towards pulse oximetry.Pulse oximeters are evidently under-used.It is urgent to formulate policies or guidelines, strengthen education and training, improve knowledge and attitudes, equip more institutions with pulse oximeters, and popularize their application in medical institutions.

Objective:To investigate the role of Sestrin2 overexpression in regulating mitochondrial fission and its mechanism in human neuroblastoma SH-SY5Y cell model of glucose and oxygen deprivation/recovery (OGD/R). Methods:(1) SH-SY5Y cells were divided into normal control group, OGD/R group, Vector group, and Sestrin2 overexpression group; Sestrin2 overexpression or empty vector stable cell lines in the Sestrin2 overexpression group and Vector group were constructed by lentivirus infection; cells in the later 3 groups were subjected to oxygen-glucose deprivation (OGD) for 4 h followed by restoration of O 2 supply for 18 h. The cell survival rate was detected by cell counting kit (CCK)-8 assay. The protein levels of Sestrin2, dynamin-related protein 1 (Drp1), mitochondrial fission protein 1 (Fis1), B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), Kelch-like ECH-related protein 1 (Keap1) in the cytoplasm and nuclear factor E2-related factor (Nrf2) in the nucleus were detected by Western blotting. The mitochondria ultrastructure was observed by transmission electron microscope. The Nrf2 nuclear translocation was detected by immunofluorescence staining. (2) Cell lines with Sestrin2 overexpression were divided into Sestrin2 overexpression group, Brusatol+ Sestrin2 overexpression group, and DMSO+ Sestrin2 overexpression group. Cells in the Brusatol+ Sestrin2 overexpression group were pretreated with normal medium containing Brusatol (Keap1/Nrf2 pathway inhibitor, final concentration: 100 nmol/L) for 4 h before OGD/R; cells in the DMSO+ Sestrin2 group were pretreated with normal medium containing DMSO (final volume fraction: 0.1%) for 4 h before OGD/R. Cells in these groups were then subjected to OGD for 4 h followed by restoration of O 2 supply for 18 h. The protein levels of Drp1, Fis1, Keap1 in the cytoplasm, and Nrf2 in the nucleus were measured by Western blotting. Results:(1) As compared with those in the OGD/R group, cells in the Sestrin2 overexpression group had significantly increased survival rate (61.33%±1.15% vs. 81.00%±3.00%), significantly up-regulated Bcl-2/Bax ratio (0.467±0.006 vs. 0.880±0.010), significantly decreased Drp1, Fis1 and cytoplasmic Keap1 protein levels (1.089±0.033 vs. 0.865±0.014; 0.829±0.009 vs. 0.350±0.007; 0.967±0.017 vs. 0.881±0.024), and significantly up-regulated nuclear Nrf2 protein level (0.627±0.025 vs. 0.957±0.015, P<0.05). The mitochondrial structure in the Sestrin2 overexpression group under electron microscope was more complete than that in the OGD/R group, and obvious nuclear translocation of Nrf2 was noted. (2) As compared with the Sestrin2 overexpression group, Brusatol+ Sestrin2 overexpression group had significantly decreased nuclear Nrf2 protein level (0.920±0.013 vs. 0.627±0.035), and statistically increased Drp1 and Fis1 protein levels (0.994±0.020 vs. 1.084±0.005; 0.728±0.010 vs. 0.906±0.022, P<0.05). Conclusion:Sestrin2 overexpression could suppress mitochondrial fission, reduce cell apoptosis, and attenuate OGD/R injury of SH-SY5Y cells by activating Keap1/Nrf2 pathway via down-regulating cytoplasmic Keap1 protein level and promoting Nrf2 nuclear translocation.

Objective To investigate the distribution characteristics and risk factors of intracranial and extracranial aterial lesions in Chinese patients with ischemic stroke . Methods In this multi‐center study ,2 310 continuously inpatients with ischemic stroke diagnosed in 20 stroke screening and prevention project base hospitals from June 2015 to M ay 2016 were enrolled . Carotid ultrasonography and transcranial color‐coded sonography or transcranial Doppler were performed in all patients to confirm the presence of cerebral artery stenosis or occlusion . According to the distribution of lesions ,the subjects were divided into 2 groups :the simple intracranial artery stenosis group and the simple extracranial artery stenosis group . T he difference of risk factors between the two groups was compared . Results Of the 2 310 patients with ischemic stroke ,1 516 ( 65 .6% ) had simple intracranial artery stenosis and 794 ( 34 .4% ) had simple extracranial artery stenosis . T he incidence of anterior circulation artery stenosis was higher in the group of intracranial artery stenosis than that in the extracranial artery stenosis group ( 68 .1% vs 48 .7% , P ＜0 .001) . Posterior circulation artery stenosis and combined anterior with posterior circulation artery stenosis were more common in patients with extracranial artery stenosis group than those in intracranial artery stenosis group ( 36 .4% vs 22 .1% ,14 .9% vs 9 .8% ;all P ＜0 .001) . Univariate analysis of risk factors for stroke showed that patients with intracranial arterial stenosis had a higher prevelence of hypertension , diabetes ,obesity ,and family history of stroke ,and their systolic blood pressure ,diastolic blood pressure , body mass index ( BM I) ,fasting blood‐glucose ,glycosylated hemoglobin ,triacylglycerol ,total cholesterol , and low‐density lipoprotein cholesterol were significantly higher than those in the extracranial arterial stenosis group ( all P ＜ 0 .05 ) . T he proportion of elderly ( ≥ 65 years old ) ,male and smokers in the extracranial arterial stenosis group was significantly higher than that in the intracranial arterial stenosis group ( all P ＜0 .05) . Multivariate logistic regression analysis showed that elderly ( ≥65 years old) ,male , and smoking history were independent risk factors for extracranial arterial stenosis ( OR＝ 2 .012 ,1 .637 , 1 .325 ,respectively ;all P ＜0 .05) . While hypertension ,diabetes ,less physical activity ,and high BM I levels were independent risk factors for simple intracranial arterial disease ( OR ＝ 1 .301 ,1 .252 ,1 .248 ,1 .030 , respectively ;all P ＜0 .05) . Conclusions There are significant differences in the distribution characteristics and risk factors of intracranial and extracranial aterial lesions in patients with ischemic stroke in China .

Objective To investigate the protective role of Sestrin2 overexpression in hypoxia and re-oxygenation injury (H/R) injury of hippocampal neurons and its mechanism in rats.Methods Neurons were enzymatically isolated from hippocampi of newborn Sprague-Dawley rats (less than 24 h old) and culturedinvitro. These neurons were randomly assigned into 4 groups (n=20) using a random number table: control group, H/R group, vector group and Sestrin2 overexpression group. The hippocampal neurons were seeded in 6-well plates at a density of 2×104 cells/mL; neurons in the latter two groups were transfected with lentiviruses containing empty vector andSestrin2overexpressed genes, respectively; the hippocampal neurons in the later three groups were subjected to oxygen-glucose deprivation (OGD) for 6 h followed by restoration of O2 supply for 20 h. The reactive oxygen species (ROS) content was detected by Reactive Species Assay Kit, and the ATP concentration was detected by ATP Assay Kit. Cell apoptosis rates were measured by flow cytometry. The levels of Sestrin2, dynamin-related protein 1 (Drp1), Fis1, and apoptosis-related proteins Bcl-2, Bax and cytochrome C (Cyt C) were measured by Western blotting. The ratio of Bcl-2 to Bax was calculated. The ultrastructure of mitochondria was observed by transmission electron microscopy.Results As compared with control group, H/R group had significantly lower ATP concentration, Bcl-2 protein expression and ratio of Bcl-2 to Bax ([11.15±0.42] nmol/mg proteinvs. [5.30±0.39] nmol/mg protein; 2.20±0.26vs. 0.91±0.02; 6.46± 0.41vs. 1.04±0.05), statistically higher average fluorescence intensity of ROS and cell apoptosis rate (152.41±17.38vs. 1530.00±14.69; 3.77％±0.74％vs. 56.57％±1.35％), and significantly higher protein levels of Sestrin2, Drp1, Fis1, Bax and Cyt C (0.66±0.06vs. 1.11±0.20; 0.48±0.03vs. 1.16±0.07; 1.14± 0.09vs. 2.47±0.09; 0.34±0.03vs. 0.88±0.04; 0.17±0.03vs. 0.30±0.03,P<0.05); what's more, the structure of mitochondria was obviously destroyed in I/R group. As compared with H/R group, Sestrin2 overexpression group had significantly increased ATP concentration, Sestrin2 and Bcl-2 protein expressions and ratio of Bcl-2 to Bax ([8.95±0.27] nmol/mg protein; 2.67±0.07; 1.80±0.19; 3.95±0.28), significantly lower average fluorescence intensity of ROS and cell apoptosis rate (337.27±15.32; 10.33％±2.60％), and statistically lower protein levels of Drp1, Fis1, Bax and Cyt C (0.43±0.02; 1.11±0.08; 0.45± 0.02; 0.17±0.02,P<0.05); the structure of mitochondria was relatively completed in Sestrin2 overexpression group.Conclusion Sestrin2 overexpression can inhibit mitochondrial fission, reduce accumulation of reactive oxygen species, improve mitochondrial energy metabolism and block mitochondria mediated apoptosis pathway, thereby alleviating I/R injury of rat hippocampal neurons.

Objective To investigate the effects of different stabilizers, time and temperature before centrifugation on the stability of homocysteine (Hcy) and other related thiols levels involving EDTA-containing whole blood.Methods Blood was drawn from 17 healthy adults and collected into tubes containing EDTA, EDTA plus NaF and EDTA plus 3-deazaadenosine(3DA),then stored on crush ice(0-4 ℃) immediately or at room temperature(25 ℃).Plasma was separated at 0, 3, 6, 24 and 48 hours, respectively.The levels of plasma total Hcy (tHcy), total cysteine (tCys), tatal cysteinylglycine (tCysGly) and tatal glutathione (tGSH) were measured by HPLC.The plasma immediately separated was used as baseline sample. Results In EDTA tubes stored at room temperature, tHcy levels increased by 38.5%, 64.2%, 141.9%, 225.4% for 3, 6, 24, and 48 h, respectively.The levels of tCysGly and tGSH increased by 20.0% and 37.9% within 3 h, however, tCys decreased by 3.5%.The levels of the thiols increase by less than 5% up to 6 h in EDTA tubes stored on crush ice.In EDTA-3DA and EDTA-NaF tubes, no statistical differences were observed in the plasma levels of tHcy, tCys,tCysGly and tGSH compared with their respective baseline values at room temperature for 3 h(EDTA-3DA tubes:F=0.01,0.94,0.09,0.01,all P>0.05;EDTA-NaF tubes:F=0.85,0.04,0.03,0.02,all P>0.05).Conclusions The EDTA-plasma levels of tHcy and other related thiols are time and temperature-dependent. There is a strong need for standardization of blood sample collection and processing in tHcy and other thiols assays. The plasma concentrations of tHcy, tCys, tCysGly and tGSH were stable for 3 h at least in the EDTA-3DA and EDTA-NaF tubes kept at room temperature.

Biochemistry is one of the important basic subjects in medical college. It is hard for students to master because of its complicated theories and abstract contents. It has been found that carrying out case-teaching method in biochemistry teaching is good for students to arouse study interest and enhance the abilities of autonomic learning, question-analyzing and question-solving as well as consolidate theory knowledge. It is worth generalizing as a new teaching method for biochemistry in medical college.

Objective To evaluate the effects of impaired glucose tolerance (IGT) on ventricular remodeling. Methods Parameters of every subject including left ventricular mass ( LVM), left ventricular mass index (LVMI), E/A ratio, 75 g oral glucose tolerance test (OGTT), ambulatory blood pressure monitoring(ABPM) data including 24-hour mean systolic blood pressure(mSBP) and 24-hour mean diastolic blood pressure(mDBP) were collected. Then the relationship of IGT and myocardial remodeling related parameters were analyzed. Results The rate of diastolic dysfunction was higher in the IGT combined with hypertensive group(74% ) compared with the hypertensive group( 39% )( x2 = 6. 5, P ＜ 0. 05 ). The rate of diastolic dysfunction was higher in the IGT group( 34% ) compared with the normal group( 10% ) (x2 = 5.2,P ＜0. 05). The rate of Left Ventricular Hypertrophy (LVH)in the IGT combined with hypertensive group (24%) was higher than the other three groups (Hypertension group 7%, IGT group 0, Normal group 0) (x2 =4.561,P ＜0.05), and there was no significance between the rest three groups (P ＞0.05).Stepwise multiple regression showed age and 2 Hours' Postprandial Blood Glucose were independent risk factors of E/A ratio. Conclusions These results suggested that IGT is a possible contributor to left ventricular hypertrophy and diastolic dysfunction, and is one of the histopathology of left ventricular remodeling.

We analyze the characteristics of foreign students and the problems in biochemistry teaching process by summarizing the practice of medical biochemistry teaching for undergraduate foreign students in Wenzhou Medical College. After careful thought on these problems,we brought forward some ideas and methods which may be useful to reform the teaching mode and improve the teaching results of medical biochemistry for foreign students.