Objective:To isolate and identify SARS-CoV-2 epidemic strains and analyze the sequence characteristics of the virus strains following serial passages.Methods:Eleven nasopharyngeal swabs positive for SARS-CoV-2 antigen were collected from December 2022. Quantitative real-time PCR was used to detect SARS-CoV-2 nucleic acid, and positive specimens were inoculated onto Vero cells for virus isolation. The isolated strains were identified by Western blot and indirect immunofluorescence assay. The morphology of the isolated strains was observed using transmission electron microscopy. Nucleic acid was extracted from the isolates and passaged viruses for further sequencing and analysis.Results:All 11 specimens tested positive for SARS-CoV-2 using quantitative real-time PCR. SARS-CoV-2 strains were successfully isolated from seven specimens, and could be adaptively cultured, passaged, and expanded on Vero cells, achieving a peak titer exceeding 10 6.25 50% cell culture infectious dose (CCID 50)/ml. Western blot and indirect immunofluorescence results showed that the isolates could be specifically recognized by monoclonal antibodies and convalescent serum against SARS-CoV-2. Transmission electron microscopy revealed oval-shaped viral particles with diameters of approximately 100 nm. Next-generation sequencing of the viral isolates demonstrated a sequence homology greater than 99.50% with the Wuhan-Hu-1 reference strain (NC_045512) and 99.98% among the seven isolated strains, and all of the isolates belonged to the Omicron BF.7 variant. Sequence analysis after continuous passage and plaque purification of the BJ-NVSI-20230005 isolate showed that compared with passages 1-3, passages 4-6 had one nucleotide site mutation (C→T) in the ORF1ab gene and a deletion of 3 bp in the E gene, which resulted in a change from leucine to phenylalanine and the deletion of valine, respectively. Polymorphisms were observed in the sequences of plaque-purified clones. Conclusions:The seven successfully isolated SARS-CoV-2 strains all belong to the SARS-CoV-2 BF.7 variant, which is consistent with the prevalence trend in mainland China in December 2022.

Ischemic stroke is a major public health problem worldwide. Although the circadian clock is involved in the process of ischemic stroke, the exact mechanism of the circadian clock in regulating angiogenesis after cerebral infarction remains unclear. In the present study, we determined that environmental circadian disruption (ECD) increased the stroke severity and impaired angiogenesis in the rat middle cerebral artery occlusion model, by measuring the infarct volume, neurological tests, and angiogenesis-related protein. We further report that Bmal1 plays an irreplaceable role in angiogenesis. Overexpression of Bmal1 promoted tube-forming, migration, and wound healing, and upregulated the vascular endothelial growth factor (VEGF) and Notch pathway protein levels. This promoting effect was reversed by the Notch pathway inhibitor DAPT, according to the results of angiogenesis capacity and VEGF pathway protein level. In conclusion, our study reveals the intervention of ECD in angiogenesis in ischemic stroke and further identifies the exact mechanism by which Bmal1 regulates angiogenesis through the VEGF-Notch1 pathway.
Rats ; Animals ; Vascular Endothelial Growth Factor A/pharmacology* ; Brain Ischemia/metabolism* ; Ischemic Stroke ; Signal Transduction ; ARNTL Transcription Factors/pharmacology* ; Neovascularization, Physiologic/physiology*

Objective:To assess the clinical efficacy of low-level laser therapy(LLLT)for the treatment of burning mouth syndrome(BMS)in elderly patients.Methods:As a randomized controlled study, 60 elderly BMS patients treated in the department of stomatology of Beijing Hospital from September 2018 to August 2021 were randomly divided into a laser group and a control group, including 7 man and 53 women, with an average age of(68.27±6.38)years.Patients in the laser group were treated with LLLT, and patients in the control group were treated with non-energy red light and oryzanol.The visual analogue scale and self-rating anxiety and depression scale were used to evaluate the two groups of patients.Results:After LLLT, the effectiveness rate of the laser group was 86.67%(26/30)on the 28th and 90th day, which was significantly higher than 63.33%(19/30)of the control group( χ2=4.356, P=0.037). When data for pre-treatment, the 28th day after treatment and the 90th day after treatment for the laser group were compared, results showed that after LLLT, pain symptoms of BMS patients were relieved and it lasted for some time, and anxiety and depression also improved, but there were episodes of relapse as time went on.Visual analogue scale and self-rating anxiety scores and depression scale scores of BMS patients for pre-treatment, the 28th and 90th days after treatment in the two groups were compared.Only self-rating anxiety scale scores of the laser group was lower than those of the control group on the 28th day, with statistical significance( t=2.622, P=0.011), indicating that LLLT could alleviate anxiety for BMS patients in the short term, but had no significant effect on patient depression.However, in the long term, LLLT had no significant effect on relieving anxiety and depression. Conclusions:LLLT has a certain effect on improving pain symptoms and anxiety in elderly BMS patients.

Background Individual lead or cadmium exposure can cause abnormal blood glucose level and changes in telomere length, and the role of telomere length in the relationship between heavy metal joint exposure and blood glucose level is still unclear. Objective To explore the role of telomere length in the relationship between lead and cadmium coexposure and blood glucose. Methods A cross-sectional study was conducted. By convenient sampling method, 600 residents living in two communities in a city in North China were selected as participants from April to June 2016. Face-to-face interviews were performed to collect general demographics and lifestyles of the participants. The peripheral blood samples of the participants were collected for blood glucose and telomere length detection, the urine samples were collected for urinary cadmium, urinary lead, and urinary creatinine measurement, and both urinary cadmium and urinary lead were corrected by urinary creatinine. The included participants were divided into a control group, a high-cadmium and low-lead group, a high-lead and low-cadmium group, and a high-lead and high-cadmium group, according to the median levels of urinary cadmium and urinary lead. A restricted cubic spline model was constructed to analyze the relationship between urinary lead/cadmium levels and blood glucose concentrations in the four groups and the relationship between cadmium exposure and telomere length in the high-lead and high-cadmium group. Intermediary model test was conducted to analyze the effect of telomere length on the relationship between exposures to lead and cadmium and blood glucose. Results The included participants were divided into the control group (n=99), the high-cadmium and low-lead group (n=91), the high-lead and low-cadmium group (n=145), and the high-lead and high-cadmium group (n=265). The differences in age, education level, per capita monthly household income, smoking, blood glucose, and telomere length were statistically significant among the four groups (P＜0.05). The high-lead and high-cadmium group had the highest blood glucose concentration, (5.63±1.68) mmol·L⁻¹, and the shortest telomere length, (2.63±1.05) Kb. The restricted cubic spline results showed that urinary cadmium level was correlated with blood glucose concentration in the high-lead and high-cadmium group (F=3.45, P=0.037), and there was a non-linear association (F=6.91, P=0.002); the association between urinary cadmium level and telomere length was also non-linear (F=5.93, P=0.043). The intermediary model test results showed that telomere length was a mediating variable between urinary cadmium level and blood glucose concentration, and the mediating effect size was 0.0192 (95%CI: 0.0007-0.0563), with a mediation ratio of 15.57%. Conclusion Correlations between urinary cadmium and blood glucose and between urinary cadmium and telomere length were observed in the high-lead and high-cadmium coexposure group, and telomere length may play a mediating role in the relationship between them.

Background Environmental pollutants can affect N⁶-methyladenosine (m⁶A) level in the body, but the change of m⁶A level in kidney after being exposed to cadmium (Cd) and the molecular mechanism of renal injury need to be further studied. Objective To analyze the associations of m⁶A modification and methyltransferases/demethylases with microRNA-21 (miR-21) and transforming growth factor- β1 (TGF - β1) in kidney of rats exposed to Cd. Methods Twenty-four SPF male SD rats were divided into 4 groups, with 6 rats in each group, and were exposed to Cd by subcutaneous injection of 2.0, 1.0, and 0.5 mg·kg⁻¹ cadmium chloride (CdCl₂) and equal volume of normal saline for 2 weeks, 7 d a week, respectively. The levels of N-acetyl-β-D-glucosidase (UNAG) and albumin (UALB) in urine, and the levels of m⁶A methylation and TGF-β1 in kidney were detected by enzyme-linked immunosorbent assay (ELISA). The level of blood urea nitrogen (BUN) was measured by urease method. The levels of renal oxidative stress indicators such as malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were detected by total bile acid method, water-soluble tetrazolium asssay, and colorimetric method respectively. The relative levels of TGF-β1, methyltransferases, and demethylases in kidney were measured by reverse transcription-polymerase chain reaction. The expression of miR-21 in kidney was detected by fluorescent quantitative polymerase chain reaction. Results After 2 weeks of exposure to Cd, the body weights of rats in the 2.0 and 1.0 mg·kg⁻¹ cadmium chloride groups decreased, and the ratio of kidney/body weight and the levels of BUN, UNAG, and TGF-β1 mRNA and protein increased in the 2.0 mg·kg⁻¹ cadmium chloride group (P<0.05). The expression levels of m⁶A modification, methyltransferases METTL3, METTL14, Wilms’ tumor 1-associated protein (WTAP), and miR-21 were increased both in the 2.0 and 1.0 mg·kg⁻¹ cadmium chloride groups, with significant differences compared with the control group (P<0.05). The results of correlation analysis showed that the m⁶A modification level was negatively correlated with SOD (r=−0.4489, P<0.05) and GSH-Px (r=−0.4874, P<0.05), METTL3 was negatively correlated with MDA (r=−0.5158, P<0.05), while there was a positive correlation between FTO and GSH-Px (r=0.4802, P<0.05). In addition, miR-21 was positively correlated with METTL3 (r=0.7491), METTL14 (r=0.6157), and WTAP (r=0.6660) (P<0.05), TGF-β1 was positively correlated with METTL3 (r=0.5025, P<0.05) but negatively correlated with FTO (r=−0.5634, P<0.05) . Conclusion Cd can induce m⁶A methylation and up-regulation of METTL3, METTL14, WTAP, and miR-21 expression levels in rat kidney tissues, indicating that m⁶A and miR-21 may be associated with Cd-induced renal fibrosis.

P450 fatty acid decarboxylase OleT from Staphylococcus aureus (OleTsA) is a novel cytochrome P450 enzyme that catalyzes the oxidative decarboxylation of fatty acids to yield primarily terminal alkenes and CO2 or minor α-and β-hydroxylated fatty acids as side-products.In this work,the interactions between a series of cycloalkyl phosphorus heterocycles (CPHs) and OleTsA were investigated in detail by fluores-cence titration experiment,ultraviolet-visible (UV-vis) and 31p NMR spectroscopies.Fluorescence titration experiment results clearly showed that a dynamic quenching occurred when CPH-6,a repre-sentative CPHs,interacted with OleTsA with a binding constant value of 15.2 × 104 M-1 at 293 K.The thermodynamic parameters (△H,△S and △G) showed that the hydrogen bond and van der Waals force played major roles in the interaction between OleTsA and CPHs.The UV-vis and 31p NMR studies indicated the penetration of CPH-6 into the interior environment of OleTsA,which greatly affects the enzymatic activity of OleTsA.Therefore,our study revealed an effective way to use phosphorus hetero-cyclic compounds to modulate the activity of cvtochrome P450 enzymes.

Background Exposure to environmental lead can cause kidney damage and telomere wear. However, the relationship among lead, peripheral blood telomere length, and glomerular filtration rate (eGFR) are unclear. Objective This study is conducted to investigate the relationships of urinary lead level with peripheral blood telomere length and renal function index eGFR, and further explore whether peripheral blood telomere length plays an intermediary role in the relationship between urinary lead level and eGFR. Methods A case-control study was conducted to select 497 residents from two communities in a city, including 230 in the control group (eGFR≥80 mL·min⁻¹) and 267 in the abnormal eGFR group (eGFR<80 mL·min⁻¹). Basic information and health information of the subjects were collected through a face-to-face questionnaire survey. Fasting morning urine was collected, and urinary lead and urinary creatinine (UCr) were detected. Fasting peripheral venous blood was collected to detect telomere length and serum creatinine (SCr) in peripheral blood leukocytes. eGFR was estimated by the Levey formula. After further adjusting for age, gender, education level, family per capita monthly income, smoking, and drinking the relationship among urinary lead level, peripheral blood telomere length, and renal function index eGFR was evaluated by mediating effect analysis. Results The overall level of creatinine-adjusted urinary lead [M (P₂₅, P₇₅)] in the abnormal eGFR group was 3.85 (1.56, 7.34) μg·g⁻¹ which was higher than that in the control group, 1.57 (0.60, 3.62) μg·g⁻¹(P<0.001). In addition, the overall level of peripheral blood telomere length in the abnormal eGFR group was 2.42 (1.89, 3.10) Kb, lower than that in the control group, 2.69 (2.09, 3.64) Kb (P<0.001). The results of mediating effect analysis showed that the magnitude of mediating effect by peripheral blood telomere length was −0.276 (95%CI: −0.708-−0.001) and it contributed 3.35% to the relationship between urinary lead level and eGFR. In women, the magnitude of mediating effect by peripheral blood telomere length was −0.484 (95%CI: −1.160-−0.023) between urinary lead level and eGFR, and the proportion of the mediating effect was 5.34%. In men, no mediating role of peripheral blood telomere length was found between urinary lead and eGFR. Conclusion Urinary lead level is closely related to renal function index eGFR and telomere length in peripheral blood. Peripheral blood telomere length plays a mediating role in the relationship between female urinary lead and eGFR in women.

Objective To explore the effect of carrying out self and mutual medical aid training program after accidental injury for primary school students on the students ′relevant knowledge .Methods 98 primary school students in a certain primary school in Wuhan were selected by convenience sampling as objects . Training content and mode of self and mutual medical aid after common accidental injuries were designed basing on the students′age and interest .Their knowledge before and after the training was compared , and the training effect was thus determined .Results The students′post-training knowledge of self and mutual medical aid after common accidental injuries was higher than before the training , in the aspects of calling 120 correctly, 6-step hand washing method , treatment of small-area burn, bandaging of forearm skin damage , wound cleaning of animal bite (91.84%vs.57.14%, 83.67%vs.20.41%, 100.00% vs.67.35%, 77.55% vs.34.69%, 89.80%vs.25.51%) (P<0.01).Conclusions Reasonably-designed self and mutual medical aid training program after common accidental injuries can effectively strengthen primary school students ′relevant abilities , which makes it worth promoting in future training .

Objective To compare the antitumor effect of self-developed albumin bound paclitaxel for injection ( PAB) and commercial albumin-bound paclitaxel for injection ( Abraxane ) . Methods The antineoplastic effects of PAB and Abraxane were evaluated in H22, Lewis and RM-1 allograft tumor mouse models after repeated intravenous injection (13. 4, 20. 0, 30. 0 and 45. 0 mg·kg-1 PAB and 20. 0 and/or 30. 0 mg·kg-1 Abraxane, respectively). Results PAB significantly inhibited H22 tumor growth at from the doses of 13. 4, 20. 0, 30. 0, and 45. 0 mg·kg-1,and the antitumor effect of PAB at 20. 0 mg·kg-1 was not significantly different from Abraxane at 20. 0 mg·kg-1 . PAB dose-dependently inhibited Lewis and RM-1 tumor growth at the doses of 20. 0, 30. 0, and 45. 0 mg·kg-1 . The no observed adverse effect level of PAB and Abraxane was 20. 0 mg· kg-1 in Lewis and RM-1 bearing C57 female mice. The antitumor effect and toxicity was not significantly different between PAB and Abraxane at equivalent doses. Conclusion At the same dose level, the antitumor activity and toxicity of PAB was equivalent to those of Abraxane.

Objective To clarify the effect of myofunctional treatment on primary and mixed dentition malocclusion.Methods Twenty-seven children were selected,3 were in primary dentition among which 2 showed deep overbite.24 were in mixed dentition and presented crowding in anterior area among which 4 children combined with anterior crossbite,2 showed deep overbite and deep overjet.All the patients were treated with myofunctional trainer such as INFANT,T4K or I2N appliances according to their age and malocclusion type.The patients were instructed to wear the trainers for at least one hour a day keeping their lips together or overnight while sleeping.Muscle exercises were done when wearing the trainer during daytime.Results After 6-10 months,24 patients who were in good compliance had their teeth aligned,deep overjet and deep overbite corrected,and facial profile improved.Conclusions Myofunctional treatment is effective on primary and mixed dentition malocclusion.It is important to have patients' good compliance.