Objective To investigate the effects of dexmedetomidine(Dex)on osteoporosis(OP)rats and possible mechanisms.Methods The rats were divided into sham operation group,osteoporosis model group(OP,replica-ting the OP rat model with bilateral ovariectomies),Dex-L,M,and H(Dex low,medium,and high dose treat-ments)groups and Dex-H+XAV-939 group(Wnt/β-catenin pathway inhibitor).Micro-CT was applied to meas-ure bone mineral density(BMD)and bone microstructure of rat femurs.The three-point bending experiment was applied to analyze the biomechanics of the femur(maximum load,fracture deflection,elastic modulus).HE stai-ning was applied to observe pathological changes in the femur of rats.ELISA method was applied to evaluate bone metabolism indicators such as alkaline phosphatase(ALP),typeⅠ procollagen amino-terminal peptide(PINP)and typeⅠcollagen cross-linked C-telopeptide(CTX-Ⅰ).The expression of Runx2 and Wnt3a was examined by Immunohistochemistry.Western blot was applied to detect the protein expression of Runx2 and Wnt3a/β-catenin pathway in femoral tissue.Results Compared to the Sham group,the bone volume and number of trabeculae in OP group were obviously reduced,the maximum load,fracture deflection,elastic modulus,BMD,Tb.Th,Tb.N,BV/TV,ALP,PINP,Runx2,Wnt3a,β-catenin expression decreased,CTX-Ⅰ increased(P＜0.05).Compared to the OP group,the bone trabecular structure in the Dex-L,M,and H groups was restored,the maxi-mum load,fracture deflection,elastic modulus,BMD,Tb.Th,Tb.N,BV/TV,ALP,PINP,Runx2,Wnt3a,β-catenin expression all increased but CTX-Ⅰ decreased(P＜0.05).Compared to the Dex-H group,the bone trabecular injury in the Dex-H+XAV-939 group showed a more severe damage.The maximum load,fracture de-flection,elastic modulus,BMD,Tb.Th,Tb.N,BV/TV,ALP,PINP,Runx2,Wnt3a,β-catenin expression decreased while CTX-Ⅰ increased(P＜0.05).Conclusions Dex may antagonize OP effects by improving bone density,biomechanical properties and microstructure.The underlying mechanism might be related to the activation of the Wnt/β-catenin signaling pathway.

Objective:To explore the optimization of the standardized assessment tool for clinical diagnosis of Chinese developmental dyslexia (DD).Methods:A cross-sectional study was conducted from May to December 2023, in which 130 primary school children in grades 1 to 3 with clinical signs of literacy lag and positive screening results on the screening scales were recruited from the outpatient clinic of Child Health Care Medical Division, Shanghai Children′s Hospital, Shanghai Jiao Tong University School of Medicine. Chinese dyslexia screening behavior checklist for primary students (CDSBC) was used as the screening scales, and supplemented by dyslexia checklist for Chinese children. Referring to the standard procedure of the"expert advice on diagnosis and intervention of Chinese developmental dyslexia", the developmental dyslexia scale for standard mandarin (DDSSM) was used to evaluate the children′s literacy-related cognitive abilities and conduct the diagnostic assessment, and divided the children into learning backward group and the DD group. The t-test and &chi;2 test were used to compare the differences in the distribution of intelligence, literacy and attention deficit hyperactivity disorder between the two groups. Spearman′s correlation was used to analyze the correlation between the scores for each cognitive ability in the DDSSM and the CDSBC. Results:Of the 130 children, 90 were male, aged (8.3±1.0) years; 40 were female, aged (8.1±0.9) years. A final diagnosis of DD was made in 59 cases, of which 41 were males. There was no statistically significant difference in operational intelligence quotient (101±15 vs.100±15, t=0.53, P>0.05) and statistically significant difference in literacy of DDSSM (32±5 vs.21±4, t=11.56, P<0.001) between the learning backward group and the DD group. Eighteen cases (25.4%) of the learning backward group were children with attention deficit subtype attention deficit hyperactivity disorder (ADHD-I), and 16 cases (27.1%) in DD group, the difference in incidence between the two groups was not statistically significant ( &chi;2=0.05, P>0.05). There were correlations between the DDSSM (for oral vocabulary, morphological awareness and orthographic awareness) and the CDSBC total score ( r=-0.42, -0.32, -0.35, all P<0.01), but the correlations for visuospatial perception and rapid automatized naming with CDSBC total score were not statistically significant ( r=-0.09 and -0.20,both P>0.05). Conclusion:For literacy-related cognitive abilities, screening scales CDSBC are not sufficiently useful for assessment, so the introduction of standardized assessment tools DDSSM is an optimization of the clinical diagnosis of Chinese DD, which is crucial for achieving accurate diagnosis and intervention.

Objective The aim is to utilize CRISPR/Cas9 gene editing technology to construct Dmd gene mutant mice with a point mutation in exon 23 of the Dmd gene. Subsequently, the phenotypic changes of the mice in muscles and immune systems are analyzed and verified, providing an evaluation model for Duchenne muscular dystrophy and other related diseases.MethodsBased on the sequence characteristics of exon 23 of the Dmd gene, small guide RNA (sgRNA) was designed and synthesized. Cas9 mRNA, sgRNA fragments, and oligo donor DNA were microinjected into fertilized eggs of C57BL/6J mice. After transferring the fertilized eggs to surrogate mice, F0 generation mice were born. After mating with F0 generation mice, offspring mice were obtained, and Dmd gene positive mutant (Dmd^Mu/+) mice were obtained after genotype identification. Male hemizygous Dmd^Mu/+(Dmd^Mu/Y) mice were selected for phenotype validation. The body weight of live 3- and 9-month-old mice were recorded. Muscle tension was evaluated through the grid test. Hearts and semitendinosus muscles were collected, and the histopathological changes were observed using HE staining. Further, the expression of Dmd protein in muscle tissue of 9-month-old mice was analyzed by Western blotting.An acute inflammation model was established in Dmd^Mu/Y mice using lipopolysaccharide induction. Peripheral blood from the submandibular vein was collected, and the changes in the proportion of neutrophils and monocytes were detected by flow cytometry.Results The results of genome sequencing and Western blotting confirmed the successful construction of Dmd gene point mutant mice (Dmd^Mu/+ mice). Dmd protein expression was not detected in skeletal muscle and myocardium of Dmd^Mu/+ mice, and it was significantly reduced compared to wild-type C57BL/6J mice (P<0.05). Compared with wild-type mice of the same background, Dmd^Mu/Y mice at 3 and 9 months of age showed significant weight loss (P<0.01) and decreased muscle tension (P<0.05). 9-month-old Dmd^Mu/Y mice exhibited significant pathological changes in skeletal muscle and myocardium, including widening of intermuscular space. Under normal condition, compared with wild-type mice, the proportion of neutrophils and monocytes in the peripheral blood of 3-month-old Dmd^Mu/Y mice was significantly lower than that of wild-type mice (P<0.01). After lipopolysaccharide stimulation, the proportion of neutrophils in peripheral blood of 3-month-old Dmd^Mu/Y mice remained significantly lower compared to that of wild-type mice (P<0.01). The proportion of neutrophils in peripheral blood of 9-month-old Dmd^Mu/Y mice significantly decreased after lipopolysaccharide induction (P<0.01), with a trend of change observed in monocytes between groups.Conclusion The successful construction of the Dmd gene mutant mouse model has confirmed the vital function of Dmd gene in maintaining normal muscle tissue morphology and muscle tone. It preliminarily indicated that Dmd gene deletion could significantly reduce the proportion of neutrophils in peripheral blood, offering a new perspective for the study of immune system alterations in Duchenne muscular dystrophy patients.