BACKGROUND: Polylactic acid copolymer bone scaffold has excellent biodegradability, and it is easy to be shaped and can promote the formation and growth of bone tissue and blood vessel.OBJECTIVE: To observe the effects of adipose-derived stem cells(ADSCs)/poly(lactic-co-glycolic acid) (PLGA) complex on the biomechanical properties after fracture healing in osteoporotic bone.METHODS: Sixty Sprague-Dawley rats were randomly divided into four groups: blank control group received no treatment; the bilateral tibial fracture model was made after 3 months of bilateral ovarian resection in model group; the bilateral tibial fracture model was made and ADSCs were implanted into the bone after 3 months of bilateral ovarian resection in cell therapy group; the bilateral tibial fracture model was made and the PLGA/ADSCs complex was implanted after 3 months of bilateral ovarian resection in combined treatment group.The bone mineral density, callus thickness, biomechanical parameters and the microstructure of the trabecular bone were detected.RESULTS AND CONCLUSION: (1) The bone density: The bone density of the model group was significantly lower than that of the blank control group (P < 0.05); the bone mineral density of the cell therapy group and the combined treatment group was higher than that of the model group (P < 0.05), but lower than that of the control group (P < 0.05); and the bone mineral density of the combination treatment group was higher than that of the cell therapy group (P < 0.05). (2)Thickness of the callus: The thickness of the callus in the cell therapy group and combined treatment group was higher than that of the model group and blank control group (P < 0.05); moreover, the thickness of the callus in the combined treatment group was higher than that of the cell therapy group (P < 0.05). (3) Biomechanical test: The failure load, stress and shear strength, elastic modulus were decreased in the model group compared with the blank control group (P < 0.05), while the shear strain increased (P < 0.05). Compared with the model group, the failure load, ultimate stress, shear strength, elastic modulus were increased in the cell therapy group and combined treatment group (P < 0.05), and the shear strain was decreased (P < 0.05). Moreover, the combined treatment group showed more changes in these biomechanical parameters (P < 0.05). (4) The trabecular bone microstructure: The model group presented with trabecular derangement, spacing increases, and even fracture and lacuna. After ADSCs or ADSCs/PLGA transplantation,the trabecular bones increased in number, thickness, and spacing, and the number of lacunae reduced. In conclusion,ADSCs combined with PLGA in the treatment of osteoporotic fracture can significantly improve the biomechanical parameters of bone tissue after healing.

BACKGROUND: SSh as a Hedgehog signal protein can promote bone development, growth and remodeling.OBJECTIVE: To investigate the effect of bone marrow mesenchymal stem cells (BMSCs) combined with Shh modified nano-hydroxyapatite/collagen (nHAC) in the repair of femoral defects in rats.METHODS: Forty-eight Sprague-Dawley rats were randomly divided into four groups, and the model of femoral defects was established in these rats. At 14 days after modeling, experimental group was implanted with the BMSCs/Shh modified nHAC, scaffold group was implanted with simple nHAC, cell scaffold group was implanted with BMSCs/nHAC,and blank control group was without any implantation. At 3, 6, 9, 12 weeks after repair, X-ray examination, bone density measurement and bone biopsy in bone defect area were performed.RESULTS AND CONCLUSION: (1) X-ray examination: The Lane-Sandhu X-ray score and bone mineral density value in the experimental group at different time points after operation were significantly higher than those in the other three groups (P < 0.05). (2) Hematoxylin-eosin staining: 12 weeks after repair, a small amount of bone tissues but no bone marrow formed in the scaffold group; a small amount of bone tissues with absence of bone marrow formed in the cell scaffold group, and the residual scaffold was visible; in the experimental group, the scaffold was completely absorbed,and mature bone and medullary cavity formed with presence of bone marrow. (3) Scanning electron microscope observation: 12 weeks after repair, irregular arrangement of bone fibers and a large number of bone fossae were observed in the scaffold group; the cell scaffold group showed a large number of osteoblasts, but bone fibers still arranged irregularly; in the presence of the Haversian system, a large number of regularly arranged bone trabeculae were detective in the experimental group. These results elucidate that the Shh modified nHAC/BMSCs complex can promote the repair of bone defects.

OBJECTIVE: To investigate the level of formaldehyde in the air of anatomical laboratories and to explore the effect of different prevention measures on reducing the level of formaldehyde. METHODS: The level of formaldehyde in two morphological laboratories of a medical college of a university were measured with a comprehensive atmospheric sampler at different physical ventilation time,different time after spraying biological enzymes and different masks. RESULTS: The level of formaldehyde decreased with the increase of ventilation time in front,middle and back of the laboratory( P < 0. 05).The level of formaldehyde at 30 and 60 minutes after spraying bio-enzymes in three parts of the laboratory was lower than that at 0 minute in the same part of the laboratory( P < 0. 05),and lower than that in the bio-enzymes non-spraying laboratory at the same part and same time point( P < 0. 05). At 0,30 and 60 minutes ventilation time points,the level of formaldehyde in the activated carbon mask group was lower than that in the normal sampling group,the non-woven mask group and the defatted gauze mask group at the same time point( P < 0. 05). CONCLUSION: Both physical ventilation and bio-enzyme degradation can reduce indoor formaldehyde pollution. Active carbon mask can achieve good protection effect.

Objective:To investigate the surgical approaches and clinical outcomes of endoscopic endonasal approaches (EEA) for trigeminal schwannomas(TSs).Methods:Clinical data, surgical videos and outpatient follow-up notes of 41 patients with TSs and underwent EEA between January 2013 to October 2022 in the Department of Neurosurgery of the First Affiliated Hospital of Nanchang University were retrospectively studied. The patients were 19 males and 22 females, with an average age of 45.3 (22-63) years old. Twenty-four patients had TSs on the left and 17 on the right. According to Jeong's classification, for 6 TSs with type MP, 2 tumours were resected by trans-Meckel's cave approach (TMCA) alone, and the remaining 4 TSs were resected by combined transclival approach (TCA). For the 4 tumours that involved infratemporal fossa(2 of type E3, 1 of type mE3 and 1 of type Mpe3), the surgery were performed via a trans-prelacrimal recess approach(TPRA), of which the operation for type Mpe3 was combined with a TMCA. The trans-laminal papyracea approach (TLPA) was applied to remove 2 tumours of type E1. The rest of 29 patients received the surgery by TMCA alone to remove tumours including 15 of types M, 10 of type Mp, 1 of type ME2, 2 of type E2 and 1 of type MpE2. Gross total tumour resection was achieved in 40 patients(97.6%), with only 1 patient (2.4%) had a subtotal tumour resection.Results:A total of 40 patients had completed the long-term follow-up, with 1 patient lost in follow-up. The average follow-up period was 34(3-101) months; No tumour recurrence or progression was observed over follow-up. After the surgery, preoperative symptoms were improved in 34 patients(89.5%). The main improved symptoms were: facial numbness(78.9%), facial pain(70.0%), headache(88.2%), mastication weakness (50.0%), poor vision (60.0%), diplopia (83.3%), and abducens nerve palsy (100%). Transient and permanent neurological deficits occurred in 8 (19.5%) and 9 (22.0%) patients, respectively. Cerebrospinal fluid leakage and internal carotid artery injury occurred in 1 patient each.Conclusion:According to the location of a tumour, an appropriate EEA should be selected and satisfactory results can be achieved for all types of tumours, except the TSs that has the main body of the tumour located in the posterior cranial fossa.

Objective To explore the expression and diagnostic value of circulating microRNA(miR)-126-3p in non-small cell lung cancer(NSCLC).Methods Multi-centred miR chips and sequencing data were col-lected to investigate the differential expression of circulating miR-126-3p in NSCLC.In order to evaluate the comprehensive expression level of circulating miR-126-3p in the cycle,the standardized mean difference(SMD)and summary receiver operating characteristic(sROC)curve were calculated,and the area under curve(AUC)of sROC curve was analyzed.Sensitivity,specificity,positive negative likelihood ratio were ex-plored,and the expression of circulating miR-126-3p was further comprehensively analyzed in combination with tissue.By using miRDB,starBase v2.0,and TargetScan 7.1,combined with up-regulated differentially expressed genes in NSCLC,potential target genes of circulating miR-126-3p were screened using complemen-tary sequence method.Results Based on six circulating miR datasets,the expression level of circulating miR-126-3p was higher than that of the control group,and the difference was statistically significant(P＜0.05).The receiver operating characteristic curves showed that circulating miR-126-3p had strong diagnostic efficacy(AUC＞0.5),and the comprehensive expression of circulating miR-126-3p was lower in 199 cases of NSCLC group than in the control group(SMD=-1.46).The sROC curve showed that circulating miR-126-3p distin-guished the NSCLC group from the control group with high accuracy(AUC=0.91),Egger's test showed no publication bias(P＞0.05),with sensitivity and specificity 0.80,and positive likelihood ratio and negative likelihood ratio were 5.37 and 0.18,respectively.In addition,a comprehensive analysis of the circulation and tissue of 1 320 NSCLC samples from 26 datasets showed that circulating miR-126-3p expression was lower in NSCLC group than in the control group(SMD=-2.07).The sROC curve showed that low-expression circu-lating miR-126-3p had high accuracy in distinguishing between the NSCLC group and the control group(AUC=0.97).In addition,potential target genes ADAM9 and SLC7A5 were screened for circulating miR-126-3p,and their expression in NSCLC group was higher than that in the control group.Conclusion Low ex-pression of circulating miR-126-3p in the circulation may be an important biomarker for high-precision screen-ing of NSCLC.

Objective To observe the relationship between functional connectivity(FC)of frontoparietal network(FPN)and cognitive function in patients with cerebral small vessel disease(CSVD)using resting-state functional MRI(rs-fMRI).Methods rs-fMRI of 50 CSVD patients with cognitive impairment(CI group),65 CSVD patients with normal cognition(NC group)and 60 healthy controls(HC group),as well as outcomes of neuropsychological tests were retrospectively analyzed.Brain regions with different FC of FPN were compared among 3 groups and between each 2 groups.Partial correlation analysis was used to evaluate the correlations of FC of brain regions value being statistically different between CI and NC groups and cognitive scores.Results Significant differences of FC in bilateral cingulate gyrus,left middle frontal gyrus,right supramarginal gyrus,right inferior parietal lobule and right medial superior frontal gyrus were found among groups(FWE correction,all P＜0.05).Compared with NC group,FC of left cingulate gyrus decreased,of right inferior frontal gyrus and right medial superior frontal gyrus increased in CI group(FWE correction,all P＜0.05).The decreased FC value of left cingulate gyrus was negatively correlated with clock drawing test score in CSVD patients(r=-0.159,P=0.049).Conclusion CSVD patients with or without CI had extensive abnormal FC of FPN,and the left cingulate gyrus was associated with patient's cognitive function.

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.