BACKGROUND:We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction,and verified the stability and reliability of the model.However,whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied. OBJECTIVE:To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view,histology and electron microscopy. METHODS:Thirty adult female small ear pigs in southern Yunnan province were selected.Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon(n=30 in the normal group),and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system(n=30 in the relaxation group).The autogenous right forelimb was used as the control group;the anterior cruciate ligament was exposed but not severed or surgically treated.At 12,24,and 48 weeks after surgery,10 animals were sacrificed,respectively.The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology.MAS score was used to evaluate the excellent and good rate of the ligament at each time point.Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization.Collagen fibers and nuclear morphology were observed,and nuclear morphology was scored.Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy. RESULTS AND CONCLUSION:(1)The ligament healing shape of the relaxation group was better at various time points after surgery,and the excellent and good rate of MAS score was higher(P<0.05).Moreover,the relaxation group could obtain higher ligament vascularization score(P<0.05).(2)The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly,and the transverse fiber connections between collagen gradually increased and thickened,suggesting that the strength and shape degree of the grafts were gradually improved,but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery.(3)The diameter,distribution density,and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points,especially in the comparison of collagen fiber diameter between and within the relaxation group(P<0.05).

Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

Objective To explore clinical effect of different intervertebral fusion devices(cage)in treating postoperative recurrent lumbar disc herniation(LDH).Methods One hundred and forty-two LDH patients with recurrence after simple in-tervertebral disc nucleus pulpoideectomy from January 2019 to January 2021 were retrospectively analyzed.All patients were treated with combined underchannel fixation and interbody fusion and divided into a single anatomical group,two-anatomical group and a single banana group according to types and numbers of implanted cage.There were 51 patients in a single anatom-ical group,included 29 males and 22 females,aged from 39 to 65 years old with an average of(53.74±5.68)years old;body mass index(BMI)ranged from 18.62 to 28.13 kg·m-2 with an average of(22.08±2.15)kg·m-2;the interval between operation and recurrence ranged from 0.5 to 4.0 years with an average of(2.7±0.8)years;5 patients with L3,4,35 patients with L4,5 and 11 patients with L5S1;a single anatomical cage was implanted.There were 46 patients in two-anatomical group,included 25 males and 21 females,aged from 37 to 66 years old with an average of(54.52±6.02)years old;BMI ranged from 18.25 to 28.44 kg· m-2 with an average of(21.74±1.83)kg·m-2;the interval between operation and recurrence ranged from 0.5 to 5.0 years with an average of(2.7±0.9)years;4 patients with L3,4,32 patients with L4,5 and 10 patients with L5S1;two-anatomical cages were im-planted.There were 45 patients in a single banana group,included 22 males and 23 females,aged from 38 to 65 years old with an average of(54.49±6.45)years old;BMI ranged from 18.85 to 28.20 kg·m-2with an average of(21.63±1.59)kg·m-2;the interval between operation and recurrence ranged from 0.5 to 5.0 years with an average of(2.6±1.0)years;3 patients with L3,4,36 patients with L4,5 and 16 patients with L5S1;a single banana cage was implanted.Operation time,intraoperative blood loss,incision length,postoperative incision drainage volume,hospital stay and complications among 3 groups were observed and compared.The height of intervertebral space before and after operation,curvature of lordosis and the postoperative interverte-bral fusion were compared.Visual analogue scale(VAS)and Oswestry disability index(ODI)were used to evaluate degree of lumbar pain and lumbar function before operation,1 and 6 months after operation,respectively.Results All patients among 3 groups were followed up at least 6 months,and no cases were fell out.There were no significant difference in operation time,in-traoperative blood loss,incision length,postoperative incision drainage volume and hospital stay among 3 groups(P＞0.05).At 6 months after operation,the height of intervertebral space in two-anatomical group and a single group were[(11.08±1.78)mm,(10.95±1.62)mm],curvature of lordosis were[(12.05±1.86)°,(11.63±1.57)°],which were higher than those in a sin-gle dissection group(10.14±1.54)mm,(10.92±1.45)°,and the difference were statistically significant(P＜0.05).The inter-body fusion rate between two-anatomical and a banana group(95.65％,95.56％)were higher than that in a single anatomical group(78.43％)at 6 months after operation(P＜0.05).VAS and ODI of lumbar among 3 groups were decreased at 1 and 6 months after operation(P＜0.05).There was no significant difference in complications among 3 groups(P＞0.05).Conclusion The three fusion devices could achieve significant results in treating postoperative recurrence of LDH,but the implantation of two-anatomical cage and a single banana cage are more helpful to maintain the height of intervertebral space and lordosis cur-vature of patients with postoperative recurrence of LDH,and obtain good intervertebral fusion results.

The feasibility of fecal-oral transmission of Trichinella spiralis larva and infectivity in feces were assessed.Six Wistar rats were infected with 4 000 T.spiralis larvae at one time.The feces of three rats(group A)were collected at 0,4,8,12,16,24,and 48 h,and then divided into four aliquots and stored at room temperature for 0,24,48,and 72 h,respectively.The number of larvae in the feces was counted under a microscope,and each aliquot containing T.spiralis larvae was fed to five Kunming mice.All mice were killed 42 days after infection.The number and reproductive capacity index(RCI)of T.spir-alis larva were calculated.The feces from another three Wistar rats(group B)were collected from 1 to 23 days after infection and DNA was extracted from each fecal sample for PCR detection of the mitochondrial atp6 gene of T.spiralis.The results showed that T.spiralis was discharged in feces at 4-16 h after infection,peaking at 8 h,with no detection after 24 h.The numbers of T.spiralis larva in fecal samples of three rats in group A were 350,400,145,and 40 at 4,8,12,and 16 h after infection,respectively.The RCI values of T.spiralis larva for samples collected at 4 h were 112.5,20.5,and 2 after storage at room temperature for 0,24,and 48 h,66.7 and 9 for samples collected at 8 h after 0 and 24 h,13.3 and 5 for samples collected at 12 after 0 and 24 h,and 10 for samples collected at 16 h after 0 h,respectively.Of the three rats in group B,two were posi-tive for the atp6 gene for 18 consecutive days,and the third was positive for 20 consecutive days.These results indicate that one-time ingestion of T.spiralis larva in quantity can discharge infectious T.spiralis larvae,which can be transmitted through the fecal-oral route.PCR analysis is appropriate for detection of the T.spiralis atp6 gene in feces,but not infectivity of T.spiralis.

Metastasis is the main risk factor for poor prognosis of laryngeal squamous cell carcinoma (LSCC) .Chemokines are closely related to metastasis in the tumor microenvironment.CXCL8 is a cyto-kine-like secreted protein that plays key roles in the malignant development of a variety of tumors,but has not been elucidated in LSCC.In this paper,we elucidated the role of CXCL8 in LSCC cells and found miRNAs that targeted CXCL8,which may become new targets for the diagnosis and treatment of LSCC.Firstly,the GEPIA showed that CXCL8 was highly expressed in head and neck cancer (P<0.05).The real-time fluorescence quantification (qRT-PCR) found that CXCL8 was highly expressed in LSCC cells.The enzyme-linked immunoassay also found that CXCL8 was highly secreted in the superna-tant of LSCC cells (P<0.001) .Then,the CCK8 assay confirmed that knockdown of CXCL8 significant-ly inhibited the proliferation of FD-LSC-1 and AMC-HN8 cells (the average inhibition rate was 34.0％and 19.5％,respectively);The EdU assay also confirmed that knockdown of CXCL8 significantly inhibi-ted the proliferation of LSCC cells (P<0.05) .The transwell assay confirmed that knockdown of CXCL8 also significantly inhibited the migration and invasion of FD-LSC-1 cell (average inhibition rate was 40.0％,38.5％,respectively);Knockdown of CXCL8 also significantly inhibited the migration and inva-sion of AMC-HN8 cell (average inhibition rate was 37.5％,53.5％,respectively ) .The analysis of bioinformatics predicted that CXCL8 may be a target of miR-513b-5p.The dual luciferase reporter assay confirmed that miR-513b-5p could bind to the CXCL8-3'UTR.QRT-PCR assay also confirmed that over-expression of miR-513b-5p could decrease the 60％ of the CXCL8 expression (P<0.01) .Cell function rescue assays found that overexpressed of CXCL8 could effectively reversed proliferation,migration and invasion of LSCC cells weakened by miR-513b-5p (P<0.05) .In summary,miR-513b-5p inhibited the proliferation,migration and invasion of LSCC cells by targeting CXCL8.

Objective:To investigate the impact of ionizing radiation(IR)on the structure and function of the testis and pro-vide some strategies for the prevention and treatment of IR-induced damage(IRD).Methods:Using radiation dose simulation,se-men analysis,hormone testing,electron microscopy and single-cell transcriptome sequencing,we assessed and analyzed a case of IRD.We established a mouse model of IRD to validate the results of single-cell sequencing,and investigated the specific biological mecha-nisms of IRD and potential strategies for its intervention.Results:IR at 1-2 Gy significantly reduced sperm concentration and mo-tility,which gradually recovered after 12 months but the percentage of morphologically normal sperm remained low.It also caused im-balanced levels of various steroid hormones,decreased testosterone and dehydroepiandrosterone sulfate,increased progesterone,prolac-tin,luteinizing hormone,and follicle-stimulating hormone.Electron microscopy revealed damages to the testis structure,including loss of germ cells,atrophy of the seminiferous tubules,nuclear membrane depression of the spermatocytes,mitochondrial atrophy and de-formation,and reduction of mitochondrial cristae.Single-cell sequencing indicated significant changes in the function of the Leydig cells and macrophages and disrupted lipid-related metabolic pathways after IRD.Administration of L-carnitine to the mouse model im-proved lipid metabolism disorders and partially alleviated IRD to the germ cells.Conclusion:Ionizing radiation can cause disorders of testicular spermatogenesis and sexual hormones and inhibit lipid metabolism pathways in Leydig cells and macrophages.Improving lipid metabolism can alleviate IRD to germ cells.

AIM To analyze the metabolites of nobiletin in rats in vivo based on characteristic ions.METHODS Ten rats were assigned into administration group and control group,and given intragastric administration of the 0.5％CMC-Na suspension of nobiletin(250 mg/kg)and 0.5％CMC-Na solution,respectively,after which plasma,urine and feces were collected,solid phase extraction method was adopted in pretreatment,UHPLC-HRMS analysis was performed.The candidate metabolites were systematically described according to diagnostic product ions,chromatographic retention time,accurate molecular weight and neutral loss fragments,after which accurate metabolites were obtained in the established metabolite data set with-CH3(m/z 15)characteristic ions as a baits.RESULTS A total of 64 metabolites were identified,whose main metabolic pathways were glucuronidation,sulfation,hydrogenation and their compound reactions.CONCLUSION This experiment elucidates the metabolites of nobiletin in rats in vivo,which provides a new reference for its further development.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To investigate the levels of serum folate and vitamin B12(VB12)and their association with the level of neurodevelopment in preschool children with autism spectrum disorder(ASD).Methods A total of 324 ASD children aged 2-6 years and 318 healthy children aged 2-6 years were recruited.Serum levels of folate and VB12 were measured using chemiluminescent immunoassay.The Social Responsiveness Scale and the Childhood Autism Rating Scale were used to assess the core symptoms of ASD children,and the Gesell Developmental Schedule was employed to evaluate the level of neurodevelopment.Results The levels of serum folate and VB12 in ASD children were significantly lower than those in healthy children(P＜0.05).Serum folate levels in ASD children were positively correlated with gross and fine motor developmental quotients(P＜0.05),and serum VB12 levels were positively correlated with adaptive behavior,fine motor,and language developmental quotients(P＜0.05).In ASD children aged 2 to＜4 years,serum folate levels were positively correlated with developmental quotients in all domains(P＜0.05),and serum VB12 levels were positively correlated with language developmental quotient(P＜0.05).In male ASD children,serum VB12 levels were positively correlated with language and personal-social developmental quotients(P＜0.05).Conclusions Serum folate and VB12 levels in preschool ASD children are lower than those in healthy children and are associated with neurodevelopmental levels,especially in ASD children under 4 years of age.Therefore,maintaining normal serum folate and VB12 levels may be beneficial for the neurodevelopment of ASD children,especially in ASD children under 4 years of age.[Chinese Journal of Contemporary Pediatrics,2024,26(4):371-377]

It has become an industry consensus that self-assembled nanoparticles (SAN) are formed by molecular recognition of chemical components in traditional Chinese medicine during the decoction process. The insoluble components in the decoction are mostly in the form of nanoparticles, which can improve the problem of poor water solubility. However, the transfer rate of these insoluble components in the decoction is still very low, which limits the efficacy of the drug. This study aimed to refine the traditional decoction self-assembly phenomenon. The self-assembled nanoparticles were constructed by micro-precipitation method (MP-SAN), and characterized by particle size, zeta potential, stability index and morphology. The formation of MP-SAN and alterations in related physicochemical properties were evaluated using modern spectroscopic and thermal analysis techniques. The quality value transmitting pattern of lignan components within the MP-SAN was assessed via high performance liquid chromatography (HPLC). The MP-SAN showed sphere-like structure with uniform morphology, particle size of (245.3 ± 3.2) nm, polydispersity index (PDI) of (0.13 ± 0.03), zeta potential of (-48.9 ± 5.9) mV and stability index (SI) of (86.05% ± 2.27%). Comprehensive analyses using ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and other techniques confirmed molecular recognition between the decoction and ethanol extraction, leading to electron rearrangement under the influence of non-covalent bonding. This resulted in the formation of nanoparticles possessing superior thermal stability. As determined by HPLC, the encapsulation rates of the index components in the MP-SAN were all greater than 75% (dehydrodiconiferyl alcohol: 77.00%; herpetolide A: 78.57%; herpetrione: 94.53%), and the transfer rates were all higher than 65% (dehydrodiconiferyl alcohol: 96.01%; herpetolide A: 67.86%; herpetrione: 65.55%), which were 1.34, 1.38 and 4.81 times compared with those of the traditional decoction. In summary, this study successfully constructed the MP-SAN based on micro-precipitation method to achieve high transfer rate and high encapsulation rate of insoluble components in docoction, which provides a pharmaceutics idea for the efficient utilization of pharmacodynamic substance basis of traditional Chinese medicine.