L1 cell adhesion molecular is a type Ⅰ membrane glycoprotein of immunoglobulin superfamily. L1 is expressed mainly in nervous system and plays important roles in nervous system development, learning and memory. L1 cytoplasmic domain (L1CD) is important for L1 function by mediating signaling. To investigate the molecular mechanisms of signaling mediated by L1CD, yeast two-hybrid assay was carried out to screen the human brain cDNA library using L1CD as the bait. After sequence analysis and BLAST, several candidates were identified. One candidate is PAX6 transcription factor. L1CD and PAX6 cDNA were cloned in expression vectors and cotransfected into COS-7 cells. The interaction between L1CD and PAX6 was verified by co-immunoprecipitation assay. These preliminary results suggest that L1CD may be involved in transcription regulation.

Objective:To establish an HPLC method for the determination of two components and the preservative in compound dextromethorphan hydrobromide syrups. Methods:An Agilent Zobax SB-C18 column(250 mm × 4. 6 mm,5 μm) was used with meth-anesulfonic acid solution (adding 4. 8g methanesulfonic acid and 10ml triethylamine into 750ml water,and adjusting the pH value to 3. 5 by phosphoric acid)-acetonitrile (75∶25) as the mobile phase at the flow rate of 1. 0 ml·min-1 and 280nm as the detection wave-length. Results:The calibration curve was linear within the range of 102-1 025μg·ml-1 for guaifenesin,15-619μg ·ml-1 for dextro-methorphan hydrobromide and 10-407μg·ml-1 for benzoic acid. The average recovery of guaifenesin, dextromethorphan hydrobromide and benzoic acid was 100. 0% (RSD=0. 35%), 100. 1%(RSD=0. 77%)and 100. 8%(RSD=0. 49%), respectively. Conclusion:The method is simple,rapid and accurate,and suitable for the quality assessment of compound dextromethorphan hydrobromide syrups.

Objective To study the effects of mild hypothermia on endothelial cell of cerebral vessels in patients with moderate or severe cerebral infarction. Methods Sixty patients with moderate or severe cerebral infar-ction were divided into 2 groups: a mild hypothermia group (30 cases) and a non-mild hypothermia group (30 cases). Endothelin (ET), endothelial nitric oxide synthases(eNOS) and von Willebrand factor(vWF) were tested with RIA or ELISA. All the patients were treated with routine medication, in addition, those in mild hypothermia group were also treated with mild hypothermia. Results The ET and vWF levels of serum and cerebrospinal fluid (CSF) in patients of mild hypothermia group were significantly lower than those of non-mild pothermia group (P

Objective To explore the relationship between the changes of Caspase 3mRNA expression and the injuried nervous cell apoptosis after rat focal cerebral ischemia/reperfusion injury who was then treated by mild hypothermia.Methods The middle cerebral arteries(MCA) of SD rats were occluded for 2 hours,and reperfused for 12 hours.Using FCM and semiquantitative RT-PCR technique,the DNA fragmentation rate and Caspase 3mRNA expression level were detected in the shamoperation group,the control group and the mild hypothermia group,respectively.Results The DNA fragmentaation rate and Caspase 3mRNA expression level in the sham operation group and the mild hypothermia group were obviously lower than those in the control group.Conclusions The significantly decreased level of Caspase-3mRNA expression may be related to the obviously decreased nervous cell apoptosis after rat cerebrall ischemia/reperfusion injury treated by the mild hypothemia.

Objective:To explore the clinical characteristics and genetic etiology of a child with Spondyloocular syndrome (SOS) in order to enhance the awareness and understanding of this disease.Methods:A 3.5-year-old boy with SOS who had presented at the Department of Medical Genetics of Hunan Children′s Hospital on August 10, 2023 due to the repeated fractures for over 2 years and after binocular cataract surgery was selected as the study subject. Clinical data of his pedigree were collected, and peripheral venous blood samples were collected for the extraction of genomic DNA and subjected to trio-whole exome sequencing. Candidate variants were verified by Sanger sequencing and analyzed with bioinformatic software. This study was approved by the Medical Ethics Committee of Hunan Children′s Hospital (No. KYSQ2022-263).Results:The child had manifested repeated fractures, bilateral bowed femur, osteoporosis, cataract, atrial septal defect, and developmental delay. Ultrasonography has revealed fetal edema, peritoneal effusion, pleural effusion and polyhydramnios. Trio-whole exome sequencing and Sanger sequencing revealed that he has harbored compound heterozygous variants of the XYLT2 gene, namely c. 1103_1104delAG (p.Gln368Argfs*8) and c. 1238_1253delinsA (p.Val413_Pro418delinsGlu), which were inherited from his phenotypically normal father and mother, respectively. Neither variant was reported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG) and recommendations from the Clinical Genome Resource (ClinGen), the c. 1103_1104delAG was predicted as a pathogenic variant (PVS1+ PM2_Supporting+ PP4), whilst the c.1238_1253delinsA was predicted as a likely pathogenic variant (PM4+ PM3+ PM2_Supporting+ PP4). Conclusion:The c. 1103_1104delAG and c. 1238_1253delinsA compound heterozygous variants of the XYLT2 gene probably underlay the pathogenesis in this child. Above finding has enriched the phenotypic and mutational spectrum of SOS, and provided a basis for the clinical diagnosis, treatment, prognosis assessment and genetic counseling for this pedigree.