Background The rat model of N-methyl-N-nitrosourea (MNU)-induced photoreceptor cell apoptosis is often used to study retinal degeneration.But the changes in the gene expression patterm in retinal degeneration in rats have not been reported.Objective This study was undertaken to investigate regulation of gene expression in the retina of MNU-induced retinal degeneration in rats by performing microarray analysis of retinal RNA.Methods Fifty 6-week-old SD rats were numbered and randomized into the normal group and the model group.The retinal degeneration model was established by a single hypodermic injection of 40 mg/kg of MNU,and the rats in the normal group received equivalent volume of physiological saline in the same way.The rats were sacrificed 12 hours or 24 hours after injection.Retinal sections from the right eyes were prepared for the measurement of the retinal thickness by histopathological examination,and retinas from the left eyes were used to confirm the differential gene expression as detected by microarray (normal group and 12 hours model group).Genes exhibiting changes in expression by ≥2.0 folds were further confirmed using real-time PCR.Results The whole thickness of the retina declined in the rats from the 24 hours model group compared to the normal group and 12 hours model group (t =9.926,P=0.002;t=2.736,P=0.028).The thickness of the outer nuclear layer was (26.58±2.90) μm in the 24 hours model group,showing a significant decrease in comparison with (38.11 ± 1.01) μm in the normal group and (35.07t3.03) μm in the 12 hours model group (t=6.028,P=0.009;t=6.839,P=0.006).However,there was no significant difference in retinal thickness between the normal group and the 12 hours model group (whole thickness:t=1.541,P=0.324;outer nuclear layer thickness:t=2.040,P=0.134).Microarray analysis of the rat genes showed that out of 17 000 genes,142 genes involved in biological process and 94 genes involved in molecular functions were differentially expressed,where most of them participate in the mitogen activated protein kinase signaling pathway,Tolllike receptor signaling pathway and apoptosis pathway.Real-time PCR analysis demonstrated that the expression of CCL2,IL-1b,CCL3,c-fos,c-myc,p53 and MMP3 were consistently up-regulated,conforming with the results from microarray analysis.Conclusions The changes in gene expression pattern appear in the early stage of MNUinduced retinal degeneration.These microarray results provided clues to understanding the molecular pathways underlying photoreceptor degeneration and indicating the directions for future studies.

Objective To investigate the influence of citalopram on the fast response action potential,slow response action potential,in vitro electrocardiogram(ECG) and in vivo ECG of cardiac myocytes,and explore its mechanism of adverse cardiac effects. Methods Conventional microelectrode technique was employed to record the fast and slow response action potentials of the isolated papillary muscles of guinea pigs.In vivo and in vitro ECG were recorded from anesthetized animals and Langendorff-perfused hearts,respectively. Results Citalopram could prolong the RR interval and QRS duration of in vivo ECG.The premature ventricular contraction and atrial ventricular block were induced by 12.5?10-6 mol/L citalopram.The maximum ascending velocity of 0 phase(Vmax),action potential amplitude(APA) and action potential duration(APD50 and APD90) were dose-dependently decreased by citalopram in the fast and slow response action potentials of guinea pigs,respectively. Conclusion Citalopram can inhibit sodium and calcium channels effectively,which may be the ionic mechanism that citalopram induces arrhythmia in the clinical practice.

Cardiovascular Diseases ; metabolism ; pathology ; Humans ; Smad Proteins ; metabolism ; Trans-Activators ; metabolism

Objective To investigate residual hearing of children with sensorineural hearing loss in whom wave V was not found in ABR testing and to emphasize the importance of behavioral audiometry in determining the residual hearing.Methods Residual hearing obtained by behavioral audiometry of 101 children with SNHL was studied in relation to the absence of wave V in both click-ABR and tone burst-ABR tests.Results All children have residual hearing of different degrees at different frequencies.There appeared to be a higher percentage of lowfrequency residual hearing than middle and high frequencies.Also,the residual hearing at low frequencies appeared to be better than those in the middle and high frequencies.Average residual hearing thresholds in the right ears from 500 to 4 000 Hz were 106.81±7.13,110.00±7.90,111.78±5.22,112.06±7.08 dB HL and those in the left ears were 98.01±3.98,111.30±7.18,112.06±7.08,108.33±7.23 dB HL.Conclusion The absence of wave V in ABR does not mean total deafness.For those children with no wave V in ABR,behavioral audiometry must be conducted to determine children's behavioral hearing thresholds in order to know their residual hearing.

Objective To observe the learning and memory ability of rats after injection of Aβ25-35 protein in different concentrations into the lateral ventricle assessed by Morris water maze test, and to explore the optimal concentration of Aβ25-35 in the preparation of AD model rats.Methods Male SD rats were randomly divided into sham operated group and model group.The rats of model group received Aβ25-35 injection in concentrations of 2 μg/μL, 4 μg/μL and 8 μg/μL, respectively.According to the Rat Brain Stereotaxic Atlas, 5 μL of aggregation of Aβ25-35 was injected into the right lateral ventricle to establish the AD rat model.7 days after successful modeling, Morris water maze was used to test thechanges of learning and memory ability of the rats.Results There was no significant difference in the average swimming speed between the two groups (P > 0.05).The escape latency time of rats in the model group was significantly increasedcompared with the sham group (P < 0.05).In the model group, the escape latency time of rats treated with 4 μg/μL and 8 μg/μL Aβ25-35 was significantly increased compared with the rats injected with 2 μg/μL (P < 0.05), while there was no significant difference between rats treated with 4 μg/μL and 8 μg/μL Aβ25-35 (P > 0.05).The activity time and distance of target quadrant of the rats injected with different concentration of Aβ25-35in the model group were significantly reduced compared with the sham group (P < 0.05), but no significant difference amongthe rats treated with different Aβ25-35 concentrations (P > 0.05).Compared with the sham-operated group, the number of platform-crossing of rats injected with different doses of Aβ25-35in the model group were significantly reduced (P < 0.05).In the model group, the rats treated with 4 μg/μL and 8 μg/μL was significantly reduced compared with the group with 2 μg/μL injection (P < 0.05).There was no significant difference between the rats injected with 4 μg/μL and 8 μg/μL (P > 0.05).Conclusions The recommended dose and concentration of Aβ25-35 to be injected into the unilateral ventricle to establisha rat model of Alzheimer's disease is 4 μg/μL in a volume of 5 μL.

BACKGROUND:At present, there are many researches about repairing articular cartilage defects. In particular, the microfracture technique has been widely used. OBJECTIVE:To observe recovery of knee joint motor function and morphological changes in tissue repair during articular cartilage defects with different directions (coronal position and sagittal position). METHODS:Articular cartilage fracture models with 2 mm-thick medial femoral condyles of rabbit knee joint were established. According to incision directions, models were assigned to coronal and sagittal groups. At 5, 10 and 20 weeks after model induction, general observation was performed. Specimens were sliced into paraffin sections, and subjected to hematoxylin-eosin staining and col agen staining. Tissue repair at the articular cartilage defects was observed using optical microscope and immunohistochemical method. After model induction, range of motion of rabbit joints was regularly examined in the two groups.RESULTS AND CONCLUSION:A white line was seen across the femoral condyles at defects in the two groups. Articular surface at defect repair was at the level of in situ cartilage, and reached a bone union. Knee joint treated by operation did not affect function. Under light microscope, partial reconstruction of subchondral bone was seen in the two groups, mainly fibrocartilage repair. The level of bony remodeling was lower than tidal line of adjacent in situ cartilage. Immunohistochemical method exhibited that type I col agen staining gradual y reduced at defects of specimens, but type II col agen staining gradual y increased. These results suggested that there was no significant difference in the recovery of motor function of knee joint and the repair of articular cartilage with different directions (coronal and sagittal position).

Objective To explore the application of diffusion weighted imaging(DWI) in diagnosis of viral encephalitis in children.Methods Conventional MR imaging(T2WI and T1WI) and DWI were performed on 20 patients with viral encephalitis diagnosed clinically.Location and number of lesions demonstrated on these imagings and percents in their abnormality were compared.Results Percen-(tage of abnormality) demonstrated on DWI was significantly higher than that on T1WI(?~2=4.44 P

Objective To observe changes of serum concentrations of interleukin-18(IL-18) and intercellular adhesion molecule-1(ICAM-1) in neonates with hypoxic-ischemic encephalopathy(HIE) and to explore the correlation of the 2 indices and its effect on patients′condition.Methods Thirty newborn infants met the criteria for HIE.There were 16 cases in mild HIE group,14 cases in moderate and severe HIE group.Twenty normal newborn infants were used as control group.The serum concentrations of IL-18 and ICAM-1 of HIE group and control group were detected using ELISA on the third day and 7th day.Results 1.The IL-18 levels of the mild,moderate and severe HIE and control groups measured within 3 days of life were (120.1?12.7),(175.1?15.4),(100.3?12.5) ng/L,respectively.The concentrations of IL-18 in HIE groups were higher than that of control group(Pa

Abstract: Objective　In order to explore the application prospects of the phenyl pyrazole insecticide fipronil for mosquito control and identify potential target genes involved in the resistance of Aedes aegypti to fipronil, and lay the foundation for an in-depth study of the resistance mechanism of Aedes aegypti to fipronil. Methods　Using Aedes aegypti sensitive strains as experimental materials, Aedes aegypti larvae were treated with fipronil, and the differences in gene expression of Aedes aegypti larvae before and after drug administration were compared at the transcriptome level using transcriptome sequencing combined with bioinformatics analysis, and the differential genes were analyzed. Results　A total of 757 differentially expressed genes were identified between the fipronil-treated group and control group, including 217 and 540 up- and down-regulated genes, respectively. Among these, the expression of glutamate-gated chloride channel (GluCls) genes varied significantly before and after treatment. Gene ontology analysis revealed that differentially expressed genes were enriched in catalytic activity, binding, metabolic processes, and membrane-related functions, while KEGG pathway analysis indicated enrichment in biosynthesis, metabolism, and life regulation processes, while the glutathione metabolic pathway was enriched in 15 differentially expressed genes. Conclusions The transcriptome results revealed that GST gene expression was significantly upregulated in fipronil-treated Aedes aegypti larvae, indicating that GST gene is involved in the development of fipronil resistance in Aedes aegypti larvae. In addition, GluCls gene expression was also significantly different before and after treatment, suggesting that GluCls migh be a potential target receptor for fipronil resistance in Aedes aegypti. As GluCls is an ideal target receptor found only in invertebrates, this discovery provides a reference and basis for further exploration of the toxicological mechanism of fipronil on Aedes aegypti.