Yang Qing | PubMed Health

PubMed2004

Saccade-vergence dynamics and interaction in children and in adults.

Peak velocity, duration and accuracy of eye movements (saccade, vergence and combined saccade-vergence eye movements) were investigated in fourteen normal children (4.5 to 12 years of age) and ten normal adults (22 to 44 years of age). Horizontal movements from both eyes were recorded simultaneously by the oculometer, a photoelectric device. Peak velocity of all eye movements, saccades, and vergence (convergence and divergence), attains adult levels by the age of 4.5 years and there is no significant change over the age range studied (4.5 to 44 years). Vergence duration is longer only in young children (below 8 years of age). The reciprocal interaction between saccade and vergence during combined movements known in adults, i.e. acceleration of the vergence by the saccade (increase of velocity and decrease of duration) and deceleration of the saccade by the vergence (decrease of velocity and increase of duration) was found to be similar in children. The accuracy of eye movements is good on average for both saccades and vergence by the age of 4.5 years, and does not change with age; an exception is the variability of saccade amplitude, which is higher in children less than 8 years old. Taken together, the results indicate early maturation of brainstem structures controlling spatio-temporal aspects of saccades, vergence and their interaction.

Adult↗

PubMedDate not supplied

Monitoring gene expression profile changes in bladder transitional cell carcinoma using cDNA microarray.

PURPOSE: Differential gene expression profiles between normal bladder mucosas and bladder transitional cell carcinomas TCC were detected. MATERIALS AND METHODS: cDNA microarrays were prepared by spotting PCR products of 12,800 human genes onto specially treated glass slides. The cDNA probes were prepared by labeling normal bladder mucosa mRNA and TCC tissue mRNA with Cy3-dUTP and Cy5-dUTP respectively through reverse transcription. The arrays were then hybridized against the cDNA probe mixture and the fluorescent signals were scanned. The ratios of Cy5/Cy3 were computed. Northern analysis was used to confirm the results of microarray hybridization. RESULTS: Eighty-three genes (0.65%), whose ratios of Cy5/Cy3 were greater than 4.0 or less than 0.25, were screened out after 10 groups of hybridization. In the cancerous tissues 28 of them showed higher expression and 55 lower. Twenty-three genes are unregistered in GenBank. These differentially expressed genes are always involved in the physiological processes such as signal transduction, apoptosis and cell cycle, etc. CONCLUSIONS: This technique provides a powerful method for quantitative analysis of the expression levels of thousands of genes in parallel, and is used to identify genes involved in TCC carcinogenesis. The data obtained by this means are comparable to those obtained by other methods. Using cDNA microarrays to define alterations in gene expression associated with a specific cancer may be an efficient way to uncover the clues to specific molecular derangements that account for its pathogenesis and thus identify potential targets for therapeutic intervention.

Aged↗