Biomedical subjects

Shuang-Zhen Liu

Publications and source records attributed to Shuang-Zhen Liu.

3 recordsLinked to original sources

PubMed2005

[Dynamic changes of MMP-2 activity in the posterior sclera of chicks with form-deprivation myopia].

OBJECTIVE: To investigate the effect of form-deprivation on level of gelatinase in the posterior sclera in chicks. METHODS: Fifty 1-day-old chicks were monocularly deprived to establish the animal model of form-deprivation myopia (FDM). According to the duration of form-deprivation the experimental chicks were divided randomly and equivalently into 5 groups, which were deprived for 3, 7, 14, 21 and 30 days respectively. Meanwhile the other eyes of the deprived chicks were used as self-control groups and chicks of the same days were chosen randomly as the normal control groups for each FDM group. At each form-deprivation point the changes of degree of diopters and axial length of chicks in each group were recorded. The levels of gelatinase in posterior sclera of the experimental eyes were measured by gelatin enzymography. RESULTS: Compared with the normal and self-control groups, the levels of MMP-2 activity in FDM groups were much higher (P <0.01). With the increase of the time of monocular deprivation these changes became more significant and reached the top after 14 days' deprivation with an inter-group statistical difference (P <0.01). The dynamic changes of MMP-2 activity were the same as those of axial length and degree of diopters in each experimental groups. There was positive correlation between the MMP-2 activity and axial length (r = 0.989, P < 0.01). But there was a negative correlation between the MMP-2 activity and refractive degree. CONCLUSION: Increase of MMP-2 activity in the posterior sclera of chicks would be a direct key factor to trigger sclera ECM remodeling process in chick FDM.

Animals↗

PubMed2005

[Multiple factor analysis of visual function in hypermetropic children].

OBJECTIVE: To investigate the characteristics of hypermetropic children whose visual acuity (VA) is declined or accompanied by esotropia. METHODS: One hundred and ninety children were given optometry, strabismus degree and binocular vision measurement. RESULTS: Declined VA appeared in 170 children, while esotropia occurred in 173. Sixty-one got binocular single vision, 17 had fusion function, and 11 had stereoaculty. Spherical equivalent had a linear relationship with VA (P < 0.01), but not with the strabismus degree (P > 0.05). The influence factors of binocular vision were age of discovery, VA and the strabismus degree, while the stereoaculty was influenced by the strabismus degree, spherical equivalent and VA. CONCLUSION: Low VA and strabismus are the most common complaint in children. Ametropia and strabismus do great harm to juvenile binocular vision, and stereoaculty is damaged seriously. We suggest an early examination of visual function in children.

Adolescent↗

PubMed2004

[Matrix metalloproteinase-2 mRNA expression in the posterior sclera of chick form-deprivation myopia].

OBJECTIVE: To investigate the dynamic changes of matrix metalloproteinase-2 (MMP-2) mRNA expression in the posterior sclera of chick form-deprivation myopia (FDM) and its possible molecular mechanism. METHODS: Fifty white 1-day-old leghorn chicks were divided randomly and equally into 5 groups. The right eye of each chick was covered with a plastic goggle at 4, 7, 14, 21, and 30 postborn days respectively to induce FDM, and the left eye served as a self-control. Meanwhile, normal age-matched chicks were provided as negative control speciments for each group. Removing the goggle at every experiment point, refractive status and axial length were determined with streak retinoscopy (without cycloplegia) and A-scan ultra-sonography under topical anaesthesia, respectively. Both eyes were collected after the chicks were killed. The total RNA in the posterior sclera was extracted traditionally using TRIZOL reagent, and then the expression levels of MMP-2 messenger RNA were analyzed by one step reverse transcriptiontase-polymerase chain reaction. RESULTS: Compared with the normal and self-control groups, the expression levels of MMP-2 mRNA in the deprived eyes significantly increased (P < 0.001). With the delay of form-deprivation duration, MMP-2 mRNA expression levels increased significantly and especially reached a highest point at the 14th day of monocular deprivation. After that the level decreased slightly, but maintained at a high level. Although there was no significant difference between the normal control group and the self-control one (P > 0.05), MMP-2 mRNA expressed slightly higher in the self-controlled eyes. CONCLUSION: As a primary element to trigger early active sclera extracellular matrix remodeling process, MMP-2 gene is probably involved in the development of FDM by excessive degradation of extraceller matrix which can make sclera thinner and the eye axis longer.

Animals↗