The Essential Function of miR-5739 in Embryonic Muscle Development

Background and Objectives@#Embryologically, mesodermal development is closely related to the development of various organs such as muscles, blood vessels, and hearts, which are the main organs that make up the body. However, treatment for mesoderm developmental disorders caused by congenital or acquired factors has so far relied on surgery and drug treatment for symptom relief, and more fundamentally, treatment for mesoderm developmental disorders is needed. @*Methods@#and Results: In our study, microRNA (miRNA), which plays an important role in the mesoderm development process, was identified and the developmental function was evaluated. miRNAs consist of small nucleotides, which act as transcription factors that bind to the 3’ untranslated region and suppressed target gene expression. We constructed the human embryonic stem cell (hESC) knockout cell line and analyzed the function and characteristics of miR-5739, which plays an important role in mesoderm lineage. miR-5739 acts as a transcription factor targeting SMA, Brachyury T, Hand1, which controls muscle proliferation and differentiation, and KDR gene, which regulates vessel formation in vitro. In vivo results suggest a role in regulating muscle proliferation and differentiation. Gene ontology analysis confirmed that the miR-5739 is closely related to genes that regulate muscle and vessel proliferation and differentiation. Importantly, abnormal expression of miR-5739 was detected in somatic cells derived from patients with congenital muscle disease. @*Conclusions@#Our study demonstrate that miR-5739 gene function significantly affects transcriptional circuits that regu-late muscle and vascular differentiation during embryonic development.

Radially patterned polycaprolactone nanofibers as an active wound dressing agent

BACKGROUND: The objectives of this study were to design polycaprolactone nanofibers with a radial pattern using a modified electrospinning method and to evaluate the effect of radial nanofiber deposition on mechanical and biological properties compared to non-patterned samples. METHODS: Radially patterned polycaprolactone nanofibers were prepared with a modified electrospinning method and compared with randomly deposited nanofibers. The surface morphology of samples was observed under scanning electron microscopy (SEM). The tensile properties of nanofibrous mats were measured using a tabletop uniaxial testing machine. Fluorescence-stained human bone marrow stem cells were placed along the perimeter of the radially patterned and randomly deposited. Their migration toward the center was observed on days 1, 4, and 7, and quantitatively measured using ImageJ software. RESULTS: Overall, there were no statistically significant differences in mechanical properties between the two types of polycaprolactone nanofibrous mats. SEM images of the obtained samples suggested that the directionality of the nanofibers was toward the central area, regardless of where the nanofibers were located throughout the entire sample. Florescence images showed stronger fluorescence inside the circle in radially aligned nanofibers, with significant differences on days 4 and 7, indicating that migration was quicker along radially aligned nanofibers than along randomly deposited nanofibers. CONCLUSIONS: In this study, we successfully used modified electrospinning to fabricate radially aligned nanofibers with similar mechanical properties to those of conventional randomly aligned nanofibers. In addition, we observed faster migration along radially aligned nanofibers than along randomly deposited nanofibers. Collectively, the radially aligned nanofibers may have the potential for tissue regeneration in combination with stem cells.

Preschool Vision Screening for 3 to 6-Year Old Children in Korea

PURPOSE: To inform the necessity of mass screening, we performed a mass screening for the detection of ocular disorders of preschool children. METHODS: Ocular examination was performed on 60, 827 children in Korea (3-6 years of age) during the period from March to October, 2000. The total of 3, 254 children were shown to have either visual acuity of less than 0.5 or anisometropia of over 2 lines. Detailed eye examination was conducted on those 3, 254 children. RESULTS: The numbers of first mass screening were 60, 826. Diagnosis consisted of refractive errors in 2, 216, amblyopia in 664, and strabismus in 235. Among the types of refractive errors, myopic astigmatism was the most common type (34.0%). Astigmatism was combined with all other types in 1, 659 children. Refractive error was the most common cause of amblyopia (88.0%) CONCLUSIONS: To prevent and treat amblyopia or strabismus, early detection and adequate care at preschool age seemed to be very effective. Participation rate for this mass-screening of eye disease during preschool age will be more increased by efforts of constiutional support and parental cooperation.

Comparison of the Clinical Effect of the 1% Rimexolone with That of 0.1% Fluorometholone Following LASIK

PURPOSE: We compared therapeutic efficacy and steroid-induced IOP elevation of 1% rimexolone with that of 0.1% fluorometholone. METHODS: Of all LASIK treated eyes from March of 2001 to December of 2002 in Sungae General Hospital, 46 eyes were treated with 1% rimexolone and 46 eyes were treated with 0.1% fluorometholone. And we measured the degree of myopic regression (1 day, 1 month, 3 month) and intraocular pressure (1 month). RESULTS: Statistically signicant difference in therapeutic efficacy of myopic regression, and no statistically signicant difference in IOP were found. The therapeutic efficacy of 1% rimexolone was higher. CONCLUSIONS: We concluded that application of 1% rimexolone was more useful in myopic regression following LASIK rather than that of 0.1% fluorometholone.