Search

To perform safe and successful corneal refractive surgery on myopic patients, corneal thickness (CT) and corneal epithelial thickness (CET) must be accurately measured. Numerous individuals with myopia wear soft contact lenses (SCLs) for the correction of visual acuity but may subsequently undergo corneal refractive surgery. The aim of the present study was therefore to investigate the effects of long-term SCL wear on the CT and the CET of myopic subjects in order to guarantee the safety and accuracy of subsequent corneal refractive surgeries. Fifty-six subjects prepared to receive refractive surgery at Jinan Mingshui Eye Hospital (Zhangqiu, China) from April to July 2013 were included in the study. CT and CET were measured in subjects immediately following discontinued SCL wear (group I, 56 eyes), and subsequently following >two weeks of discontinued SCL wear (group II, 56 eyes). Ninety-four subjects with no history of corneal contact lens wear were enrolled as a control group. The CT and CET were measured at positions with a radius of 0.0-1.0, 1.0-2.5 (divided into eight quadrants) and 2.5-3.0 mm (divided into eight quadrants) away from the corneal center using the RTVue-100 Fourier-domain anterior segment optical coherence tomography system. A significant decrease in the CT of the subjects in group II was observed, compared with that of group I and the control group (P<0.05). A significant decrease was observed in the CET of groups I and II compared with that of the control group (P<0.05). Following discontinuation of SCL wear, CET increased. However, the increased CET was unable to reach the normal range exhibited by the control group. Edema and thinning of the corneal stroma, as well as thinning of the corneal epithelium were observed in groups I and II. In conclusion, it was proposed that in clinical practice, for myopic patients following long-term SCL wear, CT and CET should be determined ≥two weeks following discontinuation of SCL wear, once a stable CT and CET are obtained. [ABSTRACT FROM AUTHOR]

STUDY QUESTION: How does L-carnitine (LC) supplementation during vitrification and in vitro maturation (IVM) of germinal vesicle stage (GV)-oocytes improve the developmental competence of the resultant metaphase II (MII) oocytes? SUMMARY ANSWER: LC supplementation during both vitrification of GV-oocytes and their subsequent IVM improved nuclear maturation as well as meiotic spindle assembly and mitochondrial distribution in MII oocytes. WHAT IS KNOWN ALREADY: Vitrification of GV-oocytes results in a lower success rate of blastocyst development compared with nonvitrified oocytes. LC supplementation during both vitrification and IVM of mouse GV-oocytes significantly improves embryonic development after IVF. STUDY DESIGN, SIZE, DURATION: GV-oocytes were collected from (B6.DBA)FI and B6 mouse strains and subjected to vitrification and warming with or without 3.72 mM LC supplementation. After IVM with or without LC supplementation, the rate of nuclear maturation and the quality of MII oocytes were evaluated. A t least 20 oocytes/group were examined, and each experiment was repeated at least three times. All experiments were conducted during 2013-2014. PARTICIPANTS/MATERIALS, SETTING, METHODS: Extrusion of the first polar body in IVM oocytes was observed asan indication of nuclear maturation. Spindle assembly and chromosomal alignment were examined by immunostaining of a-tubulin and nuclear staining with 4,6- diamidino-2-phenylindole (DAPI). Mitochondrial distribution and oxidative activity were measured by staining with Mitotracker Green Fluorescence Mitochondria (Mitotracker Green FM) and chloromethyltetramethylrosamine (Mitotracker Orange CMTMRos), respectively. A T P levels were determined by using the Bioluminescent Somatic Cell Assay Kit. MAIN RESULTS AND THE ROLE OF CHANCE: LC supplementation during both vitrification and IVM of GV-oocytes significantly increased the proportions of oocytes with normal MII spindles to the levels comparable with those of non-vitrified oocytes in both mouse strains. While vitrification of GV-oocytes lowered the proportions of MII oocytes with peripherally concentrated mitochondrial distribution compared with non-vitrified oocytes, LC supplementation significantly increased the proportion of such oocytes in the (B6.DBA)FI strain. LC supplementation decreased the proportion of oocytes with mitochondrial aggregates in both vitrified and non-vitrified oocytes in the B6 strain. The oxidative activity of mitochondria was mildly decreased by vitrification and drastically increased by LC supplementation irrespective of vitrification in both mouse strains. N o change was found in A T P levels irrespective of vitrification or LC supplementation. Results were considered to be statistically significant at P < 0.05 by either ξ ² - or t-test. LIMITATIONS, REASONS FOR CAUTION: It remains to be tested whether beneficial effect of LC supplementation during vitrification and IVM of GV-oocytes leads to fetal development and birth of healthy offspring after embryo transfer to surrogate females. WIDER IMPLICATIONS OF THE FINDINGS: This protocol has the potential to improve the quality of vitrified human oocytes and embryos during assisted reproduction treatment. STUDY FUNDING/COMPETING INTEREST: Partially supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant and Mitacs Elevate Postdoctoral Fellowship, Canada. [ABSTRACT FROM AUTHOR]

The oocytes of B6.YTIR sex-reversed female mouse mature in culture but fail to develop after fertilization because of their cytoplasmic defects. To identify the defective components, we compared the gene expression profiles between the fullygrown oocytes of B6.YTIR (XY) females and those of their XX littermates by cDNA microarray. 173 genes were found to be higher and 485 genes were lower in XY oocytes than in XX oocytes by at least 2-fold. We compared the transcript levels of selected genes by RT-PCR in XY and XX oocytes, as well as in XO oocytes missing paternal X-chromosomes. All genes tested showed comparable transcript levels between XX and XO oocytes, indicating that mRNA accumulation is well adjusted in XO oocytes. By contrast, in addition to Y-encoded genes, many genes showed significantly different transcript levels in XY oocytes. We speculate that the presence of the Y-chromosome, rather than the absence of the second X-chromosome, caused dramatic changes in the gene expression profile in the XY fully-grown oocyte. [ABSTRACT FROM AUTHOR]