ABSTRACT
Pinellia ternata belongs to the Araceae family and is a medicinal herb. The tuber is the medicinal organ with antitussive, antiemetic and anti-tumor activities. It is easy to encounter high temperature environment during the growth periods, leading to decrease of tuber production. At present, the mechanism of response to high temperature stress in P. ternata is still unknown. DNA methylation plays a vital role in plant protection against adversity stress as a way of epigenetic regulation. In this study, P. ternata was used as material for treatment of high temperature stress at 0 h, 6 h and 80 h, and methylation sensitive amplification polymorphism(MSAP) analysis was conducted on the changes of DNA methylation in its genome. The results showed that 20 pairs of MSAP primers were selected from 100 MSAP primers with multiple clear and uniform bands, and 353, 355 and 342 loci were amplified from materials of P. ternata treated in the high temperature stress 0 h, 6 h and 80 h, respectively. Cytosine methylation levels of CCGG context in the above materials were characterized as 60.91%, 44.79% and 44.74%, respectively. And the full methylation ratios were 16.71%, 22.25% and 29.24, respectively. It demonstrated that high temperature stress significantly induced the down-regulation of DNA methylation level and up-regulation of the full methylation rate in P. ternata genome. This study provides a preliminary theoretical reference for analyzing the mechanism of P. ternata responding to high temperature stress from the epigenetic perspective.
Subject(s)
DNA Methylation , Epigenesis, Genetic , Hot Temperature , Pinellia/genetics , Plants, Medicinal/geneticsABSTRACT
Background Central corneal thickness (CCT)is an important parameter to evaluate corneal healthy status and is crucial for surgical planning.However,clinical study found that the center of cornea does not correspond to the thinnest point of cornea.Thus,it is essential to characterize the minimum corneal thickness(MCT) and its location.Objective Present study was to determine the thickness and location of MCT and its relationship to the fellow eye using Pentacam High Resolution technique.Methods The 564 eyes from 282 Chinese myopic patients were reviewed in this study.The CCT,MCT,pupillary central corneal thickness(PCT) and x-y coordinate of thinnest point were bilaterally measured.Written informed consent was obtained prior to the ocular biomedical measurement.Results CCT was (540.07±31.78) μm in the right eyes and (539.24±31.06) μm in the lefi eyes; PCT was (540.25±30.75)μm in the right eyes and (539.48±31.00)μm in the left eyes.MCT was (537.87± 31.91)μm in the right eyes and (536.35±31.24)μm in the left eyes,showing significant differences in all the parameters between the right eyes and left eyes expect for PCT(CCT:P=0.046;PCT:P=0.065 ;MCT:P=0.000).The C CT,PCT and M CT were significantly correlated between the right eyes and left eyes (r =0.97,0.97,0.98,P＜ 0.01).Bland-Altman plot showed a good consistence between the both eyes.The mean distance from the center was (0.50±0.21) mm in the right eyes and (0.56±0.22)mm in the left eyes,showing a significant difference (P =0.000).The difference between CCT and MCT was approximately (2.20±1.74)μm in the right eyes and (2.88±1.75) μm in the left eyes.The location of MCT in both the right eyes and left eyes tended to symmetry along the vertical midline.The distance between the R (x,y) to transformed L (x,y) was (0.29 ± 0.17)mm and the angular distance was (28.28±28.21)degree.Conclusions This study offers a range of MCT and its location in Chinese myopic patients.The difference exists between the CCT and MCT in bilateral eyes.The location of the thinnest point tends to be symmetrical along the vertical midline between the both eyes.The changes of these parameters may be helpful for the diagnosis of some corneal diseases.
ABSTRACT
BackgroundIn an ideal eye there would be no light scattering at all,but the eye media is not optically ideal.Intraocular straylight causes a veil of light and reduction in the contrast of the retinal image and thus decrease the quality of vision.ObjectiveThe present study was to investigate the repeatability and reproducibility of C-Quant straylight meter( Oculus,Germany)in measuring retinal straylight of myopia and post-laser in situ keratomileusis(LASIK) corneas.MethodsThis is a prospective research.The consecutive 35 eyes of 21 myopic patients and 34 eyes of 22 patients who received LASIK were included in this trail.Retinal straylight was measured for 7 times at a period of time and analyzed quantificational to evaluate the repeatability of measurement.Thirty-eight eyes of 19 patients were measured again at 3-7 days for 3 times at a period of time to assess the reproducibility of C-Quant straylight meter.The mean standard difference (SD) and coefficient of variation (CV) were used as the credibility evaluation.This clinical study complied with Helsinki Declaration and the informed consent was obtained prior to the medical procedure.ResultsThe straylight Log(s) of 7 times measurement were all less than 0.95.The mean Log(s) were 0.92±0.12 and 0.93±0.17 respectively in myopia group and post-LASIK group,without statistically significant differences among 7 times measurement( F=0.335,P=0.812;F=1.000,P=0.409).The mean SD for the 7 times measurement was 0.07 Log units.SD and CV increased with the number of measurements.The differences of mean SD and CV between 3 times result and 6 times result were significant different (t =-2.080,P =0.045;t =-2.190,P =0.035 ).No difference was found between different time periods( t =-0.531,P=0.598 ).The difference of the results between two measurements from the same patient was 0.013.ConclusionsC-Quant is a noncontact,noninvade,rapid and convenient method for the measurement of straylight in myopia and post-LASIK eyes due to the high repeatability and reproducibility.
ABSTRACT
Background Clinical research showed that the corneal endothelial cell density value from different corneal specula microscopies exist diversity.The relevant literature of SP02,Tomey EM-3000 and SP3000P is still seldom up to now. Objective This research was to assess the repeatability of endothelial cell density measurements by SP02,Tomey EM-3000 and SP3000P respectively and the agreement among 3 kinds of endothelial microscopes.MethodsFifty-four healthy volunteers with the age 17-38 years old were included this research.The written informed consent was obtained from each subject before examination.The corneal endothelial cell densities in the right eyes were analyzed with SP02,Tomey EM-3000 and SP3000P respectively for 3 times under the automatic mode,and the analytical procedure of SP3000P measurement were divided into automatic mode SP3000P (A) and manual correction modes SP3000P( M).The repeatability of each specula microscopy was analyzed by calculating the intraclass correlation coefficients (ICC) and coefficient of variation ( CV ),and the 95％ confidence intervals and plotting Bland-Altman graphs were used to analyze the agreement among these methods.ResultsThe mean corneal endothelial cell densities in the population ＜24 years were significantly higher than the ones ≥ 24 years (t =3.692,P＜0.05 ),but no statistical difference was found between different gender ( t =0.335,P =0.739 ).The mean corneal endothelial cell densities were ( 3058 ± 260 ),( 2954 ± 229 ),( 2668 ± 258 ),( 2734 ± 268 ) cell/mm2 ; the ICCs were 0.957,0.940,0.972 and 0.972 and the CV were 0.063,0.061,0.056,0.058 for SP02,Tomey EM-3000,SP3000P (A) and SP3000P ( M ) respectively.The 95％ confidence intervals were ( - 100.8 - 306.8 ),( 162.6 - 617.4 ),( 109.9-494.1 ) and ( -0.6 - 132.6 ) cell/mm2 for between SP02 and Tomey EM-3000,SP3000P ( A ) and SP02,SP3000P(A) and Tomey EM-3000,SP3000P(A) and SP 3000P(M) respectively.ConclusionsSP02,Tomey EM-3000 and SP3000P(A) have good repeatability in the measurement of corneal endothelial cell density,however the outcome is different.Therefore,it is not interchangeable for the detection of corneal endothelial cell density.The differences of corneal endothelial cell density obtained from these instruments shall be paid high attention for their differences.SP3000P(A) and SP3000P(M) can be used interehangeably and SP3000P(A) is a preferable choice due to its convenience and quickness.