Ectopic co‑expression of the SOD and APX genes enhanced callus growth and in vitro regeneration in Arabidopsis

Amrina Shafi,Insha Zahoor,Tejpal Gill,Paramvir Singh Ahuja,Sanjay Kumar,Anil Kumar Singh 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.3

Antioxidant enzymes, such as superoxide dismutase (SOD) and ascorbate peroxidase (APX), play important role in ROS homeostasis in plants. In the present study, two important antioxidant enzyme-encoding genes, cytosolic Cu/Zn-SOD and APX, were isolated from Potentilla atrosanguinea and Rheum australe plants, which grow at high-altitude regions of Himalaya. Previously, we have reported cytosolic overexpression of both the genes in Arabidopsis, individually and in combination and these transgenic plants exhibit cold and salt stress tolerance. In the present study, wild-type (WT) and transgenic lines (cytosolic Cu/Zn-SOD and APX) were analysed for their regeneration potential and expression profiling of various genes involved in in vitro regeneration was carried out. Among all transgenic lines, dual transgenics showed early callus induction and shoot regeneration. Callus growth rate and in vitro regeneration capacity were significantly higher in transgenic lines compared with control plants. Interestingly, H2O2 accumulation and SOD activity were found to be higher in SOD and dual transgenic lines during callus induction and shoot regeneration stages, indicating a correlation between H2O2 and SOD activity with regeneration process. Whereas APX activity in transgenic lines was found to be decreased in regenerated shoots, cotyledons, it was increased in callus and roots. Further, expression analysis of several genes involved in callus induction and in vitro regeneration using qRT-PCR showed that the majority of genes were significantly up-regulated (two- to fourfold) during different stages of regeneration in transgenic lines. Consequently, our results substantiate that a minimal amount of H2O2 accumulation brought about by overexpression of SOD and APX genes may play an important role in early callus induction and shoot regeneration in transgenic line. The overall results will add knowledge about the role of antioxidant genes in in vitro regeneration of plants.

Experimental Evaluation of Accelerated T1rho Relaxation Quantification in Human Liver Using Limited Spin-Lock Times

Feng Zhao,Min Deng,Jing Yuan,Gao-Jun Teng,Anil T Ahuja,Yi-Xiang J. Wang 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.6

Objective: It was reported lately that to obtain consistent liver T1rho measurement, at 3T MRI using six spin-lock times (SLTs), is feasible. In this study, the feasibility of using three or two SLT points to measure liver T1rho relaxation time was explored. Materials and Methods: Seventeen healthy volunteers underwent 36 examinations. Three representative axial slices were selected to cut through the upper, middle, and lower liver. A rotary echo spin-lock pulse was implemented in a 2D fast field echo sequence. Spin-lock frequency was 500 Hz and the spin-lock times of 1, 10, 20, 30, 40, and 50 milliseconds (ms) were used for T1rho mapping. T1rho maps were constructed by using all 6 SLT points, three SLT points of 1, 20, and 50 ms, or two SLTs of 1 and 50 ms, respectively. Intra-class correlation coefficient (ICC) and Bland and Altman plot were used to assess the measurement agreement. Results: Two examinations were excluded, due to motion artifact at the SLT of 50 ms. With the remaining 34 examinations, the ICC for 6-SLT vs. 3-SLT T1rho measurements was 0.922, while the ICC for 6-SLT vs. 2-SLT T1rho measurement was 0.756. The Bland and Altman analysis showed a mean difference of 0.19 (95% limits of agreement: -1.34, 1.73) for 6-SLT vs. 3-SLT T1rho measurement, and the mean difference of 0.89 (95% limits of agreement: -1.67, 3.45) for 6-SLT vs. 2-SLT T1rho measurement. The scan re-scan reproducibility ICC (n = 11 subjects) was 0.755, 0.727, and 0.528 for 6-SLT measurement, 3-SLT measurement, and 2-SLT measurement, respectively. Conclusion: Adopting 3 SLTs of 1, 20, and 50 ms can be an acceptable alternative for the liver T1rho measurement, while 2 SLTs of 1 and 50 ms do not provide reliable measurement. Objective: It was reported lately that to obtain consistent liver T1rho measurement, at 3T MRI using six spin-lock times (SLTs), is feasible. In this study, the feasibility of using three or two SLT points to measure liver T1rho relaxation time was explored. Materials and Methods: Seventeen healthy volunteers underwent 36 examinations. Three representative axial slices were selected to cut through the upper, middle, and lower liver. A rotary echo spin-lock pulse was implemented in a 2D fast field echo sequence. Spin-lock frequency was 500 Hz and the spin-lock times of 1, 10, 20, 30, 40, and 50 milliseconds (ms) were used for T1rho mapping. T1rho maps were constructed by using all 6 SLT points, three SLT points of 1, 20, and 50 ms, or two SLTs of 1 and 50 ms, respectively. Intra-class correlation coefficient (ICC) and Bland and Altman plot were used to assess the measurement agreement. Results: Two examinations were excluded, due to motion artifact at the SLT of 50 ms. With the remaining 34 examinations, the ICC for 6-SLT vs. 3-SLT T1rho measurements was 0.922, while the ICC for 6-SLT vs. 2-SLT T1rho measurement was 0.756. The Bland and Altman analysis showed a mean difference of 0.19 (95% limits of agreement: -1.34, 1.73) for 6-SLT vs. 3-SLT T1rho measurement, and the mean difference of 0.89 (95% limits of agreement: -1.67, 3.45) for 6-SLT vs. 2-SLT T1rho measurement. The scan re-scan reproducibility ICC (n = 11 subjects) was 0.755, 0.727, and 0.528 for 6-SLT measurement, 3-SLT measurement, and 2-SLT measurement, respectively. Conclusion: Adopting 3 SLTs of 1, 20, and 50 ms can be an acceptable alternative for the liver T1rho measurement, while 2 SLTs of 1 and 50 ms do not provide reliable measurement.

Quantitative histology-based classification system for assessment of the intestinal mucosal histological changes in patients with celiac disease

Prasenjit Das,Gaurav PS Gahlot,Alka Singh,Vandana Baloda,Ramakant Rawat,Anil K Verma,Gaurav Khanna,Maitrayee Roy,Archana George,Ashok Singh,Aasma Nalwa,Prashant Ramteke,Rajni Yadav,Vineet Ahuja,Vishnu 대한장연구학회 2019 Intestinal Research Vol.17 No.3

Background/Aims: The existing histological classifications for the interpretation of small intestinal biopsies are based on qualitative parameters with high intraobserver and interobserver variations. We have developed and propose a quantitative histological classification system for the assessment of intestinal mucosal biopsies. Methods: We performed a computer-assisted quantitative histological assessment of digital images of duodenal biopsies from 137 controls and 124 patients with celiac disease (CeD) (derivation cohort). From the receiver-operating curve analysis, followed by multivariate and logistic regression analyses, we identified parameters for differentiating control biopsies from those of the patients with CeD. We repeated the quantitative histological analysis in a validation cohort (105 controls and 120 patients with CeD). On the basis of the results, we propose a quantitative histological classification system. The new classification was compared with the existing histological classifications for interobserver and intraobserver agreements by a group of qualified pathologists. Results: Among the histological parameters, intraepithelial lymphocyte count of ≥25/100 epithelial cells, adjusted villous height fold change of ≤0.7, and crypt depth-to-villous height ratio of ≥0.5 showed good discriminative power between the mucosal biopsies from the patients with CeD and those from the controls, with 90.3% sensitivity, 93.5% specificity, and 96.2% area under the curve. Among the existing histological classifications, our quantitative histological classification showed the highest intraobserver (69.7%–85.03%) and interobserver (24.6%–71.5%) agreements. Conclusions: Quantitative assessment increases the reliability of the histological assessment of mucosal biopsies in patients with CeD. Such a classification system may be used for clinical trials in patients with CeD.