The role of D2 and CP43 proteins in the bicarbonate-binding environment of Photosystem II

In Photosystem II (PS II), absorbed light energy is used to transfer electrons from water to a primary plastoquinone electron acceptor (QA) and then to the secondary plastoquinone acceptor (QB). A non-heme iron (NHI) is located between QA and QB and ligated by His residues from the D1 and D2 reaction centre protein; in addition, a bicarbonate ion forms a bidentate ligand to the NHI. Stabilisation of bicarbonate is provided by D2-Tyr244, D1-Tyr246 and the two water molecules, W622 and W582, through hydrogen bonds (PDB 4UB6). These two water molecules and amino acid residues around the bicarbonate-binding environment have been hypothesised to participate in stabilisation of a hydrogen-bond network for delivering protons via the bound HCO3- to the QB2-(H+) form of the secondary plastoquinone electron acceptor of PS II. The main purpose of this study was to investigate the importance of D2 and CP43 amino acid residues in maintaining the hydrogen-bond network to provide the stabilisation of bicarbonate and their roles in the structure, electron transfer and protonation steps in the QA-NHI-QB complex of PS II. Mutations targeting four amino acid residues from D2 protein (D2-Glu242, D2-Thr243, D2-Tyr244 and D2-Lys264) and one amino acid residue from CP43 protein (CP43-Arg448) were selected. Nearly all mutants showed impaired oxygen evolution and were highly susceptible to photodamage in the presence of PS II-specific electron acceptors; however, they were able to acclimate to high light when HCO3– was added. In addition, acceptor side electron transfer was altered in these strains, with a decrease in the forward electron transfer between QA and QB, as well as the back reaction from QA, in the presence of the PS II-specific inhibitor 3,4-dichloro-1,1-dimethyl urea (DCMU). Furthermore, all mutants except the D2-Glu242 mutant exhibited the accumulation of unassembled complexes containing the CP43 subunit and an ineffective repair mechanism was also observed in these mutants that showed delayed protein synthesis following the high-light treatment based on 35S-Met protein labelling experiments. This study indicated that the disruption of the hydrogen-bond network associated with the bicarbonate-binding environment impairs PS II assembly, electron transfer and also the repair mechanism of the photosystem following high-light-induced damage

Examining the Factors Affecting Reading Readiness of Kindergarten Students

Reading is one of the core literacy skills of every individual and early reading for children has a great impact on future learning pathways and the success of school life. The purpose of this study was to investigate the reading readiness of kindergarten students in Myanmar and examine factors affecting reading readiness. A quantitative survey method was used in this study with a total of 222 kindergarten students from seven schools in Yangon and Rakhine selected using the multistage cluster sampling method. The Myanmar Reading Assessment Test (Cronbach’s alpha of 0.925) for kindergarten was used to administer the reading readiness skills of the students. In addition, demographic factors related to students and parents’ involvement in their children’s learning were collected using a self-administered questionnaire. The statistical analysis methods used were descriptive statistics, percentiles, t test, and Analysis of Variance (ANOVA). According to the results, there were five reader groups: below basic (25.7%), basic (6.8%), satisfactory (11.3%), proficient (16.7%), and advanced (39.6%) levels. The results of the statistical analysis concluded that no preschool experiences, lower socioeconomic status, the region in which they live, and unsupportive parents were the main factors affecting reading readiness. Among these factors, preschool experience is the only solution that can be tackled to improve reading readiness than other factors. However, most children in Myanmar cannot yet access preschool programmes adequately. Therefore, the government, NGOs, INGOs, CSOs, CBOs, and other organisations should ensure that every child has the opportunity to attend preschool regardless of geographical barriers

Analyzing Social Network using Gephi

Social network analysis (SNA) is the study ofsocial networks to understand their structure andbehavior. The study of the social networks is thepossibility of collecting web log data. The data used foranalyzing social networks is relational data, which canbe obtained from different resources including contentavailable on web pages, user interaction logs andsocial interaction information provided by users. Thispaper used social interaction information fordetermining the relationship between users in thesocial networks using Gephi. An application callednetvizz was used in order to get the web log from socialnetwork. This analysis also examines how SNAmethods and tool can be used to evaluate degreedistribution and relationships between friends in asocial network

Mitochondrial DNA quantity changes in leucocytes of cancer patients on cisplatin and 5-fluorouracil regimen

Purpose: Cisplatin and 5-Fluorouracil are the critical components of therapeutic regimen in a broad range of malignancies. Their therapeutic efficacy is limited due to the development of toxic side effects and drug resistance by the cancer cells. Cisplatin toxic side effects are usually associated with mitochondrial injury in vivo and in vitro. In vitro evidence indicates that cisplatin decreases mitochondrial DNA (mtDNA) copy number. There is limited information on the effect of cisplatin on human mtDNA quantity. In order to clarify the effects of cisplatin and 5-FU on mtDNA in human, this study focused on the changes of mtDNA quantitation in cancer patients who were treated with cisplatin-based regimens. Methods: 24 blood samples from head and neck cancer patients were collected before chemotherapy and after second cycle of chemotherapy. Total DNA was extracted from peripheral blood leukocytes by salting out method. Validation of primer pairs were done by conventional PCR and checked by gel electrophoresis. The relative changes of mtDNA quantity were determined by quantitative PCR targeting Cyt-B genes normalizing with the nuclear gene PARL. Result: Comparing 24 samples, there was an increased mtDNA level after second cycle of chemotherapy, though it did Wilcoxon signed ranked test). However, 58% of the total patients had relatively increased mtDNA amount while 42% of the total patients showed decreased mtDNA amount after second cycle of chemotherapy (P<0.05, paired t-test). Conclusion: Overall, Cisplatin-based chemotherapy can affect mtDNA quantity changes in leucocytes of head and neck cancer patients

Weed Infestation in Green Gram-based Cropping Systems in Central Dry Zone of MyanmarWeed Infestation in Green Gram-based Cropping Systems in Central Dry Zone of Myanmar

The study was carried out with two objectives (1) to find out the dominant weeds and common weeds in green gram growing areas of the central dry zone, and (2) to examine weed intensity in differ-ent green gram-based cropping patterns. Dominant weed species were Echinochloa colona, Paspalum distichum and Cyperus iria in Tatkon lowland, Cynodon dactylon, Cyperus iria and Echinochloa colona in Tatkon upland, Cyperus iria and Cyperus rotundus in Magway upland. Common weed species were Cyperus iria and Echinochloa colona in Tatkon lowland, Cyperus iria and Cynodon dactylon in Tatkon upland and Achyrathes aspera, Cyperus rotundus, Cleome viscose, Commelina benghalensis, Digitaia ciliaris, Dactylonctenium aegyptimum, Leucas lanvandulifolia, Phyllanthus niruri, Richardia brasili-ensis and Scirpus juncoides in Magway upland. A total of ten green gram-based cropping patterns were mainly observed in the study areas. Among these patterns, pattern 4 in Tatkon lowland, pattern 5 in Tat-kon upland and pattern 10 in Magway upland could give benefits of reducing the weed density. Pattern 3 and pattern 1 could limit the chance of dominating weed species. Pattern 6 and pattern 9 could maintain diversity of weed flora without substantial increase of weed density in the dry zone area of Myanmar. Weed infestation in all patterns were varying with crops and associated with management practices and, accordingly, these factors may cause various weed species composition

Farmers’ Weed Management Practices in Green Gram-based Cropping Systems in Central Dry Zone of Myanmar

The aim of this study was to observe the farmers’ practices for weed control in green gram cultiva-tion in the Central Dry Zone of Myanmar. Individual interviews were conducted in 15 villages from Tatkon and Magway townships during 2015. Random simple sampling was used to select 73 green gram growers from Tatkon township and 81 growers from Magway township. Survey data analysis were done by descriptive statistics. Farmers in the study areas commonly practised a total of ten green gram-based cropping patterns. The majority of farmers practiced green gram – rice pattern (pattern-1) in Tatkon low-land, green gram – vegetable pattern (pattern-7) and green gram – cotton pattern (pattern-8) in Tatkon upland, and sesame – green gram pattern (pattern-9) in Magway upland area. Majority of respondents in the study areas traditionally practised inter-cultivation with animal drawn implements and hand weeding. Only a few farmers in both regions used chemical combined with manual control. Nobody in both re-gions used chemical control alone. Although one time of inter-cultivation and one time of hand weeding in Tatkon and three times of inter-cultivation and two times of hand weeding in Magway were mainly practised, most of farmers in Tatkon practised hoe weeding as additional methods. Frequencies of weed-ing among the study areas were different depending on type of intercrops and weed density in the field. This difference was found not only in all patterns but also within a pattern

Direct regulation of the cardiac ryanodine receptor (RyR2) by O-GlcNAcylation

Abstract Background O-GlcNAcylation is the enzymatic addition of a sugar, O-linked β-N-Acetylglucosamine, to the serine and threonine residues of proteins, and is abundant in diabetic conditions. We have previously shown that O-GlcNAcylation can trigger arrhythmias by indirectly increasing pathological Ca2+ leak through the cardiac ryanodine receptor (RyR2) via Ca2+/calmodulin-dependent kinase II (CaMKII). However, RyR2 is well known to be directly regulated by other forms of serine and threonine modification, therefore, this study aimed to determine whether RyR2 is directly modified by O-GlcNAcylation and if this also alters the function of RyR2 and Ca2+ leak. Methods O-GlcNAcylation of RyR2 in diabetic human and animal hearts was determined using western blotting. O-GlcNAcylation of RyR2 was pharmacologically controlled and the propensity for Ca2+ leak was determined using single cell imaging. The site of O-GlcNAcylation within RyR2 was determined using site-directed mutagenesis of RyR2. Results We found that RyR2 is modified by O-GlcNAcylation in human, animal and HEK293 cell models. Under hyperglycaemic conditions O-GlcNAcylation was associated with an increase in Ca2+ leak through RyR2 which persisted after CaMKII inhibition. Conversion of serine-2808 to alanine prevented an O-GlcNAcylation induced increase in Ca2+ leak. Conclusions These data suggest that the function of RyR2 can be directly regulated by O-GlcNAcylation and requires the presence of serine-2808

Additional file 1 of Direct regulation of the cardiac ryanodine receptor (RyR2) by O-GlcNAcylation

Supplementary Material

Adverse Drug Reactions in Selected Wards of the Yangon General Hospital and Yangon Specialty Hospital During the First Quarter of 2019 : An Active Pharmacovigilance Study in Myanmar

Previous studies in Europe and the USA have reported a high prevalence of adverse drug reactions (ADRs), but data on local ADRs in Myanmar are sparse. Our objective was to study ADRs in patients admitted to selected wards of Yangon General Hospital (YGH) and Yangon Specialty Hospital (YSH), Myanmar. This was a prospective observational study in three hospital wards during the first quarter of 2019. Suspected ADRs were carefully investigated in a face-to-face interview with each patient and via review of clinical records. Patients transferred to other wards or discharged were followed-up by the researchers until day 28 after admission. ADRs were divided into those that (1) led to the admission and (2) occurred during the hospital stay or after discharge (up to day 28 after admission). A total of 65 ADRs were identified, with 47 (29.4%) of 160 patients experiencing at least one ADR. Among these, 16 (24.6%) had led to hospital admission and 49 (75.4%) occurred in 31 patients during their hospital stay. Of 160 patients, 21 had taken at least one herbal remedy and six of these developed an ADR. Five ADR-drug associations (hypokalaemia with methylprednisolone, increased transaminase levels with standard antituberculosis drugs, upper gastrointestinal bleeding with nonsteroidal anti-inflammatory drugs, constipation with tramadol, and increased transaminase levels with herbal remedies) represented 18 (27.7%) of the 65 ADRs in this study. According to the Schumock and Thornton preventability scale, more than half of these ADRs (35 [53.9%]) were preventable. The present study highlights the existence of ADRs among patients attending these hospitals. The implementation of active pharmacovigilance in hospitals could be a helpful first step to improving the awareness of unwanted effects of medicines and patient safety, as well as a way to strengthen the national pharmacovigilance system in countries such as Myanmar. The online version of this article (10.1007/s40801-020-00180-0) contains supplementary material, which is available to authorized users