Naresuan University Journal
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Aquilaria crassna leaf extract selectively upregulated calreticulin surface expression, a pro-phagocytotic signal, in triple-negative breast cancer cells
Full text link During the last decade, studies of anti-cancer properties of extracts from several parts of Aquilaria species including Aquilaria crassna (A. crassna) Pierre ex Lecomte have been more attractive. Leaf extract of A. crassna Pierre ex Lecomte (AE) has been reported for medicinal activities except for anti-cancer activity in particular the enhancement of cancer-immune responses. Strategies that alter cancer phenotypes to be more sensitive to immune cell killing and/or to activate immune responses have become promising approaches for cancer therapy. We are interested in a strategy that sensitizes surviving cancer cells to express surface molecules for the enhancement of cancer cell killing by immune cells called immunogenic modulation. Thereby, this study aims to investigate the induction effect of AE on the expression of molecules reported for immunogenic modulation which are the surface expressions of calreticulin (ectoCRT), a major histocompatibility complex class I (MHC class I), and CD95/Fas death receptor. M.D. Anderson-Metastatic Breast 231 (MDA-MB 231) cell line, a triple-negative breast cancer; TNBC, was treated with various concentrations (0- 640 µg/ml) of AE for 6 hr and 12 hr and examined for the cytotoxic effect by MTT assay. The results showed that concentrations of 20-640 µg/ml of AE treatment significantly decreased the percentages of cell viability at both time points. Sublethal doses (20-320 µg/ml) caused the cell viability > 70% were further examined for the surface expressions of ectoCRT, MHC class I, and CD95 using surface immunostaining and analyzed by flow cytometer. At 12 hr after treatment, AE selectively induced ectoCRT expression but did not show any effect on MHC class I and CD95 expressions in all AE-treated populations. To further clarify the involvement of AE-induced ectoCRT in an immunogenic modulation, AE-treated living cells were chosen to investigate the expression of ectoCRT. Our results found that AE-treated living cells showed a significant increase in the relative mean fluorescence intensity (relative MFI) of ectoCRT expression and a trend to increase in ectoCRT-positive cells compared to the untreated group (0 µg/ml). Together, this is the preliminary result reporting the upregulation of ectoCRT expression by AE. In addition, AE-induced ectoCRT has been mainly found in surviving/living cells which is accorded to the criteria of immunogenic modulation. However, the role of AE-induced ectoCRT in the enhancement of cancer cell killing especially in immune cell phagocytosis needs to be further investigated.
Keywords: A. crassna leaf extract, immunogenic modulation, sublethal dose, ectoCRT, triple-negative breast cance
Assessing the Potential for the Sustainable Development of the Lower Andaman Sub-region in Thailand Using AHP and PSA Techniques
No full text Most human and city settlement is known to be in or near coastal zones. Consequently, the intense demand for coastal resource exploitation has negatively impacted coastal ecosystems. As a result of both economic development and conservation of the ecosystems, sustainability challenges have inevitably arisen. The objective of this study was to assess the potential of the sustainable development of the lower Andaman sub-region in Thailand in order to gain information for future economic development planning based on existing marine and coastal resources. The AHP and PSA techniques were used to assess the area potential. From the pairwise comparison of the important factors by experts, it was found that the most important factors were marine resources and the environment (37.6%), followed by the economy (marine fisheries and coastal tourism) and the well-being of society (32.4 and 30.0%, respectively). Moreover, the first important sub-factors were the mean of agricultural and fishery income (baht per household/per month) and mangroves (29.7 and 29.4%, respectively), followed by the number of marine animals landing at major fishing ports (tons) and income from foreign tourists (28.4 and 22.7%, respectively). Three provinces (Krabi, Trang, Satun) had the potential for marine resources and the environment and the well-being of society at a high level. Further, Krabi province had the potential for coastal tourism at a moderate level, while those of Trang and Satun provinces were at a low level. Moreover, Satun province had the potential for marine fisheries at a moderate level, but those of Krabi and Trang provinces were at a low level.
Keywords: Potential Assessment, Sustainable Development, Lower Andaman Sub-region in Thailan
What Behaviors “Strategic Teachers” Did for Pandemic-Era Modular Learning? An Exploratory Study with Basic Education Teachers in the Philippines
No full text At the height of the pandemic, the Department of Education (DepEd) in the Philippines distributed self-learning modules to basic education students as part of its learning continuity program. This practice may have brought stress and challenges to many teachers, but this has also become a catalyst for creative problem-solving. This current study was designed to identify adaptive behaviors that were perceived to characterize “strategic teachers” in the midst of modular learning at the time of the pandemic. To address this objective, 120 statements were generated from narratives of four focus groups (N = 20 teachers). After content validation, 48 statements were retained and were administered to 429 basic education teachers (Meanage = 31.024; SDage = 7.466) through Google Forms. Exploratory factor analysis was done to analyze the data. Results revealed two subsets of teachers behaviors: 1) motivating students (“Establish good relationships with students by creating a non-threatening classroom environment”), and 2) using alternative delivery modalities (“Video-record lectures for students to watch”). These findings indicate that delivering student learning and managing academic motivation, related to key domains of the Philippine Professional Standards for Teachers (PPST), are necessary, hence shall serve as priorities for capacity building and enhancement training programs towards better basic education schools in the post-COVID world.
Keywords: Teacher Behaviors, Basic Education, Exploratory Factor Analysis, Modular Learning, Post-COVI
PLA Improvement Using Nanocomposite and Plasma Modification
Full text link This work studied the effects of Oxygen (O2), Nitrogen (N2) and Air plasmas on the surface modification of Polylactic acid (PLA) films. PLA films with 0.01 mm thickness were prepared from pure PLA material, while the PLA nanocomposite was prepared by mixing pure PLA with 5.00 wt.% of Organoclay (Cloisit® 30B). The plasma discharge was operated by -800 VDC of applied voltage at 0.1 mbar. The samples were placed on the substrate inside the plasma reactor and exposed to the plasma gases for 10, 15 and 20 min. The results showed that the hydrophobic property of pure PLA film can be increased by O2 exposure for 10 min and air plasma exposure for 20 min. Whilst the hydrophilic properties of PLA nanocomposite film were elevated when exposed for 20 min to the air and N2 plasma. In addition, PLA nanocomposite film has slightly higher levels of hydrophilic properties when compared to pure PLA film as evidenced by contact angle measurement. This result implies that low-temperature plasma discharges can successfully improve the surface property of PLA film in a short operating time.
Keywords: Low-temperature plasmas, PLA modification, Nanocomposite, Plasma modifications, Surface modification
