• Journal of The Korean Association For Science Education
• /
• v.17 no.3
• /
• pp.261-271
• /
• 1997

This study evaluates on students' understanding and misunderstanding of homeostasis, classification of animals and plants, and food production in plants, and analyzes the teacher factor as a possible source of students' misconception. A total number of 863 students and 47 biology teachers at the middle and high school were randomly selected. Students' conceptions and misconceptions were measured with concept evaluation statements (CES) which was translated into Korean by author. The CES was developed and validated by Simson and Marek (1988). Teacher's misconceptions were investigated the way in which teachers marked students' work. The supposed answer given to the teachers to mark was based on misconceptions held by students tested in concept evaluation statements. The results of this study are as follows : 1. 0% of 7th Grade students, 4.5% of 9th Grade students and 5.4% of 11th Grade students understood homeostasis. There was a significant difference at the level of students' understanding of homeostasis according to schools and gender(P<0.05). Many students had a tendency of understanding the conception of the homeostasis by experiences and unscientific use of everyday language rather than a scientific concept. 2. 0.4% of 7th Grade students, 3.1% of 9th Grade students and 2.9% of 11th Grade students understood classification of animals and plants. There was a significant difference at the level of students' understanding of classification of animals and plants according to schools and gender(P<0.05). Students classified animals and plants through personal experiences and observations instead of trying to classify through microscopic analysis of animals and plants cell. 3. 1.2% of 7th Grade students, 10.3% of 9th Grade students and 19.4% of 11th Grade students understood food production in plants. There was a significant difference at the level of students' understanding of food production in plants according to schools and gender(P<0.05). Students had a misconception that food production in plants was done by an absorption of nutrients from soil not by photosynthesis. 4. A large proportion of teachers surveyed in this study appear to have misconceptions about homeostasis (38.1%), classification of animals and plants (34.1%), food production in plants (40.4%). The male teachers had. more misconceptions than female teachers(P<0.05). However, they didn't show any significant differences according to schools and teaching experience(P<0.05). 5. According to the investigation of teachers' perception, 29.8% of the teachers acknowledged that they might be a cause for students' misconceptions. This study shows that 38.3% of teachers did not understand the analyzed biological concepts precisely. By comparing the data of students and teachers, it turned out that teachers participate in the students' misconceptions. And teachers themselves acknowledged that students' misconceptions could be caused by them. Therefore. teachers' right understanding of fundamental biological concepts should precede to students' biology education. New training programs for biology teachers seem to be urgent.

• Journal of Life Science
• /
• v.5 no.1
• /
• pp.33-44
• /
• 1995

• Molecules and Cells
• /
• v.37 no.10
• /
• pp.747-752
• /
• 2014

Protein kinase C (PKC) family members phosphorylate a wide variety of protein targets and are known to be involved in diverse cellular signaling pathways. However, the role of PKC in receptor activator of NF-${\kappa}B$ ligand (RANKL) signaling has remained elusive. We now demonstrate that $PKC{\beta}$ acts as a positive regulator which inactivates glycogen synthase kinase-$3{\beta}$ (GSK-$3{\beta}$) and promotes NFATc1 induction during RANKL-induced osteoclastogenesis. Among PKCs, $PKC{\beta}$ expression is increased by RANKL. Pharmacological inhibition of $PKC{\beta}$ decreased the formation of osteoclasts which was caused by the inhibition of NFATc1 induction. Importantly, the phosphorylation of GSK-$3{\beta}$ was decreased by $PKC{\beta}$ inhibition. Likewise, down-regulation of $PKC{\beta}$ by RNA interference suppressed osteoclast differentiation, NFATc1 induction, and GSK-$3{\beta}$ phosphorylation. The administration of PKC inhibitor to the RANKL-injected mouse calvaria efficiently protected RANKL-induced bone destruction. Thus, the $PKC{\beta}$ pathway, leading to GSK-$3{\beta}$ inactivation and NFATc1 induction, has a key role in the differentiation of osteoclasts. Our results also provide a further rationale for $PKC{\beta}$'s therapeutic targeting to treat inflammation-related bone diseases.

• Journal of Pharmacopuncture
• /
• v.14 no.2
• /
• pp.81-91
• /
• 2011

Objectives & Methods: This suggestion was attempted to be elevated the recognition of common characteristics in disease. So, we performed to analyze the correlation of common cause of disease, characteristics of human body, and medical treatment. And the results are as follows. Results: 1. The cause of disease is consist of genetic factor, aging, habit, food of not good in health, weather, environment, deficit of the physical activity, stress and so on. 2. Generally, human has common and individual weakness. Individual weakness is appeared similar to the occurrence of volcano and lapse. 3. The correlation of disease and medical treatments is possible to explain using the quotation of the law of motion made by Isaac Newton, the great physicist. 4. When the process of the medical treatment was not progressed, the prognosis is determined by the correlation of the homeostasis(H') in human body and the homeostasis(H) of disease. 5. The prognosis of disease is determined by the relationship between the energy of disease(F) and medical treatment(F'). 6. The exact diagnosis is possible to predict the treatment sequence, and the facts that homeostasis in human body and disease, relationship between the energy of disease(F) and medical treatment(F'), action and reaction are important to determine the prognosis. 7. The careful observation of improving response and worsening action of disease becomes available for exact prognosis. Conclusion: The above described contents may be useful in clinical studies, and the concrete clinical reports about this will be made afterward.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.2
• /
• pp.323-329
• /
• 2018

In Escherichia coli, the transcription of genes related to metal homeostasis is activated by the presence of target metals. The promoter regions of those genes can be fused with reporter genes to generate whole-cell bioreporters (WCBs); these organisms sense the presence of target metals through reporter gene expression. However, the limited number of available promoters for sensing domains restricts the number of WCB targets. In this study, we have demonstrated an alternative method to generate novel WCBs, based on the notion that since the sensing mechanisms of WCBs are related to metal transportation systems, their properties can be modulated by disrupting metal homeostasis. Mutant E. coli strains were generated by deleting the znt-operon genes zntA, which encodes a zinc-export protein, and zntR, which encodes a znt-operon regulatory protein, to investigate the effects on the metal-sensing properties of WCBs. Deletion of zntA increased the sensitivity but abolished the selectivity of cadmium-sensing WCBs, whereas arsenic-sensing WCBs gained sensitivity toward cadmium. When zntR was deleted, cadmium-sensing WCBs lost the ability to detect cadmium, and this was recovered by introducing exogenous zntR. In addition, the metal-binding site of ZntR was genetically engineered to modulate metal selectivity. This study provides a valuable platform for the development of novel E. coli-based WCBs.

• Journal of Nutrition and Health
• /
• v.30 no.4
• /
• pp.394-405
• /
• 1997

Endogenous zinc is important for maintaining zinc homeostasis because the size of endogenous zinc pool is almost 3-4 times bigger than that of dietary zinc. The purpose of this study was to examine the phytate effect on the reabsorption of endogenous zinc and the additional Ca effect on the phytate effect. Rats were fed a casein-based diet with added sodium phytate containing either high(1.6%) or low(0.8%) Ca concentrations for 4 weeks to reduce the body zinc pool. After the depletion period, $^{65}$ Zn was given by intraperitoneal injection to label the endogenous zinc pool. Rats were then assigned into phytate or non-phytate group within the same Ca group. feces were collected for 2 weeks of the initial collection period and 1 week after dietary crossover. The ratios of excreted fecal $^{65}$ Zn radioactivity of phytate group non-phytate group were determined as a measure of the phytate effect on the endogenous zinc. Mean fecal $^{65}$ Zn radioactivity was higher in the phytate group than in the non-phytate group during the entire 3 weeks of the collection period in the low Ca group, and during the initial collection period in the high Ca group(p <0.0001). This study showed an adverse phytate effect on endogenous zinc at both high and low dietary Ca levels. Elevated dietary Ca levels showed a synergistic effect on the phytate effect on endogenous zinc(p <0.05). These results imply greater phytate effect on zinc homeostasis rather than on zinc bioavailability through complexing with the endogenous zinc which is larger portion than the dietary zinc on zinc homeostasis.

• Molecules and Cells
• /
• v.40 no.12
• /
• pp.976-985
• /
• 2017

Iron is an essential divalent ion for aerobic life. Life has evolved to maintain iron homeostasis for normal cellular and physiological functions and therefore imbalances in iron levels exert a wide range of consequences. Responses to iron dysregulation in blood development, however, remain elusive. Here, we found that iron homeostasis is critical for differentiation of Drosophila blood cells in the larval hematopoietic organ, called the lymph gland. Supplementation of an iron chelator, bathophenanthroline disulfate (BPS) results in an excessive differentiation of the crystal cell in the lymph gland. This phenotype is recapitulated by loss of Fer1HCH in the intestine, indicating that reduced levels of systemic iron enhances crystal cell differentiation. Detailed analysis of Fer1HCH-tagged-GFP revealed that Fer1HCH is also expressed in the hematopoietic systems. Lastly, blocking Fer1HCH expression in the mature blood cells showed marked increase in the blood differentiation of both crystal cells and plasmatocytes. Thus, our work suggests a relevance of systemic and local iron homeostasis in blood differentiation, prompting further investigation of molecular mechanisms underlying iron regulation and cell fate determination in the hematopoietic system.

• Toxicological Research
• /
• v.20 no.3
• /
• pp.241-250
• /
• 2004

We previously found that bisphenol A (BPA) caused neurotoxic behavioral alteration. Since disturbance of calcium homeostasis is an implicated contributor in the neurotoxic mechanism of environmental toxicants, we investigated whether BPA alters calcium homeostasis. Unlike other neurotoxic agents which cause increase of intracellular calcium level, BPA decreased $[Ca^{2+}]_i$ dose-dependently in PC12 cells and cortical neuronal cells regardless of the calcium existence in buffer. BPA at greater concentrations than 100 $\mu\textrm{M}$ reduced cell viability significantly in both types of cells. BPA also suppressed L-glutamate (L-type channel activator, 30 mM) and trifluoperazine (calmodulin antagonist, 30 $\mu\textrm{M}$)-induced increase of $[Ca^{2+}]_i$. BPA further lowered caffeine (RYR activator, 100 $\mu\textrm{M}$)-decreased $[Ca^{2+}]_i$, but did not alter dantrolene (RYR inhibitor, 100 $\mu\textrm{M}$), heparin (IP3 inhibitor, 200 units/ml) and xestospongin C (IP3 inhibitor, 5 $\mu\textrm{M}$)-decreased $[Ca^{2+}]_i$. Cell viability was not directly related to intracellular calcium change by bisphenol A that alternation of intracellular calcium may not be a direct causal factor of BPA-induced neuronal cell death.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.246-246
• /
• 2017

Salinity inhibits plant growth and restricts the efficiency of arbuscular mycorrhizal fungi. The selective uptake of nutrients from the soil and their effective transport to host roots make it essential for plant growth and development under salt stress. AMF spore associated bacteria shown to improve mycorrhizal efficiency under stress. Thus, this study aimed to understand the co-inoculation efficiency of AMF and SAB on maize growth and ion homeostasis under salt stress. Two AMF strains and one SAB were inoculated with maize either alone or in combination with one another. The results of our study showed that AMF and SAB co-inoculation significantly improved dry weight and nutrient uptake of maize under salt stress. Co-inoculation significantly reduced proline accumulation in shoots and Na+ accumulation in roots. Co-inoculation treatment also exhibited the high K+/Na+ ratios in roots at 25 mM NaCl. Mycorrhizal colonization showed positive influence for regulation of ZmAKT2, ZmSOS1 and ZmSKOR gene expressions, contributing to K+ and Na+ ion homeostasis. CLSM view showed that SAB were able move and localize into inter and intra cellular spaces of maize roots. In addition, CLSM view of AMF spores showed that gfp-tagged SAB also associated on the spore outer hyaline layer.

• Molecules and Cells
• /
• v.37 no.6
• /
• pp.487-496
• /
• 2014

Angiotensinogen (AGT), the precursor of angiotensin I, is known to be involved in tumor angiogenesis and associated with the pathogenesis of coronary atherosclerosis. This study was undertaken to determine the role played by AGT in endothelial progenitor cells (EPCs) in tumor progression and metastasis. It was found that the number of EPC colonies formed by AGT heterozygous knockout ($AGT^{+/-}$) cells was less than that formed by wild-type (WT) cells, and that the migration and tube formation abilities of $AGT^{+/-}$ EPCs were significantly lower than those of WT EPCs. In addition, the gene expressions of vascular endothelial growth factor (VEGF), Flk1, angiopoietin (Ang)-1, Ang-2, Tie-2, stromal derived factor (SDF)-1, C-X-C chemokine receptor type 4 (CXCR4), and of endothelial nitric oxide synthase (eNOS) were suppressed in $AGT^{+/-}$ EPCs. Furthermore, the expressions of hypoxia-inducible factor (HIF)-$1{\alpha}$and $-2{\alpha}$ were downregulated in $AGT^{+/-}$ early EPCs under hypoxic conditions, suggesting a blunting of response to hypoxia. Moreover, the activation of Akt/eNOS signaling pathways induced by VEGF, epithelial growth factor (EGF), or SDF-$1{\alpha}$ were suppressed in $AGT^{+/-}$ EPCs. In $AGT^{+/-}$ mice, the incorporation of EPCs into the tumor vasculature was significantly reduced, and lung tumor growth and melanoma metastasis were attenuated. In conclusion, AGT is required for hypoxia-induced vasculogenesis.