• Journal of Pharmaceutical Investigation
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• v.30 no.1
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• pp.39-45
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• 2000

We have investigated the efficacy of liposome encapsulated N-(phosphonacetyl)-L-aspartic acid (PALA) for the treatment of the C-26 murine colon tumor in Balb/c mice, and have compared it in this regard to free PALA. Healthy female Balb/c mice and C-26 tumor inoculated mice were randomized for the maximum tolerated dose (MTD) study and the in vivo therapy study, and the survival was measured after a single intraperitoneal injection of the drug. The maximum tolerated dose for intraperitoneally administered drug was found to be 750 mg/Kg for free PALA, and was greater than the maximum dose possible (150 mg/Kg) for PALA encapsulated in both DSPC and DSPG liposomes. When drug was administered one day after tumor implantation, 150 mg/Kg of PALA in DSPG liposomes increased the percentage of tumor bearing mice surviving at day 36 from 8% (buffer control) to 88%. In contrast, 150 mg/Kg free PALA increased the day 36 surviving percentage to only 25%. A 150 mg/Kg dose of PALA in DSPC liposomes increased the surviving percentage to 50%, while a 75 mg/Kg dose of PALA in sterically stabilized liposomes increased the surviving percentage to 78%. These results show that PALA in negatively charged or sterically stabilized liposomes can exhibit considerably greater potency than free PALA in C-26 tumor bearing mice.

• Journal of Pharmaceutical Investigation
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• v.30 no.2
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• pp.127-131
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• 2000

Previously, we have reported an antitumor efficacy of liposomal N-(phosphon-acetyl)-L-aspartic acid (or PALA) in C-26 tumor bearing Balb/c mice, where PALA in liposome was administered one day after tumor inoculation. In this report, we have investigated the therapeutic potency of liposomal formulation of PALA, which was administered eight days after tumor inoculation in the same C-26 tumor bearing mice. The C-26 murine colon tumor inoculated mice were randomized for the in vivo therapy and the survival was measured after a single intraperitoneal injection of the drug. When the therapy was initiated eight days after tumor inoculation, DSPC-PALA at 150 mg/kg resulted in a significant increase in median survival time (MST) of 56% over the control group which received MES/HEPES buffer alone. However, none of the free PALA and DSPG-PALA liposome doses caused a statistically significant increase in MST over control group at the 95% confidence level. At 750 mg/kg dose, free PALA caused a marginally significant improvement in MST by 34%, but both 375 mg/kg and 150 mg/kg doses of free PALA caused only a 2% and a 4% increase in MST, respectively. These results show that PALA in neutrally charged liposome can exhibit considerably greater potency than free PALA in established C-26 tumor bearing mice.

• Archives of Pharmacal Research
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• v.23 no.2
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• pp.167-171
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• 2000

We have investigated the in vitro cytotoxic effect of liposome-encapsulated N-(phospho-nacetyl)-L-aspartic acid (PALA) against C-26 murine colon cancer cells, and have compared it in this regard to free PALA. Three different PALA-containing liposomal formulations using distearoylphosphatidylcholine (DSPC), distearoylphosphatidylglycerol (DSPG), and polyethyle-neglycol-derivatized distearoylphosphatidylethanolamine (PEG-DSPE) were made and their cytotoxicity was measured. In 72 hr continuous exposure experiment with C-26 cells, the 50% growth inhibitory concentration ($IC_50$) of DSPG-PALA liposome formulation was $0.09\mu\$, which showed about 65-fold more potent than unencapsulated free PALA ($5.1\mu\$). Similar degree of increase in cytotoxicity was also observed in 1 hr exposure experiment. However the $IC_50$ of PEG-DSPE-PALA liposome and DSPC-PALA liposome were $10.7\mu\$and $11.8\mu\$respectively, which showed slightly less potent than unencapsulated free PALA. Physical characteristics of PALA-liposomes, such as the size and drug:lipid ratio were also determined. In conclusion, negatively-charged DSPG-PALA liposome showed the highest cytotoxic effect among tested on the C-26 cells in vitro.

• Korean Medical Education Review
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• v.21 no.1
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• pp.51-58
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• 2019

Although 'assessment for learning' rather than 'assessment of learning' has been emphasized recently, student learning before examinations is still unclear. The purpose of this study was to investigate pre-assessment learning activities (PALA) and to find mechanism factors (MF) that influence those activities. Moreover, we compared the PALA and MF of written exams with those of the clinical performance examination/objective structured clinical examination (CPX/OSCE) in third-year (N=121) and fourth-year (N=108) medical students. Through literature review and discussion, questionnaires with a 5-point Likert scale were developed to measure PALA and MF. PALA had the constructs of cognitive and meta-cognitive activities, and MF had sub-components of personal, interpersonal, and environmental factors. Cronbach's ${\alpha}$ coefficient was used to calculate survey reliability, while the Pearson correlation coefficient and multiple regression analysis were used to investigate the influence of MF on PALA. A paired t-test was applied to compare the PALA and MF of written exams with those of CPX/OSCE in third and fourth year students. The Pearson correlation coefficients between PALA and MF were 0.479 for written exams and 0.508 for CPX/OSCE. MF explained 24.1% of the PALA in written exams and 25.9% of PALA in CPX/OSCE. Both PALA and MF showed significant differences between written exams and CPX/OSCE in third-year students, whereas those in fourth-year students showed no differences. Educators need to consider MFs that influence the PALA to encourage 'assessment for learning'.

• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.259-264
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• 1994

Heparin binders (Cell-PALA) used for selective heparin removal from blood, were prepared by immobilizing a cationic polymer, poly(allylamine) (PALA), onto cellulose substrate by a novel method. Their absorbing capacity for heparin was compared with untreated cellulose control using heparin solution in vitro. The surface areas of obtained heparin binders and untreated cellulose were 1.36 and ($2.56{\mu} g$/$cm^2$, respectively. The amount of bound heparin to PALA immobilized celluloses was determined to be 0.16 - $0.30{\mu}g$/cm, which is much higher than that of untreated cellulose ($0.03{\mu} g$/$cm^2$). These results suggest that Cell-PALA materials can be utilized for a heparin removal system.

• Structural Engineering and Mechanics
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• v.73 no.1
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• pp.75-82
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• 2020

In this study, the problem of torsion of bars with open cross section surrounded by corrugated boundaries is analyzed. An approximate analytical solution is given using perturbation technique. First, the stress analysis for circular open cross-section for arbitrary opening angle is formulated and the problem is analytically solved. Second, the open cross-section with corrugated cross section is analyzed using perturbation method. First order contributions to the stresses and the torques have been added. The results have been exemplified and compared by considering special examples.

• Structural Engineering and Mechanics
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• v.31 no.4
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• pp.477-480
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• 2009

• Communications of the Korean Mathematical Society
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• v.29 no.1
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• pp.173-185
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• 2014

In the present paper, we consider an anomalous diffusion problem in two dimensional space involving Caputo time and Riesz-Feller fractional derivatives and then solve it by using a series involving bilateral eigen-functions. Also, we obtain a numerical approximation formula of this problem and discuss some of its particular cases.

• Bulletin of the Korean Mathematical Society
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• v.49 no.3
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• pp.621-633
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• 2012

By establishing a new summation formula for the series $_3F_2(\frac{1}{2})$, recently Rathie and Pogany have obtained an interesting result known as Kummer type II transformation for the generalized hypergeometric function $_2F_2$. Here we aim at deriving their result by using a very elementary method and presenting two elegant results for certain terminating series $_3F_2(2)$. Furthermore two interesting applications of our new results are demonstrated.

• SUVANNABHUMI
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• v.1 no.2
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• pp.21-41
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• 2009

The Art of the Buddha's Life which depicts the life and before-life of Buddha flourished in Sanci and Bharhut in the ancient India and in Gandhara during the Kushan period. More than one hundred scenes from Buddha's life were represented in the form of relief sculpture or wall painting. They are found in Gandhara and Mathura during the Kushan period, Amaravati and Nagarjunakonda during the Satavahana period, in Mathura and Sarnath during the Gupta period, and during the Pala Period. They unfolded in various forms and styles according to the text(Buddhist scripture), layout, and expressive technique. In Mathura, where the Evolution of the Buddha image was made about the same time as in Gandhara during the Kushan period, the Buddha's life was presented in a number of scenes related to the sacred sites; in four or eight scenes. In the case of the Eight Great Events of the Buddha's Life, the four scenes out of eight were different from those that were represented in Sarnath during the Gupta period, manifesting a transitional period. The Gupta period is widely known as the time when the classic artistic style was established. The art of Buddha's Life was produced only in Sarnath during this period, and it was the time when the Eight Great Events of the Buddha's Life was established as iconography, providing a model for those of the Pala period. Also, it was the time when the single image of Buddha was produced such as the 'Buddha delivering his first sermon,' 'Buddha's Enlightenment,' and 'Buddha's Death,' thus showing the emergence of the single Buddha image from the narrative Buddha's life image. In this paper, a general introduction of the relief sculpture of the Buddha's life from Sarnath during the Gupta period was given. The art of Buddha's life gave great influences on that of China, Korea, Japan and Southeast Asia, and can be emphasized as an important subject in understanding the development of the Buddhist art in East Asia. A further study will be made on the art of Buddha's Life of Southeast Asia in the future, which will enhance the understanding of the art of Buddha's Life in East Asia as a whole.