• Journal of Life Science
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• v.34 no.5
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• pp.339-355
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• 2024

The pulmonary system is a highly complex system that can only be understood by integrating its functional and structural aspects. Hence, in vivo animal models are generally used for pathological studies of pulmonary diseases and the evaluation of inhalation toxicity. However, to reduce the number of animals used in experimentation and with the consideration of animal welfare, alternative methods have been extensively developed. Notably, the Organization for Economic Co-operation and Development (OECD) and the United States Environmental Protection Agency (USEPA) have agreed to prohibit animal testing after 2030. Therefore, the latest advances in biotechnology are revolutionizing the approach to developing in vitro inhalation models. For example, lung organ-on-a-chip (OoC) and organoid models have been intensively studied alongside advancements in three-dimensional (3D) bioprinting and microfluidic systems. These modeling systems can more precisely imitate the complex biological environment compared to traditional in vivo animal experiments. This review paper addresses multiple aspects of the recent in vitro modeling systems of lung OoC and organoids. It includes discussions on the use of endothelial cells, epithelial cells, and fibroblasts composed of lung alveoli generated from pluripotent stem cells or cancer cells. Moreover, it covers lung air-liquid interface (ALI) systems, transwell membrane materials, and in silico models using artificial intelligence (AI) for the establishment and evaluation of in vitro pulmonary systems.

• Journal of Nutrition and Health
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• v.9 no.2
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• pp.59-67
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• 1976

A series of experiment was carried out to study the effect of commonly used dietary fat or oils on the growth, feed efficiency, nutrient utilizability, nitrogen retention and serum cholesterol of rats and chicks fed various fat or oils at the level of 10% during 12 weeks of experimentation. Fat and oils used in this experiment were also analyzed for the composition of some fatty acids. The main observations made are as follows: 1. All groups received fat or oils gained more body weight than unsupplemented control group except chicks fed fish oil and rapeseed oil although no statistical significance was found between treatments. It was found that body weight gain achieved by the rats fed soybean oil, rapeseed oil, animal fat or corn oil was much greater than other group and that achieved by the chicks fed corn oil and animal fat was greater than other vegetable oil groups, although no statistical significance was found among treatments. 2. Feed intake data indicated that corn oil group of both rats and chicks consumed considerably more feed than other groups. Whereas feed intake of fish oil groups was the lowest among the experimental animals indicating that fish oil might contain unfavorable compound that depresses the palatability. In feed efficiency, soybean oil group of rats and corn oil group of chicks were significantly better than other experimental groups. In general, addition of fat or oils in the diet improved feed effeciency of diet. 3. Nutrient utiIizabiIity and nitrogen retention data showed that fat in the experimental diet containing 10% fat or oils was absorbed better than crude fat in control diet. It was also found that there was no significant difference in nitrogen retention among treatment. 4. Liver fat content of rapeseed oil group was much higher than that of control group and other group. It was also noticed that feeding more polyunsaturated fatty acids resulted in higher content of Iiver fat. 5. Present data indicated that serum cholesterol content of rapeseed oil and sesame oil group of rat was the higher than that of control group. Serum cholesterol content of animal fat group of chicks was higher than other group. It was interesting to note that serum cholesterol content of chicken was higher than that of rats?regardless of the kind of oils received. 6. Analytical data revealed that fatty acid composition of vegetable oil was composed mainly of oleic acid and linoleic acid, whereas animal fat and fish oil were composed of saturated fatty acid such as, myristic and palmitic acid. It should be mentionted that the perilla oil contained a very large amount of linolenic acid (58.4%) comparing with that in order vegetable oils. Little arachidonic acid was detected in vegetable oil, whereas none in animal fat and. fish oil.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.4
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• pp.194-204
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• 2011

This study was carried out to compare the histopathological differences of liver lesions in carbon tetrachloride ($CCI_4$), dimethylnitrosamine (DMN), thioacetamide (TAA) and bile duct ligation (BDL)-induced rats. $CCl_4$, DMN and TAA were administered intraperitoneally and conducted bile duct ligation for 4 weeks to induce hepatic fibrosis. Indices of liver cell injury (steatosis, hydropic degeneration, bile duct hyperplasia, hemorrhage & hemosiderin deposition), the extent of liver fibrosis (fibrotic area) and the rate of regeneration (number of PCNA-positive cells) were investigated in each group. Liver tissues were stained with hematoxylin-eosin (HE), sirius red, prussian blue and immunostained with ${\alpha}$-smooth muscle actin (${\alpha}$-SMA), transforming growth factor-${\beta}1$ (TGF-${\beta}1$), proliferative cell nuclear antigen (PCNA), and quantified using a computerized image analysis system. Liver cell steatosis was significantly increased in $CCl_4$ and TAA groups, and hydropic degeneration and bile duct hyperplasia were significantly increased in TAA and BDL groups when compared with that in normal control, respectively. Fibrosis area was significantly increased in all four groups, especially in $CCl_4$ group. Correlation between ${\alpha}$-SMA and TGF-${\beta}1$ expressions in four groups was good. Hemorrhage area in liver parenchyma was significantly increased in DMN group only when compared with that in normal control, while hemosiderin deposition area was significantly increased in TAA and BDL groups as well as DMN group. The Number of PCNA-positive cells was significantly increased in all four groups, especially in TAA group. These results indicate that the duration and methods of hepatotoxic drug treatment are very important factors to make plans for animal experimentation on the induction of hepatic fibrogenesis in rats.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4378-4384
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• 2011

In order to evaluate the anti-oxidative capabilities of Angelica dahurica Radix ethanol extract (ADEE), we analyzed the contents of polyphenol and flavonoid compounds and the electron donating ability from ADEE. For animal experimentation, the test agent was topically applied to the artificial tanning spots which were induced by 1,500 mJ/$cm^2$ of ultraviolet B radiation on the backs of brown guinea pigs weighing approximately 450~500g. The test agent of $30{\mu}{\ell}$ was applied (6areas per group) twice a day, five days a week, for five weeks. On completion of the experiment, the animals were sacrificed under anesthetization, and the artificial tanning spots were obtained by biopsy punch and stained with H&E to observe the histological change in the epidermis and dermis. As a result, the contents of polyphenol and flavonoid compounds in ADEE were 20.7mg/g and 19.5mg/g respectively. As the for electron-donating capability of ADEE, it was observed that ADEE displays a dose-dependent antioxidative capacity of 14.8% and 19.8% at the concentration of 500 and 1000 ${\mu}g/m{\ell}$ respectively. Tissue staining with H&E revealed that the epidermis of the control group was slightly thicker than that of the other groups. However no inflammation or any other undesirable effect on the skin tissue due to ADEE was observed. These results indicate that ADEE is of value as a natural antioxidant.

• Journal of Periodontal and Implant Science
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• v.51 no.3
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• pp.213-223
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• 2021

Purpose: The atmospheric pressure plasma jet (APPJ) has been introduced as an effective disinfection method for titanium surfaces due to their massive radical generation at low temperatures. Helium (He) has been widely applied as a discharge gas in APPJ due to its bactericidal effects and was proven to be effective in our previous study. This study aimed to evaluate the safety and effects of He-APPJ application at both the cell and tissue levels. Methods: Cellular-level responses were examined using human gingival fibroblasts and osteoblasts (MC3T3-E1 cells). He-APPJ was administered to the cells in the experimental group, while the control group received only He-gas treatment. Immediate cell responses and recovery after He-APPJ treatment were examined in both cell groups. The effect of He-APPJ on osteogenic differentiation was evaluated via an alkaline phosphatase activity assay. In vivo, He-APPJ treatment was administered to rat calvarial bone and the adjacent periosteum, and samples were harvested for histological examination. Results: He-APPJ treatment for 5 minutes induced irreversible effects in both human gingival fibroblasts and osteoblasts in vitro. Immediate cell detachment of human gingival fibroblasts and osteoblasts was shown regardless of treatment time. However, the detached areas in the groups treated for 1 or 3 minutes were completely repopulated within 7 days. Alkaline phosphatase activity was not influenced by 1 or 3 minutes of plasma treatment, but was significantly lower in the 5 minute-treated group (P=0.002). In vivo, He-APPJ treatment was administered to rat calvaria and periosteum for 1 or 3 minutes. No pathogenic changes occurred at 7 days after He-APPJ treatment in the He-APPJ-treated group compared to the control group (He gas only). Conclusions: Direct He-APPJ treatment for up to 3 minutes showed no harmful effects at either the cell or tissue level.

• Journal of Periodontal and Implant Science
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• v.52 no.5
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• pp.422-434
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• 2022

Purpose: The purpose of this study was to evaluate and compare the healing patterns of 2-mm and 4-mm proximal infrabony defects adjacent to dental implants in canine mandibles. Methods: Four male beagles were used. Two groups were created: a 2-mm group (n=4) and a 4-mm group (n=4) depending on the horizontal dimension of proximal infrabony defects adjacent to implants. Bone healing patterns between the 2 groups were evaluated and compared at 8 and 16 weeks using radiographic, histological, histomorphometric, and fluorescent labelling analyses. Results: According to microcomputed tomography, the median bone volume fraction, bone mineral density, and the percentage of radiographic distance from the defect bottom to the most coronal bone-to-implant contact (radio-mcBIC) were 32.9%, 0.6 g/cm³, and 73.7% (8 weeks) and 45.7%, 0.7 g/cm³, and 76.0% (16 weeks) in the 2-mm group and 57.7%, 0.8 g/cm³, and 75.7% (8 weeks) and 50.9%, 0.8 g/cm³, and 74.7% (16 weeks) in the 4-mm group, respectively. According to histomorphometry, the median bone area fraction, mcBIC and the percentage of BIC amounted to 36.7%, 3.4 mm, and 58.4% (8 weeks) and 49.2%, 3.4 mm, and 70.2% (16 weeks) in the 2-mm group and 50.0%, 3.0 mm, and 64.8% (8 weeks) and 55.7%, 3.0 mm, and 69.6% (16 weeks) in the 4-mm group, respectively. No statistically significant differences were found between the groups for any variables (P>0.05). Conclusions: The proximal defects that measured 2 mm and 4 mm showed similar healing patterns at 8 and 16 weeks, and the top of bone formation in the defects was substantially limited to a maximum of 1.6 mm below the implant shoulder in both groups.

• Journal of Periodontal and Implant Science
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• v.54 no.2
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• pp.96-107
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• 2024

Purpose: Deproteinized bovine bone or synthetic hydroxyapatite are 2 prevalent bone grafting materials used in the clinical treatment of peri-implant bone defects. However, the differences in bone formation among these materials remain unclear. This study evaluated osteogenesis kinetics in peri-implant defects using 2 types of deproteinized bovine bone (Bio-Oss^® and Bio-Oss/Collagen^®) and 2 types of synthetic hydroxyapatite (Apaceram-AX^® and Refit^®). We considered factors including newly generated bone volume; bone, osteoid, and material occupancy; and bone-to-implant contact. Methods: A beagle model with a mandibular defect was created by extracting the bilateral mandibular third and fourth premolars. Simultaneously, an implant was inserted into the defect, and the space between the implant and the surrounding bone walls was filled with Bio-Oss, Bio-Oss/Collagen, Apaceram-AX, Refit, or autologous bone. Micro-computed tomography and histological analyses were conducted at 3 and 6 months postoperatively (Refit and autologous bone were not included at the 6-month time point due to their rapid absorption). Results: All materials demonstrated excellent biocompatibility and osteoconductivity. At 3 months, Bio-Oss and Apaceram-AX exhibited significantly greater volumes of formation than the other materials, with Bio-Oss having a marginally higher amount. However, this outcome was reversed at 6 months, with no significant difference between the 2 materials at either time point. Apaceram-AX displayed notably slower bioresorption and the largest quantity of residual material at both time points. In contrast, Refit had significantly greater bioresorption, with complete resorption and rapid maturation involving cortical bone formation at the crest at 3 months, Refit demonstrated the highest mineralized tissue and osteoid occupancy after 3 months, albeit without statistical significance. Conclusions: Overall, the materials demonstrated varying post-implantation behaviors in vivo. Thus, in a clinical setting, both the properties of these materials and the specific conditions of the defects needing reinforcement should be considered to identify the most suitable material.

• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.107-114
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• 2004

The purpose of this work was to examine the effect of peptide on blood pressure and serum lipid concentration of spontaneously hypertensive rat(SHR). This peptide was extracted from beef muscle hydrolysates and identified as hexapeptide, V-L-A-Q-Y-K. This peptide showed angiotensin converting enzymc(ACE) inhibition activity in vitro experimentation$(IC_50: I38.34{\mu}\ell$/ml). Diets containing 0.2g. 0.5g. and 1.0g of the peptide per kg body weight were fed to SHR every day for 8 weeks while the control group was ted on a diet and lml of drinking water instead of the peptide. Total cholesterol and LDL-cholesterol concentrations of the treatment groups were lower than those of the control diet feeding group. The significant suppression of systolic blood pressure was shown by increasing the concentration of peptide supplement. especially by 3 weeks of feeding. although it started fluctuating later. These results suggest that the peptide may beneficially affect blood pressure in spontaneously hypertensive rat by the 3-week administration.