• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.2
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• pp.118-125
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• 2001

Recently, biochemical analysis using hemoglobin adduct is frequently performed to evaluate the exposure to chemical carcinogens. However, data on the effect of co-exposure with other chemicals on hemoglobin adduct formation are seldom provided. The objective of this study is to evaluate the effects of pretreatment of ethanol(EtOH) and phenobarbital(PB), which are known to affect metabolism of xenobiotics, on the formation of hemoglobin adducts in the rats(Sprague-Dawley) administered benzidine(BZ). The experimental rats were divided into control, EtOH, and P8 groups. Rats were pretreated with EtOH or PB 24 hours before the oral administration of BZ. Blood sampling was taken before the administration of the chemicals and 0.5, 3, 6, 9, 12, 24, 48, 72, 96, and 144 hours after the administration of the BZ in 5 rats each. The blood was separated into hemoglobin and plasma immediately after taking the blood samples, and the adducts were undergone basic hydrolysis to convert them into aromatic amines. Hydrolyzed BZ, monoacetylbenzidine (MABZ), and 4-aminobiphenyl(4ABP) were separated by reversed-phase liquid chromatography without derivatization, and quantitative analyses of them were performed by a highperformance liquid chromatograph equipped with electrochemical detector. The quantitative amount of the metabolites was expressed by hemoglobin binding index(HBI), BZ-, MABZ-, and 4ABP-HBI of EtOH and PB groups were increased more than those of control group. These results are attributable to the fact that EtOH and PB induced N-hydroxylation related to the hemoglobin adduct formation. The ratio of N-acetylation (viz, MABZ-HBI/BZ-HBI) showed no significant difference between EtOH group and control group. It means that EtOH increased N-hydroxylation and N-acetylation in a similar degree. The N-acetylation ratio of PB group was relatively lower than control group because the PB increased N-hydroxylation induction. The N-acetylation ratios of all groups were higher than 1 during the entire experimental period. This result suggests that the effects of EtOH or PB need to be considered in the biochemical monitoring for the assessment of intermittent exposure of benzidine.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.867-881
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• 1998

The studies were carried out to investigate the phygiological changes in deep hypothermia in rabbits. Sixty rabbits were continuously cooled with femoral arterio-venous bypass circulation to rectal temperatures of $34.0{\pm}0.3^{\circ}C$(mild hypothermia), $30.0{\pm}0.3^{\circ}C$(moderate hypothermia), and $25.0{\pm}0.3^{\circ}C$(deep hypothermia). The results obtained in these experiments were summarized as follows : In mild, moderate, and deep hypothermia, MAP, HR, RR, pH, $pCO_2$, $pO_2$, $Na^+$, $K^+$, HCT, PLT, glucose, L-lactate, BUN, and creatinine were analyzed. During hypothermia, a statistically significant decrease of MAP occurred between $30^{\circ}C$ and early $25^{\circ}C$(Start) of rectal temperature while significant increases occurred between baseline($38.7^{\circ}C$) and $30^{\circ}C$. Significant decreases of HR and RR were observed in the rabbits, particularly those changes appeared to similar patterns in proportion to hypothermia. Significant decreases of pH occurred between $34^{\circ}C$ and $25^{\circ}C$, and significant increases of $pO_2$ and $pCO_2$ were observed continuously in the hypothermic rabbits. The hypothermia had no significant effect on blood $Na^+$ and serum creatinine. Blood $K^+$ significantly decreased from $3.1{\pm}0.5$(baseline) to $2.6{\pm}0.6mmol/l$($34^{\circ}C$) with the hypothermia for about 30 minutes, and significantly increased from $2.4{\pm}0.6$($25^{\circ}C$(S)) to $2.7{\pm}0.5mmol/l$($25^{\circ}C$(E)) with the hypothermia for 2 hrs. HCT significantly increased to $34^{\circ}C$, thereafter, continuously increased to $25^{\circ}C$(Start, End). PLT increased to $34^{\circ}C$, thereafter, continuously decreased to $25^{\circ}C$(Start, End). Also PLT decreased significantly from 414.3($30^{\circ}C$) to $308.8{\times}103/mm^3$($25^{\circ}C$, Start). Significant increases of blood glucose and L-lactate occurred between $30^{\circ}C$ and $25^{\circ}C$ (Start, End). Slight increase of serum BUN continuously appeared with the hypothermia. These results, such as characteristic changes of the significant decrease of pH and PLT at $34^{\circ}C$, the significant decrease of MAP at $30^{\circ}C$, and the significant increase of glucose and l-lactate at $30^{\circ}C$, suggest that homeostasis of rabbits to hypothermia rapidly decreases at $34{\sim}30^{\circ}C$ of rectal temperature. Therefore, we suggest that, during the period with the rapidly decreased homeostasis, the very carefully control and treatment need to recover hypothermic animals under the circumstances of the various hypothermic experiments and emergency medicine.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.75-82
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• 2011

There is the uncertain period of the construction in case of the products meeting the quality standard of KS M 6080, the quality is degraded because of the abrasive loss of the paint caused by vehicle tires as the traffic amount increases and of the loss and detachment of the glass beads providing the retroreflective function. The abrupt degradation of visibility causes the high frequency of traffic accidents at night and increases the traffic accident rate. Additional supplementary construction induces the direct material and construction costs. As the more cost induction effect than the direct cost, the traffic jam caused by the additional construction increases the indirect social costs such as time cost and vehicle cost. Hence, the study is concerned with performing the abrasion resistance test based on the EN 1436 standard to check and improve the quality of various road marking materials resulting in improving the durability of road marking materials. However, even though the difference in the durability lifetime of resins(binders) is bibliographically or theoretically clear, there was no difference in the durability lifetime (retroreflectivity aspect) of the road marking paint using these binders. The reason is that the bonding of beads was very insufficient or that the cross density caused by crack or freshness was low. Moreover, the measured wet retroreflectivity was distributed as the Rw3 or higher class in average on the basis of EN 1436 but was very insufficient on the basis of the minimum wet threshold retroreflectivity with 100mcd/($m^2{\cdot}lx$) managed overseas.

• The Journal of Korean Academy of Prosthodontics
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• v.22 no.1
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• pp.33-50
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• 1984

The purpose of this study was to investigate whether the ashed tooth powder is utilized as an alternative material of the implant to recovery the bony defect. For this purpose its biocompatibility was evaluated comparing to the synthetic calcium phosphate compounds, such as Syntograft and Calcitite, as well as the vacuum firing porcelain (Ceramco Inc.) which is anticipated to use as a matrix to aid sintering. Bony defects to exposure the bone marrow, $3{\times}5$ mm in size, were created in the right and left tibias of fifteen rabbits, and then the ashed tooth powder at $950^{\circ}C$, the porcelain powder, Syhtograft and Calcitite were inserted in the defects of twelve rabbits of the experimental group and the blood clot only was filled in the defects of three rabbits of the control group. The experimental and control rabbits were sacrificed at 1st, 2nd 3rd week after implantation and the histologic examination was performed. The ashed tooth powder in order to make the needed form of the implant was molded using the cylindrical mold 1 cm high, 1 cm in diameter under the pressure of $1000kg/cm^2$ and the ashed tooth powder was sintered at $1100^{\circ}C$ for 1 hour and the mixture of the porcelain powder and the ashed tooth powder at the weight ratio of 7:3, 6:4, 5:5, 4:6 were molded in the same manner and were sintered at $925^{\circ}C$. From this sintered material, square shaped implants were prepared in the dimension of $2{\times}4{\times}6mm$. The prepared implants were surgically placed in the subperiosteum of lateral surfaces of the right and left mandibular bodies. The dogs were sacrificed at 4 weeks, and then the specimens were examined using the light and scanning electron microscopes. The results of this study were obtained as follows: 1. Any inflammatory response was not noted after implanting of the ashed tooth powder, Syntograft, Calcitite and the porcelain powder during the whole experimental period after implantation. 2. Induction of the new bone formation was significantly shown in the ashed tooth powder, Syntograft and Calcitite. 3. The more the porcelain powder was contained in the implants, the more the porosity was and the bigger the pore size was under the scanning electron microscope. And there was ingrowing of the fibrous connective and the osteoid tissue. 4. The osteoid tissues were found to be directly fused to the implant of the ashed tooth powder, and the mixture implant of the porcelain powder and the ashed tooth powder at the weight ratio of 4:6 under the light and scanning electron microscopes.

• Development and Reproduction
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• v.11 no.1
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• pp.13-20
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• 2007

In all female mammals, reproductive system is one of the first biological systems to show age-related decline. Female mammals in reproductive aging, though the phenomena is somewhat species-specific, start to show declining fertility and changes of numerous physiological functions. This review will present a current information on the aging of the female reproductive hormonal axis and introduce three useful rodent models for studying this field. Middle age($8{\sim}12$ months old) in female rats and mice is comparable to the stage prior to the entry of menopause in human. In this period pulsatile and surge GnRH secretion from hypothalamus gradually attenuated, then reduced pulsatile and surge LH secretion is followed consequently. This age-related defects in GnRH-LH neuroendocrine axis seem to be highly correlated with the defects in brain signals which modulate the activities of GnRH neuron. Many researchers support the idea which the age-related hypothalamic defects are the main cause of reproductive aging, but some ovarian factors such as inhibin response also could contribute to the induction of reproductive senescence. Some rodent models are quite valuable in studying the reproductive aging. The follitropin receptor knockout(FORKO) mice, both of null and haploinsufficient state, could produce depletion of oocyte/follicle with age. Dioxin/aryl hydrocarbon receptor(AhR) knockout mice also show severe ovarian defects and poor reproductive success early in their life compared to the age-matched normal mice. Further studies on the reproductive aging will be a great help to evaluate the benefits and risks of hormone replacement therapy(HRT) and to improve the safety of HRT.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.294-302
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• 2020

Studies on the occurrence of rice preharvest sprouting (PHS) have primarily focused on temperature and rainfall duration at the time of PHS induction, but average temperature during grain filling can have a great influence on PHS. This study analyzed the effect of average temperature during grain filling on PHS occurrence and subsequent changes in grain quality after PHS. For two consecutive years, average temperature differences during grain filling were produced by varying the transplanting date. Artificial rainfall was treated under identical accumulated temperatures of 1200℃ after heading. It was confirmed that the occurrence of PHS was higher under high average temperature conditions during grain filling. In addition, the degree of grain quality reduction caused by PHS occurred more severely under high temperature conditions during grain filling. In order to reduce the risk of PHS occurrence and subsequent quality damage, it is important to control the planting date to avoid high-temperature conditions during grain filling.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2002.11a
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• pp.130-132
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• 2002

This experiment was conducted to investigate the influence of different dietary ME and CP on post-molt performance of spent laying hens. Four hundred and thirty two, ISA brown after molt induction were fed 6 experimental diets containing 3 ME(2,750, 2,800, 2,850 kcal/kg) and 2 CP(15, 17%) levels in factorial design. The influence of ME and CP were measured on body weight, egg production, egg weight and feed intake throughout 24 weeks of production. Egg mass and FCR were calculated for the entire experimental period body weight remained less in hens receiving 2,800 kcal/kg. ME and showed the highest egg Production coupled with 15% CP. Feed intake decreased with the increasing level of ME and CP. As the results of this experiment, 2,800 kcal/kg ME can be used to maintain the low body weight and to obtain higher egg production with 15% CP in induced molting hens.

• Journal of Veterinary Clinics
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• v.31 no.2
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• pp.95-101
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• 2014

Five dogs were used to determine whether 0.1% tacrolimus ointment application for one day would inhibit IgE-mediated late-phase reactions (LPRs). It was consisted of three periods: one period without therapeutic administration (control) and two periods of treatment with either the tacrolimus ointment or vehicle. Induction of IgE-mediated LPRs was induced by intradermal injections of 0.05 ml (0.14 mg/ml) of solution of goat anti-canine IgE polyclonal antibodies. Each section for mast cells (MCs) and eosinophils (EPs) was stained with acidified toluidine blue, and Luna's stain, respectively. Assessment of anti-inflammatory effect of tacrolimus ointment composed of cell counts of MC and EP from lesions of induced LPR. In normal canine biopsies, the number of dermal MCs and EPs were $12.3{\pm}1.4cells/mm^2$ and $3.1{\pm}1.3cells/mm^2$, respectively. MC counts dramatically decreased at time dependent manner after anti-IgE administration. However, the number of MCs on 6 hours after challenge was significantly less decreased in the groups treated with the tacrolimus, as compared with control and vehicle group. The number of EPs on 24 hours after challenge was significantly lower in the group treated with the tacrolimus than in the control and vehicle groups. In conclusion, this study revealed that 0.1% tacrolimus ointment in dogs may exert a potent anti-inflammatory effect on inhibition of MC degranulation and also secondary prevention of EP infiltration during LPR.

• Korean Journal of Materials Research
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• v.24 no.12
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• pp.671-676
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• 2014

It is known that bones get damaged by accidents and aging. Since the discovery of Bioglass, various kinds of ceramics have been also found to bond to living bone; some of these ceramics are already being clinically used as bone-repairing materials. In the present study, antibacterial calcium silicate gel ($Ag-30CaO{\cdot}70SiO_2$ gel) was prepared by sol-gel method in order to control the microstructure, which is related to the dissolution rate and induction period of apatite formation in body environment. In addition, biological $Ag-30CaO{\cdot}70SiO_2$ is tested. This was done to impart antimicrobial activity to the $30CaO{\cdot}70SiO_2$. Ag ion was added during sol-gel synthesis to replace the $H_2O$ added during the making of the $30CaO{\cdot}70SiO_2$ gel, which has silver solutions of various concentration. After the sol-gel process, 1N-$HNO_3$ solution was used to wash the gel when synthesizing the gel, in order to maintain the porous structure and remove PEG, water soluble polymers. Then, the apatite forming ability of the sol-gel derived CaO-$SiO_2$ gels was investigated using simulated body fluid (SBF), which had almost the same ion concentration as that of human blood plasma. The gels were analyzed by FT-IR spectroscopy, SEM observation, XRD, and fluorescent microscopy. The apatite was successfully created even after washing the gel; apatite is present in an amorphous state, and was found to affect the concentration of the Ag ion in cells in MC3T3 live & dead assay results. From these results, it is suggested that a good material that can be used to repair defects of nature bone is $Ag-30CaO{\cdot}70SiO_2$ gel.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1272-1277
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• 2007

Comparison of fruit bodies of Pleurotus ostreatus cultivar chunchu No .2 grown on the sawdust, rice straw and cotton waste substrates revealed differences in the pattern of differentiation of hyphal compartments. Required period for primordium induction of fruit bodies grown on sawdust substrate was 13 days. Physical structure shown as hardness of stipes grown on the sawdust substrate, fruit bodies were harden than control. Pileocystidia were well developed on the surface of pileus in the fruit body cultivated on rice straw. Microstructures of fruit body grown on the sawdust and cotton wastes substrates shown fast-discharge of basidiospore and sytoms ageing. Hyphae of fruit bodies formed on sawdust substrate had less stainable cytoplasmic material and many more vacuoles than hyphae of fruit bodies formed on synthetic substrate with 50% of pine sawdust, 30% of cotton seed hull and 20 of beet pulp(control).