• Title/Summary/Keyword: Human and animal experiments

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Influence of Phytase and Xylanase Supplementation on Growth Performance and Nutrient Utilisation of Broilers Offered Wheat-based Diets

  • Selle, P.H.;Ravindran, V.;Ravindran, G.;Pittolo, P.H.;Bryden, W.L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.3
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    • pp.394-402
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    • 2003
  • Individual and combined supplementation of phosphorus-adequate, wheat-based broiler diets with exogenous phytase and xylanase was evaluated in three experiments. The effects of the enzyme combination in lysine-eficient diets containing wheat and sorghum were more pronounced than those of the individual feed enzymes. The inclusion of phytase plus xylanase improved (p<0.05) weight gains (7.3%) and feed efficiency (7.0%) of broilers (7-28 days post-hatch) and apparent metabolisable energy (AME) by 0.76 MJ/kg DM. Phytase plus xylanase increased (p<0.05) the overall, apparent ileal digestibility of amino acids by 4.5% (0.781 to 0.816); this was greater than the responses to either phytase (3.6%; 0.781 to 0.809) or xylanase (0.7%; 0.781 to 0.784). Absolute increases in amino acid digestibility with the combination exceeded the sum of the individual increases generated by phytase and xylanase for alanine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, phenylalanine, threonine, tyrosine and valine. These synergistic responses may have resulted from phytase and xylanase having complementary modes of action for enhancing amino acid digestibilities and/or facilitating substrate access. The two remaining experiments were almost identical except wheat used in Experiment 2 had a higher phytate concentration and a lower estimated AME content than wheat used in Experiment 3. Individually, phytase and xylanase were generally more effective in Experiment 2, which probably reflects the higher dietary substrate levels present. Phytase plus xylanase increased (p<0.05) gains (15.4%) and feed efficiency (7.0%) of broiler chicks from 4-24 days post-hatch in Experiment 2; whereas, in Experiment 3, the combination increased (p<0.05) growth to a lesser extent (5.6%) and had no effect on feed efficiency. This difference in performance responses appeared to be 'rotein driven'as the combination increased (p<0.05) nitrogen retention in Experiment 2 but not in Experiment 3; whereas phytase plus xylanase significantly increased AME in both experiments. In Experiments 2 and 3 the combined inclusion levels of phytase and xylanase were lower that the individual additions, which demonstrates the benefits of simultaneously including phytase and xylanase in wheat-based poultry diets.

ANIMAL AND HUMAN STUDIES ON THE ROLE OF SOYBEAN, RICE AND NUTS CONSUMPTION IN HYPERCHOLESTEROLEMIA AND ATHEROSCLEROSIS

  • Imaizumi Katsumi
    • Proceedings of the Korean Society of Food Science and Nutrition Conference
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    • 2001.12a
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    • pp.61-68
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    • 2001
  • Soybean, rice and nuts are the staple foods in South East Asia. In order to clarify the function of these foods in relation to coronary heart diseases, we have done a series of experiments using animals and humans. Soybean protein preparations (SPI) in comparison with an animal protein, casein (CAS), resulted in reducing atherosclerotic lesion development in apolipoprotein (apo) E deficient mice that develop an advanced lesion similar to that in humans. This action was attributed to the protein, since the ethanol-extracted SPI (EE-SPI), from which isoflavones and saponins removed, lowered the lesion development in apo E-deficient mice. However, The EE-SPI, compared to the SPI, resulted in a decrease of mRNA for key proteins of cholesterol metabolism (low density lipoprotein receptor and cholesterol 7$\alpha$-hydroxylase) in hypercholesterolemic rats, followed by an elevation of the serum cholesterol level, indicating a contribution of isoflavones to the serum cholesterol level. Rice protein (RPI) was also effective to lower the lesion development in apo E deficient mice. Both the SPI and RPI led to an increased level of the serum NOiN03, metabolites of NO. This effect appeared to be attributed to their high content of arginine. Besides, C57BL/6J mice fed a diet containing whole grain rice had an elevation of the serum high-density lipoprotein cholesterol. Furthermore, rice bran oil and the unsaponifiable fraction that is rich in plant sterols were effective to lower serum cholesterol levels in hypercholeserolemic rats. Finally, we tested if walnuts consumption would be hypocholesterolemic for Japanese. A diet containing walnuts effectively lowered the serum total and low density lipoprotein cholesterol in Japanese men and women. These animal and human experiments would be relevant to advocate publics to keep consuming diets including soybean, rice and nuts for their healthful life.

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Effect of Dietary Fiber on Mineral Bioavailability (식이섬유가 무기질의 생체이용에 미치는 영향)

  • Choe, Myeon
    • Journal of Food Hygiene and Safety
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    • v.7 no.4
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    • pp.165-172
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    • 1992
  • Among the nutrients of biological importance, minerals are of particular interest in human nutrition because the range of adequate intake is so narrow. As the results of a series of interaction experiments between dietary fiber sources and minerals, there are many inconsistencies in the experimental data regarding the effect of dietary fibers on mineral bioavailability. the mechanism by which dietary fiber might influence mineral absorption is related to its physicochemical properties. These properties involve the ability of dietary fiber to (1) act as a weak cation exchanger, (2) decrease transit time, (3) dilute mineral concentration by increasing fecal bulk and (4) resist digestion in the large bowel. Regardless of the large number of human and animal studies available, a carful review of these publications dose not provide the answer as to whether the adverse effect of dietary fibers on mineral absorption is the fiber itself or some associated dietary factors( e.g. phytate, oxalate, ascorbate, citrate and protein, mineral-mineral interaction, etc) that are responsible for this action. As a result of the complexity of interaction that may take place between minerals. dietary fiber, and other component of food ; it becomes very difficult to blame fiber alone as a negative factor of mineral nutrition. We absolutely need more research with advanced tools rather than metabolic balance study.

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Experimental investigation of electric currents flowing through human body in electirc shock (전기충격시인체에 흐르는 전류의 실험적 고찰)

  • 김완배;안광윤;윤태원
    • 전기의세계
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    • v.29 no.1
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    • pp.21-27
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    • 1980
  • The effect of electric shock on human body is enormousness, which leads to warmth, tingling, and even death. The mean values of perception currents obtained on 91 men and 39 women are about 0.77(mA) for men and 0.57(mA) for women. The mean value for women is approximately seven tenths that of men. An individual can tolerate, with no adverse effects, repeated exposure to the reactions associated with currents of his let-go level, and the mean value of let-go currents obtained from 27 normal men is 6.29(mA). Lethal currents flowing human body is very dangerous even for a short time. So, it is necessary to have recourse to animal experiments ot determine lethal current for human. An analysis of experimental data indicates that body weight and shock duration are important factors in determining the lethal current. It is suggested that the relationship between current and shock duration is given by I=K/.root.T, and lethal current is proportional to body weight, where I is the current in milliampere, and T is the time in seconds.

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Selection of model viruses for foot-and-mouth disease virus-related-experiments (구제역 바이러스를 대체할 모델 바이러스 선별)

  • Kim, Tae-Hwan;Herath, Thilina U. B.;Kim, Jae-Hoon;Lee, Kwang-Nyeong;Park, Jong-Hyeon;Kim, Chul-Joong;Lee, Jong-Soo
    • Korean Journal of Microbiology
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    • v.53 no.4
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    • pp.304-308
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    • 2017
  • Researchers have comparatively fewer opportunities to conduct experiments on foot-and-mouth disease virus (FMDV), owing to the limited availability of biosafety level 3 facilities. Bovine rhinovirus (BRV) and human rhinovirus (HRV), which are genetically closely related to FMDV, have been evaluated in this study as model viruses for FMDV. To discover whether BRV and HRV have similar physicochemical properties as FMDV, virus susceptibility tests have been performed in different physical (pH and heat) and chemical (acidic/alkaline solutions and commercial disinfectants) conditions in vitro. Our data revealed that the physicochemical characteristics of BRV and HRV were nearly similar to those of FMDV.

Development of 68Ga-human serum albumin as a PET imaging agent for diagnosis of acute inflammation

  • Lee, Ji Youn;Kim, Hoyoung;Lee, Boeun;Kim, Young Ju;Lee, Yun-Sang;Jeong, Jae Min
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.1 no.2
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    • pp.104-108
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    • 2015
  • Human serum albumin (HSA) has potential for diagnosis and therapy in clinical setting. The purpose of experiments was to develop and evaluate $^{68}Ga$-HSA as a PET agent for diagnosis of acute inflammation. NOTA-HSA was synthesized by conjugating 2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid to HSA in 0.1 M sodium carbonate buffer (pH 9.5) and then purified using a PD-10 size-exclusion column. NOTA-HSA was labeled with $^{68}Ga$ at room temperature for 10 min, and 8.4% sodium hydrogen carbonate buffer was added for neutralization. $^{68}Ga$-NOTA-HSA was purified using alumina N plus light cartridge and $0.22{\mu}m$ syringe filter. Labeling efficiency and radiochemical purity were determined by ITLC-SG with 0.1 M citric acid. Biodistribution study was performed in a male BALB/c mice model of Carrageenan-induced acute inflammation. Animal PET study was performed in acute inflammation mice model after tail vein injection of $^{68}Ga$-HSA. This radiotracer showed high labeling efficiency (>99%) around pH 7. Biodistribution study showed higher inflamed footpad uptake than control footpad uptake. Animal PET study revealed 2 times higher uptake on inflamed footpad compared to control footpad. In these experiments, we developed $^{68}Ga$-HSA for acute inflammation PET imaging and evaluated it in a mouse disease model. The results demonstrated that $^{68}Ga$-HSA has potential as a PET imaging agent for diagnosis of acute inflammation.

Evaluation of polyglycolic acid as an animal-free biomaterial for three-dimensional culture of human endometrial cells

  • Sadegh Amiri;Zohreh Bagher;Azadeh Akbari Sene;Reza Aflatoonian;Mehdi Mehdizadeh;Peiman Broki Milan;Leila Ghazizadeh;Mahnaz Ashrafi;FatemehSadat Amjadi
    • Clinical and Experimental Reproductive Medicine
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    • v.49 no.4
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    • pp.259-269
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    • 2022
  • Objective: Animal-free scaffolds have emerged as a potential foundation for consistent, chemically defined, and low-cost materials. Because of its good potential for high biocompatibility with reproductive tissues and well-characterized scaffold design, we investigated whether polyglycolic acid (PGA) could be used as an animal-free scaffold instead of natural fibrin-agarose, which has been used successfully for three-dimensional human endometrial cell culture. Methods: Isolated primary endometrial cells was cultured on fibrin-agarose and PGA polymers and evaluated various design parameters, such as scaffold porosity and mean fiber diameter. Cytotoxicity, scanning electron microscopy (SEM), and immunostaining experiments were conducted to examine cell activity on fabricated scaffolds. Results: The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and SEM results showed that endometrial cells grew and proliferated on both scaffolds. Immunostaining showed cytokeratin and vimentin expression in seeded cells after 7 days of culture. On both scaffolds, an epithelial arrangement of cultured cells was found on the top layer and stromal arrangement matrix on the bottom layer of the scaffolds. Therefore, fibrin-agarose and PGA scaffolds successfully mimicked the human endometrium in a way suitable for in vitro analysis. Conclusion: Both fibrin-agarose and PGA scaffolds could be used to simulate endometrial structures. However, because of environmental and ethical concerns and the low cost of synthetic polymers, we recommend using PGA as a synthetic polymer for scaffolding in research instead of natural biomaterials.

Estimation of Human Carcinogenic Potency (HCP) of Carcinogens in Risk Assessment and Management. (위해성 평가 및 관리에 있어서 발암물질의 인체발암능력 평가)

  • 이병무;김대영;김세기;김근종
    • Environmental Mutagens and Carcinogens
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    • v.19 no.1
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    • pp.39-45
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    • 1999
  • Human Carcinogenic Potency (HCP) can be estimated based on human daily exposure dose to carcinogen (Dh), body weight (Wh), 10% tumorigenic dose (TD10), and slope factor at TD10 (Q10) from 2-yr bioassay data. This approach is more relevant to humans generally exposed to low doses of carcinogens and can reduce more of extrapolation errors from high dose in animal experiments to low dose in humans than HERP (human exposure dose/rodent potency dose) proposed by Ames et al. (Science, 236, 271-280, 1987). TD50 and HERP have been routinely used to compare rodent carcinogenic potency and human carcinogenic potency, but those approaches have had limitations in extrapolation of high dose to low dose in humans. The advantages of HCP are to estimate human exposure dose (Dh) by human monitoring instead of environmental monitoring, to consider slope factor (Q10) which reflects the tendency of curve at low dose, and to use TD10 which represents much lower dose thant TD50 or HERP. HCP will be a useful parameter for the estimation of human carcinogenic potency in risk assessment and management of carcinogens.

Dosimetric characterization and commissioning of a superficial electronic brachytherapy device for skin cancer treatment

  • Park, Han Beom;Kim, Hyun Nam;Lee, Ju Hyuk;Lee, Ik Jae;Choi, Jinhyun;Cho, Sung Oh
    • Nuclear Engineering and Technology
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    • v.50 no.6
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    • pp.937-943
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    • 2018
  • Background: This work presents the performance of a novel electronic brachytherapy (EBT) device and radiotherapy (RT) experiments on both skin cancer cells and animals using the device. Methods and materials: The performance of the EBT device was evaluated by measuring and analyzing the dosimetric characteristics of X-rays generated from the device. The apoptosis of skin cancer cells was analyzed using B16F10 melanoma cancer cells. Animal experiments were performed using C57BL/6 mice. Results: The X-ray characteristics of the EBT device satisfied the accepted tolerance level for RT. The results of the RT experiments on the skin cancer cells show that a significant apoptosis induction occurred after irradiation with 50 kVp X-rays generated from the EBT device. Furthermore, the results of the animal RT experiments demonstrate that the superficial X-rays significantly delay the tumor growth and that the tumor growth delay induced by irradiation with low-energy X-rays was almost the same as that induced by irradiation with a high-energy electron beam. Conclusions: The developed new EBT device has almost the same therapeutic effect on the skin cancer with a conventional linear accelerator. Consequently, the EBT device can be practically used for human skin cancer treatment in the near future.

A simple and rapid method for detection of single nucleotide variants using tailed primer and HRM analysis

  • Hyeonguk Baek;Inchul, Choi
    • Journal of Animal Reproduction and Biotechnology
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    • v.38 no.4
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    • pp.209-214
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    • 2023
  • Background: Single nucleotide polymorphisms (SNPs) are widely used genetic markers with applications in human disease diagnostics, animal breeding, and evolutionary studies, but existing genotyping methods can be labor-intensive and costly. The aim of this study is to develop a simple and rapid method for identification of a single nucleotide change. Methods: A modified Polymerase Chain Reaction Amplification of Multiple Specific Alleles (PAMSA) and high resolution melt (HRM) analysis was performed to discriminate a bovine polymorphism in the NCAPG gene (rs109570900, 1326T > G). Results: The inclusion of tails in the primers enabled allele discrimination based on PCR product lengths, detected through agarose gel electrophoresis, successfully determining various genotypes, albeit with some time and labor intensity due to the use of relatively costly high-resolution agarose gels. Additionally, high-resolution melt (HRM) analysis with tailed primers effectively distinguished the GG genotype from the TT genotype in bovine muscle cell lines, offering a reliable way to distinguish SNP polymorphisms without the need for time-consuming AS-PCR. Conclusions: Our experiments demonstrated the importance of incorporating unique mismatched bases in the allele-specific primers to prevent cross-amplification by fragmented primers. This efficient and cost-effective method, as presented here, enables genotyping laboratories to analyze SNPs using standard real-time PCR.