• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.11-18
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• 2022

An electromagnetic generator with variable stimulation parameters is required to conduct basic research on magnetic flux density and frequency for pulsed electromagnetic fields (PEMFs). In this study, we design an electromagnetic generator that can conduct basic research by providing parameters optimized for cell and animal experimental conditions through adjustable stimulation parameters. The magnetic core was selected as a solenoid capable of uniform and stable electromagnetic stimulation. The solenoid was designed in consideration of the experimental mouse and cell culture dish insertion. A voltage and current adjustable power supply for variable magnetic flux density was designed. The system was designed to be adjustable in frequency and pulse width and to enable 3-channel output. The reliability of the system and solenoid was evaluated through magnetic flux density, frequency, and pulse width measurements. The measured magnetic flux density was expressed as an image and qualitatively observed. Based on the acquired image, the stimulation area according to the magnetic flux density decrease rate was extracted. The PEMF frequency and pulse width error rates were presented as mean ± SD, and were confirmed to be 0.0928 ± 0.0934% and 0.529 ± 0.527%, respectively. The magnetic flux density decreased as the distance from the center of the solenoid increased, and decreased sharply from 60 mm or more. The length of the magnetic stimulation area according to the degree of magnetic flux density decrease was obtained through the magnetic flux density image. A PEMF generator and stimulation parameter control system suitable for cell and animal models were designed, and system reliability was evaluated.

• Journal of Life Science
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• v.22 no.10
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• pp.1428-1433
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• 2012

Longevity is an exciting but difficult subject to study because it is determined by complex processes that require the coordinated action of several genetic factors as well as physiological and environmental influences. Genetic approaches have been applied to animal models to identify the molecular mechanism responsible for longevity. Several experimental model organisms obtained over the last decades suggest that the complete deletion of a single gene by gene targeting has proven to be an invaluable tool for the discovery of the mechanisms underlying longevity. The first discovery of long-lived mutants came from Caenorhabditis elegans research, which identified the insulin/IGF-1 pathway as responsible for longevity in this worm. IGF-1 is a multifunctional polypeptide that has sequence similarity to insulin and is involved in normal growth and development of cells. Several factors in the IGF-1 system have since been studied by gene targeting in the control of longevity in lower species, including nematode and fruit fly. In addition, significant progress has been made using mice models to extend the lifespan by targeted mutations that interfere with growth hormone/IGF-1 and IGF-1 signaling cascades. A recent finding that IGF-1 is involved in aging in mice was achieved by using liver-specific knockout mutant mice, and this clearly demonstrated that the IGF-1 signal pathway can extend the lifespan in both invertebrates and vertebrate models. Although the underlying molecular mechanisms for the control of longevity are not fully understood, it is widely accepted that reduced IGF-1 signaling plays an important role in the control of aging and longevity. Several genes involved in the IGF-1 signaling system are reviewed in relation to longevity in genetically modified mice models.

• Biomolecules & Therapeutics
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• v.32 no.1
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• pp.136-145
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• 2024

People with obesity maintain low levels of inflammation; therefore, their exposure to foreign antigens can trigger an excessive immune response. In people with obesity or allergic contact dermatitis (ACD), symptoms are exacerbated by a reduction in the number of regulatory T cells (Tregs) and IL-10/TGF-β-modified macrophages (M2 macrophages) at the inflammatory site. Benefits of intermittent fasting (IF) have been demonstrated for many diseases; however, the immune responses regulated by macrophages and CD4⁺T cells in obese ACD animal models are poorly understood. Therefore, we investigated whether IF suppresses inflammatory responses and upregulates the generation of Tregs and M2 macrophages in experimental ACD animal models of obese mice. The IF regimen relieved various ACD symptoms in inflamed and adipose tissues. We showed that the IF regimen upregulates Treg generation in a TGF-β-dependent manner and induces CD4⁺T cell hypo-responsiveness. IF-M2 macrophages, which strongly express TGF-β and inhibit CD4⁺T cell proliferation, directly regulated Treg differentiation from CD4⁺T cells. These results indicate that the IF regimen enhances the TGF-β-producing ability of M2 macrophages and that the development of Tregs keeps mice healthy against ACD exacerbated by obesity. Therefore, the IF regimen may ameliorate inflammatory immune disorders caused by obesity.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.9
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• pp.1389-1396
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• 2019

Objective: The current study analysed the relationships between methane ($CH_4$) output from animal and dietary factors. Methods: The dataset was obtained from 159 Dorper${\times}$thin-tailed Han lambs from our seven studies, and $CH_4$ production and energy metabolism data were measured in vivo by an opencircuit respiratory method. All lambs were confined indoors and fed pelleted diet during the whole experimental period in all studies. Data from two-thirds of lambs were used to develop linear and multiple regressions to describe the relationship between $CH_4$ emission and dietary variables, and data from the remaining one third of lambs were used to validate the established models. Results: $CH_4$ emission (g/d) was positively related to dry matter intake (DMI) and gross energy intake (GEI) (p<0.001). $CH_4$ energy/GEI was negatively related to metabolizable energy/gross energy and metabolizable energy/digestible energy (p<0.001). Using DMI to predict $CH_4$ emission (g/d) resulted in a coefficient of determination ($R^2$) of 0.80. Using GEI, digestible energy intake, and metabolizable energy intake predict $CH_4$ energy/GEI resulted in a $R^2$ of 0.92. Conclusion: the prediction equations established in the current study are useful to develop appropriate feeding and management strategies to mitigate $CH_4$ emissions from sheep.

• Animal Bioscience
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• v.36 no.12
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• pp.1880-1888
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• 2023

Objective: The present experiment aimed to determine standardized ileal digestible (SID) lysine (Lys) requirements for pregnant sows individually housed under commercial farm conditions. Methods: Two hundred multiparous sows (parity = 5.1±2.0) on day 42 of gestation were randomly allocated to five dietary treatments with a balanced parity. Experimental diets were formulated to contain 0.22%, 0.32%, 0.42%, 0.52%, and 0.62% of SID Lys for the mid-gestation period (days 42 to 76) and 0.36%, 0.46%, 0.56%, 0.66%, and 0.76% of SID Lys for the late gestation period (days 77 to 103). All indispensable amino acids except Lys were provided at 110% of their requirement estimates. Daily feed allowance per sow was determined based on the back-fat thickness and body condition score at the second pregnancy check and on day 90 of gestation. Three different statistical models were used to estimate the SID Lys requirement. Results: Total born piglets alive per litter increased linearly and quadratically (p<0.001) as dietary SID Lys increased. For total born piglets alive per litter, the SID Lys requirement estimates ranged from 9.69 to 12.4 g/d for the mid-gestation period (1.19 to 1.52 g/Mcal metabolizable energy; 0.39% to 0.49%) and 14.6 to 17.4 g/d for the late gestation period (1.62 to 1.93 g/Mcal metabolizable energy; 0.52% to 0.62%). Conclusion: The mean values of the SID Lys requirement for the mid-gestation period and the late gestation period are 11.1 and 16.1 g/d (1.36 and 1.79 g/Mcal metabolizable energy; 0.44% and 0.58%), respectively, for maximal total born piglets alive per litter.

• Preventive Nutrition and Food Science
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• v.6 no.3
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• pp.163-169
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• 2001

To produce expanded, minimally hard extrudates from blends of raw pork meat (20%), defatted soy flour (25%), and corn starch using a single-screw extruder, various combinations of feed moisture, process temperature, and screw speed were evaluated. First series of extrusion runs were conducted according to a central composite rotatable design/response surface methodology (RSM). Upon assessing the full model for each response, insignificant terms were eliminated to determine final response surface models. Screw speed within the range evaluated was found to have no significant effect on expansion ratio (ER) or shear force (SF) of extrudates. Since examinations of the response surfaces and their generated grids of predicted values indicated that maximum ER and minimum SF were likely to be attained with a moisture-temperature combination outside the RSM experimental range, the second series of extrusion runs were conducted with several selected combinations of moisture and temperature to determine a practical optimum extrusion condition. The combination of 22.78% feed moisture, 16$0^{\circ}C$ process temperature, and 170 rpm screw speed was chosen as such a condition, and used in the final extrusion. The final product required less force to break than did commercial pretzel sticks.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.1
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• pp.45-54
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• 2017

Our study aims to determine the metabolism and excretion of novel pulmonary-targeting docetaxel liposome (DTX-LP) using the in vitro and in vivo animal experimental models. The metabolism and excretion of DTX-LP and intravenous DTX (DTX-IN) in New Zealand rabbits were determined with ultra-performance liquid chromatography tandem mass spectrometry. We found DTX-LP and DTX-IN were similarly degraded in vitro by liver homogenates and microsomes, but not metabolized by lung homogenates. Ultra-performance liquid chromatography tandem mass spectrometry identified two shared DTX metabolites. The unconfirmed metabolite $M_{un}$ differed structurally from all DTX metabolites identified to date. DTX-LP likewise had a similar in vivo metabolism to DTX-IN. Conversely, DTX-LP showed significantly diminished excretion in rabbit feces or urine, approximately halving the cumulative excretion rates compared to DTX-IN. Liposomal delivery of DTX did not alter the in vitro or in vivo drug metabolism. Delayed excretion of pulmonary-targeting DTX-LP may greatly enhance the therapeutic efficacy and reduce the systemic toxicity in the chemotherapy of non-small cell lung cancer. The identification of $M_{un}$ may further suggest an alternative species-specific metabolic pathway.

• Journal of Animal Science and Technology
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• v.64 no.3
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• pp.588-598
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• 2022

Despite vaccination, equine influenza virus (EIV) and equine herpesvirus (EHV) infections still cause highly contagious respiratory diseases in horses. Recently, concurrent vaccination with EIV and EHV was suggested as a new approach; however, there have been no reports of concurrent vaccination with recombinant canarypox EIV and inactivated EHV vaccines. In this study, we aimed to compare the EIV-specific immune responses induced by concurrent administrations of a recombinant canarypox EIV vaccine and an inactivated bivalent EHV vaccine with those induced by a single recombinant canarypox EIV vaccine in experimental horse and mouse models. Serum and peripheral blood mononuclear cells (PBMCs) were collected from immunized animals after vaccination. EIV-specific serum antibody levels, serum hemagglutinin inhibition (HI) titers, and interferon-gamma (IFN-γ) levels were measured by enzyme-linked immunosorbent assay, HI assay, and quantitative polymerase chain reaction, respectively. Concurrent EIV and EHV vaccine administration significantly increased IFN-γ production, without compromising humoral responses. Our data demonstrate that concurrent vaccination with EIV and EHV vaccines can enhance EIV-specific cellular responses in horses.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.16 no.2
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• pp.138-151
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• 2003

Although the use of acupuncture for pain has increased in recent years, the mechanisms of acupuncture analgesia (AA) remains obscure. The lack of suitable experimental animal models for persistent pain, which show clear AA, has been the major stumbling block in the investigation of the physiological mechanisms of AA. In the present study, we test AA in two knee arthritis model induced by injection of CFA or carrageenan as a chronic pain model. After induction of arthritis, the rat subsequently showed a reduced stepping force of the affected limb for the next several days. Electroacupuncture (EA) was applied to an acupuncture point each on the contralateral forelimb for 30 minutes under enflurane anesthesia. After the termination of EA, behavioral tests measuring stepping force were periodically conducted during the next several hours. EA produced a significant improvement of stepping force of the foot lasting for at least 2 hours when applied to LR2 In CFA model, and applied to ST36 in carrageenan model, but both points did not produce any significant effects in each other model. These data suggest that EA produce analgesic effect in knee arthritic pain and the analgesic effect is specific to the acupuncture point.

• Applied Microscopy
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• v.48 no.4
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• pp.102-109
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• 2018

Multiple synaptic boutons (MSBs) have been reported to be synapse with two or more postsynaptic terminals in one presynaptic terminal. These MSBs are known to be increased by various brain stimuli. In the motor cortex, increased number of MSB was observed in both acrobat training (AC) model and traumatic brain injury (TBI) model. Interestingly one is a physiological stimuli and the other is pathological insult. The purpose of this study is to compare the connectivity of MSBs between AC model and TBI model in the cerebral motor cortex, based on the hypothesis that the connectivity of MSBs might be different according to the models. The motor cortex was dissected from perfused brain of each experimental animal, the samples were prepared for routine transmission electron microscopy. The 60~70 serial sections were mounted on the one-hole grid and MSB was analyzed. The 3-dimensional analysis revealed that 94% of MSBs found in AC model synapse two postsynaptic spines from same dendrite. But, 28% MSBs from TBI models synapse two postsynaptic spines from different dendrite. This imply that the MSBs observed in motor cortex of AC model and TBI model might have different circuits for the processing the information.