• Archives of Plastic Surgery
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• 제41권3호
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• pp.201-208
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• 2014

Microsurgery is a precise surgical skill that requires an extensive training period and the supervision of expert instructors. The classical training schemes in microsurgery have started with multiday experimental courses on the rat model. These courses have offered a low threat supervised high fidelity laboratory setting in which students can steadily and rapidly progress. This simulated environment allows students to make and recognise mistakes in microsurgery techniques and thus shifts any related risks of the early training period from the operating room to the lab. To achieve a high level of skill acquisition before beginning clinical practice, students are trained on a comprehensive set of exercises the rat model can uniquely provide, with progressive complexity as competency improves. This paper presents the utility of the classical rat model in three of the earliest microsurgery training centres and the new prospects that this versatile and expansive training model offers.

• Biomolecules & Therapeutics
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• 제16권1호
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• pp.34-39
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• 2008

Oxidative stress may represent a common link between chronic liver damage and hepatic fibrosis. In the present study, we investigated activity changes of sphingomyelin catabolic enzymes, such as sphingomyelinases and ceramidases by using dimethylnitrosamine (DMN)-treated Sprague-Dawley (SD) male rats hepatic fibrosis model as a hepatic fibrosis model. Twenty rats divided into five groups received: (1) saline; (2) DMN for 1 week, (3) DMN for 2 weeks, (4) DMN for 3 weeks, and (5) DMN for 4 weeks by intraperitoneally 10 mg/kg of body weight for three consecutive days a week. Activities of acidic and neutral sphingomyelinases and acidic, neutral and alkaline ceramidases were measured in the liver and kidney from DMN-treated rats. We found increased ceramidase activities from 2-week and/or 3-week DMN treated rat livers compared to control rat liver. Acidic sphingomyelinase and alkaline ceramidase activities were significantly increased in 3-week DMN-treated rat kidneys compared to control rat kidney. Therefore, sphingolipid metabolizing enzymes and sphingolipid metabolites are supposed to be involved in liver fibrosis, although further investigation is necessary to elucidate meanings of sphingolipids during the liver fibrosis

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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• pp.53-53
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• 2001

When repolarization of neuronal action potential does not decline monotonically but interrupted by additional depolarization, this prolonged depolarization phase is referred to afterdepolarization(ADP). ADP is considered to playa crucial role in the modulation of neuronal excitability, since it contributes to burst firing. We studied the ionic mechanisms underlying ADP in the soma of dentate granule cells, using rat hippocampal slice (300${\mu}{\textrm}{m}$ in thickness) prepared from 3- to 3-week-old SD rats.(omitted)

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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• pp.38-38
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• 2001

We cloned the cDNA encoding the neuron-specific $\beta$-subunit ($\beta$4) of large-conductance calcium-activated potassium channels from rat brain and determined the DNA sequences of the entire coding region (GenBank accession; AY028605). The deduced amino acid sequences of r$\beta$4, 210 amino acids in length, are closely related to the $BK_{Ca}$ $\beta$4 subunits of other species but show only limited sequence homology to other $\beta$-subunits, $\beta$1-$\beta$3.(omitted)d)

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2003년도 추계학술대회
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• pp.131-131
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• 2003

• Journal of Korean Neurosurgical Society
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• 제61권5호
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• pp.559-567
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• 2018

Objective : The aim of this study was to evaluate the effect for biodegradable screws containing bone morphogenetic protein-2 (BMP-2) in an osteoporotic rat model. Methods : Twenty-four female Wistar rat (250-300 g, 12 weeks of age) were randomized into four groups. Three groups underwent bilateral ovariectomy (OVX). Biodegradable screws with or without BMP-2 were inserted in the proximal tibia in two implantation groups. The extracted proximal metaphysis of the tibiae were scanned by exo-vivo micro-computed tomography. Evaluated parameters included bone mineral density (BMD), trabecular bone volume (BV/TV), trabecular number, trabecular thickness, and trabecular separation (Tb.Sp). The tibia samples were pathologically evaluated by staining with by Hematoxylin and Eosin, and trichrome. Results : Trabecular formation near screw insertion site was evident only in rats receiving BMP-2 screws. BMD and BV/TV significantly differed between controls and the OVX and OVX with screw groups. However, there were no significant differences between control and OVX with screw BMP groups. Tb.Sp significantly differed between control and OVX and OVX with screw groups (p<0.05), and between the OVX and OVX with screw BMP group (p<0.05), with no statistically significant difference between control and OVX with screw BMP groups. Over the 12 weeks after surgery, bone lamellae in direct contact with the screw developed more extensive and thicker trabecular bone around the implant in the OVX with screw BMP group compared to the OVX with screw group. Conclusion : Biodegradable screws containing BMP-2 improve nearby bone conditions and enhance ostoeintegration between the implant and the osteoporotic bone.

• Mass Spectrometry Letters
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• 제14권3호
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• pp.91-103
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• 2023

As one of the most common mood disorders, numerous studies have shown depression is the main risk factor for non-suicidal self-harm. The pathogenesis of depression is complex, and a comprehensive and rapid measurement of monoamine neurotransmitters and their metabolites will be very helpful in understanding the pathogenesis of depression. Therefore, a rapid and sensitive underivatized liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous monitoring of the levels of ten neurotransmitters and their metabolites in rat serum and limbic system and successfully applied to quantify the changes of neurotransmitter levels in chronic unpredictable mild stress-induced rats. The analytes studied were mainly involved in tyrosine metabolism, tryptophan metabolism, and glutamate cycling pathways, which are important in the pathogenesis of depression. It had been verified the method was sensitive and effective, with satisfactory linearity, and met the requirements of biological sample determination. Levels of neurotransmitters in rat serum, hippocampus, amygdala, prefrontal cortex, striatum, and hypothalamus were determined via the method. The results showed serotonin, dopamine, norepinephrine, and their metabolites were decreased, glutamine was increased, and glutamate was disturbed in chronic unpredictable mild stress-induced depression rats. This method provides a new approach to studying the pathogenesis of depression and other neurological disorders.

• 대한의생명과학회지
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• 제11권1호
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• pp.45-49
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• 2005

The change of catechol-O-methyltransferase (COMT) activity during regeneration of rat liver was studied. Cytosolic, mitochondrial and microsomal COMTs activities were estimated in regenerating rat livers over a period of ten days after $70\%$ (median and left lateral lobes) partial hepatectomy. The values of Km and Vmax in the hepatic enzymes were also measured. The activities of cytosolic and microsomal COMTs in regenerating rat liver after partial hepatectomy were found to be significantly increased between the second and the third day. Whereas the mitochondrial COMT activity did not change. The Vmax values of the cytosolic and microsomal COMTs in the regenerating rat liver were significantly increased at the second day after partial hepatectomy, however, the Km values of the above hepatic enzymes did not vary in all the experimental groups. Therefore, the results suggest that the biosynthesis of COMT was increased during the regeneration of rat liver.

• 대한의생명과학회지
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• 제8권2호
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• pp.83-88
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• 2002

To investigate the skin toxicity of xylene, xylene (25 mg/$\textrm{cm}^2$) has been sequentially applied to the rat skin for four days. On the light microscopic examination, epithelium was left out with infiltration of inflammatory cells in border with dermis, and formation of new epithelial layer was shown under the inflammatory zone. Application of xylene to the rat skin showed the marked rise of cutaneous xanthine oxidase activity whereas, He activities of oxygen free radical scavenging enzymes, superoxide dismutase and glutathione S-transferase, were significantly declined. Furthermore, the content of cutaneous glutathione was more and less decreased in rat skin applied with xylene. In conclusion, these results suggest that a part of oxygen free radical may be responsible for morphological changes in skin by applying xylene to the rat skin.

• 대한의생명과학회지
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• 제12권4호
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• pp.427-433
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• 2006

We investigated the effect of propolis on the activity of antioxidant enzymes in rat liver exposed by X-ray irradiation. The dosage of propolis showed the effect of lowering the concentration of superoxide anion in irradiated rat liver, suggesting that propolis has a significant role to remove superoxide anion as an antioxidant and/or by activating the antioxidant enzyme. The activities of superoxide dismutase (SOD) and glutathione reductase (GR), disturbed by X-ray irradiation, were restored in 30 days to normal status in the group which dosed propolis before X-ray irradiation. Interestingly, catalase (CAT) and glutathione peroxidase (GPOX) activities were highly increased with feeding propolis to rat compared to untreated group, whereas glutathione s-transferase (GST) activity was little affected. Taken together, it suggests that the propolis has a protective role in the rat liver cells against X-ray irradiation by increasing and recovering the activities of antioxidant enzymes.