• The Korean Journal of Physiology and Pharmacology
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• v.13 no.5
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• pp.373-378
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• 2009

Cerebellar Purkinje cells (PCs) play a crucial role in motor functions and their progressive degeneration is closely associated with spinocerebellar ataxias. Although immunohistochemical (IHC) analysis can provide a valuable tool for understanding the pathophysiology of PC disorders, the method validation of IHC analysis with cerebellar tissue specimens is unclear. Here we present an optimized and validated IHC method using antibodies to calbindin D28k, a specific PC marker in the cerebellum. To achieve the desired sensitivity, specificity, and reproducibility, we modified IHC analysis procedures for cerebellar tissues. We found that the sensitivity of staining varies depending on the commercial source of primary antibody. In addition, we showed that a biotin-free signal amplification method using a horseradish peroxidase polymer-conjugated secondary antibody increases both the sensitivity and specificity of ICH analysis. Furthermore, we demonstrated that dye filtration using a $0.22\;{\mu}m$ filter eliminates or minimizes nonspecific staining while preserving the analytical sensitivity. These results suggest that our protocol can be adapted for future investigations aiming to understand the pathophysiology of cerebellar PC disorders and to evaluate the efficacy of therapeutic strategies for treating' these diseases.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.6
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• pp.579-589
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• 2017

Anesthetics are used extensively in surgeries and related procedures to prevent pain. However, there is some concern regarding neuronal degeneration and cognitive deficits arising from regular anesthetic exposure. Recent studies have indicated that brain-derived neurotrophic factor (BDNF) and cyclic AMP response element-binding protein (CREB) are involved in learning and memory processes. Genistein, a plant-derived isoflavone, has been shown to exhibit neuroprotective effects. The present study was performed to examine the protective effect of genistein against isoflurane-induced neurotoxicity in rats. Neonatal rats were exposed to isoflurane (0.75%, 6 hours) on postnatal day 7 (P7). Separate groups of rat pups were orally administered genistein at doses of 20, 40, or 80 mg/kg body weight from P3 to P15 and then exposed to isoflurane anesthesia on P7. Neuronal apoptosis was detected by TUNEL assay and FluoroJade B staining following isoflurane exposure. Genistein significantly reduced apoptosis in the hippocampus, reduced the expression of proapoptotic factors (Bad, Bax, and cleaved caspase-3), and increased the expression of Bcl-2 and Bcl-xL. RT-PCR analysis revealed enhanced BDNF and TrkB mRNA levels. Genistein effectively upregulated cAMP levels and phosphorylation of CREB and TrkB, leading to activation of cAMP/CREB-BDNF-TrkB signaling. PI3K/Akt signaling was also significantly activated. Genistein administration improved general behavior and enhanced learning and memory in the rats. These observations suggest that genistein exerts neuroprotective effects by suppressing isoflurane-induced neuronal apoptosis and by activating cAMP/CREB-BDNF-TrkB-PI3/Akt signaling.

• Journal of Biomedical Engineering Research
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• v.34 no.1
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• pp.14-23
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• 2013

In this study, biomechanical stability of the newly developed revision total knee arthroplasty (rTKA) was evaluated through strain and stress distribution analysis within the implanted proximal tibia using a three-dimensional finite element (FE) analysis. 2000N of compressive load (about 3 times body weight) was applied to the condyle surface on spacer, sharing by the medial (60%) and lateral (40%) condyles simulating a stance phase before toe-off. The results showed that PVMS within the revision total knee arthroplasty and the proximal tibia were less than yield strength considering safe factor 4.0 (rTKA: less than 10%, Cortical bone: less than 70%, Cancellous bone: less than 70%). The materials composed of them and the strain and stress distributions within the proximal tibia were generally well matched with those of a traditional revision total knee arthoplasty (Scorpio TS revision system, Stryker Corp., Michigan, USA) without the critical damage strain and stress, which may reduce the capacity for bone remodeling, leading to bone degeneration. This study may be useful to design parameter improvement of the revision total knee arthoplasty in biomechanical stability point of view beyond structural stability of revision total knee arthoplasty itself.

• Restorative Dentistry and Endodontics
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• v.1 no.1
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• pp.26-32
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• 1975

After a vital pulpotomy in dogs' teeth, the responses of the remaining pulp tissue under hydroxides (calcium hydroxide, magnesium hydroxide, aluminium hydroxide and zinc hydroxide) were studied histologically. The class V cavities were prepared on the teeth and the pulp was amputated. Each hydroxide was placed over the amputated tissue and the cavity was sealed with zinc oxide eugenol cement. Animals were sacrificed after 3 days, 1, 2, and 3 weeks following the operation. The teeth were decalcified, sectioned and stained with hematoxylin and eosin. Microscopic examination reveals as follows; 1. Calcium hydroxide: Inflammatory change was seen in the superficial portion of the remaining pulp tissue at the 3rd day and 1st week. The incompleted calicified material began to be deposited from the canal wall at the 2nd week, and the advanced calcified material was seen at the 3rd week. 2. Magnesium hydroxide: Severe inflammatory change was seen in the superficial portion of the remaining pulp from the 3rd day and the 1st week samples. Inflammatory change was decreased at the 2nd week and the slight calcified material was deposited from the root canal at the 3rd week. 3. Aluminium hydroxide: Severe inflammatory changes were seen in the remaining pulp tissue, the blood vessel was dilated, and the odontoblasts were destroyed at the 3rd day and 1st week. The fibrous degeneration spread to the apex at the 2nd week. There was no evidence of newly formed odontoblasts or deposition of calcified material underneath aluminium hydroxide. 4. Zinc hydroxide: The micrscopic picture was destructive. A thick necrotic layer was found under the amputated surface at the 3rd day and 1st week. Granulation tissue formation as well as chronic inflammatory changes extended to the apical area in the pulp tissue. Also there were no sign of odontoblastic formation or calcified material at the 2nd and 3rd week.

• Journal of Ginseng Research
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• v.41 no.4
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• pp.456-462
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• 2017

Background: Abnormal activation of matrix metalloproteinases (MMPs) plays an important role in UV-induced wrinkle formation, which is a major dermatological problem. This formation occurs due to the degeneration of the extracellular matrix (ECM). In this study, we investigated the cutaneous photoprotective effects of Ultraflo L treated ginseng leaf (UTGL) in hairless mice. Methods: SKH-1 hairless mice (6 weeks of age) were randomly divided into four groups (8 mice/group). UTGL formulation was applied topically to the skin of the mice for 10 weeks. The normal control group received nonvehicle and was not irradiated with UVB. The UV control (UVB) group received nonvehicle and was exposed to gradient-UVB irradiation. The groups (GA) receiving topical application of UTGL formulation were subjected to gradient-UVB irradiation on $0.5mg/cm^2$ [GA-low (GA-L)] and $1.0mg/cm^2$ [(GA-high (GA-H)] of dorsal skin area, respectively. Results: We found that topical treatment with UTGL attenuated UVB-induced epidermal thickness and impairment of skin barrier function. Additionally, UTGL suppressed the expression of MMP-2, -3, and -13 induced by UVB irradiation. Our results show that topical application of UTGL protects the skin against UVB-induced damage in hairless mice and suggest that UTGL can act as a potential agent for preventing and/or treating UVB-induced photoaging. Conclusion: UTGL possesses sunscreen properties and may exhibit photochemoprotective activities inside the skin of mice. Therefore, UTGL could be used as a potential therapeutic agent to protect the skin against UVB-induced photoaging.

• Advances in Traditional Medicine
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• v.10 no.3
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• pp.165-172
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• 2010

The present study investigated the effect of silymarin, a flavonoid, on streptozotocin (STZ) - induced diabetic dyslipidaemia in rats. Experimental diabetes was induced by a single intraperitoneal injection of STZ (60 mg/kg). Silymarin (25 mg/kg and 50 mg/kg) was orally administered to diabetic rats for a period of 15 days. Blood glucose levels, serum lipid profile and liver glycogen levels were estimated following the established procedures. Biochemical observations were supplemented with histological examination of liver sections. Oral administration of silymarin to diabetic rats significantly (P < 0.001) decreased the blood glucose levels ($259.99{\pm}23.64$ vs. $99.90{\pm}2.62$ [25 mg] & $89.17{\pm}3.32$ [50 mg]). The most interesting finding was the significant (p < 0.001) increase in HDL-cholesterol levels ($26.99{\pm}0.61$ vs. $40.55{\pm}0.52$ [25 mg] & $41.12{\pm}0.37$ [50 mg]) whereas, there was a significant decrease in serum total cholesterol (TCh), triglycerides (TG), low density lipoprotein (LDL) and very low density lipoprotein (VLDL) cholesterol levels observed in silymarin treated diabetic rats. STZ treatment caused significant degeneration of liver parenchyma, which was normalized to near normal morphology by administration of silymarin. The findings indicate that silymarin effectively improved the overall lipid profile and restored the glycogen stores in the liver of STZ-induced diabetic rats, in a dose dependent manner. The results indicate existence of abnormalities in lipid metabolism in STZ-induced diabetic rats and suggest a protective effect of silymarin in this animal model.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.7
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• pp.23-29
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• 2012

The LC-based digitally controlled oscillator (LC-DCO), a key component of the all digital phase locked loop (ADPLL), is designed using $0.18{\mu}m$ RFCMOS process with 1.8 V supply. The NMOS core with double cross-coupled pair is chosen to realize wide tuning range, and the PMOS varactor pair that has small capacitance of a few aF and the capacitive degeneration technique to shrink the capacitive element are adopted to obtain the high frequency resolution. Also, the noise filtering technique is used to improve phase noise performance. Measurement results show the center frequency of 2.7 GHz, the tuning range of 2.5 GHz and the high frequency resolution of 2.9 kHz ~7.1 kHz. Also the fine tuning range and the current consumption of the core could be controlled by using the array of PMOS transistors using current biasing. The current consumption is between 17 mA and 26 mA at 1.8V supply voltage. The proposed DCO could be used widely in various communication system.

• Annals of Clinical Neurophysiology
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• v.5 no.1
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• pp.34-38
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• 2003

Backgrounds and Objectives: In the length-dependent axonal polyneuropathy like diabetic polyneuropathy (DPN), the distal part of the longer axons are affected earlier. In cases of minimal distal axonal changes, nerve conduction studies (NCS) are frequently normal. If sural nerve is affected in the early stage of DPN, supportive parameters to detect the early axonal degeneration may be helpful. We investigated whether the sural/ulnar SNAP amplitude ratio (SUAR) may be a more sensitive indicator than sural amplitude alone in the diagnosis of early diabetic polyneuropathy. Methods: We analyzed medical records and electrophysiological studies of 141 patients with DM and 30 healthy subjects. The patients with early stage of DPN were defined as those having symptoms of neuropathy and normal NCS findings among the patients with DM. We compared SUAR between 57 patients with early stage of DPN and 71 agematched control subjects. Results: Fifty seven patients had an average SUAR of 0.8, compared to that of 1.1 in the 71 normal controls. The SUAR of less than 0.9 was supplementary predictor of axonal polyneuropathy, with the best balance of sensitivity and specificity (70%). The SUAR did not vary significantly with age, height or duration of DM. Conclusions: We conclude that the SUAR is a useful electrodiagnostic indicator to detect early stage of DPN.

• Physical Therapy Korea
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• v.18 no.1
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• pp.93-103
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• 2011

This study was implemented to verify the feasibility of motor function recovery and the appropriate period for therapy. The research began with spinal laminectomy of 40 white rats of Sprague-Dawley breed and induced them spinal crush injury. Following results were obtained by using the modified Tarlov test (MTT), Basso, Beattle, Bresnahan locomotor rating scale (EBB scale) and modified inclined plate test (MIPT). First, the measurement using the MTT confirm that the most severe aggravation and degeneration of functions are observed two days after induced injury, and no sign of neuromotor function recovery. Second, better scores were achieved by open-ground movement group on BBB locomotor rating scale test, and weight-bearing on inclined plate group show better performance on MIPT. Third, both BBB and MIPT scale manifested the peak of motor function recovery during 16th day after the injury and turn into gradual recovery gradient during 16th to 24th. Fourth, the control group showed functional recovery, however, the level of recovery was less significant when compared with group open-ground movement group and weight-bearing on inclined plate group. Hence, it was clearly manifested that the lumbar region of the spinal cord had shown the best performance when its functions were measured after the execution of specific physical training; therefore it indicated the possibility of learning specific task even in damaged lumbar regions. Thus it is expected to come out with better and more effective functional recovery if concentrated physical therapy was applied starting 4 days after the injury till 16 days, which is the period of the most active recovery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.3
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• pp.239-247
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• 2005

This study demonstrated that xenogenic human marrow mesenchymal stem cells (hMSCs) could elicit the regeneration of the sensory nerve after axotomy in the adult rats infraorbital nerves without immunosuppression. For this, we evaluated the behavioral testing for functional recovery of the nerve and histological findings at weeks 3 and 5 compared to controls. Xenogenic hMSCs did not evoke any significant inflammatory or immunologic reaction after systemic and local administrations. HMSCs-treated rats exhibited significant improvement on sensory recovery tested with von Frey monofilaments. At 5 postoperative weeks, in the hMSCs treated nerve, expression of myelin basic protein (MBP), neurofilament (NF) at the site of axotomy was higher than control. And mRNA expression of neurotropin receptor Trk precursor (TrkPre), nerve growth factor receptor (NGFR) and neuropeptide (NPY) in trigeminal ganglion were also higher. The number of myelinated nerve at distal stump and cells in trigeminal ganglion were higher in hMSC treated rats. So it was supposed that transplanted MSCs contributed to reducing post-traumatic degeneration and production of neurotrophic factors. Immunofluorescence labeling showed small portion of hMSCs (<10%) expressed a phenotypic marker of Schwann cell (S-100). Xenogenic or allogenic mesenchymal stem cells might have immune privileged characteristics and useful tool for cell based nerve repair.