• Reproductive and Developmental Biology
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• v.34 no.2
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• pp.89-94
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• 2010

Melatonin is induced by light information through the retina and leads to growth factor activation. Thus, we investigated the effects of melatonin by controlling the photoperiod of growing young rats. Male Sprague-Dawley rats (n=6; 4 weeks old) were divided into two experimental groups: the L/D group (normal photoperiod; light/dark: 12/12 h; lights on at 9:00 a.m.) and the L/L group (light/light: 24 h). Rat body weight and food consumption were measured daily for 8 weeks. After 8 weeks, the rats were anesthetized with a mixture of ketamine (50 mg/kg) and xylazine (10 mg/kg) and sacrificed. Tissue was then collected for RNA isolation (from brain, heart, liver, kidney, adrenal gland, testis, tibia, hind limb muscles). Also, serum was isolated from blood using a centrifugal separation. The L/L group had significantly lower body weight than the L/D group from 4 to 6 weeks (p<0.05). The L/D group had increased tissue mass, compared with the L/L group, but the difference was not statistically significant. The L/D group had a significantly higher melatonin concentration than the L/L group between the hours of midnight and 2:00 a.m (p<0.01). These results indicate that photoperiod length may affect the secretion of melatonin from the pineal gland. Also, the reduction of nocturnal melatonin secretion may retard the development of growing young rats. In future studies, we plan to compare exogenous melatonin administration with endogenous melatonin concentration induced by photoperiod control. Moreover, we will confirm whether the effects seen in pathological animal models can be reversed by controlling the photoperiod.

• Journal of Ginseng Research
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• v.39 no.2
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• pp.169-177
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• 2015

Background: Ginsenoside Rd (GSRd), one of the most abundant ingredients of Panax ginseng, protects the heart via multiple mechanisms including the inhibition of $Ca^{2+}$ influx.We intended to explore the effects of GSRd on L-type $Ca^{2+}$ current ($I_{Ca,L}$) and define the mechanism of the suppression of $I_{Ca,L}$ by GSRd. Methods: Perforated-patch recording and whole-cell voltage clamp techniques were applied in isolated rat ventricular myocytes. Results: (1) GSRd reduced $I_{Ca,L}$ peak amplitude in a concentration-dependent manner [half-maximal inhibitory concentration $(IC_{50})=32.4{\pm}7.1{\mu}mol/L$] and up-shifted the current-voltage (I-V) curve. (2) GSRd ($30{\mu}mol/L$) significantly changed the steady-state activation curve of $I_{Ca,L}$ ($V_{0.5}:-19.12{\pm}0.68$ vs. $-6.26{\pm}0.38mV$; n = 5, p < 0.05) and slowed down the recovery of $I_{Ca,L}$ from inactivation [the time content (${\zeta}$) from 91 ms to 136 ms, n = 5, p < 0.01]. (3) A more significant inhibitive effect of GSRd ($100{\mu}mol/L$) was identified in perforated-patch recording when compared with whole-cell recording [$65.7{\pm}3.2%$ (n = 10) vs. $31.4{\pm}5.2%$ (n = 5), p < 0.01]. (4) Pertussis toxin ($G_i$ protein inhibitor) completely abolished the $I_{Ca,L}$ inhibition induced by GSRd. There was a significant difference in inhibition potency between the two cyclic adenosine monophosphate elevating agents (isoprenaline and forskolin) prestimulation [$55{\pm}7.8%$ (n = 5) vs. $17.2{\pm}3.5%$ (n = 5), p < 0.01]. (5) 1H-[1,2,4]Oxadiazolo[4,3-a]-quinoxalin-1-one (a guanylate cyclase inhibitor) and N-acetyl-$\small{L}$-cysteine (a nitric oxide scavenger) partly recovered the $I_{Ca,L}$ inhibition induced by GSRd. (6) Phorbol-12-myristate-13-acetate (a protein kinase C activator) and GF109203X (a protein kinase C inhibitor) did not contribute to the inhibition of GSRd. Conclusion: These findings suggest that GSRd could inhibit $I_{Ca,L}$ through pertussis toxin-sensitive G protein ($G_i$) and a nitric oxide-cyclic guanosine monophosphate-dependent mechanism.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.2
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• pp.449-459
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• 1997

The main component of dental plaque is the mutan containing the a-1,3 bond. The following results were obtained by using a blue mutan to assess the factors affecting the mutan-digesting activity of Streptomyces exfoliatus isolated from soil. A clear zone was produced by mutanase-producing Streptomyces exfoliatus on the minimal essential agar containing blue mutan. Streptomyces exfoliatus digested more blue mutan in the minimal essential broth at pH 7.0 than at pH 5.5 or 8.5. Streptomyces exfoliatus digested more blue mutan at $37^{\circ}C$ than at $32^{\circ}C$ or $42^{\circ}C$ (P<0.05). When the concentration of $CaCl_2$ was increased in the minimal essential broth, the digestion of blue mutan was increased (P<0.05). The optimal concentration of KCl was 10mM to digest blue mutan, but a similar amount of blue mutan was digested at the range of 0.1mM to 6.4mM of $MgCl_2$. When the culture supernatant of Streptomyces exfoliatus was mixed with 2X brain heart infusion broth containing 0.5% yeast extract and 10% sucrose, less artificial plaque was formed by Streptococcus mutans on the orthodontic wire (P<0.05). These results indicated that the secretion of mutanase was identified in culture supernatant of mutan-digesting Streptomyces exfoliatus, suppressing the formation of artificial plaque by Streptococcus mutans.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.302-307
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• 2014

Many rhizobacteria can promote plant growth through various direct or indirect mechanisms, and their production of phytohormones such as indole-3-acetic acid (IAA) may have pronounced effects on growth and development of plants. Rhizobacterial strain isolated from rhizosphere of foxtail (Setaria viridis), Acinetobacter sp. SW5 produced 118.1 mg/L of IAA and 4.5 mg/L of gibberellin ($GA_3$) in brain heart broth medium at 2 and 1 day of incubation, respectively. In a pot test the lengths of stem and root and fresh weight of the germinated tomato seedlings treated with Acinetobacter sp. SW5 significantly increased by 26.3, 33.3, and 105.3%, respectively compared to those of the uninoculated control in 12 weeks of cultivation. When the root exudate secreted from tomato seedlings was analyzed by HPLC, 3.75 ng mg tomato $root^{-1}$ of tryptophan which is an IAA precursor was detected. Acinetobacter sp. SW5 could produce $4.06{\mu}M$ of IAA from root exudate from 8 tomato seedlings. Together with the capability of growth of Acinetobacter sp. SW5 in the tomato root exudates, this IAA secreted by bacteria might contribute to enhance the growth of tomato plants.

• Tuberculosis and Respiratory Diseases
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• v.69 no.6
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• pp.426-433
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• 2010

Background: Persistent cough has recently been found to be associated with Chlamydia pneumoniae infection. We aimed to investigate the infection rate of C. pneumonia in adult patients with chronic cough. Methods: We recruited 68 patients with persistent cough lasting in excess of 3 weeks, who visited Kangdong Sacred Heart Hospital from January 2005 to August 2005. On the first visit, chest and paranasal sinuses radiography, skin prick test of common allergens, and induced sputum samples for C. pneumoniae were performed in all of patients. Further evaluation for diagnosis included a methacholine provocation test and eosinophil counts in induced sputum. Results: The most common cause of chronic cough was upper airway cough syndrome (UACS) (26.5%), followed by eosinophilic bronchitis (20.6%) and cough variant asthma (16.2%). Idiopathic chronic cough was the cause in 33.8% of patients. The mean duration of cough was 11.7 months. C. pneumoniae was isolated by polymerase chain reaction (PCR) from one patient who had upper respiratory air way syndrome. Conclusion: Chlamydia pneumoniae appears to have a minor role as a cause of chronic cough in patients.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.486-492
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• 2013

Recently, a new disease showing symptoms such as epidermal exfoliation and muscular necrosis occurred in cultured Korean catfish. Although the mortality of fishes was low but the economic damages owing to loss of commercial value were severe. The authors isolated the causative agent from diseased fish and observed pathological changes both in naturally and artificially infected fish. The causative bacteria was identified as Aeromonas veronii. Subsequently we observed the daily death and pathological symptoms of artificially infected fish with Aeromonas veronii. Symptoms of artificially infected fish were similar to those of naturally infected fish and all fish died within 7 days after infection. Histopathological changes on the naturally infected fish revealed severe congestion and necrotic degeneration in the liver, spleen and kidney. Some bacterial aggregates with inflammatory degeneration were observed in the heart, and congestion and fibrosis in the lamina propria of digestive tube were predominant. In artificially infected fish, skin erosion and necrotic degeneration of muscle tissue around injected region were particularly manifested. Degeneration of hepatocytes in liver and hyalic degeneration around ellipsoids in spleen were partially observed. However, there were no predominant signs in digestive tube in artificially infected fish.

• Journal of Chest Surgery
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• v.32 no.3
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• pp.262-269
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• 1999

Background: To review the middle and long term results of aortic valve replacement(AVR) for 11 years, we surveyed and followed up the patients who underwent AVR. Material and Method: Between Feb. 1986 and May 1997, 134 patients underwent AVR. The patients consisted of 71 men and 63 women whose mean age was 38.9 years, ranging from 17 to 70. Result: The concomitant operations were 62 mitral valve replacement(MVR), 14 MVR + tricuspid valve annuloplasty, 10 Cabrol operation, 16 aortic annulus widening, and so forth. We used 119 mechanical(75 St. Jude Medical, 38 CarboMedics, 6 Sorin) and 15 tissue (Carpentier-Edwards) valves. Early postoperative complications occurred in 35 cases; 9 congestive heart failure, 6 low cardiac output, 5 postoperative bleeding, 5 pleural effusion, and so forth. There were 13 early postoperative deaths(9.7%) due to low cardiac output(5), CHF (2), disseminated intravascular coagulopathy(2), and so forth. The cumulative total follow-up period was 452.7 patient-years with a mean of 3.4${\pm}$3.1 years/patient. There were 9 cases of valve-related complications; anticoagulant-related bleeding(4), prosthetic valve endocarditis(2), thromboembolism(2) and prosthetic valve failure(1) occured at rate of 0.9, 0.4, 0.4, 0.2%/ pt-yr, respectively. Late valve-related death occurred in 3 cases(2.0%/pt-yr) associated with anticoagulant-related bleeding(2) and prosthetic valve endocarditis(1). Conclusion: Actuarial survival rate by Kaplan-Meier method was 91.0${\pm}$4.3 % at 11 years.

• Journal of fish pathology
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• v.13 no.2
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• pp.121-127
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• 2000

From August to October 1998, over 60% mortality of cultured striped beakperch Oplegnathus fasciatus was occurred in net cages along the southern coast of Korea. Moribund fish showed some clinical signs of lethargic behavior, dark coloration or decoloration, severe gill anemia and enlargement of spleen. Also enlarged basophilic cells showing Feulgen -positive reaction were observed in the tissue section of spleen, kidney, liver and heart of the diseased fish. GF cells inoculated with spleen homogenate of diseased fish produced cytopathic effect of enlarged and rounded cells, therefore the causative virus was isolated from diseased fish. Striped beakperch fingerlings intraperitoneally inoculated with the causative virus ($10^4TCID_{50}$/0.1 ml) revealed symptoms similar to those of naturally infected fish and died from 7 to 14 days post injection. Transmission electron microscopy revealed that the causative virus was enveloped icosahedral particle with 120~130 nm in diameter. PCR products of the expected size (500 bp) were amplified with a primer set based on the ATPase gene of RSIV(red sea bream iridovirus) using template DNAs which were extracted from the spleen of diseased fish and GF cells inoculated with the causative virus. According to the analysis of nucleotide sequence of these PCR products, the sequence from ATPase cDNA gene of the causative virus showed 95% homology with that of RSIV. These results indicate that the mass mortality in the cultured striped beakperch was caused by the infection of iridovirus similar to RSIV.

• Clinical and Experimental Emergency Medicine
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• v.3 no.3
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• pp.175-180
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• 2016

Objective Combination of ${\beta}_1-adrenergic$ receptor (AR) blockade and ${\beta}_2-AR$ activation might be a potential novel therapy for treating heart failure. However, use of ${\beta}-AR$ agonists and/or antagonists in the clinical setting is controversial because of the lack of information on cardiac inotropic or chronotropic regulation by AR signaling. Methods In this study, we performed hemodynamic evaluation by examining force frequency response (FFR), Frank-Starling relationship, and response to a non-selective ${\beta}-AR$ agonist (isoproterenol) in hearts isolated from 6-month-old transgenic (TG) mice overexpressing ${\beta}_1-$ and ${\beta}_2-ARs$ (${\beta}_1-$ and ${\beta}_2-AR$ TG mice, respectively). Results Cardiac physiologic consequences of ${\beta}_1-$ and ${\beta}_2-AR$ overexpression resulted in similar maximal response to isoproterenol and faster temporary decline of positive inotropic response in ${\beta}_2-AR$ TG mice. ${\beta}_1-AR$ TG mice showed a pronounced negative limb of FFR, whereas ${\beta}_2-AR$ TG mice showed high stimulation frequencies with low contractile depression during FFR. In contrast, Frank-Starling relationship was equally enhanced in both ${\beta}_1-$ and ${\beta}_2-AR$ TG mice. Conclusion Hemodynamic evaluation performed in the present showed a difference in ${\beta}_1-$ and ${\beta}_2-AR$ signaling, which may be due to the difference in the desensitization of ${\beta}_1-$ and ${\beta}_2-ARs$.

• Journal of Life Science
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• v.32 no.1
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• pp.44-50
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• 2022

The migration and proliferation of keratinocytes are key events in re-epithelization, itself a major phase in the wound healing process. Cuscuta japonica Choisy (CJC) is used as a traditional medicine to improve liver, heart, and intestinal function, and its extracts are reported to have various biological properties such as whitening, anti-oxidancy, and an anti-acne effect. However, it is not yet known in particular whether or not CJC essential oil (CJCEO) affects skin regeneration. In the present study, we isolated CJCEO by solvent extraction and tested its effect on wound healing responses using normal human keratinocytes, namely HaCaT cells. We found that CJCEO induced proliferation as well as migration in HaCaT cells in a dose-dependent manner. Compared with a control group, CJCEO treatment at 250 ㎍/ml increased proliferation by 239.98±5.51% in HaCaT cells in a dose and migration by 124.86±6.06%. Moreover, the oil induced sprout outgrowth and, at 250 ㎍/ml, increased collagen synthesis by 148.56±15.47% in HaCaT cells. These results demonstrate that CJCEO may promote skin regeneration and wound healing by increasing the migration, proliferation, and collagen synthesis of HaCaT cells. We therefore suggest that CJCEO could be used as a cosmetic material.