• The Korean Journal of Physiology and Pharmacology
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• v.13 no.6
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• pp.475-482
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• 2009

Rifampicin is a macrocyclic antibiotic which is used extensively for treatment against Mycobacterium tuberculosis and other mycobacterial infections. Recently, a number of studies have focused on the immune-regulatory effects of rifampicin. Therefore, we hypothesized that rifampicin may influence the TLR2 expression in LPS-activated RAW 264.7 cells. In this study, we determined that rifampicin suppresses LPS-induced TLR2 mRNA expression. The down-regulation of TLR2 expression coincided with decreased production of TNF-$\alpha$ Since NF-${\kappa}B$ is a major transcription factor that regulates genes for TLR2 and TNF-$\alpha$, we examined the effect of rifampicin on the LPS-induced NF-${\kappa}B$ activation. Rifampicin inhibited NF-${\kappa}B$ DNA-binding activity in LPS-activated RAW 264.7 cells, while it did not affect IKK$\alpha/\beta$ activity. However, rifampicin slightly inhibited the nuclear translocation of NF-${\kappa}B$ p65. In addition, rifampicin increased physical interaction between pregnane X receptor, a receptor for rifampicin, and NF-${\kappa}B$ p65, suggesting pregnane X receptor interferes with NF-${\kappa}B$ binding to DNA. Taken together, our results demonstrate that rifampicin inhibits LPS-induced TLR2 expression, at least in part, via the suppression of NF-${\kappa}B$ DNA-binding activity in RAW 264.7 cells. Thus, the present results suggest that the rifampicin-mediated inhibition of TLR2 via the suppression of NF-${\kappa}B$ DNA-binding activity may be a novel mechanism of the immune-suppressive effects of rifampicin.

• The Korean Journal of Physiology
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• v.23 no.1
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• pp.23-34
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• 1989

Gentamicin (GM) is a polybasic, aminoglycoside antibiotic used frequently for the treatment of serious gram-negative infections. The major limiting factors in the clinical use of GM as well as other aminoglycoside antibiotics are their nephrotoxicity and ototoxicity. The primary mechanism of cell injury in aminoglycoside toxicity appears to be the disruption of normal membrane function and the inhibition of $Na^{+}-K^{+}$ ATPase activity. There are both indirect and direct evidences which suggests that the effect of aminoglycoside antibiotics on $Na^{+}-K^{+}$ ATPase may explain, or contribute to, their toxicity. It has been shown that aminoglycoside reduce total ATPase activity (Kaku et al., 1973) and $Na^{+}-K^{+}$ ATPase activity (linuma et al., 1967) in the stria vascularis and spiral ligament of the guinea-pig cochlea. Lipsky and Lietman (1980) reported that aminoglycoside antibitoics inhibited the activity of $Na^{+}-K^{+}$ ATPase in microsomal fractions of the cortex and medulla of the guinea-pig kidney, isolated rat renal tubule and human erythrocyte ghosts. The present invstigation was undertaken to elucidate the mechanism of GM on human erythrocytes by examining its effect on $Na^{+}-K^{+}$ ATPase activity, actives sodium and potassium transport across red blood cell and $^{3}H-ouabain$ binding to red blood cell membranes. The results obtained are summarized as follows: 1) CM inhibited significantly both the activity of total ATPase and $Na^{+}-K^{+}$ ATPase at all concentrations tested. 2) GM inhibited active $^{22}Na$ efflux across red blood cell. When ouabain is present, the rate of $^{22}Na$ efflux was completely inhibited. When both GM and ouabain were added, the inhibitory effect of active $^{22}Na$ efflux was more pronounced. 3) Active $^{86}Rb$ influx was inhibited significantly by GM. In the presence of ouabain, the rate of $^{86}Rb$ influx is markedly inhibited. But $^{86}Rb$ influx is not appreciably altered by the presence of both GM and ouabain. 4) In the presence of GM, $^{3}H-ouabain$ binding to red blood cell membrane increased. From the above results, it may be concluded that the inhibition of active sodium and potassium transport across red blood cell by gentamicin appears to be due to the inhibition of $Na^{+}-K^{+}$ ATPase activity and an increase in ouabain binding to red blood cell membranes.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.140-145
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• 2005

Streptomyces natalensis ATCC27448 produces natamycin, a commercially important macrolide antifungal antibiotic. For molecular genetic study of S. natalensis, we have developed a system for introducing DNA into S. natalensis via conjugal transfer from Escherichia coli. An effective transformation procedure for S. natalensis was established based on transconjugation from E, coli ET12567/pUZ8002 using a ${\Phi}C31$-derived integration vector, pSET152, containing oriT and attP fragments. The high frequency was obtained on MS medium containing 10 mM $MgCl_2$ using $6.25\times10^8$ of E.coli donor cells without heat treatment of spores. In addition, southern blot analysis of exconjugants and the sequence of plasmids containing DNA flanking the insertion sites from the chromosome revealed that S. natalensis contains a single ${\Phi}C31$ attB site and at least a secondary or pseudo attB site. Similar to the case of various Streptomyces species, a single ${\Phi}C31$ attB site of S. natalensis is present within an ORF encoding a pirin-homolog, but a pseudo-attB site is present within a distinct site (GenBank accession no. $YP\_117731$) and also its sequence deviates from the consensus sequences of attB sequence.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.4
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• pp.447-455
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• 1995

Cavernous sinus thrombosis is one of the major complications of abscesses of the maxillofacial region. The initial symptoms of CST are usually pain in the eye and tenderness to pressure. this is associated with high fluctuating fever, chills, rapid pulse, and sweating. Venous obstruction subsequently causes edema of the eyelids, lacrimation, proptosis, chemosis and retinal hemorrhages. Blindness is sometimes an accompaniment of cavernous sinus thrombosis when the infection also involves the orbit. There is also cranial nerve involvement (oculomotor, troclear, abducence) and ophthalmoplegia, diminished or absent corneal reflex, ptosis, and dilation of the pupil occur. The terminal stages bring signs of advanced toxemia and meningitis. Infections of the face can cause a septic thrombosis of the cavernous sinus. Furunculosis and infected hair follicles in the nose are frequent causes. Extractions of maxillary anterior teeth in the presence of acute infection and especially curettage of the sockets under such circumstances can cause this condition. The infection is usually staphylococcal. The inflection may spread directly through the pterygoid plexus of veins and the pterygomaxillary space and then ascend into the sinus or it may spread directly from the pterygopalatine space to the orbit. This is possible because of the absence of valves in the angular, facial, and ophthalmic veins. The treatment is empirical antibiotic therapy followed by specific anbibiotic therapy based on blood or pus culture. The inflection usually involves one side, however, it may easily spread to the opposite side through the circulus sinus. Unless it is treated early, the prognosis is poor even in this doses. Occasionally the antibiotics will not adequately resolve the septic thrombus, and death ensues. the use of anticoagulants to prevent venous thrombosis has been recommended, but the efficacy of such therapy has not been substantiated. Surgical access through eye enucleation has been suggested. We report a case which demonstrates cavernous sinus thrombosis by the infection after the functional neck dissection and the intraoral reconstruction with auriculomastoid fascio-cutaneous island flap.

• Pediatric Infection and Vaccine
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• v.27 no.2
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• pp.83-89
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• 2020

Purpose: Group A streptococcus (GAS) is a common pathogen in pediatric patients and often causes acute pharyngotonsillitis and skin and soft tissue infections. In addition, bacteremia with significant morbidity and mortality can also occur. This study was conducted to describe the clinical manifestations and treatment outcomes of pediatric GAS bacteremia patients in Korea. Methods: This was a single-center, retrospective study. From January 2000 to December 2016, pediatric patients aged ≤18 years with GAS bacteremia were studied. Clinical manifestations, underlying diseases, intensive care unit stay, and antibiotic susceptibility were evaluated. Results: During the study period, 19 patients had GAS bacteremia. Ten (53%) were male, and the median age was 7.4 years (range, 0.3-17.4 years). Fourteen (74%) had chronic underlying diseases. Five (26%) were immunocompromised (leukemia and chronic kidney disease). Eight (42%) had lymphatic or vascular malformations, of which seven had lesions with signs of inflammation. Three (16%) developed pneumonia, and two of them received ventilator care. The 30-day mortality rate was 6% (1/19), and the cause of death was bacteremic pneumonia. All GAS isolates were sensitive to penicillin. Fifteen (79%) were sensitive to both erythromycin and clindamycin. Conclusions: This study identified various clinical manifestations of GAS bacteremia. GAS should be considered as a potential pathogen that can cause bacteremia and result in a serious clinical course.

• Journal of Life Science
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• v.19 no.10
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• pp.1438-1443
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• 2009

Renal fibrosis is a final common manifestation of every type of chronic kidney disease. Plasminogen activator inhibitor (PAI)-1 is induced by lipopolysaccharide (LPS) and is known to play an essential role in the progress of renal fibrosis. In this paper, we found that an isoprenoid antibiotic, ascofuranone (AF), suppresses expression of profibrotic factors, PAI-1 and promoter activity of PAI-1 induced by LPS in rat kidney fibroblast cells. We therefore investigated signaling pathway mediated inhibitory effects of LPS-induced PAI-1 by AF in rNRK-49F cells. PAI-1 expression is suppressed by treatment with kinase inhibitors for MEK-1/2, as it isin inhibition of PAI-1 expression by AF, and AF inhibits phosphorylation of ERK-1/2. This study suggest that AF suppresses expression of PAI-1 through the inhibition of an ERK-1/2-dependent signal transduction pathway. The data indicates the possibility that AF can be used to prevent the development and progression of renal fibrosis.

• Journal of fish pathology
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• v.27 no.1
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• pp.77-83
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• 2014

The monitoring was performed to survey the mortalities and medications occurred in the inland aquaculture farms of olive flounder in South Korea from May to October, 2012. Both of the indirect inquiry for entire inland farms and the sample survey for selected farms were carried out. The aquatic organism disease inspectors, who have the national licenses for the diagnosis and prevention of aquatic organism diseases and have close relationship with the farms, investigated the rates and causes of mortalities according to the standard manual. The cumulative mortalities rate by the indirect inquiry on 565 farms, was calculated to 27.18%, and the mortalities rate by infectious diseases was 22.64%. Otherwise, the mortalities rate by sample survey on 60 farms was 25.50%, 19.33% of them were caused by infectious diseases. The high mortality rates were recorded by scuticociliatosis, non-infectious loss, streptococcosis, VHS, artificial eliminations, vibriosis and gliding bacterial disease. Streptococcosis and non-infectious mortality caused to serious loss in productivity and economy of the farms, because of their outbreaks in the flounder groups over 600 g. The monitoring of medications in the selected farms revealed that formalin for the treatment of external parasites, such as scuticociliates, was the most commonly used drugs in the farms. As the antibiotic medications, amoxicillin and florfenicol for streptococcosis, and oxytetracycline and neomycin expecting wide antibacterial spectrum, were frequently prescribed.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1453-1461
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• 2007

This study was conducted to test the hypothesis that dietary supplementation with an herbal extract of Acanthopanax senticosus (AS) enhances the immune response in weaned piglets. Sixty piglets weaned at 21 days of age were randomly assigned to 3 treatment groups representing the addition of 0 or 1 g/kg of the AS extract or 0.2 g/kg of colistin (an antibiotic) to maize- and soybean meal-based diets (n = 20 per group). On days 7, 14 and 28 after initiation of the addition, total and differential counts of leucocytes, proliferating activity of peripheral lymphocytes, serum levels of immunoglobulins (Ig) and cytokines and the spleen index were determined. The AS extract decreased (p<0.05) the number of neutrophils on days 7 and 28 in comparison with the control group and reduced (p<0.05) serum interleukin-$1{\beta}$ level on day 28 compared with the other 2 groups. Dietary supplementation with the AS extract increased (p<0.05) the lymphocyte/leukocyte ratio on day 28 compared with the control group and increased the proliferating activity of lymphocytes on days 14 and 28 compared with the other 2 groups. The AS extract increased (p<0.05) the serum content of IgG on day 7 and of IgG and IgM on day 28 compared with the other 2 groups, as well as increasing the serum content of tumor necrosis factor on day 7 and spleen index on days 7 and 28 compared with the control group. Collectively, these findings suggest that the AS extract as a dietary additive enhances the cellular and humoral immune responses of weaned piglets by modulating the production of immunocytes, cytokines and antibodies.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.137-141
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• 2007

This experiment was conducted to investigate the effects of dietary yeast (Saccharomyces exguus) supplementation on growth performance, cecal microflora and fecal ammonia gas in broiler chicks. A total of two hundred seventy, 1-d-old male broiler chicks (Ross strain) were randomly allotted to nine pens (replicates), 30 birds per pen. There were three dietary treatments with three replicates. The treatments were control (virginiamycin 0.05%+salinomycin 0.03%), Saccharomyces exguus 0.5 and 1.0%. Total body weight gain were significantly higher in Saccharomyces exguus1 1.0% treatment than the control (P<0.05). Although not significant, the yeast supplementation tended to improve the feed conversion ratio. No significant differences were observed on the numbers of cecal E. coli, Salmonella and Lactobacillus in yeast treatments compared to those of control. The production of fecal ammonia gas was significantly lower in yeast treatments than the control (P<0.05). The concentrations of fecal short chain fatty acids and volatile organic compounds were not different among the groups. These results suggest the possibility that yeast (Saccharomyces exguus) could be used as the alternative of antibiotic growth promoters by improving the performance of broiler chicks. In addition, dietary yeast could improve the environment of broiler houses by reducing fecal ammonia production.

• Pediatric Infection and Vaccine
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• v.21 no.2
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• pp.144-149
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• 2014

Acute otitis media (AOM) is one of the most common childhood infectious diseases. Despite antibiotic treatment for AOM, AOM and its complication still continue to develop. Acute mastoiditis is a serious complication of AOM and epidural abscess constitutes the commonest of all intracranial complication of AOM. Neurological complication of acute mastoiditis are rare but can be life threatening. Their presentation may be masked by the use of antibiotics. We report the rare case of acute otitis media progressing to acute mastoiditis, epidural abscess formation and lateral sinus thrombophlebitis caused by Streptococcus pneumoniae in a child. She was admitted with acute otitis media with fever. Despite proper antibiotics, acute mastodititis and epidural abscess were developed, and after surgical drainage and antibiotics therapy she was recovered without sequalae.