• Tuberculosis and Respiratory Diseases
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• v.54 no.5
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• pp.532-541
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• 2003

Background : Phospholipase $A_2$ ($PLA_2$) has been known to be involved in the pathogenesis of acute lung injury (ALI) including ARDS. Since doxycycline has the property of inhibiting secretory group II $PLA_2$, the therapeutic effect of doxycycline hyclate was investigated for gut ischemia/reperfusion (I/R)-induced ALI in Sprague-Dawley rats. Methods : ALI was induced in Sprague-Dawley rats by clamping of the superior mesenteric artery for 60 min, followed by 120 min of reperfusion. To confirm the pathogenetic mechanisms of this ALI associated with neutrophilic oxidative stress, we measured bronchoalveolar lavage (BAL) protein content and lung MPO, and performed cyto-chemical electron microscopy for detection of free radicals, assay of $PLA_2$ activity and cytochrome-c reduction assay. Results : In gut I/R-induced ALI rats, protein leakage, pulmonary neutrophil accumulation, free radical production and lung $PLA_2$ activity were all increased. These effects were reversed by doxycycline hyclate. Conclusion : Doxycycline appears to be effective in ameliorating the gut I/R-induced ALI by inhibiting $PLA_2$, thereby decreasing the production of free radicals from neutrophils.

• 대한치주과학회:학술대회논문집
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• 1999.11a
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• pp.78-78
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• 1999

• Proceedings of the KTCVS Conference
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• 1995.10a
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• pp.133-133
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• 1995

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.264.1-264.1
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• 2000

• Fibers and Polymers
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• v.7 no.1
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• pp.1-7
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• 2006

Interaction of a representative antibiotic, doxycycline(Doxy), with commercial poly(acrylonitrile) (PAN) and cationic-dyeable poly(ethylene terephthalate)(PET) fiber was studied in development of infection resistant biomedical materials. Regular PET was also employed for a comparison purpose. Their interactions were investigated at different treatment temperatures, times, and pHs. Fibers were also hydrolyzed by 1% NaOH for 1 or 2 hours at $85^{\circ}C\;and\;100{\circ}C$ to study effect of hydrolysis on antibiotic sorption. Infection-resistant characteristics of the substrates were evaluated by zone of inhibition (ZOI) test. Results revealed that a significant chemical change occurred in PAN and cationic-dyeable PET due to hydrolysis. Additional functional groups obtained by hydrolysis not only enhanced sorption of the antibiotics but also provided greater ZOI values, indicating substantial improvement in sustained infection resistance properties.

• Journal of Veterinary Clinics
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• v.20 no.1
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• pp.86-90
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• 2003

Little is known to data about the in vitro activity of antimicrobial agents aganist Brucella cams (B cams) isolated from Korea. Our study aimed at determining the in vitro activities of 15 antimicrobial agents against 3 isolates and 52 isolates of B cams from dogs in 1994 and 2002, respectively. In minimal inhibitory concentration (MIC) study, minocycline and doxycycline showed the lowest MICs ( < 0.06-0.5 ug/ml). Gentamicin, streptomycin, ciprofloxacin, norfloxacin and rifampin showed MICs in the range of less than 1 ug/ml. Lincomycin and sulfisox azole showed the highest MICs ( > 32 ug/ml). Interestingly, MICs of macrolides (erythromycin, spiramycin, tylosin) against 52 isolates in 2002 were 16-64 times higher than that of 3 isolates in 1994. In minimal bactericidal concentration (MBC) study, gentamicin, streptomycin, ciprofloxacin and norfloxacin showed the lowest MBCs [0.12-1 ug/ml (1-2 times higher than MIC)], but minocycline and doxycycline showed the highest MBCs [8-32 ug/ml (128 times higher than MIC)]. Rifampin showed the MBCs in the range from 2 to 4 ug/ml (2-4 times higher than MIC).

• International Journal of Oral Biology
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• v.39 no.2
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• pp.115-120
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• 2014

Minimal inhibitory concentration (MIC) is the lowest concentration of antibiotics that inhibits the visible growth of a microorganism. It has been reported that sub-MIC of antibiotics may result in morphological alterations along with biochemical and physiological changes in bacteria. The purpose of this study was to examine morphological changes of periodontal pathogens after treatment with sub-MIC antibiotics. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis were used in this study. The MIC for amoxicillin, doxycycline, metronidazole, penicillin, and tetracycline were determined by broth dilution method. The bacterial morphology was observed with bright field microscope after incubating with sub-MIC antibiotics. The length of A. actinomycetemcomitans and F. nucleatum were increased after incubation with metronidazole; penicillin and amoxicillin. P. gingivalis were increased after incubating with metronidazole and penicillin. However, F. nucleatum showed decreased length after incubation with doxycycline and tetracycline. In this study, we observed that sub-MIC antibiotics can affect the morphology of periodontal pathogens.

• IMMUNE NETWORK
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• v.20 no.6
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• pp.47.1-47.13
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• 2020

Tetracyclines, which have long been used as broad-spectrum antibiotics, also exhibit a variety of nonantibiotic activities including anti-inflammatory and immunomodulatory properties. Tetracyclines bind to the 30S ribosome of the bacteria and inhibit protein synthesis. Unlike antimicrobial activity, the primary molecular target for the nonantibiotic activity of tetracycline remains to be clarified. Nonetheless, the therapeutic efficacies of tetracyclines, particularly minocycline and doxycycline, have been demonstrated in various animal models of autoimmune disorders, such as multiple sclerosis, rheumatoid arthritis, and asthma. In this study, we summarized the anti-inflammatory and immunomodulatory activities of tetracyclines, focusing on the mechanisms underlying these activities. In addition, we highlighted the on-going or completed clinical trials with reported outcomes.

• The Korean Journal of Pharmacology
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• v.11 no.2
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• pp.47-53
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• 1975

Pan-Korean multi-center trial of doxycycline in the treatment of upper and lower respiratory infection was carried out in the summer(from May to October) of 1975. A total of 204 patients between the ages of 3 and 75 was treated by 37 physicians including the internal medicine, pediatrics and ENT specialist in 17 general hospitals and 2 private clinics all-over the country. The dosage recommended was 200 mg on the first day of therapy followed by 100 mg daily thereafter. The pediatric dosage was 4 mg/kg on the first day and then 2mg/kg on each successive day. The subjective and objective signs of respiratory infection such as temperature, cough, sputum, pain and associated inflammatory symptoms were assessed using the carefully designed protocols and it showed rapid improvement by the fifth day (80%) of therapy. Only minor side-effects were reported and these were mild and mainly limited to gastrointestinal tract. The overall evaluation of the trial showed that 170 patients(83.3%) had a very good or good result, 13 patients (6.4%) a moderate and another 13 patients (6.4%) a negative result.

• Journal of Periodontal and Implant Science
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• v.52 no.1
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• pp.39-53
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• 2022

Purpose: This study evaluated the systemic and local effects of doxycycline (DOX) and low-intensity laser (LIL) treatment as adjuvants to scaling and root planing (SRP) in the treatment of experimental periodontitis in rats. Methods: The sample consisted of 180 male rats (Rattus norvegicus albinus, Wistar), of which 30 did not receive induction of periodontal disease (negative control [NC] group) and 150 received induction of periodontal disease in the lower first molar. After 7 days, the ligature was removed, and the animals were divided into the following groups: NT (no treatment), SRP (SRP), DOX (SRP and DOX irrigation), LIL (SRP and laser irradiation), and DOX+LIL (SRP, DOX, and LIL). The animals were euthanized at 7, 15, and 30 days; thereafter, biochemical, radiographic, histological, and immunohistochemical analyses were performed. Results: In the intragroup analysis, lower concentrations of α-1-glycoprotein acid (α-1-Ga) and complement 3 (C3) were observed in the DOX+LIL group than in all other groups at all time points, as well as lower levels of complement 4 (C4) at 15 and 30 days (P<0.001). Less bone loss was observed in the DOX, LIL, and DOX+LIL groups than in the NC and SRP groups at all time points (P<0.001). There was a smaller number of tartrate-resistant acid phosphatase (TRAP)-positive cells in the DOX+LIL group than in the other groups at all time points (P<0.001). Positive correlations were observed between the systemic levels of α-1-Ga, C3, and C4 and the number of TRAP-positive cells. Conclusions: The combination of DOX with LIL as SRP adjuvants was effective both systemically and locally for the treatment of experimental periodontitis in rats.