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Journal of Medical Microbiology Apr 2008Current prophylaxis for infected tick bites consists of personal protective measures directed towards ticks. This study compared the efficacy of a single oral dose of...
A sustained-release formulation of doxycycline hyclate (Atridox) prevents simultaneous infection of Anaplasma phagocytophilum and Borrelia burgdorferi transmitted by tick bite.
Current prophylaxis for infected tick bites consists of personal protective measures directed towards ticks. This study compared the efficacy of a single oral dose of doxycycline with that of a single injection of sustained-release doxycycline in a model of Lyme borreliosis and Anaplasma phagocytophilum infection. Dosages of doxycycline were equilibrated based on previously determined peak plasma levels in mice [oral, 2.4 microg (ml plasma)(-1); sustained release, 1.9 microg (ml plasma)(-1)] determined 8 h after inoculation. In challenge experiments where five Borrelia burgdorferi-infected and five A. phagocytophilum-infected nymphs were used per mouse, only 20 and 30 % of mice were protected from B. burgdorferi and A. phagocytophilum infection, respectively, using oral doxycycline. In contrast, 100 % of mice receiving sustained-release doxycycline were protected from A. phagocytophilum infection, as indicated by real-time PCR of blood samples, quantitative PCR and culture isolation of spleen samples, and protected against B. burgdorferi infection as demonstrated by culture of ear, heart and bladder. Although 15-40 copies of A. phagocytophilum could be amplified from the spleens of mice treated with sustained-release doxycycline, no viable A. phagocytophilum from these spleens could be cultured in HL-60 cells. In contrast, 7/10 mice receiving oral doxycycline were PCR- and culture-positive for A. phagocytophilum, with copy numbers ranging from 800 to 10 000 within the spleen, as determined by quantitative PCR. Other correlates with A. phagocytophilum infection included a significant difference in spleen mass (mean of 110 mg for sustained-release treatment versus a mean of 230 mg for oral treatment) and the number of splenic lymphoid nodules (mean of 8 for sustained-release treatment versus mean of 12.5 for oral doxycycline) as determined by histopathology. These studies indicate that a single injection of a sustained-release formulation antibiotic may offer a viable prophylactic treatment option for multiple infectious agents in patients presenting with tick bites.
Topics: Anaplasma phagocytophilum; Animals; Anti-Bacterial Agents; Antibiotic Prophylaxis; Borrelia burgdorferi; Delayed-Action Preparations; Doxycycline; Ehrlichiosis; Female; Humans; Insect Bites and Stings; Ixodes; Lyme Disease; Mice; Mice, Inbred C3H; Treatment Outcome
PubMed: 18349366
DOI: 10.1099/jmm.0.47535-0 -
Handbook of Experimental Pharmacology 2007Unlike recombinase-mediated gene manipulations, tetracycline (Tet)-controlled genetic switches permit reversible control of gene expression in the mouse. Trancriptional... (Review)
Review
Unlike recombinase-mediated gene manipulations, tetracycline (Tet)-controlled genetic switches permit reversible control of gene expression in the mouse. Trancriptional activation can be induced by activators termed tTA (Tet-Off) or rtTA (Tet-On) in the absence and presence of Tet, respectively. The Tet-Off and Tet-On systems are complementary, and the decision to choose one over the other depends on the particular experimental strategy. Both systems were optimized over the years and can now be used to develop mouse models.
Topics: Animals; Doxycycline; Gene Expression Regulation; Tetracyclines
PubMed: 17203651
DOI: 10.1007/978-3-540-35109-2_3 -
Giornale Di Batteriologia, Virologia,... 1970
Topics: Administration, Oral; Adult; Animals; Blood Proteins; Bone and Bones; Child; Doxycycline; Drug Resistance, Microbial; Humans; Mice; Oxytetracycline; Protein Binding; Staphylococcus; Tetracycline
PubMed: 5526406
DOI: No ID Found -
Journal of Periodontology Jun 2009The purpose of this study was to determine the effect of the active substance of three types of local delivery systems, doxycycline hyclate 10% (DOXY), chlorhexidine...
BACKGROUND
The purpose of this study was to determine the effect of the active substance of three types of local delivery systems, doxycycline hyclate 10% (DOXY), chlorhexidine gluconate, 2.5 mg (CHX), and minocycline hydrochloride, 1 mg (MINO), on osteoblastic cell proliferation and differentiation.
METHODS
There were four groups: control osteoblastic cells (OB) alone, OB + DOXY, OB + CHX, and OB + MINO. Trypan blue and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays were used to test osteoblastic cell viability. Cell differentiation was tested by measuring alkaline phosphatase levels. Osteoblast morphology was investigated by light and scanning electron microscopy.
RESULTS
At a concentration of 0.5 mg/ml, the Trypan blue test showed that DOXY, MINO, and CHX had significant toxicity effects on osteoblast cells compared to the control group, with a mean cell viability of 84%, 74%, and 51%, respectively (P <0.05). The MTT test showed that the control and DOXY groups were statistically significantly different (P <0.05) compared to CHX and MINO groups. The DOXY group showed a significantly higher alkaline phosphatase activity ( approximately 56%) than the control and MINO groups, and it was nearly 178% higher than the CHX group (P <0.05). The morphology of the osteoblasts seemed to be slightly altered when they were incubated with DOXY; however, with MINO, they appeared rounded with minimal attachment. In the CHX group, the osteoblasts assumed a shape of a very thin filopodia with a volcano-like nucleus.
CONCLUSIONS
At a concentration of 0.5 mg/ml, CHX and, to a lesser extent, MINO had a cytotoxic effect on osteoblast proliferation in vitro. However, DOXY seemed to enhance maturation and differentiation rather than proliferation. In addition to DOXY's beneficial effect as an adjunctive therapy to mechanical debridement in the treatment of periodontal disease, it may have an effect on periodontal regeneration.
Topics: Alkaline Phosphatase; Anti-Bacterial Agents; Anti-Infective Agents, Local; Biomarkers; Cell Adhesion; Cell Differentiation; Cell Nucleus; Cell Proliferation; Cell Shape; Cell Survival; Cells, Cultured; Chlorhexidine; Coloring Agents; Doxycycline; Drug Carriers; Female; Gels; Humans; Male; Microscopy, Electron, Scanning; Microspheres; Middle Aged; Minocycline; Osteoblasts; Pseudopodia; Tetrazolium Salts; Thiazoles; Trypan Blue
PubMed: 19485832
DOI: 10.1902/jop.2009.080574 -
International Journal of Nanomedicine 2020Despite recent advancements in surgical techniques, the repair of tendon rupture remains a challenge for surgeons. The purpose of this study was to develop novel...
BACKGROUND
Despite recent advancements in surgical techniques, the repair of tendon rupture remains a challenge for surgeons. The purpose of this study was to develop novel doxycycline-loaded biodegradable nanofibrous membranes and evaluate their efficacy for the repair of Achilles tendon rupture in a rat model.
MATERIALS AND METHODS
The drug-loaded nanofibers were prepared using the electrospinning process and drug release from the prepared membranes was investigated both in vitro and in vivo. Furthermore, the safety and efficacy of the drug-loaded nanofibrous membranes were evaluated in rats that underwent tendon surgeries. An animal behavior cage was employed to monitor the post-surgery activity of the animals.
RESULTS
The experimental results demonstrated that poly(D,L-lactide-co-glycolide) (PLGA) nanofibers released effective concentrations of doxycycline for more than 40 days post-surgery, and the systemic plasma drug concentration was low. Rats receiving implantation of doxycycline-loaded nanofibers also showed greater activities and stronger tendons post-operation.
CONCLUSION
Nanofibers loaded with doxycycline may have great potential in the repair of Achilles tendon rupture.
Topics: Absorbable Implants; Achilles Tendon; Animals; Doxycycline; Drug Delivery Systems; Drug Liberation; Membranes, Artificial; Nanofibers; Polylactic Acid-Polyglycolic Acid Copolymer; Rats; Rats, Sprague-Dawley; Tendon Injuries; Wound Healing
PubMed: 32021169
DOI: 10.2147/IJN.S217697 -
European Journal of Dermatology : EJD Jun 2023
Topics: Adult; Humans; Doxycycline
PubMed: 37594351
DOI: 10.1684/ejd.2023.4495 -
Oral Surgery, Oral Medicine, Oral... Apr 2014
Topics: Anti-Bacterial Agents; Doxycycline; Female; Humans; Male; Stomatitis, Aphthous
PubMed: 24556496
DOI: 10.1016/j.oooo.2013.12.411 -
European Journal of Pharmaceutical... Mar 2017Cholesterol has been widely used in drug delivery systems including implant. Doxycycline hyclate (DH)-loaded cholesterol in situ forming gels using N-methyl pyrrolidone...
Cholesterol has been widely used in drug delivery systems including implant. Doxycycline hyclate (DH)-loaded cholesterol in situ forming gels using N-methyl pyrrolidone as a solvent were prepared and investigated for their properties including viscosity, rheology, syringeability, gel formation, drug release, degradation and antimicrobial activities. The burst drug release of a DH-loaded in situ forming gel using cholesterol as the gelling agent was minimized when the amount of benzyl benzoate was increased. The viscosity of the system was increased as the amount of benzyl benzoate was increased with Newtonian flow. The systems were easy to inject into the target site because of their minimal force of syringeability. They could transform from solution into matrix-like structures, but formulations with higher concentrations of benzyl benzoate took a longer time. However, the degradability was decreased when the amount of benzyl benzoate was increased. These systems inhibited P. gingivalis, S. mutans and S. aureus effectively. DH-loaded cholesterol in situ forming gel system comprising 10% benzyl benzoate was the most suitable owing to its sustainable release manner for 10days and therefore was the proper formulation for periodontitis treatment.
Topics: Anti-Bacterial Agents; Bacteria; Benzoates; Cholesterol; Doxycycline; Drug Delivery Systems; Drug Liberation; Gels; Injections, Intraperitoneal; Periodontal Pocket; Pyrrolidinones; Rheology; Solvents; Viscosity
PubMed: 28027940
DOI: 10.1016/j.ejps.2016.12.023 -
Journal of the American Academy of... Nov 2005Subantimicrobial doses of doxycycline may improve outcomes in rosacea when combined with topical metronidazole and used as maintenance monotherapy. (Randomized Controlled Trial)
Randomized Controlled Trial
A randomized, double-blind, placebo-controlled trial of the combined effect of doxycycline hyclate 20-mg tablets and metronidazole 0.75% topical lotion in the treatment of rosacea.
BACKGROUND
Subantimicrobial doses of doxycycline may improve outcomes in rosacea when combined with topical metronidazole and used as maintenance monotherapy.
OBJECTIVE
The purpose of this study was to evaluate the safety and efficacy of doxycycline hyclate 20 mg (subantimicrobial dose doxycycline) administered twice daily as an adjunct to metronidazole 0.75% topical lotion in the treatment of rosacea.
METHODS
Patients received subantimicrobial doses of doxycycline twice daily plus metronidazole (n = 20) or placebo plus metronidazole (n = 20) for 12 weeks. Subantimicrobial-dose doxycycline or placebo monotherapy continued for 4 weeks. The primary efficacy measure was change from baseline in total inflammatory lesions at weeks 2 and 16.
RESULTS
Total inflammatory lesions were reduced significantly (P =.048) by week 4 and by all subsequent visits in the subantimicrobial-dose doxycycline/metronidazole group compared with placebo/metronidazole. Changes from baseline increased over time and were maintained during subantimicrobial-dose doxycycline monotherapy.
CONCLUSION
Adjunctive use of subantimicrobial dose doxycycline significantly reduced the clinical signs of rosacea compared with metronidazole alone and may be useful maintenance monotherapy.
Topics: Administration, Topical; Adult; Anti-Infective Agents; Double-Blind Method; Doxycycline; Drug Therapy, Combination; Female; Humans; Male; Metronidazole; Rosacea; Tablets
PubMed: 16243127
DOI: 10.1016/j.jaad.2005.04.069 -
Oral Health & Preventive Dentistry 2011The aim of this present clinical and microbiological study was to evaluate the efficacy of the association of locally delivered 10% doxycycline hyclate (Atridox®) with... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
The aim of this present clinical and microbiological study was to evaluate the efficacy of the association of locally delivered 10% doxycycline hyclate (Atridox®) with scaling and root planing in the periodontal treatment of smokers.
MATERIALS AND METHODS
Forty-five patients with chronic periodontitis having a minimum of two periodontal pockets (>5 mm) and satisfying the inclusion and exclusion criteria were selected. Sites were randomly assigned to scaling and root planing (SRP) or scaling and root planing followed by local application of 10% doxycycline hyclate (SRP-D). Plaque index (PI), gingival index (GI), periodontal pocket depth (PD), clinical attachment level (CAL) and total anaerobic colony count (TACC) were recorded at baseline, one month and three months respectively. Differences between baseline and each period were considered for analysis.
RESULTS
There was a significant reduction in plaque score, gingival score, periodontal pocket depth and total anaerobic colony count from baseline in both groups at all time intervals. Clinical attachment level showed a significant gain in both groups. However, PD reduction (P < 0.001) and CAL gain (P < 0.001) were significant in the test group as compared to control at the end of 3 months. Reduction in total anaerobic colony count from baseline was significant (P = 0.02) in the test group compared to control at the end of 3 months.
CONCLUSIONS
The use of locally delivered doxycycline may constitute an important adjunct for the treatment of chronic periodontitis in smokers.
Topics: Adult; Anti-Bacterial Agents; Bacteria, Anaerobic; Chronic Periodontitis; Dental Plaque Index; Dental Scaling; Doxycycline; Humans; Middle Aged; Periodontal Index; Smoking
PubMed: 21594208
DOI: No ID Found