The effect of a new wound dressing on wound healing: Biochemical and histopathological evaluation

Electrospinning process has gained importance in the production of wound dressings in recent years. The wound dressings prepared by electrospinning method provide many advantages over conventional wound dressings. The aim of this study was to assess the histological, biochemical, and immunohistochemical evaluation of collagen/doxycycline loaded nanofiber wound dressing in both acute and chronic wound healing. Full-thickness wound model was created on rats and rats were divided in two main groups: normoglycemic (acute) and hyperglycemic (chronic) groups. Each group was divided into three sub groups: not treated (control) group, treated with nanofiber wound dressing group and treated with commercial product group. Wound closure rates were measured. Oxidative events were investigated by biochemical analyses. In addition to histological studies, matrix metalloproteinase, tissue inhibitor of metalloproteinase, vascular endothelial growth factor, basic-fibroblast growth factor, and von Willebrand factor levels were investigated with immunohistochemical studies. According to the biochemical analyses, it was concluded that the nanofiber wound dressing helps to increase antioxidant capacity and decrease lipid peroxidation. Immunohistochemical studies showed that nanofiber wound dressing enhanced angiogenesis and shortened the inflammatory phase. It was concluded that an effective and safe prototype nanofiber wound dressing, which has similar wound healing effect to the commercial product, has been developed to be used in acute or chronic wound treatment.     

Tetracyclines for treating multidrug-resistant<Emphasis Type="Italic"> Acinetobacter baumannii</Emphasis> ventilator-associated pneumonia

Objective To report the use of tetracyclines for the treatment of multidrug-resistant Acinetobacter baumannii ventilator-associated pneumonia (VAP).Design Observational case series.Setting The Presley Regional Trauma Center located within the Regional Medical Center, Memphis, Tennessee, USA.Patients and participants Seven critically ill trauma patients with VAP caused by A. baumannii isolates that were resistant to all antibiotics tested except for doxycycline or minocycline.Interventions Patients were treated with IV doxycycline or minocycline for an average of 13.5 (range 9–20) days.Measurements and results Doxycycline or minocycline was successful in six of seven patients.Conclusions Doxycycline or minocycline may be effective for treating multidrug-resistant A. baumannii VAP.No financial support was used for this report.     

多西环素和博来霉素治疗恶性胸腔积液的疗效和不良反应分析

目的比较观察多西环素和博来霉素治疗恶性胸腔积液的疗效和毒副反应。方法将28例晚期肺癌合并恶性胸积液患者随机分为试验组和对照组各14例,均在给予“GP（吉西他滨＋顺铂）”方案化疗后行胸膜粘连术。试验组予以多西环素0．5g治疗,对照组予以博来霉素1mg／kg（45—60mg）治疗。每例患者至少完成1周期化疗后1周后评价疗效。结果试验组完全缓解4例,部分缓解7例,无效3例。对照组完全缓解3例,部分缓解7例,无效4例。2组,临床疗效比较差异无统计学意义（P〉0．05）。试验组不良反应发生率低于对照组,差异有统计学意义（P〈0．05）。结论多西环素与博来霉素治疗肺癌并恶性胸腔积液的疗效相当．但多西环素治疗的副反应相对较少。     

Dexamethasone and doxycycline functionalized nanoparticles enhance osteogenic properties of titanium surfaces

ObjectivesTo evaluate the effect of doxycycline and dexamethasone doped nanoparticles covering titanium surfaces, on osteoblasts proliferation and differentiation.MethodsDoxycycline and dexamethasone doped polymeric nanoparticles were applied on titanium discs (Ti-DoxNPs and Ti-DexNPs). Undoped NPs and uncovered Ti discs were used as control. Human MG-63 osteoblast-like cells were cultured. Osteoblasts proliferation was tested by MTT assay. Alkaline phosphatase activity was analyzed. Differentiation gene expression was assessed by real-time quantitative polymerase chain reaction. Scanning Electron Microscopy was performed to assess osteoblasts morphology. Mean comparisons were conducted by ANOVA and Wilcoxon or Tukey tests (p < 0.05).ResultsNo differences in osteoblasts proliferation were found. Osteoblasts grown on Ti-DoxNPs significantly increased alkaline phosphatase activity. Doxycycline and dexamethasone nanoparticles produced an over-expression of the main osteogenic proliferative genes (TGF-β1, TGF-βR1 and TGF-βR2). The expression of Runx-2 was up-regulated. The osteogenic proteins (AP, OSX and OPG) were also overexpressed on osteoblasts cultured on Ti-DoxNPs and Ti-DexNPs. The OPG/RANKL ratio was the highest when DoxNPs were present (75-fold increase with respect to the control group). DexNPs also produced a significantly higher OPG/RANKL ratio with respect to the control (20 times higher). Osteoblasts grown on titanium discs were mainly flat and polygonal in shape, with inter-cellular connections. In contrast, osteoblasts cultured on Ti-DoxNPs or Ti-DexNPs were found to be spindle-shaped and had abundant secretions on their surfaces.SignificanceDoxNPs and DexNPs were able to stimulate osteoblasts differentiation when applied on titanium surfaces, being considered potential inducers of osteogenic environment when performing regenerative procedures around titanium dental implants.     

Disrupted biomineralization in zebra mussels after exposure to bisphenol-A: Potential implications for molar-incisor hypomineralization

ObjectiveThe aetiology of molar-incisor hypomineralization (MIH) is currently unclear. A major hurdle in MIH research is the lack of adequate model systems. The study investigated the feasibility of zebra mussel (Dreissena polymorpha) as a novel model to screen potential MIH-related factors.MethodsIn four experiments with overall 46 groups (n = 7 mussels/group), six groups per experiment were incubated with 100 mg/l calcein (mineralization marker) solution for 96 h to evaluate the dynamics of shell biomineralization, another six groups with tap water only (controls). Then zebra mussels with and without calcein pre-incubation were exposed to cadmium sulfate hydrate (3CdSO₄?8H₂O) (positive control; 0, 0.01, 0.1, 1, 10 and 100 mg/l), possible aetiological factors of MIH including bisphenol-A (BPA; 0, 0.02, 0.2, 2, 20 and 200 mg/l) and erythromycin (0, 0.1, 1, 10, 100 and 1000 mg/l) as mineralization “disruptors”, and doxycycline (0, 0.1, 1, 10, 100 and 1000 mg/l) for 96 h, respectively. After two weeks, the mussels were sacrificed and shells were embedded in methylmethacrylate for fluorescence intensity analysis.ResultsMortality rate was 100% after 20, 200 mg/l BPA and 10, 100 mg/l 3CdSO₄?8H₂O exposure. Thereby, the median lethal concentration (96 h-LC50) of BPA was 6.3 mg/l (95% CI, 1.3–34.4 mg/l), and that of cadmium was 3.1 mg/l (95% CI, 0.7–10.5 mg/l). Notably, calcein fluorescence in shells significantly decreased (p < 0.05) after 2 mg/l BPA and 1 mg/l 3CdSO₄?8H₂O exposure.SignificanceThese findings suggest that BPA may disrupt biomineralization. Biomineralization in zebra mussels seems to be an effective model for investigating potential MIH-related factors.     

Clostridium difficile infection after malaria chemoprophylaxis with doxycycline: Is there an association?

Malaria chemoprophylaxis with doxycycline is commonly used in the United Kingdom and in many other countries. It is considered to be associated with an increased risk of Clostridium difficile associated diarrhea (CDAD). We describe a case of diarrhea and a positive stool assay for C. difficile in a returning traveler, and review available literature. The commonly held concept of an association between doxycycline chemoprophylaxis and CDAD is not supported by available data.     

女性生殖道解脲支原体合并人型支原体感染药敏分析及疗效观察

目的评价联合用药与单独用药治疗女性生殖道感染的疗效。方法将2009年10月-2010年10月我院妇科门诊就诊76例生殖道解脲支原体（Ureaplasma Urealyticum）合并人型支原体（Mycoplasma Hominis）感染患者随机分成2组。联合用药组：外阴阴道冲洗（0.9%氯化钠注射液稀释5%碘伏1∶10）,口服强力霉素每次4mg,1次/d,连服7d,同时干扰素栓剂置阴道深部,隔日1次,共14d。单独用药组：口服强力霉素每次4mg,1次/d,共7d。停药1周后行妇科检查,停药2周后做宫颈支原体培养。结果 76例患者对强力霉素、交沙霉素、美满霉素较敏感,敏感率依次为61.9%、59.2%和50%,而对罗红霉素、螺旋霉素、克拉霉素高度耐药,耐药率依次为90.8%、88.2%和76.3%。联合用药组总有效率92.1%,单独用药组总有效率78.9%,有显著差异（P〈0.001）。结论应用外用干扰素栓剂联合强力霉素比单独口服强力霉素治疗女性生殖道解脲支原体合并人型支原体感染效果好。     

Locally Delivered Doxycycline as an Adjunct to Mechanical Debridement at Retreatment of Periodontal Pockets: Outcome at Furcation Sites

Background: The goal was to evaluate the clinical outcome of non‐surgical retreatment at molar furcation sites by ultrasonic debridement with or without adjunctive application of locally delivered doxycycline, and to explore factors affecting the healing results. Methods: This study involves 32 patients with chronic periodontitis, who received initial pocket/root debridement by ultrasonic instrumentation, followed by random assignment to retreatment of remaining pathologic sites at 3 months by ultrasonic instrumentation with or without adjunctive local application of an 8.8% doxycycline gel. Clinical examinations of plaque, probing depth (PD), relative attachment level, furcation involvement, and bleeding after furcation probing were performed initially, before retreatment at 3 months (baseline), and 3 and 9 months after retreatment. The primary efficacy variable was reduction in the degree of furcation involvement. A multilevel logistic model was used to evaluate the impact of patient and tooth site related factors on the main outcome variable. Results: The retreatment including locally delivered doxycycline resulted in closure of 50% of degree I furcation sites, compared to 29% for sites treated with mechanical debridement only (P >0.05). Of the degree II furcation sites, 17% in the test and 11% in the control group were reduced in depth (P >0.05). The logistic multilevel model with “furcation improvement” as the dichotomous outcome variable revealed that local application of doxycycline had no statistically significant effect. The odds ratio for “furcation improvement” was 0.80 (95% confidence interval [CI], 0.65 to 0.99) for 1‐mm increase of initial vertical PD, 0.36 (95% CI, 0.17 to 0.80) for initial furcation involvement degree II compared to degree I, and 0.24 (95% CI, 0.08 to 0.72) for smokers compared to non‐smokers. Conclusion: Improvement in molar furcation involvement after non‐surgical periodontal therapy was not enhanced by adjunctive locally applied doxycycline and negatively affected by increased vertical PD and tobacco smoking.