米诺环素对压力作用下体外培养视网膜神经细胞凋亡的抑制

目的 观察米诺环素对压力系统作用下大鼠视网膜神经细胞(RNs)的活性及凋亡的影响，探讨其对受损RNs保护的可能机制。 方法 制备大鼠RNs体外加压培养模型，通过细胞形态学观察、四唑盐（MTT）比色法测定细胞活力、吖啶橙/溴化乙锭（AO/EB）染色法检测细胞凋亡率等方法观察不同浓度的米诺环素对上述损伤细胞的保护作用，并用免疫细胞化学法观察iNOS和caspase 3表达的改变。 结果 加压培养后RNs与对照组相比形态改变较明显，细胞活力降低，5393%的细胞发生凋亡。20000 μmol/L的米诺环素治疗组则细胞形态改善，活力显著增高，1729%的细胞发生凋亡；免疫细胞化学法显示细胞内iNOS和caspase-3表达较加压损伤组减少。 结论 一定剂量的米诺环素在体外可有效抑制压力引起的大鼠RNs损伤及凋亡；抑制iNOS和caspase-3的表达可能是其潜在作用机制。     

Pyoderma gangrenosum associated with ulcerative colitis and subcutaneous and splenic abscesses

Pyoderma gangrenosum is a rare, chronic, inflammatory ulcerative skin disease of unknown etiology and pathogenesis. It is often associated with systemic disease. We describe a patient with pyoderma gangrenosum associated with ulcerative colitis and aseptic abscesses of the subcutis and spleen, which have been rarely reported previously. These manifestations were cleared by combined therapy with minocycline hydrochloride and diaphenylsulfone.     

In vitro synergistic effect of minocycline combined with antifungals against Cryptococcus neoformans

BackgroundCryptococcus neoformans infections occur in immunocompromised patients, especially those with HIV infection, chemoradiotherapy after cancer, and organ transplantation. Infection can cause pneumonia and meningoencephalitis in severe cases with a high mortality rate if not treated. Although fluconazole and amphotericin B are the first-line treatments for cryptococcosis, the rate of fluconazole resistance has increased significantly due to long-term use. Minocycline is a derivative of tetracycline that exerts its antibacterial effect through inhibition of bacterial protein synthesis. It is also able to pass the blood-brain barrier to act on the central nervous system. The present study investigates the effects of minocycline in combination with antifungals in treating C. neoformans.ObjectiveTo determine in vitro interactions of minocycline combined with itraconazole, voriconazole, posaconazole, fluconazole and amphotericin B against C. neoformans.MethodsThe minimum inhibitory concentrations (MIC) of the antifungals were determined by the CLSI Clinical and Laboratory Standards Institute M27-A3 microdilution method. The in vitro synergistic effects of minocycline combined with itraconazole, voriconazole, posaconazole, fluconazole, and amphotericin B on C. neoformans were detected by the broth microdilution checkerboard technique and disk diffusion testing.Results and ConclusionThe working concentration ranges were 0.125–4 µg/mL for itraconazole, 0.03–0.125 µg/ml for voriconazole, 0.03–1 µg/ml for posaconazole, 0.25–16 µg/ml for fluconazole, and 0.125–2 µg/ml for amphotericin B. The synergistic rates of minocycline combinations against C. neoformans were 55% with itraconazole, 10% with voriconazole, 85% with posaconazole, 20% with fluconazole, and 70% with amphotericin B. The effective MIC value of minocycline in the synergistic combination decreased to 2–32 µg/ml, while the MIC of itraconazole decreased to 0.03–0.125 µg/ml, voriconazole 0.03–0.125 µg/ml, posaconazole 0.03–0.125 µg/ml, 0.125–4 µg/ml fluconazole, and 0.06–0.50 µg/ml amphotericin B. The disk diffusion assay showed that the plates containing minocycline and antifungal drugs produced inhibition zones with diameters larger than the single drug plates. Minocycline showed no antagonistic effect in the combinations. In conclusion, the combination of minocycline and azoles or amphotericin B has synergistic effects against C. neoformans in vitro.     

The tetracycline analogs minocycline and doxycycline inhibit angiogenesis in vitro by a non-metalloproteinase-dependent mechanism

The tetracycline analogs minocycline and doxycycline are inhibitors of metalloproteinases (MMPs) and have been shown to inhibit angiogenesis in vivo. To further study the mechanism of action of these compounds we tested them in an in vitro model of angiogenesis: aortic sprouting in fibrin gels. Angiogenesis was quantitated in this system by a unique application of planar morphometry. Both compounds were found to potently inhibit angiogenesis in this model. To further characterize the activity of these compounds against MMPs, we determined the IC₅₀s of both compounds against representatives of three classes of metalloproteinases: fibroblast collagenase, stromelysin, and gelatinase A. Doxycycline was found to inhibit collagenase, gelatinase A and stromelysin with IC₅₀s of 452 M, 56 M and 32 M, respectively. Minocycline was found to inhibit only stromelysin in the micromolar range with an IC₅₀ of 290 M. Since these results suggest that these compounds may not have been inhibiting in vitro angiogenesis by an MMP-dependent mechanism, we decided to test the effects of the potent MMP inhibitor BB-94. This compound failed to inhibit aortic sprouting in fibrin gels, thus strongly suggesting that both doxycycline and minocycline act by an MMP-independent mechanism. These results have implications for the mechanism of action of tetracycline analogs, particularly where they are being considered for the treatment of disorders of extracellular matrix degradation including periodontal disease, arthritis, and tumor angiogenesis.     

盐酸米诺环素软膏注满牙周袋治疗重度牙周-牙髓联合病变的临床疗效

目的 分析盐酸米诺环素软膏注满牙周袋对重度牙周-牙髓联合病变患者牙周组织再生的影响.方法 选取2019年2月至2020年2月本院收治的重度牙周-牙髓联合病变患者93例作为研究对象,将入选患者随机编号1～115号,将奇数患者58例纳入对照组,将偶数患者57例纳入观察组.两组均给予常规牙周基础治疗,观察组在此基础上给予盐酸...     

Case Study: An intraoperative finding of black bone disease in a podiatric surgery patient

Black bone disease has been recognised as a potential consequence of long-term treatment with tetracycline antibiotics. Largely documented affecting structures in the head and skull, there are few reported cases of black bone disease in the foot and ankle. The case of a 55 years old patient, who as a teenager, had undergone treatment with minocycline hydrochloride for chronic acne, and was found to have bone discolouration consistent with minocycline induced black bone disease (MIBBD) during the course of hallux valgus corrective surgery some 40 years later, is presented. In spite of the intraoperative findings, the patient’s post-operative recovery and bone healing was uneventful. The literature on minocycline induced black bone disease is reviewed.     

米诺环素在下颌阻生牙拔除后干槽症预防中的应用

目的将米诺环素放入下颌阻生牙拔除后牙槽窝,评价其预防干槽症的效果。方法选择韶关学院医学院附属医院口腔门诊拔除下颌阻生牙的患者126例,随机分成两组,试验组在拔除阻生牙后放入米诺环素,对照组不放任何材料任其自行愈合,1周后复诊观察干槽症的发生情况。结果试验组有1例干槽症发生,对照组有8例干槽症发生,两组干槽症发生率的差异有统计学意义(P0.05)。结论复杂阻生牙拔除术,由于创伤大、操作时间长,在牙槽窝放入米诺环素可预防干槽症的发生。     

米诺环素调控P2X7受体抑制BV-2细胞活化的研究*

 目的：探索P2X7受体在米诺环素(Mino)抑制脂多糖（LPS）刺激的BV-2细胞活化中的作用。方法：将体外培养的BV-2细胞分为5组：空白对照组、LPS处理组、LPS+ 0.1 μmol/L Mino组、LPS+ 1 μmol/L Mino组和LPS+ 10 μmol/L Mino组。分组处理8 h后行real-time PCR检测P2X7受体mRNA表达;处理24 h后观察各组细胞形态学变化,Western blotting检测P2X7受体蛋白表达,取细胞培养液上清行ELISA检测TNF-α和IL-1β的分泌情况。结果：经LPS处理后,BV-2细胞P2X7受体mRNA及蛋白的表达均升高,细胞培养液上清的TNF-α和IL-1β表达升高,同时伴有形态学的改变,而0.1～10 μmol/L Mino能抑制这一趋势,差异有统计学意义（P<0.01）。 结论： Mino抑制BV-2细胞活化的机制可能与抑制P2X7受体的活性相关。     

盐酸米诺环素对牙周袋内硫化物水平的影响

目的评价口臭的牙周炎患者局部应用盐酸米诺环素软膏对牙周袋内硫化物水平的影响。方法对15例以口臭为主诉的慢性牙周炎患者采用分口（split-mouth）设计,同一患者的一侧半口随机采用刮治和根面平整术（scaling and root planing,SRP）,另一侧采用SRP辅助用盐酸米诺环素软膏治疗。基线、治疗后6周、3个月时检查牙周袋内硫化物（sulfide in periodontal pockets,pS）水平、探诊深度（probing depth,PD）、临床附着水平（clinical attachment level,CAL）、出血指数（bleeding index,BI）、菌斑指数（plaque index,PLI）,在基线、治疗后6周刚果红涂片进行龈下微生物计数。结果在治疗后6周、3个月,SRP＋米诺环素组与单纯SRP组的各项临床指标均较治疗前明显改善（P〈0.05）;比较两组间pS值、PD、CAL、PLI、BI、龈下螺旋体比例,差异均无统计学意义。结论对于口臭的牙周炎的患者,盐酸米诺环素辅助SRP较单纯的SRP并未显示很大的优势;牙周治疗可持续3个月降低袋内硫化物水平。