Reducing bacterial counts in dental unit waterlines: distilled water vs. antimicrobial agents

BACKGROUND: This study evaluated five chemical disinfectants to compare their abilities to improve dental unit waterline quality and assess their effects, if any, on the biofilm layer. METHODS: Sixty new dental units, with a closed-circuit water system, were used to compare microbial levels in DUWLs treated with five antimicrobials: Listerine, Bio 2000, Rembrandt, Dentosept, and sodium fluoride to a control group of sterile distilled water alone over a six-week period. For all units, the waterlines were filled with solution, left overnight, and then flushed for 30 seconds with sterile distilled water the following morning prior to patient treatment. Waterlines were examined for biofilm buildup using scanning electron microscopy and colony-forming-unit counts. RESULTS: The sodium fluoride and the four chemical antimicrobials reduced the microbial count to 200 cfu/ml or less. Only samples taken from dental units receiving the control treatment (distilled water with no added antimicrobial) failed to meet ADA's stated goal. Examination of the SEMs revealed an apparent decrease in the biofilm mass but not elimination, despite repeated treatment with the four antimicrobial materials. CONCLUSIONS: Even in a closed-circuit water system, distilled water alone cannot reduce microbial contamination of dental treatment water from dental unit waterlines to the 200 cfu/ml ADA stated goal. However, water treated with Listerine mouthrinse, Rembrandt mouthrinse, Bio 2000, 0.5 percent sodium fluoride and Dentosept, did meet the microbial reduction goal. The biofilm apparently was reduced in volume, but not entirely eliminated. CLINICAL SIGNIFICANCE: The ADA goal of a maximum of 200 cfu/ml was achieved using any of five chemical antimicrobials and distilled water in a closed-water system. Despite the successful reduction in microbial contamination of the dental treatment water, the biofilm was not completely eliminated. Biofilm elimination and prevention would be needed through some other means.     

童年期心理虐待和忽视、述情障碍对大学生无聊倾向的影响

目的探讨童年期心理虐待和忽视、述情障碍对大学生无聊倾向的影响及其关系。方法采用大学生无聊倾向问卷(boredom proneness scale for college students,BPS)、儿童心理虐待和忽视量表(child psychological abuse and neglect scale,CPANS)、多伦多述情障碍量表(the Toronto alexithymia scale,TAS-20)对1557名大学生进行调查,采用SPSS 22.0进行描述性统计、相关分析和回归分析。结果童年心理虐待[(26.540±8.985)分]、忽视[(32.665±10.651)分]、述情障碍的识别情感维度[(19.359±4.835)分]、描述情感维度[(14.173±3.001)分],外向思维维度[(20.383±3.429)分]与无聊倾向总分[(101.109±19.735)分]、外部刺激维度[(66.022±21.079)分]存在正相关(r=0.160~0.559,均P<0.01),而与内部刺激维度[(35.132±8.207)分]存在负相关(r=-0.302~-0.104,均P<0.01)。分层回归分析显示,在控制性别和年龄的影响后,心理虐待与忽视是无聊倾向、内部刺激和外部刺激的影响因素,分别可解释总变异的14.3%,5.1%和18.2%(△F=130.561、41.968、172.711,均P<0.01)。述情障碍的识别情绪、描述情绪和外向思维是无聊倾向、内部刺激和外部刺激的影响因素,分别可解释总变异的17.5%,9.9%和25.5%(△F=134.274、60.696、234.383,P<0.01)。结论童年心理虐待和忽视、述情障碍对大学生无聊倾向存在显著影响,主要体现在对无聊倾向的外部刺激的影响上,其中述情障碍影响最大、解释力最高。     

新癀片联合盐酸米诺环素软膏治疗牙周炎效果评价

目的:探讨新癀片联合盐酸米诺环素软膏治疗牙周炎的临床疗效及对炎症因子水平的影响.方法:选择牙周炎患者150例为研究对象,根据入院时间不同将其分为对照组(75例)与观察组(75例),对照组采用盐酸米诺环素软膏治疗,观察组联合新癀片治疗,疗程均为4周;观察2组临床疗效、治疗前后龈沟液炎症因子水平、不良反应情况.结果:观察组治疗总有效率(94.66％)高于对照组(82.67％),治疗后TNF-α[(3.52±0.40)vs(4.76±0.76)ng·mL-1]、IL-6[(1.43±0.27)vs(1.96±0.35)pg·mL-1]、CRP[(13.42±2.58)vs(17.65±3.16)mg·mL-1]低于对照组,差异有统计学意义(P<0.05);观察组不良反应发生率(6.66％)高于对照组(5.34％),但差异无统计学意义(P>0.05).结论:新癀片联合盐酸米诺环素软膏治疗牙周炎可降低患者炎症因子水平,提高临床疗效,安全性高.     

Diversity,novelty, antimicrobial activity,and new antibiotics of cultivable endophytic actinobacteria isolated from psammophytes collected from Taklamakan Desert

Three hundred and twenty endophytic actinobacterial strains were isolated from psammophytes collected from Taklamakan Desert and identified. Among them, three strains already had been identified as new species of two genera and sixteen isolates showed relatively low 16S rRNA similarities < 98.6% to validly described species. Seventy-five of the isolates were selected as representative strains to screen antibacterial activity and mechanism. Forty-seven strains showed antagonistic activity against at least one of the indicator bacteria. Two Streptomyces strains produced bioactive compounds inducing DNA damage, and two Streptomyces strains produced bioactive compounds with inhibitory activity on protein biosynthesis. Notably, the strain Streptomyces sp. 8P21H-1 that demonstrated both strong antibacterial activity and inhibitory activity on protein biosynthesis was prioritized for exploring new antibiotics. Under the strategy of integrating genetics-based discovery program and MS/MS-based molecular networking, two new streptogramin-type antibiotics, i.e., acetyl-griseoviridin and desulphurizing griseoviridin, along with known griseoviridin, were isolated from the culture broth of strain 8P21H-1. Their chemical structures were determined by HR-MS, and 1D and 2D NMR. Desulphurizing griseoviridin and griseoviridin exhibited antibacterial activities by inhibiting translation.     

Association between cannabis and the eyelids: A comprehensive review

Cannabis is the most consumed illicit drug worldwide. As more countries consider bills that would legalize adult use of cannabis, health care providers, including eye care professionals (ophthalmologists, optometrists), will need to recognize ocular effects of cannabis consumption in patients. There are only 20 studies on the eyelid effects of cannabis usage as a medical treatment or a recreational drug. These include ptosis induction, an “eyelid tremor” appearance and blepharospasm attenuation. Six articles describe how adequately dosed cannabis regimens could be promising medical treatments for blepharospasm induced by psychogenic factors. Fourteen articles report eyelid tremors in intoxicated drivers and ptosis as a secondary effect in cannabinoid animal experimental models. The exact mechanism of cannabinoids connecting cannabis to the eyelids is unclear. Further studies should be conducted to better understand the cannabinoid system in relation to the eyelid and eventually develop new, effective and safe therapeutic targets derived from cannabis.