紫外线-核黄素光动力疗法对眼科常见致病细菌的体外杀菌作用

背景 金黄色葡萄球菌、表皮葡萄球菌和铜绿假单胞菌是眼科的常见致病菌,研究最佳杀菌方法对眼科的临床工作具有重要意义. 目的 观察紫外线-核黄素光动力疗法（PDT）对眼科常见致病细菌的体外杀菌作用. 方法 分别取金黄色葡萄球菌、表皮葡萄球菌和铜绿假单胞菌冻存菌各10株接种于血培养皿中,复活2次培养至对数生长期后刮取菌落,置于细菌稀释液中,制备0.5麦氏浓度的细菌悬液原液,原液稀释10倍用于PDT实验.分别用1、2、3 mW/cm2紫外线A（UVA）对不同质量分数核黄素作用后的细菌照射10、20、30 min,测量不同条件下抑菌圈直径的大小,确定最佳抑菌条件.将金黄色葡萄球菌、表皮葡萄球菌和铜绿假单胞菌分别分为正常对照组、单独核黄素作用组、单独紫外线照射组和PDT组,比较不同组间各种细菌菌落数的差异. 结果 当UVA强度为3 mW/cm2、作用30 min、核黄素质量分数为0.1％时,MH固体培养皿上抑菌圈直径接近6 mm,故上述参数为PDT法抑菌的最佳条件.正常对照组、单独核黄素作用组、单独紫外线照射组和PDT组的金黄色葡萄球菌、表皮葡萄球菌和铜绿假单胞菌的菌落数依次减少,差异均有统计学意义（F=110.990、190.841、118.197,均P=0.000）,单独紫外线照射组各种细菌的菌落数均明显少于正常对照组,差异均有统计学意义（t=14.640、7.550、5.320,P＜0.05）,PDT组各种细菌的菌落数亦明显少于正常对照组的菌落数,差异均有统计学意义（t=25.480、14.750、12.920,P＜0.05）.单独紫外线照射组细菌量较正常对照组降低46.4％～50.2％,PDT组的细菌量降低91.6％ ～96.7％,而单独核黄素作用组的细菌菌落数与正常对照组相比差异均无统计学意义（t=0.660、0.470、0.510,P＞0.05）.结论 在紫外线-核黄素PDT灭活微生物的最佳体外实验条件下,PDT法对金黄色葡萄球菌、表皮葡萄球菌和铜绿假单胞菌的杀菌效果最好.     

Merits of conjunctival frill incision in reducing trabeculectomy-induced astigmatism and patient discomfort

Purpose:To compare results of a novel “conjunctival frill/smile incision” on surgically induced astigmatism (SIA) and patient discomfort vs conventional trabeculectomy in the initial postoperative period.Methods:Sixty trabeculectomy cases were subjected to either conjunctival frill incision, performed 1.5–2.0 mm from the limbus (study group) or conventional fornix-based conjunctival flap (control group). Corneal astigmatism and suture-induced discomfort were assessed by keratometry and a self-devised patient questionnaire, respectively.Results:Both groups generated a “with the rule” SIA, which was 1.77 vs 2.42 at 1 week and reduced to 1.27 vs 1.8 in the study vs control group, after removal of sutures – both scleral flap releasable and conjunctival at 1 month. Patient discomfort score revealed enhanced comfort in 37% of patients (study group) vs 17% (control group) during the early postoperative period. After 1 month of surgery, good comfort was regained in all cases.Conclusion:This novel suturing technique results in reduced SIA, patient discomfort during the 1^st month after trabeculectomy.     

晚期鼻咽癌放疗联合辅助性化疗的临床研究

目的 分析评价晚期（N2,N3期）鼻咽癌放疗加辅助化疗的疗效.方法 86例N2,N3期鼻咽癌患者随机分为放化组（A组,46例）和单放组（B组,40例）,均首先接受根治性放疗,其后放化组46例接受辅助化疗（LV＋5Fu＋DDP）3～4个疗程.结果 放化组5年生存率43.5%,单放组37.5%（P＞0.05）;放化组远处转移发生率19.6%,单放组45%（P＜0.05）;放化组远处转移发生时间平均放疗后18.3个月,单放组7.8个月;放疗后达到CR的放化组与单放组的5年生存率为42.9%、56.5%（P＞0.05）,非CR的放化组与单放组的5年生存率为44.4%、11.8%（P＜0.05）.结论 放疗加辅助性化疗N2,N3期鼻咽癌有助于延缓远处转移发生时间,减少远处转移;对于根治性放疗后未达CR者,辅助化疗能提高生存率.     

单核苷酸多态性与复杂性皮肤病

近年来国际HapMap计划的启动和深入以及高通量基因分型技术的不断发展,将单核苷酸多态性(SNP)在复杂性疾病研究中的应用推向了一个新的高潮。利用SNP具有数量多、分布广、密度大、突变率低等特点,进行全基因组连锁研究和关联分析,有助于解决复杂疾病人群多样性的难题,为寻找复杂性皮肤病的易感基因、风险单倍型、药物靶点和个体化治疗方案开辟了新的途径。本文就复杂性皮肤病的SNP相关研究简要作一综述。     

肠内输入与静脉输入高渗盐葡萄糖溶液复苏犬烧伤休克的疗效比较

目的比较肠道和静脉两种途径应用高渗盐糖溶液(HEGS)对烧伤早期休克复苏的疗效。方法采用Beagle犬35%TBSA三度烧伤模型,随机分为烧伤不复苏组(对照组)、静脉高渗盐糖补液组(静脉补液组)和胃肠高渗盐糖补液组(胃肠补液组),后两组于伤后0.5h分别通过静脉和肠道给予1.8%HEGS,8h补液总量为1ml/(kg·1% TBSA),匀速输入,测定三组平均动脉压(MAP)、心排量指数(CI)、血容量(PV)及血浆钠离子浓度的变化。结果三组的MAP均先升高后下降(P<0.05),静脉和胃肠补液组比较无显著性差异(P>0.05),但均显著高于对照组(P<0.01);对照组的CI和PV在烧伤后持续降低(P<0.01),静脉和胃肠补液组则是先降低(P<0.05),复苏后上升,两组比较无显著性差异(P>0.05),但与对照组比较均显著升高(P<0.01);对照组血浆钠离子浓度平稳(P>0.05),静脉和胃肠补液组复苏后升高(P<0.05),三组比较,静脉补液组最高,胃肠补液组次之,对照组最低(P<0.05)。结论在35%TBSA三度烧伤早期休克的复苏中,采用肠道途径输入高渗盐糖溶液可以达到与静脉途径相似的提高心排量、补充血容量、维持血浆渗透压的效果。     

多元实验室开放训练提升医学生临床技能的实践研究

目的 为提升医学生临床技能,探索多元实验室开放训练的实施方案及效果。方法 选取2015级808名临床医学本科生,在第5、6、7学期进行多元实验室开放训练。采取多元化预约方式：个人自主网络预约、书面预约、“挂号式”网络预约;多元化开放模式：学生自主练习、“工作坊”式专项操作培训、团队补课;多元化练习模块：基本技能、专科技能、综合技能。对学生多元实验室开放训练和实习结束后两阶段进行问卷调查的结果分析;比较2015级与2014级毕业技能考试成绩。采用SPSS 20.0软件进行t检验。结果 多元化实验室开放后,92.61%（664/717）的学生对开放模式满意;93.58%（671/717）的学生对预约方式满意;94.42%（677/717）的学生认为其能促进学习动力;97.35%（698/717）的学生认为其能激发学习兴趣;96.51%（692/717）的学生认为其能帮助知识和技能的掌握。实习后返校问卷显示：98.02%（741/756）的学生认为能提升临床技能;92.33%（698/756）的学生认为能培养临床思维;95.63%（723/756）的学生认为能增强实习自信心;94.18%（712/756）的学生认为能增加职业归属感。2015级临床医学生的毕业技能考试成绩[（90.33±5.59） vs. （82.22±7.19）]和单项技能成绩均优于2014级,差异有统计学意义（P<0.001）。结论 多元实验室开放训练可激发学生学习兴趣、提高学习动力,有助于提升学生临床技能和临床思维,能增强学生实习信心和职业归属感。     

Effect of Volume Fraction of Reinforcement on Microstructure and Mechanical Properties of In Situ (Ti,Nb)B/Ti2AlNb Composites with Tailored Three-Dimensional Network Architecture

The mechanical properties of (Ti, Nb)B/Ti₂AlNb composites were expected to improve further by utilizing spark plasma sintering (SPS) and inducing the novel three-dimensional network architecture. In this study, (Ti, Nb)B/Ti₂AlNb composites with the novel architecture were successfully fabricated by ball milling the LaB₆ and Ti₂AlNb mixed powders and subsequent SPS consolidation. The influence of the (Ti, Nb)B content on the microstructure and mechanical properties of the composites was revealed by using the scanning electron microscope (SEM), transmission electron microscopy (TEM) and electronic universal testing machine. The microstructural characterization demonstrated that the boride crystallized into a B27 structure and the α₂-precipitated amount increased with the (Ti, Nb)B increasing. When the (Ti, Nb)B content reached 4.9 vol%, both the α₂ and reinforcement exhibited a continuous distribution along the prior particle boundaries (PPBs). The tensile test displayed that the tensile strength of the composites presented an increasing trend with the increasing (Ti, Nb)B content followed by a decreasing trend. The composite with a 3.2 vol% reinforcement had the optimal mechanical properties; the yield strengths of the composite at 25 and 650 °C were 998.3 and 774.9 MPa, showing an 11.8% and 9.2% improvement when compared with the Ti₂AlNb-based alloy. Overall, (Ti, Nb)B possessed an excellent strengthening effect and inhibited the strength weakening of the PPBs area at high temperatures; the reinforcement content mainly affected the mechanical properties of the (Ti, Nb)B/Ti₂AlNb composites by altering the α₂-precipitated amount and the morphology of (Ti, Nb)B in the PPBs area. Both the continuous precipitation of the brittle α₂ phase and the agglomeration of the (Ti, Nb)B reinforcement dramatically deteriorated the mechanical properties.     

Central macular thickness and subfoveal choroidal thickness changes on spectral domain optical coherence tomography after cataract surgery in pediatric population

Purpose:To evaluate the central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) changes on spectral domain optical coherence tomography (SD-OCT) after cataract surgery with intraocular lens (IOL) implantation in a pediatric population.Methods:This was a longitudinal, prospective, interventional study which included 90 pediatric patients who underwent cataract extraction with IOL implantation. Serial SD-OCT scans were done at postoperative day 1, 1-month, and 3-month follow-up. CMT and SFCT were measured at each visit.Results:A statistically significant increase in CMT was noted at 1 month (from 199.3 µm to 210.04 µm) post surgery, which declined over a 3-month period (202.70 µm, P = 0.0001). In case of SFCT, a constant increase was observed for over 3 months of follow-up (baseline: 296.52 µm; 1 month: 309.04 µm; and 3 months: 319.03 µm, P = 0.0001). The traumatic cataract group showed more pronounced changes in CMT and SFCT than the non-traumatic cataract group. No significant difference was observed regarding these parameters between those who underwent primary posterior capsulotomy (PPC) versus those who did not. None of the patients in the study group developed cystoid macular edema. These posterior segment–related anatomical changes did not affect the final visual outcomes.Conclusion:Cataract surgery induces potential inflammatory changes in the macula and choroid in pediatric patients. Such changes are more pronounced in trauma-related cases; however, they are not significant enough to affect the visual outcomes. Similarly, the additional surgical step of PPC does not induce significant anatomical or functional changes.