Non‐ablative 1550‐nm erbium‐glass and ablative 10 600‐nm carbon dioxide fractional lasers for acne scars: a randomized split‐face study with blinded response evaluation

Background Non‐ablative 1550‐nm erbium‐doped fractional photothermolysis systems (FPS) and 10 600‐nm carbon dioxide fractional laser systems (CO₂ FS) have been effectively used to treat scars. Objective We compared the efficacy and safety of single‐session treatments of FPS and CO₂ FS for acne scars through a randomized, split‐face, evaluator‐blinded study. Methods Eight patients with acne scars were enrolled in this study. Half of each subject’s face was treated with FPS and the other half was treated with CO₂ FS. We used a quartile grading scale for evaluations. Results At 3 months after the treatment, the mean grade of improvement based on clinical assessment was 2.0 ± 0.5 for FPS and 2.5 ± 0.8 for CO₂ FS. On each side treated by FPS and CO₂ FS, the mean duration of post‐therapy crusting and scaling was 2.3 and 7.4 days respectively and that of post‐therapy erythema was 7.5 and 11.5 days respectively. The mean VAS pain score was 3.9 ± 2.0 with the FPS and 7.0 ± 2.0 with the CO₂ FS. Conclusion We demonstrated the efficacy and safety of single‐session acne scar treatment using FPS and CO₂ FS in East Asian patients. We believe that our study could be used as an essential reference when choosing laser modalities for scar treatment.     

锌酞菁脂质体光动力作用引起小鼠肿瘤的细胞程序性死亡

电镜观察了锌酞菁脂质体光动力作用引起小鼠ＭＳ－２纤维肉瘤的形态学变化。发现其作用很强，并对肿瘤细胞有明显的直接影响。肿瘤细胞的结构表现出明显的程序性细胞死亡（ａｐｏｐｔｏｓｉｓ，ｐｒｏｇｒａｍｍｅｄｃｅｌｄｅａｔｈ）的特点：胞核染色质凝聚边集、核固缩、核破裂、染色质凝块流失、胞质内吞噬现象、胞膜表面肿胀粗钝的胞突形成、细胞碎裂等。加深了对锌酞菁脂质体光敏作用机理的认识，但其详细的发生机制和调节途径有待阐明。     

3－硝基－1，2，4－三唑类乏氧细胞放射增敏剂的构效关系

为了寻找毒性低、增敏作用强的乏氧细胞放射增敏剂，设计并合成了一系列５－溴－，５－甲基－，和５－未取代的３－硝基－１，２，４－三唑－１－乙酰胺类化合物，用ＨｅＬａＳ３细胞进行了体外试验。结果表明５－溴取代衍生物的增敏作用强于相应的５－甲基－或５－未取代的硝基三唑衍生物，但是它们的毒性亦增大。修饰１位乙酰胺侧链也可以改变化合物的增敏作用和亲脂性。在所测定的化合物中ＴＡ－１０１［２－（３－硝基－１－三唑基）乙酰胺］由于有高的增敏作用和低亲脂性，可能是一个有希望的放射增敏剂。     

角膜缘干细胞移植在眼科的临床应用及发展

目的:探讨角膜缘干细胞移植的应用现状及发展前景。资料来源:应用计算机检索PUBMED 2000/2007与角膜缘干细胞移植相关的文章,检索词“limbal stem cells,transplantation”,限定文献语种为“English”;同时检索万方数据库2000/2007相关文章,检索词“角膜缘干细胞,移植”,限定文献语种为中文。资料选择:共检索到相关文献180余条,选择与角膜缘干细胞的组织生物学特征、角膜缘干细胞的体外培养以及角膜缘干细胞的临床应用相关的文章。资料提炼:将初步筛选的文章进一步查找全文,排除综述和重复文献,内容相似的选择发表在权威杂志或近3年发表的文献,无论有无对照组,观察对象为人或动物均纳入。最后共纳入37篇进行综述,其中7篇研究角膜缘干细胞的组织生物学特性,8篇介绍角膜缘干细胞的体外培养,剩余22篇文章为角膜缘干细胞移植的基础和临床研究。资料综合:角膜缘干细胞移植,可以恢复正常的角膜缘屏障功能,重建眼表的完整性;而最终改善角膜的透明性和视功能。目前开展的角膜缘干细胞移植,包括自体或异体角膜缘组织移植和体外培养的角膜缘干细胞移植。自体角膜缘干细胞的移植已成为临床上较为可靠和日益成熟的治疗方法,但来源有限,且不适合双眼角膜缘病变的患者,异体角膜缘组织移植存在排斥反应,因此自体角膜缘干细胞体外培养移植术被认为是目前较理想的角膜缘干细胞移植方法,但其远期疗效需进一步临床观察。结论:目前角膜缘干细胞移植治疗严重角膜病变的研究尚处于初步阶段,自体角膜缘干细胞移植成功率是较高,自体角膜缘干细胞培养后移植治疗眼表疾病已初步获得成功,但还存在一些问题,如角膜缘干细胞生存的微环境、培养的干细胞生理、生化的免疫特性,以及黏附、增殖、分化能力等问题尚需进一步研究。     

Evaluation of an automated microbiologic blood culture device for detection of bacteria in platelet components

BACKGROUND: Automated culture methods have been used by several investigators to detect bacterial contamination of cellular blood components. We investigated several factors affecting detection by automated culture of bacteria in platelet concentrates (PCs).These factors included the initial contamination level in PCs, the PC sample volume, the PC sample time, and the white cell level in relation to bacteria levels in the PCs. STUDY DESIGN AND METHODS: Staphylococcus epidermidis or Escherichia coli was inoculated into freshly prepared PCs or white cell-reduced PCs to yield colony-forming unit (CFU) levels of 10, 1, or 0.1 per mL. At the time of inoculation (t=0) and at t=6, t=24, and t=48 hours, 0.5, 1.0, and 2.0 mL samples of the contaminated PCs were transferred into culture bottles. The presence of bacteria in the culture bottles was subsequently monitored by an automated blood culturing instrument. Bacteria levels in the PC at the time of first automated culture detection were determined by quantitative plating. RESULTS: E. coli was detected in 92 percent of experiments when 1.0- or 2.0-mL samples were taken at t=6 hours. At t=24 hours, 100-percent detection was observed with all tested inoculation volumes; however, by that time,>10(7) CFU per mL of bacteria were present in every PC. For S. epidermidis, 89 percent and 83 percent of contaminated PCs were detected with a t=24 hour sampling time and 2.0- or 1.0-mL sampling volume. Seven of 36 PCs with a 2.0-mL sampling volume and 10 of 36 PCs with a 1.0-mL sampling volume contained>10(6) CFU per mL of S. epidermidis at the time of first detection. CONCLUSION: Data from this preliminary evaluation suggest that sampling times of 24 hours or more would be necessary to provide confidence in detection of E. coli or S. epidermidis in PCs using this culture method.     

Inhibition of apoptosis by BCR-ABL in chronic myeloid leukemia

BCR-ABL expression is presumed to effect clonal expansion in chronic myeloid leukemia (CML) by deregulation of cell proliferation. However, most studies have found that relative rates of cell proliferation are not increased in CML. Moreover, we found that CML progenitors display a normal proliferative response to growth factors and do not manifest greater proliferative potential than normal progenitors. Growth of malignancies depends on an imbalance between the rate of cell production and the rate of cell death. We found that BCR-ABL expression inappropriately prolongs the growth factor-independent survival of CML myeloid progenitors and granulocytes by inhibiting apoptosis, a genetically programmed process of active cell death; inhibition of BCR- ABL expression by antisense oligonucleotides reversed the suppression of apoptosis as well as the enhancement of survival. The decreased rate of programmed cell death appears to be the primary mechanism by which BCR-ABL effects expansion of the leukemic clone in CML.     

An audit of consent refusals in clinical research at a tertiary care center in India

Background and Rationale:

Ensuring research participants’ autonomy is one of the core ethical obligations of researchers. This fundamental principle confers on every participant the right to refuse to take part in clinical research, and the measure of the number of consent refusals could be an important metric to evaluate the quality of the informed consent process. This audit examined consent refusals among Indian participants in clinical studies done at our center.

Materials and Methods:

The number of consent refusals and their reasons in 10 studies done at our center over a 5-year period were assessed. The studies were classified by the authors according to the type of participant (healthy vs patients), type of sponsor (investigator-initiated vs pharmaceutical industry), type of study (observational vs interventional), level of risk [based on the Indian Council of Medical Research (ICMR) “Ethical Guidelines for Biomedical Research on Human Participants”], available knowledge of the intervention being studied, and each patient''s disease condition.

Results:

The overall consent refusal rate was 21%. This rate was higher among patient participants [23.8% vs. healthy people (14.9%); P = 0.002], in interventional studies [33.6% vs observational studies (7.5%); P < 0.0001], in pharmaceutical industry-sponsored studies [34.7% vs investigator-initiated studies (7.2%); P < 0.0001], and in studies with greater risk (P < 0.0001). The most common reasons for consent refusals were multiple blood collections (28%), inability to comply with the study protocol (20%), and the risks involved (20%).

Conclusion:

Our audit suggests the adequacy and reasonable quality of the informed consent process using consent refusals as a metric.KEY WORDS: Autonomy, consent, India, reason, refusal, risk