An In Vitro Stereomicroscopic Evaluation of Bioactivity between Neo MTA Plus,Pro Root MTA,BIODENTINE & Glass Ionomer Cement Using Dye Penetration Method

The ideal root end filling material should form a tight seal in the root canal by adhering to the cavity walls. Several materials have been used for root end filling. The present study aims to find out and compare the bioactivity of Neo MTA Plus, Pro Root MTA White, BIODENTINE & glass ionomer cement as root end filling materials using 1% methylene blue as tracer. Materials and methods: 80 extracted human permanent maxillary anterior teeth were used in the study. They were divided into four groups. Specimens were sectioned transversely in the cervical area to separate the crown from the root. The root canal was obturated with gutta percha and zinc oxide eugenol sealers. Thereafter, each sample was resected apically by removing 3 mm of the apex and filled with different materials. Samples were kept in buffering solution at 37 °C until the recommended evaluation periods. The specimens were then suspended in 1% methylene blue for 24 h, prior to the analysis. The teeth were then sectioned, and dye penetration was examined, photographed, and evaluated under a stereomicroscope. Results: Vertical dye penetration showed significant differences across different groups. The minimum dye penetration was seen in Neo MTA plus followed by BIODENTINE, Pro Root MTA and maximum in GIC. There was no significant difference in dye penetration between Neo MTA plus and BIODENTINE both at fifteen days and one-month intervals. Conclusion: The present study suggests Neo MTA plus and BIODENTINE should be the preferred material for root end filling.     

Indicator dilution curves in the diagnosis of D-transposition of the great arteries in infancy

Paired right and left atrial indicator dilution curves performed in a series of 17 patients with D-transposition of the great arteries (D-TGA) were reviewed. Taken together, the patterns obtained from patients who had trivial mixing between the pulmonary and systemic circulations were distinctive and easily recognizable. In the presence of substantial degrees of intracardiac mixing, however, the paired curves recorded become virtually identical and cannot be distinguished from curves recorded from patients with other forms of cyanotic congenital heart disease characterized by obligatory admixture. Thus paired atrial dye curves demonstrate a high degree of diagnostic specificity for the infant with D-TGA at greatest risk, normally those with a small intracardiac shunt. Such a procedure should facilitate early balloon atrial septostomy and obviate deterioration in the infant's condition due to prolonged catheter manipulation and/or angiography.     

建立染料法荧光定量PCR检测恙虫病东方体

目的建立染料法荧光定量PCR检测恙虫病东方体。方法根据恙虫病东方体56kD外膜蛋白基因序列设计特异性引物,建立染料法(SYBR green I)实时荧光定量PCR,评估其灵敏性及特异性;并对恙虫病东方体鸡胚培养物、东方体感染小白鼠脏器标本以及恙虫病病人血样等多种样本进行检测。结果建立的荧光定量PCR标准曲线的循环阈值(Ct)与模板拷贝数呈良好的线性关系(r2=0.99),灵敏性评估显示20μl体系单PCR反应管靶基因大于28个拷贝即可被有效检测,最低检出浓度为2拷贝/μl,比普通PCR检测方法提高1~2个数量级,并且具有较好的重复性;建立的SYBR I染料法具有良好的特异性,与立氏立克次体R株等其他5种立克次体,以及被检测的其他几种病原菌DNA模板均不发生特异性扩增;用建立的染料法对东方体鸡胚培养物、东方体感染动物脏器,以及采集的现场恙虫病病人血样共59份标本进行检测,其中57份检出阳性。用该定量PCR检测恙虫病东方体实验感染小鼠的血、脾脏、肾脏、肝脏标本,结果脾脏中东方体检出量最多,肝脏和肾脏次之,血中的恙虫病东方体量较低。结论本研究建立荧光定量PCR方法均具有很高的特异性和敏感性,适合各种样本中东方体的快速检测,可用于实验室的快速诊断。     

In Situ Encapsulation of Nile Red or Doxorubicin during RAFT‐Mediated Emulsion Polymerization via Polymerization‐Induced Self‐Assembly for Biomedical Applications

Hydrophobic agents, a fluorescent dye (Nile red, NR) or an anticancer drug (doxorubicin, DOX), are encapsulated into poly((N‐[3‐(dimethylamino) propyl] methacrylamide)‐b‐poly (methyl methacrylate) (PDMAPMA‐b‐PMMA) nanoparticles (NPs) via one‐pot reversible addition‐fragmentation chain‐transfer (RAFT)‐mediated emulsion polymerization in water. The macroRAFT, PDMAPMA, is chain‐extended with the methyl methacrylate (MMA), with the hydrophobic agents soluble in MMA, resulting in loaded NPs, with either NR or DOX via polymerization‐induced self‐assembly (PISA). The NR‐loaded NPs are visualized by structured illumination microscopy (SIM), thus indicating the successful loading of the fluorescent dye into the PMMA core. The DOX‐loaded NPs exhibit a sustained release profile over 5 d, showing a small burst effect during the first 2 h, as compared with the free DOX. The DOX‐loaded NPs show higher cell toxicity than the free DOX in RAW 264.7 cell line. The results demonstrate the potential of using emulsion polymerization for synthesis of tailored and reproducible NPs encapsulating hydrophobic agents.     

Near-infrared dye bound albumin with separated imaging and therapy wavelength channels for imaging-guided photothermal therapy

Development of theranostic agent for imaging-guided photothermal therapy has been of great interest in the field of nanomedicine. However, if fluorescent imaging and photothermal ablation are conducted with the same wavelength of light, the requirements of the agent's quantum yield (QY) for imaging and therapy are controversial. In this work, our synthesized near-infrared dye, IR825, is bound with human serum albumin (HSA), forming a HSA-IR825 complex with greatly enhanced fluorescence under 600 nm excitation by as much as 100 folds compared to that of free IR825, together with a rather high absorbance but low fluorescence QY at 808 nm. Since high QY that is required for fluorescence imaging would result in reduced photothermal conversion efficiency, the unique optical behavior of HSA-IR825 enables imaging and photothermal therapy at separated wavelengths both with optimized performances. We thus use HSA-IR825 for imaging-guided photothermal therapy in an animal tumor model. As revealed by in vivo fluorescence imaging, HSA-IR825 upon intravenous injection shows high tumor uptake likely owing to the enhanced permeability and retention effect, together with low levels of retentions in other organs. While HSA is an abundant protein in human serum, IR825 is able to be excreted by renal excretion as evidenced by high-performance liquid chromatography (HPLC). In vivo tumor treatment experiment is finally carried out with HSA-IR825, achieving 100% of tumor ablation in mice using a rather low dose of IR825. Our work presents a safe, simple, yet imageable photothermal nanoprobe, promising for future clinical translation in cancer treatment.     

Impact of aging on spreading depolarizations induced by focal brain ischemia in rats

Spreading depolarization (SD) contributes to the ischemic damage of the penumbra. Although age is the largest predictor of stroke, no studies have examined age dependence of SD appearance. We characterized the electrophysiological and hemodynamic changes in young (6 weeks old, n = 7), middle-aged (9 months old, n = 6), and old (2 years old, n = 7) male Wistar rats during 30 minutes of middle cerebral artery occlusion (MCAO), utilizing multimodal imaging through a closed cranial window over the ischemic cortex: membrane potential changes (with a voltage-sensitive dye), cerebral blood volume (green light reflectance), and cerebral blood flow (CBF, laser-speckle imaging) were observed. The initial CBF drop was similar in all groups, with a significant further reduction during ischemia in old rats (p < 0.01). Age reduced the total number of SDs (p < 0.05) but increased the size of ischemic area displaying prolonged SD (p < 0.01). The growth of area undergoing prolonged SDs positively correlated with the growth of ischemic core area (p < 0.01) during MCAO. Prolonged SDs and associated hypoperfusion likely compromise cortical tissue exposed to even a short focal ischemia in aged rats.     

The pulsed‐dye laser as an adjuvant treatment modality in acne vulgaris: a randomized controlled single‐blinded trial

Background Acne vulgaris is the most common skin disease and can pose a substantial therapeutic challenge. Recently, several phototherapeutic modalities, most notably pulsed‐dye laser (PDL) treatment, have been introduced, but the published results – albeit promising – are controversial. Objectives To assess the efficacy of an adjuvant PDL treatment when combined with a proven topical treatment [fixed‐combination clindamycin 1%–benzoyl peroxide 5% hydrating gel (C/BPO)]. Methods Eighty patients (38 males and 42 females, mean ± SD age 19·7 ± 5·9 years) were randomized in a 1 : 2 ratio to receive C/BPO alone or in combination with PDL treatment (wavelength 585 nm, energy fluence 3 J cm⁻², pulse duration 0·35 ms, spot size 7 mm). Patients were evaluated at baseline and at 2 and 4 weeks after initial treatment. The primary end points were the Investigator’s Static Global Assessment (ISGA) score and lesion count; the secondary end point was the Dermatology Life Quality Index (DLQI). Results Both groups showed a significant improvement during observation [ISGA 27·1% (C/BPO) and 24·6% (C/BPO + laser), total lesion count 9·2% and 9·0%, inflammatory lesion count 36·3% and 36·9%, DLQI 54·5% and 42·5%], but there was no significant or otherwise appreciable difference between treatment modalities as far as the extent of improvement was concerned. Patients with more severe findings at baseline had a greater benefit from either therapy regimen. Conclusions Our findings do not support the concept of a substantial benefit of PDL treatment in acne vulgaris.     

Consumer available permanent hair dye products cause major allergic immune activation in an animal model

Background  p -Phenylenediamine (PPD) and related substances are ingredients of more than two-thirds of oxidative (permanent) hair dyes currently used. Although PPD is a potent skin sensitizer in predictive assays, the extent to which permanent hair dyes sensitize humans has been questioned due to the in-use conditions, e.g. the presence of couplers in the hair dye gel and rapid oxidation using a developer.
Objectives  To study the skin sensitizing potential of permanent hair dyes in mice.
Methods  Two different permanent hair dye products containing PPD were studied in CBA mice using a modified version of the local lymph node assay. The colour gel and developer (oxidant) were tested separately and in combination. Response was measured by ear swelling and cytokine production in ear tissue and serum by enzyme-linked immunosorbent assay. The immune cellular response in the draining lymph nodes was analysed by flow cytometry.
Results  Application of the colour gel both alone and mixed with the developer induced skin production of interleukin (IL)-1β, tumour necrosis factor-α and IL-6 as well as systemic IL-6 release. Both treatments induced B- and T-cell infiltration as well as T-cell proliferation within the draining lymph nodes. Treatment with the mixture induced at least 20% more skin inflammation, cytokine production and CD4+ T-cell activation compared with the colour gel alone.
Conclusions  Consumer available PPD-containing permanent hair dyes can be potent and rapid immune activators. Mixing the colour gel and developer (oxidant) increased the induction of skin inflammation compared with application of the colour gel alone.     

CFDA-SE标记虹膜色素上皮细胞的自体移植

目的探讨兔眼自体虹膜色素上皮细胞（irispigment epithelialcells，IPECs）羧基荧光素乙酰乙酸（CFDA-SE）标记后，采用单通道内路移植方法将传代的IPECs移植于视网膜神经上皮层下的可行性。方法取兔眼自体虹膜细胞分离培养并传代，于第3代经CFDA-SE染色后移植到自体视网膜神经上皮层下。术后不同时间应用彩色眼底照相、激光扫描检眼镜、光学相干断层扫描进行活体观察。不同时间点对移植眼进行切片并常规染色及免疫组化，用光学显微镜对移植细胞进行观察和评价。实验数据采用两均数的等效检验，以0．5倍标准差作为等效界值观察移植前后ZO-1和Actin表达情况。结果移植术后观察显示移植区界限清晰；激光扫描检眼镜可观察到移植区内荧光；光学相干断层扫描和HE染色均显示移植区神经上皮层下有色素上皮细胞堆积，并随时间推移堆积逐渐变平。经免疫组化显示移植区ZO-1、Actin呈棕色点，有规律的间断分布在Bruch膜上，IPECs嵌插在原始的RPECs间，且形成完整的单层。结论CFDA-SE是一种快捷、稳定、安全的活体细胞染料，在IPECs移植中可作为理想的标记物应用；我们首次使用的单通道内路移植方法具有手术快捷简单、安全、并发症少等优点。[眼科新进展2007；27（3）：165-169】