发砷的示波极谱法测定

在碘化铵—硫酸—碲体系中,应用示波极谱法测定了人发砷的含量。该法操作简便、快速,干扰离子少,不需用有机溶剂,便于普及推广。本法回收率为80.5～101.3%,变异系为3.27%,最低能检出0.02μg。同经典的DDC-Ag法进行了对比,结果差异无显著性。应用该法对成都地区312例正常人发砷含量进行了测定,结果满意。建议在研究环境污染和职业中毒中,用本法了解人发中砷的蓄积情况。     

大鼠海马结构至额前皮质和外侧隔核的侧支投射——逆行荧光双标记法

本实验用大鼠24只,采用逆行荧光染料示踪法进行双标记研究。将荧光示踪物二盐酸4′-6-双脒基-2-苯吲哚(DAPI)、碘化丙啶(PI)和依文思蓝(EB)注射入额前皮质的边缘下区以及外侧隔核。结果表明用 DAPI 和 PI 配对注射入上述区破时,可见到海马结构的腹侧下托及其 CA_1区颞侧部有明显的双标记细胞,双标记细胞多位于锥体层,偶见于放射层和起层。提示腹侧下托和 CA_1区颞侧部有侧支投射到额前皮质的边缘下区和外侧隔核。     

Ultrastructure of Amelanotic Melanocytes from Human Hair Follicles

To investigate the ultra structure of amelanotic melanocytes （AMMC）. Methods： The hair follicles obtained from normal human scalp by 0.50% collagenase type V treatment were washed with 0.1 mol/L phosphate buffer salt （PBS）. Hair-follicle cell suspensions were prepared by trypsin treatment and cultured in melanocyte medium. Remaining keratinocytes were removed by differential trypsinization. 100μg/ml geneticin was used to eliminate the contaminating fibroblasts. At third passage, the cells were trypsinized, and then washed in phosphate-buffered saline and processed for transmission electron microscopy. Results： Under transmission electron microscope, the cultured cells showed round or oval shape, with single large nuclear and the karyotheca were double deck. There were obvious euchromosome within the nucleus, and sparse heterochromosome. There were various organelles in the cytoplasm, including plentiful melanosomes with nearly similar size, mitochondria, rough endoplasmic reticule （RER） and ribosome. The electron density granules in most of the melanosomes disposed along concentric circularities. Golgi apparatus in the cells was inconspicuous. Conclusion： The ultra structure of AMMC from human hair follicles is different from that of epidermal melanocytes, and these characteristics determine the functional immature of AMMC.     

毛囊干细胞定向分化过程中Wnt信号通路介导的基因调控

皮肤的毛囊干细胞具有自我复制以及多向分化潜能,在毛囊形态发育和定向分化过程中,Wnt信号通路起决定性作用。参与这条信号通路的重要蛋白质,如Wnt蛋白、Frizzled、B—catenin、GSK313、APC、Axin等研究相对较早,且颇为深入。但对于这条通路下游的调节因子,尤其是细胞核内关键性转录因子Tcf3、Lef1,以及它们所调控的一些重要基因c—myc、eyelinDl等的研究仍处于起步阶段。本文就Wnt信号通路介导的基因调节毛囊干细胞定向分化的研究现状进行综述．为构建组织工程皮肤提供理论参考。     

染料木素对维甲酸模型大鼠血生化指标和骨密度的作用

目的 :探讨染料木素对维甲酸所致骨质疏松模型大鼠的影响 .方法 :取SD雄性大鼠 2 5 6只 ,随机分为正常对照组、模型组、骨疏康组 (5g·kg-1)、染料木素大、中、小剂量组(18,9,4 .5mg·kg-1) .给予维甲酸 70mg·kg-1·d-1灌胃 2wk(正常对照组除外 ) ,分别于不同时间从各组取 8只大鼠对体质量、血生化指标和骨密度等进行测定 .结果 :染料木素①可增加维甲酸模型大鼠的左股骨质量、左胫骨质量 (P <0 .0 5或P <0 .0 1) ;②使模型大鼠的血清Ca ,P ,Mg,CT水平明显降低 ,BGP ,ALP水平升高 ,与模型组有显著差异 (P <0 .0 5或P <0 .0 1) ;③在 4 .5mg·kg-1,9mg·kg-1时可明显增强模型大鼠的股骨、胫骨和腰椎L2 -4的骨密度 (P <0 .0 5或P <0 .0 1) .结论 :染料木素可明显改善维甲酸模型大鼠的骨密度和血生化指标 ,对骨质疏松有较好的疗效     

毛囊混合细胞在胶原/壳聚糖多孔支架上重建毛囊样结构

目的探讨利用毛囊混合细胞植入胶原／壳聚糖多孔支架内体外重建毛囊的可行性。方法用滴加法或注射法将体外培养的C57BL／6J近交系乳鼠背部皮肤毛囊混合细胞以不同传代数、不同细胞密度接种至胶原／壳聚糖多孔支架，倒置显微镜下观察支架表面或浅层的细胞生长或毛囊形成情况。将支架经10％甲醛固定后行组织学观察（H-E染色）。另用共聚焦激光扫描显微镜观察支架内活细胞的生长以及毛囊样结构的形成。结果在一定传代次数和细胞密度下，在支架内可形成具有毛干的毛囊样结构。激光共聚焦扫描显微镜发现团块内细胞排列呈同心圆状，整个三维结构似一长颈花瓶，且该结构仅见于注射法接种细胞的支架内。结论毛囊混合细胞植入胶原／壳聚糖多孔支架内体外可形成具有毛干的毛囊样结构。     

Comparative biodistribution in mice of cyanine dyes loaded in lipid nanoparticles

Two near infrared cyanine dyes, DiD (1,1′-dioctadecyl-3,3,3′,3′-tetramethylindotricarbocyanine perchlorate) and ICG (Indocyanine Green) were loaded in lipid nanoparticles (LNP). DiD-LNP and ICG-LNP presented similar physicochemical characteristics (hydrodynamic diameter, polydispersity, zeta potential), encapsulation efficiency, and colloidal stability when stored in PBS buffer. However, whereas DiD had similar biodistribution than cholesteryl-1-¹⁴C-oleate ([¹⁴C]CHO, a constituent of the nanoparticle used as a reference radiotracer), ICG displayed a different biodistribution pattern, similar to that of the free dye, indicative of its immediate leakage from the nanovector after blood injection. NMR spectroscopy using Proton NOE (Nuclear Overhauser Effect) measurements showed that the localization of the dye in the lipid nanoparticles was slightly different: ICG, more amphiphilic than DiD, was found both inside the lipid core and at particle interface, whereas DiD, more hydrophobic, appeared exclusively located inside the particle core. The ICG release rate from the particles was 7% per 1 month under storage conditions (4 °C, dark, 10% of lipids), whereas no leakage could be detected for DiD. ICG leakage increased considerably in the presence of BSA 40 g/L (45% leakage in 24 h at 100 mg/mL of lipids), because of the high affinity of the fluorophore for plasma proteins. On the contrary, no DiD leakage was observed, until high dilution of the nanoparticles which triggered their dissociation (45% leakage in 24 h at 1 mg/mL of lipids). Altogether, the subtle difference in dye localization into the nanoparticles, the partial dissociation of the LNP in diluted media, and more importantly the high ICG affinity for plasma proteins, accounted for the differences observed in the fluorescence biodistribution after tail vein injection of the dye-loaded nanoparticles.     

Green and ecofriendly bio-removal of methylene blue dye from aqueous solution using biologically activated banana peel waste

Using of bio-wastes in dye adsorption is one of the greenest influential applied techniques for the removal of dyestuff from the industrial effluents and it considered as waste management. In the current study, banana peel waste (BPW) was used as an inexpensive and eco-friendly adsorbent for methylene blue (MB) dye. Mechanical pretreatment of BPW was carried out and followed by biological activation using Rhizopus microspores. MB dye was adsorbed by mechanically pretreated BPW (mBPW) by 31%. Moreover, the day nine fermented BPW fibers (mbBPW) is the best time for R. microspores to complete activation, where adsorption ratio reached to about 96.5%. Likewise, enzymes activity was recorded the highest activity after this period of fermentation, where enzymes activity of cellulase, xylanase, lignin peroxidase, poly phenol oxidase and laccase were 0.75, 0.68, 0.38, 0.55 and 0.32 U/ml, respectively. The FT-IR, SEM and BET were used to observe the effect of treatment on the BPW. Otherwise, the kinetics study is illustrated that the adsorption of MB with mbBPW fitted with pseudo-first-order kinetic models. However, the adsorption parameters indicated that the Langmuir model is better to describe the adsorption of dye with excellent maximum adsorption capacity 991 mg/g. In conclusion, biologically activated BPW is very efficient for dye adsorption as well as waste management.