激光照射对表皮郎格罕细胞的影响

郎格罕细胞(Langerhans cell,LC)是从骨髓中的前体细胞衍化而来的树枝状细胞,主要位于表皮基底层上方。有摄取抗原,处理抗原和传递抗原的功能,起着免疫系统外围前哨的作用。LC的功能可受各种理化因子的影响,是否也会受到激光照射的影响?本文的研究目的是探讨低功率CO_2激光照射后,表皮LC的数目、形态和分布的变化情况。     

Flexible Nanosomes (SECosomes) Enable Efficient siRNA Delivery in Cultured Primary Skin Cells and in the Viable Epidermis of Ex Vivo Human Skin

The extent to which nanoscale‐engineered systems cross intact human skin and can exert pharmacological effects in viable epidermis is controversial. This research seeks to develop a new lipid‐based nanosome that enables the effective delivery of siRNA into human skin. The major finding is that an ultraflexible siRNA‐containing nanosome—prepared using DOTAP, cholesterol, sodium cholate, and 30% ethanol—penetrates into the epidermis of freshly excised intact human skin and is able to enter into the keratinocytes. The nanosomes, called surfactant‐ethanol‐cholesterol‐osomes (SECosomes), show excellent size, surface charge, morphology, deformability, transfection efficiency, stability, and skin penetration capacity after complexation with siRNA. Importantly, these nanosomes have ideal characteristics for siRNA encapsulation, in that the siRNA is stable for at least 4 weeks, they enable highly efficient transfection of in vitro cultured cells, and are shown to transport siRNA delivery through intact human skin where changes in the keratinocyte cell state are demonstrated. It is concluded that increasing flexibility in nanosomes greatly enhances their ability to cross the intact human epidermal membrane and to unload their payload into targeted epidermal cells.     

Controllable Fabrication of Transparent Macroporous Graphene Thin Films and Versatile Applications as a Conducting Platform

Graphene sheets have been demonstrated to be the building blocks for various assembly structures, which eventually determine the macroscopic properties of graphene materials. As a new assembly structure, transparent macroporous graphene thin films (MGTFs) are not readily prepared due to the restacking tendency of graphene sheets during processing. Here, an ice crystal‐induced phase separation process is proposed for preparation of transparent MGTFs. The ice crystal‐induced phase separation process exhibits several unique features, including efficient prevention of graphene oxide restacking, easy control on the transparency of the MGTFs, and wide applicability to substrates. It is shown that the MGTFs can be used as porous scaffold with high conductivity for electrochemical deposition of various semiconductors and rare metal nanoparticles such as CdSe, ZnO, and Pt, as well as successive deposition of different materials. Notably, the macroporous structures bestow the MGTFs and the nanoparticle‐decorated MGTFs (i.e., Pt@MGTF and CdSe@MGTF) enhanced performance as electrode for oxygen reduction reaction and photoelectrochemical H₂ generation.     

An ultrastructural study on the effect of streptozotocin on the islets of Langerhans in mice

The ultrastructural changes in the morphology of the islets of Langerhans in response to streptozotocin were studied in the mice pancreas. Male white albino CSI mice were given a single intravenous injection of 75 mg kg(-1) body weight streptozotocin, and were sacrificed at different time intervals up to 48 h following the treatment. Their pancreases were excised and randomly processed for electron microscopic examination. Hyperglycaemia and glucosuria were detected 8 h after treatment, became remarkably high at 24 h and persisted then after. Light and electron microscopic examination of the islets of Langerhans from treated mice revealed an early chromatin aggregation and cytoplasmic vesiculation in the central B cells during the first 2 h of treatment. Nuclear shrinkage and pyknosis with swelling of mitochondria and endoplasmic reticulum were evident 8 h later, and lysis of B cells occurred 12 h after treatment. The morphology of A and D cells at the margin of the islets and in between B cell debris looked perfectly unaltered. Macrophage infiltration among lytic B cells was seen 24 h after drug administration, which contained clear and large phagocytic vacuoles. The necrobiotic and phagocytic figures disappeared from the pancreatic sections of 48 h treated mice, and the islets were smaller in size and consisted entirely of intact A and D cells with occasional degranulated B cells. No features of apoptosis were ever recorded, and the exocrine pancreatic tissue was protected from the effect of streptozotocin. In conclusion, the present study illustrates the sequence of morphological changes that occurs in the islets of Langerhans of mice after streptozotocin administration. It also confirms that streptozotocin at a high single dose in mice produces a specific necrosis of B cells with no evidence of apoptotic figures as another mechanism of cell death.     

氯胺酮对He-Ne激光照射促人正常皮肤成纤维细胞增殖作用的影响

针对动物模型伤口的光生物调节作用，用He-Xe激光对人正常皮肤成纤维细胞增殖的促进作用作为细胞模型．研究了麻醉药氯胺酮的影响。用MTT法测定细胞增殖作用。分别研究了1．56mW／cm^2He—Ne激光(0，10，30，100和300s照射)对人正常皮肤成纤维细胞的增殖作用和氯胺酮(0，0．6，1．2和2．0μg／mL)预处理划He—Ne激光(300s照射)细胞增殖作用的影响。氯胺酮(0．6，1．2,2．0μg/mL)预处理能抑制468．7mJ／cm^2He—Ne激光促人正常皮肤成纤维细胞增殖的作用。这说明动物实验中用于麻醉的药物可能对激光促进伤口愈合的实验结果有影响。     

Vogt-Koyanagi-Harada disease and vitiligo: where does the illness begin?

Vogt-Koyanagi-Harada (VKH) disease is a disorder affecting melanocytes of the skin, ocular, auditory and central nervous system. The pathogenesis is thought to be related to an aberrant T cell-mediated immune response directed against self-antigens present in melanocytes. Vitiligo is characterized by leukoderma arising at any age but usually before 30 years of age. The pathogenesis of vitiligo still remains puzzling; many hypotheses have been proposed, such as autoimmune, genetic, autocytotoxic, neural and each may contribute having its own important pathogenetic role. The expressions of the most representative melanocytic markers as HMB-45, tyrosinase, S-100 protein were investigated on the lesional, perilesional and healthy skin of a patient affected by VKH and his young daughter with vitiligo. An electronmicroscopy (EM) study was performed on the same clinical specimens. Immunohistochemical data for melanocytic cells using HMB-45 and tyrosinase were negative in the VKH patient, while the expression of both HMB-45 and tyrosinase was detected in the perilesional and lesional skin of the vitiligo patient. By EM, it was possible to show many Langerhans cells (LC) in many differentiative phases, most of which with irregular cristae or matrix swelling in both the ultraviolet (UV)-exposed and non-UV-exposed skin of VKH lesions. In both vitiligo and VKH lesions, there is a disappearance of melanocytes and an alteration of LC distribution and mitochondrial morphology which may impair the antigen-presenting functions. The vitiligo lesions in the patient's young daughter question the VKH inheritability.     

Tuning the Rigidity of Silk Fibroin for the Transfer of Highly Stretchable Electronics

The transfer of stretchable electrodes or devices from one substrate to another thin elastomer is challenging as the elastic stamp often yields a huge strain beyond the stretchability limit of the electrodes at the debonded interface. This will not happen if the stamp is rigid. However, a rigid material cannot be used as the substrate for stretchable electrodes. Herein, silk fibroin with tunable rigidity (Young's modulus can be changed from 134 kPa to 1.84 GPa by controlling the relative humidity) is used to transfer highly stretchable metal networks as highly conformable epidermal electrodes. The silk fibroin stamp is tuned to be rigid during peeling, and then be soft and highly stretchable as a substrate when laminated on moisturized human skin. In addition, the epidermal electrodes exhibit no skin irritation or inflammation after attaching for over 10 d. The high compliance results in a lower interface impedance and lower noises of the electrode in measuring electromyographic signals, compared with commercial Ag‐AgCl gel electrodes. The strategy of tuning the rigidity at different stages of transfer is a general method that can be extended to the transfer of other stretchable electrodes and devices for epidermal electronics, human machine interfaces, and soft robotics.     

双氢青蒿素对前列腺癌裸鼠种植瘤CHOP表达的影响

目的：研究双氢青蒿素对前列腺癌PC-3细胞裸鼠种植瘤CHOP表达的情况,并探讨其作用途径及机制。方法：采用人前列腺癌PC-3细胞建立裸鼠种植瘤模型,20只模型鼠随机分为对照组、溶剂组、实验1组及实验2组,经13d干预后,免疫组织化学法检测CHOP的表达水平;透射电子显微镜观察DHA对PC-3细胞种植瘤超微结构的影响。结...     

The cells of murine sarcoma PC-103 induced by a polymeric plate secret transforming growth factor alpha

It was shown previously that cells of sarcoma PS-103 induced in mouse by subcutaneous transplantation of plastic film produce growth-stimulating activity. In this communication clone 3 sb, isolated from sarcoma PS-103, was studied. Growth factor produced by the cells of this clone stimulated proliferation of quasi-normal (3T3, NRK) cells and transformed cells both in monolayer and in semi-solid medium. It was shown by gel filtration chromatography that the main growth-stimulating activity migrated with the protein fraction m.m. 10-15 kDa. The addition of this growth factor to the culture medium significantly (90%) inhibited 125I-EGF (epidermal growth factor) binding by A-431 cells. These data suggest that the growth factor produced by the studied tumor cells is transforming growth factor alpha.     

An EDTA-KOH method to expose bone cells for scanning electron microscopy.

To observe bone cells by scanning electron microscopy (SEM), the mouse parietal bones were processed by decalcification with EDTA and digestion of collagen fibers with KOH to remove the bone matrix, in addition to the conventional preparation for SEM. The critical-point-dried specimens were split into two membranous pieces along the gaps formed by removing the bone matrix. By this method, osteoclasts showing full three-dimensional images of ruffled borders, osteoblasts showing special structures on the surfaces facing the bone matrix, and osteocytes extending many slender processes were clearly demonstrated in SEM. This new method may provide new viewpoints in bone cell biology.     

低温冷冻对皮肤组织桥粒芯糖蛋白1表达影响的实验研究

目的观察桥粒芯糖蛋白1（Desmogleinl,Dsg1）在不同温度保存皮肤组织中的分布,以探讨其与皮肤冷冻损伤的关系。方法用Dsg1抗体对5种保存条件下的皮肤组织作免疫组化染色,采用计算机图像定量分析方法测定表皮组织中的含量,并用H．E染色观察皮肤的组织结构变化。结果与新鲜皮片组相比,-196℃条件下皮肤组织结构保存较好,Dsg1含量变化不明显,而4℃、-20℃、-80℃保存皮肤组织结构破坏明显,含量亦明显下降。结论皮肤低温保存冷冻损伤可能与桥粒跨膜蛋白Dsg1破坏有关。     

Hyperspectral Fluorescence Imaging for Mouse Skin Tumor Detection

This paper presents a hyperspectral imaging technique based on laser‐induced fluorescence for non‐invasive detection of tumorous tissue on mouse skin. Hyperspectral imaging sensors collect image data in a number of narrow, adjacent spectral bands. Such high‐resolution measurement of spectral information reveals contiguous emission spectra at each image pixel useful for the characterization of constituent materials. The hyperspectral image data used in this study are fluorescence images of mouse skin consisting of 21 spectral bands in the visible spectrum of the wavelengths ranging from 440 nm to 640 nm. Fluorescence signal is measured with the use of laser excitation at 337 nm. An acousto‐optic tunable filter (AOTF) is used to capture images at 10 nm intervals. All spectral band images are spatially registered with the reference band image at 490 nm to obtain exact pixel correspondences by compensating the spatial offsets caused by the refraction differences in AOTF at different wavelengths during the image capture procedure. The unique fluorescence spectral signatures demonstrate a good separation to differentiate malignant tumors from normal tissues for rapid detection of skin cancers without biopsy.     

The use of the catastrophe theory method in simulating dynamics of multi-stage skin cancerogenesis

A mathematical model of multistage mouse skin carcinogenesis which describes a qualitative dynamics of this phenomenon is suggested. According to this model the change in the internal state of initiated cells in promotion is determined by geometry of the Whitney catastrophe into which the surface of conditions of intact cells is transformed as a result of initiation. Molecular events underlying the convertible and unconvertible expression of a transformed phenotype by an initiated cell under the promoter action, as well as the relationship of these processes to the mechanisms of oncogene activation are discussed.     

ELF and VLF Shielding Effectiveness of High-Permeability Materials

Research was conducted to determine the low-frequency shielding effectiveness of magnetic materials. Both analytical and experimental approaches were used. This work is unique in that it provides a technique for experimental separation of the various terms in the shielding expression. Expressions of shielding effectiveness of flat sheets for very low frequencies are derived, and the results of experiments with the following are given: 1) sheet materials, including AMPB-65,1 HyMu 80, conetic AA, mumetal, copper-plated AMPB-65, and galvannealed steel; 2) AMPB-65 sheets perforated with various size holes and various numbers of 0.125-inch diameter holes; 3) an overlap junction of two AMPB-65 sheets with a) various numbers of fastening screws and b) various depths of overlap; 4) overlap junctions of copper-plated AMPB-65 sheets; 5) AMPB-65 sheets clamped in Lindsay structure; and 6) honeycomb-core stainless steel sandwiches.     

Nitrogen doped anatase TiO2 sheets with dominant {001} facets for enhancing visible-light photocatalytic activity

The photocatalytic activity of TiO₂ can be mainly improved from three approaches: (1) enhancing surface energy; (2) increasing availability of visible light and (3) improving the separation efficiency of photo-induced electrons and holes. Here, we report a one-step route to obtain nitrogen (N) doped TiO₂ sheets with dominant {001} facets by a hydrothermal process. The XRD patterns confirm the better crystallinity. XPS spectrums show nitrogen acting as interstitial N or an O–Ti–N structure in TiO₂ sheets. Compared with that of TiO₂ sheets, the N doped TiO₂ sheets not only absorb visible light, but also have a large percentage of high reactive {001} facets, so the photocatalytic activities are greatly enhanced, as confirmed by the decomposition of methylene orange.     

Simultaneous Molecular and Hypoxia Imaging of Brain Tumors In Vivo Using Spectroscopic Photoacoustic Tomography

Noninvasive molecular and functional imaging in vivo is promising for detecting and monitoring various physiological conditions in animals and ultimately humans. To this end, we present a novel noninvasive technology, spectroscopic photoacoustic tomography (SPAT), which offers both strong optical absorption contrast and high ultrasonic spatial resolution. Optical contrast allows spectroscopic separation of signal contributions from multiple optical absorbers (e.g., oxyhemoglobin, deoxyhemoglobin, and a molecular contrast agent), thus enabling simultaneous molecular and functional imaging. SPAT successfully imaged with high resolution the distribution of a molecular contrast agent targeting integrin overexpressed in human U87 glioblastomas in nude mouse brains. Simultaneously, SPAT also imaged the hemoglobin oxygen saturation and the total hemoglobin concentration of the vasculature, which revealed hypoxia in tumor neovasculature. Therefore, SPAT can potentially lead to better understanding of the interrelationships between hemodynamics and specific biomarkers associated with tumor progression.     

一例Netherton综合征患者皮肤和毛发的电镜观察

目的：电镜观察Netherton综合征皮肤和毛发的超微结构改变。方法：对一例21岁Netllerton综合征男性患者的皮肤及头发毛干进行透射电镜及扫描电镜观察。结果：透射电镜观察显示，表皮角质层角质细胞分离，角质细胞间隙见板层小体、电子致密颗粒及变性桥粒，角质细胞内见多量脂滴。扫描电镜观察显示毛干呈竹节样改变伴有毛小皮断裂和剥脱。结论：表皮角质层细胞间的板层小体及电子致密颗粒是Netherton综合征特征性的超微结构。电镜观察对Netherton综合征的早期诊断有意义。     

Harvesting of Living Cell Sheets by the Dynamic Generation of Diffractive Photothermal Pattern on PEDOT

Near infrared (NIR) photothermal pattern on conductive polymer film enables unique approaches to harvest large‐area cell sheets with various patterns without the use of patterned culture dish. The NIR photothermal pattern is generated from a patterned optical lens (POL), which creates a dynamic near IR light pattern and the corresponding photothermal pattern (PTP) on the polymer film. The POL is prepared from transparent polydimethylsiloxane designed to generate various light patterns. The PTPs allow a noninvasive harvest of cultured cells as an intact living cell sheet with a high harvesting efficiency (η_cell > 100). Various PTPs are generated by the diffraction of NIR light through POLs having different micropatterns, which afford cell sheets with a desired pattern without changing the original cell morphology at cultured state. Furthermore, a large‐area living cell sheet is obtained with a detached area larger than 19 cm², which is the largest living cell sheet up to date. Further optical engineering of the harvesting system allows multiple productions of cell sheets with one dose of light. It is possible to harvest cell sheets not only from human fibroblast cells but also from human adipose‐derived stem cells, indicating that the method can be applied to engineer various cells.     

紫茎泽兰器官表面微形态的观察

紫茎泽兰为世界性的恶性杂草，严重影响了世界30多个国家的农、林、牧、副业的发展。本文利用扫描电子显微镜和光学显微镜对紫茎泽兰的茎、叶、花、果实及种子等各种器官表皮微形态特征进行了比较观察。结果表明：气孔器分布于叶的远轴面、茎表皮和总苞片的远轴面，其中在叶的远轴面上具两型性气孔器。单列多细胞表皮毛在叶的远轴面、茎表皮、总苞片的远轴面和花瓣的远轴面均有分布。具两列柄细胞的腺毛分布于总苞片的远轴面，而具单列柄细胞的腺毛见于花瓣的远轴面和茎表面。在花瓣的近轴面和柱头表面有长乳突状细胞。通过对其不同器官表面微形态性状的进一步统计分析表明，各种器官的表皮细胞大小、气孔开口度与间距、表皮毛与乳突状细胞的长度及间距等均存在显著性差异。上述观察结果，为进一步探讨外来恶性杂草紫茎泽兰的生态分布和生活习性，以及检疫部门鉴定该种植物提供重要依据。