Tattoo Removal by Split Thickness Tangential Excision

Split thickness tangential excision is a simple means of tattoo removal with very acceptable cosmetic results. The technique has several advantages. (1) The depth of skin removal may accurately be controlled as the tattoo pigment is excised with a dermatome. The major portion, if not all of the remaining pigment, is extruded and sloughs with the crust. (2) Scar formation, if it occurs at all, is negligible. (3) No donor site is created. (4) The procedure may be carried out rapidly without admitting patients to hospital, is inexpensive for patients and conserves time for physicians.     

DNA-vaccination via tattooing induces stronger humoral and cellular immune responses than intramuscular delivery supported by molecular adjuvants

Tattooing is one of a number of DNA delivery methods which results in an efficient expression of an introduced gene in the epidermal and dermal layers of the skin. The tattoo procedure causes many minor mechanical injuries followed by hemorrhage, necrosis, inflammation and regeneration of the skin and thus non-specifically stimulates the immune system. DNA vaccines delivered by tattooing have been shown to induce higher specific humoral and cellular immune responses than intramuscularly injected DNA. In this study, we focused on the comparison of DNA immunization protocols using different routes of administrations of DNA (intradermal tattoo versus intramuscular injection) and molecular adjuvants (cardiotoxin pre-treatment or GM-CSF DNA co-delivery). For this comparison we used the major capsid protein L1 of human papillomavirus type 16 as a model antigen. L1-specific immune responses were detected after three and four immunizations with 50 μg plasmid DNA. Cardiotoxin pretreatment or GM-CSF DNA co-delivery substantially enhanced the efficacy of DNA vaccine delivered intramuscularly by needle injection but had virtually no effect on the intradermal tattoo vaccination. The promoting effect of both adjuvants was more pronounced after three rather than four immunizations. However, three DNA tattoo immunizations without any adjuvant induced significantly higher L1-specific humoral immune responses than three or even four intramuscular DNA injections supported by molecular adjuvants. Tattooing also elicited significantly higher L1-specific cellular immune responses than intramuscularly delivered DNA in combination with adjuvants. In addition, the lymphocytes of mice treated with the tattoo device proliferated more strongly after mitogen stimulation suggesting the presence of inflammatory responses after tattooing. The tattoo delivery of DNA is a cost-effective method that may be used in laboratory conditions when more rapid and more robust immune responses are required.     

Electron microscopic identification and morphologic preservation of enriched populations of lung cells isolated by laser flow cytometry and cell sorting: a new technique

There is increasing need to verify the identities of cell subpopulations enriched by laser flow cytometry and fluorescence-activated cell sorting (FACS). When cell subpopulations isolated from whole organs or tissues have similar characteristics (e.g., size, granularity, staining), light, phase contrast or fluorescence microscopy may not provide sufficient resolution to identify isolated cells accurately and many flow cytometric parameters (e.g., viability, fluorescence) require the cells to be live at the point of analysis where the cell transects the laser beam. In some studies, cells identified by fluorescence microscopy as a highly enriched subpopulation were found by electron microscopy to contain significant populations of other cell types. A technique, fixation-in-flow (FIF), has been developed to increase ability to correlate morphological and laser analyses of cell subpopulations. Sheath fluid is replaced by fixative, permitting fixation to be initiated immediately after laser beam analysis of live cells. This new procedure yields improved cytoarchitectural preservation of recovered cell subpopulation(s) for evaluation by transmission or scanning electron microscopy. This report presents results from applying the methodology to identify more accurately cell subpopulations of the distal lung, specifically type II pneumocytes, Clara cells and pulmonary macrophages. A modification of this procedure was employed to isolate fibroblast subpopulations from murine lung fibroblasts grown in vitro and the procedure is being used to determine the responses of cultured fibroblasts to other permutations (e.g., X-irradiation, cytokines).     

Tattoo and piercing as signals of biological quality

Tattoos and non-conventional piercings are used in many societies. There are several social reasons for which people use these forms of body decorations (e.g., marking social status or signaling membership within a subculture). However, it is interesting why only some people within a group that uses body decoration as a badge of membership decide upon such decorations. Since both tattoos and piercings can present health risks (e.g., due to blood-borne disease transmission risk), we postulate that people who decide to have such a body decoration might have relatively higher biological quality and that tattoos/piercings can be an honest signal of genetic quality. The possible opposite hypothesis is the “attractiveness increase hypothesis,” according to which people use body decorations to increase their own physical attractiveness or to hide some shortcomings in their appearance (e.g., low body symmetry). To test these hypotheses, we compared body fluctuating asymmetry, which is considered a good measure of developmental stability, between individuals wearing tattoos and/or non-conventional piercings (n=116) and a control group (without such body decorations) (n=86). We found that majority of the absolute and relative fluctuating asymmetry indices had significantly lower values in individuals with tattoos/piercings than in the control group. This effect was strongly driven by males. Higher body symmetry of the men having tattoo or piercing indicates that this type of body decoration in the western society can be related to the honest signal of biological quality only for men. We did not find support for the “attractiveness increase hypothesis” for either sex.     

光合作用对光和CO2响应模型的研究进展

光合作用对光和CO₂响应模型是研究植物生理和植物生态学的重要工具, 可为植物光合特性对主要环境因子的响应提供科学依据。该文综述了当前光合作用对光和CO₂响应模型的研究进展和存在的问题, 并在此基础上探讨了这些模型的可能发展趋势。光合作用涉及光能的吸收、能量转换、电子传递、ATP合成、CO₂固定等一系列复杂的物理和化学反应过程。光合作用由原初反应、同化力形成和碳同化3个基本过程构成, 任一个过程均可对光合作用速率产生直接的影响。光合作用对光响应模型只涉及光能的转换, 而光合作用的生化模型包含了同化力形成和碳同化这两个基本过程。把光合作用的原初反应, 即把参与光能吸收、传递和转换的捕光色素分子的物理参数(如捕光色素分子数、捕光色素分子光能吸收截面、捕光色素分子处于激发态的平均寿命等)结合到生化模型中, 可能是今后光合作用对光响应机理模型的发展方向。     

Dose‐dependent study of effects of 532‐nm continuous wave laser on rat skin: A mechanistic insight

Visible lasers emitting in the green spectral region are being routinely employed in various medical and defense fields namely treatment of pigmented lesions, tattoo inks, port wine stains, dazzling the target or mob dispersal. Despite their increasing applications, lasers also tend to pose occupational hazards to operators, ancillary personnel, individuals undergoing laser therapies. This study was aimed at investigating the effects of different doses of 532‐nm continuous wave laser on rat skin. The present study demonstrated that higher fluences of 532‐nm continuous wave (CW) laser induces significant tissue damage through induction of tumor necrosis factor‐α, cyclooxygenase‐2, tumor protein (p53), PARP 1, caspase3 which in turn leads to tissue damage and cell death. Furthermore, level of heat shock proteins, pAkt were found up‐regulated as a cope up response to laser‐induced stress. On the basis of the findings, irradiation with 532‐nm CW laser up to 2.5 J/cm² was found within the safe exposure limits. Thus, it is probably the first attempt to demonstrate the tissue damage induced by 532‐nm CW laser on skin, which may help in choosing safe laser dose for certain skin‐based applications and evolving methods to ameliorate laser‐inflicted injuries.     

Melanin storing cells in anuran gut

1. The location, distribution and morphological characteristics of the pigment cells found in the frog gut are described. 2. The pigment cells show long and large protoplasmic projections. At the ultrastructural level, the nucleus is elongated with prominent nucleolus and dense marginal chromatin. The cytoplasm is full with pigment granules (2500-7500 A) and typical premelanosome structures have been observed. 3. The pigment cells number is higher in the esophagus and large intestine than in the stomach or small intestine and the pigment cells are always located in close contact with blood vessels and nervous structures (ganglia and fibres). 4. We have observed that the pigment content depends upon seasonal variations, increasing during the cold months. 5. We have demonstrated by histological methods that the cells pigment content is melanin. 6. According to their morphological and tinctorial characteristics the anuran gut melanin storing cells are similar to the skin epidermal melanocytes.     

Nonlinear optical absorption of photosynthetic pigment molecules in leaves

A mathematical formulation of the relationship between optical absorption coefficient of photosynthetic pigment molecules and light intensity was developed. It showed that physical parameters of photosynthetic pigment molecule (i.e., light absorption cross-section of photosynthetic pigment molecule, its average lifetime in the excited state, total photosynthetic pigment molecules, the statistical weight, or degeneracy of energy level of photosynthetic pigment molecules in the ground state and in the excited state) influenced on both the light absorption coefficient and effective light absorption cross-section of photosynthetic pigment molecules. Moreover, it also showed that both the light absorption coefficient and effective light absorption cross-section of photosynthetic pigment molecules were not constant, they decreased nonlinearly with light intensity increasing. The occupation numbers of photosynthetic pigment molecules in the excited states increased nonlinearly with light intensity increasing.     

Morphological Characteristics of the Dorsal Skin of Two Hynobiids and Their Adaptive Role in Aquatic and Terrestrial Habitats

The morphological characteristics of the dorsal skin of trunk in two species of hynobiid salamanders, Batrachuperus pinchonii and Hynobius chinensis were examined by light microscopy. The basic structures of the skin in the two species are similar and consist of two layers: epidermis and dermis. The epidermis consists of stratum corneum, stratum intermedium and stratum germinativum, while the dermis is composed of a stratum spongiosum and stratum compactum. However, some species-specific variation has been identified(e.g., the distribution of capillary vessels and gland cells, and the thickness of skin). H. chinensis is a terrestrial species and only lives in water during breeding period, but B. pinchonii is aquatic and remains aquatic throughout its lifetime. The differences in the distribution of capillary vessels and gland cells are related to their different habitats, and show a morphological adaptation.     

Comparison between TEWL and laser scanning microscopy measurements for the in vivo characterization of the human epidermal barrier

The analysis of the skin barrier properties is important in various fields of medical treatment and cosmetology. The development and improvement of topically applied substances require an objective analysis of the skin barrier characteristics. Transepidermal water loss (TEWL) measurement is the standard method to characterize epidermal barrier function. The most important disadvantage of this method though, is that it can be affected by different exogenous and endogenous factors, e.g. water content of the applied formulation and room temperature. In the present study, TEWL measurements are compared to laser scanning microscopic (LSM) measurements, concerning the use of these two methods for the non‐invasive in vivo characterization of the epidermal barrier function. The investigations were performed prior and subsequent to treatment of dry skin with a gel mixture, developed for skin treatment after radiotherapy for cancer. The present results indicate that in vivo laser scanning microscopy is an appropriate method for the characterization of the skin barrier structure without interference by external factors. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Functional genomics tools for the analysis of zebrafish pigment

Genetic model organisms are increasingly valuable in the post-genomics era to provide a basis for comparative analysis of the human genome. For higher order processes of vertebrate pigment cell biology and development, the mouse has historically been the model of choice. A complementary organism, the zebrafish (Danio rerio), shares many of the signaling and biological processes of vertebrates, e.g. neural crest development. The zebrafish has a number of characteristics that make it an especially valuable model for the study of pigment cell biology and disease. Large-scale genetic screens have identified a collection of pigmentation mutants that have already made valuable contributions to pigment research. An increasing repertoire of genomic resources such as an expressed sequence tag-based Gene Index (The Institute for Genomic Research) and improving methods of mutagenesis, transgenesis, and gene targeting make zebrafish a particularly attractive model. Morpholino phosphorodiamidate oligonucleotide (MO) 'knockdown' of pigment gene expression provides a non-conventional antisense tool for the analysis of genes involved in pigment cell biology and disease. In addition, an ongoing, reverse-genetic, MO-based screen for the rapid identification of gene function promises to be a valuable complement to other high-throughput microarray and proteomic approaches for understanding pigment cell biology. Novel reagents for zebrafish transgenesis, such as the Sleeping Beauty transposon system, continue to improve the capacity for genetic analysis in this system and ensure that the zebrafish will be a valuable genetic model for understanding a variety of biological processes and human diseases for years to come.     

Environmental pollutants and skin cancer

We are increasingly exposed to environmental pollution. Pollutants can be inhaled, ingested or come into contact with the skin depending on the form in which they occur. On metabolization, activation, or accumulation, pollutants can become extremely toxic for the vital organs and this is often related to a strong genotoxic effect. Since the skin acts as a barrier between the organism and the environment, it is frequently directly exposed to pollution. It is very often degraded by polluting agents and acts as an inlet toward other tissues. Numerous studies in man recognize and demonstrate the carcinogenic power of certain pollutants in the digestive and respiratory tracts. The "pollutants" that react most specifically with the skin are: ultraviolet radiation, polycyclic aromatic hydrocarbons (e.g., benzo[a]pyrene), volatile organic compounds (e.g., benzene), heavy metals, and ozone. Ultraviolet radiation, a "physical" pollutant, has been described as being the factor responsible for most skin cancers in man. The genotoxicity of UV light is well documented (type of lesion or mutation, etc.) and its carcinogenic effect is clearly demonstratedin vivo in man. A few epidemiological studies describe the carcinogenicity of certain pollutants such as arsenic or lead on the skin. However, most of the evidence for the role of pollutants in skin cancers comes fromin vivo animal studies or fromin vitro studies (e.g., PAHs). In this report, different studies are presented to illustrate the research strategies developed to investigate the mechanism of action of "chemical" pollutants and their potential role in human skin pathology. All the study models and the associated techniques of investigation are tools for a better understanding and thus more efficient prevention of the deleterious effects caused by the environment. This revised version was published online in August 2006 with corrections to the Cover Date.     

Thermal Transport Characteristics of Human Skin Measured In Vivo Using Ultrathin Conformal Arrays of Thermal Sensors and Actuators

Measurements of the thermal transport properties of the skin can reveal changes in physical and chemical states of relevance to dermatological health, skin structure and activity, thermoregulation and other aspects of human physiology. Existing methods for in vivo evaluations demand complex systems for laser heating and infrared thermography, or they require rigid, invasive probes; neither can apply to arbitrary regions of the body, offers modes for rapid spatial mapping, or enables continuous monitoring outside of laboratory settings. Here we describe human clinical studies using mechanically soft arrays of thermal actuators and sensors that laminate onto the skin to provide rapid, quantitative in vivo determination of both the thermal conductivity and thermal diffusivity, in a completely non-invasive manner. Comprehensive analysis of measurements on six different body locations of each of twenty-five human subjects reveal systematic variations and directional anisotropies in the characteristics, with correlations to the thicknesses of the epidermis (EP) and stratum corneum (SC) determined by optical coherence tomography, and to the water content assessed by electrical impedance based measurements. Multivariate statistical analysis establishes four distinct locations across the body that exhibit different physical properties: heel, cheek, palm, and wrist/volar forearm/dorsal forearm. The data also demonstrate that thermal transport correlates negatively with SC and EP thickness and positively with water content, with a strength of correlation that varies from region to region, e.g., stronger in the palmar than in the follicular regions.     

高产红曲黄色素菌株的选育

利用紫外、硫酸二乙酯、氯化锂和亚硝基胍复合诱变的方法,选育到一株高产黄色素的红曲霉突变株MYM2.经过稳定性实验证明,诱变得到的菌株稳定性较好,液态发酵试验黄色素色价达到100U/mL以上,黄色素色调达到3.5左右.此黄色素在300nm～600nm波长之间只有一个在410 nm附近的最大吸收峰,在pH 3～8之间稳定性较好.当pH小于3时,红曲黄色素不稳定,黄色素溶液变混浊,放置后有沉淀产生.     

Electron Microscopic Identification and Morphologic Preservation of Enriched Populations of Lung Cells Isolated by Laser Flow Cytometry and Cell Sorting: A New Technique

There is increasing need to verify the identities of cell subpopulations enriched by laser flow cytometry and fluorescence-activated cell sorting (FACS). When cell subpopulations isolated from whole organs or tissues have similar characteristics (e.g., size, granularity, staining), light, phase contrast or fluorescence microscopy may not provide sufficient resolution to identify isolated cells accurately and many flow cytometric parameters (e.g., viability, fluorescence) require the cells to be live at the point of analysis where the cell transects the laser beam. In some studies, cells identified by fluorescence microscopy as a highly enriched subpopulation were found by electron microscopy to contain significant populations of other cell types. A technique, fixation-in-flow (FIF), has been developed to increase ability to correlate morphological and laser analyses of cell subpopulations. Sheath fluid is replaced by fixative, permitting fixation to be initiated immediately after laser beam analysis of live cells. This new procedure yields improved cytoarchitectural preservation of recovered cell subpopulation(s) for evaluation by transmission or scanning electron microscopy. This report presents results from applying the methodology to identify more accurately cell subpopulations of the distal lung, specifically type II pneumocytes, Clara cells and pulmonary macrophages. A modification of this procedure was employed to isolate fibroblast subpopulations from murine lung fibroblasts grown in vitro and the procedure is being used to determine the responses of cultured fibroblasts to other permutations (e.g., X-irradiation, cytokines).     

Scavenging of photogenerated oxidative species by antimuscarinic drugs: atropine and derivatives

The quenching ability of photogenerated oxidative species by some antimuscarinic drugs generically named atropines (e.g. atropine [I] eucatropine [II], homatropine [III] and scopolamine [IV]) have been investigated employing stationary photolysis, polarographic detection of dissolved oxygen, stationary and time-resolved fluorescence spectroscopy, and laser flash photolysis. Using Rose Bengal as a dye sensitiser for singlet molecular oxygen, O(2)((1)Delta(g)), generation, compounds I-IV behave as moderate chemical plus physical quenchers of the oxidative species. Correlation between kinetic and electrochemical data indicates that the process is possibly driven by a charge-transfer interaction. The situation is somewhat more complicated employing the natural pigment riboflavin (Rf) as a sensitiser. Compounds I and II complex Rf ground state, diminishing the quenching ability towards singlet and triplet excited state of the pigment. On the other hand, compounds III and IV effectively quench Rf excited states, protecting the pigment against photodegradation. Under anaerobic conditions, semireduced Rf (Rf(.-)) is formed through quenching of excited triplet Rf. Nevertheless, although Rf(.-) is a well-known generator of the reactive species superoxide radical anion by reductive quenching in the presence of oxygen, the process of O(2)((1)Delta(g)) production prevails over superoxide radical generation, due to the relatively low rate constants for the quenching of triplet Rf by the atropines (in the order of 10(7) M(-1)s(-1) for compounds III and IV) in comparison to the rate constant for the quenching by ground state oxygen, approximately two orders of magnitude higher, yielding O(2)((1)Delta(g)). Compound I is the most promising O(2)((1)Delta(g)) physical scavenger, provided that it exhibits the higher value for the overall quenching rate constant and only 11% of the quenching process leads to its own chemical damage.     

An automated method for consistent helix assignment using turn information

A new automated helix assignment method is presented that leads to a more consistent definition of the helix termini, especially of the helix C-terminus. The method assigns a helix to segments of protein chain where adjacent helical turn structures are observed, capped by specific distorted turn types (e.g., open helical turns without a hydrogen bond) or capping motifs (e.g., the Schellman motif). Helix termini are detected by observing the behavior of the NH group in N-termini and the CO group in C-termini; in each case, the respective group must be free to interact with hydrogen bonding partners outside of the putative helix for a helix terminus to be assigned. The presented assignment method and SHAFT-assigned helices are part of Secbase and are made available with Relibase+ 3.0 and the free web version of Relibase 3.0. The method can also be used for the helix assignments of additional protein structures.     

Tetrahedron DNA dendrimers and their encapsulation of gold nanoparticles

DNA dendrimers have achieved increasing attention recently. Previously reported DNA dendrimers used Y-DNA as monomers. Tetrahedron DNA is a rigid tetrahedral cage made of DNA. Herein, we use tetrahedron DNA as monomers to prepare tetrahedron DNA dendrimers. The prepared tetrahedron DNA dendrimers have larger size compared with those made of Y-DNA. In addition, thanks to the central cavity of tetrahedron DNA monomers, some nanoscale structures (e.g., gold nanoparticles) can be encapsulated within tetrahedron DNA monomers. Tetrahedron DNA encapsulated with gold nanoparticles can be further assembled into dendrimers, guiding gold nanoparticles into clusters.     

Allopurinol-induced melanism in the tiger salamander (Ambystoma tigrinum nebulosum).

The enzyme, xanthine dehydrogenase (XDH), has been examined in Ambystoma tigrinum nebulosum with respect to its role in pigmentation. It now seems probable that the melanoid gene (m) either codes directly for XDH or is somehow intimately connected with the normal function of this enzyme. Inhibition of XDH using the drug, allopurinol, results in animals which appear to be phenocopies of melanoid mutants as described for the Mexican axolotl (Ambystoma mexicanum). The effects of allopurinol in terms of specific pigmentary alterations were examined, and a new method for analyzing heterogeneous extracts of skin pigments (e.g., purines and pteridines) is presented. The significance of the link between XDH and melanism is discussed with emphasis on possible mechanisms of pigment induction and general applicability to biological systems.