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Sample records for skin tissue heterogeneity

  1. Nanofibrous asymmetric membranes self-organized from chemically heterogeneous electrospun mats for skin tissue engineering.

    PubMed

    Wu, Chaoxi; Chen, Tian; Xin, Yanjiao; Zhang, Zhen; Ren, Zhe; Lei, Jing; Chu, Bin; Wang, Yifei; Tang, Shunqing

    2016-01-01

    Asymmetric membranes, which mimic the structure and functions of human skin, have been extensively pursued as ideal skin tissue engineering constructs. In this study, we demonstrated that nanostructured asymmetric membranes can be prepared by the self-organization of chemically heterogeneous bilayer electrospun membranes in aqueous solutions. Structurally, the skin layer consists of hydrophobic β-glucan butyrate nanofibers and its inner layer consists of hydrophilic β-glucan acetate nanofibers. After the electrospinning process, both of the layers are in a dense state. When placed in water, the skin layer absorbs little water and still remains dense, but the fibers in the inner layer become extensively hydrated and spontaneously reorganize into a fully stretched structure, resulting in a significant volume increase and a density decrease of the inner layer. SEM imaging showed that β-glucan ester nanofibers exhibited a bead-free and uniform structure. Contact angle measurement and swelling tests showed that the inner layer was highly hydrophilic with extensive swelling, but the skin layer was highly hydrophobic with little swelling. Mechanical tests indicated that the nanofibrous asymmetric membranes had good mechanical properties in both the dry and wet states. In vitro cytocompatibility tests showed that nanofibrous asymmetric membranes could promote the adhesion and proliferation of fibroblasts and keratinocytes. A preliminary in vivo study performed on a full thickness mouse skin wound model demonstrated that the nanofibrous asymmetric membranes significantly accelerated the wound healing process by promoting re-epithelialization, tissue remodeling and collagen deposition. Taken together, our study provides a novel model for the design and fabrication of nanostructured asymmetric membranes, and our β-glucan based nanofibrous asymmetric membranes could be used as an advanced platform for skin tissue engineering. PMID:27327625

  2. Biothermomechanics of skin tissues

    NASA Astrophysics Data System (ADS)

    Xu, F.; Lu, T. J.; Seffen, K. A.

    Biothermomechanics of skin is highly interdisciplinary involving bioheat transfer, burn damage, biomechanics and neurophysiology. During heating, thermally induced mechanical stress arises due to the thermal denaturation of collagen, resulting in macroscale shrinkage. Thus, the strain, stress, temperature and thermal pain/damage are highly correlated; in other words, the problem is fully coupled. The aim of this study is to develop a computational approach to examine the heat transfer process and the heat-induced mechanical response, so that the differences among the clinically applied heating modalities can be quantified. Exact solutions for temperature, thermal damage and thermal stress for a single-layer skin model were first derived for different boundary conditions. For multilayer models, numerical simulations using the finite difference method (FDM) and finite element method (FEM) were used to analyze the temperature, burn damage and thermal stress distributions in the skin tissue. The results showed that the thermomechanical behavior of skin tissue is very complex: blood perfusion has little effect on thermal damage but large influence on skin temperature distribution, which, in turn, influences significantly the resulting thermal stress field; the stratum corneum layer, although very thin, has a large effect on the thermomechanical behavior of skin, suggesting that it should be properly accounted for in the modeling of skin thermal stresses; the stress caused by non-uniform temperature distribution in the skin may also contribute to the thermal pain sensation.

  3. Skin tissue engineering.

    PubMed

    Mansbridge, Jonathan

    2008-01-01

    The major applications of tissue-engineered skin substitutes are in promoting the healing of acute and chronic wounds. Several approaches have been taken by commercial companies to develop products to address these conditions. Skin substitutes include both acellular and cellular devices. While acellular skin substitutes act as a template for dermal formation, this discussion mainly covers cellular devices. In addressing therapeutic applications in tissue engineering generally, a valuable precursor is an understanding of the mechanism of the underlying pathology. While this is straightforward in many cases, it has not been available for wound healing. Investigation of the mode of action of the tissue-engineered skin substitutes has led to considerable insight into the mechanism of formation, maintenance and treatment of chronic wounds. Four aspects mediating healing are considered here for their mechanism of action: (i) colonization of the wound bed by live fibroblasts in the implant, (ii) the secretion of growth factors, (iii) provision of a suitable substrate for cell migration, particularly keratinocytes and immune cells, and (iv) modification of the immune system by secretion of neutrophil recruiting chemokines. An early event in acute wound healing is an influx of neutrophils that destroy planktonic bacteria. However, if the bacteria are able to form biofilm, they become resistant to neutrophil action and prevent reepithelialization. In this situation the wound becomes chronic. In chronic wounds, fibroblasts show a senescence-like phenotype with decreased secretion of neutrophil chemoattractants that make it more likely that biofilms become established. Treatment of the chronic wounds involves debridement to eliminate biofilm, and the use of antimicrobials. A role of skin substitutes is to provide non-senescent fibroblasts that attract and activate neutrophils to prevent biofilm re-establishment. The emphasis of the conclusion is the importance of preventing

  4. Genetic heterogeneity of skin microvasculature.

    PubMed

    Liu, Fang; Smith, Jason; Zhang, Zhen; Cole, Richard; Herron, Bruce J

    2010-04-15

    Angiogenesis, the formation of new blood vessels from existing vasculature, is a complex process that is essential for normal embryonic development. Current models for experimental evaluation of angiogenesis often use tissue from large vessels like the aorta and umbilical vein, which are phenotypically distinct from microvasculature. We demonstrate that the utilization of skin to measure microvascular angiogenesis in embryonic and adult tissues is an efficient way to quantify microvasculature angiogenesis. We validate this approach and demonstrate its added value by showing significant differences in angiogenesis in monogenic and polygenic mouse models. We discovered that the pattern of angiogenic response among inbred mouse strains in this ex vivo assay differs from the strain distributions of previous in vivo angiogenesis assays. The difference between the ex vivo and in vivo assays may be related to systemic factors present in whole animals. Expression analysis of cultured skin biopsies from strains of mice with opposing angiogenic response was performed to identify pathways that contribute to differential angiogenic response. Increased expression of negative regulators of angiogenesis in C57Bl/6J mice was associated with lower growth rates.

  5. Skin and Soft Tissue Infections.

    PubMed

    Ramakrishnan, Kalyanakrishnan; Salinas, Robert C; Agudelo Higuita, Nelson Ivan

    2015-09-15

    Skin and soft tissue infections result from microbial invasion of the skin and its supporting structures. Management is determined by the severity and location of the infection and by patient comorbidities. Infections can be classified as simple (uncomplicated) or complicated (necrotizing or nonnecrotizing), or as suppurative or nonsuppurative. Most community-acquired infections are caused by methicillin-resistant Staphylococcus aureus and beta-hemolytic streptococcus. Simple infections are usually monomicrobial and present with localized clinical findings. In contrast, complicated infections can be mono- or polymicrobial and may present with systemic inflammatory response syndrome. The diagnosis is based on clinical evaluation. Laboratory testing may be required to confirm an uncertain diagnosis, evaluate for deep infections or sepsis, determine the need for inpatient care, and evaluate and treat comorbidities. Initial antimicrobial choice is empiric, and in simple infections should cover Staphylococcus and Streptococcus species. Patients with complicated infections, including suspected necrotizing fasciitis and gangrene, require empiric polymicrobial antibiotic coverage, inpatient treatment, and surgical consultation for debridement. Superficial and small abscesses respond well to drainage and seldom require antibiotics. Immunocompromised patients require early treatment and antimicrobial coverage for possible atypical organisms. PMID:26371732

  6. Advances in Skin Substitutes—Potential of Tissue Engineered Skin for Facilitating Anti-Fibrotic Healing

    PubMed Central

    Varkey, Mathew; Ding, Jie; Tredget, Edward E.

    2015-01-01

    Skin protects the body from exogenous substances and functions as a barrier to fluid loss and trauma. The skin comprises of epidermal, dermal and hypodermal layers, which mainly contain keratinocytes, fibroblasts and adipocytes, respectively, typically embedded on extracellular matrix made up of glycosaminoglycans and fibrous proteins. When the integrity of skin is compromised due to injury as in burns the coverage of skin has to be restored to facilitate repair and regeneration. Skin substitutes are preferred for wound coverage when the loss of skin is extensive especially in the case of second or third degree burns. Different kinds of skin substitutes with different features are commercially available; they can be classified into acellular skin substitutes, those with cultured epidermal cells and no dermal components, those with only dermal components, and tissue engineered substitutes that contain both epidermal and dermal components. Typically, adult wounds heal by fibrosis. Most organs are affected by fibrosis, with chronic fibrotic diseases estimated to be a leading cause of morbidity and mortality. In the skin, fibroproliferative disorders such as hypertrophic scars and keloid formation cause cosmetic and functional problems. Dermal fibroblasts are understood to be heterogeneous; this may have implications on post-burn wound healing since studies have shown that superficial and deep dermal fibroblasts are anti-fibrotic and pro-fibrotic, respectively. Selective use of superficial dermal fibroblasts rather than the conventional heterogeneous dermal fibroblasts may prove beneficial for post-burn wound healing. PMID:26184327

  7. Quantifying lateral tissue heterogeneities in hadron therapy

    SciTech Connect

    Pflugfelder, D.; Wilkens, J. J.; Szymanowski, H.; Oelfke, U.

    2007-04-15

    In radiotherapy with scanned particle beams, tissue heterogeneities lateral to the beam direction are problematic in two ways: they pose a challenge to dose calculation algorithms, and they lead to a high sensitivity to setup errors. In order to quantify and avoid these problems, a heterogeneity number H{sub i} as a method to quantify lateral tissue heterogeneities of single beam spot i is introduced. To evaluate this new concept, two kinds of potential errors were investigated for single beam spots: First, the dose calculation error has been obtained by comparing the dose distribution computed by a simple pencil beam algorithm to more accurate Monte Carlo simulations. The resulting error is clearly correlated with H{sub i}. Second, the analysis of the sensitivity to setup errors of single beam spots also showed a dependence on H{sub i}. From this data it is concluded that H{sub i} can be used as a criterion to assess the risks of a compromised delivered dose due to lateral tissue heterogeneities. Furthermore, a method how to incorporate this information into the inverse planning process for intensity modulated proton therapy is presented. By suppressing beam spots with a high value of H{sub i}, the unfavorable impact of lateral tissue heterogeneities can be reduced, leading to treatment plans which are more robust to dose calculation errors of the pencil beam algorithm. Additional possibilities to use the information of H{sub i} are outlined in the discussion.

  8. Periostin in skin tissue and skin-related diseases.

    PubMed

    Yamaguchi, Yukie

    2014-06-01

    Extracellular matrix (ECM) is not only involved in the maintenance of normal physiological tissue but also in interactions with other ECM components, tissue remodeling, and modulating immune responses. The skin provides a distinctive environment characterized by rich fibroblasts producing various ECM proteins, epithelial-mesenchymal interactions, and immune responses induced by external stimuli. Recently, periostin-a matricellular protein-has been highlighted for its pivotal functions in the skin. Analysis of periostin null mice has revealed that periostin contributes to collagen fibrillogenesis, collagen cross-linking, and the formation of ECM meshwork via interactions with other ECM components. Periostin expression is enhanced by mechanical stress or skin injury; this is indicative of the physiologically protective functions of periostin, which promotes wound repair by acting on keratinocytes and fibroblasts. Along with its physiological functions, periostin plays pathogenic roles in skin fibrosis and chronic allergic inflammation. In systemic sclerosis (SSc) patients, periostin levels reflect the severity of skin fibrosis. Periostin null mice have shown reduced skin fibrosis in a bleomycin-induced SSc mouse model, indicating a key role of periostin in fibrosis. Moreover, in atopic dermatitis (AD), attenuated AD phenotype has been observed in periostin null mice in a house dust mite extract-induced AD mouse model. Th2 cytokine-induced periostin acts on keratinocytes to produce inflammatory cytokines that further enhance the Th2 response, thereby sustaining and amplifying chronic allergic inflammation. Thus, periostin is deeply involved in the pathogenesis of AD and other inflammation-related disorders affecting the skin. Understanding the dynamic actions of periostin would be key to dissecting pathogenesis of skin-related diseases and to developing novel therapeutic strategies.

  9. Fibroblast heterogeneity and its implications for engineering organotypic skin models in vitro.

    PubMed

    Sriram, Gopu; Bigliardi, Paul Lorenz; Bigliardi-Qi, Mei

    2015-11-01

    Advances in cell culture methods, multidisciplinary research, clinical need to replace lost skin tissues and regulatory need to replace animal models with alternative test methods has led to development of three dimensional models of human skin. In general, these in vitro models of skin consist of keratinocytes cultured over fibroblast-populated dermal matrices. Accumulating evidences indicate that mesenchyme-derived signals are essential for epidermal morphogenesis, homeostasis and differentiation. Various studies show that fibroblasts isolated from different tissues in the body are dynamic in nature and are morphologically and functionally heterogeneous subpopulations. Further, these differences seem to be dictated by the local biological and physical microenvironment the fibroblasts reside resulting in "positional identity or memory". Furthermore, the heterogeneity among the fibroblasts play a critical role in scarless wound healing and complete restoration of native tissue architecture in fetus and oral mucosa; and excessive scar formation in diseased states like keloids and hypertrophic scars. In this review, we summarize current concepts about the heterogeneity among fibroblasts and their role in various wound healing environments. Further, we contemplate how the insights on fibroblast heterogeneity could be applied for the development of next generation organotypic skin models.

  10. Fibroblast heterogeneity and its implications for engineering organotypic skin models in vitro.

    PubMed

    Sriram, Gopu; Bigliardi, Paul Lorenz; Bigliardi-Qi, Mei

    2015-11-01

    Advances in cell culture methods, multidisciplinary research, clinical need to replace lost skin tissues and regulatory need to replace animal models with alternative test methods has led to development of three dimensional models of human skin. In general, these in vitro models of skin consist of keratinocytes cultured over fibroblast-populated dermal matrices. Accumulating evidences indicate that mesenchyme-derived signals are essential for epidermal morphogenesis, homeostasis and differentiation. Various studies show that fibroblasts isolated from different tissues in the body are dynamic in nature and are morphologically and functionally heterogeneous subpopulations. Further, these differences seem to be dictated by the local biological and physical microenvironment the fibroblasts reside resulting in "positional identity or memory". Furthermore, the heterogeneity among the fibroblasts play a critical role in scarless wound healing and complete restoration of native tissue architecture in fetus and oral mucosa; and excessive scar formation in diseased states like keloids and hypertrophic scars. In this review, we summarize current concepts about the heterogeneity among fibroblasts and their role in various wound healing environments. Further, we contemplate how the insights on fibroblast heterogeneity could be applied for the development of next generation organotypic skin models. PMID:26344860

  11. Heterogeneity of Borrelia burgdorferi in the skin.

    PubMed

    Aberer, E; Kersten, A; Klade, H; Poitschek, C; Jurecka, W

    1996-12-01

    The reliability of various in vitro techniques to identify Borrelia burgdorferi infection is still unsatisfactory. Using a high-power resolution videomicroscope and staining with the borrelia genus-specific monoclonal flagellar antibody H9724, we identified borrelial structures in skin biopsies of erythema chronicum migrans (from which borrelia later was cultured), of acrodermatitis chronica atrophicans, and of morphea. In addition to typical borreliae, we noted stained structures of varying shapes identical to borreliae found in a "borrelia-injected skin" model; identical to agar-embedded borreliae; and identical to cultured borreliae following exposure to hyperimmune sera and/or antibiotics. We conclude that the H9724-reactive structures represent various forms of B. burgdorferi rather than staining artifacts. These "atypical" forms of B. burgdorferi may represent in vivo morphologic variants of this bacterium.

  12. Heterogeneous genetic profiles in soft tissue myoepitheliomas.

    PubMed

    Hallor, Karolin H; Teixeira, Manuel R; Fletcher, Christopher D M; Bizarro, Susana; Staaf, Johan; Domanski, Henryk A; von Steyern, Fredrik Vult; Panagopoulos, Ioannis; Mandahl, Nils; Mertens, Fredrik

    2008-11-01

    Myoepithelioma, mixed tumor and parachordoma are uncommon soft tissue tumors thought to represent morphological variants of a single tumor type. The genetic basis of these neoplasms is poorly understood. However, they morphologically resemble mixed tumor of the salivary glands (also known as pleomorphic adenoma), a tumor characterized by deregulated expression of PLAG1 or HMGA2. To evaluate a possible genetic relationship between these soft tissue and salivary gland tumors, PLAG1 expression levels and the genomic status of PLAG1 and HMGA2 were investigated in five soft tissue myoepitheliomas and one pleomorphic adenoma. In addition, all tumors were cytogenetically investigated and whole genome DNA copy number imbalances were studied in five of them. The genetic profiles were heterogeneous and the only aberration common to all soft tissue myoepitheliomas was a minimally deleted region of 3.55 Mb in chromosome band 19p13. Recurrent deletion of CDKN2A suggests that inactivation of this tumor suppressor gene is pathogenetically important in a subset. Furthermore, PLAG1 rearrangement was found in a soft tissue tumor from a patient previously treated for a salivary pleomorphic adenoma, indicating either metastasis of the salivary gland lesion or that some soft tissue tumors develop through the same mechanisms as their salivary gland counterparts. PMID:18604193

  13. Fluorescence Measurement of Burned Skin Tissues

    NASA Astrophysics Data System (ADS)

    de Pedro, Hector Michael; Chang, Chuan-I.; Nguyen, Hue; Malko, Anton; Zarnani, Faranak; Glosser, Robert; Maas, D.; Idris, A.

    2011-03-01

    Early removal of affected tissues from burn patients can significantly increase the success of their recovery, since burns continue to spread and damage surrounding tissues after hours of injury. The rationale behind this procedure is that burns trigger the body's immune system to overreact, causing additional damage. Therefore it is important to locate and identify the burn (area and thickness) so that it can be removed as quickly as possible. Our project explores the use of autofluorescence as a tool to identify the burned tissues from healthy ones. Here we present that our fluorescence results show differences between burned and normal skin in both its spectra and lifetime.

  14. [Skin and tissue bank: Operational model for the recovery and preservation of tissues and skin allografts].

    PubMed

    Martínez-Flores, Francisco; Sandoval-Zamora, Hugo; Machuca-Rodriguez, Catalina; Barrera-López, Araceli; García-Cavazos, Ricardo; Madinaveitia-Villanueva, Juan Antonio

    2016-01-01

    Tissue storage is a medical process that is in the regulation and homogenisation phase in the scientific world. The international standards require the need to ensure safety and efficacy of human allografts such as skin and other tissues. The activities of skin and tissues banks currently involve their recovery, processing, storage and distribution, which are positively correlated with technological and scientific advances present in current biomedical sciences. A description is presented of the operational model of Skin and Tissue Bank at INR as successful case for procurement, recovery and preservation of skin and tissues for therapeutic uses, with high safety and biological quality. The essential and standard guidelines are presented as keystones for a tissue recovery program based on scientific evidence, and within an ethical and legal framework, as well as to propose a model for complete overview of the donation of tissues and organ programs in Mexico. Finally, it concludes with essential proposals for improving the efficacy of transplantation of organs and tissue programs. PMID:26259741

  15. [Skin and tissue bank: Operational model for the recovery and preservation of tissues and skin allografts].

    PubMed

    Martínez-Flores, Francisco; Sandoval-Zamora, Hugo; Machuca-Rodriguez, Catalina; Barrera-López, Araceli; García-Cavazos, Ricardo; Madinaveitia-Villanueva, Juan Antonio

    2016-01-01

    Tissue storage is a medical process that is in the regulation and homogenisation phase in the scientific world. The international standards require the need to ensure safety and efficacy of human allografts such as skin and other tissues. The activities of skin and tissues banks currently involve their recovery, processing, storage and distribution, which are positively correlated with technological and scientific advances present in current biomedical sciences. A description is presented of the operational model of Skin and Tissue Bank at INR as successful case for procurement, recovery and preservation of skin and tissues for therapeutic uses, with high safety and biological quality. The essential and standard guidelines are presented as keystones for a tissue recovery program based on scientific evidence, and within an ethical and legal framework, as well as to propose a model for complete overview of the donation of tissues and organ programs in Mexico. Finally, it concludes with essential proposals for improving the efficacy of transplantation of organs and tissue programs.

  16. Skin tissue generation by laser cell printing.

    PubMed

    Koch, Lothar; Deiwick, Andrea; Schlie, Sabrina; Michael, Stefanie; Gruene, Martin; Coger, Vincent; Zychlinski, Daniela; Schambach, Axel; Reimers, Kerstin; Vogt, Peter M; Chichkov, Boris

    2012-07-01

    For the aim of ex vivo engineering of functional tissue substitutes, Laser-assisted BioPrinting (LaBP) is under investigation for the arrangement of living cells in predefined patterns. So far three-dimensional (3D) arrangements of single or two-dimensional (2D) patterning of different cell types have been presented. It has been shown that cells are not harmed by the printing procedure. We now demonstrate for the first time the 3D arrangement of vital cells by LaBP as multicellular grafts analogous to native archetype and the formation of tissue by these cells. For this purpose, fibroblasts and keratinocytes embedded in collagen were printed in 3D as a simple example for skin tissue. To study cell functions and tissue formation process in 3D, different characteristics, such as cell localisation and proliferation were investigated. We further analysed the formation of adhering and gap junctions, which are fundamental for tissue morphogenesis and cohesion. In this study, it was demonstrated that LaBP is an outstanding tool for the generation of multicellular 3D constructs mimicking tissue functions. These findings are promising for the realisation of 3D in vitro models and tissue substitutes for many applications in tissue engineering. PMID:22328297

  17. Microwave thermal radiation effects on skin tissues

    NASA Astrophysics Data System (ADS)

    Yoon, Hargsoon; Song, Kyo D.; Lee, Uhn; Choi, Sang H.

    2012-10-01

    Microwave/RF energy has been used for wireless power transmission including many therapeutic applications, such as transurethral microwave therapy (TUMT). For safe uses of RF power, it is important to know how to deliver microwave energy on focused area and control the temperature changes not to drastically increase on adjacent areas. Graphical analysis of thermal loading factor is important to understand how to achieve effective transmission of microwave through the tissue. The loss mechanism while transmission often appears as thermal effects due to absorption of microwave, especially for materials such as human skin, muscles, and other organic parts including brain. In this paper, microwave thermal effects are investigated to measure temperatures, penetration depth through animal skins in terms of input power and various frequencies. This result will be compare with the case of human applications.

  18. Progress and opportunities for tissue-engineered skin

    NASA Astrophysics Data System (ADS)

    MacNeil, Sheila

    2007-02-01

    Tissue-engineered skin is now a reality. For patients with extensive full-thickness burns, laboratory expansion of skin cells to achieve barrier function can make the difference between life and death, and it was this acute need that drove the initiation of tissue engineering in the 1980s. A much larger group of patients have ulcers resistant to conventional healing, and treatments using cultured skin cells have been devised to restart the wound-healing process. In the laboratory, the use of tissue-engineered skin provides insight into the behaviour of skin cells in healthy skin and in diseases such as vitiligo, melanoma, psoriasis and blistering disorders.

  19. Ciprofloxacin versus ceftazidime in skin and soft tissue infections.

    PubMed

    Thadepalli, H; Mathai, D; Chuah, S K; Bansal, M B

    1989-02-01

    Intravenous ciprofloxacin therapy was evaluated in comparison with i.v. ceftazidime in the treatment of skin and soft tissue infections and were found to be comparable. Intravenous or peroral forms of ciprofloxacin may be used instead of intravenously given third generation cephalosporins or aminoglycosides in the treatment of even severe infections of the skin and soft tissue.

  20. Adipose tissue: cell heterogeneity and functional diversity.

    PubMed

    Esteve Ràfols, Montserrat

    2014-02-01

    There are two types of adipose tissue in the body whose function appears to be clearly differentiated. White adipose tissue stores energy reserves as fat, whereas the metabolic function of brown adipose tissue is lipid oxidation to produce heat. A good balance between them is important to maintain energy homeostasis. The concept of white adipose tissue has radically changed in the past decades, and is now considered as an endocrine organ that secretes many factors with autocrine, paracrine, and endocrine functions. In addition, we can no longer consider white adipose tissue as a single tissue, because it shows different metabolic profiles in its different locations, with also different implications. Although the characteristic cell of adipose tissue is the adipocyte, this is not the only cell type present in adipose tissue, neither the most abundant. Other cell types in adipose tissue described include stem cells, preadipocytes, macrophages, neutrophils, lymphocytes, and endothelial cells. The balance between these different cell types and their expression profile is closely related to maintenance of energy homeostasis. Increases in adipocyte size, number and type of lymphocytes, and infiltrated macrophages are closely related to the metabolic syndrome diseases. The study of regulation of proliferation and differentiation of preadipocytes and stem cells, and understanding of the interrelationship between the different cell types will provide new targets for action against these diseases. PMID:23834768

  1. Adipose tissue: cell heterogeneity and functional diversity.

    PubMed

    Esteve Ràfols, Montserrat

    2014-02-01

    There are two types of adipose tissue in the body whose function appears to be clearly differentiated. White adipose tissue stores energy reserves as fat, whereas the metabolic function of brown adipose tissue is lipid oxidation to produce heat. A good balance between them is important to maintain energy homeostasis. The concept of white adipose tissue has radically changed in the past decades, and is now considered as an endocrine organ that secretes many factors with autocrine, paracrine, and endocrine functions. In addition, we can no longer consider white adipose tissue as a single tissue, because it shows different metabolic profiles in its different locations, with also different implications. Although the characteristic cell of adipose tissue is the adipocyte, this is not the only cell type present in adipose tissue, neither the most abundant. Other cell types in adipose tissue described include stem cells, preadipocytes, macrophages, neutrophils, lymphocytes, and endothelial cells. The balance between these different cell types and their expression profile is closely related to maintenance of energy homeostasis. Increases in adipocyte size, number and type of lymphocytes, and infiltrated macrophages are closely related to the metabolic syndrome diseases. The study of regulation of proliferation and differentiation of preadipocytes and stem cells, and understanding of the interrelationship between the different cell types will provide new targets for action against these diseases.

  2. Role of tissue thickness on depth of morphologic skin damage

    NASA Astrophysics Data System (ADS)

    RajaMahmood, T. L. I.; Mat Jafri, M. Z.; Omar, Khalid M.

    2013-05-01

    Different zonal areas of the skins have different thickness and different adnexal composition. For this reason, the power density and exposure duration have to be adjusted to the area that being treated. The effects of laser expose to the different area of the skin has been studied by using the power density of 20.31 W/cm2 and the times when the cracking sound heard is the explosive duration recorded for each area of the skins. As a result, the histologic sections revealed that the explosive duration varied significantly with the difference in thickness of the skin tissue. Also, the expanding spaces between hair follicles and its surrounding tissue as well as denaturation of collagen fiberswere shownin each skin section and were mainly affected by the photothermal effect produced from the CO2 laser-skin tissue interaction.

  3. Terahertz pulse imaging in reflection geometry of human skin cancer and skin tissue

    NASA Astrophysics Data System (ADS)

    Woodward, Ruth M.; Cole, Bryan E.; Wallace, Vincent P.; Pye, Richard J.; Arnone, Donald D.; Linfield, Edmund H.; Pepper, Michael

    2002-11-01

    We demonstrate the application of terahertz pulse imaging (TPI) in reflection geometry for the study of skin tissue and related cancers both in vitro and in vivo. The sensitivity of terahertz radiation to polar molecules, such as water, makes TPI suitable for studying the hydration levels in the skin and the determination of the lateral spread of skin cancer pre-operatively. By studying the terahertz pulse shape in the time domain we have been able to differentiate between diseased and normal tissue for the study of basal cell carcinoma (BCC). Basal cell carcinoma has shown a positive terahertz contrast, and inflammation and scar tissue a negative terahertz contrast compared to normal tissue. In vivo measurements on the stratum corneum have enabled visualization of the stratum corneum-epidermis interface and the study of skin hydration levels. These results demonstrate the potential of terahertz pulse imaging for the study of skin tissue and its related disorders, both in vitro and in vivo.

  4. Tumors of the skin and soft tissues

    SciTech Connect

    Weller, R.E.

    1991-10-01

    The majority of the body surface is covered by the skin. Many internal disorders are reflected in the condition of the skin. One of the major functions of the skin is protection of the other organ systems from a variety of environmental insults. In this role, the skin itself is exposed to factors that can ultimately cause chronic diseases and cancer. Since it is relatively easy to recognize skin abnormalities, most skin cancers are brought to professional attention sooner than other types of cancer. However, due to the close resemblance between many skin neoplasms and noncancerous dermatologic disorders, these neoplasms may be mistreated for months or even years. In veterinary oncology, as in human medicine, most cancers can be effectively treated or cured following an accurate diagnosis. Once diagnosed, skin neoplasms should be aggressively treated. If causal factors are known, exposure to these factors should be limited through removal of the agent (for chemical carcinogens) or limiting exposure to the agent (for other carcinogens such as sunlight). 10 tabs. (MHB)

  5. Dielectric analysis of heterogeneous biological tissues based on mixing rule.

    PubMed

    Zhang, Liang; Liu, Peiguo; Dong, Xiuzhen; Zhou, Dongming; Shi, Xuetao

    2015-01-01

    Thus far, the measurement of dielectric properties of biological tissues has been achieved on the assumption that the biological tissues are homogeneous. In fact, most tissues should be heterogeneous because there are many small structures included in these tissues, such as blood vessel, nerve fiber and so on. When the dielectric properties of these tissues are measured by conventional sensor, the results are not the dielectric properties of tissues but the effective dielectric properties of the mixture. In this paper, the influence of the inclusion in tissues on the measurement of dielectric properties of heterogeneous biological tissues is studied and the analysis of the effective dielectric properties of heterogeneous tissues based on the mixing rule is proposed. When the coaxial probe is used to measure the dielectric properties of tissue, the results are relative to the dielectric properties of inclusion, dielectric properties of background tissue and the effective volume fraction of inclusion. Therefore, the dielectric properties of inclusion could be calculated according to mixing rule, after the effective dielectric properties are measured and the effective volume fraction of inclusion is estimated.

  6. Dielectric analysis of heterogeneous biological tissues based on mixing rule.

    PubMed

    Zhang, Liang; Liu, Peiguo; Dong, Xiuzhen; Zhou, Dongming; Shi, Xuetao

    2015-01-01

    Thus far, the measurement of dielectric properties of biological tissues has been achieved on the assumption that the biological tissues are homogeneous. In fact, most tissues should be heterogeneous because there are many small structures included in these tissues, such as blood vessel, nerve fiber and so on. When the dielectric properties of these tissues are measured by conventional sensor, the results are not the dielectric properties of tissues but the effective dielectric properties of the mixture. In this paper, the influence of the inclusion in tissues on the measurement of dielectric properties of heterogeneous biological tissues is studied and the analysis of the effective dielectric properties of heterogeneous tissues based on the mixing rule is proposed. When the coaxial probe is used to measure the dielectric properties of tissue, the results are relative to the dielectric properties of inclusion, dielectric properties of background tissue and the effective volume fraction of inclusion. Therefore, the dielectric properties of inclusion could be calculated according to mixing rule, after the effective dielectric properties are measured and the effective volume fraction of inclusion is estimated. PMID:26406034

  7. Polyethylene glycol diffusion in ex vivo skin tissue

    NASA Astrophysics Data System (ADS)

    Genin, V. D.; Tuchina, D. K.; Bashkatov, A. N.; Genina, E. A.; Tuchin, V. V.

    2015-11-01

    Optical clearing of the rat skin under the action of polyethylene glycol (PEG) with molecular weight 300 and 400 Dalton was studied ex vivo. The collimated transmittance was measured at the wavelength range 500-900 nm. It was found that collimated transmittance of skin samples increased, whereas weight, thickness and area of the samples decreased during PEG penetration in skin tissue. A mechanism of the optical clearing under the action of PEG is discussed. Taking into account the kinetics of volume and thickness of the skin samples, diffusion coefficient of PEGs in skin tissue has been estimated as (1.83±2.22)×10-6 cm2/s and (1.70±1.47)×10-6 cm2/s for PEG-300 and PEG-400, respectively. The presented results can be useful for enhancement of many methods of laser therapy and optical diagnostics of skin diseases and localization of subcutaneous neoplasms.

  8. Measurement of diffusion coefficient of propylene glycol in skin tissue

    NASA Astrophysics Data System (ADS)

    Genin, Vadim D.; Bashkatov, Alexey N.; Genina, Elina A.; Tuchin, Valery V.

    2015-03-01

    Optical clearing of the rat skin under the action of propylene glycol was studied ex vivo. It was found that collimated transmittance of skin samples increased, whereas weight and thickness of the samples decreased during propylene glycol penetration in skin tissue. A mechanism of the optical clearing under the action of propylene glycol is discussed. Diffusion coefficient of propylene glycol in skin tissue ex vivo has been estimated as (1.35±0.95)×10-7 cm2/s with the taking into account of kinetics of both weight and thickness of skin samples. The presented results can be useful for enhancement of many methods of laser therapy and optical diagnostics of skin diseases and localization of subcutaneous neoplasms.

  9. Three-Dimensional Human Tissue Models of Wounded Skin

    PubMed Central

    Egles, Christophe; Garlick, Jonathan A.; Shamis, Yulia

    2010-01-01

    Human skin equivalents (HSEs) are in vitro tissues in which a fully differentiated, stratified squamous epithelium is grown at an air–liquid interface on a Type I collagen gel harboring human dermal fibroblasts. HSEs now provide experimental human tissue models to study factors that direct re-epithelialization and epithelial–mesenchymal cross-talk following wounding. This chapter describes the fabrication of HSEs from human keratinocytes and fibroblasts and how HSEs can be modified to characterize the response of the human epithelium during wound repair. The protocols outlined first describe techniques for the generation of human tissues that closely approximate the architectural features, differentiation, and growth of human skin. This will be followed by a description of a protocol that enables HSEs to be adapted to monitor their response following wounding. These engineered human tissues provide powerful tools to study biological process in tissues that mimic the healing of human skin and of the epithelial tissue. PMID:19908015

  10. [Tissue engineering and construction of human skin in vitro].

    PubMed

    Arvelo, Francisco

    2007-09-01

    Tissue engineering is the new science that has come to make possible the growth of new organ tissue from small fragments of healthy tissue, thus partially or totally restoring the lost functions of ill tissues or organs, as shown by the achievements made with the culture of skin, cornea or cartilage. Thus far, this new science is able to ensure the recovery of lost functions and, doubtlessly, in a near future will be capable of developing tissues and organs not unlike natural ones. In our laboratory we have began the development of tissue engineering techniques for the successful construction of in vitro skin with the aim at mid term of producing cornea and cartilage. In a first clinical trial, these techniques were applied in the treatment of chronic skin lesions and the advantages and reach of these new tools were demonstrated for the effective solution of problems with would otherwise not be easily solved through the use of conventional treatments.

  11. [Tissue engineering and construction of human skin in vitro].

    PubMed

    Arvelo, Francisco

    2007-09-01

    Tissue engineering is the new science that has come to make possible the growth of new organ tissue from small fragments of healthy tissue, thus partially or totally restoring the lost functions of ill tissues or organs, as shown by the achievements made with the culture of skin, cornea or cartilage. Thus far, this new science is able to ensure the recovery of lost functions and, doubtlessly, in a near future will be capable of developing tissues and organs not unlike natural ones. In our laboratory we have began the development of tissue engineering techniques for the successful construction of in vitro skin with the aim at mid term of producing cornea and cartilage. In a first clinical trial, these techniques were applied in the treatment of chronic skin lesions and the advantages and reach of these new tools were demonstrated for the effective solution of problems with would otherwise not be easily solved through the use of conventional treatments. PMID:17853796

  12. Growing skin: Tissue expansion in pediatric forehead reconstruction

    PubMed Central

    Zollner, Alexander M.; Buganza Tepole, Adrian; Gosain, Arun K.; Kuhl, Ellen

    2011-01-01

    Tissue expansion is a common surgical procedure to grow extra skin through controlled mechanical over-stretch. It creates skin that matches the color, texture, and thickness of the surrounding tissue, while minimizing scars and risk of rejection. Despite intense research in tissue expansion and skin growth, there is a clear knowledge gap between heuristic observation and mechanistic understanding of the key phenomena that drive the growth process. Here, we show that a continuum mechanics approach, embedded in a custom-designed finite element model, informed by medical imaging, provides valuable insight into the biomechanics of skin growth. In particular, we model skin growth using the concept of an incompatible growth configuration. We characterize its evolution in time using a second-order growth tensor parameterized in terms of a scalar-valued internal variable, the in-plane area growth. When stretched beyond the physiological level, new skin is created, and the in-plane area growth increases. For the first time, we simulate tissue expansion on a patient-specific geometric model, and predict stress, strain, and area gain at three expanded locations in a pediatric skull: in the scalp, in the forehead, and in the cheek. Our results may help the surgeon to prevent tissue over-stretch and make informed decisions about expander geometry, size, placement, and inflation. We anticipate our study to open new avenues in reconstructive surgery, and enhance treatment for patients with birth defects, burn injuries, or breast tumor removal. PMID:22052000

  13. Bioglass Activated Skin Tissue Engineering Constructs for Wound Healing.

    PubMed

    Yu, Hongfei; Peng, Jinliang; Xu, Yuhong; Chang, Jiang; Li, Haiyan

    2016-01-13

    Wound healing is a complicated process, and fibroblast is a major cell type that participates in the process. Recent studies have shown that bioglass (BG) can stimulate fibroblasts to secrete a multitude of growth factors that are critical for wound healing. Therefore, we hypothesize that BG can stimulate fibroblasts to have a higher bioactivity by secreting more bioactive growth factors and proteins as compared to untreated fibroblasts, and we aim to construct a bioactive skin tissue engineering graft for wound healing by using BG activated fibroblast sheet. Thus, the effects of BG on fibroblast behaviors were studied, and the bioactive skin tissue engineering grafts containing BG activated fibroblasts were applied to repair the full skin lesions on nude mouse. Results showed that BG stimulated fibroblasts to express some critical growth factors and important proteins including vascular endothelial growth factor, basic fibroblast growth factor, epidermal growth factor, collagen I, and fibronectin. In vivo results revealed that fibroblasts in the bioactive skin tissue engineering grafts migrated into wound bed, and the migration ability of fibroblasts was stimulated by BG. In addition, the bioactive BG activated fibroblast skin tissue engineering grafts could largely increase the blood vessel formation, enhance the production of collagen I, and stimulate the differentiation of fibroblasts into myofibroblasts in the wound site, which would finally accelerate wound healing. This study demonstrates that the BG activated skin tissue engineering grafts contain more critical growth factors and extracellular matrix proteins that are beneficial for wound healing as compared to untreated fibroblast cell sheets.

  14. Growing skin: tissue expansion in pediatric forehead reconstruction.

    PubMed

    Zöllner, Alexander M; Buganza Tepole, Adrian; Gosain, Arun K; Kuhl, Ellen

    2012-07-01

    Tissue expansion is a common surgical procedure to grow extra skin through controlled mechanical over-stretch. It creates skin that matches the color, texture, and thickness of the surrounding tissue, while minimizing scars and risk of rejection. Despite intense research in tissue expansion and skin growth, there is a clear knowledge gap between heuristic observation and mechanistic understanding of the key phenomena that drive the growth process. Here, we show that a continuum mechanics approach, embedded in a custom-designed finite element model, informed by medical imaging, provides valuable insight into the biomechanics of skin growth. In particular, we model skin growth using the concept of an incompatible growth configuration. We characterize its evolution in time using a second-order growth tensor parameterized in terms of a scalar-valued internal variable, the in-plane area growth. When stretched beyond the physiological level, new skin is created, and the in-plane area growth increases. For the first time, we simulate tissue expansion on a patient-specific geometric model, and predict stress, strain, and area gain at three expanded locations in a pediatric skull: in the scalp, in the forehead, and in the cheek. Our results may help the surgeon to prevent tissue over-stretch and make informed decisions about expander geometry, size, placement, and inflation. We anticipate our study to open new avenues in reconstructive surgery and enhance treatment for patients with birth defects, burn injuries, or breast tumor removal.

  15. Nanofibrous structured biomimetic strategies for skin tissue regeneration.

    PubMed

    Jayarama Reddy, Venugopal; Radhakrishnan, Sridhar; Ravichandran, Rajeswari; Mukherjee, Shayanti; Balamurugan, Ramalingam; Sundarrajan, Subramanian; Ramakrishna, Seeram

    2013-01-01

    Mimicking porous topography of natural extracellular matrix is advantageous for successful regeneration of damaged tissues or organs. Nanotechnology being one of the most promising and growing technology today shows an extremely huge potential in the field of tissue engineering. Nanofibrous structures that mimic the native extracellular matrix and promote the adhesion of various cells are being developed as tissue-engineered scaffolds for skin, bone, vasculature, heart, cornea, nervous system, and other tissues. A range of novel biocomposite materials has been developed to enhance the bioactive or therapeutic properties of these nanofibrous scaffolds via surface modifications, including the immobilization of functional cell-adhesive ligands and bioactive molecules such as drugs, enzymes, and cytokines. In skin tissue engineering, usage of allogeneic skin is avoided to reestablish physiological continuity and also to address the challenge of curing acute and chronic wounds, which remains as the area of exploration with various biomimetic approaches. Two-dimensional, three-dimensional scaffolds and stem cells are presently used as dermal regeneration templates for the treatment of full-thickness skin defects resulting from injuries and severe burns. The present review elaborates specifically on the fabrication of nanofibrous structured strategies for wound dressings, wound healing, and controlled release of growth factors for skin tissue regeneration.

  16. Heterogeneity of white adipose tissue: molecular basis and clinical implications

    PubMed Central

    Kwok, Kelvin H M; Lam, Karen S L; Xu, Aimin

    2016-01-01

    Adipose tissue is a highly heterogeneous endocrine organ. The heterogeneity among different anatomical depots stems from their intrinsic differences in cellular and physiological properties, including developmental origin, adipogenic and proliferative capacity, glucose and lipid metabolism, insulin sensitivity, hormonal control, thermogenic ability and vascularization. Additional factors that influence adipose tissue heterogeneity are genetic predisposition, environment, gender and age. Under obese condition, these depot-specific differences translate into specific fat distribution patterns, which are closely associated with differential cardiometabolic risks. For instance, individuals with central obesity are more susceptible to developing diabetes and cardiovascular complications, whereas those with peripheral obesity are more metabolically healthy. This review summarizes the clinical and mechanistic evidence for the depot-specific differences that give rise to different metabolic consequences, and provides therapeutic insights for targeted treatment of obesity. PMID:26964831

  17. Heterogeneity of white adipose tissue: molecular basis and clinical implications.

    PubMed

    Kwok, Kelvin H M; Lam, Karen S L; Xu, Aimin

    2016-03-11

    Adipose tissue is a highly heterogeneous endocrine organ. The heterogeneity among different anatomical depots stems from their intrinsic differences in cellular and physiological properties, including developmental origin, adipogenic and proliferative capacity, glucose and lipid metabolism, insulin sensitivity, hormonal control, thermogenic ability and vascularization. Additional factors that influence adipose tissue heterogeneity are genetic predisposition, environment, gender and age. Under obese condition, these depot-specific differences translate into specific fat distribution patterns, which are closely associated with differential cardiometabolic risks. For instance, individuals with central obesity are more susceptible to developing diabetes and cardiovascular complications, whereas those with peripheral obesity are more metabolically healthy. This review summarizes the clinical and mechanistic evidence for the depot-specific differences that give rise to different metabolic consequences, and provides therapeutic insights for targeted treatment of obesity.

  18. Polarized Reflectance Measurement of Burned Skin Tissues

    NASA Astrophysics Data System (ADS)

    de Pedro, Hector Michael; Chang, Chuan-I.; Zarnani, Faranak; Glosser, Robert; Maas, D.; Idris, A.

    2011-10-01

    In the US, there are over 400,000 burn victims with 3,500 deaths in 2010. Recent evidence suggests that early removal of burn tissues can significantly increase the success of their recovery, since burns continue to spread and damage surrounding tissues after hours of injury. The rationale behind this procedure is that burns trigger the body's immune system to overreact, causing additional damage. Therefore, it is important to distinguish burn areas so that it can be removed. The problem with this is that it is difficult to recognize the margins of the burn area. In our project, we use polarized reflectance as a tool to identify the burned tissues from unburned ones.

  19. Multiscale Approach to Characterize Mechanical Properties of Tissue Engineered Skin.

    PubMed

    Tupin, S; Molimard, J; Cenizo, V; Hoc, T; Sohm, B; Zahouani, H

    2016-09-01

    Tissue engineered skin usually consist of a multi-layered visco-elastic material composed of a fibrillar matrix and cells. The complete mechanical characterization of these tissues has not yet been accomplished. The purpose of this study was to develop a multiscale approach to perform this characterization in order to link the development process of a cultured skin to the mechanical properties. As a proof-of-concept, tissue engineered skin samples were characterized at different stages of manufacturing (acellular matrix, reconstructed dermis and reconstructed skin) for two different aging models (using cells from an 18- and a 61-year-old man). To assess structural variations, bi-photonic confocal microscopy was used. To characterize mechanical properties at a macroscopic scale, a light-load micro-mechanical device that performs indentation and relaxation tests was designed. Finally, images of the internal network of the samples under stretching were acquired by combining confocal microscopy with a tensile device. Mechanical properties at microscopic scale were assessed. Results revealed that adding cells during manufacturing induced structural changes, which provided higher elastic modulus and viscosity. Moreover, senescence models exhibited lower elastic modulus and viscosity. This multiscale approach was efficient to characterize and compare skin equivalent samples and permitted the first experimental assessment of the Poisson's ratio for such tissues.

  20. 3D printing method for freeform fabrication of optical phantoms simulating heterogeneous biological tissue

    NASA Astrophysics Data System (ADS)

    Wang, Minjie; Shen, Shuwei; Yang, Jie; Dong, Erbao; Xu, Ronald

    2014-03-01

    The performance of biomedical optical imaging devices heavily relies on appropriate calibration. However, many of existing calibration phantoms for biomedical optical devices are based on homogenous materials without considering the multi-layer heterogeneous structures observed in biological tissue. Using such a phantom for optical calibration may result in measurement bias. To overcome this problem, we propose a 3D printing method for freeform fabrication of tissue simulating phantoms with multilayer heterogeneous structure. The phantom simulates not only the morphologic characteristics of biological tissue but also absorption and scattering properties. The printing system is based on a 3D motion platform with coordinated control of the DC motors. A special jet nozzle is designed to mix base, scattering, and absorption materials at different ratios. 3D tissue structures are fabricated through layer-by-layer printing with selective deposition of phantom materials of different ingredients. Different mixed ratios of base, scattering and absorption materials have been tested in order to optimize the printing outcome. A spectrometer and a tissue spectrophotometer are used for characterizing phantom absorption and scattering properties. The goal of this project is to fabricate skin tissue simulating phantoms as a traceable standard for the calibration of biomedical optical spectral devices.

  1. Wave emission on interacting heterogeneities in cardiac tissue

    NASA Astrophysics Data System (ADS)

    Hörning, Marcel; Takagi, Seiji; Yoshikawa, Kenichi

    2010-08-01

    Cardiac arrhythmias, a precursor of fibrillationlike states in the beating heart, are associated with spiral waves, which are likely to become pinned to heterogeneities. Far-field pacing (FFP) is a promising method for terminating such waves by using heterogeneities in the tissue as internal pacing sites. In this study we investigated the role of multiple obstacles and their interaction during FFP. We show that a secondary nearby obstacle can significantly modulate the minimum electrical field in FFP. Further, we show that essentially the same effect can be observed in cardiac tissue culture, which is a powerful experimental model to simulate heart activity. Here, an isotropic cell distribution leads to domain formation of locally distributed depolarization sites. Both secondary obstacles and domain formation of local depolarization sites can modulate energy requirements to originate wave propagation on obstacles. Our theoretical result was confirmed by experiments with cardiomyocyte monolayers. This result may be useful for the future application of FFP to a real beating heart.

  2. Free tissue transfer in the reconstruction of massive skin cancer.

    PubMed

    Wax, Mark K

    2009-05-01

    Skin cancer arising in the head and neck is a common occurrence. Although the vast majority of these cancers can be treated with simple excision and local reconstruction there is a subset of patients who have massive tumors that require composite tissue resection. These patients are best reconstructed with free tissue transfer. Acceptable functional and cosmetic results can be expected. Long-term survival is excellent in patients who have negative margins.

  3. A review of tissue-engineered skin bioconstructs available for skin reconstruction

    PubMed Central

    Shevchenko, Rostislav V.; James, Stuart L.; James, S. Elizabeth

    2010-01-01

    Situations where normal autografts cannot be used to replace damaged skin often lead to a greater risk of mortality, prolonged hospital stay and increased expenditure for the National Health Service. There is a substantial need for tissue-engineered skin bioconstructs and research is active in this field. Significant progress has been made over the years in the development and clinical use of bioengineered components of the various skin layers. Off-the-shelf availability of such constructs, or production of sufficient quantities of biological materials to aid rapid wound closure, are often the only means to help patients with major skin loss. The aim of this review is to describe those materials already commercially available for clinical use as well as to give a short insight to those under development. It seeks to provide skin scientists/tissue engineers with the information required to not only develop in vitro models of skin, but to move closer to achieving the ultimate goal of an off-the-shelf, complete full-thickness skin replacement. PMID:19864266

  4. Fabricating optical phantoms to simulate skin tissue properties and microvasculatures

    NASA Astrophysics Data System (ADS)

    Sheng, Shuwei; Wu, Qiang; Han, Yilin; Dong, Erbao; Xu, Ronald

    2015-03-01

    This paper introduces novel methods to fabricate optical phantoms that simulate the morphologic, optical, and microvascular characteristics of skin tissue. The multi-layer skin-simulating phantom was fabricated by a light-cured 3D printer that mixed and printed the colorless light-curable ink with the absorption and the scattering ingredients for the designated optical properties. The simulated microvascular network was fabricated by a soft lithography process to embed microchannels in polydimethylsiloxane (PDMS) phantoms. The phantoms also simulated vascular anomalies and hypoxia commonly observed in cancer. A dual-modal multispectral and laser speckle imaging system was used for oxygen and perfusion imaging of the tissue-simulating phantoms. The light-cured 3D printing technique and the soft lithography process may enable freeform fabrication of skin-simulating phantoms that embed microvessels for image and drug delivery applications.

  5. Tissue viability imaging for quantification of skin erythema and blanching

    NASA Astrophysics Data System (ADS)

    Nilsson, Gert E.; Leahy, Martin J.

    2010-02-01

    Naked eye observation has up to recently been the main method of determining skin erythema (vasodilatation) and blanching (vasoconstriction) in skin testing. Since naked eye observation is a highly subjective and investigatordependent method, it is difficult to attain reproducibility and to compare results reported by different researchers performing their studies at different laboratories. Consequently there is a need for more objective, quantitative and versatile methods in the assessment of alterations in skin erythema and blanching caused by internal and external factors such as the intake of vasoactive drugs, application of agents on the skin surface and by constituents in the environment. Since skin microcirculation is sensitive to applied pressure and heat, such methods should preferably be noninvasive and designed for remote use without touching the skin. As skin microcirculation further possesses substantial spatial variability, imaging techniques are to be preferred before single point measurements. An emerging technology based on polarization digital camera spectroscopy - Tissue Viability Imaging (TiVi) - fulfills these requirements. The principles of TiVi (1) and some of its early applications (2-5) are addressed in this paper.

  6. Skin and Soft Tissue Infections (Patera Foot) in Immigrants, Spain

    PubMed Central

    Ternavasio-de la Vega, Hugo-Guillermo; Ángel-Moreno, Alfonso; Hernández-Cabrera, Michele; Pisos-Álamo, Elena; Bolaños-Rivero, Margarita; Carranza-Rodriguez, Cristina; Calderín-Ortega, Antonio; Pérez-Arellano, José-Luis

    2009-01-01

    An unusual skin and soft tissue infection of the lower limbs has been observed in immigrants from sub-Saharan Africa who cross the Atlantic Ocean crowded on small fishing boats (pateras). Response to conventional treatment is usually poor. Extreme extrinsic factors (including new pathogens) may contribute to the etiology of the infection and its pathogenesis. PMID:19331742

  7. Optimization of permanent breast seed implant dosimetry incorporating tissue heterogeneity

    NASA Astrophysics Data System (ADS)

    Mashouf, Shahram

    Seed brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG43 formalism, which generates the dose in homogeneous water medium. Recently, AAPM task group no. 186 (TG186) emphasized the importance of accounting for heterogeneities. In this work we introduce an analytical dose calculation algorithm in heterogeneous media using CT images. The advantages over other methods are computational efficiency and the ease of integration into clinical use. An Inhomogeneity Correction Factor (ICF) is introduced as the ratio of absorbed dose in tissue to that in water medium. ICF is a function of tissue properties and independent of the source structure. The ICF is extracted using CT images and the absorbed dose in tissue can then be calculated by multiplying the dose as calculated by the TG43 formalism times ICF. To evaluate the methodology, we compared our results with Monte Carlo simulations as well as experiments in phantoms with known density and atomic compositions. The dose distributions obtained through applying ICF to TG43 protocol agreed very well with those of Monte Carlo simulations and experiments in all phantoms. In all cases, the mean relative error was reduced by at least a factor of two when ICF correction factor was applied to the TG43 protocol. In conclusion we have developed a new analytical dose calculation method, which enables personalized dose calculations in heterogeneous media using CT images. The methodology offers several advantages including the use of standard TG43 formalism, fast calculation time and extraction of the ICF parameters directly from Hounsfield Units. The methodology was implemented into our clinical treatment planning system where a cohort of 140 patients were processed to study the clinical benefits of a heterogeneity corrected dose.

  8. Skin shedding and tissue regeneration in African spiny mice (Acomys).

    PubMed

    Seifert, Ashley W; Kiama, Stephen G; Seifert, Megan G; Goheen, Jacob R; Palmer, Todd M; Maden, Malcolm

    2012-09-27

    Evolutionary modification has produced a spectrum of animal defence traits to escape predation, including the ability to autotomize body parts to elude capture. After autotomy, the missing part is either replaced through regeneration (for example, in urodeles, lizards, arthropods and crustaceans) or permanently lost (such as in mammals). Although most autotomy involves the loss of appendages (legs, chelipeds, antennae or tails, for example), skin autotomy can occur in certain taxa of scincid and gekkonid lizards. Here we report the first demonstration of skin autotomy in Mammalia (African spiny mice, Acomys). Mechanical testing showed a propensity for skin to tear under very low tension and the absence of a fracture plane. After skin loss, rapid wound contraction was followed by hair follicle regeneration in dorsal skin wounds. Notably, we found that regenerative capacity in Acomys was extended to ear holes, where the mice exhibited complete regeneration of hair follicles, sebaceous glands, dermis and cartilage. Salamanders capable of limb regeneration form a blastema (a mass of lineage-restricted progenitor cells) after limb loss, and our findings suggest that ear tissue regeneration in Acomys may proceed through the assembly of a similar structure. This study underscores the importance of investigating regenerative phenomena outside of conventional model organisms, and suggests that mammals may retain a higher capacity for regeneration than was previously believed. As re-emergent interest in regenerative medicine seeks to isolate molecular pathways controlling tissue regeneration in mammals, Acomys may prove useful in identifying mechanisms to promote regeneration in lieu of fibrosis and scarring.

  9. Uncovering of melanin fluorescence in human skin tissue

    NASA Astrophysics Data System (ADS)

    Scholz, Matthias; Stankovic, Goran; Seewald, Gunter; Leupold, Dieter

    2007-07-01

    Due to its extremely low fluorescence quantum yield, in the conventionally (one-photon) excited autofluorescence of skin tissue, melanin fluorescence is masked by several other endogenous and possibly also exogenous fluorophores (e.g. NADH, FAD, Porphyrins). A first step to enhance the melanin contribution had been realized by two-photon fs-pulse excitation in the red/near IR, based on the fact that melanin can be excited by stepwise two-photon absorption, whereas all other fluorophores in this spectral region allow only simultaneous two-photon excitation. Now, the next and decisive step has been realized: Using an extremely sensitive detection system, for the first time twophoton fluorescence of skin tissue excited with pulses in the ns-range could be measured. The motivation for this step was based on the fact that the population density of the fluorescent level resulting from a stepwise excitation has a different dependence of the pulse duration than that from a simultaneous excitation (Δt2 vs. Δt). Due to this strong discrimination between the fluorophores, practically pure melanin fluorescence can be obtained. Examples for in-vivo, ex-vivo as well as paraffin embedded skin tissue will be shown. The content of information with respect to early diagnosis of skin deseases will be discussed.

  10. [Microbiological diagnosis of infections of the skin and soft tissues].

    PubMed

    Burillo, Almudena; Moreno, Antonio; Salas, Carlos

    2007-11-01

    Skin and soft tissue infections are often seen in clinical practice, yet their microbiological diagnosis is among the most complex of laboratory tasks. The diagnosis of a skin and a soft tissue infection is generally based on clinical criteria and not microbiological results. A microbiological diagnosis is reserved for cases in which the etiology of infection is required, e.g., when the infection is particularly severe, when less common microorganisms are suspected as the causative agent (e.g. in immunocompromised patients), when response to antimicrobial treatment is poor, or when a longstanding wound does not heal within a reasonable period of time. We report the indications, sampling and processing techniques, and interpretation criteria for various culture types, including quantitative cultures from biopsy or tissue specimens and semiquantitative and qualitative cultures performed on all types of samples. For non-invasive samples taken from open wounds, application of the Q index to Gram stains is a cost-effective way to standardize sample quality assessment and interpretation of the pathogenic involvement of the different microorganisms isolated from cultures. All these issues are covered in the SEIMC microbiological procedure number 22: Diagnóstico microbiológico de las infecciones de piel y tejidos blandos (Microbiological diagnosis of infections of the skin and soft tissues) (2nd ed., 2006, www.seimc.org/protocolos/microbiologia).

  11. Mechanisms underlying heterologous skin scaffold-mediated tissue remodeling

    PubMed Central

    Mimura, Kallyne K. O.; Moraes, Andréia R.; Miranda, Aline C.; Greco, Rebecca; Ansari, Tahera; Sibbons, Paul; Greco, Karin V.; Oliani, Sonia M.

    2016-01-01

    Biocompatibility of two newly developed porcine skin scaffolds was assessed after 3, 14, 21 and 90 days of implantation in rats. Both scaffolds showed absence of cells, preservation of ECM and mechanical properties comparable to non-decellularised skin before implantation. Host cell infiltration was much prominent on both scaffolds when compared to Permacol (surgical control). At day 3, the grafts were surrounded by polymorphonuclear cells, which were replaced by a notable number of IL-6-positive cells at day 14. Simultaneously, the number of pro-inflammatory M1-macrophage was enhanced. Interestingly, a predominant pro-remodeling M2 response, with newly formed vessels, myofibroblasts activation and a shift on the type of collagen expression was sequentially delayed (around 21 days). The gene expression of some trophic factors involved in tissue remodeling was congruent with the cellular events. Our findings suggested that the responsiveness of macrophages after non-crosslinked skin scaffolds implantation seemed to intimately affect various cell responses and molecular events; and this range of mutually reinforcing actions was predictive of a positive tissue remodeling that was essential for the long-standing success of the implants. Furthermore, our study indicates that non-crosslinked biologic scaffold implantation is biocompatible to the host tissue and somehow underlying molecular events involved in tissue repair. PMID:27725772

  12. Quantifying thermal modifications on laser welded skin tissue

    NASA Astrophysics Data System (ADS)

    Tabakoglu, Hasim Ö.; Gülsoy, Murat

    2011-02-01

    Laser tissue welding is a potential medical treatment method especially on closing cuts implemented during any kind of surgery. Photothermal effects of laser on tissue should be quantified in order to determine optimal dosimetry parameters. Polarized light and phase contrast techniques reveal information about extend of thermal change over tissue occurred during laser welding application. Change in collagen structure in skin tissue stained with hematoxilen and eosin samples can be detected. In this study, three different near infrared laser wavelengths (809 nm, 980 nm and 1070 nm) were compared for skin welding efficiency. 1 cm long cuts were treated spot by spot laser application on Wistar rats' dorsal skin, in vivo. In all laser applications, 0.5 W of optical power was delivered to the tissue, 5 s continuously, resulting in 79.61 J/cm2 energy density (15.92 W/cm2 power density) for each spot. The 1st, 4th, 7th, 14th, and 21st days of recovery period were determined as control days, and skin samples needed for histology were removed on these particular days. The stained samples were examined under a light microscope. Images were taken with a CCD camera and examined with imaging software. 809 Nm laser was found to be capable of creating strong full-thickness closure, but thermal damage was evident. The thermal damage from 980 nm laser welding was found to be more tolerable. The results showed that 1070 nm laser welding produced noticeably stronger bonds with minimal scar formation.

  13. Dosimetric effect of tissue heterogeneity for 125I prostate implants

    PubMed Central

    Oliveira, Susana Maria; Teixeira, Nuno José; Fernandes, Lisete; Teles, Pedro; Vaz, Pedro

    2014-01-01

    Aim To use Monte Carlo (MC) together with voxel phantoms to analyze the tissue heterogeneity effect in the dose distributions and equivalent uniform dose (EUD) for 125I prostate implants. Background Dose distribution calculations in low dose-rate brachytherapy are based on the dose deposition around a single source in a water phantom. This formalism does not take into account tissue heterogeneities, interseed attenuation, or finite patient dimensions effects. Tissue composition is especially important due to the photoelectric effect. Materials and methods The computed tomographies (CT) of two patients with prostate cancer were used to create voxel phantoms for the MC simulations. An elemental composition and density were assigned to each structure. Densities of the prostate, vesicles, rectum and bladder were determined through the CT electronic densities of 100 patients. The same simulations were performed considering the same phantom as pure water. Results were compared via dose–volume histograms and EUD for the prostate and rectum. Results The mean absorbed doses presented deviations of 3.3–4.0% for the prostate and of 2.3–4.9% for the rectum, when comparing calculations in water with calculations in the heterogeneous phantom. In the calculations in water, the prostate D90 was overestimated by 2.8–3.9% and the rectum D0.1cc resulted in dose differences of 6–8%. The EUD resulted in an overestimation of 3.5–3.7% for the prostate and of 7.7–8.3% for the rectum. Conclusions The deposited dose was consistently overestimated for the simulation in water. In order to increase the accuracy in the determination of dose distributions, especially around the rectum, the introduction of the model-based algorithms is recommended. PMID:25337412

  14. The complexity of elastic fibre biogenesis in the skin--a perspective to the clinical heterogeneity of cutis laxa.

    PubMed

    Uitto, Jouni; Li, Qiaoli; Urban, Zsolt

    2013-02-01

    Elastic fibres are critical connective tissue components providing elasticity and resilience to skin and other tissues. These fibres are composed of elastin and a number of elastin-associated microfibrillar proteins that assemble in a complex fibre network in a multi-step process. Multiple cellular processes, including mitochondrial function, specific molecules in the secretory pathways and temporally and spatially ordered production of elastic fibre components, are required for the biogenesis of functional elastic fibres. Abnormalities in these processes can lead to loss of functional elastic fibres manifesting phenotypically as a skin disease. The paradigm of elastic fibre diseases affecting the skin is cutis laxa, a clinically and genetically heterogeneous group of disorders characterized by loose and sagging skin, frequently associated with extracutaneous manifestations in the lungs and the arterial blood vessels. The complexity of cutis laxa is emphasized by the fact that as many as 10 distinct genes can harbour mutations in this and related disorders. Understanding of the pathomechanistic pathways involved in perturbed elastic fibre assembly in cutis laxa provides information potentially helpful for the development of molecular strategies towards treatment of these, currently intractable, diseases.

  15. Tissue Expanders in Skin Deficient Ventral Hernias Utilizing Component Separation

    PubMed Central

    Molinar, Vanessa E.; Molinar, Alonso; Palladino, Humberto

    2015-01-01

    Summary: Skin deficient complex ventral hernias are complicated surgical cases that have multimodal approaches. There is no current consensus on the management of those patients who also have concomitant stomas or enterocutaneous fistula. We present 2 cases in which the senior authors were able to apply tissue expanders above and between the abdominal wall in patients with an enterocutaneous fistula or stoma. After expansion and final closure, the patients did not experience recurrent hernias. PMID:26893988

  16. Tissue Expanders in Skin Deficient Ventral Hernias Utilizing Component Separation.

    PubMed

    Agullo, Francisco J; Molinar, Vanessa E; Molinar, Alonso; Palladino, Humberto

    2015-11-01

    Skin deficient complex ventral hernias are complicated surgical cases that have multimodal approaches. There is no current consensus on the management of those patients who also have concomitant stomas or enterocutaneous fistula. We present 2 cases in which the senior authors were able to apply tissue expanders above and between the abdominal wall in patients with an enterocutaneous fistula or stoma. After expansion and final closure, the patients did not experience recurrent hernias. PMID:26893988

  17. Three-Dimensional Tissue Models of Normal and Diseased Skin

    PubMed Central

    Carlson, Mark W.; Alt-Holland, Addy; Egles, Christophe; Garlick, Jonathan A.

    2010-01-01

    Over the last decade, the development of in vitro, human, three-dimensional (3D) tissue models, known as human skin equivalents (HSEs), has furthered understanding of epidermal cell biology and provided novel experimental systems. Signaling pathways that mediate the linkage between growth and differentiation function optimally when cells are spatially organized to display the architectural features seen in vivo, but are uncoupled and lost in two-dimensional culture systems. HSEs consist of a stratified squamous epithelium grown at an air-liquid interface on a collagen matrix populated with dermal fibroblasts. These 3D tissues demonstrate in vivo–like epithelial differentiation and morphology, and rates of cell division, similar to those found in human skin. This unit describes fabrication of HSEs, allowing the generation of human tissues that mimic the morphology, differentiation, and growth of human skin, as well as disease processes of cancer and wound re-epithelialization, providing powerful new tools for the study of diseases in humans. PMID:19085986

  18. Macro- to microscale strain transfer in fibrous tissues is heterogeneous and tissue-specific.

    PubMed

    Han, Woojin M; Heo, Su-Jin; Driscoll, Tristan P; Smith, Lachlan J; Mauck, Robert L; Elliott, Dawn M

    2013-08-01

    Mechanical deformation applied at the joint or tissue level is transmitted through the macroscale extracellular matrix to the microscale local matrix, where it is transduced to cells within these tissues and modulates tissue growth, maintenance, and repair. The objective of this study was to investigate how applied tissue strain is transferred through the local matrix to the cell and nucleus in meniscus, tendon, and the annulus fibrosus, as well as in stem cell-seeded scaffolds engineered to reproduce the organized microstructure of these native tissues. To carry out this study, we developed a custom confocal microscope-mounted tensile testing device and simultaneously monitored strain across multiple length scales. Results showed that mean strain was heterogeneous and significantly attenuated, but coordinated, at the local matrix level in native tissues (35-70% strain attenuation). Conversely, freshly seeded scaffolds exhibited very direct and uniform strain transfer from the tissue to the local matrix level (15-25% strain attenuation). In addition, strain transfer from local matrix to cells and nuclei was dependent on fiber orientation and tissue type. Histological analysis suggested that different domains exist within these fibrous tissues, with most of the tissue being fibrous, characterized by an aligned collagen structure and elongated cells, and other regions being proteoglycan (PG)-rich, characterized by a dense accumulation of PGs and rounder cells. In meniscus, the observed heterogeneity in strain transfer correlated strongly with cellular morphology, where rounder cells located in PG-rich microdomains were shielded from deformation, while elongated cells in fibrous microdomains deformed readily. Collectively, these findings suggest that different tissues utilize distinct strain-attenuating mechanisms according to their unique structure and cellular phenotype, and these differences likely alter the local biologic response of such tissues and constructs in

  19. Mechanism study of skin tissue ablation by nanosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Fang, Qiyin

    Understanding the fundamental mechanisms in laser tissue ablation is essential to improve clinical laser applications by reducing collateral damage and laser pulse energy requirement. The motive of this dissertation is to study skin tissue ablation by nanosecond laser pulses in a wide spectral region from near-infrared to ultraviolet for a clear understanding of the mechanism that can be used to improve future design of the pulsed lasers for dermatology and plastic surgery. Multiple laser and optical configurations have been constructed to generate 9 to 12ns laser pulses with similar profiles at 1064. 532, 266 and 213nm for this study of skin tissue ablation. Through measurements of ablation depth as a function cf laser pulse energy, the 589nm spectral line in the secondary radiation from ablated skin tissue samples was identified as the signature of the occurrence of ablation. Subsequently, this spectral signature has been used to investigate the probabilistic process of the ablation near the threshold at the four wavelengths. Measurements of the ablation probability were conducted as a function of the electrical field strength of the laser pulse and the ablation thresholds in a wide spectral range from 1064nm to 213nm were determined. Histology analysis and an optical transmission method were applied in assessing of the ablation depth per pulse to study the ablation process at irradiance levels higher than threshold. Because more than 70% of the wet weight of the skin tissue is water, optical breakdown and backscattering in water was also investigated along with a nonlinear refraction index measurement using a z-scan technique. Preliminary studies on ablation of a gelatin based tissue phantom are also reported. The current theoretical models describing ablation of soft tissue ablation by short laser pulses were critically reviewed. Since none of the existing models was found capable of explaining the experimental results, a new plasma-mediated model was developed

  20. Coupling 3D Monte Carlo light transport in optically heterogeneous tissues to photoacoustic signal generation

    PubMed Central

    Jacques, Steven L.

    2014-01-01

    The generation of photoacoustic signals for imaging objects embedded within tissues is dependent on how well light can penetrate to and deposit energy within an optically absorbing object, such as a blood vessel. This report couples a 3D Monte Carlo simulation of light transport to stress wave generation to predict the acoustic signals received by a detector at the tissue surface. The Monte Carlo simulation allows modeling of optically heterogeneous tissues, and a simple MATLAB™ acoustic algorithm predicts signals reaching a surface detector. An example simulation considers a skin with a pigmented epidermis, a dermis with a background blood perfusion, and a 500-μm-dia. blood vessel centered at a 1-mm depth in the skin. The simulation yields acoustic signals received by a surface detector, which are generated by a pulsed 532-nm laser exposure before and after inserting the blood vessel. A MATLAB™ version of the acoustic algorithm and a link to the 3D Monte Carlo website are provided. PMID:25426426

  1. Coupling 3D Monte Carlo light transport in optically heterogeneous tissues to photoacoustic signal generation.

    PubMed

    Jacques, Steven L

    2014-12-01

    The generation of photoacoustic signals for imaging objects embedded within tissues is dependent on how well light can penetrate to and deposit energy within an optically absorbing object, such as a blood vessel. This report couples a 3D Monte Carlo simulation of light transport to stress wave generation to predict the acoustic signals received by a detector at the tissue surface. The Monte Carlo simulation allows modeling of optically heterogeneous tissues, and a simple MATLAB™ acoustic algorithm predicts signals reaching a surface detector. An example simulation considers a skin with a pigmented epidermis, a dermis with a background blood perfusion, and a 500-μm-dia. blood vessel centered at a 1-mm depth in the skin. The simulation yields acoustic signals received by a surface detector, which are generated by a pulsed 532-nm laser exposure before and after inserting the blood vessel. A MATLAB™ version of the acoustic algorithm and a link to the 3D Monte Carlo website are provided.

  2. Analytical model of diffuse reflectance spectrum of skin tissue

    SciTech Connect

    Lisenko, S A; Kugeiko, M M; Firago, V A; Sobchuk, A N

    2014-01-31

    We have derived simple analytical expressions that enable highly accurate calculation of diffusely reflected light signals of skin in the spectral range from 450 to 800 nm at a distance from the region of delivery of exciting radiation. The expressions, taking into account the dependence of the detected signals on the refractive index, transport scattering coefficient, absorption coefficient and anisotropy factor of the medium, have been obtained in the approximation of a two-layer medium model (epidermis and dermis) for the same parameters of light scattering but different absorption coefficients of layers. Numerical experiments on the retrieval of the skin biophysical parameters from the diffuse reflectance spectra simulated by the Monte Carlo method show that commercially available fibre-optic spectrophotometers with a fixed distance between the radiation source and detector can reliably determine the concentration of bilirubin, oxy- and deoxyhaemoglobin in the dermis tissues and the tissue structure parameter characterising the size of its effective scatterers. We present the examples of quantitative analysis of the experimental data, confirming the correctness of estimates of biophysical parameters of skin using the obtained analytical expressions. (biophotonics)

  3. Analytical model of diffuse reflectance spectrum of skin tissue

    NASA Astrophysics Data System (ADS)

    Lisenko, S. A.; Kugeiko, M. M.; Firago, V. A.; Sobchuk, A. N.

    2014-01-01

    We have derived simple analytical expressions that enable highly accurate calculation of diffusely reflected light signals of skin in the spectral range from 450 to 800 nm at a distance from the region of delivery of exciting radiation. The expressions, taking into account the dependence of the detected signals on the refractive index, transport scattering coefficient, absorption coefficient and anisotropy factor of the medium, have been obtained in the approximation of a two-layer medium model (epidermis and dermis) for the same parameters of light scattering but different absorption coefficients of layers. Numerical experiments on the retrieval of the skin biophysical parameters from the diffuse reflectance spectra simulated by the Monte Carlo method show that commercially available fibre-optic spectrophotometers with a fixed distance between the radiation source and detector can reliably determine the concentration of bilirubin, oxy- and deoxyhaemoglobin in the dermis tissues and the tissue structure parameter characterising the size of its effective scatterers. We present the examples of quantitative analysis of the experimental data, confirming the correctness of estimates of biophysical parameters of skin using the obtained analytical expressions.

  4. Angiotensin II regulates collagen metabolism through modulating tissue inhibitor of metalloproteinase-1 in diabetic skin tissues.

    PubMed

    Ren, Meng; Hao, Shaoyun; Yang, Chuan; Zhu, Ping; Chen, Lihong; Lin, Diaozhu; Li, Na; Yan, Li

    2013-09-01

    We investigated the effect of angiotensin II (Ang II) on matrix metalloproteinase-1 (MMP-1)/tissue inhibitor of metalloproteinase-1 (TIMP-1) balance in regulating collagen metabolism of diabetic skin. Skin tissues from diabetic model were collected, and the primary cultured fibroblasts were treated with Ang II receptor inhibitors before Ang II treatment. The collagen type I (Coll I) and collagen type III (Coll III) were measured by histochemistry. The expressions of transforming growth factor-β (TGF-β), MMP-1, TIMP-1 and propeptides of types I and III procollagens in skin tissues and fibroblasts were quantified using polymerase chain reaction (PCR), Western blot or enzyme-linked immunosorbent assay (ELISA). Collagen dysfunction was documented by changed collagen I/III ratio in streptozotocin (STZ)-injected mice compared with controls. This was accompanied by increased expression of TGF-β, TIMP-1 and propeptides of types I and III procollagens in diabetic skin tissues. In primary cultured fibroblasts, Ang II prompted collagen synthesis accompanied by increases in the expressions of TGF-β, TIMP-1 and types I and III procollagens, and these increases were inhibited by losartan, an Ang II type 1 (AT1) receptor blocker, but not affected by PD123319, an Ang II type 2 (AT2) receptor antagonist. These findings present evidence that Ang-II-mediated changes in the productions of MMP-1 and TIMP-1 occur via AT1 receptors and a TGF-β-dependent mechanism.

  5. Aminoguanidine cream ameliorates skin tissue microenvironment in diabetic rats

    PubMed Central

    Tian, Ming; Qing, Chun; Niu, Yiwen; Dong, Jiaoyun; Cao, Xiaozan; Song, Fei; Ji, Xiaoyun

    2016-01-01

    Introduction The aim of the study was to explore the effect of aminoguanidine cream on the skin tissue microenvironment in diabetic rats. Material and methods A total of 51 healthy male Sprague Dawley (SD) rats were randomly divided into three groups: the diabetes group (n = 18), the aminoguanidine group (n = 18) and the control group (n = 15). Rats in the diabetes group and aminoguanidine group were injected with 65 mg/kg streptozotocin to induce the diabetes model, and in the control group with citrate buffer. After successful induction of diabetes, the back hair of all rats was stripped by barium sulfide, and the aminoguanidine group was treated with aminoguanidine cream using disinfected cotton swabs twice every day for 40 days, while the diabetes and control groups were treated with the cream matrix. The pathological changes of skin were observed by HE staining, while the content of inflammatory cytokines (TNF-α, IL-8, ICAM and IL-1α) and the antioxidant indexes (T-AOC, GSH-PX, MPO MDA H2O2) were examined using commercial kits. Results After 40 days of treatment, the diabetes group manifested tissue lesions, whereas the aminoguanidine group seemed normal. Compared with the diabetes group, the content of inflammatory cytokines TNF-α, IL-8, ICAM and IL-1α was dramatically lower in the aminoguanidine group. T-AOC in all groups underwent dramatic changes and returned to normal finally. The activities of GSH-PX and MPO and content of H2O2 in the diabetes group were all higher than those in the aminoguanidine group. Conclusions Aminoguanidine may have a good systemic effect on alleviating the pathological changes of skin tissue in diabetic rats, which may be attributed to the regulation of GSH-PX, TNF-α, IL-8, ICAM and IL-1α. PMID:26925135

  6. Skin and soft tissue infections in the military.

    PubMed

    Lamb, Lucy; Morgan, M

    2013-09-01

    Skin and soft tissue infections (SSTI) are common in military populations regularly living and training in close contact with each other. The majority of such infections are simple and can be easily treated with antibiotics and appropriate infection control practices. Some, however, can progress to become complex and even life threatening, such as Panton-Valentine Leukocidin (PVL)-associated staphylococcus aureus pneumonia, or Streptococcus pyogenes necrotising fasciitis, which carry a mortality rate of up to 65% and 30%, respectively. This review focuses on the most important SSTIs and those more commonly affecting military personnel with advice on how they are best managed. PMID:24109144

  7. Skin and soft tissue infections in the military.

    PubMed

    Lamb, Lucy; Morgan, M

    2013-09-01

    Skin and soft tissue infections (SSTI) are common in military populations regularly living and training in close contact with each other. The majority of such infections are simple and can be easily treated with antibiotics and appropriate infection control practices. Some, however, can progress to become complex and even life threatening, such as Panton-Valentine Leukocidin (PVL)-associated staphylococcus aureus pneumonia, or Streptococcus pyogenes necrotising fasciitis, which carry a mortality rate of up to 65% and 30%, respectively. This review focuses on the most important SSTIs and those more commonly affecting military personnel with advice on how they are best managed.

  8. Estrogen deficiency heterogeneously affects tissue specific stem cells in mice.

    PubMed

    Kitajima, Yuriko; Doi, Hanako; Ono, Yusuke; Urata, Yoshishige; Goto, Shinji; Kitajima, Michio; Miura, Kiyonori; Li, Tao-Sheng; Masuzaki, Hideaki

    2015-01-01

    Postmenopausal disorders are frequently observed in various organs, but their relationship with estrogen deficiency and mechanisms remain unclear. As tissue-specific stem cells have been found to express estrogen receptors, we examined the hypothesis that estrogen deficiency impairs stem cells, which consequently contributes to postmenopausal disorders. Six-week-old C57BL/6 female mice were ovariectomized, following which they received 17β-estradiol replacement or vehicle (control). Sham-operated mice were used as healthy controls. All mice were killed for evaluation 2 months after treatments. Compared with the healthy control, ovariectomy significantly decreased uterine weight, which was partially recovered by 17β-estradiol replacement. Ovariectomy significantly increased the numbers of c-kit-positive hematopoietic stem/progenitor cells in bone marrow, but impaired their capacity to grow mixed cell-type colonies in vitro. Estrogen replacement further increased the numbers of c-kit-positive hematopoietic stem/progenitor cells in bone marrow, without significantly affecting colony growth in vitro. The number of CD105-positive mesenchymal stem cells in bone marrow also significantly decreased after ovariectomy, but completely recovered following estrogen replacement. Otherwise, neither ovariectomy nor estrogen replacement changed the number of Pax7-positive satellite cells, which are a skeletal muscle-type stem cell. Estrogen deficiency heterogeneously affected tissue-specific stem cells, suggesting a likely and direct relationship with postmenopausal disorders. PMID:26245252

  9. Skin and soft tissue infections in immunocompetent patients.

    PubMed

    Breen, James Owen

    2010-04-01

    The increasing incidence of skin and soft tissue infections requires family physicians to be familiar with the management of these conditions. Evidence of systemic infection, such as fever, tachycardia, and hypotension, is an indication for inpatient management. Urgent surgical referral is imperative for those with life-threatening or rapidly advancing infections. In patients with uncomplicated abscesses measuring less than 5 cm in diameter, surgical drainage alone is the primary therapeutic intervention. Wound irrigation using tap water has similar outcomes as irrigation using sterile water. When antimicrobials are indicated, choice of agents depends on local resistance and susceptibility patterns. In settings where suspicion of methicillin-resistant Staphylococcus aureus (MRSA) is low, beta-lactam antibiotics are the first-line treatments for uncomplicated skin and soft tissue infections without focal coalescence or trauma. When empiric coverage for MRSA is indicated and the infection is uncomplicated, oral agents, such as tetracyclines, trimethoprim/sulfamethoxazole, and clindamycin, are preferred. Vancomycin is the first-line agent for MRSA in hospitalized patients, and newer agents, such as linezolid, daptomycin, and tigecycline, should be reserved for patients who do not respond to or cannot tolerate vancomycin therapy. There are insufficient data to support eradicating the carrier state in patients with MRSA or their contacts with nasal mupirocin or antibacterial body washes. Standard infection-control precautions, including proper and frequent handwashing, are a mainstay of MRSA prevention.

  10. Plant-Derived Human Collagen Scaffolds for Skin Tissue Engineering

    PubMed Central

    Willard, James J.; Drexler, Jason W.; Das, Amitava; Roy, Sashwati; Shilo, Shani; Shoseyov, Oded

    2013-01-01

    Tissue engineering scaffolds are commonly formed using proteins extracted from animal tissues, such as bovine hide. Risks associated with the use of these materials include hypersensitivity and pathogenic contamination. Human-derived proteins lower the risk of hypersensitivity, but possess the risk of disease transmission. Methods engineering recombinant human proteins using plant material provide an alternate source of these materials without the risk of disease transmission or concerns regarding variability. To investigate the utility of plant-derived human collagen (PDHC) in the development of engineered skin (ES), PDHC and bovine hide collagen were formed into tissue engineering scaffolds using electrospinning or freeze-drying. Both raw materials were easily formed into two common scaffold types, electrospun nonwoven scaffolds and lyophilized sponges, with similar architectures. The processing time, however, was significantly lower with PDHC. PDHC scaffolds supported primary human cell attachment and proliferation at an equivalent or higher level than the bovine material. Interleukin-1 beta production was significantly lower when activated THP-1 macrophages where exposed to PDHC electrospun scaffolds compared to bovine collagen. Both materials promoted proper maturation and differentiation of ES. These data suggest that PDHC may provide a novel source of raw material for tissue engineering with low risk of allergic response or disease transmission. PMID:23298216

  11. Alterations of skin-associated lymphoid tissue in the carcinogenesis of arsenical skin cancer.

    PubMed

    Yu, H S; Chen, G S; Sheu, H M; Kao, J S; Chang, K L; Yu, C L

    1992-01-01

    We investigated the skin-associated lymphoid tissue in arsenical skin cancers, including 14 Bowen's disease, 6 basal cell carcinoma and 6 squamous cell carcinoma patients from an endemic area by immunohistochemical and morphometric methods. There was a progressive decrease of Langerhans cells in the order of normal skin, normal appearing edge and arsenical cancers. A disruption of the uniform Langerhans cell dendrites was also noticed. The Langerhans cell density in arsenical tumors did not correlate with the peritumoral infiltrates. The prominent infiltrated cells in the peritumoral area had T cell markers. The number of peritumoral T lymphocytes in squamous cell carcinoma was significantly less than that of Bowen's disease and basal cell carcinoma. Peritumoral mononuclear infiltrates in Bowen's disease and squamous cell carcinoma showed a higher helper/suppressor T cell ratio than that in basal cell carcinoma. This may be accounted for by a selective increased recruitment of helper T cells to the tumor infiltrates in Bowen's disease and squamous cell carcinoma.

  12. Tissue heterogeneity in IMRT dose calculation for lung cancer.

    PubMed

    Pasciuti, Katia; Iaccarino, Giuseppe; Strigari, Lidia; Malatesta, Tiziana; Benassi, Marcello; Di Nallo, Anna Maria; Mirri, Alessandra; Pinzi, Valentina; Landoni, Valeria

    2011-01-01

    The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiation therapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the γ function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the lung and in the tumor area. These differences are not always in DVH of the lung, although the Wilcoxon test indicated significant differences in 2 of 4 patients. Disagreement in the lung region was also found when the Γ analysis was performed. The effect on TCP is less important than for NTCP because of the slope of the curve at the level of the dose of interest. The effect of dose calculation inaccuracy is patient-dependent and strongly related to beam geometry and to the localization of the tumor. When multiple intensity-modulated beams are used, the effect of the presence of the heterogeneity on dose distribution may not always be easily predictable. PMID:20970989

  13. Skin color correction for tissue spectroscopy: demonstration of a novel approach with tissue-mimicking phantoms.

    PubMed

    Soyemi, Olusola O; Landry, Michelle R; Yang, Ye; Idwasi, Patrick O; Soller, Babs R

    2005-02-01

    The application of partial least squares (PLS) regression to visible-near-infrared (VIS-NIR) spectroscopy for modeling important blood and tissue parameters is generally complicated by the variation in skin pigmentation (melanin) across the human population. An orthogonal correction method for removing the influence of skin pigmentation has been demonstrated in diffuse reflectance spectra from two-layer tissue-mimicking phantoms. The absorption properties of the phantoms were defined by lyophilized human hemoglobin (bottom layer) and synthetic melanin (top layer). Tissue-like scattering was simulated in both layers with intralipid. The approach uses principal components analysis (PCA) loading vectors from a separate set of phantom spectra that encode the unwanted melanin variation to remove the effect of melanin from the test phantoms. The preprocessing of phantom spectra using this orthogonal correction method resulted in PLS models with reduced complexity and enhanced prediction performance. Preliminary results from a separate study that evaluates the feasibility of defining skin color variation in an experiment with a single human subject are also presented.

  14. The classification and management of skin and soft tissue infections.

    PubMed

    Cross, Louise

    2013-04-01

    Skin and soft tissue infections (SSTIs) are a common problem in patients presenting to the emergency department, varying from mild local inflammation to necrotizing fasciitis. SSTI were the 2nd most common indication for antibiotic use in Europe in 2006. Currently, the National Institute of Clinical Excellence (a UK based independent organization responsible for providing national guidance on the promotion of good health and the prevention and treatment of ill health) has not published any guidelines for the classification and management of these patients. This is a review of the evidence around attempts at developing classification systems for SSTI and their management. It also considers the financial implications for both the patient and the healthcare system and the personal ramifications for patients.

  15. Skin and Soft Tissue Infection (Cellulitis) (Beyond the Basics)

    MedlinePlus

    ... skin infections are discussed separately. (See "Patient education: Methicillin-resistant Staphylococcus aureus (MRSA) (Beyond the Basics)" and "Patient ... be caused by a skin infection known as methicillin-resistant Staphylococcus aureus (MRSA). This is discussed separately. (See " ...

  16. Simultaneous imaging of blood flow and hemoglobin concentration change in skin tissue using NIR speckle patterns

    NASA Astrophysics Data System (ADS)

    Aizu, Yoshihisa; Hirata, Tatsuya; Maeda, Takaaki; Nishidate, Izumi; Yokoi, Naomichi

    2009-07-01

    We propose a method for imaging simultaneously blood flow and hemoglobin concentration change in skin tissue using speckle patterns acquired at two wavelengths of 780 and 830 nm. Experimental results demonstrate that the method is useful for time-varying analysis of blood circulation in human forearm skin tissue from one set of sequential speckle images.

  17. Changes of color coordinates of biological tissue with superficial skin damage due to mechanical trauma

    NASA Astrophysics Data System (ADS)

    Pteruk, Vail; Mokanyuk, Olexander; Kvaternuk, Olena; Yakenina, Lesya; Kotyra, Andrzej; Romaniuk, Ryszard S.; Dussembayeva, Shynar

    2015-12-01

    Change of color coordinates of normal and pathological biological tissues is based on calculated spectral diffuse reflection. The proposed color coordinates of normal and pathological biological tissues of skin provided using standard light sources, allowing accurately diagnose skin damage due to mechanical trauma with a blunt object for forensic problems.

  18. Bacillary angiomatosis presenting as a soft-tissue tumor without skin involvement.

    PubMed

    Schinella, R A; Greco, M A

    1990-05-01

    A patient with human immunodeficiency virus infection presented with a soft-tissue mass which histologically and clinically mimicked an angiosarcoma. Ultrastructural study, however, revealed bacteria identical to those seen in cutaneous bacillary angiomatosis, but the patient had no skin lesions. To our knowledge, this represents the first report of soft tissue involvement by bacillary angiomatosis without the presence of skin lesions.

  19. Skin and soft-tissue infections caused by Aeromonas species.

    PubMed

    Chao, C M; Lai, C C; Tang, H J; Ko, W C; Hsueh, P-R

    2013-04-01

    This study investigated the clinical characteristics of patients with skin and soft-tissue infections (SSTIs) due to Aeromonas species. Patients with SSTIs caused by Aeromonas species during the period from January 2009 to December 2011 were identified from a computerized database of a regional hospital in southern Taiwan. The medical records of these patients were retrospectively reviewed. A total of 129 patients with SSTIs due to Aeromonas species were identified. A. hydrophila (n = 77, 59.7 %) was the most common pathogen, followed by A. veronii biovar sobria (n = 22, 17.1 %), A. veronii biovar veronii (n = 20, 15.5 %), A. caviae (n = 9, 7.0 %), and A. schubertii (n = 1, 0.8 %). The most common isolates obtained from patients with polymicrobial infections were Klebsiella species (n = 33), followed by Enterococcus spp. (n = 24), Enterobacter spp. (n = 21), Escherichia coli (n = 17), Staphylococcus spp. (n = 17), Streptococcus spp. (n = 17), and Acinetobacter spp. (n = 15). Liver cirrhosis and concomitant bacteremia were more common among patients with monomicrobial Aeromonas SSTIs than among patients with polymicrobial SSTIs. Nine (7 %) patients required limb amputations. The in-hospital mortality rate was 1.6 %. In conclusion, Aeromonas species should be considered as important causative pathogens of SSTIs, and most infections are polymicrobial. In addition, the clinical presentation differs markedly between patients with monomicrobial and those with polymicrobial Aeromonas SSTIs.

  20. Neutrophilic Skin Lesions in Autoimmune Connective Tissue Diseases

    PubMed Central

    Hau, Estelle; Vignon Pennamen, Marie-Dominique; Battistella, Maxime; Saussine, Anne; Bergis, Maud; Cavelier-Balloy, Benedicte; Janier, Michel; Cordoliani, Florence; Bagot, Martine; Rybojad, Michel; Bouaziz, Jean-David

    2014-01-01

    Abstract The pathophysiology of neutrophilic dermatoses (NDs) and autoimmune connective tissue diseases (AICTDs) is incompletely understood. The association between NDs and AICTDs is rare; recently, however, a distinctive subset of cutaneous lupus erythematosus (LE, the prototypical AICTD) with neutrophilic histological features has been proposed to be included in the spectrum of lupus. The aim of our study was to test the validity of such a classification. We conducted a monocentric retrospective study of 7028 AICTDs patients. Among these 7028 patients, a skin biopsy was performed in 932 cases with mainly neutrophilic infiltrate on histology in 9 cases. Combining our 9 cases and an exhaustive literature review, pyoderma gangrenosum, Sweet syndrome (n = 49), Sweet-like ND (n = 13), neutrophilic urticarial dermatosis (n = 6), palisaded neutrophilic granulomatous dermatitis (n = 12), and histiocytoid neutrophilic dermatitis (n = 2) were likely to occur both in AICTDs and autoinflammatory diseases. Other NDs were specifically encountered in AICTDs: bullous LE (n = 71), amicrobial pustulosis of the folds (n = 28), autoimmunity-related ND (n = 24), ND resembling erythema gyratum repens (n = 1), and neutrophilic annular erythema (n = 1). The improvement of AICTDS neutrophilic lesions under neutrophil targeting therapy suggests possible common physiopathological pathways between NDs and AICTDs. PMID:25546688

  1. Skin and soft tissue necrosis from calcium chloride in a deicer.

    PubMed

    Kim, Min P; Raho, Vittorio J; Mak, John; Kaynar, A Murat

    2007-01-01

    Calcium chloride salt is the principle ingredient of many commercially available deicers. Calcium chloride melts snow and ice by its osmotic action. We present a case of skin and soft tissue necrosis associated with the use of a calcium chloride-containing deicer. Although calcium chloride is known to produce soft tissue necrosis if it extravasates during intravenous administration, necrosis and skin sloughing has rarely been described after topical exposure to this salt. Calcium chloride likely produces tissue injury from the heat liberated by mixing calcium chloride with water (exothermic reaction) and from direct calcium deposits in the skin (calcinosis cutis) and soft tissue.

  2. Tissue Engineered Skin Substitutes Created by Laser-Assisted Bioprinting Form Skin-Like Structures in the Dorsal Skin Fold Chamber in Mice

    PubMed Central

    Michael, Stefanie; Sorg, Heiko; Peck, Claas-Tido; Koch, Lothar; Deiwick, Andrea; Chichkov, Boris; Vogt, Peter M.; Reimers, Kerstin

    2013-01-01

    Tissue engineering plays an important role in the production of skin equivalents for the therapy of chronic and especially burn wounds. Actually, there exists no (cellularized) skin equivalent which might be able to satisfactorily mimic native skin. Here, we utilized a laser-assisted bioprinting (LaBP) technique to create a fully cellularized skin substitute. The unique feature of LaBP is the possibility to position different cell types in an exact three-dimensional (3D) spatial pattern. For the creation of the skin substitutes, we positioned fibroblasts and keratinocytes on top of a stabilizing matrix (Matriderm®). These skin constructs were subsequently tested in vivo, employing the dorsal skin fold chamber in nude mice. The transplants were placed into full-thickness skin wounds and were fully connected to the surrounding tissue when explanted after 11 days. The printed keratinocytes formed a multi-layered epidermis with beginning differentiation and stratum corneum. Proliferation of the keratinocytes was mainly detected in the suprabasal layers. In vitro controls, which were cultivated at the air-liquid-interface, also exhibited proliferative cells, but they were rather located in the whole epidermis. E-cadherin as a hint for adherens junctions and therefore tissue formation could be found in the epidermis in vivo as well as in vitro. In both conditions, the printed fibroblasts partly stayed on top of the underlying Matriderm® where they produced collagen, while part of them migrated into the Matriderm®. In the mice, some blood vessels could be found to grow from the wound bed and the wound edges in direction of the printed cells. In conclusion, we could show the successful 3D printing of a cell construct via LaBP and the subsequent tissue formation in vivo. These findings represent the prerequisite for the creation of a complex tissue like skin, consisting of different cell types in an intricate 3D pattern. PMID:23469227

  3. Tissue engineered skin substitutes created by laser-assisted bioprinting form skin-like structures in the dorsal skin fold chamber in mice.

    PubMed

    Michael, Stefanie; Sorg, Heiko; Peck, Claas-Tido; Koch, Lothar; Deiwick, Andrea; Chichkov, Boris; Vogt, Peter M; Reimers, Kerstin

    2013-01-01

    Tissue engineering plays an important role in the production of skin equivalents for the therapy of chronic and especially burn wounds. Actually, there exists no (cellularized) skin equivalent which might be able to satisfactorily mimic native skin. Here, we utilized a laser-assisted bioprinting (LaBP) technique to create a fully cellularized skin substitute. The unique feature of LaBP is the possibility to position different cell types in an exact three-dimensional (3D) spatial pattern. For the creation of the skin substitutes, we positioned fibroblasts and keratinocytes on top of a stabilizing matrix (Matriderm®). These skin constructs were subsequently tested in vivo, employing the dorsal skin fold chamber in nude mice. The transplants were placed into full-thickness skin wounds and were fully connected to the surrounding tissue when explanted after 11 days. The printed keratinocytes formed a multi-layered epidermis with beginning differentiation and stratum corneum. Proliferation of the keratinocytes was mainly detected in the suprabasal layers. In vitro controls, which were cultivated at the air-liquid-interface, also exhibited proliferative cells, but they were rather located in the whole epidermis. E-cadherin as a hint for adherens junctions and therefore tissue formation could be found in the epidermis in vivo as well as in vitro. In both conditions, the printed fibroblasts partly stayed on top of the underlying Matriderm® where they produced collagen, while part of them migrated into the Matriderm®. In the mice, some blood vessels could be found to grow from the wound bed and the wound edges in direction of the printed cells. In conclusion, we could show the successful 3D printing of a cell construct via LaBP and the subsequent tissue formation in vivo. These findings represent the prerequisite for the creation of a complex tissue like skin, consisting of different cell types in an intricate 3D pattern.

  4. Drug delivery through the skin barrier enhanced by treatment with tissue-tolerable plasma.

    PubMed

    Lademann, Olaf; Richter, Heike; Meinke, Martina C; Patzelt, Alexa; Kramer, Axel; Hinz, Peter; Weltmann, Klaus-Dieter; Hartmann, Bernd; Koch, Stefan

    2011-06-01

    Most treatments in dermatology and cosmetology are based on the penetration of topically applied drugs into the skin or through the skin barrier to the target structure in the living tissue. In the case of healthy skin, scarcely 1% of the applied drugs pass the skin barrier, depending on their chemical properties. Therefore, different physical and chemical methods have been developed to stimulate the penetration process. All these methods are based on the partial destruction of the barrier. In this study, an electrical tissue-tolerable plasma (TTP) was used to increase the penetration of a topically applied model drug (fluorescent dye) through the skin barrier. Using laser scanning microscopy, the distribution of the model drug in different depths of the skin was investigated. It was found that the plasma treatment of the skin is a very efficient process to deliver topically applied substances into the living tissue. In the case of the non-plasma-treated skin, it was found that the fluorescent dye could be detected exclusively on the skin surface. If the dye was applied to the TTP-treated skin, it could be observed in high concentration also in deeper parts of the skin extending down to the stratum basale and the papillary structure. PMID:21371126

  5. Optical coherence tomography investigation of growth cycles of engineered skin tissue

    NASA Astrophysics Data System (ADS)

    Schmitt, Robert; Marx, Ulrich; Walles, Heike; Heymer, Andrea

    2010-02-01

    Engineered skin tissues are widely used in dermatological, pharmacological and toxicological studies and as autologous transplants in wound healing. Due to the high demand for artificial skin equivalents, there is a need for an automation of the manual production process to achieve a high-grade product. Thus, non-invasive monitoring of engineered tissue during the growth cycles is of major significance to understand and consequently improve the growth characteristics of in vitro tissue. Prior to the framework of the automation of artificial humanoid 3d-skin tissue engineering, optimal growth parameters need to be determined. The successful engineering of humanoid tissue is strongly coupled to the composition and structure of the upper epidermal and dermal skin layers. The layers are based on primary humanoid keratinocytes and a collagen - fibroblasts matrix. We applied optical coherence tomography as tissue imaging technology, which offers great potential to detect and characterize the differentiation processes of engineered skin. OCT provides a high resolution in the micron range with an imaging depth of about 1.5mm in semitransparent tissue. Due to a high quality signal to noise ratio, even small changes in signal at the boundary of the skin layers are detectable. In a study, OCT tomograms were taken after each production step of the skin equivalents and compared to the images of histologies.

  6. Vital roles of stem cells and biomaterials in skin tissue engineering

    PubMed Central

    Mohd Hilmi, Abu Bakar; Halim, Ahmad Sukari

    2015-01-01

    Tissue engineering essentially refers to technology for growing new human tissue and is distinct from regenerative medicine. Currently, pieces of skin are already being fabricated for clinical use and many other tissue types may be fabricated in the future. Tissue engineering was first defined in 1987 by the United States National Science Foundation which critically discussed the future targets of bioengineering research and its consequences. The principles of tissue engineering are to initiate cell cultures in vitro, grow them on scaffolds in situ and transplant the composite into a recipient in vivo. From the beginning, scaffolds have been necessary in tissue engineering applications. Regardless, the latest technology has redirected established approaches by omitting scaffolds. Currently, scientists from diverse research institutes are engineering skin without scaffolds. Due to their advantageous properties, stem cells have robustly transformed the tissue engineering field as part of an engineered bilayered skin substitute that will later be discussed in detail. Additionally, utilizing biomaterials or skin replacement products in skin tissue engineering as strategy to successfully direct cell proliferation and differentiation as well as to optimize the safety of handling during grafting is beneficial. This approach has also led to the cells’ application in developing the novel skin substitute that will be briefly explained in this review. PMID:25815126

  7. Vital roles of stem cells and biomaterials in skin tissue engineering.

    PubMed

    Mohd Hilmi, Abu Bakar; Halim, Ahmad Sukari

    2015-03-26

    Tissue engineering essentially refers to technology for growing new human tissue and is distinct from regenerative medicine. Currently, pieces of skin are already being fabricated for clinical use and many other tissue types may be fabricated in the future. Tissue engineering was first defined in 1987 by the United States National Science Foundation which critically discussed the future targets of bioengineering research and its consequences. The principles of tissue engineering are to initiate cell cultures in vitro, grow them on scaffolds in situ and transplant the composite into a recipient in vivo. From the beginning, scaffolds have been necessary in tissue engineering applications. Regardless, the latest technology has redirected established approaches by omitting scaffolds. Currently, scientists from diverse research institutes are engineering skin without scaffolds. Due to their advantageous properties, stem cells have robustly transformed the tissue engineering field as part of an engineered bilayered skin substitute that will later be discussed in detail. Additionally, utilizing biomaterials or skin replacement products in skin tissue engineering as strategy to successfully direct cell proliferation and differentiation as well as to optimize the safety of handling during grafting is beneficial. This approach has also led to the cells' application in developing the novel skin substitute that will be briefly explained in this review. PMID:25815126

  8. Mechanical Tissue Optical Clearing Devices: Enhancement of Light Penetration in Ex-Vivo Porcine Skin and Adipose Tissue

    PubMed Central

    Milner, Thomas E.; Baranov, Stepan; Nelson, J. Stuart

    2008-01-01

    Background and Objective The complex morphological structure of tissue and associated variations in the indices of refraction of components therein, provides a highly scattering medium for visible and near-infrared wavelengths of light. Tissue optical clearing permits delivery of light deeper into tissue, potentially improving the capabilities of various light-based therapeutic techniques, such as adipose tissue removal or reshaping. Study Design/ Materials and Methods We report results of a study to evaluate effectiveness of novel mechanical tissue optical clearing devices (TOCD) using white light photography and infrared imaging radiometry (IIR). The TOCD consists of a pin array and vacuum pressure source applied directly to the skin surface. IIR images recorded light absorption and temperature increase of ex vivo porcine skin and adipose during laser irradiation (980 and 1210 nm) before and after TOCD application. Results White light photographic images of in vivo human skin demonstrated localized compression and altered visual appearance, indicative of water and blood movement in skin. White light photographic images also showed increased visible light transport through regions of ex vivo porcine skin compressed by TOCD pins. Rate of heating in sub-dermal adipose regions beneath TOCD pins was two-fold higher following TOCD application. Conclusions Results of our study suggest that mechanical optical clearing may provide a means to deliver increased light fluence to dermal and adipose tissues. PMID:19065559

  9. Revascularization of autogenous skin grafts placed on irradiated tissue

    SciTech Connect

    Ueda, M.; Torii, S.; Kaneda, T.; Oka, T.

    1982-08-01

    Vascular changes in rat skin after irradiation were examined microangiographically. Revascularization of the skin transplanted during the chronic stage after irradiation was also studied. The results obtained through these examinations revealed higher vascular densities at the acute and the subacute stages, and low values at the chronic stages compared with those of the control. Furthermore, when the skin grafts were transplanted to the irradiated beds in the chronic stage, primary revascularization was scant, and the inhibited capillary proliferation in the recipient sites prevented new vessel penetration. This explains why grafts transplanted to previously irradiated beds fail to survive.

  10. CCN1 contributes to skin connective tissue aging by inducing age-associated secretory phenotype in human skin dermal fibroblasts.

    PubMed

    Quan, Taihao; Qin, Zhaoping; Robichaud, Patrick; Voorhees, John J; Fisher, Gary J

    2011-08-01

    Dermal connective tissue collagen is the major structural protein in skin. Fibroblasts within the dermis are largely responsible for collagen production and turnover. We have previously reported that dermal fibroblasts, in aged human skin in vivo, express elevated levels of CCN1, and that CCN1 negatively regulates collagen homeostasis by suppressing collagen synthesis and increasing collagen degradation (Quan et al. Am J Pathol 169:482-90, 2006, J Invest Dermatol 130:1697-706, 2010). In further investigations of CCN1 actions, we find that CCN1 alters collagen homeostasis by promoting expression of specific secreted proteins, which include matrix metalloproteinases and proinflammatory cytokines. We also find that CCN1-induced secretory proteins are elevated in aged human skin in vivo. We propose that CCN1 induces an "Age-Associated Secretory Phenotype", in dermal fibroblasts, which mediates collagen reduction and fragmentation in aged human skin.

  11. Skin donors and human skin allografts: evaluation of an 11-year practice and discard in a referral tissue bank.

    PubMed

    Gaucher, Sonia; Khaznadar, Zena; Gourevitch, Jean-Claude; Jarraya, Mohamed

    2016-03-01

    The Saint Louis hospital tissue bank provides skin allografts to pediatric and adult burn units in the Paris area. The aim of this study was to analyze our activity during the last 11 years focusing on the reasons for skin discard. Skin is procured solely from the back of the body, which is divided into 10 zones that are harvested and processed separately. This retrospective study included all skin donors harvested between June 2002 and June 2013, representing a total of 336 donors and 2770 zones. The donors were multiorgan heart-beating donors in 91 % of cases (n = 307). The main reason for discarding harvested skin was microbial contamination, detected in 99 donors (29 %). Most contaminants were of low pathogenicity. Other reasons for discard included positive serologic tests for 2 donors [17 zones (0.61 %)], unsuitable physical skin characteristics for 3 zones (0.11 %), the donor's medical history for 53 zones (1.91 %), and technical issues with processing or distribution for 61 zones (2.2 %). In our experience, microbial contamination continues to be the main reason for discarding potential skin allografts. However, discards are limited by separate harvesting and processing of multiple zones in each donor. PMID:26275343

  12. Keratohyalin granules are heterogeneous in ridged and non-ridged human skin: evidence from anti-filaggrin immunogold labelling of normal skin and skin of autosomal dominant ichthyosis vulgaris patients.

    PubMed

    Günzel, S; Weidenthaler, B; Hausser, I; Anton-Lamprecht, I

    1991-01-01

    Recent biochemical and morphological investigations have provided evidence for a heterogeneous composition of keratohyalin in human skin. A major component is filaggrin. In interfollicular epidermis the heterogeneity of keratohyalin is not directly visible, whereas in normal ridged skin bicomponent keratohyalin is revealed by electron microscopy. Skin biopsies of ridged and non-ridged skin of normal individuals and patients with autosomal dominant ichthyosis vulgaris (ADI)--characterized by defective keratohyalin synthesis and lack of filaggrin--were investigated by routine transmission electron microscopy and immunogold postembedding techniques using a commercial monoclonal anti-filaggrin antibody. In normal interfollicular epidermis filaggrin labelling was demonstrated on keratohyalin granules and in the lowermost cornified cells, whereas in ADI patients crumbly keratohyalin granules were present that did not show specific labelling for filaggrin. In normal ridged skin only the major (more electron-dense) component reacted with anti-filaggrin, whereas the attached (less electron-dense) component did not react. Ridged skin of ADI patients contained globular keratohyalin that did not react with anti-filaggrin, thus corresponding to the attached keratohyalin component in normal ridged skin. Our results provide a visible counterpart to the recent biochemical investigations of keratohyalin protein heterogeneity and contribute to the understanding of terminal differentiation in human skin and of the defective keratohyalin synthesis in ADI.

  13. Impact of tissue heterogeneity corrections in stereotactic body radiation therapy treatment plans for lung cancer.

    PubMed

    Herman, Tania De La Fuente; Gabrish, Heather; Herman, Terence S; Vlachaki, Maria T; Ahmad, Salahuddin

    2010-07-01

    This study aims at evaluating the impact of tissue heterogeneity corrections on dosimetry of stereotactic body radiation therapy treatment plans. Four-dimensional computed tomography data from 15 low stage non-small cell lung cancer patients was used. Treatment planning and dose calculations were done using pencil beam convolution algorithm of Varian Eclipse system with Modified Batho Power Law for tissue heterogeneity. Patient plans were generated with 6 MV co-planar non-opposing four to six field beams optimized with tissue heterogeneity corrections to deliver a prescribed dose of 60 Gy in three fractions to at least 95% of the planning target volume, keeping spinal cord dose <10 Gy. The same plans were then regenerated without heterogeneity correction by recalculating previously optimized treatment plans keeping identical beam arrangements, field fluences and monitor units. Compared with heterogeneity corrected plans, the non-corrected plans had lower average minimum, mean, and maximum tumor doses by 13%, 8%, and 6% respectively. The results indicate that tissue heterogeneity is an important determinant of dosimetric optimization of SBRT plans.

  14. Skin tissue engineering advances in severe burns: review and therapeutic applications.

    PubMed

    Chua, Alvin Wen Choong; Khoo, Yik Cheong; Tan, Bien Keem; Tan, Kok Chai; Foo, Chee Liam; Chong, Si Jack

    2016-01-01

    Current advances in basic stem cell research and tissue engineering augur well for the development of improved cultured skin tissue substitutes: a class of products that is still fraught with limitations for clinical use. Although the ability to grow autologous keratinocytes in-vitro from a small skin biopsy into sheets of stratified epithelium (within 3 to 4 weeks) helped alleviate the problem of insufficient donor site for extensive burn, many burn units still have to grapple with insufficient skin allografts which are used as intermediate wound coverage after burn excision. Alternatives offered by tissue-engineered skin dermal replacements to meet emergency demand have been used fairly successfully. Despite the availability of these commercial products, they all suffer from the same problems of extremely high cost, sub-normal skin microstructure and inconsistent engraftment, especially in full thickness burns. Clinical practice for severe burn treatment has since evolved to incorporate these tissue-engineered skin substitutes, usually as an adjunct to speed up epithelization for wound closure and/or to improve quality of life by improving the functional and cosmetic results long-term. This review seeks to bring the reader through the beginnings of skin tissue engineering, the utilization of some of the key products developed for the treatment of severe burns and the hope of harnessing stem cells to improve on current practice. PMID:27574673

  15. Optical clearing of skin tissue ex vivo with polyethylene glycol

    NASA Astrophysics Data System (ADS)

    Tuchina, D. K.; Genin, V. D.; Bashkatov, A. N.; Genina, E. A.; Tuchin, V. V.

    2016-01-01

    Alterations of the optical and structural (weight, thickness, and square) parameters of skin caused by polyethylene glycol (PEG) with molecular weights of 300 and 400 Da were studied experimentally. The objects of the study were ex vivo skin samples of albino laboratory rats. Collimated transmittance of the skin was measured in the wavelength range 500-900 nm. As a result of exposure to the agents, an increase in the collimated transmittance and a decrease in weight, thickness, and square of skin samples were observed. Analysis of the kinetics of parameters alterations allowed us to measure the diffusion coefficient of the agents in the skin as (1.83 ± 2.22) × 10-6 and (1.70 ± 1.47) × 10-6 cm2/s for PEG-300 and PEG-400, respectively, and the rate of alterations of the structural parameters. The results obtained in this study can be used for the improvement of existing and development of new methods of noninvasive diagnostics and therapy of subcutaneous diseases.

  16. Pivotal role for skin transendothelial radio-resistant anti-inflammatory macrophages in tissue repair

    PubMed Central

    Barreiro, Olga; Cibrian, Danay; Clemente, Cristina; Alvarez, David; Moreno, Vanessa; Valiente, Íñigo; Bernad, Antonio; Vestweber, Dietmar; Arroyo, Alicia G; Martín, Pilar; von Andrian, Ulrich H; Sánchez Madrid, Francisco

    2016-01-01

    Heterogeneity and functional specialization among skin-resident macrophages are incompletely understood. In this study, we describe a novel subset of murine dermal perivascular macrophages that extend protrusions across the endothelial junctions in steady-state and capture blood-borne macromolecules. Unlike other skin-resident macrophages that are reconstituted by bone marrow-derived progenitors after a genotoxic insult, these cells are replenished by an extramedullary radio-resistant and UV-sensitive Bmi1+ progenitor. Furthermore, they possess a distinctive anti-inflammatory transcriptional profile, which cannot be polarized under inflammatory conditions, and are involved in repair and remodeling functions for which other skin-resident macrophages appear dispensable. Based on all their properties, we define these macrophages as Skin Transendothelial Radio-resistant Anti-inflammatory Macrophages (STREAM) and postulate that their preservation is important for skin homeostasis. DOI: http://dx.doi.org/10.7554/eLife.15251.001 PMID:27304075

  17. [Obtention of human skin sheets by means of tissue engineering].

    PubMed

    Arvelo, Francisco; Pérez, Pedro; Cotte, Carlos

    2004-01-01

    The aim of this "in vitro" study was to develop a new system for keratinocyte culture on a dermal equivalent that enables treatment of different skin injuries. The keratinocyte where obtained from primary cell cultures derived from skin biopsies, seeded over a fibrin matrix enhanced with live human fibroblast. Cells growing over the dermal equivalent, rapidly confluences and a stratified epithelium was obtained within 20-25 days culture. Detachment of composite culture from flask is a simple and quick procedure with no need for chemical or enzyme treatments. The method described provides a number of advantages which include the large expansion of keratinocyte from the primary cell cultures without the need of a feeder layer, the availability of plasma from blood banks, and the versatile and safe manipulation of composite obtained "in vitro". All these facts allow to assure that this system could result very efficient for the treatment of all type of skin injuries.

  18. Mechanical characterization of the rat and mice skin tissues using histostructural and uniaxial data

    PubMed Central

    Karimi, Alireza; Rahmati, Seyyed Mohammadali; Navidbakhsh, Mahdi

    2015-01-01

    The skin tissue has been shown to behave like a nonlinear anisotropic material. This study was aimed to employ a constitutive fiber family equation to characterize the nonlinear anisotropic mechanical behavior of the rat and mice skin tissues in different anatomical locations, including the abdomen and back, using histostructural and uniaxial data. The rat and mice skin tissues were excised from the animals’ body and then the histological analyses were performed on each skin type to determine the mean fiber orientation angle. Afterward, the preconditioned skin tissues were subjected to a series of quasi-static axial and circumferential loads until the incidence of failure. The crucial role of fiber orientation was explicitly added into a proposed strain energy density function. The material coefficients were determined using the constrained nonlinear optimization method based on the axial and circumferential extension data of the rat and mice samples at different anatomical locations. The material coefficients of the skins were given with R2 ≥ 0.998. The results revealed a significant load-bearing capacity and stiffness of the rat abdomen compared to the rat back tissues. In addition, the mice abdomen showed a higher stiffness in the axial direction in comparison with circumferential one, while the mice back displayed its highest stiffness in the circumferential direction. The material coefficients of the rat and mice skin tissues were determined and well compared to the experimental data. The optimized fiber angles were also compared to the experimental histological data, and in all cases less than 11.85% differences were observed in both the skin tissues. PMID:25837446

  19. In vitro fluorescence measurements and Monte Carlo simulation of laser irradiation propagation in porcine skin tissue.

    PubMed

    Drakaki, E; Makropoulou, M; Serafetinides, A A

    2008-07-01

    In dermatology, the in vivo spectral fluorescence measurements of human skin can serve as a valuable supplement to standard non-invasive techniques for diagnosing various skin diseases. However, quantitative analysis of the fluorescence spectra is complicated by the fact that skin is a complex multi-layered and inhomogeneous organ, with varied optical properties and biophysical characteristics. In this work, we recorded, in vitro, the laser-induced fluorescence emission signals of healthy porcine skin, one of the animals, which is considered as one of the most common models for investigations related to medical diagnostics of human cutaneous tissues. Differences were observed in the form and intensity of the fluorescence signal of the porcine skin, which can be attributed to the different concentrations of the native fluorophores and the variable physical and biological conditions of the skin tissue. As the light transport in the tissue target is directly influencing the absorption and the fluorescence emission signals, we performed Monte Carlo simulation of the light distribution in a five-layer model of human skin tissue, with a pulsed ultraviolet laser beam.

  20. Reentry Near the Percolation Threshold in a Heterogeneous Discrete Model for Cardiac Tissue

    NASA Astrophysics Data System (ADS)

    Alonso, Sergio; Bär, Markus

    2013-04-01

    Arrhythmias in cardiac tissue are related to irregular electrical wave propagation in the heart. Cardiac tissue is formed by a discrete cell network, which is often heterogeneous. A localized region with a fraction of nonconducting links surrounded by homogeneous conducting tissue can become a source of reentry and ectopic beats. Extensive simulations in a discrete model of cardiac tissue show that a wave crossing a heterogeneous region of cardiac tissue can disintegrate into irregular patterns, provided the fraction of nonconducting links is close to the percolation threshold of the cell network. The dependence of the reentry probability on this fraction, the system size, and the degree of excitability can be inferred from the size distribution of nonconducting clusters near the percolation threshold.

  1. A simplified analytical dose calculation algorithm accounting for tissue heterogeneity for low-energy brachytherapy sources.

    PubMed

    Mashouf, Shahram; Lechtman, Eli; Beaulieu, Luc; Verhaegen, Frank; Keller, Brian M; Ravi, Ananth; Pignol, Jean-Philippe

    2013-09-21

    The American Association of Physicists in Medicine Task Group No. 43 (AAPM TG-43) formalism is the standard for seeds brachytherapy dose calculation. But for breast seed implants, Monte Carlo simulations reveal large errors due to tissue heterogeneity. Since TG-43 includes several factors to account for source geometry, anisotropy and strength, we propose an additional correction factor, called the inhomogeneity correction factor (ICF), accounting for tissue heterogeneity for Pd-103 brachytherapy. This correction factor is calculated as a function of the media linear attenuation coefficient and mass energy absorption coefficient, and it is independent of the source internal structure. Ultimately the dose in heterogeneous media can be calculated as a product of dose in water as calculated by TG-43 protocol times the ICF. To validate the ICF methodology, dose absorbed in spherical phantoms with large tissue heterogeneities was compared using the TG-43 formalism corrected for heterogeneity versus Monte Carlo simulations. The agreement between Monte Carlo simulations and the ICF method remained within 5% in soft tissues up to several centimeters from a Pd-103 source. Compared to Monte Carlo, the ICF methods can easily be integrated into a clinical treatment planning system and it does not require the detailed internal structure of the source or the photon phase-space.

  2. Stimulation of the penetration of particles into the skin by plasma tissue interaction

    NASA Astrophysics Data System (ADS)

    Lademann, O.; Richter, H.; Kramer, A.; Patzelt, A.; Meinke, M. C.; Graf, C.; Gao, Q.; Korotianskiy, E.; Rühl, E.; Weltmann, K.-D.; Lademann, J.; Koch, S.

    2011-10-01

    A high number of treatments in dermatology are based on the penetration of topically applied drugs through the skin barrier. This process is predominantly inefficient, on account of the strong protection properties of the upper skin layer - the stratum corneum. If the skin barrier is damaged, the penetration efficiency of topically applied drugs increases. Therefore, different methods have been developed to influence the barrier properties of the skin. Recently, it could be demonstrated that a cold tissue tolerable plasma (TTP) produced by a plasma-jet can strongly enhance drug delivery through the skin. These investigations were performed by using a solution of fluorescent dye as a model drug. In the present study, these investigations were carried out using fluorescent silica particles at different sizes. The aim of the study was to investigate whether or not there is a limitation in size for topically applied substances to pass through the skin barrier after plasma treatment.

  3. Terahertz pulse imaging in reflection geometry of skin tissue using time-domain analysis techniques

    NASA Astrophysics Data System (ADS)

    Woodward, Ruth M.; Wallace, Vincent P.; Cole, Bryan E.; Pye, Richard J.; Arnone, Donald D.; Linfield, Edmund H.; Pepper, Michael

    2002-06-01

    We demonstrate the application of Terahertz Pulse Imaging (TPI) in reflection geometry for the study of skin tissue and related cancers. The terahertz frequency regime of 0.1-100THz excites the vibrational modes of molecules, allowing for spectroscopic investigation. The sensitivity of terahertz to polar molecules, such as water, makes TPI suitable for studying the hydration levels in the stratum corneum and the determination of the lateral spread of skin cancer pre-operatively. By studying the terahertz pulse shape in the time domain we have been able to differentiate between diseased and normal tissue for the study of basal cell carcinoma (BCC). Measurements on scar tissue, which is known to contain less water than the surrounding skin, and on regions of inflammation, show a clear contrast in the THz image compared to normal skin. We discuss the time domain analysis techniques used to classify the different tissue types. Basal cell carcinoma shows a positive terahertz contrast, and inflammation and scar tissue shows a negative terahertz contrast compared to normal tissue. This demonstrates for the first time the potential of TPI both in the study of skin cancer and inflammatory related disorders.

  4. Tattoo ink nanoparticles in skin tissue and fibroblasts

    PubMed Central

    Twigg, Peter C; Baker, Richard; Tobin, Desmond J

    2015-01-01

    Summary Tattooing has long been practised in various societies all around the world and is becoming increasingly common and widespread in the West. Tattoo ink suspensions unquestionably contain pigments composed of nanoparticles, i.e., particles of sub-100 nm dimensions. It is widely acknowledged that nanoparticles have higher levels of chemical activity than their larger particle equivalents. However, assessment of the toxicity of tattoo inks has been the subject of little research and ink manufacturers are not obliged to disclose the exact composition of their products. This study examines tattoo ink particles in two fundamental skin components at the nanometre level. We use atomic force microscopy and light microscopy to examine cryosections of tattooed skin, exploring the collagen fibril networks in the dermis that contain ink nanoparticles. Further, we culture fibroblasts in diluted tattoo ink to explore both the immediate impact of ink pigment on cell viability and also to observe the interaction between particles and the cells. PMID:26171294

  5. Self-reported incidence of skin and soft tissue infections among deployed US military.

    PubMed

    May, Larissa; Porter, Chad; Tribble, David; Armstrong, Adam; Mostafa, Manal; Riddle, Mark

    2011-07-01

    The incidence of skin and soft tissue infections has steadily increased over the past decade, and military populations, particularly recruits, have been affected. However, the epidemiology of skin and soft tissue infections in deployed personnel has not previously been described. We conducted a cross-sectional study of United States military personnel in mid-deployment using self-reported questionnaire data containing 11 demographic questions and 20 questions related to skin and soft tissue infections. The primary outcome was self-reported incident SSTI. Descriptive analyses were conducted and incidence estimates calculated. Multivariable regression models were developed to evaluate the association between SSTI and important covariates. Self-reported treatment modalities and effect on work performance were also assessed. The study was approved by the Institutional Review Board. 2125 questionnaires were completed over 12 months using convenience sampling. 110 personnel (5%) reported one or more skin and soft tissue infection during their most recent employment, for an incidence of 52 cases per 100,000 person-days. The majority reported a single infection. A higher proportion of individuals reporting skin and soft tissue infection were female, reported antibiotic use in the 6 months prior to completing the survey, had a family member in the healthcare occupation, and were senior enlisted or officers. 40 (36%) were treated with antibiotics and 24 (22%) underwent incision and drainage. Less than 5% (3 patients) required admission. Eighty eight respondents (81%), reported no days of lost job performance. There is a higher than expected incidence of skin and soft tissue infections in deployed military personnel. Although fewer than 20% of patients report missing at least one day of work, this can have a significant impact on the military mission. Further study should be conducted into how to prevent skin and soft tissue infections in military populations. PMID:21917525

  6. Optical diffuse reflectance accessory for measurements of skin tissue by near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Marbach, R.; Heise, H. M.

    1995-02-01

    An optimized accessory for measuring the diffuse reflectance spectra of human skin tissue in the near-infrared spectral range is presented. The device includes an on-axis ellipsoidal collecting mirror with efficient illumination optics for small sampling areas of bulky body specimens. The optical design is supported by the results of a Monte Carlo simulation study of the reflectance characteristics of skin tissue. Because the results evolved from efforts to measure blood glucose noninvasively, the main emphasis is placed on the long-wavelength near-infrared range where sufficient penetration depth for radiation into tissue is still available. The accessory is applied for in vivo diffuse reflectance measurements.

  7. New derivation method and simulation of skin effect in biological tissue.

    PubMed

    Fan, Xiaoli; Zhou, Qianxiang; Liu, Zhongqi; Xie, Fang

    2015-01-01

    Based on the electrical properties of biological tissues, bioimpedance measurement technology can be employed to collect physiologic and pathologic information by measuring changes in human bioimpedance. When an alternating current (AC) is applied as a detection signal to a tissue, the current field distribution, which is affected by skin effect, is related to both the bioimpedance of the tissue and the AC frequency. These relations would possibly reduce the accuracy and reliability of the measurement. In this study, an electromagnetic theory-based method, in which cylindrical conductor were divided into layers, was used to obtain current field distribution models of human limbs. Model simulations were conducted in MATLAB. The skin effect phenomenon and its characteristics in human tissues at different frequencies were observed, thus providing essential data on skin effect, which are useful in the development of bioimpedance measurement technology. PMID:26406033

  8. The circadian clock in skin: implications for adult stem cells, tissue regeneration, cancer, aging, and immunity

    PubMed Central

    Plikus, Maksim V.; Van Spyk, Elyse Noelani; Pham, Kim; Geyfman, Mikhail; Kumar, Vivek; Takahashi, Joseph S.; Andersen, Bogi

    2015-01-01

    Historically work on peripheral circadian clocks has been focused on organs and tissues that have prominent metabolic functions, such as liver, fat and muscle. In recent years, skin is emerging as a model for studying circadian clock regulation of cell proliferation, stem cell functions, tissue regeneration, aging and carcinogenesis. Morphologically skin is complex, containing multiple cell types and structures, and there is evidence for a functional circadian clock in most, if not all, of its cell types. Despite the complexity, skin stem cell populations are well defined, experimentally tractable and exhibit prominent daily cell proliferation cycles. Hair follicle stem cells also participate in recurrent, long-lasting cycles of regeneration -- the hair growth cycles. Among other advantages of skin is a broad repertoire of available genetic tools enabling the creation of cell-type specific circadian mutants. Also, due to the accessibility of the skin, in vivo imaging techniques can be readily applied to study the circadian clock and its outputs in real time, even at the single-cell level. Skin provides the first line of defense against many environmental and stress factors that exhibit dramatic diurnal variations such as solar UV radiation and temperature. Studies have already linked the circadian clock to the control of UVB-induced DNA damage and skin cancers. Due to the important role that skin plays in the defense against microorganisms, it represents a promising model system to further explore the role of the clock in the regulation of the body's immune functions. To that end, recent studies have already linked the circadian clock to psoriasis, one of the most common immune-mediated skin disorders. The skin also provides opportunities to interrogate clock regulation of tissue metabolism in the context of stem cells and regeneration. Furthermore, many animal species feature prominent seasonal hair molt cycles, offering an attractive model for investigating the

  9. The circadian clock in skin: implications for adult stem cells, tissue regeneration, cancer, aging, and immunity.

    PubMed

    Plikus, Maksim V; Van Spyk, Elyse N; Pham, Kim; Geyfman, Mikhail; Kumar, Vivek; Takahashi, Joseph S; Andersen, Bogi

    2015-06-01

    Historically, work on peripheral circadian clocks has been focused on organs and tissues that have prominent metabolic functions, such as the liver, fat, and muscle. In recent years, skin has emerged as a model for studying circadian clock regulation of cell proliferation, stem cell functions, tissue regeneration, aging, and carcinogenesis. Morphologically, skin is complex, containing multiple cell types and structures, and there is evidence for a functional circadian clock in most, if not all, of its cell types. Despite the complexity, skin stem cell populations are well defined, experimentally tractable, and exhibit prominent daily cell proliferation cycles. Hair follicle stem cells also participate in recurrent, long-lasting cycles of regeneration: the hair growth cycles. Among other advantages of skin is a broad repertoire of available genetic tools enabling the creation of cell type-specific circadian mutants. Also, due to the accessibility of skin, in vivo imaging techniques can be readily applied to study the circadian clock and its outputs in real time, even at the single-cell level. Skin provides the first line of defense against many environmental and stress factors that exhibit dramatic diurnal variations such as solar ultraviolet (UV) radiation and temperature. Studies have already linked the circadian clock to the control of UVB-induced DNA damage and skin cancers. Due to the important role that skin plays in the defense against microorganisms, it also represents a promising model system to further explore the role of the clock in the regulation of the body's immune functions. To that end, recent studies have already linked the circadian clock to psoriasis, one of the most common immune-mediated skin disorders. Skin also provides opportunities to interrogate the clock regulation of tissue metabolism in the context of stem cells and regeneration. Furthermore, many animal species feature prominent seasonal hair molt cycles, offering an attractive model

  10. Characteristics of electrically injured skin from human hand tissue samples using Fourier transform infrared microspectroscopy.

    PubMed

    Li, Shi-Ying; Zou, Dong-Hua; Luo, Yi-Wen; Sun, Qi-Ran; Deng, Kai-Fei; Chen, Yi-Jiu; Huang, Ping

    2014-01-01

    This technical note describes a method for distinguishing normal skin tissue samples from those electrically injured by Fourier transform infrared microspectroscopy (FTIR MSP). Furthermore, the infrared spectral features of electrically injured cells and tissues were evaluated to identify molecular changes in epidermal cells. In the present study, 20 human hand tissue samples were evaluated macroscopically and histopathologically. The electrically injured skin samples were subdivided into 2 regions [normal cell regions (NCRs) and polarized cell regions (PCRs)] and 14 major spectral absorption bands were selected. The spectral results showed that the band absorbance at 1080, 1126, 1172, 1242, 1307, 1403, 1456, 1541, 2852, 2925, 2957, 3075, and 3300cm(-1) increased significantly both in the stratum and non-stratum corneum of the PCRs in electrically injured skin tissues samples. No significant difference was found between normal skin and the NCR of the electrically injured skin samples. The band absorbance ratios of A1172/A1126, A1456/A1403, and A2925/A2957 were significantly increased, whereas the A1652/A1541 ratio was decreased in the PCR of the stratum corneum and non-stratum corneum. Baseline changes from 4000 to near 1737cm(-1) were observed in the spectra of the electrically injured skin samples, which were interpreted in terms of the pathological process involved in electrical injury. FTIR-MSP presents a useful method to provide objective spectral markers for the assisted diagnosis of electrical marks.

  11. Microwave Radar Imaging of Heterogeneous Breast Tissue Integrating A Priori Information

    PubMed Central

    Kelly, Thomas N.; Sarafianou, Mantalena; Craddock, Ian J.

    2014-01-01

    Conventional radar-based image reconstruction techniques fail when they are applied to heterogeneous breast tissue, since the underlying in-breast relative permittivity is unknown or assumed to be constant. This results in a systematic error during the process of image formation. A recent trend in microwave biomedical imaging is to extract the relative permittivity from the object under test to improve the image reconstruction quality and thereby to enhance the diagnostic assessment. In this paper, we present a novel radar-based methodology for microwave breast cancer detection in heterogeneous breast tissue integrating a 3D map of relative permittivity as a priori information. This leads to a novel image reconstruction formulation where the delay-and-sum focusing takes place in time rather than range domain. Results are shown for a heterogeneous dense (class-4) and a scattered fibroglandular (class-2) numerical breast phantom using Bristol's 31-element array configuration. PMID:25435861

  12. Low-intensity infrared lasers alter actin gene expression in skin and muscle tissue

    NASA Astrophysics Data System (ADS)

    Fonseca, A. S.; Mencalha, A. L.; Campos, V. M. A.; Ferreira-Machado, S. C.; Peregrino, A. A. F.; Magalhães, L. A. G.; Geller, M.; Paoli, F.

    2013-02-01

    The biostimulative effect of low-intensity lasers is the basis for treatment of diseases in soft tissues. However, data about the influence of biostimulative lasers on gene expression are still scarce. The aim of this work was to evaluate the effects of low-intensity infrared lasers on the expression of actin mRNA in skin and muscle tissue. Skin and muscle tissue of Wistar rats was exposed to low-intensity infrared laser radiation at different fluences and frequencies. One and 24 hours after laser exposure, tissue samples were withdrawn for total RNA extraction, cDNA synthesis and evaluation of actin gene expression by quantitative polymerase chain reaction. The data obtained show that laser radiation alters the expression of actin mRNA differently in skin and muscle tissue of Wistar rats depending of the fluence, frequency and time after exposure. The results could be useful for laser dosimetry, as well as to justify the therapeutic protocols for treatment of diseases of skin and muscle tissues based on low-intensity infrared laser radiation.

  13. The use of ex vivo human skin tissue for genotoxicity testing

    SciTech Connect

    Reus, Astrid A.; Usta, Mustafa; Krul, Cyrille A.M.

    2012-06-01

    As a result of the chemical legislation concerning the registration, evaluation, authorization and restriction of chemicals (REACH), and the Seventh Amendment to the Cosmetics Directive, which prohibits animal testing in Europe for cosmetics, alternative methods for safety evaluation of chemicals are urgently needed. Current in vitro genotoxicity assays are not sufficiently predictive for the in vivo situation, resulting in an unacceptably high number of misleading positives. For many chemicals and ingredients of personal care products the skin is the first site of contact, but there are no in vitro genotoxicity assays available in the skin for additional evaluation of positive or equivocal responses observed in regulatory in vitro genotoxicity assays. In the present study ex vivo human skin tissue obtained from surgery was used for genotoxicity evaluation of chemicals by using the comet assay. Fresh ex vivo human skin tissue was cultured in an air–liquid interface and topically exposed to 20 chemicals, including true positive, misleading positive and true negative genotoxins. Based on the results obtained in the present study, the sensitivity, specificity and accuracy of the ex vivo skin comet assay to predict in vivo genotoxicity were 89%, 90% and 89%, respectively. Donor and experimental variability were mainly reflected in the magnitude of the response and not the difference between the presence and absence of a genotoxic response. The present study indicates that human skin obtained from surgery is a promising and robust model for safety evaluation of chemicals that are in direct contact with the skin. -- Highlights: ► We use human skin obtained from surgery for genotoxicity evaluation of chemicals. ► We use the comet assay as parameter for genotoxicity in ex vivo human skin. ► Sensitivity, specificity and accuracy to predict in vivo genotoxins are determined. ► Sensitivity, specificity and accuracy are 89%, 90% and 90%, respectively. ► The method

  14. Schisandrin B protects against solar irradiation-induced oxidative stress in rat skin tissue.

    PubMed

    Lam, Philip Y; Yan, Chung Wai; Chiu, Po Yee; Leung, Hoi Yan; Ko, Kam Ming

    2011-04-01

    Schisandrin B (Sch B) and schisandrin C (Sch C), but not schisandrin A and dimethyl diphenyl bicarboxylate, protected rat skin tissue against solar irradiation-induced oxidative injury, as evidenced by a reversal of solar irradiation-induced changes in cellular reduced glutathione and α-tocopherol levels, as well as antioxidant enzyme activities and malondialdehyde production. The cytochrome P-450-mediated metabolism of Sch B or Sch C caused ROS production in rat skin microsomes. Taken together, Sch B or Sch C, by virtue of its pro-oxidant action and the subsequent eliciting of a glutathione antioxidant response, may prevent photo-aging of skin.

  15. The use of ex vivo human skin tissue for genotoxicity testing.

    PubMed

    Reus, Astrid A; Usta, Mustafa; Krul, Cyrille A M

    2012-06-01

    As a result of the chemical legislation concerning the registration, evaluation, authorization and restriction of chemicals (REACH), and the Seventh Amendment to the Cosmetics Directive, which prohibits animal testing in Europe for cosmetics, alternative methods for safety evaluation of chemicals are urgently needed. Current in vitro genotoxicity assays are not sufficiently predictive for the in vivo situation, resulting in an unacceptably high number of misleading positives. For many chemicals and ingredients of personal care products the skin is the first site of contact, but there are no in vitro genotoxicity assays available in the skin for additional evaluation of positive or equivocal responses observed in regulatory in vitro genotoxicity assays. In the present study ex vivo human skin tissue obtained from surgery was used for genotoxicity evaluation of chemicals by using the comet assay. Fresh ex vivo human skin tissue was cultured in an air-liquid interface and topically exposed to 20 chemicals, including true positive, misleading positive and true negative genotoxins. Based on the results obtained in the present study, the sensitivity, specificity and accuracy of the ex vivo skin comet assay to predict in vivo genotoxicity were 89%, 90% and 89%, respectively. Donor and experimental variability were mainly reflected in the magnitude of the response and not the difference between the presence and absence of a genotoxic response. The present study indicates that human skin obtained from surgery is a promising and robust model for safety evaluation of chemicals that are in direct contact with the skin. PMID:22507867

  16. The use of ex vivo human skin tissue for genotoxicity testing.

    PubMed

    Reus, Astrid A; Usta, Mustafa; Krul, Cyrille A M

    2012-06-01

    As a result of the chemical legislation concerning the registration, evaluation, authorization and restriction of chemicals (REACH), and the Seventh Amendment to the Cosmetics Directive, which prohibits animal testing in Europe for cosmetics, alternative methods for safety evaluation of chemicals are urgently needed. Current in vitro genotoxicity assays are not sufficiently predictive for the in vivo situation, resulting in an unacceptably high number of misleading positives. For many chemicals and ingredients of personal care products the skin is the first site of contact, but there are no in vitro genotoxicity assays available in the skin for additional evaluation of positive or equivocal responses observed in regulatory in vitro genotoxicity assays. In the present study ex vivo human skin tissue obtained from surgery was used for genotoxicity evaluation of chemicals by using the comet assay. Fresh ex vivo human skin tissue was cultured in an air-liquid interface and topically exposed to 20 chemicals, including true positive, misleading positive and true negative genotoxins. Based on the results obtained in the present study, the sensitivity, specificity and accuracy of the ex vivo skin comet assay to predict in vivo genotoxicity were 89%, 90% and 89%, respectively. Donor and experimental variability were mainly reflected in the magnitude of the response and not the difference between the presence and absence of a genotoxic response. The present study indicates that human skin obtained from surgery is a promising and robust model for safety evaluation of chemicals that are in direct contact with the skin.

  17. Synthesis of highly interconnected 3D scaffold from Arothron stellatus skin collagen for tissue engineering application.

    PubMed

    Ramanathan, Giriprasath; Singaravelu, Sivakumar; Raja, M D; Sivagnanam, Uma Tiruchirapalli

    2015-11-01

    The substrate which is avidly used for tissue engineering applications should have good mechanical and biocompatible properties, and all these parameters are often considered as essential for dermal reformation. Highly interconnected three dimensional (3D) wound dressing material with enhanced structural integrity was synthesized from Arothron stellatus fish skin (AsFS) collagen for tissue engineering applications. The synthesized 3D collagen sponge (COL-SPG) was further characterized by different physicochemical methods. The scanning electron microscopy analysis of the material demonstrated that well interconnected pores with homogeneous microstructure on the surface aids higher swelling index and that the material also possessed good mechanical properties with a Young's modulus of 0.89±0.2 MPa. Biocompatibility of the 3D COL-SPG showed 92% growth for both NIH 3T3 fibroblasts and keratinocytes. Overall, the study revealed that synthesized 3D COL-SPG from fish skin will act as a promising wound dressing in skin tissue engineering.

  18. Resistance to 1,25-dihydroxyvitamin D. Association with heterogeneous defects in cultured skin fibroblasts

    SciTech Connect

    Liberman, U.A.; Eil, C.; Marx, S.J.

    1983-02-01

    The authors evaluated the interaction of (/sub 3/H)1,25(OH)/sup 2/D3 with skin fibroblasts cultured from normal subjects or from affected members of six kindreds with rickets and resistance to 1-alpha, 25(OH)/sub 2/D (1,25(OH)/sub 2/D). They analyzed two aspects of the radioligand interaction; nuclear uptake with dispersed, intact cells at 37 degrees C and binding at 0 degrees C with soluble extract (cytosol) prepared from cells disrupted in buffer. With normal fibroblasts the affinity and capacity of nuclear uptake of (/sub 3/H)1,25(OH)/sup 2/D3 were 0.5 nM and 10,300 sites per cell, respectively; for binding with cytosol these were 0.13 nM and 8,900 sites per cell, respectively. The following four patterns of interaction with (/sub 3/H)1,25(OH)/sup 2/D3 were observed with cells cultured from affected patients. In all cases where the radioligand bound with high affinity in nucleus or cytosol, the nucleus- or cytosol-associated radioligand exhibited normal sedimentation velocity on sucrose density gradients. When two kindreds exhibited similar patterns (i.e. pattern a or c) with the analyses of cultured fibroblasts, clinical features in affected members suggested that the underlying genetic defects were not identical. In conclusion: (a) Fibroblasts cultured from human skin manifest nuclear uptake and cytosol binding of (/sub 3/H)1,25(OH)/sup 2/D3 that is an expression of the genes determining these processes in target tissues. (b) Based upon data from clinical evaluations and from analyses of cultured fibroblasts, severe resistance to 1,25(OH)/sup 2/D resulted from five or six distinct genetic mutations in six kindreds.

  19. Resistance to 1,25-dihydroxyvitamin D. Association with heterogeneous defects in cultured skin fibroblasts

    SciTech Connect

    Liberman, U.A.; Eil, C.; Marx, S.J.

    1983-02-01

    We evaluated the interaction of (/sup 3/H)1,25(OH)/sub 2/D/sub 3/ with skin fibroblasts cultured from normal subjects or from affected members of six kindreds with rickets and resistance to 1-alpha, 25(OH)/sub 2/D (1,25(OH)/sub 2/D). We analyzed two aspects of the radioligand interaction; nuclear uptake with dispersed, intact cells at 37 degrees C and binding at 0 degrees C with soluble extract (cytosol) prepared from cells disrupted in buffer containing 300 mM KCl and 10 mM sodium molybdate. With normal fibroblasts the affinity and capacity of nuclear uptake of (/sup 3/H)1,25(OH)/sub 2/D/sub 3/ were 0.5 nM and 10,300 sites per cell, respectively; for binding with cytosol these were 0.13 nM and 8,900 sites per cell, respectively. In all cases where the radioligand bound with high affinity in nucleus or cytosol, the nucleus- or cytosol-associated radioligand exhibited normal sedimentation velocity on sucrose density gradients. When two kindreds exhibited similar patterns (i.e. pattern a or c) with the analyses of cultured fibroblasts, clinical features in affected members suggested that the underlying genetic defects were not identical. In conclusion: (a) Fibroblasts cultured from human skin manifest nuclear uptake and cytosol binding of (/sup 3/H)1,25(OH)/sub 2/D/sub 3/ that is an expression of the genes determining these processes in target tissues. (b) Based upon data from clinical evaluations and from analyses of cultured fibroblasts, severe resistance to 1,25(OH)/sub 2/D resulted from five or six distinct genetic mutations in six kindreds.

  20. [Skin and soft tissue infections in children: consensus on diagnosis and treatment].

    PubMed

    2014-02-01

    Skin and soft tissue infections are a common reason for consultation in primary health care centers. Data from the local epidemiology of these infections are rare, but Staphylococcus aureus and Streptococcus pyogenes are known to be the major etiologic agents. The appearance in recent years of community-originated strains of methicillin-resistant S. aureus and erythromycin-resistant pyogenes raises controversy in the choice of initial empirical treatment. This national consensus is for pediatricians, dermatologists, infectiologists and other health professionals. It is about clinical management, especially the diagnosis and treatment of community-originated skin and soft tissue infections in immunocompetent patients under the age of 19. PMID:24566790

  1. [Skin and soft tissue infections in children: consensus on diagnosis and treatment].

    PubMed

    Moyano, Mónica; Peuchot, Agustina; Giachetti, Ana Claudia; Moreno, Rina; Cancellara, Aldo; Falaschi, Andrea; Chiarelli, Gloria; Villasboas, Rosa Mabel; Corazza, Rosana; Magneres, Cecilia; Calvari, Miriam; Roldán, Daniela

    2014-04-01

    Skin and soft tissue infections are a common reason for consultation in primary health care centers. Data from the local epidemiology of these infections are rare, but Staphylococcus aureus and Streptococcus pyogenes are known to be the major etiologic agents. The appearance in recent years of community-originated strains of methicillin-resistant S. aureus and erythromycin-resistant pyogenes raises controversy in the choice of initial empirical treatment. This national consensus is for pediatricians, dermatologists, infectologists and other health professionals. It is about clinical management, especially the diagnosis and treatment of community-originated skin and soft tissue infections in immunocompetent patients under the age of 19.

  2. [Skin and soft tissue infections in children: consensus on diagnosis and treatment].

    PubMed

    2014-02-01

    Skin and soft tissue infections are a common reason for consultation in primary health care centers. Data from the local epidemiology of these infections are rare, but Staphylococcus aureus and Streptococcus pyogenes are known to be the major etiologic agents. The appearance in recent years of community-originated strains of methicillin-resistant S. aureus and erythromycin-resistant pyogenes raises controversy in the choice of initial empirical treatment. This national consensus is for pediatricians, dermatologists, infectiologists and other health professionals. It is about clinical management, especially the diagnosis and treatment of community-originated skin and soft tissue infections in immunocompetent patients under the age of 19.

  3. MRI analyses show that kinesio taping affects much more than just the targeted superficial tissues and causes heterogeneous deformations within the whole limb.

    PubMed

    Pamuk, Uluç; Yucesoy, Can A

    2015-12-16

    Kinesio taping (KT) is widely used in the treatment of sports injuries and various neuro-musculoskeletal disorders. However, it is considered as selectively effective on targeted tissues and its mechanical effects have not been quantified objectively. Ascribed to continuity of muscular and connective tissues, mechanical loading imposed can have widespread heterogeneous effects. The aim was to characterize the mechanical effects of KT objectively and to test the hypotheses that KT causes acutely, local deformations not necessarily (I) in agreement with tape adhering direction and (II) limited to the directly targeted tissues. High-resolution 3D magnetic resonance image sets were acquired in healthy human subjects (n=5) prior to and acutely after KT application over the skin along m. tibialis anterior (TA). Hip, knee and ankle angles were kept constant. Demons image registration algorithm was used to calculate local tissue deformations within the lower leg, in vivo. Mean peak tissue strains were significantly higher than strain artifacts. Only KT-to-TA region in part shows local deformations in agreement with tape adhering direction whereas, superficial skin, the rest of KT-to-TA and TA regions show deformations (up to 51.5% length change) in other directions. Non-targeted tissues also show sizable heterogeneous deformations, but in smaller amplitudes. Inter-subject variability is notable. Magnetic resonance imaging analyses allow for a detailed assessment of local tissue deformation occurring acutely after KT application. The findings confirm our hypotheses and characterize how KT affects the underlying tissues, both immediately targeted and distant. This allows revealing mechanisms that can affect clinical outcomes of KT objectively. PMID:26556717

  4. MRI analyses show that kinesio taping affects much more than just the targeted superficial tissues and causes heterogeneous deformations within the whole limb.

    PubMed

    Pamuk, Uluç; Yucesoy, Can A

    2015-12-16

    Kinesio taping (KT) is widely used in the treatment of sports injuries and various neuro-musculoskeletal disorders. However, it is considered as selectively effective on targeted tissues and its mechanical effects have not been quantified objectively. Ascribed to continuity of muscular and connective tissues, mechanical loading imposed can have widespread heterogeneous effects. The aim was to characterize the mechanical effects of KT objectively and to test the hypotheses that KT causes acutely, local deformations not necessarily (I) in agreement with tape adhering direction and (II) limited to the directly targeted tissues. High-resolution 3D magnetic resonance image sets were acquired in healthy human subjects (n=5) prior to and acutely after KT application over the skin along m. tibialis anterior (TA). Hip, knee and ankle angles were kept constant. Demons image registration algorithm was used to calculate local tissue deformations within the lower leg, in vivo. Mean peak tissue strains were significantly higher than strain artifacts. Only KT-to-TA region in part shows local deformations in agreement with tape adhering direction whereas, superficial skin, the rest of KT-to-TA and TA regions show deformations (up to 51.5% length change) in other directions. Non-targeted tissues also show sizable heterogeneous deformations, but in smaller amplitudes. Inter-subject variability is notable. Magnetic resonance imaging analyses allow for a detailed assessment of local tissue deformation occurring acutely after KT application. The findings confirm our hypotheses and characterize how KT affects the underlying tissues, both immediately targeted and distant. This allows revealing mechanisms that can affect clinical outcomes of KT objectively.

  5. Availability of thiazone as an enhancer for optical clearing of skin tissue in vitro

    NASA Astrophysics Data System (ADS)

    Jiang, Jingying; Chen, Wei; Wang, Ruikang K.; Xu, Kexin

    2008-02-01

    Dimethyl sulfoxside (DMSO) has been used as enhancer for tissue optical clearing technique. However, due to its potential toxicity and possible side effects, taking clearing effects and clinical availability into accounts, a new enhancer will be needed in order to facilitate practical application of tissue optical clearing technique to non-invasive light-based diagnostic and imaging technique. In this talk, it is our aim to introduce a new skin penetration promoter, thiazone, used in the fields of pharmaceutic industry, cosmetic, etc and investigate its availability as a new enhancer for tissue optical clearing technique. Firstly, we analyzed its structure, physical and chemical properties. And then we performed experimental investigation of the effect of DMSO and thiazone as enhancers mixed with polyethylene glycol (PEG) respectively on optical clearing of porcine skin tissue in vitro. Results of direct observation from camera reveal that thiazone has a higher penetration enhancing effect when compared with DMSO as an enhancer when porcine skin was topically impregnated by different mixed-solutions. Optical property parameters, obtained by using double integrating-spheres system and Inverse Adding-Doubling (IAD) method, showed that thiazone led to almost similar reduction in scattering to DMSO did during the same time period. Therefore, in terms of optical application and clinical safety, thiazone could be a better choice than DMSO as an enhancer for optical clearing of skin tissue.

  6. Reentry produced by small-scale heterogeneities in a discrete model of cardiac tissue

    NASA Astrophysics Data System (ADS)

    Alonso, Sergio; Bär, Markus

    2016-06-01

    Reentries are reexcitations of cardiac tissue after the passing of an excitation wave which can cause dangerous arrhythmias like tachycardia or life-threatening heart failures like fibrillation. The heart is formed by a network of cells connected by gap junctions. Under ischemic conditions some of the cells lose their connections, because gap junctions are blocked and the excitability is decreased. We model a circular region of the tissue where a fraction of connections among individual cells are removed and substituted by non-conducting material in a two-dimensional (2D) discrete model of a heterogeneous excitable medium with local kinetics based on electrophysiology. Thus, two neighbouring cells are connected (disconnected) with a probability ϕ (1 – ϕ). Such a region is assumed to be surrounded by homogeneous tissue. The circular heterogeneous area is shown to act as a source of new waves which reenter into the tissue and reexcitate the whole domain. We employ the Fenton-Karma equations to model the action potential for the local kinetics of the discrete nodes to study the statistics of the reentries in two dimensional networks with different topologies. We conclude that the probability of reentry is determined by the proximity of the fraction of disrupted connections between neighboring nodes (“cells”) in the heterogeneous region to the percolation threshold.

  7. Reentry produced by small-scale heterogeneities in a discrete model of cardiac tissue

    NASA Astrophysics Data System (ADS)

    Alonso, Sergio; Bär, Markus

    2016-06-01

    Reentries are reexcitations of cardiac tissue after the passing of an excitation wave which can cause dangerous arrhythmias like tachycardia or life-threatening heart failures like fibrillation. The heart is formed by a network of cells connected by gap junctions. Under ischemic conditions some of the cells lose their connections, because gap junctions are blocked and the excitability is decreased. We model a circular region of the tissue where a fraction of connections among individual cells are removed and substituted by non-conducting material in a two-dimensional (2D) discrete model of a heterogeneous excitable medium with local kinetics based on electrophysiology. Thus, two neighbouring cells are connected (disconnected) with a probability ϕ (1 - ϕ). Such a region is assumed to be surrounded by homogeneous tissue. The circular heterogeneous area is shown to act as a source of new waves which reenter into the tissue and reexcitate the whole domain. We employ the Fenton-Karma equations to model the action potential for the local kinetics of the discrete nodes to study the statistics of the reentries in two dimensional networks with different topologies. We conclude that the probability of reentry is determined by the proximity of the fraction of disrupted connections between neighboring nodes (“cells”) in the heterogeneous region to the percolation threshold.

  8. Nanostructured anti-bacterial poly-lactic-co-glycolic acid films for skin tissue engineering applications.

    PubMed

    Karahaliloğlu, Zeynep; Ercan, Batur; Chung, Stanley; Taylor, Erik; Denkbaş, Emir B; Webster, Thomas J

    2014-12-01

    Major issues faced with the use of today's skin grafts are infection, scar tissue formation, insufficient keratinocyte (or skin producing cells) proliferation and high production costs. To overcome these limitations, we propose here for the first time, a nanofeatured poly(lactide-co-glycolide) (PLGA) membrane as a next generation antibacterial skin graft material. An alkaline surface treatment method was used to create random nanofeatures on PLGA membranes where sodium hydroxide (NaOH) concentration and exposure times were altered to control surface morphology. Most significantly, and without the use of antibiotics, results showed a decrease in Staphylococcus aureus (a dangerous pathogen infecting skin grafts) growth for up to ∼40% after 2 days of culture on nanofeatured PLGA membranes compared to untreated controls. Results also showed that while bacteria growth was stunted, mammalian cell growth was not. Specifically, cell culture results showed an increase in human epidermal keratinocyte density, while the density of scar tissue forming human dermal fibroblasts, did not change on nanofeatured PLGA surfaces compared to the untreated controls after 3 days of culture. These findings indicate that the alkaline treatment of PLGA membranes is a promising quick and effective manner to limit scar tissue formation and bacterial invasion while increasing skin cell proliferation for improving numerous wound-healing applications. PMID:24677536

  9. Nanostructured anti-bacterial poly-lactic-co-glycolic acid films for skin tissue engineering applications.

    PubMed

    Karahaliloğlu, Zeynep; Ercan, Batur; Chung, Stanley; Taylor, Erik; Denkbaş, Emir B; Webster, Thomas J

    2014-12-01

    Major issues faced with the use of today's skin grafts are infection, scar tissue formation, insufficient keratinocyte (or skin producing cells) proliferation and high production costs. To overcome these limitations, we propose here for the first time, a nanofeatured poly(lactide-co-glycolide) (PLGA) membrane as a next generation antibacterial skin graft material. An alkaline surface treatment method was used to create random nanofeatures on PLGA membranes where sodium hydroxide (NaOH) concentration and exposure times were altered to control surface morphology. Most significantly, and without the use of antibiotics, results showed a decrease in Staphylococcus aureus (a dangerous pathogen infecting skin grafts) growth for up to ∼40% after 2 days of culture on nanofeatured PLGA membranes compared to untreated controls. Results also showed that while bacteria growth was stunted, mammalian cell growth was not. Specifically, cell culture results showed an increase in human epidermal keratinocyte density, while the density of scar tissue forming human dermal fibroblasts, did not change on nanofeatured PLGA surfaces compared to the untreated controls after 3 days of culture. These findings indicate that the alkaline treatment of PLGA membranes is a promising quick and effective manner to limit scar tissue formation and bacterial invasion while increasing skin cell proliferation for improving numerous wound-healing applications.

  10. Analytical Solution of Thermal Wave Models on Skin Tissue Under Arbitrary Periodic Boundary Conditions

    NASA Astrophysics Data System (ADS)

    Fazlali, R.; Ahmadikia, H.

    2013-01-01

    Modeling and understanding the heat transfer in biological tissues is important in medical thermal therapeutic applications. The biothermomechanics of skin involves interdisciplinary features, such as bioheat transfer, biomechanics, and burn damage. The hyperbolic thermal wave model of bioheat transfer and the parabolic Pennes bioheat transfer equations with blood perfusion and metabolic heat generation are applied for the skin tissue as a finite and semi-infinite domain when the skin surface temperature is suddenly exposed to a source of an arbitrary periodic temperature. These equations are solved analytically by Laplace transform methods. The thermal wave model results indicate that a non-Fourier model has predicted the thermal behavior correctly, compared to that of previous experiments. The results of the thermal wave model show that when the first thermal wave moves from the first boundary, the temperature profiles for finite and semi-infinite domains of skin become separated for these phenomena; the discrepancy between these profiles is negligible. The accuracy of the obtained results is validated through comparisons with existing numerical results. The results demonstrate that the non-Fourier model is significant in describing the thermal behavior of skin tissue.

  11. In vivo monitoring of external pressure induced hemodynamics in skin tissue using optical coherence tomography angiography

    NASA Astrophysics Data System (ADS)

    Choi, Woo June; Wang, Hequn; Wang, Ruikang K.

    2015-03-01

    Characterization of the relationship between external pressure and blood flow is important in the examination of pressure-induced disturbance in tissue microcirculation. Optical coherence tomography (OCT) angiography is a promising imaging technique, capable of providing the noninvasive extraction of functional vessels within the skin tissue with capillary-scale resolution. Here, we present a feasibility study of OCT angiography to monitor effect of external pressures on blood perfusion in human skin tissue in vivo. Graded external pressure is loaded normal to the surface of the nailfold tissue of a healthy human. The incremental loading is applied step by step and then followed by an immediate release. Concurrent OCT imaging of the nailfold is performed during the pre/post loading. Blood perfusion images including baseline (at pre-loading) and corresponding tissue strain maps are calculated from 3D OCT dataset obtained at the different applied pressures, allowing visualization of capillary perfusion events at stressed nailfold tissue. The results indicate that the perfusion progressively decreases with the constant increase of tissue strain. Reactive hyperemia is occurred right after the removal of the pressure corresponding to quick drop of the increased strain. The perfusion is returned to the baseline level after a few minutes. These findings suggest that OCT microangiography may have great potential for quantitatively assessing tissue microcirculation in the locally pressed tissue in vivo.

  12. Nanocapsules for drug delivery through the skin barrier by tissue-tolerable plasma

    NASA Astrophysics Data System (ADS)

    Lademann, J.; Patzelt, A.; Richter, H.; Lademann, O.; Baier, G.; Breucker, L.; Landfester, K.

    2013-08-01

    For many years, several attempts have been made to enhance skin penetration by chemical, physical or mechanical manipulation to reduce the barrier function of the skin. The present study demonstrates the possibility of penetration enhancement for 400 nm sized nanocapsules loaded with a model drug consisting of a fluorescent dye by the application of tissue-tolerable plasma (TTP). Therefore, the stability of the nanocapsules and their penetration through the skin barrier prior to and in combination with TTP application was evaluated. The results revealed that the penetration of the nanocapsules could be effectively enhanced when applied in combination with TTP, hence delivering the model drug unaffected by plasma into deeper skin layers. The stability testing showed no significant structural changes of the nanocapsules after contact with TTP. Thus, the present study introduces a new strategy for the penetration enhancement of substances by the combined utilization of nanocapsules and TTP.

  13. Multimode near-field microwave monitoring of free water content of skin and imaging of tissue.

    PubMed

    Lofland, S E; Mazzatenta, J D; Croman, J; Tyagi, S D

    2007-03-01

    We have used the near-field scanning microwave microscopy (NSMM) technique in the 1-10 GHz range to monitor the free water content of skin. The water content is interpreted from the measured dielectric properties of the epidermis. The finger skin was first hydrated by soaking in water at 37 degrees C for 30 min followed by monitoring of water content as the free water evaporated under ambient conditions. The same technique has also been employed to image a 1 cm x 1 cm sample of chicken skin. It has been shown that variations exist in the resonant frequencies and quality factors of tissue under varying physical parameters. The samples analysed were as-received and thermally dehydrated or damaged chicken tissue samples. We contrast between the dielectric properties with the optical images. We also discuss possible application of our imaging technique in clinical monitoring of the wound healing process.

  14. Multimode near-field microwave monitoring of free water content of skin and imaging of tissue

    NASA Astrophysics Data System (ADS)

    Lofland, S. E.; Mazzatenta, J. D.; Croman, J.; Tyagi, S. D.

    2007-03-01

    We have used the near-field scanning microwave microscopy (NSMM) technique in the 1-10 GHz range to monitor the free water content of skin. The water content is interpreted from the measured dielectric properties of the epidermis. The finger skin was first hydrated by soaking in water at 37 °C for 30 min followed by monitoring of water content as the free water evaporated under ambient conditions. The same technique has also been employed to image a 1 cm × 1 cm sample of chicken skin. It has been shown that variations exist in the resonant frequencies and quality factors of tissue under varying physical parameters. The samples analysed were as-received and thermally dehydrated or damaged chicken tissue samples. We contrast between the dielectric properties with the optical images. We also discuss possible application of our imaging technique in clinical monitoring of the wound healing process.

  15. Simulation study of melanoma detection in human skin tissues by laser-generated surface acoustic waves

    NASA Astrophysics Data System (ADS)

    Chen, Kun; Fu, Xing; Dorantes-Gonzalez, Dante J.; Lu, Zimo; Li, Tingting; Li, Yanning; Wu, Sen; Hu, Xiaotang

    2014-07-01

    Air pollution has been correlated to an increasing number of cases of human skin diseases in recent years. However, the investigation of human skin tissues has received only limited attention, to the point that there are not yet satisfactory modern detection technologies to accurately, noninvasively, and rapidly diagnose human skin at epidermis and dermis levels. In order to detect and analyze severe skin diseases such as melanoma, a finite element method (FEM) simulation study of the application of the laser-generated surface acoustic wave (LSAW) technique is developed. A three-layer human skin model is built, where LSAW's are generated and propagated, and their effects in the skin medium with melanoma are analyzed. Frequency domain analysis is used as a main tool to investigate such issues as minimum detectable size of melanoma, filtering spectra from noise and from computational irregularities, as well as on how the FEM model meshing size and computational capabilities influence the accuracy of the results. Based on the aforementioned aspects, the analysis of the signals under the scrutiny of the phase velocity dispersion curve is verified to be a reliable, a sensitive, and a promising approach for detecting and characterizing melanoma in human skin.

  16. Fish collagen/alginate/chitooligosaccharides integrated scaffold for skin tissue regeneration application.

    PubMed

    Chandika, Pathum; Ko, Seok-Chun; Oh, Gun-Woo; Heo, Seong-Yeong; Nguyen, Van-Tinh; Jeon, You-Jin; Lee, Bonggi; Jang, Chul Ho; Kim, GeunHyung; Park, Won Sun; Chang, Wonseok; Choi, Il-Whan; Jung, Won-Kyo

    2015-11-01

    An emerging paradigm in wound healing techniques is that a tissue-engineered skin substitute offers an alternative approach to create functional skin tissue. Here we developed a fish collagen/alginate (FCA) sponge scaffold that was functionalized by different molecular weights of chitooligosaccharides (COSs) with the use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride as a cross-linking agent. The effects of cross-linking were analyzed by Fourier transform infrared spectroscopy. The results indicate that the homogeneous materials blending and cross-linking intensity were dependent on the molecular weights of COSs. The highly interconnected porous architecture with 160-260μm pore size and over 90% porosity and COS's MW driven swelling and retention capacity, tensile property and in vitro biodegradation behavior guaranteed the FCA/COS scaffolds for skin tissue engineering application. Further improvement of these properties enhanced the cytocompatibility of all the scaffolds, especially the scaffolds containing COSs with MW in the range of 1-3kDa (FCA/COS1) showed the best cytocompatibility. These physicochemical, mechanical, and biological properties suggest that the FCA/COS1 scaffold is a superior candidate that can be used for skin tissue regeneration.

  17. Fish collagen/alginate/chitooligosaccharides integrated scaffold for skin tissue regeneration application.

    PubMed

    Chandika, Pathum; Ko, Seok-Chun; Oh, Gun-Woo; Heo, Seong-Yeong; Nguyen, Van-Tinh; Jeon, You-Jin; Lee, Bonggi; Jang, Chul Ho; Kim, GeunHyung; Park, Won Sun; Chang, Wonseok; Choi, Il-Whan; Jung, Won-Kyo

    2015-11-01

    An emerging paradigm in wound healing techniques is that a tissue-engineered skin substitute offers an alternative approach to create functional skin tissue. Here we developed a fish collagen/alginate (FCA) sponge scaffold that was functionalized by different molecular weights of chitooligosaccharides (COSs) with the use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride as a cross-linking agent. The effects of cross-linking were analyzed by Fourier transform infrared spectroscopy. The results indicate that the homogeneous materials blending and cross-linking intensity were dependent on the molecular weights of COSs. The highly interconnected porous architecture with 160-260μm pore size and over 90% porosity and COS's MW driven swelling and retention capacity, tensile property and in vitro biodegradation behavior guaranteed the FCA/COS scaffolds for skin tissue engineering application. Further improvement of these properties enhanced the cytocompatibility of all the scaffolds, especially the scaffolds containing COSs with MW in the range of 1-3kDa (FCA/COS1) showed the best cytocompatibility. These physicochemical, mechanical, and biological properties suggest that the FCA/COS1 scaffold is a superior candidate that can be used for skin tissue regeneration. PMID:26306410

  18. Real-time simulation of contact and cutting of heterogeneous soft-tissues.

    PubMed

    Courtecuisse, Hadrien; Allard, Jérémie; Kerfriden, Pierre; Bordas, Stéphane P A; Cotin, Stéphane; Duriez, Christian

    2014-02-01

    This paper presents a numerical method for interactive (real-time) simulations, which considerably improves the accuracy of the response of heterogeneous soft-tissue models undergoing contact, cutting and other topological changes. We provide an integrated methodology able to deal both with the ill-conditioning issues associated with material heterogeneities, contact boundary conditions which are one of the main sources of inaccuracies, and cutting which is one of the most challenging issues in interactive simulations. Our approach is based on an implicit time integration of a non-linear finite element model. To enable real-time computations, we propose a new preconditioning technique, based on an asynchronous update at low frequency. The preconditioner is not only used to improve the computation of the deformation of the tissues, but also to simulate the contact response of homogeneous and heterogeneous bodies with the same accuracy. We also address the problem of cutting the heterogeneous structures and propose a method to update the preconditioner according to the topological modifications. Finally, we apply our approach to three challenging demonstrators: (i) a simulation of cataract surgery (ii) a simulation of laparoscopic hepatectomy (iii) a brain tumor surgery.

  19. 3D bioprinting of vascularized, heterogeneous cell-laden tissue constructs.

    PubMed

    Kolesky, David B; Truby, Ryan L; Gladman, A Sydney; Busbee, Travis A; Homan, Kimberly A; Lewis, Jennifer A

    2014-05-21

    A new bioprinting method is reported for fabricating 3D tissue constructs replete with vasculature, multiple types of cells, and extracellular matrix. These intricate, heterogeneous structures are created by precisely co-printing multiple materials, known as bioinks, in three dimensions. These 3D micro-engineered environments open new -avenues for drug screening and fundamental studies of wound healing, angiogenesis, and stem-cell niches.

  20. Action potential duration dispersion and alternans in simulated heterogeneous cardiac tissue with a structural barrier.

    PubMed

    Krogh-Madsen, Trine; Christini, David J

    2007-02-15

    Structural barriers to wave propagation in cardiac tissue are associated with a decreased threshold for repolarization alternans both experimentally and clinically. Using computer simulations, we investigated the effects of a structural barrier on the onset of spatially concordant and discordant alternans. We used two-dimensional tissue geometry with heterogeneity in selected potassium conductances to mimic known apex-base gradients. Although we found that the actual onset of alternans was similar with and without the structural barrier, the increase in alternans magnitude with faster pacing was steeper with the barrier--giving the appearance of an earlier alternans onset in its presence. This is consistent with both experimental structural barrier findings and the clinical observation of T-wave alternans occurring at slower pacing rates in patients with structural heart disease. In ionically homogeneous tissue, discordant alternans induced by the presence of the structural barrier arose at intermediate pacing rates due to a source-sink mismatch behind the barrier. In heterogeneous tissue, discordant alternans occurred during fast pacing due to a barrier-induced decoupling of tissue with different restitution properties. Our results demonstrate a causal relationship between the presence of a structural barrier and increased alternans magnitude and action potential duration dispersion, which may contribute to why patients with structural heart disease are at higher risk for ventricular tachyarrhythmias.

  1. Human Skin Cells That Express Stage-Specific Embryonic Antigen 3 Associate with Dermal Tissue Regeneration

    PubMed Central

    Vega Crespo, Agustin; Awe, Jason P.; Reijo Pera, Renee

    2012-01-01

    Abstract Stage-specific embryonic antigen 3 (SSEA3) is a glycosphingolipid that has previously been used to identify cells with stem cell-like, multipotent, and pluripotent characteristics. A rare subpopulation of SSEA3-expressing cells exists in the dermis of adult human skin. These SSEA3-expressing cells undergo a significant increase in cell number in response to injury, suggesting a possible role in regeneration. These SSEA3-expressing regeneration-associated (SERA) cells were derived through primary cell culture, purified by fluorescence-activated cell sorting (FACS), and characterized. Longer in vitro culture of the primary skin cells led to lower SSEA3 expression stability after FACS-based purification, suggesting that the current culture conditions may need to be optimized to permit the large-scale expansion of SERA cells. The SERA cells demonstrated a global transcriptional state that was most similar to bone marrow- and fat-derived mesenchymal stem cells (MSCs), and the highest expressing SSEA3-expressing cells co-expressed CD105 (clone 35). However, while a rare population of MSCs was observed in primary human skin cell cultures that could differentiate into adipocytes, osteoblasts, or chondrocytes, SERA cells did not possess this differentiation capacity, suggesting that there are at least two different rare subpopulations in adult human skin primary cultures. The identification, efficient purification, and large-scale expansion of these rare subpopulations (SERA cells and MSCs) from heterogeneous adult human skin primary cell cultures may have applications for future patient-specific cellular therapies. PMID:23514702

  2. Tissue heterogeneity as a mechanism for localized neural stimulation by applied electric fields

    NASA Astrophysics Data System (ADS)

    Miranda, P. C.; Correia, L.; Salvador, R.; Basser, P. J.

    2007-09-01

    We investigate the heterogeneity of electrical conductivity as a new mechanism to stimulate excitable tissues via applied electric fields. In particular, we show that stimulation of axons crossing internal boundaries can occur at boundaries where the electric conductivity of the volume conductor changes abruptly. The effectiveness of this and other stimulation mechanisms was compared by means of models and computer simulations in the context of transcranial magnetic stimulation. While, for a given stimulation intensity, the largest membrane depolarization occurred where an axon terminates or bends sharply in a high electric field region, a slightly smaller membrane depolarization, still sufficient to generate action potentials, also occurred at an internal boundary where the conductivity jumped from 0.143 S m-1 to 0.333 S m-1, simulating a white-matter-grey-matter interface. Tissue heterogeneity can also give rise to local electric field gradients that are considerably stronger and more focal than those impressed by the stimulation coil and that can affect the membrane potential, albeit to a lesser extent than the two mechanisms mentioned above. Tissue heterogeneity may play an important role in electric and magnetic 'far-field' stimulation.

  3. Complex heterogeneous tissue constructs containing multiple cell types prepared by inkjet printing technology.

    PubMed

    Xu, Tao; Zhao, Weixin; Zhu, Jian-Ming; Albanna, Mohammad Z; Yoo, James J; Atala, Anthony

    2013-01-01

    This study was designed to develop a versatile method for fabricating complex and heterogeneous three-dimensional (3D) tissue constructs using simultaneous ink-jetting of multiple cell types. Human amniotic fluid-derived stem cells (hAFSCs), canine smooth muscle cells (dSMCs), and bovine aortic endothelial cells (bECs), were separately mixed with ionic cross-linker calcium chloride (CaCl(2)), loaded into separate ink cartridges and printed using a modified thermal inkjet printer. The three cell types were delivered layer-by-layer to pre-determined locations in a sodium alginate-collagen composite located in a chamber under the printer. The reaction between CaCl(2) and sodium alginate resulted in a rapid formation of a solid composite gel and the printed cells were anchored in designated areas within the gel. The printing process was repeated for several cycles leading to a complex 3D multi-cell hybrid construct. The biological functions of the 3D printed constructs were evaluated in vitro and in vivo. Each of the printed cell types maintained their viability and normal proliferation rates, phenotypic expression, and physiological functions within the heterogeneous constructs. The bioprinted constructs were able to survive and mature into functional tissues with adequate vascularization in vivo. These findings demonstrate the feasibility of fabricating complex heterogeneous tissue constructs containing multiple cell types using inkjet printing technology.

  4. Mathematical modelling of transcriptional heterogeneity identifies novel markers and subpopulations in complex tissues

    PubMed Central

    Wang, Niya; Hoffman, Eric P.; Chen, Lulu; Chen, Li; Zhang, Zhen; Liu, Chunyu; Yu, Guoqiang; Herrington, David M.; Clarke, Robert; Wang, Yue

    2016-01-01

    Tissue heterogeneity is both a major confounding factor and an underexploited information source. While a handful of reports have demonstrated the potential of supervised computational methods to deconvolute tissue heterogeneity, these approaches require a priori information on the marker genes or composition of known subpopulations. To address the critical problem of the absence of validated marker genes for many (including novel) subpopulations, we describe convex analysis of mixtures (CAM), a fully unsupervised in silico method, for identifying subpopulation marker genes directly from the original mixed gene expressions in scatter space that can improve molecular analyses in many biological contexts. Validated with predesigned mixtures, CAM on the gene expression data from peripheral leukocytes, brain tissue, and yeast cell cycle, revealed novel marker genes that were otherwise undetectable using existing methods. Importantly, CAM requires no a priori information on the number, identity, or composition of the subpopulations present in mixed samples, and does not require the presence of pure subpopulations in sample space. This advantage is significant in that CAM can achieve all of its goals using only a small number of heterogeneous samples, and is more powerful to distinguish between phenotypically similar subpopulations. PMID:26739359

  5. Feasibility of extracting tissue optical properties from amplitude OCT data during optical skin clearing

    NASA Astrophysics Data System (ADS)

    Stumpp, Oliver; Welch, A. J.; Milner, Thomas E.

    2005-04-01

    This paper investigates three different techniques to investigate the dynamic change of the attenuation coefficient in in-vitro hamster skin during optical skin clearing using a hyper-osmotic solution of 50% glycerol. The tissue is imaged using an amplitude based OCT system with a wavelength of 1290 nm during the clearing experiment. The tissue sample rested on a mirror surface and OCT images of the tissue and mirror were acquired in 1 minute intervals over a 45 minute period. Intensity profiles were obtained from averaging A-scans at each time interval. The tissue optical properties were determined by curve fitting an exponential function to the acquired intensity profiles, by linear line fit between front- and mirror surface reflection as well as by fitting the photo detector voltage at front- and mirror surface peaks to a modified expression of Beer's Law. In addition, another experimental set-up was used to evaluate focus effects on the back scattered signal from the mirror underneath an in-vitro porcine skin sample which was dehydrated in air to mimic optically cleared tissue. Both, tissue and mirror were mounted onto two independent micro translation stages in order to determine focal effects on the mirror signal. Results show that exponential curve fitting initially yields acceptable data for the attenuation coefficient but later introduces significant error due to the altered light propagation through the tissue due to the applied clearing agent. Attempting to use a linear fit between front- and mirror reflections does not yield physically meaningful data while using the detector voltage read-out in combination with Beer's law yields acceptable results comparable with tissue data published in the literature. Focal effects account for 1.5 to 2.5 dB higher signals than otherwise can be expected from the back reflection of the mirror underneath a scattering tissue sample if the mirror is in the focal plane of the input optics.

  6. Raman spectroscopic analysis of human skin tissue sections ex-vivo: evaluation of the effects of tissue processing and dewaxing

    NASA Astrophysics Data System (ADS)

    Ali, Syed M.; Bonnier, Franck; Tfayli, Ali; Lambkin, Helen; Flynn, Kathleen; McDonagh, Vincent; Healy, Claragh; Clive Lee, T.; Lyng, Fiona M.; Byrne, Hugh J.

    2013-06-01

    Raman spectroscopy coupled with K-means clustering analysis (KMCA) is employed to elucidate the biochemical structure of human skin tissue sections and the effects of tissue processing. Both hand and thigh sections of human cadavers were analyzed in their unprocessed and formalin-fixed, paraffin-processed (FFPP), and subsequently dewaxed forms. In unprocessed sections, KMCA reveals clear differentiation of the stratum corneum (SC), intermediate underlying epithelium, and dermal layers for sections from both anatomical sites. The SC is seen to be relatively rich in lipidic content; the spectrum of the subjacent layers is strongly influenced by the presence of melanin, while that of the dermis is dominated by the characteristics of collagen. For a given anatomical site, little difference in layer structure and biochemistry is observed between samples from different cadavers. However, the hand and thigh sections are consistently differentiated for all cadavers, largely based on lipidic profiles. In dewaxed FFPP samples, while the SC, intermediate, and dermal layers are clearly differentiated by KMCA of Raman maps of tissue sections, the lipidic contributions to the spectra are significantly reduced, with the result that respective skin layers from different anatomical sites become indistinguishable. While efficient at removing the fixing wax, the tissue processing also efficiently removes the structurally similar lipidic components of the skin layers. In studies of dermatological processes in which lipids play an important role, such as wound healing, dewaxed samples are therefore not appropriate. Removal of the lipids does however accentuate the spectral features of the cellular and protein components, which may be more appropriate for retrospective analysis of disease progression and biochemical analysis using tissue banks.

  7. Low-level lasers affect uncoupling protein gene expression in skin and skeletal muscle tissues

    NASA Astrophysics Data System (ADS)

    Canuto, K. S.; Sergio, L. P. S.; Paoli, F.; Mencalha, A. L.; Fonseca, A. S.

    2016-03-01

    Wavelength, frequency, power, fluence, and emission mode determine the photophysical, photochemical, and photobiological responses of biological tissues to low-level lasers. Free radicals are involved in these responses acting as second messengers in intracellular signaling processes. Irradiated cells present defenses against these chemical species to avoid unwanted effects, such as uncoupling proteins (UCPs), which are part of protective mechanisms and minimize the effects of free radical generation in mitochondria. In this work UCP2 and UCP3 mRNA gene relative expression in the skin and skeletal muscle tissues of Wistar rats exposed to low-level red and infrared lasers was evaluated. Samples of the skin and skeletal muscle tissue of Wistar rats exposed to low-level red and infrared lasers were withdrawn for total RNA extraction, cDNA synthesis, and the evaluation of gene expression by quantitative polymerase chain reaction. UCP2 and UCP3 mRNA expression was differently altered in skin and skeletal muscle tissues exposed to lasers in a wavelength-dependent effect, with the UCP3 mRNA expression dose-dependent. Alteration on UCP gene expression could be part of the biostimulation effect and is necessary to make cells exposed to red and infrared low-level lasers more resistant or capable of adapting in damaged tissues or diseases.

  8. Optical spectroscopic studies of animal skin used in modeling of human cutaneous tissue

    NASA Astrophysics Data System (ADS)

    Drakaki, E.; Makropoulou, M.; Serafetinides, A. A.; Borisova, E.; Avramov, L.; Sianoudis, J. A.

    2007-03-01

    Optical spectroscopy and in particular laser-induced autofluorescence spectroscopy (LIAFS) and diffuse reflectance spectroscopy (DRS), provide excellent possibilities for real-time, noninvasive diagnosis of different skin tissue pathologies. However, the introduction of optical spectroscopy in routine medical practice demands a statistically important data collection, independent from the laser sources and detectors used. The scientists collect databases either from patients, in vivo, or they study different animal models to obtain objective information for the optical properties of various types of normal and diseased tissue. In the present work, the optical properties (fluorescence and reflectance) of two animal skin models are investigated. The aim of using animal models in optical spectroscopy investigations is to examine the statistics of the light induced effects firstly on animals, before any extrapolation effort to humans. A nitrogen laser (λ=337.1 nm) was used as an excitation source for the autofluorescence measurements, while a tungsten-halogen lamp was used for the reflectance measurements. Samples of chicken and pig skin were measured in vitro and were compared with results obtained from measurements of normal human skin in vivo. The specific features of the measured reflectance and fluorescence spectra are discussed, while the limits of data extrapolation for each skin type are also depicted.

  9. Determination of the axial and circumferential mechanical properties of the skin tissue using experimental testing and constitutive modeling.

    PubMed

    Karimi, Alireza; Navidbakhsh, Mahdi; Haghighatnama, Maedeh; Haghi, Afsaneh Motevalli

    2015-01-01

    The skin, being a multi-layered material, is responsible for protecting the human body from the mechanical, bacterial, and viral insults. The skin tissue may display different mechanical properties according to the anatomical locations of a body. However, these mechanical properties in different anatomical regions and at different loading directions (axial and circumferential) of the mice body to date have not been determined. In this study, the axial and circumferential loads were imposed on the mice skin samples. The elastic modulus and maximum stress of the skin tissues were measured before the failure occurred. The nonlinear mechanical behavior of the skin tissues was also computationally investigated through a suitable constitutive equation. Hyperelastic material model was calibrated using the experimental data. Regardless of the anatomic locations of the mice body, the results revealed significantly different mechanical properties in the axial and circumferential directions and, consequently, the mice skin tissue behaves like a pure anisotropic material. The highest elastic modulus was observed in the back skin under the circumferential direction (6.67 MPa), while the lowest one was seen in the abdomen skin under circumferential loading (0.80 MPa). The Ogden material model was narrowly captured the nonlinear mechanical response of the skin at different loading directions. The results help to understand the isotropic/anisotropic mechanical behavior of the skin tissue at different anatomical locations. They also have implications for a diversity of disciplines, i.e., dermatology, cosmetics industry, clinical decision making, and clinical intervention.

  10. Tissue pattern recognition error rates and tumor heterogeneity in gastric cancer.

    PubMed

    Potts, Steven J; Huff, Sarah E; Lange, Holger; Zakharov, Vladislav; Eberhard, David A; Krueger, Joseph S; Hicks, David G; Young, George David; Johnson, Trevor; Whitney-Miller, Christa L

    2013-01-01

    The anatomic pathology discipline is slowly moving toward a digital workflow, where pathologists will evaluate whole-slide images on a computer monitor rather than glass slides through a microscope. One of the driving factors in this workflow is computer-assisted scoring, which depends on appropriate selection of regions of interest. With advances in tissue pattern recognition techniques, a more precise region of the tissue can be evaluated, no longer bound by the pathologist's patience in manually outlining target tissue areas. Pathologists use entire tissues from which to determine a score in a region of interest when making manual immunohistochemistry assessments. Tissue pattern recognition theoretically offers this same advantage; however, error rates exist in any tissue pattern recognition program, and these error rates contribute to errors in the overall score. To provide a real-world example of tissue pattern recognition, 11 HER2-stained upper gastrointestinal malignancies with high heterogeneity were evaluated. HER2 scoring of gastric cancer was chosen due to its increasing importance in gastrointestinal disease. A method is introduced for quantifying the error rates of tissue pattern recognition. The trade-off between fully sampling tumor with a given tissue pattern recognition error rate versus randomly sampling a limited number of fields of view with higher target accuracy was modeled with a Monte-Carlo simulation. Under most scenarios, stereological methods of sampling-limited fields of view outperformed whole-slide tissue pattern recognition approaches for accurate immunohistochemistry analysis. The importance of educating pathologists in the use of statistical sampling is discussed, along with the emerging role of hybrid whole-tissue imaging and stereological approaches.

  11. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

    NASA Astrophysics Data System (ADS)

    Shi, Chengyu; Guo, Bingqi; Cheng, Chih-Yao; Eng, Tony; Papanikolaou, Nikos

    2010-09-01

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent™ x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V100 reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95

  12. Soft tissue augmentation in skin of color: market growth, available fillers, and successful techniques.

    PubMed

    Burgess, Cheryl M

    2007-01-01

    In recent years, people of color have become an increasingly important market force for the cosmetics industry. Product lines have been expanded to accommodate a broader spectrum of skin colors and marketing strategies have been specialized in order to target specific ethnic populations. In addition, it is predicted that people with pigmented skin will eventually comprise a majority of the domestic and international population during the 21st century. Not surprisingly, people of color are increasingly seeking out products and procedures to fight the effects of aging, including an increase in surgical and nonsurgical cosmetic procedures. Among nonsurgical procedures, soft tissue augmentation has experienced dramatic growth. Today, clinicians are performing more and more of these procedures in people of color. As a result of these shifts in the cosmetics industry, clinicians performing soft tissue augmentation require increased expertise in the treatment of ethnic skin. This article reviews the important differences that exist between the appearance of the aging faces of Caucasians and people of color. In addition, soft tissue augmentation strategies and injection techniques that are specific to skin of color are discussed.

  13. Fatal skin and soft tissue infection of multidrug resistant Acinetobacter baumannii: A case report

    PubMed Central

    Ali, Aqsa; Botha, John; Tiruvoipati, Ravindranath

    2014-01-01

    INTRODUCTION Acinetobacter baumannii is usually associated with respiratory tract, urinary tract and bloodstream infections. Recent reports suggest that it is increasingly causing skin and soft tissue infections. It is also evolving as a multidrug resistant organism that can be difficult to treat. We present a fatal case of multidrug resistant A. baumannii soft tissue infection and review of relevant literature. PRESENTATION OF CASE A 41 year old morbidly obese man, with history of alcoholic liver disease presented with left superficial pre-tibial abrasions and cellulitis caused by multidrug resistant (MDR) A. baumannii. In spite of early antibiotic administration he developed extensive myositis and fat necrosis requiring extensive and multiple surgical debridements. He deteriorated despite appropriate antibiotic therapy and multiple surgical interventions with development of multi-organ failure and died. DISCUSSION Managing Acinetobacter infections remains difficult due to the array of resistance and the pathogens ability to develop new and ongoing resistance. The early diagnosis of necrotizing soft tissue infection may be challenging, but the key to successful management of patients with necrotizing soft tissue infection are early recognition and complete surgical debridement. CONCLUSION A. baumannii is emerging as an important cause of severe, life-threatening soft tissue infections. Multidrug resistant A. baumannii soft tissue infections may carry a high mortality in spite of early and aggressive treatment. Clinicians need to consider appropriate early empirical antibiotic coverage or the use of combination therapy to include MDR A. baumannii as a cause of skin and soft tissue infections. PMID:25016080

  14. Nonlinear behaviour of conduction and block in cardiac tissue with heterogeneous expression of connexin 43.

    PubMed

    Prudat, Yann; Kucera, Jan P

    2014-11-01

    Altered gap junctional coupling potentiates slow conduction and arrhythmias. To better understand how heterogeneous connexin expression affects conduction at the cellular scale, we investigated conduction in tissue consisting of two cardiomyocyte populations expressing different connexin levels. Conduction was mapped using microelectrode arrays in cultured strands of foetal murine ventricular myocytes with predefined contents of connexin 43 knockout (Cx43KO) cells. Corresponding computer simulations were run in randomly generated two-dimensional tissues mimicking the cellular architecture of the strands. In the cultures, the relationship between conduction velocity (CV) and Cx43KO cell content was nonlinear. CV first decreased significantly when Cx43KO content was increased from 0 to 50%. When the Cx43KO content was ≥60%, CV became comparable to that in 100% Cx43KO strands. Co-culturing Cx43KO and wild-type cells also resulted in significantly more heterogeneous conduction patterns and in frequent conduction blocks. The simulations replicated this behaviour of conduction. For Cx43KO contents of 10-50%, conduction was slowed due to wavefront meandering between Cx43KO cells. For Cx43KO contents ≥60%, clusters of remaining wild-type cells acted as electrical loads that impaired conduction. For Cx43KO contents of 40-60%, conduction exhibited fractal characteristics, was prone to block, and was more sensitive to changes in ion currents compared to homogeneous tissue. In conclusion, conduction velocity and stability behave in a nonlinear manner when cardiomyocytes expressing different connexin amounts are combined. This behaviour results from heterogeneous current-to-load relationships at the cellular level. Such behaviour is likely to be arrhythmogenic in various clinical contexts in which gap junctional coupling is heterogeneous.

  15. Could aging human skin use a connective tissue growth factor boost to increase collagen content?

    PubMed

    Oliver, Noelynn; Sternlicht, Mark; Gerritsen, Karin; Goldschmeding, Roel

    2010-02-01

    The roles of connective tissue growth factor (CTGF) and transforming growth factor-beta (TGF-beta), both well-known collagen production stimulators, were examined in skin aging. Aged skin and fibroblasts exhibited a coordinate decrease in CTGF, TGF-beta, and type I procollagen expression and content. CTGF knockdown and TGF-beta blockade in normal dermal fibroblasts reduced procollagen expression, whereas overexpressing CTGF increased procollagen by a TGF-beta/Smad signaling-dependent mechanism without involving Smad2/3.

  16. Skin disinfection by plasma-tissue interaction: comparison of the effectivity of tissue-tolerable plasma and a standard antiseptic.

    PubMed

    Lademann, O; Kramer, A; Richter, H; Patzelt, A; Meinke, M C; Czaika, V; Weltmann, K-D; Hartmann, B; Koch, S

    2011-01-01

    Wound healing disorders frequently occur due to biofilm formation on wound surfaces requiring conscientious wound hygiene. Often, the application of conventional liquid antiseptics is not sufficient and sustainable as (1) the borders and the surrounding of chronic wounds frequently consist of sclerotic skin, impeding an effectual penetration of these products, and (2) the hair follicles representing the reservoir for bacterial recolonization of skin surfaces are not affected. Recently, it has been reported that tissue-tolerable plasma (TTP), which is used at a temperature range between 35 and 45°C, likewise has disinfecting properties. In the present study, the effectivity of TTP and a standard liquid antiseptic was compared in vitro on porcine skin. The results revealed that TTP was able to reduce the bacterial load by 94%, although the application of the liquid antiseptic remained superior as it reduced the bacteria by almost 99%. For in vivo application, however, TTP offers several advantages. On the one hand, TTP enables the treatment of sclerotic skin as well, and on the other hand, a sustainable disinfection can be realized as, obviously, also the follicular reservoir is affected by TTP.

  17. Influence trend of temperature distribution in skin tissue generated by different exposure dose pulse laser

    NASA Astrophysics Data System (ADS)

    Shan, Ning; Wang, Zhijing; Liu, Xia

    2014-11-01

    Laser is widely applied in military and medicine fields because of its excellent capability. In order to effectively defend excess damage by laser, the thermal processing theory of skin tissue generated by laser should be carried out. The heating rate and thermal damage area should be studied. The mathematics model of bio-tissue heat transfer that is irradiated by laser is analyzed. And boundary conditions of bio-tissue are discussed. Three layer FEM grid model of bio-tissue is established. The temperature rising inducing by pulse laser in the tissue is modeled numerically by adopting ANSYS software. The changing trend of temperature in the tissue is imitated and studied under the conditions of different exposure dose pulse laser. The results show that temperature rising in the tissue depends on the parameters of pulse laser largely. In the same conditions, the pulse width of laser is smaller and its instant power is higher. And temperature rising effect in the tissue is very clear. On the contrary, temperature rising effect in the tissue is lower. The cooling time inducing by temperature rising effect in the tissue is longer along with pulse separation of laser is bigger. And the temperature difference is bigger in the pulse period.

  18. Heterogeneity and stochastic growth regulation of biliary epithelial cells dictate dynamic epithelial tissue remodeling.

    PubMed

    Kamimoto, Kenji; Kaneko, Kota; Kok, Cindy Yuet-Yin; Okada, Hajime; Miyajima, Atsushi; Itoh, Tohru

    2016-01-01

    Dynamic remodeling of the intrahepatic biliary epithelial tissue plays key roles in liver regeneration, yet the cellular basis for this process remains unclear. We took an unbiased approach based on in vivo clonal labeling and tracking of biliary epithelial cells in the three-dimensional landscape, in combination with mathematical simulation, to understand their mode of proliferation in a mouse liver injury model where the nascent biliary structure formed in a tissue-intrinsic manner. An apparent heterogeneity among biliary epithelial cells was observed: whereas most of the responders that entered the cell cycle upon injury exhibited a limited and tapering growth potential, a select population continued to proliferate, making a major contribution in sustaining the biliary expansion. Our study has highlighted a unique mode of epithelial tissue dynamics, which depends not on a hierarchical system driven by fixated stem cells, but rather, on a stochastically maintained progenitor population with persistent proliferative activity. PMID:27431614

  19. Heterogeneous receptor binding of classical quaternary muscarinic antagonists. I. Bovine tissue distribution.

    PubMed

    Roffel, A F; Ensing, K; in 't Hout, W G; de Zeeuw, R A; Zaagsma, J

    1991-01-01

    In competition experiments with the tertiary radioligand [3H]dexetimide, classical quaternary muscarinic antagonists like ipratropium bromide and N-methylscopolamine bromide distinguished two muscarinic binding sites in bovine brain (total brain minus cerebellum) membranes, in contrast to their tertiary analogues, atropine and scopolamine, which recognized only one binding site. This binding behavior was found to be almost identical in bovine striatal membranes, both in terms of binding affinities and proportions of high (Q1) and low (Q2) affinity binding sites. Both in total brain and in striatal membranes, the Q1/Q2 binding heterogeneity was independent of pirenzepine binding heterogeneity (M1/M2). In peripheral tissues, the binding properties of quaternary muscarinic antagonists varied. Whereas tertiary as well as quaternary compounds showed only high affinity binding towards muscarinic receptors in bovine atrial and left ventricular membranes, heterogeneous binding behavior was observed with quaternary but not with tertiary antagonists in bovine tracheal smooth muscle membranes. The tissue distribution found in the present study suggests that bovine tracheal smooth muscle contraction studies might shed light on the functional significance of the anomalous binding behavior of quaternary muscarinic antagonists. PMID:1824191

  20. Histopathology of Incontinence-Associated Skin Lesions: Inner Tissue Damage Due to Invasion of Proteolytic Enzymes and Bacteria in Macerated Rat Skin

    PubMed Central

    Mugita, Yuko; Minematsu, Takeo; Huang, Lijuan; Nakagami, Gojiro; Kishi, Chihiro; Ichikawa, Yoshie; Nagase, Takashi; Oe, Makoto; Noguchi, Hiroshi; Mori, Taketoshi; Abe, Masatoshi; Sugama, Junko; Sanada, Hiromi

    2015-01-01

    A common complication in patients with incontinence is perineal skin lesions, which are recognized as a form of dermatitis. In these patients, perineal skin is exposed to digestive enzymes and intestinal bacterial flora, as well as excessive water. The relative contributions of digestive enzymes and intestinal bacterial flora to skin lesion formation have not been fully shown. This study was conducted to reveal the process of histopathological changes caused by proteases and bacterial inoculation in skin maceration. For skin maceration, agarose gel containing proteases was applied to the dorsal skin of male Sprague-Dawley rats for 4 h, followed by Pseudomonas aeruginosa inoculation for 30 min. Macroscopic changes, histological changes, bacterial distribution, inflammatory response, and keratinocyte proliferation and differentiation were examined. Proteases induced digestion in the prickle cell layer of the epidermis, and slight bleeding in the papillary dermis and around hair follicles in the macerated skin without macroscopic evidence of erosion. Bacterial inoculation of the skin macerated by proteolytic solution resulted in the formation of bacteria-rich clusters comprising numerous microorganisms and inflammatory cells within the papillary dermis, with remarkable tissue damage around the clusters. Tissue damage expanded by day 2. On day 3, the proliferative keratinocyte layer was elongated from the bulge region of the hair follicles. Application of proteases and P. aeruginosa induced skin lesion formation internally without macroscopic erosion of the overhydrated area, suggesting that the histopathology might be different from regular dermatitis. The healing process of this lesion is similar to transepidermal elimination. PMID:26407180

  1. Histopathology of Incontinence-Associated Skin Lesions: Inner Tissue Damage Due to Invasion of Proteolytic Enzymes and Bacteria in Macerated Rat Skin.

    PubMed

    Mugita, Yuko; Minematsu, Takeo; Huang, Lijuan; Nakagami, Gojiro; Kishi, Chihiro; Ichikawa, Yoshie; Nagase, Takashi; Oe, Makoto; Noguchi, Hiroshi; Mori, Taketoshi; Abe, Masatoshi; Sugama, Junko; Sanada, Hiromi

    2015-01-01

    A common complication in patients with incontinence is perineal skin lesions, which are recognized as a form of dermatitis. In these patients, perineal skin is exposed to digestive enzymes and intestinal bacterial flora, as well as excessive water. The relative contributions of digestive enzymes and intestinal bacterial flora to skin lesion formation have not been fully shown. This study was conducted to reveal the process of histopathological changes caused by proteases and bacterial inoculation in skin maceration. For skin maceration, agarose gel containing proteases was applied to the dorsal skin of male Sprague-Dawley rats for 4 h, followed by Pseudomonas aeruginosa inoculation for 30 min. Macroscopic changes, histological changes, bacterial distribution, inflammatory response, and keratinocyte proliferation and differentiation were examined. Proteases induced digestion in the prickle cell layer of the epidermis, and slight bleeding in the papillary dermis and around hair follicles in the macerated skin without macroscopic evidence of erosion. Bacterial inoculation of the skin macerated by proteolytic solution resulted in the formation of bacteria-rich clusters comprising numerous microorganisms and inflammatory cells within the papillary dermis, with remarkable tissue damage around the clusters. Tissue damage expanded by day 2. On day 3, the proliferative keratinocyte layer was elongated from the bulge region of the hair follicles. Application of proteases and P. aeruginosa induced skin lesion formation internally without macroscopic erosion of the overhydrated area, suggesting that the histopathology might be different from regular dermatitis. The healing process of this lesion is similar to transepidermal elimination. PMID:26407180

  2. Histopathology of Incontinence-Associated Skin Lesions: Inner Tissue Damage Due to Invasion of Proteolytic Enzymes and Bacteria in Macerated Rat Skin.

    PubMed

    Mugita, Yuko; Minematsu, Takeo; Huang, Lijuan; Nakagami, Gojiro; Kishi, Chihiro; Ichikawa, Yoshie; Nagase, Takashi; Oe, Makoto; Noguchi, Hiroshi; Mori, Taketoshi; Abe, Masatoshi; Sugama, Junko; Sanada, Hiromi

    2015-01-01

    A common complication in patients with incontinence is perineal skin lesions, which are recognized as a form of dermatitis. In these patients, perineal skin is exposed to digestive enzymes and intestinal bacterial flora, as well as excessive water. The relative contributions of digestive enzymes and intestinal bacterial flora to skin lesion formation have not been fully shown. This study was conducted to reveal the process of histopathological changes caused by proteases and bacterial inoculation in skin maceration. For skin maceration, agarose gel containing proteases was applied to the dorsal skin of male Sprague-Dawley rats for 4 h, followed by Pseudomonas aeruginosa inoculation for 30 min. Macroscopic changes, histological changes, bacterial distribution, inflammatory response, and keratinocyte proliferation and differentiation were examined. Proteases induced digestion in the prickle cell layer of the epidermis, and slight bleeding in the papillary dermis and around hair follicles in the macerated skin without macroscopic evidence of erosion. Bacterial inoculation of the skin macerated by proteolytic solution resulted in the formation of bacteria-rich clusters comprising numerous microorganisms and inflammatory cells within the papillary dermis, with remarkable tissue damage around the clusters. Tissue damage expanded by day 2. On day 3, the proliferative keratinocyte layer was elongated from the bulge region of the hair follicles. Application of proteases and P. aeruginosa induced skin lesion formation internally without macroscopic erosion of the overhydrated area, suggesting that the histopathology might be different from regular dermatitis. The healing process of this lesion is similar to transepidermal elimination.

  3. Frequent PLAG1 gene rearrangements in skin and soft tissue myoepithelioma with ductal differentiation.

    PubMed

    Antonescu, Cristina R; Zhang, Lei; Shao, Sung Yun; Mosquera, Juan-Miguel; Weinreb, Ilan; Katabi, Nora; Fletcher, Christopher D M

    2013-07-01

    A subset of cutaneous and superficial soft tissue myoepithelial (ME) tumors displays a distinct ductal component and closely resembles mixed tumors/pleomorphic adenomas of salivary gland. As PLAG1 and HMGA2 rearrangements are the most common genetic events in pleomorphic adenomas, we sought to investigate if these abnormalities are also present in the skin/soft tissue ME lesions. In contrast, half of the deep-seated soft tissue ME tumors lacking ductal differentiation are known to be genetically unrelated, showing EWSR1 rearrangements. FISH analysis to detect PLAG1 and HMGA2 abnormalities was performed in 35 ME tumors, nine skin and 26 soft tissue, lacking EWSR1 and FUS rearrangements. For the PLAG1-rearranged tumors, FISH and RACE were performed to identify potential fusion partners, including CTNNB1 (beta-catenin) on 3p21 and LIFR (leukemia inhibitory factor receptor) on 5p13. Recurrent PLAG1 rearrangement by FISH was detected in 13 (37%) lesions, including three (33%) in the skin and 10 (38%) in the soft tissue. All were classified as benign and all except one showed abundant tubulo-ductal differentiation (comprising 12/24 [50%] of all tumors with ductal structures). A LIFR-PLAG1 fusion was detected by RACE and then confirmed by FISH in one soft tissue ME tumor with tubular formation. No CTNNB1 or LIFR abnormalities were detected in any of the remaining PLAG1-rearranged tumors. No structural HMGA2 abnormalities were detected in any of the 22 ME lesions tested. A subset of cutaneous and soft tissue ME tumors appears genetically linked to their salivary gland counterparts, displaying frequent PLAG1 gene rearrangements and occasionally LIFR-PLAG1 fusion.

  4. Heterogeneous Tissue Characterization Using Ultrasound: A Comparison of Fractal Analysis Backscatter Models on Liver Tumors.

    PubMed

    Al-Kadi, Omar S; Chung, Daniel Y F; Coussios, Constantin C; Noble, J Alison

    2016-07-01

    Assessment of tumor tissue heterogeneity via ultrasound has recently been suggested as a method for predicting early response to treatment. The ultrasound backscattering characteristics can assist in better understanding the tumor texture by highlighting the local concentration and spatial arrangement of tissue scatterers. However, it is challenging to quantify the various tissue heterogeneities ranging from fine to coarse of the echo envelope peaks in tumor texture. Local parametric fractal features extracted via maximum likelihood estimation from five well-known statistical model families are evaluated for the purpose of ultrasound tissue characterization. The fractal dimension (self-similarity measure) was used to characterize the spatial distribution of scatterers, whereas the lacunarity (sparsity measure) was applied to determine scatterer number density. Performance was assessed based on 608 cross-sectional clinical ultrasound radiofrequency images of liver tumors (230 and 378 representing respondent and non-respondent cases, respectively). Cross-validation via leave-one-tumor-out and with different k-fold methodologies using a Bayesian classifier was employed for validation. The fractal properties of the backscattered echoes based on the Nakagami model (Nkg) and its extend four-parameter Nakagami-generalized inverse Gaussian (NIG) distribution achieved best results-with nearly similar performance-in characterizing liver tumor tissue. The accuracy, sensitivity and specificity of Nkg/NIG were 85.6%/86.3%, 94.0%/96.0% and 73.0%/71.0%, respectively. Other statistical models, such as the Rician, Rayleigh and K-distribution, were found to not be as effective in characterizing subtle changes in tissue texture as an indication of response to treatment. Employing the most relevant and practical statistical model could have potential consequences for the design of an early and effective clinical therapy. PMID:27056610

  5. Tissue kallikrein in cardiovascular, cerebrovascular and renal diseases and skin wound healing.

    PubMed

    Chao, Julie; Shen, Bo; Gao, Lin; Xia, Chun-Fang; Bledsoe, Grant; Chao, Lee

    2010-04-01

    Tissue kallikrein (KLK1) processes low-molecular weight kininogen to produce vasoactive kinins, which exert biological functions via kinin receptor signaling. Using various delivery approaches, we have demonstrated that tissue kallikrein through kinin B2 receptor signaling exhibits a wide spectrum of beneficial effects by reducing cardiac and renal injuries, restenosis and ischemic stroke, and by promoting angiogenesis and skin wound healing, independent of blood pressure reduction. Protection by tissue kallikrein in oxidative organ damage is attributed to the inhibition of apoptosis, inflammation, hypertrophy and fibrosis. Tissue kallikrein also enhances neovascularization in ischemic heart and limb. Moreover, tissue kallikrein/kinin infusion not only prevents but also reverses kidney injury, inflammation and fibrosis in salt-induced hypertensive rats. Furthermore, there is a wide time window for kallikrein administration in protection against ischemic brain infarction, as delayed kallikrein infusion for 24 h after cerebral ischemia in rats is effective in reducing neurological deficits, infarct size, apoptosis and inflammation. Importantly, in the clinical setting, human tissue kallikrein has been proven to be effective in the treatment of patients with acute brain infarction when injected within 48 h after stroke onset. Finally, kallikrein promotes skin wound healing and keratinocyte migration by direct activation of protease-activated receptor 1. PMID:20180644

  6. Racial and ethnic differences in skin aging: implications for treatment with soft tissue fillers.

    PubMed

    Alexis, Andrew F; Alam, Murad

    2012-08-01

    Racial and ethnic differences in the age of onset, severity, and anatomical features of facial aging have been described. In addition, increased melanocyte lability and fibroblast reactivity are functional features that are characteristic of skin of color. These differences should be considered when treating patients with soft tissue fillers in order to achieve optimal results. Signs of facial aging in individuals with skin of color tend to be most pronounced in the periorbital and midface region with less prominent features of skin aging in the upper third of the face and a decreased tendency toward perioral rhytides and radial lip lines. As such, volumization of the midface while preserving individual and ethnic ideals of beauty is a key goal. Important treatment considerations include minimization of inflammation, epidermal injury, and bruising, which can lead to aesthetically displeasing sequelae.

  7. The neuroimmune connection interferes with tissue regeneration and chronic inflammatory disease in the skin.

    PubMed

    Peters, Eva M J; Liezmann, Christiane; Klapp, Burghard F; Kruse, Johannes

    2012-07-01

    Research over the past decades has revealed close interactions between the nervous and immune systems that regulate peripheral inflammation and link psychosocial stress with chronic somatic disease. Besides activation of the sympathetic and the hypothalamus-pituitary-adrenal axis, stress leads to increased neurotrophin and neuropeptide production in organs at the self-environment interface. The scope of this short review is to discuss key functions of these stress mediators in the skin, an exemplary stress-targeted and stress-sensitive organ. We will focus on the skin's response to acute and chronic stress in tissue regeneration and pathogenesis of allergic inflammation, psoriasis, and skin cancer to illustrate the impact of local stress-induced neuroimmune interaction on chronic inflammation. PMID:22823443

  8. The neuroimmune connection interferes with tissue regeneration and chronic inflammatory disease in the skin.

    PubMed

    Peters, Eva M J; Liezmann, Christiane; Klapp, Burghard F; Kruse, Johannes

    2012-07-01

    Research over the past decades has revealed close interactions between the nervous and immune systems that regulate peripheral inflammation and link psychosocial stress with chronic somatic disease. Besides activation of the sympathetic and the hypothalamus-pituitary-adrenal axis, stress leads to increased neurotrophin and neuropeptide production in organs at the self-environment interface. The scope of this short review is to discuss key functions of these stress mediators in the skin, an exemplary stress-targeted and stress-sensitive organ. We will focus on the skin's response to acute and chronic stress in tissue regeneration and pathogenesis of allergic inflammation, psoriasis, and skin cancer to illustrate the impact of local stress-induced neuroimmune interaction on chronic inflammation.

  9. Transient Tissue-Scale Deformation Coordinates Alignment of Planar Cell Polarity Junctions in the Mammalian Skin.

    PubMed

    Aw, Wen Yih; Heck, Bryan W; Joyce, Bradley; Devenport, Danelle

    2016-08-22

    Planar cell polarity (PCP) refers to the collective alignment of polarity along the tissue plane. In skin, the largest mammalian organ, PCP aligns over extremely long distances, but the global cues that orient tissue polarity are unknown. Here, we show that Celsr1 asymmetry arises concomitant with a gradient of tissue deformation oriented along the medial-lateral axis. This uniaxial tissue tension, whose origin remains unknown, transiently transforms basal epithelial cells from initially isotropic and disordered states into highly elongated and aligned morphologies. Reorienting tissue deformation is sufficient to shift the global axis of polarity, suggesting that uniaxial tissue strain can act as a long-range polarizing cue. Observations both in vivo and in vitro suggest that the effect of tissue anisotropy on Celsr1 polarity is not a direct consequence of cell shape but rather reflects the restructuring of cell-cell interfaces during oriented cell divisions and cell rearrangements that serve to relax tissue strain. We demonstrate that cell intercalations remodel intercellular junctions predominantly between the mediolateral interfaces of neighboring cells. This restructuring of the cell surface polarizes Celsr1, which is slow to accumulate at nascent junctions yet stably associates with persistent junctions. We propose that tissue anisotropy globally aligns Celsr1 polarity by creating a directional bias in the formation of new cell interfaces while simultaneously aligning the persistent interfaces at which Celsr1 prefers to accumulate.

  10. Transient Tissue-Scale Deformation Coordinates Alignment of Planar Cell Polarity Junctions in the Mammalian Skin.

    PubMed

    Aw, Wen Yih; Heck, Bryan W; Joyce, Bradley; Devenport, Danelle

    2016-08-22

    Planar cell polarity (PCP) refers to the collective alignment of polarity along the tissue plane. In skin, the largest mammalian organ, PCP aligns over extremely long distances, but the global cues that orient tissue polarity are unknown. Here, we show that Celsr1 asymmetry arises concomitant with a gradient of tissue deformation oriented along the medial-lateral axis. This uniaxial tissue tension, whose origin remains unknown, transiently transforms basal epithelial cells from initially isotropic and disordered states into highly elongated and aligned morphologies. Reorienting tissue deformation is sufficient to shift the global axis of polarity, suggesting that uniaxial tissue strain can act as a long-range polarizing cue. Observations both in vivo and in vitro suggest that the effect of tissue anisotropy on Celsr1 polarity is not a direct consequence of cell shape but rather reflects the restructuring of cell-cell interfaces during oriented cell divisions and cell rearrangements that serve to relax tissue strain. We demonstrate that cell intercalations remodel intercellular junctions predominantly between the mediolateral interfaces of neighboring cells. This restructuring of the cell surface polarizes Celsr1, which is slow to accumulate at nascent junctions yet stably associates with persistent junctions. We propose that tissue anisotropy globally aligns Celsr1 polarity by creating a directional bias in the formation of new cell interfaces while simultaneously aligning the persistent interfaces at which Celsr1 prefers to accumulate. PMID:27451904

  11. Tissue repair genes: the TiRe database and its implication for skin wound healing.

    PubMed

    Yanai, Hagai; Budovsky, Arie; Tacutu, Robi; Barzilay, Thomer; Abramovich, Amir; Ziesche, Rolf; Fraifeld, Vadim E

    2016-04-19

    Wound healing is an inherent feature of any multicellular organism and recent years have brought about a huge amount of data regarding regular and abnormal tissue repair. Despite the accumulated knowledge, modulation of wound healing is still a major biomedical challenge, especially in advanced ages. In order to collect and systematically organize what we know about the key players in wound healing, we created the TiRe (Tissue Repair) database, an online collection of genes and proteins that were shown to directly affect skin wound healing. To date, TiRe contains 397 entries for four organisms: Mus musculus, Rattus norvegicus, Sus domesticus, and Homo sapiens. Analysis of the TiRe dataset of skin wound healing-associated genes showed that skin wound healing genes are (i) over-conserved among vertebrates, but are under-conserved in invertebrates; (ii) enriched in extracellular and immuno-inflammatory genes; and display (iii) high interconnectivity and connectivity to other proteins. The latter may provide potential therapeutic targets. In addition, a slower or faster skin wound healing is indicative of an aging or longevity phenotype only when assessed in advanced ages, but not in the young. In the long run, we aim for TiRe to be a one-station resource that provides researchers and clinicians with the essential data needed for a better understanding of the mechanisms of wound healing, designing new experiments, and the development of new therapeutic strategies. TiRe is freely available online at http://www.tiredb.org.

  12. A novel gellan-PVA nanofibrous scaffold for skin tissue regeneration: Fabrication and characterization.

    PubMed

    Vashisth, Priya; Nikhil, Kumar; Roy, Partha; Pruthi, Parul A; Singh, Rajesh P; Pruthi, Vikas

    2016-01-20

    In this investigation, we have introduced novel electrospun gellan based nanofibers as a hydrophilic scaffolding material for skin tissue regeneration. These nanofibers were fabricated using a blend mixture of gellan with polyvinyl alcohol (PVA). PVA reduced the repulsive force of resulting solution and lead to formation of uniform fibers with improved nanostructure. Field emission scanning electron microscopy (FESEM) confirmed the average diameter of nanofibers down to 50 nm. The infrared spectra (IR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis evaluated the crosslinking, thermal stability and highly crystalline nature of gellan-PVA nanofibers, respectively. Furthermore, the cell culture studies using human dermal fibroblast (3T3L1) cells established that these gellan based nanofibrous scaffold could induce improved cell adhesion and enhanced cell growth than conventionally proposed gellan based hydrogels and dry films. Importantly, the nanofibrous scaffold are biodegradable and could be potentially used as a temporary substrate/or biomedical graft to induce skin tissue regeneration.

  13. Computer-aided multiple-head 3D printing system for printing of heterogeneous organ/tissue constructs

    NASA Astrophysics Data System (ADS)

    Jung, Jin Woo; Lee, Jung-Seob; Cho, Dong-Woo

    2016-02-01

    Recently, much attention has focused on replacement or/and enhancement of biological tissues via the use of cell-laden hydrogel scaffolds with an architecture that mimics the tissue matrix, and with the desired three-dimensional (3D) external geometry. However, mimicking the heterogeneous tissues that most organs and tissues are formed of is challenging. Although multiple-head 3D printing systems have been proposed for fabricating heterogeneous cell-laden hydrogel scaffolds, to date only the simple exterior form has been realized. Here we describe a computer-aided design and manufacturing (CAD/CAM) system for this application. We aim to develop an algorithm to enable easy, intuitive design and fabrication of a heterogeneous cell-laden hydrogel scaffolds with a free-form 3D geometry. The printing paths of the scaffold are automatically generated from the 3D CAD model, and the scaffold is then printed by dispensing four materials; i.e., a frame, two kinds of cell-laden hydrogel and a support. We demonstrated printing of heterogeneous tissue models formed of hydrogel scaffolds using this approach, including the outer ear, kidney and tooth tissue. These results indicate that this approach is particularly promising for tissue engineering and 3D printing applications to regenerate heterogeneous organs and tissues with tailored geometries to treat specific defects or injuries.

  14. Computer-aided multiple-head 3D printing system for printing of heterogeneous organ/tissue constructs.

    PubMed

    Jung, Jin Woo; Lee, Jung-Seob; Cho, Dong-Woo

    2016-01-01

    Recently, much attention has focused on replacement or/and enhancement of biological tissues via the use of cell-laden hydrogel scaffolds with an architecture that mimics the tissue matrix, and with the desired three-dimensional (3D) external geometry. However, mimicking the heterogeneous tissues that most organs and tissues are formed of is challenging. Although multiple-head 3D printing systems have been proposed for fabricating heterogeneous cell-laden hydrogel scaffolds, to date only the simple exterior form has been realized. Here we describe a computer-aided design and manufacturing (CAD/CAM) system for this application. We aim to develop an algorithm to enable easy, intuitive design and fabrication of a heterogeneous cell-laden hydrogel scaffolds with a free-form 3D geometry. The printing paths of the scaffold are automatically generated from the 3D CAD model, and the scaffold is then printed by dispensing four materials; i.e., a frame, two kinds of cell-laden hydrogel and a support. We demonstrated printing of heterogeneous tissue models formed of hydrogel scaffolds using this approach, including the outer ear, kidney and tooth tissue. These results indicate that this approach is particularly promising for tissue engineering and 3D printing applications to regenerate heterogeneous organs and tissues with tailored geometries to treat specific defects or injuries. PMID:26899876

  15. Computer-aided multiple-head 3D printing system for printing of heterogeneous organ/tissue constructs

    PubMed Central

    Jung, Jin Woo; Lee, Jung-Seob; Cho, Dong-Woo

    2016-01-01

    Recently, much attention has focused on replacement or/and enhancement of biological tissues via the use of cell-laden hydrogel scaffolds with an architecture that mimics the tissue matrix, and with the desired three-dimensional (3D) external geometry. However, mimicking the heterogeneous tissues that most organs and tissues are formed of is challenging. Although multiple-head 3D printing systems have been proposed for fabricating heterogeneous cell-laden hydrogel scaffolds, to date only the simple exterior form has been realized. Here we describe a computer-aided design and manufacturing (CAD/CAM) system for this application. We aim to develop an algorithm to enable easy, intuitive design and fabrication of a heterogeneous cell-laden hydrogel scaffolds with a free-form 3D geometry. The printing paths of the scaffold are automatically generated from the 3D CAD model, and the scaffold is then printed by dispensing four materials; i.e., a frame, two kinds of cell-laden hydrogel and a support. We demonstrated printing of heterogeneous tissue models formed of hydrogel scaffolds using this approach, including the outer ear, kidney and tooth tissue. These results indicate that this approach is particularly promising for tissue engineering and 3D printing applications to regenerate heterogeneous organs and tissues with tailored geometries to treat specific defects or injuries. PMID:26899876

  16. Computer-aided multiple-head 3D printing system for printing of heterogeneous organ/tissue constructs.

    PubMed

    Jung, Jin Woo; Lee, Jung-Seob; Cho, Dong-Woo

    2016-02-22

    Recently, much attention has focused on replacement or/and enhancement of biological tissues via the use of cell-laden hydrogel scaffolds with an architecture that mimics the tissue matrix, and with the desired three-dimensional (3D) external geometry. However, mimicking the heterogeneous tissues that most organs and tissues are formed of is challenging. Although multiple-head 3D printing systems have been proposed for fabricating heterogeneous cell-laden hydrogel scaffolds, to date only the simple exterior form has been realized. Here we describe a computer-aided design and manufacturing (CAD/CAM) system for this application. We aim to develop an algorithm to enable easy, intuitive design and fabrication of a heterogeneous cell-laden hydrogel scaffolds with a free-form 3D geometry. The printing paths of the scaffold are automatically generated from the 3D CAD model, and the scaffold is then printed by dispensing four materials; i.e., a frame, two kinds of cell-laden hydrogel and a support. We demonstrated printing of heterogeneous tissue models formed of hydrogel scaffolds using this approach, including the outer ear, kidney and tooth tissue. These results indicate that this approach is particularly promising for tissue engineering and 3D printing applications to regenerate heterogeneous organs and tissues with tailored geometries to treat specific defects or injuries.

  17. Investigation of soft tissue movement during level walking: translations and rotations of skin markers.

    PubMed

    Gao, Bo; Zheng, Naiquan Nigel

    2008-11-14

    Skin marker-based stereophotogrammetry is the most widely used technique for human motion analysis but its accuracy is mainly limited by soft tissue artifact (STA) which reflects the non-rigidity of human body segments during activities. To compensate for the effects of STA and improve the accuracy of motion analysis, it is critical to understand the behavior and characteristics of soft tissue movement. By using a non-invasive approach, this study investigated the soft tissue movement on the thigh and shank of twenty healthy subjects during level walking which is one of the most important human daily activities and the basic content of clinical gait analysis. With the measurement of inter-marker translations and rotations on each segment, a 4D picture (3D space and time) of soft tissue deformation on the thigh and shank during walking was quantified in terms of the positional and orientational change between different skin locations. Soft tissue deformation showed nonuniform distribution at different locations as well as along different directions. The range of inter-marker movement was found to be up to 19.1mm/19.6 degrees on the thigh and 9.3mm/8.6 degrees on the shank. Results in this study provide useful information for understanding soft tissue movement behavior and exploring better marker configurations. Inter-marker movement exhibited similar patterns across subjects. This finding suggests the possibility that STA has inter-subject similarity, which is contrary to the prevailing opinion. This new insight may lead to more effective STA compensation strategies for skin marker-based motion analysis.

  18. In vivo model of wound healing based on transplanted tissue-engineered skin.

    PubMed

    Geer, David J; Swartz, Daniel D; Andreadis, Stelios T

    2004-01-01

    Advances in understanding the complex process of wound healing and development of novel growth factor and gene therapies would benefit from models that mimic closely the physiology of human wounds. To this end, we developed a hybrid wound-healing model based on human tissue-engineered skin transplanted onto athymic mice. Grafted tissues were infiltrated with mouse mesenchymal cells as native and foreign dermal regions fused together. Immunohistochemical staining for human involucrin revealed that the transplanted epithelium maintained its human origin, whereas the dermis was infiltrated by numerous mouse fibroblasts and blood vessels. Grafted tissues were wounded with a 4-mm punch to create full-thickness excisional wounds. At 1 and 2 weeks, the tissues were excised and assessed for reepithelialization, differentiation, and neovascularization. Interestingly, the average rate of keratinocyte migration (120 microm/day) was similar to migration rates observed in human subjects and significantly lower than migration in mouse epidermis. Immunohistochemical staining for keratin 10, laminin, and involucrin revealed a normal pattern of differentiation in the neoepidermis. Neovascularization was significantly elevated in the granulation tissue at 1 week and subsided to the level of unwounded tissue at 2 weeks postwounding. Our data suggest that skin equivalents grafted to a mouse model may serve as a realistic model of human wound regeneration. Because skin equivalents can be prepared with patient cells and genetically modified to stimulate or suppress gene expression, this model may be ideal for addressing mechanistic questions and evaluating the efficacy of biomaterials and gene therapeutics for promoting wound healing. PMID:15363158

  19. Posttraumatic Skin and Soft-Tissue Infection due to Pseudomonas fulva

    PubMed Central

    Jiménez, Gemma; Rodríguez-Granger, Javier; Sampedro, Antonio

    2016-01-01

    We report a case of posttraumatic skin and soft-tissue infection in a patient with a left thigh wound after a traffic accident. Pseudomonas fulva was isolated from a wound aspirate and was identified to the species level by Maldi-tof. The patient responded to drainage, debridement of wound, and two weeks of intravenous antibiotic therapy. Follow-up after 3 weeks was satisfactory with healthy cover of the injured area. PMID:27752373

  20. Combined treatment for skin rejuvenation and soft-tissue augmentation of the aging face.

    PubMed

    Beer, Kenneth R

    2011-02-01

    Multiple types of anti-aging treatments are required to address the various etiologies of facial aging. Soft-tissue augmentation provides a minimally invasive option for patients seeking to look younger. However, due to changes in facial skin, musculature, fat and bone, anti-aging treatment requires a multifaceted approach. Injectable fillers may be combined with neurotoxins to resolve superficial wrinkles and restore facial volume. These modalities may be used with laser resurfacing or chemical peels to address epidermal and superficial dermal problems. Combining injectable soft-tissue augmentation treatments allows clinicians and patients to take advantage of the benefits of each modality and to address the multiple effects of facial aging. This review is based on clinical experience and a MEDLINE search for articles about volume replacement and soft-tissue augmentation. It provides a rationale that supports the use of combination techniques/products for soft-tissue augmentation.

  1. Quantitative Estimations of Thermal Damage in Skin Tissue Using Monte Carlo Simulation of Polarized Light

    NASA Astrophysics Data System (ADS)

    Lee, G. W.; Kim, T. H.; Youn, J. I.

    2016-03-01

    Thermal treatment has been used for collagen tightening and tissue contour enhancement. It is important to monitor the condition of collagenous tissue during and immediately after thermal treatment. Collagen denaturation changes the optical properties such as scattering coefficient and anisotropy. In this study, Monte Carlo simulation of polarized light was used to calculate the degree of linear polarization (DOLP) of backscattered light from thermally damaged porcine skin, and the Mueller matrix was calculated to verify the result of DOLP. We observed a decrease in the DOLP and a significant change in the radial distribution of the Mueller matrix elements at temperatures ranging from 55 to 65°C. This could be attributed to the increase in scattering coefficient and decrease in anisotropy caused by thermal denaturation in the tissue. The DOLP method has a potential implementation as a real-time closed-loop feedback system for use in various thermal treatment methods through measuring changes in optical properties of target tissues.

  2. A novel composition for in vitro and in vivo regeneration of skin and connective tissues.

    PubMed

    Gennero, Luisa; De Siena, Rocco; Denysenko, Tetyana; Roos, Maria Augusta; Calisti, Gian Franco; Martano, Manuela; Fiobellot, Simona; Panzone, Michele; Reguzzi, Stefano; Gabetti, Luisa; Vercelli, Andrea; Cavallo, Giovanni; Ricci, Elia; Pescarmona, Gian Piero

    2011-06-01

    The particular combination of polydeoxyribonucleotides, l-carnitine, calcium ions, proteolytic enzyme and other ingredients acts in a synergetic way in the regeneration of skin and connective tissues. This new formulation of active principles was tested in vitro as a cell and tissue culture medium and in vivo for various preparations in support of tissue regeneration. In vitro, the new blend allowed the maintenance of skin biopsies for more than 1 year in eutrophic conditions. Immunocytochemical analyses of fibroblasts isolated from these biopsies confirmed a significant increase of the epidermal and connective wound-healing markers such as collagen type I, collagen type IV, cytokeratin 1 (CK1), CK5, CK10 and CK14 versus controls. To examine the effects of the new compound in vivo, we studied impaired wound healing in genetically diabetic db/db mice. At day 18, diabetic mice treated with the new composition showed 100% closure of wounds and faster healing than mice treated with the other solutions. This complex of vital continuity factors or life-keeping factors could be used as a tissue-preserving solution or a cosmetic/drug/medical device to accelerate wound healing in the treatment of patients with deficient wound repair to promote the regeneration of cutaneous and connective tissues (injuries-wound, dermatitis) and prevent the recurrent relapses.

  3. [Repair of skin and soft tissue defects around the knee joints].

    PubMed

    Tan, Qian; Xu, Peng

    2015-10-01

    Skin and soft tissue defects around the knee joints are often accompanied by popliteal artery injury, patellar ligament injury, patellar fracture, and other deep tissue damage or exposure, making them challenging to repair. The principle is to repair the wound, reconstruct anatomical structure of the knee joint, and recover the knee joint function. At present the reconstruction with skin flap or myocutaneous flap is our priority. Local flap or myocutaneous flap can be used for repairing minor defects around the knee joints. Repairing with perforator flap, fascia flap, and free flap are main alternatives for covering larger and complex defects around the knee joints. During the treatment, a joint effort is mandatory, not only to repair the wound, but also to reconstruct vasculature, fix fracture, repair ligament, and finally recover the knee joint function. Therefore, the importance of multidisciplinary cooperation must be emphasized. Moreover, along with the development of new technologies, new methods, and new materials, perforator flap plays an important role in repairing skin and soft tissue defects around the knee joints.

  4. Fat tissue histological study at indocyanine green-mediated photothermal/photodynamic treatment of the skin in vivo

    NASA Astrophysics Data System (ADS)

    Yanina, Irina Yu.; Tuchin, Valery V.; Navolokin, Nikita A.; Matveeva, Olga V.; Bucharskaya, Alla B.; Maslyakova, Galina N.; Altshuler, Gregory B.

    2012-05-01

    Histological slices of skin samples with the subcutaneous adipose tissue after photothermal/photodynamic treatment are analyzed. In the case of subcutaneous indocyanine green injection and 808-nm diode laser exposure of the rat skin site in vivo, the greatest changes in tissue condition were observed. Processes were characterized by dystrophy, necrosis, and desquamation of the epithelial cells, swelling and necrosis of the connective tissue, and widespread necrosis of the subcutaneous adipose tissue. The obtained data are useful for safe layer-by-layer dosimetry of laser illumination of ICG-stained adipose tissue for treatment of obesity and cellulite.

  5. Ultraviolet emission and excitation fluorescence spectroscopic characterization of DMBA-treated Swiss Albino mice skin carcinogenesis for measuring tissue transformation

    NASA Astrophysics Data System (ADS)

    Aruna, Prakasa R.; Hemamalini, Srinivasan; Ebenezar, Jeyasingh; Ganesan, Singaravelu

    2002-05-01

    The ultraviolet fluorescence emission spectra of skin tissues under different pathological conditions were measured at 280nm excitation. At this excitation wavelength, the normal skin showed a primary peak emission at 352nm and this primary peak emission from neoplastic skin shows a blue shift with respect to normal tissue. This blue shift increases as the stage of abnormality increases and it is maximum (19nm) for well-differentiated squamous cell carcinoma. This alteration is further confirmed from fluorescence excitation spectra of the tissues for 340nm emission. The study concludes that the change in the emission of tryptophan around 340nm may be due to partial unfolding of protein.

  6. Biocomposite nanofibrous strategies for the controlled release of biomolecules for skin tissue regeneration

    PubMed Central

    Gandhimathi, Chinnasamy; Venugopal, Jayarama Reddy; Bhaarathy, Velmurugan; Ramakrishna, Seeram; Kumar, Srinivasan Dinesh

    2014-01-01

    Nanotechnology and tissue engineering have enabled engineering of nanostructured strategies to meet the current challenges in skin tissue regeneration. Electrospinning technology creates porous nanofibrous scaffolds to mimic extracellular matrix of the native tissues. The present study was performed to gain some insights into the applications of poly(l-lactic acid)-co-poly-(ε-caprolactone) (PLACL)/silk fibroin (SF)/vitamin E (VE)/curcumin (Cur) nanofibrous scaffolds and to assess their potential for being used as substrates for the culture of human dermal fibroblasts for skin tissue engineering. PLACL/SF/VE/Cur nanofibrous scaffolds were fabricated by electrospinning and characterized by fiber morphology, membrane porosity, wettability, mechanical strength, and chemical properties by Fourier transform infrared (FTIR) analysis. Human dermal fibroblasts were cultured on these scaffolds, and the cell scaffold interactions were analyzed by cell proliferation, cell morphology, secretion of collagen, expression of F-actin, and 5-chloromethylfluorescein diacetate (CMFDA) dye. The electrospun nanofiber diameter was obtained between 198±4 nm and 332±13 nm for PLACL, PLACL/SF, PLACL/SF/VE, and PLACL/SF/VE/Cur nanofibrous scaffolds. FTIR analysis showed the presence of the amide groups I, II, and III, and a porosity of up to 92% obtained on these nanofibrous scaffolds. The results showed that the fibroblast proliferation, cell morphology, F-actin, CMFDA dye expression, and secretion of collagen were significantly increased in PLACL/SF/VE/Cur when compared to PLACL nanofibrous scaffolds. The accessibility of human dermal fibroblasts cultured on PLACL/SF/VE/Cur nanofibrous scaffolds proved to be a potential scaffold for skin tissue regeneration. PMID:25336949

  7. Biocomposite nanofibrous strategies for the controlled release of biomolecules for skin tissue regeneration.

    PubMed

    Gandhimathi, Chinnasamy; Venugopal, Jayarama Reddy; Bhaarathy, Velmurugan; Ramakrishna, Seeram; Kumar, Srinivasan Dinesh

    2014-01-01

    Nanotechnology and tissue engineering have enabled engineering of nanostructured strategies to meet the current challenges in skin tissue regeneration. Electrospinning technology creates porous nanofibrous scaffolds to mimic extracellular matrix of the native tissues. The present study was performed to gain some insights into the applications of poly(l-lactic acid)-co-poly-(ε-caprolactone) (PLACL)/silk fibroin (SF)/vitamin E (VE)/curcumin (Cur) nanofibrous scaffolds and to assess their potential for being used as substrates for the culture of human dermal fibroblasts for skin tissue engineering. PLACL/SF/VE/Cur nanofibrous scaffolds were fabricated by electrospinning and characterized by fiber morphology, membrane porosity, wettability, mechanical strength, and chemical properties by Fourier transform infrared (FTIR) analysis. Human dermal fibroblasts were cultured on these scaffolds, and the cell scaffold interactions were analyzed by cell proliferation, cell morphology, secretion of collagen, expression of F-actin, and 5-chloromethylfluorescein diacetate (CMFDA) dye. The electrospun nanofiber diameter was obtained between 198±4 nm and 332±13 nm for PLACL, PLACL/SF, PLACL/SF/VE, and PLACL/SF/VE/Cur nanofibrous scaffolds. FTIR analysis showed the presence of the amide groups I, II, and III, and a porosity of up to 92% obtained on these nanofibrous scaffolds. The results showed that the fibroblast proliferation, cell morphology, F-actin, CMFDA dye expression, and secretion of collagen were significantly increased in PLACL/SF/VE/Cur when compared to PLACL nanofibrous scaffolds. The accessibility of human dermal fibroblasts cultured on PLACL/SF/VE/Cur nanofibrous scaffolds proved to be a potential scaffold for skin tissue regeneration. PMID:25336949

  8. Effects of tissue heterogeneity on the optical estimate of breast density

    PubMed Central

    Taroni, Paola; Pifferi, Antonio; Quarto, Giovanna; Spinelli, Lorenzo; Torricelli, Alessandro; Abbate, Francesca; Balestreri, Nicola; Ganino, Serena; Menna, Simona; Cassano, Enrico; Cubeddu, Rinaldo

    2012-01-01

    Breast density is a recognized strong and independent risk factor for developing breast cancer. At present, breast density is assessed based on the radiological appearance of breast tissue, thus relying on the use of ionizing radiation. We have previously obtained encouraging preliminary results with our portable instrument for time domain optical mammography performed at 7 wavelengths (635–1060 nm). In that case, information was averaged over four images (cranio-caudal and oblique views of both breasts) available for each subject. In the present work, we tested the effectiveness of just one or few point measurements, to investigate if tissue heterogeneity significantly affects the correlation between optically derived parameters and mammographic density. Data show that parameters estimated through a single optical measurement correlate strongly with mammographic density estimated by using BIRADS categories. A central position is optimal for the measurement, but its exact location is not critical. PMID:23082283

  9. Algorithms for differentiating between images of heterogeneous tissue across fluorescence microscopes

    PubMed Central

    Chitalia, Rhea; Mueller, Jenna; Fu, Henry L.; Whitley, Melodi Javid; Kirsch, David G.; Brown, J. Quincy; Willett, Rebecca; Ramanujam, Nimmi

    2016-01-01

    Fluorescence microscopy can be used to acquire real-time images of tissue morphology and with appropriate algorithms can rapidly quantify features associated with disease. The objective of this study was to assess the ability of various segmentation algorithms to isolate fluorescent positive features (FPFs) in heterogeneous images and identify an approach that can be used across multiple fluorescence microscopes with minimal tuning between systems. Specifically, we show a variety of image segmentation algorithms applied to images of stained tumor and muscle tissue acquired with 3 different fluorescence microscopes. Results indicate that a technique called maximally stable extremal regions followed by thresholding (MSER + Binary) yielded the greatest contrast in FPF density between tumor and muscle images across multiple microscopy systems. PMID:27699108

  10. Algorithms for differentiating between images of heterogeneous tissue across fluorescence microscopes

    PubMed Central

    Chitalia, Rhea; Mueller, Jenna; Fu, Henry L.; Whitley, Melodi Javid; Kirsch, David G.; Brown, J. Quincy; Willett, Rebecca; Ramanujam, Nimmi

    2016-01-01

    Fluorescence microscopy can be used to acquire real-time images of tissue morphology and with appropriate algorithms can rapidly quantify features associated with disease. The objective of this study was to assess the ability of various segmentation algorithms to isolate fluorescent positive features (FPFs) in heterogeneous images and identify an approach that can be used across multiple fluorescence microscopes with minimal tuning between systems. Specifically, we show a variety of image segmentation algorithms applied to images of stained tumor and muscle tissue acquired with 3 different fluorescence microscopes. Results indicate that a technique called maximally stable extremal regions followed by thresholding (MSER + Binary) yielded the greatest contrast in FPF density between tumor and muscle images across multiple microscopy systems.

  11. A Bioengineered Human Skin Tissue for the Treatment of Infected Wounds

    PubMed Central

    Thomas-Virnig, Christina L.; Allen-Hoffmann, B. Lynn

    2012-01-01

    Background Complex skin defects resulting from acute skin trauma and chronic, nonhealing wounds are life-threatening injuries. Infection is one of the most common obstacles to the healing of these types of wounds. Host defense peptides (HDPs) possessing a broad spectrum of activity against microorganisms and serving as innate immune modulators have emerged as potential treatment strategies for infected wounds. The Problem The increase in multidrug-resistant clinical bacterial isolates highlights the need for new and innovative anti-infective therapies for the treatment of both acute and chronic skin wounds. Basic/Clinical Science To address the critical need for new therapeutic options to reduce infection and improve wound healing, a bioengineered skin substitute (BSS) tissue has been created to act as an anti-infective living human skin tissue that provides enhanced expression of the endogenous HDP, cathelicidin. To generate a BSS exhibiting these antimicrobial properties, the clinically tested NIKS progenitor cells were employed to provide a source of genetically uniform, nontumorigenic, pathogen-free human keratinocytes that are amenable to genetic engineering using nonviral means. Clinical Care Relevance Pathogenic bacterial strains are increasingly developing antibiotic resistance, thereby forcing the clinician to use potent antibiotics with deleterious effects on keratinocyte viability and migration. Therefore, an urgent need exists for new wound therapies that can circumvent many of the problems associated with current antibiotic treatments. Conclusion Enhanced expression of cathelicidin in a genetically engineered human BSS has been shown to inhibit the bacterial growth of a multidrug-resistant clinical strain of Acinetobacter baumannii in vivo, creating a new and innovative therapeutic option for combating these debilitating wound infections while also promoting healing. PMID:24527286

  12. A heterogeneous human tissue mimicking phantom for RF heating and MRI thermal monitoring verification

    NASA Astrophysics Data System (ADS)

    Yuan, Yu; Wyatt, Cory; Maccarini, Paolo; Stauffer, Paul; Craciunescu, Oana; MacFall, James; Dewhirst, Mark; Das, Shiva K.

    2012-04-01

    This paper describes a heterogeneous phantom that mimics a human thigh with a deep-seated tumor, for the purpose of studying the performance of radiofrequency (RF) heating equipment and non-invasive temperature monitoring with magnetic resonance imaging (MRI). The heterogeneous cylindrical phantom was constructed with an outer fat layer surrounding an inner core of phantom material mimicking muscle, tumor and marrow-filled bone. The component materials were formulated to have dielectric and thermal properties similar to human tissues. The dielectric properties of the tissue mimicking phantom materials were measured with a microwave vector network analyzer and impedance probe over the frequency range of 80-500 MHz and at temperatures of 24, 37 and 45 °C. The specific heat values of the component materials were measured using a differential scanning calorimeter over the temperature range of 15-55 °C. The thermal conductivity value was obtained from fitting the curves obtained from one-dimensional heat transfer measurement. The phantom was used to verify the operation of a cylindrical four-antenna annular phased array extremity applicator (140 MHz) by examining the proton resonance frequency shift (PRFS) thermal imaging patterns for various magnitude/phase settings (including settings to focus heating in tumors). For muscle and tumor materials, MRI was also used to measure T1/T2* values (1.5 T) and to obtain the slope of the PRFS phase change versus temperature change curve. The dielectric and thermal properties of the phantom materials were in close agreement to well-accepted published results for human tissues. The phantom was able to successfully demonstrate satisfactory operation of the tested heating equipment. The MRI-measured thermal distributions matched the expected patterns for various magnitude/phase settings of the applicator, allowing the phantom to be used as a quality assurance tool. Importantly, the material formulations for the various tissue types

  13. Monte Carlo simulation of in vivo Raman spectral measurements of human skin with a multi-layered tissue optical model.

    PubMed

    Wang, Shuang; Zhao, Jianhua; Lui, Harvey; He, Qingli; Bai, Jintao; Zeng, Haishan

    2014-09-01

    Raman photon generation inside human skin and escaping to skin surface were modeled in an eight-layered skin optical model. Intrinsic Raman spectra of different skin layers were determined by microscopy measurements of excised skin tissue sections. Monte Carlo simulation was used to study the excitation light distribution and intrinsic Raman signal distortion caused by tissue reabsorption and scattering during in vivo measurements. The simulation results demonstrated how different skin layers contributed to the observed in vivo Raman spectrum. Using the strongest Raman peak at 1445 cm(-1) as an example, the simulation suggested that the integrated contributions of the stratum corneum layer is 1.3%, the epidermis layer 28%, the dermis layer 70%, and the subcutaneous fat layer 1.1%. Reasonably good matching between the calculated spectrum and the measured in vivo Raman spectra was achieved, thus demonstrated great utility of our modeling method and approaches for help understanding the clinical measurements.

  14. Poly(L-lactide-co-glycolide) thin films can act as autologous cell carriers for skin tissue engineering.

    PubMed

    Zuber, Aleksandra; Borowczyk, Julia; Zimolag, Eliza; Krok, Malgorzata; Madeja, Zbigniew; Pamula, Elzbieta; Drukala, Justyna

    2014-06-01

    Degradable aliphatic polyesters such as polylactides, polyglycolides and their copolymers are used in several biomedical and pharmaceutical applications. We analyzed the influence of poly(L-lactide-co-glycolide) (PLGA) thin films on the adhesion, proliferation, motility and differentiation of primary human skin keratinocytes and fibroblasts in the context of their potential use as cell carriers for skin tissue engineering. We did not observe visible differences in the morphology, focal contact appearance, or actin cytoskeleton organization of skin cells cultured on PLGA films compared to those cultured under control conditions. Moreover, we did not detect biologically significant differences in proliferative activity, migration parameters, level of differentiation, or expression of vinculin when the cells were cultured on PLGA films and tissue culture polystyrene. Our results indicate that PLGA films do not affect the basic functions of primary human skin keratinocytes and fibroblasts and thus show acceptable biocompatibility in vitro, paving the way for their use as biomaterials for skin tissue engineering. PMID:24825569

  15. Toad skin extract cinobufatini inhibits migration of human breast carcinoma MDA-MB-231 cells into a model stromal tissue.

    PubMed

    Nakata, Munehiro; Mori, Shuya; Kamoshida, Yo; Kawaguchi, Shota; Fujita-Yamaguchi, Yoko; Gao, Bo; Tang, Wei

    2015-08-01

    Toad skin extract cinobufatini study has been focused on anticancer activity, especially apoptosis-inducing activity by bufosteroids. The present study examined effect of the toad skin extract on cancer cell migration into model stromal tissues. Human breast carcinoma cell line MDA-MB-231 was incubated in the presence or absence of toad skin extract on a surface of reconstituted type I collagen gel as a model stromal tissue allowing the cells to migrate into the gel. Frozen sections were microscopically observed after azan staining. Data showed a decrease of cell number in a microscopic field and shortening of cell migration into the model stromal tissue in a dose dependent manner. This suggests that toad skin extract may possess migration-preventing activity in addition to cell toxicity such as apoptosis-inducing activity. The multifaceted effects including apoptosis-inducing and cancer cell migration-preventing activities would improve usefulness of toad skin extract cinobufatini as an anticancer medicine.

  16. Design of a tissue oxygenation monitor and verification on human skin

    NASA Astrophysics Data System (ADS)

    Liu, Hongyuan; Kohl-Bareis, Matthias; Huang, Xiabing

    2011-07-01

    We report the design of a tissue oxygen and temperature monitor. The non-invasive, fibre based device monitors tissue haemoglobin (Hb) and oxygen saturation (SO2) and is based on white-light reflectance spectroscopy.Visible light with wavelengths in the 500 - 650nm range is utilized. The spectroscopic algorithm takes into account the tissue scattering and melanin absorption for the calculation of tissue haemoglobin concentration and oxygen saturation. The monitor can probe superficial layers of tissue with a high spatial resolution (mm3) and a high temporal resolution (40 Hz). It provides an accurate measurement with the accuracy of SO2 at 2 % and high reliability with less than 2 % variation of continuous SO2 measurement over 12 hours. It can also form a modular system when used in conjunction with a laser Doppler monitor, enabling simultaneous measurements of Hb, SO2 and blood flow. We found experimentally that the influence of the source-detector separation on the haemoglobin parameters is small. This finding is discussed by Monte Carlo simulations for the depth sensitivity profile. The influence of probe pressure and the skin pigmentation on the measurement parameters are assessed before in vivo experimental data is presented. The combination with laser Doppler flowmetry demonstrates the importance of a measurement of both the haemoglobin and the blood flow parameters for a full description of blood tissue perfusion. This is discussed in experimental data on human skin during cuff occlusion and after hyperemisation by a pharmacological cream. Strong correlation is observed between tissue oxygen (Hb and SO2) and blood flow measurements.

  17. Experiment K-7-29: Connective Tissue Studies. Part 1; Rat Skin, Normal and Repair

    NASA Technical Reports Server (NTRS)

    Vailas, A. C.; Grindeland, R.; Ashman, R.; Choy, V.; Durnova, G.; Graf, B.; Griffith, P.; Kaplansky, A. S.; Kolis, S.; Martinez, D.; Rao, J. S.; Rayford, A. R.; Reddy, B. R.; Sears, J.; Thielke, R.; Ulm, M.; Vanderby, R.

    1994-01-01

    The skin repair studies started to be problematic for the following reasons: (1) It was very difficult to locate the wound and many lesions were not of the same dimensions. A considerable amount of time was devoted to the identification of the wound using polarized light. We understand that this experiment was added on to the overall project. Marking of the wound site and standard dimensions should be recommended for the next flight experiment. (2) The tissue was frozen, therefore thawing and fixation caused problems with some of the immunocytochemical staining for obtaining better special resolution with light microscopy image processing. Despite these problems, we were unable to detect any significant qualitative differences for the following wound markers: (1) Collagen Type 3, (2) Hematotoxylin and Eosin, and (3) Macrophage Factor 13. All protein markers were isolated from rat sources and antibodies prepared and tested for cross reactivity with other molecules at the University of Wisconsin Hybridoma Facility. However, rat skin from the non lesioned site 'normal' showed interesting biochemical results. Skin was prepared for the following measurements: (1) DNA content, (2) Collagen content by hydroxyproline, and (3) uronic acid content and estimation of ground substance. The results indicated there was a non-significant increase (10%) in the DNA concentration of skin from flight animals. However, the data expressed as a ratio DNA/Collagen estimates the cell or nuclear density that supports a given quantity of collagen showed a dramatic increase in the flight group (33%). This means flight conditions may have slowed down collagen secretion and/or increased cell proliferation in adult rat skin. Further biochemical tests are being done to determine the crosslinking of elastin which will enhance the insight to assessing changes in skin turnover.

  18. Characteristics and Young's Modulus of Collagen Fibrils from Expanded Skin Using Anisotropic Controlled Rate Self-Inflating Tissue Expander.

    PubMed

    Manssor, Nur Aini S; Radzi, Zamri; Yahya, Noor Azlin; Mohamad Yusof, Loqman; Hariri, Firdaus; Khairuddin, Nurul Hayah; Abu Kasim, Noor Hayaty; Czernuszka, Jan T

    2016-01-01

    Mechanical properties of expanded skin tissue are different from normal skin, which is dependent mainly on the structural and functional integrity of dermal collagen fibrils. In the present study, mechanical properties and surface topography of both expanded and nonexpanded skin collagen fibrils were evaluated. Anisotropic controlled rate self-inflating tissue expanders were placed beneath the skin of sheep's forelimbs. The tissue expanders gradually increased in height and reached equilibrium in 2 weeks. They were left in situ for another 2 weeks before explantation. Expanded and normal skin samples were surgically harvested from the sheep (n = 5). Young's modulus and surface topography of collagen fibrils were measured using an atomic force microscope. A surface topographic scan showed organized hierarchical structural levels: collagen molecules, fibrils and fibers. No significant difference was detected for the D-banding pattern: 63.5 ± 2.6 nm (normal skin) and 63.7 ± 2.7 nm (expanded skin). Fibrils from expanded tissues consisted of loosely packed collagen fibrils and the width of the fibrils was significantly narrower compared to those from normal skin: 153.9 ± 25.3 and 106.7 ± 28.5 nm, respectively. Young's modulus of the collagen fibrils in the expanded and normal skin was not statistically significant: 46.5 ± 19.4 and 35.2 ± 27.0 MPa, respectively. In conclusion, the anisotropic controlled rate self-inflating tissue expander produced a loosely packed collagen network and the fibrils exhibited similar D-banding characteristics as the control group in a sheep model. However, the fibrils from the expanded skin were significantly narrower. The stiffness of the fibrils from the expanded skin was higher but it was not statistically different. PMID:26836267

  19. Nanoparticle-enhanced spectral photoacoustic tomography: effect of oxygen saturation and tissue heterogeneity

    NASA Astrophysics Data System (ADS)

    Vogt, William C.; Jia, Congxian; Wear, Keith A.; Garra, Brian S.; Pfefer, T. Joshua

    2016-03-01

    Molecular imaging for breast cancer detection, infectious disease diagnostics and preclinical animal research may be achievable through combined use of targeted exogenous agents - such as nanoparticles - and spectral Photoacoustic Tomography (PAT). However, tissue heterogeneity can alter fluence distributions and acoustic propagation, corrupting measured PAT absorption spectra and complicating in vivo nanoparticle detection and quantitation. Highly absorptive vascular structures represent a common confounding factor, and variations in vessel hemoglobin saturation (SO2) may alter spectral content of signals from adjacent/deeper regions. To evaluate the impact of this effect on PAT nanoparticle detectability, we constructed heterogeneous phantoms with well-characterized channel-inclusion geometries and biologically relevant optical and acoustic properties. Phantoms contained an array of tubes at several depths filled with hemoglobin solutions doped with varying concentrations of gold nanorods with an absorption peak at 780 nm. Both overlying and target network SO2 was tuned using sodium dithionite. Phantoms were imaged from 700 to 900 nm using a custom PAT system comprised of a tunable pulsed laser and a research-grade ultrasound system. Recovered nanoparticle spectra were analyzed and compared with results from both spectrophotometry and PAT data from waterimmersed tubes containing blood and nanoparticle solutions. Results suggested that nanoparticle selection for a given PAT application should take into account expected oxygenation states of both target blood vessel and background tissue oxygenation to achieve optimal performance.

  20. Evaluation of surrogate tissues as indicators of drug activity in a melanoma skin model.

    PubMed

    Parekh, Palak R; Choudhuri, Rohini; Weyemi, Urbain; Martin, Olga A; Bonner, William M; Redon, Christophe E

    2016-08-01

    The development of novel cancer treatments is a challenging task, partly because results from model systems often fail to predict drug efficacy in humans, and also tumors are often inaccessible for biochemical analysis, preventing effective monitoring of drug activity in vivo. Utilizing a model system, we evaluated the use of drug-induced DNA damage in surrogate tissues as indicators of drug efficacy. Samples of a commercially available melanoma skin model (Mattek MLNM-FT-A375) containing keratinocyte and fibroblast layers with melanoma nodules were subjected to various chemotherapeutic regimens for one, four, or eight days. At these times they were analyzed for DNA double-stranded breaks (γH2AX foci) and apoptosis (TUNEL). A wide range of drug responses in both tumor and normal tissues were observed and cataloged. For the melanoma, the most common drug response was apoptosis. The basal keratinocyte layer, which was the most reliable indicator of drug response in the melanoma skin model, responded with γH2AX foci formation that was abrupt and transient. The relationships between tumor and surrogate tissue drug responses are complex, indicating that while surrogate tissue drug responses may be useful clinical tools, careful control of variables such as the timing of sampling may be important in interpreting the results. PMID:27339860

  1. Malondialdehyde-derived epitopes in human skin result from acute exposure to solar UV and occur in nonmelanoma skin cancer tissue.

    PubMed

    Williams, Joshua D; Bermudez, Yira; Park, Sophia L; Stratton, Steven P; Uchida, Koji; Hurst, Craig A; Wondrak, Georg T

    2014-03-01

    Cutaneous exposure to solar ultraviolet radiation (UVR) is a causative factor in photoaging and photocarcinogenesis. In human skin, oxidative stress is widely considered a key mechanism underlying the detrimental effects of acute and chronic UVR exposure. The lipid peroxidation product malondialdehyde (MDA) accumulates in tissue under conditions of increased oxidative stress, and the occurrence of MDA-derived protein epitopes, including dihydropyridine-lysine (DHP), has recently been substantiated in human skin. Here we demonstrate for the first time that acute exposure to sub-apoptogenic doses of solar simulated UV light (SSL) causes the formation of free MDA and protein-bound MDA-derived epitopes in cultured human HaCaT keratinocytes and healthy human skin. Immunohistochemical staining revealed that acute exposure to SSL is sufficient to cause an almost twenty-fold increase in general MDA- and specific DHP-epitope content in human skin. When compared to dose-matched solar simulated UVA, complete SSL was more efficient generating both free MDA and MDA-derived epitopes. Subsequent tissue microarray (TMA) analysis revealed the prevalence of MDA- and DHP-epitopes in nonmelanoma skin cancer (NMSC). In squamous cell carcinoma tissue, both MDA- and DHP-epitopes were increased more than threefold as compared to adjacent normal tissue. Taken together, these date demonstrate the occurrence of MDA-derived epitopes in both solar UVR-exposed healthy human skin and NMSC TMA tissue; however, the potential utility of these epitopes as novel biomarkers of cutaneous photodamage and a functional role in the process of skin photocarcinogenesis remain to be explored.

  2. Improved Specificity of Gene Electrotransfer to Skin Using pDNA Under the Control of Collagen Tissue-Specific Promoter.

    PubMed

    Kos, Spela; Tesic, Natasa; Kamensek, Urska; Blagus, Tanja; Cemazar, Maja; Kranjc, Simona; Lavrencak, Jaka; Sersa, Gregor

    2015-10-01

    In order to ensure safe, efficient and controlled gene delivery to skin, the improvement of delivery methods together with proper design of DNA is required. Non-viral delivery methods, such as gene electrotransfer, and the design of tissue-specific promoters are promising tools to ensure the safety of gene delivery to the skin. In the scope of our study, we evaluated a novel skin-specific plasmid DNA with collagen (COL) promoter, delivered to skin cells and skin tissue by gene electrotransfer. In vitro, we determined the specificity of the COL promoter in fibroblast cells. The specific expression under the control of COL promoter was obtained for the reporter gene DsRed as well as for therapeutic gene encoding cytokine IL-12. In vivo, the plasmid with COL promoter encoding the reporter gene DsRed was efficiently transfected to mouse skin. It resulted in the notable and controlled manner, however, in lower and shorter expression, compared to that obtained with ubiquitous promoter. The concentration of the IL-12 in the skin after the in vivo transfection of plasmid with COL promoter was in the same range as after the treatment in control conditions (injection of distilled water followed by the application of electric pulses). Furthermore, this gene delivery was local, restricted to the skin, without any evident systemic shedding of IL-12. Such specific targeting of skin cells, observed with tissue-specific COL promoter, would improve the effectiveness and safety of cutaneous gene therapies and DNA vaccines.

  3. Potential of a PLA-PEO-PLA-based scaffold for skin tissue engineering: in vitro evaluation.

    PubMed

    Garric, Xavier; Guillaume, Olivier; Dabboue, Hinda; Vert, Michel; Molès, Jean-Pierre

    2012-01-01

    This study aimed to investigate the in vitro behaviour of porous degradable scaffolds of the PLA-PEO-PLA-type designed prior to in vivo evaluation for skin tissue engineering. Two tri-block co-polymers were synthesized from PEO and DL-lactide and their degradation was studied under conditions that mimic a cutaneous wound environment. 3-D porous scaffolds with interconnected pores were fabricated using the salt leaching method and characterized by ESEM and Hg porosimetry. The degrading action of gamma sterilization was studied on the co-polymers. The less degraded one was selected to make porous scaffolds on which human dermal fibroblasts and human epidermal keratinocytes were cultured. The capacity of such scaffolds to act as a dermal equivalent was also considered. Colonization by human dermal fibroblasts was shown after hematoxylin staining and the production of major proteins normally found in the extracellular matrix was assessed by Western blotting of protein extracts. Finally, a skin substitute was generated by seeding human keratinocytes on the dermal equivalent and a new epidermis was characterized by using immuno-histological staining. Results show that gamma sterilization and that degradation under conditions that mimic skin wound healing were acceptable. The fact that fibroblasts produce extracellular matrix and that keratinocytes generated an epidermal barrier argues in favour of the interest of this type of porous scaffold for skin reconstruction.

  4. Biofilm formation by Staphylococcus aureus isolates from skin and soft tissue infections.

    PubMed

    Kwiecinski, Jakub; Kahlmeter, Gunnar; Jin, Tao

    2015-05-01

    Many diseases caused by Staphylococcus aureus are associated with biofilm formation. However, the ability of S. aureus isolates from skin and soft tissue infections to form biofilms has not yet been investigated. We tested 160 isolates from patients with various skin infections for biofilm-forming capacity in different growth media. All the isolates formed biofilms, the extent of which depended on the type of growth medium. The thickest biofilms were formed when both plasma and glucose were present in the broth; in this case, S. aureus incorporated host fibrin into the biofilm's matrix. There were no differences in the biofilm formation between isolates from different types of skin infections, except for a particularly good biofilm formation by isolates from diabetic wounds and a weaker biofilm formation by isolates from impetigo. In conclusion, biofilm formation is a universal behavior of S. aureus isolates from skin infections. In some cases, such as in diabetic wounds, a particularly strong biofilm formation most likely contributes to the chronic and recurrent character of the infection. Additionally, as S. aureus apparently uses host fibrin as part of the biofilm structure, we suggest that plasma should be included more frequently in in vitro biofilm studies. PMID:25586078

  5. The tolerance of skin grafts to postoperative radiation therapy in patients with soft-tissue sarcoma

    SciTech Connect

    Lawrence, W.T.; Zabell, A.; McDonald, H.D. )

    1986-03-01

    During the last ten years at the National Cancer Institute, 11 patients have received 12 courses of postoperative adjuvant radiation therapy to skin grafts used for wound closure after the resection of soft-tissue sarcomas. The intervals between grafting and the initiation of radiation ranged between 3 and 20 weeks, and 4 patients received chemotherapy at the same time as their radiation. Ten of the 12 irradiated grafts remained intact after the completion of therapy. One graft had several small persistently ulcerated areas that required no further surgical treatment, and one graft required a musculocutaneous flap for reconstruction of a persistent large ulcer. Acute radiation effects on the grafted skin sometimes developed at slightly lower doses than usually seen with normal skin, but these acute effects necessitated a break in therapy on only five occasions. Concurrent chemotherapy and a relatively short interval between grafting and the initiation of radiation seemed to contribute to more severe radiation reactions. This experience indicates that postoperative adjuvant radiation therapy can be delivered to skin grafted areas without undue fear of complications, especially if the graft is allowed to heal adequately prior to initiating therapy and if chemotherapy is not given in conjunction with radiation.

  6. Reproducibility of transcutaneous oximetry and laser Doppler flowmetry in facial skin and gingival tissue.

    PubMed

    Svalestad, J; Hellem, S; Vaagbø, G; Irgens, A; Thorsen, E

    2010-01-01

    Laser Doppler flowmetry (LDF) and transcutaneous oximetry (TcPO(2)) are non-invasive techniques, widely used in the clinical setting, for assessing microvascular blood flow and tissue oxygen tension, e.g. recording vascular changes after radiotherapy and hyperbaric oxygen therapy. With standardized procedures and improved reproducibility, these methods might also be applicable in longitudinal studies. The aim of this study was to evaluate the reproducibility of facial skin and gingival LDF and facial skin TcPO(2). The subjects comprised ten healthy volunteers, 5 men, aged 31-68 years. Gingival perfusion was recorded with the LDF probe fixed to a custom made, tooth-supported acrylic splint. Skin perfusion was recorded on the cheek. TcPO(2) was recorded on the forehead and cheek and in the second intercostal space. The reproducibility of LDF measurements taken after vasodilation by heat provocation was greater than for basal flow in both facial skin and mandibular gingiva. Pronounced intraday variations were observed. Interweek reproducibility assessed by intraclass correlation coefficient ranged from 0.74 to 0.96 for LDF and from 0.44 to 0.75 for TcPO(2). The results confirm acceptable reproducibility of LDF and TcPO(2) in longitudinal studies in a vascular laboratory where subjects serve as their own controls. The use of thermoprobes is recommended. Repeat measurements should be taken at the same time of day.

  7. Biofilm formation by Staphylococcus aureus isolates from skin and soft tissue infections.

    PubMed

    Kwiecinski, Jakub; Kahlmeter, Gunnar; Jin, Tao

    2015-05-01

    Many diseases caused by Staphylococcus aureus are associated with biofilm formation. However, the ability of S. aureus isolates from skin and soft tissue infections to form biofilms has not yet been investigated. We tested 160 isolates from patients with various skin infections for biofilm-forming capacity in different growth media. All the isolates formed biofilms, the extent of which depended on the type of growth medium. The thickest biofilms were formed when both plasma and glucose were present in the broth; in this case, S. aureus incorporated host fibrin into the biofilm's matrix. There were no differences in the biofilm formation between isolates from different types of skin infections, except for a particularly good biofilm formation by isolates from diabetic wounds and a weaker biofilm formation by isolates from impetigo. In conclusion, biofilm formation is a universal behavior of S. aureus isolates from skin infections. In some cases, such as in diabetic wounds, a particularly strong biofilm formation most likely contributes to the chronic and recurrent character of the infection. Additionally, as S. aureus apparently uses host fibrin as part of the biofilm structure, we suggest that plasma should be included more frequently in in vitro biofilm studies.

  8. The potential applications of fibrin-coated electrospun polylactide nanofibers in skin tissue engineering.

    PubMed

    Bacakova, Marketa; Musilkova, Jana; Riedel, Tomas; Stranska, Denisa; Brynda, Eduard; Zaloudkova, Margit; Bacakova, Lucie

    2016-01-01

    Fibrin plays an important role during wound healing and skin regeneration. It is often applied in clinical practice for treatment of skin injuries or as a component of skin substitutes. We prepared electrospun nanofibrous membranes made from poly(l-lactide) modified with a thin fibrin nanocoating. Fibrin surrounded the individual fibers in the membrane and also formed a thin fibrous mesh on several places on the membrane surface. The cell-free fibrin nanocoating remained stable in the cell culture medium for 14 days and did not change its morphology. On membranes populated with human dermal fibroblasts, the rate of fibrin degradation correlated with the degree of cell proliferation. The cell spreading, mitochondrial activity, and cell population density were significantly higher on membranes coated with fibrin than on nonmodified membranes, and this cell performance was further improved by the addition of ascorbic acid in the cell culture medium. Similarly, fibrin stimulated the expression and synthesis of collagen I in human dermal fibroblasts, and this effect was further enhanced by ascorbic acid. The expression of beta1-integrins was also improved by fibrin, and on pure polylactide membranes, it was slightly enhanced by ascorbic acid. In addition, ascorbic acid promoted deposition of collagen I in the form of a fibrous extracellular matrix. Thus, the combination of nanofibrous membranes with a fibrin nanocoating and ascorbic acid seems to be particularly advantageous for skin tissue engineering. PMID:26955273

  9. Potential of a PLA-PEO-PLA-based scaffold for skin tissue engineering: in vitro evaluation.

    PubMed

    Garric, Xavier; Guillaume, Olivier; Dabboue, Hinda; Vert, Michel; Molès, Jean-Pierre

    2012-01-01

    This study aimed to investigate the in vitro behaviour of porous degradable scaffolds of the PLA-PEO-PLA-type designed prior to in vivo evaluation for skin tissue engineering. Two tri-block co-polymers were synthesized from PEO and DL-lactide and their degradation was studied under conditions that mimic a cutaneous wound environment. 3-D porous scaffolds with interconnected pores were fabricated using the salt leaching method and characterized by ESEM and Hg porosimetry. The degrading action of gamma sterilization was studied on the co-polymers. The less degraded one was selected to make porous scaffolds on which human dermal fibroblasts and human epidermal keratinocytes were cultured. The capacity of such scaffolds to act as a dermal equivalent was also considered. Colonization by human dermal fibroblasts was shown after hematoxylin staining and the production of major proteins normally found in the extracellular matrix was assessed by Western blotting of protein extracts. Finally, a skin substitute was generated by seeding human keratinocytes on the dermal equivalent and a new epidermis was characterized by using immuno-histological staining. Results show that gamma sterilization and that degradation under conditions that mimic skin wound healing were acceptable. The fact that fibroblasts produce extracellular matrix and that keratinocytes generated an epidermal barrier argues in favour of the interest of this type of porous scaffold for skin reconstruction. PMID:21888762

  10. IL-13 from intraepithelial lymphocytes regulates tissue homeostasis and protects against carcinogenesis in the skin.

    PubMed

    Dalessandri, Tim; Crawford, Greg; Hayes, Mark; Castro Seoane, Rocio; Strid, Jessica

    2016-01-01

    The skin is under constant renewal and exposure to environmental challenges. How homeostasis is maintained alongside protective mechanisms against damage is unclear. Among the basal epithelial cells (ECs) is a population of resident intraepithelial lymphocytes (IELs) that provide host-protective immune surveillance. Here we show that IELs cross-communicate with ECs via the production of IL-13. Skin ECs are activated by IEL-derived IL-13, enabling a canonical EC stress response. In the absence of IL-13, or canonical IEL, the skin has decreased ability to repair its barrier and increased susceptibility to cutaneous carcinogenesis. IL-13 controls the rate of EC movement through the epidermis, which might explain the importance of IL-13 for epidermal integrity and its suppressive effect on skin carcinogenesis. These findings show that IL-13 acts as a molecular bridge between IELs and ECs, and reveal a critical host-defensive role for type-2 immunity in regulating EC tissue homeostasis and carcinogenesis. PMID:27357235

  11. IL-13 from intraepithelial lymphocytes regulates tissue homeostasis and protects against carcinogenesis in the skin

    PubMed Central

    Dalessandri, Tim; Crawford, Greg; Hayes, Mark; Castro Seoane, Rocio; Strid, Jessica

    2016-01-01

    The skin is under constant renewal and exposure to environmental challenges. How homeostasis is maintained alongside protective mechanisms against damage is unclear. Among the basal epithelial cells (ECs) is a population of resident intraepithelial lymphocytes (IELs) that provide host-protective immune surveillance. Here we show that IELs cross-communicate with ECs via the production of IL-13. Skin ECs are activated by IEL-derived IL-13, enabling a canonical EC stress response. In the absence of IL-13, or canonical IEL, the skin has decreased ability to repair its barrier and increased susceptibility to cutaneous carcinogenesis. IL-13 controls the rate of EC movement through the epidermis, which might explain the importance of IL-13 for epidermal integrity and its suppressive effect on skin carcinogenesis. These findings show that IL-13 acts as a molecular bridge between IELs and ECs, and reveal a critical host-defensive role for type-2 immunity in regulating EC tissue homeostasis and carcinogenesis. PMID:27357235

  12. Chitosan as a Modifying Component of Artificial Scaffold for Human Skin Tissue Engineering.

    PubMed

    Romanova, O A; Grigor'ev, T E; Goncharov, M E; Rudyak, S G; Solov'yova, E V; Krasheninnikov, S T; Saprykin, V P; Sytina, E V; Chvalun, S N; Pal'tsev, M A; Panteleev, A A

    2015-08-01

    We compared the structure and mechanical properties of scaffolds based on pure collagen, pure chitosan, and a mixture of these polymers. The role of the composition and structure of scaffolds in the maintenance of cell functions (proliferation, differentiation, and migration) was demonstrated in two experimental models: homogeneous tissue analogues (scaffold populated by fibroblasts) and complex skin equivalents (fibroblasts and keratinocytes). In contrast to collagen scaffolds, pure chitosan inhibited the growth of fibroblasts that did not form contacts with chitosan fibers, but formed specific cellular conglomerates, spheroids, and lose their ability to synthesize natural extracellular matrix. However, the use of chitosan as an additive stimulated proliferative activity of fibroblasts on collagen, which can be associated with improvement of mechanical properties of the collagen scaffolds. The effectiveness of chitosan as an additional cross-linking agent also manifested in its ability to improve significantly the resistance of collagen scaffolds to fibroblast contraction in comparison with glutaraldehyde treatment. Polymer scaffolds (without cells) accelerated complete healing of skin wounds in vivo irrespective of their composition healing, pure chitosan sponge being most effective. We concluded that the use of chitosan as the scaffold for skin equivalents populated with skin cells is impractical, whereas it can be an effective modifier of polymer scaffolds. PMID:26395628

  13. The potential applications of fibrin-coated electrospun polylactide nanofibers in skin tissue engineering

    PubMed Central

    Bacakova, Marketa; Musilkova, Jana; Riedel, Tomas; Stranska, Denisa; Brynda, Eduard; Zaloudkova, Margit; Bacakova, Lucie

    2016-01-01

    Fibrin plays an important role during wound healing and skin regeneration. It is often applied in clinical practice for treatment of skin injuries or as a component of skin substitutes. We prepared electrospun nanofibrous membranes made from poly(l-lactide) modified with a thin fibrin nanocoating. Fibrin surrounded the individual fibers in the membrane and also formed a thin fibrous mesh on several places on the membrane surface. The cell-free fibrin nanocoating remained stable in the cell culture medium for 14 days and did not change its morphology. On membranes populated with human dermal fibroblasts, the rate of fibrin degradation correlated with the degree of cell proliferation. The cell spreading, mitochondrial activity, and cell population density were significantly higher on membranes coated with fibrin than on nonmodified membranes, and this cell performance was further improved by the addition of ascorbic acid in the cell culture medium. Similarly, fibrin stimulated the expression and synthesis of collagen I in human dermal fibroblasts, and this effect was further enhanced by ascorbic acid. The expression of beta1-integrins was also improved by fibrin, and on pure polylactide membranes, it was slightly enhanced by ascorbic acid. In addition, ascorbic acid promoted deposition of collagen I in the form of a fibrous extracellular matrix. Thus, the combination of nanofibrous membranes with a fibrin nanocoating and ascorbic acid seems to be particularly advantageous for skin tissue engineering. PMID:26955273

  14. I. Microwave Apparatus for Exposing Tissue and the Effect of the Radiation on Skin Respiration

    PubMed Central

    Lawrence, J. C.

    1968-01-01

    An apparatus was designed which enabled small pieces of skin to be exposed to a uniform field of microwaves at χ-band (8,730 MHz). This was used to investigate the effect of these microwaves at selected energy levels on the metabolism of skin. It was shown that skin cultured in vitro exhibited a graded response to microwave energy, and a doseresponse curve was constructed from this data. The ED50 of this curve was 4,740 mW./sq. cm. applied for 1 second. Microscopical examination of three-day cultures of skin showed that histological abnormalities occurred if the specimens were exposed to intensities of microwaves causing more than 30% respiratory damage. The energy level at the ED30 was 2,880 mW./sq. cm. applied for 1 second. Results were consistent with the hypothesis that tissue damage caused by irradiation with microwaves was due to the energy absorbed by the specimen being converted to heat. PMID:5663427

  15. Noninvasive assessment of skin iron content in hemodialysis patients. An index of parenchymal tissue iron content

    SciTech Connect

    Friedlaender, M.M.; Kaufman, B.; Rubinger, D.; Moreb, J.; Popovtzer, M.M.; Goredetsky, R.

    1988-07-01

    Iron overload has been described in patients undergoing chronic hemodialysis. The present study was undertaken to evaluate a rapid, noninvasive method for determination of skin iron by the technique of diagnostic x-ray spectrometry (DXS). Thirty-five patients receiving chronic hemodialysis treatment entered the study and were compared with 25 normal controls. Since pathological skin iron deposition occurs mainly at the dermal-epidermal junction in the basal cells of the epidermis, measurements were made in the thenar eminence representing mainly epidermal tissue (FeE), and in the forearm representative mainly of dermis (FeD). The mean +/- SD FeE iron concentrations were equivalent to 14.5 +/- 8.8 and 18.2 +/- 10.2 parts per million wet weight tissue (ppm) and both were significantly higher than in normal controls in which they averaged 9.2 +/- 2.5 ppm (P less than 0.005) and 10.2 +/- 3.2 ppm (P less than 0.001), respectively. There was significant positive correlation between individual skin iron determinations with the total number of blood transfusions received, the rate of blood transfusion, and with serum ferritin levels. Bone marrow hemosiderin was examined in six patients and showed a similar trend. Despite correlation only with indirect indices of tissue iron, our findings suggest that DXS may serve as a reliable quick method for noninvasive estimation of nonreticuloendothelial tissue iron deposition in hemodialysis patients suspected of having transfusional iron overload. The method may be valuable in monitoring the effects of chelation therapy.

  16. Effect of mechanical tissue properties on thermal damage in skin after IR-laser ablation

    NASA Astrophysics Data System (ADS)

    Frenz, M.; Mischler, Ch.; Romano, V.; Forrer, M.; Müller, O. M.; Weber, H. P.

    1991-04-01

    The damage created instantaneously in dorsal skin and in the subjacent skeletal muscle layer after CO2 and Er3+ laser incisions is histologically and ultrastructurally investigated. Light microscopical examinations show an up to three times larger damage zone in the subcutaneous layer of skeletal muscle than in the connective tissue above. The extent of thermally altered muscle tissue is classified by different zones and characterized by comparison to long time heating injuries. The unexpectedly large damage is a result of the change of elastic properties occurring abruptly at the transition between different materials. This leads to a discontinuity of the cutting dynamics that reduces the ejection of tissue material. We show that the degree of thermal damage originates from the amount of hot material that is not ejected out of the crater acting as a secondary heat source.

  17. Effect of tissue heterogeneity on an in vivo range verification technique for proton therapy.

    PubMed

    Bentefour, El Hassane; Shikui, Tang; Prieels, Damien; Lu, Hsiao-Ming

    2012-09-01

    It was proposed recently that time-resolved dose measurements during proton therapy treatment by passively scattered beams may be used for in vivo range verification. The method was shown to work accurately in a water tank. In this paper, we further evaluated the potential of the method for more clinically relevant situations where proton beams must pass through regions with significant tissue heterogeneities. Specifically, we considered prostate treatment where the use of anterior or anterior- oblique fields was recently proposed in order to reduce rectal dose by taking advantage of the sharp distal fall-off of the Bragg peak. These beam portals pass through various parts of pubic bone and potential air cavities in the bladder and bowels. Using blocks of materials with densities equivalent to bone, air, etc, arranged in the water tank in relevant configurations, we tested the robustness of the method against range shifting and range mixing. In the former, the beam range is changed uniformly by changes in tissue density in the beam path, while in the latter, variations in tissue heterogeneities across the beam cross section causes the mixing of beam energies downstream, as often occurs when the beam travels along the interface of materials with significantly different densities. We demonstrated that in the region of interest, the method can measure water-equivalent path length with accuracy better than ±0.5 mm for pure range shifting and still reasonable accuracy for range mixing between close beam energies. In situations with range mixing between significantly different beam energies, the dose rate profiles may be simulated for verifying the beam range. We also found that the above performances can be obtained with very small amount of dose (<0.5 cGy), if silicon diodes are used as detectors. This makes the method suitable for in vivo range verification prior to each treatment delivery. PMID:22864304

  18. Suspended, Shrinkage-Free, Electrospun PLGA Nanofibrous Scaffold for Skin Tissue Engineering.

    PubMed

    Ru, Changhai; Wang, Feilong; Pang, Ming; Sun, Lining; Chen, Ruihua; Sun, Yu

    2015-05-27

    Electrospinning is a technique for creating continuous nanofibrous networks that can architecturally be similar to the structure of extracellular matrix (ECM). However, the shrinkage of electrospun mats is unfavorable for the triggering of cell adhesion and further growth. In this work, electrospun PLGA nanofiber assemblies are utilized to create a scaffold. Aided by a polypropylene auxiliary supporter, the scaffold is able to maintain long-term integrity without dimensional shrinkage. This scaffold is also able to suspend in cell culture medium; hence, keratinocyte cells seeded on the scaffold are exposed to air as required in skin tissue engineering. Experiments also show that human skin keratinocytes can proliferate on the scaffold and infiltrate into the scaffold. PMID:25941905

  19. Cyclical cell stretching of skin-derived fibroblasts downregulates connective tissue growth factor (CTGF) production.

    PubMed

    Kanazawa, Yuichiro; Nomura, Jun; Yoshimoto, Shinya; Suzuki, Toshikazu; Kita, Kazuko; Suzuki, Nobuo; Ichinose, Masaharu

    2009-01-01

    Delayed healing of skin wounds can be caused by wound instability, whereas appropriate massage or exercise prevents sclerosis and scar contracture. However, the mechanism by which wound healing is related to mechanical stress has not been fully elucidated. The present study aimed to identify whether mechanical stretching of fibroblasts reduces their production of extracellular matrix. We transferred skin fibroblasts into collagen-coated elastic silicone chambers, cultured them on a stretching apparatus, and used RT-PCR to examine the effects of mechanical stretching on the expression levels of 17 genes related to extracellular matrix production and growth factor secretion. We found that connective tissue growth factor (CTGF) was downregulated after 24 hr of cell stretching. Specifically, the CTGF mRNA and protein levels were 50% and 48% of the control levels, respectively. These findings suggest that cyclic stretching of fibroblasts contributes to anti-fibrotic processes by reducing CTGF production.

  20. Suspended, Shrinkage-Free, Electrospun PLGA Nanofibrous Scaffold for Skin Tissue Engineering.

    PubMed

    Ru, Changhai; Wang, Feilong; Pang, Ming; Sun, Lining; Chen, Ruihua; Sun, Yu

    2015-05-27

    Electrospinning is a technique for creating continuous nanofibrous networks that can architecturally be similar to the structure of extracellular matrix (ECM). However, the shrinkage of electrospun mats is unfavorable for the triggering of cell adhesion and further growth. In this work, electrospun PLGA nanofiber assemblies are utilized to create a scaffold. Aided by a polypropylene auxiliary supporter, the scaffold is able to maintain long-term integrity without dimensional shrinkage. This scaffold is also able to suspend in cell culture medium; hence, keratinocyte cells seeded on the scaffold are exposed to air as required in skin tissue engineering. Experiments also show that human skin keratinocytes can proliferate on the scaffold and infiltrate into the scaffold.

  1. Expanding the clinical and genetic heterogeneity of hereditary disorders of connective tissue.

    PubMed

    Alazami, Anas M; Al-Qattan, Sarah M; Faqeih, Eissa; Alhashem, Amal; Alshammari, Muneera; Alzahrani, Fatema; Al-Dosari, Mohammed S; Patel, Nisha; Alsagheir, Afaf; Binabbas, Bassam; Alzaidan, Hamad; Alsiddiky, Abdulmonem; Alharbi, Nasser; Alfadhel, Majid; Kentab, Amal; Daza, Riza M; Kircher, Martin; Shendure, Jay; Hashem, Mais; Alshahrani, Saif; Rahbeeni, Zuhair; Khalifa, Ola; Shaheen, Ranad; Alkuraya, Fowzan S

    2016-05-01

    Ehlers-Danlos syndrome (EDS) describes a group of clinical entities in which the connective tissue, primarily that of the skin, joint and vessels, is abnormal, although the resulting clinical manifestations can vary widely between the different historical subtypes. Many cases of hereditary disorders of connective tissue that do not seem to fit these historical subtypes exist. The aim of this study is to describe a large series of patients with inherited connective tissue disorders evaluated by our clinical genetics service and for whom a likely causal variant was identified. In addition to clinical phenotyping, patients underwent various genetic tests including molecular karyotyping, candidate gene analysis, autozygome analysis, and whole-exome and whole-genome sequencing as appropriate. We describe a cohort of 69 individuals representing 40 families, all referred because of suspicion of an inherited connective tissue disorder by their primary physician. Molecular lesions included variants in the previously published disease genes B3GALT6, GORAB, ZNF469, B3GAT3, ALDH18A1, FKBP14, PYCR1, CHST14 and SPARC with interesting variations on the published clinical phenotypes. We also describe the first recessive EDS-like condition to be caused by a recessive COL1A1 variant. In addition, exome capture in a familial case identified a homozygous truncating variant in a novel and compelling candidate gene, AEBP1. Finally, we also describe a distinct novel clinical syndrome of cutis laxa and marked facial features and propose ATP6V1E1 and ATP6V0D2 (two subunits of vacuolar ATPase) as likely candidate genes based on whole-genome and whole-exome sequencing of the two families with this new clinical entity. Our study expands the clinical spectrum of hereditary disorders of connective tissue and adds three novel candidate genes including two that are associated with a highly distinct syndrome.

  2. Expanding the clinical and genetic heterogeneity of hereditary disorders of connective tissue.

    PubMed

    Alazami, Anas M; Al-Qattan, Sarah M; Faqeih, Eissa; Alhashem, Amal; Alshammari, Muneera; Alzahrani, Fatema; Al-Dosari, Mohammed S; Patel, Nisha; Alsagheir, Afaf; Binabbas, Bassam; Alzaidan, Hamad; Alsiddiky, Abdulmonem; Alharbi, Nasser; Alfadhel, Majid; Kentab, Amal; Daza, Riza M; Kircher, Martin; Shendure, Jay; Hashem, Mais; Alshahrani, Saif; Rahbeeni, Zuhair; Khalifa, Ola; Shaheen, Ranad; Alkuraya, Fowzan S

    2016-05-01

    Ehlers-Danlos syndrome (EDS) describes a group of clinical entities in which the connective tissue, primarily that of the skin, joint and vessels, is abnormal, although the resulting clinical manifestations can vary widely between the different historical subtypes. Many cases of hereditary disorders of connective tissue that do not seem to fit these historical subtypes exist. The aim of this study is to describe a large series of patients with inherited connective tissue disorders evaluated by our clinical genetics service and for whom a likely causal variant was identified. In addition to clinical phenotyping, patients underwent various genetic tests including molecular karyotyping, candidate gene analysis, autozygome analysis, and whole-exome and whole-genome sequencing as appropriate. We describe a cohort of 69 individuals representing 40 families, all referred because of suspicion of an inherited connective tissue disorder by their primary physician. Molecular lesions included variants in the previously published disease genes B3GALT6, GORAB, ZNF469, B3GAT3, ALDH18A1, FKBP14, PYCR1, CHST14 and SPARC with interesting variations on the published clinical phenotypes. We also describe the first recessive EDS-like condition to be caused by a recessive COL1A1 variant. In addition, exome capture in a familial case identified a homozygous truncating variant in a novel and compelling candidate gene, AEBP1. Finally, we also describe a distinct novel clinical syndrome of cutis laxa and marked facial features and propose ATP6V1E1 and ATP6V0D2 (two subunits of vacuolar ATPase) as likely candidate genes based on whole-genome and whole-exome sequencing of the two families with this new clinical entity. Our study expands the clinical spectrum of hereditary disorders of connective tissue and adds three novel candidate genes including two that are associated with a highly distinct syndrome. PMID:27023906

  3. Tissue repair genes: the TiRe database and its implication for skin wound healing

    PubMed Central

    Yanai, Hagai; Budovsky, Arie; Tacutu, Robi; Barzilay, Thomer; Abramovich, Amir; Ziesche, Rolf; Fraifeld, Vadim E.

    2016-01-01

    Wound healing is an inherent feature of any multicellular organism and recent years have brought about a huge amount of data regarding regular and abnormal tissue repair. Despite the accumulated knowledge, modulation of wound healing is still a major biomedical challenge, especially in advanced ages. In order to collect and systematically organize what we know about the key players in wound healing, we created the TiRe (Tissue Repair) database, an online collection of genes and proteins that were shown to directly affect skin wound healing. To date, TiRe contains 397 entries for four organisms: Mus musculus, Rattus norvegicus, Sus domesticus, and Homo sapiens. Analysis of the TiRe dataset of skin wound healing-associated genes showed that skin wound healing genes are (i) over-conserved among vertebrates, but are under-conserved in invertebrates; (ii) enriched in extracellular and immuno-inflammatory genes; and display (iii) high interconnectivity and connectivity to other proteins. The latter may provide potential therapeutic targets. In addition, a slower or faster skin wound healing is indicative of an aging or longevity phenotype only when assessed in advanced ages, but not in the young. In the long run, we aim for TiRe to be a one-station resource that provides researchers and clinicians with the essential data needed for a better understanding of the mechanisms of wound healing, designing new experiments, and the development of new therapeutic strategies. TiRe is freely available online at http://www.tiredb.org. PMID:27049721

  4. Dystrophic amyloidosis: a local complication of tissue damage with heterogeneous distribution.

    PubMed

    Looi, L M

    1991-08-01

    Seventeen consecutive patients with dystrophic amyloidosis are reported here (eight Chinese, three Indian, three Iban, two Malay and one Caucasian). Ten were females and seven males, with ages ranging from 12 to 80 years (mean of 48 years). Five instances of dystrophic amyloidosis occurred in areas of tissue damage in the cardiovascular system, including fibrotic cardiac valves and an atheromatous plaque. Three occurred in osteoarthritic joint tissue. Of note were three occurrences in endometriotic cyst walls, four in the fibrotic walls of epidermal cysts, one in a hernial sac and one at the edge of a skin ulcer. All deposits were congophilic and exhibited green-birefringence and permanganate-resistance. Immunohistochemistry did not reveal reactivity for AA protein or immunoglobulin lambda or kappa light-chains. AP protein was detected in 35% of cases. Our results show that, besides the usual sites of osteoarthritic joints and damaged heart valves, dystrophic amyloidosis can complicate other areas of chronic tissue damage and fibrosis such as walls of cysts and ulcers. While the pathogenesis and biochemical nature remain unresolved, immunohistochemistry indicates that neither AA nor AL proteins are present in the deposits, and suggests that a different amyloid protein is involved. PMID:1757071

  5. Cellulose acetate based 3-dimensional electrospun scaffolds for skin tissue engineering applications.

    PubMed

    Atila, Deniz; Keskin, Dilek; Tezcaner, Ayşen

    2015-11-20

    Skin defects that are not able to regenerate by themselves are among the major problems faced. Tissue engineering approach holds promise for treating such defects. Development of tissue-mimicking-scaffolds that can promote healing process receives an increasing interest in recent years. In this study, 3-dimensional electrospun cellulose acetate (CA) pullulan (PULL) scaffolds were developed for the first time. PULL was intentionally used to obtain 3D structures with adjustable height. It was removed from the electrospun mesh to increase the porosity and biostability. Different ratios of the polymers were electrospun and analyzed with respect to degradation, porosity, and mechanical properties. It has been observed that fiber diameter, thickness and porosity of scaffolds increased with increased PULL content, on the other hand this resulted with higher degradation of scaffolds. Mechanical strength of scaffolds was improved after PULL removal suggesting their suitability as cell carriers. Cell culture studies were performed with the selected scaffold group (CA/PULL: 50/50) using mouse fibroblastic cell line (L929). In vitro cell culture tests showed that cells adhered, proliferated and populated CA/PULL (50/50) scaffolds showing that they are cytocompatible. Results suggest that uncrosslinked CA/PULL (50/50) electrospun scaffolds hold potential for skin tissue engineering applications. PMID:26344279

  6. Cellulose acetate based 3-dimensional electrospun scaffolds for skin tissue engineering applications.

    PubMed

    Atila, Deniz; Keskin, Dilek; Tezcaner, Ayşen

    2015-11-20

    Skin defects that are not able to regenerate by themselves are among the major problems faced. Tissue engineering approach holds promise for treating such defects. Development of tissue-mimicking-scaffolds that can promote healing process receives an increasing interest in recent years. In this study, 3-dimensional electrospun cellulose acetate (CA) pullulan (PULL) scaffolds were developed for the first time. PULL was intentionally used to obtain 3D structures with adjustable height. It was removed from the electrospun mesh to increase the porosity and biostability. Different ratios of the polymers were electrospun and analyzed with respect to degradation, porosity, and mechanical properties. It has been observed that fiber diameter, thickness and porosity of scaffolds increased with increased PULL content, on the other hand this resulted with higher degradation of scaffolds. Mechanical strength of scaffolds was improved after PULL removal suggesting their suitability as cell carriers. Cell culture studies were performed with the selected scaffold group (CA/PULL: 50/50) using mouse fibroblastic cell line (L929). In vitro cell culture tests showed that cells adhered, proliferated and populated CA/PULL (50/50) scaffolds showing that they are cytocompatible. Results suggest that uncrosslinked CA/PULL (50/50) electrospun scaffolds hold potential for skin tissue engineering applications.

  7. [First results with Integra artificial skin in the management of severe tissue defects in children].

    PubMed

    Vázquez Rueda, F; Ayala Montoro, J; Blanco López, F; Ocaña Losa, J M

    2001-07-01

    In extreme cases of tissue defects, wound coverage after excision may be problematic because of the limited existence of donor sites. An option for temporary wound coverage used in the management after early scar release is a dermal substitute: Integral artificial skin. The biosinthetic material consists of un upper silicone film and a lower layer of porous cross-linked bovine collagen and chondroitin-6-sulfate as a template for dermal regeneration after staged tangencial necrectomy. In the third and fourth weeks following application the silicone layer was easily removed and the newly formed neodermis covered with widely unmeshed thin split thickness autograft. We report 6 patients with tissue defects with open fractures in three cases, one hemorrhagic necrosis of the skin by meningococcemia who requiring amputations of all four extremities and two traumatic necrosis. Other patient has a retractil scar. All were treated with Integral and epidermical autograft. The good results with Integral regarding recovery may affect initial treatment and reconstruction planning after extensive wound injuries with tissue defects to obtain immediate wound closure.

  8. Functional heterogeneity of mast cells isolated from different microenvironments within nasal polyp tissue.

    PubMed Central

    Finotto, S; Dolovich, J; Denburg, J A; Jordana, M; Marshall, J S

    1994-01-01

    Nasal polyposis is a chronic inflammatory condition of the upper airways characterized by infiltration of activated inflammatory cells, including mast cells, both in the epithelium and in the stroma. The aim of this work was to study human mast cells derived from two different anatomical sites within the same nasal polyp tissue. To this end, we isolated two distinct mast cell populations, one from the epithelial and the other from the stromal layers of individual human nasal polyp tissues. We examined the mediator content of the two mast cell populations and found that stromal mast cells had a significantly higher content of tryptase compared with the epithelial mast cells from the same tissue. In addition, mast cells from the stromal compartment, but not those from the epithelium, released a significant amount of histamine after anti-IgE stimulation. By contrast, both populations released over 50% of the total histamine after non-specific stimuli (A23187 10(-6) M). The content of mediators and the response to immunological activation were not significantly altered in patients receiving topical steroid therapy. It remains to be determined if the observed differences are the result of an intrinsic characteristic of the mast cell populations localized to separate tissue compartments, or reflect a different in vivo exposure to stimuli such as antigens, or different surrounding structural or infiltrating cells. In conclusion, these data provide evidence of functional heterogeneity and differences in mediator content between mast cell subpopulations from a single human tissue. The failure of release of epithelial mast cell mediators from an immunologic stimulus may have implications concerning acute effects of antigen exposure in nasal polyposis. Images Fig. 1 PMID:7508349

  9. Granulomatous slack skin T-cell lymphoma: an important differential diagnosis with giant cell tumor of soft tissue.

    PubMed

    Adriano, André Ricardo; Lima, Tiago Silveira; Battistella, Maxime; Bagot, Martine

    2015-01-01

    Granulomatous slack skin is an indolent T-cell lymphoma, considered to be a variant of mycosis fungoides. Clinically it is characterized by areas of redundant skin, wrinkled, inelastic, with variable erythema and infiltration besides a poikilodermic surface. A differential diagnosis unknown to most dermatologists is the giant cell tumor of soft tissue, which is an extremely rare low-grade sarcoma. The authors report a patient who had undergone extensive surgery because of a primary diagnosis of giant cell tumor of soft tissue, but which proved to be granulomatous slack skin after a second interventional procedure with confirmatory histopathology. PMID:26734874

  10. Granulomatous slack skin T-cell lymphoma: an important differential diagnosis with giant cell tumor of soft tissue*

    PubMed Central

    Adriano, André Ricardo; Lima, Tiago Silveira; Battistella, Maxime; Bagot, Martine

    2015-01-01

    Granulomatous slack skin is an indolent T-cell lymphoma, considered to be a variant of mycosis fungoides. Clinically it is characterized by areas of redundant skin, wrinkled, inelastic, with variable erythema and infiltration besides a poikilodermic surface. A differential diagnosis unknown to most dermatologists is the giant cell tumor of soft tissue, which is an extremely rare low-grade sarcoma. The authors report a patient who had undergone extensive surgery because of a primary diagnosis of giant cell tumor of soft tissue, but which proved to be granulomatous slack skin after a second interventional procedure with confirmatory histopathology. PMID:26734874

  11. Large Scale Tissue Morphogenesis Simulation on Heterogenous Systems Based on a Flexible Biomechanical Cell Model.

    PubMed

    Jeannin-Girardon, Anne; Ballet, Pascal; Rodin, Vincent

    2015-01-01

    The complexity of biological tissue morphogenesis makes in silico simulations of such system very interesting in order to gain a better understanding of the underlying mechanisms ruling the development of multicellular tissues. This complexity is mainly due to two elements: firstly, biological tissues comprise a large amount of cells; secondly, these cells exhibit complex interactions and behaviors. To address these two issues, we propose two tools: the first one is a virtual cell model that comprise two main elements: firstly, a mechanical structure (membrane, cytoskeleton, and cortex) and secondly, the main behaviors exhibited by biological cells, i.e., mitosis, growth, differentiation, molecule consumption, and production as well as the consideration of the physical constraints issued from the environment. An artificial chemistry is also included in the model. This virtual cell model is coupled to an agent-based formalism. The second tool is a simulator that relies on the OpenCL framework. It allows efficient parallel simulations on heterogenous devices such as micro-processors or graphics processors. We present two case studies validating the implementation of our model in our simulator: cellular proliferation controlled by cell signalling and limb growth in a virtual organism. PMID:26451816

  12. Large Scale Tissue Morphogenesis Simulation on Heterogenous Systems Based on a Flexible Biomechanical Cell Model.

    PubMed

    Jeannin-Girardon, Anne; Ballet, Pascal; Rodin, Vincent

    2015-01-01

    The complexity of biological tissue morphogenesis makes in silico simulations of such system very interesting in order to gain a better understanding of the underlying mechanisms ruling the development of multicellular tissues. This complexity is mainly due to two elements: firstly, biological tissues comprise a large amount of cells; secondly, these cells exhibit complex interactions and behaviors. To address these two issues, we propose two tools: the first one is a virtual cell model that comprise two main elements: firstly, a mechanical structure (membrane, cytoskeleton, and cortex) and secondly, the main behaviors exhibited by biological cells, i.e., mitosis, growth, differentiation, molecule consumption, and production as well as the consideration of the physical constraints issued from the environment. An artificial chemistry is also included in the model. This virtual cell model is coupled to an agent-based formalism. The second tool is a simulator that relies on the OpenCL framework. It allows efficient parallel simulations on heterogenous devices such as micro-processors or graphics processors. We present two case studies validating the implementation of our model in our simulator: cellular proliferation controlled by cell signalling and limb growth in a virtual organism.

  13. Heterogeneity and stochastic growth regulation of biliary epithelial cells dictate dynamic epithelial tissue remodeling

    PubMed Central

    Kamimoto, Kenji; Kaneko, Kota; Kok, Cindy Yuet-Yin; Okada, Hajime; Miyajima, Atsushi; Itoh, Tohru

    2016-01-01

    Dynamic remodeling of the intrahepatic biliary epithelial tissue plays key roles in liver regeneration, yet the cellular basis for this process remains unclear. We took an unbiased approach based on in vivo clonal labeling and tracking of biliary epithelial cells in the three-dimensional landscape, in combination with mathematical simulation, to understand their mode of proliferation in a mouse liver injury model where the nascent biliary structure formed in a tissue-intrinsic manner. An apparent heterogeneity among biliary epithelial cells was observed: whereas most of the responders that entered the cell cycle upon injury exhibited a limited and tapering growth potential, a select population continued to proliferate, making a major contribution in sustaining the biliary expansion. Our study has highlighted a unique mode of epithelial tissue dynamics, which depends not on a hierarchical system driven by fixated stem cells, but rather, on a stochastically maintained progenitor population with persistent proliferative activity. DOI: http://dx.doi.org/10.7554/eLife.15034.001 PMID:27431614

  14. [Regenerative medicine: stem cells, cellular and matricial interactions in the reconstruction of skin and cornea by tissue engineering].

    PubMed

    Larouche, D; Lavoie, A; Proulx, S; Paquet, C; Carrier, P; Beauparlant, A; Auger, F A; Germain, L

    2009-06-01

    Considering that there is a shortage of organ donor, the aim of tissue engineering is to develop substitutes for the replacement of wounded or diseased tissues. Autologous tissue is evidently a preferable transplant material for long-term graft persistence because of the unavoidable rejection reaction occuring against allogeneic transplant. For the production of such substitutes, it is essential to control the culture conditions for post-natal human stem cells. Furthermore, histological organization and functionality of reconstructed tissues must approach those of native organs. For self-renewing tissues such as skin and cornea, tissue engineering strategies must include the preservation of stem cells during the in vitro process as well as after grafting to ensure the long-term regeneration of the transplants. We described a tissue engineering method named the self-assembly approach allowing the production of autologous living organs from human cells without any exogenous biomaterial. This approach is based on the capacity of mesenchymal cells to create in vitro their own extracellular matrix and then reform a tissue. Thereafter, various techniques allow the reorganization of such tissues in more complex organ such as valve leaflets, blood vessels, skin or cornea. These tissues offer the hope of new alternatives for organ transplantation in the future. In this review, the importance of preserving stem cells during in vitro expansion and controlling cell differentiation as well as tissue organization to ensure quality and functionality of tissue-engineered organs will be discussed, while focusing on skin and cornea. PMID:18513892

  15. Crosslinked hydrogels based on biological macromolecules with potential use in skin tissue engineering.

    PubMed

    Vulpe, Raluca; Popa, Marcel; Picton, Luc; Balan, Vera; Dulong, Virginie; Butnaru, Maria; Verestiuc, Liliana

    2016-03-01

    Zero-length crosslinked hydrogels have been synthesized by covalent linking of three natural polymers (collagen, hyaluronic acid and sericin), in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. The hydrogels have been investigated by FT-IR spectroscopy, microcalorimetry, in vitro swelling, enzymatic degradation, and in vitro cell viability studies. The obtained crosslinked hydrogels showed a macroporous structure, high swelling degree and in vitro enzymatic resistance compared to uncrosslinked collagen. The in vitro cell viability studies performed on normal human dermal fibroblasts assessed the sericin proliferation properties indicating a potential use of the hydrogels based on collagen, hyaluronic acid and sericin in skin tissue engineering.

  16. Assessment of Breast, Brain and Skin Pathological Tissue Using Full Field OCM

    NASA Astrophysics Data System (ADS)

    Dalimier, Eugénie; Assayag, Osnath; Harms, Fabrice; Boccara, A. Claude

    The aim of this chapter is to assess whether the images of the breast, brain, and skin tissue obtained by FFOCM contain sufficient detail to allow pathologists to make a diagnosis of cancer and other pathologies comparable to what was obtained by conventional histological techniques. More precisely, it is necessary to verify on FFOCM images if it is possible to differentiate a healthy area from a pathological area. The reader interested in other organs or in animal studies may find a large number of 2D or 3D images in the atlas [2].

  17. Tumor Hypoxia: Causative Mechanisms, Microregional Heterogeneities, and the Role of Tissue-Based Hypoxia Markers.

    PubMed

    Vaupel, Peter; Mayer, Arnulf

    2016-01-01

    Tumor hypoxia is a hallmark of solid malignant tumor growth, profoundly influences malignant progression and contributes to the development of therapeutic resistance. Pathogenesis of tumor hypoxia is multifactorial, with contributions from both acute and chronic factors. Spatial distribution of hypoxia within tumors is markedly heterogeneous and often changes over time, e.g., during a course of radiotherapy. Substantial changes in the oxygenation status can occur within the distance of a few cell layers, explaining the inability of currently used molecular imaging techniques to adequately assess this crucial trait. Due to the possible importance of tumor hypoxia for clinical decision-making, there is a great demand for molecular tools which may provide the necessary resolution down to the single cell level. Exogenous and endogenous markers of tumor hypoxia have been investigated for this purpose. Their potential use may be greatly enhanced by multiparametric in situ methods in experimental and human tumor tissue. PMID:27526128

  18. Association of cervical artery dissection with connective tissue abnormalities in skin and arteries.

    PubMed

    Brandt, T; Morcher, M; Hausser, I

    2005-01-01

    Spontaneous cervical artery dissections (sCAD) often occur in otherwise healthy individuals without known risk factors for stroke and frequently develop spontaneously without relevant trauma. An underlying arteriopathy leading to a so-called 'weakness of the vessel wall' and predisposing certain individuals to dissection has often been postulated. Therefore, the morphology of connective tissue, a main component of vessel wall and environment, was investigated in carotids and skin. While the overall morphology of dermal connective tissue is normal, about half of patients with sCAD show mild ultrastructural connective tissue alterations. These ultrastructural morphological aberrations can be designated either as 'Ehlers-Danlos syndrome (EDS) III-like', resembling mild findings in patients with the hypermobility type of EDS (EDS III); or coined 'EDS IV-like' with collagen fibers containing fibrils with highly variable diameters resembling mild findings in vascular EDS; or the abnormalities are restricted to the elastic fibers (with fragmentation and minicalcifications) without significant alterations in the morphology of the collagen fibrils. These findings had some similarity with the morphology found in heterozygous carriers of pseudoxanthoma elasticum. A grading scale according to the severity of the findings has been introduced. Similar connective tissue abnormalities were detected in some first-degree relatives of patients with sCAD showing hereditary at least in a subgroup. They can serve as a phenotypic marker for further genetic studies in patients with sCAD and large families to possibly identify the underlying basic molecular defect(s). Very few of patients (<5%) with sCAD and connective tissue abnormalities have clinical manifestations of skin, joint, or skeletal abnormalities of a defined heritable connective tissue disorder. In specimens of arterial walls of carotid, aortic, and renal arteries of patients with sCAD, pronounced systemic, histopathological

  19. A heterogeneous human tissue mimicking phantom for RF heating and MRI thermal monitoring verification

    PubMed Central

    Yuan, Yu; Wyatt, Cory; Maccarini, Paolo; Stauffer, Paul; Craciunescu, Oana; MacFall, James; Dewhirst, Mark; Das, Shiva K.

    2013-01-01

    This paper describes a heterogeneous phantom that mimics a human thigh with a deep seated tumor, for the purpose of studying the performance of radiofrequency (RF) heating equipment and non-invasive temperature monitoring with magnetic resonance imaging (MRI). The heterogeneous cylindrical phantom was constructed with an outer fat layer surrounding an inner core of phantom material mimicking muscle, tumor and marrow-filled bone. The component materials were formulated to have dielectric and thermal properties similar to human tissues. The dielectric properties of the tissue-mimicking phantom materials were measured with a microwave vector network analyzer and impedance probe over the frequency range of 80 – 500 MHz and at temperatures of 24°C, 37°C, and 45°C. The specific heat values of the component materials were measured using a differential scanning calorimeter over the temperature range of 15 – 55°C. The thermal conductivity value was obtained from fitting the curves obtained from one-dimensional heat transfer measurement. The phantom was used to verify the operation of a cylindrical 4-antenna annular phased array extremity applicator (140 MHz), by examining the proton resonance frequency shift (PRFS) thermal imaging patterns for various magnitude/phase settings (including settings to focus heating in tumor). For muscle and tumor materials, MR imaging was also used to measure T1/T2* values (1.5 Tesla) and to obtain the slope of the PRFS phase change vs. temperature change curve. The dielectric and thermal properties of the phantom materials were in close agreement to well-accepted published results for human tissues. The phantom was able to successfully demonstrate satisfactory operation of the tested heating equipment. The MRI-measured thermal distributions matched the expected patterns for various magnitude/phase settings of the applicator, allowing the phantom to be used as a quality assurance tool. Importantly, the material formulations for the

  20. A Molecular Clock Infers Heterogeneous Tissue Age Among Patients with Barrett’s Esophagus

    PubMed Central

    Wong, Chao-Jen; Hazelton, William D.; Kaz, Andrew M.; Willis, Joseph E.; Grady, William M.; Luebeck, E. Georg

    2016-01-01

    Biomarkers that drift differentially with age between normal and premalignant tissues, such as Barrett’s esophagus (BE), have the potential to improve the assessment of a patient’s cancer risk by providing quantitative information about how long a patient has lived with the precursor (i.e., dwell time). In the case of BE, which is a metaplastic precursor to esophageal adenocarcinoma (EAC), such biomarkers would be particularly useful because EAC risk may change with BE dwell time and it is generally not known how long a patient has lived with BE when a patient is first diagnosed with this condition. In this study we first describe a statistical analysis of DNA methylation data (both cross-sectional and longitudinal) derived from tissue samples from 50 BE patients to identify and validate a set of 67 CpG dinucleotides in 51 CpG islands that undergo age-related methylomic drift. Next, we describe how this information can be used to estimate a patient’s BE dwell time. We introduce a Bayesian model that incorporates longitudinal methylomic drift rates, patient age, and methylation data from individually paired BE and normal squamous tissue samples to estimate patient-specific BE onset times. Our application of the model to 30 sporadic BE patients’ methylomic profiles first exposes a wide heterogeneity in patient-specific BE onset times. Furthermore, independent application of this method to a cohort of 22 familial BE (FBE) patients reveals significantly earlier mean BE onset times. Our analysis supports the conjecture that differential methylomic drift occurs in BE (relative to normal squamous tissue) and hence allows quantitative estimation of the time that a BE patient has lived with BE. PMID:27168458

  1. A Molecular Clock Infers Heterogeneous Tissue Age Among Patients with Barrett's Esophagus.

    PubMed

    Curtius, Kit; Wong, Chao-Jen; Hazelton, William D; Kaz, Andrew M; Chak, Amitabh; Willis, Joseph E; Grady, William M; Luebeck, E Georg

    2016-05-01

    Biomarkers that drift differentially with age between normal and premalignant tissues, such as Barrett's esophagus (BE), have the potential to improve the assessment of a patient's cancer risk by providing quantitative information about how long a patient has lived with the precursor (i.e., dwell time). In the case of BE, which is a metaplastic precursor to esophageal adenocarcinoma (EAC), such biomarkers would be particularly useful because EAC risk may change with BE dwell time and it is generally not known how long a patient has lived with BE when a patient is first diagnosed with this condition. In this study we first describe a statistical analysis of DNA methylation data (both cross-sectional and longitudinal) derived from tissue samples from 50 BE patients to identify and validate a set of 67 CpG dinucleotides in 51 CpG islands that undergo age-related methylomic drift. Next, we describe how this information can be used to estimate a patient's BE dwell time. We introduce a Bayesian model that incorporates longitudinal methylomic drift rates, patient age, and methylation data from individually paired BE and normal squamous tissue samples to estimate patient-specific BE onset times. Our application of the model to 30 sporadic BE patients' methylomic profiles first exposes a wide heterogeneity in patient-specific BE onset times. Furthermore, independent application of this method to a cohort of 22 familial BE (FBE) patients reveals significantly earlier mean BE onset times. Our analysis supports the conjecture that differential methylomic drift occurs in BE (relative to normal squamous tissue) and hence allows quantitative estimation of the time that a BE patient has lived with BE.

  2. Effect of microwaves at X-band on guinea-pig skin in tissue culture: 3. Effect of pulsed microwaves on skin respiration and biochemistry

    PubMed Central

    Carney, S. A.; Lawrence, J. C.; Ricketts, C. R.

    1970-01-01

    Carney, S. A., Lawrence, J. C., and Ricketts, C. R. (1970).Brit. J. industr. Med.,27, 72-76. Effect of microwaves at X-band on guinea-pig skin in tissue culture. 3. Effect of pulsed microwaves on skin respiration and biochemistry. Small pieces of guinea-pig skin were exposed to known power densities of pulsed microwaves at X-band (9·6 GHz). The pulse duration was 0·25 microsecond and the pulse repetition frequency 4 KHz. The peak power was thus 1,000 times the mean power. Otherwise conditions were closely comparable with those of previous experiments using continuous microwaves. After exposure the skin was maintained on a nutrient medium in vitro. The respiration of the skin and the uptake of 35S-sulphate, 32P-phosphate, and 14C-L-proline into skin constituents were reduced by exposure. The reduction was very similar to that observed after exposure to the same mean power density of continuous microwaves. The effects are believed to be attributable to heating of the skin. PMID:5418922

  3. Biological effects of hyaluronan in connective tissues, eye, skin, venous wall. Role in aging.

    PubMed

    Robert, L; Robert, A-M; Renard, G

    2010-06-01

    Hyaluronan, as most macromolecules of the extracellular matrix, are produced by the differentiated mesenchymal cells. These cells produce also enzymes degrading hyaluronan. This results in the presence of several hyaluronan pools of different molecular weights, all capable of interacting with surrounding cells, mediated by hyaluronan binding proteins and receptors. These interactions modulate cell phenotype and produce a variety of effects conditioning the specific functions of tissues. We shall discuss here several examples studied in our laboratory, concerning skin, cornea and the venous wall. Some of these actions might even be harmful, and could play an important role in aging of connective tissues with loss of function. Some of these age-dependent modifications mediated by hyaluronan will be reviewed and commented, especially the upregulation of matrix degrading enzymes as MMP-2 and MMP-9. We shall also mention some of our experiments for finding molecules capable of counteracting the harmful effects mediated by hyaluronan.

  4. Tissue characterization of skin ulcer for bacterial infection by multiple statistical analysis of echo amplitude envelope

    NASA Astrophysics Data System (ADS)

    Omura, Masaaki; Yoshida, Kenji; Kohta, Masushi; Kubo, Takabumi; Ishiguro, Toshimichi; Kobayashi, Kazuto; Hozumi, Naohiro; Yamaguchi, Tadashi

    2016-07-01

    To characterize skin ulcers for bacterial infection, quantitative ultrasound (QUS) parameters were estimated by the multiple statistical analysis of the echo amplitude envelope based on both Weibull and generalized gamma distributions and the ratio of mean to standard deviation of the echo amplitude envelope. Measurement objects were three rat models (noninfection, critical colonization, and infection models). Ultrasound data were acquired using a modified ultrasonic diagnosis system with a center frequency of 11 MHz. In parallel, histopathological images and two-dimensional map of speed of sound (SoS) were observed. It was possible to detect typical tissue characteristics such as infection by focusing on the relationship of QUS parameters and to indicate the characteristic differences that were consistent with the scatterer structure. Additionally, the histopathological characteristics and SoS of noninfected and infected tissues were matched to the characteristics of QUS parameters in each rat model.

  5. Automatic Segmentation of Cell Nuclei in Bladder and Skin Tissue for Karyometric Analysis

    PubMed Central

    Korde, Vrushali R.; Bartels, Hubert; Barton, Jennifer; Ranger-Moore, James

    2010-01-01

    Objective To automatically segment cell nuclei in histology images of bladder and skin tissue for karyometric analysis. Study Design The four main steps in the program were as follows: median filtering and thresholding, segmentation, categorizing, and cusp correction. This robust segmentation technique used properties of the image histogram to optimally select a threshold and create closed four-way chain code nuclear segmentations. Each cell nucleus segmentation was treated as an individual object whose properties of segmentation quality were used for criteria to classify each nucleus as: throw away, salvageable, or good. An erosion/dilation procedure and re-thresholding were performed on salvageable nuclei to correct cusps. Results Ten bladder histology images were segmented both by hand and using this automatic segmentation algorithm. The automatic segmentation resulted in a sensitivity of 76.4%, defined as the percentage of hand segmented nuclei that were automatically segmented with good quality. The median proportional difference between hand and automatic segmentations over 42 nuclei each with 95 features used in karyometric analysis was 1.6%. The same procedure was performed on 10 skin histology images with a sensitivity of 83.0% and median proportional difference of 2.6%. Conclusion The close agreement in karyometric features with hand segmentation shows that automated segmentation can be used for analysis of bladder and skin histology images. PMID:19402384

  6. An in-vitro investigation of skin tissue soldering using gold nanoshells and diode laser.

    PubMed

    Nourbakhsh, Mohammad S; Khosroshahi, Mohammad E

    2011-01-01

    Gold-coated silica core nanoparticles have an optical response dictated by the plasmon resonance (PR). The wavelength at which the resonance occurs depends on the core and shell size, allowing nanoshells to be tailored for particular applications. The purpose of this study is to synthesize and use different concentrations of gold nanoshells as exogenous material for in-vitro skin tissue soldering and also to examine the effect of laser-soldering parameters on the properties of repaired skin. Two mixtures of albumin solder and different concentrations of gold nanoshells were prepared. A full-thickness incision of 2 × 20 mm(2) was made on the surface and after addition of mixtures it was irradiated by an 810-nm diode laser at different power densities. The changes of tensile strength σ(t) due to temperature rise, number of scan (N(s)), and scan velocity (V(s)) were investigated. The results showed at constant laser power density (I), σ(t) of repaired incisions increases by increasing the concentration of gold nanoshells, N(s) and decreasing V(s). It is therefore important to consider the trade-off between the scan velocity and the skin temperature for achieving an optimum operating condition. In our case, this corresponds to σ(t) = 1,610 g/cm(2) at I ∼ 60 Wcm(-2), T ∼ 65°C, Ns = 10 and Vs = 0.2 mms(-1). PMID:20623244

  7. Histological and Ultrastructural Effects of Ultrasound-induced Cavitation on Human Skin Adipose Tissue

    PubMed Central

    Li, Alessandro Quattrini; Freschi, Giancarlo; Russo, Giulia Lo

    2013-01-01

    Background: In aesthetic medicine, the most promising techniques for noninvasive body sculpturing purposes are based on ultrasound-induced fat cavitation. Liporeductive ultrasound devices afford clinically relevant subcutaneous fat pad reduction without significant adverse reactions. This study aims at evaluating the histological and ultrastructural changes induced by ultrasound cavitation on the different cell components of human skin. Methods: Control and ultrasound-treated ex vivo abdominal full-thickness skin samples and skin biopsies from patients pretreated with or without ultrasound cavitation were studied histologically, morphometrically, and ultrastructurally to evaluate possible changes in adipocyte size and morphology. Adipocyte apoptosis and triglyceride release were also assayed. Clinical evaluation of the effects of 4 weekly ultrasound vs sham treatments was performed by plicometry. Results: Compared with the sham-treated control samples, ultrasound cavitation induced a statistically significant reduction in the size of the adipocytes (P < 0.001), the appearance of micropores and triglyceride leakage and release in the conditioned medium (P < 0.05 at 15 min), or adipose tissue interstitium, without appreciable changes in microvascular, stromal, and epidermal components and in the number of apoptotic adipocytes. Clinically, the ultrasound treatment caused a significant reduction of abdominal fat. Conclusions: This study further strengthens the current notion that noninvasive transcutaneous ultrasound cavitation is a promising and safe technology for localized reduction of fat and provides experimental evidence for its specific mechanism of action on the adipocytes. PMID:25289235

  8. Heterogeneous dental follicle cells and the regeneration of complex periodontal tissues.

    PubMed

    Guo, Weihua; Chen, Lei; Gong, Kun; Ding, Bofu; Duan, Yinzhong; Jin, Yan

    2012-03-01

    Dental follicle cells (DFCs) are a heterogeneous population that exhibit a variety of phenotypes. However, it remains unclear whether DFCs can maintain stem cell characteristics, or mediate tissue-regeneration to form single or complex tissues in the periodontium, after long-term culturing. Therefore, DFCs were isolated from human impacted molars (HIM-DFCs), passaged >30 times, and then evaluated for their heterogeneity and multipotential differentiation. Morphology, proliferation, epitope profile, and mineralization characteristics of clones derived from single HIM-DFCs in vitro were also assayed. HIM-DFCs (passage #30) were found to be positive for the heterogeneous markers, Notch-1, stro-1, alkaline phosphomonoesterase (ALP), type I collagen (COL-I), type III collagen (COL-III), and osteocalcine. Moreover, passage #30 of the HDF1, 2, and 3 subclone classes identified in this study were found to express high levels of the mesenchymal stem cells markers, CD146 and Stro1. HDF3 subclones were also associated with the strongest ALP staining detected, and strongly expressed osteoblast and cementoblast markers, including COL-I, COL-III, bone sialoprotein (BSP), and Runx2. In contrast, HDF1 subclone analyzed strongly expressed COL-I and COL-III, yet weakly expressed BSP and Runx2. The HDF2 subclone was associated with the strongest proliferative capacity. To evaluate differentiation characteristics in vivo, these various cell populations were combined with ceramic bovine bone and implanted into subcutaneous pockets of nude mice. The 30th passage of subclone HDF1 and 3 were observed to contribute to fiber collagens and the mineralized matrix present, respectively, whereas HDF2 subclones were found to have a minimal role in these formations. The formation of a cementum-periodontal ligament (PDL) complex was observed 6 weeks after HIM-DFCs (passage #30) were implanted in vivo, thus suggesting that these cells maintain stem cell characteristics. Therefore, subclone HDF1

  9. Analysis of laser surgery in non-melanoma skin cancer for optimal tissue removal

    NASA Astrophysics Data System (ADS)

    Fanjul-Vélez, Félix; Salas-García, Irene; Arce-Diego, José Luis

    2015-02-01

    Laser surgery is a commonly used technique for tissue ablation or the resection of malignant tumors. It presents advantages over conventional non-optical ablation techniques, like a scalpel or electrosurgery, such as the increased precision of the resected volume, minimization of scars and shorter recovery periods. Laser surgery is employed in medical branches such as ophthalmology or dermatology. The application of laser surgery requires the optimal adjustment of laser beam parameters, taking into account the particular patient and lesion. In this work we present a predictive tool for tissue resection in biological tissue after laser surgery, which allows an a priori knowledge of the tissue ablation volume, area and depth. The model employs a Monte Carlo 3D approach for optical propagation and a rate equation for plasma-induced ablation. The tool takes into account characteristics of the specific lesion to be ablated, mainly the geometric, optical and ablation properties. It also considers the parameters of the laser beam, such as the radius, spatial profile, pulse width, total delivered energy or wavelength. The predictive tool is applied to dermatology tumor resection, particularly to different types of non-melanoma skin cancer tumors: basocellular carcinoma, squamous cell carcinoma and infiltrative carcinoma. The ablation volume, area and depth are calculated for healthy skin and for each type of tumor as a function of the laser beam parameters. The tool could be used for laser surgery planning before the clinical application. The laser parameters could be adjusted for optimal resection volume, by personalizing the process to the particular patient and lesion.

  10. Heterogeneity of Skin Surface Oxygen Level of Wrist in Relation to Acupuncture Point

    PubMed Central

    Hong, Minyoung; Park, Sarah S.; Ha, Yejin; Lee, Jaegeun; Yoo, Kwangsik; Jhon, Gil-Ja; Suh, Minah; Lee, Youngmi

    2012-01-01

    The distribution of partial oxygen pressure (pO2) is analyzed for the anterior aspect of the left wrist with an amperometric oxygen microsensor composed of a small planar Pt disk-sensing area (diameter = 25 μm). The pO2 levels vary depending on the measurement location over the wrist skin, and they are systematically monitored in the analysis for both one-dimensional single line (along the wrist transverse crease) and two-dimensional square area of the wrist region. Relatively higher pO2 values are observed at certain area in close proximity to the position of acupuncture points with statistical significance, indicating strong relationship between oxygen and acupuncture point. The used oxygen microsensor is sensitive enough to detect the pO2 variation depending on the location. This study may provide information helpful to understand possible physiological roles of the acupuncture points. PMID:22666285

  11. Collagen structural alterations contribute to stiffening of tissue after split-thickness skin grafting.

    PubMed

    Rosin, Nicole L; Agabalyan, Natacha; Olsen, Katherine; Martufi, Giampaol; Gabriel, Vincent; Biernaskie, Jeff; Di Martino, Elena S

    2016-03-01

    The gold standard treatment for full thickness injuries of the skin is autologous split-thickness skin grafting. This involves harvesting the epidermis and superficial dermis from healthy skin and transplanting it onto the prepared wound bed. The donor site regenerates spontaneously, but the appendages and cellular components from the dermal layer are excluded from the graft. As a result, the new tissue is inferior; the healed graft site is dry/itchy, has decreased elasticity, increased fragility, and altered sensory function. Because this dermal layer is composed of collagen and other extracellular matrix proteins, the aim was to characterize the changes in the dermal collagen after split thickness grafting that could contribute to a deficit in functionality. This will serve as a baseline for future studies designed to improve skin function using pharmacological or cell-based therapies for skin repair. A xenograft model whereby human split-thickness grafts were implanted into full-thickness defects on immunocompromised (athymic Nu/Nu) mice was used. The grafts were harvested 4 and 8 weeks later. The collagen microstructure was assessed with second harmonic generation with dual-photon microscopy and light polarization analysis. Collagen fiber stiffness and engagement stretch were estimated by fitting the results of biaxial mechanical tensile tests to a histo-mechanical constitutive model. The stiffness of the collagen fibril-proteoglycan complex increased from 682 ± 226 kPa/sr to 1016 ± 324 kPa/sr between 4 and 8 weeks postgrafting. At the microstructural level there were significant decreases in both thickness of collagen fibers (3.60 ± 0.34 μm vs. 2.10 ± 0.27 μm) and waviness ratio (2.04 ± 0.17 vs. 1.43 ± 0.08) of the collagen fibers postgrafting. The decrease of the macroscopic engagement stretch from 1.19 ± 0.11 to 1.09 ± 0.08 over time postgrafting mirrored the decrease in waviness measured at the microscopic level

  12. Gelatin-GAG electrospun nanofibrous scaffold for skin tissue engineering: fabrication and modeling of process parameters.

    PubMed

    Pezeshki-Modaress, Mohamad; Mirzadeh, Hamid; Zandi, Mojgan

    2015-03-01

    Electrospinning is a very useful technique for producing polymeric nanofibers by applying electrostatic forces. In this study, fabrication of novel gelatin/GAG nanofibrous mats and also the optimization of electrospinning process using response surface methodology were reported. At optimization section, gelatin/GAG blend ratio, applied voltage and feeding rate, their individual and interaction effects on the mean fiber diameter (MFD) and standard deviation of fiber diameter (SDF) were investigated. The obtained model for MFD has a quadratic relationship with gelatin/GAG blend ratio, applied voltage and feeding rate. The interactions of blend ratio and applied voltage and also applied voltage and flow rate were found significant but the interactions of blend ratio and flow rate were ignored. The optimum condition for gelatin/GAG electrospinning was also introduced using the model obtained in this study. The potential use of optimized electrospun mat in skin tissue engineering was evaluated using culturing of human dermal fibroblast cells (HDF). The SEM micrographs of HDF cells on the nanofibrous structure show that fibroblast cells can highly attach, grow and populate on the fabricated scaffold surface. The electrospun gelatin/GAG nanofibrous mats have a potential for using as scaffold for skin, cartilage and cornea tissue engineering.

  13. Data on CUX1 isoforms in idiopathic pulmonary fibrosis lung and systemic sclerosis skin tissue sections.

    PubMed

    Ikeda, Tetsurou; Fragiadaki, Maria; Shi-Wen, Xu; Ponticos, Markella; Khan, Korsa; Denton, Christopher; Garcia, Patricia; Bou-Gharios, George; Yamakawa, Akio; Morimoto, Chikao; Abraham, David

    2016-09-01

    This data article contains complementary figures related to the research article entitled, "Transforming growth factor-β-induced CUX1 isoforms are associated with fibrosis in systemic sclerosis lung fibroblasts" (Ikeda et al. (2016) [2], http://dx.doi.org/10.1016/j.bbrep.2016.06.022), which presents that TGF-β increased CUX1 binding in the proximal promoter and enhancer of the COL1A2 and regulated COL1. Further, in the scleroderma (SSc) lung and diffuse alveolar damage lung sections, CUX1 localized within the α- smooth muscle actin (α-SMA) positive cells (Fragiadaki et al., 2011) [1], "High doses of TGF-beta potently suppress type I collagen via the transcription factor CUX1" (Ikeda et al., 2016) [2]. Here we show that CUX1 isoforms are localized within α-smooth muscle actin-positive cells in SSc skin and idiopathic pulmonary fibrosis (IPF) lung tissue sections. In particular, at the granular and prickle cell layers in the SSc skin sections, CUX1 and α-SMA are co-localized. In addition, at the fibrotic loci in the IPF lung tissue sections, CUX1 localized within the α-smooth muscle actin (α-SMA) positive cells. PMID:27583344

  14. Thermal interaction of short-pulsed laser focused beams with skin tissues.

    PubMed

    Jiao, Jian; Guo, Zhixiong

    2009-07-01

    Time-dependent thermal interaction is developed in a skin tissue cylinder subjected to the irradiation of a train of short laser pulses. The skin embedded with a small tumor is stratified as three layers: epidermis, dermis and subcutaneous fat with different optical, thermal and physiological properties. The laser beam is focused to the tumor site by an objective lens for thermal therapy. The ultrafast radiation heat transfer of the focused beam is simulated by the transient discrete ordinates method. The transient Pennes bio-heat equation is solved numerically by the finite volume method with alternating direction implicit scheme. Emphasis is placed on the characterization of the focused beam propagation and absorption and the temperature rise in the focal spot. The effects of the focal spot size and location, the laser power, and the bio-heat equation are investigated. Comparisons with collimated irradiation are conducted. The focused beam can penetrate a greater depth and produce higher temperature rise at the target area, and thus reduce the possibility of thermal damage to the surrounding healthy tissue. It is ideal for killing cancerous cells and small tumors.

  15. A novel gellan-PVA nanofibrous scaffold for skin tissue regeneration: Fabrication and characterization.

    PubMed

    Vashisth, Priya; Nikhil, Kumar; Roy, Partha; Pruthi, Parul A; Singh, Rajesh P; Pruthi, Vikas

    2016-01-20

    In this investigation, we have introduced novel electrospun gellan based nanofibers as a hydrophilic scaffolding material for skin tissue regeneration. These nanofibers were fabricated using a blend mixture of gellan with polyvinyl alcohol (PVA). PVA reduced the repulsive force of resulting solution and lead to formation of uniform fibers with improved nanostructure. Field emission scanning electron microscopy (FESEM) confirmed the average diameter of nanofibers down to 50 nm. The infrared spectra (IR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis evaluated the crosslinking, thermal stability and highly crystalline nature of gellan-PVA nanofibers, respectively. Furthermore, the cell culture studies using human dermal fibroblast (3T3L1) cells established that these gellan based nanofibrous scaffold could induce improved cell adhesion and enhanced cell growth than conventionally proposed gellan based hydrogels and dry films. Importantly, the nanofibrous scaffold are biodegradable and could be potentially used as a temporary substrate/or biomedical graft to induce skin tissue regeneration. PMID:26572421

  16. Thermal interaction of short-pulsed laser focused beams with skin tissues

    NASA Astrophysics Data System (ADS)

    Jiao, Jian; Guo, Zhixiong

    2009-07-01

    Time-dependent thermal interaction is developed in a skin tissue cylinder subjected to the irradiation of a train of short laser pulses. The skin embedded with a small tumor is stratified as three layers: epidermis, dermis and subcutaneous fat with different optical, thermal and physiological properties. The laser beam is focused to the tumor site by an objective lens for thermal therapy. The ultrafast radiation heat transfer of the focused beam is simulated by the transient discrete ordinates method. The transient Pennes bio-heat equation is solved numerically by the finite volume method with alternating direction implicit scheme. Emphasis is placed on the characterization of the focused beam propagation and absorption and the temperature rise in the focal spot. The effects of the focal spot size and location, the laser power, and the bio-heat equation are investigated. Comparisons with collimated irradiation are conducted. The focused beam can penetrate a greater depth and produce higher temperature rise at the target area, and thus reduce the possibility of thermal damage to the surrounding healthy tissue. It is ideal for killing cancerous cells and small tumors.

  17. Skin and Soft Tissue Infections due to Shewanella algae – An Emerging Pathogen

    PubMed Central

    Pillai, Meera; Vinod, Vivek; Dinesh, R. Kavitha

    2015-01-01

    Introduction: Shewanella spp. are emerging human pathogens, the predominant species being Shewanella algae. Shewanella skin and soft tissue infections are more commonly seen in immunocompromised patients with a pre-existing cutaneous ulcer and most often associated with exposure to marine environments. Aim: The study was conducted to investigate the epidemiological and clinical characteristics of Shewanella skin and soft tissue infections (SSTIs) for a period of five years. Materials and Methods: All Gram-negative non-fermenting motile isolates which produced pigmented colonies and positive for oxidase and H2S were further identified with Vitek 2 system. Results: A total of 16 patients with SSTIs due to Shewanella species were identified during the period from 2010 to 2014. Majority of patients were urban, elderly and fisher men. Shewanella algae (n=12, 75%) was the predominant isolate. Skin or mucosal portal of entry was found in all patients and seawater contact was recorded in 56.25% of the patients. 81% of infections were polymicrobial, common concomitant pathogens being gut and marine flora. Peripheral vascular diseases were the predominant risk factors with comorbidities like diabetes, hypertension and hepatobiliary diseases. Third generation cephalosporins, meropenem and gentamicin were the most effective antibiotics while two of the isolates were multidrug resistant. 75% of the infected patients recovered completely and three patients died of complications. Conclusion: Shewanella algae should be considered as an emerging pathogen of SSTIs mainly in patients with chronic ulcers and at times be multidrug resistant. These infections have a good clinical outcome if prompt medical, surgical and supportive treatment is offered. PMID:25859455

  18. The influence of stromal cells on the pigmentation of tissue-engineered dermo-epidermal skin grafts.

    PubMed

    Biedermann, Thomas; Böttcher-Haberzeth, Sophie; Klar, Agnieszka S; Widmer, Daniel S; Pontiggia, Luca; Weber, Andreas D; Weber, Daniel M; Schiestl, Clemens; Meuli, Martin; Reichmann, Ernst

    2015-03-01

    It has been shown in vitro that melanocyte proliferation and function in palmoplantar skin is regulated by mesenchymal factors derived from fibroblasts. In this study, we investigated in vivo the influence of mesenchymal-epithelial interactions in human tissue-engineered skin substitutes reconstructed from palmar- and nonpalmoplantar-derived fibroblasts. Tissue-engineered dermo-epidermal analogs based on collagen type I hydrogels were populated with either human palmar or nonpalmoplantar fibroblasts and seeded with human nonpalmoplantar-derived melanocytes and keratinocytes. These skin substitutes were transplanted onto full-thickness skin wounds of immunoincompetent rats. Four weeks after transplantation the development of skin color was measured and grafts were excised and analyzed with regard to epidermal characteristics, in particular melanocyte number and function. Skin substitutes containing palmar-derived fibroblasts in comparison to nonpalmoplantar-derived fibroblasts showed (a) a significantly lighter pigmentation; (b) a reduced amount of epidermal melanin granules; and (c) a distinct melanosome expression. However, the number of melanocytes in the basal layer remained similar in both transplantation groups. These findings demonstrate that human palmar fibroblasts regulate the function of melanocytes in human pigmented dermo-epidermal skin substitutes after transplantation, whereas the number of melanocytes remains constant. This underscores the influence of site-specific stromal cells and their importance when constructing skin substitutes for clinical application. PMID:25300246

  19. The Influence of Stromal Cells on the Pigmentation of Tissue-Engineered Dermo-Epidermal Skin Grafts

    PubMed Central

    Biedermann, Thomas; Böttcher-Haberzeth, Sophie; Klar, Agnieszka S.; Widmer, Daniel S.; Pontiggia, Luca; Weber, Andreas D.; Weber, Daniel M.; Schiestl, Clemens; Meuli, Martin

    2015-01-01

    It has been shown in vitro that melanocyte proliferation and function in palmoplantar skin is regulated by mesenchymal factors derived from fibroblasts. In this study, we investigated in vivo the influence of mesenchymal–epithelial interactions in human tissue-engineered skin substitutes reconstructed from palmar- and nonpalmoplantar-derived fibroblasts. Tissue-engineered dermo-epidermal analogs based on collagen type I hydrogels were populated with either human palmar or nonpalmoplantar fibroblasts and seeded with human nonpalmoplantar-derived melanocytes and keratinocytes. These skin substitutes were transplanted onto full-thickness skin wounds of immunoincompetent rats. Four weeks after transplantation the development of skin color was measured and grafts were excised and analyzed with regard to epidermal characteristics, in particular melanocyte number and function. Skin substitutes containing palmar-derived fibroblasts in comparison to nonpalmoplantar-derived fibroblasts showed (a) a significantly lighter pigmentation; (b) a reduced amount of epidermal melanin granules; and (c) a distinct melanosome expression. However, the number of melanocytes in the basal layer remained similar in both transplantation groups. These findings demonstrate that human palmar fibroblasts regulate the function of melanocytes in human pigmented dermo-epidermal skin substitutes after transplantation, whereas the number of melanocytes remains constant. This underscores the influence of site-specific stromal cells and their importance when constructing skin substitutes for clinical application. PMID:25300246

  20. The Effects of Low Dose Irradiation on Inflammatory Response Proteins in a 3D Reconstituted Human Skin Tissue Model

    SciTech Connect

    Varnum, Susan M.; Springer, David L.; Chaffee, Mary E.; Lien, Katie A.; Webb-Robertson, Bobbie-Jo M.; Waters, Katrina M.; Sacksteder, Colette A.

    2012-12-01

    Skin responses to moderate and high doses of ionizing radiation include the induction of DNA repair, apoptosis, and stress response pathways. Additionally, numerous studies indicate that radiation exposure leads to inflammatory responses in skin cells and tissue. However, the inflammatory response of skin tissue to low dose radiation (<10 cGy) is poorly understood. In order to address this, we have utilized a reconstituted human skin tissue model (MatTek EpiDerm FT) and assessed changes in 23 cytokines twenty-four and forty eight hours following treatment of skin with either 3 or 10 cGy low-dose of radiation. Three cytokines, IFN-γ, IL-2, MIP-1α, were significantly altered in response to low dose radiation. In contrast, seven cytokines were significantly altered in response to a high radiation dose of 200 cGy (IL-2, IL-10, IL-13, IFN-γ, MIP-1α, TNF α, and VEGF) or the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (G-CSF, GM-CSF, IL-1α, IL-8, MIP-1α, MIP-1β, RANTES). Additionally, radiation induced inflammation appears to have a distinct cytokine response relative to the non-radiation induced stressor, TPA. Overall, these results indicate that there are subtle changes in the inflammatory protein levels following exposure to low dose radiation and this response is a sub-set of what is seen following a high dose in a human skin tissue model.

  1. Psoriasis Skin Inflammation-Induced microRNA-26b Targets NCEH1 in Underlying Subcutaneous Adipose Tissue.

    PubMed

    Cheung, Louisa; Fisher, Rachel M; Kuzmina, Natalia; Li, Dongqing; Li, Xi; Werngren, Olivera; Blomqvist, Lennart; Ståhle, Mona; Landén, Ning Xu

    2016-03-01

    Psoriasis is an immune-mediated inflammatory disease, which is associated with a high risk of developing systemic comorbidities, such as obesity, cardiovascular disease, and diabetes mellitus. However, the mechanistic links between psoriatic skin inflammation and systemic comorbidities remain largely unknown. MicroRNAs (miRNAs) are recently discovered gene regulators that play important roles in psoriasis skin inflammation. In this study we aimed to explore whether the skin inflammation in psoriasis affects miRNA expression of the underlying subcutaneous adipose tissue and whether this may be a link between psoriasis and comorbidities. To this end, we compared the miRNA expression profile of subcutaneous adipose tissue underneath lesional and nonlesional psoriatic skin. We further validated the differential expression of several miRNAs and characterized their expression patterns in different cell types present in subcutaneous adipose tissue. We focused on miR-26b-5p, which was highly up-regulated in subcutaneous adipose tissue underneath lesional psoriasis skin. We showed that it targets and down-regulates neutral cholesterol ester hydrolase 1, an enzyme essential for cholesterol efflux, in monocytes/macrophages, adipocytes, vascular endothelial cells, and fibroblasts. We conclude that this miRNA may serve as a mechanistic link between psoriatic skin inflammation and its systemic comorbidities. PMID:27015452

  2. Psoriasis Skin Inflammation-Induced microRNA-26b Targets NCEH1 in Underlying Subcutaneous Adipose Tissue.

    PubMed

    Cheung, Louisa; Fisher, Rachel M; Kuzmina, Natalia; Li, Dongqing; Li, Xi; Werngren, Olivera; Blomqvist, Lennart; Ståhle, Mona; Landén, Ning Xu

    2016-03-01

    Psoriasis is an immune-mediated inflammatory disease, which is associated with a high risk of developing systemic comorbidities, such as obesity, cardiovascular disease, and diabetes mellitus. However, the mechanistic links between psoriatic skin inflammation and systemic comorbidities remain largely unknown. MicroRNAs (miRNAs) are recently discovered gene regulators that play important roles in psoriasis skin inflammation. In this study we aimed to explore whether the skin inflammation in psoriasis affects miRNA expression of the underlying subcutaneous adipose tissue and whether this may be a link between psoriasis and comorbidities. To this end, we compared the miRNA expression profile of subcutaneous adipose tissue underneath lesional and nonlesional psoriatic skin. We further validated the differential expression of several miRNAs and characterized their expression patterns in different cell types present in subcutaneous adipose tissue. We focused on miR-26b-5p, which was highly up-regulated in subcutaneous adipose tissue underneath lesional psoriasis skin. We showed that it targets and down-regulates neutral cholesterol ester hydrolase 1, an enzyme essential for cholesterol efflux, in monocytes/macrophages, adipocytes, vascular endothelial cells, and fibroblasts. We conclude that this miRNA may serve as a mechanistic link between psoriatic skin inflammation and its systemic comorbidities.

  3. Linezolid versus Vancomycin in Treatment of Complicated Skin and Soft Tissue Infections

    PubMed Central

    Weigelt, John; Itani, Kamal; Stevens, Dennis; Lau, William; Dryden, Matthew; Knirsch, Charles

    2005-01-01

    Skin and soft tissue infections (SSTIs) are a common cause of morbidity in both the community and the hospital. An SSTI is classified as complicated if the infection has spread to the deeper soft tissues, if surgical intervention is necessary, or if the patient has a comorbid condition hindering treatment response (e.g., diabetes mellitus or human immunodeficiency virus). The purpose of this study was to compare linezolid to vancomycin in the treatment of suspected or proven methicillin-resistant gram-positive complicated SSTIs (CSSTIs) requiring hospitalization. This was a randomized, open-label, comparator-controlled, multicenter, multinational study that included patients with suspected or proven methicillin-resistant Staphylococcus aureus (MRSA) infections that involved substantial areas of skin or deeper soft tissues, such as cellulitis, abscesses, infected ulcers, or burns (<10% of total body surface area). Patients were randomized (1:1) to receive linezolid (600 mg) every 12 h either intravenously (i.v.) or orally or vancomycin (1 g) every 12 h i.v. In the intent-to-treat population, 92.2% and 88.5% of patients treated with linezolid and vancomycin, respectively, were clinically cured at the test-of-cure (TOC) visit (P = 0.057). Linezolid outcomes (124/140 patients or 88.6%) were superior to vancomycin outcomes (97/145 patients or 66.9%) at the TOC visit for patients with MRSA infections (P < 0.001). Drug-related adverse events were reported in similar numbers in both the linezolid and the vancomycin arms of the trial. The results of this study demonstrate that linezolid therapy is well tolerated, equivalent to vancomycin in treating CSSTIs, and superior to vancomycin in the treatment of CSSTIs due to MRSA. PMID:15917519

  4. Bone tissue heterogeneity is associated with fracture toughness: a polarization Raman spectroscopy study

    NASA Astrophysics Data System (ADS)

    Makowski, Alexander J.; Granke, Mathilde; Uppuganti, Sasidhar; Mahadevan-Jansen, Anita; Nyman, Jeffry S.

    2015-02-01

    Polarization Raman Spectroscopy has been used to demonstrate microstructural features and collagen fiber orientation in human and mouse bone, concurrently measuring both organization and composition; however, it is unclear as to what extent these measurements explain the mechanical quality of bone. In a cohort of age and gender matched cadaveric cortical bone samples (23-101 yr.), we show homogeneity of both composition and structure are associated with the age related decrease in fracture toughness. 64 samples were machined into uniform specimens and notched for mechanical fracture toughness testing and polished for Raman Spectroscopy. Fingerprint region spectra were acquired on wet bone prior to mechanical testing by sampling nine different microstructural features spaced in a 750x750 μm grid in the region of intended crack propagation. After ASTM E1820 single edge notched beam fracture toughness tests, the sample was dried in ethanol and the osteonal-interstitial border of one osteon was samples in a 32x32 grid of 2μm2 pixels for two orthogonal orientations relative to the long bone axis. Standard peak ratios from the 9 separate microstructures show heterogeneity between structures but do not sufficiently explain fracture toughness; however, peak ratios from mapping highlight both lamellar contrast (ν1Phos/Amide I) and osteon-interstitial contrast (ν1Phos/Proline). Combining registered orthogonal maps allowed for multivariate analysis of underlying biochemical signatures. Image entropy and homogeneity metrics of single principal components significantly explain resistance to crack initiation and propagation. Ultimately, a combination of polarization content and multivariate Raman signatures allowed for the association of microstructural tissue heterogeneity with fracture resistance.

  5. Global Gene Expression Analysis in PKCα-/- Mouse Skin Reveals Structural Changes in the Dermis and Defective Wound Granulation Tissue.

    PubMed

    Cooper, Nichola H; Balachandra, Jeya P; Hardman, Matthew J

    2015-12-01

    The skin's mechanical integrity is maintained by an organized and robust dermal extracellular matrix (ECM). Resistance to mechanical disruption hinges primarily on homeostasis of the dermal collagen fibril architecture, which is regulated, at least in part, by members of the small leucine-rich proteoglycan (SLRP) family. Here we present data linking protein kinase C alpha (PKCα) to the regulated expression of multiple ECM components including SLRPs. Global microarray profiling reveals deficiencies in ECM gene expression in PKCα-/- skin correlating with abnormal collagen fibril morphology, disorganized dermal architecture, and reduced skin strength. Detailed analysis of the skin and wounds from wild-type and PKCα-/- mice reveals a failure to upregulate collagen and other ECM components in response to injury, resulting in delayed granulation tissue deposition in PKCα-/- wounds. Thus, our data reveal a previously unappreciated role for PKCα in the regulation of ECM structure and deposition during skin wound healing.

  6. Evaluation of peripheral vasodilative indices in skin tissue of type 1 diabetic rats by use of RGB images

    NASA Astrophysics Data System (ADS)

    Tanaka, Noriyuki; Nishidate, Izumi; Nakano, Kazuya; Aizu, Yoshihisa; Niizeki, Kyuichi

    2016-04-01

    We investigated a method to evaluate the arterial inflow and the venous capacitance in the skin tissue of streptozotocin-induced type 1 diabetic rats from RGB digital color images. The arterial inflow and the venous capacitance in the dorsal reversed McFarlane skin flap are calculated based on the responses of change in the total blood concentration to occlusion of blood flow to and from the flap tissues at a pressure of 50 mmHg. The arterial inflow and the venous capacitance in the skin flap tissue were significantly reduced in type 1 diabetic rat group compared with the non-diabetic rat group. The results of the present study indicate the possibility of using the proposed method for evaluating the peripheral vascular dysfunctions in diabetes mellitus.

  7. Skin wound trauma, following high-dose radiation exposure, amplifies and prolongs skeletal tissue loss.

    PubMed

    Swift, Joshua M; Swift, Sibyl N; Smith, Joan T; Kiang, Juliann G; Allen, Matthew R

    2015-12-01

    The present study investigated the detrimental effects of non-lethal, high-dose (whole body) γ-irradiation on bone, and the impact that radiation combined with skin trauma (i.e. combined injury) has on long-term skeletal tissue health. Recovery of bone after an acute dose of radiation (RI; 8 Gy), skin wounding (15-20% of total body skin surface), or combined injury (RI+Wound; CI) was determined 3, 7, 30, and 120 days post-irradiation in female B6D2F1 mice and compared to non-irradiated mice (SHAM) at each time-point. CI mice demonstrated long-term (day 120) elevations in serum TRAP 5b (osteoclast number) and sclerostin (bone formation inhibitor), and suppression of osteocalcin levels through 30 days as compared to SHAM (p<0.05). Radiation-induced reductions in distal femur trabecular bone volume fraction and trabecular number through 120 days post-exposure were significantly greater than non-irradiated mice (p<0.05) and were exacerbated in CI mice by day 30 (p<0.05). Negative alterations in trabecular bone microarchitecture were coupled with extended reductions in cancellous bone formation rate in both RI and CI mice as compared to Sham (p<0.05). Increased osteoclast surface in CI animals was observed for 3 days after irradiation and remained elevated through 120 days (p<0.01). These results demonstrate a long-term, exacerbated response of bone to radiation when coupled with non-lethal wound trauma. Changes in cancellous bone after combined trauma were derived from extended reductions in osteoblast-driven bone formation and increases in osteoclast activity.

  8. Monte Carlo simulation of radiation transport in human skin with rigorous treatment of curved tissue boundaries

    NASA Astrophysics Data System (ADS)

    Majaron, Boris; Milanič, Matija; Premru, Jan

    2015-01-01

    In three-dimensional (3-D) modeling of light transport in heterogeneous biological structures using the Monte Carlo (MC) approach, space is commonly discretized into optically homogeneous voxels by a rectangular spatial grid. Any round or oblique boundaries between neighboring tissues thus become serrated, which raises legitimate concerns about the realism of modeling results with regard to reflection and refraction of light on such boundaries. We analyze the related effects by systematic comparison with an augmented 3-D MC code, in which analytically defined tissue boundaries are treated in a rigorous manner. At specific locations within our test geometries, energy deposition predicted by the two models can vary by 10%. Even highly relevant integral quantities, such as linear density of the energy absorbed by modeled blood vessels, differ by up to 30%. Most notably, the values predicted by the customary model vary strongly and quite erratically with the spatial discretization step and upon minor repositioning of the computational grid. Meanwhile, the augmented model shows no such unphysical behavior. Artifacts of the former approach do not converge toward zero with ever finer spatial discretization, confirming that it suffers from inherent deficiencies due to inaccurate treatment of reflection and refraction at round tissue boundaries.

  9. Investigation of the effect of hydration on dermal collagen in ex vivo human skin tissue using second harmonic generation microscopy

    NASA Astrophysics Data System (ADS)

    Samatham, Ravikant; Wang, Nicholas K.; Jacques, Steven L.

    2016-02-01

    Effect of hydration on the dermal collagen structure in human skin was investigated using second harmonic generation microscopy. Dog ears from the Mohs micrographic surgery department were procured for the study. Skin samples with subject aged between 58-90 years old were used in the study. Three dimensional Multiphoton (Two-photon and backward SHG) control data was acquired from the skin samples. After the control measurement, the skin tissue was either soaked in deionized water for 2 hours (Hydration) or kept at room temperature for 2 hours (Desiccation), and SHG data was acquired. The data was normalized for changes in laser power and detector gain. The collagen signal per unit volume from the dermis was calculated. The desiccated skin tissue gave higher backward SHG compared to respective control tissue, while hydration sample gave a lower backward SHG. The collagen signal decreased with increase in hydration of the dermal collagen. Hydration affected the packing of the collagen fibrils causing a change in the backward SHG signal. In this study, the use of multiphoton microscopy to study the effect of hydration on dermal structure was demonstrated in ex vivo tissue.

  10. Mapping tissue shear modulus on Thiel soft-embalmed mouse skin with shear wave optical coherence elastography

    NASA Astrophysics Data System (ADS)

    Song, Shaozhen; Joy, Joyce; Wang, Ruikang K.; Huang, Zhihong

    2015-03-01

    A quantitative measurement of the mechanical properties of biological tissue is a useful assessment of its physiologic conditions, which may aid medical diagnosis and treatment of, e.g., scleroderma and skin cancer. Traditional elastography techniques such as magnetic resonance elastography and ultrasound elastography have limited scope of application on skin due to insufficient spatial resolution. Recently, dynamic / transient elastography are attracting more applications with the advantage of non-destructive measurements, and revealing the absolute moduli values of tissue mechanical properties. Shear wave optical coherence elastography (SW-OCE) is a novel transient elastography method, which lays emphasis on the propagation of dynamic mechanical waves. In this study, high speed shear wave imaging technique was applied to a range of soft-embalmed mouse skin, where 3 kHz shear waves were launched with a piezoelectric actuator as an external excitation. The shear wave velocity was estimated from the shear wave images, and used to recover a shear modulus map in the same OCT imaging range. Results revealed significant difference in shear modulus and structure in compliance with gender, and images on fresh mouse skin are also compared. Thiel embalming technique is also proven to present the ability to furthest preserve the mechanical property of biological tissue. The experiment results suggest that SW-OCE is an effective technique for quantitative estimation of skin tissue biomechanical status.

  11. Skin and soft tissues. Management of four common infections in the nursing home patient.

    PubMed

    O'Donnell, J A; Hofmann, M T

    2001-10-01

    Common skin and soft tissue infections in nursing home patients include herpes zoster, cellulitis, pressure ulcer infections, and scables. Treatment of shingles with an oral antiviral should be started within 24 hours of symptom onset. Dissemination and bacterial superinfection require antibiotic therapy. Use of corticosteroids to prevent post-herpetic neuralgia remains controversial. Cellulitis is most often caused by Staphylococcus aureus and beta-hemolytic streptococci (groups A and B). Therapy for cellulitis is empiric; gram-negative bacilli should be covered in diabetic patients. Most pressure ulcers never become infected; for those that do, empiric therapy should cover S aureus, gram-negative bacilli, and anaerobes. Topical treatment of scables with 5% permethrin cream or 1% lindane lotion is recommended.

  12. Pseudomonas oryzihabitans: an unusual cause of skin and soft tissue infection.

    PubMed

    Tena, Daniel; Fernández, Cristina

    2015-01-01

    Skin and soft tissue infections (SSTIs) due to Pseudomonas oryzihabitans are very rare. The aim of the present study was to investigate the clinical and microbiological characteristics of this infection. We performed a retrospective review of six cases that occurred in our area over a period of 6 years, and six cases previously reported in the literature. Predisposing factors were recognized in 76.9% of patients, including previous surgery, immunosuppression, diabetes mellitus, trauma, bites and lactation. The source of infection was probably environmental in most cases. Our study shows that P. oryzihabitans should be considered a potential pathogen, especially in patients with surgical site infections, mastitis and wound infections after bites or trauma. Clinical outcome is usually favourable and treatment is not difficult due to the low level of resistance to commonly used antibiotics.

  13. Crosslinked hydrogels based on biological macromolecules with potential use in skin tissue engineering.

    PubMed

    Vulpe, Raluca; Popa, Marcel; Picton, Luc; Balan, Vera; Dulong, Virginie; Butnaru, Maria; Verestiuc, Liliana

    2016-03-01

    Zero-length crosslinked hydrogels have been synthesized by covalent linking of three natural polymers (collagen, hyaluronic acid and sericin), in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. The hydrogels have been investigated by FT-IR spectroscopy, microcalorimetry, in vitro swelling, enzymatic degradation, and in vitro cell viability studies. The obtained crosslinked hydrogels showed a macroporous structure, high swelling degree and in vitro enzymatic resistance compared to uncrosslinked collagen. The in vitro cell viability studies performed on normal human dermal fibroblasts assessed the sericin proliferation properties indicating a potential use of the hydrogels based on collagen, hyaluronic acid and sericin in skin tissue engineering. PMID:26704998

  14. [Cefditoren pivoxil: A new oral cephalosporin for skin, soft tissue and respiratory tract infections].

    PubMed

    Hernández-Martin, J; Romá, E; Salavert, M; Doménech, L; Poveda, J L

    2006-09-01

    Cefditoren pivoxil, a new-third generation cephalosporin antibiotic that has recently been granted approval in Spain, shows important activity over a large part of the pathogens causing skin, soft tissue and respiratory tract infections, including Gram-negative and Gram-positive bacteria. Cefditoren has also been shown to be stable against hydrolysis by many common beta-lactamases. Data from in vitro studies and clinical trials show this antibiotic as an oral formulation with an intrinsic activity against Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae equivalent to that of other third-generation cephalosporins administered via parenteral, like cefotaxime or ceftriaxone, thereby placing its maximal benefits mainly in the treatment of ambulatory infections. This paper reviews the main characteristics of cefditoren pivoxil (spectrum of activity, chemical structure, mechanism of action, pharmacokinetics, adverse effects and clinical efficacy) and attempts to find its place in current antibiotic therapeutics.

  15. Pseudomonas oryzihabitans: an unusual cause of skin and soft tissue infection.

    PubMed

    Tena, Daniel; Fernández, Cristina

    2015-01-01

    Skin and soft tissue infections (SSTIs) due to Pseudomonas oryzihabitans are very rare. The aim of the present study was to investigate the clinical and microbiological characteristics of this infection. We performed a retrospective review of six cases that occurred in our area over a period of 6 years, and six cases previously reported in the literature. Predisposing factors were recognized in 76.9% of patients, including previous surgery, immunosuppression, diabetes mellitus, trauma, bites and lactation. The source of infection was probably environmental in most cases. Our study shows that P. oryzihabitans should be considered a potential pathogen, especially in patients with surgical site infections, mastitis and wound infections after bites or trauma. Clinical outcome is usually favourable and treatment is not difficult due to the low level of resistance to commonly used antibiotics. PMID:26179756

  16. Cell type specific gene expression analysis of prostate needle biopsies resolves tumor tissue heterogeneity.

    PubMed

    Krönig, Malte; Walter, Max; Drendel, Vanessa; Werner, Martin; Jilg, Cordula A; Richter, Andreas S; Backofen, Rolf; McGarry, David; Follo, Marie; Schultze-Seemann, Wolfgang; Schüle, Roland

    2015-01-20

    A lack of cell surface markers for the specific identification, isolation and subsequent analysis of living prostate tumor cells hampers progress in the field. Specific characterization of tumor cells and their microenvironment in a multi-parameter molecular assay could significantly improve prognostic accuracy for the heterogeneous prostate tumor tissue. Novel functionalized gold-nano particles allow fluorescence-based detection of absolute mRNA expression levels in living cells by fluorescent activated flow cytometry (FACS). We use of this technique to separate prostate tumor and benign cells in human prostate needle biopsies based on the expression levels of the tumor marker alpha-methylacyl-CoA racemase (AMACR). We combined RNA and protein detection of living cells by FACS to gate for epithelial cell adhesion molecule (EPCAM) positive tumor and benign cells, EPCAM/CD45 double negative mesenchymal cells and CD45 positive infiltrating lymphocytes. EPCAM positive epithelial cells were further sub-gated into AMACR high and low expressing cells. Two hundred cells from each population and several biopsies from the same patient were analyzed using a multiplexed gene expression profile to generate a cell type resolved profile of the specimen. This technique provides the basis for the clinical evaluation of cell type resolved gene expression profiles as pre-therapeutic prognostic markers for prostate cancer.

  17. Cell type specific gene expression analysis of prostate needle biopsies resolves tumor tissue heterogeneity

    PubMed Central

    Krönig, Malte; Walter, Max; Drendel, Vanessa; Werner, Martin; Jilg, Cordula A.; Richter, Andreas S.; Backofen, Rolf; McGarry, David; Follo, Marie; Schultze-Seemann, Wolfgang; Schüle, Roland

    2015-01-01

    A lack of cell surface markers for the specific identification, isolation and subsequent analysis of living prostate tumor cells hampers progress in the field. Specific characterization of tumor cells and their microenvironment in a multi-parameter molecular assay could significantly improve prognostic accuracy for the heterogeneous prostate tumor tissue. Novel functionalized gold-nano particles allow fluorescence-based detection of absolute mRNA expression levels in living cells by fluorescent activated flow cytometry (FACS). We use of this technique to separate prostate tumor and benign cells in human prostate needle biopsies based on the expression levels of the tumor marker alpha-methylacyl-CoA racemase (AMACR). We combined RNA and protein detection of living cells by FACS to gate for epithelial cell adhesion molecule (EPCAM) positive tumor and benign cells, EPCAM/CD45 double negative mesenchymal cells and CD45 positive infiltrating lymphocytes. EPCAM positive epithelial cells were further sub-gated into AMACR high and low expressing cells. Two hundred cells from each population and several biopsies from the same patient were analyzed using a multiplexed gene expression profile to generate a cell type resolved profile of the specimen. This technique provides the basis for the clinical evaluation of cell type resolved gene expression profiles as pre-therapeutic prognostic markers for prostate cancer. PMID:25514598

  18. Patagonfibrase modifies protein expression of tissue factor and protein disulfide isomerase in rat skin.

    PubMed

    Peichoto, María Elisa; Santoro, Marcelo Larami

    2016-09-01

    Patagonfibrase is a hemorrhagic metalloproteinase isolated from the venom of the South American rear-fanged snake Philodryas patagoniensis, and is an important contributor to local lesions inflicted by this species. The tissue factor (TF)-factor VIIa complex, besides triggering the coagulation cascade, has been demonstrated to be involved in inflammatory events. Our aim was to determine whether patagonfibrase affects the expression of TF and protein disulfide isomerase (PDI), an enzyme that controls TF biological activity, at the site of patagonfibrase injection, and thus if they may play a role in hemostatic and inflammatory events induced by snake venoms. Patagonfibrase (60 μg/kg) was administered s.c. to rats, and after 3 h blood was collected to evaluate hemostasis parameters, and skin fragments close to the site of injection were taken to assess TF and PDI expression. Patagonfibrase did not alter blood cell counts, plasma fibrinogen levels, or levels of TF activity in plasma. However, by semiquantitative Western blotting, patagonfibrase increased TF expression by 2-fold, and decreased PDI expression by 3-fold in skin samples. In agreement, by immunohistochemical analyses, prominent TF expression was observed in the subcutaneous tissue. Thus, patagonfibrase affects the local expression of TF and PDI without inducing any systemic hemostatic disturbance, although that they may be involved in the local inflammatory events induced by hemorrhagic metalloproteinases. Once antivenom therapy is not totally effective to treat the local injury induced by snake venoms, modulation of the activity and expression of TF and/or PDI might become a strategy for treating snake envenomation. PMID:27390042

  19. Epidermal stem cells and skin tissue engineering in hair follicle regeneration.

    PubMed

    Balañá, María Eugenia; Charreau, Hernán Eduardo; Leirós, Gustavo José

    2015-05-26

    The reconstitution of a fully organized and functional hair follicle from dissociated cells propagated under defined tissue culture conditions is a challenge still pending in tissue engineering. The loss of hair follicles caused by injuries or pathologies such as alopecia not only affects the patients' psychological well-being, but also endangers certain inherent functions of the skin. It is then of great interest to find different strategies aiming to regenerate or neogenerate the hair follicle under conditions proper of an adult individual. Based upon current knowledge on the epithelial and dermal cells and their interactions during the embryonic hair generation and adult hair cycling, many researchers have tried to obtain mature hair follicles using different strategies and approaches depending on the causes of hair loss. This review summarizes current advances in the different experimental strategies to regenerate or neogenerate hair follicles, with emphasis on those involving neogenesis of hair follicles in adult individuals using isolated cells and tissue engineering. Most of these experiments were performed using rodent cells, particularly from embryonic or newborn origin. However, no successful strategy to generate human hair follicles from adult cells has yet been reported. This review identifies several issues that should be considered to achieve this objective. Perhaps the most important challenge is to provide three-dimensional culture conditions mimicking the structure of living tissue. Improving culture conditions that allow the expansion of specific cells while protecting their inductive properties, as well as methods for selecting populations of epithelial stem cells, should give us the necessary tools to overcome the difficulties that constrain human hair follicle neogenesis. An analysis of patent trends shows that the number of patent applications aimed at hair follicle regeneration and neogenesis has been increasing during the last decade. This

  20. Epidermal stem cells and skin tissue engineering in hair follicle regeneration

    PubMed Central

    Balañá, María Eugenia; Charreau, Hernán Eduardo; Leirós, Gustavo José

    2015-01-01

    The reconstitution of a fully organized and functional hair follicle from dissociated cells propagated under defined tissue culture conditions is a challenge still pending in tissue engineering. The loss of hair follicles caused by injuries or pathologies such as alopecia not only affects the patients’ psychological well-being, but also endangers certain inherent functions of the skin. It is then of great interest to find different strategies aiming to regenerate or neogenerate the hair follicle under conditions proper of an adult individual. Based upon current knowledge on the epithelial and dermal cells and their interactions during the embryonic hair generation and adult hair cycling, many researchers have tried to obtain mature hair follicles using different strategies and approaches depending on the causes of hair loss. This review summarizes current advances in the different experimental strategies to regenerate or neogenerate hair follicles, with emphasis on those involving neogenesis of hair follicles in adult individuals using isolated cells and tissue engineering. Most of these experiments were performed using rodent cells, particularly from embryonic or newborn origin. However, no successful strategy to generate human hair follicles from adult cells has yet been reported. This review identifies several issues that should be considered to achieve this objective. Perhaps the most important challenge is to provide three-dimensional culture conditions mimicking the structure of living tissue. Improving culture conditions that allow the expansion of specific cells while protecting their inductive properties, as well as methods for selecting populations of epithelial stem cells, should give us the necessary tools to overcome the difficulties that constrain human hair follicle neogenesis. An analysis of patent trends shows that the number of patent applications aimed at hair follicle regeneration and neogenesis has been increasing during the last decade. This

  1. Epidermal stem cells and skin tissue engineering in hair follicle regeneration.

    PubMed

    Balañá, María Eugenia; Charreau, Hernán Eduardo; Leirós, Gustavo José

    2015-05-26

    The reconstitution of a fully organized and functional hair follicle from dissociated cells propagated under defined tissue culture conditions is a challenge still pending in tissue engineering. The loss of hair follicles caused by injuries or pathologies such as alopecia not only affects the patients' psychological well-being, but also endangers certain inherent functions of the skin. It is then of great interest to find different strategies aiming to regenerate or neogenerate the hair follicle under conditions proper of an adult individual. Based upon current knowledge on the epithelial and dermal cells and their interactions during the embryonic hair generation and adult hair cycling, many researchers have tried to obtain mature hair follicles using different strategies and approaches depending on the causes of hair loss. This review summarizes current advances in the different experimental strategies to regenerate or neogenerate hair follicles, with emphasis on those involving neogenesis of hair follicles in adult individuals using isolated cells and tissue engineering. Most of these experiments were performed using rodent cells, particularly from embryonic or newborn origin. However, no successful strategy to generate human hair follicles from adult cells has yet been reported. This review identifies several issues that should be considered to achieve this objective. Perhaps the most important challenge is to provide three-dimensional culture conditions mimicking the structure of living tissue. Improving culture conditions that allow the expansion of specific cells while protecting their inductive properties, as well as methods for selecting populations of epithelial stem cells, should give us the necessary tools to overcome the difficulties that constrain human hair follicle neogenesis. An analysis of patent trends shows that the number of patent applications aimed at hair follicle regeneration and neogenesis has been increasing during the last decade. This

  2. Use of Clotted Human Plasma and Aprotinin in Skin Tissue Engineering: A Novel Approach to Engineering Composite Skin on a Porous Scaffold.

    PubMed

    Paul, Michelle; Kaur, Pritinder; Herson, Marisa; Cheshire, Perdita; Cleland, Heather; Akbarzadeh, Shiva

    2015-10-01

    Tissue-engineered composite skin is a promising therapy for the treatment of chronic and acute wounds, including burns. Providing the wound bed with a dermal scaffold populated by autologous dermal and epidermal cellular components can further entice host cell infiltration and vascularization to achieve permanent wound closure in a single stage. However, the high porosity and the lack of a supportive basement membrane in most commercially available dermal scaffolds hinders organized keratinocyte proliferation and stratification in vitro and may delay re-epithelization in vivo. The objective of this study was to develop a method to enable the in vitro production of a human skin equivalent (HSE) that included a porous scaffold and dermal and epidermal cells expanded ex vivo, with the potential to be used for definitive treatment of skin defects in a single procedure. A collagen-glycosaminoglycan dermal scaffold (Integra(®)) was populated with adult fibroblasts. A near-normal skin architecture was achieved by the addition of coagulated human plasma to the fibroblast-populated scaffold before seeding cultured keratinocytes. This resulted in reducing scaffold pore size and improving contact surfaces. Skin architecture and basement membrane formation was further improved by the addition of aprotinin (a serine protease inhibitor) to the culture media to inhibit premature clot digestion. Histological assessment of the novel HSE revealed expression of keratin 14 and keratin 10 similar to native skin, with a multilayered neoepidermis morphologically comparable to human skin. Furthermore, deposition of collagen IV and laminin-511 were detected by immunofluorescence, indicating the formation of a continuous basement membrane at the dermal-epidermal junction. The proposed method was efficient in producing an in vitro near native HSE using the chosen off-the-shelf porous scaffold (Integra). The same principles and promising outcomes should be applicable to other biodegradable

  3. PMMA microspheres (Artecoll) for skin and soft-tissue augmentation. Part II: Clinical investigations.

    PubMed

    Lemperle, G; Hazan-Gaúthier, N; Lemperle, M

    1995-09-01

    Artecoll is an injectable implant for long-lasting correction of wrinkles and other skin defects. Artecoll consists of fine polymethyl-methacrylate (PMMA) microspheres suspended 1:3 in a 3.5% collagen solution. The microspheres are characterized by exceptional surface smoothness, homogenicity, and purity. The size of the microspheres of 30-40 microns diameter is small enough to allow subdermal implantation using a 27-gauge needle. Phagocytosis and dislocation of the implant is prevented by fast encapsulation of each single microsphere with connective tissue. Increased scarring but no granuloma formation has been detected as is common with other injectable implants with irregular surfaces. The experience from more than 600 patients and a prospective study in 118 patients with 200 implantation sites were evaluated. The good early results have continued for 5 years. Of the patients evaluated, 89.5 percent were satisfied and would ask for the treatment again. The overall complication rate is very low, and prolonged redness or visible granules are due to implantations that are too superficial. Other applications in soft-tissue augmentation are discussed.

  4. Boundary discretization in the numerical simulation of light propagation in skin tissue: problem and strategy

    NASA Astrophysics Data System (ADS)

    Jia, Hao; Chen, Bin; Li, Dong; Zhang, Yong

    2015-02-01

    To adapt the complex tissue structure, laser propagation in a two-layered skin model is simulated to compare voxel-based Monte Carlo (VMC) and tetrahedron-based MC (TMC) methods with a geometry-based MC (GMC) method. In GMC, the interface is mathematically defined without any discretization. GMC is the most accurate but is not applicable to complicated domains. The implementation of VMC is simple because of its structured voxels. However, unavoidable errors are expected because of the zigzag polygonal interface. Compared with GMC and VMC, TMC provides a balance between accuracy and flexibility by the tetrahedron cells. In the present TMC, the body-fitted tetrahedra are generated in different tissues. No interface tetrahedral cells exist, thereby avoiding the photon reflection error in the interface cells in VMC. By introducing a distance threshold, the error caused by confused optical parameters between neighboring cells when photons are incident along the cell boundary can be avoided. The results show that the energy deposition error by TMC in the interfacial region is one-tenth to one-fourth of that by VMC, yielding more accurate computations of photon reflection, refraction, and energy deposition. The results of multilayered and n-shaped vessels indicate that a laser with a 1064-nm wavelength should be introduced to clean deep-buried vessels.

  5. Monte Carlo simulation of light propagation in skin tissue phantoms using a parallel computing method

    NASA Astrophysics Data System (ADS)

    Wu, Di M.; Zhao, S. S.; Lu, Jun Q.; Hu, Xin-Hua

    2000-06-01

    In Monte Carlo simulations of light propagating in biological tissues, photons propagating in the media are described as classic particles being scattered and absorbed randomly in the media, and their path are tracked individually. To obtain any statistically significant results, however, a large number of photons is needed in the simulations and the calculations are time consuming and sometime impossible with existing computing resource, especially when considering the inhomogeneous boundary conditions. To overcome this difficulty, we have implemented a parallel computing technique into our Monte Carlo simulations. And this moment is well justified due to the nature of the Monte Carlo simulation. Utilizing the PVM (Parallel Virtual Machine, a parallel computing software package), parallel codes in both C and Fortran have been developed on the massive parallel computer of Cray T3E and a local PC-network running Unix/Sun Solaris. Our results show that parallel computing can significantly reduce the running time and make efficient usage of low cost personal computers. In this report, we present a numerical study of light propagation in a slab phantom of skin tissue using the parallel computing technique.

  6. In vitro glycation of an endothelialized and innervated tissue-engineered skin to screen anti-AGE molecules.

    PubMed

    Cadau, Sébastien; Leoty-Okombi, Sabrina; Pain, Sabine; Bechetoille, Nicolas; André-Frei, Valérie; Berthod, François

    2015-05-01

    Glycation is one of the major processes responsible for skin aging through induction of the detrimental formation of advanced glycation end-products (AGEs). We developed an innovative tissue-engineered skin combining both a capillary-like and a nerve networks and designed a protocol to induce continuous AGEs formation by a treatment with glyoxal. We determined the optimal concentration of glyoxal to induce AGEs formation identified by carboxymethyl-lysin expression while keeping their toxic effects low. We showed that our tissue-engineered skin cultured for 44 days and treated with 200 μm glyoxal for 31 days displayed high carboxymethyl-lysine expression, which induced a progressively increased alteration of its capillary and nerve networks between 28 and 44 days. Moreover, it produced an epidermal differentiation defect evidenced by the lack of loricrin and filaggrin expression in the epidermis. These effects were almost completely prevented by addition of aminoguanidine 1.5 mm, an anti-glycation compound, and only slightly decreased by alagebrium 500 μm, an AGE-breaker molecule. This tissue-engineered skin model is the first one to combine a capillary and nerve network and to enable a continuous glycation over a long-term culture period. It is a unique tool to investigate the effects of glycation on skin and to screen new molecules that could prevent AGEs formation.

  7. In vitro glycation of an endothelialized and innervated tissue-engineered skin to screen anti-AGE molecules.

    PubMed

    Cadau, Sébastien; Leoty-Okombi, Sabrina; Pain, Sabine; Bechetoille, Nicolas; André-Frei, Valérie; Berthod, François

    2015-05-01

    Glycation is one of the major processes responsible for skin aging through induction of the detrimental formation of advanced glycation end-products (AGEs). We developed an innovative tissue-engineered skin combining both a capillary-like and a nerve networks and designed a protocol to induce continuous AGEs formation by a treatment with glyoxal. We determined the optimal concentration of glyoxal to induce AGEs formation identified by carboxymethyl-lysin expression while keeping their toxic effects low. We showed that our tissue-engineered skin cultured for 44 days and treated with 200 μm glyoxal for 31 days displayed high carboxymethyl-lysine expression, which induced a progressively increased alteration of its capillary and nerve networks between 28 and 44 days. Moreover, it produced an epidermal differentiation defect evidenced by the lack of loricrin and filaggrin expression in the epidermis. These effects were almost completely prevented by addition of aminoguanidine 1.5 mm, an anti-glycation compound, and only slightly decreased by alagebrium 500 μm, an AGE-breaker molecule. This tissue-engineered skin model is the first one to combine a capillary and nerve network and to enable a continuous glycation over a long-term culture period. It is a unique tool to investigate the effects of glycation on skin and to screen new molecules that could prevent AGEs formation. PMID:25771012

  8. A Nth-order linear algorithm for extracting diffuse correlation spectroscopy blood flow indices in heterogeneous tissues

    SciTech Connect

    Shang, Yu; Yu, Guoqiang

    2014-09-29

    Conventional semi-infinite analytical solutions of correlation diffusion equation may lead to errors when calculating blood flow index (BFI) from diffuse correlation spectroscopy (DCS) measurements in tissues with irregular geometries. Very recently, we created an algorithm integrating a Nth-order linear model of autocorrelation function with the Monte Carlo simulation of photon migrations in homogenous tissues with arbitrary geometries for extraction of BFI (i.e., αD{sub B}). The purpose of this study is to extend the capability of the Nth-order linear algorithm for extracting BFI in heterogeneous tissues with arbitrary geometries. The previous linear algorithm was modified to extract BFIs in different types of tissues simultaneously through utilizing DCS data at multiple source-detector separations. We compared the proposed linear algorithm with the semi-infinite homogenous solution in a computer model of adult head with heterogeneous tissue layers of scalp, skull, cerebrospinal fluid, and brain. To test the capability of the linear algorithm for extracting relative changes of cerebral blood flow (rCBF) in deep brain, we assigned ten levels of αD{sub B} in the brain layer with a step decrement of 10% while maintaining αD{sub B} values constant in other layers. Simulation results demonstrate the accuracy (errors < 3%) of high-order (N ≥ 5) linear algorithm in extracting BFIs in different tissue layers and rCBF in deep brain. By contrast, the semi-infinite homogenous solution resulted in substantial errors in rCBF (34.5% ≤ errors ≤ 60.2%) and BFIs in different layers. The Nth-order linear model simplifies data analysis, thus allowing for online data processing and displaying. Future study will test this linear algorithm in heterogeneous tissues with different levels of blood flow variations and noises.

  9. Source investigation of two outbreaks of skin and soft tissue infection by Mycobacterium abscessus subsp. abscessus in Venezuela.

    PubMed

    Torres-Coy, J A; Rodríguez-Castillo, B A; Pérez-Alfonzo, R; DE Waard, J H

    2016-04-01

    Outbreaks of soft tissue or skin infection due to non-tuberculous mycobacteria are reported frequently in scientific journals but in general the infection source in these outbreaks remains unknown. In Venezuela, in two distinct outbreaks, one after breast augmentation surgery and another after hydrolipoclasy therapy, 16 patients contracted a soft tissue infection due to Mycobacterium abscessus subsp. abscessus. Searching for the possible environmental infection sources in these outbreaks, initially the tap water (in the hydrolipoclasy therapy outbreak) and a surgical skin marker (in the breast implant surgery outbreak), were identified as the infection sources. Molecular typing of the strains with a variable number tandem repeat typing assay confirmed the tap water as the infection source but the molecular typing technique excluded the skin marker. We discuss the results and make a call for the implementation of stringent hygiene and disinfection guidelines for cosmetic procedures in Venezuela. PMID:26441024

  10. Practices and Procedures to Prevent the Transmission of Skin and Soft Tissue Infections in High School Athletes

    ERIC Educational Resources Information Center

    Fritz, Stephanie A.; Long, Marcus; Gaebelein, Claude J.; Martin, Madeline S.; Hogan, Patrick G.; Yetter, John

    2012-01-01

    Skin and soft tissue infections (SSTIs) are frequent in student athletes and are often caused by community-associated methicillin-resistant "Staphylococcus aureus" (CA-MRSA). We evaluated the awareness of CA-MRSA among high school coaches and athletic directors in Missouri (n = 4,408) and evaluated hygiene practices affecting SSTI transmission. Of…

  11. Evaluation of methicillin-resistant Staphylococcus aureus skin and soft-tissue infection prevention strategies at a military training center.

    PubMed

    Morrison, Stephanie M; Blaesing, Carl R; Millar, Eugene V; Chukwuma, Uzo; Schlett, Carey D; Wilkins, Kenneth J; Tribble, David R; Ellis, Michael W

    2013-08-01

    Military trainees are at high risk for skin and soft-tissue infections (SSTIs), especially those caused by methicillin-resistant Staphylococcus aureus (MRSA). A multicomponent hygiene-based SSTI prevention strategy was implemented at a military training center. After implementation, we observed 30% and 64% reductions in overall and MRSA-associated SSTI rates, respectively.

  12. Heterogeneity of ERBB2 in gastric carcinomas: a study of tissue microarray and matched primary and metastatic carcinomas.

    PubMed

    Cho, Eun Yoon; Park, Kyeongmee; Do, Ingu; Cho, Junhun; Kim, Jiyun; Lee, Jeeyun; Kim, Seonwoo; Kim, Kyoung-Mee; Sohn, Tae Sung; Kang, Won Ki; Kim, Sung

    2013-05-01

    Trastuzumab in association with systemic cytotoxic chemotherapy is a therapeutic option for patients with advanced or metastatic ERBB2+ gastric carcinoma. The status of the ERBB2 overexpression or gene amplification is an important predictive marker in gastric cancer. However, it is controversial whether the primary tumor is representative of distant metastases in terms of ERBB2 status. Quadruplicated tissue microarrays from formalin-fixed paraffin-embedded tissues from 498 advanced primary gastric carcinomas and 97 matched metastatic lymph nodes were investigated by immunohistochemistry with HercepTest and silver in situ hybridization. For further comparison, another set of 41 paired primary and distant metastatic gastric carcinomas were also tested. Intratumoral heterogeneity was defined as different results between tissue microarray cores. ERBB2-positivity was observed in 52 gastric carcinomas (10%) and was not associated with recurrence of disease or survival of patients. In ERBB2-positive primary gastric carcinomas, heterogeneous ERBB2 overexpression was observed in 21/63 (33%) gastric carcinomas and heterogeneous ERBB2 gene amplification in 14/62 (23%) cases. Repeated immunohistochemistry and silver in situ hybridization in representative paraffin tumor blocks confirmed focal ERBB2 overexpression and ERBB2 gene amplification and did not change the final results. Discrepancies in ERBB2 results between primary and paired metastatic lymph nodes were observed in 11% of cases by immunohistochemistry and 7% by silver in situ hybridization. Out of the 41 paired primary and distant metastases, 5 (12%) cases were ERBB2-positive, and discrepancy was observed in one case. Intratumoral heterogeneity and discrepant ERBB2 results in primary and metastatic tumor are not uncommon in gastric carcinoma. Results of silver in situ hybridization showed less frequent heterogeneity compared with immunohistochemistry. Wherever possible, ERBB2 immunohistochemistry testing should be

  13. Chromium Is Elevated in Fin Whale (Balaenoptera physalus) Skin Tissue and Is Genotoxic to Fin Whale Skin Cells.

    PubMed

    Wise, Catherine F; Wise, Sandra S; Thompson, W Douglas; Perkins, Christopher; Wise, John Pierce

    2015-07-01

    Hexavalent chromium (Cr(VI)) is present in the marine environment and is a known carcinogen and reproductive toxicant. Cr(VI) is the form of chromium that is well absorbed through the cell membrane. It is also the most prevalent form in seawater. We measured the total Cr levels in skin biopsies obtained from healthy free-ranging fin whales from the Gulf of Maine and found elevated levels relative to marine mammals in other parts of the world. The levels in fin whale biopsies ranged from 1.71 to 19.6 μg/g with an average level of 10.07 μg/g. We also measured the cytotoxicity and genotoxicity of Cr(VI) in fin whale skin cells. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to fin whale skin cells in a concentration-dependent manner. The concentration range used in our cell culture studies used environmentally relevant concentrations based on the biopsy measurements. These data suggest that Cr(VI) may be a concern for whales in the Gulf of Maine.

  14. SU-E-T-477: An Efficient Dose Correction Algorithm Accounting for Tissue Heterogeneities in LDR Brachytherapy

    SciTech Connect

    Mashouf, S; Lai, P; Karotki, A; Keller, B; Beachey, D; Pignol, J

    2014-06-01

    Purpose: Seed brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose surrounding the brachytherapy seeds is based on American Association of Physicist in Medicine Task Group No. 43 (TG-43 formalism) which generates the dose in homogeneous water medium. Recently, AAPM Task Group No. 186 emphasized the importance of accounting for tissue heterogeneities. This can be done using Monte Carlo (MC) methods, but it requires knowing the source structure and tissue atomic composition accurately. In this work we describe an efficient analytical dose inhomogeneity correction algorithm implemented using MIM Symphony treatment planning platform to calculate dose distributions in heterogeneous media. Methods: An Inhomogeneity Correction Factor (ICF) is introduced as the ratio of absorbed dose in tissue to that in water medium. ICF is a function of tissue properties and independent of source structure. The ICF is extracted using CT images and the absorbed dose in tissue can then be calculated by multiplying the dose as calculated by the TG-43 formalism times ICF. To evaluate the methodology, we compared our results with Monte Carlo simulations as well as experiments in phantoms with known density and atomic compositions. Results: The dose distributions obtained through applying ICF to TG-43 protocol agreed very well with those of Monte Carlo simulations as well as experiments in all phantoms. In all cases, the mean relative error was reduced by at least 50% when ICF correction factor was applied to the TG-43 protocol. Conclusion: We have developed a new analytical dose calculation method which enables personalized dose calculations in heterogeneous media. The advantages over stochastic methods are computational efficiency and the ease of integration into clinical setting as detailed source structure and tissue segmentation are not needed. University of Toronto, Natural Sciences and

  15. PLLA-collagen and PLLA-gelatin hybrid scaffolds with funnel-like porous structure for skin tissue engineering

    NASA Astrophysics Data System (ADS)

    Lu, Hongxu; Oh, Hwan Hee; Kawazoe, Naoki; Yamagishi, Kozo; Chen, Guoping

    2012-12-01

    In skin tissue engineering, a three-dimensional porous scaffold is necessary to support cell adhesion and proliferation and to guide cells moving into the repair area in the wound healing process. Structurally, the porous scaffold should have an open and interconnected porous architecture to facilitate homogenous cell distribution. Moreover, the scaffolds should be mechanically strong to protect deformation during the formation of new skin. In this study, the hybrid scaffolds were prepared by forming funnel-like collagen or gelatin sponge on a woven poly(l-lactic acid) (PLLA) mesh. The hybrid scaffolds combined the advantages of both collagen or gelatin (good cell-interactions) and PLLA mesh (high mechanical strength). The hybrid scaffolds were used to culture dermal fibroblasts for dermal tissue engineering. The funnel-like porous structure promoted homogeneous cell distribution and extracellular matrix production. The PLLA mesh reinforced the scaffold to avoid deformation. Subcutaneous implantation showed that the PLLA-collagen and PLLA-gelatin scaffolds promoted the regeneration of dermal tissue and epidermis and reduced contraction during the formation of new tissue. These results indicate that funnel-like hybrid scaffolds can be used for skin tissue regeneration.

  16. Combination effects of tissue heterogeneity and geometric targeting error in stereotactic body radiotherapy for lung cancer using CyberKnife.

    PubMed

    Kang, Ki Mun; Jeong, Bae Kwon; Choi, Hoon-Sik; Yoo, Seung Hoon; Hwang, Ui-Jung; Lim, Young Kyung; Jeong, Hojin

    2015-09-08

    We have investigated the combined effect of tissue heterogeneity and its variation associated with geometric error in stereotactic body radiotherapy (SBRT) for lung cancer. The treatment plans for eight lung cancer patients were calculated using effective path length (EPL) correction and Monte Carlo (MC) algorithms, with both having the same beam configuration for each patient. These two kinds of plans for individual patients were then subsequently recalculated with adding systematic and random geometric errors. In the ordinary treatment plans calculated with no geometric offset, the EPL calculations, compared with the MC calculations, largely overestimated the doses to PTV by ~ 21%, whereas the overestimation were markedly lower in GTV by ~ 12% due to relatively higher density of GTV than of PTV. When recalculating the plans for individual patients with assigning the systematic and random geometric errors, no significant changes in the relative dose distribution, except for overall shift, were observed in the EPL calculations, whereas largely altered in the MC calculations with a consistent increase in dose to GTV. Considering the better accuracy of MC than EPL algorithms, the present results demonstrated the strong coupling of tissue heterogeneity and geometric error, thereby emphasizing the essential need for simultaneous correction for tissue heterogeneity and geometric targeting error in SBRT of lung cancer.

  17. Heterogeneity, Cell Biology and Tissue Mechanics of Pseudostratified Epithelia: Coordination of Cell Divisions and Growth in Tightly Packed Tissues.

    PubMed

    Strzyz, P J; Matejcic, M; Norden, C

    2016-01-01

    Pseudostratified epithelia (PSE) are tightly packed proliferative tissues that are important precursors of the development of diverse organs in a plethora of species, invertebrate and vertebrate. PSE consist of elongated epithelial cells that are attached to the apical and basal side of the tissue. The nuclei of these cells undergo interkinetic nuclear migration (IKNM) which leads to all mitotic events taking place at the apical surface of the epithelium. In this review, we discuss the intricacies of proliferation in PSE, considering cell biological, as well as the physical aspects. First, we summarize the principles governing the invariability of apical nuclear migration and apical cell division as well as the importance of apical mitoses for tissue proliferation. Then, we focus on the mechanical and structural features of these tissues. Here, we discuss how the overall architecture of pseudostratified tissues changes with increased cell packing. Lastly, we consider possible mechanical cues resulting from these changes and their potential influence on cell proliferation.

  18. Discrimination between basal cell carcinoma and hair follicles in skin tissue sections by Raman micro-spectroscopy

    NASA Astrophysics Data System (ADS)

    Larraona-Puy, M.; Ghita, A.; Zoladek, A.; Perkins, W.; Varma, S.; Leach, I. H.; Koloydenko, A. A.; Williams, H.; Notingher, I.

    2011-05-01

    Skin cancer is the most common human malignancy and basal cell carcinoma (BCC) represents approximately 80% of the non-melanoma cases. Current methods of treatment require histopathological evaluation of the tissues by qualified personnel. However, this method is subjective and in some cases BCC can be confused with other structures in healthy skin, including hair follicles. In this preliminary study, we investigated the potential of Raman micro-spectroscopy (RMS) to discriminate between hair follicles and BCC in skin tissue sections excised during Mohs micrographic surgery (MMS). Imaging and diagnosis of skin sections was automatically generated using ' a priori'-built spectral model based on LDA. This model had 90 ± 9% sensitivity and 85 ± 9% specificity for discrimination of BCC from dermis and epidermis. The model used selected Raman bands corresponding to the largest spectral differences between the Raman spectra of BCC and the normal skin regions, associated mainly with nucleic acids and collagen type I. Raman spectra corresponding to the epidermis regions of the hair follicles were found to be closer to those of healthy epidermis rather than BCC. Comparison between Raman spectral images and the gold standard haematoxylin and eosin (H&E) histopathology diagnosis showed good agreement. Some hair follicle regions were misclassified as BCC; regions corresponded mainly to the outermost layer of hair follicle (basal cells) which are expected to have higher nucleic acid concentration. This preliminary study shows the ability of RMS to distinguish between BCC and other tissue structures associated to healthy skin which can be confused with BCC due to their similar morphology.

  19. Variability of antibiotic susceptibility and toxin production of Staphylococcus aureus strains isolated from skin, soft tissue, and bone related infections

    PubMed Central

    2013-01-01

    Background Staphylococcus aureus is an opportunistic commensal bacterium that mostly colonizes the skin and soft tissues. The pathogenicity of S. aureus is due to both its ability to resist antibiotics, and the production of toxins. Here, we characterize a group of genes responsible for toxin production and antibiotic resistance of S. aureus strains isolated from skin, soft tissue, and bone related infections. Results A total of 136 S. aureus strains were collected from five different types of infection: furuncles, pyomyositis, abscesses, Buruli ulcers, and osteomyelitis, from hospital admissions and out-patients in Benin. All strains were resistant to benzyl penicillin, while 25% were resistant to methicillin, and all showed sensitivity to vancomycin. Panton-Valentine leukocidin (PVL) was the most commonly produced virulence factor (70%), followed by staphylococcal enterotoxin B (44%). Exfoliative toxin B was produced by 1.3% of the strains, and was only found in isolates from Buruli ulcers. The tsst-1, sec, and seh genes were rarely detected (≤1%). Conclusions This study provides new insight into the prevalence of toxin and antibiotic resistance genes in S. aureus strains responsible for skin, soft tissue, and bone infections. Our results showed that PVL was strongly associated with pyomyositis and osteomyelitis, and that there is a high prevalence of PVL-MRSA skin infections in Benin. PMID:23924370

  20. Purification and characterization of pepsin-solubilized collagen from skin and connective tissue of giant red sea cucumber (Parastichopus californicus).

    PubMed

    Liu, Zunying; Oliveira, Alexandra C M; Su, Yi-Cheng

    2010-01-27

    Pepsin-solubilized collagen (PSC) was extracted from giant red sea cucumbers ( Parastichopus californicus ) and characterized for denaturation temperature (T(d)), maximum transition temperature (T(m)), enzyme-digested peptide maps, and gel-forming capability. SDS-PAGE showed that PSCs from giant red sea cucumber skin and connective tissue were both type I collagens, consisting of three alpha(1) chains of approximately 138 kDa each. The amino acid composition and peptide maps of PSCs digested by V8 protease were different from those of calf skin type I collagen. The T(d) and T(m) are 18.5 and 33.2 degrees C, respectively, for skin PSC and are 17.9 and 32.7 degrees C, respectively, for connective tissue PSC. Both skin and connective tissue PSCs exhibited good gel-forming capability at pH 6.5 and at an ionic strength of 300 mM salt (NaCl). Collagen isolated from giant red sea cucumbers might be used as an alternative to mammalian collagen in the food and pharmaceutical industries.

  1. A novel approach for the cryodesiccated preservation of tissue-engineered skin substitutes with trehalose.

    PubMed

    Sun, Mei; Jiang, Man; Cui, Jihong; Liu, Wei; Yin, Lu; Xu, Chunli; Wei, Qi; Yan, Xingrong; Chen, Fulin

    2016-03-01

    Tissue-engineered skin (TES) holds great promise for wound healing in the clinic. However, optimized preservation methods remain an obstacle for its wide application. In this experimental work, we developed a novel approach to preserve TES in the desiccated state with trehalose. The uptake of trehalose by fibroblasts under various conditions, including the trehalose concentration, incubation temperature and time, was studied. The cell viability was investigated by the MTT assay and CFSE/PI staining after cryodesiccation and rehydration. TES was then prepared and incubated with trehalose, and the wound healing effect was investigated after desiccated preservation. The results showed that the optimized conditions for trehalose uptake by fibroblasts were incubation in 200 mM trehalose at 37 °C for 8 h. Cryodesiccated cells and TES maintained 37.55% and 28.31% viabilities of controls, respectively. Furthermore, cryodesiccated TES exhibited a similar wound healing effect to normal TES. This novel approach enabled the preservation and transportation of TES at ambient temperature with a prolonged shelf time, which provides great advantages for the application of TES.

  2. Correlation between nasal microbiome composition and remote purulent skin and soft tissue infections.

    PubMed

    Johnson, Ryan C; Ellis, Michael W; Lanier, Jeffrey B; Schlett, Carey D; Cui, Tianyuan; Merrell, D Scott

    2015-02-01

    The incidence of skin and soft tissue infections (SSTIs) has increased dramatically over the past decade, resulting in significant morbidity in millions of otherwise healthy individuals worldwide. Certain groups, like military personnel, are at increased risk for SSTI development. Although nasal colonization with Staphylococcus aureus is an important risk factor for the development of SSTIs, it is not clear why some colonized individuals develop disease while others do not. Recent studies have revealed the importance of microbial diversity in human health. Therefore, we hypothesized that the nasal microbiome may provide valuable insight into SSTI development. To examine this hypothesis, we obtained anterior-naris samples from military trainees with cutaneous abscesses and from asymptomatic (non-SSTI) participants. We also obtained samples from within abscess cavities. Specimens were analyzed by culture, and the microbial community within each sample was characterized using a 16S sequencing-based approach. We collected specimens from 46 non-SSTI participants and from 40 participants with abscesses. We observed a significantly higher abundance of Proteobacteria in the anterior nares in non-SSTI participants (P < 0.0001) than in participants with abscesses. Additionally, we noted a significant inverse correlation between Corynebacterium spp. and S. aureus (P = 0.0001). The sensitivity of standard microbiological culture for abscesses was 71.4%. These data expand our knowledge of the complexity of the nasal and abscess microbiomes and potentially pave the way for novel therapeutic and prophylactic countermeasures against SSTI.

  3. Bi-layer scaffold of chitosan/PCL-nanofibrous mat and PLLA-microporous disc for skin tissue engineering.

    PubMed

    Lou, Tao; Leung, Matthew; Wang, Xuejun; Chang, Julia Yu Fong; Tsao, Ching Ting; Sham, Jonathan Ghing Chi; Edmondson, Dennis; Zhang, Miqin

    2014-06-01

    Current treatments for severe skin damage involve the grafting of extremely limited autogenic skin or the use of synthetic skin grafts that do not fully recapitulate the biological properties of native skin. In this study we developed a novel bi-layer scaffold that provides the microenvironmental cues favorable to promoting skin healing and regeneration. The scaffold is composed of a superficial chitosan/PCL nanofibrous mat (CP-nano mat) and an underlying PLLA microporous disc (PLLA-micro disc). The porous structure of the scaffold permits the interaction of biomolecules released from two types of cells distributed, respectively, throughout the two layers of the scaffold, but the nanofibers prevent the direct intermingling of the cell types. The CP-nano mat and PLLA-micro disc were fabricated by electrospinning and thermally induced phase separation, respectively, and host keratinoctyes as an epidermal equivalent and fibroblasts as a dermal equivalent, respectively, present in the native skin. The potential of this bi-layer scaffold to serve as a skin equivalent was evaluated by co-culture of keratinocytes and fibroblasts and subsequent assessment of cell proliferation, cell morphology, gene transcription, and protein expression. The cell proliferation was found to be greatest in co-culture on bi-layer scaffolds. The gene and protein expression analyses further confirmed that the bi-layer scaffold provided a micro-environment similar to those present in the native extracellular matrix during initial wound healing. Our study suggested that the bi-layer scaffold has great potential to serve as a skin equivalent in tissue engineering. PMID:24749404

  4. Polarimetry based partial least square classification of ex vivo healthy and basal cell carcinoma human skin tissues.

    PubMed

    Ahmad, Iftikhar; Ahmad, Manzoor; Khan, Karim; Ikram, Masroor

    2016-06-01

    Optical polarimetry was employed for assessment of ex vivo healthy and basal cell carcinoma (BCC) tissue samples from human skin. Polarimetric analyses revealed that depolarization and retardance for healthy tissue group were significantly higher (p<0.001) compared to BCC tissue group. Histopathology indicated that these differences partially arise from BCC-related characteristic changes in tissue morphology. Wilks lambda statistics demonstrated the potential of all investigated polarimetric properties for computer assisted classification of the two tissue groups. Based on differences in polarimetric properties, partial least square (PLS) regression classified the samples with 100% accuracy, sensitivity and specificity. These findings indicate that optical polarimetry together with PLS statistics hold promise for automated pathology classification. PMID:27083851

  5. The skin landscape following nonoptical capacitance imaging.

    PubMed

    Xhauflaire-Uhoda, Emmanuelle; Piérard, Gérald E; Quatresooz, Pascale

    2010-01-01

    Skin capacitance is an electrical property measurable at the level of the stratum corneum. Values are related to the moisture content of the tissue. Using the silicon image sensor technology, it has recently become possible to measure capacitance at 50 microm intervals on the skin surface. The resulting nonoptical picture corresponds to skin capacitance imaging. This novel tool for dermatologists highlights with precision the hollow skin surface patterns, including dermatoglyphics, the patterns of the shallow skin lines, and wrinkles. The topographic heterogeneity in skin surface hydration is made visible. In addition, the sweat gland and follicular openings are disclosed. Skin disorders induced by surfactants or presenting as hyperkeratotic areas, including some neoplasms, may show typical aspects. It is concluded that skin capacitance imaging brings added value to the clinical assessment performed by dermatologists. PMID:20141229

  6. In vitro study of ethosome penetration in human skin and hypertrophic scar tissue.

    PubMed

    Zhang, Zhen; Wo, Yan; Zhang, Yixin; Wang, Danru; He, Rong; Chen, Huijin; Cui, Daxiang

    2012-08-01

    The purpose of this study is to characterize a novel transdermal delivery carrier, ethosomes containing 5-fluorouracil. The delivery of drugs from ethosomes in human hypertrophic scar (HS) and the mechanisms of action of ethosomes in human HS were investigated. Percutaneous ethosome permeation was evaluated in vitro in human HS and skin using a Franz's cell. The amount of 5-fluorouracil that permeated HS and skin after 24 hours was most abundant in ethosomes via HS (E-Scar), followed by hydroethanolic solution via HS (H-Scar), ethosomes via skin (E-Skin), and hydroethanolic solution via skin (H-Skin). The penetration of ethosomes in HS and skin was analyzed by ethosomes fluorescently labeled with rhodamine 6GO using confocal laser scanning microscopy. The fluorescence intensity after application for 24 hours was highest in E-Scar, followed by E-Skin, H-Scar, and H-Skin, which indicates the penetration of ethosomes in HS was greatest. In conclusion, we consider that ethosomes are a highly efficient carrier in HS.

  7. In vitro study of ethosome penetration in human skin and hypertrophic scar tissue.

    PubMed

    Zhang, Zhen; Wo, Yan; Zhang, Yixin; Wang, Danru; He, Rong; Chen, Huijin; Cui, Daxiang

    2012-08-01

    The purpose of this study is to characterize a novel transdermal delivery carrier, ethosomes containing 5-fluorouracil. The delivery of drugs from ethosomes in human hypertrophic scar (HS) and the mechanisms of action of ethosomes in human HS were investigated. Percutaneous ethosome permeation was evaluated in vitro in human HS and skin using a Franz's cell. The amount of 5-fluorouracil that permeated HS and skin after 24 hours was most abundant in ethosomes via HS (E-Scar), followed by hydroethanolic solution via HS (H-Scar), ethosomes via skin (E-Skin), and hydroethanolic solution via skin (H-Skin). The penetration of ethosomes in HS and skin was analyzed by ethosomes fluorescently labeled with rhodamine 6GO using confocal laser scanning microscopy. The fluorescence intensity after application for 24 hours was highest in E-Scar, followed by E-Skin, H-Scar, and H-Skin, which indicates the penetration of ethosomes in HS was greatest. In conclusion, we consider that ethosomes are a highly efficient carrier in HS. PMID:22033085

  8. Improving light propagation Monte Carlo simulations with accurate 3D modeling of skin tissue

    SciTech Connect

    Paquit, Vincent C; Price, Jeffery R; Meriaudeau, Fabrice; Tobin Jr, Kenneth William

    2008-01-01

    In this paper, we present a 3D light propagation model to simulate multispectral reflectance images of large skin surface areas. In particular, we aim to simulate more accurately the effects of various physiological properties of the skin in the case of subcutaneous vein imaging compared to existing models. Our method combines a Monte Carlo light propagation model, a realistic three-dimensional model of the skin using parametric surfaces and a vision system for data acquisition. We describe our model in detail, present results from the Monte Carlo modeling and compare our results with those obtained with a well established Monte Carlo model and with real skin reflectance images.

  9. Use of Decellularized Scaffolds Combined with Hyaluronic Acid and Basic Fibroblast Growth Factor for Skin Tissue Engineering

    PubMed Central

    Wu, Zhengzheng; Fan, Lina; Xu, Bin; Lin, Yongliang; Zhang, Peng

    2015-01-01

    Skin damage is one of the common clinical skin diseases, and the main cure is the use of skin graft, especially for large area of skin injury or deep-skin damage. However, skin graft demand is far greater than that currently available. In this study, xenogeneic decellularized scaffold was prepared with pig peritoneum by a series of biochemical treatments to retain normal three-dimensional tissue scaffold and remove cells and antigenic components from the tissue. Scaffold was combined with hyaluronic acid (HA) plus two different concentrations of basic fibroblast growth factor (bFGF) and tested for its use for the repair of skin wounds. HA enhanced bFGF to adsorb to the decellularized scaffolds and slowed the release of bFGF from the scaffolds in vitro. A total of 20 rabbits were sacrificed on day 3, 6, 11, or 14 postsurgery. The wound healing rate and the thickness of dermis layer of each wound were determined for analyzing the wound repair. Statistical analysis was performed by the two-tailed Student's t-test. Wounds covered with scaffolds containing 1 μg/mL bFGF had higher wound healing rates of 47.24%, 74.69%, and 87.54%, respectively, for days 6, 11, and 14 postsurgery than scaffolds alone with wound healing rates of 28.17%, 50.31%, and 61.36% and vaseline oil gauze with wound healing rates of 24.84%, 42.75%, and 57.62%. Wounds covered with scaffolds containing 1 μg/mL bFGF showed more dermis regeneration than the other wounds and had dermis layer of 210.60, 374.40, and 774.20 μm, respectively, for days 6, 11, and 14 postsurgery compared with scaffolds alone with dermis layer of 116.60, 200.00, and 455.40 μm and vaseline oil gauze with dermis layer of 82.60, 186.20, and 384.40 μm. There was no significant difference in wound healing rates and thickness of dermis layer between wounds covered with scaffolds containing 1 and 3 μg/mL bFGF on days 3, 6, 11, and 14 postsurgery. The decellularized scaffolds combined with HA and bFGF can be further

  10. Antimicrobial susceptibility, virulence determinant carriage and molecular characteristics of Staphylococcus aureus isolates associated with skin and soft tissue infections.

    PubMed

    Yu, Fangyou; Liu, Yunling; Lv, Jinnan; Qi, Xiuqin; Lu, Chaohui; Ding, Yu; Li, Dan; Liu, Huanle; Wang, Liangxing

    2015-01-01

    A better understanding of the antimicrobial susceptibility, carriage of virulence determinants and molecular characteristics of Staphylococcus aureus isolates associated with skin and soft tissue infections (SSTIs) may provide further insights related to clinical outcomes with these infections. From January 2012 to September 2013, a total of 128 non-duplicate S. aureus isolates were recovered from patients with SSTIs. All 128 S. aureus SSTI isolates carried at least five virulence genes tested. Virulence genes detected among at least 70% of all tested isolates included hld (100%), hla (95.3%), icaA (96.9%), clf (99.2%), sdrC (79.7%), sdrD (70.3%), and sdrE (72.7%). The prevalence of MRSA isolates with 10 virulence genes tested (54.4%, 31/56) was significantly higher than that among MSSA isolates (35.2%, 25/71) (p<0.05). The positive rates of seb, sen, sem, sdrE and pvl among MRSA isolates were significantly higher than among MSSA isolates (p<0.05). ST7 and ST630 accounting for 10.9% were found to be the predominant STs. The most prevalent spa type was t091 (8.6%). MRSA-ST59-SCCmec IV was the most common clone (12.3%) among MRSA isolates whereas among MSSA isolates the dominant clone was MSSA-ST7 (15.5%). Six main clonal complexes (CCs) were found, including CC5 (52.3%), CC7 (11.7%), CC59 (8.6%), CC88 (6.3%), CC398 (4.7%), and CC121 (3.1%). A higher carriage of seb and sec was found among CC59 isolates. In comparison to CC5 and CC7 isolates, those with the highest carriage rates (>80.0%) of sdrC and sdrD, CC59 isolates had lower prevalence of these two virulence genes. All CC59 isolates were susceptible to gentamicin and trimethoprim/sulfamethoxazole, while CC5 and CC7 isolates had resistance rates to these two antimicrobials of 25.4% and 20.9%, and 40.0% and 40.0%, respectively. The resistance rates for tetracycline, clindamycin, and erythromycin among CC5 isolates were lower than among CC7 and CC59 isolates. In conclusion, the molecular typing of S. aureus SSTI

  11. Pilot study to visualise and measure skin tissue oxygenation, erythema, total haemoglobin and melanin content using index maps in healthy controls

    NASA Astrophysics Data System (ADS)

    Poxon, Ian; Wilkinson, Jack; Herrick, Ariane; Dickinson, Mark; Murray, Andrea

    2014-02-01

    We report on a method for analysing multispectral images of skin in vivo for the measurement and visualisation of skin characteristics. Four different indices were used to characterise skin tissue oxygenation, erythema, total haemoglobin and melanin content. Index values were calculated pixel-wise and combined to create index maps to visualise skin properties. Quantitative measurement of tissue oxygenation saturation was possible by calibrating the oxygenation index using a commercial, calibrated oximeter. Index maps were tested by arterial occlusion of the index finger with multispectral images taken before, during and after occlusion in a pilot study with 10 healthy controls.

  12. Treatment Failure Outcomes for Emergency Department Patients with Skin and Soft Tissue Infections

    PubMed Central

    May, Larissa S.; Zocchi, Mark; Zatorski, Catherine; Jordan, Jeanne A.; Rothman, Richard E.; Ware, Chelsea E.; Eells, Samantha; Miller, Loren

    2015-01-01

    Introduction Skin and soft tissue infections (SSTIs) are commonly evaluated in the emergency department (ED). Our objectives were to identify predictors of SSTI treatment failure within one week post-discharge in patients with cutaneous abscesses, as well as to identify predictors of recurrence within three months in that proportion of participants. Methods This was a sub-analysis of a parent study, conducted at two EDs, evaluating a new, nucleic acid amplification test (NAAT) for Staphylococcus aureus in ED patients. Patients ≥18 years receiving incision and drainage (I&D) were eligible. Patient-reported outcome data on improvement of fever, swelling, erythema, drainage, and pain were collected using a structured abstraction form at one week, one month, and three months post ED visit. Results We enrolled 272 participants (20 from a feasibility study and 252 in this trial), of which 198 (72.8%) completed one-week follow up. Twenty-seven additional one-week outcomes were obtained through medical record review rather than by the one-week follow-up phone call. One hundred ninety-three (73%) patients completed either the one- or three-month follow up. Most patients recovered from their initial infection within one week, with 10.2% of patients reporting one-week treatment failure. The odds of treatment failure were 66% lower for patients who received antibiotics following I&D at their initial visit. Overall SSTI recurrence rate was 28.0% (95% CI [21.6%–34.4%]) and associated with contact with someone infected with methicillin resistant S. aureus (MRSA), previous SSTI history, or clinician use of wound packing. Conclusion Treatment failure was reduced by antibiotic use, whereas SSTI recurrence was associated with prior contact, SSTI, or use of packing. PMID:26587085

  13. Reduced-fat bologna manufactured with poultry skin connective tissue gel.

    PubMed

    Osburn, W N; Mandigo, R W

    1998-10-01

    The objectives of this study were to determine temperature (50, 60, 70, and 80 C) and time (0.5, 1.0, 1.5, and 2.0 h) effects on the water binding ability of chicken skin connective tissue (CCT) and its ability to form model gels; to develop and determine the functionality of added water (AW, 100, 200, and 300%) CCT gels; and to evaluate the attributes of reduced-fat bologna containing 10 to 30% addition of 100 to 300% AW CCT gels. Determination of water binding and holding capacities, and objective textural and color attributes provided data suggesting the practicality of developing and incorporating AW CCT gels as water binders in reduced-fat bologna. Processing qualities, and textural and sensory attributes were analyzed to assess the feasibility of manufacturing a reduced-fat processed poultry product containing a modified poultry by-product. Heating (60 C) CCT for 0.5 h allowed the formation of model CCT gels containing 100 to 300% AW. Added water decreased CCT gel fat, protein, collagen content, and hardness due to a protein (collagen) dilution. Hydration values were sufficient to allow CCT to bind up to 300% AW. Gel fragility and syneresis were observed in higher AW CCT gels due to protein dilution, a result of the high fat content of raw CCT (approximately 40%) and added water. Percentage gel addition and AW decreased (P < 0.05) the hardness of reduced-fat CCT gel bologna. All bologna treatments exhibited acceptable sensory attributes. This study indicated the feasibility of using lower AW CCT gels as texture-modifying agents in reduced-fat comminuted meat products.

  14. Distribution of Fatal Vibrio Vulnificus Necrotizing Skin and Soft-Tissue Infections

    PubMed Central

    Huang, Kuo-Chin; Weng, Hsu-Huei; Yang, Tien-Yu; Chang, Te-Sheng; Huang, Tsan-Wen; Lee, Mel S.

    2016-01-01

    Abstract Vibrio vulnificus necrotizing skin and soft tissue infections (VNSSTIs), which have increased significantly over the past few decades, are still highly lethal and disabling diseases despite advancing antibiotic and infection control practices. We, therefore, examined the spatiotemporal distribution of worldwide reported episodes and associated mortality rates of VNSSTIs between 1966 and 2014. The PubMed and Cochrane Library databases were systematically searched for observational studies on patients with VNSSTIs. The primary outcome was all-cause mortality. We did random-effects meta-analysis to obtain estimates for primary outcomes; the estimates are presented as means plus a 95% confidence interval (CI). Data from the selected studies were also extracted and pooled for correlation analyses. Nineteen studies of 2227 total patients with VNSSTIs were analyzed. More than 95% of the episodes occurred in the subtropical western Pacific and Atlantic coastal regions of the northern hemisphere. While the number of cases and the number of deaths were not correlated with the study period (rs = 0.476 and 0.310, P = 0.233 and 0.456, respectively), the 5-year mortality rate was significantly negatively correlated with them (rs = −0.905, P = 0.002). Even so, the pooled estimate of total mortality rates from the random-effects meta-analysis was as high as 37.2% (95% CI: 0.265–0.479). These data suggest that VNSSTIs are always an important public health problem and will become more critical and urgent because of global warming. Knowing the current distribution of VNSSTIs will help focus education, policy measures, early clinical diagnosis, and appropriate medical and surgical treatment for them. PMID:26844475

  15. Electrospun Poly(lactic acid-co-glycolic acid) Scaffolds for Skin Tissue Engineering

    PubMed Central

    Kumbar, Sangamesh G.; Nukavarapu, Syam Prasad; James, Roshan; Nair, Lakshmi S.; Laurencin, Cato T.

    2008-01-01

    Electrospun fiber matrices composed of scaffolds of varying fiber diameters were investigated for potential application of severe skin loss. Few systematic studies have been performed to examine the effect of varying fiber diameter electrospun fiber matrices for skin regeneration. The present study reports the fabrication of poly[lactic acid-co-glycolic acid] (PLAGA) matrices with fiber diameters of 150–225, 200–300, 250–467, 500–900, 600–1200, 2500–3000 and 3250–6000 nm via electrospinning. All fiber matrices found to have a tensile modulus from 39.23 ± 8.15 to 79.21 ± 13.71 MPa which falls in the range for normal human skin. Further, the porous fiber matrices have porosity between 38–60 % and average pore diameters between 10–14µm. We evaluated the efficacy of these biodegradable fiber matrices as skin substitutes by seeding them with human skin fibroblasts (hSF). Human skin fibroblasts acquired a well spread morphology and showed significant progressive growth on fiber matrices in the 350–1100 nm diameter range. Collagen type III gene expression was significantly up-regulated in hSF seeded on matrices with fiber diameters in the range of 350–1100 nm. Based on the need, the proposed fiber skin substitutes can be successfully fabricated and optimized for skin fibroblast attachment and growth. PMID:18639927

  16. Towards embryonic-like scaffolds for skin tissue engineering: identification of effector molecules and construction of scaffolds.

    PubMed

    Uijtdewilligen, P J E; Versteeg, E M M; Gilissen, C; van Reijmersdal, S V; Schoppmeyer, R; Wismans, R G; Daamen, W F; van Kuppevelt, T H

    2016-01-01

    Autologous skin grafts are the gold standard for the treatment of burn wounds. In a number of cases, treatment with autologous tissue is not possible and skin substitutes are used. The outcome, however, is not optimal and improvements are needed. Inspired by scarless healing in early embryonic development, we here set out a strategy for the design and construction of embryonic-like scaffolds for skin tissue engineering. This strategy may serve as a general approach in the construction of embryonic-like scaffolds for other tissues/organ. As a first step, key effector molecules upregulated during embryonic and neonatal skin formation were identified using a comparative gene expressing analysis. A set of 20 effector molecules was identified, from which insulin-like growth factor 2 (IGF2) and sonic hedgehog (SHH) were selected for incorporation into a type I collagen-heparin scaffold. Porous scaffolds were constructed using purified collagen fibrils and 6% covalently bound heparin (to bind and protect the growth factors), and IGF2 and SHH were incorporated either individually (~0.7 and 0.4 µg/mg scaffolds) or in combination (combined ~1.5 µg/mg scaffolds). In addition, scaffolds containing hyaluronan (up to 20 µg/mg scaffold) were prepared, based on the up- or downregulation of genes involved in hyaluronan synthesis/degradation and its suggested role in scarless healing. In conclusion, based on a comprehensive gene expression analysis, a set of effector molecules and matrix molecules was identified and incorporated into porous scaffolds. The scaffolds thus prepared may create an 'embryonic-like' environment for cells to recapitulate embryonic events and for new tissues/organs.

  17. Fish collagen-based scaffold containing PLGA microspheres for controlled growth factor delivery in skin tissue engineering.

    PubMed

    Cao, Huan; Chen, Ming-Mao; Liu, Yan; Liu, Yuan-Yuan; Huang, Yu-Qing; Wang, Jian-Hua; Chen, Jing-Di; Zhang, Qi-Qing

    2015-12-01

    To design a scaffold controlled release system for skin tissue engineering, fish collagen/chitosan/chondroitin sulfate scaffolds were fabricated by freeze-drying and incorporated with bFGF-loaded PLGA microspheres (MPs). SEM showed that the scaffolds exhibited an interconnected porous structure, and the spherical MPs were uniformly distributed into the scaffolds. The higher swelling and degradation rate of scaffolds/MPs could lead to a higher diffusion rate of MPs from the scaffolds, causing an increase in the protein release. The release rate of proteins could be adjusted by the size of MPs and the ratio of collagen to chitosan of scaffolds. Circular dichroism spectroscopy and MTT of bFGF after release indicated that the released bFGF retained its structural integrity and bioactivity during preparation. Cell proliferation and in vivo evaluation results suggested that the scaffolds/MPs had a good biocompatibility and an ability to promote fibroblast cell proliferation and skin tissue regeneration. These results demonstrated that this scaffold/MP controlled release system has the potential for skin tissue engineering.

  18. Fractionation in normal tissues: the (α/β)eff concept can account for dose heterogeneity and volume effects.

    PubMed

    Hoffmann, Aswin L; Nahum, Alan E

    2013-10-01

    The simple Linear-Quadratic (LQ)-based Withers iso-effect formula (WIF) is widely used in external-beam radiotherapy to derive a new tumour dose prescription such that there is normal-tissue (NT) iso-effect when changing the fraction size and/or number. However, as conventionally applied, the WIF is invalid unless the normal-tissue response is solely determined by the tumour dose. We propose a generalized WIF (gWIF) which retains the tumour prescription dose, but replaces the intrinsic fractionation sensitivity measure (α/β) by a new concept, the normal-tissue effective fractionation sensitivity, [Formula: see text], which takes into account both the dose heterogeneity in, and the volume effect of, the late-responding normal-tissue in question. Closed-form analytical expressions for [Formula: see text] ensuring exact normal-tissue iso-effect are derived for: (i) uniform dose, and (ii) arbitrary dose distributions with volume-effect parameter n = 1 from the normal-tissue dose-volume histogram. For arbitrary dose distributions and arbitrary n, a numerical solution for [Formula: see text] exhibits a weak dependence on the number of fractions. As n is increased, [Formula: see text] increases from its intrinsic value at n = 0 (100% serial normal-tissue) to values close to or even exceeding the tumour (α/β) at n = 1 (100% parallel normal-tissue), with the highest values of [Formula: see text] corresponding to the most conformal dose distributions. Applications of this new concept to inverse planning and to highly conformal modalities are discussed, as is the effect of possible deviations from LQ behaviour at large fraction sizes. PMID:24029492

  19. How do heterogeneities in single cell rigidity influence the mechanical behavior at the tissue level?

    NASA Astrophysics Data System (ADS)

    Bi, Dapeng; Wetzel, Franziska; Fritsch, Anatol; Marchetti, M. Cristina; Manning, M. Lisa; Kaes, Josef

    It has been long recognized that solid tumor tissues are mechanically more rigid than surrounding healthy tissues. However recent experiments have shown that in primary tumor samples from patients with mammary and cervix carcinomas, cells exhibit a broad distribution of rigidities, with a higher fraction of softer and more contractile cells compared to normal tissues. This gives rise to a paradox: does softness emerge from adaptation to mechanical and chemical cues in the external microenvironment, or are soft cells already present inside a primary solid tumor? Motivated by these observations, we study a model of dense tissues that incorporates the experimental data for cell stiffness variations to reveal that, surprisingly, tumors with a significant fraction of very soft cells can still remain rigid. Moreover, in tissues with the observed distributions of cell stiffnesses, softer cells spontaneously self-organize into lines or streams, possibly facilitating cancer metastasis.

  20. NOTE: Spectra from 2.5-15 µm of tissue phantom materials, optical clearing agents and ex vivo human skin: implications for depth profiling of human skin

    NASA Astrophysics Data System (ADS)

    Viator, John A.; Choi, Bernard; Peavy, George M.; Kimel, Sol; Nelson, J. Stuart

    2003-01-01

    Infrared measurements have been used to profile or image biological tissue, including human skin. Usually, analysis of such measurements has assumed that infrared absorption is due to water and collagen. Such an assumption may be reasonable for soft tissue, but introduction of exogenous agents into skin or the measurement of tissue phantoms has raised the question of their infrared absorption spectrum. We used Fourier transform infrared spectroscopy in attenuated total reflection mode to measure the infrared absorption spectra, in the range of 2-15 µm, of water, polyacrylamide, Intralipid, collagen gels, four hyperosmotic clearing agents (glycerol, 1,3-butylene glycol, trimethylolpropane, TopicareTM), and ex vivo human stratum corneum and dermis. The absorption spectra of the phantom materials were similar to that of water, although additional structure was noted in the range of 6-10 µm. The absorption spectra of the clearing agents were more complex, with molecular absorption bands dominating between 6 and 12 µm. Dermis was similar to water, with collagen structure evident in the 6-10 µm range. Stratum corneum had a significantly lower absorption than dermis due to a lower content of water. These results suggest that the assumption of water-dominated absorption in the 2.5-6 µm range is valid. At longer wavelengths, clearing agent absorption spectra differ significantly from the water spectrum. This spectral information can be used in pulsed photothermal radiometry or utilized in the interpretation of reconstructions in which a constant μir is used. In such cases, overestimating μir will underestimate chromophore depth and vice versa, although the effect is dependent on actual chromophore depth.

  1. In-vivo characterization of endogenous porphyrin fluorescence from DMBA-treated Swiss Albino mice skin carcinogenesis for measuring tissue transformation

    NASA Astrophysics Data System (ADS)

    Ganesan, Singaravelu; Ebenezar, Jeyasingh; Hemamalini, Srinivasan; Aruna, Prakasa R.

    2002-05-01

    Steady state fluorescence spectroscopic characterization of endogenous porphyrin emission from DMBA treated skin carcinogenesis in Swiss albino mice was carried out. The emission of endogenous porphyrin from normal and abnormal skin tissues was studied both in the presence and absence of exogenous ALA to compare the resultant porphyrin emission characterictics. The mice skin is excited at 405nm and emission spectra are scanned from 430 to 700nm. The average fluorescence emission spectra of mice skin at normal and various tissues transformation conditions were found to be different. Two peaks around 460nm and 636nm were observed and they may be attributed to NADH, Elastin and collagen combination and endogenous porphyrin emission. The intensity at 636nm increases as the stage of the cancer increases. Although exogenous ALA enhances the PPIX level in tumor, the synthesis of PPIX was also found in normal surrounding skin, in fact, with higher concentration than that of tumor tissues.

  2. Factors Associated with Decision to Hospitalize Emergency Department Patients with Skin and Soft Tissue Infection

    PubMed Central

    Talan, David A.; Salhi, Bisan A.; Moran, Gregory J.; Mower, William R.; Hsieh, Yu-Hsiang; Krishnadasan, Anusha; Rothman, Richard E.

    2015-01-01

    Introduction Emergency department (ED) hospitalizations for skin and soft tissue infection (SSTI) have increased, while concern for costs has grown and outpatient parenteral antibiotic options have expanded. To identify opportunities to reduce admissions, we explored factors that influence the decision to hospitalize an ED patient with a SSTI. Methods We conducted a prospective study of adults presenting to 12 U.S. EDs with a SSTI in which physicians were surveyed as to reason(s) for admission, and clinical characteristics were correlated with disposition. We employed chi-square binary recursive partitioning to assess independent predictors of admission. Serious adverse events were recorded. Results Among 619 patients, median age was 38.7 years. The median duration of symptoms was 4.0 days, 96 (15.5%) had a history of fever, and 46 (7.5%) had failed treatment. Median maximal length of erythema was 4.0cm (IQR, 2.0–7.0). Upon presentation, 39 (6.3%) had temperature >38°C, 81 (13.1%) tachycardia, 35 (5.7%), tachypnea, and 5 (0.8%) hypotension; at the time of the ED disposition decision, these findings were present in 9 (1.5%), 11 (1.8%), 7 (1.1%), and 3 (0.5%) patients, respectively. Ninety-four patients (15.2%) were admitted, 3 (0.5%) to the intensive care unit (ICU). Common reasons for admission were need for intravenous antibiotics in 80 (85.1%; the only reason in 41.5%), surgery in 23 (24.5%), and underlying disease in 11 (11.7%). Hospitalization was significantly associated with the following factors in decreasing order of importance: history of fever (present in 43.6% of those admitted, and 10.5% discharged; maximal length of erythema >10cm (43.6%, 11.3%); history of failed treatment (16.1%, 6.0%); any co-morbidity (61.7%, 27.2%); and age >65 years (5.4%, 1.3%). Two patients required amputation and none had ICU transfer or died. Conclusion ED SSTI patients with fever, larger lesions, and co-morbidities tend to be hospitalized, almost all to non-critical areas

  3. Evolution of three dimensional skin equivalent models reconstructed in vitro by tissue engineering.

    PubMed

    Auxenfans, Celine; Fradette, Julie; Lequeux, Charlotte; Germain, Lucie; Kinikoglu, Beste; Bechetoille, Nicolas; Braye, Fabienne; Auger, François A; Damour, Odile

    2009-01-01

    Since the culture of keratinocytes on feeder layers, research to produce skin equivalents has been motivated by the challenge of treating large burns and chronic wounds and by European regulations which both require proof of the innocuousness and the effectiveness of cosmetic products, and which forbid animal testing. The dynamism in fundamental research, dermocosmetology and the pharmaceutical industry has led to the evolution and complexification of reconstructed skin. The Collagen-GAG-Chitosan sponge, as well as the self-assembly model, allow dermal reconstruction in which the neosynthesized extracellular matrix contains all of the desired macromolecules. It is deposited forming an ultrastructurally organised architecture. The quality of the dermis obtained allows the development and regeneration of a pluristratified and differentiated epidermis firmly anchored by an organised dermal-epidermal junction. Evolution of reconstructed skin into models which are more and more similar to the physiological skin results in higher graft take rates in the treatment of burns and chronic wounds, and brings to research, to dermocosmetology and to the pharmaceutical industry, a wide range of products such as pigmented, endothelialized, immunocompetent, and now adipose reconstructed skins. The present review will mainly concentrate on the latest developments in skin engineering and will mostly concern the studies carried out by our groups. PMID:19106039

  4. Nerve growth factor displays stimulatory effects on human skin and lung fibroblasts, demonstrating a direct role for this factor in tissue repair

    NASA Astrophysics Data System (ADS)

    Micera, Alessandra; Vigneti, Eliana; Pickholtz, Dalia; Reich, Reuven; Pappo, Orit; Bonini, Sergio; Maquart, François Xavier; Aloe, Luigi; Levi-Schaffer, Francesca

    2001-05-01

    Nerve growth factor (NGF) is a polypeptide which, in addition to its effect on nerve cells, is believed to play a role in inflammatory responses and in tissue repair. Because fibroblasts represent the main target and effector cells in these processes, to investigate whether NGF is involved in lung and skin tissue repair, we studied the effect of NGF on fibroblast migration, proliferation, collagen metabolism, modulation into myofibroblasts, and contraction of collagen gel. Both skin and lung fibroblasts were found to produce NGF and to express tyrosine kinase receptor (trkA) under basal conditions, whereas the low-affinity p75 receptor was expressed only after prolonged NGF exposure. NGF significantly induced skin and lung fibroblast migration in an in vitro model of wounded fibroblast and skin migration in Boyden chambers. Nevertheless NGF did not influence either skin or lung fibroblast proliferation, collagen production, or metalloproteinase production or activation. In contrast, culture of both lung and skin fibroblasts with NGF modulated their phenotype into myofibroblasts. Moreover, addition of NGF to both fibroblast types embedded in collagen gel increased their contraction. Fibrotic human lung or skin tissues displayed immunoreactivity for NGF, trkA, and p75. These data show a direct pro-fibrogenic effect of NGF on skin and lung fibroblasts and therefore indicate a role for NGF in tissue repair and fibrosis.

  5. Epidermal Stem Cells Cultured on Collagen-Modified Chitin Membrane Induce In Situ Tissue Regeneration of Full-Thickness Skin Defects in Mice

    PubMed Central

    Shen, Yan; Dai, Libing; Li, Xiaojian; Liang, Rong; Guan, Guangxiong; Zhang, Zhi; Cao, Wenjuan; Liu, Zhihe; Mei, Shirley; Liang, Weiguo; Qin, Shennan; Xu, Jiake; Chen, Honghui

    2014-01-01

    A Large scale of full-thickness skin defects is lack of auto-grafts and which requires the engineered skin substitutes for repair and regeneration. One major obstacle in skin tissue engineering is to expand epidermal stem cells (ESCs) and develop functional substitutes. The other one is the scaffold of the ESCs. Here, we applied type I collagen-modified chitin membrane to form collagen-chitin biomimetic membrane (C-CBM), which has been proved to have a great biocompatibility and degraded totally when it was subcutaneously transplanted into rat skin. ESCs were cultured, and the resulting biofilm was used to cover full-thickness skin defects in nude mice. The transplantation of ESCs- collagen- chitn biomimetic membrane (ESCs-C-CBM) has achieved in situ skin regeneration. In nude mice, compared to controls with collagen-chitin biomimetic membrane (C-CBM) only, the ESCs-C-CBM group had significantly more dermatoglyphs on the skin wound 10 w after surgery, and the new skin was relatively thick, red and elastic. In vivo experiments showed obvious hair follicle cell proliferation in the full-thickness skin defect. Stem cell markers examination showed active ESCs in repair and regeneration of skin. The results indicate that the collagen-modified chitin membrane carry with ESCs has successfully regenerated the whole skin with all the skin appendages and function. PMID:24516553

  6. Epidermal stem cells cultured on collagen-modified chitin membrane induce in situ tissue regeneration of full-thickness skin defects in mice.

    PubMed

    Shen, Yan; Dai, Libing; Li, Xiaojian; Liang, Rong; Guan, Guangxiong; Zhang, Zhi; Cao, Wenjuan; Liu, Zhihe; Mei, Shirley; Liang, Weiguo; Qin, Shennan; Xu, Jiake; Chen, Honghui

    2014-01-01

    A Large scale of full-thickness skin defects is lack of auto-grafts and which requires the engineered skin substitutes for repair and regeneration. One major obstacle in skin tissue engineering is to expand epidermal stem cells (ESCs) and develop functional substitutes. The other one is the scaffold of the ESCs. Here, we applied type I collagen-modified chitin membrane to form collagen-chitin biomimetic membrane (C-CBM), which has been proved to have a great biocompatibility and degraded totally when it was subcutaneously transplanted into rat skin. ESCs were cultured, and the resulting biofilm was used to cover full-thickness skin defects in nude mice. The transplantation of ESCs- collagen- chitn biomimetic membrane (ESCs-C-CBM) has achieved in situ skin regeneration. In nude mice, compared to controls with collagen-chitin biomimetic membrane (C-CBM) only, the ESCs-C-CBM group had significantly more dermatoglyphs on the skin wound 10 w after surgery, and the new skin was relatively thick, red and elastic. In vivo experiments showed obvious hair follicle cell proliferation in the full-thickness skin defect. Stem cell markers examination showed active ESCs in repair and regeneration of skin. The results indicate that the collagen-modified chitin membrane carry with ESCs has successfully regenerated the whole skin with all the skin appendages and function.

  7. The expression of histamine H4 receptor mRNA in the skin and other tissues of normal dogs.

    PubMed

    Eisenschenk, Melissa N C; Torres, Sheila M F; Oliveira, Simone; Been, Clint S

    2011-10-01

    The histamine 4 (H(4)) receptor was first cloned and characterized in 2000 using the human H(3) receptor DNA sequence. The H(4) receptor has been shown to participate in various aspects of inflammation, such as chemotaxis, upregulation of adhesion molecule expression and modulation of cytokine secretion. The primary goal of this study was to determine whether H(4) receptor mRNA is expressed in normal canine skin by performing an RT-PCR. An additional goal was to determine the expression of this receptor in the colon, liver, spleen and kidney. Tissues were collected from five healthy, young-adult pit bull dogs. Samples were immediately placed in RNAlater(®) solution and stored at -20°C until processed. The amplified products in all skin samples in addition to the colon, liver, spleen and kidney (variable expression) had the expected size of 400-500 bp. The sequenced amplicons matched the National Center for Biotechnology Information published sequence for the canine H(4) receptor. The study results showed that canine normal skin expresses the H(4) receptor mRNA. Further studies using immunohistochemistry should be conducted to demonstrate the expression of the H(4) receptor at the protein level and to localize the expression of this receptor in the skin. PMID:21392139

  8. Tissue-resident memory CD8+ T cells continuously patrol skin epithelia to quickly recognize local antigen

    PubMed Central

    Ariotti, Silvia; Beltman, Joost B.; Chodaczek, Grzegorz; Hoekstra, Mirjam E.; van Beek, Anna E.; Gomez-Eerland, Raquel; Ritsma, Laila; van Rheenen, Jacco; Marée, Athanasius F. M.; Zal, Tomasz; de Boer, Rob J.; Haanen, John B. A. G.; Schumacher, Ton N.

    2012-01-01

    Recent work has demonstrated that following the clearance of infection a stable population of memory T cells remains present in peripheral organs and contributes to the control of secondary infections. However, little is known about how tissue-resident memory T cells behave in situ and how they encounter newly infected target cells. Here we demonstrate that antigen-specific CD8+ T cells that remain in skin following herpes simplex virus infection show a steady-state crawling behavior in between keratinocytes. Spatially explicit simulations of the migration of these tissue-resident memory T cells indicate that the migratory dendritic behavior of these cells allows the detection of antigen-expressing target cells in physiologically relevant time frames of minutes to hours. Furthermore, we provide direct evidence for the identification of rare antigen-expressing epithelial cells by skin-patrolling memory T cells in vivo. These data demonstrate the existence of skin patrol by memory T cells and reveal the value of this patrol in the rapid detection of renewed infections at a previously infected site. PMID:23150545

  9. Effects of Intense Pulsed Light on Tissue Vascularity and Wound Healing: A Study with Mouse Island Skin Flap Model

    PubMed Central

    Cao Minh, Trinh; Xuan Hai, Do; Thi Ngoc, Pham

    2015-01-01

    Intense pulsed light (IPL) has been used extensively in aesthetic and cosmetic dermatology. To test whether IPL could change the tissue vascularity and improve wound healing, mice were separated into 4 groups. Mice in Group I were not treated with IPL, whereas, dorsal skins of mice in Groups II, III, and IV were treated with 35 J/cm2, 25 J/cm2, and 15 J/cm2 IPL, respectively. After 2 weeks, dorsal island skin flaps were raised, based on the left deep circumflex iliac vessels as pedicles; then, survival rate was assessed. Flaps in Group IV (treated with lowest dose of IPL) have a survival rate significantly higher than other groups. Counting blood vessels did not demonstrate any significant differences; however, vessel dilation was found in this group. The results show that IPL at the therapeutic doses which are usually applied to humans is harmful to mouse dorsal skin and did not enhance wound healing, whereas, IPL at much lower dose could improve wound healing. The possible mechanism is the dilation of tissue vasculature thanks to the electromagnetic character of IPL. Another mechanism could be the heat-shock protein production. PMID:25722887

  10. Effects of intense pulsed light on tissue vascularity and wound healing: a study with mouse island skin flap model.

    PubMed

    Cao Minh, Trinh; Xuan Hai, Do; Thi Ngoc, Pham

    2015-01-01

    Intense pulsed light (IPL) has been used extensively in aesthetic and cosmetic dermatology. To test whether IPL could change the tissue vascularity and improve wound healing, mice were separated into 4 groups. Mice in Group I were not treated with IPL, whereas, dorsal skins of mice in Groups II, III, and IV were treated with 35 J/cm(2), 25 J/cm(2), and 15 J/cm(2) IPL, respectively. After 2 weeks, dorsal island skin flaps were raised, based on the left deep circumflex iliac vessels as pedicles; then, survival rate was assessed. Flaps in Group IV (treated with lowest dose of IPL) have a survival rate significantly higher than other groups. Counting blood vessels did not demonstrate any significant differences; however, vessel dilation was found in this group. The results show that IPL at the therapeutic doses which are usually applied to humans is harmful to mouse dorsal skin and did not enhance wound healing, whereas, IPL at much lower dose could improve wound healing. The possible mechanism is the dilation of tissue vasculature thanks to the electromagnetic character of IPL. Another mechanism could be the heat-shock protein production.

  11. Fine mapping of tissue properties on excised samples of melanoma and skin without the need for histological staining.

    PubMed

    Tittmann, Bernhard R; Miyasaka, Chiaki; Maeva, Elena; Shum, David

    2013-02-01

    This paper develops a novel two-frequency approach for noninvasive evaluation of cancerous tissue with optimum depth and resolution. Frequencies of about 50 MHz are used in thickly sliced tissue to detect differences of the relative attenuation (C-scan mode scanning) with relatively limited resolution. Thus, suspect zones can be identified according to a quantitative criterion. These suspect zones are then selected for preparation of thin, transversal slices from within the original thick slices. Very-high-resolution (1-μm) visualization of cells is obtained at around 600 MHz on these transversal sections and adjacent sections are prepared for histological study in parallel. The technique's feasibility and potential are demonstrated on both normal and cancerous (melanoma) skin tissue. Isotropy of the specimens is experimentally verified to ensure that conditions were coherent for use of a 5-layer, angular spectrum model made to simulate longitudinal velocity, allowing estimation of longitudinal velocity from semiquantitative V(z) data.

  12. A close relationship between type 1 diabetes and vitamin A-deficiency and matrix metalloproteinase and hyaluronidase activities in skin tissues.

    PubMed

    Takahashi, Noriko; Takasu, Shingo

    2011-11-01

    Numerous wrinkles are observed in the skin of streptozotocin (STZ)-induced type 1 diabetic rats, which are similar to those seen in vitamin A-deficient (VAD) rats. Retinoic acid (RA), the active form of vitamin A, promotes the production of collagen in dermis and induces cell growth and inhibition of epidermal differentiation in skin tissues. Normal skin function is maintained by the extracellular matrix (ECM)-degrading enzymes, matrix metalloproteinase (MMP) and hyaluronidase (HAase). This study is the first comparison of MMP and HAase activities in skin tissues of type 1 diabetic, VAD and RA-treated animal models. In skin tissues of type 1 diabetic and VAD rats or VAD mice, both MMP-2 and HAase activities increased as compared with controls. In contrast, MMP and HAase activities were reduced in the skin tissues of RA-treated mice. Blood retinol levels in type 1 diabetic rats were lower than controls. These results indicate a close relationship between type 1 diabetes and vitamin A-deficiency on MMP and HAase in skin tissues, suggesting that type 1 diabetic rats could be vitamin A-deficient. Vitamin A-derived RA might be a significant regulator of ECM-degrading enzyme expression and diabetic symptoms.

  13. Skin microbiota-associated inflammation precedes autoantibody induced tissue damage in experimental epidermolysis bullosa acquisita.

    PubMed

    Ellebrecht, Christoph T; Srinivas, Girish; Bieber, Katja; Banczyk, David; Kalies, Kathrin; Künzel, Sven; Hammers, Christoph M; Baines, John F; Zillikens, Detlef; Ludwig, Ralf J; Westermann, Jürgen

    2016-04-01

    Epidermolysis bullosa acquisita (EBA) is a chronic autoimmune blistering skin disease characterized by autoantibodies against type VII collagen (COL7). Immunization of SJL/J mice with recombinant murine COL7 results in break of tolerance and skin blisters. Strikingly, despite circulating autoantibodies, the same genetic background and identical environmental conditions, 20% of mice remain healthy. To elucidate the regulation of the transition from the presence of autoantibodies to overt autoimmune disease, we characterized the innate and adaptive immune response of mice that remain healthy after immunization and compared it to mice that developed skin disease. Both clinically healthy and diseased SJL/J mice showed circulating autoantibodies and deposition of complement-fixing IgG2c autoantibodies and C3 at the dermal-epidermal junction. However, only in diseased animals significant neutrophil infiltration and increase in FcgRIV expression were observed in the skin. In contrast, the expression of T cell signature cytokines in the T cell zone of the draining lymph node was comparable between clinically healthy and diseased animals after immunization. Surprisingly, health was associated with a decreased expression of CD11c, TNFA and KC (CXCL1) in the skin prior to immunization and could be predicted with a negative predictive value of >80%. Furthermore, mice that did not develop clinical disease showed a significantly higher richness and distinctly clustered diversity of their skin microbiota before immunization. Our data indicate that the decision whether blisters develop in the presence of autoantibodies is governed in the skin rather than in the lymph node, and that a greater richness of cutaneous bacterial species appears to be protective. PMID:26341384

  14. Effects of heterogeneous structure and diffusion permeability of body tissues on decompression gas bubble dynamics.

    PubMed

    Nikolaev, V P

    2000-07-01

    To gain insight into the special nature of gas bubbles that may form in astronauts, aviators and divers, we developed a mathematical model which describes the following: 1) the dynamics of extravascular bubbles formed in intercellular cavities of a hypothetical tissue undergoing decompression; and 2) the dynamics of nitrogen tension in a thin layer of intercellular fluid and in a thick layer of cells surrounding the bubbles. This model is based on the assumption that, due to limited cellular membrane permeability for gas, a value of effective nitrogen diffusivity in the massive layer of cells in the radial direction is essentially lower compared to conventionally accepted values of nitrogen diffusivity in water and body tissues. Due to rather high nitrogen diffusivity in intercellular fluid, a bubble formed just at completion of fast one-stage reduction of ambient pressure almost instantly grows to the size determined by the initial volume of the intercellular cavity, surface tension of the fluid, the initial nitrogen tension in the tissue, and the level of final pressure. The rate of further bubble growth and maximum bubble size depend on comparatively low effective nitrogen diffusivity in the cell layer, the tissue perfusion rate, the initial nitrogen tension in the tissue, and the final ambient pressure. The tissue deformation pressure performs its conservative action on bubble dynamics only in a limited volume of tissue (at a high density of formed bubbles). Our model is completely consistent with the available data concerning the random latency times to the onset of decompression sickness (DCS) symptoms associated with hypobaric decompressions simulating extravehicular activity. We believe that this model could be used as a theoretical basis for development of more adequate methods for the DCS risk prediction.

  15. Simulations of skin and subcutaneous tissue loading in the buttocks while regaining weight-bearing after a push-up in wheelchair users.

    PubMed

    Levy, Ayelet; Kopplin, Kara; Gefen, Amit

    2013-12-01

    Pressure ulcers (PUs) are common in patients who chronically depend on a wheelchair for mobility, such as those with a spinal cord injury (SCI). In attempt to prevent the formation of PUs, pressure relieving maneuvers, such as push-ups, are commonly recommended for individuals with SCI. However, very little is known about skin and subcutaneous fat tissue load distributions during sitting and in particular their development during the process of regaining weight-bearing after a push-up. Knowledge on how these loads evolve during sitting-down is critical for understanding the susceptibility of skin to PUs. Considering the potential practical implications on guidelines for wheelchair users, we studied herein the build-up of shear loads in skin and subcutaneous fat using a model of the buttocks of a single SCI subject. Using 12 variants of our finite element (FE) model, we determined the shear loads in skin and subcutaneous fat tissues under the ischial tuberosities when sitting down on foam cushions with different stiffness properties, in healthy skin and scarred skin conditions, focusing on the time course of the build-up of tissue loads. We found substantial differences between the loading curves of skin and fat: While the fat was loaded at a nearly constant rate, skin loads increased nonlinearly - with a greater load/time slope at early skin-support contact. In the context of tissue health and prevention of PUs, this indicates that the more sensitive period with respect to skin integrity is at initial skin-support contact. We further found that the edges of a pre-existing scar are more susceptible to injury, and the greater risk for that is when a hypertrophic scar is present. Despite that this is a theoretical modeling study with associated limitations, we believe that it is already appropriate to recommend to patients to reposition themselves gradually and gently, and not to "fall" back into the wheelchair after finishing a push-up maneuver.

  16. Polymer scaffolds with no skin-effect for tissue engineering applications fabricated by thermally induced phase separation.

    PubMed

    Kasoju, Naresh; Kubies, Dana; Sedlačík, Tomáš; Janoušková, Olga; Koubková, Jana; Kumorek, Marta M; Rypáček, František

    2016-01-11

    Thermally induced phase separation (TIPS) based methods are widely used for the fabrication of porous scaffolds for tissue engineering and related applications. However, formation of a less-/non-porous layer at the scaffold's outer surface at the air-liquid interface, often known as the skin-effect, restricts the cell infiltration inside the scaffold and therefore limits its efficacy. To this end, we demonstrate a TIPS-based process involving the exposure of the just quenched poly(lactide-co-caprolactone):dioxane phases to the pure dioxane for a short time while still being under the quenching strength, herein after termed as the second quenching (2Q). Scanning electron microscopy, mercury intrusion porosimetry and contact angle analysis revealed a direct correlation between the time of 2Q and the gradual disappearance of the skin, followed by the widening of the outer pores and the formation of the fibrous filaments over the surface, with no effect on the internal pore architecture and the overall porosity of scaffolds. The experiments at various quenching temperatures and polymer concentrations revealed the versatility of 2Q in removing the skin. In addition, the in vitro cell culture studies with the human primary fibroblasts showed that the scaffolds prepared by the TIPS based 2Q process, with the optimal exposure time, resulted in a higher cell seeding and viability in contrast to the scaffolds prepared by the regular TIPS. Thus, TIPS including the 2Q step is a facile, versatile and innovative approach to fabricate the polymer scaffolds with a skin-free and fully open porous surface morphology for achieving a better cell response in tissue engineering and related applications.

  17. dsRNA Released by Tissue Damage Activates TLR3 to Drive Skin Regeneration.

    PubMed

    Nelson, Amanda M; Reddy, Sashank K; Ratliff, Tabetha S; Hossain, M Zulfiquer; Katseff, Adiya S; Zhu, Amadeus S; Chang, Emily; Resnik, Sydney R; Page, Carly; Kim, Dongwon; Whittam, Alexander J; Miller, Lloyd S; Garza, Luis A

    2015-08-01

    Regeneration of skin and hair follicles after wounding--a process known as wound-induced hair neogenesis (WIHN)--is a rare example of adult organogenesis in mammals. As such, WIHN provides a unique model system for deciphering mechanisms underlying mammalian regeneration. Here, we show that dsRNA, which is released from damaged skin, activates Toll-Like Receptor 3 (TLR3) and its downstream effectors IL-6 and STAT3 to promote hair follicle regeneration. Conversely, TLR3-deficient animals fail to initiate WIHN. TLR3 activation promotes expression of hair follicle stem cell markers and induces elements of the core hair morphogenetic program, including ectodysplasin A receptor (EDAR) and the Wnt and Shh pathways. Our results therefore show that dsRNA and TLR3 link the earliest events of mammalian skin wounding to regeneration and suggest potential therapeutic approaches for promoting hair neogenesis.

  18. Respiratory chain protein turnover rates in mice are highly heterogeneous but strikingly conserved across tissues, ages, and treatments

    PubMed Central

    Karunadharma, Pabalu P.; Basisty, Nathan; Chiao, Ying Ann; Dai, Dao-Fu; Drake, Rachel; Levy, Nick; Koh, William J.; Emond, Mary J.; Kruse, Shane; Marcinek, David; Maccoss, Michael J.; Rabinovitch, Peter S.

    2015-01-01

    The mitochondrial respiratory chain (RC) produces most of the cellular ATP and requires strict quality-control mechanisms. To examine RC subunit proteostasis in vivo, we measured RC protein half-lives (HLs) in mice by liquid chromatography-tandem mass spectrometry with metabolic [2H3]-leucine heavy isotope labeling under divergent conditions. We studied 7 tissues/fractions of young and old mice on control diet or one of 2 diet regimens (caloric restriction or rapamycin) that altered protein turnover (42 conditions in total). We observed a 6.5-fold difference in mean HL across tissues and an 11.5-fold difference across all conditions. Normalization to the mean HL of each condition showed that relative HLs were conserved across conditions (Spearman’s ρ = 0.57; P < 10–4), but were highly heterogeneous between subunits, with a 7.3-fold mean range overall, and a 2.2- to 4.6-fold range within each complex. To identify factors regulating this conserved distribution, we performed statistical analyses to study the correlation of HLs to the properties of the subunits. HLs significantly correlated with localization within the mitochondria, evolutionary origin, location of protein-encoding, and ubiquitination levels. These findings challenge the notion that all subunits in a complex turnover at comparable rates and suggest that there are common rules governing the differential proteolysis of RC protein subunits under divergent cellular conditions.—Karunadharma, P. P., Basisty, N., Chiao, Y. A., Dai, D.-F., Drake, R., Levy, N., Koh, W. J., Emond, M. J., Kruse, S., Marcinek, D., Maccoss, M. J., Rabinovitch, P. S. Respiratory chain protein turnover rates in mice are highly heterogeneous but strikingly conserved across tissues, ages, and treatments. PMID:25977255

  19. A survey of knowledge, attitudes, and practices towards skin and soft tissue infections in rural Alaska

    PubMed Central

    Gaines, Joanna; Bulkow, Lisa R.; Kinzer, Michael H.; Hennessy, Thomas W.; Klejka, Joseph A.; Bruce, Michael G.

    2016-01-01

    Background Community-acquired methicillin-resistant Staphylococcus aureus and methicillin-sensitive S. aureus infections are common to south-western Alaska and have been associated with traditional steambaths. More than a decade ago, recommendations were made to affected communities that included preventive skin care, cleaning methods for steambath surfaces, and the use of protective barriers while in steambaths to reduce the risk of S. aureus infection. Objective A review of community medical data suggested that the number of skin infection clinical encounters has increased steadily over the last 3 years and we designed a public health investigation to seek root causes. Study design Using a mixed methods approach with in-person surveys, a convenience sample (n=492) from 3 rural communities assessed the range of knowledge, attitudes and practices concerning skin infections, skin infection education messaging, prevention activities and home self-care of skin infections. Results We described barriers to implementing previous recommendations and evaluated the acceptability of potential interventions. Prior public health messages appear to have been effective in reaching community members and appear to have been understood and accepted. We found no major misconceptions regarding what a boil was or how someone got one. Overall, respondents seemed concerned about boils as a health problem and reported that they were motivated to prevent boils. We identified current practices used to avoid skin infections, such as the disinfection of steambaths. We also identified barriers to engaging in protective behaviours, such as lack of access to laundry facilities. Conclusions These findings can be used to help guide public health strategic planning and identify appropriate evidence-based interventions tailored to the specific needs of the region. PMID:26928370

  20. Changes in tissue water and indentation resistance of lymphedematous limbs accompanying low level laser therapy (LLLT) of fibrotic skin.

    PubMed

    Mayrovitz, H N; Davey, S

    2011-12-01

    Our goal was to determine effects of low-level-laser-therapy (LLLT) on skin water and tissue indentation resistance (TIR) in patients with arm (N = 38) or leg (N = 38) lymphedema. Skin water was determined from tissue dielectric constant (TDC) measurements and TIR determined from measurements of force resulting from tissue indentations of 3-4 mm. A limb-location with fibrosis was identified by palpation and treated with an LLLT device for one minute at each of five points within a 3 cm2 area. TDC and TIR at these sites and corresponding sites on the contralateral limb were measured prior to LLLT (pre-LLLT), immediately after LLLT (post-LLLT) and after a manual lymphatic drainage (MLD) session (post-MLD). Results, from arms and legs, showed that post-LLLT values of TIR and TDC were significantly less than pre-LLLT. TIR values remained significantly reduced at post-MLD whereas TDC values were not significantly different from pre-LLLT values. On follow-up visit, 17 previously LLLT treated legs were sham treated with an inactive LLLT unit and measurements replicated. A TIR and TDC change-pattern similar to that obtained with the active LLLT was obtained, but sham-related reductions in TIR and TDC immediately post sham-treatment were significantly less than achieved with the prior active LLLT treatment.

  1. Gene expression profile of cervical and skin tissues from human papillomavirus type 16 E6 transgenic mice

    PubMed Central

    Mendoza-Villanueva, D; Diaz-Chavez, J; Uribe-Figueroa, L; Rangel-Escareão, C; Hidalgo-Miranda, A; March-Mifsut, S; Jimenez-Sanchez, G; Lambert, PF; Gariglio, P

    2008-01-01

    Background Although K14E6 transgenic mice develop spontaneous tumors of the skin epithelium, no spontaneous reproductive tract malignancies arise, unless the transgenic mice were treated chronically with 17β-estradiol. These findings suggest that E6 performs critical functions in normal adult cervix and skin, highlighting the need to define E6-controlled transcriptional programs in these tissues. Methods We evaluated the expression profile of 14,000 genes in skin or cervix from young K14E6 transgenic mice compared with nontransgenic. To identify differentially expressed genes a linear model was implemented using R and the LIMMA package. Two criteria were used to select the set of relevant genes. First a set of genes with a Log-odds ≥ 3 were selected. Then, a hierarchical search of genes was based on Log Fold Changes. Results Microarray analysis identified a total of 676 and 1154 genes that were significantly up and down-regulated, respectively, in skin from K14E6 transgenic mice. On the other hand, in the cervix from K14E6 transgenic mice we found that only 97 and 252 genes were significantly up and down-regulated, respectively. One of the most affected processes in the skin from K14E6 transgenic mice was the cell cycle. We also found that skin from transgenic mice showed down-regulation of pro-apoptotic genes and genes related to the immune response. In the cervix of K14E6 transgenic mice, we could not find affected any gene related to the cell cycle and apoptosis pathways but did observe alterations in the expression of immune response genes. Pathways such as angiogenesis, cell junction and epidermis development, also were altered in their gene expression profiles in both tissues. Conclusion Expression of the HPV16 E6 oncoprotein in our model alters expression of genes that fell into several functional groups providing insights into pathways by which E6 deregulate cell cycle progression, apoptosis, the host resistance to infection and immune function

  2. Preparation and Characterization of Electrospun PLCL/Poloxamer Nanofibers and Dextran/Gelatin Hydrogels for Skin Tissue Engineering

    PubMed Central

    Sun, Hui; Xu, Feng

    2014-01-01

    In this study, two different biomaterials were fabricated and their potential use as a bilayer scaffold for skin tissue engineering applications was assessed. The upper layer biomaterial was a Poly(ε-caprolactone-co-lactide)/Poloxamer (PLCL/Poloxamer) nanofiber membrane fabricated using electrospinning technology. The PLCL/Poloxamer nanofibers (PLCL/Poloxamer, 9/1) exhibited strong mechanical properties (stress/strain values of 9.37±0.38 MPa/187.43±10.66%) and good biocompatibility to support adipose-derived stem cells proliferation. The lower layer biomaterial was a hydrogel composed of 10% dextran and 20% gelatin without the addition of a chemical crosslinking agent. The 5/5 dextran/gelatin hydrogel displayed high swelling property, good compressive strength, capacity to present more than 3 weeks and was able to support cells proliferation. A bilayer scaffold was fabricated using these two materials by underlaying the nanofibers and casting hydrogel to mimic the structure and biological function of native skin tissue. The upper layer membrane provided mechanical support in the scaffold and the lower layer hydrogel provided adequate space to allow cells to proliferate and generate extracellular matrix. The biocompatibility of bilayer scaffold was preliminarily investigated to assess the potential cytotoxicity. The results show that cell viability had not been affected when cocultured with bilayer scaffold. As a consequence, the bilayer scaffold composed of PLCL/Poloxamer nanofibers and dextran/gelatin hydrogels is biocompatible and possesses its potentially high application prospect in the field of skin tissue engineering. PMID:25405611

  3. Bone-demineralization diagnosis in a bone-tissue-skin matrix using the pulsed-chirped photothermal radar

    NASA Astrophysics Data System (ADS)

    Kaiplavil, Sreekumar; Mandelis, Andreas

    2012-02-01

    A chirped pulsed photothermal radiometric radar is introduced for the diagnosis of biological samples, especially bones with tissue and skin overlayers. The constraints imposed by the laser safety (maximum permissible exposure, MPE) ceiling on pump laser energy and the strong attenuation of thermal-wave signals in tissues significantly limit the photothermally active depth in most biological specimens to a level which is normally insufficient for practical applications (approx. 1 mm below the skin surface). A theoretical approach for improvement of signal-to-noise ratio (SNR), minimizing the static (dc) component of the photothermal signal and making use of the photothermal radiometric nonlinearity has been introduced and verified by comparing the SNR of four distinct excitation wave forms (sine-wave, square-wave, constant- width and constant duty-cycle pulses) for chirping the pump laser, under constant exposure energy. At low frequencies fixed-pulsewidth chirps of large peak power were found to be superior to all other equal-energy modalities, with an SNR improvement up to two orders of magnitude. Distinct thickness-dependent characteristic delay times in a goat bone were obtained, establishing an active depth resolution range of ca. 2.8 mm in a layered skin-fat- bone structure, a favorable result compared to the maximum reported pulsed photothermal radiometric depth resolution < 1 mm in turbid biological media. Compared to radar peak delay and amplitude, the long-delayed radar output amplitude is found to be more sensitive to subsurface conditions. Two-dimensional spatial plots of this parameter depicting the back surface conditions of bones with and without fat-tissue overlayers are presented.

  4. Detection of lumpy skin disease virus antigen and genomic DNA in formalin-fixed paraffin-embedded tissues from an Egyptian outbreak in 2006.

    PubMed

    Awadin, W; Hussein, H; Elseady, Y; Babiuk, S; Furuoka, H

    2011-10-01

    An outbreak of lumpy skin disease (LSD) was reported in 2006 in Egypt affecting 16 provinces. Biopsies and post-mortem tissue samples were collected from calves that showed typical clinical signs of LSD and fixed in formalin. These samples were collected from a private dairy farm in the Damietta province of Egypt. Formalin-fixed paraffin-embedded tissue samples were assessed using histology, and skin lesions were classified as either acute or subacute/chronic. Both lumpy skin disease virus (LSDV) DNA detected by polymerase chain reaction and LSDV antigen detected by immunohistochemistry using a capripoxvirus-specific monoclonal antibody were observed in the acute skin lesions and in some subacute/chronic skin lesions. PMID:21699673

  5. Changes in the electrical properties of the electrode-skin-underlying tissue composite during a week-long programme of neuromuscular electrical stimulation.

    PubMed

    Bîrlea, S I; Breen, P P; Corley, G J; Bîrlea, N M; Quondamatteo, F; ÓLaighin, G

    2014-02-01

    Particular neuromuscular electrical stimulation (NMES) applications require the use of the same electrodes over a long duration (>1 day) without having access to them. Under such circumstance the quality of the electrode-skin contact cannot be assessed. We used the NMES signal itself to assess the quality of the electrode-skin contact and the electrical properties of the underlying tissues over a week. A 14% decrease in the skin's stratum corneum resistance (from 20 to 17 kΩ) and a 15% decrease in the resistance of the electrodes and underlying tissues (from 550 to 460 Ω) were observed in the 14 healthy subjects investigated. A follow-on investigation of the effect of exercise-induced sweating on the electrical properties of the electrode-skin-underlying tissue composite during NMES indicated a correlation between the decrease in the resistance values observed over the course of the week and the accumulation of sweat at the electrode-skin interface. The value of the capacitance representing the dielectric properties of the skin's stratum corneum increased after exercise-induced sweating but did not change significantly over the course of the week. We conclude that valuable information about the electrode-skin-underlying tissue composite can be gathered using the NMES signal itself, and suggest that this is a practical, safe and relatively simple method for monitoring these electrical properties during long-term stimulation.

  6. Molecular characterization of Staphylococcus aureus isolates from skin and soft tissue infections samples and healthy carriers in the Central Slovenia region.

    PubMed

    Svent-Kucina, Natasa; Pirs, Mateja; Kofol, Romina; Blagus, Rok; Smrke, Dragica Maja; Bilban, Marjan; Seme, Katja

    2016-04-01

    Staphylococcus aureus is among the most important human pathogens. It is associated with different infections and is a major cause of skin and soft tissue infections (SSTIs). The aim of our study was to compare S. aureus isolates associated with SSTIs with isolates obtained from healthy carriers in the Central Slovenia region in terms of antimicrobial susceptibility, genetic diversity by clonal complex (CC)/sequence type, spa type, and by toxin gene profiling. In total, 274 S. aureus isolates were collected prospectively by culturing wound samples from 461 SSTI patients and nasal samples from 451 healthy carriers. We have demonstrated high heterogeneity in terms of CCs and spa type in both groups of isolates. The main clone among SSTI strains was Panton-Valentine leukocidin gene (pvl) positive CC121, whereas the main clone among carrier strains was CC45 carrying a large range of toxin genes. The main spa type in both groups was t091. Pvl was more frequently present in SSTI strains (31.2% SSTI vs 3.6% carrier strains) and staphylococcal enterotoxin C was more frequently present in carrier strains (1.6% SSTI vs 17.0% carrier strains). We have also demonstrated that methicillin-resistant S. aureus was a rare cause (2.8%) of SSTIs in our region.

  7. Intracellular signalling and intercellular coupling coordinate heterogeneous contractile events to facilitate tissue folding

    NASA Astrophysics Data System (ADS)

    Xie, Shicong; Martin, Adam C.

    2015-05-01

    Cellular forces generated in the apical domain of epithelial cells reshape tissues. Recent studies highlighted an important role for dynamic actomyosin contractions, called pulses, that change cell and tissue shape. Net cell shape change depends on whether cell shape is stabilized, or ratcheted, between pulses. Whether there are different classes of contractile pulses in wild-type embryos and how pulses are spatiotemporally coordinated is unknown. Here we develop a computational framework to identify and classify pulses and determine how pulses are coordinated during invagination of the Drosophila ventral furrow. We demonstrate biased transitions in pulse behaviour, where weak or unratcheted pulses transition to ratcheted pulses. The transcription factor Twist directs this transition, with cells in Twist-depleted embryos exhibiting abnormal reversed transitions in pulse behaviour. We demonstrate that ratcheted pulses have higher probability of having neighbouring contractions, and that ratcheting of pulses prevents competition between neighbouring contractions, allowing collective behaviour.

  8. Intracellular signalling and intercellular coupling coordinate heterogeneous contractile events to facilitate tissue folding

    PubMed Central

    Xie, Shicong; Martin, Adam C.

    2015-01-01

    Cellular forces generated in the apical domain of epithelial cells reshape tissues. Recent studies highlighted an important role for dynamic actomyosin contractions, called pulses, that change cell and tissue shape. Net cell shape change depends on whether cell shape is stabilized, or ratcheted, between pulses. Whether there are different classes of contractile pulses in wild-type embryos and how pulses are spatiotemporally coordinated is unknown. Here we develop a computational framework to identify and classify pulses and determine how pulses are coordinated during invagination of the Drosophila ventral furrow. We demonstrate biased transitions in pulse behaviour, where weak or unratcheted pulses transition to ratcheted pulses. The transcription factor Twist directs this transition, with cells in Twist-depleted embryos exhibiting abnormal reversed transitions in pulse behaviour. We demonstrate that ratcheted pulses have higher probability of having neighbouring contractions, and that ratcheting of pulses prevents competition between neighbouring contractions, allowing collective behaviour. PMID:26006267

  9. Antisepsis of the Skin by Treatment with Tissue-Tolerable Plasma (TTP): Risk Assessment and Perspectives

    NASA Astrophysics Data System (ADS)

    Lademann, Jürgen; Richter, Heike; Patzelt, Alexa; Meinke, Martina C.; Fluhr, Joachim W.; Kramer, Axel; Weltmann, Klaus-Dieter; Lademann, Olaf

    The application of tissue tolerable plasma (TTP) is well suited for ­disinfection of living tissue. In particular, when treating chronic wounds, it has ­several advantages in comparison to the classical application of antiseptics, which do not penetrate sufficiently into the tissue or inhibit wound regeneration. The mode of action of the plasma is mainly based on synergetic effects between temperature increase and the formation of free radicals, which destroy the bacteria and fungi.

  10. Understanding Intratumoral Heterogeneity: Lessons from the Analysis of At-Risk Tissue and Premalignant Lesions in the Colon.

    PubMed

    Sievers, Chelsie K; Leystra, Alyssa A; Clipson, Linda; Dove, William F; Halberg, Richard B

    2016-08-01

    Advances in DNA sequencing have created new opportunities to better understand the biology of cancers. Attention is currently focused on precision medicine: does a cancer carry a mutation that is targetable with already available drugs? But, the timing at which multiple, targetable mutations arise during the adenoma to carcinoma sequence remains unresolved. Borras and colleagues identified mutations and allelic imbalance in at-risk mucosa and early polyps in the human colon. Their analyses indicate that mutations in key genes can arise quite early during tumorigenesis and that polyps are often multiclonal with at least two clones. These results are consistent with the "Big Bang" model of tumorigenesis, which postulates that intratumoral heterogeneity is a consequence of a mutational burst in the first few cell divisions following initiation that drives divergence from a single founder with unique but related clones coevolving. Emerging questions center around the ancestry of the tumor and impact of early intratumoral heterogeneity on tumor establishment, growth, progression, and most importantly, response to therapeutic intervention. Additional sequencing studies in which samples, especially at-risk tissue and premalignant neoplasms, are analyzed from animal models and humans will further our understanding of tumorigenesis and lead to more effective strategies for prevention and treatment. Cancer Prev Res; 9(8); 638-41. ©2016 AACRSee related article by Borras, et al., Cancer Prev Res 2016;9(6):417-427. PMID:27199343

  11. Transcriptional heterogeneity of IgM+ cells in rainbow trout (Oncorhynchus mykiss) tissues.

    PubMed

    Abós, Beatriz; Castro, Rosario; Pignatelli, Jaime; Luque, Alfonso; González, Lucia; Tafalla, Carolina

    2013-01-01

    TWO major classes of b lymphocytes have been described to date in rainbow trout: IgM(+) and IgT(+) cells. IgM(+) cells are mainly localized in the spleen, peripheral blood and kidney but are also found in other tissues. However, differences among IgM(+) cell populations attending to its location are poorly defined in fish. Thus, the aim of this work was to characterize the expression of different immune molecules such as chemokine receptors, Toll-like receptors (TLRs) and transcription factors on sorted IgM(+) lymphocytes from different rainbow trout tissues. IgM(+) populations from blood, spleen, kidney, gills, intestine and liver were isolated by cell sorting and the constitutive levels of transcription of these genes evaluated by real-time PCR. To further characterize B cells, we identified an MS4A sequence. In humans, the MS4A family includes several genes with immune functions, such as the B cell marker CD20 or FcRβ. Subsequently, we have also evaluated the mRNA levels of this MS4A gene in the different IgM(+) populations. The relevant differences in transcriptional patterns observed for each of these IgM(+) populations analyzed, point to the presence of functionally different tissue-specific B cell populations in rainbow trout. The data shown provides a pattern of genes transcribed in IgM(+) B cells not previously revealed in teleost fish. Furthermore, the constitutive expression of all the TLR genes analyzed in IgM(+) cells suggests an important role for these cells in innate immunity.

  12. An anisotropically and heterogeneously aligned patterned electrospun scaffold with tailored mechanical property and improved bioactivity for vascular tissue engineering.

    PubMed

    Xu, He; Li, Haiyan; Ke, Qinfei; Chang, Jiang

    2015-04-29

    The development of vascular scaffolds with controlled mechanical properties and stimulatory effects on biological activities of endothelial cells still remains a significant challenge to vascular tissue engineering. In this work, we reported an innovative approach to prepare a new type of vascular scaffolds with anisotropically and heterogeneously aligned patterns using electrospinning technique with unique wire spring templates, and further investigated the structural effects of the patterned electrospun scaffolds on mechanical properties and angiogenic differentiation of human umbilical vein endothelial cells (HUVECs). Results showed that anisotropically aligned patterned nanofibrous structure was obtained by depositing nanofibers on template in a structurally different manner, one part of nanofibers densely deposited on the embossments of wire spring and formed cylindrical-like structures in the transverse direction, while others loosely suspended and aligned along the longitudinal direction, forming a three-dimensional porous microstructure. We further found that such structures could efficiently control the mechanical properties of electrospun vascular scaffolds in both longitudinal and transverse directions by altering the interval distances between the embossments of patterned scaffolds. When HUVECs were cultured on scaffolds with different microstructures, the patterned scaffolds distinctively promoted adhesion of HUVECs at early stage and proliferation during the culture period. Most importantly, cells experienced a large shape change associated with cell cytoskeleton and nuclei remodeling, leading to a stimulatory effect on angiogenesis differentiation of HUVECs by the patterned microstructures of electrospun scaffolds, and the scaffolds with larger distances of intervals showed a higher stimulatory effect. These results suggest that electrospun scaffolds with the anisotropically and heterogeneously aligned patterns, which could efficiently control the

  13. Discrimination of Basal Cell Carcinoma from Normal Skin Tissue Using High-Resolution Magic Angle Spinning 1H NMR Spectroscopy

    PubMed Central

    Mun, Je-Ho; Lee, Heonho; Yoon, Dahye; Kim, Byung-Soo; Kim, Moon-Bum; Kim, Shukmann

    2016-01-01

    High-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy is a useful tool for investigating the metabolism of various cancers. Basal cell carcinoma (BCC) is the most common skin cancer. However, to our knowledge, data on metabolic profiling of BCC have not been reported in the literature. The objective of the present study was to investigate the metabolic profiling of cutaneous BCC using HR-MAS 1H NMR spectroscopy. HR-MAS 1H NMR spectroscopy was used to analyze the metabolite profile and metabolite intensity of histopathologically confirmed BCC tissues and normal skin tissue (NST) samples. The metabolic intensity normalized to the total spectral intensities in BCC and NST was compared, and multivariate analysis was performed with orthogonal partial least-squares discriminant analysis (OPLS-DA). P values < 0.05 were considered statistically significant. Univariate analysis revealed 9 metabolites that showed statistically significant difference between BCC and NST. In multivariate analysis, the OPLS-DA models built with the HR-MAS NMR metabolic profiles revealed a clear separation of BCC from NST. The receiver operating characteristic curve generated from the results revealed an excellent discrimination of BCC from NST with an area under the curve (AUC) value of 0.961. The present study demonstrated that the metabolite profile and metabolite intensity differ between BCC and NST, and that HR-MAS 1H NMR spectroscopy can be a valuable tool in the diagnosis of BCC. PMID:26934749

  14. Discrimination of Basal Cell Carcinoma from Normal Skin Tissue Using High-Resolution Magic Angle Spinning 1H NMR Spectroscopy.

    PubMed

    Mun, Je-Ho; Lee, Heonho; Yoon, Dahye; Kim, Byung-Soo; Kim, Moon-Bum; Kim, Shukmann

    2016-01-01

    High-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy is a useful tool for investigating the metabolism of various cancers. Basal cell carcinoma (BCC) is the most common skin cancer. However, to our knowledge, data on metabolic profiling of BCC have not been reported in the literature. The objective of the present study was to investigate the metabolic profiling of cutaneous BCC using HR-MAS (1)H NMR spectroscopy. HR-MAS (1)H NMR spectroscopy was used to analyze the metabolite profile and metabolite intensity of histopathologically confirmed BCC tissues and normal skin tissue (NST) samples. The metabolic intensity normalized to the total spectral intensities in BCC and NST was compared, and multivariate analysis was performed with orthogonal partial least-squares discriminant analysis (OPLS-DA). P values < 0.05 were considered statistically significant. Univariate analysis revealed 9 metabolites that showed statistically significant difference between BCC and NST. In multivariate analysis, the OPLS-DA models built with the HR-MAS NMR metabolic profiles revealed a clear separation of BCC from NST. The receiver operating characteristic curve generated from the results revealed an excellent discrimination of BCC from NST with an area under the curve (AUC) value of 0.961. The present study demonstrated that the metabolite profile and metabolite intensity differ between BCC and NST, and that HR-MAS (1)H NMR spectroscopy can be a valuable tool in the diagnosis of BCC. PMID:26934749

  15. Topical Nicotinamide Improves Tissue Regeneration in Excisional Full-Thickness Skin Wounds: A Stereological and Pathological Study

    PubMed Central

    Ashkani Esfahani, Soheil; Khoshneviszadeh, Mahsima; Namazi, Mohammad Reza; Noorafshan, Ali; Geramizadeh, Bita; Nadimi, Elham; Razavipour, Seyedeh Tahereh

    2015-01-01

    Background: Nicotinamide (NA), the active form of vitamin-B3, is hypothesized to have positive effects on the process of wound healing; it has anti-inflammatory, antioxidant, and immunomodulatory properties, as well as an epithelization inducing action. Objectives: In the present study, we aimed to determine the effects of topical administration of NA on skin wounds, based on histomorphometrical and pathological criteria. Materials and Methods: In this study, 36 male Sprague-Dawley rats (220 ± 20 g each), with 1 cm2 circular full-thickness wounds on their backs were divided into three groups (n = 12): NA group, was treated daily with a Nicotinamide 2% gel , untreated group (control), and base group, which were treated with the vehicle (base) of the gel (carboxymethylcellulose). Skin biopsies were prepared for microscopic analyses. Inflammation, granulation tissue formation, ulceration, epithelization, wound closure rate, fibroblast proliferation, collagen synthesis, and vascularization were studied criteria. Results: The results revealed that besides improving the wound healing by its anti-inflammatory, antioxidant, and epithelization inducing effects, NA also improved tissue regeneration through the increment of fibroblast proliferation, collagen synthesis, and vascularization. Conclusions: In spite of the few reported side effects, NA can be introduced as an effective agent on the wound healing process, an adjuvant therapy and possibly a treatment by itself. However, its chemical characteristics, as well as possible adverse effects warrants further research. PMID:26839851

  16. Meshless Method with Operator Splitting Technique for Transient Nonlinear Bioheat Transfer in Two-Dimensional Skin Tissues

    PubMed Central

    Zhang, Ze-Wei; Wang, Hui; Qin, Qing-Hua

    2015-01-01

    A meshless numerical scheme combining the operator splitting method (OSM), the radial basis function (RBF) interpolation, and the method of fundamental solutions (MFS) is developed for solving transient nonlinear bioheat problems in two-dimensional (2D) skin tissues. In the numerical scheme, the nonlinearity caused by linear and exponential relationships of temperature-dependent blood perfusion rate (TDBPR) is taken into consideration. In the analysis, the OSM is used first to separate the Laplacian operator and the nonlinear source term, and then the second-order time-stepping schemes are employed for approximating two splitting operators to convert the original governing equation into a linear nonhomogeneous Helmholtz-type governing equation (NHGE) at each time step. Subsequently, the RBF interpolation and the MFS involving the fundamental solution of the Laplace equation are respectively employed to obtain approximated particular and homogeneous solutions of the nonhomogeneous Helmholtz-type governing equation. Finally, the full fields consisting of the particular and homogeneous solutions are enforced to fit the NHGE at interpolation points and the boundary conditions at boundary collocations for determining unknowns at each time step. The proposed method is verified by comparison of other methods. Furthermore, the sensitivity of the coefficients in the cases of a linear and an exponential relationship of TDBPR is investigated to reveal their bioheat effect on the skin tissue. PMID:25603180

  17. Bathing in carbon dioxide-enriched water alters protein expression in keratinocytes of skin tissue in rats

    NASA Astrophysics Data System (ADS)

    Kälsch, Julia; Pott, Leona L.; Takeda, Atsushi; Kumamoto, Hideo; Möllmann, Dorothe; Canbay, Ali; Sitek, Barbara; Baba, Hideo A.

    2016-10-01

    Beneficial effects of balneotherapy using naturally occurring carbonated water (CO2 enriched) have been known since the Middle Ages. Although this therapy is clinically applied for peripheral artery disease and skin disorder, the underlying mechanisms are not fully elucidated. Under controlled conditions, rats were bathed in either CO2-enriched water (CO2 content 1200 mg/L) or tap water, both at 37 °C, for 10 min daily over 4 weeks. Proliferation activity was assessed by Ki67 immunohistochemistry of the epidermis of the abdomen. The capillary density was assessed by immunodetection of isolectin-positive cells. Using cryo-fixed abdominal skin epidermis, follicle cells and stroma tissue containing capillaries were separately isolated by means of laser microdissection and subjected to proteomic analysis using label-free technique. Differentially expressed proteins were validated by immunohistochemistry. Proliferation activity of keratinocytes was not significantly different in the epidermis after bathing in CO2-enriched water, and also, capillary density did not change. Proteomic analysis revealed up to 36 significantly regulated proteins in the analyzed tissue. Based on the best expression profiles, ten proteins were selected for immunohistochemical validation. Only one protein, far upstream element binding protein 2 (FUBP2), was similarly downregulated in the epidermis after bathing in CO2-enriched water with both techniques. Low FUBP2 expression was associated with low c-Myc immune-expression in keratinocytes. Long-term bathing in CO2-enriched water showed a cellular protein response of epithelial cells in the epidermis which was detectable by two different methods. However, differences in proliferation activity or capillary density were not detected in the normal skin.

  18. Nucleotide excision repair is reduced in oral epithelial tissues compared with skin.

    PubMed

    Mitchell, David; Paniker, Lakshmi; Godar, Dianne

    2012-01-01

    Ultraviolet radiation (UVR) exposure to internal tissues for diagnostic, therapeutic and cosmetic procedures has increased dramatically over the past decade. The greatest increase in UVR exposure of internal tissues occurs in the cosmetic industry where it is combined with oxidizing agents for teeth whitening, often in conjunction with indoor tanning. To address potential carcinogenic risks of these procedures, we analyzed the formation and repair of the DNA photoproducts associated with the signature mutations of UVR. Radioimmunoassay was used to quantify the induction and repair of cyclobutane pyrimidine dimers and pyrimidine(6-4)pyrimidone photoproducts in DNA purified from three reconstructed tissues, EpiDerm(TM) , EpiGingival(TM) and EpiOral(TM) . We observed comparable levels of DNA damage in all tissues immediately after UVR exposure. In contrast, repair was significantly reduced in both oral tissues compared with EpiDerm(TM) . Our data suggest that UVR exposure of oral tissues can result in accumulation of DNA damage and increase the risk for carcinoma and melanoma of the mouth. Because NER is a broad-spectrum defense against DNA damage caused by a variety of agents in addition to UVR, our data suggest that the relatively low NER efficiency observed in oral tissues may have wide-ranging consequences in this highly exposed environment.

  19. Evaluation of changes in the haemoglobin of skin and muscle tissue of the calf, as induced by topical application of a nonivamide/nicoboxil cream.

    PubMed

    Warnecke, Jan M; Wendt, Thomas; Winkler, Stefan; Schak, Matthias; Schiffer, Thorsten; Kohl-Bareis, Matthias

    2014-02-01

    Topical agents like nonivamide and nicoboxil induce hyperaemisation and increase cutaneous blood flow and temperature. This study aimed to determine the effects of a nonivamide-nicoboxil cream on haemodynamics in the skin and calf muscle, via optical spectroscopy, discriminating between the changes for skin and muscle. Optical spectroscopy was applied in the visible (VIS) and near-infrared (NIR) wavelength range. The study determined the effect of the cream on changes in oxygenated (ΔoxyHb) and deoxygenated (ΔdeoxyHb) haemoglobin in skin and muscle, as well as on tissue oxygen saturation (SO2) in the skin of 14 healthy subjects. The left and right calves of the subjects were either treated with nonivamide-nicoboxil cream or were sham-administered. NIR spectroscopy allows noninvasive in-vivo examination of the oxygenation of human skeletal muscle. Topical administration of the nonivamide-nicoboxil cream significantly increased the concentration of oxygenated haemoglobin and tissue oxygen saturation in the skin, as well as the concentration of oxygenated haemoglobin in the muscle of the treated legs after 15 min, but with stronger and faster effects in the skin. The topical application of the nonivamide-nicoboxil cream increased blood flow in (smaller vessels of) the skin and muscle tissues.

  20. Effects of tissue heterogeneity on single-coil, scanning MIT imaging

    NASA Astrophysics Data System (ADS)

    Feldkamp, J. R.; Quirk, S.

    2016-03-01

    We recently reported on the use of a single induction coil to accomplish imaging of the electrical conductivity in human tissues via magnetic induction tomography (MIT). A key to the method was the development of a mapping equation that quantitatively relates an arbitrary electrical conductivity distribution to ohmic loss in a coil consisting of concentric circular loops in a plane. By making multiple coil loss measurements at a number of locations in the vicinity of the target (scan), this mapping equation can be used to build an algorithm for 3D image construction of electrical conductivity. Important assumptions behind the mathematical formula included uniform relative permittivity throughout all space and continuous variation in conductivity. In this paper, these two assumptions were tested in a series of experiments involving the use of human tissue phantoms created from agarose, doped with sufficient sodium chloride to yield physiological conductivities. Inclusions of doped agarose were scanned both while isolated and also while embedded in a matrix of agarose gel having lowered conductivity - to help evaluate the effects of abrupt permittivity change. The effects of discontinuous conductivity change were simulated by filling 5 cm diameter petri dishes with 1.4% aqueous KCl and placing them in a much larger, 14 cm diameter petri dish - gap distance varied from about 3 mm to 30 mm. In either case, we will show that these effects are minimal on resultant images, helping to further validate the mapping equation used to construct MIT images. Because of their simplicity, scans reported here did not include coil rotation. To acknowledge the importance of rotation, however, we have devoted a section of this work to illustrate the profound benefits of coil rotation during a scan - though virtual data are used, where coil rotation is more easily specified.

  1. Phenotypical heterogeneity linked to adipose tissue dysfunction in patients with Type 2 diabetes.

    PubMed

    Barchetta, Ilaria; Angelico, Francesco; Del Ben, Maria; Di Martino, Michele; Cimini, Flavia Agata; Bertoccini, Laura; Polimeni, Licia; Catalano, Carlo; Fraioli, Antonio; Del Vescovo, Riccardo; Morini, Sergio; Baroni, Marco Giorgio; Cavallo, Maria Gisella

    2016-10-01

    Adipose tissue (AT) inflammation leads to increased free fatty acid (FFA) efflux and ectopic fat deposition, but whether AT dysfunction drives selective fat accumulation in specific sites remains unknown. The aim of the present study was to investigate the correlation between AT dysfunction, hepatic/pancreatic fat fraction (HFF, PFF) and the associated metabolic phenotype in patients with Type 2 diabetes (T2D). Sixty-five consecutive T2D patients were recruited at the Diabetes Centre of Sapienza University, Rome, Italy. The study population underwent clinical examination and blood sampling for routine biochemistry and calculation of insulin secretion [homoeostasis model assessment of insulin secretion (HOMA-β%)] and insulin-resistance [homoeostasis model assessment of insulin resistance (HOMA-IR) and adipose tissue insulin resistance (ADIPO-IR)] indexes. Subcutaneous (SAT) and visceral (VAT) AT area, HFF and PFF were determined by magnetic resonance. Some 55.4% of T2D patients had non-alcoholic fatty liver disease (NAFLD); they were significantly younger and more insulin-resistant than non-NAFLD subjects. ADIPO-IR was the main determinant of HFF independently of age, sex, HOMA-IR, VAT, SAT and predicted severe NAFLD with the area under the receiver operating characteristic curve (AUROC)=0.796 (95% confidence interval: 0.65-0.94, P=0.001). PFF was independently associated with increased total adiposity but did not correlate with AT dysfunction, insulin resistance and secretion or NAFLD. The ADIPO-IR index was capable of predicting NAFLD independently of all confounders, whereas it did not seem to be related to intrapancreatic fat deposition; unlike HFF, higher PFF was not associated with relevant alterations in the metabolic profile. In conclusion, the presence and severity of AT dysfunction may drive ectopic fat accumulation towards specific targets, such as VAT and liver, therefore evaluation of AT dysfunction may contribute to the identification of different

  2. Heterogeneity of chromosomal breakage levels in epithelial tissue of ataxia-telangiectasia homozygotes and heterozygotes.

    PubMed

    Rosin, M P; Ochs, H D; Gatti, R A; Boder, E

    1989-09-01

    The objective of this study was to obtain an estimate of the frequency distribution of spontaneous chromosomal breakage occurring in vivo in oral epithelia of 20 ataxia-telangiectasia patients (A-T homozygotes) and 26 parents (A-T obligate heterozygotes). Samples of exfoliated cells were obtained from each individual by swabbing the oral cavity and preparing air-dried slides. The percentage of exfoliated cells with micronuclei (MEC frequency) was used as an in vivo indicator for the amount of chromosomal breakage occurring in the tissue. As a population group, MEC frequencies of the A-T patients differed significantly from controls (mean for A-T patients, 1.51; for controls, 0.29; P less than 0.01). However, the values observed in individual patients ranged from MEC frequencies 10- to 12-fold above control values, to frequencies overlapping the upper values observed in the controls. Similarly, MEC frequencies observed among the A-T heterozygotes differed significantly from controls (mean for A-T heterozygotes, 1.02, mean for controls, 0.29; P less than 0.01). However, only 16 of the 26 individuals sampled had MEC frequencies greater than 0.5%, the 90th percentile for controls (compared with 16 of the 20 A-T patients examined). Of the A-T patients 11 had been previously assigned to complementation groups on the basis of sensitivity to x-irradiation. Seven of the patients belonged to group A and had MEC frequencies ranging from 0.3% to 1.9% with the remaining patients belonging to group C with MEC frequencies of 0.2% to 0.9%. The data presented in this paper suggest that although levels of spontaneous breakage in epithelial tissues of A-T patients and A-T obligate heterozygotes are often significantly elevated, this is not the case in all individuals.

  3. Heterogeneous nuclear expression of the promyelocytic leukemia (PML) protein in normal and neoplastic human tissues.

    PubMed Central

    Gambacorta, M.; Flenghi, L.; Fagioli, M.; Pileri, S.; Leoncini, L.; Bigerna, B.; Pacini, R.; Tanci, L. N.; Pasqualucci, L.; Ascani, S.; Mencarelli, A.; Liso, A.; Pelicci, P. G.; Falini, B.

    1996-01-01

    The RING-finger promyelocytic leukemia (PML) protein is the product of the PML gene that fuses with the retinoic acid receptor-alpha gene in the t(15; 17) translocation of acute promyelocytic leukemia. Wild-type PML localizes in the nucleus with a typical speckled pattern that is a consequence of the concentration of the protein within discrete subnuclear domains known as nuclear bodies. Delocalization of PML from nuclear bodies has been documented in acute promyelocytic leukemia cells and suggested to contribute to leukemogenesis. In an attempt to get new insights into the function of the wild-type PML protein and to investigate whether it displays an altered expression pattern in neoplasms other than acute promyelocytic leukemia, we stained a large number of normal and neoplastic human tissues with a new murine monoclonal antibody (PG-M3) directed against the amino-terminal region of PML. As the PG-M3 epitope is partially resistant to fixatives, only cells that overexpress PML are detected by the antibody in microwave-heated paraffin sections. Among normal tissues, PML was characteristically up-regulated in activated epithelioid histiocytes and fibroblasts in a variety of pathological conditions, columnar epithelium in small active thyroid follicles, well differentiated foamy cells in the center of sebaceous glands, and hypersecretory endometria (Arias-Stella). Interferons, the PML of which is a primary target gene, and estrogens are likely to represent some of the cytokines and/or hormones that may be involved in the up-regulation of PML under these circumstances. In keeping with this concept, we found that PML is frequently overexpressed in Hodgkin and Reed-Sternberg cells of Hodgkin's disease, a tumor of cytokine-producing cells. Among solid tumors, overexpression of PML was frequently found in carcinomas of larynx and thyroid (papillary), epithelial thymomas, and Kaposi's sarcoma, whereas carcinomas of the lung, thyroid (follicular), breast, and colon were

  4. An upgraded camera-based imaging system for mapping venous blood oxygenation in human skin tissue

    NASA Astrophysics Data System (ADS)

    Li, Jun; Zhang, Xiao; Qiu, Lina; Leotta, Daniel F.

    2016-07-01

    A camera-based imaging system was previously developed for mapping venous blood oxygenation in human skin. However, several limitations were realized in later applications, which could lead to either significant bias in the estimated oxygen saturation value or poor spatial resolution in the map of the oxygen saturation. To overcome these issues, an upgraded system was developed using improved modeling and image processing algorithms. In the modeling, Monte Carlo (MC) simulation was used to verify the effectiveness of the ratio-to-ratio method for semi-infinite and two-layer skin models, and then the relationship between the venous oxygen saturation and the ratio-to-ratio was determined. The improved image processing algorithms included surface curvature correction and motion compensation. The curvature correction is necessary when the imaged skin surface is uneven. The motion compensation is critical for the imaging system because surface motion is inevitable when the venous volume alteration is induced by cuff inflation. In addition to the modeling and image processing algorithms in the upgraded system, a ring light guide was used to achieve perpendicular and uniform incidence of light. Cross-polarization detection was also adopted to suppress surface specular reflection. The upgraded system was applied to mapping of venous oxygen saturation in the palm, opisthenar and forearm of human subjects. The spatial resolution of the oxygenation map achieved is much better than that of the original system. In addition, the mean values of the venous oxygen saturation for the three locations were verified with a commercial near-infrared spectroscopy system and were consistent with previously published data.

  5. Heterogeneous fibroblasts underlie age-dependent tertiary lymphoid tissues in the kidney

    PubMed Central

    Sato, Yuki; Mii, Akiko; Hamazaki, Yoko; Fujita, Harumi; Nakata, Hirosuke; Masuda, Kyoko; Nishiyama, Shingo; Shibuya, Shinsuke; Haga, Hironori; Ogawa, Osamu; Shimizu, Akira; Narumiya, Shuh; Kaisho, Tsuneyasu; Arita, Makoto; Yanagisawa, Masashi; Sharma, Kumar; Minato, Nagahiro; Kawamoto, Hiroshi

    2016-01-01

    Acute kidney injury (AKI) is a common clinical condition defined as a rapid decline in kidney function. AKI is a global health burden, estimated to cause 2 million deaths annually worldwide. Unlike AKI in the young, which is reversible, AKI in the elderly often leads to end-stage renal disease, and the mechanism that prevents kidney repair in the elderly is unclear. Here we demonstrate that aged but not young mice developed multiple tertiary lymphoid tissues (TLTs) in the kidney after AKI. TLT size was associated with impaired renal function and increased expression of proinflammatory cytokines and homeostatic chemokines, indicating a possible contribution of TLTs to sustained inflammation after injury. Notably, resident fibroblasts from a single lineage diversified into p75 neurotrophin receptor+ (p75NTR+) fibroblasts and homeostatic chemokine–producing fibroblasts inside TLTs, and retinoic acid–producing fibroblasts around TLTs. Deletion of CD4+ cells as well as late administration of dexamethasone abolished TLTs and improved renal outcomes. Importantly, aged but not young human kidneys also formed TLTs that had cellular and molecular components similar to those of mouse TLTs. Therefore, the inhibition of TLT formation may offer a novel therapeutic strategy for AKI in the elderly.

  6. Heterogeneous fibroblasts underlie age-dependent tertiary lymphoid tissues in the kidney

    PubMed Central

    Sato, Yuki; Mii, Akiko; Hamazaki, Yoko; Fujita, Harumi; Nakata, Hirosuke; Masuda, Kyoko; Nishiyama, Shingo; Shibuya, Shinsuke; Haga, Hironori; Ogawa, Osamu; Shimizu, Akira; Narumiya, Shuh; Kaisho, Tsuneyasu; Arita, Makoto; Yanagisawa, Masashi; Sharma, Kumar; Minato, Nagahiro; Kawamoto, Hiroshi

    2016-01-01

    Acute kidney injury (AKI) is a common clinical condition defined as a rapid decline in kidney function. AKI is a global health burden, estimated to cause 2 million deaths annually worldwide. Unlike AKI in the young, which is reversible, AKI in the elderly often leads to end-stage renal disease, and the mechanism that prevents kidney repair in the elderly is unclear. Here we demonstrate that aged but not young mice developed multiple tertiary lymphoid tissues (TLTs) in the kidney after AKI. TLT size was associated with impaired renal function and increased expression of proinflammatory cytokines and homeostatic chemokines, indicating a possible contribution of TLTs to sustained inflammation after injury. Notably, resident fibroblasts from a single lineage diversified into p75 neurotrophin receptor+ (p75NTR+) fibroblasts and homeostatic chemokine–producing fibroblasts inside TLTs, and retinoic acid–producing fibroblasts around TLTs. Deletion of CD4+ cells as well as late administration of dexamethasone abolished TLTs and improved renal outcomes. Importantly, aged but not young human kidneys also formed TLTs that had cellular and molecular components similar to those of mouse TLTs. Therefore, the inhibition of TLT formation may offer a novel therapeutic strategy for AKI in the elderly. PMID:27699223

  7. Free flap transplantation combined with skin grafting and vacuum sealing drainage for repair of circumferential or sub-circumferential soft-tissue wounds of the lower leg

    PubMed Central

    Li, Run-guang; Ren, Gao-hong; Tan, Xiong-jin; Yu, Bin; Hu, Ji-jie

    2013-01-01

    Background This study is aimed at evaluating the operation techniques and clinical significance of free flap transplantation combined with skin grafting and vacuum sealing drainage (VSD) in repairing severe traumatic extensive circumferential or semi-circumferential soft-tissue defects of the lower leg. Material/Methods Thirty patients with severe lower leg injuries were treated by free flap transplantation combined with skin grafting and VSD from January 2008 to June 2011. The size of the wounds ranged from 23×8 cm to 44×28 cm and all affected more 70% of the low leg circumferential area. Wounds were complicated by exposure, necrosis, or infection of deep tissues. The wounds were first debrided and covered by VSD. When the condition of the wound had improved (5 to 7 days later), free flaps were harvested to reconstruct damaged tissue and skin grafts and VSD was used to cover granulation tissues around the transplanted flap. Results Granulation tissues developed and the area requiring flap cover decreased in all 30 patients after debridement and VSD. In 28 of 30 cases, the transplanted flaps grew well without complication. Peripheral necrosis was observed in only 2 cases, which required a second debridement and skin graft. Ten wound areas covered by grafts were left with scattered peripheral wounds, which healed with the help of 1 more skin graft or dressing change. Morphological appearance and functional recovery were satisfactory in all 30 cases. Conclusions Initial debridement and the temporary VSD cover followed after several days by free flap transplantation combined with skin grafting and VSD protection is a reliable treatment regimen for traumatic large circumferential or sub-circumferential soft tissue wounds of the lower leg with deep tissue exposure. PMID:23807087

  8. Heterogeneity among white adipose tissue depots in male C57BL/6J mice.

    PubMed

    Sackmann-Sala, Lucila; Berryman, Darlene E; Munn, Rachel D; Lubbers, Ellen R; Kopchick, John J

    2012-01-01

    The widespread prevalence of obesity has lead to extensive research on white adipose tissue (WAT), which frequently uses the C57BL/6J mouse strain as a model. In many studies, results obtained in one WAT depot are often extrapolated to all WAT. However, functional differences among WAT depots are now becoming apparent. Thus, to identify the molecular mechanisms responsible for WAT depot-specific differences under "normal" conditions, four C57BL/6J mouse WAT depots (inguinal, mesenteric, epididymal, and retroperitoneal) were analyzed. Depot proteomic profiles, along with weights, protein contents, adipocyte sizes and oxidative stress were determined. Mesenteric WAT had almost twice the protein content of the other depots analyzed. Mean adipocyte size was highest in epididymal and lowest in mesenteric and inguinal depots. The proteome of inguinal WAT displayed low levels of enzymes involved in ATP generation, glucose and lipid metabolism, and antioxidant proteins. Higher levels of these proteins were observed in mesenteric and epididymal WAT, with variable levels in the retroperitoneal depot. Some of these proteins showed depot-specific correlations with plasma levels of insulin, leptin, and adiponectin. In agreement with the proteomic data, levels of the antioxidant protein heat shock protein β1 (HSPβ1) also were lower in inguinal WAT when analyzed by western blotting and immunohistochemistry. Also, lipid peroxidation products showed similar trends. Our results are consistent with lower triglyceride turnover and lower oxidative stress in inguinal than mesenteric and epididymal WAT. The observed WAT depot-specific differences provide clues as to the mechanisms leading to these depots' respective diverse functions. PMID:21779095

  9. Myoepitheliomas of the skin and soft tissues. Report of 12 cases.

    PubMed

    Michal, M; Miettinen, M

    1999-05-01

    We describe 12 cutaneous and soft tissue myoepitheliomas, most of them in elderly patients. Morphologically the cutaneous and soft tissue myoepitheliomas revealed the same spectrum as their salivary gland counterparts. They were composed of a mixture of spindle, epithelioid and clear myoepithelial cells. Immunohistochemically they were positive to keratins and S-100 protein and reacted inconsistently with antibodies to smooth muscle actin. Morphologically they lacked any folliculo-sebaceous or apocrine differentiation. We believe that they are related to the eccrine type of cutaneous mixed tumours. Most cases had a benign behaviour, but 1 tumour metastasized, and the patient died of the tumour. Myoepitheliomas of soft tissues should be distinguished from other neoplasms with epithelial differentiation and from ossifying fibromyxoid tumour of soft parts, parachordoma and extraskeletal myxoid chondrosarcoma.

  10. The Efficacy and Safety of Arbekacin and Vancomycin for the Treatment in Skin and Soft Tissue MRSA Infection: Preliminary Study

    PubMed Central

    Hwang, Ji-Hee; Lee, Ju-Hyung; Moon, Mi-Kyoung; Kim, Ju-Sin; Won, Kyoung-Suk

    2013-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) has become a one of the most important causes of nosocomial infections, and use of vancomycin for the treatment of MRSA infection has increased. Unfortunately, vancomycin-resistant enterococcus have been reported, as well as vancomycin-resistant S. aureus. Arbekacin is an antibacterial agent and belongs to the aminoglycoside family of antibiotics. It was introduced to treat MRSA infection. We studied the clinical and bacteriological efficacy and safety of arbekacin compared to vancomycin in the treatment of infections caused by MRSA. Materials and Methods This was a retrospective case-control study of patients who were admitted to tertiary Hospital from January 1st, 2009 to December 31st, 2010, and received the antibiotics arbekacin or vancomycin. All the skin and soft tissue MRSA infected patients who received arbekacin or vancomycin were enrolled during the study period. The bacteriological efficacy response (BER) was classified with improved and failure. The improved BER was defined as no growth of MRSA, where failure was defined as growth of MRSA, culture at the end of therapy or during treatment. Clinical efficacy response (CER) was classified as improved and failure. Improved CER was defined as resolution or reduction of the majority of signs and symptoms related to the original infection. Failure was defined as no resolution and no reduction of majority of the signs and symptoms, or worsening of one or more signs and symptoms, or new symptoms or signs associated with the original infection or a new infection. Results Totally, 122 patients (63/99 in arbekacin, 59/168 in vancomycin group) with skin and soft tissue infection who recieved arbekacin or vancomcyin at least 4 days were enrolled and analysed. The bacteriological efficacy response [improved, arbekacin vs vancomycin; 73.0% (46/63), 95% confidence interval (CI) 60.3 to 83.4% vs 83.1% (49/59), 95% CI 71.0 to 91.6%] and clinical efficacy

  11. T-cell receptor heterogeneity of gamma delta T-cell clones from human female reproductive tissues.

    PubMed

    Christmas, S E; Brew, R; Deniz, G; Taylor, J J

    1993-03-01

    gamma delta T cells were isolated from human decidua parietalis, decidua basalis and cervix and cloned in the presence of interleukin-2 (IL-2). T-cell receptor (TcR) expression was then analysed and compared with that of a panel of gamma delta T-cell clones from peripheral blood. Only 17/40 (42.5%) clones from decidua parietalis were V gamma 9+/V delta 2+ as compared to 68/94 (72%) of peripheral blood clones (P < 0.005). Conversely, 50% of clones from decidua parietalis but only 15% of clones from peripheral blood were V delta 1+ (P < 0.001). At least seven distinct TcR types were identified among the panel of clones from decidua parietalis and at least six different types were expressed by the panel of 17 clones from cervix. This receptor heterogeneity was not a result of interdonor variation as in all instances where more than one clone was obtained from a single sample, individual clones having between two and five receptor types were identified. However, 23/24 (95.8%) of clones from decidua basalis were V gamma 9+/V delta 2+. Most clones from decidua parietalis and cervix, whether V gamma 9+/V delta 2+ or V delta 1+, were positive for the mucosal lymphocyte marker, HML-1, but expression was often heterogeneous within a single clone. In contrast, almost all gamma delta T-cell clones from peripheral blood were HML-1-. Thus, unlike the mouse, gamma delta T cells within these human female reproductive tissues have a diverse TcR repertoire which, in decidua parietalis, is distinct from that of peripheral blood.

  12. Exogenous delta-animolevulinic acid induces the porphyrin biosynthesis in human skin organ cultures with different porphyrin patterns in normal and malignant human tissue

    NASA Astrophysics Data System (ADS)

    Fritsch, Clemens; Batz, Janine; Bolsen, Klaus; Schulte, Klaus; Ruzicka, Thomas; Goerz, Guenter

    1995-03-01

    The carboxylation state of porphyrin metabolites causes their hydrophilic or lipophilic properties and subsequently their distribution in tissues, cells, and subcellular compartments. The profile of porphyrin metabolites either in normal skin or in malignant skin tumors after administration of (delta) -aminolevulinic acid has been studied in detail, yet. Explant cultures of normal skin and neoplastic tissues, e.g., keratoakanthoma and basal cell carcinoma, were incubated with 1 mM ALA for 36 h. Total porphyrin concentration and percentage of porphyrin metabolites were determined quantitatively in tissues and corresponding supernatants. Seventy - ninety percent of total porphyrins could be detected in the supernatants of all samples. The highly carboxylated porphyrins were the prevailing metabolites in the supernatants as well as in the tissues. The basal cell carcinoma produced significantly more protoporphyrin and the keratoakanthoma significantly more coproporphyrin as compared to normal skin. The results show that explant cultures offer an easy approach to examine the enzymatic capacity in porphyrin biosynthesis of various tissues. Benign and malignant human tissues produce different porphyrin metabolites, which may be useful for selective and more effective photodynamic diagnosis or therapy.

  13. Investigating tissue respiration and skin microhaemocirculation under adaptive changes and the synchronization of blood flow and oxygen saturation rhythms.

    PubMed

    Dunaev, A V; Sidorov, V V; Krupatkin, A I; Rafailov, I E; Palmer, S G; Stewart, N A; Sokolovski, S G; Rafailov, E U

    2014-04-01

    Multi-functional laser non-invasive diagnostic systems allow the study of a number of microcirculatory parameters, including index of blood microcirculation (Im) (by laser Doppler flowmetry, LDF) and oxygen saturation (StO2) of skin tissue (by tissue reflectance oximetry, TRO). This research aimed to use such a system to investigate the synchronization of microvascular blood flow and oxygen saturation rhythms under normal and adaptive change conditions. Studies were conducted on eight healthy volunteers of 21-49 years. These volunteers were observed between one and six months, totalling 422 basic tests (3 min each). Measurements were performed on the palmar surface of the right middle finger and the lower forearm's medial surface. Rhythmic oscillations of LDF and TRO were studied using wavelet analysis. Combined tissue oxygen consumption data for all volunteers during 'adaptive changes' increased relative to normal conditions with and without arteriovenous anastomoses. Data analysis revealed resonance and synchronized rhythms in microvascular blood flow and oxygen saturation as an adaptive change in myogenic oscillation (vasomotion) resulting from exercise and possibly psychoemotional stress. Synchronization of myogenic rhythms during adaptive changes may lead to increased oxygen consumption as a result of increased microvascular blood flow velocity.

  14. Simultaneous optical coherence and multiphoton microscopy of skin-equivalent tissue models

    NASA Astrophysics Data System (ADS)

    Barton, Jennifer K.; Tang, Shuo; Lim, Ryan; Tromberg, Bruce J.

    2007-07-01

    Three-layer skin-equivalent models (rafts) were created consisting of a collagen/fibroblast layer and an air-exposed keratinocyte layer. Rafts were imaged with a tri-modality microscope including optical coherence (OC), two-photon excited fluorescence (TPEF), and second harmonic generation (SHG) channels. Some rafts were stained with Hoechst 33343 or rhodamine 123, and some were exposed to dimethyl sulfoxide (DMSO). OC microscopy revealed signal in cell cytoplasm and nuclear membranes, and a characteristic texture in the collagen/fibroblast layer. TPEF showed signal in cell cytoplasm and from collagen, and stained specimens revealed cell nuclei or mitochondria. There was little SHG in the keratinocyte layer, but strong signal from collagen bundles. Endogenous signals were severely attenuated in DMSO treated rafts; stained samples revealed shrunken and distorted cell structure. OC, TPEF, and SHG can provide complementary and non-destructive information about raft structure and effect of chemical agents.

  15. Pathological considerations of laser-tissue interactions: light microscopic assessment of thermal damage of skin

    NASA Astrophysics Data System (ADS)

    Flotte, Thomas J.; Goetschkes, Margaret

    1992-06-01

    A variety of fixatives and stains were examined for the ability to differentially stain the extracellular matrix components of thermal damage to the skin in an attempt to provide methods for examining the extent of thermal effects. This information is important in comparing different lasers and laser parameters. Four zones of thermal damage were identified including char and three zones of less extensive damage. The lower bounds of the damage with steady state conditions for these zones were 64 - 66 degree(s)C, 80 - 85 degree(s)C, and > 100 degree(s)C. The best choices based on this study include the following: fixative: Bouin's, overall stain: H & E, inner zone stain: Pinkus' acid orcein giemsa, middle zone stain: Movat's pentachrome, and outer zone stain: the modified elastic stain presented in the appendix of this paper.

  16. Molecular characterization, expression and methylation status analysis of BMP4 gene in skin tissue of Liaoning cashmere goat during hair follicle cycle.

    PubMed

    Bai, Wen L; Dang, Yun L; Wang, Jiao J; Yin, Rong H; Wang, Ze Y; Zhu, Yu B; Cong, Yu Y; Xue, Hui L; Deng, Liang; Guo, Dan; Wang, Shi Q; Yang, Shu H

    2016-08-01

    Bone morphogenetic protein 4 (BMP4) is a member of the bone morphogenetic protein family (BMPs). It is involved in the development and cycle of hair follicle, as well as, is thought to be a potential candidate gene for cashmere traits in goats. In the present study, we isolated and characterized a full-length open reading frame (ORF) of BMP4 cDNA from the skin tissue of Liaoning cashmere goat, and investigated the transcriptional pattern and methylation status of BMP4 gene in skin tissue of this breed during different stages of hair follicle cycle. The sequence analysis indicated that the isolated cDNA was 1264-bp in length containing a complete ORF of 1230-bp. It encoded a precursor peptide of 409 amino acids with a signal peptide of 19 amino acids. The structural analysis indicated that goat BMP4 contains typical TGF-β propeptide and TGF-β domains. In skin tissue, BMP4 is generally transcribed in an ascendant pattern from anagen to telogen. The methylation level of 5' flanking regulatory region of BMP4 gene might be involved in its mRNA expression in skin tissue: a higher BMP4 methylation level in skin coincides with a lower expression of BMP4 mRNA. These results from the present work provided a foundation for further insight into the functional and regulatory characteristics of BMP4 in the development and cycle of hair follicle in Liaoning Cashmere goat. PMID:27406581

  17. Molecular characterization, expression and methylation status analysis of BMP4 gene in skin tissue of Liaoning cashmere goat during hair follicle cycle.

    PubMed

    Bai, Wen L; Dang, Yun L; Wang, Jiao J; Yin, Rong H; Wang, Ze Y; Zhu, Yu B; Cong, Yu Y; Xue, Hui L; Deng, Liang; Guo, Dan; Wang, Shi Q; Yang, Shu H

    2016-08-01

    Bone morphogenetic protein 4 (BMP4) is a member of the bone morphogenetic protein family (BMPs). It is involved in the development and cycle of hair follicle, as well as, is thought to be a potential candidate gene for cashmere traits in goats. In the present study, we isolated and characterized a full-length open reading frame (ORF) of BMP4 cDNA from the skin tissue of Liaoning cashmere goat, and investigated the transcriptional pattern and methylation status of BMP4 gene in skin tissue of this breed during different stages of hair follicle cycle. The sequence analysis indicated that the isolated cDNA was 1264-bp in length containing a complete ORF of 1230-bp. It encoded a precursor peptide of 409 amino acids with a signal peptide of 19 amino acids. The structural analysis indicated that goat BMP4 contains typical TGF-β propeptide and TGF-β domains. In skin tissue, BMP4 is generally transcribed in an ascendant pattern from anagen to telogen. The methylation level of 5' flanking regulatory region of BMP4 gene might be involved in its mRNA expression in skin tissue: a higher BMP4 methylation level in skin coincides with a lower expression of BMP4 mRNA. These results from the present work provided a foundation for further insight into the functional and regulatory characteristics of BMP4 in the development and cycle of hair follicle in Liaoning Cashmere goat.

  18. Design and Construction of Artificial Extracellular Matrix (aECM) Proteins from Escherichia coli for Skin Tissue Engineering.

    PubMed

    Low, Pearlie S J; Tjin, Monica S; Fong, Eileen

    2015-06-11

    Recombinant technology is a versatile platform to create novel artificial proteins with tunable properties. For the last decade, many artificial proteins that have incorporated functional domains derived from nature (or created de novo) have been reported. In particular, artificial extracellular matrix (aECM) proteins have been developed; these aECM proteins consist of biological domains taken from fibronectin, laminins and collagens and are combined with structural domains including elastin-like repeats, silk and collagen repeats. To date, aECM proteins have been widely investigated for applications in tissue engineering and wound repair. Recently, Tjin and coworkers developed integrin-specific aECM proteins designed for promoting human skin keratinocyte attachment and propagation. In their work, the aECM proteins incorporate cell binding domains taken from fibronectin, laminin-5 and collagen IV, as well as flanking elastin-like repeats. They demonstrated that the aECM proteins developed in their work were promising candidates for use as substrates in artificial skin. Here, we outline the design and construction of such aECM proteins as well as their purification process using the thermo-responsive characteristics of elastin.

  19. Effect of low-level laser treatment of tissue-engineered skin substitutes: contraction of collagen lattices

    NASA Astrophysics Data System (ADS)

    Ho, Gideon; Barbenel, Joseph; Grant, M. Helen

    2009-05-01

    Fibroblast-populated collagen lattices (FPCL) are widely used in tissue-engineered artificial skin substitutes, but their main drawback is that interaction of fibroblasts and matrix causes contraction of the lattice, reducing it to about 20% of its original area. The effect of low-level laser treatment (LLLT) on the behavior of 3T3 fibroblasts seeded in collagen lattices containing 20% chondroitin-6-sulphate was investigated to determine whether LLLT could control the contraction of FPCL. A He-Ne laser was used at 632.8 nm to deliver a 5-mW continuous wave with fluences from 1 to 4 J/cm2. Laser treatment at 3 J/cm2 increased contraction of collagen lattices in the absence of cells but decreased contraction of cell seeded lattices over a 7-day period. The effect was energy dependent and was not observed at 1, 2, or 4 J/cm2. There was no alteration in fibroblast viability, morphology, or mitochondrial membrane potential after any laser treatments, but the distribution of actin fibers within the cells and collagen fibers in the matrices was disturbed at 3 J/cm2. These effects contribute to the decrease in contraction observed. LLLT may offer a means to control contraction of FPCL used as artificial skin substitutes.

  20. Identification of Basonuclin2, a DNA-binding zinc-finger protein expressed in germ tissues and skin keratinocytes.

    PubMed

    Romano, Rose-Anne; Li, Hongxiu; Tummala, Ramakumar; Maul, Robert; Sinha, Satrajit

    2004-05-01

    We used a bioinformatics approach to identify Basonuclin2, the second member of the Basonuclin zinc-finger family of transcription factors. The mouse Basonuclin2 protein consists of 1049 amino acids and contains three pairs of zinc fingers in the C-terminus that show a high level of amino acid sequence similarity with Basonuclin1. In addition, other characteristic domains of Basonuclin1, such as the serine strip and a nuclear localization signal, are also present in Basonuclin2. We used genomic and in silico database analysis to identify the human and rat homologs of basonuclin2. A search of the mouse genome showed that the basonuclin2 gene maps to chromosome 4 and consists of six exons spanning approximately 300 kb. Northern blot analysis revealed multiple transcripts of basonuclin2 in tissues of the reproductive system (ovary and testis) and also in kidney and skin. We demonstrate that, as expected from sequence conservation, recombinant Basonuclin2 can bind to a sequence in the promoter of a rRNA gene previously characterized as a Basonuclin-binding site. Full-length Basonuclin2 exclusively localizes to the nucleus, indicating that it likely plays an important role in nuclear function, probably in gene regulation. Our study establishes Basonuclin2 as a novel member of the Basonuclin family. Moreover, the structural and functional similarities with Basonuclin1 suggest that Basonuclin2 may play an analogous function in germ cells and skin keratinocytes. PMID:15081112

  1. Skin and soft tissue infection management, outcomes, and follow-up in the emergency department of an urban academic hospital.

    PubMed

    Seeleang, Kanokwan; Manning, Mary Lou; Saks, Mark; Winstead, Yvette

    2014-01-01

    Skin and soft tissue infections (SSTIs) are among the most common infections treated by emergency department clinicians. The emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) as the cause of these infections prompted the Centers for Disease Control and Prevention and the Infectious Disease Society of America to publish guidelines for the outpatient management of SSTIs. This study describes the management and outcomes of emergency department patients treated for uncomplicated SSTIs who returned within 30 days of the initial visit. The study found that of 857 eligible patients, only 17.6% returned and of these, 80% had their wound checked or packing removed. The clinicians prescribed antibiotics for the majority of patients, and the selection of antibiotics typically was active against CA-MRSA. Of 91 lesions drained, 24 specimens were obtained for culture and sensitivity. The majority of the initial treatment of patients consisted of incision and drainage with antibiotic prescription. PMID:25356895

  2. Characterization of human skin cells for tissue engineering applications by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Pudlas, Marieke; Koch, Steffen; Bolwien, Carsten; Walles, Heike

    2010-02-01

    In the field of cell culture and tissue engineering is an increasing need for non-invasive methods to analyze living cells in vitro. One important application is the cell characterization in tissue engineering products. Raman spectroscopy is a method which analyzes cells without lysis, fixation or the use of any chemicals and do not affect cell vitality adversely if suitable laser powers and wavelength are used. This purely optical technique is based on inelastic scattering of laser photons by molecular vibrations of biopolymers. Basically Raman spectra of cells contain typical fingerprint regions and information about cellular properties. Characteristic peaks in Raman spectra could be assigned to biochemical molecules like proteins, nucleic acid or lipids. The distinction of cell types by a multivariate analysis of Raman spectra is possible due to their biochemical differences. As this method allows a characterization of cells without any cell damage it is a promising technology for the quality control of cells in tissue engineering or cell culture applications.

  3. Extensive heterogeneity of proteoglycans bearing fucose-branched chondroitin sulfate extracted from the connective tissue of sea cucumber.

    PubMed

    Vieira, R P; Pedrosa, C; Mourão, P A

    1993-03-01

    The major sulfated polysaccharide in the sea cucumber body wall is a fucose-branched chondroitin sulfate. This glycosaminoglycan has side-chain disaccharide units of sulfated fucopyranosyl or sulfate esters linked to the O-3 position of the beta-D-glucuronic acid residues. These unusual fucose branches and sulfate esters block the access of chondroitinases to the chondroitin sulfate core [Vieira & Mourão (1988) J. Biol. Chem. 263, 18176-18183; Vieira et al. (1991) J. Biol. Chem. 266, 13530-13536]. We now report the isolation and preliminary characterization of the proteoglycans bearing this unique fucose-branched chondroitin sulfate. They were extracted using guanidine hydrochloride solutions containing protease inhibitors and were purified by anion-exchange and gel-filtration columns. Interestingly, the sea cucumber proteoglycans were cleaved by chondroitinase AC or ABC, indicating that the beta-D-glucuronic acid residues close to the reducing end of the polysaccharide chain are neither fucosylated nor sulfated. SDS-polyacrylamide gel electrophoresis revealed several fractions of proteoglycans of different molecular sizes but containing a similar hexuronic acid/protein ratio and a similar type of glycan chain. Possibly, the low-molecular-size fractions arise from a protease cleavage of a larger molecule. In contrast with the results observed for most vertebrate proteoglycans, which contain a single core protein for each type of proteoglycan, chondroitinase AC or ABC releases from the sea cucumber proteoglycans a wide variety of core proteins. These observations are the first detailed study of a proteoglycan from invertebrate tissue and reveal extensive heterogeneity when compared with proteoglycans from vertebrate connective tissue.

  4. TAT-Mediated Acidic Fibroblast Growth Factor Delivery to the Dermis Improves Wound Healing of Deep Skin Tissue in Rat

    PubMed Central

    Tang, Lu; Zheng, Lulu; Jin, Zi; Yu, Bingjie; Wang, Zhitao; Lin, Peng; Yu, Weidan; Li, Haiyan; Li, Xiaokun; Wang, Xiaojie

    2015-01-01

    Background The definition of deep tissue injury was derived from multiple clinical cases as “A purple or maroon localized area of discolored intact skin or blood-filled blister due to damage of underlying soft tissue from pressure and/or shear”. Acidic fibroblast growth factor (aFGF) significantly improves wound healing under diabetic conditions. However, to date, the therapeutic application of aFGF has been limited, due to its low delivery efficiency and short half-life. Methodology/Principal Findings Using an animal model of magnet-induced pressure ulcers, transactivator of transcription protein (TAT)-aFGF was evaluated for transdermal delivery and wound healing. Immunohistochemistry and Western blotting were also performed to determine the expression of transforming growth factor (TGF)-β1, α-smooth muscle actin (α-SMA), CD68, proliferating cell nuclear antigen (PCNA) and TGF-β-receptor II (TGF- βRII) in cultured human dermal fibroblasts. We found that that mice treated with TAT-aFGF had higher accumulation of aFGF in both dermis and subcutaneous tissues compared with mice treated with aFGF alone. In the remodeling phase, TAT-aFGF treatment decreased the expression of α-SMA to normal levels, thereby facilitating normal wound healing processes and abrogating hypertrophic scarring. In human dermal fibroblasts, TAT-aFGF reversed the suppressive effect of TNF-α on α-SMA expression and restored TGF-βRII and TGF-β1 expression. Conclusions/Significance Our results demonstrate that TAT-aFGF has a favorable therapeutic effect on the healing of subcutaneous deep tissue injury. PMID:26271041

  5. Skin Cancer

    MedlinePlus

    ... States. The two most common types are basal cell cancer and squamous cell cancer. They usually form on the head, face, ... If not treated, some types of skin cancer cells can spread to other tissues and organs. Treatments ...

  6. Management of Normal Tissue Toxicity Associated With Chemoradiation (Primary Skin, Esophagus, and Lung)

    PubMed Central

    Yazbeck, Victor Y.; Villaruz, Liza; Haley, Marsha; Socinski, Mark A.

    2016-01-01

    Nearly one quarter of patients with lung cancer present with locally advanced disease where concurrent chemoradiotherapy is the current standard of care for patients with good performance status. Cisplatin-based concurrent chemoradiotherapy consistently showed an improvement in survival compared with sequential chemoradiotherapy, at the expense of an increase in the toxicity profile. Over the past decades, several encouraging biomarkers such as transforming growth factor-beta and radioprotective agents such as amifostine were studied but without reaching approval for patient care. We reviewed the prevalence and risk factors for different adverse effects associated with the combined chemoradiotherapy modality, especially dermatitis, mucositis, esophagitis, and pneumonitis. These adverse effects can further be divided into acute, subacute, and chronic. Dermatitis is usually rare and responds well to topical steroids and usual skin care. Acute esophagitis occurs in 30% of patients and is treated with proton pump inhibitors, promotility agents, local anesthetic, and dietary changes. Radiation pneumonitis is a subacute complication seen in 15% of patients and is usually managed with steroids. Chronic adverse effects such as radiation fibrosis and esophageal stricture occur approximately 6 months after completion of radiation therapy and are usually permanent. In this review, complications of chemoradiotherapy for patients with locally advanced lung cancer are delineated, and approaches to their management are described. Given that treatment interruption is associated with a worse outcome, patients are aggressively treated with a curative intent. Therefore, planning for treatment adverse effects improves patient tolerance, compliance, and outcome. PMID:23708070

  7. The Prevalence of S. aureus Skin and Soft Tissue Infections in Patients with Pemphigus

    PubMed Central

    Soori, Tahereh; Musavi, Seyed Gholam Abbas

    2016-01-01

    Pemphigus vulgaris are autoimmune blistering diseases that may result in significant morbidity and death. Immunosuppressive therapy of pemphigus vulgaris would predispose the patients to infections. The aim of this study was to assess the prevalence of S. aureus infection and PVL gene in patients with pemphigus admitted to dermatology clinic. Materials and Methods. This descriptive study was conducted on 196 pemphigus vulgaris patients (119 males, 77 females) admitted to dermatology clinic between 2014 and 2015. In this study, the diagnosis of pemphigus vulgaris was made by histology, immunofluorescence pattern of perilesional skin, and indirect immunofluorescence testing of serum. Data were collected through a questionnaire. Results. 59.1% of pemphigus vulgaris patients had S. aureus infection. 49 out of 116 were methicillin-resistant. PVL gene was detected in 25 out of 116 S. aureus positive patients. Conclusion. This is the first report of S. aureus infection in pemphigus patients in Iran. More than forty percent of isolates were methicillin-resistant S. aureus. PVL gene carried by methicillin-resistant S. aureus was high in this study. PMID:27800178

  8. A low dimensional entropy-based descriptor of several tissues in skin cancer histopathology samples

    NASA Astrophysics Data System (ADS)

    Álvarez, Pablo; Corredor, Germán.; García-Arteaga, Juan D.; Romero, Eduardo

    2015-12-01

    The use of low-level visual features to assign high level labels in datasets of histopathology images is a possible solution to the problems derived from manual labeling by experts. However, in many cases, the visual cues are not enough. In this article we propose the use of features derived exclusively from the spatial distribution of the cell nuclei. These features are calculated using the weight of k-nn graphs constructed from the distances between cells. Results show that there are k values with enhanced discriminatory power, especially when comparing cancerous and non-cancerous tissue.

  9. Monte Carlo evaluation of tissue heterogeneities corrections in the treatment of head and neck cancer patients using stereotactic radiotherapy.

    PubMed

    Pokhrel, Damodar; McClinton, Christopher; Sood, Sumit; Badkul, Rajeev; Saleh, Habeeb; Jiang, Hongyu; Lominska, Christopher

    2016-01-01

    The purpose of this study was to generate Monte Carlo computed dose distributions with the X-ray voxel Monte Carlo (XVMC) algorithm in the treatment of head and neck cancer patients using stereotactic radiotherapy (SRT) and compare to heterogeneity corrected pencil-beam (PB-hete) algorithm. This study includes 10 head and neck cancer patients who underwent SRT re-irradiation using heterogeneity corrected pencil-beam (PB-hete) algorithm for dose calculation. Prescription dose was 24-40 Gy in 3-5 fractions (treated 3-5 fractions per week) with at least 95% of the PTV volume receiving 100% of the prescription dose. A stereotactic head and neck localization box was attached to the base of the thermoplastic mask fixation for target localization. The gross tumor volume (GTV) and organs-at-risk (OARs) were contoured on the 3D CT images. The planning target volume (PTV) was generated from the GTV with 0 to 5 mm uniform expansion; PTV ranged from 10.2 to 64.3 cc (average = 35.0±17.5 cc). OARs were contoured on the 3D planning CT and consisted of spinal cord, brainstem, optic structures, parotids, and skin. In the BrainLab treatment planning system (TPS), clinically optimal SRT plans were generated using hybrid planning technique (combination of 3D conformal nonco-planar arcs and nonopposing static beams) for the Novalis-Tx linear accelerator consisting of high-definition multileaf collimators (HD-MLCs: 2.5 mm leaf width at isocenter) and 6 MV-SRS (1000 MU/min) beam. For the purposes of this study, treatment plans were recomputed using XVMC algorithm utilizing identical beam geometry, multileaf positions, and monitor units and compared to the corresponding clinical PB-hete plans. The Monte Carlo calculated dose distributions show small decreases (< 1.5%) in calculated dose for D99, Dmean, and Dmax of the PTV coverage between the two algorithms. However, the average target volume encompassed by the prescribed percent dose (Vp) was about 2.5% less with XVMC vs. PB-hete and

  10. Melanoma-specific marker expression in skin biopsy tissues as a tool to facilitate melanoma diagnosis.

    PubMed

    Alexandrescu, Doru T; Kauffman, C Lisa; Jatkoe, Timothy A; Hartmann, Dan P; Vener, Tatiana; Wang, Haiying; Derecho, Carlo; Rajpurohit, Yashoda; Wang, Yixin; Palma, John F

    2010-07-01

    Diagnosis of cutaneous melanoma requires accurate differentiation of true malignant tumors from highly atypical lesions, which lack the capacity to develop uncontrolled proliferation and to metastasize. We used melanoma markers from previous work to differentiate benign and atypical lesions from melanoma using paraffin-embedded tissue. This critical step in diagnosis generates the most uncertainty and discrepancy between dermatopathologists. A total of 193 biopsy tissues were selected: 47 melanomas, 48 benign nevi, and 98 atypical/suspicious, including 48 atypical nevi and 50 melanomas as later assigned by expert dermatopathologists. Performance for SILV, GDF15, and L1CAM normalized to TYR in unequivocal melanoma versus benign nevi resulted in an area under the curve (AUC) of 0.94, 0.67, and 0.5, respectively. SILV also differentiated atypical cases classified as melanoma from atypical nevi with an AUC=0.74. Furthermore, SILV showed a significant difference between suspicious melanoma and each suspicious atypia group: melanoma versus severe atypia and melanoma versus moderate atypia had P-values of 0.0077 and 0.0009, respectively. SILV showed clear discrimination between melanoma and benign unequivocal cases as well as between different atypia subgroups in the group of suspicious samples. The role and potential utility of this molecular assay as an adjunct to the morphological diagnosis of melanoma are discussed.

  11. Influence of Skin and Subcutaneous Tissue on High-Intensity Focused Ultrasound Beam: Experimental Quantification and Numerical Modeling.

    PubMed

    Grisey, Anthony; Heidmann, Marc; Letort, Veronique; Lafitte, Pauline; Yon, Sylvain

    2016-10-01

    High-intensity focused ultrasound (HIFU) enables the non-invasive thermal ablation of tumors. However, numerical simulations of the treatment remain complex and difficult to validate in clinically relevant situations. In this context, needle hydrophone measurements of the acoustic field downstream of seven rabbit tissue layers comprising skin, subcutaneous fat and muscle were performed in different geometrical configurations. Increasing curvature and thickness of the sample were found to decrease the focusing of the beam: typically, a curvature of 0.05 mm(-1) decreased the maximum pressure by 45% and doubled the focal area. A numerical model based on k-Wave Toolbox was found to be in very good agreement with the reported measurements. It was used to extrapolate the effect of the superficial tissues on peak positive and peak negative pressure at focus, which affects both cavitation and target heating. The shape of the interface was found to have a strong influence on the values, and it is therefore an important parameter to monitor or to control in the clinical practice. This also highlights the importance of modeling realistic configurations when designing treatment procedures. PMID:27471120

  12. Matrigel immobilization on the shish-kebab structured poly(ɛ-caprolactone) nanofibers for skin tissue engineering

    NASA Astrophysics Data System (ADS)

    Jing, Xin; Mi, Hao-Yang; Peng, Xiang-Fang; Turng, Lih-Sheng

    2016-03-01

    Surface properties of tissue engineering scaffolds such as topography, hydrophilicity, and functional groups play a vital role in cell adhesion, migration, proliferation, and apoptosis. First, poly(ɛ-caprolactone) (PCL) shish-kebab scaffolds (PCL-SK), which feature a three-dimensional structure comprised of electrospun PCL nanofibers covered by periodic, self-induced PCL crystal lamellae on the surface, was created to mimic the nanotopography of native collagen fibrils in the extracellular matrix (ECM). Second, matrigel was covalently immobilized on the surface of alkaline hydrolyzed PCL-SK scaffolds to enhance their hydrophilicity. This combined approach not only mimics the nanotopography of native collagen fibrils, but also simulates the surface features of collagen fibrils for cell growth. To investigate the viability of such scaffolds, HEF1 fibroblast cell assays were conducted and the results revealed that the nanotopography of the PCL-SK scaffolds facilitated cell adhesion and proliferation. The matrigel functionalization on PCL-SK scaffolds further enhanced cellular response, which suggested elevated biocompatibility and greater potential for skin tissue engineering applications.

  13. Optically-tracked handheld fluorescence imaging platform for monitoring skin response in the management of soft tissue sarcoma

    NASA Astrophysics Data System (ADS)

    Chamma, Emilie; Qiu, Jimmy; Lindvere-Teene, Liis; Blackmore, Kristina M.; Majeed, Safa; Weersink, Robert; Dickie, Colleen I.; Griffin, Anthony M.; Wunder, Jay S.; Ferguson, Peter C.; DaCosta, Ralph S.

    2015-07-01

    Standard clinical management of extremity soft tissue sarcomas includes surgery with radiation therapy. Wound complications (WCs) arising from treatment may occur due to bacterial infection and tissue breakdown. The ability to detect changes in these parameters during treatment may lead to earlier interventions that mitigate WCs. We describe the use of a new system composed of an autofluorescence imaging device and an optical three-dimensional tracking system to detect and coregister the presence of bacteria with radiation doses. The imaging device visualized erythema using white light and detected bacterial autofluorescence using 405-nm excitation light. Its position was tracked relative to the patient using IR reflective spheres and registration to the computed tomography coordinates. Image coregistration software was developed to spatially overlay radiation treatment plans and dose distributions on the white light and autofluorescence images of the surgical site. We describe the technology, its use in the operating room, and standard operating procedures, as well as demonstrate technical feasibility and safety intraoperatively. This new clinical tool may help identify patients at greater risk of developing WCs and investigate correlations between radiation dose, skin response, and changes in bacterial load as biomarkers associated with WCs.

  14. Examining the Relationships Between Bone Tissue Composition, Compositional Heterogeneity, and Fragility Fracture: A Matched Case-Controlled FTIRI Study.

    PubMed

    Boskey, Adele L; Donnelly, Eve; Boskey, Elizabeth; Spevak, Lyudmila; Ma, Yan; Zhang, Wei; Lappe, Joan; Recker, Robert R

    2016-05-01

    Fourier transform infrared imaging (FTIRI) provides information on spatial distribution of the chemical composition of thin tissue specimens at ∼7 µm spatial resolution. This study of 120 age- and bone mineral density (BMD)-matched patients was designed to investigate the association of FTIRI variables, measured in iliac crest biopsies, with fragility fractures at any site. An earlier study of 54 women found hip BMD to be a significant explanatory variable of fracture risk for cortical bone but not for cancellous bone. In the current study, where age and BMD were controlled through matching, no such association was observed, validating the pairing scheme. Our first study of unmatched iliac crest biopsies found increases in collagen maturity (cancellous and cortical bone) and mineral crystal size (cortical bone only) to be a significant explanatory variable of fracture when combined with other covariates. The ratio for collagen maturity has been correlated to the amount of enzymatic collagen cross-links. To assess the impact of other FTIRI variables (acid phosphate substitution, carbonate-to-phosphate ratio, and the pixel distribution [heterogeneity] of all relevant FTIRI variables), we examined biopsies from a matched case-controlled study, in which 60 women with fractures were each paired with an age- and BMD-matched female control. With the matched data set of 120 women, conditional logistic regression analyses revealed that significant explanatory variables of fracture were decreased carbonate-to-phosphate ratio in both cancellous (odds ratio [OR] = 0.580, 95% confidence interval [CI] 0.37-0.909, p = 0.0176) and cortical bone (OR = 0.519, 95% CI 0.325-0.829, p = 0.0061), and increased heterogeneity (broadened pixel distribution) of collagen maturity for cancellous bone (OR = 1.549, 95% CI 1.002-2.396, p = 0.0491). The observation that collagen maturity was no longer linked to fracture in age- and BMD-matched samples suggests that age

  15. Effects of copper vapor laser (CVL) on mice skin: histologic evaluation of damage and tissue stimulation

    NASA Astrophysics Data System (ADS)

    Nunes, Syllene; Moreno, E.; Oliveira, H.; Osaka, J.; Salvador, G.; Michalany, N.; Tolosa, E.

    2002-10-01

    This study was to evaluate the effects of the CVL with low energy and short pulse widths. 18 female mice, C57BL/6 (9-11 weeks old) were distributed into four groups. The control group (CG) wasn't exposed to laser beam . Group L1 had 2 laser expositions with 24 hours gap between them (0.5W). Group L2 had 3 expositions (0.5W and 0.25W) and group L3 had 4 expositions (0.25 W). It was used a CVL prototype (5lOnm, 13 Khz, pulse width of 20 ms and spot size of 0.8cm). 7 days after last laser pulse no groups presented actinic keratosis, tumors or collagen changes. CVL had effective action on pilosebaceous units. High energy with few short pulses induced hair follicles proliferation while low energy with many repetitive short pulses showed increased and specific tissue damage besides hair plugging.

  16. Noninvasive in-vivo near-infrared vibrational spectroscopic study of lipid and aqueous phases of skin and near-surface tissues

    NASA Astrophysics Data System (ADS)

    Chaiken, Joseph; Finney, William F.; Peterson, Karen P.; Peterson, Charles M.; Knudson, Paul E.; Weinstock, Ruth S.; Lein, Paul

    2000-05-01

    We report the use of near infrared vibrational spectroscopy to noninvasively probe the in-vivo lipid and aqueous phases of skin and near surface tissues under conditions of thermal and chemical modulation. We demonstrate thermally induced order- disorder transitions in lipids that can be directly compared to well known behavior of in-vitro samples of phospholipid bilayers and bulk fatty acids. We show reversible chemical modification of aqueous phase proteins which are also directly comparable to well known phenomena involving in-vitro proteins. The results of these studies demonstrate the capacity for noninvasively probing live human tissues on the molecular level using near infrared vibrational spectroscopy. This capacity suggests numerous potential applications ranging from assessing the efficacy of cosmetics, skin care treatments and transdermal therapeutic agents/treatments to serving as a diagnostic of various skin ailments, e.g. melanoma.

  17. Comparison of the antiseptic efficacy of tissue-tolerable plasma and an octenidine hydrochloride-based wound antiseptic on human skin.

    PubMed

    Lademann, J; Richter, H; Schanzer, S; Patzelt, A; Thiede, G; Kramer, A; Weltmann, K-D; Hartmann, B; Lange-Asschenfeldt, B

    2012-01-01

    Colonization and infection of wounds represent a major reason for the impairment of tissue repair. Recently, it has been reported that tissue-tolerable plasma (TTP) is highly efficient in the reduction of the bacterial load of the skin. In the present study, the antiseptic efficacy of TTP was compared to that of octenidine hydrochloride with 2-phenoxyethanol. Both antiseptic methods proved to be highly efficient. Cutaneous treatment of the skin with octenidine hydrochloride and 2-phenoxyethanol leads to a 99% elimination of the bacteria, and 74% elimination is achieved by TTP treatment. Technical challenges with an early prototype TTP device could be held responsible for the slightly reduced antiseptic properties of TTP, compared to a standard antiseptic solution, since the manual treatment of the skin surface with a small beam of the TTP device might have led to an incomplete coverage of the treated area.

  18. Evaluation of light scattering properties and chromophore concentrations in skin tissue based on diffuse reflectance signals at isosbestic wavelengths of hemoglobin

    NASA Astrophysics Data System (ADS)

    Yokokawa, Takumi; Nishidate, Izumi

    2016-04-01

    We investigate a method to evaluate light-scattering properties and chromophore concentrations in human skin tissue through diffuse reflectance spectroscopy using the reflectance signals acquired at isosbestic wavelengths of hemoglobin (420, 450, 500, and 585 nm). In the proposed method, Monte Carlo simulation-based empirical formulas are used to specify the scattering parameters of skin tissue, such as the scattering amplitude a and the scattering power b, as well as the concentration of melanin C m and the total blood concentration C tb. The use of isosbestic wavelengths of hemoglobin enables the values of C m, C tb, a, and b to be estimated independently of the oxygenation of hemoglobin. The spectrum of the reduced scattering coefficient is reconstructed from the scattering parameters. Experiments using in vivo human skin tissues were performed to confirm the feasibility of the proposed method for evaluating the changes in scattering properties and chromophore concentrations in skin tissue. The experimental results revealed that light scattering is significantly reduced by the application of a glycerol solution, which indicates an optical clearing effect due to osmotic dehydration and the matching of the refractive indices of scatterers in the epidermis.

  19. Formulation and characterization of silk fibroin films as a scaffold for adipose-derived stem cells in skin tissue engineering.

    PubMed

    Chlapanidas, T; Tosca, M C; Faragò, S; Perteghella, S; Galuzzi, M; Lucconi, G; Antonioli, B; Ciancio, F; Rapisarda, V; Vigo, D; Marazzi, M; Faustini, M; Torre, M L

    2013-01-01

    Skin substitutes are epidermal, dermal or complete bilayered constructs, composed by natural or synthetic scaffolds and by adherent cells such as fibroblasts, keratinocytes or mesenchymal stem cells. Silk fibroin is a promising polymer to realize scaffolds, since it is biocompatible, biodegradable, and exhibits excellent mechanical properties in terms of tensile strength. Moreover, fibroin can be added of others components in order to modify the biomaterial properties for the purpose. The aim of this work is to prepare silk fibroin films for adipose-derived stem cell (ADSCs) culture as a novel feeder layer for skin tissue engineering. Pectin has been added to promote the protein conformational transition and construct strength, while glycerol as plasticizer, providing biomaterial flexibility. Eighteen formulations were prepared by casting method using fibroin, pectin (range 1-10% w/w), and glycerol (range 0-20% w/w); films were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry assay, to select the optimal composition. A stable fibroin conformation was obtained using 6% w/w pectin, and the best mechanical properties were obtained using 12% w/w glycerol. Films were sterilized, and human ADSCs were seeded and cultured for 15 days. Cells adhere to the support assuming a fibroblastic-like shape and reaching confluence. The ultrastructural analysis evidences typical active-cell features and adhesion structures that promote cell anchorage to the film, thus developing a multilayered cell structure. This construct could be advantageously employed in cutaneous wound healing or where the use of ADSCs scaffold is indicated either in human or veterinary field.

  20. Gene expression identifies heterogeneity of metastatic behavior among high-grade non-translocation associated soft tissue sarcomas

    PubMed Central

    2014-01-01

    Background The biologic heterogeneity of soft tissue sarcomas (STS), even within histological subtypes, complicates treatment. In earlier studies, gene expression patterns that distinguish two subsets of clear cell renal carcinoma (RCC), serous ovarian carcinoma (OVCA), and aggressive fibromatosis (AF) were used to separate 73 STS into two or four groups with different probabilities of developing metastatic disease (PrMet). This study was designed to confirm our earlier observations in a larger independent data set. Methods We utilized these gene sets, hierarchical clustering (HC), and Kaplan-Meier analysis, to examine 309 STS, using Affymetrix chip expression profiling. Results HC using the combined AF-, RCC-, and OVCA-gene sets identified subsets of the STS samples. Analysis revealed differences in PrMet between the clusters defined by the first branch point of the clustering dendrogram (p = 0.048), and also among the four different clusters defined by the second branch points (p < 0.0001). Analysis also revealed differences in PrMet between the leiomyosarcomas (LMS), dedifferentiated liposarcomas (LipoD), and undifferentiated pleomorphic sarcomas (UPS) (p = 0.0004). HC of both the LipoD and UPS sample sets divided the samples into two groups with different PrMet (p = 0.0128, and 0.0002, respectively). HC of the UPS samples also showed four groups with different PrMet (p = 0.0007). HC found no subgroups of the LMS samples. Conclusions These data confirm our earlier studies, and suggest that this approach may allow the identification of more than two subsets of STS, each with distinct clinical behavior, and may be useful to stratify STS in clinical trials and in patient management. PMID:24950699

  1. Expression of Endothelial Nitric Oxide Synthase and Endothelin-1 in Skin Tissue from Amputated Limbs of Patients with Complex Regional Pain Syndrome

    PubMed Central

    Groeneweg, J. George; Antonissen, Claudia Heijmans; Huygen, Frank J. P. M.; Zijlstra, Freek J.

    2008-01-01

    Background and Objectives. Impaired microcirculation during the chronic stage of complex regional pain syndrome (CRPS) is related to increased vasoconstriction, tissue hypoxia, and metabolic tissue acidosis in the affected limb. Endothelial dysfunction is suggested to be the main cause of diminished blood flow. The aim of this study was to examine the distribution of endothelial nitric oxide synthase (eNOS) and endothelin-1(ET-1) relative to vascular density represented by the endothelial marker CD31-immunoreactivity in the skin tissue of patients with chronic CRPS. Methods. We performed immunohistochemical staining on sections of skin specimens obtained from the amputated limbs (one arm and one leg) of two patients with CRPS. Results. In comparison to proximal specimens we found an increased number of migrated endothelial cells as well as an increase of eNOS activity in distal dermis specimens. Conclusions. We found indications that endothelial dysfunction plays a role in chronic CRPS. PMID:18663383

  2. Expression and tissue distribution of hepatocyte growth factor (HGF) and its receptor (c-Met) in alpacas (Vicugna pacos) skins associated with white and brown coat colors.

    PubMed

    Yu, Xiuju; He, Xiaoyan; Jiang, Junbing; He, Junping; Fan, Ruiwen; Wang, Haidong; Geng, Jianjun; Dong, Changsheng

    2015-09-01

    Hepatocyte growth factor (HGF)/c-Met signaling has been considered as a key pathway in both melanocyte development and melanogenesis. To understand better the expression patterns and tissue distribution characterization of HGF and its receptor c-Met in skin of white versus brown alpaca (Vicugna pacos), we detected the tissue distribution of HGF and c-Met using immunohistochemistry and analyzed the expression patterns by using Western blot and quantitative real time PCR (qPCR). Immunohistochemistry analysis demonstrated that HGF staining robustly increased in the dermal papilla and mesenchymal cells of white alpaca skin compared with that of brown. However, c-Met staining showed strongly positive result, particularly inhair matrix and root sheath in brown alpaca skin. Western blot and qPCR results suggested that HGF and c-Met were expressed at significantly high levels in white and brown alpaca skins, respectively, and protein and transcripts possessed the same expression pattern in white and brown alpaca skins. The results suggested that HGF/c-Met signaling functions in alpaca coat color formation offer essential theoretical basis for further exploration of the role of HGF/c-Met signaling in pigment formation.

  3. In vivo analysis of tissue by Raman microprobe: examination of human skin lesions and esophagus Barrett's mucosa on an animal model

    NASA Astrophysics Data System (ADS)

    Tfayli, Ali; Piot, Olivier; Derancourt, Sylvie; Cadiot, Guillaume; Diebold, Marie D.; Bernard, Philippe; Manfait, Michel

    2006-02-01

    In the last few years, Raman spectroscopy has been increasingly used for the characterization of normal and pathological tissues. A new Raman system, constituted of optic fibers bundle coupled to an axial Raman spectrometer (Horiba Jobin Yvon SAS), was developed for in vivo investigations. Here, we present in vivo analysis on two tissues: human skin and esophagus mucosa on a rat model. The skin is a directly accessible organ, representing a high diversity of lesions and cancers. Including malignant melanoma, basal cell carcinoma and the squamous cell carcinoma, skin cancer is the cancer with the highest incidence worldwide. Several Raman investigations were performed to discriminate and classify different types of skin lesions, on thin sections of biopsies. Here, we try to characterize in vivo the different types of skin cancers in order to be able to detect them in their early stages of development and to define precisely the exeresis limits. Barrett's mucosa was also studied by in vivo examination of rat's esophagus. Barrett's mucosa, induced by gastro-esophageal reflux, is a pretumoral state that has to be carefully monitored due to its high risk of evolution in adenocarcinoma. A better knowledge of the histological transformation of esophagus epithelium in a Barrett's type will lead to a more efficient detection of the pathology for its early diagnosis. To study these changes, an animal model (rats developing Barrett's mucosa after duodenum - esophagus anastomosis) was used. Potential of vibrational spectroscopy for Barrett's mucosa identification is assessed on this model.

  4. Low-intensity red and infrared lasers affect mRNA expression of DNA nucleotide excision repair in skin and muscle tissue.

    PubMed

    Sergio, Luiz Philippe S; Campos, Vera Maria A; Vicentini, Solange C; Mencalha, Andre Luiz; de Paoli, Flavia; Fonseca, Adenilson S

    2016-04-01

    Lasers emit light beams with specific characteristics, in which wavelength, frequency, power, fluence, and emission mode properties determine the photophysical, photochemical, and photobiological responses. Low-intensity lasers could induce free radical generation in biological tissues and cause alterations in macromolecules, such as DNA. Thus, the aim of this work was to evaluate excision repair cross-complementing group 1 (ERCC1) and excision repair cross-complementing group 2 (ERCC2) messenger RNA (mRNA) expression in biological tissues exposed to low-intensity lasers. Wistar rat (n = 28, 4 for each group) skin and muscle were exposed to low-intensity red (660 nm) and near-infrared (880 nm) lasers at different fluences (25, 50, and 100 J/cm(2)), and samples of these tissues were withdrawn for RNA extraction, cDNA synthesis, and gene expression evaluation by quantitative polymerase chain reaction. Laser exposure was in continuous wave and power of 100 mW. Data show that ERCC1 and ERCC2 mRNA expressions decrease in skin (p < 0.001) exposed to near-infrared laser, but increase in muscle tissue (p < 0.001). ERCC1 mRNA expression does not alter (p > 0.05), but ERCC2 mRNA expression decreases in skin (p < 0.001) and increases in muscle tissue (p < 0.001) exposed to red laser. Our results show that ERCC1 and ERCC2 mRNA expression is differently altered in skin and muscle tissue exposed to low-intensity lasers depending on wavelengths and fluences used in therapeutic protocols.

  5. Iodothyronine deiodinase activities in fetal rat tissues at several levels of iodine deficiency: a role for the skin in 3,5,3'-triiodothyronine economy?

    PubMed

    Schröder-van der Elst, J P; van der Heide, D; Morreale de Escobar, G; Obregón, M J

    1998-05-01

    Iodothyronine deiodinases, types I, II, and III (D1, D2, and D3) activities were measured in tissues of fetal rats, at 18 and 21 days of gestation, at several levels of iodine deficiency (ID): mild ID diet (MID) and moderately severe ID, MID + 0.005% perchlorate (MID+P). D2 was present in fetal skin, increased between days 18 and 21, and also in MID and MID+P. In skin, D3 increased during ID at day 18, whereas there was a decrease at day 21. Skin T4 decreased in MID and MID+P, showing an inverse relationship with D2. Skin T3 decreased at day 18 in MID and MID+P but increased at day 21, probably because of the increased D2 and decreased D3, maintaining T3 concentrations. No effect of ID was observed on hepatic D1. D2 increased in brain and brown adipose tissue at day 21 in MID+P. No changes were found in maternal placental D2 and D3, but D2 and D3 increased in the fetal placenta at day 18 in MID+P. A higher level of D2 is present in fetal skin than in the brain. As the activity is increased, in even mild ID (and already at 18 days) it can be concluded that skin D2 is likely to be of considerable physiological importance, at least for fetal thyroid hormone economy, by contributing to the intracellular T3 content of the skin and, possibly, to the plasma T3.

  6. Molecular characterization of Staphylococcus aureus isolates causing skin and soft tissue infections in patients from Malakand, Pakistan.

    PubMed

    Madzgalla, S; Syed, M A; Khan, M A; Rehman, S S; Müller, E; Reissig, A; Ehricht, R; Monecke, S

    2016-09-01

    Comparatively few studies have been published describing Staphylococcus aureus/MRSA epidemiology in Central Asia including Pakistan. Here, we report the genotyping of Staphylococcus aureus strains (that include both methicillin-susceptible and methicillin-resistant Staphylococcus aureus) from community- and hospital-acquired skin and soft-tissue infections in a tertiary care hospital in the Malakand district of the Khyber Pakhtunkhwa Province of Pakistan. Forty-five isolates of Staphylococcus aureus were characterized by microarray hybridization. Twenty isolates (44 %) were MRSA, whereas 22 (49 %) were PVL-positive. Fourteen isolates (31 %) harboured both mecA and PVL genes. The dominant clones were CC121-MSSA (n = 15, 33 %) and the PVL-positive "Bengal Bay Clone" (ST772-MRSA-V; n = 13, 29 %). The PVL-positive CC8-MRSA-IV strain "USA300" was found once. The pandemic ST239-MRSA-III strain was absent, although it has previously been observed in Pakistan. These observations require a re-assessment of schemes for initial antibiotic therapy to cover MRSA and they emphasise the need for a rapid and non-molecular test for PVL.

  7. Managing skin and soft-tissue infection and nosocomial pneumonia caused by MRSA: a 2014 follow-up survey.

    PubMed

    Dryden, Matthew; Andrasevic, Arjana Tambic; Bassetti, Matteo; Bouza, Emilio; Chastre, Jean; Baguneid, Mo; Esposito, Silvano; Giamarellou, Helen; Gyssens, Inge; Nathwani, Dilip; Unal, Serhat; Voss, Andreas; Wilcox, Mark

    2015-04-24

    As a follow-up to our 2009 survey, in order to explore opinion and practice on the epidemiology and management of meticillin-resistant Staphylococcus aureus (MRSA) in Europe, we conducted a second survey to elicit current opinions on this topic, particularly around antibiotic choice, dose, duration and route of administration. We also aimed to further understand how the management of MRSA has evolved in Europe during the past 5 years. Members of an expert panel of infectious diseases specialists convened in London (UK) in January 2014 to identify and discuss key issues in the management of MRSA. Following this meeting, a survey was developed comprising 36 questions covering a wide range of topics on MRSA complicated skin and soft-tissue infection and nosocomial pneumonia management. The survey instrument, a web-based questionnaire, was sent to the International Society of Chemotherapy for distribution to registered European infection societies and their members. This article reports the survey results from the European respondents. At the time of the original survey, the epidemiology of MRSA varied significantly across Europe and there were differing views on best practice. The current findings suggest that the epidemiology of healthcare-associated MRSA in Europe is, if anything, even more polarised, whilst community-acquired MRSA has become much more common. However, there now appears to be a much greater knowledge of current treatment/management options, and antimicrobial stewardship has moved forward considerably in the 5 years since the last survey.

  8. Clinical MRSA isolates from skin and soft tissue infections show increased in vitro production of phenol soluble modulins

    PubMed Central

    Berlon, Nicholas R.; Qi, Robert; Sharma-Kuinkel, Batu K.; Joo, Hwang-Soo; Park, Lawrence P.; George, Dennis; Thaden, Joshua T.; Messina, Julia A.; Maskarinec, Stacey A.; Mueller-Premru, Manica; Athan, Eugene; Tattevin, Pierre; Pericas, Juan M.; Woods, Christopher W.; Otto, Michael; Fowler, Vance G.

    2016-01-01

    Summary Background Phenol-soluble modulins (PSMs) are amphipathic, pro-inflammatory proteins secreted by most Staphylococcus aureus isolates. This study tested the hypothesis that in vitro PSM production levels are associated with specific clinical phenotypes. Methods 177 methicillin-resistant S. aureus (MRSA) isolates from infective endocarditis (IE), skin and soft tissue infection (SSTI), and hospital-acquired/ventilator-associated pneumonia (HAP) were matched by geographic origin, then genotyped using spa-typing. In vitro PSM production was measured by high performance liquid chromatography/mass spectrometry. Statistical analysis was performed using Chi-squared or Kruskal–Wallis tests as appropriate. Results Spa type 1 was significantly more common in SSTI isolates (62.7% SSTI; 1.7% IE; 16.9% HAP; p < 0.0001) while HAP and IE isolates were more commonly spa type 2 (0% SSTI; 37.3% IE; 40.7% HAP; p < 0.0001). USA300 isolates produced the highest levels of PSMs in vitro. SSTI isolates produced significantly higher quantities of PSMα1-4, PSMβ1, and δ-toxin than other isolates (p < 0.001). These findings persisted when USA300 isolates were excluded from analysis. PMID:26079275

  9. Practices and Procedures to Prevent the Transmission of Skin and Soft Tissue Infections in High School Athletes

    PubMed Central

    Fritz, Stephanie A.; Long, Marcus; Gaebelein, Claude J.; Martin, Madeline S.; Hogan, Patrick G.; Yetter, John

    2013-01-01

    Skin and soft tissue infections (SSTI) are frequent in student athletes and are often caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). We evaluated the awareness of CA-MRSA among high school coaches and athletic directors in Missouri (n = 4,408) and evaluated hygiene practices affecting SSTI transmission. Of 1,642 (37%) respondents, 61% received MRSA educational information during the past year and 32% indicated their school had written guidelines for managing SSTI in athletes. Coaches and athletic directors aware of written guidelines reported a lower incidence of SSTI in student athletes (26%) compared to those without written policies (34%, p=0.03). When confronted with SSTI, 49% of respondents referred student athletes to the school nurse or a physician. A relationship exists between school policies for SSTI management and lower incidence of SSTI. Educational initiatives by school nurses in conjunction with athletic staff may lead to practices that limit SSTI in this at-risk population. PMID:22472636

  10. A population based study of seasonality of skin and soft tissue infections: implications for the spread of CA-MRSA.

    PubMed

    Wang, Xiaoxia; Towers, Sherry; Panchanathan, Sarada; Chowell, Gerardo

    2013-01-01

    Methicillin resistant Staphylococcus aureus (MRSA) is currently a major cause of skin and soft tissue infections (SSTI) in the United States. Seasonal variation of MRSA infections in hospital settings has been widely observed. However, systematic time-series analysis of incidence data is desirable to understand the seasonality of community acquired (CA)-MRSA infections at the population level. In this paper, using data on monthly SSTI incidence in children aged 0-19 years and enrolled in Medicaid in Maricopa County, Arizona, from January 2005 to December 2008, we carried out time-series and nonlinear regression analysis to determine the periodicity, trend, and peak timing in SSTI incidence in children at different age: 0-4 years, 5-9 years, 10-14 years, and 15-19 years. We also assessed the temporal correlation between SSTI incidence and meteorological variables including average temperature and humidity. Our analysis revealed a strong annual seasonal pattern of SSTI incidence with peak occurring in early September. This pattern was consistent across age groups. Moreover, SSTIs followed a significantly increasing trend over the 4-year study period with annual incidence increasing from 3.36% to 5.55% in our pediatric population of approximately 290,000. We also found a significant correlation between the temporal variation in SSTI incidence and mean temperature and specific humidity. Our findings could have potential implications on prevention and control efforts against CA-MRSA.

  11. The role of primary care prescribers in the diagnosis and management of community-associated methicillin-resistant Staphylococcus aureus skin and soft tissue infections.

    PubMed

    Lawrence, Kenneth R; Golik, Monica V; Davidson, Lisa

    2009-01-01

    Nosocomial infections caused by methicillin-resistant Staphylococcus aureus were first reported in the United States in the early 1960s. Beginning in the 1990s, healthy individuals from the community with no risk factors for resistant bacteria began presenting with methicillin-resistant Staphylococcus aureus infections, acquiring the name "community-associated methicillin-resistant Staphylococcus aureus" (CA-MRSA). CA-MRSA has a tendency to affect the skin and skin structures, generally in the form of abscesses and furuncles, carbuncles, and cellulitis. Cases of invasive infections including bacteremia, endocarditis, and necrotizing pneumonia have also been reported. A patient complaint of a "spider bite" is frequently associated with CA-MRSA. CA-MRSA and the traditional health care-associated methicillin-resistant Staphylococcus aureus are distinguished by their genetic composition, virulence factors, and susceptibility patterns to non-beta-lactam antibiotics. Appropriate management of CA-MRSA skin and skin structure infections includes incision and drainage of infected tissue and appropriate antimicrobial therapy. It has been suggested that when prevalence of CA-MRSA within a community eclipses 10%-15%, empiric use of non-beta-lactam antibiotics with in vitro activity against CA-MRSA be initiated when treating skin and skin structure infections. CA-MRSA retains susceptibility to a range of older antibiotics available in oral formulations such as minocycline, doxycycline, sulfamethoxazole-trimethoprim, moxifloxacin, levofloxacin, and clindamycin. Local susceptibility patterns and individual patient factors should guide the selection of antibiotics. PMID:19617720

  12. The role of primary care prescribers in the diagnosis and management of community-associated methicillin-resistant Staphylococcus aureus skin and soft tissue infections.

    PubMed

    Lawrence, Kenneth R; Golik, Monica V; Davidson, Lisa

    2009-01-01

    Nosocomial infections caused by methicillin-resistant Staphylococcus aureus were first reported in the United States in the early 1960s. Beginning in the 1990s, healthy individuals from the community with no risk factors for resistant bacteria began presenting with methicillin-resistant Staphylococcus aureus infections, acquiring the name "community-associated methicillin-resistant Staphylococcus aureus" (CA-MRSA). CA-MRSA has a tendency to affect the skin and skin structures, generally in the form of abscesses and furuncles, carbuncles, and cellulitis. Cases of invasive infections including bacteremia, endocarditis, and necrotizing pneumonia have also been reported. A patient complaint of a "spider bite" is frequently associated with CA-MRSA. CA-MRSA and the traditional health care-associated methicillin-resistant Staphylococcus aureus are distinguished by their genetic composition, virulence factors, and susceptibility patterns to non-beta-lactam antibiotics. Appropriate management of CA-MRSA skin and skin structure infections includes incision and drainage of infected tissue and appropriate antimicrobial therapy. It has been suggested that when prevalence of CA-MRSA within a community eclipses 10%-15%, empiric use of non-beta-lactam antibiotics with in vitro activity against CA-MRSA be initiated when treating skin and skin structure infections. CA-MRSA retains susceptibility to a range of older antibiotics available in oral formulations such as minocycline, doxycycline, sulfamethoxazole-trimethoprim, moxifloxacin, levofloxacin, and clindamycin. Local susceptibility patterns and individual patient factors should guide the selection of antibiotics.

  13. Tumor Necrosis Factor-α-induced Proteolytic Activation of Pro-matrix Metalloproteinase-9 by Human Skin Is Controlled by Down-regulating Tissue Inhibitor of Metalloproteinase-1 and Mediated by Tissue-associated Chymotrypsin-like Proteinase*

    PubMed Central

    Han, Yuan-Ping; Nien, Yih-Dar; Garner, Warren L.

    2008-01-01

    The proteolytic activation of pro-matrix metalloproteinase (MMP)-9 by conversion of the 92-kDa precursor into an 82-kDa active form has been observed in chronic wounds, tumor metastasis, and many inflammation-associated diseases, yet the mechanistic pathway to control this process has not been identified. In this report, we show that the massive expression and activation of MMP-9 in skin tissue from patients with chronically unhealed wounds could be reconstituted in vitro with cultured normal human skin by stimulation with transforming growth factor-β and tumor necrosis factor (TNF)-α. We dissected the mechanistic pathway for TNF-α induced activation of pro-MMP-9 in human skin. We found that proteolytic activation of pro-MMP-9 was mediated by a tissue-associated chymotrypsin-like proteinase, designated here as pro-MMP-9 activator (pM9A). This unidentified activator specifically converted pro-MMP-9 but not pro-MMP-2, another member of the gelatinase family. The tissue-bound pM9A was steadily expressed and not regulated by TNF-α, which indicated that the cytokine-mediated activation of pro-MMP-9 might be regulated at the inhibitor level. Indeed, the skin constantly secreted tissue inhibitor of metalloproteinase-1 at the basal state. TNF-α, but not transforming growth factor-β, down-regulated this inhibitor. The TNF-α-mediated activation of pro-MMP-9 was tightly associated with down-regulation of tissue inhibitor of metalloproteinase-1 in a dose-dependent manner. To establish this linkage, we demonstrate that the recombinant tissue inhibitor of metalloproteinase-1 could block the activation of pro-MMP-9 by either the intact skin or skin fractions. Thus, these studies suggest a novel regulation for the proteolytic activation of MMP-9 in human tissue, which is mediated by tissue-bound activator and controlled by down-regulation of a specific inhibitor. PMID:12004062

  14. A novel method for single sample multi-axial nanoindentation of hydrated heterogeneous tissues based on testing great white shark jaws.

    PubMed

    Ferrara, Toni L; Boughton, Philip; Slavich, Eve; Wroe, Stephen

    2013-01-01

    Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the great white shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of great white shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity, such as samples obtained from endangered species or pathological tissues. We also outline a method for tip-to-optic calibration that facilitates nanoindentation of soft biological tissues. Our technique may help address the critical need for a nanomechanical testing method that is applicable

  15. A Novel Method for Single Sample Multi-Axial Nanoindentation of Hydrated Heterogeneous Tissues Based on Testing Great White Shark Jaws

    PubMed Central

    Ferrara, Toni L.; Boughton, Philip; Slavich, Eve; Wroe, Stephen

    2013-01-01

    Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and non-mineralized (soft) layers and possesses a jaw geometry that is challenging to test mechanically. The aim of this study is to develop a novel method for obtaining multidirectional nanomechanical properties for both layers of jaw cartilage from a single sample, taken from the great white shark (Carcharodon carcharias). A method for obtaining multidirectional data from a single sample is necessary for examining tissue mechanics in this shark because it is a protected species and hence samples may be difficult to obtain. Results show that this method maintains hydration of samples that would otherwise rapidly dehydrate. Our study is the first analysis of nanomechanical properties of great white shark jaw cartilage. Variation in nanomechanical properties were detected in different orthogonal directions for both layers of jaw cartilage in this species. The data further suggest that the mineralized layer of shark jaw cartilage is less stiff than previously posited. Our method allows multidirectional nanomechanical properties to be obtained from a single, small, hydrated heterogeneous sample. Our technique is therefore suitable for use when specimens are rare, valuable or limited in quantity, such as samples obtained from endangered species or pathological tissues. We also outline a method for tip-to-optic calibration that facilitates nanoindentation of soft biological tissues. Our technique may help address the critical need for a nanomechanical testing method that is applicable

  16. 21 CFR 878.4011 - Tissue adhesive with adjunct wound closure device for topical approximation of skin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY... approximated skin edges of wounds from surgical incisions, including punctures from minimally invasive...

  17. 21 CFR 878.4011 - Tissue adhesive with adjunct wound closure device for topical approximation of skin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY... approximated skin edges of wounds from surgical incisions, including punctures from minimally invasive...

  18. 21 CFR 878.4011 - Tissue adhesive with adjunct wound closure device for topical approximation of skin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY... approximated skin edges of wounds from surgical incisions, including punctures from minimally invasive...

  19. 21 CFR 878.4011 - Tissue adhesive with adjunct wound closure device for topical approximation of skin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY... approximated skin edges of wounds from surgical incisions, including punctures from minimally invasive...

  20. Single-stage immediate breast reconstruction using a skin-sparing incision and definitive saline implants compared with a two-stage reconstruction using tissue expansion plus implants

    PubMed Central

    Plant, Mathew A; Scilley, Christopher G; Speechley, Mark

    2009-01-01

    BACKGROUND: Losing a breast to cancer has significant psychological ramifications, and it has been shown that minimizing this loss can have a profound impact. As a result, breast-conserving therapy or mastectomy followed by breast reconstruction have become the preferred surgical treatments for breast cancer. Limited available breast skin following mastectomy has traditionally necessitated the use of autologous tissue or tissue expansion; however, when reconstructing larger breasts, autologous tissue grafts rarely provide enough tissue and tissue expanders can often take several months to achieve the necessary tissue volume. The skin-sparing mastectomy offers a solution to this lack of skin, and as a result many new options for immediate breast reconstruction have presented. The present pilot study looks at a new method of immediate breast reconstruction involving a Wise pattern skin-sparing mastectomy with placement of a definitive, submuscular saline implant as a way to maintain a large breast size without requiring the patient to undergo a long and painful tissue expansion process. METHODS: A retrospective, case-control study was performed on 12 women who had undergone bilateral mastectomies with immediate reconstruction either with a tissue expander and later placement of definitive saline implant (control group) (n=5) or who had undergone a single-stage reconstruction involving the placement of a definitive submuscular saline implant (experimental group) (n=7). Patients were compared with respect to change in breast size, number of reoperations and operations in total, as well as satisfaction with their reconstruction. RESULTS: Patient satisfaction in both groups was relatively high and there was no statistically significant difference found between the two groups. The experimental group decreased in bra size by 1.4 cup sizes on average whereas the control group experienced no change on average; however, one-third of patient data had to be discarded for

  1. Protective effects of β-glucan against oxidative injury induced by 2.45-GHz electromagnetic radiation in the skin tissue of rats.

    PubMed

    Ceyhan, Ali Murat; Akkaya, Vahide Baysal; Güleçol, Şeyma Celik; Ceyhan, Betül Mermi; Özgüner, Fehmi; Chen, WenChieh

    2012-09-01

    In recent times, there is widespread use of 2.45-GHz irradiation-emitting devices in industrial, medical, military and domestic application. The aim of the present study was to investigate the effect of 2.45-GHz electromagnetic radiation (EMR) on the oxidant and antioxidant status of skin and to examine the possible protective effects of β-glucans against the oxidative injury. Thirty-two male Wistar albino rats were randomly divided into four equal groups: control; sham exposed; EMR; and EMR + β-glucan. A 2.45-GHz EMR emitted device from the experimental exposure was applied to the EMR group and EMR + β-glucan group for 60 min daily, respectively, for 4 weeks. β-glucan was administered via gavage at a dose of 50 mg/kg/day before each exposure to radiation in the treatment group. The activities of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), as well as the concentration of malondialdehyde (MDA) were measured in tissue homogenates of the skin. Exposure to 2.45-GHz EMR caused a significant increase in MDA levels and CAT activity, while the activities of SOD and GSH-Px decreased in skin tissues. Systemic β-glucan significantly reversed the elevation of MDA levels and the reduction of SOD activities. β-glucan treatment also slightly enhanced the activity of CAT and prevented the depletion of GSH-Px activity caused by EMR, but not statistically significantly. The present study demonstrated the role of oxidative mechanisms in EMR-induced skin tissue damages and that β-glucan could ameliorate oxidative skin injury via its antioxidant properties.

  2. Ovarian teratoma displaying a wide variety of tissue components in a broiler chicken (Gallus Domesticus): morphological heterogeneity of pluripotential germ cell during tumorigenesis

    PubMed Central

    Ohfuji, S.

    2016-01-01

    Spontaneous ovarian teratoma was found in a seven-week-old female Chunky broiler chicken that was slaughtered for food. On post-mortem inspection, a spherical tumor mass attaching to a juvenile ovary was found in the abdominal cavity. Histopathologically, the tumor was comprised of immature mesenchymal stroma and a variety of mature tissue elements of mesodermal and ectodermal origin. In addition, there were multiple indistinguishable tissue elements, which showed no malignant cytological features but were unidentifiable as to corresponding embryological layer of origin. These heterogeneous teratoma tissues consisted of a variety of glandular, cystic, duct-like, and tubular structures, some of which exhibited a lining by a mixture of both keratinizing/non-keratinizing stratified squamous epithelial cells and cuboidal/columnar epithelial cells. The ovarian tetatoma was considered a benign and congenital one. The highly diverse differentiation of the teratoma might have manifested a morphological aspect of intrinsic character of the pluripotential germ cells during tumorigenesis. PMID:27303655

  3. Ovarian teratoma displaying a wide variety of tissue components in a broiler chicken (Gallus Domesticus): morphological heterogeneity of pluripotential germ cell during tumorigenesis.

    PubMed

    Ohfuji, S

    2016-01-01

    Spontaneous ovarian teratoma was found in a seven-week-old female Chunky broiler chicken that was slaughtered for food. On post-mortem inspection, a spherical tumor mass attaching to a juvenile ovary was found in the abdominal cavity. Histopathologically, the tumor was comprised of immature mesenchymal stroma and a variety of mature tissue elements of mesodermal and ectodermal origin. In addition, there were multiple indistinguishable tissue elements, which showed no malignant cytological features but were unidentifiable as to corresponding embryological layer of origin. These heterogeneous teratoma tissues consisted of a variety of glandular, cystic, duct-like, and tubular structures, some of which exhibited a lining by a mixture of both keratinizing/non-keratinizing stratified squamous epithelial cells and cuboidal/columnar epithelial cells. The ovarian tetatoma was considered a benign and congenital one. The highly diverse differentiation of the teratoma might have manifested a morphological aspect of intrinsic character of the pluripotential germ cells during tumorigenesis. PMID:27303655

  4. Hydrocellular foam dressings promote wound healing associated with decrease in inflammation in rat periwound skin and granulation tissue, compared with hydrocolloid dressings.

    PubMed

    Yamane, Takumi; Nakagami, Gojiro; Yoshino, Sawako; Shimura, Mari; Kitamura, Aya; Kobayashi-Hattori, Kazuo; Oishi, Yuichi; Nishijima, Yoshimi; Minematsu, Takeo; Sanada, Hiromi

    2015-01-01

    The effects of modern dressings on inflammation, which represent the earliest phase of wound healing, are poorly understood. We investigated the effects of modern hydrocellular foam dressings (HCFs) on wound healing and on the gene expression levels of the inflammatory markers--interleukin (IL)-1β, IL-6, and IL-10--in rat periwound skin and granulation tissue by quantitative reverse transcription-polymerase chain reaction. HCF absorbed significantly higher volume of water than hydrocolloid dressing (HCD) and increased the contraction of wounds. Polymorphonuclear neutrophils were massively infiltrated to the wound edge and boarded between granulation and dermis in the HCD group. IL-1β, IL-6, and IL-10 mRNA levels were significantly decreased in the periwound skin around the wounds and granulation tissue covered with HCF. These findings suggest that HCF may promote wound healing along with decrease in inflammation by reducing gene expression levels of IL-1β, IL-6, and IL-10.

  5. Biaxial mechanical characterization of bat wing skin.

    PubMed

    Skulborstad, A J; Swartz, S M; Goulbourne, N C

    2015-06-01

    The highly flexible and stretchable wing skin of bats, together with the skeletal structure and musculature, enables large changes in wing shape during flight. Such compliance distinguishes bat wings from those of all other flying animals. Although several studies have investigated the aerodynamics and kinematics of bats, few have examined the complex histology and mechanical response of the wing skin. This work presents the first biaxial characterization of the local deformation, mechanical properties, and fiber kinematics of bat wing skin. Analysis of these data has provided insight into the relationships among the structural morphology, mechanical properties, and functionality of wing skin. Large spatial variations in tissue deformation and non-negligible fiber strains in the cross-fiber direction for both chordwise and spanwise fibers indicate fibers should be modeled as two-dimensional elements. The macroscopic constitutive behavior was anisotropic and nonlinear, with very low spanwise and chordwise stiffness (hundreds of kilopascals) in the toe region of the stress-strain curve. The structural arrangement of the fibers and matrix facilitates a low energy mechanism for wing deployment and extension, and we fabricate examples of skins capturing this mechanism. We propose a comprehensive deformation map for the entire loading regime. The results of this work underscore the importance of biaxial field approaches for soft heterogeneous tissue, and provide a foundation for development of bio-inspired skins to probe the effects of the wing skin properties on aerodynamic performance. PMID:25895436

  6. Distribution of Fatal Vibrio Vulnificus Necrotizing Skin and Soft-Tissue Infections: A Systematic Review and Meta-Analysis.

    PubMed

    Huang, Kuo-Chin; Weng, Hsu-Huei; Yang, Tien-Yu; Chang, Te-Sheng; Huang, Tsan-Wen; Lee, Mel S

    2016-02-01

    Vibrio vulnificus necrotizing skin and soft tissue infections (VNSSTIs), which have increased significantly over the past few decades, are still highly lethal and disabling diseases despite advancing antibiotic and infection control practices. We, therefore, examined the spatiotemporal distribution of worldwide reported episodes and associated mortality rates of VNSSTIs between 1966 and 2014. The PubMed and Cochrane Library databases were systematically searched for observational studies on patients with VNSSTIs. The primary outcome was all-cause mortality. We did random-effects meta-analysis to obtain estimates for primary outcomes; the estimates are presented as means plus a 95% confidence interval (CI). Data from the selected studies were also extracted and pooled for correlation analyses.Nineteen studies of 2227 total patients with VNSSTIs were analyzed. More than 95% of the episodes occurred in the subtropical western Pacific and Atlantic coastal regions of the northern hemisphere. While the number of cases and the number of deaths were not correlated with the study period (rs = 0.476 and 0.310, P = 0.233 and 0.456, respectively), the 5-year mortality rate was significantly negatively correlated with them (rs = -0.905, P = 0.002). Even so, the pooled estimate of total mortality rates from the random-effects meta-analysis was as high as 37.2% (95% CI: 0.265-0.479).These data suggest that VNSSTIs are always an important public health problem and will become more critical and urgent because of global warming. Knowing the current distribution of VNSSTIs will help focus education, policy measures, early clinical diagnosis, and appropriate medical and surgical treatment for them.

  7. Distribution of Fatal Vibrio Vulnificus Necrotizing Skin and Soft-Tissue Infections: A Systematic Review and Meta-Analysis.

    PubMed

    Huang, Kuo-Chin; Weng, Hsu-Huei; Yang, Tien-Yu; Chang, Te-Sheng; Huang, Tsan-Wen; Lee, Mel S

    2016-02-01

    Vibrio vulnificus necrotizing skin and soft tissue infections (VNSSTIs), which have increased significantly over the past few decades, are still highly lethal and disabling diseases despite advancing antibiotic and infection control practices. We, therefore, examined the spatiotemporal distribution of worldwide reported episodes and associated mortality rates of VNSSTIs between 1966 and 2014. The PubMed and Cochrane Library databases were systematically searched for observational studies on patients with VNSSTIs. The primary outcome was all-cause mortality. We did random-effects meta-analysis to obtain estimates for primary outcomes; the estimates are presented as means plus a 95% confidence interval (CI). Data from the selected studies were also extracted and pooled for correlation analyses.Nineteen studies of 2227 total patients with VNSSTIs were analyzed. More than 95% of the episodes occurred in the subtropical western Pacific and Atlantic coastal regions of the northern hemisphere. While the number of cases and the number of deaths were not correlated with the study period (rs = 0.476 and 0.310, P = 0.233 and 0.456, respectively), the 5-year mortality rate was significantly negatively correlated with them (rs = -0.905, P = 0.002). Even so, the pooled estimate of total mortality rates from the random-effects meta-analysis was as high as 37.2% (95% CI: 0.265-0.479).These data suggest that VNSSTIs are always an important public health problem and will become more critical and urgent because of global warming. Knowing the current distribution of VNSSTIs will help focus education, policy measures, early clinical diagnosis, and appropriate medical and surgical treatment for them. PMID:26844475

  8. Molecular Epidemiology of Staphylococcus aureus among Patients with Skin and Soft Tissue Infections in Two Chinese Hospitals

    PubMed Central

    Gu, Fei-Fei; Chen, Ye; Dong, De-Ping; Song, Zhen; Guo, Xiao-Kui; Ni, Yu-Xing; Han, Li-Zhong

    2016-01-01

    Background: Staphylococcus aureus is one of the predominant causes of skin and soft tissue infections (SSTIs), but limited data were available regarding the characterization of S. aureus from SSTIs patients in Jiangsu Province in China. We aimed to investigate the molecular epidemiology of S. aureus among SSTIs patients in two hospitals of Jiangsu Province. Methods: Sixty-two patients with SSTIs from two Chinese hospitals in Jiangsu Province were enrolled in this study, and 62 S. aureus isolates were collected from February 2014 to January 2015. S. aureus isolates were characterized by antimicrobial susceptibility testing, toxin gene detection, and molecular typing with sequence type, Staphylococcus protein A gene type, accessory gene regulator (agr) group, and Staphylococcal cassette chromosome mec type. Results: Sixteen (25.8%) methicillin-resistant S. aureus (MRSA) isolates were detected, and there was no isolate found resistant to vancomycin, teicoplanin, sulfamethoxazole-trimethoprim, and linezolid. The sei was the toxin gene most frequently found, and no lukS/F-PV-positive isolates were detected among the SSTIs’ patients. Molecular analysis revealed that ST398 (10/62, 16.1%; 2 MRSA and 8 methicillin-susceptible S. aureus) to be the dominant clone, followed by ST5 (8/62, 12.9%) and ST7 (8/62, 12.9%). Conclusions: The livestock ST398 was the most common clone among patients with S. aureus SSTIs in Jiangsu Province, China. Surveillance and further studies on the important livestock ST398 clone in human infections are necessarily requested. PMID:27647191

  9. RNA-Seq Analysis of the Host Response to Staphylococcus aureus Skin and Soft Tissue Infection in a Mouse Model

    PubMed Central

    Brady, Rebecca A.; Bruno, Vincent M.; Burns, Drusilla L.

    2015-01-01

    Staphylococcus aureus is a leading cause of skin and soft tissue infections (SSTI), which are primarily self-limiting. We conducted a comprehensive analysis of the host transcriptome during a S. aureus SSTI to provide insight on the protective mechanisms that thwart these infections. We utilized a murine SSTI model in which one ear is epicutaneously challenged while the other is not. We then harvested these infected and uninfected ears, as well as ears from naïve mice, at one, four, and seven days post-challenge, and performed RNA sequencing (RNA-seq) using the Illumina platform. RNA-seq data demonstrated a robust response at the site of infection. Comparison of gene expression profiles between infected ears and the non-infected ears of challenged mice defined the local response to infection, while comparisons of expression profiles of non-infected ears from challenged mice to ears of naïve mice revealed changes in gene expression levels away from the site indicative of a systemic response. Over 1000 genes exhibited increased expression locally at all tested time points. The local response was more robust than the systemic response. Through evaluation of the RNA-seq data using the Upstream Regulator Analytic as part of the Ingenuity Pathway Analysis software package, we found that changes in the activation and inhibition of regulatory pathways happen first locally, and lag behind systemically. The activated pathways are highly similar at all three time points during SSTI, suggesting a stable global response over time. Transcript increases and pathway activation involve pro- and anti-inflammatory mediators, chemotaxis, cell signaling, keratins, and TH1/TH17 cytokines. Transcript decreases and pathway inhibition demonstrate that metabolic genes and anti-inflammatory pathways are repressed. These data provide insight on the host responses that may aid in resolution of this self-limited S. aureus infection, and may shed light on potential immune correlates of

  10. Epidemiology and Outcomes of Complicated Skin and Soft Tissue Infections among Inpatients in Southern China from 2008 to 2013

    PubMed Central

    Gao, Weiguo; Ouyang, Wenwei; Wei, Jia; Wen, Zehuai

    2016-01-01

    Complicated skin and soft tissue infections (cSSTI) are some of the most commonly treated infections in hospitals, and place heavy economic burdens on patients and society. Here we report the findings from an analysis of cSSTI based on a retrospective study which was conducted within the Chinese inpatient population. We focused our research on the analysis of the patient population, antibiotic treatment, clinical outcome and economic burden. The study population comprised 527 selected patients hospitalized between 2008 and 2013. Among the hospitalizations with microbiological diagnoses, 61.41% (n = 113) were diagnosed as infected with Gram-positive bacteria, while 46.20% (n = 85) were infected with Gram-negative bacteria. The most commonly found Gram-positive bacteria was Staphylococcus aureus (40.76%, n = 75), and the most common Gram-negative bacteria was Escherichia coli (14.13%, n = 26). About 20% of the Staphylococcus aureus were methicillin-resistant. The resistance rate of isolated Staphylococcus aureus or Escherichia coli to penicillin was around 90%; in contrast, the resistance rate to vancomycin, linezolid or imipenem was low (<20%). A large percentage of patients were treated with cephalosporins and fluoroquinolones, while vancomycin and imipenem were also included to treat drug-resistant pathogens. Over half of the hospitalizations (58.43%, n = 336) experienced treatment modifications. The cost to patients with antibiotic modifications was relatively higher than to those without. In conclusion, our study offers an analysis of the disease characteristics, microbiological diagnoses, treatment patterns and clinical outcomes of cSSTI in four hospitals in Guangdong Province, and sheds lights on the current clinical management of cSSTI in China. PMID:26918456

  11. Comparative Exoproteomics and Host Inflammatory Response in Staphylococcus aureus Skin and Soft Tissue Infections, Bacteremia, and Subclinical Colonization

    PubMed Central

    Liew, Yun Khoon; Awang Hamat, Rukman; van Belkum, Alex; Chong, Pei Pei

    2015-01-01

    The exoproteome of Staphylococcus aureus contains enzymes and virulence factors that are important for host adaptation. We investigated the exoprotein profiles and cytokine/chemokine responses obtained in three different S. aureus-host interaction scenarios by using two-dimensional gel electrophoresis (2-DGE) and two-dimensional immunoblotting (2D-IB) combined with tandem mass spectrometry (MS/MS) and cytometric bead array techniques. The scenarios included S. aureus bacteremia, skin and soft tissue infections (SSTIs), and healthy carriage. By the 2-DGE approach, 12 exoproteins (the chaperone protein DnaK, a phosphoglycerate kinase [Pgk], the chaperone GroEL, a multisensor hybrid histidine kinase, a 3-methyl-2-oxobutanoate hydroxymethyltransferase [PanB], cysteine synthase A, an N-acetyltransferase, four isoforms of elongation factor Tu [EF-Tu], and one signature protein spot that could not be reliably identified by MS/MS) were found to be consistently present in more than 50% of the bacteremia isolates, while none of the SSTI or healthy-carrier isolates showed any of these proteins. By the 2D-IB approach, we also identified five antigens (methionine aminopeptidase [MetAPs], exotoxin 15 [Set15], a peptidoglycan hydrolase [LytM], an alkyl hydroperoxide reductase [AhpC], and a haptoglobin-binding heme uptake protein [HarA]) specific for SSTI cases. Cytokine and chemokine production varied during the course of different infection types and carriage. Monokine induced by gamma interferon (MIG) was more highly stimulated in bacteremia patients than in SSTI patients and healthy carriers, especially during the acute phase of infection. MIG could therefore be further explored as a potential biomarker of bacteremia. In conclusion, 12 exoproteins from bacteremia isolates, MIG production, and five antigenic proteins identified during SSTIs should be further investigated for potential use as diagnostic markers. PMID:25809633

  12. Epidemiology and Outcomes of Complicated Skin and Soft Tissue Infections among Inpatients in Southern China from 2008 to 2013.

    PubMed

    Li, Xiaoyan; Chen, Yunqin; Gao, Weiguo; Ouyang, Wenwei; Wei, Jia; Wen, Zehuai

    2016-01-01

    Complicated skin and soft tissue infections (cSSTI) are some of the most commonly treated infections in hospitals, and place heavy economic burdens on patients and society. Here we report the findings from an analysis of cSSTI based on a retrospective study which was conducted within the Chinese inpatient population. We focused our research on the analysis of the patient population, antibiotic treatment, clinical outcome and economic burden. The study population comprised 527 selected patients hospitalized between 2008 and 2013. Among the hospitalizations with microbiological diagnoses, 61.41% (n = 113) were diagnosed as infected with Gram-positive bacteria, while 46.20% (n = 85) were infected with Gram-negative bacteria. The most commonly found Gram-positive bacteria was Staphylococcus aureus (40.76%, n = 75), and the most common Gram-negative bacteria was Escherichia coli (14.13%, n = 26). About 20% of the Staphylococcus aureus were methicillin-resistant. The resistance rate of isolated Staphylococcus aureus or Escherichia coli to penicillin was around 90%; in contrast, the resistance rate to vancomycin, linezolid or imipenem was low (<20%). A large percentage of patients were treated with cephalosporins and fluoroquinolones, while vancomycin and imipenem were also included to treat drug-resistant pathogens. Over half of the hospitalizations (58.43%, n = 336) experienced treatment modifications. The cost to patients with antibiotic modifications was relatively higher than to those without. In conclusion, our study offers an analysis of the disease characteristics, microbiological diagnoses, treatment patterns and clinical outcomes of cSSTI in four hospitals in Guangdong Province, and sheds lights on the current clinical management of cSSTI in China. PMID:26918456

  13. Common Protein Biomarkers Assessed by Reverse Phase Protein Arrays Show Considerable Intratumoral Heterogeneity in Breast Cancer Tissues

    PubMed Central

    Buchner, Theresa; Thulke, Sabrina; Wolff, Claudia; Höfler, Heinz; Becker, Karl-Friedrich; Avril, Stefanie

    2012-01-01

    Proteins are used as prognostic and predictive biomarkers in breast cancer. However, the variability of protein expression within the same tumor is not well studied. The aim of this study was to assess intratumoral heterogeneity in protein expression levels by reverse-phase-protein-arrays (RPPA) (i) within primary breast cancers and (ii) between axillary lymph node metastases from the same patient. Protein was extracted from 106 paraffin-embedded samples from 15 large (≥3 cm) primary invasive breast cancers, including different zones within the primary tumor (peripheral, intermediate, central) as well as 2–5 axillary lymph node metastases in 8 cases. Expression of 35 proteins including 15 phosphorylated proteins representing the HER2, EGFR, and uPA/PAI-1 signaling pathways was assessed using reverse-phase-protein-arrays. All 35 proteins showed considerable intratumoral heterogeneity within primary breast cancers with a mean coefficient of variation (CV) of 31% (range 22–43%). There were no significant differences between phosphorylated (CV 32%) and non-phosphorylated proteins (CV 31%) and in the extent of intratumoral heterogeneity within a defined tumor zone (CV 28%, range18–38%) or between different tumor zones (CV 24%, range 17–38%). Lymph node metastases from the same patient showed a similar heterogeneity in protein expression (CV 27%, range 18–34%). In comparison, the variation amongst different patients was higher in primary tumors (CV 51%, range 29–98%) and lymph node metastases (CV 65%, range 40–146%). Several proteins showed significant differential expression between different tumor stages, grades, histological subtypes and hormone receptor status. Commonly used protein biomarkers of breast cancer, including proteins from HER2, uPA/PAI-1 and EGFR signaling pathways showed higher than previously reported intratumoral heterogeneity of expression levels both within primary breast cancers and between lymph node metastases from the same

  14. Common protein biomarkers assessed by reverse phase protein arrays show considerable intratumoral heterogeneity in breast cancer tissues.

    PubMed

    Malinowsky, Katharina; Raychaudhuri, Mithu; Buchner, Theresa; Thulke, Sabrina; Wolff, Claudia; Höfler, Heinz; Becker, Karl-Friedrich; Avril, Stefanie

    2012-01-01

    Proteins are used as prognostic and predictive biomarkers in breast cancer. However, the variability of protein expression within the same tumor is not well studied. The aim of this study was to assess intratumoral heterogeneity in protein expression levels by reverse-phase-protein-arrays (RPPA) (i) within primary breast cancers and (ii) between axillary lymph node metastases from the same patient. Protein was extracted from 106 paraffin-embedded samples from 15 large (≥3 cm) primary invasive breast cancers, including different zones within the primary tumor (peripheral, intermediate, central) as well as 2-5 axillary lymph node metastases in 8 cases. Expression of 35 proteins including 15 phosphorylated proteins representing the HER2, EGFR, and uPA/PAI-1 signaling pathways was assessed using reverse-phase-protein-arrays. All 35 proteins showed considerable intratumoral heterogeneity within primary breast cancers with a mean coefficient of variation (CV) of 31% (range 22-43%). There were no significant differences between phosphorylated (CV 32%) and non-phosphorylated proteins (CV 31%) and in the extent of intratumoral heterogeneity within a defined tumor zone (CV 28%, range 18-38%) or between different tumor zones (CV 24%, range 17-38%). Lymph node metastases from the same patient showed a similar heterogeneity in protein expression (CV 27%, range 18-34%). In comparison, the variation amongst different patients was higher in primary tumors (CV 51%, range 29-98%) and lymph node metastases (CV 65%, range 40-146%). Several proteins showed significant differential expression between different tumor stages, grades, histological subtypes and hormone receptor status. Commonly used protein biomarkers of breast cancer, including proteins from HER2, uPA/PAI-1 and EGFR signaling pathways showed higher than previously reported intratumoral heterogeneity of expression levels both within primary breast cancers and between lymph node metastases from the same patient. Assessment

  15. Antimicrobial resistance profile of Staphylococcus aureus isolates obtained from skin and soft tissue infections of outpatients from a university hospital in Recife - PE, Brazil*

    PubMed Central

    Caraciolo, Fabiana Beserra; Maciel, Maria Amélia Vieira; dos Santos, Josemir Belo; Rabelo, Marcelle Aquino; Magalhães, Vera

    2012-01-01

    BACKGROUND Staphylococcus aureus has a notable ability to acquire resistance to antibiotics, and methicillin resistance represents a growing public health problem. Methicillin-resistant S. aureus (MRSA) has also become important outside the hospital environment, particularly in the United States. In Brazil, since 2005, cases of community skin infections caused by MRSA have been reported, but resistance studies involving outpatients are scarce. OBJECTIVE To know the resistance profile of S. aureus involved in skin and soft tissue infections of patients seen at the Dermatology outpatient clinic of a university hospital in Recife, Pernambuco State, northeastern Brazil. METHODS Prospective study involving 30 patients with skin and soft tissue infections, seen at the Dermatology outpatient clinic from May until November 2011. To evaluate the susceptibility of S. aureus to antibiotics, the disk diffusion method and oxacillin screening agar were used. RESULTS From a total of 30 samples of skin lesions, 19 (63%) had positive culture for S. aureus. The following resistance patterns of S. aureus were observed: penicillin, 95%; tetracycline, 32%; erythromycin, 21%; gentamicin, 16%; cefoxitin, 11%; oxacillin, 11%; trimethoprim-sulfamethoxazole, 11%; chloramphenicol, 11%; clindamycin, 5% ; and ciprofloxacin, 0%. One of the identified MRSA was obtained from a patient without risk factors for its acquisition, and was resistant, beyond to the beta-lactams, only to tetracycline. CONCLUSIONS With regard to the resistance patterns of S. aureus, resistances to tetracycline, erythromycin and gentamicin were the highest. It was documented, for the first time in Pernambuco, a case of skin infection caused by community-associated MRSA. PMID:23197204

  16. Use of a Tissue Engineered Human Skin Model to Investigate the Effects of Wounding and of an Anti-Inflammatory on Melanoma Cell Invasion.

    PubMed

    Marques, Claudia Mirian de Godoy; MacNeil, Sheila

    2016-01-01

    An increasing number of studies suggest inflammation stimulates tumour invasion. In melanoma, despite recent advances in targeted therapy and immunomodulatory therapies, this cancer remains difficult to treat. Our previous studies show melanoma cells interact with skin cells in their invasion into tissue engineered skin and suggest inflammation stimulates invasion. The aim of this study was to investigate the use of an anti-inflammatory on melanoma invasion. To do this we developed a wounded and inflamed in vitro 3D melanoma model in which to investigate the use of an anti-inflammatory on melanoma invasion. The tissue engineered skin model was based on human de-epidermised acellular dermis to which keratinocytes, fibroblasts and three different melanoma cell lines were added in various combinations. A simple incisional wound was made in the model and TNF-α and fibrin were added to simulate conditions of inflammation. Topical ibuprofen in a hydrogel was added and the extent of melanoma invasion into the dermis was assessed under the various conditions. The results showed that penetration of two of the cell lines (HBL and A375SM) into the tissue engineered skin was exacerbated by wounding and ibuprofen significantly decreased invasion of A375SM cells and slightly reduced invasion of HBL cells. A third cell line, C8161, was aggressively invasive under all conditions to an extent that was not influenced by wounding, TNF-α or the addition of ibuprofen. In summary, the results for one these cell lines (and a trend for a second cell line) support the hypothesis that a wound environment is conducive to melanoma invasion but the local addition of an anti-inflammatory drug such as ibuprofen may attenuate invasion.

  17. Use of a Tissue Engineered Human Skin Model to Investigate the Effects of Wounding and of an Anti-Inflammatory on Melanoma Cell Invasion

    PubMed Central

    Marques, Claudia Mirian de Godoy; MacNeil, Sheila

    2016-01-01

    An increasing number of studies suggest inflammation stimulates tumour invasion. In melanoma, despite recent advances in targeted therapy and immunomodulatory therapies, this cancer remains difficult to treat. Our previous studies show melanoma cells interact with skin cells in their invasion into tissue engineered skin and suggest inflammation stimulates invasion. The aim of this study was to investigate the use of an anti-inflammatory on melanoma invasion. To do this we developed a wounded and inflamed in vitro 3D melanoma model in which to investigate the use of an anti-inflammatory on melanoma invasion. The tissue engineered skin model was based on human de-epidermised acellular dermis to which keratinocytes, fibroblasts and three different melanoma cell lines were added in various combinations. A simple incisional wound was made in the model and TNF-α and fibrin were added to simulate conditions of inflammation. Topical ibuprofen in a hydrogel was added and the extent of melanoma invasion into the dermis was assessed under the various conditions. The results showed that penetration of two of the cell lines (HBL and A375SM) into the tissue engineered skin was exacerbated by wounding and ibuprofen significantly decreased invasion of A375SM cells and slightly reduced invasion of HBL cells. A third cell line, C8161, was aggressively invasive under all conditions to an extent that was not influenced by wounding, TNF-α or the addition of ibuprofen. In summary, the results for one these cell lines (and a trend for a second cell line) support the hypothesis that a wound environment is conducive to melanoma invasion but the local addition of an anti-inflammatory drug such as ibuprofen may attenuate invasion. PMID:27270229

  18. Defensive effects of fullerene-C60 dissolved in squalane against the 2,4-nonadienal-induced cell injury in human skin keratinocytes HaCaT and wrinkle formation in 3D-human skin tissue model.

    PubMed

    Kato, Shinya; Aoshima, Hisae; Saitoh, Yasukazu; Miwa, Nobuhiko

    2010-02-01

    We dissolved fullerene-C60 in squalane (LipoFullerene; LF-SQ, C60-eq.: 500 ppm) and examined its defensive effects against 2,4-nonadienal (NDA)-induced cell injury in HaCaT keratinocytes and wrinkle formation in three dimensional (3D)-human skin tissue model. NDA is an analog of 4-hydroxynonenal, one of major causes for human body odor indicative of aging and a lipophilic cell injury factor. Cell viability (% of the control) decreased to 31.6% on treatment with NDA (40 microM), but it increased to 66.0-97.5% when LF-SQ of 1-4% (C60-eq.: 5-20 ppm) was administered for 5 hr before NDA addition. The defensive effect by LF-SQ was superior to that of "squalane" alone at the same doses. NDA-induced DNA-fragmentation in HaCaT cells was suppressed by LF-SQ administered for 5 hr before NDA treatment, and LF-SQ protected HaCaT cells against apoptosis-like cell death. LF-SQ did not appreciably defend against hydrogen peroxide, though LF-SQ effectively defended against tert-butylhydroperoxide, a type of the intermediate hydrophilicity-lipophilicity degree out of other reactive oxygen species. The scanning electron microscopy demonstrated that NDA caused wrinkles and abnormal scales on keratinocytes of 3D-human skin tissue model, and structural homogeneity of the interstratum was broken, any of which were, however, markedly suppressed with LF-SQ. Squalane alone exhibited defensive effect against the skin tissue injury to some extent, but which was inferior to LF-SQ. LF-SQ might effectively capture and scavenge lipid radicals generated inside the cell membrane, because squalane acts as a lipophilic carrier of C60. C60 dissolved in squalane can be expected to serve as a cosmeceutical ingredient for anti-wrinkle formation.

  19. A microneedle-based method for the characterization of diffusion in skin tissue using doxorubicin as a model drug.

    PubMed

    Mansoor, Iman; Lai, Jacqueline; Ranamukhaarachchi, Sahan; Schmitt, Veronika; Lambert, Dana; Dutz, Jan; Häfeli, Urs O; Stoeber, Boris

    2015-01-01

    Hollow microneedles can overcome the stratum corneum (SC) barrier and deposit a compound directly into the viable epidermis or the dermis, unlike adhesive patches that rely on drug diffusion across the SC. The traditional one-dimensional methods used to study the diffusivity of drugs across the skin layers are not very accurate for hollow microneedles, since the ejection of compounds out of microneedle lumens resembles a point-source spreading in all directions and is highly dependent on injection depth. This paper presents a technique that is useful for studying drug injection using hollow microneedles at various depths below the SC. This technique uses confocal microscopy to image the distribution of a fluorescent compound in the skin after injection. The fluorescence distribution in the skin is observed over time and applied to a spherical Gaussian diffusion model for limited source diffusion to determine the diffusion coefficient of the compound in the skin. Applied to freshly excised pig skin, the diffusion coefficient for the anti-cancer drug doxorubicin was measured as 4.61 × 10(-9) cm(2)/s, while the diffusion coefficient in previously refrigerated or frozen pig skin was 1.31 × 10(-8) cm(2)/s and 4.21 × 10(-8) cm(2)/s, respectively. Our data suggests that skin storage conditions can substantially alter the diffusion of drugs. The use of refrigerated and, even more so, previously frozen skin should be avoided for quantitative transdermal drug delivery studies.

  20. [Susceptibilities of multidrug-resistant pathogens responsible for complicated skin and soft tissue infections to standard bacteriophage cocktails].

    PubMed

    Gündoğdu, Aycan; Kılıç, Hüseyin; Ulu Kılıç, Ayşegül; Kutateladze, Mzia

    2016-04-01

    Skin and soft tissue infections (SSTIs) may represent a wide clinical spectrum from cellulitis to high-mortality associated necrotizing fasciitis. Limitations in therapy due to the multiple drug resistance, leads to increase in the morbidity and mortality rates, especially in complicated SSTIs such as diabetic foot, decubitus, and surgical wound infections. Therefore, alternative treatment strategies other than antibiotics are needed in appropriate clinical conditions. "Bacteriophage therapy", which is an old method and has been used as part of standard treatment in some countries such as Georgia and Russia, has again become popular worldwide. The aim of this study was to investigate the in vitro susceptibilities of multidrug-resistant (MDR) pathogens isolated from patients with complicated SSTIs, against standard bacteriophage (phage) cocktails. Six different ready-made phage preparations [Pyophage, Intestiphage, ENKO, SES, Fersisi and Staphylococcal Bacteriophage (Sb)] used in this study have been provided by G. Eliava Institute, Georgia. Because of the absence of ready-made phage preparations for Acinetobacter baumannii and Klebsiella pneumoniae, Φ1-Φ7 and ΦKL1- ΦKL3 phages were used provided from the same institute's phage library, respectively. Isolation and identification of the pathogens from abscess and wound samples of patients with SSTIs were performed by conventional methods and automatized VITEK(®)-2 (bioMerieux, ABD) system. Antimicrobial susceptibility testing was conducted complying CLSI standards' and the bacteria that were resistant to at least two different antibiotic groups were considered as MDR. Accordingly, a total of 33 isolates, nine of them were E.coli (8 ESBL and 1 ESBL + carbapenemase positive); nine were MDR P.aeruginosa; nine were MDR A.baumannii; three were methicillin-resistant Staphylococcus aureus (MRSA) and three were K.pneumoniae (1 ESBL, 1 carbapenemase and 1 ESBL + carbapenemase positive) were included in the study. The

  1. Specific Behaviors Predict Staphylococcus aureus Colonization and Skin and Soft Tissue Infections Among Human Immunodeficiency Virus-Infected Persons.

    PubMed

    Crum-Cianflone, Nancy F; Wang, Xun; Weintrob, Amy; Lalani, Tahaniyat; Bavaro, Mary; Okulicz, Jason F; Mende, Katrin; Ellis, Michael; Agan, Brian K

    2015-04-01

    Background.  Few data exist on the incidence and risk factors of Staphylococcus aureus colonization and skin and soft tissue infections (SSTIs) among patients infected with human immunodeficiency virus (HIV). Methods.  Over a 2-year period, we prospectively evaluated adults infected with HIV for incident S aureus colonization at 5 body sites and SSTIs. Cox proportional hazard models using time-updated covariates were performed. Results.  Three hundred twenty-two participants had a median age of 42 years (interquartile range, 32-49), an HIV duration of 9.4 years (2.7-17.4), and 58% were on highly active antiretroviral therapy (HAART). Overall, 102 patients (32%) became colonized with S aureus with an incidence rate of 20.6 (95% confidence interval [CI], 16.8-25.0) per 100 person-years [PYs]. Predictors of colonization in the final multivariable model included illicit drug use (hazard ratios [HR], 4.26; 95% CI, 1.33-13.69) and public gym use (HR 1.66, 95% CI, 1.04-2.66), whereas antibacterial soap use was protective (HR, 0.50; 95% CI, 0.32-0.78). In a separate model, perigenital colonization was associated with recent syphilis infection (HR, 4.63; 95% CI, 1.01-21.42). Fifteen percent of participants developed an SSTI (incidence rate of 9.4 cases [95% CI, 6.8-12.7] per 100 PYs). Risk factors for an SSTI included incident S aureus colonization (HR 2.52; 95% CI, 1.35-4.69), public shower use (HR, 2.59; 95% CI, 1.48-4.56), and hospitalization (HR 3.54; 95% CI, 1.67-7.53). The perigenital location for S aureus colonization was predictive of SSTIs. Human immunodeficiency virus-related factors (CD4 count, HIV RNA level, and HAART) were not associated with colonization or SSTIs. Conclusions.  Specific behaviors, but not HIV-related factors, are predictors of colonization and SSTIs. Behavioral modifications may be the most important strategies in preventing S aureus colonization and SSTIs among persons infected with HIV. PMID:26380335

  2. Efficacy and safety of daptomycin for skin and soft tissue infections: a systematic review with trial sequential analysis

    PubMed Central

    Liu, Chao; Mao, Zhi; Yang, Mengmeng; Kang, Hongjun; Liu, Hui; Pan, Liang; Hu, Jie; Luo, Jun; Zhou, Feihu

    2016-01-01

    Background Skin and soft tissue infections (SSTIs) are significant indications for antibiotic treatment. Daptomycin, a novel antibiotic, has been registered and licensed to be used in the treatment of these infections. However, its efficacy and safety remain controversial. Objective The objective of this study was to conduct a systematic review with trial sequential analysis (TSA) to evaluate the efficacy and safety of daptomycin for the treatment of SSTIs and to analyze whether the available sample size has been large enough and is conclusive. Methods PubMed, the Cochrane Library, and EMBASE were searched for published randomized controlled trials (RCTs) that compared daptomycin with other antibiotics in adult patients with SSTIs up to February 2016. Results This meta-analysis included eight randomized controlled trials (n=2,002). There was no difference in either the clinical success rate (intention-to-treat population: relative risk [RR] =1.04, 95% confidence interval [CI] =0.99–1.10, P=0.12; clinically evaluable population: RR =1.00, 95% CI =0.97–1.04, P=0.82) or the microbiological success rate (RR =1.00, 95% CI =0.95–1.06, P=0.92) between the daptomycin and comparator groups for treating SSTIs, which was confirmed by TSA. Compared with vancomycin, daptomycin exhibited no advantage in increasing the clinical success rate (RR =1.03, 95% CI =0.95–1.13, P=0.47), and this was also confirmed by TSA. All-cause mortality, overall treatment-related adverse events, and creatine phosphokinase events were similar between these two groups. Conclusion Daptomycin and comparator drugs are equally efficacious with regard to clinical and microbiological success for patients with SSTIs, and TSA showed that no additional randomized controlled trials are required. Although daptomycin is a good alternative when other antibiotics are contraindicated for patients with SSTIs and it can serve as a first-line treatment for SSTIs, clinicians should be aware of potential adverse

  3. Characterization of Staphylococcus aureus Isolated from Non-Native Patients with Skin and Soft Tissue Infections in Shanghai

    PubMed Central

    Yang, Hai-Hui; Zhu, Yue-Qiu; Guo, Xiao-Kui; Ni, Yu-Xing; Han, Li-Zhong

    2015-01-01

    Background Staphylococcus aureus is one predominant cause of skin and soft-tissue infections (SSTIs), but little information exists regarding the characterization of S. aureus from non-native patients with SSTIs in China. Methods In this study, we enrolled 52 non-native patients with S. aureus SSTIs, and 65 native control patients with S. aureus SSTIs in Shanghai. 52 and 65 S. aureus isolates were collected from both groups, respectively. S. aureus isolates were characterized by antimicrobial susceptibility testing, toxin gene detection, and molecular typing with sequence type, spa type, agr group and SCCmec type. Results Methicillin-resistant S. aureus (MRSA) was detected in 8 non-native patients and 14 native patients with SSTIs. Overall, antimicrobial susceptibilities of S. aureus isolated from non-native patients were found higher than those from native patients. CC59 (ST338 and ST59) was found in a total of 14 isolates (4 from non-native patients; 10 from native patients), 9 of which were carrying lukS/F-PV (3 from non-native patients; 6 from native patients). ST7 was found in 12 isolates and all 12 isolates were found in native patients. The livestock-associated clone ST398 was found in 11 isolates (6 from non-native patients; 5 from native patients), and 5 ST398 lukS/F-PV-positive methicillin-susceptible S. aureus (MSSA) were all discovered among non-native patients. The molecular epidemiology of S. aureus isolated from non-native patients was quite different from those from native patients. lukS/F-PV was more frequent in isolates originating from non-native patients with SSTIs compared to native patients (31 vs. 7, P <0.0001). Conclusions CC59 was the most common clonal complex among patients with SSTIs in Shanghai. The other most common sequence types were ST7 and Livestock ST398. The molecular epidemiology of S. aureus isolated from non-native patients was quite different from those from native patients. S. aureus isolated from non-native patients was

  4. In-to-Out Body Antenna-Independent Path Loss Model for Multilayered Tissues and Heterogeneous Medium

    PubMed Central

    Kurup, Divya; Vermeeren, Günter; Tanghe, Emmeric; Joseph, Wout; Martens, Luc

    2015-01-01

    In this paper, we investigate multilayered lossy and heterogeneous media for wireless body area networks (WBAN) to develop a simple, fast and efficient analytical in-to-out body path loss (PL) model at 2.45 GHz and, thus, avoid time-consuming simulations. The PL model is an antenna-independent model and is validated with simulations in layered medium, as well as in a 3D human model using electromagnetic solvers. PMID:25551483

  5. Patients With Burns Versus Patients With Complex Skin and Soft-Tissue Disease: An Analysis of Outcomes in the United States.

    PubMed

    Maximus, Steven; Phelan, Michael; Joe, Victor C

    2016-01-01

    With the incidence of burns decreasing nationally, burn units are caring for more patients with nonburn conditions. The American Burn Association National Burn Repository does not currently report data regarding patients cared for in burn units without a diagnosis of burn. Using the National Inpatient Sample, we examined if there was a difference in characteristics and outcomes of patients admitted for burns compared with those with a primary admitting diagnosis of necrotizing skin infections and soft-tissue infections and exfoliative skin conditions. This is a retrospective study querying the National Inpatient Sample database to identify 56,102 patients from 2007 to 2012 who were admitted with a diagnosis of a burn (burn group). This group was then compared with 375,857 patients who had a primary admitting diagnosis of a necrotizing skin and/or soft-tissue infection or exfoliative skin conditions (nonburn group). Clinical and demographic variables were analyzed to determine characteristics of each patient group including length of stay, disposition, complications, comorbidities, and mortality. The average age of the nonburn group was 63.7 years, whereas the average age of the burn group was 40.1 years. Overall length of stay was higher in the nonburn patients than in burn patients (10.5 vs 8.4 days, P < .001). Nonburn patients had a higher rate of medical comorbidities. Nonburn patients had higher rates of mortality (6.9% vs 2.7%) and complications. After adjusting for confounders, such as age, gender, ethnicity, and comorbidities, the nonburn group was found to have higher rates of all recorded complications. Burn patients were more likely to undergo a major operating room procedure (39.3% vs 28.1%) and routine discharge (68.4% vs 26.3%) compared with the nonburn group. Patients with necrotizing skin and soft-tissue infections and exfoliative skin conditions are older, have more comorbidities, higher complication rates, and higher mortality rates than burn

  6. Segmentation of heterogeneous or small FDG PET positive tissue based on a 3D-locally adaptive random walk algorithm.

    PubMed

    Onoma, D P; Ruan, S; Thureau, S; Nkhali, L; Modzelewski, R; Monnehan, G A; Vera, P; Gardin, I

    2014-12-01

    A segmentation algorithm based on the random walk (RW) method, called 3D-LARW, has been developed to delineate small tumors or tumors with a heterogeneous distribution of FDG on PET images. Based on the original algorithm of RW [1], we propose an improved approach using new parameters depending on the Euclidean distance between two adjacent voxels instead of a fixed one and integrating probability densities of labels into the system of linear equations used in the RW. These improvements were evaluated and compared with the original RW method, a thresholding with a fixed value (40% of the maximum in the lesion), an adaptive thresholding algorithm on uniform spheres filled with FDG and FLAB method, on simulated heterogeneous spheres and on clinical data (14 patients). On these three different data, 3D-LARW has shown better segmentation results than the original RW algorithm and the three other methods. As expected, these improvements are more pronounced for the segmentation of small or tumors having heterogeneous FDG uptake.

  7. Evaluation of haemoglobin changes of skin and muscle tissue of the calf induced by topical application of a nonivamide / nicoboxil cream

    NASA Astrophysics Data System (ADS)

    Warnecke, Jan; Wendt, Thomas; Schak, Matthias; Schiffer, Thorsten; Bloch, Wilhelm; Kohl-Bareis, Matthias

    2011-07-01

    Topical agents inducing hyperaemisation like nonivamide or nicoboxil increase cutaneous blood flow and temperature and induce erythema. It is not proven up to now whether there is also a hyperaemisation effect in skeletal muscle. This study has the objective to determine the effects of a nonivamide / nicoboxil cream on haemodynamics in skin and calf muscle via optical spectroscopy in the visible and near-infrared with a separation of changes for skin and muscle. Left and right calves of 14 healthy subjects were treated with a nonivamide / nicoboxil cream or mock administration, and cutaneous and muscle haemoglobin were measured using a combined NIRS / VIS sensor. The topical application of the cream increased the concentration of oxygenated haemoglobin and tissue oxygen saturation significantly in skin as well as in muscle of the treated legs already after 15 minutes, with stronger and faster effects in skin. In contrast, the change in deoxygenated haemoglobin was found to be small. The kinetic of all changes varied widely between the subjects. The found haemoglobin changes might explain the beneficial effect of hyperaemisation creams for the treatment of minor injuries.

  8. Optical devices used for image analysis of pigmented skin lesions: a proposal for quality assurance protocol using tissue-like phantoms.

    PubMed

    Lualdi, M; Colombo, A; Carrara, M; Scienza, L; Tomatis, S; Marchesini, R

    2006-12-01

    Different technological tools have been developed to aid in the diagnosis of pigmented skin lesions, including cameras working with conventional RGB colour systems, epiluminescence microscopy and spectrophotometric methods using visible and near infrared wavelengths. All the different procedures should provide in an objective and reproducible fashion quantitative measurements of the colour and shape features of a given skin mole. At present, many devices have been introduced in experimental stages for clinical diagnosis, mainly used to provide to the clinicians an objective, computer-assisted second opinion. As for any diagnostic instruments, optical devices should also be subjected to a dedicated quality assurance protocol in order to evaluate the response repeatability of each device (intra-instrument agreement) and to check the accordance among the responses of different devices (inter-instrument agreement). The aim of this study was to design a quality assurance protocol for optical devices dedicated to image analysis of pigmented skin lesions and, in case, to detect cutaneous melanoma by using suitable tissue-like phantoms as standard references that enable testing of both hardware and software components. As an example, we report the results of intra-instrument and inter-instrument agreement when the protocol was applied on a series of 30 SpectroShade instruments, a novel optical device based on multi-spectral image analysis of colour and shape features of pigmented skin lesion.

  9. Expression and Distribution of the Guanine Nucleotide-binding Protein Subunit Alpha-s in Mice Skin Tissues and Its Association with White and Black Coat Colors

    PubMed Central

    Yin, Zhihong; Zhao, Xin; Wang, Zhun; Li, Zhen; Bai, Rui; Yang, Shanshan; Zhao, Min; Pang, Quanhai

    2016-01-01

    Guanine nucleotide-binding protein subunit alpha-s (Gnαs) is a small subunit of the G protein-couple signaling pathway, which is involved in the formation of coat color. The expression level and distribution of Gnαs were detected by quantitative real-time-polymerase chain reaction (qPCR), western blot, and immunohistochemistry to investigate the underlying mechanisms of coat color in white and black skin tissues of mice. qPCR and western blot results suggested that Gnαs was expressed at significantly higher levels in black mice compared with that of white mice, and transcripts and protein possessed the same expression in both colors. Immunohistochemistry demonstrated Gnαs staining in the root sheath and dermal papilla in hair follicle of mice skins. The results indicated that the Gnαs gene was expressed in both white and black skin tissues, and the expression level of Gnαs in the two types of color was different. Therefore, Gnαs may be involved in the coat color formation in mice. PMID:26954226

  10. Soft tissue artefacts of the human back: comparison of the sagittal curvature of the spine measured using skin markers and an open upright MRI.

    PubMed

    Zemp, Roland; List, Renate; Gülay, Turgut; Elsig, Jean Pierre; Naxera, Jaroslav; Taylor, William R; Lorenzetti, Silvio

    2014-01-01

    Soft tissue artefact affects the determination of skeletal kinematics. Thus, it is important to know the accuracy and limitations of kinematic parameters determined and modelled based on skin marker data. Here, the curvature angles, as well as the rotations of the lumbar and thoracic segments, of seven healthy subjects were determined in the sagittal plane using a skin marker set and compared to measurements taken in an open upright MRI scanner in order to understand the influence of soft tissue artefact at the back. The mean STA in the flexed compared to the extended positions were 10.2±6.1 mm (lumbar)/9.3±4.2 mm (thoracic) and 10.7±4.8 mm (lumbar)/9.2±4.9 mm (thoracic) respectively. A linear regression of the lumbar and thoracic curvatures between the marker-based measurements and MRI-based measurements resulted in coefficients of determination, R2, of 0.552 and 0.385 respectively. Skin marker measurements therefore allow for the assessment of changes in the lumbar and thoracic curvature angles, but the absolute values suffer from uncertainty. Nevertheless, this marker set appears to be suitable for quantifying lumbar and thoracic spinal changes between quasi-static whole body postural changes.

  11. Development and evaluation of a regression equation of prediction for fat-free soft tissue in heterogenous populations of cattle.

    PubMed

    Jenkins, T G; Leymaster, K A; MacNeil, M D

    1995-12-01

    Regression equations to predict kilograms of fat-free soft tissue (the sum of water and protein from chemical analyses) were developed from data collected on 526 steers and heifers. Straightbred animals representing Angus, Braunvieh, Charolais, Gelbvieh, Hereford, Limousin, Pinzgauer, Red Poll, and Simmental breeds of cattle contributed to the data set. Cattle ranged in slaughter weight and age from approximately 350 to 575 kg and from 13 to 23 mo, respectively. Diets (100% ground alfalfa, 67% ground alfalfa and 33% ground corn or 33% ground alfalfa and 67% ground corn) were cross-classified with breed and sex. Estimative traits included in the equation were warm carcass weight, fat depth at the 12th rib, and body impedance. Carcass soft-tissue samples were taken for determination of chemical constituents. The prediction equation accounted for 94% of the variation in fat-free soft tissue of the carcass. Adjusting for breed-sex-diet contemporary groups increased the R2 value by 2% units. The prediction model was evaluated using data collected on 65 steers sired by Charolais or by Hereford bulls at the Ft Keogh Livestock and Range Research Laboratory (Miles City, MT). Postweaning feeding strategies and slaughter ages varied among these animals. Carcass weight, back fat depth, and resistive impedance measures were recorded. Carcass soft-tissue samples were taken for determination of chemical constituents. Values of estimator variables recorded at Ft. Keogh were used in the regression equation to predict fat-free soft tissue for each animal. The values for kilogram of fat-free soft tissue determined from chemical analysis were regressed on predicted fat-free soft tissue. the results indicate that fat-free soft tissue of carcasses can be accurately predicted using estimative traits that do not diminish carcass value. PMID:8655437

  12. Development and evaluation of a regression equation of prediction for fat-free soft tissue in heterogenous populations of cattle.

    PubMed

    Jenkins, T G; Leymaster, K A; MacNeil, M D

    1995-12-01

    Regression equations to predict kilograms of fat-free soft tissue (the sum of water and protein from chemical analyses) were developed from data collected on 526 steers and heifers. Straightbred animals representing Angus, Braunvieh, Charolais, Gelbvieh, Hereford, Limousin, Pinzgauer, Red Poll, and Simmental breeds of cattle contributed to the data set. Cattle ranged in slaughter weight and age from approximately 350 to 575 kg and from 13 to 23 mo, respectively. Diets (100% ground alfalfa, 67% ground alfalfa and 33% ground corn or 33% ground alfalfa and 67% ground corn) were cross-classified with breed and sex. Estimative traits included in the equation were warm carcass weight, fat depth at the 12th rib, and body impedance. Carcass soft-tissue samples were taken for determination of chemical constituents. The prediction equation accounted for 94% of the variation in fat-free soft tissue of the carcass. Adjusting for breed-sex-diet contemporary groups increased the R2 value by 2% units. The prediction model was evaluated using data collected on 65 steers sired by Charolais or by Hereford bulls at the Ft Keogh Livestock and Range Research Laboratory (Miles City, MT). Postweaning feeding strategies and slaughter ages varied among these animals. Carcass weight, back fat depth, and resistive impedance measures were recorded. Carcass soft-tissue samples were taken for determination of chemical constituents. Values of estimator variables recorded at Ft. Keogh were used in the regression equation to predict fat-free soft tissue for each animal. The values for kilogram of fat-free soft tissue determined from chemical analysis were regressed on predicted fat-free soft tissue. the results indicate that fat-free soft tissue of carcasses can be accurately predicted using estimative traits that do not diminish carcass value.

  13. Laser Capture Microdissection of Cervical Human Papillomavirus Infections: Copy Number of the Virus in Cancerous and Normal Tissue and Heterogeneous DNA Methylation

    PubMed Central

    Kalantari, Mina; Garcia-Carranca, Alejandro; Morales-Vazquez, Claudia Dalia; Zuna, Rosemary; Montiel, Delia Perez; Calleja-Macias, Itzel E.; Johansson, Bo; Andersson, Sonia; Bernard, Hans-Ulrich

    2009-01-01

    Research on the pathogenicity of human papillomaviruses (HPVs) during cervical carcinogenesis often relies on the study of homogenized tissue or cultured cells. This approach does not detect molecular heterogeneities within the infected tissue. It is desirable to understand molecular properties in specific histological contexts. We asked whether Laser Capture Microdissection (LCM) of archival cervical tumors in combination with real-time polymerase chain reaction and bisulfite sequencing permits (i) sensitive DNA diagnosis of small clusters of formalin fixed cells, (ii) quantification of HPV DNA in neoplastic and normal cells, and (iii) analysis of HPV DNA methylation, a marker of tumor progression. We analyzed 26 tumors containing HPV-16 or 18. We prepared DNA from LCM dissected thin sections of 100 to 2000 cells, and analyzed aliquots corresponding to between nine and 70 cells. We detected nine to 630 HPV-16 genome copies and one to 111 HPV-18 genome copies per tumor cell, respectively. In 17 of the 26 samples, HPV DNA existed in histologically normal cells distant from the margins of the tumors, but at much lower concentrations than in the tumor, suggesting that HPVs can infect at low levels without pathogenic changes. Methylation of HPV DNA, a biomarker of integration of the virus into cellular DNA, could be measured only in few samples due to limited sensitivity, and indicated heterogeneous methylation patterns in small clusters of cancerous and normal cells. LCM is powerful to study molecular parameters of cervical HPV infections like copy number, latency and epigenetics. PMID:19497607

  14. Psoriatic arthritis: embracing pathogenetic and clinical heterogeneity?

    PubMed

    McInnes, Iain B

    2016-01-01

    Psoriatic arthritis (PsA) is a clinically heterogeneous condition of skin, joint, enthesis and bone that provides considerable unmet therapeutic need. Recent treatment advances have offered new opportunities to improve quality of life and long term well being for afflicted patients. It is timely therefore, to consider the underlying heterogeneity inherent in the disease from a pathologic aspect so as to best optimise the choice and order of therapeutic application over time. Herein I will discuss the various contributions made by immune pathways to discrete tissue compartments that in turn might allow a more targeted approach to the management of PsA in which different tissues express variable severity of involvement. PMID:27586796

  15. Healing and evaluating guinea pig skin incision after surgical suture and laser tissue by welding using in vivo Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Alimova, A.; Sriramoju, V.; Chakraverty, R.; Muthukattil, R.; Alfano, R. R.

    2010-02-01

    Changes in collagen in the wound during the healing process of guinea pig skin following surgical incisions and LTW was evaluated using in vivo, using Raman spectroscopy. Raman spectroscopy provided information regarding the internal structure of the proteins. After the incisions were closed either by suturing or by LTW the ratio of the Raman peaks of the amide III (1247 cm-1) band to a peak at 1326 cm-1 used to evaluate the progression of collagen deposition. Histopathology was used as the gold standard. LTW skin demonstrated better healing than sutured skin, exhibiting minimal hyperkeratosis, minimal collagen deposition, near-normal surface contour, and minimal loss of dermal appendages. This work is important to plastic surgery.

  16. Effects of UV radiation and diet on polyunsaturated fatty acids in the skin, ocular tissue and dorsal muscle of Atlantic salmon (Salmo salar) held in outdoor rearing tanks.

    PubMed

    Arts, Michael T; Browman, Howard I; Jokinen, Ilmari E; Skiftesvik, Anne Berit

    2010-01-01

    The effect of UV radiation (UVR) on juvenile Atlantic salmon (Salmo salar) was assessed by measuring the fatty acid (FA) profiles of muscle, dorsal and ventral skin, and ocular tissues following 4-month long exposures to four different UVR treatments in outdoor rearing tanks. Fish were fed two different diets (Anchovy- and Herring-oil based) that differed in polyunsaturated fatty acid (PUFA) concentrations. Anchovy-fed salmon had higher concentrations of ALA (alpha-linoleic acid; 18:3n-3), EPA (eicosapentaenoic acid; 20:5n-3) and DPA (docosapentaenoic acid, 22:5n-3) in their muscle tissues than fish fed the Herring feed. Fish subjected to enhanced UVB levels had higher concentrations of LIN (linolenic acid, 18:2n-6) and ALA, total omega-6 FA and SAFA (saturated fatty acids) in their tissues compared with fish in reduced UV treatments. Concentrations of ALA, LIN, GLA (gamma-linolenic acid; 18:3n-6), EPA, PUFA and total FA were higher in ventral skin of fish exposed to enhanced UVB compared with fish in reduced UV treatments. Salmon exposed to reduced UV weighed more per-unit-length than fish exposed to ambient sunlight. The FA profiles suggest that fish exposed to UV radiation were more quiescent than fish in the reduced UV treatments resulting in a buildup of catabolic substrates.

  17. Oxytetracycline depletion from skin-on fillet tissue of coho salmon fed oxytetracycline medicated feed in freshwater at temperatures less than 9°C

    USGS Publications Warehouse

    Meinertz, Jeffery R.; Gaikowski, Mark P.; Stehly, Guy R.; Gingerich, William H.; Evered, Joy A.

    2001-01-01

    Oxytetracycline (OTC) is a broad spectrum antibacterial agent approved in the USA for treating certain bacterial diseases in salmonids cultured in freshwater at temperatures greater than or equal to 9°C. This study was conducted to provide the information necessary to expand the OTC label to include treatment of diseased salmonids cultured in freshwater at temperatures below 9°C. The study was designed to treat juvenile coho salmon (Oncorhynchus kisutch) with OTC-medicated feed and determine the depletion of OTC from the skin-on fillet tissue. Oxytetracycline depletion was evaluated in juvenile coho salmon (weight range, 13–62 g) fed OTC-medicated feed at a rate of 88.2 mg OTC/kg body weight/day for 10 days. Pairs of skin-on fillets were taken from individual fish on days 4 and 10 during the treatment phase and on days 1, 4, 8, 14, and 19 during the depletion phase. Water temperatures during the study period ranged from 4.1°C to 8.5°C. The OTC concentrations in medicated feed and skin-on fillets were determined with high-performance liquid chromatography methods. The maximum mean OTC concentration in fillet tissue was 932 ng/g, 1 day after the last treatment and decreased to 32 ng/g 19 days after the last treatment. The log-linear loss of OTC from the fillet tissue was biphasic with a terminal phase half-life of 4.9 days.

  18. Spread of community-acquired meticillin-resistant Staphylococcus aureus skin and soft-tissue infection within a family: implications for antibiotic therapy and prevention.

    PubMed

    Amir, N H; Rossney, A S; Veale, J; O'Connor, M; Fitzpatrick, F; Humphreys, H

    2010-04-01

    Outbreaks or clusters of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) within families have been reported. We describe a family cluster of CA-MRSA skin and soft-tissue infection where CA-MRSA was suspected because of recurrent infections which failed to respond to flucloxacillin. While the prevalence of CA-MRSA is low worldwide, CA-MRSA should be considered in certain circumstances depending on clinical presentation and risk assessment. Surveillance cultures of family contacts of patients with MRSA should be considered to help establish the prevalence of CA-MRSA and to inform the optimal choice of empiric antibiotic treatment.

  19. Targeting Staphylococcus aureus α-toxin as a novel approach to reduce severity of recurrent skin and soft-tissue infections.

    PubMed

    Sampedro, Georgia R; DeDent, Andrea C; Becker, Russell E N; Berube, Bryan J; Gebhardt, Michael J; Cao, Hongyuan; Bubeck Wardenburg, Juliane

    2014-10-01

    Staphyococcus aureus frequently causes recurrent skin and soft-tissue infection (SSTI). In the pediatric population, elevated serum antibody targeting S. aureus α-toxin is correlated with a reduced incidence of recurrent SSTI. Using a novel model of recurrent SSTI, we demonstrated that expression of α-toxin during primary infection increases the severity of recurrent disease. Antagonism of α-toxin by either a dominant-negative toxin mutant or a small molecule inhibitor of the toxin receptor ADAM10 during primary infection reduces reinfection abscess severity. Early neutralization of α-toxin activity during S. aureus SSTI therefore offers a new therapeutic strategy to mitigate primary and recurrent disease.

  20. Comparative Genomic, MicroRNA, and Tissue Analyses Reveal Subtle Differences between Non-Diabetic and Diabetic Foot Skin

    PubMed Central

    Ramirez, Horacio A.; Liang, Liang; Pastar, Irena; Rosa, Ashley M.; Stojadinovic, Olivera; Zwick, Thomas G.; Kirsner, Robert S.; Maione, Anna G.; Garlick, Jonathan A.; Tomic-Canic, Marjana

    2015-01-01

    Diabetes Mellitus (DM) is a chronic, severe disease rapidly increasing in incidence and prevalence and is associated with numerous complications. Patients with DM are at high risk of developing diabetic foot ulcers (DFU) that often lead to lower limb amputations, long term disability, and a shortened lifespan. Despite this, the effects of DM on human foot skin biology are largely unknown. Thus, the focus of this study was to determine whether DM changes foot skin biology predisposing it for healing impairment and development of DFU. Foot skin samples were collected from 20 patients receiving corrective foot surgery and, using a combination of multiple molecular and cellular approaches, we performed comparative analyses of non-ulcerated non-neuropathic diabetic foot skin (DFS) and healthy non-diabetic foot skin (NFS). MicroRNA (miR) profiling of laser captured epidermis and primary dermal fibroblasts from both DFS and NFS samples identified 5 miRs de-regulated in the epidermis of DFS though none reached statistical significance. MiR-31-5p and miR-31-3p were most profoundly induced. Although none were significantly regulated in diabetic fibroblasts, miR-29c-3p showed a trend of up-regulation, which was confirmed by qPCR in a prospective set of 20 skin samples. Gene expression profiling of full thickness biopsies identified 36 de-regulated genes in DFS (>2 fold-change, unadjusted p-value ≤ 0.05). Of this group, three out of seven tested genes were confirmed by qPCR: SERPINB3 was up-regulated whereas OR2A4 and LGR5 were down-regulated in DFS. However no morphological differences in histology, collagen deposition, and number of blood vessels or lymphocytes were found. No difference in proliferative capacity was observed by quantification of Ki67 positive cells in epidermis. These findings suggest DM causes only subtle changes to foot skin. Since morphology, mRNA and miR levels were not affected in a major way, additional factors, such as neuropathy, vascular