Natural Origin Materials for Osteochondral Tissue Engineering.

Science.gov (United States)

Bonani, Walter; Singhatanadgige, Weerasak; Pornanong, Aramwit; Motta, Antonella

2018-01-01

Materials selection is a critical aspect for the production of scaffolds for osteochondral tissue engineering. Synthetic materials are the result of man-made operations and have been investigated for a variety of tissue engineering applications. Instead, the products of physiological processes and the metabolic activity of living organisms are identified as natural materials. Over the recent decades, a number of natural materials, namely, biopolymers and bioceramics, have been proposed as the main constituent of osteochondral scaffolds, but also as cell carriers and signaling molecules. Overall, natural materials have been investigated both in the bone and in the cartilage compartment, sometimes alone, but often in combination with other biopolymers or synthetic materials. Biopolymers and bioceramics possess unique advantages over their synthetic counterparts due similarity with natural extracellular matrix, the presence of cell recognition sites and tunable chemistry. However, the characteristics of natural origin materials can vary considerably depending on the specific source and extraction process. A deeper understanding of the relationship between material variability and biological activity and the definition of standardized manufacturing procedures will be crucial for the future of natural materials in tissue engineering.

In vitro aging of mineralized collagen-based composite as guided tissue regeneration membrane

Energy Technology Data Exchange (ETDEWEB)

Pan, S.X. [Department of Prothodontics, School of Stomatology, Peking University, Beijing 100875 (China)]. E-mail: sx_pan@sina.com; Li, Y. [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Feng, H.L. [Department of Prothodontics, School of Stomatology, Peking University, Beijing 100875 (China); Bai, W. [Department of Prothodontics, School of Stomatology, Peking University, Beijing 100875 (China); Gu, Y.Y. [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

2006-05-15

The technique of guided tissue regeneration (GTR) has been developed for the regeneration of periodontal tissues, bone around natural teeth and dental implants. The aim of this study is to investigate the biodegradability and mechanic behavior of a novel mineralized nano-hydroxyapatite/collagen/poly (lactic acid) (nHAC/PLA) composite as GTR membrane in vitro. The elastic modulus and maximum tensile strength of GTR film samples with different nHAC/PLA ratio were measured to get an optimal nHAC/PLA ratio. Thermogravimetric analysis was conducted to evaluate the change of the inorganic component in the samples during the process of in vitro aging. Morphology of samples was checked by using scanning electron microscopy. On the basis of the above results, it can be concluded that the GTR membranes maintained integrity and the original appearance throughout the 1-month in vitro aging. There is an active dissolution and deposition process of crystals which is propitious to the bone formation on the surface of the composite membrane. The optimal nHAC/PLA ratio of the novel membrane is 0.4:1. For a longer period of bone repair, PLA with higher molecular weight should be chosen as the scaffold for the GTR membrane.

Uniformly-dispersed nanohydroxapatite-reinforced poly(ε-caprolactone) composite films for tendon tissue engineering application

Energy Technology Data Exchange (ETDEWEB)

Tong, Shi Yun [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117 576 (Singapore); Wang, Zuyong, E-mail: zuyong.nus@gmail.com [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117 576 (Singapore); Lim, Poon Nian [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117 576 (Singapore); Wang, Wilson [Department of Orthopaedic Surgery, National University of Singapore, 5 Lower Kent Ridge Road, Singapore 119 074 (Singapore); Thian, Eng San, E-mail: mpetes@nus.edu.sg [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117 576 (Singapore)

2017-01-01

Regeneration of injuries at tendon-to-bone interface (TBI) remains a challenging issue due to the complex tissue composition involving both soft tendon tissues and relatively hard bone tissues. Tissue engineering using polymeric/ceramic composites has been of great interest to generate scaffolds for tissue's healing at TBI. Herein, we presented a novel method to blend polymers and bioceramics for tendon tissue engineering application. A homogeneous composite comprising of nanohydroxyapatite (nHA) particles in poly(ε-caprolactone) (PCL) matrix was obtained using a combination of solvent and mechanical blending process. X-ray diffraction analysis showed that the as-fabricated PCL/nHA composite film retained phase-pure apatite and semi-crystalline properties of PCL. Infrared spectroscopy spectra confirmed that the PCL/nHA composite film exhibited the characteristics functional groups of PCL and nHA, without alteration to the chemical properties of the composite. The incorporation of nHA resulted in PCL/nHA composite film with improved mechanical properties such as Young's Modulus and ultimate tensile stress, which were comparable to that of the native human rotator tendon. Seeding with human tenocytes, cells attached on the PCL/nHA composite film, and after 14 days of culturing, these cells could acquire elongated morphology without induced cytotoxicity. PCL/nHA composite film could also result in increased cell metabolism with prolonged culturing, which was comparable to that of the PCL group and higher than that of the nHA group. All these results demonstrated that the developed technique of combining solvent and mechanical blending could be applied to fabricate composite films with potential for tendon tissue engineering applications. - Highlights: • A novel method fabricating polymeric/nanoceramic composite film was proposed. • The method involved solvent and mechanical blending to form a homogeneous film. • The film retained physicochemical

Biochemical composition of muscle tissue of penaeid prawns

Digital Repository Service at National Institute of Oceanography (India)

Achuthankutty, C.T.; Parulekar, A.H.

Biochemical composition of muscle tissue of females belonging to four species of penaeid prawns, viz. Metapenaeus affinis, M. dobsoni, Penaeus merguiensis and Parapenaeopsis stylifera, inhabiting the coastal waters of Goa, India, was estimated...

Determination of elemental tissue composition following proton treatment using positron emission tomography

International Nuclear Information System (INIS)

Cho, Jongmin; Ibbott, Geoffrey; Gillin, Michael; Gonzalez-Lepera, Carlos; Min, Chul Hee; Zhu, Xuping; El Fakhri, Georges; Paganetti, Harald; Mawlawi, Osama

2013-01-01

Positron emission tomography (PET) has been suggested as an imaging technique for in vivo proton dose and range verification after proton induced-tissue activation. During proton treatment, irradiated tissue is activated and decays while emitting positrons. In this paper, we assessed the feasibility of using PET imaging after proton treatment to determine tissue elemental composition by evaluating the resultant composite decay curve of activated tissue. A phantom consisting of sections composed of different combinations of 1 H, 12 C, 14 N, and 16 O was irradiated using a pristine Bragg peak and a 6 cm spread-out Bragg-peak (SOBP) proton beam. The beam ranges defined at 90% distal dose were 10 cm; the delivered dose was 1.6 Gy for the near monoenergetic beam and 2 Gy for the SOBP beam. After irradiation, activated phantom decay was measured using an in-room PET scanner for 30 min in list mode. Decay curves from the activated 12 C and 16 O sections were first decomposed into multiple simple exponential decay curves, each curve corresponding to a constituent radioisotope, using a least-squares method. The relative radioisotope fractions from each section were determined. These fractions were used to guide the decay curve decomposition from the section consisting mainly of 12 C + 16 O and calculate the relative elemental composition of 12 C and 16 O. A Monte Carlo simulation was also used to determine the elemental composition of the 12 C + 16 O section. The calculated compositions of the 12 C + 16 O section using both approaches (PET and Monte Carlo) were compared with the true known phantom composition. Finally, two patients were imaged using an in-room PET scanner after proton therapy of the head. Their PET data and the technique described above were used to construct elemental composition ( 12 C and 16 O) maps that corresponded to the proton-activated regions. We compared the 12 C and 16 O compositions of seven ROIs that corresponded to the vitreous humor, adipose

Tissue biocompatibility of kevlar aramid fibers and polymethylmethacrylate, composites in rabbits.

Science.gov (United States)

Henderson, J D; Mullarky, R H; Ryan, D E

1987-01-01

Two groups of female NZW rabbits were implanted in the paravertebral muscles with aramid (du Pont Kevlar aramid 49) fibers and aramid-polymethylmethacrylate (PMMA) composites for 14 and 28 days. Rabbits were killed at these times periods, necropsies performed, sites scored for gross tissue response, and tissue specimens containing the implants removed for histopathological evaluation. A mild fibrous tissue reaction was observed around all implants containing aramid fiber similar to that observed around the silicone control implant. Some foreign body giant cells were also present adjacent to the fibers. An intense necrotic inflammatory reaction was present around the positive control material (PVC Y-78). The tissue response to implantation of aramid fiber and fiber-PMMA composites indicates that aramid is a biocompatible material.

Earth-approaching asteroids: Populations, origin, and compositional types

Science.gov (United States)

Shoemaker, E. M.; Helin, E. F.

1978-01-01

Origin, physical properties, and discovery history of smaller asteroids are reviewed. They appear to link the main belt objects, namely the comets and meteorites. Physical observations suggest that a wide variety of compositional types are represented among the near-earth asteroids; the apparent rarity of carbonaceous objects is stated.

Advancing biomaterials of human origin for tissue engineering

Science.gov (United States)

Chen, Fa-Ming; Liu, Xiaohua

2015-01-01

Biomaterials have played an increasingly prominent role in the success of biomedical devices and in the development of tissue engineering, which seeks to unlock the regenerative potential innate to human tissues/organs in a state of deterioration and to restore or reestablish normal bodily function. Advances in our understanding of regenerative biomaterials and their roles in new tissue formation can potentially open a new frontier in the fast-growing field of regenerative medicine. Taking inspiration from the role and multi-component construction of native extracellular matrices (ECMs) for cell accommodation, the synthetic biomaterials produced today routinely incorporate biologically active components to define an artificial in vivo milieu with complex and dynamic interactions that foster and regulate stem cells, similar to the events occurring in a natural cellular microenvironment. The range and degree of biomaterial sophistication have also dramatically increased as more knowledge has accumulated through materials science, matrix biology and tissue engineering. However, achieving clinical translation and commercial success requires regenerative biomaterials to be not only efficacious and safe but also cost-effective and convenient for use and production. Utilizing biomaterials of human origin as building blocks for therapeutic purposes has provided a facilitated approach that closely mimics the critical aspects of natural tissue with regard to its physical and chemical properties for the orchestration of wound healing and tissue regeneration. In addition to directly using tissue transfers and transplants for repair, new applications of human-derived biomaterials are now focusing on the use of naturally occurring biomacromolecules, decellularized ECM scaffolds and autologous preparations rich in growth factors/non-expanded stem cells to either target acceleration/magnification of the body's own repair capacity or use nature's paradigms to create new tissues for

The importance of the biomimetic composites components for recreating the optical properties and molecular composition of intact dental tissues.

Science.gov (United States)

Seredin, P. V.; Goloshchapov, D. L.; Gushchin, M. S.; Ippolitov, Y. A.; Prutskij, T.

2017-11-01

The objective of this paper was to investigate whether it is possible to obtain biomimetic materials recreating the luminescent properties and molecular composition of intact dental tissues. Biomimetic materials were produced and their properties compared with native dental tissues. In addition, the overall contribution of the organic and non-organic components in the photoluminescence band was investigated. The results showed that it is possible to develop biomimetic materials with similar molecular composition and optical properties to native dental tissues for the early identification of dental caries.

Factors affecting the tissues composition of pork belly.

Science.gov (United States)

Duziński, K; Knecht, D; Lisiak, D; Janiszewski, P

2015-11-01

Bellies derived from the commercial population of pig carcasses are diverse in terms of tissue composition. Knowledge of the factors influencing it and the expected results, permits quick and easy evaluation of raw material. The study was designed to determine the factors affecting the tissues composition of pork bellies and to estimate their lean meat content. The research population (n=140 pig carcasses) was divided into groups according to sex (gilts, barrows), half-carcass mass (meat content class: S (⩾60%), E (55% to 60%), U (50% to 55%), R (meat content affected the growth of the fat and skin mass in a linear way. No differences were observed between class S and E in terms of belly muscle mass. A 0.37% higher share of belly in the half-carcass was found for barrows (Pmeat content in bellies, suggesting they may be used directly in the production line.

Breast tissue composition and its dependence on demographic risk factors for breast cancer: non-invasive assessment by time domain diffuse optical spectroscopy.

Directory of Open Access Journals (Sweden)

Paola Taroni

Full Text Available Breast tissue composition is recognized as a strong and independent risk factor for breast cancer. It is a heritable feature, but is also significantly affected by several other elements (e.g., age, menopause. Nowadays it is quantified by mammographic density, thus requiring the use of ionizing radiation. Optical techniques are absolutely non-invasive and have already proved effective in the investigation of biological tissues, as they are sensitive to tissue composition and structure.Time domain diffuse optical spectroscopy was performed at 7 wavelengths (635-1060 nm on 200 subjects to derive their breast tissue composition (in terms of water, lipid and collagen content, blood parameters (total hemoglobin content and oxygen saturation level, and information on the microscopic structure (scattering amplitude and power. The dependence of all optically-derived parameters on age, menopausal status, body mass index, and use of oral contraceptives, and the correlation with mammographic density were investigated.Younger age, premenopausal status, lower body mass index values, and use of oral contraceptives all correspond to significantly higher water, collagen and total hemoglobin content, and lower lipid content (always p < 0.05 and often p < 10-4, while oxygen saturation level and scattering parameters show significant dependence only on some conditions. Even when age-adjusted groups of subjects are compared, several optically derived parameters (and in particular always collagen and total hemoglobin content remain significantly different.Time domain diffuse optical spectroscopy can probe non-invasively breast tissue composition and physiologic blood parameters, and provide information on tissue structure. The measurement is suitable for in vivo studies and monitoring of changes in breast tissue (e.g., with age, lifestyle, chemotherapy, etc. and to gain insight into related processes, like the origin of cancer risk associated with breast density.

Compression properties and dissolution of bioactive glass S53P4 and n-butyl-2 cyanoacrylate tissue adhesive-composite.

Science.gov (United States)

Sarin, Jussi; Hiltunen, Markus; Hupa, Leena; Pulkkinen, Jaakko; Vallittu, Pekka K

2016-09-28

Bioactive glass (BG)-containing fiber-reinforced composite implants, typically screw-retained, have started to be used clinically. In this study, we tested the mechanical strength of composites formed by a potential implant adhesive of n-butyl-2-cyanoacrylate glue and BG S53P4 particles. Water immersion for 3, 10 or 30 days had no adverse effect on the compression strength. When cyanoacrylate glue-BG-composites were subjected to simulated body fluid immersion, the average pH rose to 7.52 (SD 0.066) from the original value of 7.35 after 7 days, and this pH increment was smaller compared to BG particle-group or fibrin glue-BG-composite group. Based on these results n-butyl-2 cyanoacrylate glue, by potentially producing a strong adhesion, might be considered a possible alternative for fixation of BG S53P4 containing composite implants. However, the mechanical and solubility properties of the cyanoacrylate glue may not encourage the use of this tissue adhesive with BG particles.

Analysing breast tissue composition with MRI using currently available short, simple sequences

International Nuclear Information System (INIS)

Chau, A.C.M.; Hua, J.; Taylor, D.B.

2016-01-01

Aim: To determine the most robust commonly available magnetic resonance imaging (MRI) sequence to quantify breast tissue composition at 1.5 T. Materials and methods: Two-dimensional (2D) T1-weighted, Dixon fat, Dixon water and SPAIR images were obtained from five participants and a breast phantom using a 1.5 T Siemens Aera MRI system. Manual segmentation of the breasts was performed, and an in-house computer program was used to generate signal intensity histograms. Relative trough depth and relative peak separation were used to determine the robustness of the images for quantifying the two breast tissues. Total breast volumes and percentage breast densities calculated using the four sequences were compared. Results: Dixon fat histograms had consistently low relative trough depth and relative peak separation compared to those obtained using other sequences. There was no significant difference in total breast volumes and percentage breast densities of the participants or breast phantom using Dixon fat and 2D T1-weighted histograms. Dixon water and SPAIR histograms were not suitable for quantifying breast tissue composition. Conclusion: Dixon fat images are the most robust for the quantification of breast tissue composition using a signal intensity histogram. - Highlights: • Signal intensity histogram analysis can determine robustness of images for quantification of breast tissue composition. • Dixon fat images are the most robust. • The characteristics of the signal intensity histograms from Dixon water and SPAIR images make quantification unsuitable.

Fabrication of chitin-chitosan/nano TiO2-composite scaffolds for tissue engineering applications.

Science.gov (United States)

Jayakumar, R; Ramachandran, Roshni; Divyarani, V V; Chennazhi, K P; Tamura, H; Nair, S V

2011-03-01

In this study, we prepared chitin-chitosan/nano TiO(2) composite scaffolds using lyophilization technique for bone tissue engineering. The prepared composite scaffold was characterized using SEM, XRD, FTIR and TGA. In addition, swelling, degradation and biomineralization capability of the composite scaffolds were evaluated. The developed composite scaffold showed controlled swelling and degradation when compared to the control scaffold. Cytocompatibility of the scaffold was assessed by MTT assay and cell attachment studies using osteoblast-like cells (MG-63), fibroblast cells (L929) and human mesenchymal stem cells (hMSCs). Results indicated no sign of toxicity and cells were found attached to the pore walls within the scaffolds. These results suggested that the developed composite scaffold possess the prerequisites for tissue engineering scaffolds and it can be used for tissue engineering applications. Copyright © 2010 Elsevier B.V. All rights reserved.

Heterogeneity of the radiosensitivity and origins of tissue macrophage colony-forming cells

Energy Technology Data Exchange (ETDEWEB)

Oghiso, Yoichi; Yamada, Yutaka (National Inst. of Radiological Sciences, Chiba (Japan))

1992-12-01

Previous studies suggest that the radiosensitivity and origin of tissue macrophage precursors differ from those of hemopoietic macrophage colony-forming units (CFU-Ms) committed to macrophage-lineage cells. We assessed the origins of tissue macrophage colony-forming cells (M-CFCs) in mice by comparing their kinetics and radiosensitivities in the normal steady state and under the conditions of bone marrow depletion by [sup 89]Sr-administration and/or splenectomy. The results indicate that the radiosensitive peritoneal M-CFCs elicited by thioglycollate are derived from bone marrow macrophage precursors; where as alveolar M-CFCs, which are radioresistant, are self-sustained locally and independent of hemopoietic macrophage precursors. In contrast, highly radiosensitive liver M-CFCs are probably derived from CFU-Ms that appear to be propagated in the spleen in association with hemopoietic responses. (author).

Homogenization of tissues via picosecond-infrared laser (PIRL) ablation: Giving a closer view on the in-vivo composition of protein species as compared to mechanical homogenization.

Science.gov (United States)

Kwiatkowski, M; Wurlitzer, M; Krutilin, A; Kiani, P; Nimer, R; Omidi, M; Mannaa, A; Bussmann, T; Bartkowiak, K; Kruber, S; Uschold, S; Steffen, P; Lübberstedt, J; Küpker, N; Petersen, H; Knecht, R; Hansen, N O; Zarrine-Afsar, A; Robertson, W D; Miller, R J D; Schlüter, H

2016-02-16

Posttranslational modifications and proteolytic processing regulate almost all physiological processes. Dysregulation can potentially result in pathologic protein species causing diseases. Thus, tissue species proteomes of diseased individuals provide diagnostic information. Since the composition of tissue proteomes can rapidly change during tissue homogenization by the action of enzymes released from their compartments, disease specific protein species patterns can vanish. Recently, we described a novel, ultrafast and soft method for cold vaporization of tissue via desorption by impulsive vibrational excitation (DIVE) using a picosecond-infrared-laser (PIRL). Given that DIVE extraction may provide improved access to the original composition of protein species in tissues, we compared the proteome composition of tissue protein homogenates after DIVE homogenization with conventional homogenizations. A higher number of intact protein species was observed in DIVE homogenates. Due to the ultrafast transfer of proteins from tissues via gas phase into frozen condensates of the aerosols, intact protein species were exposed to a lesser extent to enzymatic degradation reactions compared with conventional protein extraction. In addition, total yield of the number of proteins is higher in DIVE homogenates, because they are very homogenous and contain almost no insoluble particles, allowing direct analysis with subsequent analytical methods without the necessity of centrifugation. Enzymatic protein modifications during tissue homogenization are responsible for changes of the in-vivo protein species composition. Cold vaporization of tissues by PIRL-DIVE is comparable with taking a snapshot at the time of the laser irradiation of the dynamic changes that occur continuously under in-vivo conditions. At that time point all biomolecules are transferred into an aerosol, which is immediately frozen. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Preparation and characterization of chitosan-heparin composite matrices for blood contacting tissue engineering

International Nuclear Information System (INIS)

He Qing; Gong Kai; Gong Yandao; Zhang Xiufang; Ao Qiang; Zhang Lihai; Hu Min

2010-01-01

Chitosan has been widely used for biomaterial scaffolds in tissue engineering because of its good mechanical properties and cytocompatibility. However, the poor blood compatibility of chitosan has greatly limited its biomedical utilization, especially for blood contacting tissue engineering. In this study, we exploited a polymer blending procedure to heparinize the chitosan material under simple and mild conditions to improve its antithrombogenic property. By an optimized procedure, a macroscopically homogeneous chitosan-heparin (Chi-Hep) blended suspension was obtained, with which Chi-Hep composite films and porous scaffolds were fabricated. X-ray photoelectron spectroscopy and sulfur elemental analysis confirmed the successful immobilization of heparin in the composite matrices (i.e. films and porous scaffolds). Toluidine blue staining indicated that heparin was distributed homogeneously in the composite matrices. Only a small amount of heparin was released from the matrices during incubation in normal saline for 10 days. The composite matrices showed improved blood compatibility, as well as good mechanical properties and endothelial cell compatibility. These results suggest that the Chi-Hep composite matrices are promising candidates for blood contacting tissue engineering.

Composition, structure, and properties of iron-rich nontronites of different origins

Energy Technology Data Exchange (ETDEWEB)

Palchik, N. A., E-mail: nadezhda@igm.nsc.ru; Grigorieva, T. N.; Moroz, T. N. [Russian Academy of Sciences, Sobolev Institute of Geology and Mineralogy, Siberian Branch (Russian Federation)

2013-03-15

The composition, structure, and properties of smectites of different origins have been studied by X-ray diffraction, IR spectroscopy, scanning electron microscopy, and microprobe analysis. The results showed that nontronites of different origins differ in composition, properties, morphology, and IR spectroscopic characteristics. Depending on the degree of structural order and the negative charge of iron-silicate layers in nontronites, the shift of the 001 reflection to smaller angles as a result of impregnation with ethylene glycol (this shift is characteristic of the smectite group) occurs differently. The calculated values of the parameter b (from 9.11 to 9.14A) are valid for the extreme terms of dioctahedral smectite representatives: nontronites.

Legal Issues Related to Donation of Organs, Tissues and Cells of Human Origin

Directory of Open Access Journals (Sweden)

Gabriela Mironov

2010-06-01

Full Text Available Scientific developments, positive changes in attitude of the man and the new legal framework allow the donation of organs, tissues and cells of human origin. In this context it is necessary to clarifywhether the donation covered by the special law is, legally, one and the same as that covered by the Romanian Civil Code in force and qualified the successor’s right to accept or reject late withdrawals for transplantation. The right to life and physical integrity is personal patrimony; it is a subjective civil right that has no economic content and it cannot be measured in money. Consequently, the content of these rights can not be expressed in money, the property does not belong to their owner. Given the above view, "the right of disposal" to donation of organs, tissues and cells of human origin is an attribute of ownership, right to life and physical integrity, as a personal right that is an intimate attribute patrimonial related to the person’s right to dispose of his body as it wishes, within the law. Addressing these issues it is necessary to clarify the legal consequences of donating organs, tissues and cells of human origin, considering that medical activities are becoming more numerous.

Fatty acid composition of muscle and heart tissue of Nile perch ...

African Journals Online (AJOL)

The fatty acid composition in the heart tissue and muscle tissue of the Nile perch, Lates niloticus, and Nile tilapia, Oreochromis niloticus populations from Lakes Kioga and Victoria was determined by methanolysis and gas chromatography of the resulting fatty acid methyl esters. The analytical data were treated by ...

Alfalfa stem tissues: Cell wall deposition, composition, and degradability

NARCIS (Netherlands)

Jung, H.G.; Engels, F.M.

2002-01-01

Declining cell wall degradability of alfalfa (Medicago sativa L.) stems with maturation limits the nutritional value of alfalfa for ruminants. This study characterized changes in cell wall concentration, composition, and degradability by rumen microbes resulting from alfalfa stem tissue

Compton scattering spectrum as a source of information of normal and neoplastic breast tissues' composition

Energy Technology Data Exchange (ETDEWEB)

Antoniassi, M.; Conceicao, A.L.C. [Departamento de Fisica-Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, 14040-901 Sao Paulo (Brazil); Poletti, M.E., E-mail: poletti@ffclrp.usp.br [Departamento de Fisica-Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, 14040-901 Sao Paulo (Brazil)

2012-07-15

In this work we measured X-ray scatter spectra from normal and neoplastic breast tissues using photon energy of 17.44 keV and a scattering angle of 90 Degree-Sign , in order to study the shape (FWHM) of the Compton peaks. The obtained results for FWHM were discussed in terms of composition and histological characteristics of each tissue type. The statistical analysis shows that the distribution of FWHM of normal adipose breast tissue clearly differs from all other investigated tissues. Comparison between experimental values of FWHM and effective atomic number revealed a strong correlation between them, showing that the FWHM values can be used to provide information about elemental composition of the tissues. - Highlights: Black-Right-Pointing-Pointer X-ray scatter spectra from normal and neoplastic breast tissues were measured. Black-Right-Pointing-Pointer Shape (FWHM) of Compton peak was related with elemental composition and characteristics of each tissue type. Black-Right-Pointing-Pointer A statistical hypothesis test showed clear differences between normal and neoplastic breast tissues. Black-Right-Pointing-Pointer There is a strong correlation between experimental values of FWHM and effective atomic number. Black-Right-Pointing-Pointer Shape (FWHM) of Compton peak can be used to provide information about elemental composition of the tissues.

Chitosan composite three dimensional macrospheric scaffolds for bone tissue engineering.

Science.gov (United States)

Vyas, Veena; Kaur, Tejinder; Thirugnanam, Arunachalam

2017-11-01

The present work deals with the fabrication of chitosan composite scaffolds with controllable and predictable internal architecture for bone tissue engineering. Chitosan (CS) based composites were developed by varying montmorillonite (MMT) and hydroxyapatite (HA) combinations to fabricate macrospheric three dimensional (3D) scaffolds by direct agglomeration of the sintered macrospheres. The fabricated CS, CS/MMT, CS/HA and CS/MMT/HA 3D scaffolds were characterized for their physicochemical, biological and mechanical properties. The XRD and ATR-FTIR studies confirmed the presence of the individual constituents and the molecular interaction between them, respectively. The reinforcement with HA and MMT showed reduced swelling and degradation rate. It was found that in comparison to pure CS, the CS/HA/MMT composites exhibited improved hemocompatibility and protein adsorption. The sintering of the macrospheres controlled the swelling ability of the scaffolds which played an important role in maintaining the mechanical strength of the 3D scaffolds. The CS/HA/MMT composite scaffold showed 14 folds increase in the compressive strength when compared to pure CS scaffolds. The fabricated scaffolds were also found to encourage the MG 63 cell proliferation. Hence, from the above studies it can be concluded that the CS/HA/MMT composite 3D macrospheric scaffolds have wider and more practical application in bone tissue regeneration applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Stable hydrogen, oxygen and sulfur isotopes composition in different tissues of cattle

International Nuclear Information System (INIS)

Sun Fengmei; Shi Guangyu; Wang Huiwen; Yang Shuming

2012-01-01

In order to research on stable hydrogen, oxygen, sulfur isotopes composition in different tissues of cattle, as well as the breed, δ 2 H and δ 34 S values of different defatted muscle, cattle tail hair, blood, liver, also δ 2h and δ 18 O values of water from muscle were determined by isotope ratio mass spectrometry. The stable sulfur isotope composition was not affected by cattle variety, meanwhile the hydrogen was uncertain; the δ 2 H and δ 34 S values between different defatted muscle, blood, liver, cattle hair were significantly different, at the same time the δ 34 S and δ 2 H values between each tissue were not significantly correlated; the δ 2 H values were strongly correlated with the δ 18 O values of muscle water. The above results indicated that stable sulfur and hydrogen isotopes fractionation in the various tissues were discrepant, thus the proper tissue should be selected according to the purpose and object in the beef traceability. (authors)

Sensitivity of low energy brachytherapy Monte Carlo dose calculations to uncertainties in human tissue composition

Energy Technology Data Exchange (ETDEWEB)

Landry, Guillaume; Reniers, Brigitte; Murrer, Lars; Lutgens, Ludy; Bloemen-Van Gurp, Esther; Pignol, Jean-Philippe; Keller, Brian; Beaulieu, Luc; Verhaegen, Frank [Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Departement de Radio-Oncologie et Centre de Recherche en Cancerologie, de l' Universite Laval, CHUQ, Pavillon L' Hotel-Dieu de Quebec, Quebec G1R 2J6 (Canada) and Departement de Physique, de Genie Physique et d' Optique, Universite Laval, Quebec G1K 7P4 (Canada); Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands) and Medical Physics Unit, McGill University, Montreal General Hospital, Montreal, Quebec H3G 1A4 (Canada)

2010-10-15

Purpose: The objective of this work is to assess the sensitivity of Monte Carlo (MC) dose calculations to uncertainties in human tissue composition for a range of low photon energy brachytherapy sources: {sup 125}I, {sup 103}Pd, {sup 131}Cs, and an electronic brachytherapy source (EBS). The low energy photons emitted by these sources make the dosimetry sensitive to variations in tissue atomic number due to the dominance of the photoelectric effect. This work reports dose to a small mass of water in medium D{sub w,m} as opposed to dose to a small mass of medium in medium D{sub m,m}. Methods: Mean adipose, mammary gland, and breast tissues (as uniform mixture of the aforementioned tissues) are investigated as well as compositions corresponding to one standard deviation from the mean. Prostate mean compositions from three different literature sources are also investigated. Three sets of MC simulations are performed with the GEANT4 code: (1) Dose calculations for idealized TG-43-like spherical geometries using point sources. Radial dose profiles obtained in different media are compared to assess the influence of compositional uncertainties. (2) Dose calculations for four clinical prostate LDR brachytherapy permanent seed implants using {sup 125}I seeds (Model 2301, Best Medical, Springfield, VA). The effect of varying the prostate composition in the planning target volume (PTV) is investigated by comparing PTV D{sub 90} values. (3) Dose calculations for four clinical breast LDR brachytherapy permanent seed implants using {sup 103}Pd seeds (Model 2335, Best Medical). The effects of varying the adipose/gland ratio in the PTV and of varying the elemental composition of adipose and gland within one standard deviation of the assumed mean composition are investigated by comparing PTV D{sub 90} values. For (2) and (3), the influence of using the mass density from CT scans instead of unit mass density is also assessed. Results: Results from simulation (1) show that variations

Development of keratin–chitosan–gelatin composite scaffold for soft tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Kakkar, Prachi [Central Leather Research Institute (Council of Scientific and Industrial Research), Adyar, Chennai 600020 (India); Verma, Sudhanshu; Manjubala, I. [Biomedical Engineering Division, School of Bio Sciences and Technology, VIT University, Vellore 632014 (India); Madhan, B., E-mail: bmadhan76@yahoo.co.in [Central Leather Research Institute (Council of Scientific and Industrial Research), Adyar, Chennai 600020 (India)

2014-12-01

Keratin has gained much attention in the recent past as a biomaterial for wound healing owing to its biocompatibility, biodegradability, intrinsic biological activity and presence of cellular binding motifs. In this paper, a novel biomimetic scaffold containing keratin, chitosan and gelatin was prepared by freeze drying method. The prepared keratin composite scaffold had good structural integrity. Fourier Transform Infrared (FTIR) spectroscopy showed the retention of the native structure of individual biopolymers (keratin, chitosan, and gelatin) used in the scaffold. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) results revealed a high thermal denaturation temperature of the scaffold (200–250 °C). The keratin composite scaffold exhibited tensile strength (96 kPa), compression strength (8.5 kPa) and water uptake capacity (> 1700%) comparable to that of a collagen scaffold, which was used as control. The morphology of the keratin composite scaffold observed using a Scanning Electron Microscope (SEM) exhibited good porosity and interconnectivity of pores. MTT assay using NIH 3T3 fibroblast cells demonstrated that the cell viability of the keratin composite scaffold was good. These observations suggest that the keratin–chitosan–gelatin composite scaffold is a promising alternative biomaterial for tissue engineering applications. - Highlights: • Fabrication of novel Keratin-Chitosan-Gelatin composite scaffold • Keratin composite scaffold shows excellent water uptake capacity and porosity • Keratin composite scaffold shows good thermal and physical stability • Biocompatibility of the developed scaffold is comparable to collagen scaffolds • Developed scaffold is a promising material for soft tissue engineering applications.

Adult Tissue-Derived Stem Cells and Tolerance Induction in Nonhuman Primates for Vascularized Composite Allograft Transplantation

Science.gov (United States)

2017-10-01

AWARD NUMBER: W81XWH-16-2-0042 TITLE: Adult Tissue-Derived Stem Cells and Tolerance Induction in Nonhuman Primates for Vascularized Composite...2017 2. REPORT TYPE Annual 3. DATES COVERED 30 Sep 2016 - 29 Sep 2017 4. TITLE AND SUBTITLE Adult Tissue-Derived Stem Cells and Tolerance Induction...Distribution Unlimited 13. SUPPLEMENTARY NOTES The utilization of adult derived adipose stem cells administration in composite tissue transplantation

Leg tissue composition and physico-chemical parameters of sheep meat fed annatto coproduct

Directory of Open Access Journals (Sweden)

Dorgival Morais de Lima Júnior

2017-10-01

Full Text Available Our objective was to evaluate leg tissue composition and physico-chemical quality parameters of sheep meat fed with increasing levels of annatto coproduct. 32 male uncastrated animals without a defined breed were randomized in four treatments (0, 100, 200 and 300 g kg-1 of annatto coproduct in the DM diet. After 78 days of confinement, the animals were slaughtered and body components were recorded. Reconstituted leg weight, total muscle weight, biceps weight and semitendinosus weight showed a negative linear behavior (P 0.05 were found for leg tissue composition (%, muscle:bone ratio, relative fat or leg muscle. Meat physico-chemical parameters (color, shear force, water retention capacity and cooking losses were not affected by the inclusion of the annatto coproduct in the diet. The annatto coproduct can be included in up to 300 g kg-1 of dietary dry matter without negative effects to the leg tissue composition (% and physical parameters of confined sheep meat.

Optical study on the dependence of breast tissue composition and structure on subject anamnesis

Science.gov (United States)

Taroni, Paola; Quarto, Giovanna; Pifferi, Antonio; Abbate, Francesca; Balestreri, Nicola; Menna, Simona; Cassano, Enrico; Cubeddu, Rinaldo

2015-07-01

Time domain multi-wavelength (635 to 1060 nm) optical mammography was performed on 200 subjects to estimate their average breast tissue composition in terms of oxy- and deoxy-hemoglobin, water, lipid and collagen, and structural information, as provided by scattering parameters (amplitude and power). Significant (and often marked) dependence of tissue composition and structure on age, menopausal status, body mass index, and use of oral contraceptives was demonstrated.

Development of high strength hydroxyapatite for bone tissue regeneration using nanobioactive glass composites

Science.gov (United States)

Shrivastava, Pragya; Dalai, Sridhar; Sudera, Prerna; Sivam, Santosh Param; Vijayalakshmi, S.; Sharma, Pratibha

2013-02-01

With an increasing demand of biocompatible bone substitutes for the treatment of bone diseases and bone tissue regeneration, bioactive glass composites are being tested to improvise the osteoconductive as well as osteoinductive properties. Nanobioactive glass (nBG) composites, having composition of SiO2 70 mol%, CaO 26 mol % and P2O5 4 mol% were prepared by Freeze drying method using PEG-PPG-PEG co-polymer. Polymer addition improves the mechanical strength and porosity of the scaffold of nBG. Nano Bioactive glass composites upon implantation undergo specific reactions leading to the formation of crystalline hydroxyapatite (HA). This is tested in vitro using Simulated Body Fluid (SBF). This high strength hydroxyapatite (HA) layer acts as osteoconductive in cellular environment, by acting as mineral base of bones, onto which new bone cells proliferate leading to new bone formation. Strength of the nBG composites as well as HA is in the range of cortical and cancellous bone, thus proving significant for bone tissue regeneration substitutes.

Development of high strength hydroxyapatite for bone tissue regeneration using nanobioactive glass composites

International Nuclear Information System (INIS)

Shrivastava, Pragya; Dalai, Sridhar; Vijayalakshmi, S.; Sudera, Prerna; Sivam, Santosh Param; Sharma, Pratibha

2013-01-01

With an increasing demand of biocompatible bone substitutes for the treatment of bone diseases and bone tissue regeneration, bioactive glass composites are being tested to improvise the osteoconductive as well as osteoinductive properties. Nanobioactive glass (nBG) composites, having composition of SiO 2 70 mol%, CaO 26 mol % and P 2 O 5 4 mol% were prepared by Freeze drying method using PEG-PPG-PEG co-polymer. Polymer addition improves the mechanical strength and porosity of the scaffold of nBG. Nano Bioactive glass composites upon implantation undergo specific reactions leading to the formation of crystalline hydroxyapatite (HA). This is tested in vitro using Simulated Body Fluid (SBF). This high strength hydroxyapatite (HA) layer acts as osteoconductive in cellular environment, by acting as mineral base of bones, onto which new bone cells proliferate leading to new bone formation. Strength of the nBG composites as well as HA is in the range of cortical and cancellous bone, thus proving significant for bone tissue regeneration substitutes.

3D printing of composite tissue with complex shape applied to ear regeneration

International Nuclear Information System (INIS)

Lee, Jung-Seob; Hong, Jung Min; Jung, Jin Woo; Shim, Jin-Hyung; Cho, Dong-Woo; Oh, Jeong-Hoon

2014-01-01

In the ear reconstruction field, tissue engineering enabling the regeneration of the ear's own tissue has been considered to be a promising technology. However, the ear is known to be difficult to regenerate using traditional methods due to its complex shape and composition. In this study, we used three-dimensional (3D) printing technology including a sacrificial layer process to regenerate both the auricular cartilage and fat tissue. The main part was printed with poly-caprolactone (PCL) and cell-laden hydrogel. At the same time, poly-ethylene-glycol (PEG) was also deposited as a sacrificial layer to support the main structure. After complete fabrication, PEG can be easily removed in aqueous solutions, and the procedure for removing PEG has no effect on the cell viability. For fabricating composite tissue, chondrocytes and adipocytes differentiated from adipose-derived stromal cells were encapsulated in hydrogel to dispense into the cartilage and fat regions, respectively, of ear-shaped structures. Finally, we fabricated the composite structure for feasibility testing, satisfying expectations for both the geometry and anatomy of the native ear. We also carried out in vitro assays for evaluating the chondrogenesis and adipogenesis of the cell-printed structure. As a result, the possibility of ear regeneration using 3D printing technology which allowed tissue formation from the separately printed chondrocytes and adipocytes was demonstrated. (paper)

Thermogel-Coated Poly(ε-Caprolactone Composite Scaffold for Enhanced Cartilage Tissue Engineering

Directory of Open Access Journals (Sweden)

Shao-Jie Wang

2016-05-01

Full Text Available A three-dimensional (3D composite scaffold was prepared for enhanced cartilage tissue engineering, which was composed of a poly(ε-caprolactone (PCL backbone network and a poly(lactide-co-glycolide-block-poly(ethylene glycol-block-poly(lactide-co-glycolide (PLGA–PEG–PLGA thermogel surface. The composite scaffold not only possessed adequate mechanical strength similar to native osteochondral tissue as a benefit of the PCL backbone, but also maintained cell-friendly microenvironment of the hydrogel. The PCL network with homogeneously-controlled pore size and total pore interconnectivity was fabricated by fused deposition modeling (FDM, and was impregnated into the PLGA–PEG–PLGA solution at low temperature (e.g., 4 °C. The PCL/Gel composite scaffold was obtained after gelation induced by incubation at body temperature (i.e., 37 °C. The composite scaffold showed a greater number of cell retention and proliferation in comparison to the PCL platform. In addition, the composite scaffold promoted the encapsulated mesenchymal stromal cells (MSCs to differentiate chondrogenically with a greater amount of cartilage-specific matrix production compared to the PCL scaffold or thermogel. Therefore, the 3D PCL/Gel composite scaffold may exhibit great potential for in vivo cartilage regeneration.

Demineralized dentin matrix composite collagen material for bone tissue regeneration.

Science.gov (United States)

Li, Jianan; Yang, Juan; Zhong, Xiaozhong; He, Fengrong; Wu, Xiongwen; Shen, Guanxin

2013-01-01

Demineralized dentin matrix (DDM) had been successfully used in clinics as bone repair biomaterial for many years. However, particle morphology of DDM limited it further applications. In this study, DDM and collagen were prepared to DDM composite collagen material. The surface morphology of the material was studied by scanning electron microscope (SEM). MC3T3-E1 cells responses in vitro and tissue responses in vivo by implantation of DDM composite collagen material in bone defect of rabbits were also investigated. SEM analysis showed that DDM composite collagen material evenly distributed and formed a porous scaffold. Cell culture and animal models results indicated that DDM composite collagen material was biocompatible and could support cell proliferation and differentiation. Histological evaluation showed that DDM composite collagen material exhibited good biocompatibility, biodegradability and osteoconductivity with host bone in vivo. The results suggested that DDM composite collagen material might have a significant clinical advantage and potential to be applied in bone and orthopedic surgery.

[The elemental composition of teeth hard tissues depending on the state of the environment].

Science.gov (United States)

Suladze, N; Shishniashvili, T; Margvelashvili, V; Kobakhidze, K

2014-01-01

At present, great attention is paid to the origin of man-made micro elemental anomalies. To monitor the state of the environment and its effects on the human body, of great importance is the determination of the amount and distribution of various chemical elements in the dentin and enamel of the teeth. To determine the essential (Ca, Zn, Mn, Ni), conditionally essential (Rb, Ni, Sr) and toxic (Pb, Hg) trace elements in the mineralized tissues of the teeth and to identify the relationship between the elemental composition of the tooth structure and the state of the general and dental health depending on the state of the environment, we have examined 29 children aged 3-4 years who have carried out analysis of hard tissue of teeth (teeth used for remote medical reasons) for the maintenance of nine chemical elements. Children living in a relatively environmentally favorable conditions essential value and conditionally essential elements in the mineralized tissues of the teeth were within normal limits, and toxic elements slightly increased limits that differ from those of children living in environmentally disadvantaged areas. In particular, these essential elements were significantly reduced (except for zinc), as indicators of toxic elements - mercury and lead, increased by 12.5% and 44.5%, respectively, which is clearly reflected on the state of dental health because noted decompensated form of tooth decay. Thus, deviations in a state of general and dental health of children associated with an imbalance of macro-and microelements in the mineralized tissues of the teeth.

Donor-recipient human leukocyte antigen matching practices in vascularized composite tissue allotransplantation: a survey of major transplantation centers.

Science.gov (United States)

Ashvetiya, Tamara; Mundinger, Gerhard S; Kukuruga, Debra; Bojovic, Branko; Christy, Michael R; Dorafshar, Amir H; Rodriguez, Eduardo D

2014-07-01

Vascularized composite tissue allotransplant recipients are often highly sensitized to human leukocyte antigens because of multiple prior blood transfusions and other reconstructive operations. The use of peripheral blood obtained from dead donors for crossmatching may be insufficient because of life support measures taken for the donor before donation. No study has been published investigating human leukocyte antigen matching practices in this field. A survey addressing human leukocyte antigen crossmatching methods was generated and sent to 22 vascularized composite tissue allotransplantation centers with active protocols worldwide. Results were compiled by center and compared using two-tailed t tests. Twenty of 22 centers (91 percent) responded to the survey. Peripheral blood was the most commonly reported donor sample for vascularized composite tissue allotransplant crossmatching [78 percent of centers (n=14)], with only 22 percent (n=4) using lymph nodes. However, 56 percent of the 18 centers (n=10) that had performed vascularized composite tissue allotransplantation reported that they harvested lymph nodes for crossmatching. Of responding individuals, 62.5 percent (10 of 16 individuals) felt that lymph nodes were the best donor sample for crossmatching. A slight majority of vascularized composite tissue allotransplant centers that have performed clinical transplants have used lymph nodes for human leukocyte antigen matching, and centers appear to be divided on the utility of lymph node harvest. The use of lymph nodes may offer a number of potential benefits. This study highlights the need for institutional review board-approved crossmatching protocols specific to vascularized composite tissue allotransplantation, and the need for global databases for sharing of vascularized composite tissue allotransplantation experiences.

The rapid manufacture of uniform composite multicellular-biomaterial micropellets, their assembly into macroscopic organized tissues, and potential applications in cartilage tissue engineering.

Science.gov (United States)

Babur, Betul Kul; Kabiri, Mahboubeh; Klein, Travis Jacob; Lott, William B; Doran, Michael Robert

2015-01-01

We and others have published on the rapid manufacture of micropellet tissues, typically formed from 100-500 cells each. The micropellet geometry enhances cellular biological properties, and in many cases the micropellets can subsequently be utilized as building blocks to assemble complex macrotissues. Generally, micropellets are formed from cells alone, however when replicating matrix-rich tissues such as cartilage it would be ideal if matrix or biomaterials supplements could be incorporated directly into the micropellet during the manufacturing process. Herein we describe a method to efficiently incorporate donor cartilage matrix into tissue engineered cartilage micropellets. We lyophilized bovine cartilage matrix, and then shattered it into microscopic pieces having average dimensions manufacture of thousands of replica composite micropellets, with each micropellet having a material/CD core and a cellular surface. This micropellet organization enabled the rapid bulking up of the micropellet core matrix content, and left an adhesive cellular outer surface. This morphological organization enabled the ready assembly of the composite micropellets into macroscopic tissues. Generically, this is a versatile method that enables the rapid and uniform integration of biomaterials into multicellular micropellets that can then be used as tissue building blocks. In this study, the addition of CD resulted in an approximate 8-fold volume increase in the micropellets, with the donor matrix functioning to contribute to an increase in total cartilage matrix content. Composite micropellets were readily assembled into macroscopic cartilage tissues; the incorporation of CD enhanced tissue size and matrix content, but did not enhance chondrogenic gene expression.

Design and characterization of a biodegradable composite scaffold for ligament tissue engineering.

Science.gov (United States)

Hayami, James W S; Surrao, Denver C; Waldman, Stephen D; Amsden, Brian G

2010-03-15

Herein we report on the development and characterization of a biodegradable composite scaffold for ligament tissue engineering based on the fundamental morphological features of the native ligament. An aligned fibrous component was used to mimic the fibrous collagen network and a hydrogel component to mimic the proteoglycan-water matrix of the ligament. The composite scaffold was constructed from cell-adherent, base-etched, electrospun poly(epsilon-caprolactone-co-D,L-lactide) (PCLDLLA) fibers embedded in a noncell-adherent photocrosslinked N-methacrylated glycol chitosan (MGC) hydrogel seeded with primary ligament fibroblasts. Base etching improved cellular adhesion to the PCLDLLA material. Cells within the MGC hydrogel remained viable (72 +/- 4%) during the 4-week culture period. Immunohistochemistry staining revealed ligament ECM markers collagen type I, collagen type III, and decorin organizing and accumulating along the PCLDLLA fibers within the composite scaffolds. On the basis of these results, it was determined that the composite scaffold design was a viable alternative to the current approaches used for ligament tissue engineering and merits further study. (c) 2009 Wiley Periodicals, Inc.

Effect of Strain, Region, and Tissue Composition on Glucose Partitioning in Meniscus Fibrocartilage.

Science.gov (United States)

Kleinhans, Kelsey L; Jackson, Alicia R

2017-03-01

A nearly avascular tissue, the knee meniscus relies on diffusive transport for nutritional supply to cells. Nutrient transport depends on solute partitioning in the tissue, which governs the amount of nutrients that can enter a tissue. The purpose of the present study was to investigate the effects of mechanical strain, tissue region, and tissue composition on the partition coefficient of glucose in meniscus fibrocartilage. A simple partitioning experiment was employed to measure glucose partitioning in porcine meniscus tissues from two regions (horn and central), from both meniscal components (medial and lateral), and at three levels of compression (0%, 10%, and 20%). Partition coefficient values were correlated to strain level, water volume fraction, and glycosaminoglycan (GAG) content of tissue specimens. Partition coefficient values ranged from 0.47 to 0.91 (n = 48). Results show that glucose partition coefficient is significantly (p < 0.001) affected by compression, decreasing with increasing strain. Furthermore, we did not find a statistically significant effect of tissue when comparing medial versus lateral (p = 0.181) or when comparing central and horn regions (p = 0.837). There were significant positive correlations between tissue water volume fraction and glucose partitioning for all groups. However, the correlation between GAG content and partitioning was only significant in the lateral horn group. Determining how glucose partitioning is affected by tissue composition and loading is necessary for understanding nutrient availability and related tissue health and/or degeneration. Therefore, this study is important for better understanding the transport and nutrition-related mechanisms of meniscal degeneration.

Biomimetic composite coating on rapid prototyped scaffolds for bone tissue engineering.

Science.gov (United States)

Arafat, M Tarik; Lam, Christopher X F; Ekaputra, Andrew K; Wong, Siew Yee; Li, Xu; Gibson, Ian

2011-02-01

The objective of this present study was to improve the functional performance of rapid prototyped scaffolds for bone tissue engineering through biomimetic composite coating. Rapid prototyped poly(ε-caprolactone)/tri-calcium phosphate (PCL/TCP) scaffolds were fabricated using the screw extrusion system (SES). The fabricated PCL/TCP scaffolds were coated with a carbonated hydroxyapatite (CHA)-gelatin composite via biomimetic co-precipitation. The structure of the prepared CHA-gelatin composite coating was studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Compressive mechanical testing revealed that the coating process did not have any detrimental effect on the mechanical properties of the scaffolds. The cell-scaffold interaction was studied by culturing porcine bone marrow stromal cells (BMSCs) on the scaffolds and assessing the proliferation and bone-related gene and protein expression capabilities of the cells. Confocal laser microscopy and SEM images of the cell-scaffold constructs showed a uniformly distributed cell sheet and accumulation of extracellular matrix in the interior of CHA-gelatin composite-coated PCL/TCP scaffolds. The proliferation rate of BMSCs on CHA-gelatin composite-coated PCL/TCP scaffolds was about 2.3 and 1.7 times higher than that on PCL/TCP scaffolds and CHA-coated PCL/TCP scaffolds, respectively, by day 10. Furthermore, reverse transcription polymerase chain reaction and Western blot analysis revealed that CHA-gelatin composite-coated PCL/TCP scaffolds stimulate osteogenic differentiation of BMSCs the most, compared with PCL/TCP scaffolds and CHA-coated PCL/TCP scaffolds. These results demonstrate that CHA-gelatin composite-coated rapid prototyped PCL/TCP scaffolds are promising for bone tissue engineering. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Photoperiod affects daily torpor and tissue fatty acid composition in deer mice

Science.gov (United States)

Geiser, Fritz; McAllan, B. M.; Kenagy, G. J.; Hiebert, Sara M.

2007-04-01

Photoperiod and dietary lipids both influence thermal physiology and the pattern of torpor of heterothermic mammals. The aim of the present study was to test the hypothesis that photoperiod-induced physiological changes are linked to differences in tissue fatty acid composition of deer mice, Peromyscus maniculatus (˜18-g body mass). Deer mice were acclimated for >8 weeks to one of three photoperiods (LD, light/dark): LD 8:16 (short photoperiod), LD 12:12 (equinox photoperiod), and LD 16:8 (long photoperiod). Deer mice under short and equinox photoperiods showed a greater occurrence of torpor than those under long photoperiods (71, 70, and 14%, respectively). The duration of torpor bouts was longest in deer mice under short photoperiod (9.3 ± 2.6 h), intermediate under equinox photoperiod (5.1 ± 0.3 h), and shortest under long photoperiod (3.7 ± 0.6 h). Physiological differences in torpor use were associated with significant alterations of fatty acid composition in ˜50% of the major fatty acids from leg muscle total lipids, whereas white adipose tissue fatty acid composition showed fewer changes. Our results provide the first evidence that physiological changes due to photoperiod exposure do result in changes in lipid composition in the muscle tissue of deer mice and suggest that these may play a role in survival of low body temperature and metabolic rate during torpor, thus, enhancing favourable energy balance over the course of the winter.

Single walled carbon nanotube composites for bone tissue engineering.

Science.gov (United States)

Gupta, Ashim; Woods, Mia D; Illingworth, Kenneth David; Niemeier, Ryan; Schafer, Isaac; Cady, Craig; Filip, Peter; El-Amin, Saadiq F

2013-09-01

The purpose of this study was to develop single walled carbon nanotubes (SWCNT) and poly lactic-co-glycolic acid (PLAGA) composites for orthopedic applications and to evaluate the interaction of human stem cells (hBMSCs) and osteoblasts (MC3T3-E1 cells) via cell growth, proliferation, gene expression, extracellular matrix production and mineralization. PLAGA and SWCNT/PLAGA composites were fabricated with various amounts of SWCNT (5, 10, 20, 40, and 100 mg), characterized and degradation studies were performed. Cells were seeded and cell adhesion/morphology, growth/survival, proliferation and gene expression analysis were performed to evaluate biocompatibility. Imaging studies demonstrated uniform incorporation of SWCNT into the PLAGA matrix and addition of SWCNT did not affect the degradation rate. Imaging studies revealed that MC3T3-E1 and hBMSCs cells exhibited normal, non-stressed morphology on the composites and all were biocompatible. Composites with 10 mg SWCNT resulted in highest rate of cell proliferation (p PLAGA composites imparted beneficial cellular growth capabilities and gene expression, and mineralization abilities were well established. These results demonstrate the potential of SWCNT/PLAGA composites for musculoskeletal regeneration and bone tissue engineering (BTE) and are promising for orthopedic applications. Copyright © 2013 Orthopaedic Research Society.

Multiplatform analysis of 12 cancer types reveals molecular classification within and across tissues of origin

DEFF Research Database (Denmark)

Hoadley, Katherine A; Yau, Christina; Wolf, Denise M

2014-01-01

Recent genomic analyses of pathologically defined tumor types identify "within-a-tissue" disease subtypes. However, the extent to which genomic signatures are shared across tissues is still unclear. We performed an integrative analysis using five genome-wide platforms and one proteomic platform...... on 3,527 specimens from 12 cancer types, revealing a unified classification into 11 major subtypes. Five subtypes were nearly identical to their tissue-of-origin counterparts, but several distinct cancer types were found to converge into common subtypes. Lung squamous, head and neck, and a subset...

Comparative carcass and tissue nutrient composition of transgenic Yorkshire pigs expressing phytase in the saliva and conventional Yorkshire pigs.

Science.gov (United States)

Forsberg, C W; Meidinger, R G; Ajakaiye, A; Murray, D; Fan, M Z; Mandell, I B; Phillips, J P

2014-10-01

A transgenic line of Yorkshire (YK) pigs named the Cassie (CA) line was produced with a low copy number phytase transgene inserted in the genome. The transgenic line efficiently digests P, Ca, and other major minerals of plant dietary origin. The objectives of this study were to 1) compare carcass and tissue nutrient composition and meat quality traits for third generation hemizygous CA line market BW finisher pigs (n = 24) with age-matched conventional YK finisher pigs (n = 24) and 2) examine effects of outbreeding with high-index conventional YK boars on modifying carcass leanness from the third to sixth generations in CA line finisher boars (n = 73) and gilts (n = 103). Cassie boars (n = 12) and CA gilts (n = 12) were fed diets without supplemental P and comparable numbers of age-matched YK boars and gilts fed diets containing supplement P were raised throughout the finisher phase. The pigs were slaughtered and then fabricated into commercial pork primals before meat composition and quality evaluation. Proximate and major micronutrient composition was determined on tissues including fat, kidney, lean, liver, and skin. The main difference observed was greater (P = 0.033) crude fat content in CA boar carcasses and increased (P phytase action rather than to insertion of the transgene. However, from a meat composition perspective, transgenic expression of phytase in the CA line of YK pigs had little overall effect on meat composition. Outbreeding of high-index CA gilts with high-index commercial YK boars linearly reduced (P = 0.002) back fat thickness with a corresponding linear increase (P = 0.001) in lean yield in finisher CA gilts, although no change in these parameters was observed in CA finisher boars. The increase in lean yield in CA gilts by selective breeding without affecting the level of salivary phytase activity documents the value of conventional genetic selection in conjunction with genetic modification.

Silk-fibrin/hyaluronic acid composite gels for nucleus pulposus tissue regeneration.

Science.gov (United States)

Park, Sang-Hyug; Cho, Hongsik; Gil, Eun Seok; Mandal, Biman B; Min, Byoung-Hyun; Kaplan, David L

2011-12-01

Scaffold designs are critical for in vitro culture of tissue-engineered cartilage in three-dimensional environments to enhance cellular differentiation for tissue engineering and regenerative medicine. In the present study we demonstrated silk and fibrin/hyaluronic acid (HA) composite gels as scaffolds for nucleus pulposus (NP) cartilage formation, providing both biochemical support for NP outcomes as well as fostering the retention of size of the scaffold during culture due to the combined features of the two proteins. Passage two (P2) human chondrocytes cultured in 10% serum were encapsulated within silk-fibrin/HA gels. Five study groups with fibrin/HA gel culture (F/H) along with varying silk concentrations (2% silk gel only, fibrin/HA gel culture with 1% silk [F/H+1S], 1.5% silk [F/H+1.5S], and 2% silk [F/H+2S]) were cultured in serum-free chondrogenic defined media (CDM) for 4 weeks. Histological examination with alcian blue showed a defined chondrogenic area at 1 week in all groups that widened homogenously until 4 weeks. In particular, chondrogenic differentiation observed in the F/H+1.5S had no reduction in size throughout the culture period. The results of biochemical and molecular biological evaluations supported observations made during histological examination. Mechanical strength measurements showed that the silk mixed gels provided stronger mechanical properties for NP tissue than fibrin/HA composite gels in CDM. This effect could potentially be useful in the study of in vitro NP tissue engineering as well as for clinical implications for NP tissue regeneration.

Reconstruction with vascularized composite tissue in patients with excessive injury following surgery and irradiation

International Nuclear Information System (INIS)

Serafin, D.; DeLand, M.; Lesesne, C.B.; Smith, P.J.; Noell, K.T.; Georgiade, N.

1982-01-01

The biological effects of a single high dose of radiation are examined. Both cellular injury and repair are reviewed during early, intermediate, and late phases. Anticipated composite tissue morbidity is detailed for therapeutic radiation doses administered to the head and neck, breast and thorax, and perineum. Patients who demonstrated excessive time-dose fractionation values were irradiated with lower x-ray energies. Those in whom there was an overlap of treatment fields presented a serious challenge to the reconstructive surgeon. Judicious selection of well-vascularized composite tissue outside the portals of irradiation, preferably with a long vascular pedicle, facilitated reconstruction. When possible, both donor and recipient vasculature should be outside the irradiated area to ensure uninterrupted blood flow to the transferred or transplanted tissue

Effect of oral oleoyl-estrone on adipose tissue composition in male rats.

Science.gov (United States)

Remesar, X; Fernández-López, J A; Blay, M T; Savall, P; Salas, A; Díaz-Silva, M; Esteve, M; Grasa, M M; Alemany, M

2002-08-01

To determine whether the oral administration of oleoyl-estrone has similar mass-decreasing effects on the main different sites of white adipose tissue (WAT). Adult male Zucker lean rats were given a daily oral gavage of oleoyl-estrone (OE, 10 micromol/kg) in 0.2 ml of sunflower oil for 10 days, and were compared with controls receiving only the oil. The mass of the main WAT sites: subcutaneous, epididymal, mesenteric, retroperitoneal, gluteal, perirenal and interscapular, as well as perirenal and interscapular brown adipose tissue (BAT), were dissected and studied. The tissue weight, DNA, protein, lipid and total cholesterol content, together with the levels of leptin and acyl-estrone in the larger WAT and BAT masses, were measured. The weights of WAT depots were correlated with body weight but those of BAT were not. Cell size was maximal for epididymal and mesenteric and minimal for subcutaneous and retroperitoneal WAT and BAT. Differences were detected in DNA, and in protein and lipid content between distinct WAT sites. OE treatment tended to decrease cell number and cell size in WAT; only small differences in composition were found between WAT locations inside the visceral cavity and those outside. Decreases in lipid content were maximal in mesenteric fat. Leptin and acyl-estrone content were fairly uniform at the different WAT sites, except for high concentrations in gluteal WAT. OE induced a greater decrease in leptin and acyl-estrone than in DNA and lipids; changes in these hormones were fairly parallel in all sites. In general, the differences in composition between visceral and peripheral subcutaneous WAT and their responses to OE were less marked than the individual differences observed between specific sites, regardless of location. WAT sites are fairly diverse in composition, but their response to OE treatment was uniform. OE decreased the weight of WAT through reduction of both cell numbers and size; but did not change the mass or composition of BAT

The rapid manufacture of uniform composite multicellular-biomaterial micropellets, their assembly into macroscopic organized tissues, and potential applications in cartilage tissue engineering.

Directory of Open Access Journals (Sweden)

Betul Kul Babur

Full Text Available We and others have published on the rapid manufacture of micropellet tissues, typically formed from 100-500 cells each. The micropellet geometry enhances cellular biological properties, and in many cases the micropellets can subsequently be utilized as building blocks to assemble complex macrotissues. Generally, micropellets are formed from cells alone, however when replicating matrix-rich tissues such as cartilage it would be ideal if matrix or biomaterials supplements could be incorporated directly into the micropellet during the manufacturing process. Herein we describe a method to efficiently incorporate donor cartilage matrix into tissue engineered cartilage micropellets. We lyophilized bovine cartilage matrix, and then shattered it into microscopic pieces having average dimensions < 10 μm diameter; we termed this microscopic donor matrix "cartilage dust (CD". Using a microwell platform, we show that ~0.83 μg CD can be rapidly and efficiently incorporated into single multicellular aggregates formed from 180 bone marrow mesenchymal stem/stromal cells (MSC each. The microwell platform enabled the rapid manufacture of thousands of replica composite micropellets, with each micropellet having a material/CD core and a cellular surface. This micropellet organization enabled the rapid bulking up of the micropellet core matrix content, and left an adhesive cellular outer surface. This morphological organization enabled the ready assembly of the composite micropellets into macroscopic tissues. Generically, this is a versatile method that enables the rapid and uniform integration of biomaterials into multicellular micropellets that can then be used as tissue building blocks. In this study, the addition of CD resulted in an approximate 8-fold volume increase in the micropellets, with the donor matrix functioning to contribute to an increase in total cartilage matrix content. Composite micropellets were readily assembled into macroscopic cartilage

Cellularized cylindrical fiber/hydrogel composites for ligament tissue engineering.

Science.gov (United States)

Thayer, Patrick S; Dimling, Anna F; Plessl, Daniel S; Hahn, Mariah R; Guelcher, Scott A; Dahlgren, Linda A; Goldstein, Aaron S

2014-01-13

Electrospun meshes suffer from poor cell infiltration and limited thickness, which restrict their use to thin tissue applications. Herein, we demonstrate two complementary processes to overcome these limitations and achieve elastomeric composites that may be suitable for ligament repair. First, C3H10T1/2 mesenchymal stem cells were incorporated into electrospun meshes using a hybrid electrospinning/electrospraying process. Second, electrospun meshes were rolled and formed into composites with an interpenetrating polyethylene glycol (PEG) hydrogel network. Stiffer composites were formed from poly(lactic-co-glycolic acid) (PLGA) meshes, while softer and more elastic composites were formed from poly(ester-urethane urea) (PEUUR) meshes. As-spun PLGA and PEUUR rolled meshes had tensile moduli of 19.2 ± 1.9 and 0.86 ± 0.34 MPa, respectively, which changed to 11.6 ± 4.8 and 1.05 ± 0.39 MPa with the incorporation of a PEG hydrogel phase. In addition, cyclic tensile testing indicated that PEUUR-based composites deformed elastically to at least 10%. Finally, C3H10T1/2 cells incorporated into electrospun meshes survived the addition of the PEG phase and remained viable for up to 5 days. These results indicate that the fabricated cellularized composites are support cyclic mechanical conditioning, and have potential application in ligament repair.

A novel basalt fiber-reinforced polylactic acid composite for hard tissue repair.

Science.gov (United States)

Chen, Xi; Li, Yan; Gu, Ning

2010-08-01

A basalt fiber (BF) was, for the first time, introduced into a poly(l-lactic acid) (PLLA) matrix as innovative reinforcement to fabricate composite materials for hard tissue repair. Firstly, BF/PLLA composites and pure PLLA were produced by the methods of solution blending and freeze drying. The results showed that basalt fibers can be uniformly dispersed in the PLLA matrix and significantly improve the mechanical properties and hydrophilicity of the PLLA matrix. The presence of basalt fibers may retard the polymer degradation rate and neutralize the acid degradation from PLLA. Osteoblasts were cultured in vitro to evaluate the cytocompatibility of the composite. An MTT assay revealed that osteoblasts proliferated well for 7 days and there was little difference found in their viability on both PLLA and BF/PLLA films, which was consistent with the alkaline phosphatase (ALP) activity results. A fluorescent staining observation showed that osteoblasts grew well on the composites. SEM images displayed that osteoblasts tended to grow along the fiber axis. The formation of mineralized nodules was observed on the films by Alizarin red S staining. These results suggest that the presence of basalt fibers does not noticeably affect osteoblastic behavior and the designed composites are osteoblast compatible. It is concluded that basalt fibers, as reinforcing fibers, may have promising applications in hard tissue repair.

A novel basalt fiber-reinforced polylactic acid composite for hard tissue repair

International Nuclear Information System (INIS)

Chen Xi; Li Yan; Gu Ning

2010-01-01

A basalt fiber (BF) was, for the first time, introduced into a poly(l-lactic acid) (PLLA) matrix as innovative reinforcement to fabricate composite materials for hard tissue repair. Firstly, BF/PLLA composites and pure PLLA were produced by the methods of solution blending and freeze drying. The results showed that basalt fibers can be uniformly dispersed in the PLLA matrix and significantly improve the mechanical properties and hydrophilicity of the PLLA matrix. The presence of basalt fibers may retard the polymer degradation rate and neutralize the acid degradation from PLLA. Osteoblasts were cultured in vitro to evaluate the cytocompatibility of the composite. An MTT assay revealed that osteoblasts proliferated well for 7 days and there was little difference found in their viability on both PLLA and BF/PLLA films, which was consistent with the alkaline phosphatase (ALP) activity results. A fluorescent staining observation showed that osteoblasts grew well on the composites. SEM images displayed that osteoblasts tended to grow along the fiber axis. The formation of mineralized nodules was observed on the films by Alizarin red S staining. These results suggest that the presence of basalt fibers does not noticeably affect osteoblastic behavior and the designed composites are osteoblast compatible. It is concluded that basalt fibers, as reinforcing fibers, may have promising applications in hard tissue repair.

Hand transplantation and vascularized composite tissue allografts in orthopaedics and traumatology.

Science.gov (United States)

Schuind, F

2010-05-01

Composite tissue allograft (CTA) is defined as heterologous transplantation of a complex comprising skin and subcutaneous, neurovascular and mesenchymal tissue. Such techniques allow complex reconstruction using matched tissue, without donor site morbidity. The potential indications in orthopaedics-traumatology could in the future be more frequent than the present indications of heart, lung, liver, kidney and pancreas transplantation. International clinical experience clearly demonstrates the feasibility of CTA, both surgically and immunologically. However, immunosuppression remains indispensable, exposing the patient to risks that are not acceptable for purely functional surgery, except in very particular indications. The main hope for the future lies in induction of graft-specific tolerance. Copyright 2010 Elsevier Masson SAS. All rights reserved.

Mandibular reconstruction with composite microvascular tissue transfer

International Nuclear Information System (INIS)

Coleman, J.J. III; Wooden, W.A.

1990-01-01

Microvascular free tissue transfer has provided a variety of methods of restoring vascularized bone and soft tissue to difficult defects created by tumor resection and trauma. Over 7 years, 26 patients have undergone 28 free flaps for mandibular reconstruction, 15 for primary squamous cell carcinoma of the floor of the mouth or tongue, 7 for recurrent tumor, and 6 for other reasons [lymphangioma (1), infection (1), gunshot wound (1), and osteoradionecrosis (3)]. Primary reconstruction was performed in 19 cases and secondary in 9. All repairs were composite flaps including 12 scapula, 5 radial forearm, 3 fibula, 2 serratus, and 6 deep circumflex iliac artery. Mandibular defects included the symphysis alone (7), symphysis and body (5), symphysis-body-ramus condyle (2), body or ramus (13), and bilateral body (1). Fourteen patients had received prior radiotherapy to adjuvant or curative doses. Eight received postoperative radiotherapy. All patients had initially successful vascularized reconstruction by clinical examination (28) and positive radionuclide scan (22 of 22). Bony stability was achieved in 25 of 26 patients and oral continence in 24 of 26. One complete flap loss occurred at 14 days. Complications of some degree developed in 22 patients including partial skin necrosis (3), orocutaneous fistula (3), plate exposure (1), donor site infection (3), fracture of reconstruction (1), and fracture of the radius (1). Microvascular transfer of bone and soft tissue allows a reliable reconstruction--despite previous radiotherapy, infection, foreign body, or surgery--in almost every situation in which mandible and soft tissue are absent. Bony union, a healed wound, and reasonable function and appearance are likely despite early fistula, skin loss, or metal plate or bone exposure

Mandibular reconstruction with composite microvascular tissue transfer

Energy Technology Data Exchange (ETDEWEB)

Coleman, J.J. III; Wooden, W.A. (Emory Univ. School of Medicine, Atlanta, GA (USA))

1990-10-01

Microvascular free tissue transfer has provided a variety of methods of restoring vascularized bone and soft tissue to difficult defects created by tumor resection and trauma. Over 7 years, 26 patients have undergone 28 free flaps for mandibular reconstruction, 15 for primary squamous cell carcinoma of the floor of the mouth or tongue, 7 for recurrent tumor, and 6 for other reasons (lymphangioma (1), infection (1), gunshot wound (1), and osteoradionecrosis (3)). Primary reconstruction was performed in 19 cases and secondary in 9. All repairs were composite flaps including 12 scapula, 5 radial forearm, 3 fibula, 2 serratus, and 6 deep circumflex iliac artery. Mandibular defects included the symphysis alone (7), symphysis and body (5), symphysis-body-ramus condyle (2), body or ramus (13), and bilateral body (1). Fourteen patients had received prior radiotherapy to adjuvant or curative doses. Eight received postoperative radiotherapy. All patients had initially successful vascularized reconstruction by clinical examination (28) and positive radionuclide scan (22 of 22). Bony stability was achieved in 25 of 26 patients and oral continence in 24 of 26. One complete flap loss occurred at 14 days. Complications of some degree developed in 22 patients including partial skin necrosis (3), orocutaneous fistula (3), plate exposure (1), donor site infection (3), fracture of reconstruction (1), and fracture of the radius (1). Microvascular transfer of bone and soft tissue allows a reliable reconstruction--despite previous radiotherapy, infection, foreign body, or surgery--in almost every situation in which mandible and soft tissue are absent. Bony union, a healed wound, and reasonable function and appearance are likely despite early fistula, skin loss, or metal plate or bone exposure.

Poly (Ethylene Glycol)-Based Hydrogels as Self-Inflating Tissue Expanders with Tunable Mechanical and Swelling Properties.

Science.gov (United States)

Jamadi, Mahsa; Shokrollahi, Parvin; Houshmand, Behzad; Joupari, Mortaza Daliri; Mashhadiabbas, Fatemeh; Khademhosseini, Ali; Annabi, Nasim

2017-08-01

Tissue expansion is used by plastic/reconstructive surgeons to grow additional skin/tissue for replacing or repairing lost or damaged soft tissues. Recently, hydrogels have been widely used for tissue expansion applications. Herein, a self-inflating tissue expander blend composition from three different molecular weights (2, 6, and 10 kDa) of poly (ethylene glycol) diacrylate (PEGDA) hydrogel with tunable mechanical and swelling properties is presented. The in vitro results demonstrate that, of the eight studied compositions, P6 (PEGDA 6 kDa:10 kDa (50:50)) and P8 (PEGDA 6 kDa:10 kDa (35:65)) formulations provide a balance of mechanical property and swelling capability suitable for tissue expansion. Furthermore, these expanders can be compressed up to 60% of their original height and can be loaded and unloaded cyclically at least ten times with no permanent deformation. The in vivo results indicate that these two engineered blend compositions are capable to generate a swelling pressure sufficient to dilate the surrounding tissue while retaining their original shape. The histological analyses reveal the formation of fibrous capsule at the interface between the implant and the subcutaneous tissue with no signs of inflammation. Ultimately, controlling the PEGDA chain length shows potential for the development of self-inflating tissue expanders with tunable mechanical and swelling properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Autologous Cartilage Chip Transplantation Improves Repair Tissue Composition Compared With Marrow Stimulation.

Science.gov (United States)

Christensen, Bjørn Borsøe; Olesen, Morten Lykke; Lind, Martin; Foldager, Casper Bindzus

2017-06-01

Repair of chondral injuries by use of cartilage chips has recently demonstrated clinical feasibility. To investigate in vivo cartilage repair outcome of autologous cartilage chips compared with marrow stimulation in full-thickness cartilage defects in a minipig model. Controlled laboratory study. Six Göttingen minipigs received two 6-mm chondral defects in the medial and lateral trochlea of each knee. The two treatment groups were (1) autologous cartilage chips embedded in fibrin glue (ACC) (n = 12) and (2) marrow stimulation (MST) (n = 12). The animals were euthanized after 6 months, and the composition of repair tissue was quantitatively determined using histomorphometry. Semiquantitative evaluation was performed by means of the International Cartilage Repair Society (ICRS) II score. Collagen type II staining was used to further evaluate the repair tissue composition. Significantly more hyaline cartilage was found in the ACC (17.1%) compared with MST (2.9%) group ( P cartilage repair tissue compared with MST at 6 months postoperatively. Further studies are needed to investigate ACC as a possible alternative first-line treatment for focal cartilage injuries in the knee.

Lipoproteins in Drosophila melanogaster—Assembly, Function, and Influence on Tissue Lipid Composition

Science.gov (United States)

Palm, Wilhelm; Sampaio, Julio L.; Brankatschk, Marko; Carvalho, Maria; Mahmoud, Ali; Shevchenko, Andrej; Eaton, Suzanne

2012-01-01

Interorgan lipid transport occurs via lipoproteins, and altered lipoprotein levels correlate with metabolic disease. However, precisely how lipoproteins affect tissue lipid composition has not been comprehensively analyzed. Here, we identify the major lipoproteins of Drosophila melanogaster and use genetics and mass spectrometry to study their assembly, interorgan trafficking, and influence on tissue lipids. The apoB-family lipoprotein Lipophorin (Lpp) is the major hemolymph lipid carrier. It is produced as a phospholipid-rich particle by the fat body, and its secretion requires Microsomal Triglyceride Transfer Protein (MTP). Lpp acquires sterols and most diacylglycerol (DAG) at the gut via Lipid Transfer Particle (LTP), another fat body-derived apoB-family lipoprotein. The gut, like the fat body, is a lipogenic organ, incorporating both de novo–synthesized and dietary fatty acids into DAG for export. We identify distinct requirements for LTP and Lpp-dependent lipid mobilization in contributing to the neutral and polar lipid composition of the brain and wing imaginal disc. These studies define major routes of interorgan lipid transport in Drosophila and uncover surprising tissue-specific differences in lipoprotein lipid utilization. PMID:22844248

Primary mucosa-associated lymphoid tissue thyroid lymphoma: a rare thyroid neoplasm of extrathyroid origin

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Dimitrios Hadjidakis

2012-01-01

Full Text Available Primary thyroid lymphoma is a rare malignancy, representing 2-8% of all thyroid malignancies and 1-2% of all extranodal lymphomas. The majority of cases concern non-Hodgkin`s lymphoma of B cell origin, following by Hodgkin’s disease, T cell lymphomas and rarely marginal zone B-cell mucosa-associated lymphoid tissue (MALT lymphomas. MALT lymphomas have been associated with long-standing autoimmune Hashimoto`s thyroiditis. We present the case of a 44-years-old woman with thyroid MALT lymphoma in the background of multinodular goiter of autoimmune origin.

Mesenchymal Stem Cells of Dental Origin for Inducing Tissue Regeneration in Periodontitis: A Mini-Review

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Beatriz Hernández-Monjaraz

2018-03-01

Full Text Available Periodontitis is a chronic disease that begins with a period of inflammation of the supporting tissues of the teeth table and then progresses, destroying the tissues until loss of the teeth occurs. The restoration of the damaged dental support apparatus is an extremely complex process due to the regeneration of the cementum, the periodontal ligament, and the alveolar bone. Conventional treatment relies on synthetic materials that fill defects and replace lost dental tissue, but these approaches are not substitutes for a real regeneration of tissue. To address this, there are several approaches to tissue engineering for regenerative dentistry, among them, the use of stem cells. Mesenchymal stem cells (MSC can be obtained from various sources of adult tissues, such as bone marrow, adipose tissue, skin, and tissues of the orofacial area. MSC of dental origin, such as those found in the bone marrow, have immunosuppressive and immunotolerant properties, multipotency, high proliferation rates, and the capacity for tissue repair. However, they are poorly used as sources of tissue for therapeutic purposes. Their accessibility makes them an attractive source of mesenchymal stem cells, so this review describes the field of dental stem cell research and proposes a potential mechanism involved in periodontal tissue regeneration induced by dental MSC.

Determination of quantitative tissue composition by iterative reconstruction on 3D DECT volumes

Energy Technology Data Exchange (ETDEWEB)

Magnusson, Maria [Linkoeping Univ. (Sweden). Dept. of Electrical Engineering; Linkoeping Univ. (Sweden). Dept. of Medical and Health Sciences, Radiation Physics; Linkoeping Univ. (Sweden). Center for Medical Image Science and Visualization (CMIV); Malusek, Alexandr [Linkoeping Univ. (Sweden). Dept. of Medical and Health Sciences, Radiation Physics; Linkoeping Univ. (Sweden). Center for Medical Image Science and Visualization (CMIV); Nuclear Physics Institute AS CR, Prague (Czech Republic). Dept. of Radiation Dosimetry; Muhammad, Arif [Linkoeping Univ. (Sweden). Dept. of Medical and Health Sciences, Radiation Physics; Carlsson, Gudrun Alm [Linkoeping Univ. (Sweden). Dept. of Medical and Health Sciences, Radiation Physics; Linkoeping Univ. (Sweden). Center for Medical Image Science and Visualization (CMIV)

2011-07-01

Quantitative tissue classification using dual-energy CT has the potential to improve accuracy in radiation therapy dose planning as it provides more information about material composition of scanned objects than the currently used methods based on single-energy CT. One problem that hinders successful application of both single- and dual-energy CT is the presence of beam hardening and scatter artifacts in reconstructed data. Current pre- and post-correction methods used for image reconstruction often bias CT attenuation values and thus limit their applicability for quantitative tissue classification. Here we demonstrate simulation studies with a novel iterative algorithm that decomposes every soft tissue voxel into three base materials: water, protein, and adipose. The results demonstrate that beam hardening artifacts can effectively be removed and accurate estimation of mass fractions of each base material can be achieved. Our iterative algorithm starts with calculating parallel projections on two previously reconstructed DECT volumes reconstructed from fan-beam or helical projections with small conebeam angle. The parallel projections are then used in an iterative loop. Future developments include segmentation of soft and bone tissue and subsequent determination of bone composition. (orig.)

Origin of the Moon Unveiled by its Heavy Iron Isotope Composition

Science.gov (United States)

Poitrasson, F.; Halliday, A. N.; Lee, D.; Levasseur, S.; Teutsch, N.

2002-12-01

The origin of the Moon has long been of interest and although the Giant Impact theory is currently the preferred explanation, unequivocal supporting evidence has been lacking. We have measured the iron isotope compositions of Shergotty-Nakhla-Chassigny meteorites and eucrites thought to come from Mars and Vesta, as well as samples from the Moon and the mafic Earth using high precision plasma source mass spectrometry. The mean iron isotope composition of the lunar samples, expressed in the conventional delta notation (d57Fe/54Fe) with respect to the IRMM-14 isotopic standard, is heavier (0.221 per mil (0.041: one standard deviation, 10 samples)) than those of the Earth (0.119 per mil (0.044, 7 samples)), which themselves are heavier than Martian meteorites (0.009 per mil (0.024, 6 samples)) and the eucrites measured (0.033 per mil (0.038, 7 samples)). Student's t-test calculations show that the Moon and Earth means are different from each other and from those of the other planetary bodies at >99% level of significance. The iron isotope compositions show no simple relationship with planetary heliocentric position, mantle oxygen fugacity, volatile content, or planet size. Similarly, these results do not support an origin of the Moon through co-accretion with the Earth, or as a fragment ejected from the Earth's mantle, or as another planet captured by the early Earth. In contrast, these data can be explained if the Earth, and especially the Moon, went through partial vaporisation and condensation leading to kinetic iron isotopic fractionation. Our data are also consistent with the suggested levels of enrichment of refractory elements for the bulk Earth and Moon. These new iron isotope results thus provide strong support for the origin of the Moon through a giant impact between the proto-Earth and another planet. Raleigh kinetic fractionation calculations indicate that only 1% loss of the current Fe budget of the Moon is required to explain its heavier isotopic

The donor management algorithm in transplantation of a composite facial tissue allograft.. First experience in Russia

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V. V. Uyba

2016-01-01

Full Text Available In the period from 2005 to December 2015, 37 transplantations of vascularized composite facial tissue allografts (VCAs were performed in the world. A vascularized composite tissue allotransplantation has been recognized as a solid organ transplantation rather than a special kind of tissue transplantation. The recent classification of composite tissue allografts into the category of donor organs gave rise to a number of organizational, ethical, legal, technical, and economic problems. In May 2015, the first successful transplantation of a composite facial tissue allograft was performed in Russia. The article describes our experience of multiple team interactions at donor management stage when involved in the identification, conditioning, harvesting, and delivering donor organs to various hospitals. A man, aged 51 years old, diagnosed with traumatic brain injury became a donor after the diagnosis of brain deathhad been made, his death had been ascertained, and the requested consent for organ donation had been obtained from relatives. At donor management stage, a tracheostomy was performed and a posthumous facial mask was molded. The "face first, concurrent completion" algorithm was chosen for organ harvesting and facial VCA procurement; meanwhile, the facial allograft was procured as the "full face" category. The total surgery duration from the incision to completing the procurement (including that of solid organs made 8 hours 20 minutes. Immediately after the procurement, the facial VCA complex was sent to the St. Petersburg clinic by medical aircraft transportation, and was there transplanted 9 hours later. Donor kidneys were transported to Moscow bycivil aviation and transplanted 17 and 20 hours later. The authors believe that this clinical case report demonstrates the feasibility and safety of multiple harvesting of solid organs and a vascularized composite facial tissue allograft. However, this kind of surgery requires an essential

Fabrication and Characterization of Collagen-Immobilized Porous PHBV/HA Nano composite Scaffolds for Bone Tissue Engineering

International Nuclear Information System (INIS)

Jin-Young, B.; Zhi-Cai, X.; Giseop, K.; Keun-Byoung, Y.; Soo-Young, P.; Lee, S.P.; Inn-Kyu, K.

2012-01-01

The porous composite scaffolds (PHBV/HA) consisting of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and hydroxyapatite (HA) were fabricated using a hot-press machine and salt-leaching. Collagen (type I) was then immobilized on the surface of the porous PHBV/HA composite scaffolds to improve tissue compatibility. The structure and morphology of the collagen-immobilized composite scaffolds (PHBV/HA/Col) were investigated using a scanning electron microscope (SEM), Fourier transform infrared (FTIR), and electron spectroscopy for chemical analysis (ESCA). The potential of the porous PHBV/HA/Col composite scaffolds for use as a bone scaffold was assessed by an experiment with osteoblast cells (MC3T3-E1) in terms of cell adhesion, proliferation, and differentiation. The results showed that the PHBV/HA/Col composite scaffolds possess better cell adhesion and significantly higher proliferation and differentiation than the PHBV/HA composite scaffolds and the PHBV scaffolds. These results suggest that the PHBV/HA/Col composite scaffolds have a high potential for use in the field of bone regeneration and tissue engineering.

Harvesting Season and Botanical Origin Interferes in Production and Nutritional Composition of Bee Pollen

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ADRIANA F. NEGRÃO

2018-02-01

Full Text Available ABSTRACT We aimed to evaluate the frequency of bee pollen production, its botanical origin and chemical composition when collected in different seasons. Our results indicate that higher proteins (22.80 ± 3.09% and flavonoids (2789.87 ± 1396.00 μg 100g-1 levels were obtained in the winter season, which also showed greater pollen production (134.50 ± 35.70 grams and predominance of the Myrtaceae family. As for spring we found high concentrations of lipids (4.62 ± 2.26% and low ash content (2.22 ± 0.39%. Regarding the amino acid composition and vitamin C content, we found no differences between the averages throughout the seasons. Our results highlight the importance of understanding not only the botanical origin and the chemical composition of bee pollen, but also the harvesting frequency of this product by bees, so that it becomes possible to supplement the colonies in times of natural food resources shortage.

Preparation of dexamethasone-loaded biphasic calcium phosphate nanoparticles/collagen porous composite scaffolds for bone tissue engineering.

Science.gov (United States)

Chen, Ying; Kawazoe, Naoki; Chen, Guoping

2018-02-01

Although bone is regenerative, its regeneration capacity is limited. For bone defects beyond a critical size, further intervention is required. As an attractive strategy, bone tissue engineering (bone TE) has been widely investigated to repair bone defects. However, the rapid and effective bone regeneration of large non-healing defects is still a great challenge. Multifunctional scaffolds having osteoinductivity and osteoconductivity are desirable to fasten functional bone tissue regeneration. In the present study, biomimetic composite scaffolds of collagen and biphasic calcium phosphate nanoparticles (BCP NPs) with a controlled release of dexamethasone (DEX) and the controlled pore structures were prepared for bone TE. DEX was introduced in the BCP NPs during preparation of the BCP NPs and hybridized with collagen scaffolds, which pore structures were controlled by using pre-prepared ice particulates as a porogen material. The composite scaffolds had well controlled and interconnected pore structures, high mechanical strength and a sustained release of DEX. The composite scaffolds showed good biocompatibility and promoted osteogenic differentiation of hMSCs when used for three-dimensional culture of human bone marrow-derived mesenchymal stem cells. Subcutaneous implantation of the composite scaffolds at the dorsa of athymic nude mice demonstrated that they facilitated the ectopic bone tissue regeneration. The results indicated the DEX-loaded BCP NPs/collagen composite scaffolds had high potential for bone TE. Scaffolds play a crucial role for regeneration of large bone defects. Biomimetic scaffolds having the same composition of natural bone and a controlled release of osteoinductive factors are desirable for promotion of bone regeneration. In this study, composite scaffolds of collagen and biphasic CaP nanoparticles (BCP NPs) with a controlled release nature of dexamethasone (DEX) were prepared and their porous structures were controlled by using ice particulates

Relative Composition of Fibrous Connective and Fatty/Glandular Tissue in Connective Tissue Grafts Depends on the Harvesting Technique but not the Donor Site of the Hard Palate.

Science.gov (United States)

Bertl, Kristina; Pifl, Markus; Hirtler, Lena; Rendl, Barbara; Nürnberger, Sylvia; Stavropoulos, Andreas; Ulm, Christian

2015-12-01

Whether the composition of palatal connective tissue grafts (CTGs) varies depending on donor site or harvesting technique in terms of relative amounts of fibrous connective tissue (CT) and fatty/glandular tissue (FGT) is currently unknown and is histologically assessed in the present study. In 10 fresh human cadavers, tissue samples were harvested in the anterior and posterior palate and in areas close to (marginal) and distant from (apical) the mucosal margin. Mucosal thickness, lamina propria thickness (defined as the extent of subepithelial portion of the biopsy containing ≤25% or ≤50% FGT), and proportions of CT and FGT were semi-automatically estimated for the entire mucosa and for CTGs virtually harvested by split-flap (SF) preparation minimum 1 mm deep or after deepithelialization (DE). Palatal mucosal thickness, ranging from 2.35 to 6.89 mm, and histologic composition showed high interindividual variability. Lamina propria thickness (P >0.21) and proportions of CT (P = 0.48) and FGT (P = 0.15) did not differ significantly among the donor sites (anterior, posterior, marginal, apical). However, thicker palatal tissue was associated with higher FGT content (P tissue composition in the hard palate, DE-harvested CTG contains much larger amounts of CT and much lower amounts of FGT than SF-harvested CTG, irrespective of the harvesting site.

Dual growth factor delivery from bilayered, biodegradable hydrogel composites for spatially-guided osteochondral tissue repair

NARCIS (Netherlands)

Lu, S.; Lam, J.; Trachtenberg, J.E.; Lee, E.J.; Seyednejad, H.; van den Beucken, J.J.; Tabata, Y.; Wong, M.E.; Jansen, J.A.; Mikos, A.G.; Kasper, F.K.

2014-01-01

The present work investigated the use of biodegradable hydrogel composite scaffolds, based on the macromer oligo(poly(ethylene glycol) fumarate) (OPF), to deliver growth factors for the repair of osteochondral tissue in a rabbit model. In particular, bilayered OPF composites were used to mimic the

Perfusion decellularization of a human limb: A novel platform for composite tissue engineering and reconstructive surgery.

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Mattia Francesco Maria Gerli

Full Text Available Muscle and fasciocutaneous flaps taken from autologous donor sites are currently the most utilized approach for trauma repair, accounting annually for 4.5 million procedures in the US alone. However, the donor tissue size is limited and the complications related to these surgical techniques lead to morbidities, often involving the donor sites. Alternatively, recent reports indicated that extracellular matrix (ECM scaffolds boost the regenerative potential of the injured site, as shown in a small cohort of volumetric muscle loss patients. Perfusion decellularization is a bioengineering technology that allows the generation of clinical-scale ECM scaffolds with preserved complex architecture and with an intact vascular template, from a variety of donor organs and tissues. We recently reported that this technology is amenable to generate full composite tissue scaffolds from rat and non-human primate limbs. Translating this platform to human extremities could substantially benefit soft tissue and volumetric muscle loss patients providing tissue- and species-specific grafts. In this proof-of-concept study, we show the successful generation a large-scale, acellular composite tissue scaffold from a full cadaveric human upper extremity. This construct retained its morphological architecture and perfusable vascular conduits. Histological and biochemical validation confirmed the successful removal of nuclear and cellular components, and highlighted the preservation of the native extracellular matrix components. Our results indicate that perfusion decellularization can be applied to produce human composite tissue acellular scaffolds. With its preserved structure and vascular template, these biocompatible constructs, could have significant advantages over the currently implanted matrices by means of nutrient distribution, size-scalability and immunological response.

The use of stable isotope compositions of selected elements in food origin control

International Nuclear Information System (INIS)

Wierzchnicki, R.

2002-01-01

Stable isotope ratios have been used widely for authentication of foodstuffs especially for detection of added water and sugar in fruit juices and wines. Hydrogen and oxygen composition are particularly interesting probes for geographical origin and authenticity identification. Carbon and nitrogen composition of fruits contains the finger-print of their metabolism and growing condition. Exemplary data are presented which demonstrated the usefulness of the Isotope Ratio Mass Spectrometry (IRMS) methods for authenticating wines and fruits (juice and pulp). (author)

Self-assembled high-strength hydroxyapatite/graphene oxide/chitosan composite hydrogel for bone tissue engineering.

Science.gov (United States)

Yu, Peng; Bao, Rui-Ying; Shi, Xiao-Jun; Yang, Wei; Yang, Ming-Bo

2017-01-02

Graphene hydrogel has shown greatly potentials in bone tissue engineering recently, but it is relatively weak in the practical use. Here we report a facile method to synthesize high strength composite graphene hydrogel. Graphene oxide (GO), hydroxyapatite (HA) nanoparticles (NPs) and chitosan (CS) self-assemble into a 3-dimensional hydrogel with the assistance of crosslinking agent genipin (GNP) for CS and reducing agent sodium ascorbate (NaVC) for GO simultaneously. The dense and oriented microstructure of the resulted composite gel endows it with high mechanical strength, high fixing capacity of HA and high porosity. These properties together with the good biocompatibility make the ternary composite gel a promising material for bone tissue engineering. Such a simultaneous crosslinking and reduction strategy can also be applied to produce a variety of 3D graphene-polymer based nanocomposites for biomaterials, energy storage materials and adsorbent materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

A critical evaluation of body composition modalities used to assess adipose and skeletal muscle tissue in cancer.

Science.gov (United States)

Di Sebastiano, Katie M; Mourtzakis, Marina

2012-10-01

The majority of cancer patients experience some form of body composition change during the disease trajectory. For example, breast cancer patients undergoing chemotherapy and prostate cancer patients undergoing androgen deprivation therapy gain fat and lose skeletal muscle, which are associated with increased risk of cancer recurrence and clinical comorbidities. In contrast, advanced cancer patients, such as lung and colorectal cancer patients, experience symptoms of cancer cachexia (accelerated loss of skeletal muscle with or without adipose tissue loss), which are associated with decreased treatment response and poorer survival rates in advanced cancers. The heterogeneity of body composition features and their diverse implications across different cancer populations supports the need for accurate quantification of muscle and adipose tissue. Use of appropriate body composition modalities will facilitate an understanding of the complex relationship between body composition characteristics and clinical outcomes. This will ultimately support the development and evaluation of future therapeutic interventions that aim to counter muscle loss and fat gain in cancer populations. Despite the various metabolic complications that may confound the accurate body composition measurement in cancer patients (i.e., dehydration may confound lean tissue measurement), there are no guidelines for selecting the most appropriate modalities to make these measurements. In this review we outline specific considerations for choosing the most optimal approaches of lean and adipose tissue measurements among different cancer populations. Anthropometric measures, bioelectrical impedance analysis, air displacement plethysmography, dual-energy X-ray absorptiometry, computed tomography, and magnetic resonance imaging will be discussed.

Heavy Metal Content in Chilean Fish Related to Habitat Use, Tissue Type and River of Origin.

Science.gov (United States)

Copaja, S V; Pérez, C A; Vega-Retter, C; Véliz, D

2017-12-01

In this study, we analyze the concentration of ten metals in two freshwater fish-the benthic catfish Trichomycterus areolatus and the limnetic silverside Basilichthys microlepidotus-in order to detect possible accumulation differences related to fish habitat (benthic or pelagic), tissue type (gill, liver and muscle), and the river of origin (four different rivers) in central Chile. The MANOVA performed with all variables and metals, revealed independent effects of fish, tissue and river. In the case of the fish factor, Cu, Cr, Mo and Zn showed statistically higher concentrations in catfish compared with silverside for all tissues and in all rivers (p food sources and respiration.

Soft tissue wound healing around teeth and dental implants.

Science.gov (United States)

Sculean, Anton; Gruber, Reinhard; Bosshardt, Dieter D

2014-04-01

To provide an overview on the biology and soft tissue wound healing around teeth and dental implants. This narrative review focuses on cell biology and histology of soft tissue wounds around natural teeth and dental implants. The available data indicate that: (a) Oral wounds follow a similar pattern. (b) The tissue specificities of the gingival, alveolar and palatal mucosa appear to be innately and not necessarily functionally determined. (c) The granulation tissue originating from the periodontal ligament or from connective tissue originally covered by keratinized epithelium has the potential to induce keratinization. However, it also appears that deep palatal connective tissue may not have the same potential to induce keratinization as the palatal connective tissue originating from an immediately subepithelial area. (d) Epithelial healing following non-surgical and surgical periodontal therapy appears to be completed after a period of 7–14 days. Structural integrity of a maturing wound between a denuded root surface and a soft tissue flap is achieved at approximately 14-days post-surgery. (e) The formation of the biological width and maturation of the barrier function around transmucosal implants requires 6–8 weeks of healing. (f) The established peri-implant soft connective tissue resembles a scar tissue in composition, fibre orientation, and vasculature. (g) The peri-implant junctional epithelium may reach a greater final length under certain conditions such as implants placed into fresh extraction sockets versus conventional implant procedures in healed sites. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Fabrication of nanocrystalline hydroxyapatite doped degradable composite hollow fiber for guided and biomimetic bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Zhang Ning [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Nichols, Heather L. [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Tylor, Shila [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Wen Xuejun [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States)]. E-mail: xjwen@clemson.edu

2007-04-15

Natural bone tissue possesses a nanocomposite structure interwoven in a three-dimensional (3-D) matrix, which plays critical roles in conferring appropriate physical and biological properties to the bone tissue. Single type of material may not be sufficient to mimic the composition, structure and properties of native bone, therefore, composite materials consisting of both polymers, bioceramics, and other inorganic materials have to be designed. Among a variety of candidate materials, polymer-nanoparticle composites appear most promising for bone tissue engineering applications because of superior mechanical properties, improved durability, and surface bioactivity when compared with conventional polymers or composites. The long term objective of this project is to use highly aligned, bioactive, biodegradable scaffold mimicking natural histological structure of human long bone, and to engineer and regenerate human long bone both in vitro and in vivo. In this study, bioactive, degradable, and highly permeable composite hollow fiber membranes (HFMs) were fabricated using a wet phase phase-inversion approach. The structure of the hollow fiber membranes was examined using scanning electron microscopy (SEM); degradation behavior was examined using weigh loss assay, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC); and bioactivity was evaluated with the amount of calcium deposition from the culture media onto HFM surface. Doping PLGA HFMs with nanoHA results in a more bioactive and slower degrading HFM than pure PLGA HFMs.

Variations in growth, survival and carbon isotope composition (delta(13)C) among Pinus pinaster populations of different geographic origins.

Science.gov (United States)

Correia, Isabel; Almeida, Maria Helena; Aguiar, Alexandre; Alía, Ricardo; David, Teresa Soares; Pereira, João Santos

2008-10-01

To evaluate differences in growth and adaptability of maritime pine (Pinus pinaster Ait.), we studied growth, polycyclism, needle tissue carbon isotope composition (delta(13)C) as an estimate of water-use efficiency (WUE) and survival of seven populations at 10 years of age growing in a performance trial at a provenance test site in Escaroupim, Portugal. Six populations were from relatively high rainfall sites in Portugal and southwestern France (Atlantic group), and one population was from a more arid Mediterranean site in Spain. There were significant differences between some populations in total height, diameter at breast height, delta(13)C of bulk needle tissue, polycyclism and survival. A population from central Portugal (Leiria, on the Atlantic coast) was the tallest and had the lowest delta(13)C. Overall, the variation in delta(13)C was better explained by the mean minimum temperatures of the coldest month than by annual precipitation at the place of origin. Analyses of the relationships between delta(13)C and growth or survival revealed a distinct pattern for the Mediterranean population, with low delta(13)C (and WUE) associated with the lowest growth potential and reduced survival. There were significant negative correlations between delta(13)C and height or survival in the Atlantic group. Variation in polycyclism was correlated with annual precipitation at the place of origin. Some Atlantic populations maintained a high growth potential while experiencing moderate water stress. A detailed knowledge of the relationships between growth, survival and delta(13)C in contrasting environments will enhance our ability to select populations for forestry or conservation.

Fetal subcutaneous tissue measurements in pregnancy as a predictor of neonatal total body composition.

Science.gov (United States)

O'Connor, Clare; Doolan, Anne; O'Higgins, Amy; Segurado, Ricardo; Sheridan-Pereiraet, Margaret; Turner, Michael J; Stuart, Bernard; Kennelly, Máireád M

2014-10-01

The purpose of this study was to examine the relationship between prenatal measures of subcutaneous tissue as surrogate markers of fetal nutritional status and correlate them with neonatal total body composition. This prospective longitudinal study of 62 singleton pregnancies obtained serial biometry and subcutaneous tissue measurements at 28, 33 and 38 weeks gestation. These measurements were then correlated with neonatal body composition, which was analysed using the PEAPOD™ Infant Body Composition System (Cosmed USA, Concord, CA, USA). At 38 weeks gestation, fetal abdominal subcutaneous tissue (FAST) in millimetres was significantly associated with infant fat mass at delivery (+64 g per mm of FAST, p < 0.001). Thigh fat (TF) at 28 weeks gestation was associated with infant fat mass at delivery (+79 g/mm TF, p = 0.023). TF at 38 weeks gestation was associated with infant fat mass (+63/mm TF, p = 0.004). TF and FAST at 38 weeks were also predictive of both birth weight and increased abdominal circumference (AC) (p = 0.001) with FAST measurement predicting an additional 5.7 mm in AC per millimetre of FAST (p = 0.002) and TF predicting an additional 6.9 mm per mm of TF (p = 0.002). We believe that this study further validates the use of prenatal measures of subcutaneous tissue and may help to highlight fetuses at risk of newborn adiposity and metabolic syndrome. © 2014 John Wiley & Sons, Ltd.

A new test phantom with different breast tissue compositions for image quality assessment in conventional and digital mammography

International Nuclear Information System (INIS)

Pachoud, Marc; Lepori, D; Valley, Jean-Francois; Verdun, Francis R

2004-01-01

Our objective is to describe a new test phantom that permits the objective assessment of image quality in conventional and digital mammography for different types of breast tissue. A test phantom, designed to represent a compressed breast, was made from tissue equivalent materials. Three separate regions, with different breast tissue compositions, are used to evaluate low and high contrast resolution, spatial resolution and image noise. The phantom was imaged over a range of kV using a Contour 2000 (Bennett) mammography unit with a Kodak MinR 2190-MinR L screen-film combination and a Senograph 2000D (General Electric) digital mammography unit. Objective image quality assessments for different breast tissue compositions were performed using the phantom for conventional and digital mammography. For a similar mean glandular dose (MGD), the digital system gives a significantly higher contrast-to-noise ratio (CNR) than the screen-film system for 100% glandular tissue. In conclusion, in mammography, a range of exposure conditions is used for imaging because of the different breast tissue compositions encountered clinically. Ideally, the patient dose-image quality relationship should be optimized over the range of exposure conditions. The test phantom presented in this work permits image quality parameters to be evaluated objectively for three different types of breast tissue. Thus, it is a useful tool for optimizing the patient dose-image quality relationship

Determining the origin of cells in tissue engineered skin substitutes: a pilot study employing in situ hybridization.

Science.gov (United States)

Weber, Andreas Daniel; Pontiggia, Luca; Biedermann, Thomas; Schiestl, Clemens; Meuli, Martin; Reichmann, Ernst

2011-03-01

Definitive and high-quality coverage of large and, in particular, massive skin defects remains a significant challenge in burn as well as plastic and reconstructive surgery because of donor site shortage. A novel and promising approach to overcome these problems is tissue engineering of skin. Clearly, before eventual clinical application, engineered skin substitutes of human origin must be grafted and then evaluated in animal models. For the various tests to be conducted it is indispensable to be able to identify human cells as such in culture and also to distinguish between graft and recipient tissue after transplantation. Here we describe a tool to identify human cells in vitro and in vivo. In situ hybridization allows for the detection and localization of specific DNA or RNA sequences in morphologically preserved cells in culture or tissue sections, respectively. We used digoxigenin-labeled DNA probes corresponding to human-specific Alu repeats in order to identify human keratinocytes grown in culture together with rat cells, and also to label split and full thickness skin grafts of human origin after transplantation on immuno-incompetent rats. Digoxigenin-labeled DNA probing resulted in an intensive nuclear staining of human cells, both in culture and after transplantation onto recipient animals, while recipient animal cells (rat cells) did not stain. In situ hybridization using primate-specific Alu probes reliably allows distinguishing between cells of human and non-human origin both in culture as well as in histological sections. This method is an essential tool for those preclinical experiments (performed on non-primate animals) that must be conducted before novel tissue engineered skin substitutes might be introduced into clinical practice.

Composition of MRI phantom equivalent to human tissues

International Nuclear Information System (INIS)

Kato, Hirokazu; Kuroda, Masahiro; Yoshimura, Koichi; Yoshida, Atsushi; Hanamoto, Katsumi; Kawasaki, Shoji; Shibuya, Koichi; Kanazawa, Susumu

2005-01-01

We previously developed two new MRI phantoms (called the CAG phantom and the CAGN phantom), with T1 and T2 relaxation times equivalent to those of any human tissue at 1.5 T. The conductivity of the CAGN phantom is equivalent to that of most types of human tissue in the frequency range of 1 to 130 MHz. In this paper, the relaxation times of human tissues are summarized, and the composition of the corresponding phantoms are provided in table form. The ingredients of these phantoms are carrageenan as the gelling agent, GdCl 3 as a T1 modifier, agarose as a T2 modifier, NaCl (CAGN phantom only) as a conductivity modifier, NaN 3 as an antiseptic, and distilled water. The phantoms have T1 values of 202-1904 ms and T2 values of 38-423 ms when the concentrations of GdCl 3 and agarose are varied from 0-140 μmol/kg, and 0%-1.6%, respectively, and the CAGN phantom has a conductivity of 0.27-1.26 S/m when the NaCl concentration is varied from 0%-0.7%. These phantoms have sufficient strength to replicate a torso without the use of reinforcing agents, and can be cut by a knife into any shape. We anticipate the CAGN phantom to be highly useful and practical for MRI and hyperthermia-related research

Origin and composition of particulate organic matter in a macrotidal turbid estuary: The Gironde Estuary, France

Science.gov (United States)

Savoye, Nicolas; David, Valérie; Morisseau, François; Etcheber, Henri; Abril, Gwenaël; Billy, Isabelle; Charlier, Karine; Oggian, Georges; Derriennic, Hervé; Sautour, Benoît

2012-08-01

At the interface between continent and ocean, estuaries receive particles, and especially particulate organic matter (POM) originating from these two reservoirs, but also produce POM, through autochthonous primary production. The origin and composition of surface POM in the Gironde Estuary (SW France) and the environmental forcing of its variability was investigated using the data set produced by the French Coastal Monitoring Network SOMLIT (Service d'Observation en Milieu LITtoral; monthly like sampling during years 2007-2009). This estuary is considered as a model of macrotidal turbid estuaries. Using elemental and isotopic composition of the POM, we estimated that, at the inner estuary space scale and inter-annual time scale, surface particulate organic carbon (POC) was composed of terrestrial POM originated from the turbidity maximum (96.4%; refractory POC) and flood events (1.6%; labile and refractory POC), and of riverine (0.1%), estuarine (0.8%) and marine (1.1%) phytoplankton, i.e. that POC was 98% and 2% of terrestrial and phytoplankton origin, respectively. However, there was a clear spatial gradient: the phytoplankton contribution increases from ca. 1% in the upper and middle estuary to 8.5% in the lower estuary, where light condition is more favourable to plankton growth. The low contribution of phytoplankton to the POC is a characteristic of the Gironde estuary and contrast with other large temperate estuaries. Statistical analysis indicates that salinity, river flow and SPM concentration, and thus associated hydro-dynamic and sedimentary processes, were the only environmental forcings to the composition of surface POC in this system, at intra- and inter-annual time scale. In contrast, temperature and nutrient concentrations, and thus associated processes, do not force this composition of POC. By combining POC fluxes entering the inner estuary (literature data), POC loss as dissolved organic carbon and CO2 and as sediment trapping within the inner

Richly innervated soft tissues covering the superficial aspect of the extensor origin in patients with chronic painful tennis elbow - Implication for treatment?

Science.gov (United States)

Spang, C; Alfredson, H

2017-06-01

Tennis elbow is difficult to treat. The results of surgical treatments are not convincing. Treatment studies on Achilles and patellar tendinopathy targeting the richly innervated and vascularized soft tissues outside the tendon have shown promising outcomes. The innervation patterns in the fibrous/fatty tissues superficially to the elbow extensor origin have not been clarified. Nine tissue specimens from the fibrous/fatty tissue covering the extensor origin was taken from seven patients (mean age: 45 years) undergoing surgical treatment for chronic painful tennis elbow. The specimens were stained for morphology (haematoxylin and eosin, H and E) and immunohistochemically for general nerve marker protein gene product 9.5 (PGP 9.5) and markers for sympathetic (tyrosine hydroxylase, TH) and sensory nerve fibres (calcitonin gene-related peptide, CGRP). All specimens contained multiple blood vessels and nerve structures indicated by morphology and immunoreactions. There was a frequent occurrence of TH reactions, especially peri-vascularly, but also in nerve fascicles. Immunoreactions for CGRP were seen in nerve fascicles and isolated nerve fibres. The results provide new information on the innervation patterns of the superficial tissues of the extensor origin and their potential as source of tennis elbow pain. IV.

Fatty acid composition of adipose tissue triglycerides after weight loss and weight maintenance

DEFF Research Database (Denmark)

Kunešová, M; Hlavatý, P; Tvrzická, E

2012-01-01

Fatty acid composition of adipose tissue changes with weight loss. Palmitoleic acid as a possible marker of endogenous lipogenesis or its functions as a lipokine are under debate. Objective was to assess the predictive role of adipose triglycerides fatty acids in weight maintenance in participants...... of the DIOGENES dietary intervention study. After an 8-week low calorie diet (LCD) subjects with > 8 % weight loss were randomized to 5 ad libitum weight maintenance diets for 6 months: low protein (P)/low glycemic index (GI) (LP/LGI), low P/high GI (LP/HGI), high P/low GI (HP/LGI), high P/high GI (HP....../HGI), and a control diet. Fatty acid composition in adipose tissue triglycerides was determined by gas chromatography in 195 subjects before the LCD (baseline), after LCD and weight maintenance. Weight change after the maintenance phase was positively correlated with baseline adipose palmitoleic (16:1n-7...

The immune cell composition in Barrett's metaplastic tissue resembles that in normal duodenal tissue.

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Alexandra Lind

Full Text Available BACKGROUND AND OBJECTIVE: Barrett's esophagus (BE is characterized by the transition of squamous epithelium into columnar epithelium with intestinal metaplasia. The increased number and types of immune cells in BE have been indicated to be due to a Th2-type inflammatory process. We tested the alternative hypothesis that the abundance of T-cells in BE is caused by a homing mechanism that is found in the duodenum. PATIENTS AND METHODS: Biopsies from BE and duodenal tissue from 30 BE patients and duodenal tissue from 18 controls were characterized by immmunohistochemistry for the presence of T-cells and eosinophils(eos. Ex vivo expanded T-cells were further phenotyped by multicolor analysis using flowcytometry. RESULTS: The high percentage of CD4(+-T cells (69±3% (mean±SEM/n = 17, by flowcytometry, measured by flowcytometry and immunohistochemistry, and the presence of non-activated eosinophils found in BE by immunohistochemical staining, were not different from that found in duodenal tissue. Expanded lymphocytes from these tissues had a similar phenotype, characterized by a comparable but low percentage of αE(CD103 positive CD4(+cells (44±5% in BE, 43±4% in duodenum of BE and 34±7% in duodenum of controls and a similar percentage of granzyme-B(+CD8(+ cells(44±5% in BE, 33±6% in duodenum of BE and 36±7% in duodenum of controls. In addition, a similar percentage of α4β7(+ T-lymphocytes (63±5% in BE, 58±5% in duodenum of BE and 62±8% in duodenum of controls was found. Finally, mRNA expression of the ligand for α4β7, MAdCAM-1, was also similar in BE and duodenal tissue. No evidence for a Th2-response was found as almost no IL-4(+-T-cells were seen. CONCLUSION: The immune cell composition (lymphocytes and eosinophils and expression of intestinal adhesion molecule MAdCAM-1 is similar in BE and duodenum. This supports the hypothesis that homing of lymphocytes to BE tissue is mainly caused by intestinal homing signals rather than to an

Composite Tissue Transplant of Hand or Arm: A Health Technology Assessment.

Science.gov (United States)

2016-01-01

Injuries to arms and legs following severe trauma can result in the loss of large regions of tissue, disrupting healing and function and sometimes leading to amputation of the damaged limb. People experiencing amputations of the hand or arm could potentially benefit from composite tissue transplant, which is being performed in some countries. Currently, there are no composite tissue transplant programs in Canada. We conducted a systematic review of the literature, with no restriction on study design, examining the effectiveness and cost-effectiveness of hand and arm transplant. We assessed the overall quality of the clinical evidence with GRADE. We developed a Markov decision analytic model to determine the cost-effectiveness of transplant versus standard care for a healthy adult with a hand amputation. Incremental cost-effectiveness ratios (ICERs) were calculated using a 30-year time horizon. We also estimated the impact on provincial health care costs if these transplants were publicly funded in Ontario. Compared to pre-transplant function, patients' post-transplant function was significantly better. For various reasons, 17% of transplanted limbs were amputated, 6.4% of patients died within the first year after the transplant, and 10.6% of patients experienced chronic rejections. GRADE quality of evidence for all outcomes was very low. In the cost-effectiveness analysis, single-hand transplant was dominated by standard care, with increased costs ($735,647 CAD vs. $61,429) and reduced quality-adjusted life-years (QALYs) (10.96 vs. 11.82). Double-hand transplant also had higher costs compared with standard care ($633,780), but it had an increased effectiveness of 0.17 QALYs, translating to an ICER of $3.8 million per QALY gained. In most sensitivity analyses, ICERs for bilateral hand transplant were greater than $1 million per QALY gained. A hand transplant program would lead to an estimated annual budget impact of $0.9 million to $1.2 million in the next 3 years

Attenuation of the gamma rays in tissues

International Nuclear Information System (INIS)

Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Vega C, H.R.

2005-01-01

The mass and lineal attenuation coefficient and of hepatic tissue, muscular, osseous and of brain before gamma rays of 10 -3 to 10 5 MeV were calculated. For the case of the osseous tissue the calculation was made for the cartilage, the cortical tissue and the bone marrow. During the calculations the elementary composition of the tissues of human origin was used. The calculations include by separate the Photoelectric effect, the Compton scattering and the Pair production, as well as the total. For to establish a comparison with the attenuation capacities, the coefficients of the water, the aluminum and the lead also were calculated. The study was complemented measuring the attenuation coefficient of hepatic tissue of bovine before gamma rays of 0.662 MeV of a source of 137 Cs. The measurement was made through of an experiment of photons transmission through samples frozen of hepatic tissue and with a Geiger-Mueller detector. (Author)

Cell-laden hydrogels for osteochondral and cartilage tissue engineering.

Science.gov (United States)

Yang, Jingzhou; Zhang, Yu Shrike; Yue, Kan; Khademhosseini, Ali

2017-07-15

Despite tremendous advances in the field of regenerative medicine, it still remains challenging to repair the osteochondral interface and full-thickness articular cartilage defects. This inefficiency largely originates from the lack of appropriate tissue-engineered artificial matrices that can replace the damaged regions and promote tissue regeneration. Hydrogels are emerging as a promising class of biomaterials for both soft and hard tissue regeneration. Many critical properties of hydrogels, such as mechanical stiffness, elasticity, water content, bioactivity, and degradation, can be rationally designed and conveniently tuned by proper selection of the material and chemistry. Particularly, advances in the development of cell-laden hydrogels have opened up new possibilities for cell therapy. In this article, we describe the problems encountered in this field and review recent progress in designing cell-hydrogel hybrid constructs for promoting the reestablishment of osteochondral/cartilage tissues. Our focus centers on the effects of hydrogel type, cell type, and growth factor delivery on achieving efficient chondrogenesis and osteogenesis. We give our perspective on developing next-generation matrices with improved physical and biological properties for osteochondral/cartilage tissue engineering. We also highlight recent advances in biomanufacturing technologies (e.g. molding, bioprinting, and assembly) for fabrication of hydrogel-based osteochondral and cartilage constructs with complex compositions and microarchitectures to mimic their native counterparts. Despite tremendous advances in the field of regenerative medicine, it still remains challenging to repair the osteochondral interface and full-thickness articular cartilage defects. This inefficiency largely originates from the lack of appropriate tissue-engineered biomaterials that replace the damaged regions and promote tissue regeneration. Cell-laden hydrogel systems have emerged as a promising tissue

Porous starch/cellulose nanofibers composite prepared by salt leaching technique for tissue engineering.

Science.gov (United States)

Nasri-Nasrabadi, Bijan; Mehrasa, Mohammad; Rafienia, Mohammad; Bonakdar, Shahin; Behzad, Tayebeh; Gavanji, Shahin

2014-08-08

Starch/cellulose nanofibers composites with proper porosity pore size, mechanical strength, and biodegradability for cartilage tissue engineering have been reported in this study. The porous thermoplastic starch-based composites were prepared by combining film casting, salt leaching, and freeze drying methods. The diameter of 70% nanofibers was in the range of 40-90 nm. All samples had interconnected porous morphology; however an increase in pore interconnectivity was observed when the sodium chloride ratio was increased in the salt leaching. Scaffolds with the total porogen content of 70 wt% exhibited adequate mechanical properties for cartilage tissue engineering applications. The water uptake ratio of nanocomposites was remarkably enhanced by adding 10% cellulose nanofibers. The scaffolds were partially destroyed due to low in vitro degradation rate after more than 20 weeks. Cultivation of isolated rabbit chondrocytes on the fabricated scaffold proved that the incorporation of nanofibers in starch structure improves cell attachment and proliferation. Copyright © 2014 Elsevier Ltd. All rights reserved.

The biocompatibility of carbon hydroxyapatite/β-glucan composite for bone tissue engineering studied with Raman and FTIR spectroscopic imaging.

Science.gov (United States)

Sroka-Bartnicka, Anna; Kimber, James A; Borkowski, Leszek; Pawlowska, Marta; Polkowska, Izabela; Kalisz, Grzegorz; Belcarz, Anna; Jozwiak, Krzysztof; Ginalska, Grazyna; Kazarian, Sergei G

2015-10-01

The spectroscopic approaches of FTIR imaging and Raman mapping were applied to the characterisation of a new carbon hydroxyapatite/β-glucan composite developed for bone tissue engineering. The composite is an artificial bone material with an apatite-forming ability for the bone repair process. Rabbit bone samples were tested with an implanted bioactive material for a period of several months. Using spectroscopic and chemometric methods, we were able to determine the presence of amides and phosphates and the distribution of lipid-rich domains in the bone tissue, providing an assessment of the composite's bioactivity. Samples were also imaged in transmission using an infrared microscope combined with a focal plane array detector. CaF2 lenses were also used on the infrared microscope to improve spectral quality by reducing scattering artefacts, improving chemometric analysis. The presence of collagen and lipids at the bone/composite interface confirmed biocompatibility and demonstrate the suitability of FTIR microscopic imaging with lenses in studying these samples. It confirmed that the composite is a very good background for collagen growth and increases collagen maturity with the time of the bone growth process. The results indicate the bioactive and biocompatible properties of this composite and demonstrate how Raman and FTIR spectroscopic imaging have been used as an effective tool for tissue characterisation.

Neuroblastoma originating from soft tissue at the crus and its radiological feature

International Nuclear Information System (INIS)

Hirota, Shozo; Hanaguri, Katsuro; Hase, Mamoru; Sako, Masao.

1984-01-01

A very rare case of neuroblastoma originated from soft tissue at the crus in an adult man was reported especially about its radiological feature. Plain X-ray film of the leg showed slight distension of the distance between the tibia and fibula at the proximal portion of the crus. Bone scintigram using sup(99m)Tc-MDP revealed abnormal accumulation at the right upper crus. CT showed a low density mass with smooth margin being at the right upper crus. In femoral angiography, irregular arterial encasement, hypervascular fine tumor vessels, inhomogeneous tumor stain and venous obstruction were shown. Radiological findings made sure the mass to be a primary malignant soft tissue tumor at the right upper crus. Operative finding corroborated the mass to be a malignant one and the tumor extent to correspond to the angiographic diagnosis. The mass was microscopically diagnosed as neuroblastoma. It has been noted that neuroblastoma in childhood had shown extraosseous accumulation of bone seeking agent in a high frequency. Even if in an adult patient, extraosseous accumulation of bone seeking agent in soft tissue tumor, shown in this case, would suggest a mass to be indicative of neuroblastoma. Angiographically, neuroblastoma was said not to show a constant pattern. In the presented case, angiography was very significant in diagnosis of malignancy and tumor extent. (author)

Combined spectroscopic imaging and chemometric approach for automatically partitioning tissue types in human prostate tissue biopsies

Science.gov (United States)

Haka, Abigail S.; Kidder, Linda H.; Lewis, E. Neil

2001-07-01

We have applied Fourier transform infrared (FTIR) spectroscopic imaging, coupling a mercury cadmium telluride (MCT) focal plane array detector (FPA) and a Michelson step scan interferometer, to the investigation of various states of malignant human prostate tissue. The MCT FPA used consists of 64x64 pixels, each 61 micrometers 2, and has a spectral range of 2-10.5 microns. Each imaging data set was collected at 16-1 resolution, resulting in 512 image planes and a total of 4096 interferograms. In this article we describe a method for separating different tissue types contained within FTIR spectroscopic imaging data sets of human prostate tissue biopsies. We present images, generated by the Fuzzy C-Means clustering algorithm, which demonstrate the successful partitioning of distinct tissue type domains. Additionally, analysis of differences in the centroid spectra corresponding to different tissue types provides an insight into their biochemical composition. Lastly, we demonstrate the ability to partition tissue type regions in a different data set using centroid spectra calculated from the original data set. This has implications for the use of the Fuzzy C-Means algorithm as an automated technique for the separation and examination of tissue domains in biopsy samples.

Highly Concentrated Alginate-Gellan Gum Composites for 3D Plotting of Complex Tissue Engineering Scaffolds

Directory of Open Access Journals (Sweden)

Ashwini Rahul Akkineni

2016-04-01

Full Text Available In tissue engineering, additive manufacturing (AM technologies have brought considerable progress as they allow the fabrication of three-dimensional (3D structures with defined architecture. 3D plotting is a versatile, extrusion-based AM technology suitable for processing a wide range of biomaterials including hydrogels. In this study, composites of highly concentrated alginate and gellan gum were prepared in order to combine the excellent printing properties of alginate with the favorable gelling characteristics of gellan gum. Mixtures of 16.7 wt % alginate and 2 or 3 wt % gellan gum were found applicable for 3D plotting. Characterization of the resulting composite scaffolds revealed an increased stiffness in the wet state (15%–20% higher Young’s modulus and significantly lower volume swelling in cell culture medium compared to pure alginate scaffolds (~10% vs. ~23%. Cytocompatibility experiments with human mesenchymal stem cells (hMSC revealed that cell attachment was improved—the seeding efficiency was ~2.5–3.5 times higher on the composites than on pure alginate. Additionally, the composites were shown to support hMSC proliferation and early osteogenic differentiation. In conclusion, print fidelity of highly concentrated alginate-gellan gum composites was comparable to those of pure alginate; after plotting and crosslinking, the scaffolds possessed improved qualities regarding shape fidelity, mechanical strength, and initial cell attachment making them attractive for tissue engineering applications.

Tissue-specific composite cell aggregates drive periodontium tissue regeneration by reconstructing a regenerative microenvironment.

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Zhu, Bin; Liu, Wenjia; Zhang, Hao; Zhao, Xicong; Duan, Yan; Li, Dehua; Jin, Yan

2017-06-01

Periodontitis is the most common cause of periodontium destruction. Regeneration of damaged tissue is the expected treatment goal. However, the regeneration of a functional periodontal ligament (PDL) insertion remains a difficulty, due to complicated factors. Recently, periodontal ligament stem cells (PDLSCs) and bone marrow-derived mesenchymal stem cells (BMMSCs) have been shown to participate in PDL regeneration, both pathologically and physiologically. Besides, interactions affect the biofunctions of different derived cells during the regenerative process. Therefore, the purpose of this study was to discuss the different derived composite cell aggregate (CA) systems of PDLSCs and BMMSCs (iliac-derived or jaw-derived) for periodontium regeneration under regenerative microenvironment reconstruction. Our results showed although all three mono-MSC CAs were compacted and the cells arranged regularly in them, jaw-derived BMMSC (JBMMSC) CAs secreted more extracellular matrix than the others. Furthermore, PDLSC/JBMMSC compound CAs highly expressed ALP, Col-I, fibronectin, integrin-β1 and periostin, suggesting that their biofunction is more appropriate for periodontal structure regeneration. Inspiringly, PDLSC/JBMMSC compound CAs regenerated more functional PDL-like tissue insertions in both nude mice ectopic and minipig orthotopic transplantation. The results indicated that the different derived CAs of PDLSCs/JBMMSCs provided an appropriate regenerative microenvironment facilitating a more stable and regular regeneration of functional periodontium tissue. This method may provide a possible strategy to solve periodontium defects in periodontitis and powerful experimental evidence for clinical applications in the future. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Tissue viscoelasticity is related to tissue composition but may not fully predict the apparent-level viscoelasticity in human trabecular bone – An experimental and finite element study

DEFF Research Database (Denmark)

Ojanen, X.; Tanska, P.; Malo, M. K.H.

2017-01-01

Trabecular bone is viscoelastic under dynamic loading. However, it is unclear how tissue viscoelasticity controls viscoelasticity at the apparent-level. In this study, viscoelasticity of cylindrical human trabecular bone samples (n = 11, male, age 18–78 years) from 11 proximal femurs were charact......). These findings indicate that bone tissue viscoelasticity is affected by tissue composition but may not fully predict the macroscale viscoelasticity in human trabecular bone....

Dietary fat composition influences tissue lipid profile and gene expression in Fischer-344 rats.

Science.gov (United States)

Zhou, Albert L; Hintze, Korry J; Jimenez-Flores, Rafael; Ward, Robert E

2012-12-01

The AIN-76A diet causes fatty liver in rodents when fed for long periods of time. The aim of this study was to utilize fatty acid analysis and transcriptomics to investigate the effects of different fat sources in the AIN-76A diet on tissue lipid profiles and gene expression in male, weanling Fischer-344 rats. Animals were fed isocaloric diets that differed only in the fat source: (1) corn oil (CO) (2) anhydrous milk fat (AMF), and (3) AMF supplemented with 10% phospholipids from the milk fat globule membrane (AMF-MFGM). There were no differences in food intake, body weight, growth rate, or body fat composition among the groups, and the fatty acid compositions of red blood cells (RBC), plasma, muscle, and visceral adipose tissues reflected the dietary fat sources. Modifying the fat source resulted in 293 genes differentially regulated in skeletal muscle, 1,124 in adipose, and 831 in liver as determined by analysis of variance (ANOVA). Although tissue fatty acid profiles mostly reflected the diet, there were several quantitative differences in lipid classes in the liver and plasma. The AMF diet resulted in the highest level of hepatic triacylglycerols, but the lowest level in plasma. The CO diet resulted in significant accumulation of hepatic unesterified fatty acids and decreased DGAT expression and activity, a potential trigger for steatohepatitis. These results indicate that the fatty acid composition and presence of polar lipids in the AIN-76A diets have significant effects on lipid partitioning, gene expression, and potentially the development of liver pathology.

Novel synthesis strategy for composite hydrogel of collagen/hydroxyapatite-microsphere originating from conversion of CaCO3 templates.

Science.gov (United States)

Wei, Qingrong; Lu, Jian; Wang, Qiaoying; Fan, Hongsong; Zhang, Xingdong

2015-03-20

Inspired by coralline-derived hydroxyapatite, we designed a methodological route to synthesize carbonated-hydroxyapatite microspheres from the conversion of CaCO3 spherulite templates within a collagen matrix under mild conditions and thus constructed the composite hydrogel of collagen/hydroxyapatite-microspheres. Fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) were employed to confirm the successful generation of the carbonated hydroxyapatite phase originating from CaCO3, and the ratios of calcium to phosphate were tracked over time. Variations in the weight portion of the components in the hybrid gels before and after the phase transformation of the CaCO3 templates were identified via thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) shows these composite hydrogels have a unique multiscale microstructure consisting of a collagen nanofibril network and hydroxyapatite microspheres. The relationship between the hydroxyapatite nanocrystals and the collagen fibrils was revealed by transmission electron microscopy (TEM) in detail, and the selected area electron diffraction (SAED) pattern further confirmed the results of the XRD analyses which show the typical low crystallinity of the generated hydroxyapatite. This smart synthesis strategy achieved the simultaneous construction of microscale hydroxyapatite particles and collagen fibrillar hydrogel, and appears to provide a novel route to explore an advanced functional hydrogel materials with promising potentials for applications in bone tissue engineering and reconstruction medicine.

Gestational age dependent changes of the fetal brain, liver and adipose tissue fatty acid compositions in a population with high fish intakes

NARCIS (Netherlands)

Kuipers, Remko S.; Luxwolda, Martine F.; Offringa, Pieter J.; Boersma, E. Rudy; Dijck-Brouwer, D. A. Janneke; Muskiet, Frits A. J.

2012-01-01

Introduction: There are no data on the intrauterine fatty acid (FA) compositions of brain, liver and adipose tissue of infants born to women with high fish intakes. Subjects and methods: We analyzed the brain (n = 18), liver (n = 14) and adipose tissue (n = 11) FA compositions of 20 stillborn

Richly innervated soft tissues covering the superficial aspect of the extensor origin in patients with chronic painful tennis elbow – Implication for treatment?

Science.gov (United States)

Spang, C.; Alfredson, H.

2017-01-01

Background: Tennis elbow is difficult to treat. The results of surgical treatments are not convincing. Treatment studies on Achilles and patellar tendinopathy targeting the richly innervated and vascularized soft tissues outside the tendon have shown promising outcomes. The innervation patterns in the fibrous/fatty tissues superficially to the elbow extensor origin have not been clarified. Methods: Nine tissue specimens from the fibrous/fatty tissue covering the extensor origin was taken from seven patients (mean age: 45 years) undergoing surgical treatment for chronic painful tennis elbow. The specimens were stained for morphology (haematoxylin & eosin, H&E) and immunohistochemically for general nerve marker protein gene product 9.5 (PGP 9.5) and markers for sympathetic (tyrosine hydroxylase, TH) and sensory nerve fibres (calcitonin gene-related peptide, CGRP). Results: All specimens contained multiple blood vessels and nerve structures indicated by morphology and immunoreactions. There was a frequent occurrence of TH reactions, especially peri-vascularly, but also in nerve fascicles. Immunoreactions for CGRP were seen in nerve fascicles and isolated nerve fibres. Conclusion: The results provide new information on the innervation patterns of the superficial tissues of the extensor origin and their potential as source of tennis elbow pain. Level of Evidence: IV. PMID:28574416

3D Printing and Electrospinning of Composite Hydrogels for Cartilage and Bone Tissue Engineering

Directory of Open Access Journals (Sweden)

Arianna De Mori

2018-03-01

Full Text Available Injuries of bone and cartilage constitute important health issues costing the National Health Service billions of pounds annually, in the UK only. Moreover, these damages can become cause of disability and loss of function for the patients with associated social costs and diminished quality of life. The biomechanical properties of these two tissues are massively different from each other and they are not uniform within the same tissue due to the specific anatomic location and function. In this perspective, tissue engineering (TE has emerged as a promising approach to address the complexities associated with bone and cartilage regeneration. Tissue engineering aims at developing temporary three-dimensional multicomponent constructs to promote the natural healing process. Biomaterials, such as hydrogels, are currently extensively studied for their ability to reproduce both the ideal 3D extracellular environment for tissue growth and to have adequate mechanical properties for load bearing. This review will focus on the use of two manufacturing techniques, namely electrospinning and 3D printing, that present promise in the fabrication of complex composite gels for cartilage and bone tissue engineering applications.

Genetic origin and composition of a natural hybrid poplar Populus???jrtyschensis from two distantly related species

OpenAIRE

Jiang, Dechun; Feng, Jianju; Dong, Miao; Wu, Guili; Mao, Kangshan; Liu, Jianquan

2016-01-01

Background The factors that contribute to and maintain hybrid zones between distinct species are highly variable, depending on hybrid origins, frequencies and fitness. In this study, we aimed to examine genetic origins, compositions and possible maintenance of Populus???jrtyschensis, an assumed natural hybrid between two distantly related species. This hybrid poplar occurs mainly on the floodplains along the river valleys between the overlapping distributions of the two putative parents. Resu...

Mesenchymal Stem Cell Therapy for Nerve Regeneration and Immunomodulation after Composite Tissue Allotransplantation

Science.gov (United States)

2012-02-01

10-1-0927 TITLE: Mesenchymal Stem Cell Therapy for Nerve Regeneration and Immunomodulation after Composite Tissue Allotransplantation...immunosuppression. Bone Marrow Derived Mesenchymal stem cells (BM-MSCs) are pluripotent cells, capable of differentiation along multiple mesenchymal lineages into...As part of implemented transition from University of Pittsburgh to Johns Hopkins University, we optimized our mesenchymal stem cell (MSC) isolation

SU-F-T-46: The Effect of Inter-Seed Attenuation and Tissue Composition in Prostate 125I Brachytherapy Dose Calculations

Energy Technology Data Exchange (ETDEWEB)

Tamura, K; Araki, F; Ohno, T [Kumamoto University, Kumamoto, Kumamoto (Japan)

2016-06-15

Purpose: To investigate the difference of dose distributions with/without the effect of inter-seed attenuation and tissue compositions in prostate {sup 125}I brachytherapy dose calculations, using Monte Carlo simulations of Particle and Heavy Ion Transport code System (PHITS). Methods: The dose distributions in {sup 125}I prostate brachytherapy were calculated using PHITS for non-simultaneous and simultaneous alignments of STM1251 sources in water or prostate phantom for six patients. The PHITS input file was created from DICOM-RT file which includes source coordinates and structures for clinical target volume (CTV) and organs at risk (OARs) of urethra and rectum, using in-house Matlab software. Photon and electron cutoff energies were set to 1 keV and 100 MeV, respectively. The dose distributions were calculated with the kerma approximation and the voxel size of 1 × 1 × 1 mm{sup 3}. The number of incident photon was set to be the statistical uncertainty (1σ) of less than 1%. The effect of inter-seed attenuation and prostate tissue compositions was evaluated from dose volume histograms (DVHs) for each structure, by comparing to results of the AAPM TG-43 dose calculation (without the effect of inter-seed attenuation and prostate tissue compositions). Results: The dose reduction due to the inter-seed attenuation by source capsules was approximately 2% for CTV and OARs compared to those of TG-43. In additions, by considering prostate tissue composition, the D{sub 90} and V{sub 100} of CTV reduced by 6% and 1%, respectively. Conclusion: It needs to consider the dose reduction due to the inter-seed attenuation and tissue composition in prostate {sup 125}I brachytherapy dose calculations.

The extracellular matrix: Structure, composition, age-related differences, tools for analysis and applications for tissue engineering.

Science.gov (United States)

Kular, Jaspreet K; Basu, Shouvik; Sharma, Ram I

2014-01-01

The extracellular matrix is a structural support network made up of diverse proteins, sugars and other components. It influences a wide number of cellular processes including migration, wound healing and differentiation, all of which is of particular interest to researchers in the field of tissue engineering. Understanding the composition and structure of the extracellular matrix will aid in exploring the ways the extracellular matrix can be utilised in tissue engineering applications especially as a scaffold. This review summarises the current knowledge of the composition, structure and functions of the extracellular matrix and introduces the effect of ageing on extracellular matrix remodelling and its contribution to cellular functions. Additionally, the current analytical technologies to study the extracellular matrix and extracellular matrix-related cellular processes are also reviewed.

Biomineralization of Engineered Spider Silk Protein-Based Composite Materials for Bone Tissue Engineering

Directory of Open Access Journals (Sweden)

John G. Hardy

2016-07-01

Full Text Available Materials based on biodegradable polyesters, such as poly(butylene terephthalate (PBT or poly(butylene terephthalate-co-poly(alkylene glycol terephthalate (PBTAT, have potential application as pro-regenerative scaffolds for bone tissue engineering. Herein, the preparation of films composed of PBT or PBTAT and an engineered spider silk protein, (eADF4(C16, that displays multiple carboxylic acid moieties capable of binding calcium ions and facilitating their biomineralization with calcium carbonate or calcium phosphate is reported. Human mesenchymal stem cells cultured on films mineralized with calcium phosphate show enhanced levels of alkaline phosphatase activity suggesting that such composites have potential use for bone tissue engineering.

Fabrication and in vitro evaluation of a sponge-like bioactive-glass/gelatin composite scaffold for bone tissue engineering

International Nuclear Information System (INIS)

Nadeem, Danish; Kiamehr, Mostafa; Yang, Xuebin; Su, Bo

2013-01-01

In this work a bioactive composite scaffold, comprised of bioactive-glass and gelatin, is introduced. Through direct foaming a sponge-like composite of a sol–gel derived bioactive-glass (70S30C; 70% SiO 2 , 30% CaO) and porcine gelatin was developed for use as a biodegradable scaffold for bone tissue engineering. The composite was developed to provide a suitable alternative to synthetic polymer based scaffolds, allowing directed regeneration of bone tissue. The fabricated scaffold was characterised through X-ray microtomography, scanning electron and light microscopy demonstrating a three dimensionally porous and interconnected structure, with an average pore size (170 μm) suitable for successful cell proliferation and tissue ingrowth. Acellular bioactivity was assessed through apatite formation during submersion in simulated body fluid (SBF) whereby the rate and onset of apatite nucleation was found to be comparable to that of bioactive-glass. Modification of dehydrothermal treatment parameters induced varying degrees of crosslinking, allowing the degradation of the composite to be tailored to suit specific applications and establishing its potential for a wide range of applications. Use of genipin to supplement crosslinking by dehydrothermal treatment provided further means of modifying degradability. Biocompatibility of the composite was qualified through successful cultures of human dental pulp stem cells (HDPSCs) on samples of the composite scaffold. Osteogenic differentiation of HDPSCs and extracellular matrix deposition were confirmed through positive alkaline phosphatase staining and immunohistochemistry. - Highlights: ► Optimised composition and fabrication produced sponge-like porosity (pore size ∼ 170 μm). ► Maximum aqueous stability via dehydrothermal treatment at 145 °C, for 48 h ► Biocompatibility and osteogenic potential confirmed via successful HDPSC cultures. ► Minimal toxicity exhibited in optimally crosslinked samples (10 m

Fabrication and in vitro evaluation of a sponge-like bioactive-glass/gelatin composite scaffold for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Nadeem, Danish [Biomaterials Engineering Group, School of Oral and Dental Sciences, University of Bristol, BS1 2LY (United Kingdom); Kiamehr, Mostafa [Biomaterials and Tissue Engineering Group, Leeds Dental Institute, University of Leeds, LS2 9LU (United Kingdom); Yang, Xuebin [Biomaterials and Tissue Engineering Group, Leeds Dental Institute, University of Leeds, LS2 9LU (United Kingdom); NIHR Leeds Musculoskeletal Biomedical Research Unit, Chapel Allerton Hospital, Leeds LS7 4SA (United Kingdom); Su, Bo, E-mail: b.su@bristol.ac.uk [Biomaterials Engineering Group, School of Oral and Dental Sciences, University of Bristol, BS1 2LY (United Kingdom)

2013-07-01

In this work a bioactive composite scaffold, comprised of bioactive-glass and gelatin, is introduced. Through direct foaming a sponge-like composite of a sol–gel derived bioactive-glass (70S30C; 70% SiO{sub 2}, 30% CaO) and porcine gelatin was developed for use as a biodegradable scaffold for bone tissue engineering. The composite was developed to provide a suitable alternative to synthetic polymer based scaffolds, allowing directed regeneration of bone tissue. The fabricated scaffold was characterised through X-ray microtomography, scanning electron and light microscopy demonstrating a three dimensionally porous and interconnected structure, with an average pore size (170 μm) suitable for successful cell proliferation and tissue ingrowth. Acellular bioactivity was assessed through apatite formation during submersion in simulated body fluid (SBF) whereby the rate and onset of apatite nucleation was found to be comparable to that of bioactive-glass. Modification of dehydrothermal treatment parameters induced varying degrees of crosslinking, allowing the degradation of the composite to be tailored to suit specific applications and establishing its potential for a wide range of applications. Use of genipin to supplement crosslinking by dehydrothermal treatment provided further means of modifying degradability. Biocompatibility of the composite was qualified through successful cultures of human dental pulp stem cells (HDPSCs) on samples of the composite scaffold. Osteogenic differentiation of HDPSCs and extracellular matrix deposition were confirmed through positive alkaline phosphatase staining and immunohistochemistry. - Highlights: ► Optimised composition and fabrication produced sponge-like porosity (pore size ∼ 170 μm). ► Maximum aqueous stability via dehydrothermal treatment at 145 °C, for 48 h ► Biocompatibility and osteogenic potential confirmed via successful HDPSC cultures. ► Minimal toxicity exhibited in optimally crosslinked samples (10 m

Advancing biomaterials of human origin for tissue engineering

OpenAIRE

Chen, Fa-Ming; Liu, Xiaohua

2015-01-01

Biomaterials have played an increasingly prominent role in the success of biomedical devices and in the development of tissue engineering, which seeks to unlock the regenerative potential innate to human tissues/organs in a state of deterioration and to restore or reestablish normal bodily function. Advances in our understanding of regenerative biomaterials and their roles in new tissue formation can potentially open a new frontier in the fast-growing field of regenerative medicine. Taking in...

The origin and composition of cucurbit "phloem" exudate.

Science.gov (United States)

Zhang, Cankui; Yu, Xiyan; Ayre, Brian G; Turgeon, Robert

2012-04-01

Cucurbits exude profusely when stems or petioles are cut. We conducted studies on pumpkin (Cucurbita maxima) and cucumber (Cucumis sativus) to determine the origin and composition of the exudate. Morphometric analysis indicated that the exudate is too voluminous to derive exclusively from the phloem. Cold, which inhibits phloem transport, did not interfere with exudation. However, ice water applied to the roots, which reduces root pressure, rapidly diminished exudation rate. Sap was seen by microscopic examination to flow primarily from the fascicular phloem in cucumber, and several other cucurbit species, but primarily from the extrafascicular phloem in pumpkin. Following exposure of leaves to 14CO2, radiolabeled stachyose and other sugars were detected in the exudate in proportions expected of authentic phloem sap. Most of this radiolabel was released during the first 20 s. Sugars in exudate were dilute. The sugar composition of exudate from extrafascicular phloem near the edge of the stem differed from that of other sources in that it was high in hexose and low in stachyose. We conclude that sap is released from cucurbit phloem upon wounding but contributes negligibly to total exudate volume. The sap is diluted by water from cut cells, the apoplast, and the xylem. Small amounts of dilute, mobile sap from sieve elements can be obtained, although there is evidence that it is contaminated by the contents of other cell types. The function of P-proteins may be to prevent water loss from the xylem as well as nutrient loss from the phloem.

Exposure of tumor-bearing mice to extremely high-frequency electromagnetic radiation modifies the composition of fatty acids in thymocytes and tumor tissue.

Science.gov (United States)

Gapeyev, Andrew B; Kulagina, Tatiana P; Aripovsky, Alexander V

2013-08-01

To test the participation of fatty acids (FA) in antitumor effects of extremely high-frequency electromagnetic radiation (EHF EMR), the changes in the FA composition in the thymus, liver, blood plasma, muscle tissue, and tumor tissue in mice with Ehrlich solid carcinoma exposed to EHF EMR were studied. Normal and tumor-bearing mice were exposed to EHF EMR with effective parameters (42.2 GHz, 0.1 mW/cm2, 20 min daily during five consecutive days beginning the first day after the inoculation of tumor cells). Fatty acid composition of various organs and tissues of mice were determined using a gas chromatography. It was shown that the exposure of normal mice to EHF EMR or tumor growth significantly increased the content of monounsaturated FA (MUFA) and decreased the content of polyunsaturated FA (PUFA) in all tissues examined. Exposure of tumor-bearing mice to EHF EMR led to the recovery of FA composition in thymocytes to the state that is typical for normal animals. In other tissues of tumor-bearing mice, the exposure to EHF EMR did not induce considerable changes that would be significantly distinguished between disturbances caused by EHF EMR exposure or tumor growth separately. In tumor tissue which is characterized by elevated level of MUFA, the exposure to EHF EMR significantly decreased the summary content of MUFA and increased the summary content of PUFA. The recovery of the FA composition in thymocytes and the modification of the FA composition in the tumor under the influence of EHF EMR on tumor-bearing animals may have crucial importance for elucidating the mechanisms of antitumor effects of the electromagnetic radiation.

In vitro evaluation of alginate/halloysite nanotube composite scaffolds for tissue engineering

International Nuclear Information System (INIS)

Liu, Mingxian; Dai, Libing; Shi, Huizhe; Xiong, Sheng; Zhou, Changren

2015-01-01

In this study, a series of alginate/halloysite nanotube (HNTs) composite scaffolds were prepared by solution-mixing and freeze-drying method. HNTs are incorporated into alginate to improve both the mechanical and cell-attachment properties of the scaffolds. The interfacial interactions between alginate and HNTs were confirmed by the atomic force microscope (AFM), transmission electron microscope (TEM) and FTIR spectroscopy. The mechanical, morphological, and physico-chemical properties of the composite scaffolds were investigated. The composite scaffolds exhibit significant enhancement in compressive strength and compressive modulus compared with pure alginate scaffold both in dry and wet states. A well-interconnected porous structure with size in the range of 100–200 μm and over 96% porosity is found in the composite scaffolds. X-ray diffraction (XRD) result shows that HNTs are uniformly dispersed and partly oriented in the composite scaffolds. The incorporation of HNTs leads to increase in the scaffold density and decrease in the water swelling ratio of alginate. HNTs improve the stability of alginate scaffolds against enzymatic degradation in PBS solution. Thermogravimetrica analysis (TGA) shows that HNTs can improve the thermal stability of the alginate. The mouse fibroblast cells display better attachment to the alginate/HNT composite than those to the pure alginate, suggesting the good cytocompatibility of the composite scaffolds. Alginate/HNT composite scaffolds exhibit great potential for applications in tissue engineering. - Highlights: • We fabricated HNTs reinforced alginate composite scaffolds for biomedical applications. • The hydrogen bond interactions between HNTs and alginate are confirmed. • HNTs can significantly enhance the mechanical properties of alginate scaffold. • The scaffolds exhibit a highly porous structure with interconnected pores. • HNTs can improve the cell attachment and proliferation on alginate

In vitro evaluation of alginate/halloysite nanotube composite scaffolds for tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Liu, Mingxian [Department of Materials Science and Engineering, Jinan University, Guangzhou 510632 (China); Dai, Libing [Guangzhou Institute of Traumatic Surgery, Guangzhou Red Cross Hospital Medical College, Jinan University, Guangzhou 510220 (China); Shi, Huizhe; Xiong, Sheng [Institute of Biomedicine, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou 510632 (China); Zhou, Changren, E-mail: tcrz9@jnu.edu.cn [Department of Materials Science and Engineering, Jinan University, Guangzhou 510632 (China)

2015-04-01

In this study, a series of alginate/halloysite nanotube (HNTs) composite scaffolds were prepared by solution-mixing and freeze-drying method. HNTs are incorporated into alginate to improve both the mechanical and cell-attachment properties of the scaffolds. The interfacial interactions between alginate and HNTs were confirmed by the atomic force microscope (AFM), transmission electron microscope (TEM) and FTIR spectroscopy. The mechanical, morphological, and physico-chemical properties of the composite scaffolds were investigated. The composite scaffolds exhibit significant enhancement in compressive strength and compressive modulus compared with pure alginate scaffold both in dry and wet states. A well-interconnected porous structure with size in the range of 100–200 μm and over 96% porosity is found in the composite scaffolds. X-ray diffraction (XRD) result shows that HNTs are uniformly dispersed and partly oriented in the composite scaffolds. The incorporation of HNTs leads to increase in the scaffold density and decrease in the water swelling ratio of alginate. HNTs improve the stability of alginate scaffolds against enzymatic degradation in PBS solution. Thermogravimetrica analysis (TGA) shows that HNTs can improve the thermal stability of the alginate. The mouse fibroblast cells display better attachment to the alginate/HNT composite than those to the pure alginate, suggesting the good cytocompatibility of the composite scaffolds. Alginate/HNT composite scaffolds exhibit great potential for applications in tissue engineering. - Highlights: • We fabricated HNTs reinforced alginate composite scaffolds for biomedical applications. • The hydrogen bond interactions between HNTs and alginate are confirmed. • HNTs can significantly enhance the mechanical properties of alginate scaffold. • The scaffolds exhibit a highly porous structure with interconnected pores. • HNTs can improve the cell attachment and proliferation on alginate.

Development of an injectable chitosan/marine collagen composite gel

International Nuclear Information System (INIS)

Wang Wei; Itoh, Soichiro; Aizawa, Tomoyasu; Demura, Makoto; Okawa, Atsushi; Sakai, Katsuyoshi; Ohkuma, Tsuneo

2010-01-01

A chitosan/marine-originated collagen composite has been developed. This composite gel was characterized and its biocompatibility, as well as an inflammatory reaction, was observed. The chitosan gel including N-3-carboxypropanoil-6-O-(carboxymethyl) chitosan of 3 mol%, 6-O-(carboxymethyl) chitosan of 62 mol% and 6-O-(carboxymethyl) chitin of 35 mol% was prepared and compounded with the salmon atelocollagen (SA) gel at different mixture ratios. The composite gels were injected subcutaneously in to the back of rats. The specimens were harvested for a histological survey as well as a tumor necrosis factor-alpha (TNF-α) assay by ELISA. The inflammatory cell infiltration and release of TNF-α were successively controlled low with the ratio of SA to chitosan at 10:90 or 20:80. The SA gel first, within 2 weeks, and then chitosan in the composite gel were slowly absorbed after implantation, followed by soft tissue formation. It is expected that this composite gel will be available as a carrier for tissue filler and drug delivery systems.

Preparation and comparative characterization of keratin–chitosan and keratin–gelatin composite scaffolds for tissue engineering applications

International Nuclear Information System (INIS)

Balaji, S.; Kumar, Ramadhar; Sripriya, R.; Kakkar, Prachi; Ramesh, D. Vijaya; Reddy, P. Neela Kanta; Sehgal, P.K.

2012-01-01

We report fabrication of three dimensional scaffolds with well interconnected matrix of high porosity using keratin, chitosan and gelatin for tissue engineering and other biomedical applications. Scaffolds were fabricated using porous Keratin–Gelatin (KG), Keratin–Chitosan (KC) composites. The morphology of both KG and KC was investigated using SEM. The scaffolds showed high porosity with interconnected pores in the range of 20–100 μm. They were further tested by FTIR, DSC, CD, tensile strength measurement, water uptake and swelling behavior. In vitro cell adhesion and cell proliferation tests were carried out to study the biocompatibility behavior and their application as an artificial skin substitute. Both KG and KC composite scaffolds showed similar properties and patterns for cell proliferation. Due to rapid degradation of gelatin in KG, we found that it has limited application as compared to KC scaffold. We conclude that KC scaffold owing to its slow degradation and antibacterial properties would be a better substrate for tissue engineering and other biomedical application. Highlights: ► Extraction of reduced keratin from horn meal. ► Preparation of keratin–gelatin and keratin–chitosan composite scaffolds. ► Characterizations of the composite scaffolds. ► Comparative cytotoxicity analysis on NIH3T3 fibroblasts.

Fabrication of Chitin/Poly(butylene succinate/Chondroitin Sulfate Nanoparticles Ternary Composite Hydrogel Scaffold for Skin Tissue Engineering

Directory of Open Access Journals (Sweden)

S. Deepthi

2014-12-01

Full Text Available Skin loss is one of the oldest and still not totally resolved problems in the medical field. Since spontaneous healing of the dermal defects would not occur, the regeneration of full thickness of skin requires skin substitutes. Tissue engineering constructs would provide a three dimensional matrix for the reconstruction of skin tissue and the repair of damage. The aim of the present work is to develop a chitin based scaffold, by blending it with poly(butylene succinate (PBS, an aliphatic, biodegradable and biocompatible synthetic polymer with excellent mechanical properties. The presence of chondroitin sulfate nanoparticles (CSnp in the scaffold would favor cell adhesion. A chitin/PBS/CSnp composite hydrogel scaffold was developed and characterized by SEM (Scanning Electron Microscope, FTIR (Fourier Transform Infrared Spectroscopy, and swelling ratio of scaffolds were analyzed. The scaffolds were evaluated for the suitability for skin tissue engineering application by cytotoxicity, cell attachment, and cell proliferation studies using human dermal fibroblasts (HDF. The cytotoxicity and cell proliferation studies using HDF confirm the suitability of the scaffold for skin regeneration. In short, these results show promising applicability of the developed chitin/PBS/CSnps ternary composite hydrogel scaffolds for skin tissue regeneration.

Fabrication and Properties of Silica Gel/Calcium Sulfate/Strontium-doped β-tricalcium Phosphate Composite Porous Scaffolds for Bone Tissue Engineering

Directory of Open Access Journals (Sweden)

QIN Xiao-su

2018-03-01

Full Text Available The calcium sulfate/strontium-doped β-tricalcium phosphate composite spherical pellets was fabricated, using the calcium sulfate/strontium-doped β-TCP as raw material, and through the stirring spray drying method, and then composite spherical pellets were combined with silica gel, porous silica gel/calcium sulfate/strontium-doped β-tricalcium phosphate scaffold was obtained by stacking aggregation method in the mould. The XRD, SEM and FT-IR, etc are employed to examine the chemical composition, composite morphology and structure characteristics, and the degradability, porosity, mechanical properties and cytotoxicity of the scaffolds materials were studied. The results reveal that the composite porous scaffolds have irregular pore structure with pore size between 0.2-1.0mm, and they have a large number of micropores on each of the composite spherical pellets, with the aperture between 50-200μm. Moreover, the porosity of the composite scaffolds is about 62%, which can meet the requirements of scaffolds for bone tissue engineering in porosity; the cytotoxicity tests show the composite scaffolds have no cytotoxic effect and it has good degradation. Therefore, it has good application prospect in bone tissue engineering of the bone defect repair of non-bearing site.

Effect of physical exercise on blood lipids and adipose tissue composition in young healthy men

NARCIS (Netherlands)

Danner, S. A.; Wieling, W.; Havekes, L.; Leuven, J. G.; Smit, E. M.; Dunning, A. J.

1984-01-01

In a prospective, controlled study, the influence of strenuous physical exercise on plasma total cholesterol, HDL cholesterol, apolipoprotein A-I, total triglycerides and fatty acid composition of adipose tissue was studied during 7 months of training in 15 senior oarsmen and 21 controls matched for

A Practical Standardized Composite Nutrition Score Based on Lean Tissue Index: Application in Nutrition Screening and Prediction of Outcome in Hemodialysis Population.

Science.gov (United States)

Chen, Huan-Sheng; Cheng, Chun-Ting; Hou, Chun-Cheng; Liou, Hung-Hsiang; Chang, Cheng-Tsung; Lin, Chun-Ju; Wu, Tsai-Kun; Chen, Chang-Hsu; Lim, Paik-Seong

2017-07-01

Rapid screening and monitoring of nutritional status is mandatory in hemodialysis population because of the increasingly encountered nutritional problems. Considering the limitations of previous composite nutrition scores applied in this population, we tried to develop a standardized composite nutrition score (SCNS) using low lean tissue index as a marker of protein wasting to facilitate clinical screening and monitoring and to predict outcome. This retrospective cohort used 2 databases of dialysis populations from Taiwan between 2011 and 2014. First database consisting of data from 629 maintenance hemodialysis patients was used to develop the SCNS and the second database containing data from 297 maintenance hemodialysis patients was used to validate this developed score. SCNS containing albumin, creatinine, potassium, and body mass index was developed from the first database using low lean tissue index as a marker of protein wasting. When applying this score in the original database, significantly higher risk of developing protein wasting was found for patients with lower SCNS (odds ratio 1.38 [middle tertile vs highest tertile, P < .0001] and 2.40 [lowest tertile vs middle tertile, P < .0001]). The risk of death was also shown to be higher for patients with lower SCNS (hazard ratio 4.45 [below median level vs above median level, P < .0001]). These results were validated in the second database. We developed an SCNS consisting of 4 easily available biochemical parameters. This kind of scoring system can be easily applied in different dialysis facilities for screening and monitoring of protein wasting. The wide application of body composition monitor in dialysis population will also facilitate the development of specific nutrition scoring model for individual facility. Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Macronutrient composition determines accumulation of persistent organic pollutants from dietary exposure in adipose tissue of mice

DEFF Research Database (Denmark)

Myrmel, Lene Secher; Fjære, Even; Midtbø, Lisa Kolden

2016-01-01

in metabolism and elimination of xenobiotics. Exposure to POPs, either as single compounds or mixtures, had no effect on obesity development, glucose tolerance or insulin sensitivity. In conclusion, this study demonstrates that the dietary composition of macronutrients profoundly modulates POP accumulation...... in adipose tissues adding an additional parameter to be included in future studies. Our results indicate that alterations in macronutrient composition might be an additional route for reducing total body burden of POPs....

The adipose tissue of origin influences the biological potential of human adipose stromal cells isolated from mediastinal and subcutaneous fat depots

Directory of Open Access Journals (Sweden)

Camilla Siciliano

2016-09-01

Full Text Available Indirect evidence suggests that adipose tissue-derived stromal cells (ASCs possess different physiological and biological variations related to the anatomical localization of the adipose depots. Accordingly, to investigate the influence of the tissue origin on the intrinsic properties of ASCs and to assess their response to specific stimuli, we compared the biological, functional and ultrastructural properties of two ASC pools derived from mediastinal and subcutaneous depots (thoracic compartment by means of supplements such as platelet lysate (PL and FBS. Subcutaneous ASCs exhibited higher proliferative and clonogenic abilities than mediastinal counterpart, as well as increased secreted levels of IL-6 combined with lower amount of VEGF-C. In contrast, mediastinal ASCs displayed enhanced pro-angiogenic and adipogenic differentiation properties, increased cell diameter and early autophagic processes, highlighted by electron microscopy. Our results further support the hypothesis that the origin of adipose tissue significantly defines the biological properties of ASCs, and that a homogeneric function for all ASCs cannot be assumed.

The Relationship between Ethnic Classroom Composition and Turkish-Origin and German Students' Reading Performance and Sense of Belonging.

Science.gov (United States)

Mok, Sog Yee; Martiny, Sarah E; Gleibs, Ilka H; Keller, Melanie M; Froehlich, Laura

2016-01-01

Past research on ethnic composition effects on migrant and ethnic majority students' performance has reported inconclusive results: Some studies have found no relationship between the proportion of migrant students in school and students' performance, some revealed positive effects, whereas others showed negative effects of the proportion of migrant students. Most of the studies did not consider whether an increase in the proportion of migrant students in the classroom has different effects on migrant and ethnic majority students' performance. For this reason, the present study (N = 9215) extends previous research by investigating the cross-level interaction effect of the proportion of Turkish-origin students in classrooms on Turkish-origin and German students' reading performance with data based on the German National Assessment Study 2008/2009 in the school subject German. In addition, we examined the cross-level interaction effect of Turkish-origin students' proportion on sense of belonging to school for Turkish-origin and German students, as sense of belonging has been shown to be an important predictor of well-being and integration. No cross-level interaction effect on performance emerged. Only a small negative main effect of the Turkish-origin students' proportion on all students' performance was found. As predicted, we showed a cross-level interaction on sense of belonging. Only Turkish-origin students' sense of belonging was positively related to the proportion of Turkish-origin students: The more Turkish-origin students there were in a classroom, the higher Turkish-origin students' sense of belonging. German students' sense of belonging was not related to the ethnic classroom composition. Implications of the results in the educational context are discussed.

STEM CELL ORIGIN DIFFERENTLY AFFECTS BONE TISSUE ENGINEERING STRATEGIES.

Directory of Open Access Journals (Sweden)

Monica eMattioli-Belmonte

2015-09-01

Full Text Available Bone tissue engineering is a promising research area for the improvement of traditional bone grafting procedure drawbacks. Thanks to the capability of self-renewal and multi-lineage differentiation, stem cells are one of the major actors in tissue engineering approaches, and adult mesenchymal stem cells (MSCs are considered to be appropriate for regenerative medicine strategies. Bone marrow MSCs (BM-MSCs are the earliest- discovered and well-known stem cell population used in bone tissue engineering. However, several factors hamper BM-MSC clinical application and subsequently, new stem cell sources have been investigated for these purposes. The successful identification and combination of tissue engineering, scaffold, progenitor cells, and physiologic signalling molecules enabled the surgeon to design, recreate the missing tissue in its near natural form. On the basis of these considerations, we analysed the capability of two different scaffolds, planned for osteochondral tissue regeneration, to modulate differentiation of adult stem cells of dissimilar local sources (i.e. periodontal ligament, maxillary periosteum as well as adipose-derived stem cells, in view of possible craniofacial tissue engineering strategies. We demonstrated that cells are differently committed toward the osteoblastic phenotype and therefore, considering their peculiar features, they may alternatively represent interesting cell sources in different stem cell-based bone/periodontal tissue regeneration approaches.

Fiber/collagen composites for ligament tissue engineering: influence of elastic moduli of sparse aligned fibers on mesenchymal stem cells.

Science.gov (United States)

Thayer, Patrick S; Verbridge, Scott S; Dahlgren, Linda A; Kakar, Sanjeev; Guelcher, Scott A; Goldstein, Aaron S

2016-08-01

Electrospun microfibers are attractive for the engineering of oriented tissues because they present instructive topographic and mechanical cues to cells. However, high-density microfiber networks are too cell-impermeable for most tissue applications. Alternatively, the distribution of sparse microfibers within a three-dimensional hydrogel could present instructive cues to guide cell organization while not inhibiting cell behavior. In this study, thin (∼5 fibers thick) layers of aligned microfibers (0.7 μm) were embedded within collagen hydrogels containing mesenchymal stem cells (MSCs), cultured for up to 14 days, and assayed for expression of ligament markers and imaged for cell organization. These microfibers were generated through the electrospinning of polycaprolactone (PCL), poly(ester-urethane) (PEUR), or a 75/25 PEUR/PCL blend to produce microfiber networks with elastic moduli of 31, 15, and 5.6 MPa, respectively. MSCs in composites containing 5.6 MPa fibers exhibited increased expression of the ligament marker scleraxis and the contractile phenotype marker α-smooth muscle actin versus the stiffer fiber composites. Additionally, cells within the 5.6 MPa microfiber composites were more oriented compared to cells within the 15 and 31 MPa microfiber composites. Together, these data indicate that the mechanical properties of microfiber/collagen composites can be tuned for the engineering of ligament and other target tissues. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1894-1901, 2016. © 2016 Wiley Periodicals, Inc.

Amino acid composition in determination of collagen origin and assessment of physical factors effects.

Science.gov (United States)

Gauza-Włodarczyk, Marlena; Kubisz, Leszek; Włodarczyk, Dariusz

2017-11-01

The amino acid composition of collagen is a characteristic feature of this protein. Collagen, irrespective of its origin, contains 19 amino acids, including hydroxyproline which does not occur in other proteins. Its atypical amino acid composition is characterized by high content of proline and glycine, as well as the absence of cysteine. This paper shows the comparison of qualitative composition of amino acids of fish skin (FS) collagen, bovine Achilles tendon (BAT) collagen, and bone collagen. Results demonstrate that FS collagen as well as BAT collagen contains no cysteine and significantly different amount of hydroxyproline. In BAT collagen hydroxyproline content is 30% higher than hydroxyproline content of FS collagen. In bone collagen the amount of hydroxyproline is two times more than in FS collagen. Furthermore, it is shown that sensitivity to radiation of individual amino acids varies and depends on the absorbed dose of ionizing radiation. The changes observed in the amino acid composition become very intense for the doses of 500kGy and 1000kGy. Copyright © 2017 Elsevier B.V. All rights reserved.

A Novel High Mechanical Property PLGA Composite Matrix Loaded with Nanodiamond-Phospholipid Compound for Bone Tissue Engineering.

Science.gov (United States)

Zhang, Fan; Song, Qingxin; Huang, Xuan; Li, Fengning; Wang, Kun; Tang, Yixing; Hou, Canglong; Shen, Hongxing

2016-01-20

A potential bone tissue engineering material was produced from a biodegradable polymer, poly(lactic-co-glycolic acid) (PLGA), loaded with nanodiamond phospholipid compound (NDPC) via physical mixing. On the basis of hydrophobic effects and physical absorption, we modified the original hydrophilic surface of the nanodiamond (NDs) with phospholipids to be amphipathic, forming a typical core-shell structure. The ND-phospholipid weight ratio was optimized to generate sample NDPC50 (i.e., ND-phospholipid weight ratio of 100:50), and NDPC50 was able to be dispersed in a PLGA matrix at up to 20 wt %. Compared to a pure PLGA matrix, the introduction of 10 wt % of NDPC (i.e., sample NDPC50-PF10) resulted in a significant improvement in the material's mechanical and surface properties, including a decrease in the water contact angle from 80 to 55°, an approximately 100% increase in the Young's modulus, and an approximate 550% increase in hardness, thus closely resembling that of human cortical bone. As a novel matrix supporting human osteoblast (hFOB1.19) growth, NDPC50-PFs with different amounts of NDPC50 demonstrated no negative effects on cell proliferation and osteogenic differentiation. Furthermore, we focused on the behaviors of NDPC-PFs implanted into mice for 8 weeks and found that NDPC-PFs induced acceptable immune response and can reduce the rapid biodegradation of PLGA matrix. Our results represent the first in vivo research on ND (or NDPC) as nanofillers in a polymer matrix for bone tissue engineering. The high mechanical properties, good in vitro and in vivo biocompatibility, and increased mineralization capability suggest that biodegradable PLGA composite matrices loaded with NDPC may potentially be useful for a variety of biomedical applications, especially bone tissue engineering.

Greener synthesis of electrospun collagen/hydroxyapatite composite fibers with an excellent microstructure for bone tissue engineering

Science.gov (United States)

Zhou, Yuanyuan; Yao, Hongchang; Wang, Jianshe; Wang, Dalu; Liu, Qian; Li, Zhongjun

2015-01-01

In bone tissue engineering, collagen/hydroxyapatite (HAP) fibrous composite obtained via electrospinning method has been demonstrated to support the cells’ adhesion and bone regeneration. However, electrospinning of natural collagen often requires the use of cytotoxic organic solvents, and the HAP crystals were usually aggregated and randomly distributed within a fibrous matrix of collagen, limiting their clinical potential. Here, an effective and greener method for the preparation of collagen/HAP composite fibers was developed for the first time, and this green product not only had 40 times higher mechanical properties than that previously reported, but also had an excellent microstructure similar to that of natural bone. By dissolving type I collagen in environmentally friendly phosphate buffered saline/ethanol solution instead of the frequently-used cytotoxic organic solvents, followed with the key step of desalination, co-electrospinning the collagen solution with the HAP sol, generates a collagen/HAP composite with a uniform and continuous fibrous morphology. Interestingly, the nano-HAP needles were found to preferentially orient along the longitudinal direction of the collagen fibers, which mimicked the nanostructure of natural bones. Based on the characterization of the related products, the formation mechanism for this novel phenomenon was proposed. After cross-linking with 1-ethyl-3-(3-dimethyl-aminopropyl)-1-carbodiimide hydrochloride/N-hydroxysuccinimide, the obtained composite exhibited a significant enhancement in mechanical properties. In addition, the biocompatibility of the obtained composite fibers was evaluated by in vitro culture of the human myeloma cells (U2-OS). Taken together, the process outlined herein provides an effective, non-toxic approach for the fabrication of collagen/HAP composite nanofibers that could be good candidates for bone tissue engineering. PMID:25995630

Non-invasive optical estimate of tissue composition to differentiate malignant from benign breast lesions: A pilot study

Science.gov (United States)

Taroni, Paola; Paganoni, Anna Maria; Ieva, Francesca; Pifferi, Antonio; Quarto, Giovanna; Abbate, Francesca; Cassano, Enrico; Cubeddu, Rinaldo

2017-01-01

Several techniques are being investigated as a complement to screening mammography, to reduce its false-positive rate, but results are still insufficient to draw conclusions. This initial study explores time domain diffuse optical imaging as an adjunct method to classify non-invasively malignant vs benign breast lesions. We estimated differences in tissue composition (oxy- and deoxyhemoglobin, lipid, water, collagen) and absorption properties between lesion and average healthy tissue in the same breast applying a perturbative approach to optical images collected at 7 red-near infrared wavelengths (635-1060 nm) from subjects bearing breast lesions. The Discrete AdaBoost procedure, a machine-learning algorithm, was then exploited to classify lesions based on optically derived information (either tissue composition or absorption) and risk factors obtained from patient’s anamnesis (age, body mass index, familiarity, parity, use of oral contraceptives, and use of Tamoxifen). Collagen content, in particular, turned out to be the most important parameter for discrimination. Based on the initial results of this study the proposed method deserves further investigation.

Automated segmentation of muscle and adipose tissue on CT images for human body composition analysis

Science.gov (United States)

Chung, Howard; Cobzas, Dana; Birdsell, Laura; Lieffers, Jessica; Baracos, Vickie

2009-02-01

The ability to compute body composition in cancer patients lends itself to determining the specific clinical outcomes associated with fat and lean tissue stores. For example, a wasting syndrome of advanced disease associates with shortened survival. Moreover, certain tissue compartments represent sites for drug distribution and are likely determinants of chemotherapy efficacy and toxicity. CT images are abundant, but these cannot be fully exploited unless there exist practical and fast approaches for tissue quantification. Here we propose a fully automated method for segmenting muscle, visceral and subcutaneous adipose tissues, taking the approach of shape modeling for the analysis of skeletal muscle. Muscle shape is represented using PCA encoded Free Form Deformations with respect to a mean shape. The shape model is learned from manually segmented images and used in conjunction with a tissue appearance prior. VAT and SAT are segmented based on the final deformed muscle shape. In comparing the automatic and manual methods, coefficients of variation (COV) (1 - 2%), were similar to or smaller than inter- and intra-observer COVs reported for manual segmentation.

Composite cell sheet for periodontal regeneration: crosstalk between different types of MSCs in cell sheet facilitates complex periodontal-like tissue regeneration.

Science.gov (United States)

Zhang, Hao; Liu, Shiyu; Zhu, Bin; Xu, Qiu; Ding, Yin; Jin, Yan

2016-11-14

Tissue-engineering strategies based on mesenchymal stem cells (MSCs) and cell sheets have been widely used for periodontal tissue regeneration. However, given the complexity in periodontal structure, the regeneration methods using a single species of MSC could not fulfill the requirement for periodontal regeneration. We researched the interaction between the periodontal ligament stem cells (PDLSCs) and jaw bone marrow-derived mesenchymal stem cells (JBMMSCs), and constructed a composite cell sheet comprising both of the above MSCs to regenerate complex periodontium-like structures in nude mice. Our results show that by co-culturing PDLSCs and JBMMSCs, the expressions of bone and extracellular matrix (ECM)-related genes and proteins were significantly improved in both MSCs. Further investigations showed that, compared to the cell sheet using PDLSCs or JBMMSCs, the composite stem cell sheet (CSCS), which comprises these two MSCs, expressed higher levels of bone- and ECM-related genes and proteins, and generated a composite structure more similar to the native periodontal tissue physiologically in vivo. In conclusion, our results demonstrate that the crosstalk between PDLSCs and JBMMSCs in cell sheets facilitate regeneration of complex periodontium-like structures, providing a promising new strategy for physiological and functional regeneration of periodontal tissue.

Enhanced mechanical properties and biocompatibility of novel hydroxyapatite/TOPAS hybrid composite for bone tissue engineering applications

Energy Technology Data Exchange (ETDEWEB)

Ain, Qurat Ul [Department of Materials Engineering, School of Chemical and Materials Engineering, National University of Sciences and Technology, H-12, Islamabad (Pakistan); Khan, Ahmad Nawaz, E-mail: ahmad.nawaz@scme.nust.edu.pk [Department of Materials Engineering, School of Chemical and Materials Engineering, National University of Sciences and Technology, H-12, Islamabad (Pakistan); Nabavinia, Mahboubeh [Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA (United States); Mujahid, Mohammad [Department of Materials Engineering, School of Chemical and Materials Engineering, National University of Sciences and Technology, H-12, Islamabad (Pakistan)

2017-06-01

The bioactivity and mechanical properties of hybrid composites of hydroxyapatite (HA) in cyclic olefinic copolymer (COC) also known commercially as TOPAS are investigated, first time, for regeneration and repair of the bone tissues. HA is synthesized to obtain the spherically shaped nanoparticles in the size range of 60 ± 20 nm. Various concentrations of HA ranging from 1 to 30 wt% are dispersed in TOPAS using sodium dodecyl sulfate (SDS) coupling agent for better dispersion and interaction of hydrophilic HA with hydrophobic TOPAS. Scanning electron microscope shows the uniform dispersion of HA ≤ 10 wt% in TOPAS and at higher concentrations > 10 wt%, agglomeration occurs in the hybrid composites. Tunable mechanical properties are achieved as the compressive modulus and strength are increased around 140% from 6.4 to 15.3 MPa and 185% from 0.26 to 0.74 MPa, respectively. Such increase in the mechanical properties of TOPAS is attributed to the anchoring of the polymer chains in the vicinity of HA nanoparticles owing to better dispersion and interfacial interactions. In comparison to neat TOPAS, hybrid composites of TOPAS/HA promoted the cell adhesion and proliferation significantly. The cell density and proliferation of TOPAS/HA hybrid composites is enhanced 9 and 3 folds, respectively, after 1 day culturing in preosteoblasts cells. Moreover, the morphology of cells changed from spherical to flattened spread morphology demonstrating clearly the migration of the cells for the formation of interconnected cellular network. Additionally, very few dead cells are found in hybrid composites showing their cytocompatibility. Overall, the hybrid composites of TOPAS/HA exhibited superior strength and stiffness along with enhanced cytocompatibility for bone tissue engineering applications. - Highlights: • TOPAS/HA hybrid composites exhibited enhanced mechanical properties owing to better dispersion and interaction of HA. • Without affecting the degradation rate, the

Enhanced mechanical properties and biocompatibility of novel hydroxyapatite/TOPAS hybrid composite for bone tissue engineering applications

International Nuclear Information System (INIS)

Ain, Qurat Ul; Khan, Ahmad Nawaz; Nabavinia, Mahboubeh; Mujahid, Mohammad

2017-01-01

The bioactivity and mechanical properties of hybrid composites of hydroxyapatite (HA) in cyclic olefinic copolymer (COC) also known commercially as TOPAS are investigated, first time, for regeneration and repair of the bone tissues. HA is synthesized to obtain the spherically shaped nanoparticles in the size range of 60 ± 20 nm. Various concentrations of HA ranging from 1 to 30 wt% are dispersed in TOPAS using sodium dodecyl sulfate (SDS) coupling agent for better dispersion and interaction of hydrophilic HA with hydrophobic TOPAS. Scanning electron microscope shows the uniform dispersion of HA ≤ 10 wt% in TOPAS and at higher concentrations > 10 wt%, agglomeration occurs in the hybrid composites. Tunable mechanical properties are achieved as the compressive modulus and strength are increased around 140% from 6.4 to 15.3 MPa and 185% from 0.26 to 0.74 MPa, respectively. Such increase in the mechanical properties of TOPAS is attributed to the anchoring of the polymer chains in the vicinity of HA nanoparticles owing to better dispersion and interfacial interactions. In comparison to neat TOPAS, hybrid composites of TOPAS/HA promoted the cell adhesion and proliferation significantly. The cell density and proliferation of TOPAS/HA hybrid composites is enhanced 9 and 3 folds, respectively, after 1 day culturing in preosteoblasts cells. Moreover, the morphology of cells changed from spherical to flattened spread morphology demonstrating clearly the migration of the cells for the formation of interconnected cellular network. Additionally, very few dead cells are found in hybrid composites showing their cytocompatibility. Overall, the hybrid composites of TOPAS/HA exhibited superior strength and stiffness along with enhanced cytocompatibility for bone tissue engineering applications. - Highlights: • TOPAS/HA hybrid composites exhibited enhanced mechanical properties owing to better dispersion and interaction of HA. • Without affecting the degradation rate, the

N-3 Polyunsaturated Fatty Acids of Marine Origin and Multifocality in Human Breast Cancer.

Directory of Open Access Journals (Sweden)

Lobna Ouldamer

Full Text Available The microenvironment of breast epithelial tissue may contribute to the clinical expression of breast cancer. Breast epithelial tissue, whether healthy or tumoral, is directly in contact with fat cells, which in turn could influence tumor multifocality. In this pilot study we investigated whether the fatty acid composition of breast adipose tissue differed according to breast cancer focality.Twenty-three consecutive women presenting with non-metastatic breast cancer underwent breast-imaging procedures including Magnetic Resonance Imaging prior to treatment. Breast adipose tissue specimens were collected during breast surgery. We established a biochemical profile of adipose tissue fatty acids by gas chromatography. We assessed whether there were differences according to breast cancer focality.We found that decreased levels in breast adipose tissue of docosahexaenoic and eicosapentaenoic acids, the two main polyunsaturated n-3 fatty acids of marine origin, were associated with multifocality.These differences in lipid content may contribute to mechanisms through which peritumoral adipose tissue fuels breast cancer multifocality.

N-3 Polyunsaturated Fatty Acids of Marine Origin and Multifocality in Human Breast Cancer.

Science.gov (United States)

Ouldamer, Lobna; Goupille, Caroline; Vildé, Anne; Arbion, Flavie; Body, Gilles; Chevalier, Stephan; Cottier, Jean Philippe; Bougnoux, Philippe

2016-01-01

The microenvironment of breast epithelial tissue may contribute to the clinical expression of breast cancer. Breast epithelial tissue, whether healthy or tumoral, is directly in contact with fat cells, which in turn could influence tumor multifocality. In this pilot study we investigated whether the fatty acid composition of breast adipose tissue differed according to breast cancer focality. Twenty-three consecutive women presenting with non-metastatic breast cancer underwent breast-imaging procedures including Magnetic Resonance Imaging prior to treatment. Breast adipose tissue specimens were collected during breast surgery. We established a biochemical profile of adipose tissue fatty acids by gas chromatography. We assessed whether there were differences according to breast cancer focality. We found that decreased levels in breast adipose tissue of docosahexaenoic and eicosapentaenoic acids, the two main polyunsaturated n-3 fatty acids of marine origin, were associated with multifocality. These differences in lipid content may contribute to mechanisms through which peritumoral adipose tissue fuels breast cancer multifocality.

Intervertebral Disc Tissue Engineering with Natural Extracellular Matrix-Derived Biphasic Composite Scaffolds.

Directory of Open Access Journals (Sweden)

Baoshan Xu

Full Text Available Tissue engineering has provided an alternative therapeutic possibility for degenerative disc diseases. However, we lack an ideal scaffold for IVD tissue engineering. The goal of this study is to fabricate a novel biomimetic biphasic scaffold for IVD tissue engineering and evaluate the feasibility of developing tissue-engineered IVD in vitro and in vivo. In present study we developed a novel integrated biphasic IVD scaffold using a simple freeze-drying and cross-linking technique of pig bone matrix gelatin (BMG for the outer annulus fibrosus (AF phase and pig acellular cartilage ECM (ACECM for the inner nucleus pulposus (NP phase. Histology and SEM results indicated no residual cells remaining in the scaffold that featured an interconnected porous microstructure (pore size of AF and NP phase 401.4 ± 13.1 μm and 231.6 ± 57.2 μm, respectively. PKH26-labeled AF and NP cells were seeded into the scaffold and cultured in vitro. SEM confirmed that seeded cells could anchor onto the scaffold. Live/dead staining showed that live cells (green fluorescence were distributed in the scaffold, with no dead cells (red fluorescence being found. The cell-scaffold constructs were implanted subcutaneously into nude mice and cultured for 6 weeks in vivo. IVD-like tissue formed in nude mice as confirmed by histology. Cells in hybrid constructs originated from PKH26-labeled cells, as confirmed by in vivo fluorescence imaging system. In conclusion, the study demonstrates the feasibility of developing a tissue-engineered IVD in vivo with a BMG- and ACECM-derived integrated AF-NP biphasic scaffold. As well, PKH26 fluorescent labeling with in vivo fluorescent imaging can be used to track cells and analyse cell--scaffold constructs in vivo.

Pullulan-based composite scaffolds for bone tissue engineering: Improved osteoconductivity by pore wall mineralization.

Science.gov (United States)

Amrita; Arora, Aditya; Sharma, Poonam; Katti, Dhirendra S

2015-06-05

Porous hydrogels have been explored for bone tissue engineering; however their poor mechanical properties make them less suitable as bone graft substitutes. Since incorporation of fillers is a well-accepted method for improving mechanical properties of hydrogels, in this work pullulan hydrogels were reinforced with nano-crystalline hydroxyapatite (nHAp) (5 wt% nHAp in hydrogel) and poly(3-hydroxybutyrate) (PHB) fibers (3 wt% fibers in hydrogel) containing nHAp (3 wt% nHAp in fibers). Addition of these fillers to pullulan hydrogel improved compressive modulus of the scaffold by 10 fold. However, the hydrophilicity of pullulan did not support adhesion and spreading of cells. To overcome this limitation, porous composite scaffolds were modified using a double diffusion method that enabled deposition of hydroxyapatite on pore walls. This method resulted in rapid and uniform coating of HAp throughout the three-dimensional scaffolds which not only rendered them osteoconductive in vitro but also led to an improvement in their compressive modulus. These results demonstrate the potential of mineralized pullulan-based composite scaffolds in non-load bearing bone tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

Origin and composition of Mercury

International Nuclear Information System (INIS)

Lewis, J.S.

1988-01-01

The predictions of the expected range of composition of Mercury at the time of its formation made on the basis of a suite of condensation-accretion models of Mercury spanning a range of condensation temperature and accretion sampling functions appropriate to Mercury are examined. It is concluded that these compositonal models can, if modified to take into account the nonselective loss of most of the silicate component of the planet during accretion, provide compositional predictions for the Weidenschilling (1978, 1980) mechanism for the accretion of a metal-rich Mercury. The silicate portion would, in this case, contain 3.6 to 4.5 percent alumina, roughly 1 percent of alkali oxides, and between 0.5 and 6 percent FeO

Differential effects of diet composition and timing of feeding behavior on rat brown adipose tissue and skeletal muscle peripheral clocks.

NARCIS (Netherlands)

De Goede, P.; Sen, Satish; Oosterman, Johanneke E; Kalsbeek, A.

2018-01-01

The effects of feeding behavior and diet composition,as well as their possible interactions,on daily (clock) gene expression rhythms have mainly been studied in the liver, and to a lesser degree in white adipose tissue(WAT), but hardly in other metabolic tissues such as skeletal muscle (SM) and

Enhanced mechanical properties and biocompatibility of novel hydroxyapatite/TOPAS hybrid composite for bone tissue engineering applications.

Science.gov (United States)

Ain, Qurat Ul; Khan, Ahmad Nawaz; Nabavinia, Mahboubeh; Mujahid, Mohammad

2017-06-01

The bioactivity and mechanical properties of hybrid composites of hydroxyapatite (HA) in cyclic olefinic copolymer (COC) also known commercially as TOPAS are investigated, first time, for regeneration and repair of the bone tissues. HA is synthesized to obtain the spherically shaped nanoparticles in the size range of 60±20nm. Various concentrations of HA ranging from 1 to 30wt% are dispersed in TOPAS using sodium dodecyl sulfate (SDS) coupling agent for better dispersion and interaction of hydrophilic HA with hydrophobic TOPAS. Scanning electron microscope shows the uniform dispersion of HA≤10wt% in TOPAS and at higher concentrations >10wt%, agglomeration occurs in the hybrid composites. Tunable mechanical properties are achieved as the compressive modulus and strength are increased around 140% from 6.4 to 15.3MPa and 185% from 0.26 to 0.74MPa, respectively. Such increase in the mechanical properties of TOPAS is attributed to the anchoring of the polymer chains in the vicinity of HA nanoparticles owing to better dispersion and interfacial interactions. In comparison to neat TOPAS, hybrid composites of TOPAS/HA promoted the cell adhesion and proliferation significantly. The cell density and proliferation of TOPAS/HA hybrid composites is enhanced 9 and 3 folds, respectively, after 1day culturing in preosteoblasts cells. Moreover, the morphology of cells changed from spherical to flattened spread morphology demonstrating clearly the migration of the cells for the formation of interconnected cellular network. Additionally, very few dead cells are found in hybrid composites showing their cytocompatibility. Overall, the hybrid composites of TOPAS/HA exhibited superior strength and stiffness along with enhanced cytocompatibility for bone tissue engineering applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Human Genetic Ancestral Composition Correlates with the Origin of Mycobacterium leprae Strains in a Leprosy Endemic Population.

Science.gov (United States)

Cardona-Castro, Nora; Cortés, Edwin; Beltrán, Camilo; Romero, Marcela; Badel-Mogollón, Jaime E; Bedoya, Gabriel

2015-01-01

Recent reports have suggested that leprosy originated in Africa, extended to Asia and Europe, and arrived in the Americas during European colonization and the African slave trade. Due to colonization, the contemporary Colombian population is an admixture of Native-American, European and African ancestries. Because microorganisms are known to accompany humans during migrations, patterns of human migration can be traced by examining genomic changes in associated microbes. The current study analyzed 118 leprosy cases and 116 unrelated controls from two Colombian regions endemic for leprosy (Atlantic and Andean) in order to determine possible associations of leprosy with patient ancestral background (determined using 36 ancestry informative markers), Mycobacterium leprae genotype and/or patient geographical origin. We found significant differences between ancestral genetic composition. European components were predominant in Andean populations. In contrast, African components were higher in the Atlantic region. M. leprae genotypes were then analyzed for cluster associations and compared with the ancestral composition of leprosy patients. Two M. leprae principal clusters were found: haplotypes C54 and T45. Haplotype C54 associated with African origin and was more frequent in patients from the Atlantic region with a high African component. In contrast, haplotype T45 associated with European origin and was more frequent in Andean patients with a higher European component. These results suggest that the human and M. leprae genomes have co-existed since the African and European origins of the disease, with leprosy ultimately arriving in Colombia during colonization. Distinct M. leprae strains followed European and African settlement in the country and can be detected in contemporary Colombian populations.

Bio-based polyurethane for tissue engineering applications: How hydroxyapatite nanoparticles influence the structure, thermal and biological behavior of polyurethane composites.

Science.gov (United States)

Gabriel, Laís P; Santos, Maria Elizabeth M Dos; Jardini, André L; Bastos, Gilmara N T; Dias, Carmen G B T; Webster, Thomas J; Maciel Filho, Rubens

2017-01-01

In this work, thermoset polyurethane composites were prepared by the addition of hydroxyapatite nanoparticles using the reactants polyol polyether and an aliphatic diisocyanate. The polyol employed in this study was extracted from the Euterpe oleracea Mart. seeds from the Amazon Region of Brazil. The influence of hydroxyapatite nanoparticles on the structure and morphology of the composites was studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), the structure was evaluated by Fourier transform infrared spectroscopy (FT-IR), thermal properties were analyzed by thermogravimetry analysis (TGA), and biological properties were studied by in vitro and in vivo studies. It was found that the addition of HA nanoparticles promoted fibroblast adhesion while in vivo investigations with histology confirmed that the composites promoted connective tissue adherence and did not induce inflammation. In this manner, this study supports the further investigation of bio-based, polyurethane/hydroxyapatite composites as biocompatible scaffolds for numerous tissue engineering applications. Copyright © 2016 Elsevier Inc. All rights reserved.

A novel squid pen chitosan/hydroxyapatite/β-tricalcium phosphate composite for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Shavandi, Amin, E-mail: amin.shavandi@postgrad.otago.ac.nz [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Department of Applied Sciences, University of Otago, Dunedin (New Zealand); Bekhit, Alaa El-Din A. [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Sun, Zhifa; Ali, Azam [Department of Physics, University of Otago, Dunedin (New Zealand); Gould, Maree [Department of Anatomy, University of Otago, Dunedin (New Zealand)

2015-10-01

Squid pen chitosan was used in the fabrication of biocomposite scaffolds for bone tissue engineering. Hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) obtained from waste mussel shells were used as the calcium phosphate source. The composite was prepared using 2.5% tripolyphosphate (TPP) and 1% glycerol as a cross-linker and plasticizer, respectively. The weight percent (wt.%) ratios of the ceramic components in the composite were 20/10/70, 30/20/50 and 40/30/30 (HA/β-TCP/Chi). The biodegradation rate and structural properties of the scaffolds were investigated. Scanning electron microscopy (SEM) and microCT(μCT) results indicated that the composites have a well defined lamellar structure with an average pore size of 200 μm. The porosity of the composites decreased from 88 to 56% by increasing the ratio of HA/β-TCP from 30 to 70%. After 28 days of incubation in a physiological solution, the scaffolds were degraded by approximately 30%. In vitro investigations showed that the composites were cytocompatible and supported the growth of L929 and Saos-2 cells. The obtained data suggests that the squid pen chitosan composites are potential candidates for bone regeneration. - Highlights: • Biocomposite scaffolds were made from mussel shells HA and β-TCP, and squid pin chitosan. • The porosity of the composites decreased with an increase in HA/β-TCP ratio. • Composites were cytocompatible and supported the growth of L929 and Saos-2 cells. • Composite containing 50% HA and β-TCP had the best mechanical properties.

Composite microsphere-functionalized scaffold for the controlled release of small molecules in tissue engineering

Directory of Open Access Journals (Sweden)

Laura Pandolfi

2016-01-01

Full Text Available Current tissue engineering strategies focus on restoring damaged tissue architectures using biologically active scaffolds. The ideal scaffold would mimic the extracellular matrix of any tissue of interest, promoting cell proliferation and de novo extracellular matrix deposition. A plethora of techniques have been evaluated to engineer scaffolds for the controlled and targeted release of bioactive molecules to provide a functional structure for tissue growth and remodeling, as well as enhance recruitment and proliferation of autologous cells within the implant. Recently, novel approaches using small molecules, instead of growth factors, have been exploited to regulate tissue regeneration. The use of small synthetic molecules could be very advantageous because of their stability, tunability, and low cost. Herein, we propose a chitosan–gelatin scaffold functionalized with composite microspheres consisting of mesoporous silicon microparticles and poly(dl-lactic-co-glycolic acid for the controlled release of sphingosine-1-phospate, a small molecule of interest. We characterized the platform with scanning electron microscopy, Fourier transform infrared spectroscopy, and confocal microscopy. Finally, the biocompatibility of this multiscale system was analyzed by culturing human mesenchymal stem cells onto the scaffold. The presented strategy establishes the basis of a versatile scaffold for the controlled release of small molecules and for culturing mesenchymal stem cells for regenerative medicine applications.

Compositional breast imaging using a dual-energy mammography protocol

International Nuclear Information System (INIS)

Laidevant, Aurelie D.; Malkov, Serghei; Flowers, Chris I.; Kerlikowske, Karla; Shepherd, John A.

2010-01-01

Purpose: Mammography has a low sensitivity in dense breasts due to low contrast between malignant and normal tissue confounded by the predominant water density of the breast. Water is found in both adipose and fibroglandular tissue and constitutes most of the mass of a breast. However, significant protein mass is mainly found in the fibroglandular tissue where most cancers originate. If the protein compartment in a mammogram could be imaged without the influence of water, the sensitivity and specificity of the mammogram may be improved. This article describes a novel approach to dual-energy mammography, full-field digital compositional mammography (FFDCM), which can independently image the three compositional components of breast tissue: water, lipid, and protein. Methods: Dual-energy attenuation and breast shape measures are used together to solve for the three compositional thicknesses. Dual-energy measurements were performed on breast-mimicking phantoms using a full-field digital mammography unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the compositional compartments. They were made of two main stacks of thicknesses around 2 and 4 cm. Twenty-six thickness and composition combinations were used to derive the compositional calibration using a least-squares fitting approach. Results: Very high accuracy was achieved with a simple cubic fitting function with root mean square errors of 0.023, 0.011, and 0.012 cm for the water, lipid, and protein thicknesses, respectively. The repeatability (percent coefficient of variation) of these measures was tested using sequential images and was found to be 0.5%, 0.5%, and 3.3% for water, lipid, and protein, respectively. However, swapping the location of the two stacks of the phantom on the imaging plate introduced further errors showing the need for more complete system uniformity corrections. Finally, a preliminary breast image is presented of each of the compositional

Developing bioactive composite scaffolds for bone tissue engineering

Science.gov (United States)

Chen, Yun

bone-like apatite/collagen composite coating. Saos-2 osteoblast-like cells were used to evaluate the cellular behaviors on these biomimetic coatings. Cell morphologies on the surfaces of PLLA films and scaffolds, PLLA films and scaffolds with apatite coating, and PLLA films and scaffolds with apatite/collagen composite coating were studied by SEM. Cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrasodium bromide (MTT) assay. In addition, differentiated cell function was assessed by measuring alkaline phosphatase activity. These results suggested that the apatite coating and apatite/collagen composite coating fabricated through the accelerated biomimetic processes could improve the interactions between osteoblasts and PLLA. The composite coating was more effective than apatite coating in improving such interactions. PLLA scaffolds coated with submicron collagen fibrils and submicron apatite paticulates are expected to be one of the promising 3D substrates for bone tissue engineering. To facilitate coating into scaffolds, the flowing condition was introduced into the accelerated biomimetic process. The apatite formed in the different sites in the scaffold was characterized using SEM. It was found that the accelerated biomimetic process performed in the flowing condition yielded more uniform spatial distribution of apatite particles than that in the regular shaking condition. This work provides a novel condition for obtaining uniform spatial distribution of bone-like apatite within the scaffolds in a timely manner, which is expected to facilitate uniform distribution of attached cells within the scaffoldsin vitro and in vivo.

Response of stem cells from different origins to biphasic calcium phosphate bioceramics.

Science.gov (United States)

Lobo, Sonja E; Glickman, Robert; da Silva, Wagner N; Arinzeh, Treena L; Kerkis, Irina

2015-08-01

Biphasic calcium phosphate (BCP) bioceramics have been successfully applied in a broad variety of presentation forms and with different ratios of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP). BCPs have been loaded with stem cells from different origins for bone tissue engineering purposes, but evidence of stem cell behavior on different compositions (various HA/β-TCP ratios) and physical features of BCPs is limited. We compared the adhesion, proliferation, viability and osteogenic potential of human mesenchymal stem cells (MSCs) on granular BCPs with equal HA/β-TCP ratio of diverse particle sizes and on porous blocks which had different chemical compositions. In addition, the osteogenic differentiation of MSCs was compared to adipose-derived (ADSC) and dental pulp (DPSC) stem cells, as well as to pre-osteoblasts on a particulate BCP. MSCs growing on granular BCPs demonstrated increased number as compared to MSCs growing on blocks. Cells proliferated to a greater extent on small granular BCPs, while large granular BCPs and blocks promoted cell differentiation. Surprisingly, the expression of genes involved in osteogenesis was upregulated in MSCs on bioceramics in basal medium which indicates that BCPs may have osteoinductive potential. This was confirmed with the upregulation of osteochondrogenic markers, at different time points, when stem cells from various tissues were grown on the BCP. This study demonstrates that BCPs, depending on their physical features and chemical composition, modulate stem cell behavior, and that stem cells from different origins are inherently distinct in their gene expression profile and can be triggered toward osteochondrogenic fate by BCPs.

Surface modification of nanofibrous polycaprolactone/gelatin composite scaffold by collagen type I grafting for skin tissue engineering

International Nuclear Information System (INIS)

Gautam, Sneh; Chou, Chia-Fu; Dinda, Amit K.; Potdar, Pravin D.; Mishra, Narayan C.

2014-01-01

In the present study, a tri-polymer polycaprolactone (PCL)/gelatin/collagen type I composite nanofibrous scaffold has been fabricated by electrospinning for skin tissue engineering and wound healing applications. Firstly, PCL/gelatin nanofibrous scaffold was fabricated by electrospinning using a low cost solvent mixture [chloroform/methanol for PCL and acetic acid (80% v/v) for gelatin], and then the nanofibrous PCL/gelatin scaffold was modified by collagen type I (0.2–1.5 wt.%) grafting. Morphology of the collagen type I-modified PCL/gelatin composite scaffold that was analyzed by field emission scanning electron microscopy (FE-SEM), showed that the fiber diameter was increased and pore size was decreased by increasing the concentration of collagen type I. Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric (TG) analysis indicated the surface modification of PCL/gelatin scaffold by collagen type I immobilization on the surface of the scaffold. MTT assay demonstrated the viability and high proliferation rate of L929 mouse fibroblast cells on the collagen type I-modified composite scaffold. FE-SEM analysis of cell-scaffold construct illustrated the cell adhesion of L929 mouse fibroblasts on the surface of scaffold. Characteristic cell morphology of L929 was also observed on the nanofiber mesh of the collagen type I-modified scaffold. Above results suggest that the collagen type I-modified PCL/gelatin scaffold was successful in maintaining characteristic shape of fibroblasts, besides good cell proliferation. Therefore, the fibroblast seeded PCL/gelatin/collagen type I composite nanofibrous scaffold might be a potential candidate for wound healing and skin tissue engineering applications. - Highlights: • PCL/gelatin/collagen type I scaffold was fabricated for skin tissue engineering. • PCL/gelatin/collagen type I scaffold showed higher fibroblast growth than PCL/gelatin one. • PCL/gelatin/collagen type I might be one of the ideal scaffold for

Composites structures for bone tissue reconstruction

International Nuclear Information System (INIS)

Neto, W.; Santos, João; Avérous, L.; Schlatter, G.; Bretas, Rosario

2015-01-01

The search for new biomaterials in the bone reconstitution field is growing continuously as humane life expectation and bone fractures increase. For this purpose, composite materials with biodegradable polymers and hydroxyapatite (HA) have been used. A composite material formed by a film, nanofibers and HA has been made. Both, the films and the non-woven mats of nanofibers were formed by nanocomposites made of butylene adipate-co-terephthalate (PBAT) and HA. The techniques used to produce the films and nanofibers were spin coating and electrospinning, respectively. The composite production and morphology were evaluated. The composite showed an adequate morphology and fibers size to be used as scaffold for cell growth

Composites structures for bone tissue reconstruction

Science.gov (United States)

Neto, W.; Santos, João.; Avérous, L.; Schlatter, G.; Bretas, Rosario.

2015-05-01

The search for new biomaterials in the bone reconstitution field is growing continuously as humane life expectation and bone fractures increase. For this purpose, composite materials with biodegradable polymers and hydroxyapatite (HA) have been used. A composite material formed by a film, nanofibers and HA has been made. Both, the films and the non-woven mats of nanofibers were formed by nanocomposites made of butylene adipate-co-terephthalate (PBAT) and HA. The techniques used to produce the films and nanofibers were spin coating and electrospinning, respectively. The composite production and morphology were evaluated. The composite showed an adequate morphology and fibers size to be used as scaffold for cell growth.

Stable isotope composition of cocoa beans of different geographical origin.

Science.gov (United States)

Perini, Matteo; Bontempo, Luana; Ziller, Luca; Barbero, Alice; Caligiani, Augusta; Camin, Federica

2016-09-01

The isotopic profile (δ(13) C, δ(15) N, δ(18) O, δ(2) H, δ(34) S) was used to characterise a wide selection of cocoa beans from different renowned production areas (Africa, Asia, Central and South America). The factors most influencing the isotopic signatures of cocoa beans were climate and altitude for δ(13) C and the isotopic composition of precipitation water for δ(18) O and δ(2) H, whereas δ(15) N and δ(34) S were primarily affected by geology and fertilisation practises. Multi-isotopic analysis was shown to be sufficiently effective in determining the geographical origin of cocoa beans, and combining it with Canonical Discriminant Analysis led to more than 80% of samples being correctly reclassified. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Chemical composition of the thermomineral waters of Josanicka Banja spa as an origin indicator, balneological valorization and geothermal potential

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Milenić Dejan R.

2015-01-01

Full Text Available The chemical composition of the groundwater is directly dependent on the geological structure, hydrogeological and hydrochemical characteristics and as such it represents an output result of all the factors and processes which take place in the environment within which they were formed. The chemical composition of thermomineral waters often represents a crucial factor in determining the origin, balneological valorization and geothermal potential of the resources. This work presents the analysis of origin, belneological valorization and geothermal potential of Josanicka Banja spa, on the basis of the results gained through making the analyisis of chemical contents of the thermomineral waters which occur in the area. The ratio of concentrations of specific chemical components in the thermomineral waters of Josanicka Banja has served as the basic tool for ascertaining the origin of these waters. On the basis of the analysis of the main anion-cation and gas compositions as well as the contents of specific micro-components, a balneological valorization of these resources has been carried out. Apart from that this work also presents the calculation of the expected temperatures in the primary geothermal reservoir, which was carried out on the basis of the results of chemical analysis of thermomineral waters that occur in the area. Geothermal potential of about 4 MWt and significant contents of balneologically active components of the chemical composition of these waters, open up a possibility for their multi-purpose use, which is also presented in the work. [Projekat Ministarstva nauke Republike Srbije, br. TR 33053

Maternal nutritional manipulations program adipose tissue dysfunction in offspring

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Simon eLecoutre

2015-05-01

Full Text Available Based on the concept of Developmental Origin of Health and Disease, both human and animal studies have demonstrated a close link between nutrient supply perturbations in the fetus or neonate (i.e., maternal undernutrition, obesity, gestational diabetes and/or rapid catch-up growth and increased risk of adult-onset obesity. Indeed, the adipose tissue has been recognized as a key target of developmental programming in a sex-and depot-specific manner. Despite different developmental time windows, similar mechanisms of adipose tissue programming have been described in rodents and in bigger mammals (sheep, primates. Maternal nutritional manipulations reprogram offspring’s adipose tissue resulting in series of alterations: enhanced adipogenesis and lipogenesis, impaired sympathetic activity with reduced noradrenergic innervations and thermogenesis as well as low-grade inflammation. These changes affect adipose tissue development, distribution and composition predisposing offspring to fat accumulation. Modifications of hormonal tissue sensitivity (i.e., leptin, insulin, glucocorticoids and/or epigenetic mechanisms leading to persistent changes in gene expression may account for long-lasting programming across generations.

Seasonal biochemical changes in composition of body wall tissues of sea cucumber Apostichopus japonicus

Science.gov (United States)

Gao, Fei; Xu, Qiang; Yang, Hongsheng

2011-03-01

Seasonal Variation in proximate, amino acid and fatty acid composition of the body wall of sea cucumber Apostichopus japonicus was evaluated. The proximate composition, except for ash content, changed significantly among seasons ( P<0.05). Alanine, glycine, glutamic acid and asparagic acid were the most abundant amino acids. Total amino acid and essential amino acid Contents both varied clearly with seasons ( P<0.05). 16:0 and 16:ln7 were the primary saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) respectively for all months. EPA (20:5n-3), AA (20:4n-6) and DHA (22:6n-3) were the major polyunsaturated fatty acids (PUFA). The proportions of SFA and PUFA yielded significant seasonal variations ( P<0.001), but MUFA did not changed significantly. The results indicated that the biochemical compositions of the body wall in A. japonicus were significantly influenced by seasons and that the body wall tissue is an excellent source of protein, MUFA and n-3 PUFA for humans.

Human Genetic Ancestral Composition Correlates with the Origin of Mycobacterium leprae Strains in a Leprosy Endemic Population.

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Nora Cardona-Castro

Full Text Available Recent reports have suggested that leprosy originated in Africa, extended to Asia and Europe, and arrived in the Americas during European colonization and the African slave trade. Due to colonization, the contemporary Colombian population is an admixture of Native-American, European and African ancestries. Because microorganisms are known to accompany humans during migrations, patterns of human migration can be traced by examining genomic changes in associated microbes. The current study analyzed 118 leprosy cases and 116 unrelated controls from two Colombian regions endemic for leprosy (Atlantic and Andean in order to determine possible associations of leprosy with patient ancestral background (determined using 36 ancestry informative markers, Mycobacterium leprae genotype and/or patient geographical origin. We found significant differences between ancestral genetic composition. European components were predominant in Andean populations. In contrast, African components were higher in the Atlantic region. M. leprae genotypes were then analyzed for cluster associations and compared with the ancestral composition of leprosy patients. Two M. leprae principal clusters were found: haplotypes C54 and T45. Haplotype C54 associated with African origin and was more frequent in patients from the Atlantic region with a high African component. In contrast, haplotype T45 associated with European origin and was more frequent in Andean patients with a higher European component. These results suggest that the human and M. leprae genomes have co-existed since the African and European origins of the disease, with leprosy ultimately arriving in Colombia during colonization. Distinct M. leprae strains followed European and African settlement in the country and can be detected in contemporary Colombian populations.

Characterization of elasticity and hydration of composite hydrogel based on collagen-iota carrageenan as a corneal tissue engineering

Science.gov (United States)

Rinawati, M.; Triastuti, J.; Pursetyo, K. T.

2018-04-01

The cornea is a refractive element of the eye that serves to continue the stimulation of light into the eye it has a clear, transparent, elastic and relatively thick tissue. Factors caused corneal blindness, are dystrophy, keratoconus, corneal scaring. Hydrogels can be made from polysaccharide derivatives that have gelation properties such as iota carrageenan. Therefore, it is a need to develop composite hydrogel based collagen-iota carragenan as an engineeried corneal tissue with high elasticity and hydration properties. Collagen hydrogel has a maximum water content an has equlibrium up to 40 %, less than the human cornea, 81 % and under normal hydration conditions, the human cornea can transmit 87 % of visible light. In addition, the refractive index on the surface of the cornea with air is 1.375-1.380. Based on this study, it is necessary to conduct research on the development and composition of hydrogel composite collagen-iota carrageen hydrogen based on. The best result was K5 (5:5) treatment, which has the equilibrium water content of 87.07 % and viscosity of 10.7346 Pa.s.

Gestational age dependent content, composition and intrauterine accretion rates of fatty acids in fetal white adipose tissue

NARCIS (Netherlands)

Kuipers, Remko S.; Luxwolda, Martine F.; Offringa, Pieter J.; Martini, Ingrid A.; Boersma, E. Rudy; Dijck-Brouwer, D. A. Janneke; Muskiet, Frits A. J.

2012-01-01

Background: Little is known about the gestational age (GA) dependent content, composition and intrauterine accretion rates of fatty acids (FA) in fetal white adipose tissue (WAT). Objective & design: To acquire this information, we collected abdominal subcutaneous WAT samples from 40 preterm and

Tissue-engineered collateral ligament composite allografts for scapholunate ligament reconstruction: an experimental study.

Science.gov (United States)

Endress, Ryan; Woon, Colin Y L; Farnebo, Simon J; Behn, Anthony; Bronstein, Joel; Pham, Hung; Yan, Xinrui; Gambhir, Sanjiv S; Chang, James

2012-08-01

In patients with chronic scapholunate (SL) dissociation or dynamic instability, ligament repair is often not possible, and surgical reconstruction is indicated. The ideal graft ligament would recreate both anatomical and biomechanical properties of the dorsal scapholunate ligament (dorsal SLIL). The finger proximal interphalangeal joint (PIP joint) collateral ligament could possibly be a substitute ligament. We harvested human PIP joint collateral ligaments and SL ligaments from 15 cadaveric limbs. We recorded ligament length, width, and thickness, and measured the biomechanical properties (ultimate load, stiffness, and displacement to failure) of native dorsal SLIL, untreated collateral ligaments, decellularized collateral ligaments, and SL repairs with bone-collateral ligament-bone composite collateral ligament grafts. As proof of concept, we then reseeded decellularized bone-collateral ligament-bone composite grafts with green fluorescent protein-labeled adipo-derived mesenchymal stem cells and evaluated them histologically. There was no difference in ultimate load, stiffness, and displacement to failure among native dorsal SLIL, untreated and decellularized collateral ligaments, and SL repairs with tissue-engineered collateral ligament grafts. With pair-matched untreated and decellularized scaffolds, there was no difference in ultimate load or stiffness. However, decellularized ligaments revealed lower displacement to failure compared with untreated ligaments. There was no difference in displacement between decellularized ligaments and native dorsal SLIL. We successfully decellularized grafts with recently described techniques, and they could be similarly reseeded. Proximal interphalangeal joint collateral ligament-based bone-collateral ligament-bone composite allografts had biomechanical properties similar to those of native dorsal SLIL. Decellularization did not adversely affect material properties. These tissue-engineered grafts may offer surgeons another

Preparation and characterization of gelatin–hydroxyapatite composite microspheres for hard tissue repair

International Nuclear Information System (INIS)

Chao, Shao Ching; Wang, Ming-Jia; Pai, Nai-Su; Yen, Shiow-Kang

2015-01-01

Gelatin–hydroxyapatite composite microspheres composed of 21% gelatin (G) and 79% hydroxyapatite (HA) with uniform morphology and controllable size were synthesized from a mixed solution of Ca(NO 3 ) 2 , NH 4 H 2 PO 4 and gelatin by a wet-chemical method. Material analyses such as X-ray diffraction (XRD), scanning/transmission electron microscopy examination (SEM/TEM) and inductively coupled plasma-mass spectroscopy (ICP-MS) were used to characterize G–HA microspheres by analyzing their crystalline phase, microstructure, morphology and composition. HA crystals precipitate along G fibers to form nano-rods with diameters of 6–10 nm and tangle into porous microspheres after blending. The cell culture indicates that G–HA composite microspheres without any toxicity could enhance the proliferation and differentiation of osteoblast-like cells. In a rat calvarial defect model, G–HA bioactive scaffolds were compared with fibrin glue (F) and Osteoset® Bone Graft Substitute (OS) for their capacity of regenerating bone. Four weeks post-implantation, new bone, mineralization, and expanded blood vessel area were found in G–HA scaffolds, indicating greater osteoconductivity and bioactivity than F and OS. - Highlights: • G–HA composite microspheres were prepared by hydroxyapatite and gelatin. • In vitro tests indicated that the G–HA microspheres were biocompatible and bioactive. • In in vitro tests, G–HA microspheres could be applied in hard tissue engineering. • G–HA had healed the bone defect and provides a high proportion of surface area to open space

Common factors method to predict the carcass composition tissue in kid goats

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Helen Fernanda Barros Gomes

2013-03-01

Full Text Available The objective of this work was to analyze the interrelations among weights and carcass measures of the longissimus lumborum muscle thickness and area, and of sternum tissue thickness, measured directly on carcass and by ultrasound scan. Measures were taken on live animals and after slaughter to develop models of multiple linear regression, to estimate the composition of shoulder blade, from selected variables in 89 kids of both genders and five breed groups, raised in feedlot system. The variables considered relevant and not redundant on the information they carry, for the common factor analysis, were used in the carcass composition estimate development models. The presuppositions of linear regression models relative to residues were evaluated, the estimated residues were subjected to analysis of variance and the means were compared by the Student t test. Based in these results, the group of 32 initial variables could be reduced to four variables: hot carcass weight, rump perimeter, leg length and tissue height at the fourth sternum bone. The analysis of common factors was shown as an effective technique to study the interrelations among the independent variables. The measures of carcass dimension, alone, did not add any information to hot carcass weight. The carcass muscle weight can be estimated with high precision from simple models, without the need for information related to gender and breed, and they could be built based on carcass weight, which makes it easy to be applied. The fat and bones estimate models were not as accurate.

Tissue composition of the leg and meat quality of sheep fed castor bean hulls in replacement of tifton hay

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Stela Antas Urbano

2013-10-01

Full Text Available The effects of replacing Tifton hay with castor bean hulls (0, 33, 66 and 100% on the leg tissue composition, chemical composition, physicochemical parameters and sensorial traits of sheep meat were studied. A total of 28 non-castrated sheep averaging seven months in age with an average initial weight of 19.5±4.3 kg were assigned to a randomized block design with four treatments and seven replicates and were slaughtered after 70 days of confinement. At slaughter, body weight and leg, muscle and bone weights decreased linearly, whereas the muscle-to-bone ratio increased linearly according to the treatments. There was a quadratic effect on yellow intensity (maximum of 8.05 with replacement of 54.5% and the percentage of cooking losses (minimum of 33.8% with replacement of 45.17%. The treatment employed did not affect either the chemical composition or sensorial traits of the lamb meat. Although replacing Tifton hay with castor bean hulls alters the tissue composition of the leg as well as some physicochemical parameters of the meat, the sensory analysis indicated good acceptability of the meat, regardless of the inclusion of this byproduct.

Novel scalable silicone elastomer and poly(2-hydroxyethyl methacrylate) (PHEMA) composite materials for tissue engineering and drug delivery applications

DEFF Research Database (Denmark)

Mohanty, Soumyaranjan; Hemmingsen, Mette; Wojcik, Magdalena

2013-01-01

material with increased hydrophilicity in regard to virgin silicone elastomer, making it suitable as a scaffold for tissue engineering and with the concomitant possibility for delivering drug from the scaffold to the tissue. Interpenetrating polymer networks (IPNs) of silicone elastomer and PHEMA......In recent years hydrogels have received increasing attention as potential materials for applications in regenerative medicine. They can be used for scaffold materials providing structural integrity to tissue constructs, for controlled delivery of drugs and proteins to cell and tissues......, and for support materials in tissue growth. However, the real challenge is to obtain sufficiently good mechanical properties of the hydrogel. The present study shows the combination of two normally non-compatible materials, silicone elastomer and poly(2-hydroxyethyl methacrylate) (PHEMA), into a novel composite...

A fish protein hydrolysate alters fatty acid composition in liver and adipose tissue and increases plasma carnitine levels in a mouse model of chronic inflammation.

Science.gov (United States)

Bjørndal, Bodil; Berge, Christ; Ramsvik, Marie Sannes; Svardal, Asbjørn; Bohov, Pavol; Skorve, Jon; Berge, Rolf K

2013-10-07

There is growing evidence that fish protein hydrolysate (FPH) diets affect mitochondrial fatty acid metabolism in animals. The aim of the study was to determine if FPH could influence fatty acid metabolism and inflammation in transgene mice expressing human tumor necrosis factor alpha (hTNFα). hTNFα mice (C57BL/6 hTNFα) were given a high-fat (23%, w/w) diet containing 20% casein (control group) or 15% FPH and 5% casein (FPH group) for two weeks. After an overnight fast, blood, adipose tissue, and liver samples were collected. Gene expression and enzyme activity was analysed in liver, fatty acid composition was analyzed in liver and ovarian white adipose tissue, and inflammatory parameters, carnitine, and acylcarnitines were analyzed in plasma. The n-3/n-6 fatty acid ratio was higher in mice fed the FPH diet than in mice fed the control diet in both adipose tissue and liver, and the FPH diet affected the gene expression of ∆6 and ∆9 desaturases. Mice fed this diet also demonstrated lower hepatic activity of fatty acid synthase. Concomitantly, a lower plasma INF-γ level was observed. Plasma carnitine and the carnitine precursor γ-butyrobetaine was higher in the FPH-group compared to control, as was plasma short-chained and medium-chained acylcarnitine esters. The higher level of plasma acetylcarnitine may reflect a stimulated mitochondrial and peroxisomal β-oxidation of fatty acids, as the hepatic activities of peroxisomal acyl-CoA oxidase 1 and mitochondrial carnitine palmitoyltransferase-II were higher in the FPH-fed mice. The FPH diet was shown to influence hepatic fatty acid metabolism and fatty acid composition. This indicates that effects on fatty acid metabolism are important for the bioactivity of protein hydrolysates of marine origin.

Measurement of breast tissue composition with dual energy cone-beam computed tomography: A postmortem study

Energy Technology Data Exchange (ETDEWEB)

Ding Huanjun; Ducote, Justin L.; Molloi, Sabee [Department of Radiological Sciences, University of California, Irvine, California 92697 (United States)

2013-06-15

Purpose: To investigate the feasibility of a three-material compositional measurement of water, lipid, and protein content of breast tissue with dual kVp cone-beam computed tomography (CT) for diagnostic purposes. Methods: Simulations were performed on a flat panel-based computed tomography system with a dual kVp technique in order to guide the selection of experimental acquisition parameters. The expected errors induced by using the proposed calibration materials were also estimated by simulation. Twenty pairs of postmortem breast samples were imaged with a flat-panel based dual kVp cone-beam CT system, followed by image-based material decomposition using calibration data obtained from a three-material phantom consisting of water, vegetable oil, and polyoxymethylene plastic. The tissue samples were then chemically decomposed into their respective water, lipid, and protein contents after imaging to allow direct comparison with data from dual energy decomposition. Results: Guided by results from simulation, the beam energies for the dual kVp cone-beam CT system were selected to be 50 and 120 kVp with the mean glandular dose divided equally between each exposure. The simulation also suggested that the use of polyoxymethylene as the calibration material for the measurement of pure protein may introduce an error of -11.0%. However, the tissue decomposition experiments, which employed a calibration phantom made out of water, oil, and polyoxymethylene, exhibited strong correlation with data from the chemical analysis. The average root-mean-square percentage error for water, lipid, and protein contents was 3.58% as compared with chemical analysis. Conclusions: The results of this study suggest that the water, lipid, and protein contents can be accurately measured using dual kVp cone-beam CT. The tissue compositional information may improve the sensitivity and specificity for breast cancer diagnosis.

Lipid composition of hepatic and adipose tissues from normal cats and from cats with idiopathic hepatic lipidosis.

Science.gov (United States)

Hall, J A; Barstad, L A; Connor, W E

1997-01-01

The purpose of this study was to characterize the lipid classes in hepatic and adipose tissues from cats with idiopathic hepatic lipidosis (IHL). Concentrations of triglyceride, phospholipid phosphorus, and free and total cholesterol were determined in lipid extracts of liver homogenates from 5 cats with IHL and 5 healthy control cats. Total fatty acid composition of liver and adipose tissue was also compared. Triglyceride accounted for 34% of liver by weight in cats with IHL (338 +/- 38 mg/g wet liver) versus 1% in control cats (9.9 +/- 1.0 mg/g wet liver, P hepatic tissue in the 2 groups differed; palmitate was higher (19.5 +/- 1.1% of total fatty acids in cats with IHL versus 9.2 +/- 2.7% in controls, P hepatic triglyceride in cats with IHL is the mobilization of fatty acids from adipose tissue.

Composite hydrogel of chitosan-poly(hydroxybutyrate-co-valerate) with chondroitin sulfate nanoparticles for nucleus pulposus tissue engineering.

Science.gov (United States)

Nair, Manitha B; Baranwal, Gaurav; Vijayan, Prajuna; Keyan, Kripa S; Jayakumar, R

2015-12-01

Intervertebral disc degeneration, occurring mainly in nucleus pulposus (NP), is a leading cause of low back pain. In seeking to mitigate this condition, investigators in the field of NP tissue engineering have increasingly studied the use of hydrogels. However, these hydrogels should possess appropriate mechanical strength and swelling pressure, and concurrently support the proliferation of chondrocyte-like cells. The objective of this study was to develop and validate a composite hydrogel for NP tissue engineering, made of chitosan-poly(hydroxybutyrate-co-valerate) (CP) with chondroitin sulfate (CS) nanoparticles, without using a cross linker. The water uptake ability, as well as the viscoelastic properties of this composite hydrogel, was similar to native tissue, as reflected in the complex shear modulus and stress relaxation values. The hydrogel could withstand varying stress corresponding to daily activities like lying down (0.01 MPa), sitting (0.5 MPa) and standing (1.0 MPa) under dynamic conditions. The hydrogels were stable in PBS for 2 weeks and its stiffness, elastic and viscous modulus did not alter significantly during this period. Both CP and CP-CS hydrogels could assist the viability and adhesion of adipose derived rat mesenchymal stem cells (ADMSCs). The viability and chondrogenic differentiation of MSCs was significantly enhanced in presence of CS nanoparticles. Thus, CS nanoparticles-incorporated chitosan-PHBV hydrogels offer great potential for NP tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

Prediction of Local Ultimate Strain and Toughness of Trabecular Bone Tissue by Raman Material Composition Analysis

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Roberto Carretta

2015-01-01

Full Text Available Clinical studies indicate that bone mineral density correlates with fracture risk at the population level but does not correlate with individual fracture risk well. Current research aims to better understand the failure mechanism of bone and to identify key determinants of bone quality, thus improving fracture risk prediction. To get a better understanding of bone strength, it is important to analyze tissue-level properties not influenced by macro- or microarchitectural factors. The aim of this pilot study was to identify whether and to what extent material properties are correlated with mechanical properties at the tissue level. The influence of macro- or microarchitectural factors was excluded by testing individual trabeculae. Previously reported data of mechanical parameters measured in single trabeculae under tension and bending and its compositional properties measured by Raman spectroscopy was evaluated. Linear and multivariate regressions show that bone matrix quality but not quantity was significantly and independently correlated with the tissue-level ultimate strain and postyield work (r=0.65–0.94. Principal component analysis extracted three independent components explaining 86% of the total variance, representing elastic, yield, and ultimate components according to the included mechanical parameters. Some matrix parameters were both included in the ultimate component, indicating that the variation in ultimate strain and postyield work could be largely explained by Raman-derived compositional parameters.

Engineering of Corneal Tissue through an Aligned PVA/Collagen Composite Nanofibrous Electrospun Scaffold.

Science.gov (United States)

Wu, Zhengjie; Kong, Bin; Liu, Rui; Sun, Wei; Mi, Shengli

2018-02-24

Corneal diseases are the main reason of vision loss globally. Constructing a corneal equivalent which has a similar strength and transparency with the native cornea, seems to be a feasible way to solve the shortage of donated cornea. Electrospun collagen scaffolds are often fabricated and used as a tissue-engineered cornea, but the main drawback of poor mechanical properties make it unable to meet the requirement for surgery suture, which limits its clinical applications to a large extent. Aligned polyvinyl acetate (PVA)/collagen (PVA-COL) scaffolds were electrospun by mixing collagen and PVA to reinforce the mechanical strength of the collagen electrospun scaffold. Human keratocytes (HKs) and human corneal epithelial cells (HCECs) inoculated on aligned and random PVA-COL electrospun scaffolds adhered and proliferated well, and the aligned nanofibers induced orderly HK growth, indicating that the designed PVA-COL composite nanofibrous electrospun scaffold is suitable for application in tissue-engineered cornea.

Greener synthesis of electrospun collagen/hydroxyapatite composite fibers with an excellent microstructure for bone tissue engineering

Directory of Open Access Journals (Sweden)

Zhou YY

2015-04-01

Full Text Available Yuanyuan Zhou,1,2 Hongchang Yao,1 Jianshe Wang,1 Dalu Wang,1 Qian Liu,1 Zhongjun Li11College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, People’s Republic of China; 2Institute of Enviromental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, People’s Republic of ChinaAbstract: In bone tissue engineering, collagen/hydroxyapatite (HAP fibrous composite obtained via electrospinning method has been demonstrated to support the cells’ adhesion and bone regeneration. However, electrospinning of natural collagen often requires the use of cytotoxic organic solvents, and the HAP crystals were usually aggregated and randomly distributed within a fibrous matrix of collagen, limiting their clinical potential. Here, an effective and greener method for the preparation of collagen/HAP composite fibers was developed for the first time, and this green product not only had 40 times higher mechanical properties than that previously reported, but also had an excellent microstructure similar to that of natural bone. By dissolving type I collagen in environmentally friendly phosphate buffered saline/ethanol solution instead of the frequently-used cytotoxic organic solvents, followed with the key step of desalination, co-electrospinning the collagen solution with the HAP sol, generates a collagen/HAP composite with a uniform and continuous fibrous morphology. Interestingly, the nano-HAP needles were found to preferentially orient along the longitudinal direction of the collagen fibers, which mimicked the nanostructure of natural bones. Based on the characterization of the related products, the formation mechanism for this novel phenomenon was proposed. After cross-linking with 1-ethyl-3-(3-dimethyl-aminopropyl-1-carbodiimide hydrochloride/N-hydroxysuccinimide, the obtained composite exhibited a significant enhancement in mechanical properties. In addition, the biocompatibility of the

Silicone-based composite materials simulate breast tissue to be used as ultrasonography training phantoms.

Science.gov (United States)

Ustbas, Burcin; Kilic, Deniz; Bozkurt, Ayhan; Aribal, Mustafa Erkin; Akbulut, Ozge

2018-03-02

A silicone-based composite breast phantom is fabricated to be used as an education model in ultrasonography training. A matrix of silicone formulations is tracked to mimic the ultrasonography and tactile response of human breast tissue. The performance of two different additives: (i) silicone oil and (ii) vinyl-terminated poly (dimethylsiloxane) (PDMS) are monitored by a home-made acoustic setup. Through the use of 75 wt% vinyl-terminated PDMS in two-component silicone elastomer mixture, a sound velocity of 1.29 ± 0.09 × 10 3  m/s and an attenuation coefficient of 12.99 ± 0.08 dB/cm-values those match closely to the human breast tissue-are measured with 5 MHz probe. This model can also be used for needle biopsy as well as for self-exam trainings. Herein, we highlight the fabrication of a realistic, durable, accessible, and cost-effective training platform that contains skin layer, inner breast tissue, and tumor masses. Copyright © 2018. Published by Elsevier B.V.

[The connective tissues, from the origin of the concept to its "Maturation" to extracellular matrix. Application to ocular tissues. Contribution to the history of medical sciences].

Science.gov (United States)

Labat-Robert, J; Robert, L; Pouliquen, Y

2011-06-01

The "Tissue" concept emerged apparently in the medical literature at about the French revolution, during the second half of the 18(th) century. It was found in the texts written by the physicians of Béarn and Montpellier, the Bordeu-s and also by the famous physician, Felix Vicq d'Azyr, the last attending physician of the queen Marie-Antoinette, "Bordeu et al. (1775) et Pouliquen (2009)". It was elaborated into a coherent doctrine somewhat later by Xavier Bichat, considered as the founder of modern pathological anatomy, Bichat. With the advent of histochemistry, from the beginning of the 20(th) century, several of the principal macromolecular components of connective tissues, collagens, elastin, "acid mucopolysaccharides" (later glycosaminoglycans and proteoglycans) and finally structural glycoproteins were characterized. These constituents of connective tissues were then designated as components of the extracellular matrix (ECM), closely associated to the cellular components of these tissues by adhesive (structural) glycoproteins as fibronectin, several others and cell receptors, "recognising" ECM-components as integrins, the elastin-receptor and others. This molecular arrangement fastens cells to the ECM-components they synthesize and mediates the exchange of informations between the cells to the ECM (inside-out) and also from the ECM-components to the cells (outside-in). This macromolecular arrangement is specific for each tissue as a result of the differentiation of their cellular components. It is also the basis and condition of the fulfillment of the specific functions of differentiated tissues. This is a short description of the passage of the "tissue" concept from its vague origin towards its precise identification at the cellular and molecular level up to the recognition of its functional importance and its establishment as an autonomous science. This can be considered as a new example of the importance of metaphors for the progress of science, Keller

Erupted complex composite odontoma: Report of two atypical cases

Directory of Open Access Journals (Sweden)

Preeti Tomar Bhattacharya

2015-01-01

Full Text Available Odontomas are nonaggressive, hamartomatous developmental malformations of odontogenic origin. They are considered one of the most common odontogenic lesions composed by diverse dental tissues. They may interfere with the eruption of an associated tooth and are more prevalent in the posterior mandible. The eruption of a complex odontoma into the oral cavity is rare. Here, we report such two rare cases of gigantic erupted complex composite odontomas.

Preparation of a biomimetic composite scaffold from gelatin/collagen and bioactive glass fibers for bone tissue engineering

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Sharifi, Esmaeel; Azami, Mahmoud [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Kajbafzadeh, Abdol-Mohammad [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Pediatric Urology, Children' s Hospital Medical Center, Tehran, Iran (IRI) (Iran, Islamic Republic of); Moztarzadeh, Fatollah [Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran (Iran, Islamic Republic of); Faridi-Majidi, Reza [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shamousi, Atefeh; Karimi, Roya [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ai, Jafar, E-mail: jafar_ai@tums.ac.ir [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Brain and Spinal Injury Research Center (BASIR), Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2016-02-01

Bone tissue is a composite material made of organic and inorganic components. Bone tissue engineering requires scaffolds that mimic bone nature in chemical and mechanical properties. This study proposes a novel method for preparing composite scaffolds that uses sub-micron bioglass fibers as the organic phase and gelatin/collagen as the inorganic phase. The scaffolds were constructed by using freeze drying and electro spinning methods and their mechanical properties were enhanced by using genipin crosslinking agent. Electron microscopy micrographs showed that the structure of composite scaffolds were porous with pore diameters of approximately 70–200 μm, this was again confirmed by mercury porosimetery. These pores are suitable for osteoblast growth. The diameters of the fibers were approximately 150–450 nm. Structural analysis confirmed the formation of desirable phases of sub-micron bioglass fibers. Cellular biocompatibility tests illustrated that scaffolds containing copper ion in the bioglass structure had more cell growth and osteoblast attachment in comparison to copper-free scaffolds. - Highlights: • Fabrication of 45S5 sub-micron bioglass fiber using electrospinning method. • Production of copper doped submicron bioglass fibers on 45S5 bioglass base by electrospinning sol gel route method. • Incorporation of bioglass/Cu-bioglass sub-micron fibers into gelatin/collagen matrix to form biomimetic composite scaffold which were non-cytotoxic according to MTT assay. • Discovering that copper can decrease the glass transition temperatures and enhance osteoblast cell adhesion and viability.

Preparation of a biomimetic composite scaffold from gelatin/collagen and bioactive glass fibers for bone tissue engineering

International Nuclear Information System (INIS)

Sharifi, Esmaeel; Azami, Mahmoud; Kajbafzadeh, Abdol-Mohammad; Moztarzadeh, Fatollah; Faridi-Majidi, Reza; Shamousi, Atefeh; Karimi, Roya; Ai, Jafar

2016-01-01

Bone tissue is a composite material made of organic and inorganic components. Bone tissue engineering requires scaffolds that mimic bone nature in chemical and mechanical properties. This study proposes a novel method for preparing composite scaffolds that uses sub-micron bioglass fibers as the organic phase and gelatin/collagen as the inorganic phase. The scaffolds were constructed by using freeze drying and electro spinning methods and their mechanical properties were enhanced by using genipin crosslinking agent. Electron microscopy micrographs showed that the structure of composite scaffolds were porous with pore diameters of approximately 70–200 μm, this was again confirmed by mercury porosimetery. These pores are suitable for osteoblast growth. The diameters of the fibers were approximately 150–450 nm. Structural analysis confirmed the formation of desirable phases of sub-micron bioglass fibers. Cellular biocompatibility tests illustrated that scaffolds containing copper ion in the bioglass structure had more cell growth and osteoblast attachment in comparison to copper-free scaffolds. - Highlights: • Fabrication of 45S5 sub-micron bioglass fiber using electrospinning method. • Production of copper doped submicron bioglass fibers on 45S5 bioglass base by electrospinning sol gel route method. • Incorporation of bioglass/Cu-bioglass sub-micron fibers into gelatin/collagen matrix to form biomimetic composite scaffold which were non-cytotoxic according to MTT assay. • Discovering that copper can decrease the glass transition temperatures and enhance osteoblast cell adhesion and viability.

Elemental composition of 'normal' and Alzheimer brain tissue by INA and PIXE analyses

International Nuclear Information System (INIS)

Stedman, J.D.; Spyrou, N.M.

1997-01-01

Instrumental methods based on the nuclear and atomic properties of the elements have been used for many years to determine elemental concentrations in a variety of materials for biomedical, industrial and environmental applications. These methods offer high sensitivity for accurate trace element measurements, suffer few interfering or competing effects. Present no blank problems and are convenient for both research and routine analyses. The present article describes the use of two trace element techniques. Firstly the use of activation of stable nuclei irradiated by neutrons in the core of a low power research reactor as a means of detection of elements through the resulting gamma-rays emitted. Secondly, the observations of the interactions of energetic ion beams with the material in order to identify elemental species. Over recent years there has been some interest in determining the elemental composition of 'normal' and Alzheimer affected brain tissue, however literature findings are inconsistent. Possible reasons for discrepancies need to be identified for further progress to be made. Here, post-mortem tissue samples, provided by the Alzheimer's Disease Brain Bank, Institute of Psychiatry, London, were taken from the frontal, occipital, parietal and temporal lobes of both hemispheres of brains from 13 'normal' and 19 Alzheimer subjects. The elemental composition of the samples was determined using the analytical techniques of INAA (instrumental neutron activation analysis), RBS (Rutherford back-scattering) and PIXE (particle induced x-ray emission). The principal findings are summarised here. (author)

Quantitative Susceptibility Mapping of Human Brain Reflects Spatial Variation in Tissue Composition

Science.gov (United States)

Li, Wei; Wu, Bing; Liu, Chunlei

2011-01-01

Image phase from gradient echo MRI provides a unique contrast that reflects brain tissue composition variations, such as iron and myelin distribution. Phase imaging is emerging as a powerful tool for the investigation of functional brain anatomy and disease diagnosis. However, the quantitative value of phase is compromised by its nonlocal and orientation dependent properties. There is an increasing need for reliable quantification of magnetic susceptibility, the intrinsic property of tissue. In this study, we developed a novel and accurate susceptibility mapping method that is also phase-wrap insensitive. The proposed susceptibility mapping method utilized two complementary equations: (1) the Fourier relationship of phase and magnetic susceptibility; and (2) the first-order partial derivative of the first equation in the spatial frequency domain. In numerical simulation, this method reconstructed the susceptibility map almost free of streaking artifact. Further, the iterative implementation of this method allowed for high quality reconstruction of susceptibility maps of human brain in vivo. The reconstructed susceptibility map provided excellent contrast of iron-rich deep nuclei and white matter bundles from surrounding tissues. Further, it also revealed anisotropic magnetic susceptibility in brain white matter. Hence, the proposed susceptibility mapping method may provide a powerful tool for the study of brain physiology and pathophysiology. Further elucidation of anisotropic magnetic susceptibility in vivo may allow us to gain more insight into the white matter microarchitectures. PMID:21224002

Preparation and characterization of gelatin–hydroxyapatite composite microspheres for hard tissue repair

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Chao, Shao Ching [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China); Department of Minimally Invasive Skull Neurosurgery, Neurological Institute, Taichung Veterans General Hospital, 1650 Taiwan Boulevard, Sect. 4, Taichung, Taiwan (China); Department of Neurosurgery, ChangHua Hospital, Ministry of Health and Welfare, 80 Chung Cheng Road, Sect. 2 Chiu Kuan Village, Changhua 500, Taiwan (China); Wang, Ming-Jia; Pai, Nai-Su [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China); Yen, Shiow-Kang, E-mail: skyen@dragon.nchu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China)

2015-12-01

Gelatin–hydroxyapatite composite microspheres composed of 21% gelatin (G) and 79% hydroxyapatite (HA) with uniform morphology and controllable size were synthesized from a mixed solution of Ca(NO{sub 3}){sub 2}, NH{sub 4}H{sub 2}PO{sub 4} and gelatin by a wet-chemical method. Material analyses such as X-ray diffraction (XRD), scanning/transmission electron microscopy examination (SEM/TEM) and inductively coupled plasma-mass spectroscopy (ICP-MS) were used to characterize G–HA microspheres by analyzing their crystalline phase, microstructure, morphology and composition. HA crystals precipitate along G fibers to form nano-rods with diameters of 6–10 nm and tangle into porous microspheres after blending. The cell culture indicates that G–HA composite microspheres without any toxicity could enhance the proliferation and differentiation of osteoblast-like cells. In a rat calvarial defect model, G–HA bioactive scaffolds were compared with fibrin glue (F) and Osteoset® Bone Graft Substitute (OS) for their capacity of regenerating bone. Four weeks post-implantation, new bone, mineralization, and expanded blood vessel area were found in G–HA scaffolds, indicating greater osteoconductivity and bioactivity than F and OS. - Highlights: • G–HA composite microspheres were prepared by hydroxyapatite and gelatin. • In vitro tests indicated that the G–HA microspheres were biocompatible and bioactive. • In in vitro tests, G–HA microspheres could be applied in hard tissue engineering. • G–HA had healed the bone defect and provides a high proportion of surface area to open space.

Renal cell carcinoma primary cultures maintain genomic and phenotypic profile of parental tumor tissues

International Nuclear Information System (INIS)

Cifola, Ingrid; Magni, Fulvio; Signorini, Stefano; Battaglia, Cristina; Perego, Roberto A; Bianchi, Cristina; Mangano, Eleonora; Bombelli, Silvia; Frascati, Fabio; Fasoli, Ester; Ferrero, Stefano; Di Stefano, Vitalba; Zipeto, Maria A

2011-01-01

Clear cell renal cell carcinoma (ccRCC) is characterized by recurrent copy number alterations (CNAs) and loss of heterozygosity (LOH), which may have potential diagnostic and prognostic applications. Here, we explored whether ccRCC primary cultures, established from surgical tumor specimens, maintain the DNA profile of parental tumor tissues allowing a more confident CNAs and LOH discrimination with respect to the original tissues. We established a collection of 9 phenotypically well-characterized ccRCC primary cell cultures. Using the Affymetrix SNP array technology, we performed the genome-wide copy number (CN) profiling of both cultures and corresponding tumor tissues. Global concordance for each culture/tissue pair was assayed evaluating the correlations between whole-genome CN profiles and SNP allelic calls. CN analysis was performed using the two CNAG v3.0 and Partek software, and comparing results returned by two different algorithms (Hidden Markov Model and Genomic Segmentation). A very good overlap between the CNAs of each culture and corresponding tissue was observed. The finding, reinforced by high whole-genome CN correlations and SNP call concordances, provided evidence that each culture was derived from its corresponding tissue and maintained the genomic alterations of parental tumor. In addition, primary culture DNA profile remained stable for at least 3 weeks, till to third passage. These cultures showed a greater cell homogeneity and enrichment in tumor component than original tissues, thus enabling a better discrimination of CNAs and LOH. Especially for hemizygous deletions, primary cultures presented more evident CN losses, typically accompanied by LOH; differently, in original tissues the intensity of these deletions was weaken by normal cell contamination and LOH calls were missed. ccRCC primary cultures are a reliable in vitro model, well-reproducing original tumor genetics and phenotype, potentially useful for future functional approaches

The origin of the elements. Chapter 3

International Nuclear Information System (INIS)

Tayler, R.J.

1980-01-01

The paper is concerned with the questions: how the present chemical composition is related to the original composition of the Universe, and what was the nature of that original composition. In particular, the chemical evolution of the Galaxy is discussed. Section headings are: observations of chemical composition (stars, cosmic gases, galaxies, element abundance); theoretical considerations (nucleosynthesis); cosmological element production (the Hot Big Bang theory); galactic nucleosynthesis. (U.K.)

The materials used in bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Tereshchenko, V. P., E-mail: tervp@ngs.ru; Kirilova, I. A.; Sadovoy, M. A.; Larionov, P. M. [Novosibirsk Research Institute of Traumatology and Orthopedics n.a. Ya.L. Tsivyan, Novosibirsk (Russian Federation)

2015-11-17

Bone tissue engineering looking for an alternative solution to the problem of skeletal injuries. The method is based on the creation of tissue engineered bone tissue equivalent with stem cells, osteogenic factors, and scaffolds - the carriers of these cells. For production of tissue engineered bone equivalent is advisable to create scaffolds similar in composition to natural extracellular matrix of the bone. This will provide optimal conditions for the cells, and produce favorable physico-mechanical properties of the final construction. This review article gives an analysis of the most promising materials for the manufacture of cell scaffolds. Biodegradable synthetic polymers are the basis for the scaffold, but it alone cannot provide adequate physical and mechanical properties of the construction, and favorable conditions for the cells. Addition of natural polymers improves the strength characteristics and bioactivity of constructions. Of the inorganic compounds, to create cell scaffolds the most widely used calcium phosphates, which give the structure adequate stiffness and significantly increase its osteoinductive capacity. Signaling molecules do not affect the physico-mechanical properties of the scaffold, but beneficial effect is on the processes of adhesion, proliferation and differentiation of cells. Biodegradation of the materials will help to fulfill the main task of bone tissue engineering - the ability to replace synthetic construct by natural tissues that will restore the original anatomical integrity of the bone.

Monte Carlo study of voxel S factor dependence on tissue density and atomic composition

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Amato, Ernesto, E-mail: eamato@unime.it [University of Messina, Department of Biomedical Sciences and of Morphologic and Functional Imaging, Section of Radiological Sciences, via Consolare Valeria, 1, I-98125 Messina (Italy); Italiano, Antonio [INFN – Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Messina (Italy); Baldari, Sergio [University of Messina, Department of Biomedical Sciences and of Morphologic and Functional Imaging, Section of Radiological Sciences, via Consolare Valeria, 1, I-98125 Messina (Italy)

2013-11-21

Voxel dosimetry is a common approach to the internal dosimetry of non-uniform activity distributions in nuclear medicine therapies with radiopharmaceuticals and in the estimation of the radiation hazard due to internal contamination of radionuclides. Aim of the present work is to extend our analytical approach for the calculation of voxel S factors to materials different from the soft tissue. We used a Monte Carlo simulation in GEANT4 of a voxelized region of each material in which the source of monoenergetic electrons or photons was uniformly distributed within the central voxel, and the energy deposition was scored over the surrounding 11×11×11 voxels. Voxel S factors were obtained for the following standard ICRP materials: Adipose tissue, Bone cortical, Brain, Lung, Muscle skeletal and Tissue soft with 1 g cm{sup −3} density. Moreover, we considered the standard ICRU materials: Bone compact and Muscle striated. Voxel S factors were represented as a function of the “normalized radius”, defined as the ratio between the source–target voxel distance and the voxel side. We found that voxel S factors and related analytical fit functions are mainly affected by the tissue density, while the material composition gives only a slight contribution to the difference between data series, which is negligible for practical purposes. Our results can help in broadening the dosimetric three-dimensional approach based on voxel S factors to other tissues where diagnostic and therapeutic radionuclides can be taken up and radiation can propagate.

Monte Carlo study of voxel S factor dependence on tissue density and atomic composition

International Nuclear Information System (INIS)

Amato, Ernesto; Italiano, Antonio; Baldari, Sergio

2013-01-01

Voxel dosimetry is a common approach to the internal dosimetry of non-uniform activity distributions in nuclear medicine therapies with radiopharmaceuticals and in the estimation of the radiation hazard due to internal contamination of radionuclides. Aim of the present work is to extend our analytical approach for the calculation of voxel S factors to materials different from the soft tissue. We used a Monte Carlo simulation in GEANT4 of a voxelized region of each material in which the source of monoenergetic electrons or photons was uniformly distributed within the central voxel, and the energy deposition was scored over the surrounding 11×11×11 voxels. Voxel S factors were obtained for the following standard ICRP materials: Adipose tissue, Bone cortical, Brain, Lung, Muscle skeletal and Tissue soft with 1 g cm −3 density. Moreover, we considered the standard ICRU materials: Bone compact and Muscle striated. Voxel S factors were represented as a function of the “normalized radius”, defined as the ratio between the source–target voxel distance and the voxel side. We found that voxel S factors and related analytical fit functions are mainly affected by the tissue density, while the material composition gives only a slight contribution to the difference between data series, which is negligible for practical purposes. Our results can help in broadening the dosimetric three-dimensional approach based on voxel S factors to other tissues where diagnostic and therapeutic radionuclides can be taken up and radiation can propagate

Bioceramic/Poly (glycolic-poly (lactic acid composite induces mineralized barrier after direct capping of rat tooth pulp tissue

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Alfonso Gala-Garcia

2010-03-01

Full Text Available The aim of this study was to observe the histopathological pulp response following direct pulp capping of mechanically exposed teeth in rats with a composite of beta-tricalcium phosphate-hydroxyapatite bioceramic (BC and poly (glycolic-poly (lactic acid (PLGA material or a calcium hydroxide [Ca(OH2] material, compared to BC alone and a negative control of water. Pulp of the maxillary molars was exposed, followed by capping with the experimental material. The pulpal tissue response was assessed post-operatively at 1, 7, 14 and 30 d, followed by histological analysis. The Ca(OH2 group exhibited severe acute inflammatory cell infiltration at day 14. However after 30 d, a new hard tissue with macro porous obliteration of the pulp chamber and a characteristic necrotic area had appeared. BC and Ca(OH2 capping were associated with moderate inflammation and dentinal bridge similar. Meanwhile, in the BC/PLGA composite group, there was moderate inflammatory infiltrate and formation of a dense and complete dentinal bridge. In conclusion, the BC/PLGA composite material showed a large zone of tertiary dentin, and effectively reorganized the dentin-pulp complex.

In vitro evaluation of three-dimensional single-walled carbon nanotube composites for bone tissue engineering.

Science.gov (United States)

Gupta, Ashim; Main, Benjamin J; Taylor, Brittany L; Gupta, Manu; Whitworth, Craig A; Cady, Craig; Freeman, Joseph W; El-Amin, Saadiq F

2014-11-01

The purpose of this study was to develop three-dimensional single-walled carbon nanotube composites (SWCNT/PLAGA) using 10-mg single-walled carbon nanotubes (SWCNT) for bone regeneration and to determine the mechanical strength of the composites, and to evaluate the interaction of MC3T3-E1 cells via cell adhesion, growth, survival, proliferation, and gene expression. PLAGA (polylactic-co-glycolic acid) and SWCNT/PLAGA microspheres and composites were fabricated, characterized, and mechanical testing was performed. MC3T3-E1 cells were seeded and cell adhesion/morphology, growth/survival, proliferation, and gene expression analysis were performed to evaluate biocompatibility. Imaging studies demonstrated microspheres with uniform shape and smooth surfaces, and uniform incorporation of SWCNT into PLAGA matrix. The microspheres bonded in a random packing manner while maintaining spacing, thus resembling trabeculae of cancellous bone. Addition of SWCNT led to greater compressive modulus and ultimate compressive strength. Imaging studies revealed that MC3T3-E1 cells adhered, grew/survived, and exhibited normal, nonstressed morphology on the composites. SWCNT/PLAGA composites exhibited higher cell proliferation rate and gene expression compared with PLAGA. These results demonstrate the potential of SWCNT/PLAGA composites for musculoskeletal regeneration, for bone tissue engineering, and are promising for orthopedic applications as they possess the combined effect of increased mechanical strength, cell proliferation, and gene expression. © 2014 Wiley Periodicals, Inc.

Titanium-hydroxyapatite composites sintered at low temperature for tissue engineering: in vitro cell support and biocompatibility.

Science.gov (United States)

Comín, Romina; Cid, Mariana P; Grinschpun, Luciano; Oldani, Carlos; Salvatierra, Nancy A

2017-04-26

In clinical orthopedics, a critical problem is the bone tissue loss produced by a disease or injury. The use of composites from titanium and hydroxyapatite for biomedical applications has increased due to the resulting advantageous combination of hydroxyapatite bioactivity and favorable mechanical properties of titanium. Powder metallurgy is a simple and lower-cost method that uses powder from titanium and hydroxyapatite to obtain composites having hydroxyapatite phases in a metallic matrix. However, this method has certain limitations arising from thermal decomposition of hydroxyapatite in the titanium-hydroxyapatite system above 800°C. We obtained a composite from titanium and bovine hydroxyapatite powders sintered at 800°C and evaluated its bioactivity and cytocompatibility according to the ISO 10993 standard. Surface analysis and bioactivity of the composite was evaluated by X-ray diffraction and SEM. MTT assay was carried out to assess cytotoxicity on Vero and NIH3T3 cells. Cell morphology and cell adhesion on the composite surface were analyzed using fluorescence and SEM. We obtained a porous composite with hydroxyapatite particles well integrated in titanium matrix which presented excellent bioactivity. Our data did not reveal any toxicity of titanium-hydroxyapatite composite on Vero or NIH3T3 cells. Moreover, extracts from composite did not affect cell morphology or density. Finally, NIH3T3 cells were capable of adhering to and proliferating on the composite surface. The composite obtained displayed promising biomedical applications through the simple method of powder metallurgy. Additionally, these findings provide an in vitro proof for adequate biocompatibility of titanium-hydroxyapatite composite sintered at 800°C.

Variation in oil content and fatty acid composition of sesame accessions from different origins

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C. Kurt

2018-03-01

Full Text Available Oil content and fatty acid composition are very important parameters for the human consumption of oilseed crops. Twenty-four sesame accessions including seven collected from various geographical regions of Turkey and 11 from different countries were investigated under field conditions for two consecutive years (2015 and 2016. The sesame accessions varied widely in their oil content and fatty acid compositions. The oil content varied between 44.6 and 53.1% with an average value of 48.15%. The content of oleic acids, linoleic acid, linolenic acid, palmitic acid,and stearic acid varied between 36.13–43.63%, 39.13–46.38%, 0.28–0.4%, 8.19–10.26%, and 4.63–6.35%, respectively. When total oil content and fatty acid composition were compared, Turkish sesame showed wide variation in oil and fatty acid compositions compared to those from other countries. However, the accessions from other countries were fewer compared to those from Turkey. It is essential to compare oil and fatty acid composition using a large number of germ plasm from different origins. In sesame oil, the average contents of oleic acid and linoleic acid were 39.02% and 43.64%, respectively, and their combined average content was 82.66%, representing the major fatty acid components in the oil from the sesame accessions used in the present study. The results obtained in this study provide useful information for the identification of better parents with high linoleic and oleic acid contents for developing elite sesame varieties with traits which are beneficial to consumer health.

Viscoelastic behaviour of hydrogel-based composites for tissue engineering under mechanical load.

Science.gov (United States)

Kocen, Rok; Gasik, Michael; Gantar, Ana; Novak, Saša

2017-03-06

Along with biocompatibility, bioinductivity and appropriate biodegradation, mechanical properties are also of crucial importance for tissue engineering scaffolds. Hydrogels, such as gellan gum (GG), are usually soft materials, which may benefit from the incorporation of inorganic particles, e.g. bioactive glass, not only due to the acquired bioactivity, but also due to improved mechanical properties. They exhibit complex viscoelastic properties, which can be evaluated in various ways. In this work, to reliably evaluate the effect of the bioactive glass (BAG) addition on viscoelastic properties of the composite hydrogel, we employed and compared the three most commonly used techniques, analyzing their advantages and limitations: monotonic uniaxial unconfined compression, small amplitude oscillatory shear (SAOS) rheology and dynamic mechanical analysis (DMA). Creep and small amplitude dynamic strain-controlled tests in DMA are suggested as the best ways for the characterization of mechanical properties of hydrogel composites, whereas the SAOS rheology is more useful for studying the hydrogel's processing kinetics, as it does not induce volumetric changes even at very high strains. Overall, the results confirmed a beneficial effect of BAG (nano)particles on the elastic modulus of the GG-BAG composite hydrogel. The Young's modulus of 6.6 ± 0.8 kPa for the GG hydrogel increased by two orders of magnitude after the addition of 2 wt.% BAG particles (500-800 kPa).

Laminated electrospun nHA/PHB-composite scaffolds mimicking bone extracellular matrix for bone tissue engineering

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Chen, Zhuoyue [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Song, Yue [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Zhang, Jing [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Key Laboratory of Resource Biology and Modern Biotechnology in Western China, Ministry of Education, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province, 710069 (China); Liu, Wei [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Cui, Jihong, E-mail: cjh@nwu.edu.cn [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Key Laboratory of Resource Biology and Modern Biotechnology in Western China, Ministry of Education, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province, 710069 (China); and others

2017-03-01

Electrospinning is an effective means to generate nano- to micro-scale polymer fibers resembling native extracellular matrix for tissue engineering. However, a major problem of electrospun materials is that limited pore size and porosity may prevent adequate cellular infiltration and tissue ingrowth. In this study, we first prepared thin layers of hydroxyapatite nanoparticle (nHA)/poly-hydroxybutyrate (PHB) via electrospinning. We then laminated the nHA/PHB thin layers to obtain a scaffold for cell seeding and bone tissue engineering. The results demonstrated that the laminated scaffold possessed optimized cell-loading capacity. Bone marrow mesenchymal stem cells (MSCs) exhibited better adherence, proliferation and osteogenic phenotypes on nHA/PHB scaffolds than on PHB scaffolds. Thereafter, we seeded MSCs onto nHA/PHB scaffolds to fabricate bone grafts. Histological observation showed osteoid tissue formation throughout the scaffold, with most of the scaffold absorbed in the specimens 2 months after implantation, and blood vessels ingrowth into the graft could be observed in the graft. We concluded that electrospun and laminated nanoscaled biocomposite scaffolds hold great therapeutic potential for bone regeneration. - Highlights: • We laminated the nHA/PHB layers to obtain a scaffold for bone tissue engineering. • The laminated scaffold performed optimized cell-loading capacity. • MSCs exhibited osteogenic phenotypes on the laminated scaffold. • Osteoid tissue formed throughout the laminated scaffold after 2 months in vivo. The laminated bio-composite scaffolds can be applied to bone regeneration.

Laminated electrospun nHA/PHB-composite scaffolds mimicking bone extracellular matrix for bone tissue engineering

International Nuclear Information System (INIS)

Chen, Zhuoyue; Song, Yue; Zhang, Jing; Liu, Wei; Cui, Jihong

2017-01-01

Electrospinning is an effective means to generate nano- to micro-scale polymer fibers resembling native extracellular matrix for tissue engineering. However, a major problem of electrospun materials is that limited pore size and porosity may prevent adequate cellular infiltration and tissue ingrowth. In this study, we first prepared thin layers of hydroxyapatite nanoparticle (nHA)/poly-hydroxybutyrate (PHB) via electrospinning. We then laminated the nHA/PHB thin layers to obtain a scaffold for cell seeding and bone tissue engineering. The results demonstrated that the laminated scaffold possessed optimized cell-loading capacity. Bone marrow mesenchymal stem cells (MSCs) exhibited better adherence, proliferation and osteogenic phenotypes on nHA/PHB scaffolds than on PHB scaffolds. Thereafter, we seeded MSCs onto nHA/PHB scaffolds to fabricate bone grafts. Histological observation showed osteoid tissue formation throughout the scaffold, with most of the scaffold absorbed in the specimens 2 months after implantation, and blood vessels ingrowth into the graft could be observed in the graft. We concluded that electrospun and laminated nanoscaled biocomposite scaffolds hold great therapeutic potential for bone regeneration. - Highlights: • We laminated the nHA/PHB layers to obtain a scaffold for bone tissue engineering. • The laminated scaffold performed optimized cell-loading capacity. • MSCs exhibited osteogenic phenotypes on the laminated scaffold. • Osteoid tissue formed throughout the laminated scaffold after 2 months in vivo. The laminated bio-composite scaffolds can be applied to bone regeneration.

Fatty acid composition of ostrich (Struthio camelus abdominal adipose tissue

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Daniela Belichovska

2015-03-01

Full Text Available Fatty acid composition of foods has a great impact on nutrition and health. Therefore, thе determination and knowledge of the fatty acid composition of food is very important for nutrition. Due to the high nutritional characteristics of ostrich meat and its products, the research determining their quality is of topical interest. The aim of the present investigation was the determination of fatty acid composition of ostrich adipose tissue. The content of fatty acids was determined according to AOAC Official Methods of Analysis and determination was performed using a gas chromatograph with a flame-ionization detector (GC-FID. The results are expressed as a percentage of the total content of fatty acids. The method was validated and whereupon the following parameters were determined: linearity, precision, recovery, limit of detection and limit of quantification. The repeatability was within of 0.99 to 2.15%, reproducibility from 2.01 to 4.57%, while recovery ranged from 94.89 to 101.03%. According to these results, this method is accurate and precise and can be used for analysis of fatty acids in foods. It was concluded that the content of saturated fatty acids (SFA accounted 34.75%, of monounsaturated fatty acids (MUFA 38.37%, of polyunsaturated fatty acids (PUFA 26.88%, of total unsaturated fatty acids (UFA 65.25% and of desirable fatty acids (DFA (total unsaturated + stearic acid 70.37% of the analysed samples. The ratio polyunsaturated/saturated fatty acids accounted 0.77. The most present fatty acid is the oleic (C18:1n9c with 28.31%, followed by palmitic (C16:0 with 27.12% and linoleic (C18:2n6c acid with 25.08%. Other fatty acids are contained in significantly lower quantities.

Interpretation of groundwater origin in the Velenje coal mine on the basis of isotope composition

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Janko Urbanc

2002-12-01

Full Text Available The aim of the investigation was to determine the isotopic properties of cave waters from the Velenje coal mine and define the recharge areas of individual aquifers. With regard to the oxygen isotope composition, groundwater in the Velenje coal mine can beclassified into three types. Typical d18O values of the first type are around -9 ‰ and are found in surface waters in the vicinity of the mine, therefore it is supposed that these waters are recharged locally. The second type is represented mainly by waters from thelower part of the pliocene aquifer. The average oxygen composition of these waters is about -11 ‰. This isotope composition is considerably different from the isotope composition of recent waters from the mine’s vicinity, which leads to the conclusion that these are older, fossile waters. These waters also have a very high degree of mineralization and consequently conductivity. Waters of the third type have average δ18O values around -10 ‰ and originate mainly from triassic dolomites. These waters could be a mixture of recentand old waters, but it is also possible that they flow into the coal mine from the higher areas of Paški Kozjak.

A numerical simulation of the origin and composition of the groundwater below Aespoe

International Nuclear Information System (INIS)

Svensson, Urban

1999-02-01

An attempt is made to calculate the origin (in the time and space) of the waters found below Aespoe. It is assumed that the present water composition is due to the conditions prevailing after the last glaciation (initial conditions) and the hydrological events after this time (resulting in transient boundary conditions). The total time span simulated is from 10,000 years BP to 5 000 years AP. The different water types are tracked by solving an advection/diffusion equation for each of the identified water types. This novel technique is called the 'fluid population method' and is a simple and straightforward computational technique. Results from the simulation include the distribution of different water types in space and time and some detailed results for the conditions at 450 metres below Aespoe (water composition transport time to ground level). The main conclusion from the study is that the simulation model gives plausible results. However, the uncertainties about the basic conceptual model and the boundary conditions do not presently make a direct comparison with field data meaningful

Terpenoid Compositions and Botanical Origins of Late Cretaceous and Miocene Amber from China

Science.gov (United States)

Shi, Gongle; Dutta, Suryendu; Paul, Swagata; Wang, Bo; Jacques, Frédéric M. B.

2014-01-01

The terpenoid compositions of the Late Cretaceous Xixia amber from Central China and the middle Miocene Zhangpu amber from Southeast China were analyzed by gas chromatography-mass spectrometry (GC-MS) to elucidate their botanical origins. The Xixia amber is characterized by sesquiterpenoids, abietane and phyllocladane type diterpenoids, but lacks phenolic abietanes and labdane derivatives. The molecular compositions indicate that the Xixia amber is most likely contributed by the conifer family Araucariaceae, which is today distributed primarily in the Southern Hemisphere, but widely occurred in the Northern Hemisphere during the Mesozoic according to paleobotanical evidence. The middle Miocene Zhangpu amber is characterized by amyrin and amyrone-based triterpenoids and cadalene-based sesquiterpenoids. It is considered derived from the tropical angiosperm family Dipterocarpaceae based on these compounds and the co-occurring fossil winged fruits of the family in Zhangpu. This provides new evidence for the occurrence of a dipterocarp forest in the middle Miocene of Southeast China. It is the first detailed biomarker study for amber from East Asia. PMID:25354364

Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in diagnosis of pleural effusion of malignant origin.

Science.gov (United States)

Fiorelli, Alfonso; Ricci, Serena; Feola, Antonia; Mazzella, Antonio; D'Angelo, Luigi; Santini, Mario; Di Domenico, Marina; Di Carlo, Angelina

2016-04-01

The aim of the present study was to evaluate the diagnostic accuracy of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in differentiating benign from malignant exudative pleural effusions. This is a unicentre observational study including 97 consecutive patients with exudative pleural effusions. Metalloproteinase-9, tissue inhibitor of metalloproteinase-1, lactate dehydrogenase, ferritin, carcinoembryonic antigen and carbohydrate antigen 15-3 were measured in pleural effusion and serum by enzyme-linked immunosorbent assay. The activity of metalloproteinase-9 was also evaluated by substrate zymography. The data were correlated with final diagnosis of pleural effusions to evaluate the diagnostic accuracy. Of the 97 eligible patients, 6 were excluded. Of the 91 patients included in the study, 70 had malignant pleural effusions and 21 had benign pleural effusions. Both in sera and pleural effusions, matrix metalloproteinase-9 (P effusion (P effusion metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 levels showed higher value of sensitivity (97 and 91%, respectively) and specificity (90 and 95%, respectively) compared with other standard markers. Serum metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 levels showed similar results. Among 70 neoplastic patients, 29 had negative pleural cytology. Of these, 25 presented elevated levels of metalloproteinase-9 and tissue inhibitor of metalloproteinase-1, whereas 4 patients had elevated levels of one of the two markers. Our results showed that metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 might be valuable markers in differentiating benign from malignant pleural effusions. Their levels are neither influenced by the histology and tumour origin nor by the presence of tumour cells in pleural effusions. Thus, their use in clinical practice could help in the selection of patients needing more invasive procedures, such as thoracoscopic biopsy. © The Author 2016

Surface modification of nanofibrous polycaprolactone/gelatin composite scaffold by collagen type I grafting for skin tissue engineering.

Science.gov (United States)

Gautam, Sneh; Chou, Chia-Fu; Dinda, Amit K; Potdar, Pravin D; Mishra, Narayan C

2014-01-01

In the present study, a tri-polymer polycaprolactone (PCL)/gelatin/collagen type I composite nanofibrous scaffold has been fabricated by electrospinning for skin tissue engineering and wound healing applications. Firstly, PCL/gelatin nanofibrous scaffold was fabricated by electrospinning using a low cost solvent mixture [chloroform/methanol for PCL and acetic acid (80% v/v) for gelatin], and then the nanofibrous PCL/gelatin scaffold was modified by collagen type I (0.2-1.5wt.%) grafting. Morphology of the collagen type I-modified PCL/gelatin composite scaffold that was analyzed by field emission scanning electron microscopy (FE-SEM), showed that the fiber diameter was increased and pore size was decreased by increasing the concentration of collagen type I. Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric (TG) analysis indicated the surface modification of PCL/gelatin scaffold by collagen type I immobilization on the surface of the scaffold. MTT assay demonstrated the viability and high proliferation rate of L929 mouse fibroblast cells on the collagen type I-modified composite scaffold. FE-SEM analysis of cell-scaffold construct illustrated the cell adhesion of L929 mouse fibroblasts on the surface of scaffold. Characteristic cell morphology of L929 was also observed on the nanofiber mesh of the collagen type I-modified scaffold. Above results suggest that the collagen type I-modified PCL/gelatin scaffold was successful in maintaining characteristic shape of fibroblasts, besides good cell proliferation. Therefore, the fibroblast seeded PCL/gelatin/collagen type I composite nanofibrous scaffold might be a potential candidate for wound healing and skin tissue engineering applications. © 2013.

Attenuation of the gamma rays in tissues; Atenuacion de los rayos gamma en tejidos

Energy Technology Data Exchange (ETDEWEB)

Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Vega C, H.R. [Unidad Academica de Estudios Nucleares, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2005-07-01

The mass and lineal attenuation coefficient and of hepatic tissue, muscular, osseous and of brain before gamma rays of 10{sup -3} to 10{sup 5} MeV were calculated. For the case of the osseous tissue the calculation was made for the cartilage, the cortical tissue and the bone marrow. During the calculations the elementary composition of the tissues of human origin was used. The calculations include by separate the Photoelectric effect, the Compton scattering and the Pair production, as well as the total. For to establish a comparison with the attenuation capacities, the coefficients of the water, the aluminum and the lead also were calculated. The study was complemented measuring the attenuation coefficient of hepatic tissue of bovine before gamma rays of 0.662 MeV of a source of {sup 137} Cs. The measurement was made through of an experiment of photons transmission through samples frozen of hepatic tissue and with a Geiger-Mueller detector. (Author)

Phytochemical composition and antioxidant activity of Tuscan bee pollen of different botanic origins

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V. Domenici

2015-06-01

Full Text Available Within the apicultural products, the honey bee-pollen is growing in commercial interest due to its high nutritional properties. For the first time, bee-pollen samples from Tuscany (Italy were studied to evaluate botanical origin, phytochemical composition and antioxidant activity. The investigated pollen loads were composed of three botanical families: Castanea, Rubus and Cistus.The highest levels of proteins and lipids were detected in Rubus pollen. Castanea pollen contained greater polyphenols, flavonoids and anthocyanins content, while the highest flavonols level wasdetected in Cistus pollen. These results were also confirmed by front-face fluorescence spectroscopy, used here, for the first time, as a fast tool to characterize bee-pollens.

Composition and structure of porcine digital flexor tendon-bone insertion tissues.

Science.gov (United States)

Chandrasekaran, Sandhya; Pankow, Mark; Peters, Kara; Huang, Hsiao-Ying Shadow

2017-11-01

Tendon-bone insertion is a functionally graded tissue, transitioning from 200 MPa tensile modulus at the tendon end to 20 GPa tensile modulus at the bone, across just a few hundred micrometers. In this study, we examine the porcine digital flexor tendon insertion tissue to provide a quantitative description of its collagen orientation and mineral concentration by using Fast Fourier Transform (FFT) based image analysis and mass spectrometry, respectively. Histological results revealed uniformity in global collagen orientation at all depths, indicative of mechanical anisotropy, although at mid-depth, the highest fiber density, least amount of dispersion, and least cellular circularity were evident. Collagen orientation distribution obtained through 2D FFT of histological imaging data from fluorescent microscopy agreed with past measurements based on polarized light microscopy. Results revealed global fiber orientation across the tendon-bone insertion to be preserved along direction of physiologic tension. Gradation in the fiber distribution orientation index across the insertion was reflective of a decrease in anisotropy from the tendon to the bone. We provided elemental maps across the fibrocartilage for its organic and inorganic constituents through time-of-flight secondary ion mass spectrometry (TOF-SIMS). The apatite intensity distribution from the tendon to bone was shown to follow a linear trend, supporting past results based on Raman microprobe analysis. The merit of this study lies in the image-based simplified approach to fiber distribution quantification and in the high spatial resolution of the compositional analysis. In conjunction with the mechanical properties of the insertion tissue, fiber, and mineral distribution results for the insertion from this may potentially be incorporated into the development of a structural constitutive approach toward computational modeling. Characterizing the properties of the native insertion tissue would provide the

Do very small adipocytes in subcutaneous adipose tissue (a proposed risk factor for insulin insensitivity have a fetal origin?

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Mette Olaf Nielsen

2016-08-01

Conclusions: The present study showed that greater preponderance of very small adipocytes, increased collagen infiltration and reduced subcutaneous lipid accumulation ability, as well as altered perirenal fat preferences for accumulation of C14:0 can have a fetal origin. Disturbance of normal (subcutaneous adipose tissue development may play a key role in linking fetal malnutrition to disease risk later in life.

The geographical origin and chemical composition in phellinus mushrooms measured by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Lim, J.M.; Sun, G.M.; Moon, J.H.; Chung, Y.S.; Lee, J.H.; Kim, K.H.

2012-01-01

In order to expand the utilization of phellinus mushrooms as a dietary supplement, we attempted to evaluate the chemical composition by measuring its inorganic elemental content with the aid of instrumental neutron activation analysis (INAA). Twenty seven phellinus mushrooms samples were collected from Korea, Cambodia, and Vietnam. A total of 28 elements were analyzed in the phellinus mushroom samples using the INAA. The concentrations of Ca, K, and Mg are much higher than those of other elements in phellinus mushroom samples. The sum of determined elemental concentration in Cambodia samples was about 2-6 times higher than those in Korea and Vietnam samples, respectively. Based on our measurement data, we attempted to discriminate the geographical origin using principal components analysis (PCA) and linear discriminant analysis (LDA). The geographical origins of all samples were clearly classified with correct classification rate of 100%. (author)

Ag-loaded MgSrFe-layered double hydroxide/chitosan composite scaffold with enhanced osteogenic and antibacterial property for bone engineering tissue.

Science.gov (United States)

Cao, Dandan; Xu, Zhengliang; Chen, Yixuan; Ke, Qinfei; Zhang, Changqing; Guo, Yaping

2018-02-01

Bone tissue engineering scaffolds for the reconstruction of large bone defects should simultaneously promote osteogenic differentiation and avoid postoperative infection. Herein, we develop, for the first time, Ag-loaded MgSrFe-layered double hydroxide/chitosan (Ag-MgSrFe/CS) composite scaffold. This scaffold exhibits three-dimensional interconnected macroporous structure with a pore size of 100-300 μm. The layered double hydroxide nanoplates in the Ag-MgSrFe/CS show lateral sizes of 200-400 nm and thicknesses of ∼50 nm, and the Ag nanoparticles with particle sizes of ∼20 nm are uniformly dispersed on the scaffold surfaces. Human bone marrow-derived mesenchymal stem cells (hBMSCs) present good adhesion, spreading, and proliferation on the Ag-MgSrFe/CS composite scaffold, suggesting that the Ag and Sr elements in the composite scaffold have no toxicity to hBMSCs. When compared with MgFe/CS composite scaffold, the Ag-MgSrFe/CS composite scaffold has better osteogenic property. The released Sr 2+ ions from the composite scaffold enhance the alkaline phosphatase activity of hBMSCs, promote the extracellular matrix mineralization, and increase the expression levels of osteogenic-related RUNX2 and BMP-2. Moreover, the Ag-MgSrFe/CS composite scaffold possesses good antibacterial property because the Ag nanoparticles in the composite scaffold effectively prevent biofilm formation against S. aureus. Hence, the Ag-MgSrFe/CS composite scaffold with excellent osteoinductivity and antibacterial property has a great potential for bone tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 863-873, 2018. © 2017 Wiley Periodicals, Inc.

Determination of atomic number and composition of human enamel

International Nuclear Information System (INIS)

Nogueira, M.S.; Rodas Duran, J.E.

2001-01-01

The teeth are organs of complicated structure that consist, partly, of hard tissue containing in its interior the dental pulp, rich in vases and nerves. The main mass of the tooth is constituted by the dentine, which is covered with hard tissues and of epithelial origin called enamel. The dentine of the human teeth used in this work were completely removed and the teeth were cut with a device with a diamond disc. In this work the chemical composition of the human enamel was determined, which showed a high percentage of Ca and P, in agreement with the results found in the literature. The effective atomic number of the material and the half-value layer in the energy range of diagnostic X-ray beams were determined. Teeth could be used to evaluated the public's individual doses as well as for retrospective dosimetry what confirms the importance of their effective atomic number and composition determination. (author)

Changes of stable isotopes carbon-13 and nitrogen-15 in different tissues of cattle

International Nuclear Information System (INIS)

Sun Fengmei; Yu Hongxia; Wu Wei; Yang Shuming

2009-01-01

Stable isotope analysis is a potential tool for tracing food origin. The stable carbon and nitrogen isotope composition in different tissues of two varieties of cattle under the same culture condition were investigated. δ 13 C and δ 15 N values of different defatted muscle and crude fat, cattle tail hair, blood, liver and feed were determined by isotope ratio mass spectrometry, and statistical analysis was carried out. The results showed that stable isotopes of carbon and nitrogen composition was not affected by cattle variety; the δ 13 C values between different defatted muscle, blood, liver and cattle hair were not significantly different, but δ 15 N value in the liver was much higher than other muscle and the δ 13 C values didn't show difference among all the crude fat samples. So these results indicated that isotope fractionation in the various tissue was discrepant. (authors)

Fourier transform infrared imaging microspectroscopy and tissue-level mechanical testing reveal intraspecies variation in mouse bone mineral and matrix composition.

Science.gov (United States)

Courtland, Hayden-William; Nasser, Philip; Goldstone, Andrew B; Spevak, Lyudmila; Boskey, Adele L; Jepsen, Karl J

2008-11-01

Fracture susceptibility is heritable and dependent upon bone morphology and quality. However, studies of bone quality are typically overshadowed by emphasis on bone geometry and bone mineral density. Given that differences in mineral and matrix composition exist in a variety of species, we hypothesized that genetic variation in bone quality and tissue-level mechanical properties would also exist within species. Sixteen-week-old female A/J, C57BL/6J (B6), and C3H/HeJ (C3H) inbred mouse femora were analyzed using Fourier transform infrared imaging and tissue-level mechanical testing for variation in mineral composition, mineral maturity, collagen cross-link ratio, and tissue-level mechanical properties. A/J femora had an increased mineral-to-matrix ratio compared to B6. The C3H mineral-to-matrix ratio was intermediate of A/J and B6. C3H femora had reduced acid phosphate and carbonate levels and an increased collagen cross-link ratio compared to A/J and B6. Modulus values paralleled mineral-to-matrix values, with A/J femora being the most stiff, B6 being the least stiff, and C3H having intermediate stiffness. In addition, work-to-failure varied among the strains, with the highly mineralized and brittle A/J femora performing the least amount of work-to-failure. Inbred mice are therefore able to differentially modulate the composition of their bone mineral and the maturity of their bone matrix in conjunction with tissue-level mechanical properties. These results suggest that specific combinations of bone quality and morphological traits are genetically regulated such that mechanically functional bones can be constructed in different ways.

Effect of chemical composition on corneal tissue response to photopolymerized materials comprising 2-hydroxyethyl methacrylate and acrylic acid

Energy Technology Data Exchange (ETDEWEB)

Lai, Jui-Yang, E-mail: jylai@mail.cgu.edu.tw

2014-01-01

The purpose of this work was to investigate the relationship between the feed composition of 2-hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc) and hydrogel material compatibility towards ocular anterior segment tissues, particularly the corneal endothelium. The monomer solutions of HEMA and AAc were mixed at varying volume ratios of 92:0, 87:5, 82:10, 77:15, and 72:20, and were subjected to UV irradiation. Then, the 7-mm-diameter membrane implants made from photopolymerized materials were placed into the ocular anterior chamber for 4 days and assessed by biomicroscopic examinations, corneal thickness measurements, and quantitative real-time reverse transcription polymerase chain reaction analyses. The poly(HEMA-co-AAc) implants prepared from the solution mixture containing 0–10 vol.% AAc displayed good biocompatibility. However, with increasing volume ratio of AAc and HEMA from 15:77 to 20:72, the enhanced inflammatory response, decreased endothelial cell density, and increased ocular score and corneal thickness were observed, probably due to the influence of surface charge of copolymer membranes. On the other hand, the ionic pump function of corneal endothelium exposed to photopolymerized membranes was examined by analyzing the Na{sup +},K{sup +}-ATPase alpha 1 subunit (ATP1A1) expression level. The presence of the implants having higher amount of AAc incorporated in the copolymers (i.e., 15.1 to 24.7 μmol) and zeta potential (i.e., -38.6 to − 56.5 mV) may lead to abnormal transmembrane transport. It is concluded that the chemical composition of HEMA/AAc has an important influence on the corneal tissue responses to polymeric biomaterials. - Highlights: • We examine the corneal tissue responses to photopolymerized biomaterials. • Carboxyl groups in copolymers increased with increasing volume ratio of AAc/HEMA. • 15–20 vol.% AAc raised ocular score and caused corneal endothelial loss and edema. • High anionic charge density stimulated inflammation

Composition of α-tocopherol and fatty acids in porcine tissues after dietary supplementation with vitamin E and different fat sources

DEFF Research Database (Denmark)

Lauridsen, Charlotte; Theil, Peter Kappel; Jensen, Søren Krogh

2013-01-01

in transfer of α-tocopherol, and oxidation and metabolism of fatty acids. From day 28 to 56 of age, pigs were provided 5% of tallow, fish oil or sunflower oil and 85, 150, or 300 mg/kg of all-rac-α-tocopheryl acetate. Samples of liver, heart, and adipose tissue were obtained from littermates at day 56. Tissue...... fatty acid composition was highly influenced by dietary fat sources. Dietary fatty acid composition (Pfish oil...... lower in pigs fed fish oil compared to other treatments, whereas the fatty acid oxidation, as indicated by the expression of PPAR-α, was higher when sunflower and fish oil was provided (P=0.03). Expression of α-TTP in liver was higher in pigs fed fish oil (P=0.01). Vitamin E supplementation did...

X-ray photoelectron emission spectromicroscopic analysis of arborescent lycopsid cell wall composition and Carboniferous coal ball preservation

Energy Technology Data Exchange (ETDEWEB)

Boyce, C. Kevin [Department of the Geophysical Sciences, University of Chicago, Chicago, IL 60637 (United States); Abrecht, Mike; Zhou, Dong; Gilbert, P.U.P.A. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)

2010-08-01

Two alternative processes complicate understanding of the biochemical origins and geochemical alteration of organic matter over geologic time: selective preservation of original biopolymers and in situ generation of new geopolymers. One of the best constrained potential sources of bio- and geochemical information about extinct fossil plants is frequently overlooked. Permineralized anatomically preserved plant fossils allow analysis of individual cell and tissue types that have an original biochemical composition already known from living plants. The original composition of more enigmatic fossils can be constrained by geochemical comparisons to tissues of better understood fossils from the same locality. This strategy is possible using synchrotron-based techniques for submicron-scale imaging with X-rays over a range of frequencies in order to provide information concerning the relative abundance of different organic bonds with X-ray Absorption Near Edge Spectroscopy. In this study, X-ray PhotoElectron Emission spectroMicroscopy (X-PEEM) was used to analyze the tissues of Lepidodendron, one of the lycopsid trees that were canopy dominants of many Pennsylvanian coal swamp forests. Its periderm or bark - the single greatest biomass contributor to many Late Paleozoic coals - is found to have a greater aliphatic content and an overall greater density of organic matter than lignified wood. Because X-PEEM allows simultaneous analysis of organic matter and matrix calcite in fully mineralized fossils, this technique also has great potential for analysis of fossil preservation, including documentation of significant traces of organic matter entrained in the calcite crystal fabric that fills the cell lumens. (author)

Isotopic composition and origin of the precipitation in Northern Chile

International Nuclear Information System (INIS)

Aravena, R.; Suzuki, O.; Pena, H.; Pollastri, A.; Fuenzalida, H.; Grilli, A.

1999-01-01

A 3 a data set of isotopes in precipitation from northern Chile show a very distinct pattern, with δ 18 O values ranging between -18 and -15per thousand at high altitude stations, compared to δ 18 O values between -10 and -6per thousand at the lower altitude areas. The 18 O-depleted values observed in the high altitude area, the Altiplano, are related to processes that affect the air masses that originated over the Atlantic, cross the Amazon Basin (continental effect), ascend the Andes (altitude effect) and precipitated (convective effect) in the Altiplano. It is postulated that a second source of moisture, associated with air masses from the Pacific, may contribute to the 18 O-enriched values observed in the lower altitude areas. Similar isotopic patterns are documented in springs and groundwater indicating that the data presented in this paper are an accurate representation of the long term behavior isotopic composition of rain in northern Chile. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Isotopic composition and origin of the precipitation in Northern Chile

Energy Technology Data Exchange (ETDEWEB)

Aravena, R. [Department of Earth Sciences, University of Waterloo, Waterloo (Canada); Suzuki, O. [Exploracion y Desarrollo de Recursos Hidricos, Santiago (Chile); Pena, H. [Direccion General de Aguas, Ministerio de Obras Publicas, Santiago (Chile); Pollastri, A. [Comision Chilena de Energia Nuclear, Santiago (Chile); Fuenzalida, H. [Departamento de Geofisica, Universidad of Chile, Santiago (Chile); Grilli, A. [Empresa Metropolitana de Obras Sanitarias, Santiago (Chile)

1999-06-01

A 3 a data set of isotopes in precipitation from northern Chile show a very distinct pattern, with {delta}{sup 18}O values ranging between -18 and -15per thousand at high altitude stations, compared to {delta}{sup 18}O values between -10 and -6per thousand at the lower altitude areas. The {sup 18}O-depleted values observed in the high altitude area, the Altiplano, are related to processes that affect the air masses that originated over the Atlantic, cross the Amazon Basin (continental effect), ascend the Andes (altitude effect) and precipitated (convective effect) in the Altiplano. It is postulated that a second source of moisture, associated with air masses from the Pacific, may contribute to the {sup 18}O-enriched values observed in the lower altitude areas. Similar isotopic patterns are documented in springs and groundwater indicating that the data presented in this paper are an accurate representation of the long term behavior isotopic composition of rain in northern Chile. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Establishment of Human Neural Progenitor Cells from Human Induced Pluripotent Stem Cells with Diverse Tissue Origins

Directory of Open Access Journals (Sweden)

Hayato Fukusumi

2016-01-01

Full Text Available Human neural progenitor cells (hNPCs have previously been generated from limited numbers of human induced pluripotent stem cell (hiPSC clones. Here, 21 hiPSC clones derived from human dermal fibroblasts, cord blood cells, and peripheral blood mononuclear cells were differentiated using two neural induction methods, an embryoid body (EB formation-based method and an EB formation method using dual SMAD inhibitors (dSMADi. Our results showed that expandable hNPCs could be generated from hiPSC clones with diverse somatic tissue origins. The established hNPCs exhibited a mid/hindbrain-type neural identity and uniform expression of neural progenitor genes.

[The composition of the gastrointestinal bacterial flora of mouse embryos and the placenta tissue bacterial flora].

Science.gov (United States)

Lei, D; Lin, Y; Jiang, X; Lan, L; Zhang, W; Wang, B X

2017-03-02

Objective: To explore the composition of the gastrointestinal bacterial flora of mouse embryos and the placenta tissue bacterial flora. Method: Twenty-four specimens were collected from pregnant Kunming mouse including 8 mice of early embryonic (12-13 days) gastrointestinal tissues, 8 cases of late embryonic (19-20 days)gastrointestinal tissues, 8 of late pregnancy placental tissues.The 24 samples were extracted by DNeasy Blood & Tissue kit for high-throughput DNA sequencing. Result: The level of Proteobacteria, Bacteroidetes, Actino-bacteria and Firmicutes were predominantin all specimens.The relative content of predominant bacterial phyla in each group: Proteobacteria (95.00%, 88.14%, 87.26%), Bacteroidetes(1.71%, 2.15%, 2.63%), Actino-Bacteria(1.16%, 4.10%, 3.38%), Firmicutes(0.75%, 2.62%, 2.01%). At the level of family, there were nine predominant bacterial families in which Enterobacteriaeae , Shewanel laceae and Moraxellaceae were dominant.The relative content of dominant bacterial family in eachgroup: Enterobacteriaeae (46.99%, 44.34%, 41.08%), Shewanellaceae (21.99%, 21.10%, 19.05%), Moraxellaceae (9.18%, 7.09%, 5.64%). From the species of flora, the flora from fetal gastrointestinal in early pregnancy and late pregnancy (65.44% and 62.73%) were the same as that from placenta tissue in the late pregnancy.From the abundance of bacteria, at the level of family, the same content of bacteria in three groups accounted for 78.16%, 72.53% and 65.78% respectively. Conclusion: It was proved that the gastrointestinal bacterial flora of mouse embryos and the placenta tissue bacterial flora were colonized. At the same time the bacteria are classified.

Influence of feeding graded levels of canned sardines on the inflammatory markers and tissue fatty acid composition of Wistar rats.

Science.gov (United States)

Rodrigues, Pedro O; Martins, Susana V; Lopes, Paula A; Ramos, Cristina; Miguéis, Samuel; Alfaia, Cristina M; Pinto, Rui M A; Rolo, Eva A; Bispo, Paulo; Batista, Irineu; Bandarra, Narcisa M; Prates, José A M

2014-08-14

Canned sardines are a ready-to-use fish product with excellent nutritional properties owing to its high n-3 long-chain PUFA content, mainly EPA (20 : 5n-3) and DHA (22 : 6n-3). The present study aimed to assess the effect of two dosages of canned sardines, recommended for the primary and secondary prevention of human CVD, on the inflammatory marker concentrations and fatty acid composition of erythrocytes and key metabolic tissues (liver, muscle, adipose tissue and brain) in the rat model. Wistar rats were fed a diet containing 11 % (w/w) of canned sardines (low-sardine (LS) diet) and a diet containing 22 % (w/w) of canned sardines (high-sardine (HS) diet) for 10 weeks. Daily food intake, weight gain, and organ and final body weights were not affected by the dietary treatments. The concentrations of total cholesterol, HDL-cholesterol and LDL-cholesterol decreased in both the LS and HS groups, while those of alanine aminotransferase and adiponectin increased. The concentrations of IL-1β increased only with the highest dosage of sardine. The dose-dependent influence of the graded levels of EPA+DHA was tissue specific. Compared with that of other tissues and erythrocytes, the fatty acid composition of the brain was less affected by the canned sardine-supplemented diets. In contrast, the retroperitoneal adipose tissue was highly responsive. The deposition ratios of EPA and DHA indicated that the LS diet was optimal for DHA deposition across the tissues, except in the retroperitoneal adipose tissue. Taken together, our findings indicate that a LS diet positively affects plasma lipid profiles and inflammatory mediators, whereas a HS diet has contradictory effects on IL-1β, which, in turn, is not associated with variations in the concentrations of other pro-inflammatory cytokines. This finding requires further investigation and pathophysiological understanding.

Synchrotron soft X-ray imaging and fluorescence microscopy reveal novel features of asbestos body morphology and composition in human lung tissues

Directory of Open Access Journals (Sweden)

Polentarutti Maurizio

2011-02-01

Full Text Available Abstract Background Occupational or environmental exposure to asbestos fibres is associated with pleural and parenchymal lung diseases. A histopathologic hallmark of exposure to asbestos is the presence in lung parenchyma of the so-called asbestos bodies. They are the final product of biomineralization processes resulting in deposition of endogenous iron and organic matter (mainly proteins around the inhaled asbestos fibres. For shedding light on the formation mechanisms of asbestos bodies it is of fundamental importance to characterize at the same length scales not only their structural morphology and chemical composition but also to correlate them to the possible alterations in the local composition of the surrounding tissues. Here we report the first correlative morphological and chemical characterization of untreated paraffinated histological lung tissue samples with asbestos bodies by means of soft X-ray imaging and X-Ray Fluorescence (XRF microscopy, which reveals new features in the elemental lateral distribution. Results The X-ray absorption and phase contrast images and the simultaneously monitored XRF maps of tissue samples have revealed the location, distribution and elemental composition of asbestos bodies and associated nanometric structures. The observed specific morphology and differences in the local Si, Fe, O and Mg content provide distinct fingerprints characteristic for the core asbestos fibre and the ferruginous body. The highest Si content is found in the asbestos fibre, while the shell and ferruginous bodies are characterized by strongly increased content of Mg, Fe and O compared to the adjacent tissue. The XRF and SEM-EDX analyses of the extracted asbestos bodies confirmed an enhanced Mg deposition in the organic asbestos coating. Conclusions The present report demonstrates the potential of the advanced synchrotron-based X-ray imaging and microspectroscopy techniques for studying the response of the lung tissue to the

Variation in tissue outcome of ovine and human engineered heart valve constructs : relevance for tissue engineering

NARCIS (Netherlands)

Geemen, van D.; Driessen - Mol, A.; Grootzwagers, L.G.M.; Soekhradj - Soechit, R.S.; Riem Vis, P.W.; Baaijens, F.P.T.; Bouten, C.V.C.

AIM: Clinical application of tissue engineered heart valves requires precise control of the tissue culture process to predict tissue composition and mechanical properties prior to implantation, and to understand the variation in tissue outcome. To this end we investigated cellular phenotype and

Renal cell carcinoma primary cultures maintain genomic and phenotypic profile of parental tumor tissues.

Science.gov (United States)

Cifola, Ingrid; Bianchi, Cristina; Mangano, Eleonora; Bombelli, Silvia; Frascati, Fabio; Fasoli, Ester; Ferrero, Stefano; Di Stefano, Vitalba; Zipeto, Maria A; Magni, Fulvio; Signorini, Stefano; Battaglia, Cristina; Perego, Roberto A

2011-06-13

Clear cell renal cell carcinoma (ccRCC) is characterized by recurrent copy number alterations (CNAs) and loss of heterozygosity (LOH), which may have potential diagnostic and prognostic applications. Here, we explored whether ccRCC primary cultures, established from surgical tumor specimens, maintain the DNA profile of parental tumor tissues allowing a more confident CNAs and LOH discrimination with respect to the original tissues. We established a collection of 9 phenotypically well-characterized ccRCC primary cell cultures. Using the Affymetrix SNP array technology, we performed the genome-wide copy number (CN) profiling of both cultures and corresponding tumor tissues. Global concordance for each culture/tissue pair was assayed evaluating the correlations between whole-genome CN profiles and SNP allelic calls. CN analysis was performed using the two CNAG v3.0 and Partek software, and comparing results returned by two different algorithms (Hidden Markov Model and Genomic Segmentation). A very good overlap between the CNAs of each culture and corresponding tissue was observed. The finding, reinforced by high whole-genome CN correlations and SNP call concordances, provided evidence that each culture was derived from its corresponding tissue and maintained the genomic alterations of parental tumor. In addition, primary culture DNA profile remained stable for at least 3 weeks, till to third passage. These cultures showed a greater cell homogeneity and enrichment in tumor component than original tissues, thus enabling a better discrimination of CNAs and LOH. Especially for hemizygous deletions, primary cultures presented more evident CN losses, typically accompanied by LOH; differently, in original tissues the intensity of these deletions was weaken by normal cell contamination and LOH calls were missed. ccRCC primary cultures are a reliable in vitro model, well-reproducing original tumor genetics and phenotype, potentially useful for future functional approaches

ORIGINAL ARTICLES Staphylococcus aureus skin and soft-tissue ...

African Journals Online (AJOL)

(MRSA) has become a key pathogen in skin and soft-tissue infections. (SSTIs). The emergence of ..... SSTI isolates; (iii) improved hospital infection control guidelines and practices to prevent .... So exposed in the field. And he'll never run off ...

Peroneal perforator-based peroneus longus tendon and sural neurofasciocutaneous composite flap transfer for a large soft-tissue defect of the forearm: A case report.

Science.gov (United States)

Hayashida, Kenji; Saijo, Hiroto; Fujioka, Masaki

2018-01-01

We describe the use of a composite flap composed of a sural neurofasciocutaneous flap and a vascularized peroneus longus tendon for the reconstruction of severe composite forearm tissue defects in a patient. A 43-year-old man had his left arm caught in a conveyor belt resulting in a large soft-tissue defect of 18 × 11 cm over the dorsum forearm. The extensor carpi radialis, superficial radial nerve, and radial artery were severely damaged. A free neurofasciocutaneous composite flap measuring 16 × 11 cm was outlined on the patient's left lower leg to allow simultaneous skin, tendon, nerve, and artery reconstruction. The flap, which included the peroneus longus tendon, was elevated on the subfascial plane. After the flap was transferred to the recipient site, the peroneal artery was anastomosed to the radial artery in a flow-through manner. The vascularized tendon graft with 15 cm in length was used to reconstruct the extensor carpi radialis longus tendon defect using an interlacing suture technique. As the skin paddle of the sural neurofasciocutaneous flap and the vascularized peroneus longus tendon graft were linked by the perforator and minimal fascial tissue, the skin paddle was able to rotate and slide with comparative ease. The flap survived completely without any complications. The length of follow-up was 12 months and was uneventful. Range of motion of his left wrist joint was slightly limited to 75 degrees. This novel composite flap may be useful for reconstructing long tendon defects associated with extensive forearm soft tissue defects. © 2016 Wiley Periodicals, Inc.

Experimental model for composite tissue allotransplantations Modelo experimental para alotransplantes de tecido composto

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Lydia Masako Ferreira

2004-12-01

Full Text Available In homologous transplantation or allotranplantation of limbs, the great tissue diversity causes variability in the rejection process and, consequently, its immunology is very complex. Thus, limb transplantation is the most used prototype of compound tissue transplantation among the protocols of experimental studies. Composite tissue allotransplantation represents the experimental model to study the homologous transplantation (from an individual to another of vascularized, innervated musclecutaneous units, joints, bone or even the whole member. Groups of rats were undergone allogeneic hindlimb transplantation. The receptors were randomized and control groups were established as: Control Group A: Autograft controls (F344 rats had its limbs reimplanted and no immunosuppressive therapy. Control Group B: Allograft controls (BN rats limbs were transplanted to F344. Composite tissue homotransplantation allows the inclusion of innervated muscle-cutaneous units, joint and bone or even the hole limb, is considerably applicable in cases of congenital absence or deformity, trauma or greater resection due to malignant tumor. For many complex deformities, these transplantations would allow a more precise reconstruction than the current reconstruction techniques.Nos transplantes alógenos de membro a grande variabilidade de tecidos (pele, subcutâneo, músculo, osso, medula óssea, gânglios linfáticos, cartilagem, nervo, vasos, tendão, articulação leva a grande variação dentro do processo de rejeição e consequentemente a sua imunologia é bastante complexa. Os transplantes alógenos de tecido composto representam o modelo experimental para se estudar o transplante homólogo (de um indivíduo para outro de unidades músculo cutâneas inervadas, vascularizadas, articulações, osso ou mesmo de todo o membro. Os receptores foram randomizados e os grupos controle foram estabelecidos como: grupo controle A: transplante autógeno de membro em que ratos F344

A LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) for biological tissue impedance analysis and equivalent circuit modelling

KAUST Repository

Bera, Tushar Kanti

2016-12-05

Under an alternating electrical signal, biological tissues produce a complex electrical bioimpedance that is a function of tissue composition and applied signal frequencies. By studying the bioimpedance spectra of biological tissues over a wide range of frequencies, we can noninvasively probe the physiological properties of these tissues to detect possible pathological conditions. Electrical impedance spectroscopy (EIS) can provide the spectra that are needed to calculate impedance parameters within a wide range of frequencies. Before impedance parameters can be calculated and tissue information extracted, impedance spectra should be processed and analyzed by a dedicated software program. National Instruments (NI) Inc. offers LabVIEW, a fast, portable, robust, user-friendly platform for designing dataanalyzing software. We developed a LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) to analyze the electrical impedance spectra for tissue characterization in medical, biomedical and biological applications. Here, we test, calibrate and evaluate the performance of LEBISDI on the impedance data obtained from simulation studies as well as the practical EIS experimentations conducted on electronic circuit element combinations and the biological tissue samples. We analyze the Nyquist plots obtained from the EIS measurements and compare the equivalent circuit parameters calculated by LEBISDI with the corresponding original circuit parameters to assess the accuracy of the program developed. Calibration studies show that LEBISDI not only interpreted the simulated and circuitelement data accurately, but also successfully interpreted tissues impedance data and estimated the capacitive and resistive components produced by the compositions biological cells. Finally, LEBISDI efficiently calculated and analyzed variation in bioimpedance parameters of different tissue compositions, health and temperatures. LEBISDI can also be used for human tissue

A LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) for biological tissue impedance analysis and equivalent circuit modelling

KAUST Repository

Bera, Tushar Kanti; Jampana, Nagaraju; Lubineau, Gilles

2016-01-01

Under an alternating electrical signal, biological tissues produce a complex electrical bioimpedance that is a function of tissue composition and applied signal frequencies. By studying the bioimpedance spectra of biological tissues over a wide range of frequencies, we can noninvasively probe the physiological properties of these tissues to detect possible pathological conditions. Electrical impedance spectroscopy (EIS) can provide the spectra that are needed to calculate impedance parameters within a wide range of frequencies. Before impedance parameters can be calculated and tissue information extracted, impedance spectra should be processed and analyzed by a dedicated software program. National Instruments (NI) Inc. offers LabVIEW, a fast, portable, robust, user-friendly platform for designing dataanalyzing software. We developed a LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) to analyze the electrical impedance spectra for tissue characterization in medical, biomedical and biological applications. Here, we test, calibrate and evaluate the performance of LEBISDI on the impedance data obtained from simulation studies as well as the practical EIS experimentations conducted on electronic circuit element combinations and the biological tissue samples. We analyze the Nyquist plots obtained from the EIS measurements and compare the equivalent circuit parameters calculated by LEBISDI with the corresponding original circuit parameters to assess the accuracy of the program developed. Calibration studies show that LEBISDI not only interpreted the simulated and circuitelement data accurately, but also successfully interpreted tissues impedance data and estimated the capacitive and resistive components produced by the compositions biological cells. Finally, LEBISDI efficiently calculated and analyzed variation in bioimpedance parameters of different tissue compositions, health and temperatures. LEBISDI can also be used for human tissue

Sex identification of polar bears from blood and tissue samples

Science.gov (United States)

Amstrup, Steven C.; Garner, G.W.; Cronin, M.A.; Patton, J.C.

1993-01-01

Polar bears (Ursus maritimus) can be adversely affected by hunting and other human perturbations because of low population densities and low reproduction rates. The sustainable take of adult females may be as low as 1.5% of the population. Females and accompanying young are most vulnerable to hunting, and hunters have not consistently reported the sex composition of the harvest, therefore a method to confirm the sexes of polar bears harvested in Alaska is needed. Evidence of the sex of harvested animals is often not available, but blood or other tissue samples often are. We extracted DNA from tissue and blood samples, and amplified segments of zinc finger (ZFX and ZFY) genes from both X and Y chromosomes with the polymerase chain reaction. Digestion of amplified portions of the X chromosome with the restriction enzyme HaeIII resulted in subdivision of the original amplified segment into four smaller fragments. Digestion with HaeIII did not subdivide the original segment amplified from the Y chromosome. The differing fragment sizes produced patterns in gel electrophoresis that distinguished samples from male and female bears 100% of the time. This technique is applicable to the investigation of many wildlife management and research questions.

Skin-associated lymphoid tissues (SALT): origins and functions

International Nuclear Information System (INIS)

Streilein, J.W.

1983-01-01

The skin has an unusual set of immunologic requirements. It is confronted by a specialized set of pathogenic organisms and environmental chemicals that represent a distinctive spectrum of antigenic specificities. Skin is subjected to physicochemical stresses such as irradiation with ultraviolet light that alter dramatically its immunologic properties. It is proposed that nature has provided skin with a unique collection of lymphoid cells, reticular cells, and organized lymphoid organs to deal with these special demands. Evidence in favor of the existence of skin-associated lymphoid tissues (SALT) includes (1) the cutaneous microenvironment is capable on its own of accepting, processing, and presenting nominal antigen; (2) strategically located peripheral lymph nodes are able to accept immunogenic signals derived from skin; (3) subsets of T lymphocytes display differential affinity for skin and its associated peripheral nodes; and (4) acquisition of this affinity by T cells is determined at least in part by differentiation signals received in situ from resident cutaneous cells. Responsibility for the establishment and integration of SALT rests with keratinocytes, Langerhans cells, and immunocompetent lymphocytes, each of which contributes uniquely to the synthesis. Together they provide skin with immune surveillance that effectively prejudices against the development of cutaneous neoplasms and persistent infection with intracellular pathogens. In patients who have been under long-term immunosuppressive therapy, the large majority of nonlymphoid malignancies arise within the skin, rather than other types of tissues. These data suggest that immune surveillance, once thought to be an immune defense operative in all somatic tissues, is a specialized immune function dedicated to the skin and mediated by SALT

Hydrogels for precision meniscus tissue engineering: a comprehensive review.

Science.gov (United States)

Rey-Rico, Ana; Cucchiarini, Magali; Madry, Henning

The meniscus plays a pivotal role to preserve the knee joint homeostasis. Lesions to the meniscus are frequent, have a reduced ability to heal, and may induce tibiofemoral osteoarthritis. Current reconstructive therapeutic options mainly focus on the treatment of lesions in the peripheral vascularized region. In contrast, few approaches are capable of stimulating repair of damaged meniscal tissue in the central, avascular portion. Tissue engineering approaches are of high interest to repair or replace damaged meniscus tissue in this area. Hydrogel-based biomaterials are of special interest for meniscus repair as its inner part contains relatively high proportions of proteoglycans which are responsible for the viscoelastic compressive properties and hydration grade. Hydrogels exhibiting high water content and providing a specific three-dimensional (3D) microenvironment may be engineered to precisely resemble this topographical composition of the meniscal tissue. Different polymers of both natural and synthetic origins have been manipulated to produce hydrogels hosting relevant cell populations for meniscus regeneration and provide platforms for meniscus tissue replacement. So far, these compounds have been employed to design controlled delivery systems of bioactive molecules involved in meniscal reparative processes or to host genetically modified cells as a means to enhance meniscus repair. This review describes the most recent advances on the use of hydrogels as platforms for precision meniscus tissue engineering.

Fabrication and characterization of PCL/gelatin composite nanofibrous scaffold for tissue engineering applications by electrospinning method

International Nuclear Information System (INIS)

Gautam, Sneh; Dinda, Amit Kumar; Mishra, Narayan Chandra

2013-01-01

In the present study, composite nanofibrous tissue engineering-scaffold consisting of polycaprolactone and gelatin, was fabricated by electrospinning method, using a new cost-effective solvent mixture: chloroform/methanol for polycaprolactone (PCL) and acetic acid for gelatin. The morphology of the nanofibrous scaffold was investigated by using field emission scanning electron microscopy (FE-SEM) which clearly indicates that the morphology of nanofibers was influenced by the weight ratio of PCL to gelatin in the solution. Uniform fibers were produced only when the weight ratio of PCL/gelatin is sufficiently high (10:1). The scaffold was further characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric (TG) analysis, and X-ray diffraction (XRD). FT-IR and TG analysis indicated some interactions between PCL and gelatin molecules within the scaffold, while XRD results demonstrated crystalline nature of PCL/gelatin composite scaffold. Cytotoxicity effect of scaffold on L929 mouse fibroblast cells was evaluated by MTT assay and cell proliferation on the scaffold was confirmed by DNA quantification. Positive results of MTT assay and DNA quantification L929 mouse fibroblast cells indicated that the scaffold made from the combination of natural polymer (gelatin) and synthetic polymer (PCL) may serve as a good candidate for tissue engineering applications. - Highlights: ► PCL/Gelatin scaffold was successfully fabricated by electrospinning method. ► PCL in CHCl 3 /CH 3 OH and gelatin in acetic acid: a novel polymer-solvent system. ► The morphology of nanofibers was influenced by the weight ratio of PCL/gelatin. ► Chemical interactions between PCL and gelatin molecules enhanced cell growth. ► Cell culture studies indicate the suitability of scaffold for tissue regeneration

In Vitro Degradation of PHBV Scaffolds and nHA/PHBV Composite Scaffolds Containing Hydroxyapatite Nanoparticles for Bone Tissue Engineering

Directory of Open Access Journals (Sweden)

Naznin Sultana

2012-01-01

Full Text Available This paper investigated the long-term in vitro degradation properties of scaffolds based on biodegradable polymers and osteoconductive bioceramic/polymer composite materials for the application of bone tissue engineering. The three-dimensional porous scaffolds were fabricated using emulsion-freezing/freeze-drying technique using poly(hydroxybutyrate-co-hydroxyvalerate (PHBV which is a natural biodegradable and biocompatible polymer. Nanosized hydroxyapatite (nHA particles were successfully incorporated into the PHBV scaffolds to render the scaffolds osteoconductive. The PHBV and nHA/PHBV scaffolds were systematically evaluated using various techniques in terms of mechanical strength, porosity, porous morphology, and in vitro degradation. PHBV and nHA/PHBV scaffolds degraded over time in phosphate-buffered saline at 37°C. PHBV polymer scaffolds exhibited slow molecular weight loss and weight loss in the in vitro physiological environment. Accelerated weight loss was observed in nHA incorporated PHBV composite scaffolds. An increasing trend of crystallinity was observed during the initial period of degradation time. The compressive properties decreased more than 40% after 5-month in vitro degradation. Together with interconnected pores, high porosity, suitable mechanical properties, and slow degradation profile obtained from long-term degradation studies, the PHBV scaffolds and osteoconductive nHA/PHBV composite scaffolds showed promises for bone tissue engineering application.

Titanium dioxide (TiO2) nanoparticles filled poly(d,l lactid acid) (PDLLA) matrix composites for bone tissue engineering

NARCIS (Netherlands)

Gerhardt, L.C.; Jell, G.M.R.; Boccaccini, A.R.

2007-01-01

Titanium dioxide (TiO2) nanoparticles were investigated for bone tissue engineering applications with regard to bioactivity and particle cytotoxicity. Composite films on the basis of poly(d,l lactid acid) (PDLLA) filled with 0, 5 and 30 wt% TiO2 nanoparticles were processed by solvent casting.

The composition of engineered cartilage at the time of implantation determines the likelihood of regenerating tissue with a normal collagen architecture.

Science.gov (United States)

Nagel, Thomas; Kelly, Daniel J

2013-04-01

The biomechanical functionality of articular cartilage is derived from both its biochemical composition and the architecture of the collagen network. Failure to replicate this normal Benninghoff architecture in regenerating articular cartilage may in turn predispose the tissue to failure. In this article, the influence of the maturity (or functionality) of a tissue-engineered construct at the time of implantation into a tibial chondral defect on the likelihood of recapitulating a normal Benninghoff architecture was investigated using a computational model featuring a collagen remodeling algorithm. Such a normal tissue architecture was predicted to form in the intact tibial plateau due to the interplay between the depth-dependent extracellular matrix properties, foremost swelling pressures, and external mechanical loading. In the presence of even small empty defects in the articular surface, the collagen architecture in the surrounding cartilage was predicted to deviate significantly from the native state, indicating a possible predisposition for osteoarthritic changes. These negative alterations were alleviated by the implantation of tissue-engineered cartilage, where a mature implant was predicted to result in the formation of a more native-like collagen architecture than immature implants. The results of this study highlight the importance of cartilage graft functionality to maintain and/or re-establish joint function and suggest that engineering a tissue with a native depth-dependent composition may facilitate the establishment of a normal Benninghoff collagen architecture after implantation into load-bearing defects.

GLOBAL CONSULTATION ON ESTABLISHMENT A UNIFIED SURVEILLANCE SYSTEM FOR DONATION AND TRANSPLANTATION OF ORGANS, TISSUES AND CELLS OF HUMAN ORIGIN

Directory of Open Access Journals (Sweden)

O. V. Orlova

2011-01-01

Full Text Available From from February 7th to 9th 2011, the World Health Organization (WHO, the Italian National Transplant Cen- tre and the EU-funded Project «Vigilance and Surveillance of Substances of Human Origin» joined forces to organise a major global consultation that took place in Bologna, Italy. The scope of the project included organs, tissues and cells for transplantation and for assisted reproduction. The participants represented regulatory and non-regulatory government agencies, professional societies and scientific and clinical specialities from all WHO regions. The meeting explored the work already carried out on-line and agreed on priorities for the future deve- lopment of the Project «Vigilance and Surveillance of Substances of Human Origin». 

The Origin and Composition of Cucurbit “Phloem” Exudate1[OA

Science.gov (United States)

Zhang, Cankui; Yu, Xiyan; Ayre, Brian G.; Turgeon, Robert

2012-01-01

Cucurbits exude profusely when stems or petioles are cut. We conducted studies on pumpkin (Cucurbita maxima) and cucumber (Cucumis sativus) to determine the origin and composition of the exudate. Morphometric analysis indicated that the exudate is too voluminous to derive exclusively from the phloem. Cold, which inhibits phloem transport, did not interfere with exudation. However, ice water applied to the roots, which reduces root pressure, rapidly diminished exudation rate. Sap was seen by microscopic examination to flow primarily from the fascicular phloem in cucumber, and several other cucurbit species, but primarily from the extrafascicular phloem in pumpkin. Following exposure of leaves to 14CO2, radiolabeled stachyose and other sugars were detected in the exudate in proportions expected of authentic phloem sap. Most of this radiolabel was released during the first 20 s. Sugars in exudate were dilute. The sugar composition of exudate from extrafascicular phloem near the edge of the stem differed from that of other sources in that it was high in hexose and low in stachyose. We conclude that sap is released from cucurbit phloem upon wounding but contributes negligibly to total exudate volume. The sap is diluted by water from cut cells, the apoplast, and the xylem. Small amounts of dilute, mobile sap from sieve elements can be obtained, although there is evidence that it is contaminated by the contents of other cell types. The function of P-proteins may be to prevent water loss from the xylem as well as nutrient loss from the phloem. PMID:22331409

Characterization of Size, Composition and Origins of Dust in Fusion Devices. Summary Report of the Second Research Coordination Meeting

International Nuclear Information System (INIS)

Braams, B.J.; Skinner, C.H.

2010-11-01

Eleven experts on processes of dust in fusion experiments met for the 2nd Research Coordination Meeting (RCM) of the Coordinated Research Project (CRP) on 'Characterization of size, composition and origins of dust in fusion devices' held at IAEA Headquarters 21-23 June 2010. Participants summarized their studies on dust in fusion experiments and reviewed progress made since the first RCM. Gaps in knowledge were identified and a plan of work for the remainder of the CRP was developed. Presentations, discussions and recommendations of the RCM are summarized in this report. Eleven experts on processes of dust in fusion experiments met for the 2nd Research Coordination Meeting (RCM) of the Coordinated Research Project (CRP) on 'Characterization of size, composition and origins of dust in fusion devices' held at IAEA Headquarters 21-23 June 2010. Participants summarized their studies on dust in fusion experiments and reviewed progress made since the first RCM. Gaps in knowledge were identified and a plan of work for the remainder of the CRP was developed. Presentations, discussions and recommendations of the RCM are summarized in this report. (author)

Dietary conjugated linoleic acids affect tissue lipid composition but not de novo lipogenesis in finishing pigs

OpenAIRE

Bee , Giuseppe

2001-01-01

International audience; Dietary conjugated linoleic acids (CLA) have been reported to profoundly affect lipid metabolism and to act as repartitioning agents. Currently, little is known about their effect on the fatty acid profile of tissue lipids in pigs. In the present study we determined the lipid composition of the backfat inner (BFI) and outer layer (BFO), omental fat (OF) and intramuscular fat (IMF) of the longissimus dorsi muscle in 24 Swiss Large White pigs fed diets supplemented eithe...

Comparison of intratumoral FDG and Cu-ATSM distributions in cancer tissue originated spheroid (CTOS) xenografts, a tumor model retaining the original tumor properties

International Nuclear Information System (INIS)

Furukawa, Takako; Yuan, Qinghua; Jin, Zhao-Hui; Aung, Winn; Yoshii, Yukie; Hasegawa, Sumitaka; Endo, Hiroko; Inoue, Masahiro; Zhang, Ming-Rong; Fujibayashi, Yasuhisa; Saga, Tsuneo

2014-01-01

Introduction: The intratumoral distributions of [ 18 F]FDG and [ 64 Cu]Cu-ATSM have been reported to be similar in adenocarcinomas but different in squamous cell carcinoma (SCC) in clinical studies. In the present study, we compared the intratumoral distributions of these two tracers in cancer tissue originated spheroid (CTOS) xenografts derived from adenocarcinoma and SCC, which retain the histological characteristics of the original tumors, and in cancer cell line xenografts of corresponding origin, to investigate the underlying mechanism of the distinct FDG and Cu-ATSM distribution patterns in adenocarcinoma and SCC. Methods: CTOSs derived from colon adenocarcinoma and lung SCC and cell lines established from colon adenocarcinoma and lung SCC, which were used for comparison, were subcutaneously transplanted into immunodeficient mice. One hour after administering [ 14 C]FDG and [ 64 Cu]Cu-ATSM, the intratumoral distributions were compared in the xenografts by using dual-tracer autoradiography. Adjacent sections were evaluated for necrosis, vasculature anatomy, Ki-67 antigen, and pimonidazole adducts using hematoxylin and eosin and immunohistochemical staining. Results: There was a higher regional overlap of high FDG and Cu-ATSM accumulations in the adenocarcinoma CTOS xenografts than in the SCC CTOS xenografts, while the overlap in the adenocarcinoma cell line xenograft was lower than that observed in the SCC cell line. High FDG accumulation occurred primarily in proximity to necrotic or pimonidazole adduct positive regions, while high Cu-ATSM accumulation occurred primarily in live cell regions separate from the necrotic regions. The adenocarcinoma CTOS xenograft had the stereotypical glandular structure, resulting in more intricately mixed regions of live and necrotic cells compared to those observed in the SCC CTOS or the cell line xenografts. Conclusion: Tumor morphological characteristics, specifically the spatial distribution of live and necrotic cell

Calculation of neutron kerma in tissues

International Nuclear Information System (INIS)

Vega C, H.R.; Manzanares A, E.

2004-01-01

Neutron kerma of normal and tumor tissues has been calculated using the tissues elemental concentration. A program developed in Math cad contains the kerma factors of C, H, O, N, Na, Mg, P, S, Cl, K, etc. that are in normal and tumor human tissues. Having the elemental composition of any human tissue the neutron kerma can be calculated. The program was tested using the elemental composition of tumor tissues such as sarcoma, melanoma, carcinoma and adenoid cystic, also neutron kerma for adipose and muscle tissue for normal adult was calculated. The results are in agreement with those published in literature. The neutron kerma for water was also calculated because in some dosimetric calculations water is used to describe normal and tumor tissues. From this comparison was found that at larger energies kerma factors are approximately the same, but energies less than 100 eV the differences are large. (Author)

In vitro cytocompatibility evaluation of chitosan/graphene oxide 3D scaffold composites designed for bone tissue engineering.

Science.gov (United States)

Dinescu, Sorina; Ionita, Mariana; Pandele, Andreea Madalina; Galateanu, Bianca; Iovu, Horia; Ardelean, Aurel; Costache, Marieta; Hermenean, Anca

2014-01-01

Extensively studied nowadays, graphene oxide (GO) has a benefic effect on cell proliferation and differentiation, thus holding promise for bone tissue engineering (BTE) approaches. The aim of this study was not only to design a chitosan 3D scaffold improved with GO for optimal BTE, but also to analyze its physicochemical properties and to evaluate its cytocompatibility and ability to support cell metabolic activity and proliferation. Overall results show that the addition of GO in the scaffold's composition improved mechanical properties and pore formation and enhanced the bioactivity of the scaffold material for tissue engineering. The new developed CHT/GO 3 wt% scaffold could be a potential candidate for further in vitro and in vivo osteogenesis studies and BTE approaches.

Multi-element, multi-compound isotope profiling as a means to distinguish the geographical and varietal origin of fermented cocoa (Theobroma cacao L.) beans.

Science.gov (United States)

Diomande, Didier; Antheaume, Ingrid; Leroux, Maël; Lalande, Julie; Balayssac, Stéphane; Remaud, Gérald S; Tea, Illa

2015-12-01

Multi-element stable isotope ratios have been assessed as a means to distinguish between fermented cocoa beans from different geographical and varietal origins. Isotope ratios and percentage composition for C and N were measured in different tissues (cotyledons, shells) and extracts (pure theobromine, defatted cocoa solids, protein, lipids) obtained from fermented cocoa bean samples. Sixty-one samples from 24 different geographical origins covering all four continental areas producing cocoa were analyzed. Treatment of the data with unsupervised (Principal Component Analysis) and supervised (Partial Least Squares Discriminant Analysis) multiparametric statistical methods allowed the cocoa beans from different origins to be distinguished. The most discriminant variables identified as responsible for geographical and varietal differences were the δ(15)N and δ(13)C values of cocoa beans and some extracts and tissues. It can be shown that the isotope ratios are correlated with the altitude and precipitation conditions found in the different cocoa-growing regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Differential effects of diet composition and timing of feeding behavior on rat brown adipose tissue and skeletal muscle peripheral clocks

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Paul de Goede

2018-01-01

Full Text Available The effects of feeding behavior and diet composition, as well as their possible interactions, on daily (clock gene expression rhythms have mainly been studied in the liver, and to a lesser degree in white adipose tissue (WAT, but hardly in other metabolic tissues such as skeletal muscle (SM and brown adipose tissues (BAT. We therefore subjected male Wistar rats to a regular chow or free choice high-fat-high sugar (fcHFHS diet in combination with time restricted feeding (TRF to either the light or dark phase. In SM, all tested clock genes lost their rhythmic expression in the chow light fed group. In the fcHFHS light fed group rhythmic expression for some, but not all, clock genes was maintained, but shifted by several hours. In BAT the daily rhythmicity of clock genes was maintained for the light fed groups, but expression patterns were shifted as compared with ad libitum and dark fed groups, whilst the fcHFHS diet made the rhythmicity of clock genes become more pronounced. Most of the metabolic genes in BAT tissue tested did not show any rhythmic expression in either the chow or fcHFHS groups. In SM Pdk4 and Ucp3 were phase-shifted, but remained rhythmically expressed in the chow light fed groups. Rhythmic expression was lost for Ucp3 whilst on the fcHFHS diet during the light phase. In summary, both feeding at the wrong time of day and diet composition disturb the peripheral clocks in SM and BAT, but to different degrees and thereby result in a further desynchronization between metabolically active tissues such as SM, BAT, WAT and liver.

Biocompatibility, osteointegration, osteoconduction, and biodegradation of a hydroxyapatite-polyhydroxybutyrate composite

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Emily Correna Carlo Reis

2010-08-01

Full Text Available In this work, biocompatibility, osteointegration, osteoconductivity, and biodegradation of a hydroxyapatite polyhydroxybutyrate new composite were evaluated. The composite was implanted in rabbits' bone defects and clinical, radiographic, histological, and histomorphometric data of these animals were compared with those of unfilled defects on the days 8th, 45th, and 90th after surgery. No significant differences existed between the groups for the evaluated clinical parameters. Radiographs showed bone-composite direct contact. Bone formed within the defect, interface and inside the composite. Significant differences were found between the bone and connective tissues percentage within the defect at all dates and at the interface on the 45th day, bone tissue prevailing. Composite's biodegradation signs were evident: giant cells on the surface of composite fragments separated from the original block in the absence of inflammatory infiltrate. These data supported that such composite was biocompatible, biodegradable, osteoconductive and integrate to bone.A biocompatibilidade, osteointegração, osteocondução e biodegradação de um novo compósito de hidroxiapatita e polihidroxibutirato foram avaliados. O compósito foi implantado em defeitos ósseos em coelhos e dados clínicos, radiográficos, histológicos e histomorfométricos foram comparados aos de defeitos não preenchidos aos 8, 45 e 90 dias após a cirurgia. Não foram observadas diferenças significantes entre os grupos para os parâmetros clínicos avaliados. Contato direto entre osso e compósito foi observado nas radiografias. Tecido ósseo se formou dentro do defeito, interface e dentro do compósito. Foram observadas diferenças significativas entre a porcentagem dos tecidos ósseo e conjuntivo dentro do defeito em todas as datas de avaliação e na interface aos 45 dias, com predominância do tecido ósseo. Sinais de biodegradação foram observados: células gigantes na superf

Natural Hg isotopic composition of different Hg compounds in mammal tissues as a proxy for in vivo breakdown of toxic methylmercury.

Science.gov (United States)

Perrot, Vincent; Masbou, Jeremy; Pastukhov, Mikhail V; Epov, Vladimir N; Point, David; Bérail, Sylvain; Becker, Paul R; Sonke, Jeroen E; Amouroux, David

2016-02-01

In the last decade, specific attention has been paid to total mercury (HgT) stable isotopic composition, especially in natural samples such as aquatic organisms, due to its potential to track the cycle of this toxic element in the environment. Here, we investigated Hg Compound Specific stable Isotopic Composition (CSIC) of natural inorganic Hg (iHg) and methylmercury (MMHg) in various tissues of aquatic mammals (Beluga whale from the Arctic marine environment and seals from the freshwater lake Baikal, Russia). In seals' organs the variation in mass dependent fractionation (MDF, δ(202)Hg) for total Hg was significantly correlated to the respective fraction of iHg and MMHg compounds, with MMHg being enriched by ∼ 3‰ in heavier isotopes relative to iHg. On the other hand, we observe insignificant variation in Hg mass independent isotope fractionation (MIF, Δ(199)Hg) among iHg and MMHg in all organs for the same mammal species and MMHg in prey items. MIF signatures suggest that both MMHg and iHg in aquatic mammals have the same origin (i.e., MMHg from food), and are representative of Hg photochemistry in the water column of the mammal ecosystem. MDF signatures of Hg compounds indicate that MMHg is demethylated in vivo before being stored in the muscle, and the iHg formed is stored in the liver, and to a lesser extent in the kidney, before excretion. Thus, Hg CSIC analysis in mammals can be a powerful tool for tracing the metabolic response to Hg exposure.

Aligned poly(L-lactic-co-e-caprolactone) electrospun microfibers and knitted structure: a novel composite scaffold for ligament tissue engineering.

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Vaquette, Cédryck; Kahn, Cyril; Frochot, Céline; Nouvel, Cécile; Six, Jean-Luc; De Isla, Natalia; Luo, Li-Hua; Cooper-White, Justin; Rahouadj, Rachid; Wang, Xiong

2010-09-15

We developed a novel technique involving knitting and electrospinning to fabricate a composite scaffold for ligament tissue engineering. Knitted structures were coated with poly(L-lactic-co-e-caprolactone) (PLCL) and then placed onto a rotating cylinder and a PLCL solution was electrospun onto the structure. Highly aligned 2-microm-diameter microfibers covered the space between the stitches and adhered to the knitted scaffolds. The stress-strain tensile curves exhibited an initial toe region similar to the tensile behavior of ligaments. Composite scaffolds had an elastic modulus (150 +/- 14 MPa) similar to the modulus of human ligaments. Biological evaluation showed that cells proliferated on the composite scaffolds and they spontaneously orientated along the direction of microfiber alignment. The microfiber architecture also induced a high level of extracellular matrix secretion, which was characterized by immunostaining. We found that cells produced collagen type I and type III, two main components found in ligaments. After 14 days of culture, collagen type III started to form a fibrous network. We fabricated a composite scaffold having the mechanical properties of the knitted structure and the morphological properties of the aligned microfibers. It is difficult to seed a highly macroporous structure with cells, however the technique we developed enabled an easy cell seeding due to presence of the microfiber layer. Therefore, these scaffolds presented attractive properties for a future use in bioreactors for ligament tissue engineering. (c) 2010 Wiley Periodicals, Inc.

Novel nanohybrid MTA compositions

DEFF Research Database (Denmark)

Lovschall, Henrik; Ranjkesh, Bahram

Original Mineral Trioxide Aggregate (MTA) has been recommended for various uses in endodontics. MTA is a calcia, silica, alumina containing hydraulic cement with long setting time, calcium hydroxide release, and high pH. It possesses antibacterial and sealing properties. Interestingly, recent...... studies describe hydroxyapatite crystals form over MTA when it comes in contact with simulated physiological tissue fluid. On the basis of available evidence it appears that MTA efficiently develop superior marginal adaptation in humid environments. Observations suggest MTA is suitable material for pulp...... modified calcia-silica-alumina-sulphate composition with soluble fluorides, radiocontrast material, and nanosilicate. iMTA thereby demonstrate a remarkably high compressive strength in comparison to several commonly used dental cements. Reduction of iMTA setting time to 2-10 min with either flowable...

Melting of the Primitive Mercurian Mantle, Insights into the Origin of Its Surface Composition

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Boujibar, A.; Righter, K.; Rapp, J. F.; Ross, D. K.; Pando, K. M.; Danielson, L. R.; Fontaine, E.

2016-01-01

Recent findings of the MESSENGER mission on Mercury have brought new evidence for its reducing nature, widespread volcanism and surface compositional heteregeneity. MESSENGER also provided major elemental ratios of its surface that can be used to infer large-scale differentiation processes and the thermal history of the planet. Mercury is known as being very reduced, with very low Fe-content and high S and alkali contents on its surface. Its bulk composition is therefore likely close to EH enstatite chondrites. In order to elucidate the origin of the chemical diversity of Mercury's surface, we determined the melting properties of EH enstatite chondrites, at pressures between 1 bar and 3 GPa and oxygen fugacity of IW-3 to IW-5, using piston-cylinder experiments, combined with a previous study on EH4 melting at 1 bar. We found that the presence of Ca-rich sulfide melts induces significant decrease of Ca-content in silicate melts at low pressure and low degree of melting (F). Also at pressures lower than 3 GPa, the SiO2-content decreases with F, while it increases at 3 GPa. This is likely due to the chemical composition of the bulk silicate which has a (Mg+Fe+Ca)/Si ratio very close to 1 and to the change from incongruent to congruent melting of enstatite. We then tested whether the various chemical compositions of Mercury's surface can result from mixing between two melting products of EH chondrites. We found that the majority of the geochemical provinces of Mercury's surface can be explained by mixing of two melts, with the exception of the High-Al plains that require an Al-rich source. Our findings indicate that Mercury's surface could have been produced by polybaric melting of a relatively primitive mantle.

The Study on Biocompatibility of Porous nHA/PLGA Composite Scaffolds for Tissue Engineering with Rabbit Chondrocytes In Vitro

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Lei Chen

2013-01-01

Full Text Available Objective. To examine the biocompatibility of a novel nanohydroxyapatite/poly[lactic-co-glycolic acid] (nHA/PLGA composite and evaluate its feasibility as a scaffold for cartilage tissue engineering. Methods. Chondrocytes of fetal rabbit were cultured with nHA/PLGA scaffold in vitro and the cell viability was assessed by MTT assay first. Cells adhering to nHA/PLGA scaffold were then observed by inverted microscope and scanning electron microscope (SEM. The cell cycle profile was analyzed by flow cytometry. Results. The viability of the chondrocytes on the scaffold was not affected by nHA/PLGA comparing with the control group as it was shown by MTT assay. Cells on the surface and in the pores of the scaffold increased in a time-dependent manner. Results obtained from flow cytometry showed that there was no significant difference in cell cycle profiles between the coculture group and control (P>0.05. Conclusion. The porous nHA/PLGA composite scaffold is a biocompatible and good kind of scaffold for cartilage tissue engineering.

Fatty acid composition of muscle and adipose tissues of indigenous Caribbean goats under varying nutritional densities.

Science.gov (United States)

Liméa, L; Alexandre, G; Berthelot, V

2012-02-01

The effects of a concentrate diet on growth, carcass fat, and fatty acid (FA) composition of muscle (supraspinatus), perirenal, and intermuscular adipose tissues of Creole goats (n = 32) were evaluated. Goats were fed a tropical green forage Digitaria decumbens ad libitum with no concentrate (G0) or 1 of 3 levels of concentrate: 140 (G100), 240 (G200), and 340 g•d(-1) (G300), respectively. Goats were slaughtered according to the standard procedure at the commercial BW (22 to 24 kg of BW). Goats fed the concentrate diets (G100, G200, and G300) had greater ADG (P 0.05). Increased concentrate supplementation did not affect (P > 0.05) the proportion of MUFA in all tissues and had very little effect on SFA in perirenal tissue, but increased the PUFA proportion in muscle (P < 0.05). The major effect of feeding increased concentrate was an increase in n-6 PUFA proportions in all tissues (P < 0.001) and, surprisingly, a decrease in n-3 PUFA (P < 0.001). Focusing on FA, which are supposed to have a beneficial or an adverse effect on human health, feeding increased concentrate did not increase the content of any cholesterol-increasing SFA in meat, but increased the n-6/n-3 ratio above 4 when more than 240 g of concentrate was fed per day.

PHBV/PLLA-based composite scaffolds fabricated using an emulsion freezing/freeze-drying technique for bone tissue engineering: surface modification and in vitro biological evaluation

International Nuclear Information System (INIS)

Sultana, Naznin; Wang Min

2012-01-01

Tissue engineering combines living cells with biodegradable materials and/or bioactive components. Composite scaffolds containing biodegradable polymers and nanosized osteoconductive bioceramic with suitable properties are promising for bone tissue regeneration. In this paper, based on blending two biodegradable and biocompatible polymers, namely poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(l-lactic acid) (PLLA) with incorporated nano hydroxyapatite (HA), three-dimensional composite scaffolds with controlled microstructures and an interconnected porous structure, together with high porosity, were fabricated using an emulsion freezing/freeze-drying technique. The influence of various parameters involved in the emulsion freezing/freeze-drying technique was studied for the fabrication of good-quality polymer scaffolds based on PHBV polymers. The morphology, mechanical properties and crystallinity of PHBV/PLLA and HA in PHBV/PLLA composite scaffolds and PHBV polymer scaffolds were studied. The scaffolds were coated with collagen in order to improve wettability. During in vitro biological evaluation study, it was observed that SaOS-2 cells had high attachment on collagen-coated scaffolds. Significant improvement in cell proliferation and alkaline phosphatase activity for HA-incorporated composite scaffolds was observed due to the incorporation of HA. After 3 and 7 days of culture on all scaffolds, SaOS-2 cells also had normal morphology and growth. These results indicated that PHBV/PLLA-based scaffolds fabricated via an emulsion freezing/freeze-drying technique were favorable sites for osteoblastic cells and are promising for the applications of bone tissue engineering.

The relationship between maternal body composition in early pregnancy and foetal mid-thigh soft-tissue thickness in the third trimester in a high-risk obstetric population.

Science.gov (United States)

Anglim, Breffini; Farah, Nadine; O'Connor, Clare; Daly, Niamh; Kennelly, Mairead M; Turner, Michael J

2017-07-01

Maternal obesity is an emerging challenge in contemporary obstetrics. To date there has been no study analysing the relationship between specific maternal body composition measurements and foetal soft-tissue measurements. The aim of this study was to determine whether measurement of maternal body composition at booking predicts foetal soft-tissue trajectories in the third trimester. We analysed the relationship between foetal thigh in the third trimester and both maternal BMI and body composition using the Tanita digital scales in the first trimester. Foetal subcutaneous thigh tissue measurements were obtained at intervals of 28, 32 and 36 weeks of gestation. A total of 160 women were identified. There was a direct correlation between MTST at 36 weeks and BMI (p = .002). There was a positive correlation between MTST at 36 weeks and leg fat mass (p = .13) and leg fat free mass (p = .013). There was a positive correlation between arm fat free mass and MTST at 36 weeks. We showed there is an association between maternal fat distribution and foetal subcutaneous thigh tissue measurements. MTST may be more useful in determining if a child is at risk of macrosomia. Impact statement Previous studies have suggested that maternal obesity programmes intrauterine foetal adiposity and growth. The aim of this study was to examine the relationship in a high-risk obstetric population between measurements of maternal body composition in early pregnancy and the assessment of foetal adiposity in the third trimester using serial ultrasound measurements of mid-thigh soft-tissue thickness. BMI is only a surrogate measurement of fat and does not measure fat distribution. Our study shows the distribution of both maternal fat and fat-free mass in early pregnancy may be positively associated with foetal soft-tissue measurements in the third trimester. Maternal arthropometric measurements other than BMI may help predict babies at risk of macrosomia and neonatal adiposity.

Determination of the origin of unknown irradiated nuclear fuel.

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Nicolaou, G

2006-01-01

An isotopic fingerprinting method is presented to determine the origin of unknown nuclear material with forensic importance. Spent nuclear fuel of known origin has been considered as the 'unknown' nuclear material in order to demonstrate the method and verify its prediction capabilities. The method compares, using factor analysis, the measured U, Pu isotopic compositions of the 'unknown' material with U, Pu isotopic compositions simulating well known spent fuels from a range of commercial nuclear power stations. Then, the 'unknown' fuel has the same origin as the commercial fuel with which it exhibits the highest similarity in U, Pu compositions.

Determination of the origin of unknown irradiated nuclear fuel

International Nuclear Information System (INIS)

Nicolaou, G.

2006-01-01

An isotopic fingerprinting method is presented to determine the origin of unknown nuclear material with forensic importance. Spent nuclear fuel of known origin has been considered as the 'unknown' nuclear material in order to demonstrate the method and verify its prediction capabilities. The method compares, using factor analysis, the measured U, Pu isotopic compositions of the 'unknown' material with U, Pu isotopic compositions simulating well known spent fuels from a range of commercial nuclear power stations. Then, the 'unknown' fuel has the same origin as the commercial fuel with which it exhibits the highest similarity in U, Pu compositions

Transcriptome architecture across tissues in the pig

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Folch Josep M

2008-04-01

Full Text Available Abstract Background Artificial selection has resulted in animal breeds with extreme phenotypes. As an organism is made up of many different tissues and organs, each with its own genetic programme, it is pertinent to ask: How relevant is tissue in terms of total transcriptome variability? Which are the genes most distinctly expressed between tissues? Does breed or sex equally affect the transcriptome across tissues? Results In order to gain insight on these issues, we conducted microarray expression profiling of 16 different tissues from four animals of two extreme pig breeds, Large White and Iberian, two males and two females. Mixed model analysis and neighbor – joining trees showed that tissues with similar developmental origin clustered closer than those with different embryonic origins. Often a sound biological interpretation was possible for overrepresented gene ontology categories within differentially expressed genes between groups of tissues. For instance, an excess of nervous system or muscle development genes were found among tissues of ectoderm or mesoderm origins, respectively. Tissue accounted for ~11 times more variability than sex or breed. Nevertheless, we were able to confidently identify genes with differential expression across tissues between breeds (33 genes and between sexes (19 genes. The genes primarily affected by sex were overall different than those affected by breed or tissue. Interaction with tissue can be important for differentially expressed genes between breeds but not so much for genes whose expression differ between sexes. Conclusion Embryonic development leaves an enduring footprint on the transcriptome. The interaction in gene × tissue for differentially expressed genes between breeds suggests that animal breeding has targeted differentially each tissue's transcriptome.

Species and life-history affects the utility of otolith chemical composition to determine natal stream-of-origin in Pacific salmon

Science.gov (United States)

Zimmerman, Christian E.; Swanson, Heidi K.; Volk, Eric C.; Kent, Adam J.R.

2013-01-01

To test the utility of otolith chemical composition as a tool for determining the natal stream of origin for salmon, we examined water chemistry and otoliths of juvenile and adult Chum Salmon Oncorhynchus keta and Coho Salmon O. kisutch from three watersheds (five rivers) in the Norton Sound region of Alaska. The two species are characterized by different life histories: Coho Salmon rear in freshwater for up to 3 years, whereas Chum Salmon emigrate from freshwater shortly after emergence. We used laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry (MS) to quantify element: Ca ratios for Mg, Mn, Zn, Sr, and Ba, and we used multicollector LA-ICP-MS to determine 87Sr:86Sr ratios in otolith regions corresponding to the period of freshwater residence. Significant differences existed in both water and otolith elemental composition, suggesting that otolith composition could be used to discriminate the natal origin of Coho Salmon and Chum Salmon but only when 87Sr:86Sr ratios were included in the discriminant function analyses. The best discriminant model included 87Sr:86Sr ratios, and without 87Sr:86Sr ratios it was difficult to discriminate among watersheds and rivers. Classification accuracy was 80% for Coho Salmon and 68% for Chum Salmon, indicating that this method does not provide sufficient sensitivity to estimate straying rates of Pacific salmon at the scale we studied.

Bio-composites composed of a solid free-form fabricated polycaprolactone and alginate-releasing bone morphogenic protein and bone formation peptide for bone tissue regeneration.

Science.gov (United States)

Kim, MinSung; Jung, Won-Kyo; Kim, GeunHyung

2013-11-01

Biomedical scaffolds should be designed with highly porous three-dimensional (3D) structures that have mechanical properties similar to the replaced tissue, biocompatible properties, and biodegradability. Here, we propose a new composite composed of solid free-form fabricated polycaprolactone (PCL), bone morphogenic protein (BMP-2) or bone formation peptide (BFP-1), and alginate for bone tissue regeneration. In this study, PCL was used as a mechanical supporting component to enhance the mechanical properties of the final biocomposite and alginate was used as the deterring material to control the release of BMP-2 and BFP-1. A release test revealed that alginate can act as a good release control material. The in vitro biocompatibilities of the composites were examined using osteoblast-like cells (MG63) and the alkaline phosphatase (ALP) activity and calcium deposition were assessed. The in vitro test results revealed that PCL/BFP-1/Alginate had significantly higher ALP activity and calcium deposition than the PCL/BMP-2/Alginate composite. Based on these findings, release-controlled BFP-1 could be a good growth factor for enhancement of bone tissue growth and the simple-alginate coating method will be a useful tool for fabrication of highly functional biomaterials through release-control supplementation.

The influence of parenteral nitrogen feeding on free amino acid composition of blood serum and hepatic tissue of irradiated rats

International Nuclear Information System (INIS)

Mil'ko, V.I.; Kirichenko, A.V.; Chalaya, L.A.

1985-01-01

A considerable change in the free am ino acid composition of blood serum and hepatic tissued was noted on the 7th and 14th days following total-body X-irradiation of rats with a dose of 2.9 Gy. The total free amino acid content of blood serum increased and that of hepatic tissue decreased by 85% (on an average) as compared to the intact controls. Quantitative changes in the content of individual amino acids were analysed. Polyamine injected enterally for 7 days and parenterally for 3 days after irradiation a the elimination of the postirradiation changes in the amino acid balance

Short communication: Suitability of fluorescence spectroscopy for characterization of commercial milk of different composition and origin.

Science.gov (United States)

Ntakatsane, M P; Yang, X Q; Lin, M; Liu, X M; Zhou, P

2011-11-01

Thirteen milk brands comprising 76 pasteurized and UHT milk samples of various compositions (whole, reduced fat, skimmed, low lactose, and high protein) were obtained from local supermarkets, and milk samples manufactured in various countries were discriminated using front-face fluorescence spectroscopy (FFFS) coupled with chemometric tools. The emission spectra of Maillard reaction products and riboflavin (MRP/RF; 400 to 600 nm) and tryptophan (300 to 400 nm) were recorded using FFFS, and the excitation wavelengths were set at 360 nm for MRP/RF and 290 nm for tryptophan. Principal component analysis (PCA) was applied to analyze the normalized spectra. The PCA of spectral information from MRP/RF discriminated the milk samples originating in different countries, and PCA of spectral information from tryptophan discriminated the samples according to composition. The fluorescence spectral data were compared with liquid chromatography-mass spectrometry results for the glycation extent of the milk samples, and a positive association (R(2)=0.84) was found between the degree of glycation of α-lactalbumin and the MRP/RF spectral data. This study demonstrates the ability and sensitivity of FFFS to rapidly discriminate and classify commercial milk with various compositions and processing conditions. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

FREE AMINO ACID COMPOSITION IN SCOTS PINE TISSUES UNDER STRESS IMPACT IN RHIZOSPHERE

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Sudachkova N.E.

2007-12-01

Full Text Available The free amino acid content in the needles and the inner bark of stems and roots of 8-13-ages self-sawn trees of Pinus sylvestris L. in Central Siberia in experimental and natural conditions was compared. The experiments imitated an influence of long-seasonal or permafrost, soil drought and root hypoxia, concomitant flooding. The aim of the investigation was to expose the adaptive changes of these metabolites composition under stress impact. All of types of stress influences changed the total free amino acid content in the tissues of different morphological tree parts: the cooling of root system caused a deposit of free amino acids in overground tree part, the water deficit stimulated an accumulation of free amino acids in root inner bark, the flooding decreased the amino acid content in all tissues. The ratio in a group of amino acids with glutamic acid as metabolic precursor (-aminobutyric (GABA, proline, arginine, citrulline and ornithine changed under different stress impact. The cold stress in rhizosphere caused GABA accumulation in the needles and stem but not in the roots in the period of soil thawing. The moderate moisture deficit had not an influence on GABA content, the flooding caused GABA accumulation only in new needles. The maximal exceeding above control were marked for the sum of arginine and its metabolic precursors citrulline and ornithine. The group of these compounds may be considered as stress metabolites for scots pine, but specificity of depositing of these amino acids at water stress requires additional proofs. Since the proline accumulation was showed in separate times in the different tissues under all of investigated stressors impact, the specificity of proline as indicator of water stress in scots pine tissues is debatable. The disturbance of donor-acceptor connections in experiment with cooling resulted to the amino acid accumulation in stem inner bark, in experiment with drought – in root inner bark.

Genetic origin and composition of a natural hybrid poplar Populus × jrtyschensis from two distantly related species.

Science.gov (United States)

Jiang, Dechun; Feng, Jianju; Dong, Miao; Wu, Guili; Mao, Kangshan; Liu, Jianquan

2016-04-18

The factors that contribute to and maintain hybrid zones between distinct species are highly variable, depending on hybrid origins, frequencies and fitness. In this study, we aimed to examine genetic origins, compositions and possible maintenance of Populus × jrtyschensis, an assumed natural hybrid between two distantly related species. This hybrid poplar occurs mainly on the floodplains along the river valleys between the overlapping distributions of the two putative parents. We collected 566 individuals from 45 typical populations of P. × jrtyschensis, P. nigra and P. laurifolia. We genotyped them based on the sequence variations of one maternally inherited chloroplast DNA (cpDNA) fragment and genetic polymorphisms at 20 SSR loci. We further sequenced eight nuclear genes for 168 individuals from 31 populations. Two groups of cpDNA haplotypes characteristic of P. nigra and P. laurifolia respectively were both recovered for P. × jrtyschensis. Genetic structures and coalescent tests of two sets of nuclear population genetic data suggested that P. × jrtyschensis originated from hybridizations between the two assumed parental species. All examined populations of P. × jrtyschensis comprise mainly F1 hybrids from interspecific hybridizations between P. nigra and P. laurifolia. In the habitats of P. × jrtyschensis, there are lower concentrations of soil nitrogen than in the habitats occupied by the other two species. Our extensive examination of the genetic composition of P. × jrtyschensis suggested that it is typical of F1-dominated hybrid zones. This finding plus the low concentration of soil nitrogen in the floodplain soils support the F1-dominated bounded hybrid superiority hypothesis of hybrid zone maintenance for this particular hybrid poplar.

Impact of thermal pretreatment and MSW origin on composition and hydrolysability in a sugar platform biorefinery

Science.gov (United States)

Vaurs, L. P.; Heaven, S.; Banks, C. J.

2018-03-01

Municipal solid waste (MSW) is a widely available large volume source of lignocellulosic material containing a waste paper/cardboard mixture which can be converted into fermentable sugars via cellulolytic enzyme hydrolysis in a sugar platform biorefinery. Thermal pretreatments are generally applied to MSW to facilitate the extraction of the lignocellulosic material from recyclable materials (plastics, metals etc.) and improve the paper pulp conversion to sugars. Applying high temperature might enhance food waste solubilisation but may collapse cellulose fibre decreasing its hydrolysability. Low temperature pre-treatment will reduce the energy demand but might result in highly contaminated pulp. Preliminary results showed that the enzymatic hydrolysis performances were dependent on the MSW origins. Using 8 different samples, the impact of thermal pretreatment and MSW origin on pulp composition and hydrolysability was assessed in this work. Low pre-treatment temperature produced pulp which contained less lignocellulosic material but which hydrolysed to a higher degree than MSW treated at high temperatures. High temperature pre-treatment could have exposed more of the inhibiting lignin to cellulase. This information would have a significant economic impact on a commercial plant as expensive autoclave could be advantageously replaced by a cheaper process. Glucan conversions were also found to vary depending on the region, the recycling rate possibly because of the lower recycling rate resulting in the use of less paper additive in the material or the difference in paper production technology (chemical VS mechanical pulping). This could also be explained by the differences in paper composition.

Composite Match Index with Application of Interior Deformation Field Measurement from Magnetic Resonance Volumetric Images of Human Tissues

Directory of Open Access Journals (Sweden)

Penglin Zhang

2012-01-01

Full Text Available Whereas a variety of different feature-point matching approaches have been reported in computer vision, few feature-point matching approaches employed in images from nonrigid, nonuniform human tissues have been reported. The present work is concerned with interior deformation field measurement of complex human tissues from three-dimensional magnetic resonance (MR volumetric images. To improve the reliability of matching results, this paper proposes composite match index (CMI as the foundation of multimethod fusion methods to increase the reliability of these various methods. Thereinto, we discuss the definition, components, and weight determination of CMI. To test the validity of the proposed approach, it is applied to actual MR volumetric images obtained from a volunteer’s calf. The main result is consistent with the actual condition.

Biofunctional Ionic-Doped Calcium Phosphates: Silk Fibroin Composites for Bone Tissue Engineering Scaffolding.

Science.gov (United States)

Pina, S; Canadas, R F; Jiménez, G; Perán, M; Marchal, J A; Reis, R L; Oliveira, J M

2017-01-01

The treatment and regeneration of bone defects caused by traumatism or diseases have not been completely addressed by current therapies. Lately, advanced tools and technologies have been successfully developed for bone tissue regeneration. Functional scaffolding materials such as biopolymers and bioresorbable fillers have gained particular attention, owing to their ability to promote cell adhesion, proliferation, and extracellular matrix production, which promote new bone growth. Here, we present novel biofunctional scaffolds for bone regeneration composed of silk fibroin (SF) and β-tricalcium phosphate (β-TCP) and incorporating Sr, Zn, and Mn, which were successfully developed using salt-leaching followed by a freeze-drying technique. The scaffolds presented a suitable pore size, porosity, and high interconnectivity, adequate for promoting cell attachment and proliferation. The degradation behavior and compressive mechanical strengths showed that SF/ionic-doped TCP scaffolds exhibit improved characteristics for bone tissue engineering when compared with SF scaffolds alone. The in vitro bioactivity assays using a simulated body fluid showed the growth of an apatite layer. Furthermore, in vitro assays using human adipose-derived stem cells presented different effects on cell proliferation/differentiation when varying the doping agents in the biofunctional scaffolds. The incorporation of Zn into the scaffolds led to improved proliferation, while the Sr- and Mn-doped scaffolds presented higher osteogenic potential as demonstrated by DNA quantification and alkaline phosphatase activity. The combination of Sr with Zn led to an influence on cell proliferation and osteogenesis when compared with single ions. Our results indicate that biofunctional ionic-doped composite scaffolds are good candidates for further in vivo studies on bone tissue regeneration. © 2017 S. Karger AG, Basel.

Determination of composition and structure of spongy bone tissue in human head of femur by Raman spectral mapping.

Science.gov (United States)

Kozielski, M; Buchwald, T; Szybowicz, M; Błaszczak, Z; Piotrowski, A; Ciesielczyk, B

2011-07-01

Biomechanical properties of bone depend on the composition and organization of collagen fibers. In this study, Raman microspectroscopy was employed to determine the content of mineral and organic constituents and orientation of collagen fibers in spongy bone in the human head of femur at the microstructural level. Changes in composition and structure of trabecula were illustrated using Raman spectral mapping. The polarized Raman spectra permit separate analysis of local variations in orientation and composition. The ratios of ν₂PO₄³⁻/Amide III, ν₄PO₄³⁻/Amide III and ν₁CO₃²⁻/ν₂PO₄³⁻ are used to describe relative amounts of spongy bone components. The ν₁PO₄³⁻/Amide I ratio is quite susceptible to orientation effect and brings information on collagen fibers orientation. The results presented illustrate the versatility of the Raman method in the study of bone tissue. The study permits better understanding of bone physiology and evaluation of the biomechanical properties of bone.

Origin of particulate organic carbon in the marine atmosphere as indicated by it stable carbon isotopic composition

International Nuclear Information System (INIS)

Chesselet, R.; Fontugne, M.; Buat-Menard, P.; Ezat, U.; Lambert, C.E.

1981-01-01

Organic carbon concentration and isotopic composition were determined in samples of atmospheric particulate matter collected in 1979 at remote marine locations (Enewetak atoll, Sargasso Sea) during the SEAREX (Sea-Air Exchange) program field experiments. Atmospheric Particulate Organic Carbon (POC) concentrations were found to be in the range of 0.3 to 1.2 mg. m -3 , in agreement with previous literature data. The major mass of POC was found on the smallest particles (r 13 C/ 12 C of the small particles is close to the one expected (d 13 C = 26 +- 2 0 //sub infinity/) for atmospheric POC of continental origin. For all the samples analysed so far, it appears that more than 80% of atmospheric POC over remote marine areas is of continental origin. This can be explained either by long-range transport of small sized continental organic aserosols or by the production of POC in the marine atmosphere from a vapor phase organic carbon pool of continental origin. The POC in the large size fraction of marine aerosols ( 13 C = -21 +- 2 0 / 00 ) for POC associated with sea-salt droplets transported to the marine atmosphere

Preparation and biological properties of a novel composite scaffold of nano-hydroxyapatite/chitosan/carboxymethyl cellulose for bone tissue engineering

Directory of Open Access Journals (Sweden)

Chengdong Xiong

2009-07-01

Full Text Available Abstract In this study, we report the physico-chemical and biological properties of a novel biodegradable composite scaffold made of nano-hydroxyapatite and natural derived polymers of chitosan and carboxymethyl cellulose, namely, n-HA/CS/CMC, which was prepared by freeze-drying method. The physico-chemical properties of n-HA/CS/CMC scaffold were tested by infrared absorption spectra (IR, transmission electron microscope(TEM, scanning electron microscope(SEM, universal material testing machine and phosphate buffer solution (PBS soaking experiment. Besides, the biological properties were evaluated by MG63 cells and Mesenchymal stem cells (MSCs culture experiment in vitro and a short period implantation study in vivo. The results show that the composite scaffold is mainly formed through the ionic crossing-linking of the two polyions between CS and CMC, and n-HA is incorporated into the polyelectrolyte matrix of CS-CMC without agglomeration, which endows the scaffold with good physico-chemical properties such as highly interconnected porous structure, high compressive strength and good structural stability and degradation. More important, the results of cells attached, proliferated on the scaffold indicate that the scaffold is non-toxic and has good cell biocompatibility, and the results of implantation experiment in vivo further confirm that the scaffold has good tissue biocompatibility. All the above results suggest that the novel degradable n-HA/CS/CMC composite scaffold has a great potential to be used as bone tissue engineering material.

Preparation and biological properties of a novel composite scaffold of nano-hydroxyapatite/chitosan/carboxymethyl cellulose for bone tissue engineering

Science.gov (United States)

Liuyun, Jiang; Yubao, Li; Chengdong, Xiong

2009-01-01

In this study, we report the physico-chemical and biological properties of a novel biodegradable composite scaffold made of nano-hydroxyapatite and natural derived polymers of chitosan and carboxymethyl cellulose, namely, n-HA/CS/CMC, which was prepared by freeze-drying method. The physico-chemical properties of n-HA/CS/CMC scaffold were tested by infrared absorption spectra (IR), transmission electron microscope(TEM), scanning electron microscope(SEM), universal material testing machine and phosphate buffer solution (PBS) soaking experiment. Besides, the biological properties were evaluated by MG63 cells and Mesenchymal stem cells (MSCs) culture experiment in vitro and a short period implantation study in vivo. The results show that the composite scaffold is mainly formed through the ionic crossing-linking of the two polyions between CS and CMC, and n-HA is incorporated into the polyelectrolyte matrix of CS-CMC without agglomeration, which endows the scaffold with good physico-chemical properties such as highly interconnected porous structure, high compressive strength and good structural stability and degradation. More important, the results of cells attached, proliferated on the scaffold indicate that the scaffold is non-toxic and has good cell biocompatibility, and the results of implantation experiment in vivo further confirm that the scaffold has good tissue biocompatibility. All the above results suggest that the novel degradable n-HA/CS/CMC composite scaffold has a great potential to be used as bone tissue engineering material. PMID:19594953

The interplay between tissue growth and scaffold degradation in engineered tissue constructs

KAUST Repository

O’Dea, R. D.

2012-09-18

In vitro tissue engineering is emerging as a potential tool to meet the high demand for replacement tissue, caused by the increased incidence of tissue degeneration and damage. A key challenge in this field is ensuring that the mechanical properties of the engineered tissue are appropriate for the in vivo environment. Achieving this goal will require detailed understanding of the interplay between cell proliferation, extracellular matrix (ECM) deposition and scaffold degradation. In this paper, we use a mathematical model (based upon a multiphase continuum framework) to investigate the interplay between tissue growth and scaffold degradation during tissue construct evolution in vitro. Our model accommodates a cell population and culture medium, modelled as viscous fluids, together with a porous scaffold and ECM deposited by the cells, represented as rigid porous materials. We focus on tissue growth within a perfusion bioreactor system, and investigate how the predicted tissue composition is altered under the influence of (1) differential interactions between cells and the supporting scaffold and their associated ECM, (2) scaffold degradation, and (3) mechanotransduction-regulated cell proliferation and ECM deposition. Numerical simulation of the model equations reveals that scaffold heterogeneity typical of that obtained from μCT scans of tissue engineering scaffolds can lead to significant variation in the flow-induced mechanical stimuli experienced by cells seeded in the scaffold. This leads to strong heterogeneity in the deposition of ECM. Furthermore, preferential adherence of cells to the ECM in favour of the artificial scaffold appears to have no significant influence on the eventual construct composition; adherence of cells to these supporting structures does, however, lead to cell and ECM distributions which mimic and exaggerate the heterogeneity of the underlying scaffold. Such phenomena have important ramifications for the mechanical integrity of

The Origin of Mercury's Surface Composition, an Experimental Investigation

Science.gov (United States)

Boujibar, A.; Righter, K.; Rapp, J. F.; Ross, D. K.; Pando, K. M.; Danielson, L. R.; Fontaine, E.

2016-01-01

Introduction: Results from MESSENGER spacecraft have confirmed the reduced nature of Mercury, based on its high core/mantle ratio and its FeO-poor and S-rich surface. Moreover, high resolution images revealed large volcanic plains and abundant pyroclastic deposits, suggesting major melting stages of the Mercurian mantle. In addition, MESSENGER has provided the most precise data to date on major elemental compositions of Mercury's surface. These results revealed considerable chemical heterogeneities that suggested several stages of differentiation and re-melting processes. This interpretation was challenged by our experimental previous study, which showed a similar compositional variation in the melting products of enstatite chondrites, which are a possible Mercury analogue. However, these experimental melts were obtained over a limited range of pressure (1 bar to 1 gigapascal) and were not compared to the most recent elemental maps. Therefore, here we extend the experimental dataset to higher pressures and perform a more quantitative comparison with Mercury's surface compositions measured by MESSENGER. In particular, we test whether these chemical heterogeneities result from mixing between polybaric melts. Our experiments and models show that the majority of chemical diversity of Mercury's surface can result from melting of a primitive mantle compositionally similar to enstatite chondrites in composition at various depths and degrees of melting. The high-Mg region's composition is reproduced by melting at high pressure (3 gigapascals) (Tab. 1), which is consistent with previous interpretation as being a large degraded impact basin based on its low elevation and thin average crust. While low-Mg NVP (North Volcanic Plains) are the result of melting at low pressure (1 bar), intermediate-Mg NVP, Caloris Basin and Rachmaninoff result from mixing of a high-pressure (3 gigapascals) and low-pressure components (1 bar for Rachmaninoff and 1 gigapascal for the other regions

Engineering complex orthopaedic tissues via strategic biomimicry.

Science.gov (United States)

Qu, Dovina; Mosher, Christopher Z; Boushell, Margaret K; Lu, Helen H

2015-03-01

The primary current challenge in regenerative engineering resides in the simultaneous formation of more than one type of tissue, as well as their functional assembly into complex tissues or organ systems. Tissue-tissue synchrony is especially important in the musculoskeletal system, wherein overall organ function is enabled by the seamless integration of bone with soft tissues such as ligament, tendon, or cartilage, as well as the integration of muscle with tendon. Therefore, in lieu of a traditional single-tissue system (e.g., bone, ligament), composite tissue scaffold designs for the regeneration of functional connective tissue units (e.g., bone-ligament-bone) are being actively investigated. Closely related is the effort to re-establish tissue-tissue interfaces, which is essential for joining these tissue building blocks and facilitating host integration. Much of the research at the forefront of the field has centered on bioinspired stratified or gradient scaffold designs which aim to recapitulate the structural and compositional inhomogeneity inherent across distinct tissue regions. As such, given the complexity of these musculoskeletal tissue units, the key question is how to identify the most relevant parameters for recapitulating the native structure-function relationships in the scaffold design. Therefore, the focus of this review, in addition to presenting the state-of-the-art in complex scaffold design, is to explore how strategic biomimicry can be applied in engineering tissue connectivity. The objective of strategic biomimicry is to avoid over-engineering by establishing what needs to be learned from nature and defining the essential matrix characteristics that must be reproduced in scaffold design. Application of this engineering strategy for the regeneration of the most common musculoskeletal tissue units (e.g., bone-ligament-bone, muscle-tendon-bone, cartilage-bone) will be discussed in this review. It is anticipated that these exciting efforts will

Engineering Complex Orthopaedic Tissues via Strategic Biomimicry

Science.gov (United States)

Qu, Dovina; Mosher, Christopher Z.; Boushell, Margaret K.; Lu, Helen H.

2014-01-01

The primary current challenge in regenerative engineering resides in the simultaneous formation of more than one type of tissue, as well as their functional assembly into complex tissues or organ systems. Tissue-tissue synchrony is especially important in the musculoskeletal system, whereby overall organ function is enabled by the seamless integration of bone with soft tissues such as ligament, tendon, or cartilage, as well as the integration of muscle with tendon. Therefore, in lieu of a traditional single-tissue system (e.g. bone, ligament), composite tissue scaffold designs for the regeneration of functional connective tissue units (e.g. bone-ligament-bone) are being actively investigated. Closely related is the effort to re-establish tissue-tissue interfaces, which is essential for joining these tissue building blocks and facilitating host integration. Much of the research at the forefront of the field has centered on bioinspired stratified or gradient scaffold designs which aim to recapitulate the structural and compositional inhomogeneity inherent across distinct tissue regions. As such, given the complexity of these musculoskeletal tissue units, the key question is how to identify the most relevant parameters for recapitulating the native structure-function relationships in the scaffold design. Therefore, the focus of this review, in addition to presenting the state-of-the-art in complex scaffold design, is to explore how strategic biomimicry can be applied in engineering tissue connectivity. The objective of strategic biomimicry is to avoid over-engineering by establishing what needs to be learned from nature and defining the essential matrix characteristics that must be reproduced in scaffold design. Application of this engineering strategy for the regeneration of the most common musculoskeletal tissue units (e.g. bone-ligament-bone, muscle-tendon-bone, cartilage-bone) will be discussed in this review. It is anticipated that these exciting efforts will

Composite material

Science.gov (United States)

Hutchens, Stacy A [Knoxville, TN; Woodward, Jonathan [Solihull, GB; Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN

2012-02-07

A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

Biomaterials for Tissue Engineering

Science.gov (United States)

Lee, Esther J.; Kasper, F. Kurtis; Mikos, Antonios G.

2013-01-01

Biomaterials serve as an integral component of tissue engineering. They are designed to provide architectural framework reminiscent of native extracellular matrix in order to encourage cell growth and eventual tissue regeneration. Bone and cartilage represent two distinct tissues with varying compositional and mechanical properties. Despite these differences, both meet at the osteochondral interface. This article presents an overview of current biomaterials employed in bone and cartilage applications, discusses some design considerations, and alludes to future prospects within this field of research. PMID:23820768

The effect of platelet-rich plasma on composite graft survival.

Science.gov (United States)

Jeon, Yeo Reum; Kang, Eun Hye; Yang, Chae Eun; Yun, In Sik; Lee, Won Jai; Lew, Dae Hyun

2014-08-01

Composite grafts are suitable for facial reconstruction because of good color matching, low donor-site morbidity, acceptable texture, and easy surgical techniques. However, their use is limited to small defects and by unpredictable survival rates. As platelet-rich plasma contains large numbers of growth factors and has been widely used for tissue regeneration, this study aimed to investigate platelet-rich plasma as an adjuvant to enhance composite graft survival. Twenty New Zealand White rabbits were used, and chondrocutaneous composite grafts were applied to their ears. The grafts were then returned to their original positions after rotation to block the original circulation from the base of the graft. Each of the individual ears was assigned randomly into one of two groups: experimental (n=20; platelet-rich plasma group) or control (n=20; control group). The surrounding skin of the composite graft was injected with either 1.0 ml of platelet-rich plasma derived from autologous whole blood in the platelet-rich plasma group or normal saline in the control group. Graft survival, cutaneous blood flow, CD31-stained vessels, and vascular endothelial growth factor protein levels were examined. Twelve days after surgery, graft viability in the platelet-rich plasma group was higher than in the control group. Blood perfusion was also higher in the platelet-rich plasma group. Compared with the control group, the number of CD31 blood vessels and vascular endothelial growth factor expression levels were significantly increased in the platelet-rich plasma group. The authors' results suggest that platelet-rich plasma restores the perfusion of composite grafts by enhancing revascularization and may exert therapeutic effects on the survival of composite grafts.

Fabrication, characterization, and in vitro evaluation of poly(lactic acid glycolic acid)/nano-hydroxyapatite composite microsphere-based scaffolds for bone tissue engineering in rotating bioreactors.

Science.gov (United States)

Lv, Qing; Nair, Lakshmi; Laurencin, Cato T

2009-12-01

Dynamic flow culture bioreactor systems have been shown to enhance in vitro bone tissue formation by facilitating mass transfer and providing mechanical stimulation. Our laboratory has developed a biodegradable poly (lactic acid glycolic acid) (PLAGA) mixed scaffold consisting of lighter-than-water (LTW) and heavier-than-water (HTW) microspheres as potential matrices for engineering tissue using a high aspect ratio vessel (HARV) rotating bioreactor system. We have demonstrated enhanced osteoblast differentiation and mineralization on PLAGA scaffolds in the HARV rotating bioreactor system when compared with static culture. The objective of the present study is to improve the mechanical properties and bioactivity of polymeric scaffolds by designing LTW polymer/ceramic composite scaffolds suitable for dynamic culture using a HARV bioreactor. We employed a microsphere sintering method to fabricate three-dimensional PLAGA/nano-hydroxyapatite (n-HA) mixed scaffolds composed of LTW and HTW composite microspheres. The mechanical properties, pore size and porosity of the composite scaffolds were controlled by varying parameters, such as sintering temperature, sintering time, and PLAGA/n-HA ratio. The PLAGA/n-HA (4:1) scaffold sintered at 90 degrees C for 3 h demonstrated the highest mechanical properties and an appropriate pore structure for bone tissue engineering applications. Furthermore, evaluation human mesenchymal stem cells (HMSCs) response to PLAGA/n-HA scaffolds was performed. HMSCs on PLAGA/n-HA scaffolds demonstrated enhanced proliferation, differentiation, and mineralization when compared with those on PLAGA scaffolds. Therefore, PLAGA/n-HA mixed scaffolds are promising candidates for HARV bioreactor-based bone tissue engineering applications. Copyright 2008 Wiley Periodicals, Inc.

Influence of plant root morphology and tissue composition on phenanthrene uptake: Stepwise multiple linear regression analysis

International Nuclear Information System (INIS)

Zhan, Xinhua; Liang, Xiao; Xu, Guohua; Zhou, Lixiang

2013-01-01

Polycyclic aromatic hydrocarbons (PAHs) are contaminants that reside mainly in surface soils. Dietary intake of plant-based foods can make a major contribution to total PAH exposure. Little information is available on the relationship between root morphology and plant uptake of PAHs. An understanding of plant root morphologic and compositional factors that affect root uptake of contaminants is important and can inform both agricultural (chemical contamination of crops) and engineering (phytoremediation) applications. Five crop plant species are grown hydroponically in solutions containing the PAH phenanthrene. Measurements are taken for 1) phenanthrene uptake, 2) root morphology – specific surface area, volume, surface area, tip number and total root length and 3) root tissue composition – water, lipid, protein and carbohydrate content. These factors are compared through Pearson's correlation and multiple linear regression analysis. The major factors which promote phenanthrene uptake are specific surface area and lipid content. -- Highlights: •There is no correlation between phenanthrene uptake and total root length, and water. •Specific surface area and lipid are the most crucial factors for phenanthrene uptake. •The contribution of specific surface area is greater than that of lipid. -- The contribution of specific surface area is greater than that of lipid in the two most important root morphological and compositional factors affecting phenanthrene uptake

[Influence of deuterium depleted water on freeze-dried tissue isotopic composition and morphofunctional body performance in rats of different generations].

Science.gov (United States)

Dzhimak, S S; Baryshev, M G; Basov, A A; Timakov, A A

2014-01-01

The influence of deuterium depleted water on the body of different rats generations was investigated in physiological conditions. As a result of this study it was established that the most significant and rapid reduction in D/H equilibrium was observed in plasma (by 36.2%), and lyophilized kidney tissues (by 15.8%). Less pronounced deuterium decrease was characteristic of liver tissue (9.3%) and heart (8.5%). Stabilization of the isotopic exchange reaction rate was fixed in the blood and tissues of rats, starting from the second generation. At the same time when deuterium depleted water (40 ppm) was used in dietary intake, the change in morphological and functional parameters in laboratory animals associated with the processes of adaptation to the effects of substress isotopic D/H gradient was also noted. The study shows that modification of:only drinking water intake regime can't significantly change the deuterium content in tissues of metabolically active organs, because of the concurrent deuterium receipt in food substances of plant and animal origin.

Egg origin determination efforts

International Nuclear Information System (INIS)

Horvath, A.; Futo, I.; Vodila, G.; Palcsu, L.

2012-01-01

Complete text of publication follows. As a co-operation with the Poultry Product Board, egg and drinking water samples were received in order to investigate whether the country of origin of the egg can be determined based on its stable isotope composition with the aim of market protection of the Hungarian eggs against the mislabelled foreign ones. The scientific background is that drinking water of egg laying hens is assumed to reflect the composition of regional precipitation, and it is also an input data in the process of egg formation. In the first sampling, altogether 23 sets of egg and drinking water samples were received from different production sites covering the whole area of Hungary. The egg white samples were vacuum distilled and frozen out by liquid nitrogen at -196 deg C. The process was monitored by two vacuum gauges. Water frozen out together with the drinking water samples was measured were measured by a Thermo Finnigan Delta PLUS XP isotope ratio mass spectrometer using a GasBench II peripheral unit equipped with a GC-autosampler. As a second issue, additionally, elemental composition of egg shells were also performed for series of Hungarian, Czech and Polish egg samples by energy dispersive X-ray fluorescence. The drinking waters fit well to the Global Meteoric Water Line indicating their precipitation origin. It was experienced that the water in egg white gets enriched compared to the drinking water (Δ 18 O = -4.9 ± 1.0 per thousand and Δ D = -21.8 ± 6.4 per thousand), however, this shift is independent of the type of the hens, since the mean shifts in the eggs of Tetra and Hy-line hens are similar within error bar. For more depleted drinking water, the shift of the egg white was higher than for more enriched ones. This can be due to the contribution of the nutriment isotopic composition. The water isotope composition of the Hungarian eggs investigated was δ 18 O = -4.8 - -7.3 per thousand and δD = -46.0 - -70.7 per thousand, therefore egg

Phenolic Contents and Compositions in Skins of Red Wine Grape Cultivars among Various Genetic Backgrounds and Originations

Directory of Open Access Journals (Sweden)

Lei Zhu

2012-03-01

Full Text Available In order to analyze and compare the phenolic characteristics of red wine grapes with diverse genetic backgrounds, skin phenolics among 21 different cultivars belonging to Vitis vinifera L., East Asian and North American Vitis species and hybrids, as well as 2 varieties of muscadine grapes were estimated by HPLC-MS/MS. There were 45 anthocyanins, 28 flavonols, 8 flavan-3-ols, 9 cinnamic acids, 5 benzoic acids, 5 ellagic acids and 2 stilbenes detected in all the samples. Total contents of each phenolic type varied significantly among the different grape cultivars investigated. There was also a large variability in the phenolic compositions of different grape groups. The differences in anthocyanin composition were obvious between V. vinifera and non-V. vinifera grapes and also between the grapes originating from Eurasia and North America. Quercetin-3-glucuronide and quercetin-3-glucoside were marker flavonol compounds for Euvitis grape skins. Flavan-3-ol monomers were dominant in the skins of muscadine and non-V. amurensis East Asian grapes, whereas polymers were more common in V. vinifera and North American grapes. The muscadine grapes were very rich in flavonols, flavan-3-ols and ellagic acids. Via principal component analysis, these grape cultivars were clustered into three groups according to their characteristic phenolic content and composition.

Bee waxes: a model of characterization for using as base simulator tissue in teletherapy with photons

International Nuclear Information System (INIS)

Silva, Rogerio Matias Vidal da; Souza, Divanizia do Nascimento

2011-01-01

This paper presents a model of characterization and selection of bee waxes which makes possible to certify the usage viability of that base simulator tissue in the manufacture of appropriated objects for external radiotherapy with mega volt photon beams. The work was divide into three stages, where was evaluated physical and chemical properties besides the aspects related to the capacity of beam attenuation. All the process was carefully accompanied related to the wax origin such as the bee specimen and the flora surrounding the beehives. The chemical composition of the waxes is similar to others simulators usually used in radiotherapy. The behavior of mass attenuation coefficient in the radiotherapeutic energy range is comparable to other simulators, and consequently to the soft tissue. The proposed model is efficient and allows the affirmative that the usage of determined bee wax as base simulator tissue is convenient

Tissue-specific extracellular matrix coatings for the promotion of cell proliferation and maintenance of cell phenotype.

Science.gov (United States)

Zhang, Yuanyuan; He, Yujiang; Bharadwaj, Shantaram; Hammam, Nevin; Carnagey, Kristen; Myers, Regina; Atala, Anthony; Van Dyke, Mark

2009-08-01

Recent studies have shown that extracellular matrix (ECM) substitutes can have a dramatic impact on cell growth, differentiation and function. However, these ECMs are often applied generically and have yet to be developed for specific cell types. In this study, we developed tissue-specific ECM-based coating substrates for skin, skeletal muscle and liver cell cultures. Cellular components were removed from adult skin, skeletal muscle, and liver tissues, and the resulting acellular matrices were homogenized and dissolved. The ECM solutions were used to coat culture dishes. Tissue matched and non-tissue matched cell types were grown on these coatings to assess adhesion, proliferation, maintenance of phenotype and cell function at several time points. Each cell type showed better proliferation and differentiation in cultures containing ECM from their tissue of origin. Although subtle compositional differences in the three ECM types were not investigated in this study, these results suggest that tissue-specific ECMs provide a culture microenvironment that is similar to the in vivo environment when used as coating substrates, and this new culture technique has the potential for use in drug development and the development of cell-based therapies.

Effect of gamma radiation and accelerated aging on the mechanical and thermal behavior of HDPE/HA nano-composites for bone tissue regeneration.

Science.gov (United States)

Alothman, Othman Y; Almajhdi, Fahad N; Fouad, H

2013-09-24

The replacement of hard tissues demands biocompatible and sometimes bioactive materials with properties similar to those of bone. Nano-composites made of biocompatible polymers and bioactive inorganic nano particles such as HDPE/HA have attracted attention as permanent bone substitutes due to their excellent mechanical properties and biocompatibility. The HDPE/HA nano-composite is prepared using melt blending at different HA loading ratios. For evaluation of the degradation by radiation, gamma rays of 35 kGy, and 70 kGy were used to irradiate the samples at room temperature in vacuum. The effects of accelerated ageing after gamma irradiation on morphological, mechanical and thermal properties of HDPE/HA nano-composites were measured. In Vitro test results showed that the HDPE and all HDPE/HA nano-composites do not exhibit any cytotoxicity to WISH cell line. The results also indicated that the tensile properties of HDPE/HA nano-composite increased with increasing the HA content except fracture strain decreased. The dynamic mechanical analysis (DMA) results showed that the storage and loss moduli increased with increasing the HA ratio and the testing frequency. Finally, it is remarked that all properties of HDPE/HA is dependent on the irradiation dose and accelerated aging. Based on the experimental results, it is found that the addition of 10%, 20% and 30% HA increases the HDPE stiffness by 23%, 44 and 59% respectively. At the same time, the G' increased from 2.25E11 MPa for neat HDPE to 4.7E11 MPa when 30% HA was added to the polymer matrix. Also, significant improvements in these properties have been observed due to irradiation. Finally, the overall properties of HDPE and its nano-composite properties significantly decreased due to aging and should be taken into consideration in the design of bone substitutes. It is attributed that the developed HDPE/HA nano-composites could be a good alternative material for bone tissue regeneration due to their acceptable

Study on the meat isotopic composition for origin identification

Directory of Open Access Journals (Sweden)

Irina Chernukha

2018-03-01

Full Text Available Russian consumer and governmental authorities are equally concerned to know where food products come from. This requires more accurate and specialized methods for the evaluation of geographical location. The following methods are used: chemometrics, histological and histochemical, genomic and proteomic, microbiological, immunochemical and mass spectrometric. Method of stable isotope analysis is becoming increasingly promising nowadays for the identification of meat and meat products' place of origin. The isotope ratios of the four elements - carbon, nitrogen, oxygen and hydrogen, are mainly determined. The method is successfully used to identify a country of origin of wines, juices and water. The aim of the research was to study the stable isotope ratios for pork and beef samples purchased in Moscow supermarkets (Russian Federation. The country of production of meat samples was determined according to specifications and/or labels. The geography of countries of meat samples origin includes Europe, both America continents and Australia. Databases collected by the All-Russian Scientific Research Institute of the Brewing, Non-Alcoholic and Wine Industrywere used for the analysis and interpretation of the results. Values of 13С/12С, δ13С, 18О/16О, δ18О, 2Н/1Н, δ2Н for 30 pork and beef samples from 13 countries were obtained. Differences in stable isotope ratios were found depending on place of origin. The data correlated with the oxygen isotope characteristics for wine, which were in the range from 2.5 to 4.5 ppm. According to the 13С/12С, δ13С results, the assumption was made about a false indication of the region for the beef sample. Despite the fact that beef was labeled as a product of Lithuania, the region of origin was most probably defined as Germany. The studies carried out showed the possibility to identify the region of raw meat origin by the stable isotope ratio.

The Role of a Platelet Lysate-Based Compartmentalized System as a Carrier of Cells and Platelet-Origin Cytokines for Periodontal Tissue Regeneration.

Science.gov (United States)

Babo, Pedro S; Cai, Xinjie; Plachokova, Adelina S; Reis, Rui L; Jansen, John A; Gomes, Manuela E; Walboomers, X Frank

2016-10-01

Currently available clinical therapies are not capable to regenerate tissues that are lost by periodontitis. Tissue engineering can be applied as a strategy to regenerate reliably the tissues and function of damaged periodontium. A prerequisite for this regeneration is the colonization of the defect with the adequate cell populations. In this study, we proposed a bilayered system composed of (1) a platelet lysate (PL)-based construct produced by crosslinking of PL proteins with genipin (gPL) for the delivery of rat periodontal ligament cells (rat-PDLCs); combined with (2) an injectable composite consisting of calcium phosphate cement incorporated with PL-loaded poly(d, l-lactic-co-glycolic acid) microspheres. This system was expected to promote periodontal regeneration by the delivery of adequate progenitor cells and providing a stable system enriched with adequate cytokines and growth factors for the orchestration of tissue regrowth in periodontal defects. The bilayered system was tested in a three-wall intrabony defect in rats and the healing of periodontal tissue was assessed 6 weeks after surgery. Results showed that the bilayered system was able to promote the regrowth of functional periodontal tissues, both with (cells + gPL) and without the loading of PDLCs (gPL). Significant connective tissue attachment (45.0 ± 15.0% and 64.0 ± 15.0% for gPL and cells + gPL group, respectively) and new bone area (33.8 ± 21% and 21.3 ± 3% for gPL and cells + gPL group, respectively) were observed. Nevertheless, rat PDLCs delivered with gPL construct in the defect area were hardly visible 6 weeks after surgery and did not contribute for the regeneration of new periodontal tissue. Overall, our findings show that the bilayered system promotes the stabilization of PL proteins on the root surface and has a positive effect in the repair of periodontal tissues both in quality and in quantity.

SU-E-T-409: Evaluation of Tissue Composition Effect On Dose Distribution in Radiotherapy with 6 MV Photon Beam of a Medical Linac

Energy Technology Data Exchange (ETDEWEB)

Ghorbani, M; Tabatabaei, Z; Noghreiyan, A Vejdani [Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, NV (United States)

2015-06-15

Purpose: The aim of this study is to evaluate soft tissue composition effect on dose distribution for various soft tissues and various depths in radiotherapy with 6 MV photon beam of a medical linac. Methods: A phantom and Siemens Primus linear accelerator were simulated using MCNPX Monte Carlo code. In a homogeneous cubic phantom, six types of soft tissue and three types of tissue-equivalent materials were defined separately. The soft tissues were muscle (skeletal), adipose tissue, blood (whole), breast tissue, soft tissue (9-component) and soft tissue (4-component). The tissue-equivalent materials included: water, A-150 tissue-equivalent plastic and perspex. Photon dose relative to dose in 9-component soft tissue at various depths on the beam’s central axis was determined for the 6 MV photon beam. The relative dose was also calculated and compared for various MCNPX tallies including,F8, F6 and,F4. Results: The results of the relative photon dose in various materials relative to dose in 9-component soft tissue and using different tallies are reported in the form of tabulated data. Minor differences between dose distributions in various soft tissues and tissue-equivalent materials were observed. The results from F6 and F4 were practically the same but different with,F8 tally. Conclusion: Based on the calculations performed, the differences in dose distributions in various soft tissues and tissue-equivalent materials are minor but they could be corrected in radiotherapy calculations to upgrade the accuracy of the dosimetric calculations.

Tissue engineered vascular grafts: Origins, development, and current strategies for clinical application.

Science.gov (United States)

Benrashid, Ehsan; McCoy, Christopher C; Youngwirth, Linda M; Kim, Jina; Manson, Roberto J; Otto, James C; Lawson, Jeffrey H

2016-04-15

Since the development of a dependable and durable synthetic non-autogenous vascular conduit in the mid-twentieth century, the field of vascular surgery has experienced tremendous growth. Concomitant with this growth, development in the field of bioengineering and the development of different tissue engineering techniques have expanded the armamentarium of the surgeon for treating a variety of complex cardiovascular diseases. The recent development of completely tissue engineered vascular conduits that can be implanted for clinical application is a particularly exciting development in this field. With the rapid advances in the field of tissue engineering, the great hope of the surgeon remains that this conduit will function like a true blood vessel with an intact endothelial layer, with the ability to respond to endogenous vasoactive compounds. Eventually, these engineered tissues may have the potential to supplant older organic but not truly biologic technologies, which are used currently. Copyright © 2015 Elsevier Inc. All rights reserved.

Associations of physical activity and inactivity with body tissue composition among healthy Polish women and women after mastectomy.

Science.gov (United States)

Czerniak, U; Demuth, A; Skrzypczak, M

2014-10-01

The aim of the study is to determine the relationship between physical activity and body composition among healthy women and women who have had mastectomy. This is in order to establish whether physical activity of women after breast cancer treatment improves composition and distribution of body mass components to a degree which will allow to achieve the body composition of healthy women. Research material consists of anthropometric measurements (body height, weight) of women and bioelectric impedance analysis (BIA) of body composition (using Akern - BIA 101 composition analyzer). Intensity of activity was assessed using the Physical Activity International Questionnaire. The sample consisted of 76 healthy women (active 44.74%, inactive 55.26%) and 70 females after mastectomy (54.29% and 45.71%, respectively). Mean chronological age of women after mastectomy was 53.40 years, SD=7.55, and of the healthy ones 52.38 years SD=11.01). A significant difference in body composition was noted among active and inactive women after mastectomy; namely the active females had lower weight (by approximately 12 kg), body mass index (BMI), level of fat mass (by approximately 8%) and (by approximately 5%) total body water. The active healthy women had 6% less fat mass, almost 4% more body water and 6% more fat free mass. Programmed physical activity undertaken by women after mastectomy is recommended and produces good results in the form of reduction of excessive body fat tissue. Through physical activity these women are able to achieve the same level of fat mass as healthy women. Copyright © 2014 Elsevier GmbH. All rights reserved.

Characterization of size, composition and origins of dust in fusion devices. Summary report of the 1. research coordination meeting

International Nuclear Information System (INIS)

Clark, R.E.H.

2009-03-01

Nine experts on dust formation and their physical and behavioural characteristics attended the first Research Coordination Meeting (RCM) on Characterization of Size, Composition and Origins of Dust in Fusion Devices held at IAEA Headquarters on 10-12 December 2008. Participants summarized recent relevant developments related to dust in fusion devices. The specific objectives of the CRP and a detailed work plan were formulated. Discussions, conclusions and recommendations of the RCM are briefly described in this report. (author)

THE INFLUENCE OF THE CHEMICAL COMPOSITION OF DIFFERENT ORIGIN BEANS (PHASEOLUS VULGARIS L. ON TOLERANCE TO THE BEAN WEEVIL (ACANTHOSCELIDES OBTECTUS SAY STROKE

Directory of Open Access Journals (Sweden)

A ODAGIU

2003-07-01

Full Text Available Bean weevil Acanthoscelides obtectus Say is a very harmful pest. When pest control lacks it can produce 100% damages in stocked seeds. Research performed in Romania emphasized the importance of resistant or tolerant origins use besides the quarantine and fight measures in order to limit the stroke of this pest (Manolache et al., 1966; Marghitu et al., 1978. Research aimed to establish the chemical composition of the beans of different origins in the same time with correlation between the different chemical components and their tolerance against A. obtectus stroke.

Pyrosequencing of the bacteria associated with Platygyra carnosus corals with skeletal growth anomalies reveals differences in bacterial community composition in apparently healthy and diseased tissues

Directory of Open Access Journals (Sweden)

Jenny Chun-Yee Ng

2015-10-01

Full Text Available Corals are rapidly declining globally due to coral diseases. Skeletal growth anomalies (SGA or coral tumors are a group of coral diseases that affect coral reefs worldwide, including Hong Kong waters in the Indo-Pacific region. To better understand how bacterial communities may vary in corals with SGA, for the first time, we examined the bacterial composition associated with the apparently healthy and the diseased tissues of SGA-affected Platgyra carnosus using 16S ribosomal rRNA gene pyrosequencing. Taxonomic analysis revealed Proteobacteria, Bacteroidetes, Cyanobacteria, and Actinobacteria as the main phyla in both the apparently healthy and the diseased tissues. A significant difference in the bacterial community composition was observed between the two conditions at the OTU level. Diseased tissues were associated with higher abundances of Acidobacteria and Gemmatimonadetes, and a lower abundance of Spirochaetes. Several OTUs belonging to Rhodobacteraceae, Rhizobiales, Gammaproteobacteria, and Cytophaga-Flavobacterium-Bacteroidetes (CFB were strongly associated with the diseased tissues. These groups of bacteria may contain potential pathogens involved with the development of SGA or opportunistic secondary or tertiary colonizers that proliferated upon the health-compromised coral host. We suggest that these bacterial groups to be further studied based on inoculation experiments and testing of Koch’s postulates in efforts to understand the etiology and progression of SGA.

Sugar Composition and Molecular Weight Distribution of Cell Wall Polysaccharides in Outer and Inner Tissues from Segments of Dark Grown Squash (Cucurbita maxima Duch.) Hypocotyls.

Science.gov (United States)

Wakabayashi, K; Sakurai, N; Kuraishi, S

1990-07-01

The elongation growth of stem segments is determined by the outer cell layers (epidermis and collenchyma). We measured the sugar composition and molecular weight distribution of pectin and hemicellulose fractions obtained from inner and outer tissues of squash (Cucurbita maxima Duch.) hypocotyls. In addition, we studied the changes in these parameters after a 9 hour period of incubation of the segments. The results show that outer tissues have higher molecular weight pectin and hemicellulose compared to inner tissues (2-3 times higher). Incubation results in a 13 to 25% decrease in the amount of pectin and hemicellulose in inner tissues and an increase of 11 to 32% in the outer tissues. This increase in the outer tissues is accompanied by a decrease in the molecular weight of some of the components. These results clearly show that cell wall metabolism during elongation growth differs markedly in inner and outer tissues, and that future studies on the effect of auxin need to take these differences into account.

Tissue

Directory of Open Access Journals (Sweden)

David Morrissey

2012-01-01

Full Text Available Purpose. In vivo gene therapy directed at tissues of mesenchymal origin could potentially augment healing. We aimed to assess the duration and magnitude of transene expression in vivo in mice and ex vivo in human tissues. Methods. Using bioluminescence imaging, plasmid and adenoviral vector-based transgene expression in murine quadriceps in vivo was examined. Temporal control was assessed using a doxycycline-inducible system. An ex vivo model was developed and optimised using murine tissue, and applied in ex vivo human tissue. Results. In vivo plasmid-based transgene expression did not silence in murine muscle, unlike in liver. Although maximum luciferase expression was higher in muscle with adenoviral delivery compared with plasmid, expression reduced over time. The inducible promoter cassette successfully regulated gene expression with maximum levels a factor of 11 greater than baseline. Expression was re-induced to a similar level on a temporal basis. Luciferase expression was readily detected ex vivo in human muscle and tendon. Conclusions. Plasmid constructs resulted in long-term in vivo gene expression in skeletal muscle, in a controllable fashion utilising an inducible promoter in combination with oral agents. Successful plasmid gene transfection in human ex vivo mesenchymal tissue was demonstrated for the first time.

Chemical Composition and Amounts of Mineral Elements in Honeybee-Collected Pollen in Relation to Botanical Origin

Directory of Open Access Journals (Sweden)

Taha El-Kazafy Abdou

2015-06-01

Full Text Available This study was conducted at the apiary of the Agricultural and Veterinary Training and Research Station, King Faisal University, Al-Ahsa, Saudi Arabia. The purpose was to study the relationship between the botanical origin and chemical composition of bee-collected pollen. The amount of mineral elements present in bee-collected pollen was also studied. The composition of pollen loads showed the maximum contents of dry matter, ash, glucose, fructose, magnesium (Mg, phosphorus (P, and manganese (Mn for the date palm; the maximum contents of protein, calcium (Ca, and zinc (Zn for alfalfa; the maximum contents of fiber, and copper (Cu for the sunflower; the maximum contents of the lipids and iron (Fe for summer squash; and the maximum contents of sodium (Na, and potassium (K for rape. Calcium was found to be correlated in a significantly (p<0.01 positive way with K, Na, Mg, P, Mn, and Zn. Copper, though, was correlated in a significantly (p<0.01 negative way with Ca, Mg, P, Mn, and Zn. The high levels of protein, ash, glucose, and fructose, and low lipid content found in bee-pollen from the date palm and from alfalfa, mean that pollen from the date palm and from alfalfa make an excellent food supplement. It was concluded, that the chemical composition of beecollected pollen can be correlated with the plant species from which pollen was collected.

Adaptive Breast Radiation Therapy Using Modeling of Tissue Mechanics: A Breast Tissue Segmentation Study

International Nuclear Information System (INIS)

Juneja, Prabhjot; Harris, Emma J.; Kirby, Anna M.; Evans, Philip M.

2012-01-01

Purpose: To validate and compare the accuracy of breast tissue segmentation methods applied to computed tomography (CT) scans used for radiation therapy planning and to study the effect of tissue distribution on the segmentation accuracy for the purpose of developing models for use in adaptive breast radiation therapy. Methods and Materials: Twenty-four patients receiving postlumpectomy radiation therapy for breast cancer underwent CT imaging in prone and supine positions. The whole-breast clinical target volume was outlined. Clinical target volumes were segmented into fibroglandular and fatty tissue using the following algorithms: physical density thresholding; interactive thresholding; fuzzy c-means with 3 classes (FCM3) and 4 classes (FCM4); and k-means. The segmentation algorithms were evaluated in 2 stages: first, an approach based on the assumption that the breast composition should be the same in both prone and supine position; and second, comparison of segmentation with tissue outlines from 3 experts using the Dice similarity coefficient (DSC). Breast datasets were grouped into nonsparse and sparse fibroglandular tissue distributions according to expert assessment and used to assess the accuracy of the segmentation methods and the agreement between experts. Results: Prone and supine breast composition analysis showed differences between the methods. Validation against expert outlines found significant differences (P<.001) between FCM3 and FCM4. Fuzzy c-means with 3 classes generated segmentation results (mean DSC = 0.70) closest to the experts' outlines. There was good agreement (mean DSC = 0.85) among experts for breast tissue outlining. Segmentation accuracy and expert agreement was significantly higher (P<.005) in the nonsparse group than in the sparse group. Conclusions: The FCM3 gave the most accurate segmentation of breast tissues on CT data and could therefore be used in adaptive radiation therapy-based on tissue modeling. Breast tissue segmentation

Adaptive Breast Radiation Therapy Using Modeling of Tissue Mechanics: A Breast Tissue Segmentation Study

Energy Technology Data Exchange (ETDEWEB)

Juneja, Prabhjot, E-mail: Prabhjot.Juneja@icr.ac.uk [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom); Harris, Emma J. [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom); Kirby, Anna M. [Department of Academic Radiotherapy, Royal Marsden National Health Service Foundation Trust, Sutton (United Kingdom); Evans, Philip M. [Joint Department of Physics, Institute of Cancer Research, Sutton (United Kingdom)

2012-11-01

Purpose: To validate and compare the accuracy of breast tissue segmentation methods applied to computed tomography (CT) scans used for radiation therapy planning and to study the effect of tissue distribution on the segmentation accuracy for the purpose of developing models for use in adaptive breast radiation therapy. Methods and Materials: Twenty-four patients receiving postlumpectomy radiation therapy for breast cancer underwent CT imaging in prone and supine positions. The whole-breast clinical target volume was outlined. Clinical target volumes were segmented into fibroglandular and fatty tissue using the following algorithms: physical density thresholding; interactive thresholding; fuzzy c-means with 3 classes (FCM3) and 4 classes (FCM4); and k-means. The segmentation algorithms were evaluated in 2 stages: first, an approach based on the assumption that the breast composition should be the same in both prone and supine position; and second, comparison of segmentation with tissue outlines from 3 experts using the Dice similarity coefficient (DSC). Breast datasets were grouped into nonsparse and sparse fibroglandular tissue distributions according to expert assessment and used to assess the accuracy of the segmentation methods and the agreement between experts. Results: Prone and supine breast composition analysis showed differences between the methods. Validation against expert outlines found significant differences (P<.001) between FCM3 and FCM4. Fuzzy c-means with 3 classes generated segmentation results (mean DSC = 0.70) closest to the experts' outlines. There was good agreement (mean DSC = 0.85) among experts for breast tissue outlining. Segmentation accuracy and expert agreement was significantly higher (P<.005) in the nonsparse group than in the sparse group. Conclusions: The FCM3 gave the most accurate segmentation of breast tissues on CT data and could therefore be used in adaptive radiation therapy-based on tissue modeling. Breast tissue

[Strategies to choose scaffold materials for tissue engineering].

Science.gov (United States)

Gao, Qingdong; Zhu, Xulong; Xiang, Junxi; Lü, Yi; Li, Jianhui

2016-02-01

Current therapies of organ failure or a wide range of tissue defect are often not ideal. Transplantation is the only effective way for long time survival. But it is hard to meet huge patients demands because of donor shortage, immune rejection and other problems. Tissue engineering could be a potential option. Choosing a suitable scaffold material is an essential part of it. According to different sources, tissue engineering scaffold materials could be divided into three types which are natural and its modified materials, artificial and composite ones. The purpose of tissue engineering scaffold is to repair the tissues or organs damage, so could reach the ideal recovery in its function and structure aspect. Therefore, tissue engineering scaffold should even be as close as much to the original tissue or organs in function and structure. We call it "organic scaffold" and this strategy might be the drastic perfect substitute for the tissues or organs in concern. Optimized organization with each kind scaffold materials could make up for biomimetic structure and function of the tissue or organs. Scaffold material surface modification, optimized preparation procedure and cytosine sustained-release microsphere addition should be considered together. This strategy is expected to open new perspectives for tissue engineering. Multidisciplinary approach including material science, molecular biology, and engineering might find the most ideal tissue engineering scaffold. Using the strategy of drawing on each other strength and optimized organization with each kind scaffold material to prepare a multifunctional biomimetic tissue engineering scaffold might be a good method for choosing tissue engineering scaffold materials. Our research group had differentiated bone marrow mesenchymal stem cells into bile canaliculi like cells. We prepared poly(L-lactic acid)/poly(ε-caprolactone) biliary stent. The scaffold's internal played a part in the long-term release of cytokines which

The origin of vertebrate limbs.

Science.gov (United States)

Coates, M I

1994-01-01

The earliest tetrapod limbs are polydactylous, morphologically varied and do not conform to an archetypal pattern. These discoveries, combined with the unravelling of limb developmental morphogenetic and regulatory mechanisms, have prompted a re-examination of vertebrate limb evolution. The rich fossil record of vertebrate fins/limbs, although restricted to skeletal tissues, exceeds the morphological diversity of the extant biota, and a systematic approach to limb evolution produces an informative picture of evolutionary change. A composite framework of several phylogenetic hypotheses is presented incorporating living and fossil taxa, including the first report of an acanthodian metapterygium and a new reconstruction of the axial skeleton and caudal fin of Acanthostega gunnari. Although significant nodes in vertebrate phylogeny remain poorly resolved, clear patterns of morphogenetic evolution emerge: median fin origination and elaboration initially precedes that of paired fins; pectoral fins initially precede pelvic fin development; evolving patterns of fin distribution, skeletal tissue diversity and structural complexity become decoupled with increased taxonomic divergence. Transformational sequences apparent from the fish-tetrapod transition are reiterated among extant lungfishes, indicating further directions for comparative experimental research. The evolutionary diversification of vertebrate fin and limb patterns challenges a simple linkage between Hox gene conservation, expression and morphology. A phylogenetic framework is necessary in order to distinguish shared from derived characters in experimental model regulatory systems. Hox and related genomic evolution may include convergent patterns underlying functional and morphological diversification. Brachydanio is suggested as an example where tail-drive patterning demands may have converged with the regulation of highly differentiated limbs in tetrapods.

Characterization and mechanical performance study of silk/PVA cryogels: towards nucleus pulposus tissue engineering.

Science.gov (United States)

Neo, Puay Yong; Shi, Pujiang; Goh, James Cho-Hong; Toh, Siew Lok

2014-10-20

Poly (vinyl) alcohol (PVA) cryogels are reported in the literature for application in nucleus pulposus (NP) replacement strategies. However, these studies are mainly limited to acellular approaches-in part due to the high hydrophilicity of PVA gels that renders cellular adhesion difficult. Silk is a versatile biomaterial with excellent biocompatibility. We hypothesize that the incorporation of silk with PVA will (i) improve the cell-hosting abilities of PVA cryogels and (ii) allow better tailoring of physical properties of the composite cryogels for an NP tissue engineering purpose. 5% (wt/vol) PVA is blended with 5% silk fibroin (wt/vol) to investigate the effect of silk : PVA ratios on the cryogels' physical properties. Results show that the addition of silk results in composite cryogels that are able to swell to more than 10 times its original dry weight and rehydrate to at least 70% of its original wet weight. Adding at least 20% silk significantly improves surface hydrophobicity and is correlated with an improvement in cell-hosting abilities. Cell-seeded cryogels also display an increment in compressive modulus and hoop stress values. In all, adding silk to PVA creates cryogels that can be potentially used as NP replacements.

Molecular composition and paleobotanical origin of Eocene resin ...

Indian Academy of Sciences (India)

dation of plant tissues by sealing and protecting wounds (van Aarssen ... taceous whereas the evolution of conifers predates ... mainly to angiosperm plants of Dipterocarpaceae ..... cation, classification and nomenclature of resinites; Org. Geochem. 18 829–841. Appanah S 1993 Mass flowering of dipterocarp forests in the.

In vitro-ex vivo correlations between a cell-laden hydrogel and mucosal tissue for screening composite delivery systems.

Science.gov (United States)

Blakney, Anna K; Little, Adam B; Jiang, Yonghou; Woodrow, Kim A

2016-11-01

Composite delivery systems where drugs are electrospun in different layers and vary the drug stacking-order are posited to affect bioavailability. We evaluated how the formulation characteristics of both burst- and sustained-release electrospun fibers containing three physicochemically diverse drugs: dapivirine (DPV), maraviroc (MVC) and tenofovir (TFV) affect in vitro and ex vivo release. We developed a poly(hydroxyethyl methacrylate) (pHEMA) hydrogel release platform for the rapid, inexpensive in vitro evaluation of burst- and sustained-release topical or dermal drug delivery systems with varying microarchitecture. We investigated properties of the hydrogel that could recapitulate ex vivo release into nonhuman primate vaginal tissue. Using a dimethyl sulfoxide extraction protocol and high-performance liquid chromatography analysis, we achieved >93% recovery from the hydrogels and >88% recovery from tissue explants for all three drugs. We found that DPV loading, but not stacking order (layers of fiber containing a single drug) or microarchitecture (layers with isolated drug compared to all drugs in the same layer) impacted the burst release in vitro and ex vivo. Our burst-release formulations showed a correlation for DPV accumulation between the hydrogel and tissue (R 2 =   0.80), but the correlation was not significant for MVC or TFV. For the sustained-release formulations, the PLGA/PCL content did not affect TFV release in vitro or ex vivo. Incorporation of cells into the hydrogel matrix improved the correlation between hydrogel and tissue explant release for TFV. We expect that this hydrogel-tissue mimic may be a promising preclinical model to evaluate topical or transdermal drug delivery systems with complex microarchitectures.

Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications

Energy Technology Data Exchange (ETDEWEB)

Pon-On, Weeraphat, E-mail: fsciwpp@ku.ac.th [Department of Physics, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University (Thailand); Department of Physiology, Faculty of Science, Mahidol University (Thailand); Tang, I-Ming [ThEP Center, Commission of Higher Education, 328 Si Ayutthaya Rd. (Thailand); Department of Materials Science, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand)

2014-05-01

In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze–thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. - Graphical abstract: Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications. - Highlights: • Preparation of PVABG:ChiCol hybrid composites and their bioactivities • Mechanical

Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications

International Nuclear Information System (INIS)

Pon-On, Weeraphat; Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Tang, I-Ming

2014-01-01

In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze–thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. - Graphical abstract: Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications. - Highlights: • Preparation of PVABG:ChiCol hybrid composites and their bioactivities • Mechanical

CELLULAR CONTROL OF CONNECTIVE TISSUE MATRIX TENSION†

OpenAIRE

Langevin, Helene M.; Nedergaard, Maiken; Howe, Alan

2013-01-01

The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occur...

The International Registry on Hand and Composite Tissue Transplantation.

Science.gov (United States)

Petruzzo, Palmina; Lanzetta, Marco; Dubernard, Jean-Michel; Landin, Luis; Cavadas, Pedro; Margreiter, Raimund; Schneeberger, Stephan; Breidenbach, Warren; Kaufman, Christina; Jablecki, Jerzy; Schuind, Frédéric; Dumontier, Christian

2010-12-27

The International Registry on Hand and Composite Tissue Transplantation was founded in May 2002, and the analysis of all cases with follow-up information up to July 2010 is presented here. From September 1998 to July 2010, 49 hands (17 unilateral and 16 bilateral hand transplantations, including 1 case of bilateral arm transplantation) have been reported, for a total of 33 patients. They were 31 men and 2 women (median age 32 years). Time since hand loss ranged from 2 months to 34 years, and in 46% of cases, the level of amputation was at wrist. Immunosuppressive therapy included tacrolimus, mycophenolate mofetil, sirolimus, and steroids; polyclonal or monoclonal antibodies were used for induction. Topical immunosuppression was also used in several cases. Follow-up ranges from 1 month to 11 years. One patient died on day 65. Three patients transplanted in the Western countries have lost their graft, whereas until September 2009, seven hand grafts were removed for noncompliance to the immunosuppressive therapy in China. Eighty-five percent of recipients experienced at least one episode of acute rejection within the first year, and they were reversible when promptly treated. Side effects included opportunistic infections, metabolic complications, and malignancies. All patients developed protective sensibility, 90% of them developed tactile sensibility, and 82.3% also developed a discriminative sensibility. Motor recovery enabled patients to perform most daily activities. Hand transplantation is a complex procedure, and its success is based on patient's compliance and his or her careful evaluation before and after transplantation.

3D bio-etching of a complex composite-like embryonic tissue.

Science.gov (United States)

Hazar, Melis; Kim, Yong Tae; Song, Jiho; LeDuc, Philip R; Davidson, Lance A; Messner, William C

2015-08-21

Morphogenesis involves a complex series of cell signaling, migration and differentiation events that are coordinated as tissues self-assemble during embryonic development. Collective cell movements such as those that occur during morphogenesis have typically been studied in 2D with single layers of cultured cells adhering to rigid substrates such as glass or plastic. In vivo, the intricacies of the 3D microenvironment and complex 3D responses are pivotal in the formation of functional tissues. To study such processes as collective cell movements within 3D multilayered tissues, we developed a microfluidic technique capable of producing complex 3D laminar multicellular structures. We call this technique "3D tissue-etching" because it is analogous to techniques used in the microelectromechanics (MEMS) field where complex 3D structures are built by successively removing material from a monolithic solid through subtractive manufacturing. We use a custom-designed microfluidic control system to deliver a range of tissue etching reagents (detergents, chelators, proteases, etc.) to specific regions of multilayered tissues. These tissues were previously isolated by microsurgical excision from embryos of the African claw-toed frog, Xenopus laevis. The ability to shape the 3D form of multicellular tissues and to control 3D stimulation will have a high impact on tissue engineering and regeneration applications in bioengineering and medicine as well as provide significant improvements in the synthesis of highly complex 3D integrated multicellular biosystems.

Association between increased epicardial adipose tissue volume and coronary plaque composition.

Science.gov (United States)

Yamashita, Kennosuke; Yamamoto, Myong Hwa; Ebara, Seitarou; Okabe, Toshitaka; Saito, Shigeo; Hoshimoto, Koichi; Yakushiji, Tadayuki; Isomura, Naoei; Araki, Hiroshi; Obara, Chiaki; Ochiai, Masahiko

2014-09-01

To assess the relationship between epicardial adipose tissue volume (EATV) and plaque vulnerability in significant coronary stenosis using a 40-MHz intravascular ultrasound (IVUS) imaging system (iMap-IVUS), we analyzed 130 consecutive patients with coronary stenosis who underwent dual-source computed tomography (CT) and cardiac catheterization. Culprit lesions were imaged by iMap-IVUS before stenting. The iMAP-IVUS system classified coronary plaque components as fibrous, lipid, necrotic, or calcified tissue, based on the radiofrequency spectrum. Epicardial adipose tissue was measured as the tissue ranging from -190 to -30 Hounsfield units. EATV, calculated as the sum of the fat areas on short-axis images, was 85.0 ± 34.0 cm(3). There was a positive correlation between EATV and the percentage of necrotic plaque tissue (R (2) = 0.34, P EATV and the percentage of fibrous tissue (R (2) = 0.24, P EATV (β = 0.14, P = 0.02) were independently associated with the percentage of necrotic plaque tissue. An increase in EATV was associated with the development of coronary atherosclerosis and, potentially, with the most dangerous type of plaque.

Osteochondral tissue engineering: scaffolds, stem cells and applications

Science.gov (United States)

Nooeaid, Patcharakamon; Salih, Vehid; Beier, Justus P; Boccaccini, Aldo R

2012-01-01

Osteochondral tissue engineering has shown an increasing development to provide suitable strategies for the regeneration of damaged cartilage and underlying subchondral bone tissue. For reasons of the limitation in the capacity of articular cartilage to self-repair, it is essential to develop approaches based on suitable scaffolds made of appropriate engineered biomaterials. The combination of biodegradable polymers and bioactive ceramics in a variety of composite structures is promising in this area, whereby the fabrication methods, associated cells and signalling factors determine the success of the strategies. The objective of this review is to present and discuss approaches being proposed in osteochondral tissue engineering, which are focused on the application of various materials forming bilayered composite scaffolds, including polymers and ceramics, discussing the variety of scaffold designs and fabrication methods being developed. Additionally, cell sources and biological protein incorporation methods are discussed, addressing their interaction with scaffolds and highlighting the potential for creating a new generation of bilayered composite scaffolds that can mimic the native interfacial tissue properties, and are able to adapt to the biological environment. PMID:22452848

Natural Polymer-Cell Bioconstructs for Bone Tissue Engineering.

Science.gov (United States)

Titorencu, Irina; Albu, Madalina Georgiana; Nemecz, Miruna; Jinga, Victor V

2017-01-01

The major goal of bone tissue engineering is to develop bioconstructs which substitute the functionality of damaged natural bone structures as much as possible if critical-sized defects occur. Scaffolds that mimic the structure and composition of bone tissue and cells play a pivotal role in bone tissue engineering applications. First, composition, properties and in vivo synthesis of bone tissue are presented for the understanding of bone formation. Second, potential sources of osteoprogenitor cells have been investigated for their capacity to induce bone repair and regeneration. Third, taking into account that the main property to qualify one scaffold as a future bioconstruct for bone tissue engineering is the biocompatibility, the assessments which prove it are reviewed in this paper. Forth, various types of natural polymer- based scaffolds consisting in proteins, polysaccharides, minerals, growth factors etc, are discussed, and interaction between scaffolds and cells which proved bone tissue engineering concept are highlighted. Finally, the future perspectives of natural polymer-based scaffolds for bone tissue engineering are considered. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Investigation of the differentiation of ex vivo nerve and fat tissues using laser-induced breakdown spectroscopy (LIBS): Prospects for tissue-specific laser surgery.

Science.gov (United States)

Mehari, Fanuel; Rohde, Maximillian; Kanawade, Rajesh; Knipfer, Christian; Adler, Werner; Klämpfl, Florian; Stelzle, Florian; Schmidt, Michael

2016-10-01

In the present study, the elemental compositions of fat and nerve tissue during their plasma mediated laser ablation are studied in the context of tissue differentiation for laser surgery applications by using Laser-Induced Breakdown Spectroscopy (LIBS). Tissue samples of porcine fat and nerve were prepared as ex vivo experimental objects. Plasma mediated laser ablation is performed using an Nd : YAG laser in open air and under normal stray light conditions. The performed measurements suggest that the two tissue types show a high similarity in terms of qualitative elemental composition while at the same time revealing a distinct difference in the concentration of the constituent elements. Different analysis approaches are evaluated and discussed to optimize the tissue-differentiation performance of the LIBS approach. Plasma mediated laser tissue ablation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Incorporation of lysosomal sequestration in the mechanistic model for prediction of tissue distribution of basic drugs.

Science.gov (United States)

Assmus, Frauke; Houston, J Brian; Galetin, Aleksandra

2017-11-15

The prediction of tissue-to-plasma water partition coefficients (Kpu) from in vitro and in silico data using the tissue-composition based model (Rodgers & Rowland, J Pharm Sci. 2005, 94(6):1237-48.) is well established. However, distribution of basic drugs, in particular into lysosome-rich lung tissue, tends to be under-predicted by this approach. The aim of this study was to develop an extended mechanistic model for the prediction of Kpu which accounts for lysosomal sequestration and the contribution of different cell types in the tissue of interest. The extended model is based on compound-specific physicochemical properties and tissue composition data to describe drug ionization, distribution into tissue water and drug binding to neutral lipids, neutral phospholipids and acidic phospholipids in tissues, including lysosomes. Physiological data on the types of cells contributing to lung, kidney and liver, their lysosomal content and lysosomal pH were collated from the literature. The predictive power of the extended mechanistic model was evaluated using a dataset of 28 basic drugs (pK a ≥7.8, 17 β-blockers, 11 structurally diverse drugs) for which experimentally determined Kpu data in rat tissue have been reported. Accounting for the lysosomal sequestration in the extended mechanistic model improved the accuracy of Kpu predictions in lung compared to the original Rodgers model (56% drugs within 2-fold or 88% within 3-fold of observed values). Reduction in the extent of Kpu under-prediction was also evident in liver and kidney. However, consideration of lysosomal sequestration increased the occurrence of over-predictions, yielding overall comparable model performances for kidney and liver, with 68% and 54% of Kpu values within 2-fold error, respectively. High lysosomal concentration ratios relative to cytosol (>1000-fold) were predicted for the drugs investigated; the extent differed depending on the lysosomal pH and concentration of acidic phospholipids among

Characterization of Size, Composition and Origins of Dust in Fusion Devices. Summary Report of the Third Research Coordination Meeting

International Nuclear Information System (INIS)

Braams, B.J.

2013-02-01

Twelve experts on processes of dust in fusion experiments met at IAEA Headquarters 30 November - 02 December 2011 for the 3rd Research Coordination Meeting (RCM) of the Coordinated Research Project (CRP) on ''Characterization of size, composition and origins of dust in fusion devices.'' Participants reviewed their work done in the course of the CRP and the current state of knowledge, and they made plans for a dust database and a final CRP report. Presentations, discussions and recommendations of the RCM are summarized here. (author)

Sugar Composition and Molecular Weight Distribution of Cell Wall Polysaccharides in Outer and Inner Tissues from Segments of Dark Grown Squash (Cucurbita maxima Duch.) Hypocotyls 1

Science.gov (United States)

Wakabayashi, Kazuyuki; Sakurai, Naoki; Kuraishi, Susumu

1990-01-01

The elongation growth of stem segments is determined by the outer cell layers (epidermis and collenchyma). We measured the sugar composition and molecular weight distribution of pectin and hemicellulose fractions obtained from inner and outer tissues of squash (Cucurbita maxima Duch.) hypocotyls. In addition, we studied the changes in these parameters after a 9 hour period of incubation of the segments. The results show that outer tissues have higher molecular weight pectin and hemicellulose compared to inner tissues (2-3 times higher). Incubation results in a 13 to 25% decrease in the amount of pectin and hemicellulose in inner tissues and an increase of 11 to 32% in the outer tissues. This increase in the outer tissues is accompanied by a decrease in the molecular weight of some of the components. These results clearly show that cell wall metabolism during elongation growth differs markedly in inner and outer tissues, and that future studies on the effect of auxin need to take these differences into account. PMID:16667612

Effects of increased pCO2 and geographic origin on purple sea urchin (Strongylocentrotus purpuratus) calcite elemental composition

Science.gov (United States)

LaVigne, M.; Hill, T. M.; Sanford, E.; Gaylord, B.; Russell, A. D.; Lenz, E. A.; Hosfelt, J. D.; Young, M. K.

2012-12-01

Ocean acidification will likely have negative impacts on invertebrates producing skeletons composed of calcium carbonate. Skeletal solubility is partly controlled by the incorporation of "foreign" ions (such as Mg and Sr) into the crystal lattice of these skeletal structures, a process that is sensitive to a variety of biological and environmental factors. Here we explore the effects of life stage, oceanographic region of origin, and changes in the partial pressure of carbon dioxide in seawater (pCO2) on trace elemental composition in the purple sea urchin (Strongylocentrotus purpuratus). We show that, similar to other urchin taxa, adult purple sea urchins have the ability to precipitate skeleton composed of a range of biominerals spanning low to high magnesium calcites. Mg/Ca and Sr/Ca ratios were substantially lower in adult spines compared to adult tests. On the other hand, trace elemental composition was invariant among adults collected from four oceanographically distinct regions along the US west coast (Oregon, Northern California, Central California, and Southern California). Skeletons of newly settled juvenile urchins that originated from adults from the four regions exhibited intermediate Mg/Ca and Sr/Ca between adult spine and test endmembers, indicating that skeleton precipitated during early life stages is more soluble than adult spines and less soluble than adult tests. Mean skeletal Mg/Ca or Sr/Ca of juvenile skeleton did not vary with source region when larvae were reared under present-day, global-average seawater carbonate conditions (400 ppm; pH = 8.02 ± 0.03 1 SD; Ωcalcite = 3.3 ± 0.2 1 SD). However, when reared under elevated CO2 (900 ppm; pH = 7.72 ± 0.03; Ωcalcite = 1.8 ± 0.1), skeletal Sr/Ca in juveniles exhibited increased variance across the four regions. Although larvae from the northern populations (Oregon, Northern California, Central California) did not exhibit differences in Mg or Sr incorporation under elevated CO2 (Sr/Ca = 2

Cosmic ray: Studying the origin

International Nuclear Information System (INIS)

Szabelski, J.

1997-01-01

Investigations of the origin of cosmic rays are presented. Different methods are discussed: studies of cosmic gamma rays of energy from 30 MeV to about 10 15 eV (since photons point to their places of origin), studies of the mass composition of cosmic rays (because it reflects source morphology), and studies of cosmic rays with energy above 1O 19 eV (for these are the highest energies observed in nature). (author)

Lymphoid Tissue Grafts in Man

Energy Technology Data Exchange (ETDEWEB)

Kay, H. E.M. [Royal Marsden Hospital, Institute of Cancer Research, London (United Kingdom)

1969-07-15

Grafts of lymphoid tissue or of lymphoid stem cells may be appropriate in the treatment of some congenital immune deficiency disorders. The reasons for preferring tissues of foetal origin are discussed and the evidence for foetal immunocompetence is briefly summarized. Methods of storing foetal liver cells and cells or fragments of thymus are mentioned, and the organization of the Foetal Tissue Bank of the Royal Marsden Hospital is described. Clinical data from transplantation of lymphoid cells in various immune deficiency disorders are briefly presented. (author)

Origins of GEMS Grains

Science.gov (United States)

Messenger, S.; Walker, R. M.

2012-01-01

Interplanetary dust particles (IDPs) collected in the Earth s stratosphere contain high abundances of submicrometer amorphous silicates known as GEMS grains. From their birth as condensates in the outflows of oxygen-rich evolved stars, processing in interstellar space, and incorporation into disks around new stars, amorphous silicates predominate in most astrophysical environments. Amorphous silicates were a major building block of our Solar System and are prominent in infrared spectra of comets. Anhydrous interplanetary dust particles (IDPs) thought to derive from comets contain abundant amorphous silicates known as GEMS (glass with embedded metal and sulfides) grains. GEMS grains have been proposed to be isotopically and chemically homogenized interstellar amorphous silicate dust. We evaluated this hypothesis through coordinated chemical and isotopic analyses of GEMS grains in a suite of IDPs to constrain their origins. GEMS grains show order of magnitude variations in Mg, Fe, Ca, and S abundances. GEMS grains do not match the average element abundances inferred for ISM dust containing on average, too little Mg, Fe, and Ca, and too much S. GEMS grains have complementary compositions to the crystalline components in IDPs suggesting that they formed from the same reservoir. We did not observe any unequivocal microstructural or chemical evidence that GEMS grains experienced prolonged exposure to radiation. We identified four GEMS grains having O isotopic compositions that point to origins in red giant branch or asymptotic giant branch stars and supernovae. Based on their O isotopic compositions, we estimate that 1-6% of GEMS grains are surviving circumstellar grains. The remaining 94-99% of GEMS grains have O isotopic compositions that are indistinguishable from terrestrial materials and carbonaceous chondrites. These isotopically solar GEMS grains either formed in the Solar System or were completely homogenized in the interstellar medium (ISM). However, the

Influence of Spray-dried Hydroxyapatite-5-Fluorouracil Granules on Cell Lines Derived from Tissues of Mesenchymal Origin

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Tim Scharnweber

2008-11-01

Full Text Available In our previous work we described the preparation and characterization of spray dried hydroxyapatite micro granules loaded with 5-fluorouracil (5-FU. These loaded particles are used as a model drug delivery system (DDS. In this study we examined the in vitro response of two cell lines derived from different tissues to 5-FU loaded granules (LG. Both cell lines, either L929 cells of a mouse fibroblast lineage or cells originating from a rat osteosarcoma (ROS 17/2.8 showed a dose dependent decrease in cell proliferation in response to 5-FU-, either dissolved in the culture medium or loaded onto particles. The response of the two cell lines to loaded and nonloaded particles was different. The effect of LG and of a corresponding concentration of free 5-FU was practically the same for the ROS 17/2.8 cells indicating that ROS 17/2.8 cells were not affected by the carrier material. In contrast, L929 cells showed a slight decrease in cell proliferation also in the presence of granules not loaded with 5-FU. This is thought to be attributed to the inhibition of mitogenesis by phosphocitrates, already demonstrated in fibroblasts. In summary, we found that the loaded 5-FU kept its effectivity after the spray drying process and that the response towards the granules varied with cell type. This is the first step towards a tissue specific DDS.

Tablet-level origin of toughening in abalone shells and translation to synthetic composite materials.

Science.gov (United States)

Espinosa, Horacio D; Juster, Allison L; Latourte, Felix J; Loh, Owen Y; Gregoire, David; Zavattieri, Pablo D

2011-02-01

Nacre, the iridescent material in seashells, is one of many natural materials employing hierarchical structures to achieve high strength and toughness from relatively weak constituents. Incorporating these structures into composites is appealing as conventional engineering materials often sacrifice strength to improve toughness. Researchers hypothesize that nacre's toughness originates within its brick-and-mortar-like microstructure. Under loading, bricks slide relative to each other, propagating inelastic deformation over millimeter length scales. This leads to orders-of-magnitude increase in toughness. Here, we use in situ atomic force microscopy fracture experiments and digital image correlation to quantitatively prove that brick morphology (waviness) leads to transverse dilation and subsequent interfacial hardening during sliding, a previously hypothesized dominant toughening mechanism in nacre. By replicating this mechanism in a scaled-up model synthetic material, we find that it indeed leads to major improvements in energy dissipation. Ultimately, lessons from this investigation may be key to realizing the immense potential of widely pursued nanocomposites.

Preparation and Characterization of Biomimetic Hydroxyapatite-Resorbable Polymer Composites for Hard Tissue Repair

Science.gov (United States)

Hiebner, Kristopher Robert

Autografts are the orthopedic "gold standard" for repairing bone voids. Autografts are osteoconductive and do not elicit an immune response, but they are in short supply and require a second surgery to harvest the bone graft. Allografts are currently the most common materials used for the repair of segmental defects in hard tissue. Unlike autografts, allografts can cause an undesirable immune response and the possibility of disease transmission is a major concern. As an alternative to the above approaches, recent research efforts have focused on the use of composite materials made from hydroxyapatite (HA) and bioresorbable polymers, such as poly-L-lactide (PLLA). Recent results have shown that the surface hydroxides on HA can initiate the ring opening polymerization (ROP) of L-lactide and other lactones creating a composite with superior interfacial strength. This thesis demonstrates that the surface of porous biologically derived HA substrates, such as coralline HA and trabecular bone, can be used to initiate the ROP of L-lactide and other lactones from the vapor phase. This process increases the strength of the porous scaffold through the deposition of a thin, uniform polymer coating, while maintaining the porous structure. The kinetics of the chemical vapor deposition polymerization (CVDP) are described using a quartz crystal microbalance (QCM). The reaction temperature and monomer vapor pressure are found to affect the rate of the polymerization. Also described in this thesis is the preparation of a porous polymer scaffold that mimics the structure of demineralized bone matrix (DBM). This demineralized bone matrix simulant (DBMS) is created using anorganic bovine bone as a template to initiate the polymerization of various lactones, followed by the removal of the HA scaffold. This material retained its shape and exhibits mechanical properties superior to DBM. Finally it is shown that HA can be used to initiate the ROP of a-caprolactam and the biocompatibility

Composition of hot ions /0.1-16 keV/e/ as observed by the GEOS and ISEE mass spectrometers and inferences for the origin and circulation of magnetospheric plasmas

Science.gov (United States)

Balsiger, H.

1981-01-01

The composition of hot magnetospheric plasma through different regions of the magnetosphere is described on the basis of mass spectrometer measurements by the GEOS 1, GEOS 2, and ISEE-1 spacecraft. Coordinated composition measurements on the different spacecraft also provide information on the spatial and temporal characteristics of the plasma during storms. Data on ion origins are also provided.

New Coll–HA/BT composite materials for hard tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Zanfir, Andrei Vlad [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Material Science, “Politehnica” University of Bucharest, 1-7 Gh. Polizu Street, RO-011061 Bucharest (Romania); Voicu, Georgeta, E-mail: getav2001@yahoo.co.uk [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Material Science, “Politehnica” University of Bucharest, 1-7 Gh. Polizu Street, RO-011061 Bucharest (Romania); Busuioc, Cristina; Jinga, Sorin Ion [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Material Science, “Politehnica” University of Bucharest, 1-7 Gh. Polizu Street, RO-011061 Bucharest (Romania); Albu, Madalina Georgiana [Department of Collagen, Branch of Leather and Footwear Research, National Institute of Research and Development for Textile and Leather, 93 I. Minulescu Street, RO-031215 Bucharest (Romania); Iordache, Florin [Department of Fetal and Adult Stem Cell Therapy, “Nicolae Simionescu” Institute of Cellular Biology and Pathology of Romanian Academy, 8 B.P. Hasdeu Street, RO-050568 Bucharest (Romania)

2016-05-01

The integration of ceramic powders in composite materials for bone scaffolds can improve the osseointegration process. This work was aimed to the synthesis and characterization of new collagen–hydroxyapatite/barium titanate (Coll–HA/BT) composite materials starting from barium titanate (BT) nanopowder, hydroxyapatite (HA) nanopowder and collagen (Coll) gel. BT nanopowder was produced by combining two wet-chemical approaches, sol–gel and hydrothermal methods. The resulting materials were characterized in terms of phase composition and microstructure by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. Moreover, the biocompatibility and bioactivity of the composite materials were assessed by in vitro tests. The synthesized BT particles exhibit an average size of around 35 nm and a spherical morphology, with a pseudo-cubic or tetragonal symmetry. The diffraction spectra of Coll–HA and Coll–HA/BT composite materials indicate a pronounced interaction between Col and the mineral phases, meaning a good mineralization of Col fibres. As well, the in vitro tests highlight excellent osteoinductive properties for all biological samples, especially for Coll–HA/BT composite materials, fact that can be attributed to the ferromagnetic properties of BT. - Highlights: • Collagen–hydroxyapatite/barium titanate composite materials were synthesized. • Barium titanate was produced by combining the sol–gel and hydrothermal methods. • The in vitro tests highlight excellent osteoinductive properties for all samples.

New Coll–HA/BT composite materials for hard tissue engineering

International Nuclear Information System (INIS)

Zanfir, Andrei Vlad; Voicu, Georgeta; Busuioc, Cristina; Jinga, Sorin Ion; Albu, Madalina Georgiana; Iordache, Florin

2016-01-01

The integration of ceramic powders in composite materials for bone scaffolds can improve the osseointegration process. This work was aimed to the synthesis and characterization of new collagen–hydroxyapatite/barium titanate (Coll–HA/BT) composite materials starting from barium titanate (BT) nanopowder, hydroxyapatite (HA) nanopowder and collagen (Coll) gel. BT nanopowder was produced by combining two wet-chemical approaches, sol–gel and hydrothermal methods. The resulting materials were characterized in terms of phase composition and microstructure by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. Moreover, the biocompatibility and bioactivity of the composite materials were assessed by in vitro tests. The synthesized BT particles exhibit an average size of around 35 nm and a spherical morphology, with a pseudo-cubic or tetragonal symmetry. The diffraction spectra of Coll–HA and Coll–HA/BT composite materials indicate a pronounced interaction between Col and the mineral phases, meaning a good mineralization of Col fibres. As well, the in vitro tests highlight excellent osteoinductive properties for all biological samples, especially for Coll–HA/BT composite materials, fact that can be attributed to the ferromagnetic properties of BT. - Highlights: • Collagen–hydroxyapatite/barium titanate composite materials were synthesized. • Barium titanate was produced by combining the sol–gel and hydrothermal methods. • The in vitro tests highlight excellent osteoinductive properties for all samples.

Effect of Linseed Oil Dietary Supplementation on Fatty Acid Composition and Gene Expression in Adipose Tissue of Growing Goats

Directory of Open Access Journals (Sweden)

M. Ebrahimi

2013-01-01

Full Text Available This study was conducted to determine the effects of feeding oil palm frond silage based diets with added linseed oil (LO containing high α-linolenic acid (C18:3n-3, namely, high LO (HLO, low LO (LLO, and without LO as the control group (CON on the fatty acid (FA composition of subcutaneous adipose tissue and the gene expression of peroxisome proliferator-activated receptor (PPARα, PPAR-γ, and stearoyl-CoA desaturase (SCD in Boer goats. The proportion of C18:3n-3 in subcutaneous adipose tissue was increased (P<0.01 by increasing the LO in the diet, suggesting that the FA from HLO might have escaped ruminal biohydrogenation. Animals fed HLO diets had lower proportions of C18:1 trans-11, C18:2n-6, CLA cis-9 trans-11, and C20:4n-6 and higher proportions of C18:3n-3, C22:5n-3, and C22:6n-3 in the subcutaneous adipose tissue than animals fed the CON diets, resulting in a decreased n-6:n-3 fatty acid ratio (FAR in the tissue. In addition, feeding the HLO diet upregulated the expression of PPAR-γ (P<0.05 but downregulated the expression of SCD (P<0.05 in the adipose tissue. The results of the present study show that LO can be safely incorporated in the diets of goats to enrich goat meat with potential health beneficial FA (i.e., n-3 FA.

The origin of Wolf-Rayet stars

International Nuclear Information System (INIS)

Doom, C.

1987-01-01

The paper reviews the origin of Wolf-Rayet (WR) stars, with emphasis on the so-called Population I WR stars which are associated with the young and luminous stellar population. A description is given of the observational characteristics i.e. classification, luminosities composition, etc. of WR stars. The origin and evolution of WR stars is described, including the single, binary, subtypes and ratio WR/O. The interaction of the WR stars with their environment is discussed with respect to the energy deposition and composition anomalies. A brief account of the discovery of WR stars in other galaxies is given. Finally, some of the main issues in the research into the structure and evolution of WR stars are outlined. (U.K.)

Enhanced Bone Tissue Regeneration by Porous Gelatin Composites Loaded with the Chinese Herbal Decoction Danggui Buxue Tang.

Directory of Open Access Journals (Sweden)

Wen-Ling Wang

Full Text Available Danggui Buxue Tang (DBT is a traditional Chinese herbal decoction containing Radix Astragali and Radix Angelicae sinensis. Pharmacological results indicate that DBT can stimulate bone cell proliferation and differentiation. The aim of the study was to investigate the efficacy of adding DBT to bone substitutes on bone regeneration following bone injury. DBT was incorporated into porous composites (GGT made from genipin-crosslinked gelatin and β-triclacium phosphates as bone substitutes (GGTDBT. The biological response of mouse calvarial bone to these composites was evaluated by in vivo imaging systems (IVIS, micro-computed tomography (micro-CT, and histology analysis. IVIS images revealed a stronger fluorescent signal in GGTDBT-treated defect than in GGT-treated defect at 8 weeks after implantation. Micro-CT analysis demonstrated that the level of repair from week 4 to 8 increased from 42.1% to 71.2% at the sites treated with GGTDBT, while that increased from 33.2% to 54.1% at GGT-treated sites. These findings suggest that the GGTDBT stimulates the innate regenerative capacity of bone, supporting their use in bone tissue regeneration.

Composition-function relations of cartilaginous tissues engineered from chondrocytes and mesenchymal stem cells isolated from bone marrow and infrapatellar fat pad.

Science.gov (United States)

Vinardell, T; Buckley, C T; Thorpe, S D; Kelly, D J

2011-10-01

The objective of this study was to determine the functional properties of cartilaginous tissues generated by porcine MSCs isolated from different tissue sources, and to compare these properties to those derived from chondrocytes (CCs). MSCs were isolated from bone marrow (BM) and infrapatellar fat pad (FP), while CCs were harvested from the articular surface of the femoro-patellar joint. Culture-expanded CCs and MSCs were encapsulated in agarose hydrogels and cultured in the presence of TGFβ3. Samples were analysed biomechanically, biochemically and histologically at days 0, 21 and 42. After 42 days in free swelling culture, mean GAG content was 1.50% w/w in CC-seeded constructs, compared to 0.95% w/w in FP- and 0.43% w/w in BM-seeded constructs. Total collagen accumulation was highest in FP constructs. DNA content increased with time for all the groups. The mechanical functionality of cartilaginous tissues engineered using CCs was superior to that generated from either source of MSCs. Differences were also observed in the spatial distribution of matrix components in tissues engineered using CCs and MSCs, which appears to have a strong influence on the apparent mechanical properties of the constructs. Therefore, while functional cartilaginous tissues can be engineered using MSCs isolated from different sources, the spatial composition of these tissues is unlike that generated using chondrocytes, suggesting that MSCs and chondrocytes respond differently to the regulatory factors present within developing cartilaginous constructs. Copyright © 2010 John Wiley & Sons, Ltd.

Longterm survival and reason for failure of anterior composite restoration

Directory of Open Access Journals (Sweden)

Nina Djustiana

2016-06-01

Full Text Available Composites resin restorations have been used for repairing and restoring anterior teeth for decades due to the growing needs for a cost- effective aesthetic restoration and the advancement in dental material and polymer technology. Failure of composite restorations cannot be neglected, due to multiple factors, i.e. failure to diagnose the gingival tissue, inadequate tissue management, quality of remaining tooth structure, and inadequate preparation. The aim of this review is to improve clinical performances of direct composite as permanent restorations. Long lasting aesthetic composite restorations required proper mouth preparations ,which  includes supporting and dental hard tissue preparations, tooth preparation, proper isolation, bonding procedures, light cure unit, and the resin composite itself.

Origin of the chemical elements

Energy Technology Data Exchange (ETDEWEB)

Tayler, R J

1984-05-01

The subject is discussed in relation to the composition of initially created matter and changes which have occurred during the life history of the universe, with particular reference to our galaxy and nearby galaxies. Headings are: observations of element abundances (stars, gas clouds in our own and nearby galaxies, hot gas in galaxy clusters, the solar system); the originally created matter (Big Bang theory and early nuclear reactions); processes changing observed composition (galactic evolution; nuclear fusion reactions in stellar interiors; chemical composition of a highly evolved massive star); supernovae (production of heavy elements); chemical evolution of the galaxy; production of very heavy elements (s process, r process).

Effect of anti-sclerostin therapy and osteogenesis imperfecta on tissue-level properties in growing and adult mice while controlling for tissue age.

Science.gov (United States)

Sinder, Benjamin P; Lloyd, William R; Salemi, Joseph D; Marini, Joan C; Caird, Michelle S; Morris, Michael D; Kozloff, Kenneth M

2016-03-01

Bone composition and biomechanics at the tissue-level are important contributors to whole bone strength. Sclerostin antibody (Scl-Ab) is a candidate anabolic therapy for the treatment of osteoporosis that increases bone formation, bone mass, and bone strength in animal studies, but its effect on bone quality at the tissue-level has received little attention. Pre-clinical studies of Scl-Ab have recently expanded to include diseases with altered collagen and material properties such as osteogenesis imperfecta (OI). The purpose of this study was to investigate the role of Scl-Ab on bone quality by determining bone material composition and tissue-level mechanical properties in normal wild type (WT) tissue, as well as mice with a typical OI Gly➔Cys mutation (Brtl/+) in type I collagen. Rapidly growing (3-week-old) and adult (6-month-old) WT and Brtl/+ mice were treated for 5weeks with Scl-Ab. Fluorescent guided tissue-level bone composition analysis (Raman spectroscopy) and biomechanical testing (nanoindentation) were performed at multiple tissue ages. Scl-Ab increased mineral to matrix in adult WT and Brtl/+ at tissue ages of 2-4wks. However, no treatment related changes were observed in mineral to matrix levels at mid-cortex, and elastic modulus was not altered by Scl-Ab at any tissue age. Increased mineral-to-matrix was phenotypically observed in adult Brtl/+ OI mice (at tissue ages>3wks) and rapidly growing Brtl/+ (at tissue ages>4wks) mice compared to WT. At identical tissue ages defined by fluorescent labels, adult mice had generally lower mineral to matrix ratios and a greater elastic modulus than rapidly growing mice, demonstrating that bone matrix quality can be influenced by animal age and tissue age alike. In summary, these data suggest that Scl-Ab alters the matrix chemistry of newly formed bone while not affecting the elastic modulus, induces similar changes between Brtl/+ and WT mice, and provides new insight into the interaction between tissue age and

Gel spinning of silk tubes for tissue engineering

Science.gov (United States)

Lovett, Michael; Cannizzaro, Christopher; Vunjak-Novakovic, Gordana; Kaplan, David L.

2011-01-01

Tubular vessels for tissue engineering are typically fabricated using a molding, dipping, or electrospinning technique. While these techniques provide some control over inner and outer diameters of the tube, they lack the ability to align the polymers or fibers of interest throughout the tube. This is an important aspect of biomaterial composite structure and function for mechanical and biological impact of tissue outcomes. We present a novel aqueous process system to spin tubes from biopolymers and proteins such as silk fibroin. Using silk as an example, this method of winding an aqueous solution around a reciprocating rotating mandrel offers substantial improvement in the control of the tube properties, specifically with regard to winding pattern, tube porosity, and composite features. Silk tube properties are further controlled via different post-spinning processing mechanisms such as methanol-treatment, air-drying, and lyophilization. This approach to tubular scaffold manufacture offers numerous tissue engineering applications such as complex composite biomaterial matrices, blood vessel grafts and nerve guides, among others. PMID:18801570

Tracing common origins of Genomic Islands in prokaryotes based on genome signature analyses.

Science.gov (United States)

van Passel, Mark Wj

2011-09-01

Horizontal gene transfer constitutes a powerful and innovative force in evolution, but often little is known about the actual origins of transferred genes. Sequence alignments are generally of limited use in tracking the original donor, since still only a small fraction of the total genetic diversity is thought to be uncovered. Alternatively, approaches based on similarities in the genome specific relative oligonucleotide frequencies do not require alignments. Even though the exact origins of horizontally transferred genes may still not be established using these compositional analyses, it does suggest that compositionally very similar regions are likely to have had a common origin. These analyses have shown that up to a third of large acquired gene clusters that reside in the same genome are compositionally very similar, indicative of a shared origin. This brings us closer to uncovering the original donors of horizontally transferred genes, and could help in elucidating possible regulatory interactions between previously unlinked sequences.

Cosmic ray: Studying the origin

Energy Technology Data Exchange (ETDEWEB)

Szabelski, J. [Cosmic Ray Laboratory, Soltan Institute for Nuclear Studies, Lodz (Poland)

1997-12-31

Investigations of the origin of cosmic rays are presented. Different methods are discussed: studies of cosmic gamma rays of energy from 30 MeV to about 10{sup 15} eV (since photons point to their places of origin), studies of the mass composition of cosmic rays (because it reflects source morphology), and studies of cosmic rays with energy above 1O{sup 19} eV (for these are the highest energies observed in nature). (author) 101 refs, 19 figs, 7 tabs

Bacterial microbiota compositions of naturally fermented milk are shaped by both geographic origin and sample type.

Science.gov (United States)

Zhong, Z; Hou, Q; Kwok, L; Yu, Z; Zheng, Y; Sun, Z; Menghe, B; Zhang, H

2016-10-01

Naturally fermented dairy products contain a rich microbial biodiversity. This study aimed to provide an overview on the bacterial microbiota biodiversity of 85 samples, previously collected across a wide region of China, Mongolia, and Russia. Data from these 85 samples, including 55 yogurts, 18 naturally fermented yak milks, 6 koumisses, and 6 cheeses, were retrieved and collectively analyzed. The most prevalent phyla shared across samples were Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria, which together accounted for 99% of bacterial sequences. The predominant genera were Lactobacillus, Lactococcus, Streptococcus, Acetobacter, Acinetobacter, Leuconostoc, and Macrococcus, which together corresponded to 96.63% of bacterial sequences. Further multivariate statistical analyses revealed significant differences in the microbiota structure across sample geographic origin and type. First, on the principal coordinate score plot, samples representing the 3 main sample collection regions (Russia, Xinjiang, and Tibet) were mostly located respectively in the upper left, lower right, and lower left quadrants, although slight overlapping occurred. In contrast, samples from the minor sampling areas (Inner Mongolia, Mongolia, Gansu, and Sichuan) were predominantly distributed in the lower left quadrant. These results suggest a possible association between sample geographical origin and microbiota composition. Second, bacterial microbiota structure was stratified by sample type. In particular, the microbiota of cheese was largely distinct from the other sample types due to its high abundances of Lactococcus and Streptococcus. The fermented yak milk microbiota was most like that of the yogurts. Koumiss samples had the lowest microbial diversity and richness. In conclusion, both geographic origin and sample type shape the microbial diversity of naturally fermented milk. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights

Maternal 5mCpG Imprints at the PARD6G-AS1 and GCSAML Differentially Methylated Regions Are Decoupled From Parent-of-Origin Expression Effects in Multiple Human Tissues

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Graziela de Sá Machado Araújo

2018-03-01

Full Text Available A hallmark of imprinted genes in mammals is the occurrence of parent-of-origin-dependent asymmetry of DNA cytosine methylation (5mC of alleles at CpG islands (CGIs in their promoter regions. This 5mCpG asymmetry between the parental alleles creates allele-specific imprinted differentially methylated regions (iDMRs. iDMRs are often coupled to the transcriptional repression of the methylated allele and the activation of the unmethylated allele in a tissue-specific, developmental-stage-specific and/or isoform-specific fashion. iDMRs function as regulatory platforms, built through the recruitment of chemical modifications to histones to achieve differential, parent-of-origin-dependent chromatin segmentation states. Here, we used a comparative computational data mining approach to identify 125 novel constitutive candidate iDMRs that integrate the maximal number of allele-specific methylation region records overlapping CGIs in human methylomes. Twenty-nine candidate iDMRs display gametic 5mCpG asymmetry, and another 96 are candidate secondary iDMRs. We established the maternal origin of the 5mCpG imprints of one gametic (PARD6G-AS1 and one secondary (GCSAML iDMRs. We also found a constitutively hemimethylated, nonimprinted domain at the PWWP2AP1 promoter CGI with oocyte-derived methylation asymmetry. Given that the 5mCpG level at the iDMRs is not a sufficient criterion to predict active or silent locus states and that iDMRs can regulate genes from a distance of more than 1 Mb, we used RNA-Seq experiments from the Genotype-Tissue Expression project and public archives to assess the transcriptional expression profiles of SNPs across 4.6 Mb spans around the novel maternal iDMRs. We showed that PARD6G-AS1 and GCSAML are expressed biallelically in multiple tissues. We found evidence of tissue-specific monoallelic expression of ZNF124 and OR2L13, located 363 kb upstream and 419 kb downstream, respectively, of the GCSAML iDMR. We hypothesize that the GCSAML

Bioactive glass-based scaffolds for bone tissue engineering

NARCIS (Netherlands)

Will, J.; Gerhardt, L.C.; Boccaccini, A.R.

2012-01-01

Originally developed to fill and restore bone defects, bioactive glasses are currently also being intensively investigated for bone tissue engineering applications. In this chapter, we review and discuss current knowledge on porous bone tissue engineering scaffolds made from bioactive silicate

Measurement of the incorporation of orally administered arachidonic acid into tissue lipids

International Nuclear Information System (INIS)

Kulmacz, R.J.; Sivarajan, M.; Lands, W.E.

1986-01-01

The applicability of a stable isotope method to monitor the mixing of dietary arachidonic acid with endogenous arachidonic acid in tissue lipids was evaluated. Rats were fed octadeuterated arachidonic acid during a 20-day period, and the entry of the dietary acid into lipid esters of various tissues was examined by gas chromatography-mass spectrometric (GC-MS) analysis of their fatty acids. The rats were maintained on a fat-free diet from weaning until 63 days old to enhance the ratio of the dietary acid to endogenous arachidonate. Three separate forms of eicosatetraenoic acid in the tissue lipids could be distinguished by GC-MS: octadeuterated arachidonic acid (recent dietary origin), unlabeled arachidonic acid (maternal origin) and unlabeled 4,7,10,13-eicosatetraenoic acid (originating from palmitoleic acid). The total eicosatetraenoic acid in the tissue lipids contained about 90% arachidonate from recent dietary origin in lung, kidney, heart and fat, 70% in muscle and liver and 27% in brain. The n-7 isomer of eicosatetraenoic acid was estimated to make up 6% or less of the total eicosatetraenoic acid in lung, kidney, brain, muscle and heart tissue lipids, but it comprised around 15% of the total eicosatetraenoic acid in liver. The unlabeled arachidonic acid of maternal origin thus comprised only about 10% of the eicosatetraenoic acid in all tissues examined except muscle and brain, where it was 24% and 70% of the eicosatetraenoic acid, respectively

Adiposity, lipogenesis, and fatty acid composition of subcutaneous and intramuscular adipose tissues of Brahman and Angus crossbred cattle.

Science.gov (United States)

Campbell, E M G; Sanders, J O; Lunt, D K; Gill, C A; Taylor, J F; Davis, S K; Riley, D G; Smith, S B

2016-04-01

The objective of this study was to demonstrate differences in aspects of adipose tissue cellularity, lipid metabolism, and fatty and cholesterol composition in Angus and Brahman crossbred cattle. We hypothesized that in vitro measures of lipogenesis would be greater in three-fourths Angus progeny than in three-fourths Brahman progeny, especially in intramuscular (i.m.) adipose tissue. Progeny ( = 227) were fed a standard, corn-based diet for approximately 150 d before slaughter. Breed was considered to be the effect of interest and was forced into the model. There were 9 breed groups including all 4 kinds of three-fourths Angus calves: Angus bulls Angus-sired F cows ( = 32), Angus bulls Brahman-sired F cows ( = 20), Brahman-sired F bulls Angus cows ( = 24), and Angus-sired F bulls Angus cows ( = 20). There were all 4 kinds of three-fourths Brahman calves: Brahman bulls Brahman-sired F cows ( = 21), Brahman bulls Angus-sired F cows ( = 43), Brahman-sired F bulls Brahman cows ( = 26), and Angus-sired F bulls Brahman cows ( = 13). Additionally, F calves (one-half Brahman and one-half Angus) were produced only from Brahman-sired F bulls Angus-sired F cows ( = 28). Contrasts were calculated when breed was an important fixed effect, using the random effect family(breed) as the error term. Most contrasts were nonsignificant ( > 0.10). Those that were significant ( Angus > F, three-fourths Brahman > F, and three-fourths crossbred progeny combined > F), s.c. adipocyte volume (three-fourths Angus > F and three-fourths bloods combined > F), lipogenesis from acetate in s.c. adipose tissue (three-fourths Brahman calves from Brahman dams > three-fourths Brahman calves from F dams), and percentage 18:3-3 in s.c. adipose tissue (three-fourths Brahman calves from Brahman-sired F dams Angus-sired F dams). Intramuscular adipocyte volume ( Angus cattle. Additionally, several differences were observed in i.m. adipose tissue that were consistent with this being a less-developed adipose

Evaluating protein incorporation and release in electrospun composite scaffolds for bone tissue engineering applications.

Science.gov (United States)

Briggs, Tonye; Matos, Jeffrey; Collins, George; Arinzeh, Treena Livingston

2015-10-01

Electrospun polymer/ceramic composites have gained interest for use as scaffolds for bone tissue engineering applications. In this study, we investigated methods to incorporate Platelet Derived Growth Factor-BB (PDGF-BB) in electrospun polycaprolactone (PCL) or PCL prepared with polyethylene oxide (PEO), where both contained varying levels (up to 30 wt %) of ceramic composed of biphasic calcium phosphates, hydroxyapatite (HA)/β-tricalcium phosphate (TCP). Using a model protein, lysozyme, we compared two methods of protein incorporation, adsorption and emulsion electrospinning. Adsorption of lysozyme on scaffolds with ceramic resulted in minimal release of lysozyme over time. Using emulsion electrospinning, lysozyme released from scaffolds containing a high concentration of ceramic where the majority of the release occurred at later time points. We investigated the effect of reducing the electrostatic interaction between the protein and the ceramic on protein release with the addition of the cationic surfactant, cetyl trimethylammonium bromide (CTAB). In vitro release studies demonstrated that electrospun scaffolds prepared with CTAB released more lysozyme or PDGF-BB compared with scaffolds without the cationic surfactant. Human mesenchymal stem cells (MSCs) on composite scaffolds containing PDGF-BB incorporated through emulsion electrospinning expressed higher levels of osteogenic markers compared to scaffolds without PDGF-BB, indicating that the bioactivity of the growth factor was maintained. This study revealed methods for incorporating growth factors in polymer/ceramic scaffolds to promote osteoinduction and thereby facilitate bone regeneration. © 2015 Wiley Periodicals, Inc.

Origin, composition and quality of suspended particulate organic matter in relation to freshwater inflow in a South Texas estuary

Science.gov (United States)

Lebreton, Benoit; Beseres Pollack, Jennifer; Blomberg, Brittany; Palmer, Terence A.; Adams, Leslie; Guillou, Gaël; Montagna, Paul A.

2016-03-01

South Texas has a semi-arid climate with a large interannual variability of freshwater inflows. This study sought to define how changes in freshwater inflow affect the composition, quantity and quality of suspended particulate organic matter (SPOM) in a South Texas estuary: the Mission-Aransas estuary. The study was implemented 1.5 months after a large rain event in September 2010 and continued for 10 months of drought conditions. The composition of SPOM originating from rivers, the Gulf of Mexico and the estuary were determined using stable isotopes (δ13C, δ15N and δ34S). The quantity and quality of SPOM were assessed using organic carbon content, chlorophyll a concentrations and C/chl a ratios. Our results demonstrated that autochthonous phytoplankton was the dominant component of SPOM in the Mission-Aransas estuary during droughts. Benthic organic matter from local primary producers (i.e., seagrass, salt marsh plants, benthic microalgae) did not influence SPOM composition, either as fresh material or as detritus. A comparison with a positive estuary (i.e., Sabine-Neches estuary, TX) indicates that decreases in freshwater inflow may lead to decreases of terrestrial organic matter inputs and to increase the ratio of autochtonous phytoplanktonic material in SPOM.

A review of fibrin and fibrin composites for bone tissue engineering.

Science.gov (United States)

Noori, Alireza; Ashrafi, Seyed Jamal; Vaez-Ghaemi, Roza; Hatamian-Zaremi, Ashraf; Webster, Thomas J

2017-01-01

Tissue engineering has emerged as a new treatment approach for bone repair and regeneration seeking to address limitations associated with current therapies, such as autologous bone grafting. While many bone tissue engineering approaches have traditionally focused on synthetic materials (such as polymers or hydrogels), there has been a lot of excitement surrounding the use of natural materials due to their biologically inspired properties. Fibrin is a natural scaffold formed following tissue injury that initiates hemostasis and provides the initial matrix useful for cell adhesion, migration, proliferation, and differentiation. Fibrin has captured the interest of bone tissue engineers due to its excellent biocompatibility, controllable biodegradability, and ability to deliver cells and biomolecules. Fibrin is particularly appealing because its precursors, fibrinogen, and thrombin, which can be derived from the patient's own blood, enable the fabrication of completely autologous scaffolds. In this article, we highlight the unique properties of fibrin as a scaffolding material to treat bone defects. Moreover, we emphasize its role in bone tissue engineering nanocomposites where approaches further emulate the natural nanostructured features of bone when using fibrin and other nanomaterials. We also review the preparation methods of fibrin glue and then discuss a wide range of fibrin applications in bone tissue engineering. These include the delivery of cells and/or biomolecules to a defect site, distributing cells, and/or growth factors throughout other pre-formed scaffolds and enhancing the physical as well as biological properties of other biomaterials. Thoughts on the future direction of fibrin research for bone tissue engineering are also presented. In the future, the development of fibrin precursors as recombinant proteins will solve problems associated with using multiple or single-donor fibrin glue, and the combination of nanomaterials that allow for the

Fatty acid composition of total lipids and phospholipids of muscular tissue and brain of rats under the impact of vibration

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N. M. Kostyshyn

2016-06-01

Full Text Available Fatty acids are important structural components of biological membranes, energy substrate of cells involved in fixing phospholipid bilayer proteins, and acting as regulators and modulators of enzymatic activity. Under the impact of vibration oscillations there can occur shifts in the ratio of different groups of fatty acids, and degrees of their saturation may change. The imbalance between saturated, monounsaturated and polyunsaturated fatty acids, which occurs later in the cell wall, disrupts fluidity and viscosity of lipid phase and causes abnormal cellular metabolism. Aim. In order to study the impact of vibration on the level of fatty acids of total lipids in muscular tissue and fatty acid composition of phospholipids in muscles and brain, experimental animals have been exposed to vertical vibration oscillations with different frequency for 28 days. Methods and results. Tissues fragments of hip quadriceps and brain of rats were used for obtaining methyl esters of fatty acids studied by the method of gas-liquid chromatography. It was found that the lipid content, ratio of its separate factions and fatty acid composition in muscular tissue and brain of animals with the action of vibration considerably varies. With the increase of vibration acceleration tendency to increase in absolute quantity of total lipids fatty acids can be observed at the account of increased level of saturated and monounsaturated ones. These processes are caused by activation of self-defense mechanisms of the body under the conditions of deviations from stabilized physiological norm, since adaptation requires certain structural and energy costs. Increase in the relative quantity of saturated and monounsaturated fatty acids in phospholipids of muscles and brain and simultaneous reduction in concentration of polyunsaturated fatty acids are observed. Conclusion. These changes indicate worsening of structural and functional organization of muscles and brain cell membranes of

Tissue-Specific Fatty Acids Response to Different Diets in Common Carp (Cyprinus carpio L.)

Science.gov (United States)

Böhm, Markus; Schultz, Sebastian; Koussoroplis, Apostolos-Manuel; Kainz, Martin J.

2014-01-01

Fish depend on dietary fatty acids (FA) to support their physiological condition and health. Exploring the FA distribution in common carp (Cyprinus carpio), one of the world's most consumed freshwater fish, is important to understand how and where FA of different sources are allocated. We investigated diet effects on the composition of polar and neutral lipid fatty acids (PLFA and NLFA, respectively) in eight different tissues (dorsal and ventral muscle, heart, kidney, intestine, eyes, liver and adipose tissue) of common carp. Two-year old carp were exposed to three diet sources (i.e., zooplankton, zooplankton plus supplementary feeds containing vegetable, VO, or fish oil, FO) with different FA composition. The PLFA and NLFA response was clearly tissue-specific after 210 days of feeding on different diets. PLFA were generally rich in omega-3 polyunsaturated FA and only marginally influenced by dietary FA, whereas the NLFA composition strongly reflected dietary FA profiles. However, the NLFA composition in carp tissues varied considerably at low NLFA mass ratios, suggesting that carp is able to regulate the NLFA composition and thus FA quality in its tissues when NLFA contents are low. Finally, this study shows that FO were 3X more retained than VO as NLFA particularly in muscle tissues, indicating that higher nutritional quality feeds are selectively allocated into tissues and thus available for human consumption. PMID:24733499

Tissue-specific fatty acids response to different diets in common carp (Cyprinus carpio L.).

Science.gov (United States)

Böhm, Markus; Schultz, Sebastian; Koussoroplis, Apostolos-Manuel; Kainz, Martin J

2014-01-01

Fish depend on dietary fatty acids (FA) to support their physiological condition and health. Exploring the FA distribution in common carp (Cyprinus carpio), one of the world's most consumed freshwater fish, is important to understand how and where FA of different sources are allocated. We investigated diet effects on the composition of polar and neutral lipid fatty acids (PLFA and NLFA, respectively) in eight different tissues (dorsal and ventral muscle, heart, kidney, intestine, eyes, liver and adipose tissue) of common carp. Two-year old carp were exposed to three diet sources (i.e., zooplankton, zooplankton plus supplementary feeds containing vegetable, VO, or fish oil, FO) with different FA composition. The PLFA and NLFA response was clearly tissue-specific after 210 days of feeding on different diets. PLFA were generally rich in omega-3 polyunsaturated FA and only marginally influenced by dietary FA, whereas the NLFA composition strongly reflected dietary FA profiles. However, the NLFA composition in carp tissues varied considerably at low NLFA mass ratios, suggesting that carp is able to regulate the NLFA composition and thus FA quality in its tissues when NLFA contents are low. Finally, this study shows that FO were 3X more retained than VO as NLFA particularly in muscle tissues, indicating that higher nutritional quality feeds are selectively allocated into tissues and thus available for human consumption.

Tissue-specific fatty acids response to different diets in common carp (Cyprinus carpio L..

Directory of Open Access Journals (Sweden)

Markus Böhm

Full Text Available Fish depend on dietary fatty acids (FA to support their physiological condition and health. Exploring the FA distribution in common carp (Cyprinus carpio, one of the world's most consumed freshwater fish, is important to understand how and where FA of different sources are allocated. We investigated diet effects on the composition of polar and neutral lipid fatty acids (PLFA and NLFA, respectively in eight different tissues (dorsal and ventral muscle, heart, kidney, intestine, eyes, liver and adipose tissue of common carp. Two-year old carp were exposed to three diet sources (i.e., zooplankton, zooplankton plus supplementary feeds containing vegetable, VO, or fish oil, FO with different FA composition. The PLFA and NLFA response was clearly tissue-specific after 210 days of feeding on different diets. PLFA were generally rich in omega-3 polyunsaturated FA and only marginally influenced by dietary FA, whereas the NLFA composition strongly reflected dietary FA profiles. However, the NLFA composition in carp tissues varied considerably at low NLFA mass ratios, suggesting that carp is able to regulate the NLFA composition and thus FA quality in its tissues when NLFA contents are low. Finally, this study shows that FO were 3X more retained than VO as NLFA particularly in muscle tissues, indicating that higher nutritional quality feeds are selectively allocated into tissues and thus available for human consumption.

Explosive composition containing water

Energy Technology Data Exchange (ETDEWEB)

Cattermole, G.R.; Lyerly, W.M.; Cummings, A.M.

1971-11-26

This addition to Fr. 1,583,223, issued 31 May 1968, describes an explosive composition containing a water in oil emulsion. The composition contains an oxidizing mineral salt, a nitrate base salt as sensitizer, water, an organic fuel, a lipophilic emulsifier, and incorporates gas bubbles. The composition has a performance which is improved over and above the original patent.

Mechanically Reinforced Catechol-Containing Hydrogels with Improved Tissue Gluing Performance

Directory of Open Access Journals (Sweden)

Jun Feng

2017-11-01

Full Text Available In situ forming hydrogels with catechol groups as tissue reactive functionalities are interesting bioinspired materials for tissue adhesion. Poly(ethylene glycol (PEG–catechol tissue glues have been intensively investigated for this purpose. Different cross-linking mechanisms (oxidative or metal complexation and cross-linking conditions (pH, oxidant concentration, etc. have been studied in order to optimize the curing kinetics and final cross-linking degree of the system. However, reported systems still show limited mechanical stability, as expected from a PEG network, and this fact limits their potential application to load bearing tissues. Here, we describe mechanically reinforced PEG–catechol adhesives showing excellent and tunable cohesive properties and adhesive performance to tissue in the presence of blood. We used collagen/PEG mixtures, eventually filled with hydroxyapatite nanoparticles. The composite hydrogels show far better mechanical performance than the individual components. It is noteworthy that the adhesion strength measured on skin covered with blood was >40 kPa, largely surpassing (>6 fold the performance of cyanoacrylate, fibrin, and PEG–catechol systems. Moreover, the mechanical and interfacial properties could be easily tuned by slight changes in the composition of the glue to adapt them to the particular properties of the tissue. The reported adhesive compositions can tune and improve cohesive and adhesive properties of PEG–catechol-based tissue glues for load-bearing surgery applications.

Compositional profile and variation of Distillers Dried Grains with Solubles from various origins with focus on non-starch polysaccharides

DEFF Research Database (Denmark)

Pedersen, Mads Brøgger; Dalsgaard, S.; Knudsen, Knud Erik Bach

2014-01-01

nutrients (e.g. protein, fat, fibre and minerals) after fermentation of starch to ethanol. Corn DDGS differentiated from wheat DDGS by a greater content of fat (P≤0.006), insoluble-NSP (Pcellulose (P=0.032), and arabinose/xylose (P....001). Wheat DDGS differentiated from corn DDGS by a greater content of ash (P=0.001), soluble-NSP (Plignin (P...Corn-, wheat- and mixed cereal Distillers' Dried Grains with Solubles (DDGS) were investigated for compositional variability among DDGS origins, ethanol plants, and the relationship between corn and corresponding DDGS. A total of 138 DDGS samples were analyzed by use of Near Infrared Reflectance...

Determination of atomic number and composition of human enamel; Determinacao da composicao e numero atomico efetivo do esmalte humano

Energy Technology Data Exchange (ETDEWEB)

Nogueira, M.S. [Centro Regional de Ciencias Nucleares (CRCN), Recife, PE (Brazil); Rodas Duran, J.E. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica

2001-07-01

The teeth are organs of complicated structure that consist, partly, of hard tissue containing in its interior the dental pulp, rich in vases and nerves. The main mass of the tooth is constituted by the dentine, which is covered with hard tissues and of epithelial origin called enamel. The dentine of the human teeth used in this work were completely removed and the teeth were cut with a device with a diamond disc. In this work the chemical composition of the human enamel was determined, which showed a high percentage of Ca and P, in agreement with the results found in the literature. The effective atomic number of the material and the half-value layer in the energy range of diagnostic X-ray beams were determined. Teeth could be used to evaluated the public's individual doses as well as for retrospective dosimetry what confirms the importance of their effective atomic number and composition determination. (author)

Genome-Wide Epigenetic Characterization of Tissues from Three Germ Layers Isolated from Sheep Fetuses

OpenAIRE

Capra, Emanuele; Toschi, Paola; Del Corvo, Marcello; Lazzari, Barbara; Scapolo, Pier A.; Loi, Pasqualino; Williams, John L.; Stella, Alessandra; Ajmone-Marsan, Paolo

2017-01-01

DNA methylation of regulatory and growth-related genes contributes to fetal programming which is important for maintaining the correct development of three germ layers of the embryo that develope into different tissues and organs, and which persists into adult life. In this study, a preliminary epigenetic screen was performed to define genomic regions that are involved in fetal epigenome remodeling. Embryonic ectodermic tissues (origin of nervous tissue), mesenchymal tissues (origin of connec...

Engineering Complex Tissues

Science.gov (United States)

MIKOS, ANTONIOS G.; HERRING, SUSAN W.; OCHAREON, PANNEE; ELISSEEFF, JENNIFER; LU, HELEN H.; KANDEL, RITA; SCHOEN, FREDERICK J.; TONER, MEHMET; MOONEY, DAVID; ATALA, ANTHONY; VAN DYKE, MARK E.; KAPLAN, DAVID; VUNJAK-NOVAKOVIC, GORDANA

2010-01-01

This article summarizes the views expressed at the third session of the workshop “Tissue Engineering—The Next Generation,” which was devoted to the engineering of complex tissue structures. Antonios Mikos described the engineering of complex oral and craniofacial tissues as a “guided interplay” between biomaterial scaffolds, growth factors, and local cell populations toward the restoration of the original architecture and function of complex tissues. Susan Herring, reviewing osteogenesis and vasculogenesis, explained that the vascular arrangement precedes and dictates the architecture of the new bone, and proposed that engineering of osseous tissues might benefit from preconstruction of an appropriate vasculature. Jennifer Elisseeff explored the formation of complex tissue structures based on the example of stratified cartilage engineered using stem cells and hydrogels. Helen Lu discussed engineering of tissue interfaces, a problem critical for biological fixation of tendons and ligaments, and the development of a new generation of fixation devices. Rita Kandel discussed the challenges related to the re-creation of the cartilage-bone interface, in the context of tissue engineered joint repair. Frederick Schoen emphasized, in the context of heart valve engineering, the need for including the requirements derived from “adult biology” of tissue remodeling and establishing reliable early predictors of success or failure of tissue engineered implants. Mehmet Toner presented a review of biopreservation techniques and stressed that a new breakthrough in this field may be necessary to meet all the needs of tissue engineering. David Mooney described systems providing temporal and spatial regulation of growth factor availability, which may find utility in virtually all tissue engineering and regeneration applications, including directed in vitro and in vivo vascularization of tissues. Anthony Atala offered a clinician’s perspective for functional tissue

The Microbiome of Seriola lalandi of Wild and Aquaculture Origin Reveals Differences in Composition and Potential Function

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Carolina Ramírez

2017-09-01

Full Text Available Seriola lalandi is an economically important species that is globally distributed in temperate and subtropical marine waters. Aquaculture production of this species has had problems associated with intensive fish farming, such as disease outbreaks or nutritional deficiencies causing high mortalities. Intestinal microbiota has been involved in many processes that benefit the host, such as disease control, stimulation of the immune response, and the promotion of nutrient metabolism, among others. However, little is known about the potential functionality of the microbiota and the differences in the composition between wild and aquacultured fish. Here, we assayed the V4-region of the 16S rRNA gene using high-throughput sequencing. Our results showed that there are significant differences between S. lalandi of wild and aquaculture origin (ANOSIM and PERMANOVA, P < 0.05. At the genus level, a total of 13 genera were differentially represented between the two groups, all of which have been described as beneficial microorganisms that have an antagonistic effect against pathogenic bacteria, improve immunological parameters and growth performance, and contribute to nutrition. Additionally, the changes in the presumptive functions of the intestinal microbiota of yellowtail were examined by predicting the metagenomes using PICRUSt. The most abundant functional categories were those corresponding to the metabolism of cofactors and vitamins, amino acid metabolism and carbohydrate metabolism, revealing differences in the contribution of the microbiota depending on the origin of the animals. To our knowledge, this is the first study to characterize and compare the intestinal microbiota of S. lalandi of wild and aquaculture origin using high-throughput sequencing.

The Microbiome of Seriola lalandi of Wild and Aquaculture Origin Reveals Differences in Composition and Potential Function.

Science.gov (United States)

Ramírez, Carolina; Romero, Jaime

2017-01-01

Seriola lalandi is an economically important species that is globally distributed in temperate and subtropical marine waters. Aquaculture production of this species has had problems associated with intensive fish farming, such as disease outbreaks or nutritional deficiencies causing high mortalities. Intestinal microbiota has been involved in many processes that benefit the host, such as disease control, stimulation of the immune response, and the promotion of nutrient metabolism, among others. However, little is known about the potential functionality of the microbiota and the differences in the composition between wild and aquacultured fish. Here, we assayed the V4-region of the 16S rRNA gene using high-throughput sequencing. Our results showed that there are significant differences between S. lalandi of wild and aquaculture origin (ANOSIM and PERMANOVA, P < 0.05). At the genus level, a total of 13 genera were differentially represented between the two groups, all of which have been described as beneficial microorganisms that have an antagonistic effect against pathogenic bacteria, improve immunological parameters and growth performance, and contribute to nutrition. Additionally, the changes in the presumptive functions of the intestinal microbiota of yellowtail were examined by predicting the metagenomes using PICRUSt. The most abundant functional categories were those corresponding to the metabolism of cofactors and vitamins, amino acid metabolism and carbohydrate metabolism, revealing differences in the contribution of the microbiota depending on the origin of the animals. To our knowledge, this is the first study to characterize and compare the intestinal microbiota of S. lalandi of wild and aquaculture origin using high-throughput sequencing.

Elemental composition of skin tissue by PIXE and INAA analyses

International Nuclear Information System (INIS)

Hollands, R.; Spyrou, N.M.

1997-01-01

Hypertrophic scars are a particular type of scar that can form after any type of dermal injury. They are unsightly, red, elevated above normal skin level, itchy and painful. At present no-one knows why these scars form. Due to the differences between scar tissue and normal skin it was decided to analyse skin tissue which at a later date would be compared to scar tissue. Spit skin graft (epidermis) samples as well as full thickness skin (epidermis to dermis) tissue were analysed using PIXE and RBS with a 2 MeV proton beam. The epidermis was compared to the dermis to see if there were any variations between the two. In all the samples P, S, Cl, K, Ca, Fe, and Cd were detected and in a majority of the samples Zn and Ba were found, using PIXE. It was found that, between the epidermis and dermis, there was an significant increase in P in the epidermis in both full thickness and split skin graft samples. Complementary elemental analysis was also performed using neutron activation, and Br, Na and Zn were detected. (author)

Quantitative ultrasound tissue characterization in shoulder and thigh muscles – a new approach

DEFF Research Database (Denmark)

Nielsen, P.K.; Jensen, B.R.; Darvann, Tron Andre

2006-01-01

Background: The echogenicity patterns of ultrasound scans contain information of tissue composition in muscles. The aim was: ( 1) to develop a quantitative ultrasound image analysis to characterize tissue composition in terms of intensity and structure of the ultrasound images, and ( 2) to use th...

A constitutive model of soft tissue: From nanoscale collagen to tissue continuum

KAUST Repository

Tang, Huang

2009-04-08

Soft collagenous tissue features many hierarchies of structure, starting from tropocollagen molecules that form fibrils, and proceeding to a bundle of fibrils that form fibers. Here we report the development of an atomistically informed continuum model of collagenous tissue. Results from full atomistic and molecular modeling are linked with a continuum theory of a fiber-reinforced composite, handshaking the fibril scale to the fiber and continuum scale in a hierarchical multi-scale simulation approach. Our model enables us to study the continuum-level response of the tissue as a function of cross-link density, making a link between nanoscale collagen features and material properties at larger tissue scales. The results illustrate a strong dependence of the continuum response as a function of nanoscopic structural features, providing evidence for the notion that the molecular basis for protein materials is important in defining their larger-scale mechanical properties. © 2009 Biomedical Engineering Society.

A short review: Recent advances in electrospinning for bone tissue regeneration

Directory of Open Access Journals (Sweden)

Song-Hee Shin

2012-12-01

Full Text Available Nanofibrous structures developed by electrospinning technology provide attractive extracellular matrix conditions for the anchorage, migration, and differentiation of tissue cells, including those responsible for the regeneration of hard tissues. Together with the ease of set up and cost-effectiveness, the possibility to produce nanofibers with a wide range of compositions and morphologies is the merit of electrospinning. Significant efforts have exploited the development of bone regenerative nanofibers, which includes tailoring of composite/hybrid compositions that are bone mimicking and the surface functionalization such as mineralization. Moreover, by utilizing bioactive molecules such as adhesive proteins, growth factors, and chemical drugs, in concert with the nanofibrous matrices, it is possible to provide artificial materials with improved cellular responses and therapeutic efficacy. These studies have mainly focused on the regulation of stem cell behaviors for use in regenerative medicine and tissue engineering. While there are some challenges in achieving controllable delivery of bioactive molecules and complex-shaped three-dimensional scaffolds for tissue engineering, the electrospun nanofibrous matrices can still have a beneficial impact in the area of hard-tissue regeneration.

Adipose tissue macrophages: going off track during obesity

NARCIS (Netherlands)

Boutens, L.; Stienstra, R.

2016-01-01

Inflammation originating from the adipose tissue is considered to be one of the main driving forces for the development of insulin resistance and type 2 diabetes in obese individuals. Although a plethora of different immune cells shapes adipose tissue inflammation, this review is specifically

Origins of gene, genetic code, protein and life

Indian Academy of Sciences (India)

We have further presented the [GADV]-protein world hypothesis of the origin of life as well as a hypothesis of protein production, suggesting that proteins were originally produced by random peptide formation of amino acids restricted in specific amino acid compositions termed as GNC-, SNS- and GC-NSF(a)-0th order ...

Mechanical properties of human atherosclerotic intima tissue.

Science.gov (United States)

Akyildiz, Ali C; Speelman, Lambert; Gijsen, Frank J H

2014-03-03

Progression and rupture of atherosclerotic plaques in coronary and carotid arteries are the key processes underlying myocardial infarctions and strokes. Biomechanical stress analyses to compute mechanical stresses in a plaque can potentially be used to assess plaque vulnerability. The stress analyses strongly rely on accurate representation of the mechanical properties of the plaque components. In this review, the composition of intima tissue and how this changes during plaque development is discussed from a mechanical perspective. The plaque classification scheme of the American Heart Association is reviewed and plaques originating from different vascular territories are compared. Thereafter, an overview of the experimental studies on tensile and compressive plaque intima properties are presented and the results are linked to the pathology of atherosclerotic plaques. This overview revealed a considerable variation within studies, and an enormous dispersion between studies. Finally, the implications of the dispersion in experimental data on the clinical applications of biomechanical plaque modeling are presented. Suggestions are made on mechanical testing protocol for plaque tissue and on using a standardized plaque classification scheme. This review identifies the current status of knowledge on plaque mechanical properties and the future steps required for a better understanding of the plaque type specific material properties. With this understanding, biomechanical plaque modeling may eventually provide essential support for clinical plaque risk stratification. Copyright © 2014 Elsevier Ltd. All rights reserved.

Leiomyoma originating from axilla: A rare case report and differential diagnosis.

Science.gov (United States)

Kim, Ho Jun; Baek, Sang Oon; Rha, Eun Young; Lee, Jun Yong; Han, Hyun Ho

2016-07-01

Leiomyoma is a form of benign tumor originated in hypertrophy of the smooth muscles, which is most prevalent in the uterus and gastrointestinal tract. However, Leiomyoma originating from smooth muscle at the vessels lying on deep soft tissue is very rare. Our case was a rare case of leiomyoma originating from the axillary region, which was initially diagnosed as a fibroadenoma on radiological examination. The mass was separated from surrounding tissues and totally resected. Pathologically, hematoxylin-eosin-stained biopsy tissue showed the typical findings of leiomyoma. Postoperative follow-up observation was done for 1 year, without any complications or recurrence. Notably, a leiomyoma in the axillary region is difficult to differentiate from other benign or malignant tumors on preoperative radiological examinations such as ultrasonography or computed tomgraphy. Therefore, when an indefinite asymptomatic mass that is not lymphadenopathy or common benign tumor is identified in the axillary region, leiomyoma can be considered as one of the differential diagnoses.

Microtomography evaluation of dental tissue wear surface induced by in vitro simulated chewing cycles on human and composite teeth

Directory of Open Access Journals (Sweden)

Rossella Bedini

2012-01-01

Full Text Available In this study a 3D microtomography display of tooth surfaces after in vitro dental wear tests has been obtained. Natural teeth have been compared with prosthetic teeth, manufactured by three different polyceramic composite materials. The prosthetic dental element samples, similar to molars, have been placed in opposition to human teeth extracted by paradontology diseases. After microtomography analysis, samples have been subjected to in vitro fatigue test cycles by servo-hydraulic mechanical testing machine. After the fatigue test, each sample has been subjected again to microtomography analysis to obtain volumetric value changes and dental wear surface images. Wear surface images were obtained by 3D reconstruction software and volumetric value changes were measured by CT analyser software. The aim of this work has been to show the potential of microtomography technique to display very clear and reliable wear surface images. Microtomography analysis methods to evaluate volumetric value changes have been used to quantify dental tissue and composite material wear.

Tissue equivalence in neutron dosimetry

International Nuclear Information System (INIS)

Nutton, D.H.; Harris, S.J.

1980-01-01

A brief review is presented of the essential features of neutron tissue equivalence for radiotherapy and gives the results of a computation of relative absorbed dose for 14 MeV neutrons, using various tissue models. It is concluded that for the Bragg-Gray equation for ionometric dosimetry it is not sufficient to define the value of W to high accuracy and that it is essential that, for dosimetric measurements to be applicable to real body tissue to an accuracy of better than several per cent, a correction to the total absorbed dose must be made according to the test and tissue atomic composition, although variations in patient anatomy and other radiotherapy parameters will often limit the benefits of such detailed dosimetry. (U.K.)

Autopsy Tissue Program

International Nuclear Information System (INIS)

Fox, T.; Tietjen, G.

1979-01-01

The Autopsy Tissue Program was begun in 1960. To date, tissues on 900 or more persons in 7 geographic regions have been collected and analyzed for plutonium content. The tissues generally consist of lung, liver, kidney, lymph, bone, and gonadal tissue for each individual. The original objective of the program was to determine the level of plutonium in human tissues due solely to fall-out from weapons testing. The baseline thus established was to be used to evaluate future changes. From the first, this program was beset with chemical and statistical difficulties. Many factors whose effects were not recognized and not planned for were found later to be important. Privacy and ethical considerations hindered the gathering of adequate data. Since the chemists were looking for amounts of plutonium very close to background, possible contamination was a very real problem. Widely used chemical techniques introduced a host of statistical problems. The difficulties encountered touch on areas common to large data sets, unusual outlier detection methods, minimum detection limits, problems with Aliquot sizes, and time-trends in the data. The conclusions point out areas to which the biologists will have to devote much more careful attention than was believed

Composition and origin of rhyolite melt intersected by drilling in the Krafla geothermal field, Iceland

Science.gov (United States)

Zierenberg, R.A.; Schiffman, P.; Barfod, G.H.; Lesher, C.E.; Marks, N.E.; Lowenstern, Jacob B.; Mortensen, A.K.; Pope, E.C.; Bird, D.K.; Reed, M.H.; Friðleifsson, G.O.; Elders, W.A.

2013-01-01

The Iceland Deep Drilling Project Well 1 was designed as a 4- to 5-km-deep exploration well with the goal of intercepting supercritical hydrothermal fluids in the Krafla geothermal field, Iceland. The well unexpectedly drilled into a high-silica (76.5 % SiO2) rhyolite melt at approximately 2.1 km. Some of the melt vesiculated while extruding into the drill hole, but most of the recovered cuttings are quenched sparsely phyric, vesicle-poor glass. The phenocryst assemblage is comprised of titanomagnetite, plagioclase, augite, and pigeonite. Compositional zoning in plagioclase and exsolution lamellae in augite and pigeonite record changing crystallization conditions as the melt migrated to its present depth of emplacement. The in situ temperature of the melt is estimated to be between 850 and 920 °C based on two-pyroxene geothermometry and modeling of the crystallization sequence. Volatile content of the glass indicated partial degassing at an in situ pressure that is above hydrostatic (~16 MPa) and below lithostatic (~55 MPa). The major element and minor element composition of the melt are consistent with an origin by partial melting of hydrothermally altered basaltic crust at depth, similar to rhyolite erupted within the Krafla Caldera. Chondrite-normalized REE concentrations show strong light REE enrichment and relative flat patterns with negative Eu anomaly. Strontium isotope values (0.70328) are consistent with mantle-derived melt, but oxygen and hydrogen isotope values are depleted (3.1 and −118 ‰, respectively) relative to mantle values. The hydrogen isotope values overlap those of hydrothermal epidote from rocks altered by the meteoric-water-recharged Krafla geothermal system. The rhyolite melt was emplaced into and has reacted with a felsic intrusive suite that has nearly identical composition. The felsite is composed of quartz, alkali feldspar, plagioclase, titanomagnetite, and augite. Emplacement of the rhyolite magma has resulted in partial melting of

Origin of solar system

Energy Technology Data Exchange (ETDEWEB)

Pokorny, Z.

1984-01-01

The generally accepted concept has it that the Sun and the planets originated almost simultaneously from nebula (the nebular hypothesis). It is assumed that the temperature of the nebula decreased in the direction from the centre which led to the segregation of elements and to the different chemical composition of the individual planets. The planets formed either from the gravitational collapse of part of the nebula or by gradual accretion. In the scenario of the origin of the solar system there are many blank spots, namely as concerns the initial stages of development and the period when the formation of the planets had ''almost been completed''.

Origin of solar system

International Nuclear Information System (INIS)

Pokorny, Z.

1984-01-01

The generally accepted concept has it that the Sun and the planets originated almost simultaneously from nebula (the nebular hypothesis). It is assumed that the temperature of the nebula decreased in the direction from the centre which led to the segregation of elements and to the different chemical composition of the individual planets. The planets formed either from the gravitational collapse of part of the nebula or by gradual accretion. In the scenario of the origin of the solar system there are many blank spots, namely as concerns the initial stages of development and the period when the formation of the planets had ''almost been completed''. (Ha)

Synthesis and characterization of hydroxyapatite-gelatine composite materials for orthopaedic application

International Nuclear Information System (INIS)

Yanovska, A.; Kuznetsov, V.; Stanislavov, A.; Husak, E.; Pogorielov, M.; Starikov, V.; Bolshanina, S.; Danilchenko, S.

2016-01-01

The composite materials based on hydroxyapatite (HA) and gelatine (Gel) with addition of silver and zirconium oxide were obtained. The study investigates a combination of low powered ultrasonic irradiation and low concentration of gelatine in the co-precipitation synthesis. These composites have different weight ratios of organic/inorganic components and may be synthesized in two ways: simple mixing and co-precipitation. Both of which were compared. The estimation of porosity, in vivo testing, surface morphology and phase composition as well as the IR-analysis were provided. Hydroxyapatite was the main crystalline phase in obtained composites. While around powdered HA-Gel composite the connective tissue capsule is formed without bone tissue formation, HA-Gel-Ag porous composite implantation leads to formation of new bone tissue and activation of cell proliferation. Addition of silver ions into composite material allows decreasing inflammation on the first stage of implantation and has positive effect on bone tissue formation. Some of the obtained composite materials containing silver or ZrO_2 are biocompatible. bio-resorbable and osteoconductive with high level of porosity (75–85%). - Highlights: • Hydroxyapatite-gelatine composites with addition of Ag"+ and ZrO_2 were obtained. • Composites were synthesized in two ways: simple mixing and co-precipitation. • Co-precipitation synthesis combined ultrasonic treatment and low concentration of gelatine. • Obtained composites have different weight ratios of organic/inorganic components. • Some composites are osteoconductive and all of them have high level of porosity (75–85%).

Childhood Soft Tissue Sarcoma Treatment (PDQ®)—Health Professional Version

Science.gov (United States)

Pediatric soft tissue sarcomas are a heterogenous group of malignant tumors that originate from primitive mesenchymal tissue and account for 7% of all childhood tumors. Get detailed information about clinical presentation, diagnosis, prognosis, and treatment of newly diagnosed and recurrent soft tissue sarcoma in this summary for clinicians.

78 FR 40101 - Certain Tissue Paper Products from the People's Republic of China: Affirmative Final...

Science.gov (United States)

2013-07-03

... subject to the order are cut-to-length sheets of tissue paper having a basis weight not exceeding 29 grams... determine that tissue paper processed by ARPP in India from PRC-origin jumbo rolls and/or cut sheets of...-origin tissue paper (jumbo rolls and/or cut sheets) that were entered, or withdrawn from warehouse, for...

Composition, oxygen isotope geochemistry, and origin of smectite in the metalliferous sediments of the Bauer Deep, southeast Pacific

Energy Technology Data Exchange (ETDEWEB)

Cole, T G [Imperial Coll. of Science and Technology, London (UK). Geology Dept.

1985-01-01

The sediments of the Bauer Deep, an open ocean basin situated on the northwest Nazca Plate in the southeast Pacific, constitute a regional metalliferous deposit dominated by authigenic smectite. Two 2-metre long cores from the Bauer Deep were examined to investigate the nature and origin of the smectite. Infra-red and Mossbauer spectroscopy, and wet chemical analysis (LiBO/sub 2/ fusion) of isolated smectite, indicate the mineral is a Mg-rich, Al-rich nontronite. Oxygen isotopic compositions for isolated smectite are uniform and translate to a non-hydrothermal temperature of formation of about 3 deg C. SEM observations show an abundance of well-preserved biogenic opal in surface and near surface sediment but postburial dissolution and transformation of this phase to smectite is evident at depth. Smectite formation is the result of interaction between iron oxyhydroxide, ponded in the Bauer Deep following a hydrothermal origin at the adjacent East Pacific Rise, and biogenic opal. A reaction mechanism is proposed. Regional factors control smectite formation. In particular, formation is inhibited in areas of CaCO/sub 3/ accumulation (topographic elevations) but favoured in areas of oxyhydroxide and opal ponding (topographic depressions.)

Composition, oxygen isotope geochemistry, and origin of smectite in the metalliferous sediments of the Bauer Deep, southeast Pacific

International Nuclear Information System (INIS)

Cole, T.G.

1985-01-01

The sediments of the Bauer Deep, an open ocean basin situated on the northwest Nazca Plate in the southeast Pacific, constitute a regional metalliferous deposit dominated by authigenic smectite. Two 2-metre long cores from the Bauer Deep were examined to investigate the nature and origin of the smectite. Infra-red and Mossbauer spectroscopy, and wet chemical analysis (LiBO 2 fusion) of isolated smectite, indicate the mineral is a Mg-rich, Al-rich nontronite. Oxygen isotopic compositions for isolated smectite are uniform and translate to a non-hydrothermal temperature of formation of about 3 deg C. SEM observations show an abundance of well-preserved biogenic opal in surface and near surface sediment but postburial dissolution and transformation of this phase to smectite is evident at depth. Smectite formation is the result of interaction between iron oxyhydroxide, ponded in the Bauer Deep following a hydrothermal origin at the adjacent East Pacific Rise, and biogenic opal. A reaction mechanism is proposed. Regional factors control smectite formation. In particular, formation is inhibited in areas of CaCO 3 accumulation (topographic elevations) but favoured in areas of oxyhydroxide and opal ponding (topographic depressions.) (author)

Origin of energetic ions in the polar cusp inferred from ion composition measurements by the Viking satellite

Directory of Open Access Journals (Sweden)

G. Kremser

1995-06-01

Full Text Available The magnetospheric ion composition spectrometer MICS on the Swedish Viking satellite provided measurements of the ion composition in the energy range 10.1 keV/e\\leqE/Q\\leq326.0 keV/e. Data obtained during orbit 842 were used to investigate the ion distribution in the northern polar cusp and its vicinity. The satellite traversed the outer ring current, boundary region, cusp proper and plasma mantle during its poleward movement. H+ and He++ ions were encountered in all of these regions. He+ ions were present only in the ring current. The number of O+ and O++ ions was very small. Heavy high-charge state ions typical for the solar wind were observed for the first time, most of them in the poleward part of the boundary region and in the cusp proper. The H+ ions exhibited two periods with high intensities. One of them, called the BR/CP event, appeared at energies up to 50 keV. It started at the equatorward limit of the boundary region and continued into the cusp proper. Energy spectra indicate a ring current origin for the BR/CP event. Pitch angle distributions show downward streaming of H+ ions at its equatorward limit and upward streaming on the poleward side. This event is interpreted as the result of pitch angle scattering of ring current ions by fluctuations in the magnetopause current layer in combination with poleward convection. The other of the two periods with high H+ ion intensities, called the accelerated ion event, was superimposed on the BR/CP event. It was restricted to energies \\leq15 keV and occurred in the poleward part of the boundary region. This event is regarded as the high-energy tail of magnetosheath ions that were accelerated while penetrating into the magnetosphere. The cusp region thus contains ions of magnetospheric as well as of magnetosheath origin. The appearance of the ions depends, in addition to the ion source, on the magnetic field configuration and dynamic processes inside and close to the cusp.

Arbuscular mycorrhizal fungal community composition affected by original elevation rather than translocation along an altitudinal gradient on the Qinghai-Tibet Plateau

Science.gov (United States)

Yang, Wei; Zheng, Yong; Gao, Cheng; Duan, Ji-Chuang; Wang, Shi-Ping; Guo, Liang-Dong

2016-11-01

Elucidating arbuscular mycorrhizal (AM) fungal responses to elevation changes is critical to improve understanding of microbial function in ecosystems under global asymmetrical climate change scenarios. Here we examined AM fungal community in a two-year reciprocal translocation of vegetation-intact soil blocks along an altitudinal gradient (3,200 m to 3,800 m) in an alpine meadow on the Qinghai-Tibet Plateau. AM fungal spore density was significantly higher at lower elevation than at higher elevation regardless of translocation, except that this parameter was significantly increased by upward translocation from original 3,200 m to 3,400 m and 3,600 m. Seventy-three operational taxonomic units (OTUs) of AM fungi were recovered using 454-pyrosequencing of 18S rDNA sequences at a 97% sequence similarity. Original elevation, downward translocation and upward translocation did not significantly affect AM fungal OTU richness. However, with increasing altitude the OTU richness of Acaulosporaceae and Ambisporaceae increased, but the OTU richness of Gigasporaceae and Glomeraceae decreased generally. The AM fungal community composition was significantly structured by original elevation but not by downward translocation and upward translocation. Our findings highlight that compared with the short-term reciprocal translocation, original elevation is a stronger determinant in shaping AM fungal community in the Qinghai-Tibet alpine meadow.

Functional Attachment of Soft Tissues to Bone: Development, Healing, and Tissue Engineering

Science.gov (United States)

Lu, Helen H.; Thomopoulos, Stavros

2014-01-01

Connective tissues such as tendons or ligaments attach to bone across a multitissue interface with spatial gradients in composition, structure, and mechanical properties. These gradients minimize stress concentrations and mediate load transfer between the soft and hard tissues. Given the high incidence of tendon and ligament injuries and the lack of integrative solutions for their repair, interface regeneration remains a significant clinical challenge. This review begins with a description of the developmental processes and the resultant structure-function relationships that translate into the functional grading necessary for stress transfer between soft tissue and bone. It then discusses the interface healing response, with a focus on the influence of mechanical loading and the role of cell-cell interactions. The review continues with a description of current efforts in interface tissue engineering, highlighting key strategies for the regeneration of the soft tissue–to-bone interface, and concludes with a summary of challenges and future directions. PMID:23642244

Preparation of tissue samples for X-ray fluorescence microscopy

International Nuclear Information System (INIS)

Chwiej, Joanna; Szczerbowska-Boruchowska, Magdalena; Lankosz, Marek; Wojcik, Slawomir; Falkenberg, Gerald; Stegowski, Zdzislaw; Setkowicz, Zuzanna

2005-01-01

As is well-known, trace elements, especially metals, play an important role in the pathogenesis of many disorders. The topographic and quantitative elemental analysis of pathologically changed tissues may shed some new light on processes leading to the degeneration of cells in the case of selected diseases. An ideal and powerful tool for such purpose is the Synchrotron Microbeam X-ray Fluorescence technique. It enables the carrying out of investigations of the elemental composition of tissues even at the single cell level. The tissue samples for histopathological investigations are routinely fixed and embedded in paraffin. The authors try to verify the usefulness of such prepared tissue sections for elemental analysis with the use of X-ray fluorescence microscopy. Studies were performed on rat brain samples. Changes in elemental composition caused by fixation in formalin or paraformaldehyde and embedding in paraffin were examined. Measurements were carried out at the bending magnet beamline L of the Hamburger Synchrotronstrahlungslabor HASYLAB in Hamburg. The decrease in mass per unit area of K, Br and the increase in P, S, Fe, Cu and Zn in the tissue were observed as a result of the fixation. For the samples embedded in paraffin, a lower level of most elements was observed. Additionally, for these samples, changes in the composition of some elements were not uniform for different analyzed areas of rat brain

Preparation of tissue samples for X-ray fluorescence microscopy

Energy Technology Data Exchange (ETDEWEB)

Chwiej, Joanna [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland)]. E-mail: jchwiej@novell.ftj.agh.edu.pl; Szczerbowska-Boruchowska, Magdalena [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Lankosz, Marek [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Wojcik, Slawomir [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Falkenberg, Gerald [Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen-Synchrotron, Notkestr. 85, Hamburg (Germany); Stegowski, Zdzislaw [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Setkowicz, Zuzanna [Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Ingardena 6, 30-060 Cracow (Poland)

2005-12-15

As is well-known, trace elements, especially metals, play an important role in the pathogenesis of many disorders. The topographic and quantitative elemental analysis of pathologically changed tissues may shed some new light on processes leading to the degeneration of cells in the case of selected diseases. An ideal and powerful tool for such purpose is the Synchrotron Microbeam X-ray Fluorescence technique. It enables the carrying out of investigations of the elemental composition of tissues even at the single cell level. The tissue samples for histopathological investigations are routinely fixed and embedded in paraffin. The authors try to verify the usefulness of such prepared tissue sections for elemental analysis with the use of X-ray fluorescence microscopy. Studies were performed on rat brain samples. Changes in elemental composition caused by fixation in formalin or paraformaldehyde and embedding in paraffin were examined. Measurements were carried out at the bending magnet beamline L of the Hamburger Synchrotronstrahlungslabor HASYLAB in Hamburg. The decrease in mass per unit area of K, Br and the increase in P, S, Fe, Cu and Zn in the tissue were observed as a result of the fixation. For the samples embedded in paraffin, a lower level of most elements was observed. Additionally, for these samples, changes in the composition of some elements were not uniform for different analyzed areas of rat brain.

Evaluation of bone tissue response to a sealer containing mineral trioxide aggregate.

Science.gov (United States)

Assmann, Eloísa; Böttcher, Daiana Elisabeth; Hoppe, Carolina Bender; Grecca, Fabiana Soares; Kopper, Patrícia Maria Poli

2015-01-01

This study analyzed bone tissue reactions to MTA Fillapex (Ângelus Industria de Produtos Odontológicos Ltda, Londrina, Brazil) compared with an epoxy resin-based material in the femur of Wistar rats. Bone tissue reactions were evaluated in 15 animals after 7, 30, and 90 days (n = 5 per period). Three surgical cavities were prepared on the femur and filled with 0.2 mL MTA Fillapex, AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany), or no sealer (negative control). By the end of each experimental period, 5 animals were randomly euthanized. The samples were histologically processed and analyzed using a light microscope. The presence of inflammatory cells, fibers, and hard tissue barrier formation was evaluated. Differences among the groups and between the 3 experimental periods were evaluated by using 2-way analysis of variance followed by the Bonferroni post hoc test (P ≤ .05). MTA Fillapex scored significantly higher for neutrophils at 7 days than at 90. At 7 days, the same occurred when comparing MTA Fillapex with AH Plus. The presence of lymphocytes/plasmocytes significantly decreased over time in all groups. Macrophages, giant cells, eosinophils, and fiber condensation presented no differences among groups and periods. Within 90 days, all groups presented complete hard tissue barrier formation. The presence of mineral trioxide aggregate in MTA Fillapex composition did not improve the bone tissue repair. The presence of sealers provided the re-establishment of the original bone tissue structure and the inflammatory response decreased over time, so they can be considered biocompatible. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The origin of the chemical elements

International Nuclear Information System (INIS)

Tayler, R.J.

1984-01-01

The subject is discussed in relation to the composition of initially created matter and changes which have occurred during the life history of the universe, with particular reference to our galaxy and nearby galaxies. Headings are: observations of element abundances (stars, gas clouds in our own and nearby galaxies, hot gas in galaxy clusters, the solar system); the originally created matter (Big Bang theory and early nuclear reactions); processes changing observed composition (galactic evolution; nuclear fusion reactions in stellar interiors; chemical composition of a highly evolved massive star); supernovae (production of heavy elements); chemical evolution of the galaxy; production of very heavy elements (s process, r process). (U.K.)

Brazilian Red Propolis—Chemical Composition and Botanical Origin

Directory of Open Access Journals (Sweden)

Andreas Daugsch

2008-01-01

Full Text Available Propolis contains resinous substances collected by honey bees from various plant sources and has been used as a traditional folk medicine since ca 300 BC. Nowadays, the use of evidence-based complementary and alternative medicine (CAM is increasing rapidly and so is the use of propolis in order to treat or support the treatment of various diseases. Much attention has been focused on propolis from Populus sp. (Salicaceae and Baccharis dracunculifolia (Asteracea, but scientific information about the numerous other types of propolis is still sparse. We gathered six samples of red propolis in five states of Northeastern Brazil. The beehives were located near woody perennial shrubs along the sea and river shores. The bees were observed to collect red resinous exudates on Dalbergia ecastophyllum (L Taub. (Leguminosae to make propolis. The flavonoids of propolis and red resinous exudates were investigated using reversed-phase high-performance liquid chromatography and reversed-phase high-performance thin-layer chromatography. We conclude that the botanical origin of the reddish propolis is D. ecastophyllum. In areas where this source (D. ecastophyllum was scarce or missing, bees were collecting resinous material from other plants. Propolis, which contained the chemical constituents from the main botanical origin, showed higher antimicrobial activity.

Dynamic impact indentation of hydrated biological tissues and tissue surrogate gels

Science.gov (United States)

Ilke Kalcioglu, Z.; Qu, Meng; Strawhecker, Kenneth E.; Shazly, Tarek; Edelman, Elazer; VanLandingham, Mark R.; Smith, James F.; Van Vliet, Krystyn J.

2011-03-01

For both materials engineering research and applied biomedicine, a growing need exists to quantify mechanical behaviour of tissues under defined hydration and loading conditions. In particular, characterisation under dynamic contact-loading conditions can enable quantitative predictions of deformation due to high rate 'impact' events typical of industrial accidents and ballistic insults. The impact indentation responses were examined of both hydrated tissues and candidate tissue surrogate materials. The goals of this work were to determine the mechanical response of fully hydrated soft tissues under defined dynamic loading conditions, and to identify design principles by which synthetic, air-stable polymers could mimic those responses. Soft tissues from two organs (liver and heart), a commercially available tissue surrogate gel (Perma-Gel™) and three styrenic block copolymer gels were investigated. Impact indentation enabled quantification of resistance to penetration and energy dissipative constants under the rates and energy densities of interest for tissue surrogate applications. These analyses indicated that the energy dissipation capacity under dynamic impact increased with increasing diblock concentration in the styrenic gels. Under the impact rates employed (2 mm/s to 20 mm/s, corresponding to approximate strain energy densities from 0.4 kJ/m3 to 20 kJ/m3), the energy dissipation capacities of fully hydrated soft tissues were ultimately well matched by a 50/50 triblock/diblock composition that is stable in ambient environments. More generally, the methodologies detailed here facilitate further optimisation of impact energy dissipation capacity of polymer-based tissue surrogate materials, either in air or in fluids.

A composition-based cartilage model for the assessment of compositional changes during cartilage damage and adaptation

NARCIS (Netherlands)

Wilson, W.; Huyghe, J.M.R.J.; Donkelaar, van C.C.

2006-01-01

The composition of articular cartilage changes with progression of osteoarthritis. Since compositional changes are associated with changes in the mechanical properties of the tissue, they are relevant for understanding how mechanical loading induces progression. The objective of this study is to

A review of fibrin and fibrin composites for bone tissue engineering

Directory of Open Access Journals (Sweden)

Noori A

2017-07-01

Full Text Available Alireza Noori,1 Seyed Jamal Ashrafi,2 Roza Vaez-Ghaemi,3 Ashraf Hatamian-Zaremi,4 Thomas J Webster5 1Department of Tissue Engineering and Applied Cell Sciences, Faculty of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, 2School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran; 3Department of Chemical and Biological Engineering, Faculty of Biomedical Engineering, The University of British Columbia, Vancouver, BC, Canada; 4Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran; 5Department of Chemical Engineering, Northeastern University, Boston, MA, USA Abstract: Tissue engineering has emerged as a new treatment approach for bone repair and regeneration seeking to address limitations associated with current therapies, such as autologous bone grafting. While many bone tissue engineering approaches have traditionally focused on synthetic materials (such as polymers or hydrogels, there has been a lot of excitement surrounding the use of natural materials due to their biologically inspired properties. Fibrin is a natural scaffold formed following tissue injury that initiates hemostasis and provides the initial matrix useful for cell adhesion, migration, proliferation, and differentiation. Fibrin has captured the interest of bone tissue engineers due to its excellent biocompatibility, controllable biodegradability, and ability to deliver cells and biomolecules. Fibrin is particularly appealing because its precursors, fibrinogen, and thrombin, which can be derived from the patient’s own blood, enable the fabrication of completely autologous scaffolds. In this article, we highlight the unique properties of fibrin as a scaffolding material to treat bone defects. Moreover, we emphasize its role in bone tissue engineering nanocomposites where approaches further emulate the natural nanostructured features of bone when using fibrin and other nanomaterials. We also review the

Water Absorption Behavior of Hemp Hurds Composites

Science.gov (United States)

Stevulova, Nadezda; Cigasova, Julia; Purcz, Pavol; Schwarzova, Ivana; Kacik, Frantisek; Geffert, Anton

2015-01-01

In this paper, water sorption behavior of 28 days hardened composites based on hemp hurds and inorganic binder was studied. Two kinds of absorption tests on dried cube specimens in deionized water bath at laboratory temperature were performed. Short-term (after one hour water immersion) and long-term (up to 180 days) water absorption tests were carried out to study their durability. Short-term water sorption behavior of original hemp hurds composites depends on mean particle length of hemp and on binder nature. The comparative study of long-term water sorption behavior of composites reinforced with original and chemically modified hemp hurds in three reagents confirmed that surface treatment of filler influences sorption process. Based on evaluation of sorption curves using a model for composites based on natural fibers, diffusion of water molecules in composite reinforced with original and chemically modified hemp hurds is anomalous in terms of the Fickian behavior. The most significant decrease in hydrophility of hemp hurds was found in case of hemp hurds modified by NaOH and it relates to change in the chemical composition of hemp hurds, especially to a decrease in average degree of cellulose polymerization as well as hemicellulose content.

Electroactive Tissue Scaffolds with Aligned Pores as Instructive Platforms for Biomimetic Tissue Engineering.

Science.gov (United States)

Hardy, John G; Cornelison, R Chase; Sukhavasi, Rushi C; Saballos, Richard J; Vu, Philip; Kaplan, David L; Schmidt, Christine E

2015-01-14

Tissues in the body are hierarchically structured composite materials with tissue-specific chemical and topographical properties. Here we report the preparation of tissue scaffolds with macroscopic pores generated via the dissolution of a sacrificial supramolecular polymer-based crystal template (urea) from a biodegradable polymer-based scaffold (polycaprolactone, PCL). Furthermore, we report a method of aligning the supramolecular polymer-based crystals within the PCL, and that the dissolution of the sacrificial urea yields scaffolds with macroscopic pores that are aligned over long, clinically-relevant distances ( i.e ., centimeter scale). The pores act as topographical cues to which rat Schwann cells respond by aligning with the long axis of the pores. Generation of an interpenetrating network of polypyrrole (PPy) and poly(styrene sulfonate) (PSS) in the scaffolds yields electroactive tissue scaffolds that allow the electrical stimulation of Schwann cells cultured on the scaffolds which increases the production of nerve growth factor (NGF).

[Composite digital allotransplants: surgical technique and different applications].

Science.gov (United States)

Casoli, V; Rousvoal, A; Zirak, C; Bakhach, J; Guimberteau, J-C

2007-10-01

Microsurgery and human allotransplantation progress as well as the improvement of immunosuppressive drugs actually allow the development of the composite tissue allotransplantation. One of the latest challenges in plastic surgery is to restore the anatomic and functional structures using similar tissues. Composite tissue allotransplantation will probably reach this goal. Our work is to find new surgical techniques for the reconstruction of the osteotendinous apparatus of the long digits. In this paper, we will demonstrate the surgical technique to harvest the allotransplant and its modulation in the reconstruction of various digital defects.

Particle spectra and mass composition in the ultra-high energy region in the framework of the Galactic origin of cosmic rays

Directory of Open Access Journals (Sweden)

Lagutin A.A.

2017-01-01

Full Text Available The possibility for a self-consistent description of all the basic features of the observed cosmic ray spectra and primary composition variations in the energy range of 1015 ÷ 1020 eV within the Galactic origin scenario is examined. We assume the existence of Galactic sources that accelerate particles up to ∼ 3 · 1018Z eV and take into account a highly inhomogeneous (fractal-like distribution of matter and magnetic fields in the Galaxy that leads to extremely large free paths of particles (“Lévy flights”, along with an overwhelming contribution to the cosmic ray fluxes observed above ∼1018 eV from particles reaching the Solar System without scattering. Our scenario was refined on the basis of recent experimental results on primary mass composition. Model predictions, which could be verified with the improved high-precision measurements in the nearest future are discussed.

Adipose tissue expandability and the early origins of PCOS.

Science.gov (United States)

de Zegher, Francis; Lopez-Bermejo, Abel; Ibáñez, Lourdes

2009-11-01

The most prevalent phenotypes of polycystic ovary syndrome (PCOS) are characterized by insulin resistance and androgen excess. The adipose tissue (AT) expandability hypothesis explains the development of insulin resistance in obesity and in cases of AT deficit. In line with this hypothesis, we propose that hyperinsulinemic androgen excess in PCOS is often underpinned by exhaustion of the capacity to expand subcutaneous AT in a metabolically safe way. Such exhaustion might occur when a positive energy imbalance meets a normal fat-storage capacity and/or when a normal energy balance faces a low fat storage capacity. This concept thus explains how PCOS phenotypes might result from obesity, prenatal growth restraint or a genetic lipodystrophy, or, experimentally, from prenatal androgen excess.

Radiation synthesis of gelatin/CM-chitosan/{beta}-tricalcium phosphate composite scaffold for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Zhou Ying [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Xu Ling, E-mail: lingxu@pku.edu.cn [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang Xiangmei; Zhao Yinghui [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Zhai Maolin [Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

2012-05-01

A series of biodegradable composite scaffolds was fabricated from an aqueous solution of gelatin, carboxymethyl chitosan (CM-chitosan) and {beta}-tricalcium phosphate ({beta}-TCP) by radiation-induced crosslinking at ambient temperature. Ultrasonic treatment on the polymer solutions significantly influenced the distribution of {beta}-TCP particles. An ultrasonic time of 20 min, followed by 30 kGy irradiation induced a crosslinked scaffold with homogeneous distribution of {beta}-TCP particles, interconnected porous structure, sound swelling capacity and mechanical strength. Fourier Transform Infrared Spectroscopy and X-ray Diffraction analysis indicated that {beta}-TCP successfully incorporated with the network of gelatin and CM-chitosan. In vivo implantation of the scaffold into the mandible of beagle dog revealed that the scaffolds had excellent biocompatibility and the presence of {beta}-TCP can accelerate bone regeneration. The comprehensive results of this study paved way for the application of gelatin/CM-chitosan/{beta}-TCP composite scaffolds as candidate of bone tissue engineering material. - Highlights: Black-Right-Pointing-Pointer Radiation induced a crosslinked scaffold with interconnected porous structure. Black-Right-Pointing-Pointer Ultrasonic time of 20 min led to homogenerously distribution of {beta}-TCP. Black-Right-Pointing-Pointer Increasing amount of {beta}-TCP would restrict the swelling properties. Black-Right-Pointing-Pointer Proper fraction of {beta}-TCP will promote the mechanical properties of the scaffolds. Black-Right-Pointing-Pointer Hybrid of {beta}-TCP promoted the bone regeneration of the mandibles of beagle dogs.

Synthesis and characterization of hydroxyapatite-gelatine composite materials for orthopaedic application

Energy Technology Data Exchange (ETDEWEB)

Yanovska, A., E-mail: biophy@yandex.ru [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Kuznetsov, V. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Stanislavov, A. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Husak, E. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Pogorielov, M. [Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Starikov, V. [National Technical University ”Kharkov Polytechnic Institute”, 21 Frunze Str., 61002, Kharkov (Ukraine); Bolshanina, S. [Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Danilchenko, S. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine)

2016-11-01

The composite materials based on hydroxyapatite (HA) and gelatine (Gel) with addition of silver and zirconium oxide were obtained. The study investigates a combination of low powered ultrasonic irradiation and low concentration of gelatine in the co-precipitation synthesis. These composites have different weight ratios of organic/inorganic components and may be synthesized in two ways: simple mixing and co-precipitation. Both of which were compared. The estimation of porosity, in vivo testing, surface morphology and phase composition as well as the IR-analysis were provided. Hydroxyapatite was the main crystalline phase in obtained composites. While around powdered HA-Gel composite the connective tissue capsule is formed without bone tissue formation, HA-Gel-Ag porous composite implantation leads to formation of new bone tissue and activation of cell proliferation. Addition of silver ions into composite material allows decreasing inflammation on the first stage of implantation and has positive effect on bone tissue formation. Some of the obtained composite materials containing silver or ZrO{sub 2} are biocompatible. bio-resorbable and osteoconductive with high level of porosity (75–85%). - Highlights: • Hydroxyapatite-gelatine composites with addition of Ag{sup +} and ZrO{sub 2} were obtained. • Composites were synthesized in two ways: simple mixing and co-precipitation. • Co-precipitation synthesis combined ultrasonic treatment and low concentration of gelatine. • Obtained composites have different weight ratios of organic/inorganic components. • Some composites are osteoconductive and all of them have high level of porosity (75–85%).

Impact of intra- and extra-osseous soft tissue composition on changes in bone mineral density with weight loss and regain.

Science.gov (United States)

Bosy-Westphal, Anja; Later, Wiebke; Schautz, Britta; Lagerpusch, Merit; Goele, Kristin; Heller, Martin; Glüer, Claus-C; Müller, Manfred J

2011-07-01

Recent studies report a significant gain in bone mineral density (BMD) after diet-induced weight loss. This might be explained by a measurement artefact. We therefore investigated the impact of intra- and extra-osseous soft tissue composition on bone measurements by dual X-ray absorptiometry (DXA) in a longitudinal study of diet-induced weight loss and regain in 55 women and 17 men (19-46 years, BMI 28.2-46.8 kg/m(2)). Total and regional BMD were measured before and after 12.7 ± 2.2 week diet-induced weight loss and 6 months after significant weight regain (≥30%). Hydration of fat free mass (FFM) was assessed by a 3-compartment model. Skeletal muscle (SM) mass, extra-osseous adipose tissue, and bone marrow were measured by whole body magnetic resonance imaging (MRI). Mean weight loss was -9.2 ± 4.4 kg (P BMAT) were not related to changes in BMD.

Tissue and Organ 3D Bioprinting.

Science.gov (United States)

Xia, Zengmin; Jin, Sha; Ye, Kaiming

2018-02-01

Three-dimensional (3D) bioprinting enables the creation of tissue constructs with heterogeneous compositions and complex architectures. It was initially used for preparing scaffolds for bone tissue engineering. It has recently been adopted to create living tissues, such as cartilage, skin, and heart valve. To facilitate vascularization, hollow channels have been created in the hydrogels by 3D bioprinting. This review discusses the state of the art of the technology, along with a broad range of biomaterials used for 3D bioprinting. It provides an update on recent developments in bioprinting and its applications. 3D bioprinting has profound impacts on biomedical research and industry. It offers a new way to industrialize tissue biofabrication. It has great potential for regenerating tissues and organs to overcome the shortage of organ transplantation.

Preparation of collagen/polyurethane/knitted silk as a composite scaffold for tendon tissue engineering.

Science.gov (United States)

Sharifi-Aghdam, Maryam; Faridi-Majidi, Reza; Derakhshan, Mohammad Ali; Chegeni, Arash; Azami, Mahmoud

2017-07-01

The main objective of this study was to prepare a hybrid three-dimensional scaffold that mimics natural tendon tissues. It has been found that a knitted silk shows good mechanical strength; however, cell growth on the bare silk is not desirable. Hence, electrospun collagen/polyurethane combination was used to cover knitted silk. A series of collagen and polyurethane solutions (4%-7% w/v) in aqueous acetic acid were prepared and electrospun. According to obtained scanning electron microscopy images from pure collagen and polyurethane nanofibers, concentration was set constant at 5% (w/v) for blend solutions of collagen/polyurethane. Afterward, blend solutions with the weight ratios of 75/25, 50/50 and 25/75 were electrospun. Scanning electron microscopy images demonstrated the smooth and uniform morphology for the optimized nanofibers. The least fibers diameter among three weight ratios was found for collagen/polyurethane (25/75) which was 100.86 ± 40 nm and therefore was selected to be electrospun on the knitted silk. Attenuated total reflectance-Fourier transform infrared spectra confirmed the chemical composition of obtained electrospun nanofibers on the knitted silk. Tensile test of the specimens including blend nanofiber, knitted silk and commercial tendon substitute examined and indicated that collagen/polyurethane-coated knitted silk has appropriate mechanical properties as a scaffold for tendon tissue engineering. Then, Alamar Blue assay of the L929 fibroblast cell line seeded on the prepared scaffolds demonstrated appropriate viability of the cells with a significant proliferation on the scaffold containing more collagen content. The results illustrate that the designed structure would be promising for being used as a temporary substitute for tendon repair.

Skeletal muscle connective tissue

DEFF Research Database (Denmark)

Brüggemann, Dagmar Adeline

in the structure of fibrous collagen and myofibers at high-resolution. The results demonstrate that the collagen composition in the extra cellular matrix of Gadus morhua fish muscle is much more complex than previously anticipated, as it contains type III, IV, V  and VI collagen in addition to type I. The vascular....... Consequently, functional structures, ensuring "tissue maintenance" must form a major role of connective tissue, in addition that is to the force transmitting structures one typically finds in muscle. Vascular structures have also been shown to change their mechanical properties with age and it has been shown...

Photoactivated Composite Biomaterial for Soft Tissue Restoration in Rodents and in Humans

OpenAIRE

Hillel, Alexander T.; Unterman, Shimon; Nahas, Zayna; Reid, Branden; Coburn, Jeannine M.; Axelman, Joyce; Chae, Jemin J.; Guo, Qiongyu; Trow, Robert; Thomas, Andrew; Hou, Zhipeng; Lichtsteiner, Serge; Sutton, Damon; Matheson, Christine; Walker, Patricia

2011-01-01

Soft tissue reconstruction often requires multiple surgical procedures that can result in scars and disfiguration. Facial soft tissue reconstruction represents a clinical challenge because even subtle deformities can severely affect an individual’s social and psychological function. We therefore developed a biosynthetic soft tissue replacement composed of poly(ethylene glycol) (PEG) and hyaluronic acid (HA) that can be injected and photocrosslinked in situ with transdermal ligh...

Biomarkers of Habitual Fish Intake in Adipose-Tissue

DEFF Research Database (Denmark)

Marckmann, P.; Lassen, Anne Dahl; Haraldsdottir, H.

1995-01-01

The association between habitual fish and marine n-3 polyunsaturated fatty acid (PUFA) intake, and the fatty acid composition of subcutaneous fat was studied in 24 healthy young volunteers. Habitual dietary intakes were estimated from three 7-d weighed food records made at months 0, 5, and 8...... of the 8-mo study period. The adipose tissue fatty acid composition of each individual was determined by gas chromatography as the mean of two gluteal biopsies, obtained in the first and the last month of the study. The daily consumption of fish and of marine n-3 PUFAs in absolute terms (g....../d) was significantly associated with adipose tissue docosahexaenoic acid content (DHA; r = 0.55 and 0.58, respectively, P acid contents. Our study indicates that the adipose tissue DHA content is the biomarker of choice for the assessment of long...

Optimization of Polymer-ECM Composite Scaffolds for Tissue Engineering: Effect of Cells and Culture Conditions on Polymeric Nanofiber Mats

Directory of Open Access Journals (Sweden)

Ritu Goyal

2017-01-01

Full Text Available The design of composite tissue scaffolds containing an extracellular matrix (ECM and synthetic polymer fibers is a new approach to create bioactive scaffolds that can enhance cell function. Currently, studies investigating the effects of ECM-deposition and decellularization on polymer degradation are still lacking, as are data on optimizing the stability of the ECM-containing composite scaffolds during prolonged cell culture. In this study, we develop fibrous scaffolds using three polymer compositions, representing slow (E0000, medium (E0500, and fast (E1000 degrading materials, to investigate the stability, degradation, and mechanics of the scaffolds during ECM deposition and decellularization, and during the complete cellularization-decell-recell cycle. We report data on percent molecular weight (% Mw retention of polymeric fiber mats, changes in scaffold stiffness, ECM deposition, and the presence of fibronectin after decellularization. We concluded that the fast degrading E1000 (Mw retention ≤ 50% after 28 days was not sufficiently stable to allow scaffold handling after 28 days in culture, while the slow degradation of E0000 (Mw retention ≥ 80% in 28 days did not allow deposited ECM to replace the polymer support. The scaffolds made from medium degrading E0500 (Mw retention about 60% at 28 days allowed the gradual replacement of the polymer network with cell-derived ECM while maintaining the polymer network support. Thus, polymers with an intermediate rate of degradation, maintaining good scaffold handling properties after 28 days in culture, seem best suited for creating ECM-polymer composite scaffolds.

Periodontal tissue engineering strategies based on nonoral stem cells.

Science.gov (United States)

Requicha, João Filipe; Viegas, Carlos Alberto; Muñoz, Fernando; Reis, Rui Luís; Gomes, Manuela Estima

2014-01-01

Periodontal disease is an inflammatory disease which constitutes an important health problem in humans due to its enormous prevalence and life threatening implications on systemic health. Routine standard periodontal treatments include gingival flaps, root planning, application of growth/differentiation factors or filler materials and guided tissue regeneration. However, these treatments have come short on achieving regeneration ad integrum of the periodontium, mainly due to the presence of tissues from different embryonic origins and their complex interactions along the regenerative process. Tissue engineering (TE) aims to regenerate damaged tissue by providing the repair site with a suitable scaffold seeded with sufficient undifferentiated cells and, thus, constitutes a valuable alternative to current therapies for the treatment of periodontal defects. Stem cells from oral and dental origin are known to have potential to regenerate these tissues. Nevertheless, harvesting cells from these sites implies a significant local tissue morbidity and low cell yield, as compared to other anatomical sources of adult multipotent stem cells. This manuscript reviews studies describing the use of non-oral stem cells in tissue engineering strategies, highlighting the importance and potential of these alternative stem cells sources in the development of advanced therapies for periodontal regeneration. Copyright © 2013 Wiley Periodicals, Inc.

Degradation and biocompatibility of porous nano-hydroxyapatite/polyurethane composite scaffold for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Dong Zhihong [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China); Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); Li Yubao, E-mail: nic7504@scu.edu.cn [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China); Zou Qin [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China)

2009-04-01

Porous scaffold containing 30 wt% nano-hydroxyapatite (n-HA) and 70 wt% polyurethane (PU) from castor oil was prepared by a foaming method and investigated by X-ray diffraction (XRD), Fourier transform infrared absorption (FTIR), scanning electron microscopy (SEM) techniques. The results show that n-HA particles disperse homogeneously in the PU matrix. The porous scaffold has not only macropores of 100-800 {mu}m in size but also a lot of micropores on the walls of macropores. The porosity and compressive strength of scaffold are 80% and 271 kPa, respectively. After soaking in simulated body fluid (SBF), hydrolysis and deposition partly occur on the scaffold. The biological evaluation in vitro and in vivo shows that the n-HA/PU scaffold is non-cytotoxic and degradable. The porous structure provides a good microenvironment for cell adherence, growth and proliferation. The n-HA/PU composite scaffold can be satisfied with the basic requirement for tissue engineering, and has the potential to be applied in repair and substitute of human menisci of the knee-joint and articular cartilage.

A composite chitosan-gelatin bi-layered, biomimetic macroporous scaffold for blood vessel tissue engineering.

Science.gov (United States)

Badhe, Ravindra V; Bijukumar, Divya; Chejara, Dharmesh R; Mabrouk, Mostafa; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Kondiah, Pierre P D; Pillay, Viness

2017-02-10

A composite chitosan-gelatin macroporous hydrogel-based scaffold with bi-layered tubular architecture was engineered by solvent casting-co-particulate leaching. The scaffold constituted an inner macroporous layer concealed by a non-porous outer layer mimicking the 3D matrix of blood vessels with cellular adhesion and proliferation. The scaffold was evaluated for its morphological, physicochemical, physicomechanical and biodurability properties employing SEM, FTIR, DSC, XRD, porositometry, rheology and texture analysis. The fluid uptake and biodegradation in the presence of lysozymes was also investigated. Cellular attachment and proliferation was analysed using human dermal fibroblasts (HDF-a) seeded onto the scaffold and evaluated by MTT assay, SEM, and confocal microscopy. Results demonstrated that the scaffold had a desirable tensile strength=95.81±11kPa, elongation at break 112.5±13%, porosity 82% and pores between 100 and 230μm, 50% in vitro biodegradation at day 16 and proliferated fibroblasts over 20 days. These results demonstrate that scaffold may be an excellent tubular archetype for blood vessel tissue engineering. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nature, Origin, Potential Composition, and Climate Impact of the Asian Tropopause Aerosol Layer (ATAL)

Science.gov (United States)

Fairlie, T. D.; Vernier, J.-P.; Thomason, L. W.; Natarajan, M.; Bedka, K.; Wienhold, F.; Bian J.; Martinsson, B.

2015-01-01

Satellite observations from SAGE II and CALIPSO indicate that summertime aerosol extinction has more than doubled in the Asian Tropopause Aerosol Layer (ATAL) since the late 1990s. Here we show remote and in-situ observations, together with results from a chemical transport model (CTM), to explore the likely composition, origin, and radiative forcing of the ATAL. We show in-situ balloon measurements of aerosol backscatter, which support the high levels observed by CALIPSO since 2006. We also show in situ measurements from aircraft, which indicate a predominant carbonaceous contribution to the ATAL (Carbon/Sulfur ratios of 2- 10), which is supported by the CTM results. We show that the peak in ATAL aerosol lags by 1 month the peak in CO from MLS, associated with deep convection over Asia during the summer monsoon. This suggests that secondary formation and growth of aerosols in the upper troposphere on monthly timescales make a significant contribution to ATAL. Back trajectory calculations initialized from CALIPSO observations provide evidence that deep convection over India is a significant source for ATAL through the vertical transport of pollution to the upper troposphere.

Magnetite/CdTe magnetic-fluorescent composite nanosystem for magnetic separation and bio-imaging

International Nuclear Information System (INIS)

Kale, Anup; Yadav, Prasad; Gholap, Haribhau; Jog, J P; Ogale, Satishchandra; Kale, Sonia; Shastry, Padma; Pasricha, Renu; Lefez, Benoit; Hannoyer, Beatrice

2011-01-01

A new synthesis protocol is described to obtain a CdTe decorated magnetite bifunctional nanosystem via dodecylamine (DDA) as cross linker. High resolution transmission electron microscopy (HRTEM), energy-dispersive x-ray spectroscopy (EDAX), vibrating sample magnetometry (VSM), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and fluorescence microscopy are used to characterize the constitution, size, composition and physical properties of these superparamagnetic-fluorescent nanoparticles. These CdTe decorated magnetite nanoparticles were then functionalized with anti-epidermal growth factor receptor (EGFR) antibody to specifically target cells expressing this receptor. The EGFR is a transmembrane glycoprotein and is expressed on tumor cells from different tissue origins including human leukemic cell line Molt-4 cells. The magnetite-CdTe composite nanosystem is shown to perform excellently for specific selection, magnetic separation and fluorescent detection of EGFR positive Molt-4 cells from a mixed population. Flow cytometry and confocal laser scanning microscopy results show that this composite nanosystem has great potential in antibody functionalized magnetic separation and imaging of cells using cell surface receptor antibody.

Allogeneic transplantation of programmable cells of monocytic origin (PCMO) improves angiogenesis and tissue recovery in critical limb ischemia (CLI): a translational approach.

Science.gov (United States)

Berndt, Rouven; Hummitzsch, Lars; Heß, Katharina; Albrecht, Martin; Zitta, Karina; Rusch, Rene; Sarras, Beke; Bayer, Andreas; Cremer, Jochen; Faendrich, Fred; Groß, Justus

2018-04-27

Employing growth factor-induced partial reprogramming in vitro, peripheral human blood monocytes can acquire a state of plasticity along with expression of various markers of pluripotency. These so-called programmable cells of monocytic origin (PCMO) hold great promise in regenerative therapies. The aim of this translational study was to explore and exploit the functional properties of PCMO for allogeneic cell transplantation therapy in critical limb ischemia (CLI). Using our previously described differentiation protocol, murine and human monocytes were differentiated into PCMO. We examined paracrine secretion of pro-angiogenic and tissue recovery-associated proteins under hypoxia and induction of angiogenesis by PCMO in vitro. Allogeneic cell transplantation of PCMO was performed in a hind limb ischemia mouse model in comparison to cell transplantation of native monocytes and a placebo group. Moreover, we analyzed retrospectively four healing attempts with PCMO in patients with peripheral artery disease (PAD; Rutherford classification, stage 5 and 6). Statistical analysis was performed by using one-way ANOVA, Tukey's test or the Student's t test, p < 0.05. Cell culture experiments revealed good resilience of PCMO under hypoxia, enhanced paracrine release of pro-angiogenic and tissue recovery-associated proteins and induction of angiogenesis in vitro by PCMO. Animal experiments demonstrated significantly enhanced SO 2 saturation, blood flow, neoangiogenesis and tissue recovery after treatment with PCMO compared to treatment with native monocytes and placebo. Finally, first therapeutic application of PCMO in humans demonstrated increased vascular collaterals and improved wound healing in patients with chronic CLI without exaggerated immune response, malignant processes or extended infection after 12 months. In all patients minor and/or major amputations of the lower extremity could be avoided. In summary, PCMO improve angiogenesis and tissue recovery in chronic

Rules of Origin as Commercial Policy Instruments.

OpenAIRE

Falvey, Rod; Reed, Geoff

1997-01-01

This article examines the role of rules of origin as a commercial policy instrument that targets the input composition of imports. Using a three-country, partial equilibrium structure, we demonstrate conditions under which the imposition of a binding rule will be welfare improving for an importer facing competitive export suppliers. We further show that employing rules of origin in this way would be complementary to, rather than a substitute for, conventional optimal tariffs. Copyright Econom...

Biomimetic nanoclay scaffolds for bone tissue engineering

Science.gov (United States)

Ambre, Avinash Harishchandra

Tissue engineering offers a significant potential alternative to conventional methods for rectifying tissue defects by evoking natural regeneration process via interactions between cells and 3D porous scaffolds. Imparting adequate mechanical properties to biodegradable scaffolds for bone tissue engineering is an important challenge and extends from molecular to macroscale. This work focuses on the use of sodium montmorillonite (Na-MMT) to design polymer composite scaffolds having enhanced mechanical properties along with multiple interdependent properties. Materials design beginning at the molecular level was used in which Na-MMT clay was modified with three different unnatural amino acids and further characterized using Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD). Based on improved bicompatibility with human osteoblasts (bone cells) and intermediate increase in d-spacing of MMT clay (shown by XRD), 5-aminovaleric acid modified clay was further used to prepare biopolymer (chitosan-polygalacturonic acid complex) scaffolds. Osteoblast proliferation in biopolymer scaffolds containing 5-aminovaleric acid modified clay was similar to biopolymer scaffolds containing hydroxyapatite (HAP). A novel process based on biomineralization in bone was designed to prepare 5-aminovaleric acid modified clay capable of imparting multiple properties to the scaffolds. Bone-like apatite was mineralized in modified clay and a novel nanoclay-HAP hybrid (in situ HAPclay) was obtained. FTIR spectroscopy indicated a molecular level organic-inorganic association between the intercalated 5-aminovaleric acid and mineralized HAP. Osteoblasts formed clusters on biopolymer composite films prepared with different weight percent compositions of in situ HAPclay. Human MSCs formed mineralized nodules on composite films and mineralized extracellular matrix (ECM) in composite scaffolds without the use of osteogenic supplements. Polycaprolactone (PCL), a synthetic polymer, was

Contribution of collagen fibers to the compressive stiffness of cartilaginous tissues.

Science.gov (United States)

Römgens, Anne M; van Donkelaar, Corrinus C; Ito, Keita

2013-11-01

Cartilaginous tissues such as the intervertebral disk are predominantly loaded under compression. Yet, they contain abundant collagen fibers, which are generally assumed to contribute to tensile loading only. Fiber tension is thought to originate from swelling of the proteoglycan-rich nucleus. However, in aged or degenerate disk, proteoglycans are depleted, whereas collagen content changes little. The question then rises to which extend the collagen may contribute to the compressive stiffness of the tissue. We hypothesized that this contribution is significant at high strain magnitudes and that the effect depends on fiber orientation. In addition, we aimed to determine the compression of the matrix. Bovine inner and outer annulus fibrosus specimens were subjected to incremental confined compression tests up to 60 % strain in radial and circumferential direction. The compressive aggregate modulus was determined per 10 % strain increment. The biochemical composition of the compressed specimens and uncompressed adjacent tissue was determined to compute solid matrix compression. The stiffness of all specimens increased nonlinearly with strain. The collagen-rich outer annulus was significantly stiffer than the inner annulus above 20 % compressive strain. Orientation influenced the modulus in the collagen-rich outer annulus. Finally, it was shown that the solid matrix was significantly compressed above 30 % strain. Therefore, we concluded that collagen fibers significantly contribute to the compressive stiffness of the intervertebral disk at high strains. This is valuable for understanding the compressive behavior of collagen-reinforced tissues in general, and may be particularly relevant for aging or degenerate disks, which become more fibrous and less hydrated.

Electroactive Tissue Scaffolds with Aligned Pores as Instructive Platforms for Biomimetic Tissue Engineering

Directory of Open Access Journals (Sweden)

John G. Hardy

2015-01-01

Full Text Available Tissues in the body are hierarchically structured composite materials with tissue-specific chemical and topographical properties. Here we report the preparation of tissue scaffolds with macroscopic pores generated via the dissolution of a sacrificial supramolecular polymer-based crystal template (urea from a biodegradable polymer-based scaffold (polycaprolactone, PCL. Furthermore, we report a method of aligning the supramolecular polymer-based crystals within the PCL, and that the dissolution of the sacrificial urea yields scaffolds with macroscopic pores that are aligned over long, clinically-relevant distances (i.e., centimeter scale. The pores act as topographical cues to which rat Schwann cells respond by aligning with the long axis of the pores. Generation of an interpenetrating network of polypyrrole (PPy and poly(styrene sulfonate (PSS in the scaffolds yields electroactive tissue scaffolds that allow the electrical stimulation of Schwann cells cultured on the scaffolds which increases the production of nerve growth factor (NGF.

Effects of Human Adipose-Derived Stem Cells on the Survival of Rabbit Ear Composite Grafts

Directory of Open Access Journals (Sweden)

Chae Min Kim

2017-09-01

Full Text Available Background Composite grafts are frequently used for facial reconstruction. However, the unpredictability of the results and difficulties with large defects are disadvantages. Adipose-derived stem cells (ADSCs express several cytokines, and increase the survival of random flaps and fat grafts owing to their angiogenic potential. Methods This study investigated composite graft survival after ADSC injection. Circular chondrocutaneous composite tissues, 2 cm in diameter, from 15 New Zealand white rabbits were used. Thirty ears were randomly divided into 3 groups. In the experimental groups (1 and 2, ADSCs were subcutaneously injected 7 days and immediately before the operation, respectively. Similarly, phosphate-buffered saline was injected in the control group just before surgery in the same manner as in group 2. In all groups, chondrocutaneous composite tissue was elevated, rotated 90 degrees, and repaired in its original position. Skin flow was assessed using laser Doppler 1, 3, 6, 9, and 12 days after surgery. At 1 and 12 days after surgery, the viable area was assessed using digital photography; the rabbits were euthanized, and immunohistochemical staining for CD31 was performed to assess neovascularization. Results The survival of composite grafts increased significantly with the injection of ADSCs (P<0.05. ADSC injection significantly improved neovascularization based on anti-CD31 immunohistochemical analysis and vascular endothelial growth factor expression (P<0.05 in both group 1 and group 2 compared to the control group. No statistically significant differences in graft survival, anti-CD31 neovascularization, or microcirculation were found between groups 1 and 2. Conclusions Treatment with ADSCs improved the composite graft survival, as confirmed by the survival area and histological evaluation. The differences according to the injection timing were not significant.

Origin and chemical composition of evaporite deposits

Science.gov (United States)

Moore, George William

1960-01-01

A comparative study of marine evaporite deposits forming at the present time along the pacific coast of central Mexico and evaporite formations of Permian age in West Texas Basin was made in order to determine if the modern sediments provide a basis for understanding environmental conditions that existed during deposition of the older deposits. The field work was supplemented by investigations of artificial evaporite minerals precipitated in the laboratory and by study of the chemical composition of halite rock of different geologic ages. The environment of deposition of contemporaneous marine salt deposits in Mexico is acidic, is strongly reducing a few centimeters below the surface, and teems with microscopic life. Deposition of salt, unlike that of many other sediments, is not wholly a constructional phenomenon. Permanent deposits result only if a favorable balance exists between deposition in the dry season and dissolution in the wet season. Evaporite formations chosen for special study in the West Texas Basin are, in ascending order, the Castile, Salado, and Rustler formations, which have a combined thickness of 1200 meters. The Castile formation is largely composed of gypsum rock, the Salado, halite rock, and the Rustler, quartz and carbonate sandstone. The lower part of the Castile formation is bituminous and contains limestone laminae. The Castile and Rustler formations thicken to the south at the expense of salt of the intervening Salado formation. The clastic rocks of the Rustler formation are interpreted as the deposits of a series of barrier islands north of which halite rock of the Salado was deposited. The salt is believed to have formed in shallow water of uniform density that was mixed by the wind. Where water depth exceeded the depth of the wind mixing, density stratification developed, and gypsum was deposited. Dense water of high salinity below the density discontinuity was overlain by less dense, more normally saline water which was derived from

Localization of trefoil factor family peptide 3 (TFF3) in epithelial tissues originating from the three germ layers of developing mouse embryo.

Science.gov (United States)

Bijelić, Nikola; Belovari, Tatjana; Tolušić Levak, Maja; Baus Lončar, Mirela

2017-08-20

Trefoil factor family (TFF) peptides are involved in the maintenance of epithelial integrity and epithelial restitution. Mature epithelial tissues originate from different embryonic germ layers. The objective of this research was to explore the presence and localization of TFF3 peptide in mouse embryonic epithelia and to examine if the occurrence of TFF3 peptide is germ layer-dependent. Mouse embryos (14-18 days old) were fixed in 4% paraformaldehyde and embedded in paraffin. Immunohistochemistry was performed with affinity purified rabbit anti-TFF3 antibody, goat anti-rabbit biotinylated secondary antibody and streptavidin-horseradish peroxidase, followed by 3,3'-diaminobenzidine. TFF3 peptide was present in the gastric and intestinal mucosa, respiratory mucosa in the upper and lower airways, pancreas, kidney tubules, epidermis, and oral cavity. The presence and localization of TFF3 peptide was associated with the embryonic stage and tissue differentiation. TFF3 peptide distribution specific to the germ layers was not observed. The role of TFF3 peptide in cell migration and differentiation, immune response, and apoptosis might be associated with specific embryonic epithelial cells. TFF3 peptide may also be considered as a marker for mucosal maturation.

Localization of trefoil factor family peptide 3 (TFF3 in epithelial tissues originating from the three germ layers of developing mouse embryo

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Nikola Bijelić

2017-08-01

Full Text Available Trefoil factor family (TFF peptides are involved in the maintenance of epithelial integrity and epithelial restitution. Mature epithelial tissues originate from different embryonic germ layers. The objective of this research was to explore the presence and localization of TFF3 peptide in mouse embryonic epithelia and to examine if the occurrence of TFF3 peptide is germ layer-dependent. Mouse embryos (14-18 days old were fixed in 4% paraformaldehyde and embedded in paraffin. Immunohistochemistry was performed with affinity purified rabbit anti-TFF3 antibody, goat anti-rabbit biotinylated secondary antibody and streptavidin-horseradish peroxidase, followed by 3,3'-diaminobenzidine. TFF3 peptide was present in the gastric and intestinal mucosa, respiratory mucosa in the upper and lower airways, pancreas, kidney tubules, epidermis, and oral cavity. The presence and localization of TFF3 peptide was associated with the embryonic stage and tissue differentiation. TFF3 peptide distribution specific to the germ layers was not observed. The role of TFF3 peptide in cell migration and differentiation, immune response, and apoptosis might be associated with specific embryonic epithelial cells. TFF3 peptide may also be considered as a marker for mucosal maturation.