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Sample records for tissue-engineered lacrimal gland

  1. An in vitro evaluation of various biomaterials for the development of a tissue-engineered lacrimal gland

    Science.gov (United States)

    Selvam, Shivaram

    The most common cause of ocular morbidity in developed countries is dry eye, many cases of which are due to lacrimal insufficiency. It has been established that lacrimal insufficiency results from processes caused by both immune-related and non-immune related events such as Sjogren's syndrome, Stevens-Johnson syndrome, chemical and thermal injuries and ocular cicatricial pemphigoid. Patients with these conditions would benefit from repair of their damaged lacrimal tissue by the creation of a replacement for the lacrimal gland. The new field of tissue engineering built on the interface between principles and methods of the life sciences with those of engineering to develop biocompatible materials has created the possibility for repairing or replacing damaged tissues. This thesis explores the use of tissue engineering principles for the development of a tissue-engineered lacrimal gland. This thesis also contributes to the development of a novel model for addressing lacrimal gland physiology and epithelial fluid transport. The first part of the research work focused on the evaluation of morphological and physiological properties of purified lacrimal gland acinar cells (pLGACs) cultured on various biopolymers: silicone, collagen I, poly-D,L-lactide-co-glycolide (PLGA; 85:15 and 50:50), and poly-L-lactic acid (PLLA) in the presence and absence of an extracellular matrix, MatrigelRTM. Results indicated that PLLA demonstrated the best support expression of acinar cell-like morphology. The second part demonstrated the ex vivo reconstitution of an electrophysiologically functional lacrimal gland tissue on porous polyester membrane scaffolds. Results showed that pLGACs were capable of establishing continuous epithelial monolayers that generate active ionic fluxes consistent with current models for Na +-dependent Cl-- secretion. The third part outlined the fabrication of porous PLLA membranes, the optimal biomaterial for culturing lacrimal epithelial cells. Microporous PLLA

  2. Development of Causative Treatment Strategies for Lacrimal Gland Insufficiency by Tissue Engineering and Cell Therapy. Part 2: Reconstruction of Lacrimal Gland Tissue: What Has Been Achieved So Far and What Are the Remaining Challenges?

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    Massie, Isobel; Dietrich, Jana; Roth, Mathias; Geerling, Gerd; Mertsch, Sonja; Schrader, Stefan

    2016-10-01

    The lacrimal gland is located in the upper temporal compartment of the orbita, and along with the ocular surface, eye lids, and sensory and motor nerves forms the lacrimal functional unit (LFU). The LFU is responsible for producing, distributing, and maintaining the tear film in order to maintain a smooth, moist, and regular ocular surface epithelium such that appropriate refractive properties are achieved and the eyeball is protected against dust, debris, and pathogens. If the main lacrimal gland is impaired (due to either disease or injury), this balance is disrupted, and severe quantitative dry eye syndrome (DES) can develop. DES treatments remain palliative, with the most commonly used therapies being based on tear substitution, tear retention, and control of inflammation on the ocular surface. Causative treatments such as salivary gland transplantation have shown to reduce symptoms in very severe cases, however can cause problems on the ocular surface due to different properties of saliva and tears. Therefore, causative approaches for treating DES by regeneration or reconstruction of lacrimal gland tissue depending on disease severity seem highly appealing. This article reviews current approaches for in vitro reconstruction of lacrimal gland tissue. Finally, the limitations that must be overcome before a new, tissue-engineered therapy may be delivered to clinic will be discussed.

  3. Morphological Features of the Porcine Lacrimal Gland and Its Compatibility for Human Lacrimal Gland Xenografting

    OpenAIRE

    Henker, Robert; Scholz, Michael; Gaffling, Simone; Asano, Nagayoshi; Hampel, Ulrike; Garreis, Fabian; Hornegger, Joachim; Paulsen, Friedrich

    2013-01-01

    In this study, we present first data concerning the anatomical structure, blood supply and location of the lacrimal gland of the pig. Our data indicate that the porcine lacrimal gland may serve as a potential xenograft candidate in humans or as an animal model for engineering of a bioartificial lacrimal gland tissue construct for clinical application. For this purpose, we used different macroscopic preparation techniques and digital reconstruction of the histological gland morphology to gain ...

  4. Morphological features of the porcine lacrimal gland and its compatibility for human lacrimal gland xenografting.

    Science.gov (United States)

    Henker, Robert; Scholz, Michael; Gaffling, Simone; Asano, Nagayoshi; Hampel, Ulrike; Garreis, Fabian; Hornegger, Joachim; Paulsen, Friedrich

    2013-01-01

    In this study, we present first data concerning the anatomical structure, blood supply and location of the lacrimal gland of the pig. Our data indicate that the porcine lacrimal gland may serve as a potential xenograft candidate in humans or as an animal model for engineering of a bioartificial lacrimal gland tissue construct for clinical application. For this purpose, we used different macroscopic preparation techniques and digital reconstruction of the histological gland morphology to gain new insights and important information concerning the feasibility of a lacrimal gland transplantation from pig to humans in general. Our results show that the lacrimal gland of the pig reveals a lot of morphological similarities to the analogous human lacrimal gland and thus might be regarded as a xenograft in the future. This is true for a similar anatomical location within the orbit as well as for the feeding artery supply to the organ. Functional differences concerning the composition of the tear fluid, due to a different secretory unit distribution within the gland tissue will, however, be a challenge in future investigations.

  5. Morphological features of the porcine lacrimal gland and its compatibility for human lacrimal gland xenografting.

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    Robert Henker

    Full Text Available In this study, we present first data concerning the anatomical structure, blood supply and location of the lacrimal gland of the pig. Our data indicate that the porcine lacrimal gland may serve as a potential xenograft candidate in humans or as an animal model for engineering of a bioartificial lacrimal gland tissue construct for clinical application. For this purpose, we used different macroscopic preparation techniques and digital reconstruction of the histological gland morphology to gain new insights and important information concerning the feasibility of a lacrimal gland transplantation from pig to humans in general. Our results show that the lacrimal gland of the pig reveals a lot of morphological similarities to the analogous human lacrimal gland and thus might be regarded as a xenograft in the future. This is true for a similar anatomical location within the orbit as well as for the feeding artery supply to the organ. Functional differences concerning the composition of the tear fluid, due to a different secretory unit distribution within the gland tissue will, however, be a challenge in future investigations.

  6. [Eye-associated lymphoid tissue (EALT) is continuously spread throughout the ocular surface from the lacrimal gland to the lacrimal drainage system].

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    Knop, E; Knop, N

    2003-11-01

    Components of the mucosal immune system (MALT) have been identified in the conjunctiva (as CALT) and the lacrimal drainage system (as LDALT). Their structural and functional relation with the established immune protection by the lacrimal gland is unclear. Macroscopically normal and complete tissues of the conjunctiva, lacrimal drainage system and lacrimal gland from human body donors were investigated by analysis of translucent whole mounts, and using histology, immunohistology as well as scanning and transmission electron microscopy. A typical diffuse lymphoid tissue, composed of effector cells of the immune system (T-lymphocytes and IgA producing plasma cells) under an epithelium that contains the IgA transporter SC, is not isolated in the conjunctiva and lacrimal drainage system. It is anatomically continuous from the lacrimal gland along its excretory ducts into the conjunctiva and from there via the lacrimal canaliculi into the lacrimal drainage system. Lymphoid follicles occur in a majority (about 60%) and with bilateral symmetry. The topography of CALT corresponds to the position of the cornea in the closed eye. These results show that the MALT of the lacrimal gland, conjunctiva and lacrimal drainage system constitute an anatomical and functional unit for immune protection of the ocular surface. Therefore it should be integrated as an "eye-associated lymphoid tissue" (EALT) into the MALT system of the body. EALT can detect ocular surface antigens by the lymphoid follicles and can supply other organs and the ocular surface including the lacrimal gland with specific effector cells via the regulated recirculation of lymphoid cells.

  7. Bioengineered Lacrimal Gland Organ Regeneration in Vivo

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    Masatoshi Hirayama

    2015-07-01

    Full Text Available The lacrimal gland plays an important role in maintaining a homeostatic environment for healthy ocular surfaces via tear secretion. Dry eye disease, which is caused by lacrimal gland dysfunction, is one of the most prevalent eye disorders and causes ocular discomfort, significant visual disturbances, and a reduced quality of life. Current therapies for dry eye disease, including artificial tear eye drops, are transient and palliative. The lacrimal gland, which consists of acini, ducts, and myoepithelial cells, develops from its organ germ via reciprocal epithelial-mesenchymal interactions during embryogenesis. Lacrimal tissue stem cells have been identified for use in regenerative therapeutic approaches aimed at restoring lacrimal gland functions. Fully functional organ replacement, such as for tooth and hair follicles, has also been developed via a novel three-dimensional stem cell manipulation, designated the Organ Germ Method, as a next-generation regenerative medicine. Recently, we successfully developed fully functional bioengineered lacrimal gland replacements after transplanting a bioengineered organ germ using this method. This study represented a significant advance in potential lacrimal gland organ replacement as a novel regenerative therapy for dry eye disease. In this review, we will summarize recent progress in lacrimal regeneration research and the development of bioengineered lacrimal gland organ replacement therapy.

  8. Expression profiles of aquaporins in rat conjunctiva, cornea, lacrimal gland and Meibomian gland.

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    Yu, Dongfang; Thelin, William R; Randell, Scott H; Boucher, Richard C

    2012-10-01

    The aim of the study was to elucidate aquaporin (AQP) family member mRNA expression and protein expression/localization in the rat lacrimal functional unit. The mRNA expression of all rat AQPs (AQP0-9, 11-12) in palpebral, fornical, and bulbar conjunctiva, cornea, lacrimal gland, and Meibomian gland was measured by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and real time RT-PCR. Antibodies against AQP1, 3, 4, 5, 9, and 11 were used in Western blotting and immunohistochemistry to determine protein expression and distribution. Our study demonstrated characteristic AQP expression profiles in rat ocular tissues. AQP1, 3, 4, 5, 8, 9, 11, and 12 mRNA were detected in conjunctiva. AQP0, 1, 2, 3, 4, 5, 6, 11, and 12 mRNA were expressed in cornea. AQP0, 1, 2, 3, 4, 5, 7, 8, and 11 mRNA were detected in lacrimal gland. AQP1, 3, 4, 5, 7, 8, 9, 11, and 12 mRNA were identified in Meibomian gland. By Western blot, AQP1, 3, 5, and 11 were detected in conjunctiva; AQP1, 3, 5, and 11 were identified in cornea; AQP1, 3, 4, 5, and 11 were detected in lacrimal gland; and AQP1, 3, 4, 5, 9, and 11 were present in Meibomian gland. Immunohistochemistry localized AQPs to distinct sites in the various tissues. This study rigorously analyzed AQPs expression and localization in rat conjunctiva, cornea, lacrimal gland, and Meibomian gland tissues. Our findings provide a comprehensive platform for further investigation into the physiological or pathophysiological relevance of AQPs in ocular surface. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Cytokeratin expression in mouse lacrimal gland germ epithelium.

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    Hirayama, Masatoshi; Liu, Ying; Kawakita, Tetsuya; Shimmura, Shigeto; Tsubota, Kazuo

    2016-05-01

    The lacrimal gland secretes tear fluids that protect the ocular surface epithelium, and its dysfunction leads to dry eye disease (DED). The functional restoration of the lacrimal gland by engraftment of a bioengineered lacrimal gland using lacrimal gland germ epithelial cells has been proposed to cure DED in mice. Here, we investigate the expression profile of cytokeratins in the lacrimal gland germ epithelium to clarify their unique characteristics. We performed quantitative polymerase chain reaction (Q-PCR) and immunohistochemistry (IHC) analysis to clarify the expression profile of cytokeratin in the lacrimal gland germ epithelium. The mRNA expression of keratin (KRT) 5, KRT8, KRT14, KRT15, and KRT18 in the lacrimal gland germ epithelium was increased compared with that in mouse embryonic stem cells and the lacrimal gland germ mesenchyme, as analyzed by Q-PCR. The expression level of KRT15 increased in the transition from stem cells to lacrimal gland germ epithelium, then decreased as the lacrimal gland matured. IHC revealed that the expression set of these cytokeratins in the lacrimal gland germ epithelium was different from that in the adult lacrimal gland. The expression of KRT15 was observed in the lacrimal gland germ epithelium, and it segmentalized into some of the basal cells in the intercanulated duct in mature gland. We determined the expression profile of cytokeratins in the lacrimal gland epithelium, and identified KRT15 as a candidate unique cellular marker for the lacrimal gland germ epithelium. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Lacrimal Gland Radiosensitivity in Uveal Melanoma Patients

    International Nuclear Information System (INIS)

    Muller, Karin; Nowak, Peter J.C.M.; Naus, Nicole; Pan, Connie de; Santen, Cornelis A. van; Levendag, Peter; Luyten, Gre P.M.

    2009-01-01

    Purpose: To find a dose-volume effect for inhomogeneous irradiated lacrimal glands. Methods and Materials: Between 1999 and 2006, 72 patients (42 men and 30 women) were treated with fractionated stereotactic radiotherapy in a prospective, nonrandomized clinical trial (median follow-up, 32 months). A total dose of 50 Gy was given on 5 consecutive days. The mean of all Schirmer test results obtained ≥6 months after treatment was correlated with the radiation dose delivered to the lacrimal gland. Also, the appearance of dry eye syndrome (DES) was related to the lacrimal gland dose distribution. Results: Of the 72 patients, 17 developed a late Schirmer value <10 mm; 9 patients developed DES. A statistically significant relationship was found between the received median dose in the lacrimal gland vs. reduced tear production (p = 0.000) and vs. the appearance of DES (p = 0.003), respectively. A median dose of 7 Gy/fraction to the lacrimal gland caused a 50% risk of low Schirmer results. A median dose of 10 Gy resulted in a 50% probability of DES. Conclusion: We found a clear dose-volume relationship for irradiated lacrimal glands with regard to reduced tear production and the appearance of DES.

  11. Lacrimal Gland Pathologies from an Anatomical Perspective

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    Mahmut Sinan Abit

    2015-06-01

    Full Text Available Most of the patients in our daily practice have one or more ocular surface disorders including conjucntivitis, keratitis, dry eye disease, meibomian gland dysfunction, contact lens related symptoms, refractive errors,computer vision syndrome. Lacrimal gland has an important role in all above mentioned pathologies due to its major secretory product. An anatomical and physiological knowledge about lacrimal gland is a must in understanding basic and common ophthalmological cases. İn this paper it is aimed to explain the lacrimal gland diseases from an anatomical perspective.

  12. Development of lacrimal gland spheroids for lacrimal gland tissue regeneration.

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    Massie, Isobel; Spaniol, Kristina; Barbian, Andreas; Geerling, Gerd; Metzger, Marco; Schrader, Stefan

    2018-04-01

    Severe dry eye syndrome resulting from lacrimal gland (LG) dysfunction can cause blindness, yet treatments remain palliative. In vitro reconstruction of LG tissue could provide a curative treatment. We aimed to combine epithelial cells with endothelial cells and mesenchymal stem cells (MSCs) to form a 3D functional unit. Epithelial cells and MSCs were isolated from porcine LG; endothelial cells were isolated from human foreskin. MSCs were characterised (flow cytometry and differentiation potential assays). All 3 cell types were combined on Matrigel and spheroid formation observed. Spheroids were characterised [immunohistochemistry (IHC) and transmission electron microscopy] and function assessed (β-hexosaminidase assay). Spheroids were transferred to decellularised jejunum (SIS-Muc) in dynamic cultures for 1 week before further characterisation. MSCs did not express CD31 but expressed CD44 and CD105 and differentiated towards osteogenic and adipogenic lineages. Spheroids formed on Matrigel within 18 hr, contracting to ~10% of the well area (p function was increased in spheroids cf. monolayer controls (p function (p < .05), viability (p < .05), and proliferation decreased, whilst apoptosis increased. On SIS-Muc under dynamic culture, however, spheroids continued to proliferate to repopulate SIS-Muc. IHC revealed LG epithelial cells coexpressing pan-cytokeratin and lysozyme, as well as endothelial cells and MSCs and cells remained capable of responding to carbachol (p < .05). These spheroids could form the basis of a regenerative medicine treatment approach for dry eye syndrome. In vivo studies are required to evaluate this further. Copyright © 2017 John Wiley & Sons, Ltd.

  13. The Aging Lacrimal Gland: Changes in Structure and Function

    OpenAIRE

    Rocha, Eduardo M.; Alves, Monica; Rios, J. David; Dartt, Darlene A.

    2008-01-01

    The afferent nerves of the cornea and conjunctiva, efferent nerves of the lacrimal gland, and the lacrimal gland are a functional unit that works cooperatively to produce the aqueous component of tears. A decrease in the lacrimal gland secretory function can lead to dry eye disease. Because aging is a risk factor for dry eye disease, study of the changes in the function of the lacrimal gland functional unit with age is important for developing treatments to prevent dry eye disease. No one mec...

  14. The aging lacrimal gland: changes in structure and function.

    Science.gov (United States)

    Rocha, Eduardo M; Alves, Monica; Rios, J David; Dartt, Darlene A

    2008-10-01

    The afferent nerves of the cornea and conjunctiva, efferent nerves of the lacrimal gland, and the lacrimal gland are a functional unit that works cooperatively to produce the aqueous component of tears. A decrease in the lacrimal gland secretory function can lead to dry eye disease. Because aging is a risk factor for dry eye disease, study of the changes in the function of the lacrimal gland functional unit with age is important for developing treatments to prevent dry eye disease. No one mechanism is known to induce the changes that occur with aging, although multiple different mechanisms have been associated with aging. These fall into two theoretical categories: programmed theories of aging (immunological, genetic, apoptotic, and neuroendocrine) and error theories of aging (protein alteration, somatic mutation, etc). Lacrimal glands undergo structural and functional alteration with increasing age. In mouse models of aging, it has been shown that neural stimulation of protein secretion is an early target of aging, accompanied by an increase in mast cells and lipofuscin accumulation. Hyperglycemia and increased lymphocytic infiltration can contribute to this loss of function at older ages. These findings suggest that an increase in oxidative stress may play a role in the loss of lacrimal gland function with age. For the afferent and efferent neural components of the lacrimal gland functional unit, immune or inflammatory mediated decrease in nerve function could contribute to loss of lacrimal gland secretion with age. More research in this area is critically needed.

  15. Human lacrimal gland regeneration: Perspectives and review of literature.

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    Tiwari, Shubha; Ali, Mohammad Javed; Vemuganti, Geeta K

    2014-01-01

    The human lacrimal gland is an essential component of the lacrimal functional unit (LFU). Any perturbation of this unit can lead to the debilitating morbid condition called the dry eye syndrome (DES). The current line of therapy available for dry eye remains supportive and palliative with the patient being dependent on life long and frequent administration of lubricating eye drops. Even advanced therapies like punctual plugs, cyclosporine B administration, and salivary gland auto-transplantation have led to a limited success. Under these scenarios, the option of cell based therapy needs to be explored to provide better and long term relief to these patients. This review gives an overview of the efforts in lacrimal gland regeneration and examines the past and ongoing research in cell based therapies in animals as well as human lacrimal gland cultures. The authors discuss their first of its kind functionally viable human lacrimal gland in vitro culture system from fresh exenteration specimens. A brief overview of research in near future and the potential implications of lacrimal gland regenerative therapies have been discussed.

  16. The Radiological Spectrum of Orbital Pathologies that Involve the Lacrimal Gland and the Lacrimal Fossa

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    Jung, Won Sang; Ahn, Kook Jin; Park, Mi Ra; Kim, Ji Young; Choi, Jae Jeong; Kim, Bum Soo; Hahn, Seong Tai [Catholic University College of Medicine, Seoul (Korea, Republic of)

    2007-08-15

    CT and MRI are utilized to differentiate between different types of masses and to determine the extent of lesions involving the lacrimal gland and the fossa. In lacrimal gland epithelial tumors, benign pleomorphic adenomas are seen most commonly with a well defined benign appearance, and a malignant adenoid cystic carcinoma is seen with a typical invasive malignant appearance. However, a malignant myoepithelial carcinoma is seen with a benign looking appearance. Lymphomatous lesions of the lacrimal gland include a broad spectrum ranging from reactive hyperplasia to malignant lymphoma. These lesions can be very difficult to differentiate both radiologically and pathologically. Generally, lymphomas tend to occur in older patients. The developmental cystic lesions found in the lacrimal fossa such as dermoid and epidermoid cysts can be diagnosed when the cyst involves the superior temporal quadrant of the orbit and manifests as a nonenhancing cystic mass and, in case of a lipoma, it is diagnosed as a total fatty mass. However, masses of granulocytic sarcoma and xanthogranuloma, as well as vascular masses, such as a hemangiopericytoma, are difficult to diagnose correctly on the basis of preoperative imaging findings alone. Clinically, the lesions of the lacrimal gland and fossa are found as palpable masses in the superior lateral aspect of the orbit, and these lesions constitute about 5-13% of all of the orbital masses confirmed by biopsy. Many different pathological entities arise from the lacrimal gland and fossa, and as each of them requires a different therapeutic approach, the radiological characterization of each lesion is important. Approximately, half of the lacrimal gland masses are tumors of epithelial origin and the rest are lesions that arise from lymphoid or inflammatory diseases. Pseudotumors, metastatic masses and developmental cysts may also occur in the lacrimal fossa. This paper aims to discuss the radiologic findings of the lesions that are found in

  17. The Radiological Spectrum of Orbital Pathologies that Involve the Lacrimal Gland and the Lacrimal Fossa

    International Nuclear Information System (INIS)

    Jung, Won Sang; Ahn, Kook Jin; Park, Mi Ra; Kim, Ji Young; Choi, Jae Jeong; Kim, Bum Soo; Hahn, Seong Tai

    2007-01-01

    CT and MRI are utilized to differentiate between different types of masses and to determine the extent of lesions involving the lacrimal gland and the fossa. In lacrimal gland epithelial tumors, benign pleomorphic adenomas are seen most commonly with a well defined benign appearance, and a malignant adenoid cystic carcinoma is seen with a typical invasive malignant appearance. However, a malignant myoepithelial carcinoma is seen with a benign looking appearance. Lymphomatous lesions of the lacrimal gland include a broad spectrum ranging from reactive hyperplasia to malignant lymphoma. These lesions can be very difficult to differentiate both radiologically and pathologically. Generally, lymphomas tend to occur in older patients. The developmental cystic lesions found in the lacrimal fossa such as dermoid and epidermoid cysts can be diagnosed when the cyst involves the superior temporal quadrant of the orbit and manifests as a nonenhancing cystic mass and, in case of a lipoma, it is diagnosed as a total fatty mass. However, masses of granulocytic sarcoma and xanthogranuloma, as well as vascular masses, such as a hemangiopericytoma, are difficult to diagnose correctly on the basis of preoperative imaging findings alone. Clinically, the lesions of the lacrimal gland and fossa are found as palpable masses in the superior lateral aspect of the orbit, and these lesions constitute about 5-13% of all of the orbital masses confirmed by biopsy. Many different pathological entities arise from the lacrimal gland and fossa, and as each of them requires a different therapeutic approach, the radiological characterization of each lesion is important. Approximately, half of the lacrimal gland masses are tumors of epithelial origin and the rest are lesions that arise from lymphoid or inflammatory diseases. Pseudotumors, metastatic masses and developmental cysts may also occur in the lacrimal fossa. This paper aims to discuss the radiologic findings of the lesions that are found in

  18. Isolated bilateral congenital lacrimal gland agenesis – Report of two cases

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    Manar Alwohaib

    2017-10-01

    Full Text Available Congenital lacrimal gland agenesis, also called congenital alacrima, is a rare cause of dry eye and is characterized by aplasia or hypoplasia of lacrimal glands. We present two 5-year old children with congenital lacrimal gland agenesis. The two cases had the final diagnosis of isolated bilateral congenital lacrimal gland agenesis and we document the clinical aspects, treatment and present a literature review related to this rare condition. Keywords: Alacrima, Lacrimal gland, Lacrimal gland agenesis, Punctal plugs

  19. Establishing human lacrimal gland cultures with secretory function.

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    Shubha Tiwari

    Full Text Available PURPOSE: Dry eye syndrome is a multifactorial chronic disabling disease mainly caused by the functional disruptions in the lacrimal gland. The treatment involves palliation like ocular surface lubrication and rehydration. Cell therapy involving replacement of the gland is a promising alternative for providing long-term relief to patients. This study aimed to establish functionally competent lacrimal gland cultures in-vitro and explore the presence of stem cells in the native gland and the established in-vitro cultures. METHODS: Fresh human lacrimal gland from patients undergoing exenteration was harvested for cultures after IRB approval. The freshly isolated cells were evaluated by flow cytometry for expression of stem cell markers ABCG2, high ALDH1 levels and c-kit. Cultures were established on Matrigel, collagen and HAM and the cultured cells evaluated for the presence of stem cell markers and differentiating markers of epithelial (E-cadherin, EpCAM, mesenchymal (Vimentin, CD90 and myofibroblastic (α-SMA, S-100 origin by flow cytometry and immunocytochemistry. The conditioned media was tested for secretory proteins (scIgA, lactoferrin, lysozyme post carbachol (100 µM stimulation by ELISA. RESULTS: Native human lacrimal gland expressed ABCG2 (mean±SEM: 3.1±0.61%, high ALDH1 (3.8±1.26% and c-kit (6.7±2.0%. Lacrimal gland cultures formed a monolayer, in order of preference on Matrigel, collagen and HAM within 15-20 days, containing a heterogeneous population of stem-like and differentiated cells. The epithelial cells formed 'spherules' with duct like connections, suggestive of ductal origin. The levels of scIgA (47.43 to 61.56 ng/ml, lysozyme (24.36 to 144.74 ng/ml and lactoferrin (32.45 to 40.31 ng/ml in the conditioned media were significantly higher than the negative controls (p<0.05 for all comparisons. CONCLUSION: The study reports the novel finding of establishing functionally competent human lacrimal gland cultures in-vitro. It also

  20. Age, gender, and interracial variability of normal lacrimal gland volume using MRI.

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    Bukhari, Amal A; Basheer, Naushad A; Joharjy, Heba I

    2014-01-01

    Aimed to evaluate normal volume of the lacrimal gland in patients of different age groups and race. All MRI studies of the brain that were done between June 2012 and April 2013 were examined. Lacrimal glands were identified using fat-saturated fluid-attenuated inversion recovery (FLAIR) images, and the volumes were calculated using TeraRecon iNtuition viewer. Volumes for the right and left lacrimal glands were recorded for persons of different age groups and race, and the results were compared with those of a randomly selected group of patients who had undergone the same calculation method using CT of the brain, orbit, or paranasal sinuses. The authors included 998 lacrimal glands of 499 patients. The mean volumes for the right and left lacrimal glands were 0.770 and 0.684 cm, respectively. Lacrimal glands were larger in women; the largest volumes were observed during the second decade of life. Mean volumes also varied with race: 0.840 cm in Asians, 0.790 cm in Africans, 0.760 cm in Indians, and 0.710 cm in Middle Easterners. The consultant neuroradiologist and the intern showed excellent agreement for measurements of lacrimal gland volume. No significant difference was observed between lacrimal gland measurements method on MRI and CT. Lacrimal gland volume varies according to age, gender, race, and laterality. Measurements with MRI using fat-saturated FLAIR images and TeraRecon iNtuition viewer software are reliable, accurate, and can be used by junior staff with less radiation exposure to patients.

  1. Review: The Lacrimal Gland and Its Role in Dry Eye

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    Christopher D. Conrady

    2016-01-01

    Full Text Available The human tear film is a 3-layered coating of the surface of the eye and a loss, or reduction, in any layer of this film may result in a syndrome of blurry vision and burning pain of the eyes known as dry eye. The lacrimal gland and accessory glands provide multiple components to the tear film, most notably the aqueous. Dysfunction of these glands results in the loss of aqueous and other products required in ocular surface maintenance and health resulting in dry eye and the potential for significant surface pathology. In this paper, we have reviewed products of the lacrimal gland, diseases known to affect the gland, and historical and emerging dry eye therapies targeting lacrimal gland dysfunction.

  2. Radiological features of endocrine orbitopathy involving lacrimal gland

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    V. G. Likhvantseva

    2014-07-01

    Full Text Available According to orbit computer tomography, lacrimal gland is involved in autoimmune process in 26.8% of patients with Graves’ orbitopathy. A short orbit is a predisposing factor of the lacrimal gland (LG involvement in the autoimmune process. In addition to increasing of the size of the lacrimal gland, formed thickening of the optic nerve in 1 cm from the eye posterior pole (in 60% of cases, the increase in x-ray density of orbital portions of optic nerve, proved «shortening» of length in axial projection with reliable reduc- tion of length to width ratio (with increase in width at the same time up to 5.8±0.2 are roentgenological features of this сlinical form. Change of spatial topography in orbit with reduction of the conversion rate was associated with increased rate of optic neuropathydevelopment.

  3. Isolated lacrimal gland involvement in Rosai-Dorfman-Destombes disease

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    Gulwani Hanni

    2008-01-01

    Full Text Available Rosai-Dorfman-Destombes (sinus histiocytosis with massive lymphadenopathy disease is an uncommon disease characterized by benign proliferation of histiocytes, with painless lymph node enlargement and frequent extranodal disease. Orbital involvement occurs in 9-11% of cases. However, isolated Rosai-Dorfman-Destombes disease of the lacrimal gland without any systemic involvement is very rare with only three case reports. We describe here one such young male patient with unilateral lacrimal gland swelling. Excision biopsy revealed almost complete replacement of the lacrimal gland by lymphocytes, plasma cells and large pale histiocytes. The latter exhibited emperipolesis and stained positive for S-100 and CD68 on immunohistochemistry. Patient is well and has no other manifestation or recurrence of the disease during a follow-up of 24 months.

  4. B cell receptor signaling pathway involved in benign lymphoepithelial lesions of the lacrimal gland

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    Xiao-Na Wang

    2017-05-01

    Full Text Available AIM: To detect the expression of B cell receptor signaling pathway (BCRSP in lacrimal gland benign lymphoepithelial lesions (LGBLEL. METHODS: Gene microarray was used to compare whole-genome expression in lacrimal gland tissues from LGBLEL patients to tissues from orbital cavernous hemangioma (control tissues. Expression of BCRSP was confirmed by polymerase chain reaction (PCR and immunohistochemistry. RESULTS: The expression of 22 genes of the BCRSP increased significantly in LGBLEL patients. PCR analysis showed that CD22, CR2, and BTK were all highly expressed in LGBLEL tissues. Immunohistochemical analysis showed that CR2 protein was present in LGBLEL, but CD22 and BTK proteins were negative. CR2, CD22, and BTK were not observed in the orbital cavernous hemangiomas with either PCR or immunohistochemistry. CONCLUSION: BCRSP might be involved in the pathogenesis of LGBLEL.

  5. Lacrimal gland ductal carcinomas

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    Andreasen, Simon; Grauslund, Morten; Heegaard, Steffen

    2017-01-01

    and xerophtalmia; case 2: A 53-year-old man, presented with headache, proptosis and chemosis and case 3: A 73-year-old man, presenting with chemosis and a corneal abscess. All three cases were characterized morphologically including immunohistochemistry and genetically with fluorescence in situ hybridization (FISH...... HER2 amplification was found in cases 2 and 3. CONCLUSION: This study identified a spectrum of genetic events and pattern of protein expression in DC of the lacrimal gland similar to a subset of carcinomas of the breast and ductal carcinomas of the salivary glands. For therapeutic purposes...

  6. Clinical analysis and follow-up of 191 cases of lacrimal gland occupying lesions

    Directory of Open Access Journals (Sweden)

    Peng-Peng Wu

    2017-02-01

    Full Text Available AIM: To investigate the clinical characteristics and follow-up of 191 patients with lacrimal glandoccupying lesions. METHODS: We selected 191 patients(221 eyeswith lacrimal gland occupancy from January 2011 to August 2015. All patients underwent lacrimal gland tumor removal and were followed up for 1a. RESULTS: In the 191 patients(221 eyes, 44 were male(49 eyesand 147 were female(172 eyes. There were inflammatory lesions in 171 eyes, constituted by IgG4 sclerosing dacryocystitis 66 eyes, 27 eyes of chronic lacrimal gland, lacrimal gland prolapse with inflammatory enlargement 54 eyes, Grave's disease in 24 eyes; 16 eyes of lymphoid hyperplastic lesions, constituted by malignant lymphoma in 6 eyes, benign lymphoid hyperplasia in 10 eyes; epithelial lesions in 34 eyes, constituted by pleomorphic adenoma in 26 eyes, 2 eyes of pleomorphic adenocarcinoma, adenoid cystic carcinoma in 3 eyes, 3 eyes of adenocarcinoma. Lacrimal glandoccupying lesions with IgG4 sclerosing dacryocystitis, lacrimal gland prolapse associated with inflammatory enlargement were the most common, of which 159 eyes of Han, Uighur 36 eyes, Kazak 16 eyes, 10 eyes of Mongolian. After surgery, mainly symptoms were dry eye, crying with no tears, with bilateral lacrimal gland removed significantly, but the local use of artificial tears can ease those symptoms with no serious adverse reactions. CONCLUSION: History and imaging characteristics of lacrimal gland-occupying lesions give a great help to the diagnosis and differential diagnosis. In Xinjiang region, lacrimal gland, with non-epithelial lesions is the most common, followed by epithelial lesions, occurred in the Han, Uighur patients, and rare occurred in other ethnic. Dry eye after surgery and crying with no tears are the main symptoms. Patients with short course of disease and dry eye tend to delay the removal of patients.

  7. Dietary lactoferrin alleviates age-related lacrimal gland dysfunction in mice.

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    Motoko Kawashima

    Full Text Available BACKGROUND: Decrease in lacrimal gland secretory function is related to age-induced dry eye disease. Lactoferrin, the main glycoprotein component of tears, has multiple functions, including anti-inflammatory effects and the promotion of cell growth. We investigated how oral administration of lactoferrin affects age-related lacrimal dysfunction. METHODS AND FINDINGS: Twelve-month-old male C57BL/6Cr Slc mice were randomly divided into a control fed group and an oral lactoferrin treatment group. Tear function was measured at a 6-month time-point. After euthanasia, the lacrimal glands were subjected to histological examination with 8-hydroxy-2'-deoxyguanosine (8-OHdG antibodies, and serum concentrations of 8-OHdG and hexanoyl-lysine adduct (HEL were evaluated. Additionally, monocyte chemotactic protein-1(MCP-1 and tumor necrosis factor-α (TNF-α gene expression levels were determined by real-time PCR. The volume of tear secretion was significantly larger in the treated group than in the control. Lactoferrin administration reduced inflammatory cell infiltration and the MCP-1 and TNF-α expression levels. Serum concentrations of 8-OHdG and HEL in the lactoferrin group were lower than those in the control group and were associated with attenuated 8-OHdG immunostaining of the lacrimal glands. CONCLUSION: Oral lactoferrin administration preserves lacrimal gland function in aged mice by attenuating oxidative damage and suppressing subsequent gland inflammation.

  8. MUC19 expression in human ocular surface and lacrimal gland and its alteration in Sjögren syndrome patients.

    Science.gov (United States)

    Yu, D F; Chen, Y; Han, J M; Zhang, H; Chen, X P; Zou, W J; Liang, L Y; Xu, C C; Liu, Z G

    2008-02-01

    This study investigated the expression of MUC19, a newly discovered gel-forming mucin gene, in normal human lacrimal functional unit components and its alteration in Sjögren syndrome patients. Real-time PCR and immunohistochemistry were performed to determine the expression of MUC19 and MUC5AC in human cornea, conjunctiva, and lacrimal gland tissues. Conjunctival impression cytology specimens were collected from normal control subjects and Sjögren syndrome patients for Real-time PCR, PAS staining, and immunohistochemistry assays. In addition, conjunctiva biopsy specimens from both groups were examined for the expression differences of MUC19 and MUC5AC at both mRNA and protein level. The MUC19 mRNA was found to be present in cornea, conjunctiva and lacrimal gland tissues. The immunohistochemical staining of mucins showed that MUC19 was expressed in epithelial cells from corneal, conjunctival, and lacrimal gland tissues. In contrast, MUC5AC mRNA was only present in conjunctiva and lacrimal gland tissues, but not in cornea. Immunostaining demonstrates the co-staining of MUC19 and MUC5AC in conjunctival goblet cells. Consistent with the significant decrease of mucous secretion, both MUC19 and MUC5AC were decreased in conjunctiva of Sjögren syndrome patients compared to normal subjects. Considering the contribution of gel-forming mucins to the homeostasis of the ocular surface, the decreased expression of MUC19 and MUC5AC in Sjögren syndrome patients suggested that these mucins may be involved in the disruption of the ocular surface homeostasis in this disease.

  9. Human lacrimal gland regeneration: Perspectives and review of literature

    OpenAIRE

    Tiwari, Shubha; Ali, Mohammad Javed; Vemuganti, Geeta K.

    2014-01-01

    The human lacrimal gland is an essential component of the lacrimal functional unit (LFU). Any perturbation of this unit can lead to the debilitating morbid condition called the dry eye syndrome (DES). The current line of therapy available for dry eye remains supportive and palliative with the patient being dependent on life long and frequent administration of lubricating eye drops. Even advanced therapies like punctual plugs, cyclosporine B administration, and salivary gland auto-transplantat...

  10. Lacrimal drainage-associated lymphoid tissue (LDALT): a part of the human mucosal immune system.

    Science.gov (United States)

    Knop, E; Knop, N

    2001-03-01

    Mucosa-associated lymphoid tissue (MALT) specifically protects mucosal surfaces. In a previous study of the human conjunctiva, evidence was also found for the presence of MALT in the lacrimal sac. The present study, therefore, aims to investigate its morphology and topographical distribution in the human lacrimal drainage system. Lacrimal drainage systems (n = 51) obtained from human cadavers were investigated by clearing flat wholemounts or by serial sections of tissue embedded in paraffin, OCT compound, or epoxy resin. These were further analyzed by histology, immunohistochemistry, and electron microscopy. All specimens showed the presence of lymphocytes and plasma cells as a diffuse lymphoid tissue in the lamina propria, together with intraepithelial lymphocytes and occasional high endothelial venules (HEV). It formed a narrow layer along the canaliculi that became thicker in the cavernous parts. The majority of lymphocytes were T cells, whereas B cells were interspersed individually or formed follicular centers. T cells were positive for CD8 and the human mucosa lymphocyte antigen (HML-1). Most plasma cells were positive for IgA and the overlying epithelium expressed its transporter molecule secretory component (SC). Basal mucous glands were present in the lacrimal canaliculi and in the other parts accompanied by alveolar and acinar glands, all producing IgA-rich secretions. Primary and secondary lymphoid follicles possessing HEV were present in about half of the specimens. The term lacrimal drainage-associated lymphoid tissue (LDALT) is proposed here to describe the lymphoid tissue that is regularly present and belongs to the common mucosal immune system and to the secretory immune system. It is suggested that it may form a functional unit together with the lacrimal gland and conjunctiva, connected by tear flow, lymphocyte recirculation, and probably the neural reflex arc, and play a major role in preserving ocular surface integrity.

  11. Adenoid cystic carcinomas of the salivary gland, lacrimal gland, and breast are morphologically and genetically similar but have distinct microRNA expression profiles.

    Science.gov (United States)

    Andreasen, Simon; Tan, Qihua; Agander, Tina Klitmøller; Steiner, Petr; Bjørndal, Kristine; Høgdall, Estrid; Larsen, Stine Rosenkilde; Erentaite, Daiva; Olsen, Caroline Holkmann; Ulhøi, Benedicte Parm; von Holstein, Sarah Linéa; Wessel, Irene; Heegaard, Steffen; Homøe, Preben

    2018-02-21

    Adenoid cystic carcinoma is among the most frequent malignancies in the salivary and lacrimal glands and has a grave prognosis characterized by frequent local recurrences, distant metastases, and tumor-related mortality. Conversely, adenoid cystic carcinoma of the breast is a rare type of triple-negative (estrogen and progesterone receptor, HER2) and basal-like carcinoma, which in contrast to other triple-negative and basal-like breast carcinomas has a very favorable prognosis. Irrespective of site, adenoid cystic carcinoma is characterized by gene fusions involving MYB, MYBL1, and NFIB, and the reason for the different clinical outcomes is unknown. In order to identify the molecular mechanisms underlying the discrepancy in clinical outcome, we characterized the phenotypic profiles, pattern of gene rearrangements, and global microRNA expression profiles of 64 salivary gland, 9 lacrimal gland, and 11 breast adenoid cystic carcinomas. All breast and lacrimal gland adenoid cystic carcinomas had triple-negative and basal-like phenotypes, while salivary gland tumors were indeterminate in 13% of cases. Aberrations in MYB and/or NFIB were found in the majority of cases in all three locations, whereas MYBL1 involvement was restricted to tumors in the salivary gland. Global microRNA expression profiling separated salivary and lacrimal gland adenoid cystic carcinoma from their respective normal glands but could not distinguish normal breast adenoid cystic carcinoma from normal breast tissue. Hierarchical clustering separated adenoid cystic carcinomas of salivary gland origin from those of the breast and placed lacrimal gland carcinomas in between these. Functional annotation of the microRNAs differentially expressed between salivary gland and breast adenoid cystic carcinoma showed these as regulating genes involved in metabolism, signal transduction, and genes involved in other cancers. In conclusion, microRNA dysregulation is the first class of molecules separating adenoid

  12. Salivation induced better lacrimal gland function in dry eyes.

    Science.gov (United States)

    Pramanik, T; Ghising, R

    2009-12-01

    The dry eye syndrome is a common eye symptom causing blurry vision. To meet the demand of the modem world students and professionals are compelled to expose themselves to the computer screen for long stretch of time, which is one of the causes of dry eye. It is not always feasible to instil eyes with artificial tears time to time to protect them from dryness. Rather to adopt any simple physiological process associated with optimum lacrimation is a better option to keep eyes moist during computer works. Volunteers (n = 22) having mild dry eyes participated in this study. Tear production was assessed by Schirmer test by keeping Schirmer strip on ocular surface for 5 minutes and recording the length of the moistened area. Then the subject was allowed to keep a piece of lopsy candy (a sour fruit pulp mixed with sugar that is sweet and sour in taste) in mouth for 5 minutes that caused salivation. During salivation, again tear production was assessed. [It was standardized in such a way that, the length of the moistened strip will be 25 - 30 mm for normal eyes, 15 - 10 mm for dry eye, 06 - 10 mm for mild dry eye, 02 - 05 mm for moderate dryness and 00 - 01 mm for severe dry eye.] Tear production was found to be increased significantly (supported by increased length of moistened area of Schirmer strip) during salivation especially in dry eye in all volunteers. The lacrimal gland is the major contributor to the aqueous layer of the tear film which consists of water, electrolytes and proteins; secretion of which are under tight neural control. Anticholinergic agents play an important role in ocular dryness because of hypo-secretion. The sensory root of facial nucleus contains efferent preganglionic parasympathetic fibers for submandibular and sublingual salivary gland and lacrimal gland. The sensory root conveys gustatory fibers from the presulcul area (anterior two-third) of the tongue via the chorda tympani and via the palatine and greater petrosal nerve, taste fibers from

  13. Epithelial tumours of the lacrimal gland

    DEFF Research Database (Denmark)

    von Holstein, Sarah Linéa; Coupland, Sarah E; Briscoe, Daniel

    2013-01-01

    of the lacrimal gland, displacement of the eyeball, reduced eye motility and diplopia. Pain and symptoms of short duration before the first ophthalmic consultation are characteristic of malignant tumours. The histological diagnosis determines the subsequent treatment regimen and provides important clues regarding...

  14. Immunoglobulin G4-related dacyroadenitis presenting as bilateral chorioretinal folds from severely enlarged lacrimal glands

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    Toru Kurokawa

    2018-03-01

    Conclusions and importance: This is the first account of chorioretinal fold formation by severely enlarged lacrimal glands appearing in IgG4-related dacryoadenitis. Chorioretinal fold formation by an enlarged lacrimal gland occurring bilaterally may represent a basis for suspecting IgG4-related dacryoadenitis. Prompt treatment is recommended for patients presenting with very large lacrimal glands to avoid visual impairment.

  15. Correlation of secretion of retinol and protein by the lacrimal gland

    International Nuclear Information System (INIS)

    Ubels, J.L.; Rismondo, V.

    1986-01-01

    Retinol, which is present in tears, is secreted by the lacrimal gland. Retinol secretion is stimulated by cholinergic drugs and vasoactive intestinal peptide with characteristics very similar to the exocytotic secretion of protein by the lacrimal gland, suggesting that retinol and protein are secreted by similar mechanisms. The authors investigated this by cannulating the lacrimal gland ducts of rabbits and collecting lacrimal gland fluid (LGF) under conditions of maximal flow stimulated by IV injection of pilocarpine (400 μg/kg) every 20 min for 4.5 hr. Over this period LGF protein concentration decreased 36.4% from 22.8 +/- 1.94 mg/ml to 8.29 1.86 mg/ml while retinol decreased 37% from 55.1 +/- 16.2 ng/ml to 20.4 +/- 6.5 ng/ml. The retinol/protein ratio remained constant at 2.88 ng/mg. This demonstrates a strong correlation between retinol and protein secretion, suggesting that retinol may be protein bound. To investigate binding of retinol to LGF protein, LGF was incubated with 3 H-retinol. The bound and unbound retinol were separated on a Lipidex 1000 column. Retinol binding was linear over a range of 1.25-200 nM 3 H-retinol. Binding was not inhibited by PCMBS or addition of a 100-fold excess of unlabeled retinol and was not increased by prior extraction of endogenous retinol from the LGF. This indicates that the binding of retinol to LGF protein is non-specific. Retinol therefore appears to be secreted by the lacrimal gland cells in non-specific association with protein

  16. Complement System in the Pathogenesis of Benign Lymphoepithelial Lesions of the Lacrimal Gland.

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    Jing Li

    Full Text Available We aimed to examine the potential involvement of local complement system gene expression in the pathogenesis of benign lymphoepithelial lesions (BLEL of the lacrimal gland.We collected data from 9 consecutive pathologically confirmed patients with BLEL of the lacrimal gland and 9 cases with orbital cavernous hemangioma as a control group, and adopted whole genome microarray to screen complement system-related differential genes, followed by RT-PCR verification and in-depth enrichment analysis (Gene Ontology analysis of the gene sets.The expression of 14 complement system-related genes in the pathologic tissue, including C2, C3, ITGB2, CR2, C1QB, CR1, ITGAX, CFP, C1QA, C4B|C4A, FANCA, C1QC, C3AR1 and CFHR4, were significantly upregulated while 7 other complement system-related genes, C5, CFI, CFHR1|CFH, CFH, CD55, CR1L and CFD were significantly downregulated in the lacrimal glands of BLEL patients. The microarray results were consistent with RT-PCR analysis results. Immunohistochemistry analysis of C3c and C1q complement component proteins in the resected tissue were positive in BLEL patients, while the control group had negative expression of these proteins. Gene ontology (GO analysis revealed that activation of the genes of complement system-mediated signaling pathways were the most enriched differential gene group in BLEL patients.Local expression of complement components is prominently abnormal in BLEL, and may well play a role in its pathogenesis.

  17. MR imaging of the lacrimal gland. Age-related and gender-dependent changes in size and structure

    International Nuclear Information System (INIS)

    Ueno, H.; Ariji, E.; Izumi, M.; Uetani, M.; Hayashi, K.; Nakamura, T.

    1996-01-01

    Purpose: The subject of this study was to define age-related and gender-dependent changes in MR features of the lacrimal gland. Material and Methods: MR images were retrospectively analyzed in 104 normal subjects aged 2-79 years to measure thickness and area of the lacrimal gland, its MR signal intensity ratio, and SD of the MR signal intensity profile. Results: Thickness and area of the lacrimal gland decreased with age in women (p<0.001), but not in men. Furthermore, MR signal intensity ratio of the lacrimal gland showed an age-related increase in women (p<0.001), but not in men. On the other hand, SD of the MR signal intensity increased with age in both women and men (p<0.001). Conclusion: These findings demonstrate that gender has a significant influence on lacrimal gland structure during development and aging. (orig.)

  18. The pathology of dry eye: the interaction between the ocular surface and lacrimal glands.

    Science.gov (United States)

    Stern, M E; Beuerman, R W; Fox, R I; Gao, J; Mircheff, A K; Pflugfelder, S C

    1998-11-01

    Most dry-eye symptoms result from an abnormal, nonlubricative ocular surface that increases shear forces under the eyelids and diminishes the ability of the ocular surface to respond to environmental challenges. This ocular-surface dysfunction may result from immunocompromise due to systemic autoimmune disease or may occur locally from a decrease in systemic androgen support to the lacrimal gland as seen in aging, most frequently in the menopausal female. Components of the ocular surface (cornea, conjunctiva, accessory lacrimal glands, and meibomian glands), the main lacrimal gland, and interconnecting innervation act as a functional unit. When one portion is compromised, normal lacrimal support of the ocular surface is impaired. Resulting immune-based inflammation can lead to lacrimal gland and neural dysfunction. This progression yields the OS symptoms associated with dry eye. Restoration of lacrimal function involves resolution of lymphocytic activation and inflammation. This has been demonstrated in the MRL/lpr mouse using systemic androgens or cyclosporine and in the dry-eye dog using topical cyclosporine. The efficacy of cyclosporine may be due to its immunomodulatory and antiinflammatory (phosphatase inhibitory capability) functions on the ocular surface, resulting in a normalization of nerve traffic. Although the etiologies of dry eye are varied, common to all ocular-surface disease is an underlying cytokine/receptor-mediated inflammatory process. By treating this process, it may be possible to normalize the ocular surface/lacrimal neural reflex and facilitate ocular surface healing.

  19. The surgical management of lacrimal gland pseudotumors

    NARCIS (Netherlands)

    Mombaerts, I.; Schlingemann, R. O.; Goldschmeding, R.; Noorduyn, L. A.; Koornneef, L.

    1996-01-01

    PURPOSE: Lacrimal gland pseudotumors belong to the group of orbital pseudotumor. Systemic corticosteroids are advocated as the primary treatment of choice in orbital pseudotumor, but recurrent and refractory cases are commonly described. In this retrospective study, the authors evaluate alteerative

  20. Mucoepidermoid carcinoma ex pleomorphic adenoma of the lacrimal gland: A rare presentation

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    Lily Daniel

    2014-01-01

    Full Text Available Carcinoma ex pleomorphic adenoma in lacrimal gland is a rare entity unlike its salivary gland counterpart. This rare tumor poses a diagnostic challenge to clinicians as pre-operative diagnosis is difficult and diagnosis is only by careful pathological assessment. We report this uncommon lesion in a 62-year-old lady, wherein the malignant component was mucoepidermoid carcinoma. The elderly patient remained clinically and radiologically free of the tumor for two years after complete excision of the tumor but computed tomography at the end of two and a half years showed a recurrent lesion in the region of the lacrimal gland. This makes long term follow up of patients with these rare lacrimal tumors imperative with a minimum period of at least five years.

  1. Salivary gland scintigraphy with 99mTc-pertechnetate in Sjoegren's syndro Relationship to clinicopathologic features of salivary and lacrimal glands

    International Nuclear Information System (INIS)

    Saito, Tohru; Fukuda, Hiroshi; Horikawa, Masa-aki; Ohmori, Kei-ichi; Shindoh, Masanobu; Amemiya, Akira

    1997-01-01

    Salivary gland scintigraphy was performed on 52 patients who were suspected of having Sjoegren's syndrome (SS), and the results were compared with clinicopathologic features of the salivary and lacrimal glands. The time-activity curves which were obtained from computer-assisted analysis of 99m Tc-pertechnetate ( 99m Tc) scintigraphy were classified into four types (normal, median, flat and sloped types). The stimulated parotid flow rate decreased and the incidence of SS-related sialographic and histopathologic findings increased significantly as the scintigraphic abnormality advanced. In addition, the lacrimal gland function decreased and the proportion of patients diagnosed as having keratoconjunctivitis sicca (KCS) increased significantly as the scintigraphic abnormality advanced. These results indicate that the results of scintigraphy are related not only to the clinicopathologic features of the salivary glands but also to the lacrimal gland functions in SS. (au) 25 refs

  2. Granulomatosis with polyangiitis confined to lacrimal gland, a case report.

    Science.gov (United States)

    Zuazo, F; González, M; Abdala, A; Olvera-Morales, O; Monroy, M H; Rodríguez-Reyes, A; Tovilla-Canales, J L; Nava-Castañeda, Á

    2017-11-01

    A 43 year-old woman consulted due to 2 months of swelling on the superolateral side of the left orbit, with pain and erythema. An excisional biopsy was performed that revealed vasculitis with polyangiitis of the lacrimal gland. A systemic study showed that no other system was compromised. Orbital involvement occurs in up to 60% of patients with granulomatosis with polyangiitis. The involvement of the lacrimal gland is rare and often unilateral. Serological tests are generally negative, both in initial stages, as in localized forms of the disease. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Dynamic Ocular Surface and Lacrimal Gland Changes Induced in Experimental Murine Dry Eye

    Science.gov (United States)

    Xiao, Bing; Wang, Yu; Reinach, Peter S.; Ren, Yueping; Li, Jinyang; Hua, Shanshan; Lu, Huihui; Chen, Wei

    2015-01-01

    Dry eye disease can be a consequence of lacrimal gland insufficiency in Sjögren’s Syndrome or increased tear film evaporation despite normal lacrimal gland function. To determine if there is a correlation between severity effects in these models and underlying pathophysiological responses, we compared the time dependent changes in each of these parameters that occur during a 6 week period. Dry eye was induced in 6-week-old female C57BL/6 mice by exposing them to an Intelligently Controlled Environmental System (ICES). Sixty mice were housed in ICES for 1, 2, 4 and 6 weeks respectively. Twelve were raised in normal environment and received subcutaneous injections of scopolamine hydrobromide (SCOP) 3 times daily for 5 days. Another sixty mice were housed in a normal environment and received no treatment. Corneal fluorescein staining along with corneal MMP-9 and caspase-3 level measurements were performed in parallel with the TUNEL assay. Interleukin-17(IL-17), IL-23, IL-6, IL-1, TNF-α, IFN-γ and TGF-β2 levels were estimated by real-time PCR measurements of conjunctival and lacrimal gland samples (LGs). Immunohistochemistry of excised LGs along with flow cytometry in cervical lymph nodes evaluated immune cell infiltration. Light and transmission electron microscopy studies evaluated LGs cytoarchitectural changes. ICES induced corneal epithelial destruction and apoptosis peaked at 2 weeks and kept stable in the following 4 weeks. In the ICES group, lacrimal gland proinflammatory cytokine level increases were much lower than those in the SCOP group. In accord with the lower proinflammatory cytokine levels, in the ICES group, lacrimal gland cytosolic vesicular density and size exceeded that in the SCOP group. ICES and SCOP induced murine dry eye effects became progressively more severe over a two week period. Subsequently, the disease process stabilized for the next four weeks. ICES induced local effects in the ocular surface, but failed to elicit lacrimal gland

  4. Dynamic ocular surface and lacrimal gland changes induced in experimental murine dry eye.

    Science.gov (United States)

    Xiao, Bing; Wang, Yu; Reinach, Peter S; Ren, Yueping; Li, Jinyang; Hua, Shanshan; Lu, Huihui; Chen, Wei

    2015-01-01

    Dry eye disease can be a consequence of lacrimal gland insufficiency in Sjögren's Syndrome or increased tear film evaporation despite normal lacrimal gland function. To determine if there is a correlation between severity effects in these models and underlying pathophysiological responses, we compared the time dependent changes in each of these parameters that occur during a 6 week period. Dry eye was induced in 6-week-old female C57BL/6 mice by exposing them to an Intelligently Controlled Environmental System (ICES). Sixty mice were housed in ICES for 1, 2, 4 and 6 weeks respectively. Twelve were raised in normal environment and received subcutaneous injections of scopolamine hydrobromide (SCOP) 3 times daily for 5 days. Another sixty mice were housed in a normal environment and received no treatment. Corneal fluorescein staining along with corneal MMP-9 and caspase-3 level measurements were performed in parallel with the TUNEL assay. Interleukin-17(IL-17), IL-23, IL-6, IL-1, TNF-α, IFN-γ and TGF-β2 levels were estimated by real-time PCR measurements of conjunctival and lacrimal gland samples (LGs). Immunohistochemistry of excised LGs along with flow cytometry in cervical lymph nodes evaluated immune cell infiltration. Light and transmission electron microscopy studies evaluated LGs cytoarchitectural changes. ICES induced corneal epithelial destruction and apoptosis peaked at 2 weeks and kept stable in the following 4 weeks. In the ICES group, lacrimal gland proinflammatory cytokine level increases were much lower than those in the SCOP group. In accord with the lower proinflammatory cytokine levels, in the ICES group, lacrimal gland cytosolic vesicular density and size exceeded that in the SCOP group. ICES and SCOP induced murine dry eye effects became progressively more severe over a two week period. Subsequently, the disease process stabilized for the next four weeks. ICES induced local effects in the ocular surface, but failed to elicit lacrimal gland

  5. Lacrimal gland accumulation of 67Ga-citrate in patients with Sjoegren's syndrome

    International Nuclear Information System (INIS)

    Tanabe, M.; Tamai, T.; Satoh, K.; Kojima, K.; Hasegawa, E.; Matsuo, N.; Satoh, C.; Murakami, T.H.

    1984-01-01

    The extent of 67 Ga accumulation in the two lacrimal glands in patients with keratoconjunctivitis sicca (KCS) of Sjoegren's syndrome was studied. Of the two main groups one consisted of 69 subjects without ophthalmic complaints (control group), the other consisted of 26 patients with KCS of Sjoegren's syndome. Of the 26 patients with KCS, 7 has been diagnosed as probable KCS (probable sub-group) and the other 19 had been diagnosed definite KCS (definite sub-group). About 3 mCi (111 MBq) 67 Ga-citrate was injected IV into each subject and this was followed by scintigraphy at 24, 48, and 72 h after the injection of 67 Ga. A positive finding in the lacrimal gland was noted in 64 of 69 subjects (92.7%) in the control group and in 7 of 7 patients (100%) with probable KCS. Three of 19 patients with definite KCS (15.7%) showed positive findings under scintigraphy. When the scintigraphic finding in the lacrimal gland is not positive in patients with suspected KCS of Sjoegren's syndrome, they can then be diagnosed with little risk as definite KCS cases. Shirmer's test was performed on subjects in the probable and definite groups. There was statistical significance between the positive and equivocal or negative scintigraphic finding and Schirmer's values. These results suggest a correlation between gallium accumulation in the lacrimal gland and the tear production. (orig.)

  6. An Update on Tumors of the Lacrimal Gland

    DEFF Research Database (Denmark)

    Andreasen, Simon; Esmaeli, Bita; Holstein, Sarah Linéa von

    2017-01-01

    are a growing mass at the site of the lacrimal gland, including displacement of the eyeball, decreased motility, diplopia, and ptosis. Pain is the cardinal symptom of an adenoid cystic carcinoma. Radiological findings characteristically include an oval, well-demarcated mass for benign lesions whereas malignant...

  7. Pleomorphic adenocarcinoma of the lacrimal gland with multiple intracranial and spinal metastases

    Directory of Open Access Journals (Sweden)

    Kim Se

    2007-03-01

    Full Text Available Abstract Background Pleomorphic adenoma of the lacrimal gland is known to undergo malignant transformation when incompletely excised. Even if such a malignant change occurs, intracranial direct invasion and leptomeningeal seeding are seldom encountered. Case presentation A 50-year-old woman presented with malignant transformation associated with both intracranial invasion and multiple intracranial and spinal disseminations in the third recurrence of pleomorphic adenoma of the lacrimal gland, 6 years after initial treatment. MRI demonstrated increased extent of orbital mass, extending to the cavernous sinus. The patient underwent intensity-modulated radiation therapy (IMRT and Gamma Knife radiosurgery. Follow-up MRI showed multiple leptomeningeal disseminations to the intracranium and spine. Conclusion It is important to recognize that leptomeningeal intracranial and spinal disseminations of pleomorphic adenocarcinoma can occur, although it is extremely rare. To our knowledge, we report the first case of pleomorphic adenocarcinoma of the lacrimal gland presumably metastasizing to the intracranium and spine.

  8. Regulating temporospatial dynamics of morphogen for structure formation of the lacrimal gland by chitosan biomaterials.

    Science.gov (United States)

    Hsiao, Ya-Chuan; Yang, Tsung-Lin

    2017-01-01

    The lacrimal gland is an important organ responsible for regulating tear synthesis and secretion. The major work of lacrimal gland (LG) is to lubricate the ocular surface and maintain the health of eyes. Functional deterioration of the lacrimal gland happens because of aging, diseases, or therapeutic complications, but without effective treatments till now. The LG originates from the epithelium of ocular surface and develops by branching morphogenesis. To regenerate functional LGs, it is required to explore the way of recapitulating and facilitating the organ to establish the intricate and ramified structure. In this study, we proposed an approach using chitosan biomaterials to create a biomimetic environment beneficial to the branching structure formation of developing LG. The morphogenetic effect of chitosan was specific and optimized to promote LG branching. With chitosan, increase in temporal expression and local concentration of endogenous HGF-related molecules creates an environment around the emerging tip of LG epithelia. By efficiently enhancing downstream signaling of HGF pathways, the cellular activities and behaviors were activated to contribute to LG branching morphogenesis. The morphogenetic effect of chitosan was abolished by either ligand or receptor deprivation, or inhibition of downstream signaling transduction. Our results elucidated the underlying mechanism accounting for chitosan morphogenetic effects on LG, and also proposed promising approaches with chitosan to assist tissue structure formation of the LG. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Long-term impairment of the lacrimal glands after radioiodine therapy: a cross-sectional study

    International Nuclear Information System (INIS)

    Zettinig, Georg; Fueger, Barbara J.; Pirich, Christian; Dudczak, Robert; Hanselmayer, Georg; Nepp, Johannes; Hofmann, Andrea

    2002-01-01

    Impairment of the lacrimal glands after external radiation has been well documented, but there are only a few reports on the effects of radioiodine therapy on the lacrimal glands. Long-term effects of high-dose radioiodine therapy on tear secretion have not previously been studied. We investigated 175 eyes of 88 patients with a history of radioiodine therapy for thyroid carcinoma (68 females, 20 males; mean age 55±16 years, range 17-81 years) and compared them with a sex- and age-matched control group (n=39). All patients had been given at least 2.96 GBq iodine-131 (maximal administered activity 22.3 GBq 131 I). An ophthalmological investigation was performed 64±71 months (range 3-317 months) after initial radioiodine therapy by a single ophthalmologist. Lacrimal gland function was evaluated with three different function tests. External eye morphology was considered, and detailed ophthalmological history-taking was performed. Patients with factors known to affect lacrimal gland function (contact lenses, autoimmune disorders, history of additional radiation exposure) were excluded from the study. A total of 81 patients (92%) had at least one abnormal function test indicating impaired lacrimal gland function. Schirmer's tear test was decreased (<10 mm/5 min) in 47 of the 88 patients and definitely abnormal (<5 mm/5 min) in 35 patients. A tear film break-up time of <10 s was found in 78 patients, and 62 patients had a definitely abnormal break-up time of <5 s. The lacrimal lipid layer was impaired in 43 patients. The function tests were all significantly altered in the study group as compared with the controls (P<0.005, P<0.001, P<0.001, respectively). Both subjective symptoms of dry eye (P<0.01) and changes in the external eye morphology (P<0.001) were significantly more prevalent in the study group. Our findings suggest that in the majority of patients, lacrimal gland function may be permanently impaired after high-dose radioiodine therapy. All three layers of the

  10. Lacrimal Gland Pleomorphic Adenoma and Carcinoma ex Pleomorphic Adenoma

    DEFF Research Database (Denmark)

    von Holstein, Sarah L; Fehr, André; Persson, Marta

    2014-01-01

    To study genetic alterations in lacrimal gland pleomorphic adenoma (PA) and carcinoma ex pleomorphic adenoma (Ca-ex-PA) with focus on copy number changes and expression patterns of the translocation target genes PLAG1, HMGA2, and CRTC1-MAML2 in relation to clinical data....

  11. Effect of radioactive iodine therapy on lacrimal gland functions in patients with hyperthyroidism.

    Science.gov (United States)

    Aydogan, Fusun; Ayhan Tuzcu, Esra; Aydogan, Akin; Akkucuk, Seckin; Coskun, Mesut; Ustun, Ihsan; Gökçe, Cumali

    2014-04-01

    Radioactive iodine (RAI) therapy is preferred in the treatment of hyperthyroidism because of its effectiveness, noninvasiveness, and low costs. I has been detected in extrathyroidal tissues, such as in gastric mucosa, salivary glands, and lacrimal glands. To the best of our knowledge, there is no publication concerning the effects of RAI therapy for hyperthyroidism on tear production. In the present study, we evaluated whether or not the lacrimal glands are affected after RAI therapy when compared with pretreatment period. The Schirmer and tear break-up time (TBUT) tests were used to assess 32 eyes of 16 patients with conditions that were diagnosed as hyperthyroidism before and at 3 and 6 months after RAI treatment. In addition, pretreatment values of patients were compared with that of controls. It was evaluated whether or not a correlation exists between the results and the dose or iodine uptake values. There was no significant difference between pretreatment values of Schirmer and TBUT tests obtained in the patient group and those of the control group (P > 0.05). In the patient group, there was a significant difference between the posttreatment and pretreatment values (P < 0.05). There was a positive correlation between uptake values obtained at 24 hours and the values obtained by TBUT and Schirmer tests on both eyes at 3 and 6 months. At 6 months, the uptake value at 24 hours was 28.83 ± 60 for both eyes in patients with TBUT test values less than 10, whereas it was 39.25 ± 7.88 for the right eye and 39.00 ± 6.85 for the left eyes in patients with TBUT test values greater than 10. The difference was statistically significant (P < 0.05). In our study, we concluded that the decrease in mucin and aqueous production occurs due to affected lacrimal glands by RAI therapy; however, this effect is not dose dependent.

  12. The effect of short-term vitamin E against radioiodine-induced early lacrimal gland damage

    International Nuclear Information System (INIS)

    Acar, Ugur; Atilgan, Hasan Ikbal; Acar, Damla Erginturk; Yalniz-Akkaya, Zuleyha; Korkmaz, Meliha; Koca, Goekhan; Yumusak, Nihat

    2013-01-01

    Radioiodine (RAI) is a well-known radionuclide which is used in vivo both for diagnostic and therapeutic purposes, particularly for the treatment of hyperthyroidism and thyroid cancer. Vitamin E is a well-known antioxidant vitamin. The aim of this study was to evaluate whether there was a protective effect of short-term vitamin E on RAI-induced lacrimal gland early damage in experimental animal models. Twentyfour rats were randomly divided into two groups. The first group (RAI group) was administreted 3 mCi 131 I by gastric gavage and 1 mL physiological saline intraperitoneally. The second group (RAI+Vitamin E) was administrated 3 mCi 131 I by gastric gavage and 1 mL vitamin E intraperitoneally. After 24 h of the last dose being administered on the 7th day, the animals were decapitated. The lacrimal glands [Intraorbital (IG), extraorbital (EG) and harderian glands (HG)] of the rats were removed for histopathological examination. Periductal and/or periacinar fibrosis in all lacrimal glands were observed to be statistically significantly less frequent in the RAI + Vitamin E group compared to the RAI group. The existence of the abnormal lobular pattern and peripheral basophilia and irregular nucleus shape in IG and in EG, the poorly defined acidophilic cell outline and periductal infiltration in IG and in HG were observed to be statistically significantly less frequent in the RAI + Vitamin E group than in the RAI group. According to study results, histopathological examinations revealed that vitamin E protects rat lacrimal glands against RAI-related early damage. (author)

  13. Cytochrome P450 3A expression and activity in the rabbit lacrimal gland: glucocorticoid modulation and the impact on androgen metabolism.

    Science.gov (United States)

    Attar, Mayssa; Ling, Kah-Hiing John; Tang-Liu, Diane D-S; Neamati, Nouri; Lee, Vincent H L

    2005-12-01

    Cytochrome P450 3A (CYP3A) is an enzyme of paramount importance to drug metabolism. The expression and activity of CYP3A, an enzyme responsible for active androgen clearance, was investigated in the rabbit lacrimal gland. Analysis of CYP3A expression and activity was performed on lacrimal gland tissues obtained from naïve untreated and treated New Zealand White rabbits. For 5 days, treated rabbits received daily administration of vehicle or 0.1% or 1.0% dexamethasone, in the lower cul-de-sac of each eye. Changes in mRNA expression were monitored by real-time RT-PCR. Protein expression was confirmed by Western blot. Functional activity was measured by monitoring the metabolism of CYP3A probe substrates-namely, 7-benzyloxyquinoline (BQ) and [3H]testosterone. Cytochrome P450 heme protein was detected at a concentration of 44.6 picomoles/mg protein, along with its redox partner NADPH reductase and specifically CYP3A6 in the naïve rabbit lacrimal gland. Genes encoding CYP3A6, in addition to the pregnane-X-receptor (PXR) and P-glycoprotein (P-gp) were expressed in the untreated tissue. BQ dealkylation was measured in the naïve rabbit lacrimal gland at a rate of 14 +/- 7 picomoles/mg protein per minute. Changes in CYP3A6, P-gp, and androgen receptor mRNA expression levels were detected after dexamethasone treatment. In addition, dexamethasone treatment resulted in significant increases in BQ dealkylation and CYP3A6-mediated [3H]testosterone metabolism. Concomitant increases in CYP3A6-mediated hydroxylated testosterone metabolites were observed in the treated rabbits. Furthermore, ketoconazole, all-trans retinoic acid, and cyclosporine inhibited CYP3A6 mediated [3H]testosterone 6beta hydroxylation in a concentration-dependent manner, with IC50 ranging from 3.73 to 435 microM. The results demonstrate, for the first time, the expression and activity of CYP3A6 in the rabbit lacrimal gland. In addition, this pathway was shown to be subject to modulation by a commonly

  14. Clinical Research on Benign Lymphoepithelial Lesions of Lacrimal Gland in 20 Chinese Patients

    Directory of Open Access Journals (Sweden)

    Jian-Min Ma

    2015-01-01

    Full Text Available Background: Benign lymphoepithelial lesion (BLEL is characterized by symmetric bilateral swelling of the lacrimal and salivary glands and considered a subtype of immunoglobulin G4 (IgG4-related sclerosing disease, the etiology and pathogenesis of which has not been determined. The purpose of the present study was to analyze the clinical features of BLEL in the lacrimal gland and the relationship between the serum level of IgG4 and BLEL. Methods: Twenty consecutive patients with BLEL diagnosed in Department of Ophthalmology at Beijing Tongren Hospital, Capital Medical University between January 2012 and December 2013 were observed. The clinical features, imaging findings, laboratory tests, treatments and follow-up status of these 20 consecutive patients were analyzed. Results: In all 20 patients, the ratio of male to female was 1:4, the ages ranged from 28 to 57 years, the ratio of unilateral to bilateral eyes involvement was 1:4, and painless uncongested symmetrical swelling of the upper eyelid was the main clinical manifestation. Orbital magnetic resonance imaging (MRI showed that all patients involved lacrimal gland, which were obviously enlarged with equal signals in T1W images and T2W images and obvious enhancement on contrast MRI. Extraocular muscles were involved in 5 patients, salivary gland in 8 patients, and frontal nerve in 3 patients. Serum IgG4 concentration was elevated in 18 patients. The treatment strategy mainly included surgery and steroid administration. Three patients were lost to follow-up, 17 patients reached complete response, and no recurrence was observed. Conclusions: Eyelid swelling is the typical symptom of BLEL. Most of the patients involved bilateral lacrimal glands. High serum IgG4 level and abundant IgG4-positive plasma cell infiltration are the important features, which can be found in most of BLEL patients. Surgery combined with glucocorticoids is an efficient treatment strategy.

  15. Derangements of lacrimal drainage-associated lymphoid tissue (LDALT) in human chronic dacryocystitis.

    Science.gov (United States)

    Ali, Mohammad Javed; Mulay, Kaustubh; Pujari, Aditi; Naik, Milind N

    2013-12-01

    To study the changes in the lacrimal drainage-associated lymphoid tissue of the lacrimal sac in human chronic dacryocystitis and its possible implications in understanding the immune defense mechanisms and etiopathogenesis of primary acquired nasolacrimal duct obstruction. Retrospective interventional study involving 200 lacrimal sacs of 164 consecutive patients seen between July 2009 and July 2012. Data collected include demographics, clinical presentation, laterality, age at presentation, duration of symptoms, diagnostic irrigation, indications for a dacyrocystectomy, pattern and severity of lymphoid infiltrate, types of lymphoid follicles and their locations, plasma cells, and other cellular infiltrates. The associated epithelial, stromal, and luminal changes with an emphasis on acini, mucosal glands, blood vessels, lymphatics, and goblet cells were also noted. Immunohistochemistry using CD3, CD20, CD138, and immunoglobulin A were used to substantiate the lymphoid tissues of the lacrimal sac. A total of 200 lacrimal sacs were obtained from dacryocystectomy of 164 patients. The patients included 60.5% (99/164) females and 39.6% (65/164) males, with a mean age of 58.4 years at presentation. Laterality showed a predominance of left lacrimal sacs (55%, 110/200) as compared to the right lacrimal sacs (45%, 90/200). Symptoms of epiphora and discharge of more than 6 months duration were considered to be chronic. Lymphoid infiltrate pattern was diffuse in majority of the sacs (81%, 162/200), with subepithelial and intraepithelial together being the commonest location (46.5%, 93/200). Distinct lymphoid follicles were seen in 28% (56/200). Most of the sacs showed mild plasma cell infiltration (66.5%, 133/200). IgA-rich secretions were noted in the lumen and the lining epithelium in 34.5% (69/200). Other common changes noted include increase in the goblet cells (82%, 164/200), dilated lymphatics (94%, 188/200), proliferating blood vessels (99%, 198/200), thickened

  16. An alpha-adrenergic receptor mechanism controlling potassium permeability in the rat lacrimal gland acinar cell

    International Nuclear Information System (INIS)

    Parod, R.J.; Putney, J.W. Jr.

    1978-01-01

    Rat lacrimal gland slices, incubated in a balanced, buffered salt solution, were found to be physiologically stable for up to 2 hr with respect to 0 2 consumption, extracellular space, and water and ion content. The release of 86 Rb serves as a good substitute for 42 K in monitoring the movement of K through the cell membrane. Adrenaline appears to increase membrane permeability to K as evidenced by an increase in the rate of 86 Rb efflux. This response to adrenaline was blocked by phentolamine but not by propranolol and was mimicked by phenylephrine but not by isoprenaline. The magnitude of the 86 Rb release indicates that it is being released, at least in part, from the lacrimal gland acinar cell. It is concluded that the lacrimal gland acinar cell has an α-adrenergic receptor, activation of which leads to an increase in membrane permeability to K. (author)

  17. Primary lymphocytic lymphoma of lacrimal gland.

    Science.gov (United States)

    Romero-Caballero, M D; Lozano-García, I; Gómez-Molina, C; Gil-Liñán, A I; Arcas, I

    2017-02-01

    We report a case of primary small-cell lymphocytic lacrimal gland lymphoma in a male diagnosed with primary antiphospholipid syndrome. These rare lymphomas are usually presented in the clinic as disseminations secondary to chronic lymphocytic leukaemia, and the primary site is rare in the orbit. Non-Hodgkin lymphomas are a heterogeneous group of tumours. Although treatment in the IE stage is usually radiotherapy, due to its association with antiphospholipid syndrome, systemic treatment with rituximab was administered. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Myoepithelial Cells: Their Origin and Function in Lacrimal Gland Morphogenesis, Homeostasis, and Repair.

    Science.gov (United States)

    Makarenkova, Helen P; Dartt, Darlene A

    2015-09-01

    Lacrimal gland (LG) is an exocrine tubuloacinar gland that secretes the aqueous layer of the tear film. LG epithelium is composed of ductal, acinar, and myoepithelial cells (MECs) bordering the basal lamina and separating the epithelial layer from the extracellular matrix. Mature MECs have contractile ability and morphologically resemble smooth muscle cells; however, they exhibit features typical for epithelial cells, such as the presence of specific cytokeratin filaments. Increasing evidence supports the assertion that myoepithelial cells (MECs) play key roles in the lacrimal gland development, homeostasis, and stabilizing the normal structure and polarity of LG secretory acini. MECs take part in the formation of extracellular matrix gland and participate in signal exchange between epithelium and stroma. MECs have a high level of plasticity and are able to differentiate into several cell lineages. Here, we provide a review on some of the MEC characteristics and their role in LG morphogenesis, maintenance, and repair.

  19. CRTC1-MAML2 gene fusion in mucoepidermoid carcinoma of the lacrimal gland

    DEFF Research Database (Denmark)

    von Holstein, Sarah Linea; Fehr, André; Heegaard, Steffen

    2012-01-01

    -grade MEC of the lacrimal gland. There were no signs of recurrence or metastases during a five-year follow-up. Using RT-PCR and FISH we demonstrated that the tumor was positive for the CRTC1-MAML2 gene fusion previously shown to be associated with in particular low-grade salivary MECs with favorable...... prognosis. By immunohistochemistry we showed that the majority of tumor cells, including epidermoid, intermediate and mucous producing cells, expressed the CRTC1-MAML2 fusion protein. In contrast, 15 non-MEC lacrimal neoplasm were fusion-negative. Our findings show that lacrimal MEC is not only clinically...... anatomical sites and organs. Moreover, our findings indicate that the CRTC1-MAML2 fusion may be a useful diagnostic and prognostic biomarker for lacrimal MEC....

  20. Lacrimal gland-derived IL-22 regulates IL-17-mediated ocular mucosal inflammation

    Science.gov (United States)

    Ji, Yong Woo; Mittal, Sharad K.; Hwang, Ho Sik; Chang, Eun-Ju; Lee, Joon H.; Seo, Yuri; Yeo, Areum; Noh, Hyemi; Lee, Hye Sun; Chauhan, Sunil K.; Lee, Hyung Keun

    2016-01-01

    Inflammatory damage of mucosal surface of the eye is a hallmark of dry eye disease (DED), and in severe cases can lead to significant discomfort, visual impairment, and blindness. DED is a multifactorial autoimmune disorder with a largely unknown pathogenesis. Using a cross-sectional patient study and a well-characterized murine model of DED, herein we investigated the immunoregulatory function of interleukin-22 (IL-22) in the pathogenesis of DED. We found that IL-22 levels were elevated in lacrimal fluids of DED patients and inversely correlated with severity of disease. Acinar cells of the lacrimal glands, not inflammatory immune cells, are the primary source of IL-22, which suppresses inflammation in ocular surface epithelial cells upon desiccating stress. Moreover, loss of function analyses using IL-22 knock-out mice demonstrated that IL-22 is essential for suppression of ocular surface infiltration of Th17 cells and inhibition of DED induction. Our novel findings elucidate immunoregulatory function of lacrimal gland-derived IL-22 in inhibiting IL-17-mediated ocular surface epitheliopathy in DED thus making IL-22 a new relevant therapeutic target. PMID:28051088

  1. Recurrent rearrangements of the PLAG1 and HMGA2 genes in lacrimal gland pleomorphic adenoma and carcinoma ex pleomorphic adenoma

    DEFF Research Database (Denmark)

    Andreasen, Simon; von Holstein, Sarah L; Homøe, Preben

    2018-01-01

    PURPOSE: Lacrimal gland tumours constitute a wide spectrum of neoplastic lesions that are histologically similar to tumours of the salivary gland. In the salivary gland, pleomorphic adenoma (PA) is frequently characterized by recurrent chromosomal rearrangements of the PLAG1 and HMGA2 genes......, a genetic feature retained in carcinoma ex pleomorphic adenoma (ca-ex-PA) that makes it possible to distinguish ca-ex-PA from de novo carcinomas. However, whether PLAG1 and HMGA2 gene rearrangements are found in lacrimal gland PA and ca-ex-PA is not known. METHODS: Twenty-one lacrimal gland PAs and four ca......-ex-PAs were retrospectively reviewed and subjected to break-apart fluorescence in situ hybridization (FISH) for rearrangements of the PLAG1 gene. Cases without PLAG1 abnormalities were subjected to HMGA2 break-apart FISH. Immunohistochemical staining for PLAG1 and HMGA2 protein was performed and correlated...

  2. Carbon-ion radiotherapy for locally advanced primary or postoperative recurrent epithelial carcinoma of the lacrimal gland

    International Nuclear Information System (INIS)

    Mizoguchi, Nobutaka; Tsuji, Hiroshi; Toyama, Shingo; Kamada, Tadashi; Tsujii, Hirohiko; Nakayama, Yuko; Mizota, Atsushi; Ohnishi, Yoshitaka

    2015-01-01

    Purpose: To evaluate the applicability of carbon ion beams for the treatment of carcinoma of the lacrimal gland with regard to normal tissue morbidity and local tumor control. Methods and materials: Between April 2002 and January 2011, 21 patients with locally advanced primary epithelial carcinoma of the lacrimal gland were enrolled in a Phase I/II clinical trial of carbon-ion radiotherapy (CIRT) at the National Institute of Radiological Sciences. Acute radiation toxicity was the primary endpoint of this dose-escalation study and the late toxicity, local control, and overall survival were additionally evaluated as secondary endpoints. Of the 21 subjects enrolled, all patients were followed for more than 6 months and analyzed. Results: The radiation dose was increased from the initial dose of 48.0 Gy equivalents (GyE)/12 fractions at 10% increments up to 52.8 GyE. Of the 21 patients, five received a total dose of 48.0 GyE, and 16 received a total dose of 52.8 GyE. No patient developed grade 3 or higher skin toxicity. As late ocular/visual toxicity, three patients had grade 3 retinopathy and seven patients lost their vision. Among the 10 patients treated until May 2005, five patients had local recurrence, three of whom had marginal recurrence. Therefore, the margin for the CTV (clinical target volume) was set to a range according to the orbital exenteration since June 2005. After the application of the extended margin, no local recurrence has been observed. The three-year overall survival and local control rates were 82.2% and 79.0%, respectively. Conclusion: CIRT can be applied for primary epithelial carcinoma of the lacrimal gland, with a borderline acceptable morbidity and sufficient antitumor effect when an extended margin is adopted

  3. Effect of P2X(7) receptor knockout on exocrine secretion of pancreas, salivary glands and lacrimal glands

    DEFF Research Database (Denmark)

    Novak, Ivana; Jans, Ida M; Wohlfahrt, Louise

    2010-01-01

    the P2X(7) receptors affect fluid secretion in pancreas, salivary glands and tear glands. We monitored gland secretions in in vivo preparations of wild-type and P2X(7)(-/-) (Pfizer) mice stimulated with pilocarpine. In cell preparations from pancreas, parotid and lacrimal glands we measured ATP release...... and intracellular Ca(2+) activity using Fura-2. The data showed that pancreatic secretion and salivary secretions were reduced in P2X(7)(-/-) mice, and in contrast, tear secretion was increased in P2X(7)(-/-) mice. The secretory phenotype was also dependent on the sex of the animal, such that males were more...

  4. Comparison of telomere length and association with progenitor cell markers in lacrimal gland between Sjögren syndrome and non-Sjögren syndrome dry eye patients.

    Science.gov (United States)

    Kawashima, Motoko; Kawakita, Tetsuya; Maida, Yoshiko; Kamoi, Mizuka; Ogawa, Yoko; Shimmura, Shigeto; Masutomi, Kenkichi; Tsubota, Kazuo

    2011-01-01

    Indicators of aging such as disruption of telomeric function due to shortening may be more frequent in dysfunctional lacrimal gland. The aims of this study were to 1) determine the viability of quantitative fluorescence in situ hybridization of telomeres (telo-FISH) for the assessment of telomere length in lacrimal gland in Sjögren and non- Sjögren syndrome patients; and 2) investigate the relationship between progenitor cell markers and telomere length in both groups. Quantitative fluorescence in situ hybridization with a peptide nucleic acid probe complementary to the telomere repeat sequence was performed on frozen sections from human lacrimal gland tissues. The mean fluorescence intensity of telomere spots was automatically quantified by image analysis as relative telomere length in lacrimal gland epithelial cells. Immunostaining for p63, nucleostemin, ATP-binding cassette, sub-family G, member 2 (ABCG2), and nestin was also performed. Telomere intensity in the Sjögren syndrome group (6,785.0±455) was significantly lower than that in the non-Sjögren syndrome group (7,494.7±477; p=0.02). Among the samples from the non-Sjögren syndrome group, immunostaining revealed that p63 was expressed in 1-3 acinar cells in each acinar unit and continuously in the basal layer of duct cells. In contrast, in the Sjögren syndrome group, p63 and nucleostemin showed a lower level of expression. ABCG2 was expressed in acinar cells in both sjogren and non-Sjogren syndrome. The results of this study indicate that 1) telo-FISH is a viable method of assessing telomere length in lacrimal gland, and 2) telomere length in Sjögren syndrome is shorter and associated with lower levels of expression of p63 and nucleostemin than in non-Sjögren syndrome.

  5. [Structuro-functional units of the salivary and lacrimal glands].

    Science.gov (United States)

    Kostilenko, Iu P; Mysliuk, I V; Deviatkin, E A

    1986-09-01

    By means of the multilayer graphic and plastic reconstruction methods using series of semithin sections, spatial tridimensional organization of the epithelial complexes and blood microcirculatory bed in the rat palatal salivary glands and the lacrimal gland of the human newborn have been studied. Since their ducts serve not only for discharging their secrete into the external medium, but also for accumulation (as collectors), the sublobular unit--adenomere should be referred to as a part of elementary level of organization of the epithelial complexes. The adenomere has in its composition a collecting centrally situating duct. However, while studying structure of the blood microcirculatory bed, it is found out that there is not any strict territorial correspondence between its functional units and structural units of the glandular epithelium. Nevertheless, giving a great importance to a tight syntopic connection of the collecting ducts of the adenomeres with the postcapillary venules (that belong to filtrating microvessels), these are sublobular units--adenomeres that are distinguished as structural-functional units in the glands.

  6. Adenoid cystic carcinomas of the salivary gland, lacrimal gland, and breast are morphologically and genetically similar but have distinct microRNA expression profiles

    DEFF Research Database (Denmark)

    Andreasen, Simon; Tan, Qihua; Agander, Tina Klitmøller

    2018-01-01

    Adenoid cystic carcinoma is among the most frequent malignancies in the salivary and lacrimal glands and has a grave prognosis characterized by frequent local recurrences, distant metastases, and tumor-related mortality. Conversely, adenoid cystic carcinoma of the breast is a rare type of triple......-negative (estrogen and progesterone receptor, HER2) and basal-like carcinoma, which in contrast to other triple-negative and basal-like breast carcinomas has a very favorable prognosis. Irrespective of site, adenoid cystic carcinoma is characterized by gene fusions involving MYB, MYBL1, and NFIB, and the reason...... for the different clinical outcomes is unknown. In order to identify the molecular mechanisms underlying the discrepancy in clinical outcome, we characterized the phenotypic profiles, pattern of gene rearrangements, and global microRNA expression profiles of 64 salivary gland, 9 lacrimal gland, and 11 breast...

  7. Cl--HCO-3 antiport in rat lacrimal gland

    International Nuclear Information System (INIS)

    Lambert, R.W.; Bradley, M.E.; Mircheff, A.K.

    1988-01-01

    With the use of analytical subcellular fractionation and tracer uptake methods the authors have demonstrated the presence of a Cl - -HCO - 3 antiport mechanism in the rat exorbital lacrimal gland. They find that outwardly directed gradients of HCO - 3 and of 35 Cl - accelerated the flux of 36 Cl - into isolated membrane vesicles. Because vesicle membrane potentials were clamped to 0 mV with K + -valinomycin, the observed anion gradient-dependent acceleration of Cl - influx could not be attributed to conductive fluxes. The antiporter had an apparent K 0.5 for Cl - between 6 and 10 mM. It was sensitive to the stilbene derivatives 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS) and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). It was also sensitive to the loop diuretic furosemide, which has frequently been used in tests for NaKCl 2 symporter activity. Other anions inhibited anion gradient-driven Cl - influx in the sequence SCN - > NO - 3 > Cl - HCO - 3 > SO 2- 4 . The density distribution of Cl - -HCO - 3 antiport activity indicated that ∼80% of the transporter was associated with intracellular membranes, suggesting the presence of cytoplasmic pools of functional antiporters. Because several studies have already shown the presence of Na + -H + antiporter activity in lacrimal acinar cell basolateral membranes, a cellular model for lacrimal acinar electrolyte secretion is proposed in which a parallel array of Cl - -HCO - 3 and Na + -H + antiporters mediates the Na + -dependent accumulation of Cl - against its electrochemical potential gradient

  8. Comparison of telomere length and association with progenitor cell markers in lacrimal gland between Sjögren syndrome and non-Sjögren syndrome dry eye patients

    Science.gov (United States)

    Kawashima, Motoko; Maida, Yoshiko; Kamoi, Mizuka; Ogawa, Yoko; Shimmura, Shigeto; Masutomi, Kenkichi; Tsubota, Kazuo

    2011-01-01

    Purpose Indicators of aging such as disruption of telomeric function due to shortening may be more frequent in dysfunctional lacrimal gland. The aims of this study were to 1) determine the viability of quantitative fluorescence in situ hybridization of telomeres (telo-FISH) for the assessment of telomere length in lacrimal gland in Sjögren and non- Sjögren syndrome patients; and 2) investigate the relationship between progenitor cell markers and telomere length in both groups. Methods Quantitative fluorescence in situ hybridization with a peptide nucleic acid probe complementary to the telomere repeat sequence was performed on frozen sections from human lacrimal gland tissues. The mean fluorescence intensity of telomere spots was automatically quantified by image analysis as relative telomere length in lacrimal gland epithelial cells. Immunostaining for p63, nucleostemin, ATP-binding cassette, sub-family G, member 2 (ABCG2), and nestin was also performed. Results Telomere intensity in the Sjögren syndrome group (6,785.0±455) was significantly lower than that in the non-Sjögren syndrome group (7,494.7±477; p=0.02). Among the samples from the non-Sjögren syndrome group, immunostaining revealed that p63 was expressed in 1–3 acinar cells in each acinar unit and continuously in the basal layer of duct cells. In contrast, in the Sjögren syndrome group, p63 and nucleostemin showed a lower level of expression. ABCG2 was expressed in acinar cells in both sjogren and non-Sjogren syndrome. Conclusions The results of this study indicate that 1) telo-FISH is a viable method of assessing telomere length in lacrimal gland, and 2) telomere length in Sjögren syndrome is shorter and associated with lower levels of expression of p63 and nucleostemin than in non-Sjögren syndrome. PMID:21655359

  9. Effects of extract of Buddleja officinalis on partial inflammation of lacrimal gland in castrated rabbits with dry eye.

    Science.gov (United States)

    Yao, Xiao-Lei; Peng, Qing-Hua; Peng, Jun; Tan, Han-Yu; Wu, Quan-Long; Wu, Da-Li; Chen, Mei; Li, Chuan-Ke; Li, Dian; Zhu, Hui-An

    2010-01-01

    To assess the effects of extract of Buddleja officinalis on tear secretion volume, tear film stability, expressions of TGF-β1, IL-1β, TNF-α in lacrimal gland of castrated rabbits with dry eye. A total of 30 victory rabbits were divided averagely into normal group(A), model group(B), therapy group with low dose extract of Buddleja officinalis (C), therapy group with high dose extract of Buddleja officinalis (D) and therapy group with genistein (E). The dry eye model was established with orchiectomy on Group B, C, D, E. Group C, D, E were administered intragastrically with corresponding dose extract of Buddleja officinalis or genistein for 30 days. All rabbits were detected with SIT. TGF-β1, IL-1β, TNF-α were detected with immunohistochemistry and the ultrastructure of lacrimal gland was observed under transmission electron microscope. The SIT value of group C, D, E were respectively 13.167±4.957, 14.667±5.279, 8.667±0.516, obviously higher than that of group B 5.667±2.338 (PBuddleja officinalis can adjust lacrimal gland partial inflammation of dry eye.

  10. A new dry eye mouse model produced by exorbital and intraorbital lacrimal gland excision.

    Science.gov (United States)

    Shinomiya, Katsuhiko; Ueta, Mayumi; Kinoshita, Shigeru

    2018-01-24

    Chronic dry eye is an increasingly prevalent condition worldwide, with resulting loss of visual function and quality of life. Relevant, repeatable, and stable animal models of dry eye are still needed. We have developed an improved surgical mouse model for dry eye based on severe aqueous fluid deficiency, by excising both the exorbital and intraorbital lacrimal glands (ELG and ILG, respectively) of mice. After ELG plus ILG excision, dry eye symptoms were evaluated using fluorescein infiltration observation, tear production measurement, and histological evaluation of ocular surface. Tear production in the model mice was significantly decreased compared with the controls. The corneal fluorescein infiltration score of the model mice was also significantly increased compared with the controls. Histological examination revealed significant severe inflammatory changes in the cornea, conjunctiva or meibomian glands of the model mice after surgery. In the observation of LysM-eGFP (+/-) mice tissues, postsurgical infiltration of green fluorescent neutrophils was observed in the ocular surface tissues. We theorize that the inflammatory changes on the ocular surface of this model were induced secondarily by persistent severe tear reduction. The mouse model will be useful for investigations of both pathophysiology as well as new therapies for tear-volume-reduction type dry eye.

  11. The role of calcium in the receptor mediated control of potassium permeability in the rat lacrimal gland

    International Nuclear Information System (INIS)

    Parod, R.J.; Putney, J.W. Jr.

    1978-01-01

    In the presence of extracellular Ca, adrenaline stimulated by a large increase in the rate of K ( 86 Rb) release from rat lacrimal slices, followed by a lower, more sustained rate. In the absence of extracellular Ca, adrenaline elicited only a transient release of 86 Rb. The artificial introduction of Ca into the cytosol by the ionophore A-23187 could also initiate the release of 86 Rb. In a zero-Ca medium, if either adrenaline or carbachol produced a transient release of 86 Rb, the tissue could not respond to the other agonist with a transient release unless Ca was momentarily reintroduced to the medium. If Ca was present in a limiting concentration, the Ca-dependent rate of 86 Rb release elicited from a lacrimal slice exposed simultaneously to carbachol and adrenaline was not significantly different from the release seen with carbachol alone. It is concluded that the agonist-induced release of K from the lacrimal gland consists of both a Ca-independent phase which is initiated by the release of a limited pool of Ca, and a Ca-dependent phase which is mediated by the influx of extracellular Ca. It is also concluded that both α-adrenergic and muscarinic receptors occupation activate a common, post-receptor mechanism which may be responsible for both phases of K release. (author)

  12. Radioiodine therapy effect on lacrimal gland function in patients with thyroid cancer

    International Nuclear Information System (INIS)

    Fard-Esfahani, A.; Mirshekarpour, H.; Fallahi, B.; Eftekhari, M.; Takavar, A.; Beiki, D.; Ansari-Gilani, K.; Saghari, M.

    2007-01-01

    Full text: Objectives: There is a limited number of case reports published in the past decade confirming the radioiodine presence in the tear. These observations as well as reported cases of salivary and lacrimal gland dysfunction after radioiodine therapy stimulated investigators to clarify whether lacrimal gland function can be affected postradioiodine therapy. Hence we planned a historical cohort study. Methods: We studied 100 eyes of 50 patients who had received high doses (accumulative dose: 100-450mCi) of I-131 (exposed group) for treatment of differentiated thyroid carcinoma with their latest admission at least 3 months ago. Dry eye symptoms (obtained via a standard questionnaire) and Schirmer I test results (mm/5 min) of this exposed group were compared with those of an unexposed group (100 eyes of 50 individuals) matched by sex and age. Cases with any other known cause(s) of dry eye were not included in either group. Results: The study demonstrated a significantly lower wetting amount of the Schirmer paper in exposed group compared to unexposed one. In the group of patients who have undergone radio-iodine therapy, results were 0-4 mm in 21%, 5-9 mm in 20% and 10 mm or more in 59%. These results were seen in the unexposed group in 6%, 17% and 77% respectively. In evaluating the symptoms, 51% of the exposed eyes and 50% of the unexposed ones revealed at least one of the mentioned dry eye symptoms in the questionnaire. Data analysis showed no significant difference between the number of symptoms of the two groups, but 2 symptoms (burning, unrelated to light and erythema) were significantly higher in the exposed eyes. From 9 exposed eyes complaining of erythema, Schirmer test result was abnormal only in 2 (one patient). Also among the 10 eyes with burning symptom (unrelated to light) one patient (2 eyes) revealed abnormal Schirmer test result. Conclusion: Long-term reduction in the tear secretion from major and/or minor lacrimal glands is seen after high

  13. Aire-deficient mice provide a model of corneal and lacrimal gland neuropathy in Sjögren's syndrome.

    Directory of Open Access Journals (Sweden)

    Feeling Y Chen

    Full Text Available Sjögren's syndrome (SS is a chronic, autoimmune exocrinopathy that leads to severe dryness of the mouth and eyes. Exocrine function is highly regulated by neuronal mechanisms but little is known about the link between chronic inflammation, innervation and altered exocrine function in the diseased eyes and exocrine glands of SS patients. To gain a better understanding of neuronal regulation in the immunopathogenesis of autoimmune exocrinopathy, we profiled a mouse model of spontaneous, autoimmune exocrinopathy that possess key characteristics of peripheral neuropathy experienced by SS patients. Mice deficient in the autoimmune regulator (Aire gene developed spontaneous, CD4+ T cell-mediated exocrinopathy and aqueous-deficient dry eye that were associated with loss of nerves innervating the cornea and lacrimal gland. Changes in innervation and tear secretion were accompanied by increased proliferation of corneal epithelial basal cells, limbal expansion of KRT19-positive progenitor cells, increased vascularization of the peripheral cornea and reduced nerve function in the lacrimal gland. In addition, we found extensive loss of MIST1+ secretory acinar cells in the Aire -/- lacrimal gland suggesting that acinar cells are a primary target of the disease, Finally, topical application of ophthalmic steroid effectively restored corneal innervation in Aire -/- mice thereby functionally linking nerve loss with local inflammation in the aqueous-deficient dry eye. These data provide important insight regarding the relationship between chronic inflammation and neuropathic changes in autoimmune-mediated dry eye. Peripheral neuropathies characteristic of SS appear to be tightly linked with the underlying immunopathological mechanism and Aire -/- mice provide an excellent tool to explore the interplay between SS-associated immunopathology and peripheral neuropathy.

  14. Aire-deficient mice provide a model of corneal and lacrimal gland neuropathy in Sjögren's syndrome.

    Science.gov (United States)

    Chen, Feeling Y; Lee, Albert; Ge, Shaokui; Nathan, Sara; Knox, Sarah M; McNamara, Nancy A

    2017-01-01

    Sjögren's syndrome (SS) is a chronic, autoimmune exocrinopathy that leads to severe dryness of the mouth and eyes. Exocrine function is highly regulated by neuronal mechanisms but little is known about the link between chronic inflammation, innervation and altered exocrine function in the diseased eyes and exocrine glands of SS patients. To gain a better understanding of neuronal regulation in the immunopathogenesis of autoimmune exocrinopathy, we profiled a mouse model of spontaneous, autoimmune exocrinopathy that possess key characteristics of peripheral neuropathy experienced by SS patients. Mice deficient in the autoimmune regulator (Aire) gene developed spontaneous, CD4+ T cell-mediated exocrinopathy and aqueous-deficient dry eye that were associated with loss of nerves innervating the cornea and lacrimal gland. Changes in innervation and tear secretion were accompanied by increased proliferation of corneal epithelial basal cells, limbal expansion of KRT19-positive progenitor cells, increased vascularization of the peripheral cornea and reduced nerve function in the lacrimal gland. In addition, we found extensive loss of MIST1+ secretory acinar cells in the Aire -/- lacrimal gland suggesting that acinar cells are a primary target of the disease, Finally, topical application of ophthalmic steroid effectively restored corneal innervation in Aire -/- mice thereby functionally linking nerve loss with local inflammation in the aqueous-deficient dry eye. These data provide important insight regarding the relationship between chronic inflammation and neuropathic changes in autoimmune-mediated dry eye. Peripheral neuropathies characteristic of SS appear to be tightly linked with the underlying immunopathological mechanism and Aire -/- mice provide an excellent tool to explore the interplay between SS-associated immunopathology and peripheral neuropathy.

  15. Reversible lacrimal gland-protective regulatory T-cell dysfunction underlies male-specific autoimmune dacryoadenitis in the non-obese diabetic mouse model of Sjögren syndrome

    Science.gov (United States)

    Lieberman, Scott M; Kreiger, Portia A; Koretzky, Gary A

    2015-01-01

    CD4+ CD25+ Foxp3+ regulatory T (Treg) cells are required to maintain immunological tolerance; however, defects in specific organ-protective Treg cell functions have not been demonstrated in organ-specific autoimmunity. Non-obese diabetic (NOD) mice spontaneously develop lacrimal and salivary gland autoimmunity and are a well-characterized model of Sjögren syndrome. Lacrimal gland disease in NOD mice is male-specific, but the role of Treg cells in this sex-specificity is not known. This study aimed to determine if male-specific autoimmune dacryoadenitis in the NOD mouse model of Sjögren syndrome is the result of lacrimal gland-protective Treg cell dysfunction. An adoptive transfer model of Sjögren syndrome was developed by transferring cells from the lacrimal gland-draining cervical lymph nodes of NOD mice to lymphocyte-deficient NOD-SCID mice. Transfer of bulk cervical lymph node cells modelled the male-specific dacryoadenitis that spontaneously develops in NOD mice. Female to female transfers resulted in dacryoadenitis if the CD4+ CD25+ Treg-enriched population was depleted before transfer; however, male to male transfers resulted in comparable dacryoadenitis regardless of the presence or absence of Treg cells within the donor cell population. Hormone manipulation studies suggested that this Treg cell dysfunction was mediated at least in part by androgens. Surprisingly, male Treg cells were capable of preventing the transfer of dacryoadenitis to female recipients. These data suggest that male-specific factors promote reversible dysfunction of lacrimal gland-protective Treg cells and, to our knowledge, form the first evidence for reversible organ-protective Treg cell dysfunction in organ-specific autoimmunity. PMID:25581706

  16. Evaluation of Accessory Lacrimal Gland in Muller's Muscle Conjunctival Resection Specimens for Precursor Cell Markers and Biological Markers of Dry Eye Disease.

    Science.gov (United States)

    Ali, Marwan; Shah, Dhara; Pasha, Zeeshan; Jassim, Sarmad H; Jassim Jaboori, Assraa; Setabutr, Pete; Aakalu, Vinay K

    2017-04-01

    The accessory lacrimal glands (ALGs) are an understudied component of the tear functional unit, even though they are important in the development of dry eye syndrome (DES). To advance our understanding of aging changes, regenerative potential, and histologic correlates to human characteristics, we investigated human ALG tissue from surgical samples to determine the presence or absence of progenitor cell markers and lacrimal epithelial markers and to correlate marker expression to relevant patient characteristics. ALG tissues obtained from Muller's muscle conjunctival resection (MMCR) specimens were created using tissue microarrays (TMAs). Immunofluorescence staining of MMCR sections was performed using primary antibodies specific to cell protein markers. Cell marker localization in TMAs was then assessed by two blinded observers using a standardized scoring system. Patient characteristics including age, race, and status of ocular surface health were then compared against expression of stem cell markers. Human ALG expressed a number of epithelial markers, and in particular, histatin-1 was well correlated with the expression of epithelial markers and was present in most acini. In addition, we noted the presence of precursor cell markers nestin, ABCG2, and CD90 in ALG tissue. There was a decrease in precursor cell marker expression with increasing age. Finally, we noted that a negative association was present between histatin-1 expression and DES. Thus, we report for the first time that human ALG tissues contain precursor marker-positive cells and that this marker expression may decrease with increasing age. Moreover, histatin-1 expression may be decreased in DES. Future studies will be performed to use these cell markers to isolate and culture lacrimal epithelial cells from heterogeneous tissues, determine the relevance of histatin-1 expression to DES, and isolate candidate precursor cells from ALG tissue.

  17. Light and electron microscopic study of the eyelids, conjunctiva-associated lymphoid tissue and lacrimal gland in Bilgorajska Goose (Anser anser).

    Science.gov (United States)

    Klećkowska-Nawrot, Joanna; Nowaczyk, Renata; Goździewska-Harłajczuk, Karolina; Barszcz, Karolina; Kowalczyk, Artur; Łukaszewicz, Ewa

    2016-01-01

    Normal structure of the accessory organs of the eye is essential for normal eye physiology. Among the most important accessory organs of the eye are the eyelids, the conjunctiva-associated lymphoid tissue (CALT) and the lacrimal gland (LG). The aim of this study was to demonstrate the histological structure of the eyelids and LG by histochemical and ultrastructural analysis. The study was performed on 13 adult female Bilgorajska geese. Eyelid samples were stained with the Alcian blue (AB pH 2.5) and periodic acid-Schiff (PAS) methods. Staining methods used for LG were AB pH 2.5, aldehyde fuchsin (AF), PAS and Hale's dialysed iron (HDI). Within the connective tissue of the eyelids, well-developed, diffuse, CALT follicles were observed, mostly under the conjunctival epithelium. Numerous lymphocytes were present within loose connective tissue. Staining of the eyelids with the PAS method demonstrated the presence of goblet cells of a mucous nature, and AB pH 2.5 staining indicated the presence of sulfated acid mucopolysaccharides. PAS staining of LG revealed the presence of secretory cells containing weakly PAS-positive granules. All epithelial cells of the corpus glandulae and the duct systems reacted positively to AB pH 2.5. HDI staining detected the presence of carboxylated acid mucopolysaccharides. Transmission electron microscopy investigations revealed two types of secretory epithelial cells in LG. Both types of LG cells contained drop-like secretory vesicles of different sizes with low or high electron density in cytoplasm, as well as small and large lipid vacuoles, and numerous small primary lysosomes.

  18. The role of the lacrimal functional unit in the pathophysiology of dry eye.

    Science.gov (United States)

    Stern, Michael E; Gao, Jianping; Siemasko, Karyn F; Beuerman, Roger W; Pflugfelder, Stephen C

    2004-03-01

    The majority of dry eye symptoms are due to a chronic inflammation of the lacrimal functional unit resulting in a loss of tear film integrity and normal function. This leads to a reduction in the ability of the ocular surface to respond to environmental challenges. The underlying cause of tear film dysfunction is the alteration of tear aqueous, mucin, and lipid components. This may result from a systemic autoimmune disease or a local autoimmune event. A lack of systemic androgen support to the lacrimal gland has been shown to be a facilitative factor in the initiation of this type of pathophysiology. Tear secretion is controlled by the lacrimal functional unit consisting of the ocular surface (cornea, conjunctiva, accessory lacrimal glands, and meibomian glands), the main lacrimal gland and the interconnecting innervation. If any portion of this functional unit is compromised, lacrimal gland support to the ocular surface is impeded. Factors such as neurogenic inflammation and T cell involvement in the disease pathogenesis as well as newly developed animal models of ocular surface inflammation are discussed.

  19. Evaluation of Accessory Lacrimal Gland in Muller’s Muscle Conjunctival Resection Specimens for Precursor Cell Markers and Biological Markers of Dry Eye Disease

    Science.gov (United States)

    Ali, Marwan; Shah, Dhara; Pasha, Zeeshan; Jassim, Sarmad H.; Jaboori, Assraa Jassim; Setabutr, Pete; Aakalu, Vinay K.

    2017-01-01

    Purpose The accessory lacrimal glands (ALG) are an understudied component of the tear functional unit, even though they are important in the development of dry eye syndrome (DES). To advance our understanding of aging changes, regenerative potential and histologic correlates to human characteristics, we investigated human ALG tissue from surgical samples to determine the presence or absence of progenitor cell markers and lacrimal epithelial markers and to correlate marker expression to relevant patient characteristics. Materials and Methods ALG tissues obtained from Muller’s Muscle Conjunctival Resection (MMCR) specimens were created using tissue microarrays (TMAs). Immunofluorescence staining of MMCR sections was performed using primary antibodies specific to cell protein markers. Cell marker localization in TMAs was then assessed by two blinded observers using a standardized scoring system. Patient characteristics including age, race, and status of ocular surface health were then compared against expression of stem cell markers. Results Human ALG expressed a number of epithelial markers, and in particular, histatin-1 was well correlated with the expression of epithelial markers and was present in most acini. In addition, we noted the presence of precursor cell markers nestin, ABCG2 and CD90 in ALG tissue. There was a decrease in precursor cell marker expression with increasing age. Finally, we noted that a negative association was present between histatin-1 expression and DES. Conclusions Thus, we report for the first time that human ALG tissues contain precursor marker positive cells and that this marker expression may decrease with increasing age. Moreover, histatin-1 expression may be decreased in DES. Future studies will be performed to use these cell markers to isolate and culture lacrimal epithelial cells from heterogeneous tissues, determine the relevance of histatin-1 expression to DES and isolate candidate precursor cells from ALG tissue. PMID:27612554

  20. Efficacy of laser stimulation of the lacrimal gland and collagen punctual occlusion in the treatment of dry-eye syndrome

    Science.gov (United States)

    Switka-Wieclawska, Iwona; Kecik, Tadeusz; Ciszewska, Joanna

    1997-10-01

    In this study we would like to monitor the tear secretion during a 7 day period of temporary intracanalicular occlusion and laser stimulation of lacrimal gland in a small group of female suffering of dry eye syndrome.

  1. Radioiodine treatment effects of lacrimal glands function in patients with thyroid cancer

    International Nuclear Information System (INIS)

    Fard Esfahani, A.; Akhzari, F.; Mirshekarpour, H.; Saghari, M.; Izadyar, S.; Esmaili, J.; Fallahi, B.; Beiki, D.; Takavar, A.

    2005-01-01

    There is a limited number of case reports published in the past decade confirming the radio-iodine presence in the tear. These observations as well as reported cases of salivary and lacrimal gland dysfunction after radioiodine therapy stimulated investigators to clarify whether lacrimal gland function can be affected post-radioiodine therapy. Hence we planned a historical cohort study to evaluate this effect. Methods: we studied 100 eyes of 50 patients who were referred to the nuclear medicine department of Dr. Shariati hospital from 01.1383 to 02.1384 and had received high doses (accumulative dose: 100-450mCi) of 1-131 treatment of differentiated thyroid carcinoma with their latest admission at least 3 months previously. Dry eye symptoms (obtained via a standard questionnaire) and Schirmer I test results (mm/5min) of this group were compared with those of an unexposed group (1 00 eyes of 50 individuals) matched by sex and age. Cases with another known cause(s) of dry eye were not included in either group. Results: 51% of the exposed eyes and 50% of the unexposed ones revealed at least one of the dry eye symptoms in the questionnaire. Data analysis showed no significant difference between the number of symptoms of two groups, but 2 symptoms (burning, unrelated to light and rythema) were significantly higher in the exposed eyes. From 9 exposed eyes complaining of erythema, Schirmer test result was abnormal only in 2 (one patient). Also among the 10 eyes with burning symptom (unrelated to light) one patient (2 eyes) revealed abnormal Schirmer test result. The study also demonstrated a significantly lower wetting amount of the Schirmer paper in exposed group compared to others. In the patients undergone radio-iodine therapy, results were 0-4 mm in 21%, 5-9 mm in 20% and 10 mm or more in 59%. These results were seen in the unexposed group in 6%, 17% and 77%, respectively. File review of the 21 exposed eyes with 0-4 mm Schirmer test results revealed presence of the

  2. Prevention of radiochemotherapy-induced toxicity with amifostine in patients with malignant orbital tumors involving the lacrimal gland: a pilot study

    International Nuclear Information System (INIS)

    Goldblum, David; Ghadjar, Pirus; Curschmann, Juergen; Greiner, Richard; Aebersold, Daniel

    2008-01-01

    To use amifostine concurrently with radiochemotherapy (CT-RT) or radiotherapy (RT) alone in order to prevent dry eye syndrome in patients with malignancies located in the fronto-orbital region. Five patients (2 males, 3 females) with diagnosed malignancies (Non-Hodgkin B-cell Lymphoma, neuroendocrine carcinoma) involving the lacrimal gland, in which either combined CT-RT or local RT were indicated, were prophylactically treated with amifostine (500 mg sc). Single RT fraction dose, total dose and treatment duration were individually adjusted to the patient's need. Acute and late adverse effects were recorded using the RTOG score. Subjective and objective dry eye assessment was performed for the post-treatment control of lacrimal gland function. All patients have completed CT-RT or RT as indicated. The median total duration of RT was 29 days (range, 23 – 39 days) and the median total RT dose was 40 Gy (range, 36 – 60 Gy). Median lacrimal gland exposure was 35.9 Gy (range, 16.8 – 42.6 Gy). Very good partial or complete tumor remission was achieved in all patients. The treatment was well tolerated without major toxic reactions. Post-treatment control did not reveal in any patient either subjective or objective signs of a dry eye syndrome. The addition of amifostine to RT/CT-RT of patients with tumors localized in orbital region was found to be associated with absence of dry eye syndrome

  3. Denervation of the Lacrimal Gland Leads to Corneal Hypoalgesia in a Novel Rat Model of Aqueous Dry Eye Disease.

    Science.gov (United States)

    Aicher, Sue A; Hermes, Sam M; Hegarty, Deborah M

    2015-10-01

    Some dry eye disease (DED) patients have sensitized responses to corneal stimulation, while others experience hypoalgesia. Many patients have normal tear production, suggesting that reduced tears are not always the cause of DED sensory dysfunction. In this study, we show that disruption of lacrimal innervation can produce hypoalgesia without changing basal tear production. Injection of a saporin toxin conjugate into the extraorbital lacrimal gland of male Sprague-Dawley rats was used to disrupt cholinergic innervation to the gland. Tear production was assessed by phenol thread test. Corneal sensory responses to noxious stimuli were assessed using eye wipe behavior. Saporin DED animals were compared to animals treated with atropine to produce aqueous DED. Cholinergic innervation and acetylcholine content of the lacrimal gland were significantly reduced in saporin DED animals, yet basal tear production was normal. Saporin DED animals demonstrated normal eye wipe responses to corneal application of capsaicin, but showed hypoalgesia to corneal menthol. Corneal nerve fiber density was normal in saporin DED animals. Atropine-treated animals had reduced tear production but normal responses to ocular stimuli. Because only menthol responses were impaired, cold-sensitive corneal afferents appear to be selectively altered in our saporin DED model. Hypoalgesia is not due to reduced tear production, since we did not observe hypoalgesia in an atropine DED model. Corneal fiber density is unaltered in saporin DED animals, suggesting that molecular mechanisms of nociceptive signaling may be impaired. The saporin DED model will be useful for exploring the mechanism underlying corneal hypoalgesia.

  4. Bottom-up assembly of salivary gland microtissues for assessing myoepithelial cell function.

    Science.gov (United States)

    Ozdemir, Tugba; Srinivasan, Padma Pradeepa; Zakheim, Daniel R; Harrington, Daniel A; Witt, Robert L; Farach-Carson, Mary C; Jia, Xinqiao; Pradhan-Bhatt, Swati

    2017-10-01

    Myoepithelial cells are flat, stellate cells present in exocrine tissues including the salivary glands. While myoepithelial cells have been studied extensively in mammary and lacrimal gland tissues, less is known of the function of myoepithelial cells derived from human salivary glands. Several groups have isolated tumorigenic myoepithelial cells from cancer specimens, however, only one report has demonstrated isolation of normal human salivary myoepithelial cells needed for use in salivary gland tissue engineering applications. Establishing a functional organoid model consisting of myoepithelial and secretory acinar cells is therefore necessary for understanding the coordinated action of these two cell types in unidirectional fluid secretion. Here, we developed a bottom-up approach for generating salivary gland microtissues using primary human salivary myoepithelial cells (hSMECs) and stem/progenitor cells (hS/PCs) isolated from normal salivary gland tissues. Phenotypic characterization of isolated hSMECs confirmed that a myoepithelial cell phenotype consistent with that from other exocrine tissues was maintained over multiple passages of culture. Additionally, hSMECs secreted basement membrane proteins, expressed adrenergic and cholinergic neurotransmitter receptors, and released intracellular calcium [Ca 2+ i ] in response to parasympathetic agonists. In a collagen I contractility assay, activation of contractile machinery was observed in isolated hSMECs treated with parasympathetic agonists. Recombination of hSMECs with assembled hS/PC spheroids in a microwell system was used to create microtissues resembling secretory complexes of the salivary gland. We conclude that the engineered salivary gland microtissue complexes provide a physiologically relevant model for both mechanistic studies and as a building block for the successful engineering of the salivary gland for restoration of salivary function in patients suffering from hyposalivation. Copyright © 2017

  5. Ectodermal Differentiation of Wharton's Jelly Mesenchymal Stem Cells for Tissue Engineering and Regenerative Medicine Applications.

    Science.gov (United States)

    Jadalannagari, Sushma; Aljitawi, Omar S

    2015-06-01

    Mesenchymal stem cells (MSCs) from Wharton's jelly (WJ) of the human umbilical cord are perinatal stem cells that have self-renewal ability, extended proliferation potential, immunosuppressive properties, and are accordingly excellent candidates for tissue engineering. These MSCs are unique, easily accessible, and a noncontroversial cell source of regeneration in medicine. Wharton's jelly mesenchymal stem cells (WJMSCs) are multipotent and capable of multilineage differentiation into cells like adipocytes, bone, cartilage, and skeletal muscle upon exposure to appropriate conditions. The ectoderm is one of the three primary germ layers found in the very early embryo that differentiates into the epidermis, nervous system (spine, peripheral nerves, brain), and exocrine glands (mammary, sweat, salivary, and lacrimal glands). Accumulating evidence shows that MSCs obtained from WJ have an ectodermal differentiation potential. The current review examines this differentiation potential of WJMSC into the hair follicle, skin, neurons, and sweat glands along with discussing the potential utilization of such differentiation in regenerative medicine.

  6. Interleukin-6 inhibits apoptosis of exocrine gland tissues under inflammatory conditions.

    Science.gov (United States)

    Zhou, Jing; Jin, Jun-O; Patel, Ekta S; Yu, Qing

    2015-12-01

    Interleukin (IL)-6 is a multi-functional cytokine that can either promote or suppress tissue inflammation depending on the specific disease context. IL-6 is elevated in the exocrine glands and serum of patients with Sjögren's syndrome (SS), but the specific role of IL-6 in the pathogenesis of this disease has not been defined. In this study, we showed that IL-6 expression levels were increased with age in C56BL/6.NOD-Aec1Aec2 mice, a primary SS model, and higher than the control C57BL/6 mice. To assess the role of IL-6 during the immunological phase of SS development, a neutralizing anti-IL-6 antibody was administered into 16 week-old female C56BL/6.NOD-Aec1Aec2 mice, 3 times weekly for a consecutive 8 weeks. Neutralization of endogenous IL-6 throughout the immunological phase of SS development led to increased apoptosis, caspase-3 activation, leukocytic infiltration, and IFN-γ- and TNF-α production in the salivary gland. To further determine the effect of IL-6 on the apoptosis of exocrine gland cells, recombinant human IL-6 or the neutralizing anti-IL-6 antibody was injected into female C57BL/6 mice that received concurrent injection of anti-CD3 antibody to induce the apoptosis of exocrine gland tissues. Neutralization of IL-6 enhanced, whereas administration of IL-6 inhibited apoptosis and caspase-3 activation in salivary and lacrimal glands in this model. The apoptosis-suppressing effect of IL-6 was associated with up-regulation of Bcl-xL and Mcl-1 in both glands. Moreover, IL-6 treatment induced activation of STAT3 and up-regulated Bcl-xL and Mcl-1 gene expression in a human salivary gland epithelial cell line. In conclusion, IL-6 inhibits the apoptosis of exocrine gland tissues and exerts a tissue-protective effect under inflammatory conditions including SS. These findings suggest the possibility of using this property of IL-6 to preserve exocrine gland tissue integrity and function under autoimmune and inflammatory conditions. Copyright © 2015 Elsevier

  7. Exocrine gland dysfunction in MC5-R-deficient mice: evidence for coordinated regulation of exocrine gland function by melanocortin peptides.

    Science.gov (United States)

    Chen, W; Kelly, M A; Opitz-Araya, X; Thomas, R E; Low, M J; Cone, R D

    1997-12-12

    The effects of pituitary-derived melanocortin peptides are primarily attributed to ACTH-mediated adrenocortical glucocorticoid production. Identification of a widely distributed receptor for ACTH/MSH peptides, the melanocortin-5 receptor (MC5-R), suggested non-steroidally mediated systemic effects of these peptides. Targeted disruption of the MC5-R produced mice with a severe defect in water repulsion and thermoregulation due to decreased production of sebaceous lipids. High levels of MC5-R was found in multiple exocrine tissues, including Harderian, preputial, lacrimal, and sebaceous glands, and was also shown to be required for production and stress-regulated synthesis of porphyrins by the Harderian gland and ACTH/MSH-regulated protein secretion by the lacrimal gland. These data show a requirement for the MC5-R in multiple exocrine glands for the production of numerous products, indicative of a coordinated system for regulation of exocrine gland function by melanocortin peptides.

  8. Rapamycin Eye Drops Suppress Lacrimal Gland Inflammation In a Murine Model of Sjögren's Syndrome

    Science.gov (United States)

    Shah, Mihir; Edman, Maria C.; Reddy Janga, Srikanth; Yarber, Frances; Meng, Zhen; Klinngam, Wannita; Bushman, Jonathan; Ma, Tao; Liu, Siyu; Louie, Stan; Mehta, Arjun; Ding, Chuanqing; MacKay, J. Andrew; Hamm-Alvarez, Sarah F.

    2017-01-01

    Purpose To evaluate the efficacy of topical rapamycin in treating autoimmune dacryoadenitis in a mouse model of Sjögren's syndrome. Methods We developed rapamycin in a poly(ethylene glycol)-distearoyl phosphatidylethanolamine (PEG-DSPE) micelle formulation to maintain solubility. Rapamycin or PEG-DSPE eye drops (vehicle) were administered in a well-established Sjögren's syndrome disease model, the male nonobese diabetic (NOD) mice, twice daily for 12 weeks starting at 8 weeks of age. Mouse tear fluid was collected and tear Cathepsin S, a putative tear biomarker for Sjögren's syndrome, was measured. Lacrimal glands were retrieved for histological evaluation, and quantitative real-time PCR of genes associated with Sjögren's syndrome pathogenesis. Tear secretion was measured using phenol red threads, and corneal fluorescein staining was used to assess corneal integrity. Results Lymphocytic infiltration of lacrimal glands from rapamycin-treated mice was significantly (P = 0.0001) reduced by 3.8-fold relative to vehicle-treated mice after 12 weeks of treatment. Rapamycin, but not vehicle, treatment increased tear secretion and decreased corneal fluorescein staining after 12 weeks. In rapamycin-treated mice, Cathepsin S activity was significantly reduced by 3.75-fold in tears (P eye. PMID:28122086

  9. Effect of P2X(7) receptor knockout on exocrine secretion of pancreas, salivary glands and lacrimal glands.

    Science.gov (United States)

    Novak, Ivana; Jans, Ida M; Wohlfahrt, Louise

    2010-09-15

    The purinergic P2X(7) receptors are expressed in different cell types where they have varied functions, including regulation of cell survival. The P2X(7) receptors are also expressed in exocrine glands, but their integrated role in secretion is unclear. The aim of our study was to determine whether the P2X(7) receptors affect fluid secretion in pancreas, salivary glands and tear glands. We monitored gland secretions in in vivo preparations of wild-type and P2X(7)(-/-) (Pfizer) mice stimulated with pilocarpine. In cell preparations from pancreas, parotid and lacrimal glands we measured ATP release and intracellular Ca(2+) activity using Fura-2. The data showed that pancreatic secretion and salivary secretions were reduced in P2X(7)(-/-) mice, and in contrast, tear secretion was increased in P2X(7)(-/-) mice. The secretory phenotype was also dependent on the sex of the animal, such that males were more dependent on the P2X(7) receptor expression. ATP release in all cell preparations could be elicited by carbachol and other agonists, and this was independent of the P2X(7) receptor expression. ATP and carbachol increased intracellular Ca(2+) activity, but responses depended on the gland type, presence of the P2X(7) receptor and the sex of the animal. Together, these results demonstrate that cholinergic stimulation leads to release of ATP that can via P2X(7) receptors up-regulate pancreatic and salivary secretion but down-regulate tear secretion. Our data also indicate that there is an interaction between purinergic and cholinergic receptor signalling and that function of the P2X(7) receptor is suppressed in females. We conclude that the P2X(7) receptors are important in short-term physiological regulation of exocrine gland secretion.

  10. Effect of P2X7 receptor knockout on exocrine secretion of pancreas, salivary glands and lacrimal glands

    Science.gov (United States)

    Novak, Ivana; Jans, Ida M; Wohlfahrt, Louise

    2010-01-01

    The purinergic P2X7 receptors are expressed in different cell types where they have varied functions, including regulation of cell survival. The P2X7 receptors are also expressed in exocrine glands, but their integrated role in secretion is unclear. The aim of our study was to determine whether the P2X7 receptors affect fluid secretion in pancreas, salivary glands and tear glands. We monitored gland secretions in in vivo preparations of wild-type and P2X7−/− (Pfizer) mice stimulated with pilocarpine. In cell preparations from pancreas, parotid and lacrimal glands we measured ATP release and intracellular Ca2+ activity using Fura-2. The data showed that pancreatic secretion and salivary secretions were reduced in P2X7−/− mice, and in contrast, tear secretion was increased in P2X7−/− mice. The secretory phenotype was also dependent on the sex of the animal, such that males were more dependent on the P2X7 receptor expression. ATP release in all cell preparations could be elicited by carbachol and other agonists, and this was independent of the P2X7 receptor expression. ATP and carbachol increased intracellular Ca2+ activity, but responses depended on the gland type, presence of the P2X7 receptor and the sex of the animal. Together, these results demonstrate that cholinergic stimulation leads to release of ATP that can via P2X7 receptors up-regulate pancreatic and salivary secretion but down-regulate tear secretion. Our data also indicate that there is an interaction between purinergic and cholinergic receptor signalling and that function of the P2X7 receptor is suppressed in females. We conclude that the P2X7 receptors are important in short-term physiological regulation of exocrine gland secretion. PMID:20643770

  11. Vasoactive intestinal polypeptide (VIP) innervation of the human eyelid glands.

    Science.gov (United States)

    Seifert, P; Spitznas, M

    1999-06-01

    This study was conducted to obtain morphological proof of innervating nerve fibres in the glands of the human eyelid (accessory lacrimal glands of Wolfring, meibomian glands, goblet cells, glands of Zeis, glands of Moll, sweat glands, glands of lanugo hair follicles) and identification of the secretomotorically active neuropeptide vasoactive intestinal polypeptide (VIP) as a common transmitter. Epoxy-embedded ultrathin sections of tissue samples from human eyelids were studied using electron microscopy. Paraffin sections fixed in Bouin-Hollande solution were immunostained with rabbit antiserum against VIP. With the electron microscope we were able to identify nerves in the glandular stroma of all the glands examined with the exception of goblet cells. Intraepithelial single axons were only seen in the parenchyma of Wolfring glands. The morphological findings corresponded with the immunological finding of VIP-positive, nerve-like structures in the same locations, with the exception of lanugo hair follicle glands, and goblet cells. Our findings indicate that the glands of the eyelids and main lacrimal gland represent a functional unit with VIP as a possible common stimulating factor. Copyright 1999 Academic Press.

  12. Lacritin and Other New Proteins of the Lacrimal Functional Unit

    OpenAIRE

    McKown, Robert L.; Wang, Ningning; Raab, Ronald W.; Karnati, Roy; Zhang, Yinghui; Williams, Patricia B.; Laurie, Gordon W.

    2008-01-01

    The lacrimal functional unit (LFU) is defined by the 2007 International Dry Eye WorkShop as ‘an integrated system comprising the lacrimal glands, ocular surface (cornea, conjunctiva and meibomian glands) and lids, and the sensory and motor nerves that connect them’. The LFU maintains a healthy ocular surface primarily through a properly functioning tear film that provides protection, lubrication, and an environment for corneal epithelial cell renewal. LFU cells express thousands of proteins. ...

  13. Role of chemotherapy and molecularly targeted agents in the treatment of adenoid cystic carcinoma of the lacrimal gland.

    Science.gov (United States)

    Le Tourneau, Christophe; Razak, Albiruni R A; Levy, Christine; Calugaru, Valentin; Galatoire, Olivier; Dendale, Rémi; Desjardins, Laurence; Gan, Hui K

    2011-11-01

    Adenoid cystic carcinoma (ACC) is the most common malignant epithelial cancer of the lacrimal gland. Despite a slow rate of growth, ACCs are ultimately associated with poor clinical outcome. Given the rarity of this disease, most recommendations regarding therapy are guided by expert opinion and retrospective data rather than level 1 evidence. Surgery and postoperative radiation therapy are commonly used as initial local treatment. In patients at high risk of recurrence, concomitant platinum-based chemotherapy may be added to postoperative radiotherapy in an attempt to enhance radio-sensitivity. While encouraging responses have been reported with intra-arterial neoadjuvant chemotherapy, this strategy is associated with substantial toxicity and should be considered investigational. For patients with metastatic disease not amenable to surgery or radiotherapy, chemotherapy may have a role based on its modest efficacy in non-lacrimal ACC. Similarly, molecular targeted agents may have a role, although the agents tested to date in non-lacrimal ACC have been disappointing. A better understanding of the biology of ACC will be crucial to the future success of developing targeted agents for this disease.

  14. p38 Mitogen-activated protein kinase modulates exocrine secretion in rabbit lacrimal gland.

    Science.gov (United States)

    Carlsson, Stina K; Gierow, J Peter

    2012-03-01

    The lacrimal gland (LG) is an exocrine gland important for secretion of the tear film. The kinase p38 has important signal transduction functions, e.g. in gene transcription, but has previously not been known to modulate exocrine secretion. The aim of the current study was to investigate the role of p38 in carbachol (Cch)-induced LG secretion in LG acinar cells in vitro. Western blotting was used to determine the phosphorylation status of p38 and p42/44 and determine expression of p38 isoforms. To determine the effect of p38 inhibition on LG secretion, PD 169316, a general p38 inhibitor, and SB 239063, an inhibitor of p38α and β, were added to the cells prior to secretion measurements. The results revealed activation of p38 mediated by Cch stimulation and inhibition of Cch-induced secretion as a result of p38 inhibition. The inhibition was observed with PD 169316 isoforms, but not with SB 239063. The p38δ isoform was shown to have robust expression both by Western blotting of acinar cells and immunofluorescence of the whole gland. In conclusion, p38 activation mediates secretion in cholinergic stimulation of rabbit LG cells.

  15. Image fusion analysis of 99mTc-HYNIC-octreotide scintigraphy and CT/MRI in patients with thyroid-associated orbitopathy: the importance of the lacrimal gland

    International Nuclear Information System (INIS)

    Kainz, Hartmann; Donnemiller, Eveline; Gabriel, Michael; Decristoforo, Clemens; Moncayo, Roy; Bale, Reto; Kovacs, Peter

    2003-01-01

    The aim of this study was to describe the anatomical structures that show uptake of the somatostatin analogue octreotide in patients with thyroid-associated orbitopathy (TAO). The study population comprised a series of 20 TAO patients attending the out-patient thyroid clinic and 12 patients presenting head or neck tumours. Scintigraphy was carried out with our newly developed tracer, technetium-99m labelled EDDA-HYNIC-TOC ( 99m Tc-TOC). Morphological imaging was done with either magnetic resonance imaging or X-ray computed tomography without contrast medium. Both imaging procedures were done within an interval of 3-4 weeks. For the image fusion procedure, specific external reference markers were used for each imaging modality. The markers were screwed onto a reference frame, which was held in place via a vacuum-fixed mouthpiece. The anatomical structure showing tracer uptake that was most frequently recognised was the lacrimal gland, followed by the retronasal area, cervical lymph structures, salivary glands, the anterior insertion points of the extra-ocular muscles and discrete areas of the neck extensor muscles. The lacrimal gland and the retronasal area showed the highest and most frequent uptake of 99m Tc-TOC in TAO patients, whereas such uptake did not occur in the retrobulbar space. In spite of knowledge of these results of image fusion, no changes in the involved structures could be detected on morphological imaging. It is concluded that binding of 99m Tc-TOC is more frequently localised to the anterior compartment of the eye and to the neck. The previously used term ''orbital'' uptake should be abandoned and replaced by a descriptive term relating to the anatomically recognised structure showing tracer accumulation, i.e. the lacrimal gland. The uptake of octreotide by lymphoid and salivary glands opens a new field of investigation related to the physiology of somatostatin. (orig.)

  16. Altered morphology and function of the lacrimal functional unit in protein kinase C{alpha} knockout mice.

    Science.gov (United States)

    Chen, Zhuo; Li, Zhijie; Basti, Surendra; Farley, William J; Pflugfelder, Stephen C

    2010-11-01

    Protein kinase C (PKC) α plays a major role in the parasympathetic neural stimulation of lacrimal gland (LG) secretion. It also has been reported to have antiapoptotic properties and to promote cell survival. Therefore, the hypothesis for the present study was that PKCα knockout ((-/-)) mice have impaired ocular surface-lacrimal gland signaling, rendering them susceptible to desiccating stress and impaired corneal epithelial wound healing. In this study, the lacrimal function unit (LFU) and the stressed wound-healing response were examined in PKCα(-/-) mice. In PKCα(+/+) control mice and PKCα(-/-) mice, tear production, osmolarity, and clearance rate were evaluated before and after experimental desiccating stress. Histology and immunofluorescent staining of PKC and epidermal growth factor were performed in tissues of the LFU. Cornified envelope (CE) precursor protein expression and cell proliferation were evaluated. The time course of healing and degree of neutrophil infiltration was evaluated after corneal epithelial wounding. Compared with the PKCα(+/+) mice, the PKCα(-/-) mice were noted to have significantly increased lacrimal gland weight, with enlarged, carbohydrate-rich, PAS-positive acinar cells; increased corneal epithelia permeability, with reduced CE expression; and larger conjunctival epithelial goblet cells. The PKCα(-/-) mice showed more rapid corneal epithelial healing, with less neutrophil infiltration and fewer proliferating cells than did the PKCα(+/+) mice. The PKCα(-/-) mice showed lower tear production, which appeared to be caused by impaired secretion by the LG and conjunctival goblet cells. Despite their altered tear dynamics, the PKCα(-/-) mice demonstrated more rapid corneal epithelial wound healing, perhaps due to decreased neutrophil infiltration.

  17. Canine lacrimal and third eyelid superficial glands’ macroscopic and morphometric characteristics Aspectos macroscópicos e morfométricos das glândulas lacrimal e superficial da terceira pálpebra de cães (Canis familiares; LINNAEUS, 1758

    Directory of Open Access Journals (Sweden)

    Vânia Pais Cabral

    2005-04-01

    Full Text Available The lacrimal and third eyelid superficial glands produce the aqueous component of the preocular tear film. In this research, morphologic and morphometric assessments of the parenchyma and stroma of both lacrimal glands of healthy adult mongrel dogs were performed. Both lacrimal and third eyelid glands of fourteen dogs were collected, summing fifty-six samples. The macroscopic and morphometric data were statistically analyzed, according to the glandular type (lacrimal and third eyelid superficial glands and sexual dimorphism (male or female. The lacrimal glands were significantly larger and longer than the superficial glands of the third eyelid. Expressive morphometric differences of interlobular duct, lymphocytic infiltration, interlobular vessels and secretory parenchyma between the two glandular types were encountered. The lacrimal glands from the male subjects were significantly larger than those from female ones, as well as the superficial glands of the third eyelid were thicker. The higher lymphocyte infiltration and poorer secretor parenchyma in female dogs may be one of the reasons for the higher incidence of keratoconjunctiviti sicca (KCS in such canine population.As glândulas lacrimal e superficial da terceira pálpebra atuam produzindo o componente aquoso do filme lacrimal. Nesta pesquisa, estudaram-se aspectos morfológicos e morfométricos do parênquima e do estroma de ambas as glândulas em cães mestiços, hígidos, adultos (machos ou fêmeas. As glândulas lacrimal e superficial da terceira pálpebra de 14 cães foram colhidas, totalizando 56 amostras. Foram estudadas, à estatística, as variáveis macroscópicas e morfométricas, comparando-as quanto ao tipo glandular (lacrimal e superficial da terceira pálpebra e quanto ao dimorfismo sexual (macho e fêmea. Às glândulas lacrimais foram significativamente maiores comparativamente as superficiais da terceira pálpebra. Foram evidenciados diferenças morfom

  18. Altered Morphology and Function of the Lacrimal Functional Unit in Protein Kinase Cα Knockout Mice

    Science.gov (United States)

    Chen, Zhuo; Li, Zhijie; Basti, Surendra; Farley, William J.

    2010-01-01

    Purpose. Protein kinase C (PKC) α plays a major role in the parasympathetic neural stimulation of lacrimal gland (LG) secretion. It also has been reported to have antiapoptotic properties and to promote cell survival. Therefore, the hypothesis for the present study was that PKCα knockout (−/−) mice have impaired ocular surface–lacrimal gland signaling, rendering them susceptible to desiccating stress and impaired corneal epithelial wound healing. In this study, the lacrimal function unit (LFU) and the stressed wound-healing response were examined in PKCα−/− mice. Methods. In PKCα+/+ control mice and PKCα−/− mice, tear production, osmolarity, and clearance rate were evaluated before and after experimental desiccating stress. Histology and immunofluorescent staining of PKC and epidermal growth factor were performed in tissues of the LFU. Cornified envelope (CE) precursor protein expression and cell proliferation were evaluated. The time course of healing and degree of neutrophil infiltration was evaluated after corneal epithelial wounding. Results. Compared with the PKCα+/+ mice, the PKCα−/− mice were noted to have significantly increased lacrimal gland weight, with enlarged, carbohydrate-rich, PAS-positive acinar cells; increased corneal epithelia permeability, with reduced CE expression; and larger conjunctival epithelial goblet cells. The PKCα−/− mice showed more rapid corneal epithelial healing, with less neutrophil infiltration and fewer proliferating cells than did the PKCα+/+ mice. Conclusions. The PKCα−/− mice showed lower tear production, which appeared to be caused by impaired secretion by the LG and conjunctival goblet cells. Despite their altered tear dynamics, the PKCα−/− mice demonstrated more rapid corneal epithelial wound healing, perhaps due to decreased neutrophil infiltration. PMID:20505191

  19. Impedance Biosensors and Deep Crater Salivary Gland Scaffolds for Tissue Engineering

    Science.gov (United States)

    Schramm, Robert A.

    The salivary gland is a complex, branching organ whose primary biological function is the production of the fluid critical to alimentary function and the lubrication and maintenance of the oral cavity, saliva. The most frequent disruption of the salivary organ system is one in which the rate of supply of saliva into the oral cavity is diminished, and this may vary from a minor reduction, to near cessation. Regenerative medicine is a field which seeks to find ways to overcome the symptoms of organ malfunction or damage by inducing regrowth, repair and replacement of partial or whole organ function. Historically, the only methods available to medical experts were certain chemical drugs and transplantation, each of which suffers from significant risks and drawbacks. Tissue Engineering arose in the past few decades thanks to the seminal work of Robert Langer with the charter mission of finding new biomaterials and techniques to achieve these ends. The original concept of tissue engineering was the cell or tissue scaffold, which is supports the regrowth of cells by making intimate contact with adherent cells, and induces improved regrowth in vitro or in vivo by providing mechanical or chemical signaling cues. Epithelial cell types such as salivary glands have structural functional polarity at the cellular level, an apical side which faces a void, and a basal side which faces the support substrate. While 3D scaffolds such as hydrogels maximize interaction area between cells and substrate, they struggle to develop cohesive tissues beyond the scale of small cellular clusters . 2D scaffolds enforce a defined polarity by allowing cell interaction at only one side of the cell. Langer pioneered the use of polymer nanofibers as the premier synthetic 2D scaffold biomaterial, due to their exceptionally high nano-scale surface area, and collagen-imitating structure. Prior work has established PLGA nanofibers, which allow salivary cells to attach, proliferate, and generate a

  20. Effects of eye drops of Buddleja officinalis Maxim. extract on lacrimal gland cell apoptosis in castrated rats with dry eye.

    Science.gov (United States)

    Peng, Qing-hua; Yao, Xiao-lei; Wu, Quan-long; Tan, Han-yu; Zhang, Jing-rong

    2010-03-01

    To explore the possible mechanism of eye drops of Buddleja officinalis extract in treating dry eye of castrated rats by analyzing the expressions of Bax and Bcl-2 proteins. Forty-five Wistar male rats were randomly divided into sham-operated group, untreated group and eye drops of Buddleja officinalis Maxim. extract (treatment) group. The dry eye model was established with orchiectomy in the untreated group and treatment group. Rats in the treatment group were treated with eye drops of Buddleja officinalis Maxim. extract, one drop once, three times daily. Eyes of rats in the sham-operated group and untreated group were instilled with normal saline. After one-, two-, or three-month treatment, five rats in each group were scarified respectively. Then samples were taken to detect related indices. Expressions of Bax and Bcl-2 of lacrimal gland were checked by immunohistochemical method and quantity of apoptotic cells was counted. After one-, two- or three-month treatment, the quantities of expressions of Bax in acinar epithelial cells and glandular tube cells were significantly lower, and those of Bcl-2 were significantly higher in the treatment group than in the untreated group, and the quantities of apoptotic cells of the treatment group were significantly lower than those of the untreated group (PBuddleja officinalis Maxim. are flavonoids, which can significantly inhibit cell apoptosis in lacrimal gland.

  1. Lacrimal neuralgia: so far, a missing cranial neuralgia.

    Science.gov (United States)

    Pareja, Juan A; Cuadrado, María-Luz

    2013-10-01

    The lacrimal nerve supplies the lacrimal gland, the lateral upper eyelid, and a small cutaneous area adjacent to the external CANTHUS . First division trigeminal neuralgia, supraorbital/supratrochlear neuralgia, and infraorbital neuralgia have been acknowledged as neuralgic causes of pain in the forehead and periorbit. However, the lacrimal nerve has never been identified as a source of facial pain. Here we report two cases of lacrimal neuralgia. A 66-year-old woman had continuous pain in the lateral aspect of her left superior eyelid and an adjacent area of the temple since age 64. A 33-year-old woman suffered from continuous pain in a small area next to the lateral CANTHUS of her left eye since age 25. In both patients the superoexternal edge of the orbit was tender. In addition, sensory dysfunction could be demonstrated within the painful area. Anaesthetic blockades of the lacrimal nerve with lidocaine 2% resulted in complete but short-lasting relief. Pregabalin provided a complete response in the first patient. The second patient was refractory to various oral and topical drugs and different radiofrequency procedures, but she eventually obtained partial relief with pregabalin. Lacrimal neuralgia should be considered among the neuralgic causes of orbital and periorbital pain.

  2. Lacrimal hypofunction as a new mechanism of dry eye in visual display terminal users.

    Directory of Open Access Journals (Sweden)

    Shigeru Nakamura

    Full Text Available BACKGROUND: Dry eye has shown a marked increase due to visual display terminal (VDT use. It remains unclear whether reduced blinking while focusing can have a direct deleterious impact on the lacrimal gland function. To address this issue that potentially affects the life quality, we conducted a large-scale epidemiological study of VDT users and an animal study. METHODOLOGY/PRINCIPAL FINDINGS: Cross sectional survey carried out in Japan. A total of 1025 office workers who use VDT were enrolled. The association between VDT work duration and changes in tear film status, precorneal tear stability, lipid layer status and tear secretion were analyzed. For the animal model study, the rat VDT user model, placing rats onto a balance swing in combination with exposure to an evaporative environment was used to analyze lacrimal gland function. There was no positive relationship between VDT working duration and change in tear film stability and lipid layer status. The odds ratio for decrease in Schirmer score, index of tear secretion, were significantly increased with VDT working year (P = 0.012 and time (P = 0.005. The rat VDT user model, showed chronic reduction of tear secretion and was accompanied by an impairment of the lacrimal gland function and morphology. This dysfunction was recovered when rats were moved to resting conditions without the swing. CONCLUSIONS/SIGNIFICANCE: These data suggest that lacrimal gland hypofunction is associated with VDT use and may be a critical mechanism for VDT-associated dry eye. We believe this to be the first mechanistic link to the pathogenesis of dry eye in office workers.

  3. Evaluation of the Adhesive Properties of the Cornea by Means of Optical Coherence Tomography in Patients with Meibomian Gland Dysfunction and Lacrimal Tear Deficiency

    OpenAIRE

    Napoli, Pietro Emanuele; Coronella, Franco; Satta, Giovanni Maria; Galantuomo, Maria Silvana; Fossarello, Maurizio

    2014-01-01

    Objective The aim was to determine the influence of meibomian gland dysfunction (MGD) and aqueous tear deficiency dry eye (ADDE) on the adhesive properties of the central cornea by means of optical coherence tomography (OCT), and to investigate the relationship between corneal adhesiveness and classical tear tests, as well as the reliability of results, in these lacrimal functional unit disorders. Design Prospective, case-control study. Methods Twenty-eight patients with MGD and 27 patients w...

  4. Multiple Natural and Experimental Inflammatory Rabbit Lacrimal Gland Phenotypes

    Science.gov (United States)

    Mircheff, Austin K.; Wang, Yanru; Schechter, Joel E.; Li, Meng; Tong, Warren; Attar, Mayssa; Chengalvala, Murty; Harmuth, Joe; Prusakiewicz, Jeffery J.

    2016-01-01

    Purpose To investigate lacrimal gland (LG) immunophysiological and immune-mediated inflammatory process (IMIP) phenotype diversity. Methods Ex vivo matured dendritic cells (mDC) were loaded with acinar cell microparticles (MP). Peripheral blood lymphocytes (PBL) were activated in mixed cell reactions with mDC and injected directly into autologous, unilateral LG (1° ATD-LG) of two rabbit cohorts, one naïve, one immunized with a LG lysate membrane fraction (Pi). Autoimmune IgG titers were assayed by ELISA, MCR PBL stimulation indices (SI) by [3H]-thymidine incorporation. Schirmer tests without and with topical anesthetic (STT-I, STT-IA) and rose Bengal (RB) staining tests were performed. H&E and immunohistochemically stained sections were examined. RNA yields and selected transcript abundances were measured. Immune cell number and transcript abundance data were submitted to Principal Component Analysis (PCA). Results Immunizing Pi dose influenced SI but not IgG titers. STT scores were decreased, and rose Bengal scores increased, by day 118 after immunization. Previous immunization exacerbated scores in 1° ATD-eyes and exacerbated 1° ATD-LG atrophy. IMIP were evident in 2° ATD-LG as well as 1° ATD-LG. PCA described diverse immunophysiological phenotypes in control LG and diverse IMIP phenotypes in ATD-LG. IgG titers and SI pre-adoptive transfer were significantly associated with certain post-adoptive transfer IMIP phenotype features, and certain LG IMIP features were significantly associated with RB and STT IA scores. Conclusions The underlying variability of normal states may contribute to the diversity of experimental IMIP phenotypes. The ability to generate and characterize diverse phenotypes may lead to phenotype-specific diagnostic and therapeutic paradigms. PMID:27423911

  5. Human papillomavirus: cause of epithelial lacrimal sac neoplasia?

    DEFF Research Database (Denmark)

    Sjö, Nicolai Christian; von Buchwald, Christian; Cassonnet, Patricia

    2007-01-01

    PURPOSE: Epithelial tumours of the lacrimal sac are rare but important entities that may carry grave prognoses. In this study the prevalence and possible role of human papillomavirus (HPV) infection in epithelial tumours of the lacrimal sac were evaluated. METHODS: Five papillomas and six...... 11 RNA was demonstrated in two papillomas. CONCLUSIONS: By analysing 11 epithelial lacrimal sac papillomas and carcinomas using PCR, DNA ISH and RNA ISH, we found HPV DNA in all investigated transitional epithelium tumours of the lacrimal sac. HPV RNA was present in two of eight epithelial lacrimal...... sac tumours positive for HPV DNA. As RNA degrades fast in paraffin-embedded tissue, only a small fraction of DNA-positive tumours can be expected to be RNA-positive. We therefore suggest that HPV infection is associated with the development of lacrimal sac papillomas and carcinomas....

  6. Epithelial Markers aSMA, Krt14, and Krt19 Unveil Elements of Murine Lacrimal Gland Morphogenesis and Maturation.

    Science.gov (United States)

    Kuony, Alison; Michon, Frederic

    2017-01-01

    As an element of the lacrimal apparatus, the lacrimal gland (LG) produces the aqueous part of the tear film, which protects the eye surface. Therefore, a defective LG can lead to serious eyesight impairment. Up to now, little is known about LG morphogenesis and subsequent maturation. In this study, we delineated elements of the cellular and molecular events involved in LG formation by using three epithelial markers, namely aSMA, Krt14, and Krt19. While aSMA marked a restricted epithelial population of the terminal end buds (TEBs) in the forming LG, Krt14 was found in the whole embryonic LG epithelial basal cell layer. Interestingly, Krt19 specifically labeled the presumptive ductal domain and subsequently, the luminal cell layer. By combining these markers, the Fucci reporter mouse strain and genetic fate mapping of the Krt14 + population, we demonstrated that LG epithelium expansion is fuelled by a patterned cell proliferation, and to a lesser extent by epithelial reorganization and possible mesenchymal-to-epithelial transition. We pointed out that this epithelial reorganization, which is associated with apoptosis, regulated the lumen formation. Finally, we showed that the inhibition of Notch signaling prevented the ductal identity from setting, and led to a LG covered by ectopic TEBs. Taken together our results bring a deeper understanding on LG morphogenesis, epithelial domain identity, and organ expansion.

  7. Tissue engineering in dentistry.

    Science.gov (United States)

    Abou Neel, Ensanya Ali; Chrzanowski, Wojciech; Salih, Vehid M; Kim, Hae-Won; Knowles, Jonathan C

    2014-08-01

    of this review is to inform practitioners with the most updated information on tissue engineering and its potential applications in dentistry. The authors used "PUBMED" to find relevant literature written in English and published from the beginning of tissue engineering until today. A combination of keywords was used as the search terms e.g., "tissue engineering", "approaches", "strategies" "dentistry", "dental stem cells", "dentino-pulp complex", "guided tissue regeneration", "whole tooth", "TMJ", "condyle", "salivary glands", and "oral mucosa". Abstracts and full text articles were used to identify causes of craniofacial tissue loss, different approaches for craniofacial reconstructions, how the tissue engineering emerges, different strategies of tissue engineering, biomaterials employed for this purpose, the major attempts to engineer different dental structures, finally challenges and future of tissue engineering in dentistry. Only those articles that dealt with the tissue engineering in dentistry were selected. There have been a recent surge in guided tissue engineering methods to manage periodontal diseases beyond the traditional approaches. However, the predictable reconstruction of the innate organisation and function of whole teeth as well as their periodontal structures remains challenging. Despite some limited progress and minor successes, there remain distinct and important challenges in the development of reproducible and clinically safe approaches for oral tissue repair and regeneration. Clearly, there is a convincing body of evidence which confirms the need for this type of treatment, and public health data worldwide indicates a more than adequate patient resource. The future of these therapies involving more biological approaches and the use of dental tissue stem cells is promising and advancing. Also there may be a significant interest of their application and wider potential to treat disorders beyond the craniofacial region. Considering the

  8. Aquaporins and Gland Secretion.

    Science.gov (United States)

    Delporte, Christine

    2017-01-01

    Aquaporins (AQPs ) are expressed in most exocrine and endocrine secretory glands. Consequently, summarizing the expression and functions of AQPs in secretory glands represents a daunting task considering the important number of glands present in the body, as well as the number of mammalian AQPs - thirteen. The roles played by AQPs in secretory processes have been investigated in many secretory glands. However, despite considerable research, additional studies are clearly needed to pursue our understanding of the role played by AQPs in secretory processes. This book chapter will focus on summarizing the current knowledge on AQPs expression and function in the gastrointestinal tract , including salivary glands, gastric glands, Duodenal Brunner's gland, liver and gallbladder, intestinal goblets cells, exocrine and endocrine pancreas, as well as few other secretory glands including airway submucosal glands, lacrimal glands, mammary glands and eccrine sweat glands.

  9. TH17 cells mediate inflammation in a novel model of spontaneous experimental autoimmune lacrimal keratoconjunctivitis with neural damage.

    Science.gov (United States)

    Seo, Kyoung Yul; Kitamura, Kazuya; Han, Soo Jung; Kelsall, Brian

    2017-09-27

    Dry eye disease (DED) affects one third of the population worldwide. In prior studies, experimental autoimmune lacrimal keratoconjunctivitis (EALK) induced by desiccating stress in mice has been used as a model of DED. This model is complicated by a requirement for exogenous epithelial cell injury and administration of anticholinergic agents with broad immunologic effects. We sought to develop a novel mouse model of EALK and to demonstrate the responsible pathogenic mechanisms. CD4 + CD45RB high naive T cells with and without CD4 + CD45RB low regulatory T cells were adoptively transferred to C57BL/10 recombination-activating gene 2 (Rag2) -/- mice. The eyes, draining lymph nodes, lacrimal glands, and surrounding tissues of mice with and without spontaneous keratoconjunctivitis were evaluated for histopathologic changes, cellular infiltration, and cytokine production in tissues and isolated cells. Furthermore, the integrity of the corneal nerves was evaluated using whole-tissue immunofluorescence imaging. Gene-deficient naive T cells or RAG2-deficient hosts were evaluated to assess the roles of IFN-γ, IL-17A, and IL-23 in disease pathogenesis. Finally, cytokine levels were determined in the tears of patients with DED. EALK developed spontaneously in C57BL/10 Rag2 -/- mice after adoptive transfer of CD4 + CD45RB high naive T cells and was characterized by infiltration of CD4 + T cells, macrophages, and neutrophils. In addition to lacrimal keratoconjunctivitis, mice had damage to the corneal nerve, which connects components of the lacrimal functional unit. Pathogenic T-cell differentiation was dependent on IL-23p40 and controlled by cotransferred CD4 + CD45RB low regulatory T cells. T H 17 rather than T H 1 CD4 + cells were primarily responsible for EALK, even though levels of both IL-17 and IFN-γ were increased in inflammatory tissues, likely because of their ability to drive expression of CXC chemokines within the cornea and the subsequent influx of myeloid cells

  10. A link between interferon and augmented plasmin generation in exocrine gland damage in Sjögren's syndrome.

    Science.gov (United States)

    Gliozzi, Maria; Greenwell-Wild, Teresa; Jin, Wenwen; Moutsopoulos, Niki M; Kapsogeorgou, Efstathia; Moutsopoulos, Haralampos M; Wahl, Sharon M

    2013-02-01

    Sjögren's syndrome is an autoimmune disease that targets exocrine glands, but often exhibits systemic manifestations. Infiltration of the salivary and lacrimal glands by lymphoid and myeloid cells orchestrates a perpetuating immune response leading to exocrine gland damage and dysfunction. Th1 and Th17 lymphocyte populations and their products recruit additional lymphocytes, including B cells, but also large numbers of macrophages, which accumulate with disease progression. In addition to cytokines, chemokines, chitinases, and lipid mediators, macrophages contribute to a proteolytic milieu, underlying tissue destruction, inappropriate repair, and compromised glandular functions. Among the proteases enhanced in this local environment are matrix metalloproteases (MMP) and plasmin, generated by plasminogen activation, dependent upon plasminogen activators, such as tissue plasminogen activator (tPA). Not previously associated with salivary gland pathology, our evidence implicates enhanced tPA in the context of inflamed salivary glands revolving around lymphocyte-mediated activation of macrophages. Tracking down the mechanism of macrophage plasmin activation, the cytokines IFNγ and to a lesser extent, IFNα, via Janus kinase (JAK) and signal transducer and activator of transcription (STAT) activation, were found to be pivotal for driving the plasmin cascade of proteolytic events culminating in perpetuation of the inflammation and tissue damage, and suggesting intervention strategies to blunt irreversible tissue destruction. Published by Elsevier Ltd.

  11. An Ectopic Thyroid Gland and Tissue in the Goat Pituitary Gland – A ...

    African Journals Online (AJOL)

    An Ectopic Thyroid Gland and Tissue in the Goat Pituitary Gland – A Short Communication. H B O'Hara, D Oduor-Okele, S Gombe. Abstract. No Abstract. Kenya Veterinarian Vol. 15 1991: pp. 45-46. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  12. Exérese do segmento vertical do canalículo lacrimal na síndrome do olho seco: estudo preliminar Removal of the vertical portion of the lacrimal canaliculus in dry eye syndrome

    Directory of Open Access Journals (Sweden)

    Eliana Forno

    2005-04-01

    Full Text Available OBJETIVO: Avaliar a eficácia e possíveis complicações da remoção do segmento vertical do canalículo lacrimal, em pacientes com síndrome do olho seco grave. MÉTODOS: Seis canalículos de quatro pacientes, 3 dos quais tinham o diagnóstico de olho seco associado à síndrome de Sjögren primária e o quarto, ceratoconjuntivite sicca por remoção completa de glândula lacrimal, foram submetidos a exérese do segmento vertical do canalículo lacrimal. Os critérios de inclusão foram: sinais e sintomas de olho seco que não melhoraram com tratamento clínico, Schirmer menor que 5 mm, rosa bengala corando córnea e conjuntiva e casos de recanalização após eletrocauterização dos pontos. Os pontos lacrimais foram avaliados por exame biomicroscópico após 7, 15, 30, 90 e 180 dias da cirurgia. RESULTADOS: No período de seguimento, nenhum canalículo sofreu recanalização. Em cinco olhos, houve diminuição da ceratite ponteada difusa e dos filamentos corneanos e melhora nos valores do teste de Schirmer e rosa bengala. No olho submetido à remoção completa da glândula lacrimal, a córnea ainda apresentava ceratite ponteada difusa, mesmo após dois meses de cirurgia. Não houve alterações da margem palpebral. CONCLUSÃO: Esta técnica, além de mostrar-se efetiva e simples para oclusão permanente do canalículo lacrimal, não cursou com complicações observadas em outros procedimentos.PURPOSE: To demonstrate the efficacy and possible complications of a surgical technique that includes the removal of the vertical portion of the lacrimal canaliculus in patients with dry eye syndrome. METHODS: A study was performed on six canaliculi of six eyes (four patients. Three patients had dry eye, associated with primary Sjögren syndrome. One of the four patients developed keratoconjuntivitis sicca due to lacrimal gland removal. The criteria included: patients with symptoms of dry eye that did not improve even with the continuous use of

  13. Tissue engineering: state of the art in oral rehabilitation.

    Science.gov (United States)

    Scheller, E L; Krebsbach, P H; Kohn, D H

    2009-05-01

    More than 85% of the global population requires repair or replacement of a craniofacial structure. These defects range from simple tooth decay to radical oncologic craniofacial resection. Regeneration of oral and craniofacial tissues presents a formidable challenge that requires synthesis of basic science, clinical science and engineering technology. Identification of appropriate scaffolds, cell sources and spatial and temporal signals (the tissue engineering triad) is necessary to optimize development of a single tissue, hybrid organ or interface. Furthermore, combining the understanding of the interactions between molecules of the extracellular matrix and attached cells with an understanding of the gene expression needed to induce differentiation and tissue growth will provide the design basis for translating basic science into rationally developed components of this tissue engineering triad. Dental tissue engineers are interested in regeneration of teeth, oral mucosa, salivary glands, bone and periodontium. Many of these oral structures are hybrid tissues. For example, engineering the periodontium requires growth of alveolar bone, cementum and the periodontal ligament. Recapitulation of biological development of hybrid tissues and interfaces presents a challenge that exceeds that of engineering just a single tissue. Advances made in dental interface engineering will allow these tissues to serve as model systems for engineering other tissues or organs of the body. This review will begin by covering basic tissue engineering principles and strategic design of functional biomaterials. We will then explore the impact of biomaterials design on the status of craniofacial tissue engineering and current challenges and opportunities in dental tissue engineering.

  14. Cloning, overexpression, purification, crystallization and preliminary X-ray analysis of a female-specific lipocalin (FLP) expressed in the lacrimal glands of Syrian hamsters

    International Nuclear Information System (INIS)

    Dubey, Ved Prakash; Pal, Biswajit; Srikantan, Subramanya; Pottabathini, Sambhavi; De, Prabir Kumar; Sankaranarayanan, Rajan

    2010-01-01

    A female-specific lacrimal protein from Syrian hamsters has been crystallized by the sitting-drop vapour-diffusion method. The crystals belonged to space group P2 1 2 1 2 1 and diffraction data were collected to 1.86 Å resolution. Proteins belonging to the lipocalin superfamily are usually secretory proteins of molecular mass ∼20 kDa with a hydrophobic pocket for the binding and transport of diverse small ligands. Various lipocalins have been associated with many biological processes, e.g. immunomodulation, odorant transport, pheromonal activity, retinoid transport, cancer-cell interactions etc. However, the exact functions of many lipocalins and the ligands bound by them are unclear. Previously, the cDNA of a 20 kDa lipocalin (FLP) which is female-specifically expressed in the lacrimal glands of Syrian (golden) hamsters and secreted in the tears of females has been identified and cloned. His-tagged recombinant FLP (rFLP) has now been cloned, overexpressed in Escherichia coli as a soluble protein and purified to homogeneity using Ni-affinity followed by size-exclusion chromatography. Purified rFLP was crystallized using the sitting-drop vapour-diffusion method. The crystals tested belonged to space group P2 1 2 1 2 1 and diffracted to beyond 1.86 Å resolution. Solvent-content analysis indicated the presence of one monomer in the asymmetric unit

  15. Insulin replacement restores the vesicular secretory apparatus in the diabetic rat lacrimal gland

    Directory of Open Access Journals (Sweden)

    Ana Carolina Dias

    2015-06-01

    Full Text Available ABSTRACT Purpose: In the lacrimal gland (LG acinar cells, signaling regulates the release of secretory vesicles through specific Rab and SNARE exocytotic proteins. In diabetes mellitus (DM, the LGs are dysfunctional. The aim of this work was to determine if secretory apparatus changes were associated with any effects on the secretory vesicles (SV in diabetic rats as well as the expression levels of constituent Rab and members of the SNARE family, and if insulin supplementation reversed those changes. Methods: DM was induced in male Wistar rats with an intravenous dose of streptozotocin (60 mg/kg. One of the two diabetic groups was then treated every other day with insulin (1 IU. A third control group was injected with vehicle. After 10 weeks, Western blotting and RT-PCR were used to compared the Rab and SNARE secretory factor levels in the LGs. Transmission electron microscopy evaluated acinar cell SV density and integrity. Results: In the diabetes mellitus group, there were fewer and enlarged SV. The Rab 27b, Rab 3d, and syntaxin-1 protein expression declined in the rats with diabetes mellitus. Insulin treatment restored the SV density and the Rab 27b and syntaxin expression to their control protein levels, whereas the Vamp 2 mRNA expression increased above the control levels. Conclusions: Diabetes mellitus LG changes were associated with the declines in protein expression levels that were involved in supporting exocytosis and vesicular formation. They were partially reversed by insulin replacement therapy. These findings may help to improve therapeutic management of dry eye in diabetes mellitus.

  16. A Chronic Autoimmune Dry Eye Rat Model with Increase in Effector Memory T Cells in Eyeball Tissue.

    Science.gov (United States)

    Hou, Aihua; Bose, Tanima; Chandy, K George; Tong, Louis

    2017-06-07

    Dry eye disease is a very common condition that causes morbidity and healthcare burden and decreases the quality of life. There is a need for a suitable dry eye animal model to test novel therapeutics to treat autoimmune dry eye conditions. This protocol describes a chronic autoimmune dry eye rat model. Lewis rats were immunized with an emulsion containing lacrimal gland extract, ovalbumin, and complete Freund's adjuvant. A second immunization with the same antigens in incomplete Freund's adjuvant was administered two weeks later. These immunizations were administered subcutaneously at the base of the tail. To boost the immune response at the ocular surface and lacrimal glands, lacrimal gland extract and ovalbumin were injected into the forniceal subconjunctiva and lacrimal glands 6 weeks after the first immunization. The rats developed dry eye features, including reduced tear production, decreased tear stability, and increased corneal damage. Immune profiling by flow cytometry showed a preponderance of CD3 + effector memory T cells in the eyeball.

  17. Anti-inflammatory effects of rebamipide eyedrop administration on ocular lesions in a murine model of primary Sjögren's syndrome.

    Directory of Open Access Journals (Sweden)

    Rieko Arakaki

    Full Text Available Topical therapy is effective for dry eye, and its prolonged effects should help in maintaining the quality of life of patients with dry eye. We previously reported that the oral administration of rebamipide (Reb, a mucosal protective agent, had a potent therapeutic effect on autoimmune lesions in a murine model of Sjögren's syndrome (SS. However, the effects of topical treatment with Reb eyedrops on the ocular lesions in the murine model of SS are unknown.Reb eyedrops were administered to the murine model of SS aged 4-8 weeks four times daily. Inflammatory lesions of the extraorbital and intraorbital lacrimal glands and Harderian gland tissues were histologically evaluated. The direct effects of Reb on the lacrimal glands were analyzed using cultured lacrimal gland cells. Tear secretions of Reb-treated mice were significantly increased compared with those of untreated mice. In addition to the therapeutic effect of Reb treatment on keratoconjunctivitis, severe inflammatory lesions of intraorbital lacrimal gland tissues in this model of SS were resolved. The mRNA expression levels of IL-10 and mucin 5Ac in conjunctival tissues from Reb-treated mice was significantly increased compared with those of control mice. Moreover, lactoferrin production from lacrimal gland cells was restored by Reb treatment.Topical Reb administration had an anti-inflammatory effect on the ocular autoimmune lesions in the murine model of SS and a protective effect on the ocular surfaces.

  18. The salivary glands in Sjögren's syndrome : pathogenetic aspects of the initiation of sialoadenitis

    NARCIS (Netherlands)

    S.C.A. van Blokland (Saskia)

    2001-01-01

    textabstractSjögren's syndrome is a chronic inflammatory disorder with autoimmune etiology, affecting primarily the salivary and lacrimal glands. In these glands. focallymphocytic infiltrates develop. This is accompanied by decreased production of saliva and tears. resulting in patients complaining

  19. [Lacrimal sac tumors presenting as lacrimal obstruction. Retrospective study in Mexican patients 2007-2012].

    Science.gov (United States)

    Coloma-González, I; Flores-Preciado, J; Ceriotto, A; Corredor-Casas, S; Salcedo-Casillas, G

    2014-06-01

    To determine the demographic and clinical data of primary tumors of the lacrimal sac presenting as lacrimal obstruction. Retrospective and descriptive study was conducted between the years 2007 to 2012 on all patients undergoing surgery for low lacrimal obstruction at Dr. Luis Sanchez Bulnes Hospital, an Association for the prevention of blindness in Mexico IAP. Primary tumors of the lacrimal sac represented 2.5% of all lacrimal obstructions, being more common in women than in men (8:1). The large majority (89%) of the cases were non-epithelial, with lymphoid lesions being the most frequent. Benign tumors were presented at a younger age (50 years old) than malignant (70 years old). One-third (33%) of cases were unexpected findings during surgery (100% benign). Just over half (55%) were malignant tumors (1.4% of obstructions), all of them lymphoproliferative lesions. The most frequent clinical tumor was in the inner edge, either with or without epiphora. The progression time varied according to the degree of aggressiveness of the lymphoma (3 months-10 years). Lacrimal sac tumors are rare, but they must be taken into account in patients with an unusual clinical presentation of lacrimal obstruction. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  20. Oral administration of royal jelly restores tear secretion capacity in rat blink-suppressed dry eye model by modulating lacrimal gland function.

    Directory of Open Access Journals (Sweden)

    Toshihiro Imada

    Full Text Available Tears are secreted from the lacrimal gland (LG, a dysfunction in which induces dry eye, resulting in ocular discomfort and visual impairment. Honey bee products are used as a nutritional source in daily life and medicine; however, little is known about their effects on dry eye. The aim of the present study was to investigate the effects of honey bee products on tear secretion capacity in dry eye. We selected raw honey, propolis, royal jelly (RJ, pollen, or larva from commercially available honey bee products. Tear secretion capacity was evaluated following the oral administration of each honey bee product in a rat blink-suppressed dry eye model. Changes in tear secretion, LG ATP content, and LG mitochondrial levels were measured. RJ restored the tear secretion capacity and decrease in LG ATP content and mitochondrial levels to the largest extent. Royal jelly can be used as a preventative intervention for dry eye by managing tear secretion capacity in the LG.

  1. Association of Bone Morphogenetic Protein 6 With Exocrine Gland Dysfunction in Patients With Sjögren’s Syndrome and in Mice

    Science.gov (United States)

    Yin, Hongen; Cabrera-Perez, Javier; Lai, Zhenan; Michael, Drew; Weller, Melodie; Swaim, William D.; Liu, Xibao; Catalán, Marcelo A.; Rocha, Eduardo M.; Ismail, Nevien; Afione, Sandra; Rana, Noreen A.; Di Pasquale, Giovanni; Alevizos, Ilias; Ambudkar, Indu; Illei, Gabor G.; Chiorini, John A.

    2014-01-01

    Objective Primary Sjögren’s syndrome (SS) is characterized by autoimmune activation and loss of function in secretory epithelia. The present study was undertaken to investigate and characterize changes in the epithelia associated with the loss of gland function in primary SS. Methods To identify changes in epithelial gene expression, custom microarrays were probed with complementary RNA (cRNA) isolated from minor salivary glands (MSGs) of female patients with primary SS who had low focus scores and low salivary flow rates, and the results were compared with those obtained using cRNA from the MSGs of sex-matched healthy volunteers. The effect of bone morphogenetic protein 6 (BMP-6) on salivary gland function was tested using adeno-associated virus–mediated gene transfer to the salivary glands of C57BL/6 mice. Results A significant increase in expression of BMP-6 was observed in RNA isolated from SS patients compared with healthy volunteers. Overexpression of BMP-6 locally in the salivary or lacrimal glands of mice resulted in the loss of fluid secretion as well as changes in the connective tissue of the salivary gland. Assessment of the fluid movement in either isolated acinar cells from mice overexpressing BMP-6 or a human salivary gland cell line cultured with BMP-6 revealed a loss in volume regulation in these cells. Lymphocytic infiltration in the submandibular gland of BMP-6 vector–treated mice was increased. No significant changes in the production of proinflammatory cytokines or autoantibodies associated with SS (anti-Ro/SSA and anti-La/SSB) were found after BMP-6 overexpression. Conclusion In addition to identifying BMP-6 expression in association with xerostomia and xerophthalmia in primary SS, the present results suggest that BMP-6–induced salivary and lacrimal gland dysfunction in primary SS is independent of the autoantibodies and immune activation associated with the disease. PMID:23982860

  2. Lacrimal dacryoscintigraphy

    International Nuclear Information System (INIS)

    von Denffer, H.; Dressler, J.; Pabst, H.W.

    1984-01-01

    Lacrimal dacryoscintigraphy facilitates definite diagnosis of obstructions and stenosis of the lacrimal drainage system with little stress to the patient. Together with x-ray dacryocystography it is an important diagnostic tool especially for pre- and postoperative evaluation of the drainage apparatus. Dacryoscintigraphy is the best method for measuring the dynamics of tear drainage especially in the canaliculi. Although it is not a substitute for other methods in general use, it complements them and expands their diagnostic accuracy

  3. Time course of ocular surface and lacrimal gland changes in a new scopolamine-induced dry eye model.

    Science.gov (United States)

    Viau, Sabrina; Maire, Marie-Annick; Pasquis, Bruno; Grégoire, Stéphane; Fourgeux, Cynthia; Acar, Niyazi; Bretillon, Lionel; Creuzot-Garcher, Catherine P; Joffre, Corinne

    2008-06-01

    The aim of this study was to set up an animal model of dry eye showing disturbance in several components of the lacrimal functional unit, and to describe the time course of the appearance of clinical signs and inflammatory markers. Dry eye was induced in 6-week-old female Lewis rats by a systemic and continuous delivery of scopolamine via osmotic pumps implanted subcutaneously. We first determined the appropriate dose of scopolamine (6, 12.5, or 25 mg/day) for 28 days. In a second set of experiments, we determined markers after 1, 2, 3, 7, 10, 17, or 28 days of a 12.5-mg/day dose. Clinical signs of corneal dryness were evaluated in vivo using fluorescein staining. MHC II expression and mucin Muc5AC production were detected on the conjunctival epithelium using immunostaining. The level of IL-1beta, IL-6, TNF-alpha, and IFN-gamma mRNA was evaluated by real-time polymerase chain reaction in conjunctiva and exorbital lacrimal gland (LG). Lipids were extracted from the exorbital LG for fatty acid analysis. Daily scopolamine doses of 12.5 mg and 25 mg applied for a 28-day period induced keratitis, a decrease in Muc5AC immunostaining density in the conjunctival epithelium, and modifications in the fatty acid composition of the exorbital LG. Animals treated with a 12.5-mg/day dose of scopolamine exhibited an increase in corneal fluorescein staining after 2, 10, and 28 days. All animals exhibited unilateral or bilateral keratitis after 17 days. In the conjunctival epithelium, a significant decrease in Muc5AC immunostaining density was observed at early and late time points, and MHC II expression tended to be increased after 1, 7, 10, and 28 days, without reaching statistical significance. The levels of TNF-alpha, IL-1beta and IL-6 mRNA were increased with scopolamine treatment in both conjunctiva and exorbital LG. Arachidonic acid and the Delta5 desaturase index were significantly increased in the exorbital LG of dry eye animals at each time point. This systemic and

  4. Cytopathology and exocrine dysfunction induced in ex vivo rabbit lacrimal gland acinar cell models by chronic exposure to histamine or serotonin.

    Science.gov (United States)

    McDonald, Michelle L; Wang, Yanru; Selvam, Shivaram; Nakamura, Tamako; Chow, Robert H; Schechter, Joel E; Yiu, Samuel C; Mircheff, Austin K

    2009-07-01

    Lacrimal immunohistopathology has diverse clinical presentations, suggesting that inflammatory mediators exert diverse influences. Chronic exposure to agonistic acetylcholine receptor autoantibodies has been studied previously; the present work addressed mediators that signal through other G protein-coupled receptors. Acinus-like structures and reconstituted acinar epithelial monolayers from rabbit lacrimal glands were exposed to varying concentrations of histamine or 5-hydroxytryptamine (5-HT) for 20 hours. Net and vectorial beta-hexosaminidase secretion, cytosolic Ca(2+) (Ca(i)) elevation, apical recruitment of p150(Glued), actin microfilament meshwork organization, and ultrastructure were assessed. Histamine and 5-HT acutely stimulated beta-hexosaminidase secretion at lower, but not higher, concentrations. Neither of them acutely elevated Ca(i) levels. Both recruited p150(Glued) at concentrations that failed to induce secretion. Chronic exposure to 10 mM histamine inhibited carbachol (CCh)-induced beta-hexosaminidase secretion and prevented the formation of continuous monolayers; 1 mM 5-HT partially inhibited secretion at the apical medium. Neither altered secretion to the basal medium. Chronic exposure to histamine or 5-HT partially decreased CCh induced Ca(i) elevations and p150(Glued) recruitment, even at concentrations that did not inhibit secretion. Both expanded acinar lumina and thickened microfilament meshworks, and both caused homotypic fusion of secretory vesicles and formation of aqueous vacuoles in the apical and basal cytoplasm. Chronic exposure to forskolin, which activates adenylyl cyclase, induced similar cytopathologic changes but impaired secretion modestly and only at the highest concentration tested. Inflammatory mediators that signal through G protein-coupled receptors cause acinar cell cytopathology and dose-dependent reductions of CCh-induced beta-hexosaminidase secretion. Although agonistic acetylcholine receptor autoantibodies may cause

  5. Loss of PKCδ results in characteristics of Sjögren's syndrome including salivary gland dysfunction.

    Science.gov (United States)

    Banninger, G P; Cha, S; Said, M S; Pauley, K M; Carter, C J; Onate, M; Pauley, B A; Anderson, S M; Reyland, M E

    2011-09-01

    Chronic infiltration of lymphocytes into the salivary and lacrimal glands of patients with Sjögren's syndrome (SS) leads to destruction of acinar cells and loss of exocrine function. Protein kinase C-delta (PKCδ) is known to play a critical role in B-cell maintenance. Mice in which the PKCδ gene has been disrupted have a loss of B-cell tolerance, multiple organ lymphocytic infiltration, and altered apoptosis. To determine whether PKCδ contributes to the pathogenesis of SS, we quantified changes in indicators of SS in PKCδ-/- mice as a function of age. Salivary gland histology, function, the presence of autoantibodies, and cytokine expression were examined. Submandibular glands were examined for the presence of lymphocytic infiltrates, and the type of infiltrating lymphocyte and cytokine deposition was evaluated by immunohistochemistry. Serum samples were tested by autoantibody screening, which was graded by its staining pattern and intensity. Salivary gland function was determined by saliva collection at various ages. PKCδ-/- mice have reduced salivary gland function, B220+ B-cell infiltration, anti-nuclear antibody production, and elevated IFN-γ in the salivary glands as compared to PKCδ+/+ littermates. PKCδ-/- mice have exocrine gland tissue damage indicative of a SS-like phenotype. © 2011 John Wiley & Sons A/S.

  6. Association of bone morphogenetic protein 6 with exocrine gland dysfunction in patients with Sjögren's syndrome and in mice.

    Science.gov (United States)

    Yin, Hongen; Cabrera-Perez, Javier; Lai, Zhenan; Michael, Drew; Weller, Melodie; Swaim, William D; Liu, Xibao; Catalán, Marcelo A; Rocha, Eduardo M; Ismail, Nevien; Afione, Sandra; Rana, Noreen A; Di Pasquale, Giovanni; Alevizos, Ilias; Ambudkar, Indu; Illei, Gabor G; Chiorini, John A

    2013-12-01

    Primary Sjögren's syndrome (SS) is characterized by autoimmune activation and loss of function in secretory epithelia. The present study was undertaken to investigate and characterize changes in the epithelia associated with the loss of gland function in primary SS. To identify changes in epithelial gene expression, custom microarrays were probed with complementary RNA (cRNA) isolated from minor salivary glands (MSGs) of female patients with primary SS who had low focus scores and low salivary flow rates, and the results were compared with those obtained using cRNA from the MSGs of sex-matched healthy volunteers. The effect of bone morphogenetic protein 6 (BMP-6) on salivary gland function was tested using adeno-associated virus-mediated gene transfer to the salivary glands of C57BL/6 mice. A significant increase in expression of BMP-6 was observed in RNA isolated from SS patients compared with healthy volunteers. Overexpression of BMP-6 locally in the salivary or lacrimal glands of mice resulted in the loss of fluid secretion as well as changes in the connective tissue of the salivary gland. Assessment of the fluid movement in either isolated acinar cells from mice overexpressing BMP-6 or a human salivary gland cell line cultured with BMP-6 revealed a loss in volume regulation in these cells. Lymphocytic infiltration in the submandibular gland of BMP-6 vector-treated mice was increased. No significant changes in the production of proinflammatory cytokines or autoantibodies associated with SS (anti-Ro/SSA and anti-La/SSB) were found after BMP-6 overexpression. In addition to identifying BMP-6 expression in association with xerostomia and xerophthalmia in primary SS, the present results suggest that BMP-6-induced salivary and lacrimal gland dysfunction in primary SS is independent of the autoantibodies and immune activation associated with the disease. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  7. Lacrimal drainage system obstruction associated to radioactive iodine therapy for thyroid carcinoma; Obstrucao de vias lacrimais associada ao tratamento radioiodoterapico de carcinoma de tireoide

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Fabricio Lopes da; Lunardelli, Patricia; Matayoshi, Suzana, E-mail: suzana.matayoshi@gmail.com [Setor de Plastica Ocular, Divisao de Clinica Oftalmologica, Universidade de Sao Paulo (HC/FM/USP), Sao Paulo (SP) (Brazil)

    2012-03-15

    Purpose: To report the finding of nasolacrimal drainage system obstruction associated with radio iodine therapy and to review clinical data and the surgical treatment outcome of this rare complication. Methods: We retrospectively analyzed ophthalmological data of patients with history of thyroid carcinoma that underwent radioactive iodine I-131 therapy and were referred to lacrimal surgery. Results: 17 patients with thyroid cancer treated with thyroidectomy and radioactive iodine I-131 therapy presented symptomatic nasolacrimal duct obstruction after 13.2 months following cancer treatment. 11 patients presented bilateral epiphora, 8 had lacrimal sac mucocele. Age range was 30 to 80 years, 10 patients had less than or equal to 49 years. The mean cumulative dose of radioiodine was 571mCi (range: 200-1200 mCi). Nasal obstruction symptoms and increased salivary glands were also present in 53% of patients. All subjects underwent dacryocystorhinostomy. Dilation of the lacrimal sac and increased intraoperative bleeding was also observed in 3 younger patients. Complete epiphora and dacryocystitis resolution after surgery occurred in 82.4%, and partial in 17.6% (3 patients that still presented unilateral relapse after correction of bilateral obstruction). Mean follow-up was 6 months (range: 2-24 months). Conclusions: Cumulative high dose of radioiodine, nasal and salivary gland dysfunction are associated with lacrimal drainage obstruction. We observed a great percentage of younger patients presenting dacryocystitis when compared to the idiopathic dacryostenosis. Radioactive iodine uptake by nasolacrimal duct mucosa with subsequent inflammation, edema and fibrosis seems to have a relationship to lacrimal duct obstruction. The knowledge of this complication is important for the study and proper management of these patients (author)

  8. Adipose tissue and adrenal glands: novel pathophysiological mechanisms and clinical applications.

    Science.gov (United States)

    Kargi, Atil Y; Iacobellis, Gianluca

    2014-01-01

    Hormones produced by the adrenal glands and adipose tissues have important roles in normal physiology and are altered in many disease states. Obesity is associated with changes in adrenal function, including increase in adrenal medullary catecholamine output, alterations of the hypothalamic-pituitary-adrenal (HPA) axis, elevations in circulating aldosterone together with changes in adipose tissue glucocorticoid metabolism, and enhanced adipocyte mineralocorticoid receptor activity. It is unknown whether these changes in adrenal endocrine function are in part responsible for the pathogenesis of obesity and related comorbidities or represent an adaptive response. In turn, adipose tissue hormones or "adipokines" have direct effects on the adrenal glands and interact with adrenal hormones at several levels. Here we review the emerging evidence supporting the existence of "cross talk" between the adrenal gland and adipose tissue, focusing on the relevance and roles of their respective hormones in health and disease states including obesity, metabolic syndrome, and primary disorders of the adrenals.

  9. Adipose Tissue and Adrenal Glands: Novel Pathophysiological Mechanisms and Clinical Applications

    Directory of Open Access Journals (Sweden)

    Atil Y. Kargi

    2014-01-01

    Full Text Available Hormones produced by the adrenal glands and adipose tissues have important roles in normal physiology and are altered in many disease states. Obesity is associated with changes in adrenal function, including increase in adrenal medullary catecholamine output, alterations of the hypothalamic-pituitary-adrenal (HPA axis, elevations in circulating aldosterone together with changes in adipose tissue glucocorticoid metabolism, and enhanced adipocyte mineralocorticoid receptor activity. It is unknown whether these changes in adrenal endocrine function are in part responsible for the pathogenesis of obesity and related comorbidities or represent an adaptive response. In turn, adipose tissue hormones or “adipokines” have direct effects on the adrenal glands and interact with adrenal hormones at several levels. Here we review the emerging evidence supporting the existence of “cross talk” between the adrenal gland and adipose tissue, focusing on the relevance and roles of their respective hormones in health and disease states including obesity, metabolic syndrome, and primary disorders of the adrenals.

  10. Dacryoscintigraphy

    International Nuclear Information System (INIS)

    Heyman, S.; Katowitz, J.A.

    1985-01-01

    An adequate flow of tears is important for the normal function of the eye. The tears serve several purposes, such as providing an optically uniform field, a lubricating and antibacterial function, as well as nourishing the cornea. The lacrimal gland, accessory lacrimal gland tissue, and secretions of the meibomian and mucous glands of the conjunctiva contribute to the formation of tears. Tearing occurs when the tear production is excessive or there is an abnormality of drainage. Tearing (epiphora) is the most frequent symptom of lacrimal drainage dysfunction. The diagnosis and treatment of tearing disorders present some of the most common challenges facing the clinician

  11. Tissue engineering

    CERN Document Server

    Fisher, John P; Bronzino, Joseph D

    2007-01-01

    Increasingly viewed as the future of medicine, the field of tissue engineering is still in its infancy. As evidenced in both the scientific and popular press, there exists considerable excitement surrounding the strategy of regenerative medicine. To achieve its highest potential, a series of technological advances must be made. Putting the numerous breakthroughs made in this field into a broad context, Tissue Engineering disseminates current thinking on the development of engineered tissues. Divided into three sections, the book covers the fundamentals of tissue engineering, enabling technologies, and tissue engineering applications. It examines the properties of stem cells, primary cells, growth factors, and extracellular matrix as well as their impact on the development of tissue engineered devices. Contributions focus on those strategies typically incorporated into tissue engineered devices or utilized in their development, including scaffolds, nanocomposites, bioreactors, drug delivery systems, and gene t...

  12. Lacrimal system physiology: radioisotope study

    International Nuclear Information System (INIS)

    De Rossi, G.; Salvatori, M.; Focosi, F.; Dickmann, A.

    1982-01-01

    Lacrimal scintigraphy was used to illustrate the physiology of the lacrimal drainage system in 37 normal patients. Sup(99m)Tc-pertechnetate was dropped on to the conjunctive near the lateral chantus and serial images were displayed dynamically on a video display. It was concluded that this technique provides a very sensitive and reproducible test of the functional status of nasolacrimal drainage along with a graphic documentation at any given time and thus could be extremely useful in the diagnosis of lacrimal pathology. (U.K.)

  13. Bilateral congenital lacrimal fistulas in an adult as part of ectrodactyly-ectodermal dysplasia-clefting syndrome: A rare anomaly.

    Science.gov (United States)

    Ghosh, Debangshu; Saha, Somnath; Basu, Sumit Kumar

    2015-10-01

    Ectrodactyly-ectodermal dysplasia and clefting syndrome or "Lobster claw" deformity is a rare congenital anomaly that affects tissues of ectodermal and mesodermal origin. Nasolacrimal duct (NLD) obstruction with or without atresia of lacrimal passage is a common finding of such a syndrome. The authors report here even a rarer presentation of the syndrome which manifested as bilateral NLD obstruction and lacrimal fistula along with cleft lip and palate, syndactyly affecting all four limbs, mild mental retardation, otitis media, and sinusitis. Lacrimal duct obstruction and fistula were managed successfully with endoscopic dacryocystorhinostomy (DCR) which is a good alternative to lacrimal probing or open DCR in such a case.

  14. Bilateral congenital lacrimal fistulas in an adult as part of ectrodactyly-ectodermal dysplasia-clefting syndrome: A rare anomaly

    Directory of Open Access Journals (Sweden)

    Debangshu Ghosh

    2015-01-01

    Full Text Available Ectrodactyly-ectodermal dysplasia and clefting syndrome or "Lobster claw" deformity is a rare congenital anomaly that affects tissues of ectodermal and mesodermal origin. Nasolacrimal duct (NLD obstruction with or without atresia of lacrimal passage is a common finding of such a syndrome. The authors report here even a rarer presentation of the syndrome which manifested as bilateral NLD obstruction and lacrimal fistula along with cleft lip and palate, syndactyly affecting all four limbs, mild mental retardation, otitis media, and sinusitis. Lacrimal duct obstruction and fistula were managed successfully with endoscopic dacryocystorhinostomy (DCR which is a good alternative to lacrimal probing or open DCR in such a case.

  15. Gefarnate stimulates mucin-like glycoprotein secretion in conjunctival tissue and ameliorates corneal epithelial damage in animal dry-eye models

    Directory of Open Access Journals (Sweden)

    Dota A

    2013-01-01

    Full Text Available Atsuyoshi Dota, Yuko Takaoka-Shichijo, Masatsugu NakamuraOphthalmic Research and Development Center, Santen Pharmaceutical Co, Ltd, Ikoma-shi, Nara, JapanPurpose: The aim of this study was to evaluate the effect of gefarnate on mucin-like glycoprotein secretion in isolated rabbit conjunctival tissue, and on corneal epithelial damage in rabbit and cat dry-eye models.Methods: Conjunctival tissue isolated from rabbits was treated with gefarnate. Mucin-like glycoprotein was detected in the culture supernatant by an enzyme-linked lectin assay. Gefarnate ointment was topically applied to eyes once daily for 7 days in the rabbit dry-eye model, in which the lacrimal glands, Harderian gland, and nictitating membrane were removed, or for 4 weeks in the cat dry-eye model, in which the lacrimal gland and nictitating membrane were removed. Corneal epithelial damage was evaluated by measurement of corneal permeability by rose bengal in the rabbit model or by fluorescein staining in the cat model.Results: Gefarnate stimulated mucin-like glycoprotein secretion in conjunctival tissue in a dose-dependent manner. In the rabbit dry-eye model, application of gefarnate ointment to the eyes resulted in a dose-dependent decrease in rose bengal permeability in the cornea, with the effect being significant at concentrations of ≥0.3%. In the cat dry-eye model, application of gefarnate ointment resulted in a significant decrease in the corneal fluorescein staining score.Conclusion: These results suggest that gefarnate stimulates in vitro secretion of mucin-like glycoprotein in conjunctival tissue and ameliorates corneal epithelial damage in animal dry-eye models. Gefarnate may therefore be effective for treating dry eye.Keywords: gefarnate, fluorescein staining, rose bengal permeability, rabbit, cat, dry eye

  16. Benign mixed tumor of the lacrimal sac

    Directory of Open Access Journals (Sweden)

    Jong-Suk Lee

    2015-01-01

    Full Text Available Neoplasms of the lacrimal drainage system are uncommon, but potentially life-threatening and are often difficult to diagnose. Among primary lacrimal sac tumors, benign mixed tumors are extremely rare. Histologically, benign mixed tumors have been classified as a type of benign epithelial tumor. Here we report a case of benign mixed tumor of the lacrimal sac.

  17. Adrenal gland volume, intra-abdominal and pericardial adipose tissue in major depressive disorder.

    Science.gov (United States)

    Kahl, Kai G; Schweiger, Ulrich; Pars, Kaweh; Kunikowska, Alicja; Deuschle, Michael; Gutberlet, Marcel; Lichtinghagen, Ralf; Bleich, Stefan; Hüper, Katja; Hartung, Dagmar

    2015-08-01

    Major depressive disorder (MDD) is associated with an increased risk for the development of cardio-metabolic diseases. Increased intra-abdominal (IAT) and pericardial adipose tissue (PAT) have been found in depression, and are discussed as potential mediating factors. IAT and PAT are thought to be the result of a dysregulation of the hypothalamus-pituitary-adrenal axis (HPAA) with subsequent hypercortisolism. Therefore we examined adrenal gland volume as proxy marker for HPAA activation, and IAT and PAT in depressed patients. Twenty-seven depressed patients and 19 comparison subjects were included in this case-control study. Adrenal gland volume, pericardial, intraabdominal and subcutaneous adipose tissue were measured by magnetic resonance imaging. Further parameters included factors of the metabolic syndrome, fasting cortisol, fasting insulin, and proinflammatory cytokines. Adrenal gland and pericardial adipose tissue volumes, serum concentrations of cortisol and insulin, and serum concentrations tumor-necrosis factor-α were increased in depressed patients. Adrenal gland volume was positively correlated with intra-abdominal and pericardial adipose tissue, but not with subcutaneous adipose tissue. Our findings point to the role of HPAA dysregulation and hypercortisolism as potential mediators of IAT and PAT enlargement. Further studies are warranted to examine whether certain subtypes of depression are more prone to cardio-metabolic diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Light microscopic detection of sugar residues in glycoconjugates of salivary glands and the pancreas with lectin-horseradish peroxidase conjugates. I. Mouse.

    Science.gov (United States)

    Schulte, B A; Spicer, S S

    1983-12-01

    Mouse salivary glands and pancreases were stained with a battery of ten horseradish peroxidase-conjugated lectins. Lectin staining revealed striking differences in the structure of oligosaccharides of stored intracellular secretory glycoproteins and glycoconjugates associated with the surface of epithelial cells lining excretory ducts. The percentage of acinar cells containing terminal alpha-N-acetylgalactosamine residues varied greatly in submandibular glands of 30 male mice, but all submandibular acinar cells contained oligosaccharides with terminal sialic acid and penultimate beta-galactose residues. The last named dimer was abundant in secretory glycoprotein of all mucous acinar cells in murine sublingual glands and an additional 20-50% of these cells in all glands contained terminal N-acetylglucosamine residues. In contrast, terminal alpha-N-acetylgalactosamine was abundant in sublingual serous demilune secretions. Serous acinar cells in the exorbital lacrimal gland, posterior lingual gland, parotid gland and pancreas exhibited a staining pattern unique to each organ. In contrast, the apical cytoplasm and surface of striated duct epithelial cells in the submandibular, sublingual, parotid and exorbital lacrimal gland stained similarly. A comparison of staining with conjugated lectins reported biochemically to have very similar carbohydrate binding specificity has revealed some remarkable differences in their reactivity, suggesting different binding specificity for the same terminal sugars having different glycosidic linkages or with different penultimate sugar residues.

  19. Lacritin and other new proteins of the lacrimal functional unit.

    Science.gov (United States)

    McKown, Robert L; Wang, Ningning; Raab, Ronald W; Karnati, Roy; Zhang, Yinghui; Williams, Patricia B; Laurie, Gordon W

    2009-05-01

    The lacrimal functional unit (LFU) is defined by the 2007 International Dry Eye WorkShop as 'an integrated system comprising the lacrimal glands, ocular surface (cornea, conjunctiva and meibomian glands) and lids, and the sensory and motor nerves that connect them'. The LFU maintains a healthy ocular surface primarily through a properly functioning tear film that provides protection, lubrication, and an environment for corneal epithelial cell renewal. LFU cells express thousands of proteins. Over 200 new LFU proteins have been discovered in the last decade. Lacritin is a new LFU-specific growth factor in human tears that flows through ducts to target corneal epithelial cells on the ocular surface. When applied topically in rabbits, lacritin appears to increase the volume of basal tear secretion. Lacritin is one of only a handful of tear proteins preliminarily reported to be downregulated in blepharitis and in two dry eye syndromes. Computational analysis predicts an ordered C-terminal domain that binds the corneal epithelial cell surface proteoglycan syndecan-1 (SDC1) and is required for lacritin's low nanomolar mitogenic activity. The lacritin-binding site on the N-terminus of SDC1 is exposed by heparanase. Heparanase is constitutively expressed by the corneal epithelium and appears to be a normal constituent of tears. Binding triggers rapid signaling to downstream NFAT and mTOR. A wealth of other new proteins, originally designated as hypothetical when first identified by genomic sequencing, are expressed by the human LFU including: ALS2CL, ARHGEF19, KIAA1109, PLXNA1, POLG, WIPI1 and ZMIZ2. Their demonstrated or implied roles in human genetic disease or basic cellular functions are fuel for new investigation. Addressing topical areas in ocular surface physiology with new LFU proteins may reveal interesting new biological mechanisms and help get to the heart of ocular surface dysfunction.

  20. Clinical analysis of endoscopic common canaliculus opening operation for lacrimal sac anastomotic occlusion

    Directory of Open Access Journals (Sweden)

    Yang-Yang Xie

    2016-01-01

    Full Text Available AIM:To investigate the effect and safety of endoscopic common canaliculus opening operation for lacrimal sac anastomotic occlusion, in order to guide the clinical application.METHODS:Retrospective clinical study. Sixty-six patients(70 eyeswith lacrimal sac anastomotic occlusion were selected as the research subjects. All patients were treated by endoscopic common canaliculus opening operation. The post-operation follow-up lasted for 3~24mo. Subjective feelings of patients were recorded through the collection of clinical data, out-patient follow-up and telephone follow-up. The operation effect and complications were observed, as well as the effect of treatment on complications. Meanwhile, the data was analyzed for evaluating the clinical efficacy of endoscopic common canaliculus opening operation.RESULTS:Epiphora was disappeared or obviously improved in 68 eyes(97%, with lacrimal irrigating fluently and no obstacle. The post-operative complications included:51 eyes(73%with foreign body sensation in inner canthus, 22 eyes(31%with foreign body sensation in the nose occasionally, 4 eyes(6%with granulation tissue proliferation at the opening of common canaliculus, 16 eyes(23%with localized congestion of the bulbar conjunctiva, and 3 eyes(4%with lacrimal drainage tube out.CONCLUSION: Endoscopic common canaliculus opening operation can treat the lacrimal sac anastomotic occlusion. This operation is characterized by high success rate, less complications, safe and efficient, and it is worth clinical promotion.

  1. 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

  2. Lacrimal scintigraphy in the diagnosis of epiphora

    International Nuclear Information System (INIS)

    Hanna, I.T.; MacEwen, C.J.; Kennedy, N.

    1992-01-01

    The value of lacrimal scintigraphy in the assessment of nasolacrimal duct obstruction was determined by comparing the results with syringing in 67 patients (83 eyes). As expected, of 28 lacrimal drainage systems which were obstructed on syringing, 23 (82%) had abnormalities of tear drainage on scintigraphy. However, in 55 lacrimal drainage systems that were patent on syringing, 19 (35%) were normal, but in 36 (65%) abnormalities not apparent on syringing were detected on scintigraphy. Thus scintigraphy is a very useful technique in the assessment of nasolacrimal duct obstruction particularly in systems patent on syringing. Since the site of obstruction can be determined, lacrimal scintigraphy can facilitate the planning of the appropriate surgery. (author)

  3. Magnetic resonance imaging of the fetal efferent lacrimal pathways

    International Nuclear Information System (INIS)

    Brugger, Peter C.; Weber, Michael; Prayer, Daniela

    2010-01-01

    To study the prenatal development of the efferent lacrimal pathways with magnetic resonance imaging (MRI), with special reference to the pathogenesis of congenital dacryocystoceles (CDCCs). A total of 751 MRI studies of singleton fetuses [19-40 gestational weeks (GW)] were retrospectively evaluated. Visibility of the efferent lacrimal pathways was assessed on high-resolution T2-weighted sequences and the maximum transverse lacrimal sac diameter was recorded. Fluid-filled lacrimal sacs/nasolacrimal ducts could be demonstrated in 31.7% of fetuses, either unilaterally (50.6%) or bilaterally (49.4%). Visualization was age-dependent: demonstration frequency increased from 24 to 32 GW (60%) and decreased until term. Lacrimal sac diameters varied between 1.9 and 10.5 mm, but showed no correlation with gestational age. Lacrimal sacs with diameters >5 mm were considered to represent CDDC and were found in 2.76% of third-trimester fetuses. Fluid-filled efferent lacrimal pathways are a normal finding depending on gestational age. Visualization reflects the effect of two processes that occur over a protracted period of time: opening of the eye lids and lacrimal puncta, and the opening of the Hasner's membrane. Establishing the normal dimensions of the relatively large fetal lacrimal sacs allowed CDCC to be defined and showed a 2.76% incidence of CDCC in third-trimester fetuses. (orig.)

  4. Magnetic resonance imaging of the fetal efferent lacrimal pathways

    Energy Technology Data Exchange (ETDEWEB)

    Brugger, Peter C. [Medical University of Vienna, Integrative Morphology Group, Centre for Anatomy and Cell Biology, Vienna (Austria); Weber, Michael [Medical University of Vienna, Department of Radiology, Vienna (Austria); Prayer, Daniela [Medical University of Vienna, Division of Neuroradiology and Musculoskeletal Radiology, Department of Radiology, Vienna (Austria)

    2010-08-15

    To study the prenatal development of the efferent lacrimal pathways with magnetic resonance imaging (MRI), with special reference to the pathogenesis of congenital dacryocystoceles (CDCCs). A total of 751 MRI studies of singleton fetuses [19-40 gestational weeks (GW)] were retrospectively evaluated. Visibility of the efferent lacrimal pathways was assessed on high-resolution T2-weighted sequences and the maximum transverse lacrimal sac diameter was recorded. Fluid-filled lacrimal sacs/nasolacrimal ducts could be demonstrated in 31.7% of fetuses, either unilaterally (50.6%) or bilaterally (49.4%). Visualization was age-dependent: demonstration frequency increased from 24 to 32 GW (60%) and decreased until term. Lacrimal sac diameters varied between 1.9 and 10.5 mm, but showed no correlation with gestational age. Lacrimal sacs with diameters >5 mm were considered to represent CDDC and were found in 2.76% of third-trimester fetuses. Fluid-filled efferent lacrimal pathways are a normal finding depending on gestational age. Visualization reflects the effect of two processes that occur over a protracted period of time: opening of the eye lids and lacrimal puncta, and the opening of the Hasner's membrane. Establishing the normal dimensions of the relatively large fetal lacrimal sacs allowed CDCC to be defined and showed a 2.76% incidence of CDCC in third-trimester fetuses. (orig.)

  5. Clinical observation of the treatment for chronic dacryocystitis under lacrimal endoscope

    Directory of Open Access Journals (Sweden)

    Hong-Ling Lü

    2013-08-01

    Full Text Available AIM:To evaluate the clinical efficacy of lacrimal dredge under lacrimal endoscope for treating chronic dacryocystitis. METHODS: Sixty patients(64 eyeswith chronic dacryocystitis were examined and treated by lacrimal endoscope combined with full lacrimal intubation. All patients were followed up for 3-6 months postoperatively. RESULTS: Forty-five eyes of 64 eyes were cured, no tears, irrigation of lacrimal passage unobstructed. Thirteen eyes get partly recover, but there were still mild overflow tears, and although lacrimal passages can be flushed, but there were still partly lacrimal duct obstruction. The rest 6 eyes were invalid and still tears, irrigation of lacrimal passage obstructed. The total effective rate was 90.6%. CONCLUSION: The diagnosis and treatment of nasolacrimal duct obstruction under lacrimal endoscope is a safe and effective way.

  6. Recent advances on biomedical applications of scaffolds in wound healing and dermal tissue engineering.

    Science.gov (United States)

    Rahmani Del Bakhshayesh, Azizeh; Annabi, Nasim; Khalilov, Rovshan; Akbarzadeh, Abolfazl; Samiei, Mohammad; Alizadeh, Effat; Alizadeh-Ghodsi, Mohammadreza; Davaran, Soodabeh; Montaseri, Azadeh

    2018-06-01

    The tissue engineering field has developed in response to the shortcomings related to the replacement of the tissues lost to disease or trauma: donor tissue rejection, chronic inflammation and donor tissue shortages. The driving force behind the tissue engineering is to avoid the mentioned issues by creating the biological substitutes capable of replacing the damaged tissue. This is done by combining the scaffolds, cells and signals in order to create the living, physiological, three-dimensional tissues. A wide variety of skin substitutes are used in the treatment of full-thickness injuries. Substitutes made from skin can harbour the latent viruses, and artificial skin grafts can heal with the extensive scarring, failing to regenerate structures such as glands, nerves and hair follicles. New and practical skin scaffold materials remain to be developed. The current article describes the important information about wound healing scaffolds. The scaffold types which were used in these fields were classified according to the accepted guideline of the biological medicine. Moreover, the present article gave the brief overview on the fundamentals of the tissue engineering, biodegradable polymer properties and their application in skin wound healing. Also, the present review discusses the type of the tissue engineered skin substitutes and modern wound dressings which promote the wound healing.

  7. Engineering Three-dimensional Epithelial Tissues Embedded within Extracellular Matrix.

    Science.gov (United States)

    Piotrowski-Daspit, Alexandra S; Nelson, Celeste M

    2016-07-10

    The architecture of branched organs such as the lungs, kidneys, and mammary glands arises through the developmental process of branching morphogenesis, which is regulated by a variety of soluble and physical signals in the microenvironment. Described here is a method created to study the process of branching morphogenesis by forming engineered three-dimensional (3D) epithelial tissues of defined shape and size that are completely embedded within an extracellular matrix (ECM). This method enables the formation of arrays of identical tissues and enables the control of a variety of environmental factors, including tissue geometry, spacing, and ECM composition. This method can also be combined with widely used techniques such as traction force microscopy (TFM) to gain more information about the interactions between cells and their surrounding ECM. The protocol can be used to investigate a variety of cell and tissue processes beyond branching morphogenesis, including cancer invasion.

  8. Mucosal tolerance disruption favors disease progression in an extraorbital lacrimal gland excision model of murine dry eye.

    Science.gov (United States)

    Guzmán, Mauricio; Keitelman, Irene; Sabbione, Florencia; Trevani, Analía S; Giordano, Mirta N; Galletti, Jeremías G

    2016-10-01

    Dry eye is a highly prevalent immune disorder characterized by a dysfunctional tear film and a Th1/Th17 T cell response at the ocular surface. The specificity of these pathogenic effector T cells remains to be determined, but auto-reactivity is considered likely. However, we have previously shown that ocular mucosal tolerance to an exogenous antigen is disrupted in a scopolamine-induced murine dry eye model and that it is actually responsible for disease progression. Here we report comparable findings in an entirely different murine model of dry eye that involves resection of the extraorbital lacrimal glands but no systemic muscarinic receptor blockade. Upon ocular instillation of ovalbumin, a delayed breakdown in mucosal tolerance to this antigen was observed in excised but not in sham-operated mice, which was mediated by interferon γ- and interleukin 17-producing antigen-specific T cells. Consistently, antigen-specific regulatory T cells were detectable in sham-operated but not in excised mice. As for other models of ocular surface disorders, epithelial activation of the NF-κB pathway by desiccating stress was determinant in the mucosal immune outcome. Underscoring the role of mucosal tolerance disruption in dry eye pathogenesis, its prevention by a topical NF-κB inhibitor led to reduced corneal damage in excised mice. Altogether these results show that surgically originated desiccating stress also initiates an abnormal Th1/Th17 T cell response to harmless exogenous antigens that reach the ocular surface. This event might actually contribute to corneal damage and challenges the conception of dry eye as a strictly autoimmune disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Effect of mitomycin combined with Nd-YAG laser on cell proliferation and invasion as well as MEK/ERK signaling pathway in obstructive lacrimal duct model

    Directory of Open Access Journals (Sweden)

    Yu Yan

    2017-11-01

    Full Text Available Objective: To study the effect of mitomycin (MMC combined with Nd-YAG laser on cell proliferation and invasion as well as MEK/ERK signaling pathway in obstructive lacrimal duct model. Methods: New Zealand rabbits were selected as experimental animals and divided into model group, laser group and MMC + laser group; obstructive lacrimal duct model was established, then laser group were given Nd-YAG laser intervention, and MMC + laser group were given Nd-YAG laser combined with mitomycin intervention. 2 months after intervention, the expression of proliferation molecules, invasion molecules and MEK-ERK signaling molecules in lacrimal duct tissue were measured. Results: TGF-β, CTGF, PCNA, Ki-67, Col-I, Col-III, MEK, ERK1/2, MMP2 and MMP9 protein levels in lacrimal duct tissue of laser group were significantly higher than those of model group while TSG-6, Cthrc1 and TIMP1 protein levels were significantly lower than those of model group; TGF-β, CTGF, PCNA, Ki- 67, Col-I, Col-III, MEK, ERK1/2, MMP2 and MMP9 protein levels in lacrimal duct tissue of MMC + laser group were significantly lower than those of laser group while TSG-6, Cthrc1 and TIMP1 protein levels were significantly higher than those of laser group. Conclusion: Mitomycin can inhibit cell proliferation and invasion as well as MEK/ERK signaling pathway activation in obstructive lacrimal duct model after Nd-YAG laser treatment.

  10. Dacryoscintigraph evaluation of the repaired lacrimal drainage system

    International Nuclear Information System (INIS)

    Hoehn, J.G.; Vitale, P.; Elliott, R.A. Jr.

    1976-01-01

    We have used dacryoscintigraphy to study the efficiency of the lacrimal system following the repair of a divided lower canaliculus in 4 children. This test has been reliable in evaluating lacrimal function and suggests that a canaliculus can be repaired and splinted satisfactorily. Our experience with dacryoscintigraphy confirms that it is a safe comfortable, and reliable method for studying the patency of the lacrimal drainage system

  11. Salisphere derived c-Kit+ cell transplantation restores tissue homeostasis in irradiated salivary gland

    International Nuclear Information System (INIS)

    Nanduri, Lalitha S.Y.; Lombaert, Isabelle M.A.; Zwaag, Marianne van der; Faber, Hette; Brunsting, Jeanette F.; Os, Ronald P. van; Coppes, Robert P.

    2013-01-01

    Introduction: During radiotherapy salivary glands of head and neck cancer patients are unavoidably co-irradiated, potentially resulting in life-long impairment. Recently we showed that transplantation of salisphere-derived c-Kit expressing cells can functionally regenerate irradiated salivary glands. This study aims to select a more potent subpopulation of c-Kit + cells, co-expressing stem cell markers and to investigate whether long-term tissue homeostasis is restored after stem cell transplantation. Methods and results: Salisphere derived c-Kit + cells that co-expressed CD24 and/or CD49f markers, were intra-glandularly injected into 15 Gy irradiated submandibular glands of mice. Particularly, c-Kit + /CD24 + /CD49f + cell transplanted mice improved saliva production (54.59 ± 11.1%) versus the irradiated control group (21.5 ± 8.7%). Increase in expression of cells with differentiated duct cell markers like, cytokeratins (CK8, 18, 7 and 14) indicated functional recovery of this compartment. Moreover, ductal stem cell marker expression like c-Kit, CD133, CD24 and CD49f reappeared after transplantation indicating long-term functional maintenance potential of the gland. Furthermore, a normalization of vascularization as indicated by CD31 expression and reduction of fibrosis was observed, indicative of normalization of the microenvironment. Conclusions: Our results show that stem cell transplantation not only rescues hypo-salivation, but also restores tissue homeostasis of the irradiated gland, necessary for long-term maintenance of adult tissue

  12. K5/K14-positive cells contribute to salivary gland-like breast tumors with myoepithelial differentiation

    DEFF Research Database (Denmark)

    Boecker, Werner; Stenman, Goeran; Loening, Thomas

    2013-01-01

    different cell lineages and define their cellular hierarchy in tumors with myoepithelial differentiation. isTILT analysis of a series of 28 breast, salivary, and lacrimal gland tumors, including pleomorphic adenomas (n=8), epithelial-myoepithelial tumors (n=9), and adenoid cystic carcinomas (n=11) revealed...... heterologeous cell differentiations such as squamous and mesenchymal progenies. p63 was co-expressed with K5/K14 in basal-like progenitor cells, myoepithelial, and squamous cells but not in glandular cells. Our results show that the corresponding counterpart tumors of breast and salivary/lacrimal glands have....... For that reason, we performed an in situ triple immunofluorescence lineage/differentiation tracing (isTILT) and qRT-PCR study of basal (K5/K14), glandular (K7/K8/18), and epidermal-specific squamous (K10) keratins, p63, and smooth muscle actin (SMA; myoepithelial marker) with the aim to construct and trace...

  13. The salivary glands in Sjögren's syndrome : pathogenetic aspects of the initiation of sialoadenitis

    OpenAIRE

    Blokland, Saskia

    2001-01-01

    textabstractSjögren's syndrome is a chronic inflammatory disorder with autoimmune etiology, affecting primarily the salivary and lacrimal glands. In these glands. focallymphocytic infiltrates develop. This is accompanied by decreased production of saliva and tears. resulting in patients complaining of dry eyes and a dry mouth. First reports in which the combination of a dry mouth and dry eyes was described date from late 19th and early 2Qth century. In 1933. Henrik Sjögren. a Swedish ophthalm...

  14. Concise review: can the intrinsic power of branching morphogenesis be used for engineering epithelial tissues and organs?

    Science.gov (United States)

    Nigam, Sanjay K

    2013-12-01

    Branching morphogenesis is critical to the development of organs such as kidney, lung, mammary gland, prostate, pancreas, and salivary gland. Essentially, an epithelial bud becomes an iterative tip-stalk generator (ITSG) able to form a tree of branching ducts and/or tubules. In different organs, branching morphogenesis is governed by similar sets of genes. Epithelial branching has been recapitulated in vitro (or ex vivo) using three-dimensional cell culture and partial organ culture systems, and several such systems relevant to kidney tissue engineering are discussed here. By adapting systems like these it may be possible to harness the power inherent in the ITSG program to propagate and engineer epithelial tissues and organs. It is also possible to conceive of a universal ITSG capable of propagation that may, by recombination with organ-specific mesenchymal cells, be used for engineering many organ-like tissues similar to the organ from which the mesenchyme cells were derived, or toward which they are differentiated (from stem cells). The three-dimensional (3D) branched epithelial structure could act as a dynamic branching cellular scaffold to establish the architecture for the rest of the tissue. Another strategy-that of recombining propagated organ-specific ITSGs in 3D culture with undifferentiated mesenchymal stem cells-is also worth exploring. If feasible, such engineered tissues may be useful for the ex vivo study of drug toxicity, developmental biology, and physiology in the laboratory. Over the long term, they have potential clinical applications in the general fields of transplantation, regenerative medicine, and bioartificial medical devices to aid in the treatment of chronic kidney disease, diabetes, and other diseases.

  15. Adipose Tissue and Adrenal Glands: Novel Pathophysiological Mechanisms and Clinical Applications

    OpenAIRE

    Kargi, Atil Y.; Iacobellis, Gianluca

    2014-01-01

    Hormones produced by the adrenal glands and adipose tissues have important roles in normal physiology and are altered in many disease states. Obesity is associated with changes in adrenal function, including increase in adrenal medullary catecholamine output, alterations of the hypothalamic-pituitary-adrenal (HPA) axis, elevations in circulating aldosterone together with changes in adipose tissue glucocorticoid metabolism, and enhanced adipocyte mineralocorticoid receptor activity. It is unkn...

  16. Comparative study of the lacrimal dacryocyscintigraphy and contrast dacryocystography in epiphora

    International Nuclear Information System (INIS)

    Kim, Jan Dee; Sohn, Myung Hee; Han, Young Min; Lee, Sang Hoon; Kim, Soo Hyun; Chung, Gyung Ho; Kim, Chung Soo; Choi, Ki Chul

    1995-01-01

    The purpose of this study was to compare contrast dacryocystography with lacrimal dacryoscintigraphy in correlation with epiphora, superiority in localization of the site of obstruction and discomfort of patient during procedures. Lacrimal dacryoscintigraphy and contrast dacryocystography were performed in 200 lacrimal drainage systems in 100 patients who were referred to our hospital with epiphora since January, 1993. Lacrimal dacryoscintigraphy showed 88% in correlation with epiphora, 90% in positive predictive value and 74% in negative predictive value. Contrast dacryocystography showed 72% in correlation with epiphora, 97% in positive predictive value and 60% in negative predictive value. Contrast dacryocystography was superior to lacrimal dacryoscintigraphy in localization of the site of the obstruction because of limitation of resolution of 6 mm pin hole collimator. But discomfort of patient was variable and severe on contrast dacryocystography. When obstruction is suspected, we recommend the lacrimal dacryoscintigraphy as initial radiographic study. If adequate information is not available and confirmation is necessary, contrast dacryocystography should be done in next step. Inspite of patients symptom, if finding of contrast dacryocystography is normal, lacrimal dacryoscintigraphy should be performed to exclude functional obstruction

  17. The lacrimal system: diagnosis, management, and surgery

    National Research Council Canada - National Science Library

    Cohen, Adam J; Mercandetti, Michael; Brazzo, Brian G

    2006-01-01

    ... and techniques presented represent the state of the art of lacrimal diagnosis and surgery. There is mention of lacrimal infection dating back to the Code of Hammurabi in 2250 BC, but it was not until the late 1800s that real progress began to be made. Toti, an ENT surgeon in Florence, Italy, described external dacryocystorhinostomy (DCR) with turb...

  18. Degradable polymers for tissue engineering

    NARCIS (Netherlands)

    van Dijkhuizen-Radersma, Riemke; Moroni, Lorenzo; van Apeldoorn, Aart A.; Zhang, Zheng; Grijpma, Dirk W.; van Blitterswijk, Clemens A.

    2008-01-01

    This chapter elaborates the degradable polymers for tissue engineering and their required scaffold material in tissue engineering. It recognizes the examples of degradable polymers broadly used in tissue engineering. Tissue engineering is the persuasion of the body to heal itself through the

  19. Lacrimal system pathology in patients with malignant thyroid tumors after radioactive iodine therapy, and its correction methods

    Directory of Open Access Journals (Sweden)

    Natalya Yu. Beldovskaya

    2017-12-01

    Full Text Available Introduction. Radioactive iodine therapy after thyroidectomy is the standard of differentiated thyroid cancer treatment in the modern world. Main dose-dependent side effects described in the literature include: sialadenitis, xerostomia, taste and/or odor loss, swelling of surrounding tissues. Ophthalmic complications are rarely reported. Aim. To assess the lacrimal system condition in patients after radioactive iodine therapy for thyroid cancer. Material and methods. The study included 17 patients (34 eyes. There were female patients aged 19 to 43 years (mean age was 31 years who underwent a course of radioactive iodine therapy for thyroid cancer. All of them complained of periodic or constant tearing in the period from 2 months to 1 year after therapy course. In four patients, there was a permanent or periodic mucopurulent discharge when pressing on the lacrimal sac area. All patients underwent a standard ophthalmological examination, including visual acuity testing, anterior segment biomicroscopy, ophthalmoscopy, and tear production tests. Dye disappearance test, Jones I and II tests, lacrimal pathways irrigation, and, if necessary, cone-ray computer tomography with preliminary lacrimal pathways contrasting were performed to evaluate the tear outflow abnormalities. Results. Tear production disorders were detected in 20 eyes (58.8% (among them, moderate dry eye syndrome was diagnosed in 3 cases; tear outflow pathology was revealed in 14 eyes (41.2% (namely naso-lacrimal duct obstruction and stenosis, and chronic purulent dacryocystitis. For patients with tear production pathology artificial tears were prescribed, and endoscopic endonasal dacryocystorhinostomy was performed in cases of tear outflow disturbances. Conclusion. The use of radioactive iodine in doses exceeding 80 mCi leads to the development of lacrimal system pathology: dry eye syndrome of various severity, and tear outflow disorders. Lacrimal system pathology significantly worsens

  20. Engineering Musculoskeletal Tissue Interfaces

    Directory of Open Access Journals (Sweden)

    Ece Bayrak

    2018-04-01

    Full Text Available Tissue engineering aims to bring together biomaterials, cells, and signaling molecules within properly designed microenvironments in order to create viable treatment options for the lost or malfunctioning tissues. Design and production of scaffolds and cell-laden grafts that mimic the complex structural and functional features of tissues are among the most important elements of tissue engineering strategy. Although all tissues have their own complex structure, an even more complex case in terms of engineering a proper carrier material is encountered at the tissue interfaces, where two distinct tissues come together. The interfaces in the body can be examined in four categories; cartilage-bone and ligament-bone interfaces at the knee and the spine, tendon-bone interfaces at the shoulder and the feet, and muscle-tendon interface at the skeletal system. These interfaces are seen mainly at the soft-to-hard tissue transitions and they are especially susceptible to injury and tear due to the biomechanical inconsistency between these tissues where high strain fields are present. Therefore, engineering the musculoskeletal tissue interfaces remain a challenge. This review focuses on recent advancements in strategies for musculoskeletal interface engineering using different biomaterial-based platforms and surface modification techniques.

  1. Cell and Tissue Engineering

    CERN Document Server

    2012-01-01

    “Cell and Tissue Engineering” introduces the principles and new approaches in cell and tissue engineering. It includes both the fundamentals and the current trends in cell and tissue engineering, in a way useful both to a novice and an expert in the field. The book is composed of 13 chapters all of which are written by the leading experts. It is organized to gradually assemble an insight in cell and tissue function starting form a molecular nano-level, extending to a cellular micro-level and finishing at the tissue macro-level. In specific, biological, physiological, biophysical, biochemical, medical, and engineering aspects are covered from the standpoint of the development of functional substitutes of biological tissues for potential clinical use. Topics in the area of cell engineering include cell membrane biophysics, structure and function of the cytoskeleton, cell-extracellular matrix interactions, and mechanotransduction. In the area of tissue engineering the focus is on the in vitro cultivation of ...

  2. Mesenchymal stem cells delivered in a microsphere-based engineered skin contribute to cutaneous wound healing and sweat gland repair.

    Science.gov (United States)

    Huang, Sha; Lu, Gang; Wu, Yan; Jirigala, Enhe; Xu, Yongan; Ma, Kui; Fu, Xiaobing

    2012-04-01

    Bone-marrow-derived mesenchymal stem cells (BM-MSCs) can contribute to wound healing after skin injury. However, the role of BM-MSCs on repairing skin appendages in renewal tissues is incompletely explored. Moreover, most preclinical studies suggest that the therapeutic effects afforded by BM-MSCs transplantation are short-lived and relatively unstable. To assess whether engrafted bone-marrow-derived mesenchymal stem cells via a delivery system can participate in cutaneous wound healing and sweat-gland repair in mice. For safe and effective delivery of BM-MSCs to wounds, epidermal growth factor (EGF) microspheres were firstly developed to both support cells and maintain appropriate stimuli, then cell-seeded microspheres were incorporated with biomimetic scaffolds and thus fabricated an engineered skin construct with epithelial differentiation and proliferative potential. The applied efficacy was examined by implanting them into excisional wounds on both back and paws of hind legs in mice. After 3 weeks, BM-MSC-engineered skin (EGF loaded) treated wounds exhibited accelerated healing with increased re-epithelialization rates and less skin contraction. Furthermore, histological and immunofluorescence staining analysis revealed sweat glands-like structures became more apparent in BM-MSC-engineered skin (EGF loaded) treated wounds but the number of implanted BM-MSCs were decreased gradually in later phases of healing progression. Our study suggests that BM-MSCs delivered by this EGF microspheres-based engineered skin model may be a promising strategy to repair sweat glands and improve cutaneous wound healing after injury and success in this study might provide a potential benefit for BM-MSCs administration clinically. Copyright © 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  3. Scintigraphy of the lacrimal drainage system

    International Nuclear Information System (INIS)

    Denffer, H. von; Dressler, J.; Technische Univ. Muenchen

    1978-01-01

    A new scintigraphic method, the radionuclide dacryography, to evaluate lacrimal drainage and its disorders is described. A drop of sup(99m)Tc-pertechnetate is dropped onto the eyes and the transport of the nuclide is registered by a scintillation camera. By this method it is easy to verify, under physiological conditions, suspected obstructions of the lacrimal drainage system and to determine its localization. The absorbed radiation dose using radionuclide dacryography is very low as compared to radiological methods. (orig.) [de

  4. [Prognostic value of lacrimal duct diagnostics after tube removal : Retrospective analysis of risk of relapse during the first postoperative year after transcanalicular lacrimal duct surgery with silicone tubing].

    Science.gov (United States)

    Böhm, M; Heichel, J; Bredehorn-Mayr, T; Lautenschläger, C; Struck, H-G

    2017-05-01

    Transcanalicular lacrimal duct surgery has become more important over the past two decades. The aim of the study was to prove the prognostic value of postoperative lacrimal syringing and the testing of spontaneous drainage of lacrimal fluid immediately after tube removal. A total of 110 cases with postoperative lacrimal syringing and 183 cases with verification of the postoperative lacrimal fluid drainage performed between January 2001 and August 2008 were retrospectively evaluated. The indication for postoperative diagnostics was set by the investigator. The prognostic value of these two procedures was determined by using prognostic parameters (positive predictive value, PPV; negative predictive value, NPV) and analyzing recurrence nonexistence via Cox regression and Kaplan-Meier estimator. The observation period was limited to 12 months. Predominantly, recurrence was defined on the patient's satisfaction and absence of symptoms, which was determined with the help of a questionnaire. Postoperative verification of the lacrimal syringing is a suitable instrument to estimate surgical success within the first year after lacrimal surgery with a PPV of 92.31%. Testing of the spontaneous drainage of lacrimal fluid after tube removal reached a PPV of 63.33%. The proven prognostic value shows that syringing of the lacrimal duct and verification of spontaneous drainage should be integrated into postoperative care in a standardized manner. Hereby, early information for the patient about the expected result of the surgical procedure is enabled.

  5. Clinical pathology observation on orbit IgG4 related disease

    Directory of Open Access Journals (Sweden)

    Ji-Hua Guo

    2015-09-01

    Full Text Available AIM:To discuss clinical pathological features of orbit IgG4 related disease(IgG4-RD. METHODS: The clinical pathological materials of 23 patients(35 eyeswith orbit IgG4-RD were collected. They were observed in terms of histology and immunohistochemistry, and its clinical and pathologic characteristics were summarized. RESULTS: There were 23 patients(35 eyeswith orbit IgG4-RD(8 male patients, 9 eyes; 15 female patients, 26 eyes, with an average age of 52.1 year-old(from age 28 to 72. 19 patients(30 eyesoccured in lacrimal gland and 4 cases(5 eyesin other places, and they went to hospital for lacrimal gland cyst or exophthalmos. There were 11 cases in one side and 12 cases in both sides. The disease lasted from 1mo to 10a, averaging 27mo. It recureded in one patient(1 eyeafter 1mo. In general inspection: Gray nodular goiter, thin fibrous coat wrapping around the lacrimal gland could be observed. Histologic characteristics: lacrimal gland bubble and catheter group shrinked or even disappeared, substituted by lymphocyte, plasma cells and lymphoid follicle and accompanied with fibrosis. Immunohistochemical staining: IgG4 positive plasma cells of 23 cases(35 eyeswas >50/HPF, and IgG4/IgG ratio of positive plasma cells was >40%. CONCLUSION: Orbit IgG4-RD mainly occures in lacrimal gland tissue, and expression of IgG4 can be detected through histologic characteristics and immunohistochemical staining. IgG4-RD should be screened, prevented and treated in the early phase.

  6. Effects of large pressure amplitude low frequency noise in the parotid gland perivasculo-ductal connective tissue.

    Science.gov (United States)

    Oliveira, Pedro; Brito, José; Mendes, João; da Fonseca, Jorge; Águas, Artur; Martins dos Santos, José

    2013-01-01

    In tissues and organs exposed to large pressure amplitude low frequency noise fibrosis occurs in the absence of inflammatory signs, which is thought to be a protective response. In the parotid gland the perivasculo-ductal connective tissue surrounds arteries, veins and the ductal tree. Perivasculo-ductal connective tissue is believed to function as a mechanical stabilizer of the glandular tissue. In order to quantify the proliferation of perivasculo-ductal connective tissue in large pressure amplitude low frequency noise-exposed rats we used sixty Wistar rats which were equally divided into 6 groups. One group kept in silence, and the remaining five exposed to continuous large pressure amplitude low frequency noise: g1-168h (1 week); g2-504h (3 weeks); g3-840h (5 weeks); g4-1512h (9 weeks); and g5-2184h (13 weeks). After exposure, parotid glands were removed and the perivasculo-ductal connective tissue area was measured in all groups. We applied ANOVA statistical analysis, using SPSS 13.0. The global trend is an increase in the average perivasculo-ductal connective tissue areas, that develops linearly and significantly with large pressure amplitude low frequency noise exposure time (p connective tissue. Hence, these results show that in response to large pressure amplitude low frequency noise exposure, rat parotid glands increase their perivasculo-ductal connective tissue.

  7. Movement of the lacrimal canalicular wall under intracanalicular pressure changes observed with dacryoendoscopy.

    Science.gov (United States)

    Kakizaki, Hirohiko; Takahashi, Yasuhiro; Mito, Hidenori; Nakamura, Yasuhisa

    2015-01-01

    Movement of the lacrimal canalicular wall has been speculated to occur during blinking. Movement of the common internal ostium has been observed under nasal endoscopy, and pressure changes in the lacrimal canalicular cavity have been observed with a pressure sensor; however, lacrimal canalicular wall movement under pressure changes has not been observed. To examine movement of the lacrimal canalicular wall under intracanalicular pressure changes using dacryoendoscopy. The authors examined 20 obstruction-free lacrimal canaliculi in 10 patients. A dacryoendoscope was inserted, and water was poured into the intracanalicular cavity via the dacryoendoscope's water channel. The water was then poured or suctioned to cause positive or negative pressure changes in the intracanalicular cavity, and movement of the lacrimal canalicular wall was examined. The lacrimal canalicular wall moved flexibly with pressure changes. Under positive pressure, the intracanalicular cavity was dilated; however, it narrowed under negative pressure. The extent of movement was more dramatic in the common canalicular portion than the proximal canalicular portion. Intracanalicular pressure changes cause movement of the lacrimal canalicular wall. There was a consistent relationship between intracanalicular cavity changes and pressure changes, possibly contributing to lacrimal drainage of the canaliculus.

  8. Nitric oxide-induced signalling in rat lacrimal acinar cells

    DEFF Research Database (Denmark)

    Looms, Dagnia Karen; Tritsaris, K.; Dissing, S.

    2002-01-01

    -adrenergic stimulation and not by a rise in [Ca2+]i alone.   We show that in rat lacrimal acinar cells, NO and cGMP induce Ca2+ release from intracellular stores via G kinase activation. However, the changes in [Ca2+]i are relatively small, suggesting that this pathway plays a modulatory role in Ca2+ signalling, thus...... not by itself causing fast transient increases in [Ca2+]i. In addition, we suggest that endogenously produced NO activated by ß-adrenergic receptor stimulation, plays an important role in signalling to the surrounding tissue....

  9. Calorie restriction: A new therapeutic intervention for age-related dry eye disease in rats

    International Nuclear Information System (INIS)

    Kawashima, Motoko; Kawakita, Tetsuya; Okada, Naoko; Ogawa, Yoko; Murat, Dogru; Nakamura, Shigeru; Nakashima, Hideo; Shimmura, Shigeto; Shinmura, Ken; Tsubota, Kazuo

    2010-01-01

    A decrease in lacrimal gland secretory function is closely related to aging and leads to an increased prevalence of dry eye syndrome. Since calorie restriction (CR) is considered to prevent functional decline of various organs due to aging, we hypothesized that CR could prevent age-related lacrimal dysfunction. Six-month-old male Fischer 344 rats were randomly divided into ad libitum (AL) and CR (-35%) groups. After 6 months of CR, tear function was examined under conscious state. After euthanasia, lacrimal glands were subjected to histological examination, tear protein secretion stimulation test with Carbachol, and assessment of oxidative stress with 8-hydroxy-2 deoxyguanosine (8-OHdG) and 4-hydroxynonenal (HNE) antibodies. CR significantly improved tear volume and tended to increase tear protein secretion volume after stimulation with Carbachol compared to AL. The acinar unit density was significantly higher in the CR rats compared to AL rats. Lacrimal glands in the CR rats showed a lesser degree of interstitial fibrosis. CR reduced the concentration of 8-OHdG and the extent of staining with HNE in the lacrimal gland, compared to AL. Furthermore, our electron microscopic observations showed that mitochondrial structure of the lacrimal gland obtained from the middle-aged CR rats was preserved in comparison to the AL rats. Collectively, these results demonstrate for the first time that CR may attenuate oxidative stress related damage in the lacrimal gland with preservation of lacrimal gland functions. Although molecular mechanism(s) by which CR maintains lacrimal gland function remains to be resolved, CR might provide a novel therapeutic strategy for treating dry eye syndrome.

  10. Calorie restriction: A new therapeutic intervention for age-related dry eye disease in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kawashima, Motoko; Kawakita, Tetsuya; Okada, Naoko; Ogawa, Yoko [Department of Ophthalmology, Keio University School of Medicine, Tokyo (Japan); Murat, Dogru [Department of Ocular Surface and Visual Optics, Keio University School of Medicine, Tokyo (Japan); Nakamura, Shigeru; Nakashima, Hideo [Research Center, Ophtecs Corporation, Hyogo (Japan); Shimmura, Shigeto [Department of Ophthalmology, Keio University School of Medicine, Tokyo (Japan); Shinmura, Ken [Division of Geriatric Medicine, Department of Internal Medicine, Keio University School of Medicine, Tokyo (Japan); Tsubota, Kazuo, E-mail: tsubota@sc.itc.keio.ac.jp [Department of Ophthalmology, Keio University School of Medicine, Tokyo (Japan)

    2010-07-09

    A decrease in lacrimal gland secretory function is closely related to aging and leads to an increased prevalence of dry eye syndrome. Since calorie restriction (CR) is considered to prevent functional decline of various organs due to aging, we hypothesized that CR could prevent age-related lacrimal dysfunction. Six-month-old male Fischer 344 rats were randomly divided into ad libitum (AL) and CR (-35%) groups. After 6 months of CR, tear function was examined under conscious state. After euthanasia, lacrimal glands were subjected to histological examination, tear protein secretion stimulation test with Carbachol, and assessment of oxidative stress with 8-hydroxy-2 deoxyguanosine (8-OHdG) and 4-hydroxynonenal (HNE) antibodies. CR significantly improved tear volume and tended to increase tear protein secretion volume after stimulation with Carbachol compared to AL. The acinar unit density was significantly higher in the CR rats compared to AL rats. Lacrimal glands in the CR rats showed a lesser degree of interstitial fibrosis. CR reduced the concentration of 8-OHdG and the extent of staining with HNE in the lacrimal gland, compared to AL. Furthermore, our electron microscopic observations showed that mitochondrial structure of the lacrimal gland obtained from the middle-aged CR rats was preserved in comparison to the AL rats. Collectively, these results demonstrate for the first time that CR may attenuate oxidative stress related damage in the lacrimal gland with preservation of lacrimal gland functions. Although molecular mechanism(s) by which CR maintains lacrimal gland function remains to be resolved, CR might provide a novel therapeutic strategy for treating dry eye syndrome.

  11. Normal tissue complication probability for salivary glands

    International Nuclear Information System (INIS)

    Rana, B.S.

    2008-01-01

    The purpose of radiotherapy is to make a profitable balance between the morbidity (due to side effects of radiation) and cure of malignancy. To achieve this, one needs to know the relation between NTCP (normal tissue complication probability) and various treatment variables of a schedule viz. daily dose, duration of treatment, total dose and fractionation along with tissue conditions. Prospective studies require that a large number of patients be treated with varied schedule parameters and a statistically acceptable number of patients develop complications so that a true relation between NTCP and a particular variable is established. In this study Salivary Glands Complications have been considered. The cases treated in 60 Co teletherapy machine during the period 1994 to 2002 were analyzed and the clinicians judgement in ascertaining the end points was the only means of observations. The only end points were early and late xerestomia which were considered for NTCP evaluations for a period of 5 years

  12. Computational Modeling in Tissue Engineering

    CERN Document Server

    2013-01-01

    One of the major challenges in tissue engineering is the translation of biological knowledge on complex cell and tissue behavior into a predictive and robust engineering process. Mastering this complexity is an essential step towards clinical applications of tissue engineering. This volume discusses computational modeling tools that allow studying the biological complexity in a more quantitative way. More specifically, computational tools can help in:  (i) quantifying and optimizing the tissue engineering product, e.g. by adapting scaffold design to optimize micro-environmental signals or by adapting selection criteria to improve homogeneity of the selected cell population; (ii) quantifying and optimizing the tissue engineering process, e.g. by adapting bioreactor design to improve quality and quantity of the final product; and (iii) assessing the influence of the in vivo environment on the behavior of the tissue engineering product, e.g. by investigating vascular ingrowth. The book presents examples of each...

  13. Introduction to tissue engineering and application for cartilage engineering.

    Science.gov (United States)

    de Isla, N; Huseltein, C; Jessel, N; Pinzano, A; Decot, V; Magdalou, J; Bensoussan, D; Stoltz, J-F

    2010-01-01

    Tissue engineering is a multidisciplinary field that applies the principles of engineering, life sciences, cell and molecular biology toward the development of biological substitutes that restore, maintain, and improve tissue function. In Western Countries, tissues or cells management for clinical uses is a medical activity governed by different laws. Three general components are involved in tissue engineering: (1) reparative cells that can form a functional matrix; (2) an appropriate scaffold for transplantation and support; and (3) bioreactive molecules, such as cytokines and growth factors that will support and choreograph formation of the desired tissue. These three components may be used individually or in combination to regenerate organs or tissues. Thus the growing development of tissue engineering needs to solve four main problems: cells, engineering development, grafting and safety studies.

  14. Laminin active peptide/agarose matrices as multifunctional biomaterials for tissue engineering.

    Science.gov (United States)

    Yamada, Yuji; Hozumi, Kentaro; Aso, Akihiro; Hotta, Atsushi; Toma, Kazunori; Katagiri, Fumihiko; Kikkawa, Yamato; Nomizu, Motoyoshi

    2012-06-01

    Cell adhesive peptides derived from extracellular matrix components are potential candidates to afford bio-adhesiveness to cell culture scaffolds for tissue engineering. Previously, we covalently conjugated bioactive laminin peptides to polysaccharides, such as chitosan and alginate, and demonstrated their advantages as biomaterials. Here, we prepared functional polysaccharide matrices by mixing laminin active peptides and agarose gel. Several laminin peptide/agarose matrices showed cell attachment activity. In particular, peptide AG73 (RKRLQVQLSIRT)/agarose matrices promoted strong cell attachment and the cell behavior depended on the stiffness of agarose matrices. Fibroblasts formed spheroid structures on the soft AG73/agarose matrices while the cells formed a monolayer with elongated morphologies on the stiff matrices. On the stiff AG73/agarose matrices, neuronal cells extended neuritic processes and endothelial cells formed capillary-like networks. In addition, salivary gland cells formed acini-like structures on the soft matrices. These results suggest that the peptide/agarose matrices are useful for both two- and three-dimensional cell culture systems as a multifunctional biomaterial for tissue engineering. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Molecular, cellular, and tissue engineering

    CERN Document Server

    Bronzino, Joseph D

    2015-01-01

    Known as the bible of biomedical engineering, The Biomedical Engineering Handbook, Fourth Edition, sets the standard against which all other references of this nature are measured. As such, it has served as a major resource for both skilled professionals and novices to biomedical engineering. Molecular, Cellular, and Tissue Engineering, the fourth volume of the handbook, presents material from respected scientists with diverse backgrounds in molecular biology, transport phenomena, physiological modeling, tissue engineering, stem cells, drug delivery systems, artificial organs, and personalized medicine. More than three dozen specific topics are examined, including DNA vaccines, biomimetic systems, cardiovascular dynamics, biomaterial scaffolds, cell mechanobiology, synthetic biomaterials, pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, nanobiomaterials for tissue engineering, biomedical imaging of engineered tissues, gene therapy, noninvasive targeted protein and peptide drug deliver...

  16. Comparative transcriptome profiling of dairy goat microRNAs from dry period and peak lactation mammary gland tissues.

    Directory of Open Access Journals (Sweden)

    Zhuanjian Li

    Full Text Available BACKGROUND: MicroRNAs (miRNAs are small noncoding RNA molecules that serve as important post-transcriptional gene expression regulators by targeting messenger RNAs for post-transcriptional endonucleolytic cleavage or translational inhibition. miRNAs play important roles in many biological processes. Extensive high-throughput sequencing studies of miRNAs have been performed in several animal models. However, little is known about the diversity of these regulatory RNAs in goat (Capra hircus, which is one of the most important agricultural animals and the oldest domesticated species raised worldwide. Goats have long been used for their milk, meat, hair (including cashmere, and skins throughout much of the world. RESULTS: In this study, two small RNA libraries were constructed based on dry period and peak lactation dairy goat mammary gland tissues and sequenced using the Illumina-Solexa high-throughput sequencing technology. A total of 346 conserved and 95 novel miRNAs were identified in the dairy goat. miRNAs expression was confirmed by qRT-PCR in nine tissues and in the mammary gland during different stages of lactation. In addition, several candidate miRNAs that may be involved in mammary gland development and lactation were found by comparing the miRNA expression profiles in different tissues and developmental stages of the mammary gland. CONCLUSIONS: This study reveals the first miRNAs profile related to the biology of the mammary gland in the dairy goat. The characterization of these miRNAs could contribute to a better understanding of the molecular mechanisms of lactation physiology and mammary gland development in the dairy goat.

  17. Calorie restriction: A new therapeutic intervention for age-related dry eye disease in rats.

    Science.gov (United States)

    Kawashima, Motoko; Kawakita, Tetsuya; Okada, Naoko; Ogawa, Yoko; Murat, Dogru; Nakamura, Shigeru; Nakashima, Hideo; Shimmura, Shigeto; Shinmura, Ken; Tsubota, Kazuo

    2010-07-09

    A decrease in lacrimal gland secretory function is closely related to aging and leads to an increased prevalence of dry eye syndrome. Since calorie restriction (CR) is considered to prevent functional decline of various organs due to aging, we hypothesized that CR could prevent age-related lacrimal dysfunction. Six-month-old male Fischer 344 rats were randomly divided into ad libitum (AL) and CR (-35%) groups. After 6months of CR, tear function was examined under conscious state. After euthanasia, lacrimal glands were subjected to histological examination, tear protein secretion stimulation test with Carbachol, and assessment of oxidative stress with 8-hydroxy-2 deoxyguanosine (8-OHdG) and 4-hydroxynonenal (HNE) antibodies. CR significantly improved tear volume and tended to increase tear protein secretion volume after stimulation with Carbachol compared to AL. The acinar unit density was significantly higher in the CR rats compared to AL rats. Lacrimal glands in the CR rats showed a lesser degree of interstitial fibrosis. CR reduced the concentration of 8-OHdG and the extent of staining with HNE in the lacrimal gland, compared to AL. Furthermore, our electron microscopic observations showed that mitochondrial structure of the lacrimal gland obtained from the middle-aged CR rats was preserved in comparison to the AL rats. Collectively, these results demonstrate for the first time that CR may attenuate oxidative stress related damage in the lacrimal gland with preservation of lacrimal gland functions. Although molecular mechanism(s) by which CR maintains lacrimal gland function remains to be resolved, CR might provide a novel therapeutic strategy for treating dry eye syndrome. Copyright 2010 Elsevier Inc. All rights reserved.

  18. [Study on sweat gland regeneration induced by microenvironment of three-dimensional bioprinting].

    Science.gov (United States)

    Yao, B; Xie, J F; Huang, S; Fu, X B

    2017-01-20

    Sweat glands are abundant in the body surface and essential for thermoregulation. Sweat glands fail to conduct self-repair in patients with large area of burn and trauma, and the body temperature of patients increases in hot climate, which may cause shock or even death. Now, co-culture system, reprogramming, and tissue engineering have made progresses in inducing sweat gland regeneration, but the inductive efficiency and duration need to be improved. Cellular microenvironment can regulate cell biological behavior, including cell migration and cell differentiation. This article reviews the studies of establishment of microenvironment in vitro by three-dimensional bioprinting technology to induce sweat gland regeneration.

  19. Tissue bionics: examples in biomimetic tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Green, David W [Bone and Joint Research Group, Developmental Origins of Health and Disease, General Hospital, University of Southampton, SO16 6YD (United Kingdom)], E-mail: Hindoostuart@googlemail.com

    2008-09-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic.

  20. Tissue bionics: examples in biomimetic tissue engineering

    International Nuclear Information System (INIS)

    Green, David W

    2008-01-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic

  1. TOLL-LIKE RECEPTORS IN FAT BODY AND SALIVARY GLAND TISSUES IN THE CATTLE TICK Rhipicephalus microplus

    Directory of Open Access Journals (Sweden)

    Sabrina Rita da Fonseca Rezende

    2016-11-01

    Full Text Available ABSTRACT. Rezende S.deF., Fontenele M.R., Masuda C.A., de Oliveira P.L., Araujo H.M.M., Bittencourt V.R.E.P. & Leite M.de S. Toll-like receptors in fat body and salivary gland tissues in the cattle tick Rhipicephalus microplus. [Receptores Toll-like em corpo gorduroso e glândula salivar do carrapato bovino Rhipicephalus microplus]. Revista Brasileira de Medicina Veterinária, 38(supl. 3:47-53, 2016. Programa de Pós-Graduação em Ciências Veterinárias, Anexo 1, Instituto de Veterinária, Universidade Federal Rural do Estado do Rio de Janeiro, BR 465, KM 47, Seropédica, RJ 23890-000, Brasil. E-mail: milaneleite@ufrrj.br Toll-like receptors (TLRs play an important role in the recognition of pathogen components and subsequent activation of the innate immune response, which then leads to development of immune responses. In arthropods the fat body and salivary glands are important organs in the defense system against invading pathogens. In this study, we identified for the first time the presence of TLRs in fat body and salivary gland tissues of cattle tick Rhipicephalus microplus. Our results show that the expression of TLRs in fat body tissue are not found in all cells, but is specific to some cell types, in salivary glands TLRs protein expression occur in acini structure. We suggest that immune pathways are active in both fat body and salivary glands in the tick. The potential use of TLRs as a target for vaccine formulations against is discussed.

  2. The influence of parotid gland sparing on radiation damages of dental hard tissues.

    Science.gov (United States)

    Hey, Jeremias; Seidel, Johannes; Schweyen, Ramona; Paelecke-Habermann, Yvonne; Vordermark, Dirk; Gernhardt, Christian; Kuhnt, Thomas

    2013-07-01

    The aim of the present study was to evaluate whether radiation damage on dental hard tissue depends on the mean irradiation dose the spared parotid gland is subjected to or on stimulated whole salivary flow rate. Between June 2002 and October 2008, 70 patients with neck and cancer curatively irradiated were included in this study. All patients underwent dental treatment referring to the guidelines and recommendations of the German Society of Dental, Oral and Craniomandibular Sciences prior, during, and after radiotherapy (RT). During the follow-up period of 24 months, damages on dental hard tissues were classified according to the RTOG/EORTC guidelines. The mean doses (D(mean)) during spared parotid gland RT were determined. Stimulated whole saliva secretion flow rates (SFR) were measured before RT and 1, 6, 12, 24 months after RT. Thirty patients showed no carious lesions (group A), 18 patients developed sporadic carious lesions (group B), and 22 patients developed general carious lesions (group C). Group A patients received a D mean of 21.2 ± 11.04 Gy. Group B patients received a D(mean) of 26.5 ± 11.59 Gy and group C patients received a D(mean) of 33.9 ± 9.93 Gy, respectively. The D(mean) of group A was significantly lower than the D(mean) of group C (p dental hard tissue correlates with increased mean irradiation doses as well as decreased salivary flow rates. Parotid gland sparing resulting in a dose below 20 Gy reduces radiation damage on dental hard tissues, and therefore, the dose may act as a predictor for the damage to be expected.

  3. Chitin Scaffolds in Tissue Engineering

    Science.gov (United States)

    Jayakumar, Rangasamy; Chennazhi, Krishna Prasad; Srinivasan, Sowmya; Nair, Shantikumar V.; Furuike, Tetsuya; Tamura, Hiroshi

    2011-01-01

    Tissue engineering/regeneration is based on the hypothesis that healthy stem/progenitor cells either recruited or delivered to an injured site, can eventually regenerate lost or damaged tissue. Most of the researchers working in tissue engineering and regenerative technology attempt to create tissue replacements by culturing cells onto synthetic porous three-dimensional polymeric scaffolds, which is currently regarded as an ideal approach to enhance functional tissue regeneration by creating and maintaining channels that facilitate progenitor cell migration, proliferation and differentiation. The requirements that must be satisfied by such scaffolds include providing a space with the proper size, shape and porosity for tissue development and permitting cells from the surrounding tissue to migrate into the matrix. Recently, chitin scaffolds have been widely used in tissue engineering due to their non-toxic, biodegradable and biocompatible nature. The advantage of chitin as a tissue engineering biomaterial lies in that it can be easily processed into gel and scaffold forms for a variety of biomedical applications. Moreover, chitin has been shown to enhance some biological activities such as immunological, antibacterial, drug delivery and have been shown to promote better healing at a faster rate and exhibit greater compatibility with humans. This review provides an overview of the current status of tissue engineering/regenerative medicine research using chitin scaffolds for bone, cartilage and wound healing applications. We also outline the key challenges in this field and the most likely directions for future development and we hope that this review will be helpful to the researchers working in the field of tissue engineering and regenerative medicine. PMID:21673928

  4. Quality of Vision in Eyes With Epiphora Undergoing Lacrimal Passage Intubation.

    Science.gov (United States)

    Koh, Shizuka; Inoue, Yasushi; Ochi, Shintaro; Takai, Yoshihiro; Maeda, Naoyuki; Nishida, Kohji

    2017-09-01

    To investigate visual function and optical quality in eyes with epiphora undergoing lacrimal passage intubation. Prospective case series. Thirty-four eyes of 30 patients with lacrimal passage obstruction were enrolled. Before and 1 month after lacrimal passage intubation, functional visual acuity (FVA), higher-order aberrations (HOAs), lower tear meniscus, and tear clearance were assessed. An FVA measurement system was used to examine changes in continuous visual acuity (VA) over time, and visual function parameters such as FVA, visual maintenance ratio, and blink frequency were obtained. Sequential ocular HOAs were measured for 10 seconds after the blink using a wavefront sensor. Aberration data were analyzed in the central 4 mm for coma-like, spherical-like, and total HOAs. Fluctuation and stability indices of the total HOAs over time were calculated. Lower tear meniscus was assessed by anterior segment optical coherence tomography. After lacrimal passage intubation, visual function significantly improved, as indicated by improved FVA (P = .003) and visual maintenance ratio (P function and optical quality via patency of the lacrimal passage. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Biomaterials for tissue engineering applications.

    Science.gov (United States)

    Keane, Timothy J; Badylak, Stephen F

    2014-06-01

    With advancements in biological and engineering sciences, the definition of an ideal biomaterial has evolved over the past 50 years from a substance that is inert to one that has select bioinductive properties and integrates well with adjacent host tissue. Biomaterials are a fundamental component of tissue engineering, which aims to replace diseased, damaged, or missing tissue with reconstructed functional tissue. Most biomaterials are less than satisfactory for pediatric patients because the scaffold must adapt to the growth and development of the surrounding tissues and organs over time. The pediatric community, therefore, provides a distinct challenge for the tissue engineering community. Copyright © 2014. Published by Elsevier Inc.

  6. Successful repair of injury to the eyelid, lacrimal passage, and extraocular muscle

    Directory of Open Access Journals (Sweden)

    Shah, Shreya Mehul

    2016-03-01

    Full Text Available Introduction: Injury is a known cause of monocular blindness. Ocular trauma may affect lacrimal canaliculi and the extraocular muscle. We report this case as it includes injury to lid, lacrimal canaliculi and inferior rectus. Case description: A 25-year-old male presented with an injury caused by a sharp object that resulted in a conjunctival tear, lid tear involving the lacrimal canal, and rupture of the inferior rectus muscle. All of the structures were repaired successfully during a single procedure. Conclusion: An extraocular injury involving the conjunctiva, lid, lacrimal passages, and extraocular muscles can be repaired successfully during a single procedure.

  7. Commercial considerations in tissue engineering.

    Science.gov (United States)

    Mansbridge, Jonathan

    2006-10-01

    Tissue engineering is a field with immense promise. Using the example of an early tissue-engineered skin implant, Dermagraft, factors involved in the successful commercial development of devices of this type are explored. Tissue engineering has to strike a balance between tissue culture, which is a resource-intensive activity, and business considerations that are concerned with minimizing cost and maximizing customer convenience. Bioreactor design takes place in a highly regulated environment, so factors to be incorporated into the concept include not only tissue culture considerations but also matters related to asepsis, scaleup, automation and ease of use by the final customer. Dermagraft is an allogeneic tissue. Stasis preservation, in this case cryopreservation, is essential in allogeneic tissue engineering, allowing sterility testing, inventory control and, in the case of Dermagraft, a cellular stress that may be important for hormesis following implantation. Although the use of allogeneic cells provides advantages in manufacturing under suitable conditions, it raises the spectre of immunological rejection. Such rejection has not been experienced with Dermagraft. Possible reasons for this and the vision of further application of allogeneic tissues are important considerations in future tissue-engineered cellular devices. This review illustrates approaches that indicate some of the criteria that may provide a basis for further developments. Marketing is a further requirement for success, which entails understanding of the mechanism of action of the procedure, and is illustrated for Dermagraft. The success of a tissue-engineered product is dependent on many interacting operations, some discussed here, each of which must be performed simultaneously and well.

  8. Tissue Engineering of the Penis

    Directory of Open Access Journals (Sweden)

    Manish N. Patel

    2011-01-01

    Full Text Available Congenital disorders, cancer, trauma, or other conditions of the genitourinary tract can lead to significant organ damage or loss of function, necessitating eventual reconstruction or replacement of the damaged structures. However, current reconstructive techniques are limited by issues of tissue availability and compatibility. Physicians and scientists have begun to explore tissue engineering and regenerative medicine strategies for repair and reconstruction of the genitourinary tract. Tissue engineering allows the development of biological substitutes which could potentially restore normal function. Tissue engineering efforts designed to treat or replace most organs are currently being undertaken. Most of these efforts have occurred within the past decade. However, before these engineering techniques can be applied to humans, further studies are needed to ensure the safety and efficacy of these new materials. Recent progress suggests that engineered urologic tissues and cell therapy may soon have clinical applicability.

  9. IgG4 immunostaining and its implications in orbital inflammatory disease.

    Directory of Open Access Journals (Sweden)

    Amanda J Wong

    Full Text Available OBJECTIVE: IgG4-related disease is an emerging clinical entity which frequently involves tissue within the orbit. In order to appreciate the implications of IgG4 immunostaining, we analyzed gene expression and the prevalence of IgG4- immunostaining among subjects with orbital inflammatory diseases. METHODS: We organized an international consortium to collect orbital biopsies from 108 subjects including 22 with no known orbital disease, 42 with nonspecific orbital inflammatory disease (NSOI, 26 with thyroid eye disease (TED, 12 with sarcoidosis, and 6 with granulomatosis with polyangiitis (GPA. Lacrimal gland and orbital adipose tissue biopsies were immunostained for IgG4 or IgG secreting plasma cells. RNA transcripts were quantified by Affymetrix arrays. RESULTS: None of the healthy controls or subjects with TED had substantial IgG4 staining. Among the 63 others, the prevalence of significant IgG4-immunostaining ranged from 11 to 39% depending on the definition for significant. IgG4 staining was detectable in the majority of tissues from subjects with GPA and less commonly in tissue from subjects with sarcoidosis or NSOI. The detection of IgG4+ cells correlated with inflammation in the lacrimal gland based on histology. IgG4 staining tissue expressed an increase in transcripts associated with inflammation, especially B cell-related genes. Functional annotation analysis confirmed this. CONCLUSION: IgG4+ plasma cells are common in orbital tissue from patients with sarcoidosis, GPA, or NSOI. Even using the low threshold of 10 IgG4+ cells/high powered field, IgG4 staining correlates with increased inflammation in the lacrimal gland based on histology and gene expression.

  10. IgG4 Immunostaining and Its Implications in Orbital Inflammatory Disease

    Science.gov (United States)

    Wong, Amanda J.; Planck, Stephen R.; Choi, Dongseok; Harrington, Christina A.; Troxell, Megan L.; Houghton, Donald C.; Stauffer, Patrick; Wilson, David J.; Grossniklaus, Hans E.; Dailey, Roger A.; Ng, John D.; Steele, Eric A.; Harris, Gerald J.; Czyz, Craig; Foster, Jill A.; White, Valerie A.; Dolman, Peter J.; Kazim, Michael; Patel, Payal J.; Edward, Deepak P.; Katan, Hind al; Hussain, Hailah al; Selva, Dinesh; Yeatts, R. Patrick; Korn, Bobby S.; Kikkawa, Don O.; Rosenbaum, James T.

    2014-01-01

    Objective IgG4-related disease is an emerging clinical entity which frequently involves tissue within the orbit. In order to appreciate the implications of IgG4 immunostaining, we analyzed gene expression and the prevalence of IgG4- immunostaining among subjects with orbital inflammatory diseases. Methods We organized an international consortium to collect orbital biopsies from 108 subjects including 22 with no known orbital disease, 42 with nonspecific orbital inflammatory disease (NSOI), 26 with thyroid eye disease (TED), 12 with sarcoidosis, and 6 with granulomatosis with polyangiitis (GPA). Lacrimal gland and orbital adipose tissue biopsies were immunostained for IgG4 or IgG secreting plasma cells. RNA transcripts were quantified by Affymetrix arrays. Results None of the healthy controls or subjects with TED had substantial IgG4 staining. Among the 63 others, the prevalence of significant IgG4-immunostaining ranged from 11 to 39% depending on the definition for significant. IgG4 staining was detectable in the majority of tissues from subjects with GPA and less commonly in tissue from subjects with sarcoidosis or NSOI. The detection of IgG4+ cells correlated with inflammation in the lacrimal gland based on histology. IgG4 staining tissue expressed an increase in transcripts associated with inflammation, especially B cell-related genes. Functional annotation analysis confirmed this. Conclusion IgG4+ plasma cells are common in orbital tissue from patients with sarcoidosis, GPA, or NSOI. Even using the low threshold of 10 IgG4+ cells/high powered field, IgG4 staining correlates with increased inflammation in the lacrimal gland based on histology and gene expression. PMID:25303270

  11. Interaction of corneal nociceptive stimulation and lacrimal secretion.

    Science.gov (United States)

    Situ, Ping; Simpson, Trefford L

    2010-11-01

    To investigate the interaction between corneal stimuli at different positions and tear secretion and to establish relationships between nociceptive stimuli detection thresholds and stimulated tearing. Using a computerized Belmonte-esthesiometer, mechanical and chemical stimuli, from 0% to 200% of the threshold in 50% steps, were delivered (in random order) to the central and peripheral (approximately 2-mm inside the limbus) cornea during four separate sessions to 15 subjects. Immediately after each stimulus, tear meniscus height (TMH) was measured using optical coherence tomography to quantify the amount of lacrimal secretion, and subjects reported whether they felt tears starting to accumulate in their eyes. Thresholds (50% detection) for detection of tearing were estimated. TMH increased with increasing stimulus intensity (P lacrimation reflex. Central mechanical corneal stimulation is the most effective stimulus-position pairing and appears to be the major sensory driving force for reflex tear secretion by the lacrimal functional unit.

  12. The growth of tissue engineering.

    Science.gov (United States)

    Lysaght, M J; Reyes, J

    2001-10-01

    This report draws upon data from a variety of sources to estimate the size, scope, and growth rate of the contemporary tissue engineering enterprise. At the beginning of 2001, tissue engineering research and development was being pursued by 3,300 scientists and support staff in more than 70 startup companies or business units with a combined annual expenditure of over $600 million. Spending by tissue engineering firms has been growing at a compound annual rate of 16%, and the aggregate investment since 1990 now exceeds $3.5 billion. At the beginning of 2001, the net capital value of the 16 publicly traded tissue engineering startups had reached $2.6 billion. Firms focusing on structural applications (skin, cartilage, bone, cardiac prosthesis, and the like) comprise the fastest growing segment. In contrast, efforts in biohybrid organs and other metabolic applications have contracted over the past few years. The number of companies involved in stem cells and regenerative medicine is rapidly increasing, and this area represents the most likely nidus of future growth for tissue engineering. A notable recent trend has been the emergence of a strong commercial activity in tissue engineering outside the United States, with at least 16 European or Australian companies (22% of total) now active.

  13. Comparison of mouse mammary gland imaging techniques and applications: Reflectance confocal microscopy, GFP Imaging, and ultrasound

    International Nuclear Information System (INIS)

    Tilli, Maddalena T; Parrish, Angela R; Cotarla, Ion; Jones, Laundette P; Johnson, Michael D; Furth, Priscilla A

    2008-01-01

    Genetically engineered mouse models of mammary gland cancer enable the in vivo study of molecular mechanisms and signaling during development and cancer pathophysiology. However, traditional whole mount and histological imaging modalities are only applicable to non-viable tissue. We evaluated three techniques that can be quickly applied to living tissue for imaging normal and cancerous mammary gland: reflectance confocal microscopy, green fluorescent protein imaging, and ultrasound imaging. In the current study, reflectance confocal imaging offered the highest resolution and was used to optically section mammary ductal structures in the whole mammary gland. Glands remained viable in mammary gland whole organ culture when 1% acetic acid was used as a contrast agent. Our application of using green fluorescent protein expressing transgenic mice in our study allowed for whole mammary gland ductal structures imaging and enabled straightforward serial imaging of mammary gland ducts in whole organ culture to visualize the growth and differentiation process. Ultrasound imaging showed the lowest resolution. However, ultrasound was able to detect mammary preneoplastic lesions 0.2 mm in size and was used to follow cancer growth with serial imaging in living mice. In conclusion, each technique enabled serial imaging of living mammary tissue and visualization of growth and development, quickly and with minimal tissue preparation. The use of the higher resolution reflectance confocal and green fluorescent protein imaging techniques and lower resolution ultrasound were complementary

  14. Regucalcin expression in bovine tissues and its regulation by sex steroid hormones in accessory sex glands.

    Directory of Open Access Journals (Sweden)

    Laura Starvaggi Cucuzza

    Full Text Available Regucalcin (RGN is a mammalian Ca2+-binding protein that plays an important role in intracellular Ca2+ homeostasis. Recently, RGN has been identified as a target gene for sex steroid hormones in the prostate glands and testis of rats and humans, but no studies have focused on RGN expression in bovine tissues. Thus, in the present study, we examined RGN mRNA and protein expression in the different tissues and organs of veal calves and beef cattle. Moreover, we investigated whether RGN expression is controlled through sex steroid hormones in bovine target tissues, namely the bulbo-urethral and prostate glands and the testis. Sex steroid hormones are still illegally used in bovine husbandry to increase muscle mass. The screening of the regulation and function of anabolic sex steroids via modified gene expression levels in various tissues represents a new approach for the detection of illicit drug treatments. Herein, we used quantitative PCR, western blot and immunohistochemistry analyses to demonstrate RGN mRNA and protein expression in bovine tissues. In addition, estrogen administration down-regulated RGN gene expression in the accessory sex glands of veal calves and beef cattle, while androgen treatment reduced RGN gene expression only in the testis. The confirmation of the regulation of RGN gene expression through sex steroid hormones might facilitate the potential detection of hormone abuse in bovine husbandry. Particularly, the specific response in the testis suggests that this tissue is ideal for the detection of illicit androgen administration in veal calves and beef cattle.

  15. Extracellular matrix and tissue engineering applications

    NARCIS (Netherlands)

    Fernandes, H.A.M.; Moroni, Lorenzo; van Blitterswijk, Clemens; de Boer, Jan

    2009-01-01

    The extracellular matrix is a key component during regeneration and maintenance of tissues and organs, and it therefore plays a critical role in successful tissue engineering as well. Tissue engineers should recognise that engineering technology can be deduced from natural repair processes. Due to

  16. Neoproteoglycans in tissue engineering

    Science.gov (United States)

    Weyers, Amanda; Linhardt, Robert J.

    2014-01-01

    Proteoglycans, comprised of a core protein to which glycosaminoglycan chains are covalently linked, are an important structural and functional family of macromolecules found in the extracellular matrix. Advances in our understanding of biological interactions have lead to a greater appreciation for the need to design tissue engineering scaffolds that incorporate mimetics of key extracellular matrix components. A variety of synthetic and semisynthetic molecules and polymers have been examined by tissue engineers that serve as structural, chemical and biological replacements for proteoglycans. These proteoglycan mimetics have been referred to as neoproteoglycans and serve as functional and therapeutic replacements for natural proteoglycans that are often unavailable for tissue engineering studies. Although neoproteoglycans have important limitations, such as limited signaling ability and biocompatibility, they have shown promise in replacing the natural activity of proteoglycans through cell and protein binding interactions. This review focuses on the recent in vivo and in vitro tissue engineering applications of three basic types of neoproteoglycan structures, protein–glycosaminoglycan conjugates, nano-glycosaminoglycan composites and polymer–glycosaminoglycan complexes. PMID:23399318

  17. Structural organization of the thyroid gland and interrenal tissue with reference to endocrine parenchyma in short mackerel, Rastrelliger brachysoma (Bleeker, 1851

    Directory of Open Access Journals (Sweden)

    Sinlapachai Senarat

    2016-01-01

    Full Text Available The first investigations of the thyroid gland and interrenal tissue with reference to the endocrine parenchyma of short mackerel Rastrelliger brachysoma were subjected to histological analysis. Specimens were collected during the fishing season (October to November 2013 from the Upper Gulf of Thailand. Under a light microscope, the thyroid gland of R. brachysoma was distinctly found located within the branchial region. Within this gland, it consists of several follicles among afferent brachial arteries. Each follicle exclusively contained a colloid that was surrounded by a simple, cuboidal, follicle epithelium. Histological study showed that the localization of interrenal tissue was in the anterior kidney. This tissue was composed of two parts based on the structural compositions and cell types; (i the stromal compartment was constituted of various interrenal cells and (ii the interstitial compartment contained the connective tissue, leucocytes and blood sinuses, with reference to the lymphatic tissue.

  18. Accumulation of radioactivity in rat brain and peripheral tissues including salivary gland after intravenous administration of 14C-D-aspartic acid

    International Nuclear Information System (INIS)

    Imai, Kazuhiro; Fukushima, Takeshi; Santa, Tomofumi; Homma, Hiroshi; Sugihara, Juko; Kodama, Hirohiko; Yoshikawa, Masayoshi.

    1997-01-01

    After the intravenous administration of 14 C-D-aspartic acid (Asp) into Sprague-Dawley rats (male, 7-week-old), the distribution and elimination of radioactivity was investigated by the whole body autoradiography. High radioactivities were detected in pineal gland, pituitary gland and salivary gland at 30 min after administration. The other tissues detected were liver, lung, adrenal gland, pancreas and spleen where D-Asp was reported to occur naturally. After 24 hr, the radioactivities were still detected at high levels in the pineal, pituitary and salivary glands. The data suggested the natural occurrence of D-Asp in salivary gland. After careful examination utilizing fluorescent derivatization and chiral separation by high-performance liquid chromatography, the presence of D-Asp was, for the first time, demonstrated in salivary gland in situ, the concentration of which was 7.85 ± 1.0 nmol/g. The administration of 14 C-L-Asp was also carried out. The data suggested that D-Asp in the circulating blood is one of the sources of the tissue D-Asp. (author)

  19. Radionuclidedacryography for diagnosis of lacrimal obstruction

    International Nuclear Information System (INIS)

    Dressler, J.; Denffer, H.V.; Gullotta, U.; Pabst, H.W.

    1982-01-01

    The lacrimal drainage systems of 69 eyes were studied by both radionuclidedacryography (RND) and conventional X-ray dacryocystography (DCG). Sequential scanning is peformed by employing a small volume of Tc-99m as an eye drop a gamma camera with a specially designed pinhole collimator. Compared to DCG the radionuclide method is more reliable in detecting functional blockage of the lacrimal drainage apparatus (LDA). No radiographically detected stenosis was missed by RND but in 6 out of 44 patients the site of obstruction was localisized somewhat higher up in the LDA. RND is recommended as a valuable diagnostic tool in all patients with epiphora, especially in follow up studies before and after surgical treatment and radiotherapy in the region of the LDA

  20. Alteration of gene expression in mammary gland tissue of dairy cows in response to dietary unsaturated fatty acids

    NARCIS (Netherlands)

    Mach Casellas, N.; Jacobs, A.A.A.; Kruijt, L.; Baal, van J.; Smits, M.C.J.

    2014-01-01

    The aim of this study was to determine the effects of unprotected dietary unsaturated fatty acids (UFA) from different plant oils on gene expression in the mammary gland of grazing dairy cows. Milk composition and gene expression in the mammary gland tissue were evaluated in grazing dairy cows

  1. Invasive fibrous thyroiditis (Riedel's struma): a manifestation of multifocal fibrosclerosis? A case report with review of the literature.

    NARCIS (Netherlands)

    Lange, W E de; Freling, N J; Molenaar, W M; Doorenbos, H

    1989-01-01

    A patient is described with Riedel's thyroiditis and invasive fibrous growth in parathyroid, lacrimal glands, and retroperitoneally. It is proposed that Riedel's thyroiditis is not a disease in its own right but a manifestation of a generalized disease of fibrous tissues.

  2. Insertion of a self-expandable metallic stent in canine lacrimal Sac : a long-term evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Young; Sung, Kyu Bo; Yoon, Hyun Ki [Univ. of Ulsan, Ulsan (Korea, Republic of). College of Medicine; Kwon, Soon Tae [Chungnam National Univ., Taejon (Korea, Republic of). Medical School; Lee, Ho Jung; Lee, In Chul; Kim, Tae Hyung; Park, Sang Soo; Huh, Soo Jin [Univ. of Ulsan, Ulsan (Korea, Republic of). College of Medicine

    1998-01-01

    To evaluate the feasibility and long-term outcome of the use of self-expandable metallic Z-stents in the canine lacrimal sac. Stent placement was technically successful and well tolerated in all but one lacrimal sac, in which the stent was misplaced. At three and six months after stent placement, stent wires were not encased by epithelium, but at nine months, and one, two and three years after placement, six of the 12 stents had become encased in a proliferation of this where the stent wires contacted the lacrimal sac wall. In no lacrimal system in which stent placement had been successful was migration, stenosis or obstruction of the lacrimal system observed. One misplaced stent caused obstruction of the lacrimal sac, however . In 11 of 12 case (92%), fluoroscopic placement of an expandable metallic stent in the canine lacrimal sac was successful: in 6 of 8 cases (75%), the stent wires became encased by a proliferation of mucosa, but during long-term follow-up of 9 months to 3 years, no obstruction was observed. (author). 20 refs., 1 tab., 5 figs.

  3. Insertion of a self-expandable metallic stent in canine lacrimal Sac : a long-term evaluation

    International Nuclear Information System (INIS)

    Song, Ho Young; Sung, Kyu Bo; Yoon, Hyun Ki; Kwon, Soon Tae; Lee, Ho Jung; Lee, In Chul; Kim, Tae Hyung; Park, Sang Soo; Huh, Soo Jin

    1998-01-01

    To evaluate the feasibility and long-term outcome of the use of self-expandable metallic Z-stents in the canine lacrimal sac. Stent placement was technically successful and well tolerated in all but one lacrimal sac, in which the stent was misplaced. At three and six months after stent placement, stent wires were not encased by epithelium, but at nine months, and one, two and three years after placement, six of the 12 stents had become encased in a proliferation of this where the stent wires contacted the lacrimal sac wall. In no lacrimal system in which stent placement had been successful was migration, stenosis or obstruction of the lacrimal system observed. One misplaced stent caused obstruction of the lacrimal sac, however . In 11 of 12 case (92%), fluoroscopic placement of an expandable metallic stent in the canine lacrimal sac was successful: in 6 of 8 cases (75%), the stent wires became encased by a proliferation of mucosa, but during long-term follow-up of 9 months to 3 years, no obstruction was observed. (author). 20 refs., 1 tab., 5 figs

  4. Computed tomography of lacrimal fossa tumors

    International Nuclear Information System (INIS)

    Park, Chan Sup; Kim, Young Goo; Chang, Kee Hyun

    1985-01-01

    The lacrimal fossa can be involved by a wide spectrum of orbital pathology. The correct diagnosis is important to avoid unnecessary procedure and to do appropriate management. 14 patients with mass lesions in the lacrimal fossa were evaluated with computed tomography (CT) and clinical findings. The results were as follows: 1. Final diagnosis of 14 cases with lacrimal fossa tumors was pleomorphic adenoma in 3 cases, adenoid cystic carcinoma in 1 case, pseudotumor in 5 cases, lymphoma in 2 cases, neurofibroma in 1 case, chloroma in 1 case and metastatic adenocarcinoma in 1 case. 2. The duration of symptoms of pleomorphic adenoma was more than 1 year and characteristic CT findings were globular masses with pressure erosion of the adjacent bone. Patient with adenoid cystic carcinoma had a short history of symptoms. CT showed a fusiform mass but intracranial extension with frank destruction of sphenoid bone. 3. Patients with pseudotumor and lymphoma had symptoms for less than 1 year. The CT findings were ill-defined infiltrative patterns with scleral thickening and the differential diagnosis of them was difficult. 4. The margins of neurofibroma and chloroma were well defined while that of the metastic adenocarcinoma was ill-defined. 5. The degree and the extent of the contrast enhancement gave no benefit in the differential diagnosis of each disease entities and even of the benign and malignant lesions

  5. The state of «the pituitary gland - thyroid gland system» in the young men with undifferentiated dysplasia of the connective tissue

    Directory of Open Access Journals (Sweden)

    P. A. Yurchenko

    2013-01-01

    Full Text Available To investigate the state of «the pituitary gland-thyroid gland system» in the patients with undifferentiated dysplasia of the connective tissue (UDCT 83 young men of the call up age (18.2±0.4 y.o. were examined. The control group consisted of 26 practically healthy young men of the same age (18.5±0.2 y.o.. Autoimmune thyroiditis (AIT was diagnosed in 32.5 % of the men with UDCT. The rate of the internal (visceral phenotypical signs of UDCT in this group was significantly higher than in the men with UDCT but without thyroid problems.

  6. Evaluation of the lacrimal system by radiological methods

    International Nuclear Information System (INIS)

    Francisco, Fabiano Celli; Francisco, Vivian Frida Murta; Mendonca Junior, Adhemar Azevedo de; Carvalho, Antonio Carlos Pires; Fonseca, Lea Mirian Barbosa da; Gutfilen, Bianca; Francisco, Marina Celli

    2007-01-01

    The authors perform a revisional and iconographic study of the lacrimal system by means of radiological methods, namely, conventional radiography, linear tomography, computed tomography and magnetic resonance imaging. Image methods are essential to define diagnosis and therapy, considering that besides demonstrating alterations of the lacrimal system, they may indicate the patients with better prognosis associated with the surgical approach. Considering the lower cost, lower radiation dose, low rate of complications, and level of information that can be obtained dacryocystography by means of linear tomography is recommended as the initial investigation method. (author)

  7. Micro- and nanotechnology in cardiovascular tissue engineering

    International Nuclear Information System (INIS)

    Zhang Boyang; Xiao Yun; Hsieh, Anne; Thavandiran, Nimalan; Radisic, Milica

    2011-01-01

    While in nature the formation of complex tissues is gradually shaped by the long journey of development, in tissue engineering constructing complex tissues relies heavily on our ability to directly manipulate and control the micro-cellular environment in vitro. Not surprisingly, advancements in both microfabrication and nanofabrication have powered the field of tissue engineering in many aspects. Focusing on cardiac tissue engineering, this paper highlights the applications of fabrication techniques in various aspects of tissue engineering research: (1) cell responses to micro- and nanopatterned topographical cues, (2) cell responses to patterned biochemical cues, (3) controlled 3D scaffolds, (4) patterned tissue vascularization and (5) electromechanical regulation of tissue assembly and function.

  8. A milk protein gene promoter directs the expression of human tissue plasminogen activator cDNA to the mammary gland in transgenic mice

    International Nuclear Information System (INIS)

    Pittius, C.W.; Hennighausen, L.; Lee, E.; Westphal, H.; Nicols, E.; Vitale, J.; Gordon, K.

    1988-01-01

    Whey acidic protein (WAP) is a major whey protein in mouse milk. Its gene is expressed in the lactating mammary gland and is inducible by steroid and peptide hormones. A series of transgenic mice containing a hybrid gene in which human tissue plasminogen activator (tPA) cDNA is under the control of the murine WAP gene promoter had previously been generated. In this study, 21 tissues from lactating and virgin transgenic female mice containing the WAP-tPA hybrid gene were screened for the distribution of murine WAP and human tPA transcripts. Like the endogenous WAP RNA, WAP-tPA RNA was expressed predominantly in mammary gland tissue and appeared to be inducible by lactation. Whereas WAP transcripts were not detected in 22 tissues of virgin mice, low levels of WAP-tPA RNA, which were not modulated during lactation, were found in tongue, kidney, and sublingual gland. These studies demonstrate that the WAP gene promoter can target the expression of a transgene to the mammary gland and that this expression is inducible during lactation

  9. Biomechanics and mechanobiology in functional tissue engineering

    Science.gov (United States)

    Guilak, Farshid; Butler, David L.; Goldstein, Steven A.; Baaijens, Frank P.T.

    2014-01-01

    The field of tissue engineering continues to expand and mature, and several products are now in clinical use, with numerous other preclinical and clinical studies underway. However, specific challenges still remain in the repair or regeneration of tissues that serve a predominantly biomechanical function. Furthermore, it is now clear that mechanobiological interactions between cells and scaffolds can critically influence cell behavior, even in tissues and organs that do not serve an overt biomechanical role. Over the past decade, the field of “functional tissue engineering” has grown as a subfield of tissue engineering to address the challenges and questions on the role of biomechanics and mechanobiology in tissue engineering. Originally posed as a set of principles and guidelines for engineering of load-bearing tissues, functional tissue engineering has grown to encompass several related areas that have proven to have important implications for tissue repair and regeneration. These topics include measurement and modeling of the in vivo biomechanical environment; quantitative analysis of the mechanical properties of native tissues, scaffolds, and repair tissues; development of rationale criteria for the design and assessment of engineered tissues; investigation of the effects biomechanical factors on native and repair tissues, in vivo and in vitro; and development and application of computational models of tissue growth and remodeling. Here we further expand this paradigm and provide examples of the numerous advances in the field over the past decade. Consideration of these principles in the design process will hopefully improve the safety, efficacy, and overall success of engineered tissue replacements. PMID:24818797

  10. Biological aspects of tissue-engineered cartilage.

    Science.gov (United States)

    Hoshi, Kazuto; Fujihara, Yuko; Yamawaki, Takanori; Harai, Motohiro; Asawa, Yukiyo; Hikita, Atsuhiko

    2018-04-01

    Cartilage regenerative medicine has been progressed well, and it reaches the stage of clinical application. Among various techniques, tissue engineering, which incorporates elements of materials science, is investigated earnestly, driven by high clinical needs. The cartilage tissue engineering using a poly lactide scaffold has been exploratorily used in the treatment of cleft lip-nose patients, disclosing good clinical results during 3-year observation. However, to increase the reliability of this treatment, not only accumulation of clinical evidence on safety and usefulness of the tissue-engineered products, but also establishment of scientific background on biological mechanisms, are regarded essential. In this paper, we reviewed recent trends of cartilage tissue engineering in clinical practice, summarized experimental findings on cellular and matrix changes during the cartilage regeneration, and discussed the importance of further studies on biological aspects of tissue-engineered cartilage, especially by the histological and the morphological methods.

  11. Synthetic biology meets tissue engineering.

    Science.gov (United States)

    Davies, Jamie A; Cachat, Elise

    2016-06-15

    Classical tissue engineering is aimed mainly at producing anatomically and physiologically realistic replacements for normal human tissues. It is done either by encouraging cellular colonization of manufactured matrices or cellular recolonization of decellularized natural extracellular matrices from donor organs, or by allowing cells to self-organize into organs as they do during fetal life. For repair of normal bodies, this will be adequate but there are reasons for making unusual, non-evolved tissues (repair of unusual bodies, interface to electromechanical prostheses, incorporating living cells into life-support machines). Synthetic biology is aimed mainly at engineering cells so that they can perform custom functions: applying synthetic biological approaches to tissue engineering may be one way of engineering custom structures. In this article, we outline the 'embryological cycle' of patterning, differentiation and morphogenesis and review progress that has been made in constructing synthetic biological systems to reproduce these processes in new ways. The state-of-the-art remains a long way from making truly synthetic tissues, but there are now at least foundations for future work. © 2016 Authors; published by Portland Press Limited.

  12. Radiation induced dry eye: problem and potential remedies

    International Nuclear Information System (INIS)

    Vemuganti, Geeta K.; Tiwari, Shubha

    2016-01-01

    Advances in orbital radiotherapy have significantly increased therapeutic efficiency and reduced the side effects but a significant proportion of patients are still seen with ophthalmic complication like dry eye syndrome (DES). The treatment of DES involves temporary palliative therapies like ocular surface lubrication and rehydration. We aimed at establishing the human lacrimal gland cultures and evaluating for the presence of stem cells and secretory potential. Using human lacrimal gland tissues obtained from samples of therapeutic exenteration post-radiotherapy, we established a monolayer as well as 3D lacrispheres that show evidence of stem cells, secretory acinar cells, duct like formation and other cells like myoepithelial cells and duct like cells. The stem cells were identified as CD 117 positive that co-segregated with G0/G1 phase, ALDH high, label retaining cells and high clone forming ability. The most promising evidence of its secretory function was seen in the presence of tear substances like lysosymes, lactiferrin, and scIg A in the conditioned media of the lacrimal gland cultures. This novel development would pave way for development of a functionally competent 3D construct for potential clinical application in severe cases of radiation induced dry eye. (author)

  13. Reverse engineering development: Crosstalk opportunities between developmental biology and tissue engineering.

    Science.gov (United States)

    Marcucio, Ralph S; Qin, Ling; Alsberg, Eben; Boerckel, Joel D

    2017-11-01

    The fields of developmental biology and tissue engineering have been revolutionized in recent years by technological advancements, expanded understanding, and biomaterials design, leading to the emerging paradigm of "developmental" or "biomimetic" tissue engineering. While developmental biology and tissue engineering have long overlapping histories, the fields have largely diverged in recent years at the same time that crosstalk opportunities for mutual benefit are more salient than ever. In this perspective article, we will use musculoskeletal development and tissue engineering as a platform on which to discuss these emerging crosstalk opportunities and will present our opinions on the bright future of these overlapping spheres of influence. The multicellular programs that control musculoskeletal development are rapidly becoming clarified, represented by shifting paradigms in our understanding of cellular function, identity, and lineage specification during development. Simultaneously, advancements in bioartificial matrices that replicate the biochemical, microstructural, and mechanical properties of developing tissues present new tools and approaches for recapitulating development in tissue engineering. Here, we introduce concepts and experimental approaches in musculoskeletal developmental biology and biomaterials design and discuss applications in tissue engineering as well as opportunities for tissue engineering approaches to inform our understanding of fundamental biology. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2356-2368, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  14. Did androgen-binding protein paralogs undergo neo- and/or Subfunctionalization as the Abp gene region expanded in the mouse genome?

    Science.gov (United States)

    Karn, Robert C; Chung, Amanda G; Laukaitis, Christina M

    2014-01-01

    The Androgen-binding protein (Abp) region of the mouse genome contains 30 Abpa genes encoding alpha subunits and 34 Abpbg genes encoding betagamma subunits, their products forming dimers composed of an alpha and a betagamma subunit. We endeavored to determine how many Abp genes are expressed as proteins in tears and saliva, and as transcripts in the exocrine glands producing them. Using standard PCR, we amplified Abp transcripts from cDNA libraries of C57BL/6 mice and found fifteen Abp gene transcripts in the lacrimal gland and five in the submandibular gland. Proteomic analyses identified proteins corresponding to eleven of the lacrimal gland transcripts, all of them different from the three salivary ABPs reported previously. Our qPCR results showed that five of the six transcripts that lacked corresponding proteins are expressed at very low levels compared to those transcripts with proteins. We found 1) no overlap in the repertoires of expressed Abp paralogs in lacrimal gland/tears and salivary glands/saliva; 2) substantial sex-limited expression of lacrimal gland/tear expressed-paralogs in males but no sex-limited expression in females; and 3) that the lacrimal gland/tear expressed-paralogs are found exclusively in ancestral clades 1, 2 and 3 of the five clades described previously while the salivary glands/saliva expressed-paralogs are found only in clade 5. The number of instances of extremely low levels of transcription without corresponding protein production in paralogs specific to tears and saliva suggested the role of subfunctionalization, a derived condition wherein genes that may have been expressed highly in both glands ancestrally were down-regulated subsequent to duplication. Thus, evidence for subfunctionalization can be seen in our data and we argue that the partitioning of paralog expression between lacrimal and salivary glands that we report here occurred as the result of adaptive evolution.

  15. [Investigations on the physiology of the glands of carnivorous plants : IV. The kinetics of chloride secretion by the gland tissue of Nepenthes].

    Science.gov (United States)

    Lüttge, U

    1966-03-01

    The transport of chloride in isolated tissue from Nepenthes pitchers was investigated using (36)Cl(-), an Aminco-Cotlove chloride-titrator for the determinations of Cl(-) concentrations, and KCN and AsO 4 (-) -as metabolic inhibitors.The tissue was brought in contact with different experimental solutions (=medium). The surface corresponding to the outside of the pitchers was cut with a razor blade to remove the cutinized epidermal layer. At this surface the Cl(-) uptake from the medium is a metabolic process which depends on the Cl(-)-concentration of the medium in a manner that corresponds to the MICHAELIS-MENTEN kinetics. The Michaelis-constant of this transport step was 3×10(-2)M. The Cl(-)-efflux into the medium, however, is a passive process.The opposite surface of the tissue slices (corresponding to the inside of the pitchers) carries the glands. The chloride secretion taking place here is also dependent on metabolism. In vitro it occurs even when a high gradient of chloride concentration has been set up between the medium and the solution which is in contact with the glands. In vivo the Cl(-)-concentration of the pitcher fluid and the amount of Cl(-) per gram of tissue water are almost equal.The rôle of chloride in the physiology of Nepenthes is still under investigation, A correlation between the chloride content of the pitcher fluid and its enzymatic activity (Casein-test), however, could already be demonstrated.

  16. Cell-Based Strategies for Meniscus Tissue Engineering

    Science.gov (United States)

    Niu, Wei; Guo, Weimin; Han, Shufeng; Zhu, Yun; Liu, Shuyun; Guo, Quanyi

    2016-01-01

    Meniscus injuries remain a significant challenge due to the poor healing potential of the inner avascular zone. Following a series of studies and clinical trials, tissue engineering is considered a promising prospect for meniscus repair and regeneration. As one of the key factors in tissue engineering, cells are believed to be highly beneficial in generating bionic meniscus structures to replace injured ones in patients. Therefore, cell-based strategies for meniscus tissue engineering play a fundamental role in meniscal regeneration. According to current studies, the main cell-based strategies for meniscus tissue engineering are single cell type strategies; cell coculture strategies also were applied to meniscus tissue engineering. Likewise, on the one side, the zonal recapitulation strategies based on mimicking meniscal differing cells and internal architectures have received wide attentions. On the other side, cell self-assembling strategies without any scaffolds may be a better way to build a bionic meniscus. In this review, we primarily discuss cell seeds for meniscus tissue engineering and their application strategies. We also discuss recent advances and achievements in meniscus repair experiments that further improve our understanding of meniscus tissue engineering. PMID:27274735

  17. Aloe Vera for Tissue Engineering Applications

    Directory of Open Access Journals (Sweden)

    Shekh Rahman

    2017-02-01

    Full Text Available Aloe vera, also referred as Aloe barbadensis Miller, is a succulent plant widely used for biomedical, pharmaceutical and cosmetic applications. Aloe vera has been used for thousands of years. However, recent significant advances have been made in the development of aloe vera for tissue engineering applications. Aloe vera has received considerable attention in tissue engineering due to its biodegradability, biocompatibility, and low toxicity properties. Aloe vera has been reported to have many biologically active components. The bioactive components of aloe vera have effective antibacterial, anti-inflammatory, antioxidant, and immune-modulatory effects that promote both tissue regeneration and growth. The aloe vera plant, its bioactive components, extraction and processing, and tissue engineering prospects are reviewed in this article. The use of aloe vera as tissue engineering scaffolds, gels, and films is discussed, with a special focus on electrospun nanofibers.

  18. Aloe Vera for Tissue Engineering Applications.

    Science.gov (United States)

    Rahman, Shekh; Carter, Princeton; Bhattarai, Narayan

    2017-02-14

    Aloe vera, also referred as Aloe barbadensis Miller, is a succulent plant widely used for biomedical, pharmaceutical and cosmetic applications. Aloe vera has been used for thousands of years. However, recent significant advances have been made in the development of aloe vera for tissue engineering applications. Aloe vera has received considerable attention in tissue engineering due to its biodegradability, biocompatibility, and low toxicity properties. Aloe vera has been reported to have many biologically active components. The bioactive components of aloe vera have effective antibacterial, anti-inflammatory, antioxidant, and immune-modulatory effects that promote both tissue regeneration and growth. The aloe vera plant, its bioactive components, extraction and processing, and tissue engineering prospects are reviewed in this article. The use of aloe vera as tissue engineering scaffolds, gels, and films is discussed, with a special focus on electrospun nanofibers.

  19. Multilayer scaffolds in orthopaedic tissue engineering.

    Science.gov (United States)

    Atesok, Kivanc; Doral, M Nedim; Karlsson, Jon; Egol, Kenneth A; Jazrawi, Laith M; Coelho, Paulo G; Martinez, Amaury; Matsumoto, Tomoyuki; Owens, Brett D; Ochi, Mitsuo; Hurwitz, Shepard R; Atala, Anthony; Fu, Freddie H; Lu, Helen H; Rodeo, Scott A

    2016-07-01

    The purpose of this study was to summarize the recent developments in the field of tissue engineering as they relate to multilayer scaffold designs in musculoskeletal regeneration. Clinical and basic research studies that highlight the current knowledge and potential future applications of the multilayer scaffolds in orthopaedic tissue engineering were evaluated and the best evidence collected. Studies were divided into three main categories based on tissue types and interfaces for which multilayer scaffolds were used to regenerate: bone, osteochondral junction and tendon-to-bone interfaces. In vitro and in vivo studies indicate that the use of stratified scaffolds composed of multiple layers with distinct compositions for regeneration of distinct tissue types within the same scaffold and anatomic location is feasible. This emerging tissue engineering approach has potential applications in regeneration of bone defects, osteochondral lesions and tendon-to-bone interfaces with successful basic research findings that encourage clinical applications. Present data supporting the advantages of the use of multilayer scaffolds as an emerging strategy in musculoskeletal tissue engineering are promising, however, still limited. Positive impacts of the use of next generation scaffolds in orthopaedic tissue engineering can be expected in terms of decreasing the invasiveness of current grafting techniques used for reconstruction of bone and osteochondral defects, and tendon-to-bone interfaces in near future.

  20. Design Approaches to Myocardial and Vascular Tissue Engineering.

    Science.gov (United States)

    Akintewe, Olukemi O; Roberts, Erin G; Rim, Nae-Gyune; Ferguson, Michael A H; Wong, Joyce Y

    2017-06-21

    Engineered tissues represent an increasingly promising therapeutic approach for correcting structural defects and promoting tissue regeneration in cardiovascular diseases. One of the challenges associated with this approach has been the necessity for the replacement tissue to promote sufficient vascularization to maintain functionality after implantation. This review highlights a number of promising prevascularization design approaches for introducing vasculature into engineered tissues. Although we focus on encouraging blood vessel formation within myocardial implants, we also discuss techniques developed for other tissues that could eventually become relevant to engineered cardiac tissues. Because the ultimate solution to engineered tissue vascularization will require collaboration between wide-ranging disciplines such as developmental biology, tissue engineering, and computational modeling, we explore contributions from each field.

  1. Scientific and industrial status of tissue engineering ...

    African Journals Online (AJOL)

    Tissue engineering is a newly emerging field targeting many unresolved health problems. So far, the achievements of this technology in the production of different tissue engineered substitutes were promising. This review is intended to describe, briefly and in a simple language, what tissue engineering is, what the ...

  2. Biomaterials for tissue engineering: summary

    Science.gov (United States)

    Christenson, L.; Mikos, A. G.; Gibbons, D. F.; Picciolo, G. L.; McIntire, L. V. (Principal Investigator)

    1997-01-01

    This article summarizes presentations and discussion at the workshop "Enabling Biomaterial Technology for Tissue Engineering," which was held during the Fifth World Biomaterials Congress in May 1996. Presentations covered the areas of material substrate architecture, barrier effects, and cellular response, including analysis of biomaterials challenges involved in producing specific tissue-engineered products.

  3. Microgel Technology to Advance Modular Tissue Engineering

    NARCIS (Netherlands)

    Kamperman, Tom

    2018-01-01

    The field of tissue engineering aims to restore the function of damaged or missing tissues by combining cells and/or a supportive biomaterial scaffold into an engineered tissue construct. The construct’s design requirements are typically set by native tissues – the gold standard for tissue

  4. Maintenance of the Extracellular Matrix in Rat Anterior Pituitary Gland: Identification of Cells Expressing Tissue Inhibitors of Metalloproteinases.

    Science.gov (United States)

    Azuma, Morio; Tofrizal, Alimuddin; Maliza, Rita; Batchuluun, Khongorzul; Ramadhani, Dini; Syaidah, Rahimi; Tsukada, Takehiro; Fujiwara, Ken; Kikuchi, Motoshi; Horiguchi, Kotaro; Yashiro, Takashi

    2015-12-25

    The extracellular matrix (ECM) is important in creating cellular environments in tissues. Recent studies have demonstrated that ECM components are localized in anterior pituitary cells and affect cell activity. Thus, clarifying the mechanism responsible for ECM maintenance would improve understanding of gland function. Tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of matrix metalloproteinases and participate in ECM degradation. In this study, we investigated whether cells expressing TIMPs are present in rat anterior pituitary gland. Reverse transcription polymerase chain reaction was used to analyze expression of the TIMP family (TIMP1-4), and cells producing TIMPs in the gland were identified by using in situ hybridization. Expression of TIMP1, TIMP2, and TIMP3 mRNAs was detected, and the TIMP-expressing cells were located in the gland. The TIMP-expressing cells were also investigated by means of double-staining with in situ hybridization and immunohistochemical techniques. Double-staining revealed that TIMP1 mRNA was expressed in folliculostellate cells. TIMP2 mRNA was detected in folliculostellate cells, prolactin cells, and thyroid-stimulating hormone cells. TIMP3 mRNA was identified in endothelial cells, pericytes, novel desmin-immunopositive perivascular cells, and folliculostellate cells. These findings indicate that TIMP1-, TIMP2-, and TIMP3-expressing cells are present in rat anterior pituitary gland and that they are involved in maintaining ECM components.

  5. Maintenance of the Extracellular Matrix in Rat Anterior Pituitary Gland: Identification of Cells Expressing Tissue Inhibitors of Metalloproteinases

    International Nuclear Information System (INIS)

    Azuma, Morio; Tofrizal, Alimuddin; Maliza, Rita; Batchuluun, Khongorzul; Ramadhani, Dini; Syaidah, Rahimi; Tsukada, Takehiro; Fujiwara, Ken; Kikuchi, Motoshi; Horiguchi, Kotaro; Yashiro, Takashi

    2015-01-01

    The extracellular matrix (ECM) is important in creating cellular environments in tissues. Recent studies have demonstrated that ECM components are localized in anterior pituitary cells and affect cell activity. Thus, clarifying the mechanism responsible for ECM maintenance would improve understanding of gland function. Tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of matrix metalloproteinases and participate in ECM degradation. In this study, we investigated whether cells expressing TIMPs are present in rat anterior pituitary gland. Reverse transcription polymerase chain reaction was used to analyze expression of the TIMP family (TIMP1-4), and cells producing TIMPs in the gland were identified by using in situ hybridization. Expression of TIMP1, TIMP2, and TIMP3 mRNAs was detected, and the TIMP-expressing cells were located in the gland. The TIMP-expressing cells were also investigated by means of double-staining with in situ hybridization and immunohistochemical techniques. Double-staining revealed that TIMP1 mRNA was expressed in folliculostellate cells. TIMP2 mRNA was detected in folliculostellate cells, prolactin cells, and thyroid-stimulating hormone cells. TIMP3 mRNA was identified in endothelial cells, pericytes, novel desmin-immunopositive perivascular cells, and folliculostellate cells. These findings indicate that TIMP1-, TIMP2-, and TIMP3-expressing cells are present in rat anterior pituitary gland and that they are involved in maintaining ECM components

  6. Is the digestive gland of Mytilus galloprovincialis a tissue of choice for estimating cadmium exposure by means of metallothioneins?

    International Nuclear Information System (INIS)

    Raspor, Biserka; Dragun, Zrinka; Erk, Marijana; Ivankovic, Dusica; Pavicic, Jasenka

    2004-01-01

    A study performed over 12 months with caged mussels Mytilus galloprovincialis in the coastal marine zone, which is under urban pressure, reveals a temporal variation of digestive gland mass, which causes 'biological dilution' of cytosolic metallothionein (MT) and trace metal (Cd, Cu, Zn, Fe, Mn) concentrations. The dilution effect was corrected by expressing the cytosolic MT and metal concentrations as the tissue content. Consequently, the changes of the average digestive gland mass coincide with the changes of MT and trace metal contents. From February to June, MT contents are nearly twice and trace metal contents nearly three times higher than those of the other months. The period of increased average digestive gland mass, of MT and trace metal contents probably overlaps with the sexual maturation of mussels (gametogenesis) and enhanced food availability. Since natural factors contribute more to the MT content than the sublethal levels of Cd, the digestive gland of M. galloprovincialis is not considered as a tissue of choice for estimating Cd exposure by means of MTs

  7. Co-localization of lymphoid aggregates and lymphatic networks in nose- (NALT) and lacrimal duct-associated lymphoid tissue (LDALT) of mice.

    Science.gov (United States)

    Lohrberg, Melanie; Pabst, Reinhard; Wilting, Jörg

    2018-01-25

    The lymphatic vascular pattern in the head of mice has rarely been studied, due to problems of sectioning and immunostaining of complex bony structures. Therefore, the association of head lymphoid tissues with the lymphatics has remained unknown although the mouse is the most often used species in immunology. Here, we studied the association of nasal and nasolacrimal duct lymphatics with lymphoid aggregates in 14-day-old and 2-month-old mice. We performed paraffin sectioning of whole, decalcified heads, and immunostaining with the lymphatic endothelial cell-specific antibodies Lyve-1 and Podoplanin. Most parts of the nasal mucous membrane do not contain any lymphatics. Only the region of the inferior turbinates contains lymphatic networks, which are connected to those of the palatine. Nose-associated lymphoid tissue (NALT) is restricted to the basal parts of the nose, which contain lymphatics. NALT is continued occipitally and can be found at both sides along the sphenoidal sinus, again in close association with lymphatic networks. Nasal lymphatics are connected to those of the ocular region via a lymphatic network along the nasolacrimal duct (NLD). By this means, lacrimal duct-associated lymphoid tissue (LDALT) has a dense supply with lymphatics. NALT and LDALT play a key role in the immune system of the mouse head, where they function as primary recognition sites for antigens. Using the dense lymphatic networks along the NLD described in this study, these antigens reach lymphatics near the palatine and are further drained to lymph nodes of the head and neck region. NALT and LDALT develop in immediate vicinity of lymphatic vessels. Therefore, we suggest a causative connection of lymphatic vessels and the development of lymphoid tissues.

  8. Development of a Tissue-Engineered Lymphatic Graft Using Nanocomposite Polymer for the Treatment of Secondary Lymphedema.

    Science.gov (United States)

    Kanapathy, Muholan; Kalaskar, Deepak; Mosahebi, Afshin; Seifalian, Alexander M

    2016-03-01

    Damage of the lymphatic vessels, commonly due to surgical resection for cancer treatment, leads to secondary lymphedema. Tissue engineering approach offers a possible solution to reconstruct this damage with the use of lymphatic graft to re-establish the lymphatic flow, hence preventing lymphedema. The aim of this study is to develop a tissue-engineered lymphatic graft using nanocomposite polymer and human dermal lymphatic endothelial cells (HDLECs). A nanocomposite polymer, the polyhedral oligomeric silsequioxane-poly(carbonate-urea)urethane (POSS-PCU), which has enhanced mechanical, chemical, and physical characteristics, was used to develop the lymphatic graft. POSS-PCU has been used clinically for the world's first synthetic trachea, lacrimal duct, and is currently undergoing clinical trial for coronary artery bypass graft. Two designs and fabrication methods were used to manufacture the conduits. The fabrication method, the mechanical and physical properties, as well as the hydraulic conductivity were tested. This is followed by in vitro cell culture analysis to test the cytocompatibility of HDLEC with the polymer surface. Using the casted extrusion method, the nanocomposite lymphatic graft demonstrates desirable mechanical property and hydraulic conductivity to re-establish the lymphatic flow. The conduit has high tensile strength (casted: 74.86 ± 5.74 MPa vs. coagulated: 31.33 ± 3.71 MPa; P nanocomposite polymer. It displays excellent mechanical property and cytocompatibility to HDLECs, offering much promise for clinical applications and as a new treatment option for secondary lymphedema. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  9. Quantitative radiation dose-response relationships for normal tissues in man. II. Response of the salivary glands during radiotherapy

    International Nuclear Information System (INIS)

    Mossman, K.L.

    1983-01-01

    A quantitative dose-response curve for salivary gland function in patients during radiotherapy is presented. Salivary-function data used in this study were obtained from four previously published reports. All patients were treated with 60 Co teletherapy to the head and neck using conventional treatment techniques. Salivary dysfunction was determined at specific dose levels by comparing salivary flow rates before therapy with flow rates at specific dose intervals during radiotherapy up to a total dose of 6000 cGy. Fifty percent salivary dysfunction occurred after 1000 cGy and eighty percent dysfunction was observed by the end of the therapy course (6000 cGy). The salivary-function curve was also compared to the previously published dose-response curve for taste function. Comparisons of the two curves indicate that salivary dysfunction precedes taste loss and that the shapes of the dose-response curves are different. A new term, tissue tolerance ratio, defined as the ratio of responses of two tissues given the same radiation dose, was used to make the comparisons between gustatory and salivary gland tissue effects. Measurements of salivary gland function and analysis of dose-response curves may be useful in evaluating chemical modifiers of radiation response

  10. Entire lacrimal sac within the ethmoid sinus: outcomes of powered endoscopic dacryocystorhinostomy

    Directory of Open Access Journals (Sweden)

    Ali MJ

    2016-07-01

    Full Text Available Mohammad Javed Ali, Swati Singh, Milind N NaikInstitute of Dacryology, LV Prasad Eye Institute, Hyderabad, India Background: The aim of this study was to report the outcomes of powered endoscopic dacryocystorhinostomy (PEnDCR in patients with lacrimal sac within the sinus.Materials and methods: Retrospective analysis was performed on all patients who underwent PEnDCR and were intraoperatively documented to have complete lacrimal sac in sinus. Data collected included demographics, clinical presentations, associated lacrimal and nasal anomalies, intraoperative findings, intraoperative guidance, complications, postoperative ostium behavior, and anatomical and functional success. A minimum follow-up of 6 months postsurgery was considered for final analysis.Results: A total of 17 eyes of 15 patients underwent PEnDCR using standard protocols, but with additional intraoperative guidance where required and careful maneuvering in the ethmoid sinus. The mean age of the patients was 37.2 (range 17–60 years. Of the unilateral cases, 69% (nine of 13 showed left-side predisposition; 80% of patients showed regurgitation on pressure over the lacrimal sac area. Associated lacrimal and nasal anomalies were observed in 13.3% (two of 15 and 40% (six of 15, respectively. At a mean follow-up of 6.6 months, anatomical and functional success were observed in 93.3% (14 of 15. One patient showed failure secondary to cicatricial closure of the ostium.Conclusion: An entire sac within an ethmoid sinus poses a surgical challenge. Good sinus-surgery training, thorough knowledge of endoscopic anatomy, careful maneuvering, and use of intraoperative navigation guidance result in good outcomes with PEnDCR.Keywords: lacrimal sac, ethmoid sinus, endoscopic, DCR

  11. Restoration of CFTR Activity in Ducts Rescues Acinar Cell Function and Reduces Inflammation in Pancreatic and Salivary Glands of Mice.

    Science.gov (United States)

    Zeng, Mei; Szymczak, Mitchell; Ahuja, Malini; Zheng, Changyu; Yin, Hongen; Swaim, William; Chiorini, John A; Bridges, Robert J; Muallem, Shmuel

    2017-10-01

    Sjögren's syndrome and autoimmune pancreatitis are disorders with decreased function of salivary, lacrimal glands, and the exocrine pancreas. Nonobese diabetic/ShiLTJ mice and mice transduced with the cytokine BMP6 develop Sjögren's syndrome and chronic pancreatitis and MRL/Mp mice are models of autoimmune pancreatitis. Cystic fibrosis transmembrane conductance regulator (CFTR) is a ductal Cl -  channel essential for ductal fluid and HCO 3 - secretion. We used these models to ask the following questions: is CFTR expression altered in these diseases, does correction of CFTR correct gland function, and most notably, does correcting ductal function correct acinar function? We treated the mice models with the CFTR corrector C18 and the potentiator VX770. Glandular, ductal, and acinar cells damage, infiltration, immune cells and function were measured in vivo and in isolated duct/acini. In the disease models, CFTR expression is markedly reduced. The salivary glands and pancreas are inflamed with increased fibrosis and tissue damage. Treatment with VX770 and, in particular, C18 restored salivation, rescued CFTR expression and localization, and nearly eliminated the inflammation and tissue damage. Transgenic overexpression of CFTR exclusively in the duct had similar effects. Most notably, the markedly reduced acinar cell Ca 2+ signaling, Orai1, inositol triphosphate receptors, Aquaporin 5 expression, and fluid secretion were restored by rescuing ductal CFTR. Our findings reveal that correcting ductal function is sufficient to rescue acinar cell function and suggests that CFTR correctors are strong candidates for the treatment of Sjögren's syndrome and pancreatitis. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

  12. [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

  13. Tissue Engineering in Regenerative Dental Therapy

    Directory of Open Access Journals (Sweden)

    Hiral Jhaveri-Desai

    2011-01-01

    Full Text Available Tissue engineering is amongst the latest exciting technologies having impacted the field of dentistry. Initially considered as a futuristic approach, tissue engineering is now being successfully applied in regenerative surgery. This article reviews the important determinants of tissue engineering and how they contribute to the improvement of wound healing and surgical outcomes in the oral region. Furthermore, we shall address the clinical applications of engineering involving oral and maxillofacial surgical and periodontal procedures along with other concepts that are still in experimental phase of development. This knowledge will aid the surgical and engineering researchers to comprehend the collaboration between these fields leading to extounding dental applications and to ever-continuing man-made miracles in the field of human science.

  14. Stem cells in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Jeong Min [Department of Preventive and Social Dentistry and Institute of Oral Biology, College of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Kim, Byung-Chul; Park, Jae-Hong; Kwon, Il Keun; Hwang, Yu-Shik [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, College of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Mantalaris, Anathathios, E-mail: yshwang@khu.ac.k [Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom)

    2010-12-15

    Bone tissue engineering has been one of the most promising areas of research, providing a potential clinical application to cure bone defects. Recently, various stem cells including embryonic stem cells (ESCs), bone marrow-derived mesenchymal stem cells (BM-MSCs), umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), adipose tissue-derived stem cells (ADSCs), muscle-derived stem cells (MDSCs) and dental pulp stem cells (DPSCs) have received extensive attention in the field of bone tissue engineering due to their distinct biological capability to differentiate into osteogenic lineages. The application of these stem cells to bone tissue engineering requires inducing in vitro differentiation of these cells into bone forming cells, osteoblasts. For this purpose, efficient in vitro differentiation towards osteogenic lineage requires the development of well-defined and proficient protocols. This would reduce the likelihood of spontaneous differentiation into divergent lineages and increase the available cell source for application to bone tissue engineering therapies. This review provides a critical examination of the various experimental strategies that could be used to direct the differentiation of ESC, BM-MSC, UCB-MSC, ADSC, MDSC and DPSC towards osteogenic lineages and their potential applications in tissue engineering, particularly in the regeneration of bone. (topical review)

  15. Stem cells in bone tissue engineering

    International Nuclear Information System (INIS)

    Seong, Jeong Min; Kim, Byung-Chul; Park, Jae-Hong; Kwon, Il Keun; Hwang, Yu-Shik; Mantalaris, Anathathios

    2010-01-01

    Bone tissue engineering has been one of the most promising areas of research, providing a potential clinical application to cure bone defects. Recently, various stem cells including embryonic stem cells (ESCs), bone marrow-derived mesenchymal stem cells (BM-MSCs), umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), adipose tissue-derived stem cells (ADSCs), muscle-derived stem cells (MDSCs) and dental pulp stem cells (DPSCs) have received extensive attention in the field of bone tissue engineering due to their distinct biological capability to differentiate into osteogenic lineages. The application of these stem cells to bone tissue engineering requires inducing in vitro differentiation of these cells into bone forming cells, osteoblasts. For this purpose, efficient in vitro differentiation towards osteogenic lineage requires the development of well-defined and proficient protocols. This would reduce the likelihood of spontaneous differentiation into divergent lineages and increase the available cell source for application to bone tissue engineering therapies. This review provides a critical examination of the various experimental strategies that could be used to direct the differentiation of ESC, BM-MSC, UCB-MSC, ADSC, MDSC and DPSC towards osteogenic lineages and their potential applications in tissue engineering, particularly in the regeneration of bone. (topical review)

  16. Imaging in cellular and tissue engineering

    CERN Document Server

    Yu, Hanry

    2013-01-01

    Details on specific imaging modalities for different cellular and tissue engineering applications are scattered throughout articles and chapters in the literature. Gathering this information into a single reference, Imaging in Cellular and Tissue Engineering presents both the fundamentals and state of the art in imaging methods, approaches, and applications in regenerative medicine. The book underscores the broadening scope of imaging applications in cellular and tissue engineering. It covers a wide range of optical and biological applications, including the repair or replacement of whole tiss

  17. Intrasellar Symptomatic Salivary Gland Rest

    Directory of Open Access Journals (Sweden)

    Chih-Hao Chen

    2007-05-01

    Full Text Available Ectopic salivary gland tissue in sellar turcica is frequently observed in microscopic examination at autopsy. This tissue is considered clinically silent. Only 2 symptomatic cases have been previously reported. Here we report a 28-year-old woman presenting with galactorrhea and hyperprolactinemia. Magnetic resonance imaging revealed a 6×5-mm nodule in the posterior aspect of the pituitary gland. This nodule showed isointensity on T1- and T2-weighted images and less enhancement on post-contrast T1-weighted images. Transsphenoidal exploration revealed a cystic lesion within the pituitary gland, which consisted of a grayish gelatinous content. The pathologic examination confirmed the diagnosis of salivary gland rest.

  18. Membrane supported scaffold architectures for tissue engineering

    NARCIS (Netherlands)

    Bettahalli Narasimha, M.S.

    2011-01-01

    Tissue engineering aims at restoring or regenerating a damaged tissue. Often the tissue recreation occurs by combining cells, derived from a patient biopsy, onto a 3D porous matrix, functioning as a scaffold. One of the current limitations of tissue engineering is the inability to provide sufficient

  19. Nanomaterials for Craniofacial and Dental Tissue Engineering.

    Science.gov (United States)

    Li, G; Zhou, T; Lin, S; Shi, S; Lin, Y

    2017-07-01

    Tissue engineering shows great potential as a future treatment for the craniofacial and dental defects caused by trauma, tumor, and other diseases. Due to the biomimetic features and excellent physiochemical properties, nanomaterials are of vital importance in promoting cell growth and stimulating tissue regeneration in tissue engineering. For craniofacial and dental tissue engineering, the frequently used nanomaterials include nanoparticles, nanofibers, nanotubes, and nanosheets. Nanofibers are attractive for cell invasion and proliferation because of their resemblance to extracellular matrix and the presence of large pores, and they have been used as scaffolds in bone, cartilage, and tooth regeneration. Nanotubes and nanoparticles improve the mechanical and chemical properties of scaffold, increase cell attachment and migration, and facilitate tissue regeneration. In addition, nanofibers and nanoparticles are also used as a delivery system to carry the bioactive agent in bone and tooth regeneration, have better control of the release speed of agent upon degradation of the matrix, and promote tissue regeneration. Although applications of nanomaterials in tissue engineering remain in their infancy with numerous challenges to face, the current results indicate that nanomaterials have massive potential in craniofacial and dental tissue engineering.

  20. Primary parotid gland lymphoma: a case report

    Directory of Open Access Journals (Sweden)

    Paraskevas Katsaronis

    2011-08-01

    Full Text Available Abstract Introduction Mucosa associated lymphoid tissue lymphomas are the most common lymphomas of the salivary glands. The benign lymphoepithelial lesion is also a lymphoproliferative disease that develops in the parotid gland. In the present case report, we describe one case of benign lymphoepithelial lesion with a subsequent low transformation to grade mucosa associated lymphoid tissue lymphoma appearing as a cystic mass in the parotid gland. Case presentation A 78-year-old Caucasian female smoker was referred to our clinic with a non-tender left facial swelling that had been present for approximately three years. The patient underwent resection of the left parotid gland with preservation of the left facial nerve through a preauricular incision. The pathology report was consistent with a low-grade marginal-zone B-cell non-Hodgkin lymphoma (mucosa associated lymphoid tissue lymphoma following benign lymphoepithelial lesion of the gland. Conclusions Salivary gland mucosa associated lymphoid tissue lymphoma should be considered in the differential diagnosis of cystic or bilateral salivary gland lesions. Parotidectomy is recommended in order to treat the tumor and to ensure histological diagnosis for further follow-up planning. Radiotherapy and chemotherapy should be considered in association with surgery in disseminated forms or after removal.

  1. Micro- and nanotechnology in cardiovascular tissue engineering.

    Science.gov (United States)

    Zhang, Boyang; Xiao, Yun; Hsieh, Anne; Thavandiran, Nimalan; Radisic, Milica

    2011-12-09

    While in nature the formation of complex tissues is gradually shaped by the long journey of development, in tissue engineering constructing complex tissues relies heavily on our ability to directly manipulate and control the micro-cellular environment in vitro. Not surprisingly, advancements in both microfabrication and nanofabrication have powered the field of tissue engineering in many aspects. Focusing on cardiac tissue engineering, this paper highlights the applications of fabrication techniques in various aspects of tissue engineering research: (1) cell responses to micro- and nanopatterned topographical cues, (2) cell responses to patterned biochemical cues, (3) controlled 3D scaffolds, (4) patterned tissue vascularization and (5) electromechanical regulation of tissue assembly and function.

  2. Gene therapy for cartilage and bone tissue engineering

    CERN Document Server

    Hu, Yu-Chen

    2014-01-01

    "Gene Therapy for Cartilage and Bone Tissue Engineering" outlines the tissue engineering and possible applications of gene therapy in the field of biomedical engineering as well as basic principles of gene therapy, vectors and gene delivery, specifically for cartilage and bone engineering. It is intended for tissue engineers, cell therapists, regenerative medicine scientists and engineers, gene therapist and virologists. Dr. Yu-Chen Hu is a Distinguished Professor at the Department of Chemical Engineering, National Tsing Hua University and has received the Outstanding Research Award (National Science Council), Asia Research Award (Society of Chemical Engineers, Japan) and Professor Tsai-Teh Lai Award (Taiwan Institute of Chemical Engineers). He is also a fellow of the American Institute for Medical and Biological Engineering (AIMBE) and a member of the Tissue Engineering International & Regenerative Medicine Society (TERMIS)-Asia Pacific Council.

  3. Real-time mapping of salt glands on the leaf surface of Cynodon dactylon L. using scanning electrochemical microscopy.

    Science.gov (United States)

    Parthasarathy, Meera; Pemaiah, Brindha; Natesan, Ravichandran; Padmavathy, Saralla R; Pachiappan, Jayaraman

    2015-02-01

    Salt glands are specialized organelles present in the leaf tissues of halophytes, which impart salt-tolerance capability to the plant species. These glands are usually identified only by their morphology using conventional staining procedures coupled with optical microscopy. In this work, we have employed scanning electrochemical microscopy to identify the salt glands not only by their morphology but also by their salt excretion behavior. Bermuda grass (Cynodon dactylon L.) species was chosen for the study as they are known to be salt-tolerant and contain salt glands on leaf surfaces. Scanning electrochemical microscopy performed in sodium chloride medium in the presence and absence of potassium ferrocyanide as redox mediator, reveals the identity of salt glands. More insight into the ion expulsion behavior of these glands was obtained by mapping lateral and vertical variations in ion concentrations using surface impedance measurements which indicated five times higher resistance over the salt glands compared to the surrounding tissues and bulk solution. The protocol could be used to understand the developmental processes in plants grown in different soil/water conditions in order to improve salt tolerance of food crops by genetic engineering and hence improve their agricultural productivity.

  4. Bone tissue engineering scaffolding: computer-aided scaffolding techniques.

    Science.gov (United States)

    Thavornyutikarn, Boonlom; Chantarapanich, Nattapon; Sitthiseripratip, Kriskrai; Thouas, George A; Chen, Qizhi

    Tissue engineering is essentially a technique for imitating nature. Natural tissues consist of three components: cells, signalling systems (e.g. growth factors) and extracellular matrix (ECM). The ECM forms a scaffold for its cells. Hence, the engineered tissue construct is an artificial scaffold populated with living cells and signalling molecules. A huge effort has been invested in bone tissue engineering, in which a highly porous scaffold plays a critical role in guiding bone and vascular tissue growth and regeneration in three dimensions. In the last two decades, numerous scaffolding techniques have been developed to fabricate highly interconnective, porous scaffolds for bone tissue engineering applications. This review provides an update on the progress of foaming technology of biomaterials, with a special attention being focused on computer-aided manufacturing (Andrade et al. 2002) techniques. This article starts with a brief introduction of tissue engineering (Bone tissue engineering and scaffolds) and scaffolding materials (Biomaterials used in bone tissue engineering). After a brief reviews on conventional scaffolding techniques (Conventional scaffolding techniques), a number of CAM techniques are reviewed in great detail. For each technique, the structure and mechanical integrity of fabricated scaffolds are discussed in detail. Finally, the advantaged and disadvantage of these techniques are compared (Comparison of scaffolding techniques) and summarised (Summary).

  5. Bioactive glass in tissue engineering

    Science.gov (United States)

    Rahaman, Mohamed N.; Day, Delbert E.; Bal, B. Sonny; Fu, Qiang; Jung, Steven B.; Bonewald, Lynda F.; Tomsia, Antoni P.

    2011-01-01

    This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. PMID:21421084

  6. Piezoelectric polymers as biomaterials for tissue engineering applications.

    Science.gov (United States)

    Ribeiro, Clarisse; Sencadas, Vítor; Correia, Daniela M; Lanceros-Méndez, Senentxu

    2015-12-01

    Tissue engineering often rely on scaffolds for supporting cell differentiation and growth. Novel paradigms for tissue engineering include the need of active or smart scaffolds in order to properly regenerate specific tissues. In particular, as electrical and electromechanical clues are among the most relevant ones in determining tissue functionality in tissues such as muscle and bone, among others, electroactive materials and, in particular, piezoelectric ones, show strong potential for novel tissue engineering strategies, in particular taking also into account the existence of these phenomena within some specific tissues, indicating their requirement also during tissue regeneration. This referee reports on piezoelectric materials used for tissue engineering applications. The most used materials for tissue engineering strategies are reported together with the main achievements, challenges and future needs for research and actual therapies. This review provides thus a compilation of the most relevant results and strategies and a start point for novel research pathways in the most relevant and challenging open questions. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Using Polymeric Scaffolds for Vascular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Alida Abruzzo

    2014-01-01

    Full Text Available With the high occurrence of cardiovascular disease and increasing numbers of patients requiring vascular access, there is a significant need for small-diameter (<6 mm inner diameter vascular graft that can provide long-term patency. Despite the technological improvements, restenosis and graft thrombosis continue to hamper the success of the implants. Vascular tissue engineering is a new field that has undergone enormous growth over the last decade and has proposed valid solutions for blood vessels repair. The goal of vascular tissue engineering is to produce neovessels and neoorgan tissue from autologous cells using a biodegradable polymer as a scaffold. The most important advantage of tissue-engineered implants is that these tissues can grow, remodel, rebuild, and respond to injury. This review describes the development of polymeric materials over the years and current tissue engineering strategies for the improvement of vascular conduits.

  8. Modeling collagen remodeling in tissue engineered cardiovascular tissues

    NARCIS (Netherlands)

    Soares, A.L.F.

    2012-01-01

    Commonly, heart valve replacements consist of non-living materials lacking the ability to grow, repair and remodel. Tissue engineering (TE) offers a promising alternative to these replacement strategies since it can overcome its disadvantages. The technique aims to create an autologous living tissue

  9. Characteristics of Labial Gland Mesenchymal Stem Cells of Healthy Individuals and Patients with Sjögren's Syndrome: A Preliminary Study.

    Science.gov (United States)

    Wang, Shi-Qin; Wang, Yi-Xiang; Hua, Hong

    2017-08-15

    Sjögren's syndrome (SS) is a systemic autoimmune disease that is characterized by focal lymphocytic infiltration into exocrine organs such as salivary and lacrimal glands, resulting in dry mouth and eyes, and other systemic injuries. There is no curative clinical therapy for SS, and stem cell therapy has shown great potential in this area. The mesenchymal stem cells (MSCs) in the salivary glands of healthy individuals and in patients with SS have not been extensively studied. The aim of this study was to elucidate the characteristics of MSCs from the labial glands of healthy controls and of those from patients with SS to elucidate the related pathogenesis and to uncover potential avenues for novel clinical interventions. Labial glands from patients with SS and healthy subjects were obtained, and MSCs were isolated and cultured by using the tissue adherent method. The MSC characteristics of the cultured cells were confirmed by using morphology, proliferation, colony forming-unit (CFU) efficiency, and multipotentiality, including osteogenic, adipogenic, and salivary gland differentiation. The MSCs from the healthy controls and SS patients expressed characteristic MSC markers, including CD29, CD44, CD73, CD90, and CD105; they were negative for CD34, CD45, and CD106, and also negative for the salivary gland epithelium markers (CD49f and CD117). Labial gland MSCs from both groups were capable of osteogenic and adipogenic differentiation. The CFU efficiency and adipogenic differentiation potential of MSCs were significantly lower in the SS group compared with the healthy controls. Cells from both groups could also be induced into salivary gland-like cells. Real-time polymerase chain reaction and immunofluorescence staining showed that the gene and protein expression of AMY1, AQP5, and ZO-1 in cells from the SS group was lower than that in cells from the healthy group. Thus, MSCs from the labial glands in patients with SS could lack certain characteristics and functions

  10. Oligoaniline-based conductive biomaterials for tissue engineering.

    Science.gov (United States)

    Zarrintaj, Payam; Bakhshandeh, Behnaz; Saeb, Mohammad Reza; Sefat, Farshid; Rezaeian, Iraj; Ganjali, Mohammad Reza; Ramakrishna, Seeram; Mozafari, Masoud

    2018-05-01

    The science and engineering of biomaterials have improved the human life expectancy. Tissue engineering is one of the nascent strategies with an aim to fulfill this target. Tissue engineering scaffolds are one of the most significant aspects of the recent tissue repair strategies; hence, it is imperative to design biomimetic substrates with suitable features. Conductive substrates can ameliorate the cellular activity through enhancement of cellular signaling. Biocompatible polymers with conductivity can mimic the cells' niche in an appropriate manner. Bioconductive polymers based on aniline oligomers can potentially actualize this purpose because of their unique and tailoring properties. The aniline oligomers can be positioned within the molecular structure of other polymers, thus painter acting with the side groups of the main polymer or acting as a comonomer in their backbone. The conductivity of oligoaniline-based conductive biomaterials can be tailored to mimic the electrical and mechanical properties of targeted tissues/organs. These bioconductive substrates can be designed with high mechanical strength for hard tissues such as the bone and with high elasticity to be used for the cardiac tissue or can be synthesized in the form of injectable hydrogels, particles, and nanofibers for noninvasive implantation; these structures can be used for applications such as drug/gene delivery and extracellular biomimetic structures. It is expected that with progress in the fields of biomaterials and tissue engineering, more innovative constructs will be proposed in the near future. This review discusses the recent advancements in the use of oligoaniline-based conductive biomaterials for tissue engineering and regenerative medicine applications. The tissue engineering applications of aniline oligomers and their derivatives have recently attracted an increasing interest due to their electroactive and biodegradable properties. However, no reports have systematically reviewed

  11. 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

  12. Silk fibroin in tissue engineering.

    Science.gov (United States)

    Kasoju, Naresh; Bora, Utpal

    2012-07-01

    Tissue engineering (TE) is a multidisciplinary field that aims at the in vitro engineering of tissues and organs by integrating science and technology of cells, materials and biochemical factors. Mimicking the natural extracellular matrix is one of the critical and challenging technological barriers, for which scaffold engineering has become a prime focus of research within the field of TE. Amongst the variety of materials tested, silk fibroin (SF) is increasingly being recognized as a promising material for scaffold fabrication. Ease of processing, excellent biocompatibility, remarkable mechanical properties and tailorable degradability of SF has been explored for fabrication of various articles such as films, porous matrices, hydrogels, nonwoven mats, etc., and has been investigated for use in various TE applications, including bone, tendon, ligament, cartilage, skin, liver, trachea, nerve, cornea, eardrum, dental, bladder, etc. The current review extensively covers the progress made in the SF-based in vitro engineering and regeneration of various human tissues and identifies opportunities for further development of this field. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Nanoparticles for bone tissue engineering.

    Science.gov (United States)

    Vieira, Sílvia; Vial, Stephanie; Reis, Rui L; Oliveira, J Miguel

    2017-05-01

    Tissue engineering (TE) envisions the creation of functional substitutes for damaged tissues through integrated solutions, where medical, biological, and engineering principles are combined. Bone regeneration is one of the areas in which designing a model that mimics all tissue properties is still a challenge. The hierarchical structure and high vascularization of bone hampers a TE approach, especially in large bone defects. Nanotechnology can open up a new era for TE, allowing the creation of nanostructures that are comparable in size to those appearing in natural bone. Therefore, nanoengineered systems are now able to more closely mimic the structures observed in naturally occurring systems, and it is also possible to combine several approaches - such as drug delivery and cell labeling - within a single system. This review aims to cover the most recent developments on the use of different nanoparticles for bone TE, with emphasis on their application for scaffolds improvement; drug and gene delivery carriers, and labeling techniques. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:590-611, 2017. © 2017 American Institute of Chemical Engineers.

  14. [High resolution functional magnetic resonance tomography with Gd-DTPA eyedrops in diagnosis of lacrimal apparatus diseases].

    Science.gov (United States)

    Hoffmann, K T; Anders, N; Hosten, N; Holschbach, A; Walkow, T; Sörensen, R; Hartmann, C; Felix, R

    1998-08-01

    Both dacryocystography and dacryoscintigraphy are well established in the evaluation of stenoses of the lacrimal drainage system. They provide limited information about the ductal anatomy itself and about periductal structures. MR imaging was evaluated for its capability to directly visualize the lacrimal drainage system in detail and simultaneously provide functional characterization of dacryostenosis. Twenty-seven lacrimal drainage systems of 23 patients suffering from epiphora were examined in an MR unit before and after conjunctival and intravenous application of Gd-DTPA using a surface coil. Dacryostenosis was found in 23 of 27 lacrimal systems. Stenoses were localized to the canalicular (n = 3), saccular (n = 8), and ductal (n = 12) level, and were classified as stenosis or occlusion. MR imaging with conjunctival contrast application allows within one examination both detailed morphological and functional assessment of the lacrimal drainage system with depiction of surrounding structures. Limitations arise mainly from demands on technical and patient-related preconditions.

  15. Injectable biomaterials for adipose tissue engineering

    International Nuclear Information System (INIS)

    Young, D A; Christman, K L

    2012-01-01

    Adipose tissue engineering has recently gained significant attention from materials scientists as a result of the exponential growth of soft tissue filler procedures being performed within the clinic. While several injectable materials are currently being marketed for filling subcutaneous voids, they often face limited longevity due to rapid resorption. Their inability to encourage natural adipose formation or ingrowth necessitates repeated injections for a prolonged effect and thus classifies them as temporary fillers. As a result, a significant need for injectable materials that not only act as fillers but also promote in vivo adipogenesis is beginning to be realized. This paper will discuss the advantages and disadvantages of commercially available soft tissue fillers. It will then summarize the current state of research using injectable synthetic materials, biopolymers and extracellular matrix-derived materials for adipose tissue engineering. Furthermore, the successful attributes observed across each of these materials will be outlined along with a discussion of the current difficulties and future directions for adipose tissue engineering. (paper)

  16. Bladder tissue engineering through nanotechnology.

    Science.gov (United States)

    Harrington, Daniel A; Sharma, Arun K; Erickson, Bradley A; Cheng, Earl Y

    2008-08-01

    The field of tissue engineering has developed in phases: initially researchers searched for "inert" biomaterials to act solely as replacement structures in the body. Then, they explored biodegradable scaffolds--both naturally derived and synthetic--for the temporary support of growing tissues. Now, a third phase of tissue engineering has developed, through the subcategory of "regenerative medicine." This renewed focus toward control over tissue morphology and cell phenotype requires proportional advances in scaffold design. Discoveries in nanotechnology have driven both our understanding of cell-substrate interactions, and our ability to influence them. By operating at the size regime of proteins themselves, nanotechnology gives us the opportunity to directly speak the language of cells, through reliable, repeatable creation of nanoscale features. Understanding the synthesis of nanoscale materials, via "top-down" and "bottom-up" strategies, allows researchers to assess the capabilities and limits inherent in both techniques. Urology research as a whole, and bladder regeneration in particular, are well-positioned to benefit from such advances, since our present technology has yet to reach the end goal of functional bladder restoration. In this article, we discuss the current applications of nanoscale materials to bladder tissue engineering, and encourage researchers to explore these interdisciplinary technologies now, or risk playing catch-up in the future.

  17. Digital subtraction radiography in the study of the lacrimal system

    International Nuclear Information System (INIS)

    Falaschi, F.; Pieri, L.; Perri, G.; Signorini, G.; Genovese Ebert, F.

    1988-01-01

    The authors emphasize the usefulness of digital dacrycystography (DCG), as compared with various current technoques. Utilizing a radiographic unit equipped with a video-fluoroscopic system and interfaced to a digital video-processor, several digitalized images are acquired before, during and after the injection of contrast medium. Final images are obtained by subtraction of suitable pairs of source frames. Twenty-six patients affected by epiphora have been examined so far. In 21 cases digital subtraction DCG allowed an accurate visualization of the lacrimal system; in the other five patients the amount of information was acceptable. This methodology allows the assessment of both the normal anatomy of the lacrimal passages and their pathological patterns, such as obstructions, stenoses, fistulas, chronic dacrycystites, lacrimal stones. The examination is easy and quick to perform, with no discomfort for the patient. Digital subtraction DCG proves thus to be a very valuable technique thanks to its possible electronic elaboration - i.e. the subtraction and the magnification of images - to its better contrast resolution, and to the possibility it yields of dynamic studies under radioscopic control

  18. Mechanical design criteria for intervertebral disc tissue engineering.

    Science.gov (United States)

    Nerurkar, Nandan L; Elliott, Dawn M; Mauck, Robert L

    2010-04-19

    Due to the inability of current clinical practices to restore function to degenerated intervertebral discs, the arena of disc tissue engineering has received substantial attention in recent years. Despite tremendous growth and progress in this field, translation to clinical implementation has been hindered by a lack of well-defined functional benchmarks. Because successful replacement of the disc is contingent upon replication of some or all of its complex mechanical behaviors, it is critically important that disc mechanics be well characterized in order to establish discrete functional goals for tissue engineering. In this review, the key functional signatures of the intervertebral disc are discussed and used to propose a series of native tissue benchmarks to guide the development of engineered replacement tissues. These benchmarks include measures of mechanical function under tensile, compressive, and shear deformations for the disc and its substructures. In some cases, important functional measures are identified that have yet to be measured in the native tissue. Ultimately, native tissue benchmark values are compared to measurements that have been made on engineered disc tissues, identifying where functional equivalence was achieved, and where there remain opportunities for advancement. Several excellent reviews exist regarding disc composition and structure, as well as recent tissue engineering strategies; therefore this review will remain focused on the functional aspects of disc tissue engineering. Copyright 2009 Elsevier Ltd. All rights reserved.

  19. Evaluation of the adhesive properties of the cornea by means of optical coherence tomography in patients with meibomian gland dysfunction and lacrimal tear deficiency.

    Science.gov (United States)

    Napoli, Pietro Emanuele; Coronella, Franco; Satta, Giovanni Maria; Galantuomo, Maria Silvana; Fossarello, Maurizio

    2014-01-01

    The aim was to determine the influence of meibomian gland dysfunction (MGD) and aqueous tear deficiency dry eye (ADDE) on the adhesive properties of the central cornea by means of optical coherence tomography (OCT), and to investigate the relationship between corneal adhesiveness and classical tear tests, as well as the reliability of results, in these lacrimal functional unit disorders. Prospective, case-control study. Twenty-eight patients with MGD and 27 patients with ADDE were studied. A group of 32 healthy subjects of similar age and gender distribution served as a control group. The adhesive properties of the anterior corneal surface were measured by OCT, based on the retention time of adhesion marker above it, in all participants. An excellent (≥5 minutes), borderline (within 3-5 minutes), fair (within 1-3 minutes) and poor (<1 minute) values of corneal adhesiveness were found, respectively, in 0%, 7.1%, 64.3% and 28.6% of MGD, in 0%, 7.4%, 63% and 29.6% of ADDE, and in 31.3%, 65.6%, 3.1% and 0% of healthy patients. The differences in time of corneal adhesiveness between MGD and healthy patients, as well as between ADDE and healthy patients, were found to be statistically significant (p<0.001; p<0.001; respectively). Conversely, no statistical significant differences between MGD and ADDE were found (p = 0.952). Data analysis revealed a statistically significant correlation between corneal adhesiveness and clinical tests of dry eye, as well as an excellent degree of inter-rater reliability and reproducibility for OCT measurements (p<0.001). ADDE and MGD share similar abnormalities on OCT imaging. Decreased adhesive properties of the anterior cornea were identified as a common feature of MGD and ADDE. This simple OCT approach may provide new clues into the mechanism and evaluation of dry eye syndrome.

  20. Evaluation of the adhesive properties of the cornea by means of optical coherence tomography in patients with meibomian gland dysfunction and lacrimal tear deficiency.

    Directory of Open Access Journals (Sweden)

    Pietro Emanuele Napoli

    Full Text Available The aim was to determine the influence of meibomian gland dysfunction (MGD and aqueous tear deficiency dry eye (ADDE on the adhesive properties of the central cornea by means of optical coherence tomography (OCT, and to investigate the relationship between corneal adhesiveness and classical tear tests, as well as the reliability of results, in these lacrimal functional unit disorders.Prospective, case-control study.Twenty-eight patients with MGD and 27 patients with ADDE were studied. A group of 32 healthy subjects of similar age and gender distribution served as a control group. The adhesive properties of the anterior corneal surface were measured by OCT, based on the retention time of adhesion marker above it, in all participants.An excellent (≥5 minutes, borderline (within 3-5 minutes, fair (within 1-3 minutes and poor (<1 minute values of corneal adhesiveness were found, respectively, in 0%, 7.1%, 64.3% and 28.6% of MGD, in 0%, 7.4%, 63% and 29.6% of ADDE, and in 31.3%, 65.6%, 3.1% and 0% of healthy patients. The differences in time of corneal adhesiveness between MGD and healthy patients, as well as between ADDE and healthy patients, were found to be statistically significant (p<0.001; p<0.001; respectively. Conversely, no statistical significant differences between MGD and ADDE were found (p = 0.952. Data analysis revealed a statistically significant correlation between corneal adhesiveness and clinical tests of dry eye, as well as an excellent degree of inter-rater reliability and reproducibility for OCT measurements (p<0.001.ADDE and MGD share similar abnormalities on OCT imaging. Decreased adhesive properties of the anterior cornea were identified as a common feature of MGD and ADDE. This simple OCT approach may provide new clues into the mechanism and evaluation of dry eye syndrome.

  1. Trends in Tissue Engineering for Blood Vessels

    Directory of Open Access Journals (Sweden)

    Judee Grace Nemeno-Guanzon

    2012-01-01

    Full Text Available Over the years, cardiovascular diseases continue to increase and affect not only human health but also the economic stability worldwide. The advancement in tissue engineering is contributing a lot in dealing with this immediate need of alleviating human health. Blood vessel diseases are considered as major cardiovascular health problems. Although blood vessel transplantation is the most convenient treatment, it has been delimited due to scarcity of donors and the patient’s conditions. However, tissue-engineered blood vessels are promising alternatives as mode of treatment for blood vessel defects. The purpose of this paper is to show the importance of the advancement on biofabrication technology for treatment of soft tissue defects particularly for vascular tissues. This will also provide an overview and update on the current status of tissue reconstruction especially from autologous stem cells, scaffolds, and scaffold-free cellular transplantable constructs. The discussion of this paper will be focused on the historical view of cardiovascular tissue engineering and stem cell biology. The representative studies featured in this paper are limited within the last decade in order to trace the trend and evolution of techniques for blood vessel tissue engineering.

  2. Biodegradable Polymer-Based Scaffolds for Bone Tissue Engineering

    CERN Document Server

    Sultana, Naznin

    2013-01-01

    This book addresses the principles, methods and applications of biodegradable polymer based scaffolds for bone tissue engineering. The general principle of bone tissue engineering is reviewed and the traditional and novel scaffolding materials, their properties and scaffold fabrication techniques are explored. By acting as temporary synthetic extracellular matrices for cell accommodation, proliferation, and differentiation, scaffolds play a pivotal role in tissue engineering. This book does not only provide the comprehensive summary of the current trends in scaffolding design but also presents the new trends and directions for scaffold development for the ever expanding tissue engineering applications.

  3. 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.

  4. Next Generation Tissue Engineering of Orthopedic Soft Tissue-to-Bone Interfaces

    Science.gov (United States)

    Boys, Alexander J.; McCorry, Mary Clare; Rodeo, Scott; Bonassar, Lawrence J.; Estroff, Lara A.

    2017-01-01

    Soft tissue-to-bone interfaces are complex structures that consist of gradients of extracellular matrix materials, cell phenotypes, and biochemical signals. These interfaces, called entheses for ligaments, tendons, and the meniscus, are crucial to joint function, transferring mechanical loads and stabilizing orthopedic joints. When injuries occur to connected soft tissue, the enthesis must be re-established to restore function, but due to structural complexity, repair has proven challenging. Tissue engineering offers a promising solution for regenerating these tissues. This prospective review discusses methodologies for tissue engineering the enthesis, outlined in three key design inputs: materials processing methods, cellular contributions, and biochemical factors. PMID:29333332

  5. Fundamentals of bladder tissue engineering | Mahfouz | African ...

    African Journals Online (AJOL)

    Fundamentals of bladder tissue engineering. ... could affect the bladder and lead to eventual loss of its integrity, with the need for replacement or repair. ... Tissue engineering relies upon three essential pillars; the scaffold, the cells seeded on ...

  6. Implante de plug lacrimal termosensível para tratamento da síndrome da disfunção lacrimal Thermo sensitive punctum plug implant for the treatment of dysfunctional tear syndrome

    Directory of Open Access Journals (Sweden)

    Juliana Silverio

    2010-08-01

    Full Text Available OBJETIVO: Avaliar os resultados da oclusão de ponto lacrimal reversível com o uso de plugs termosensíveis para o tratamento da síndrome da disfunção lacrimal. MÉTODOS: Dezoito olhos de 9 pacientes com diagnóstico de olho seco foram selecionados e submetidos à oclusão reversível de ponto lacrimal com o uso de plugs termosensíveis, e acompanhados por 60 dias através de questionário OSDI e testes com fluoresceína, rosa bengala e Schirmer. RESULTADOS: Em todos os pacientes estudados houve melhora nos sintomas de olho seco e melhora nos parâmetros oftalmológicos pesquisados. Em apenas 1 dos pacientes a melhora dos sintomas foi pequena, e não houve diminuição na dependência de colírio lubrificante. Nos outros 8 pacientes houve diminuição no uso de colírio. Durante o estudo não ocorreram complicações infecciosas ou de extrusão. CONCLUSÃO: Oclusão temporária do ponto lacrimal com SmartPlug tm parece ser uma opção efetiva para o tratamento da síndrome da disfunção lacrimal quando o uso de lubrificantes não é suficiente. Sua colocação é relativamente simples e segura, porém estudos mais longos são necessários.PURPOSE: To evaluate the results of occlusion of the lacrimal punctum reversible with the use of thermosensitive plugs to treat the dysfunctional tear syndrome. METHODS: Eighteen eyes of 9 patients with dry eye were selected and subjected to reversible occlusion of the lacrimal punctum with the use of thermosensitive plugs and were followed for 60 days through the OSDI questionnaire, fluorescein staining, rose bengal staining and Schirmer's test. RESULTS: in all studied patients there was improvement in dry eye symptoms and in ophthalmic parameters studied. In only 1 of the patients, symptom improvement was small, and no decrease in dependence on lubricating drops. In the other 8 patients there was a decrease in the use of eye drops. During the study there were no infectious complications or extrusion

  7. Evaluation criterions and establishment of dry eye model of rats induced by BTX-B

    Directory of Open Access Journals (Sweden)

    Hai-Feng Zhu

    2015-09-01

    Full Text Available AIM: To establish dry eye model of rats induced by botulinum toxin B(BTX-Band provide the basis for the pathogenesis and experimental treatment of dry eye caused by inflammation. METHODS: Thirty-six healthy female SD rats were selected and divided into four groups randomly, and the experimental group included three groups, which were individually injected 0.1mL 1.25, 5, and 10mU BTX-B solution on the right lacrimal gland; the control group was injected 0.1mL normal saline on the right lacrimal gland, then received Schirmer Ⅰ test(SⅠtand examination of corneal fluorescein(FLstaining respectively at the 3, 7, 14 and 28d. The other 32 rats were selected and divided into two groups randomly, the rats in the experimental group were injected 0.1mL 1.25mU BTX-B solution on the right lacrimal gland and then five rats were randomly chosen to be removed lacrimal gland tissue respectively at the 3, 7, 14, 21, 42d. The Lacritin protein was detected in the qualitative and quantitative way by immunofluorescence and Western-blot, and the histopathological test was received by routine HE staining. RESULTS: The three groups in the experimental group during the preparation of the model appeared that tear secretions decreased and corneal epithelium got damaged at 3d, but there was no significant difference for each other of two changes(P>0.05. The change was reached the peak at 7d and improved at 14d. The tear secretions returned to normal level at 28d, but the damage of corneal epithelium was still existed. The expression of Lacritin protein was only observed in acinar cells of both experimental group and control group, and the content of Lacritin protein in the experimental group decreased significantly. The decreasing situation appeared at 3d, reached the peak at 7d, improved at 14d, began to recover at 28d, and returned to the normal level at 42d. CONCLUSION: Dry eye model of SD rats can be successfully established by lacrimal gland injection of 1.25mU BTX

  8. 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

  9. Cell microenvironment engineering and monitoring for tissue engineering and regenerative medicine: the recent advances.

    Science.gov (United States)

    Barthes, Julien; Özçelik, Hayriye; Hindié, Mathilde; Ndreu-Halili, Albana; Hasan, Anwarul; Vrana, Nihal Engin

    2014-01-01

    In tissue engineering and regenerative medicine, the conditions in the immediate vicinity of the cells have a direct effect on cells' behaviour and subsequently on clinical outcomes. Physical, chemical, and biological control of cell microenvironment are of crucial importance for the ability to direct and control cell behaviour in 3-dimensional tissue engineering scaffolds spatially and temporally. In this review, we will focus on the different aspects of cell microenvironment such as surface micro-, nanotopography, extracellular matrix composition and distribution, controlled release of soluble factors, and mechanical stress/strain conditions and how these aspects and their interactions can be used to achieve a higher degree of control over cellular activities. The effect of these parameters on the cellular behaviour within tissue engineering context is discussed and how these parameters are used to develop engineered tissues is elaborated. Also, recent techniques developed for the monitoring of the cell microenvironment in vitro and in vivo are reviewed, together with recent tissue engineering applications where the control of cell microenvironment has been exploited. Cell microenvironment engineering and monitoring are crucial parts of tissue engineering efforts and systems which utilize different components of the cell microenvironment simultaneously can provide more functional engineered tissues in the near future.

  10. Cell Microenvironment Engineering and Monitoring for Tissue Engineering and Regenerative Medicine: The Recent Advances

    Directory of Open Access Journals (Sweden)

    Julien Barthes

    2014-01-01

    Full Text Available In tissue engineering and regenerative medicine, the conditions in the immediate vicinity of the cells have a direct effect on cells’ behaviour and subsequently on clinical outcomes. Physical, chemical, and biological control of cell microenvironment are of crucial importance for the ability to direct and control cell behaviour in 3-dimensional tissue engineering scaffolds spatially and temporally. In this review, we will focus on the different aspects of cell microenvironment such as surface micro-, nanotopography, extracellular matrix composition and distribution, controlled release of soluble factors, and mechanical stress/strain conditions and how these aspects and their interactions can be used to achieve a higher degree of control over cellular activities. The effect of these parameters on the cellular behaviour within tissue engineering context is discussed and how these parameters are used to develop engineered tissues is elaborated. Also, recent techniques developed for the monitoring of the cell microenvironment in vitro and in vivo are reviewed, together with recent tissue engineering applications where the control of cell microenvironment has been exploited. Cell microenvironment engineering and monitoring are crucial parts of tissue engineering efforts and systems which utilize different components of the cell microenvironment simultaneously can provide more functional engineered tissues in the near future.

  11. Automatic segmentation of colon glands using object-graphs.

    Science.gov (United States)

    Gunduz-Demir, Cigdem; Kandemir, Melih; Tosun, Akif Burak; Sokmensuer, Cenk

    2010-02-01

    Gland segmentation is an important step to automate the analysis of biopsies that contain glandular structures. However, this remains a challenging problem as the variation in staining, fixation, and sectioning procedures lead to a considerable amount of artifacts and variances in tissue sections, which may result in huge variances in gland appearances. In this work, we report a new approach for gland segmentation. This approach decomposes the tissue image into a set of primitive objects and segments glands making use of the organizational properties of these objects, which are quantified with the definition of object-graphs. As opposed to the previous literature, the proposed approach employs the object-based information for the gland segmentation problem, instead of using the pixel-based information alone. Working with the images of colon tissues, our experiments demonstrate that the proposed object-graph approach yields high segmentation accuracies for the training and test sets and significantly improves the segmentation performance of its pixel-based counterparts. The experiments also show that the object-based structure of the proposed approach provides more tolerance to artifacts and variances in tissues.

  12. Growing tissues in real and simulated microgravity: new methods for tissue engineering.

    Science.gov (United States)

    Grimm, Daniela; Wehland, Markus; Pietsch, Jessica; Aleshcheva, Ganna; Wise, Petra; van Loon, Jack; Ulbrich, Claudia; Magnusson, Nils E; Infanger, Manfred; Bauer, Johann

    2014-12-01

    Tissue engineering in simulated (s-) and real microgravity (r-μg) is currently a topic in Space medicine contributing to biomedical sciences and their applications on Earth. The principal aim of this review is to highlight the advances and accomplishments in the field of tissue engineering that could be achieved by culturing cells in Space or by devices created to simulate microgravity on Earth. Understanding the biology of three-dimensional (3D) multicellular structures is very important for a more complete appreciation of in vivo tissue function and advancing in vitro tissue engineering efforts. Various cells exposed to r-μg in Space or to s-μg created by a random positioning machine, a 2D-clinostat, or a rotating wall vessel bioreactor grew in the form of 3D tissues. Hence, these methods represent a new strategy for tissue engineering of a variety of tissues, such as regenerated cartilage, artificial vessel constructs, and other organ tissues as well as multicellular cancer spheroids. These aggregates are used to study molecular mechanisms involved in angiogenesis, cancer development, and biology and for pharmacological testing of, for example, chemotherapeutic drugs or inhibitors of neoangiogenesis. Moreover, they are useful for studying multicellular responses in toxicology and radiation biology, or for performing coculture experiments. The future will show whether these tissue-engineered constructs can be used for medical transplantations. Unveiling the mechanisms of microgravity-dependent molecular and cellular changes is an up-to-date requirement for improving Space medicine and developing new treatment strategies that can be translated to in vivo models while reducing the use of laboratory animals.

  13. Tumor Engineering: The Other Face of Tissue Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Ghajar, Cyrus M; Bissell, Mina J

    2010-03-09

    Advances in tissue engineering have been accomplished for years by employing biomimetic strategies to provide cells with aspects of their original microenvironment necessary to reconstitute a unit of both form and function for a given tissue.We believe that the most critical hallmark of cancer is loss of integration of architecture and function; thus, it stands to reason that similar strategies could be employed to understand tumor biology. In this commentary, we discuss work contributed by Fischbach-Teschl and colleagues to this special issue of Tissue Engineering in the context of 'tumor engineering', that is, the construction of complex cell culture models that recapitulate aspects of the in vivo tumor microenvironment to study the dynamics of tumor development, progression, and therapy on multiple scales. We provide examples of fundamental questions that could be answered by developing such models, and encourage the continued collaboration between physical scientists and life scientists not only for regenerative purposes, but also to unravel the complexity that is the tumor microenvironment. In 1993, Vacanti and Langer cast a spotlight on the growing gap between patients in need of organ transplants and the amount of available donor organs; they reaffirmed that tissue engineering could eventually address this problem by 'applying principles of engineering and the life sciences toward the development of biological substitutes. Mortality figures and direct health care costs for cancer patients rival those of patients who experience organ failure. Cancer is the second leading cause of death in the United States (Source: American Cancer Society) and it is estimated that direct medical costs for cancer patients approach $100B yearly in the United States alone (Source: National Cancer Institute). In addition, any promising therapy that emerges from the laboratory costs roughly $1.7B to take from bench to bedside. Whereas we have indeed waged war on

  14. Cell–scaffold interaction within engineered tissue

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Haiping; Liu, Yuanyuan, E-mail: Yuanyuan_liu@shu.edu.cn; Jiang, Zhenglong; Chen, Weihua; Yu, Yongzhe; Hu, Qingxi

    2014-05-01

    The structure of a tissue engineering scaffold plays an important role in modulating tissue growth. A novel gelatin–chitosan (Gel–Cs) scaffold with a unique structure produced by three-dimensional printing (3DP) technology combining with vacuum freeze-drying has been developed for tissue-engineering applications. The scaffold composed of overall construction, micro-pore, surface morphology, and effective mechanical property. Such a structure meets the essential design criteria of an ideal engineered scaffold. The favorable cell–matrix interaction supports the active biocompatibility of the structure. The structure is capable of supporting cell attachment and proliferation. Cells seeded into this structure tend to maintain phenotypic shape and secreted large amounts of extracellular matrix (ECM) and the cell growth decreased the mechanical properties of scaffold. This novel biodegradable scaffold has potential applications for tissue engineering based upon its unique structure, which acts to support cell growth. - Highlights: • The scaffold is not only for providing a surface for cell residence but also for determining cell phenotype and retaining structural integrity. • The mechanical property of scaffold can be affected by activities of cell. • The scaffold provides a microenvironment for cell attachment, growth, and migration.

  15. Development of multilayer constructs for tissue engineering

    NARCIS (Netherlands)

    Bettahalli, N. M. S.; Groen, N.; Steg, H.; Unadkat, H.; de Boer, J.; van Blitterswijk, C. A.; Wessling, M.; Stamatialis, D.

    The rapidly developing field of tissue engineering produces living substitutes that restore, maintain or improve the function of tissues or organs. In contrast to standard therapies, the engineered products become integrated within the patient, affording a potentially permanent and specific cure of

  16. Development of multilayer constructs for tissue engineering

    NARCIS (Netherlands)

    Bettahalli Narasimha, M.S.; Groen, N.; Steg, H.; Unadkat, H.V.; de Boer, Jan; van Blitterswijk, Clemens; Wessling, Matthias; Stamatialis, Dimitrios

    2014-01-01

    The rapidly developing field of tissue engineering produces living substitutes that restore, maintain or improve the function of tissues or organs. In contrast to standard therapies, the engineered products become integrated within the patient, affording a potentially permanent and specific cure of

  17. Engineering flesh : towards professional responsibility for 'lived bodies' in tissue engineering

    NARCIS (Netherlands)

    Derksen, M.H.G.

    2008-01-01

    Engineering Flesh. Towards professional responsibility for ‘lived bodies’ in Tissue Engineering This study analyses the work of biomedical engineers as normative work that affects people’s daily lives as bodies. In biomedical engineering, engineers study bodies as machine-like objects and develop

  18. Pericyte-targeting drug delivery and tissue engineering

    Directory of Open Access Journals (Sweden)

    Kang E

    2016-05-01

    Full Text Available Eunah Kang,1 Jong Wook Shin2 1School of Chemical Engineering and Material Science, 2Division of Allergic and Pulmonary Medicine, Department of Internal Medicine, College of Medicine, Chung-Ang University, Dongjak-Gu, Seoul, South Korea Abstract: Pericytes are contractile mural cells that wrap around the endothelial cells of capillaries and venules. Depending on the triggers by cellular signals, pericytes have specific functionality in tumor microenvironments, properties of potent stem cells, and plasticity in cellular pathology. These features of pericytes can be activated for the promotion or reduction of angiogenesis. Frontier studies have exploited pericyte-targeting drug delivery, using pericyte-specific peptides, small molecules, and DNA in tumor therapy. Moreover, the communication between pericytes and endothelial cells has been applied to the induction of vessel neoformation in tissue engineering. Pericytes may prove to be a novel target for tumor therapy and tissue engineering. The present paper specifically reviews pericyte-specific drug delivery and tissue engineering, allowing insight into the emerging research targeting pericytes. Keywords: pericytes, pericyte-targeting drug delivery, tissue engineering, platelet-derived growth factor, angiogenesis, vascular remodeling

  19. Tissue engineering of ligaments for reconstructive surgery.

    Science.gov (United States)

    Hogan, MaCalus V; Kawakami, Yohei; Murawski, Christopher D; Fu, Freddie H

    2015-05-01

    The use of musculoskeletal bioengineering and regenerative medicine applications in orthopaedic surgery has continued to evolve. The aim of this systematic review was to address tissue-engineering strategies for knee ligament reconstruction. A systematic review of PubMed/Medline using the terms "knee AND ligament" AND "tissue engineering" OR "regenerative medicine" was performed. Two authors performed the search, independently assessed the studies for inclusion, and extracted the data for inclusion in the review. Both preclinical and clinical studies were reviewed, and the articles deemed most relevant were included in this article to provide relevant basic science and recent clinical translational knowledge concerning "tissue-engineering" strategies currently used in knee ligament reconstruction. A total of 224 articles were reviewed in our initial PubMed search. Non-English-language studies were excluded. Clinical and preclinical studies were identified, and those with a focus on knee ligament tissue-engineering strategies including stem cell-based therapies, growth factor administration, hybrid biomaterial, and scaffold development, as well as mechanical stimulation modalities, were reviewed. The body of knowledge surrounding tissue-engineering strategies for ligament reconstruction continues to expand. Presently, various tissue-engineering techniques have some potential advantages, including faster recovery, better ligamentization, and possibly, a reduction of recurrence. Preclinical research of these novel therapies continues to provide promising results. There remains a need for well-designed, high-powered comparative clinical studies to serve as a foundation for successful translation into the clinical setting going forward. Level IV, systematic review of Level IV studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  20. The effects of diabetes on the rat parotid gland

    International Nuclear Information System (INIS)

    Park, Chull Jea; Hwang, Eui Hwan; Lee, Sang Rae

    1996-01-01

    The purpose of the study was to observe microscopic change of salivary gland tissue, which is a cause of xerostomia in diabetic condition; for this target, the author injected streptozotocin 0.1 ml/100 gm b.w. on the rat, Sprague Dawley, to induce diabetes, and then observed microscopic changes in parotid gland tissue using light microscopy and electron microscopy. The results were as follows: 1. Parotid gland tissue of the diabetic rat was atrophied or degenerated in lapse of experimental time, but began to re pair from 14 days alter diabetic induction. 2. In the basal lamina of the vessel of parotid gland tissue in the diabetic rat, lamina lucida was discontinued and la mina densa was increased in thickness, but the number of capillary was gradually increased and dilated. 3. In acinic and intercalated ductal cells of parotid gland in the diabetic rat, changes of mitochondria, RER, secretor y granule, free ribosome were prominent. In conclusion, the present study demonstrated that degenerative changes of the parotid gland tissue were due to not completely thickening of the basal lamina of vessels, but many other causal factors, because thickness of the basal lamina of vessels was not related with degenerative changes.

  1. Cardiac tissue engineering

    Directory of Open Access Journals (Sweden)

    MILICA RADISIC

    2005-03-01

    Full Text Available We hypothesized that clinically sized (1-5 mm thick,compact cardiac constructs containing physiologically high density of viable cells (~108 cells/cm3 can be engineered in vitro by using biomimetic culture systems capable of providing oxygen transport and electrical stimulation, designed to mimic those in native heart. This hypothesis was tested by culturing rat heart cells on polymer scaffolds, either with perfusion of culture medium (physiologic interstitial velocity, supplementation of perfluorocarbons, or with electrical stimulation (continuous application of biphasic pulses, 2 ms, 5 V, 1 Hz. Tissue constructs cultured without perfusion or electrical stimulation served as controls. Medium perfusion and addition of perfluorocarbons resulted in compact, thick constructs containing physiologic density of viable, electromechanically coupled cells, in contrast to control constructs which had only a ~100 mm thick peripheral region with functionally connected cells. Electrical stimulation of cultured constructs resulted in markedly improved contractile properties, increased amounts of cardiac proteins, and remarkably well developed ultrastructure (similar to that of native heart as compared to non-stimulated controls. We discuss here the state of the art of cardiac tissue engineering, in light of the biomimetic approach that reproduces in vitro some of the conditions present during normal tissue development.

  2. Engineering Parameters in Bioreactor's Design: A Critical Aspect in Tissue Engineering

    Science.gov (United States)

    Amoabediny, Ghassem; Pouran, Behdad; Tabesh, Hadi; Shokrgozar, Mohammad Ali; Haghighipour, Nooshin; Khatibi, Nahid; Mottaghy, Khosrow; Zandieh-Doulabi, Behrouz

    2013-01-01

    Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors. PMID:24000327

  3. Engineering parameters in bioreactor's design: a critical aspect in tissue engineering.

    Science.gov (United States)

    Salehi-Nik, Nasim; Amoabediny, Ghassem; Pouran, Behdad; Tabesh, Hadi; Shokrgozar, Mohammad Ali; Haghighipour, Nooshin; Khatibi, Nahid; Anisi, Fatemeh; Mottaghy, Khosrow; Zandieh-Doulabi, Behrouz

    2013-01-01

    Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors.

  4. Primary mucosa-associated lymphoid tissue (MALT) lymphoma of thyroid gland arising from coexisting Hashimoto's thyroiditis: a case report

    International Nuclear Information System (INIS)

    Lee, Sang Kwon; Kwon, Sun Young; Kim, Young Hwan; Choi, Jin Soo; Sohn, Chul Ho; Lee, Hee Jung; Woo, Seong Ku; Suh, Soo Ji

    2006-01-01

    We report herein on a case of primary mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid gland in a 57-year-old woman with coexisting Hashimoto's thyroiditis, and we include its characteristic imaging, histopathologic and immunohistochemical findings

  5. Stafne bone cavity with ectopic salivary gland tissue in the anterior of mandible

    Directory of Open Access Journals (Sweden)

    Parviz Deyhimi

    2016-01-01

    Full Text Available Stafne bone cavities (SBCs are uncommon well-demarcated defects of the mandible, which often occur in the posterior portion of the jaw bone and are usually asymptomatic. Furthermore, SBC is found in men aged 50-70-year-old. Anterior mandibular variants of SBC are very rare. This article describes a case of anterior SBC in a 45-year-old man that resembled endodontic periapical lesions. Upon histopathological examination, it turned out to be a normal salivary gland tissue.

  6. Engineered Muscle Actuators: Cells and Tissues

    National Research Council Canada - National Science Library

    Dennis, Robert G; Herr, Hugh; Parker, Kevin K; Larkin, Lisa; Arruda, Ellen; Baar, Keith

    2007-01-01

    .... Our primary objectives were to engineer living skeletal muscle actuators in culture using integrated bioreactors to guide tissue development and to maintain tissue contractility, to achieve 50...

  7. Primary Mucosa-Associated Lymphoid Tissue Lymphoma of the Salivary Glands: A Multicenter Rare Cancer Network Study

    Energy Technology Data Exchange (ETDEWEB)

    Anacak, Yavuz, E-mail: yavuz.anacak@ege.edu.tr [Department of Radiation Oncology, Ege University Medical School, Izmir (Turkey); Miller, Robert C. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Constantinou, Nikos [Department of Hematology, Theagenion Cancer Center, Thessaloniki (Greece); Mamusa, Angela M. [Division of Hematology, Armando Businco Cancer Center, Cagliari (Italy); Epelbaum, Ron [Department of Oncology, Rambam Medical Center, Haifa (Israel); Li Yexiong [Department of Radiation Oncology, Cancer Hospital of Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Calduch, Anna Lucas [Servicio de Oncologia Radioterapica, Institut Catala d' Oncologia, Barcelona (Spain); Kowalczyk, Anna [Department of Oncology and Radiotherapy, Medical University of Gdansk (Poland); Weber, Damien C. [Department of Radiation Oncology, Geneva University Hospital (Switzerland); Kadish, Sidney P. [Department of Radiation Oncology, University of Massachusetts Medical School/Center, North Worcester, MA (United States); Bese, Nuran [Department of Radiation Oncology, Istanbul University Cerrahpasa Medical School, Istanbul (Turkey); Poortmans, Philip [Institute Verbeeten, Tilburg (Netherlands); Kamer, Serra [Department of Radiation Oncology, Ege University Medical School, Izmir (Turkey); Ozsahin, Mahmut [Department of Radiation Oncology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland)

    2012-01-01

    Purpose: Involvement of salivary glands with mucosa-associated lymphoid tissue (MALT) lymphoma is rare. This retrospective study was performed to assess the clinical profile, treatment outcome, and prognostic factors of MALT lymphoma of the salivary glands. Methods and Materials: Thirteen member centers of the Rare Cancer Network from 10 countries participated, providing data on 63 patients. The median age was 58 years; 47 patients were female and 16 were male. The parotid glands were involved in 49 cases, submandibular in 15, and minor glands in 3. Multiple glands were involved in 9 patients. Staging was as follows: IE in 34, IIE in 12, IIIE in 2, and IV in 15 patients. Results: Surgery (S) alone was performed in 9, radiotherapy (RT) alone in 8, and chemotherapy (CT) alone in 4 patients. Forty-one patients received combined modality treatment (S + RT in 23, S + CT in 8, RT + CT in 4, and all three modalities in 6 patients). No active treatment was given in one case. After initial treatment there was no tumor in 57 patients and residual tumor in 5. Tumor progression was observed in 23 (36.5%) (local in 1, other salivary glands in 10, lymph nodes in 11, and elsewhere in 6). Five patients died of disease progression and the other 5 of other causes. The 5-year disease-free survival, disease-specific survival, and overall survival were 54.4%, 93.2%, and 81.7%, respectively. Factors influencing disease-free survival were use of RT, stage, and residual tumor (p < 0.01). Factors influencing disease-specific survival were stage, recurrence, and residual tumor (p < 0.01). Conclusions: To our knowledge, this report represents the largest series of MALT lymphomas of the salivary glands published to date. This disease may involve all salivary glands either initially or subsequently in 30% of patients. Recurrences may occur in up to 35% of patients at 5 years; however, survival is not affected. Radiotherapy is the only treatment modality that improves disease-free survival.

  8. An Overview of Recent Patents on Musculoskeletal Interface Tissue Engineering

    Science.gov (United States)

    Rao, Rohit T.; Browe, Daniel P.; Lowe, Christopher J.; Freeman, Joseph W.

    2018-01-01

    Interface tissue engineering involves the development of engineered grafts that promote integration between multiple tissue types. Musculoskeletal tissue interfaces are critical to the safe and efficient transmission of mechanical forces between multiple musculoskeletal tissues e.g. between ligament and bone tissue. However, these interfaces often do not physiologically regenerate upon injury, resulting in impaired tissue function. Therefore, interface tissue engineering approaches are considered to be particularly relevant for the structural restoration of musculoskeletal tissues interfaces. In this article we provide an overview of the various strategies used for engineering musculoskeletal tissue interfaces with a specific focus on the recent important patents that have been issued for inventions that were specifically designed for engineering musculoskeletal interfaces as well as those that show promise to be adapted for this purpose. PMID:26577344

  9. 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

  10. 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

  11. Tissue Engineering: Toward a New Era of Medicine.

    Science.gov (United States)

    Shafiee, Ashkan; Atala, Anthony

    2017-01-14

    The goal of tissue engineering is to mitigate the critical shortage of donor organs via in vitro fabrication of functional biological structures. Tissue engineering is one of the most prominent examples of interdisciplinary fields, where scientists with different backgrounds work together to boost the quality of life by addressing critical health issues. Many different fields, such as developmental and molecular biology, as well as technologies, such as micro- and nanotechnologies and additive manufacturing, have been integral for advancing the field of tissue engineering. Over the past 20 years, spectacular advancements have been achieved to harness nature's ability to cure diseased tissues and organs. Patients have received laboratory-grown tissues and organs made out of their own cells, thus eliminating the risk of rejection. However, challenges remain when addressing more complex solid organs such as the heart, liver, and kidney. Herein, we review recent accomplishments as well as challenges that must be addressed in the field of tissue engineering and provide a perspective regarding strategies in further development.

  12. Bioreactors in tissue engineering - principles, applications and commercial constraints.

    Science.gov (United States)

    Hansmann, Jan; Groeber, Florian; Kahlig, Alexander; Kleinhans, Claudia; Walles, Heike

    2013-03-01

    Bioreactor technology is vital for tissue engineering. Usually, bioreactors are used to provide a tissue-specific physiological in vitro environment during tissue maturation. In addition to this most obvious application, bioreactors have the potential to improve the efficiency of the overall tissue-engineering concept. To date, a variety of bioreactor systems for tissue-specific applications have been developed. Of these, some systems are already commercially available. With bioreactor technology, various functional tissues of different types were generated and cultured in vitro. Nevertheless, these efforts and achievements alone have not yet led to many clinically successful tissue-engineered implants. We review possible applications for bioreactor systems within a tissue-engineering process and present basic principles and requirements for bioreactor development. Moreover, the use of bioreactor systems for the expansion of clinically relevant cell types is addressed. In contrast to cell expansion, for the generation of functional three-dimensional tissue equivalents, additional physical cues must be provided. Therefore, bioreactors for musculoskeletal tissue engineering are discussed. Finally, bioreactor technology is reviewed in the context of commercial constraints. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Functional tissue engineering : ten more years of progress

    NARCIS (Netherlands)

    Guilak, F.; Baaijens, F.P.T.

    2014-01-01

    "Functional tissue engineering" is a subset of the field of tissue engineering that was proposed by the United States National Committee on Biomechanics over a decade ago in order to place more emphasis on the roles of biomechanics and mechanobiology in tissue repair and regeneration. Over the past

  14. Micro-/nano-engineered cellular responses for soft tissue engineering and biomedical applications.

    Science.gov (United States)

    Tay, Chor Yong; Irvine, Scott Alexander; Boey, Freddy Y C; Tan, Lay Poh; Venkatraman, Subbu

    2011-05-23

    The development of biomedical devices and reconstruction of functional ex vivo tissues often requires the need to fabricate biomimetic surfaces with features of sub-micrometer precision. This can be achieved with the advancements in micro-/nano-engineering techniques, allowing researchers to manipulate a plethora of cellular behaviors at the cell-biomaterial interface. Systematic studies conducted on these 2D engineered surfaces have unraveled numerous novel findings that can potentially be integrated as part of the design consideration for future 2D and 3D biomaterials and will no doubt greatly benefit tissue engineering. In this review, recent developments detailing the use of micro-/nano-engineering techniques to direct cellular orientation and function pertinent to soft tissue engineering will be highlighted. Particularly, this article aims to provide valuable insights into distinctive cell interactions and reactions to controlled surfaces, which can be exploited to understand the mechanisms of cell growth on micro-/nano-engineered interfaces, and to harness this knowledge to optimize the performance of 3D artificial soft tissue grafts and biomedical applications. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Biomaterials in myocardial tissue engineering

    Science.gov (United States)

    Reis, Lewis A.; Chiu, Loraine L. Y.; Feric, Nicole; Fu, Lara; Radisic, Milica

    2016-01-01

    Cardiovascular disease is the leading cause of death in the developed world, and as such there is a pressing need for treatment options. Cardiac tissue engineering emerged from the need to develop alternate sources and methods of replacing tissue damaged by cardiovascular diseases, as the ultimate treatment option for many who suffer from end-stage heart failure is a heart transplant. In this review we focus on biomaterial approaches to augment injured or impaired myocardium with specific emphasis on: the design criteria for these biomaterials; the types of scaffolds—composed of natural or synthetic biomaterials, or decellularized extracellular matrix—that have been used to develop cardiac patches and tissue models; methods to vascularize scaffolds and engineered tissue, and finally injectable biomaterials (hydrogels)designed for endogenous repair, exogenous repair or as bulking agents to maintain ventricular geometry post-infarct. The challenges facing the field and obstacles that must be overcome to develop truly clinically viable cardiac therapies are also discussed. PMID:25066525

  16. Application of polarization OCT in tissue engineering

    Science.gov (United States)

    Yang, Ying; Ahearne, Mark; Bagnaninchi, Pierre O.; Hu, Bin; Hampson, Karen; El Haj, Alicia J.

    2008-02-01

    For tissue engineering of load-bearing tissues, such as bone, tendon, cartilage, and cornea, it is critical to generate a highly organized extracellular matrix. The major component of the matrix in these tissues is collagen, which usually forms a highly hierarchical structure with increasing scale from fibril to fiber bundles. These bundles are ordered into a 3D network to withstand forces such as tensile, compressive or shear. To induce the formation of organized matrix and create a mimic body environment for tissue engineering, in particular, tendon tissue engineering, we have fabricated scaffolds with features to support the formation of uniaxially orientated collagen bundles. In addition, mechanical stimuli were applied to stimulate tissue formation and matrix organization. In parallel, we seek a nondestructive tool to monitor the changes within the constructs in response to these external stimulations. Polarizationsensitive optical coherence tomography (PSOCT) is a non-destructive technique that provides functional imaging, and possesses the ability to assess in depth the organization of tissue. In this way, an engineered tissue construct can be monitored on-line, and correlated with the application of different stimuli by PSOCT. We have constructed a PSOCT using a superluminescent diode (FWHM 52nm) in this study and produced two types of tendon constructs. The matrix structural evolution under different mechanical stimulation has been evaluated by the PSOCT. The results in this study demonstrate that PSOCT was a powerful tool enabling us to monitor non-destructively and real time the progressive changes in matrix organization and assess the impact of various stimuli on tissue orientation and growth.

  17. Challenges and opportunities for tissue-engineering polarized epithelium.

    Science.gov (United States)

    Paz, Ana C; Soleas, John; Poon, James C H; Trieu, Dennis; Waddell, Thomas K; McGuigan, Alison P

    2014-02-01

    The epithelium is one of the most important tissue types in the body and the specific organization of the epithelial cells in these tissues is important for achieving appropriate function. Since many tissues contain an epithelial component, engineering functional epithelium and understanding the factors that control epithelial maturation and organization are important for generating whole artificial organ replacements. Furthermore, disruption of the cellular organization leads to tissue malfunction and disease; therefore, engineered epithelium could provide a valuable in vitro model to study disease phenotypes. Despite the importance of epithelial tissues, a surprisingly limited amount of effort has been focused on organizing epithelial cells into artificial polarized epithelium with an appropriate structure that resembles that seen in vivo. In this review, we provide an overview of epithelial tissue organization and highlight the importance of cell polarization to achieve appropriate epithelium function. We next describe the in vitro models that exist to create polarized epithelium and summarize attempts to engineer artificial epithelium for clinical use. Finally, we highlight the opportunities that exist to translate strategies from tissue engineering other tissues to generate polarized epithelium with a functional structure.

  18. Engineering vascular development for tissue regeneration

    NARCIS (Netherlands)

    Rivron, N.C.

    2010-01-01

    Tissue engineering and regenerative medicine aim at restoring a damaged tissue by recreating in vitro or promoting its regeneratin in vovo. The vasculature is central to these therapies for the irrigation of the defective tissue (oxygen, nutrients or circulating regenerative cells) and as an

  19. Engineering spinal fusion: evaluating ceramic materials for cell based tissue engineered approaches

    NARCIS (Netherlands)

    Wilson, C.E.

    2011-01-01

    The principal aim of this thesis was to advance the development of tissue engineered posterolateral spinal fusion by investigating the potential of calcium phosphate ceramic materials to support cell based tissue engineered bone formation. This was accomplished by developing several novel model

  20. Controlled drug release for tissue engineering.

    Science.gov (United States)

    Rambhia, Kunal J; Ma, Peter X

    2015-12-10

    Tissue engineering is often referred to as a three-pronged discipline, with each prong corresponding to 1) a 3D material matrix (scaffold), 2) drugs that act on molecular signaling, and 3) regenerative living cells. Herein we focus on reviewing advances in controlled release of drugs from tissue engineering platforms. This review addresses advances in hydrogels and porous scaffolds that are synthesized from natural materials and synthetic polymers for the purposes of controlled release in tissue engineering. We pay special attention to efforts to reduce the burst release effect and to provide sustained and long-term release. Finally, novel approaches to controlled release are described, including devices that allow for pulsatile and sequential delivery. In addition to recent advances, limitations of current approaches and areas of further research are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Developing 3D microstructures for tissue engineering

    DEFF Research Database (Denmark)

    Mohanty, Soumyaranjan

    casting process to generate various large scale tissue engineering constructs with single pore geometry with the desired mechanical stiffness and porosity. In addition, a new technique was developed to fa bricate dual-pore scaffolds for various tissue-engineering applications where 3D printing...... materials have been developed and tested for enhancing the differentiation of hiPSC-derived hepatocytes and fabricating biodegradable scaffolds for in-vivo tissue engineering applications. Along with various scaffolds fabrication methods we finally presented an optimized study of hepatic differentiation...... of hiPSC-derived DE cells cultured for 25 days in a 3D perfusion bioreactor system with an array of 16 small-scale tissue-bioreactors with integrated dual-pore pore scaffolds and flow rates. Hepatic differentiation and functionality of hiPSC-derived hepatocytes were successfully assessed and compared...

  2. Avaliação do filme lacrimal de pacientes com distonia facial durante tratamento com toxina botulínica tipo A Lacrimal film evaluation of patients with facial dystonia during botulinum toxin type A treatment

    Directory of Open Access Journals (Sweden)

    Patricia Grativol Costa

    2006-06-01

    Full Text Available OBJETIVO: Determinar o efeito da toxina botulínica no filme lacrimal em pacientes com distonia facial. MÉTODOS: Foram incluídos 24 pacientes portadores de blefaroespasmo essencial e espasmo hemifacial que receberam aplicação de toxina botulínica tipo A que foram submetidos à propedêutica do filme lacrimal previamente à aplicação e após, com 7 e 30 dias. RESULTADOS: Houve diminuição das queixas de olho seco trinta dias após a aplicação, entretanto, o tempo de ruptura do filme lacrimal e o teste de Schirmer não demonstraram variação significativa entre os períodos pré-tratamento e 1 mês da aplicação. Em relação ao teste de coloração com rosa bengala, todos os olhos que coraram no pré-tratamento, melhoraram na última avaliação. CONCLUSÃO: A injeção de toxina botulínica pode aliviar as queixas de olho seco nos pacientes com distonia facial pela provável ação de inibição do orbicular na sua função de bomba lacrimal.PURPOSE: To determine the effect of botulinum toxin injection in the eyelid on lacrimal film in patients with facial dystonia. METHODS: Twenty-four patients with essential blepharospasm and hemifacial spasm were submitted to botulinum toxin injection and lacrimal film tests were performed before the application and after seven and thirty days. RESULTS: There was improvement in symptoms of dry eye and rose bengal test, however, the breakup time and Schirmer's test did not show significant variation between pretreatment and after 1 month of follow-up. CONCLUSION: The dry eye symptoms in patients with facial dystonia may be attenuated by botulinum toxin due to its possible inhibitory effect on the orbicular muscle leading to a decrease in lacrimal pump.

  3. The role of mechanical loading in ligament tissue engineering.

    Science.gov (United States)

    Benhardt, Hugh A; Cosgriff-Hernandez, Elizabeth M

    2009-12-01

    Tissue-engineered ligaments have received growing interest as a promising alternative for ligament reconstruction when traditional transplants are unavailable or fail. Mechanical stimulation was recently identified as a critical component in engineering load-bearing tissues. It is well established that living tissue responds to altered loads through endogenous changes in cellular behavior, tissue organization, and bulk mechanical properties. Without the appropriate biomechanical cues, new tissue formation lacks the necessary collagenous organization and alignment for sufficient load-bearing capacity. Therefore, tissue engineers utilize mechanical conditioning to guide tissue remodeling and improve the performance of ligament grafts. This review provides a comparative analysis of the response of ligament and tendon fibroblasts to mechanical loading in current bioreactor studies. The differential effect of mechanical stimulation on cellular processes such as protease production, matrix protein synthesis, and cell proliferation is examined in the context of tissue engineering design.

  4. MicroRNAs in skin tissue engineering.

    Science.gov (United States)

    Miller, Kyle J; Brown, David A; Ibrahim, Mohamed M; Ramchal, Talisha D; Levinson, Howard

    2015-07-01

    35.2 million annual cases in the U.S. require clinical intervention for major skin loss. To meet this demand, the field of skin tissue engineering has grown rapidly over the past 40 years. Traditionally, skin tissue engineering relies on the "cell-scaffold-signal" approach, whereby isolated cells are formulated into a three-dimensional substrate matrix, or scaffold, and exposed to the proper molecular, physical, and/or electrical signals to encourage growth and differentiation. However, clinically available bioengineered skin equivalents (BSEs) suffer from a number of drawbacks, including time required to generate autologous BSEs, poor allogeneic BSE survival, and physical limitations such as mass transfer issues. Additionally, different types of skin wounds require different BSE designs. MicroRNA has recently emerged as a new and exciting field of RNA interference that can overcome the barriers of BSE design. MicroRNA can regulate cellular behavior, change the bioactive milieu of the skin, and be delivered to skin tissue in a number of ways. While it is still in its infancy, the use of microRNAs in skin tissue engineering offers the opportunity to both enhance and expand a field for which there is still a vast unmet clinical need. Here we give a review of skin tissue engineering, focusing on the important cellular processes, bioactive mediators, and scaffolds. We further discuss potential microRNA targets for each individual component, and we conclude with possible future applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Mammary gland stem cells

    DEFF Research Database (Denmark)

    Fridriksdottir, Agla J R; Petersen, Ole W; Rønnov-Jessen, Lone

    2011-01-01

    Distinct subsets of cells, including cells with stem cell-like properties, have been proposed to exist in normal human breast epithelium and breast carcinomas. The cellular origins of epithelial cells contributing to gland development, tissue homeostasis and cancer are, however, still poorly...... and differences between mouse and human gland development with particular emphasis on the identity and localization of stem cells, and the influence of the surrounding microenvironment. It is concluded that while recent advances in the field have contributed immense insight into how the normal mammary gland...... develops and is maintained, significant discrepancies exist between the mouse and human gland which should be taken into consideration in current and future models of mammary stem cell biology....

  6. Engineering Microvascularized 3D Tissue Using Alginate-Chitosan Microcapsules.

    Science.gov (United States)

    Zhang, Wujie; Choi, Jung K; He, Xiaoming

    2017-02-01

    Construction of vascularized tissues is one of the major challenges of tissue engineering. The goal of this study was to engineer 3D microvascular tissues by incorporating the HUVEC-CS cells with a collagen/alginate-chitosan (AC) microcapsule scaffold. In the presence of AC microcapsules, a 3D vascular-like network was clearly observable. The results indicated the importance of AC microcapsules in engineering microvascular tissues -- providing support and guiding alignment of HUVEC-CS cells. This approach provides an alternative and promising method for constructing vascularized tissues.

  7. Engineering Microvascularized 3D Tissue Using Alginate-Chitosan Microcapsules

    OpenAIRE

    Zhang, Wujie; Choi, Jung K.; He, Xiaoming

    2017-01-01

    Construction of vascularized tissues is one of the major challenges of tissue engineering. The goal of this study was to engineer 3D microvascular tissues by incorporating the HUVEC-CS cells with a collagen/alginate-chitosan (AC) microcapsule scaffold. In the presence of AC microcapsules, a 3D vascular-like network was clearly observable. The results indicated the importance of AC microcapsules in engineering microvascular tissues -- providing support and guiding alignment of HUVEC-CS cells. ...

  8. Expediting the transition from replacement medicine to tissue engineering.

    Science.gov (United States)

    Coury, Arthur J

    2016-06-01

    In this article, an expansive interpretation of "Tissue Engineering" is proposed which is in congruence with classical and recent published definitions. I further simplify the definition of tissue engineering as: "Exerting systematic control of the body's cells, matrices and fluids." As a consequence, many medical therapies not commonly considered tissue engineering are placed in this category because of their effect on the body's responses. While the progress of tissue engineering strategies is inexorable and generally positive, it has been subject to setbacks as have many important medical therapies. Medical practice is currently undergoing a transition on several fronts (academics, start-up companies, going concerns) from the era of "replacement medicine" where body parts and functions are replaced by mechanical, electrical or chemical therapies to the era of tissue engineering where health is restored by regeneration generation or limitation of the body's tissues and functions by exploiting our expanding knowledge of the body's biological processes to produce natural, healthy outcomes.

  9. Sjogren's syndrome combined with MALT lymphoma

    International Nuclear Information System (INIS)

    Han, Won Jeong; Cha, Sang Yun; Kim, Eun Kyung

    2000-01-01

    Sjogren's syndrome is a chronic inflammatory disease that predominantly affects salivary, lacrimal, and other exocrine glands. We report a case of Sjogren's syndrome combined with MALT (mucose associated lymphoid tissue) lymphoma which occurred in the parotid gland. A 57-year-old female with the complaint of painful swelling and lymph node enlargement was referred to our department. Sialograms of both parotid glands showed globular collections of contrast material uniformly distributed throughout the parotid gland. Salivary scintigraphy showed decreased uptake of the parotid gland. CT scan showed larger, slightly more dense parotid gland than normal and honeycomb glandular appearance. Also, It showed discrete, slightly more enhanced round mass in the left parotid gland. Histopathological finding showed replacement of salivary gland parenchyma with dense small lymphocytic infiltration having the feature of epimyoepithelial islands. Kappa light chain restriction of interglandular plasma cell could be seen.

  10. Bioactive polymeric scaffolds for tissue engineering

    Directory of Open Access Journals (Sweden)

    Scott Stratton

    2016-12-01

    Full Text Available A variety of engineered scaffolds have been created for tissue engineering using polymers, ceramics and their composites. Biomimicry has been adopted for majority of the three-dimensional (3D scaffold design both in terms of physicochemical properties, as well as bioactivity for superior tissue regeneration. Scaffolds fabricated via salt leaching, particle sintering, hydrogels and lithography have been successful in promoting cell growth in vitro and tissue regeneration in vivo. Scaffold systems derived from decellularization of whole organs or tissues has been popular due to their assured biocompatibility and bioactivity. Traditional scaffold fabrication techniques often failed to create intricate structures with greater resolution, not reproducible and involved multiple steps. The 3D printing technology overcome several limitations of the traditional techniques and made it easier to adopt several thermoplastics and hydrogels to create micro-nanostructured scaffolds and devices for tissue engineering and drug delivery. This review highlights scaffold fabrication methodologies with a focus on optimizing scaffold performance through the matrix pores, bioactivity and degradation rate to enable tissue regeneration. Review highlights few examples of bioactive scaffold mediated nerve, muscle, tendon/ligament and bone regeneration. Regardless of the efforts required for optimization, a shift in 3D scaffold uses from the laboratory into everyday life is expected in the near future as some of the methods discussed in this review become more streamlined.

  11. Microfluidic systems for stem cell-based neural tissue engineering.

    Science.gov (United States)

    Karimi, Mahdi; Bahrami, Sajad; Mirshekari, Hamed; Basri, Seyed Masoud Moosavi; Nik, Amirala Bakhshian; Aref, Amir R; Akbari, Mohsen; Hamblin, Michael R

    2016-07-05

    Neural tissue engineering aims at developing novel approaches for the treatment of diseases of the nervous system, by providing a permissive environment for the growth and differentiation of neural cells. Three-dimensional (3D) cell culture systems provide a closer biomimetic environment, and promote better cell differentiation and improved cell function, than could be achieved by conventional two-dimensional (2D) culture systems. With the recent advances in the discovery and introduction of different types of stem cells for tissue engineering, microfluidic platforms have provided an improved microenvironment for the 3D-culture of stem cells. Microfluidic systems can provide more precise control over the spatiotemporal distribution of chemical and physical cues at the cellular level compared to traditional systems. Various microsystems have been designed and fabricated for the purpose of neural tissue engineering. Enhanced neural migration and differentiation, and monitoring of these processes, as well as understanding the behavior of stem cells and their microenvironment have been obtained through application of different microfluidic-based stem cell culture and tissue engineering techniques. As the technology advances it may be possible to construct a "brain-on-a-chip". In this review, we describe the basics of stem cells and tissue engineering as well as microfluidics-based tissue engineering approaches. We review recent testing of various microfluidic approaches for stem cell-based neural tissue engineering.

  12. 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.

  13. Tissue engineering and surgery: from translational studies to human trials

    Directory of Open Access Journals (Sweden)

    Vranckx Jan Jeroen

    2017-06-01

    Full Text Available Tissue engineering was introduced as an innovative and promising field in the mid-1980s. The capacity of cells to migrate and proliferate in growth-inducing medium induced great expectancies on generating custom-shaped bioconstructs for tissue regeneration. Tissue engineering represents a unique multidisciplinary translational forum where the principles of biomaterial engineering, the molecular biology of cells and genes, and the clinical sciences of reconstruction would interact intensively through the combined efforts of scientists, engineers, and clinicians. The anticipated possibilities of cell engineering, matrix development, and growth factor therapies are extensive and would largely expand our clinical reconstructive armamentarium. Application of proangiogenic proteins may stimulate wound repair, restore avascular wound beds, or reverse hypoxia in flaps. Autologous cells procured from biopsies may generate an ‘autologous’ dermal and epidermal laminated cover on extensive burn wounds. Three-dimensional printing may generate ‘custom-made’ preshaped scaffolds – shaped as a nose, an ear, or a mandible – in which these cells can be seeded. The paucity of optimal donor tissues may be solved with off-the-shelf tissues using tissue engineering strategies. However, despite the expectations, the speed of translation of in vitro tissue engineering sciences into clinical reality is very slow due to the intrinsic complexity of human tissues. This review focuses on the transition from translational protocols towards current clinical applications of tissue engineering strategies in surgery.

  14. Co-culture systems-based strategies for articular cartilage tissue engineering.

    Science.gov (United States)

    Zhang, Yu; Guo, Weimin; Wang, Mingjie; Hao, Chunxiang; Lu, Liang; Gao, Shuang; Zhang, Xueliang; Li, Xu; Chen, Mingxue; Li, Penghao; Jiang, Peng; Lu, Shibi; Liu, Shuyun; Guo, Quanyi

    2018-03-01

    Cartilage engineering facilitates repair and regeneration of damaged cartilage using engineered tissue that restores the functional properties of the impaired joint. The seed cells used most frequently in tissue engineering, are chondrocytes and mesenchymal stem cells. Seed cells activity plays a key role in the regeneration of functional cartilage tissue. However, seed cells undergo undesirable changes after in vitro processing procedures, such as degeneration of cartilage cells and induced hypertrophy of mesenchymal stem cells, which hinder cartilage tissue engineering. Compared to monoculture, which does not mimic the in vivo cellular environment, co-culture technology provides a more realistic microenvironment in terms of various physical, chemical, and biological factors. Co-culture technology is used in cartilage tissue engineering to overcome obstacles related to the degeneration of seed cells, and shows promise for cartilage regeneration and repair. In this review, we focus first on existing co-culture systems for cartilage tissue engineering and related fields, and discuss the conditions and mechanisms thereof. This is followed by methods for optimizing seed cell co-culture conditions to generate functional neo-cartilage tissue, which will lead to a new era in cartilage tissue engineering. © 2017 Wiley Periodicals, Inc.

  15. The self-assembling process and applications in tissue engineering

    Science.gov (United States)

    Lee, Jennifer K.; Link, Jarrett M.; Hu, Jerry C. Y.; Athanasiou, Kyriacos A.

    2018-01-01

    Tissue engineering strives to create neotissues capable of restoring function. Scaffold-free technologies have emerged that can recapitulate native tissue function without the use of an exogenous scaffold. This chapter will survey, in particular, the self-assembling and self-organization processes as scaffold-free techniques. Characteristics and benefits of each process are described, and key examples of tissues created using these scaffold-free processes are examined to provide guidance for future tissue engineering developments. This chapter aims to explore the potential of self-assembly and self-organization scaffold-free approaches, detailing the recent progress in the in vitro tissue engineering of biomimetic tissues with these methods, toward generating functional tissue replacements. PMID:28348174

  16. 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

  17. Recombinant protein scaffolds for tissue engineering

    International Nuclear Information System (INIS)

    Werkmeister, Jerome A; Ramshaw, John A M

    2012-01-01

    New biological materials for tissue engineering are now being developed using common genetic engineering capabilities to clone and express a variety of genetic elements that allow cost-effective purification and scaffold fabrication from these recombinant proteins, peptides or from chimeric combinations of these. The field is limitless as long as the gene sequences are known. The utility is dependent on the ease, product yield and adaptability of these protein products to the biomedical field. The development of recombinant proteins as scaffolds, while still an emerging technology with respect to commercial products, is scientifically superior to current use of natural materials or synthetic polymer scaffolds, in terms of designing specific structures with desired degrees of biological complexities and motifs. In the field of tissue engineering, next generation scaffolds will be the key to directing appropriate tissue regeneration. The initial period of biodegradable synthetic scaffolds that provided shape and mechanical integrity, but no biological information, is phasing out. The era of protein scaffolds offers distinct advantages, particularly with the combination of powerful tools of molecular biology. These include, for example, the production of human proteins of uniform quality that are free of infectious agents and the ability to make suitable quantities of proteins that are found in low quantity or are hard to isolate from tissue. For the particular needs of tissue engineering scaffolds, fibrous proteins like collagens, elastin, silks and combinations of these offer further advantages of natural well-defined structural scaffolds as well as endless possibilities of controlling functionality by genetic manipulation. (topical review)

  18. Cryopreservation of tissue engineered constructs for bone.

    Science.gov (United States)

    Kofron, Michelle D; Opsitnick, Natalie C; Attawia, Mohamed A; Laurencin, Cato T

    2003-11-01

    The large-scale clinical use of tissue engineered constructs will require provisions for its mass availability and accessibility. Therefore, it is imperative to understand the effects of low temperature (-196 degrees C) on the tissue engineered biological system. Initial studies used samples of the osteoblast-like cell line (SaOS-2) adhered to a two-dimensional poly(lactide-co-glycolide) thin film (2D-PLAGA) or a three-dimensional poly(lactide-co-glycolide) sintered microsphere matrix (3D-PLAGA) designed for bone tissue engineering. Experimental samples were tested for their ability to maintain cell viability, following low temperature banking for one week, in solutions of the penetrating cryoprotective agents, dimethylsulfoxide (DMSO), ethylene glycol, and glycerol. Results indicated the DMSO solution yielded the greatest percent cell survival for SaOS-2 cells adhered to both the 2D- and 3D-PLAGA scaffolds; therefore, DMSO was used to cryopreserve mineralizing primary rabbit osteoblasts cells adhered to 2D-PLAGA matrices for 35 days. Results indicated retention of the extracellular matrix architecture as no statistically significant difference in the pre- and post-thaw mineralized structures was measured. Percent cell viability of the mineralized constructs following low temperature storage was approximately 50%. These are the first studies to address the issue of preservation techniques for tissue engineered constructs. The ability to successfully cryopreserve mineralized tissue engineered matrices for bone may offer an unlimited and readily available source of bone-like materials for orthopaedic applications.

  19. Tear clearance measurement in patients with dry eye syndrome using quantitative lacrimal scintigraphy

    International Nuclear Information System (INIS)

    Gencoglu, E.A.; Dursun, D.; Akova, Y.A.; Cengiz, F.; Yalcin, H.; Koyuncu, A.

    2005-01-01

    The aim of this study was to evaluate the tear clearance in patients with dry eye syndrome using quantitative lacrimal scintigraphy. We investigated 21 patients (42 eyes; 18 women, 3 men; mean age, 63.19±13.33 years) with dry eye syndrome. Additionally, for the sake of comparison, 12 normal subjects of the same age group (24 eyes; 10 women, 2 men; mean age, 68.25±2.63 years) were included. Lacrimal scintigraphy, Schirmer-1 test, break-up time (BUT), and rose bengal ocular surface vital staining were performed in these cases. According to the results of lacrimal scintigraphy, the mean value of T1/2 was 4.16±1.22 minutes and the mean value of radioisotope (RI) was 14.15%±2.30% in normal subjects. However, in patients with dry eye syndrome, these values were 20.59±1.97 minutes and 55.64%±6.90%, respectively. Consistent with the results of ophthalmologic tests, the mean Schirmer-1 value was 12.46±2.10 mm, the mean value of BUT was 14.36±3.40 seconds, and the mean staining value of the rose bengal was 1.98±0.80 in normal subjects, whereas these values were 1.36±0.49 mm, 5.46±1.33 seconds, 6.62±0.86, respectively, in patients with dry eye syndrome. When we compared the results of lacrimal scintigraphy and the results of ophthalmologic tests, an inverse correlation was noted between both the T1/2 and RI values and both the Schirmer-1 and BUT values in all subjects (p<0.001). However, there was a greater positive correlation between the rose bengal ocular surface staining value and both the T1/2 and RI values in all cases (p<0.001). In the current study, it was concluded that although the lacrimal drainage system was normal, tear clearance was significantly delayed in dry eye patients. With this study, we have shown that quantitative lacrimal scintigraphy, which is an objective, practical, and noninvasive method, appears to be useful for the assessment of the tear clearance in patients with dry eye syndrome. (author)

  20. Computed tomography of the vesicular glands: anatomical animal model (Oryctolagus cuniculus)

    International Nuclear Information System (INIS)

    Dimitrov, R.; Stamatova-Yovcheva, K.; Hamza, S.; Toneva, Y.

    2014-01-01

    Spiral CT is a non-invasive imaging method of choice for animal anatomical studies. The aim of the study was to establish the imaging anatomical features of the vesicular glands in the rabbit. Eight sexually mature healthy clinically male New Zealand rabbits of 18 months of age with body weight from 2.8 kg to 3.2 kg were used. The animals were anesthetized. As contrast medium Opti-ray350 was administrated. The computed tomography scan was complied with certain bone and soft tissue markers. For this purpose, a whole body multi-slice spiral computed tomography scanner was used. The both soft tissue glands were heterogeneous and relatively hyperdense structures, and defined in detail from the adjacent soft tissues. The urinary bladder neck was ventrally to the glands. Both vesicular glands were better differentiated each other when the rabbit is examined in abdominal recumbence. In dorsal recumbence the shape of the transversal image of the glandular finding was oval. In abdominal recumbence both the left and right soft tissue vesicular gland were defined. Transversal anatomical computed tomographic investigation of the rabbit vesicular gland is a detailed and definitive method, to study the normal morphology of these glands. Key words: Vesicular Gland. Helical Computed Tomography. Anatomy. Rabbit

  1. Engineering Parameters in Bioreactor’s Design: A Critical Aspect in Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Nasim Salehi-Nik

    2013-01-01

    Full Text Available Bioreactors are important inevitable part of any tissue engineering (TE strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors.

  2. 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

  3. Nuclear hBD-1 accumulation in malignant salivary gland tumours

    International Nuclear Information System (INIS)

    Wenghoefer, M; Merkelbach-Bruse, S; Fischer, HP; Novak, N; Winter, J; Pantelis, A; Dommisch, H; Götz, W; Reich, R; Bergé, S; Martini, M; Allam, JP; Jepsen, S

    2008-01-01

    Whereas the antimicrobial peptides hBD-2 and -3 are related to inflammation, the constitutively expressed hBD-1 might function as 8p tumour suppressor gene and thus play a key role in control of transcription and induction of apoptosis in malignant epithelial tumours. Therefore this study was conducted to characterise proteins involved in cell cycle control and host defence in different benign and malignant salivary gland tumours in comparison with healthy salivary gland tissue. 21 paraffin-embedded tissue samples of benign (n = 7), and malignant (n = 7) salivary gland tumours as well as healthy (n = 7) salivary glands were examined immunohistochemically for the expression of p53, bcl-2, and hBD-1, -2, -3. HBD-1 was distributed in the cytoplasm of healthy salivary glands and benign salivary gland tumours but seems to migrate into the nucleus of malignant salivary gland tumours. Pleomorphic adenomas showed cytoplasmic as well as weak nuclear hBD-1 staining. HBD-1, 2 and 3 are traceable in healthy salivary gland tissue as well as in benign and malignant salivary gland tumours. As hBD-1 is shifted from the cytoplasm to the nucleus in malignant salivary gland tumours, we hypothesize that it might play a role in the oncogenesis of these tumours. In pleomorphic adenomas hBD-1 might be connected to their biologic behaviour of recurrence and malignant transformation

  4. Bone tissue engineering using silica-based mesoporous nanobiomaterials:Recent progress.

    Science.gov (United States)

    Shadjou, Nasrin; Hasanzadeh, Mohammad

    2015-10-01

    Bone disorders are of significant concern due to increase in the median age of our population. It is in this context that tissue engineering has been emerging as a valid approach to the current therapies for bone regeneration/substitution. Tissue-engineered bone constructs have the potential to alleviate the demand arising from the shortage of suitable autograft and allograft materials for augmenting bone healing. Silica based mesostructured nanomaterials possessing pore sizes in the range 2-50 nm and surface reactive functionalities have elicited immense interest due to their exciting prospects in bone tissue engineering. In this review we describe application of silica-based mesoporous nanomaterials for bone tissue engineering. We summarize the preparation methods, the effect of mesopore templates and composition on the mesopore-structure characteristics, and different forms of these materials, including particles, fibers, spheres, scaffolds and composites. Also, the effect of structural and textural properties of mesoporous materials on development of new biomaterials for production of bone implants and bone cements was discussed. Also, application of different mesoporous materials on construction of manufacture 3-dimensional scaffolds for bone tissue engineering was discussed. It begins by giving the reader a brief background on tissue engineering, followed by a comprehensive description of all the relevant components of silica-based mesoporous biomaterials on bone tissue engineering, going from materials to scaffolds and from cells to tissue engineering strategies that will lead to "engineered" bone. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. 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.

  6. From stem to roots: Tissue engineering in endodontics

    Science.gov (United States)

    Kala, M.; Banthia, Priyank; Banthia, Ruchi

    2012-01-01

    The vitality of dentin-pulp complex is fundamental to the life of tooth and is a priority for targeting clinical management strategies. Loss of the tooth, jawbone or both, due to periodontal disease, dental caries, trauma or some genetic disorders, affects not only basic mouth functions but aesthetic appearance and quality of life. One novel approach to restore tooth structure is based on biology: regenerative endodontic procedure by application of tissue engineering. Regenerative endodontics is an exciting new concept that seeks to apply the advances in tissue engineering to the regeneration of the pulp-dentin complex. The basic logic behind this approach is that patient-specific tissue-derived cell populations can be used to functionally replace integral tooth tissues. The development of such ‘test tube teeth’ requires precise regulation of the regenerative events in order to achieve proper tooth size and shape, as well as the development of new technologies to facilitate these processes. This article provides an extensive review of literature on the concept of tissue engineering and its application in endodontics, providing an insight into the new developmental approaches on the horizon. Key words:Regenerative, tissue engineering, stem cells, scaffold. PMID:24558528

  7. Textile Technologies and Tissue Engineering: A Path Towards Organ Weaving

    Science.gov (United States)

    Akbari, Mohsen; Tamayol, Ali; Bagherifard, Sara; Serex, Ludovic; Mostafalu, Pooria; Faramarzi, Negar; Mohammadi, Mohammad Hossein

    2016-01-01

    Textile technologies have recently attracted great attention as potential biofabrication tools for engineering tissue constructs. Using current textile technologies, fibrous structures can be designed and engineered to attain the required properties that are demanded by different tissue engineering applications. Several key parameters such as physiochemical characteristics of fibers, pore size and mechanical properties of the fabrics play important role in the effective use of textile technologies in tissue engineering. This review summarizes the current advances in the manufacturing of biofunctional fibers. Different textile methods such as knitting, weaving, and braiding are discussed and their current applications in tissue engineering are highlighted. PMID:26924450

  8. Biological augmentation and tissue engineering approaches in meniscus surgery.

    Science.gov (United States)

    Moran, Cathal J; Busilacchi, Alberto; Lee, Cassandra A; Athanasiou, Kyriacos A; Verdonk, Peter C

    2015-05-01

    The purpose of this review was to evaluate the role of biological augmentation and tissue engineering strategies in meniscus surgery. Although clinical (human), preclinical (animal), and in vitro tissue engineering studies are included here, we have placed additional focus on addressing preclinical and clinical studies reported during the 5-year period used in this review in a systematic fashion while also providing a summary review of some important in vitro tissue engineering findings in the field over the past decade. A search was performed on PubMed for original works published from 2009 to March 31, 2014 using the term "meniscus" with all the following terms: "scaffolds," "constructs," "cells," "growth factors," "implant," "tissue engineering," and "regenerative medicine." Inclusion criteria were the following: English-language articles and original clinical, preclinical (in vivo), and in vitro studies of tissue engineering and regenerative medicine application in knee meniscus lesions published from 2009 to March 31, 2014. Three clinical studies and 18 preclinical studies were identified along with 68 tissue engineering in vitro studies. These reports show the increasing promise of biological augmentation and tissue engineering strategies in meniscus surgery. The role of stem cell and growth factor therapy appears to be particularly useful. A review of in vitro tissue engineering studies found a large number of scaffold types to be of promise for meniscus replacement. Limitations include a relatively low number of clinical or preclinical in vivo studies, in addition to the fact there is as yet no report in the literature of a tissue-engineered meniscus construct used clinically. Neither does the literature provide clarity on the optimal meniscus scaffold type or biological augmentation with which meniscus repair or replacement would be best addressed in the future. There is increasing focus on the role of mechanobiology and biomechanical and

  9. The Application of Tissue Engineering Procedures to Repair the Larynx

    Science.gov (United States)

    Ringel, Robert L.; Kahane, Joel C.; Hillsamer, Peter J.; Lee, Annie S.; Badylak, Stephen F.

    2006-01-01

    The field of tissue engineering/regenerative medicine combines the quantitative principles of engineering with the principles of the life sciences toward the goal of reconstituting structurally and functionally normal tissues and organs. There has been relatively little application of tissue engineering efforts toward the organs of speech, voice,…

  10. Tissue engineering and regenerative medicine: manufacturing challenges.

    Science.gov (United States)

    Williams, D J; Sebastine, I M

    2005-12-01

    Tissue engineering and regenerative medicine are interdisciplinary fields that apply principles of engineering and life sciences to develop biological substitutes, typically composed of biological and synthetic components, that restore, maintain or improve tissue function. Many tissue engineering technologies are still at a laboratory or pre-commercial scale. The short review paper describes the most significant manufacturing and bio-process challenges inherent in the commercialisation and exploitation of the exciting results emerging from the biological and clinical laboratories exploring tissue engineering and regenerative medicine. A three-generation road map of the industry has been used to structure a view of these challenges and to define where the manufacturing community can contribute to the commercial success of the products from these emerging fields. The first-generation industry is characterised by its demonstrated clinical applications and products in the marketplace, the second is characterised by emerging clinical applications, and the third generation is characterised by aspirational clinical applications. The paper focuses on the cost reduction requirement of the first generation of the industry to allow more market penetration and consequent patient impact. It indicates the technological requirements, for instance the creation of three-dimensional tissue structures, and value chain issues in the second generation of the industry. The third-generation industry challenges lie in fundamental biological and clinical science. The paper sets out a road map of these generations to identify areas for research.

  11. Engineering complex tissue-like microgel arrays for evaluating stem cell differentiation

    DEFF Research Database (Denmark)

    Guermani, Enrico; Shaki, Hossein; Mohanty, Soumyaranjan

    2016-01-01

    Development of tissue engineering scaffolds with native-like biology and microarchitectures is a prerequisite for stem cell mediated generation of off-the-shelf-tissues. So far, the field of tissue engineering has not full-filled its grand potential of engineering such combinatorial scaffolds...... for engineering functional tissues. This is primarily due to the many challenges associated with finding the right microarchitectures and ECM compositions for optimal tissue regeneration. Here, we have developed a new microgel array to address this grand challenge through robotic printing of complex stem cell...... platform will be used for high-throughput identification of combinatorial and native-like scaffolds for tissue engineering of functional organs....

  12. Oxidative stress induced inflammation initiates functional decline of tear production.

    Directory of Open Access Journals (Sweden)

    Yuichi Uchino

    Full Text Available Oxidative damage and inflammation are proposed to be involved in an age-related functional decline of exocrine glands. However, the molecular mechanism of how oxidative stress affects the secretory function of exocrine glands is unclear. We developed a novel mev-1 conditional transgenic mouse model (Tet-mev-1 using a modified tetracycline system (Tet-On/Off system. This mouse model demonstrated decreased tear production with morphological changes including leukocytic infiltration and fibrosis. We found that the mev-1 gene encodes Cyt-1, which is the cytochrome b(560 large subunit of succinate-ubiquinone oxidoreductase in complex II of mitochondria (homologous to succinate dehydrogenase C subunit (SDHC in humans. The mev-1 gene induced excessive oxidative stress associated with ocular surface epithelial damage and a decrease in protein and aqueous secretory function. This new model provides evidence that mitochondrial oxidative damage in the lacrimal gland induces lacrimal dysfunction resulting in dry eye disease. Tear volume in Tet-mev-1 mice was lower than in wild type mice and histopathological analyses showed the hallmarks of lacrimal gland inflammation by intense mononuclear leukocytic infiltration and fibrosis in the lacrimal gland of Tet-mev-1 mice. These findings strongly suggest that oxidative stress can be a causative factor for the development of dry eye disease.

  13. Textile Technologies and Tissue Engineering: A Path Toward Organ Weaving.

    Science.gov (United States)

    Akbari, Mohsen; Tamayol, Ali; Bagherifard, Sara; Serex, Ludovic; Mostafalu, Pooria; Faramarzi, Negar; Mohammadi, Mohammad Hossein; Khademhosseini, Ali

    2016-04-06

    Textile technologies have recently attracted great attention as potential biofabrication tools for engineering tissue constructs. Using current textile technologies, fibrous structures can be designed and engineered to attain the required properties that are demanded by different tissue engineering applications. Several key parameters such as physiochemical characteristics of fibers, microarchitecture, and mechanical properties of the fabrics play important roles in the effective use of textile technologies in tissue engineering. This review summarizes the current advances in the manufacturing of biofunctional fibers. Different textile methods such as knitting, weaving, and braiding are discussed and their current applications in tissue engineering are highlighted. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Adenoid cystic carcinoma of the minor salivary glands

    International Nuclear Information System (INIS)

    Kwon, Kyung Yun; Lee, Kyung Ho; Kim, Dong Youn; Choi, Karp Shik

    1997-01-01

    Adenoid cystic carcinoma is a malignant salivary gland tumor with typical histologic patterns. The majority of the se tumors occurs in the minor salivary glands, especially mucosa of the hard palate. The authors experienced the patients, who complained the tumor-like soft tissue masses on the palatal and mouth floor area. After careful analysis of clinical, radiological and histopathological findings, we diagnosed them as adenoid cystic carcinomas in the minor salivary glands, obtained results were as follows : 1. Main clinical symptoms were a slow growing soft tissue mass with normal intact mucosa on the palatal area, and soft tissue mass with mild pain on the mouth floor area. 2. In the radiographic examinations, soft tissue masses were observed with invasion to adjacent structures, and moderate defined, heterogeneous soft tissue mass with enhanced margin, respectively. 3. In the histopathologic examinations, dark-stained, small uniform ballad's cells in the hyaline or fibrous stroma were observed as solid and cribriform patterns, respectively.

  15. Effects of Aging in Dry Eye

    Science.gov (United States)

    de Paiva, Cintia S.

    2017-01-01

    Dry eye affects millions of people worldwide and causes eye well recognized risk factors for dry eye. Anatomical and inflammation-induced age-related changes affect all components of the lacrimal gland functional unit, inclusive of lacrimal gland, conjunctiva, meibomian gland and compromise ocular surface health. There is increased evidence that inflammation plays a role in dry eye. This review will summarize the current knowledge about aging and dry eye, inclusive of lessons learned from animal models and promising therapies. PMID:28282314

  16. Stem cell homing-based tissue engineering using bioactive materials

    Science.gov (United States)

    Yu, Yinxian; Sun, Binbin; Yi, Chengqing; Mo, Xiumei

    2017-06-01

    Tissue engineering focuses on repairing tissue and restoring tissue functions by employing three elements: scaffolds, cells and biochemical signals. In tissue engineering, bioactive material scaffolds have been used to cure tissue and organ defects with stem cell-based therapies being one of the best documented approaches. In the review, different biomaterials which are used in several methods to fabricate tissue engineering scaffolds were explained and show good properties (biocompatibility, biodegradability, and mechanical properties etc.) for cell migration and infiltration. Stem cell homing is a recruitment process for inducing the migration of the systemically transplanted cells, or host cells, to defect sites. The mechanisms and modes of stem cell homing-based tissue engineering can be divided into two types depending on the source of the stem cells: endogenous and exogenous. Exogenous stem cell-based bioactive scaffolds have the challenge of long-term culturing in vitro and for endogenous stem cells the biochemical signal homing recruitment mechanism is not clear yet. Although the stem cell homing-based bioactive scaffolds are attractive candidates for tissue defect therapies, based on in vitro studies and animal tests, there is still a long way before clinical application.

  17. Miíase na topografia de saco lacrimal

    Directory of Open Access Journals (Sweden)

    Simone Haber Duellberg von Faber Bison

    2016-02-01

    Full Text Available RESUMO A miíase é a infestação dos tecidos humanos por larvas Diptera. O comprometimento ocular é raro. Os autores apresentam um caso de miíase na topografia do saco lacrimal e discutem as modalidades terapêuticas para o tratamento desta doença.

  18. Sjogren's syndrome combined with MALT lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Han, Won Jeong; Cha, Sang Yun; Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University, Yongin (Korea, Republic of)

    2000-06-15

    Sjogren's syndrome is a chronic inflammatory disease that predominantly affects salivary, lacrimal, and other exocrine glands. We report a case of Sjogren's syndrome combined with MALT (mucose associated lymphoid tissue) lymphoma which occurred in the parotid gland. A 57-year-old female with the complaint of painful swelling and lymph node enlargement was referred to our department. Sialograms of both parotid glands showed globular collections of contrast material uniformly distributed throughout the parotid gland. Salivary scintigraphy showed decreased uptake of the parotid gland. CT scan showed larger, slightly more dense parotid gland than normal and honeycomb glandular appearance. Also, It showed discrete, slightly more enhanced round mass in the left parotid gland. Histopathological finding showed replacement of salivary gland parenchyma with dense small lymphocytic infiltration having the feature of epimyoepithelial islands. Kappa light chain restriction of interglandular plasma cell could be seen.

  19. Traction force microscopy of engineered cardiac tissues.

    Science.gov (United States)

    Pasqualini, Francesco Silvio; Agarwal, Ashutosh; O'Connor, Blakely Bussie; Liu, Qihan; Sheehy, Sean P; Parker, Kevin Kit

    2018-01-01

    Cardiac tissue development and pathology have been shown to depend sensitively on microenvironmental mechanical factors, such as extracellular matrix stiffness, in both in vivo and in vitro systems. We present a novel quantitative approach to assess cardiac structure and function by extending the classical traction force microscopy technique to tissue-level preparations. Using this system, we investigated the relationship between contractile proficiency and metabolism in neonate rat ventricular myocytes (NRVM) cultured on gels with stiffness mimicking soft immature (1 kPa), normal healthy (13 kPa), and stiff diseased (90 kPa) cardiac microenvironments. We found that tissues engineered on the softest gels generated the least amount of stress and had the smallest work output. Conversely, cardiomyocytes in tissues engineered on healthy- and disease-mimicking gels generated significantly higher stresses, with the maximal contractile work measured in NRVM engineered on gels of normal stiffness. Interestingly, although tissues on soft gels exhibited poor stress generation and work production, their basal metabolic respiration rate was significantly more elevated than in other groups, suggesting a highly ineffective coupling between energy production and contractile work output. Our novel platform can thus be utilized to quantitatively assess the mechanotransduction pathways that initiate tissue-level structural and functional remodeling in response to substrate stiffness.

  20. Articular cartilage: from formation to tissue engineering.

    Science.gov (United States)

    Camarero-Espinosa, Sandra; Rothen-Rutishauser, Barbara; Foster, E Johan; Weder, Christoph

    2016-05-26

    Hyaline cartilage is the nonlinear, inhomogeneous, anisotropic, poro-viscoelastic connective tissue that serves as friction-reducing and load-bearing cushion in synovial joints and is vital for mammalian skeletal movements. Due to its avascular nature, low cell density, low proliferative activity and the tendency of chondrocytes to de-differentiate, cartilage cannot regenerate after injury, wear and tear, or degeneration through common diseases such as osteoarthritis. Therefore severe damage usually requires surgical intervention. Current clinical strategies to generate new tissue include debridement, microfracture, autologous chondrocyte transplantation, and mosaicplasty. While articular cartilage was predicted to be one of the first tissues to be successfully engineered, it proved to be challenging to reproduce the complex architecture and biomechanical properties of the native tissue. Despite significant research efforts, only a limited number of studies have evolved up to the clinical trial stage. This review article summarizes the current state of cartilage tissue engineering in the context of relevant biological aspects, such as the formation and growth of hyaline cartilage, its composition, structure and biomechanical properties. Special attention is given to materials development, scaffold designs, fabrication methods, and template-cell interactions, which are of great importance to the structure and functionality of the engineered tissue.

  1. Integrated approaches to spatiotemporally directing angiogenesis in host and engineered tissues.

    Science.gov (United States)

    Kant, Rajeev J; Coulombe, Kareen L K

    2018-03-15

    The field of tissue engineering has turned towards biomimicry to solve the problem of tissue oxygenation and nutrient/waste exchange through the development of vasculature. Induction of angiogenesis and subsequent development of a vascular bed in engineered tissues is actively being pursued through combinations of physical and chemical cues, notably through the presentation of topographies and growth factors. Presenting angiogenic signals in a spatiotemporal fashion is beginning to generate improved vascular networks, which will allow for the creation of large and dense engineered tissues. This review provides a brief background on the cells, mechanisms, and molecules driving vascular development (including angiogenesis), followed by how biomaterials and growth factors can be used to direct vessel formation and maturation. Techniques to accomplish spatiotemporal control of vascularization include incorporation or encapsulation of growth factors, topographical engineering, and 3D bioprinting. The vascularization of engineered tissues and their application in angiogenic therapy in vivo is reviewed herein with an emphasis on the most densely vascularized tissue of the human body - the heart. Vascularization is vital to wound healing and tissue regeneration, and development of hierarchical networks enables efficient nutrient transfer. In tissue engineering, vascularization is necessary to support physiologically dense engineered tissues, and thus the field seeks to induce vascular formation using biomaterials and chemical signals to provide appropriate, pro-angiogenic signals for cells. This review critically examines the materials and techniques used to generate scaffolds with spatiotemporal cues to direct vascularization in engineered and host tissues in vitro and in vivo. Assessment of the field's progress is intended to inspire vascular applications across all forms of tissue engineering with a specific focus on highlighting the nuances of cardiac tissue

  2. Fabrication of scaffolds in tissue engineering: A review

    Science.gov (United States)

    Zhao, Peng; Gu, Haibing; Mi, Haoyang; Rao, Chengchen; Fu, Jianzhong; Turng, Lih-sheng

    2018-03-01

    Tissue engineering (TE) is an integrated discipline that involves engineering and natural science in the development of biological materials to replace, repair, and improve the function of diseased or missing tissues. Traditional medical and surgical treatments have been reported to have side effects on patients caused by organ necrosis and tissue loss. However, engineered tissues and organs provide a new way to cure specific diseases. Scaffold fabrication is an important step in the TE process. This paper summarizes and reviews the widely used scaffold fabrication methods, including conventional methods, electrospinning, three-dimensional printing, and a combination of molding techniques. Furthermore, the differences among the properties of tissues, such as pore size and distribution, porosity, structure, and mechanical properties, are elucidated and critically reviewed. Some studies that combine two or more methods are also reviewed. Finally, this paper provides some guidance and suggestions for the future of scaffold fabrication.

  3. Esophageal tissue engineering: Current status and perspectives.

    Science.gov (United States)

    Poghosyan, T; Catry, J; Luong-Nguyen, M; Bruneval, P; Domet, T; Arakelian, L; Sfeir, R; Michaud, L; Vanneaux, V; Gottrand, F; Larghero, J; Cattan, P

    2016-02-01

    Tissue engineering, which consists of the combination and in vivo implantation of elements required for tissue remodeling toward a specific organ phenotype, could be an alternative for classical techniques of esophageal replacement. The current hybrid approach entails creation of an esophageal substitute composed of an acellular matrix and autologous epithelial and muscle cells provides the most successful results. Current research is based on the use of mesenchymal stem cells, whose potential for differentiation and proangioogenic, immune-modulator and anti-inflammatory properties are important assets. In the near future, esophageal substitutes could be constructed from acellular "intelligent matrices" that contain the molecules necessary for tissue regeneration; this should allow circumvention of the implantation step and still obtain standardized in vivo biological responses. At present, tissue engineering applications to esophageal replacement are limited to enlargement plasties with absorbable, non-cellular matrices. Nevertheless, the application of existing clinical techniques for replacement of other organs by tissue engineering in combination with a multiplication of translational research protocols for esophageal replacement in large animals should soon pave the way for health agencies to authorize clinical trials. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  4. Case report of Mikulicz`s disease: A modern concept of an old entity

    Directory of Open Access Journals (Sweden)

    Božić Ksenija

    2016-01-01

    Full Text Available Introduction. Modern knowlegde defines Mikulicz´s disease as a part of immunoglobulin G4-related disease. The main feature is the presence of lymphoplasmacytic infiltrates, immunoglobulin G4 plasma cells positivity, distinctive storiform fibrosis and moderate eosinophilia. Case report. A 59-years old male presented with a mild keratoconjuctivitis sicca and enlarged lacrimal and salivary glands during the last two years. Althought clinical presentation of the patient was typical, earlier testing did not pinpoint Mikulicz ´s disease. By typical clinical presentation, elevated serum immunoglobulin G4 level and histopathological finding of lacrimal glands tissue we diagnosed Mikulicz´s disease successfully treated with corticosteroid therapy. Conclusion. We reported the first case of IgG4-related Mikulicz´s disease in Serbia. Our report highlights IgG4-related Mikulicz` s disease as an important differential diagnosis with Sjögren`s syndrome and lymphoproliferative disease in rheumatological practice.

  5. Discrimination of prostate cancer from normal peripheral zone and central gland tissue by using dynamic contrast-enhanced MR imaging

    NARCIS (Netherlands)

    Engelbrecht, Marc R.; Huisman, Henkjan J.; Laheij, Robert J. F.; Jager, Gerrit J.; van Leenders, Geert J. L. H.; Hulsbergen-van de Kaa, Christina A.; de La Rosette, Jean J. M. C. H.; Blickman, Johan G.; Barentsz, Jelle O.

    2003-01-01

    PURPOSE: To evaluate which parameters of dynamic magnetic resonance (MR) imaging and T2 relaxation rate would result in optimal discrimination of prostatic carcinoma from normal peripheral zone (PZ) and central gland (CG) tissues and to correlate these parameters with tumor stage, Gleason score,

  6. Engineering a concept: the creation of tissue engineering.

    Science.gov (United States)

    Williams, D

    1997-12-01

    Tissue engineering is a fashionable phrase and a new concept. This article analyses what is meant by this term and discusses some of the products that may emerge from the translation of this concept into clinical reality.

  7. Mechanostimulation Protocols for Cardiac Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Marco Govoni

    2013-01-01

    Full Text Available Owing to the inability of self-replacement by a damaged myocardium, alternative strategies to heart transplantation have been explored within the last decades and cardiac tissue engineering/regenerative medicine is among the present challenges in biomedical research. Hopefully, several studies witness the constant extension of the toolbox available to engineer a fully functional, contractile, and robust cardiac tissue using different combinations of cells, template bioscaffolds, and biophysical stimuli obtained by the use of specific bioreactors. Mechanical forces influence the growth and shape of every tissue in our body generating changes in intracellular biochemistry and gene expression. That is why bioreactors play a central role in the task of regenerating a complex tissue such as the myocardium. In the last fifteen years a large number of dynamic culture devices have been developed and many results have been collected. The aim of this brief review is to resume in a single streamlined paper the state of the art in this field.

  8. Generating an Engineered Adipose Tissue Flap Using an External Suspension Device.

    Science.gov (United States)

    Wan, Jinlin; Dong, Ziqing; Lei, Chen; Lu, Feng

    2016-07-01

    The tissue-engineering chamber technique can generate large volumes of adipose tissue, which provides a potential solution for the complex reconstruction of large soft-tissue defects. However, major drawbacks of this technique are the foreign-body reaction and the volume limitation imposed by the chamber. In this study, the authors developed a novel tissue-engineering method using a specially designed external suspension device that generates an optimized volume of adipose flap and avoids the implantation of foreign material. The rabbits were processed using two different tissue-engineering methods, the external suspension device technique and the traditional tissue-engineering chamber technique. The adipose flaps generated by the external suspension device had a normal adipose tissue structure that was as good as that generated by the traditional tissue-engineering chamber, but the flap volume was much larger. The final volume of the engineered adipose flap grew between weeks 0 and 36 from 5.1 ml to 30.7 ml in the traditional tissue-engineering chamber group and to 80.5 ml in the external suspension device group. During the generation process, there were no marked differences between the two methods in terms of structural and cellular changes of the flap, except that the flaps in the traditional tissue-engineering chamber group had a thicker capsule at the early stage. In addition, the enlarged flaps generated by the external suspension device could be reshaped into specific shapes by the implant chamber. This minimally invasive external suspension device technique can generate large-volume adipose flaps. Combined with a reshaping method, this technique should facilitate clinical application of adipose tissue engineering.

  9. In vivo outcomes of tissue-engineered osteochondral grafts.

    Science.gov (United States)

    Bal, B Sonny; Rahaman, Mohamed N; Jayabalan, Prakash; Kuroki, Keiichi; Cockrell, Mary K; Yao, Jian Q; Cook, James L

    2010-04-01

    Tissue-engineered osteochondral grafts have been synthesized from a variety of materials, with some success at repairing chondral defects in animal models. We hypothesized that in tissue-engineered osteochondral grafts synthesized by bonding mesenchymal stem cell-loaded hydrogels to a porous material, the choice of the porous scaffold would affect graft healing to host bone, and the quality of cell restoration at the hyaline cartilage surface. Bone marrow-derived allogeneic mesenchymal stem cells were suspended in hydrogels that were attached to cylinders of porous tantalum metal, allograft bone, or a bioactive glass. The tissue-engineered osteochondral grafts, thus created were implanted into experimental defects in rabbit knees. Subchondral bone restoration, defect fill, bone ingrowth-implant integration, and articular tissue quality were compared between the three subchondral materials at 6 and 12 weeks. Bioactive glass and porous tantalum were superior to bone allograft in integrating to adjacent host bone, regenerating hyaline-like tissue at the graft surface, and expressing type II collagen in the articular cartilage.

  10. Synthetic biodegradable functional polymers for tissue engineering: a brief review

    OpenAIRE

    BaoLin, GUO; MA, Peter X.

    2014-01-01

    Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly (glyce...

  11. Quantitative scintigraphy analysis of the normal lacrimal drainage using 99mTc radioisotope

    International Nuclear Information System (INIS)

    Bittar, Marcos Daniel Ramos.

    1994-01-01

    The dynamics of the lacrimal drainage system was studied in 37 normal patients including 16 males and 21 females by means of a radioisotope 99m Tc (technetium as pertechnetate in a normal saline solution), a gamma camera and a computer. After instillation of 10 μl normal saline solution containing 99m Tc in the conjunctival sac a scintigram was taken at the beginning and at the end of 10 minutes measuring time and images were recorded every 5 seconds. Two areas were studied: conjunctival and lacrimal sac. 39 refs., 17 figs., 1 tab

  12. Primary mucosa-associated lymphoid tissue (MALT) lymphoma of thyroid gland arising from coexisting Hashimoto's thyroiditis: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Kwon; Kwon, Sun Young; Kim, Young Hwan; Choi, Jin Soo; Sohn, Chul Ho; Lee, Hee Jung; Woo, Seong Ku; Suh, Soo Ji [Dongsan Medical Center, Keimyung University, Daegue (Korea, Republic of)

    2006-07-15

    We report herein on a case of primary mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid gland in a 57-year-old woman with coexisting Hashimoto's thyroiditis, and we include its characteristic imaging, histopathologic and immunohistochemical findings.

  13. Three-dimensional bioprinting in tissue engineering and regenerative medicine.

    Science.gov (United States)

    Gao, Guifang; Cui, Xiaofeng

    2016-02-01

    With the advances of stem cell research, development of intelligent biomaterials and three-dimensional biofabrication strategies, highly mimicked tissue or organs can be engineered. Among all the biofabrication approaches, bioprinting based on inkjet printing technology has the promises to deliver and create biomimicked tissue with high throughput, digital control, and the capacity of single cell manipulation. Therefore, this enabling technology has great potential in regenerative medicine and translational applications. The most current advances in organ and tissue bioprinting based on the thermal inkjet printing technology are described in this review, including vasculature, muscle, cartilage, and bone. In addition, the benign side effect of bioprinting to the printed mammalian cells can be utilized for gene or drug delivery, which can be achieved conveniently during precise cell placement for tissue construction. With layer-by-layer assembly, three-dimensional tissues with complex structures can be printed using converted medical images. Therefore, bioprinting based on thermal inkjet is so far the most optimal solution to engineer vascular system to the thick and complex tissues. Collectively, bioprinting has great potential and broad applications in tissue engineering and regenerative medicine. The future advances of bioprinting include the integration of different printing mechanisms to engineer biphasic or triphasic tissues with optimized scaffolds and further understanding of stem cell biology.

  14. Surface modification of polyester biomaterials for tissue engineering

    International Nuclear Information System (INIS)

    Jiao Yanpeng; Cui Fuzhai

    2007-01-01

    Surfaces play an important role in a biological system for most biological reactions occurring at surfaces and interfaces. The development of biomaterials for tissue engineering is to create perfect surfaces which can provoke specific cellular responses and direct new tissue regeneration. The improvement in biocompatibility of biomaterials for tissue engineering by directed surface modification is an important contribution to biomaterials development. Among many biomaterials used for tissue engineering, polyesters have been well documented for their excellent biodegradability, biocompatibility and nontoxicity. However, poor hydrophilicity and the lack of natural recognition sites on the surface of polyesters have greatly limited their further application in the tissue engineering field. Therefore, how to introduce functional groups or molecules to polyester surfaces, which ideally adjust cell/tissue biological functions, becomes more and more important. In this review, recent advances in polyester surface modification and their applications are reviewed. The development of new technologies or methods used to modify polyester surfaces for developing their biocompatibility is introduced. The results of polyester surface modifications by surface morphological modification, surface chemical group/charge modification, surface biomacromolecule modification and so on are reported in detail. Modified surface properties of polyesters directly related to in vitro/vivo biological performances are presented as well, such as protein adsorption, cell attachment and growth and tissue response. Lastly, the prospect of polyester surface modification is discussed, especially the current conception of biomimetic and molecular recognition. (topical review)

  15. Self-Organization and the Self-Assembling Process in Tissue Engineering

    Science.gov (United States)

    Eswaramoorthy, Rajalakshmanan; Hadidi, Pasha; Hu, Jerry C.

    2015-01-01

    In recent years, the tissue engineering paradigm has shifted to include a new and growing subfield of scaffoldless techniques which generate self-organizing and self-assembling tissues. This review aims to provide a cogent description of this relatively new research area, with special emphasis on applications toward clinical use and research models. Particular emphasis is placed on providing clear definitions of self-organization and the self-assembling process, as delineated from other scaffoldless techniques in tissue engineering and regenerative medicine. Significantly, during formation, self-organizing and self-assembling tissues display biological processes similar to those that occur in vivo. These help lead to the recapitulation of native tissue morphological structure and organization. Notably, functional properties of these tissues also approach native tissue values; some of these engineered tissues are already in clinical trials. This review aims to provide a cohesive summary of work in this field, and to highlight the potential of self-organization and the self-assembling process to provide cogent solutions to current intractable problems in tissue engineering. PMID:23701238

  16. Clinical research of the micro-invasive treatments for chronic dacryocystitis with the fifth generation lacrimal endoscope

    Directory of Open Access Journals (Sweden)

    Yong-Zhe Tang

    2015-06-01

    Full Text Available AIM: To investigate the methods, effect and security of the micro-invasive treatments for chronic dacryocystitis with the fifth generation lacrimal endoscope, and to evaluate its clinical application.METHODS:In this case-control study, 120 patients(120 eyeswith chronic dacryocystitis were collected from April 2013 to July 2014 in our department. The patients were randomly divided into observation group(the fifth generation endoscopic lacrimal microdrill with full intubation group, 62 cases 62 eyesand control group(external dacryocystorhinostomy group, 58 cases 58 eyes. The effective rate and complication were observed and compared between two groups after operation. Statistical package SPSS 13.0 was used for statistical analysis.RESULTS: The effective rate of observation group was 91.9%, and control group was 96.6%, there was no statistically significant difference between the two groups(P>0.05. Hemorrhage occurred in observation group and control group was 35.5% and 79.3%, respectively, additionally palpebral oedema was 19.4% and 55.2%, respectively, there were statistically significant differences between the two groups(PCONCLUSION: The fifth generation lacrimal endoscope is more flexible than traditional one-piece lacrimal endoscope during the operation, it can treat chronic dacryocystitis by directly observing nasolacrimal duct obstruction site and dredge the obstruction under microdrilling with full lacrimal intubation. It was not only good clinical curative effect, but also safer, more efficient than the external dacryocystorhinostomy, visualization and micro-invasive are its special advantage, and worthy for further clinical application.

  17. Morphometric study of the avian adrenal gland.

    Science.gov (United States)

    Aire, T A

    1980-01-01

    The interrenal and medullary cords as well as the blood vessels and connective tissue proportions in the adrenal glands of the male Nigerian fowl (Gallus domesticus) and guinea-fowl (Numida meleagris) were studied by microstereological techniques. Laying domestic fowl of the Rhode Island Red breed were entirely defeathered and maintained in a hot, humid pen for a period of three months, after which the adrenal glands were also studied microstereologically. Interrenal cord width was also measured in all the birds studied. The interrenal cords of the subscapular zone were consistently wider than those cords in the inner zone of the adrenal glands. This clearly suggested morphological zoning. The proportion of interrenal tissue was significantly greater in the guinea-fowl than in the Nigerian fowl, but the medullary tissue and the blood vessels and connective tissue were not significantly different. Interrenal hypoplasia or medullary hyperplasia occurred in the defeathered Rhode Island Red fowl as compared to the control birds of the same breed and sex. The significance of these findings is discussed. PMID:7440402

  18. Crossing kingdoms: Using decellularized plants as perfusable tissue engineering scaffolds.

    Science.gov (United States)

    Gershlak, Joshua R; Hernandez, Sarah; Fontana, Gianluca; Perreault, Luke R; Hansen, Katrina J; Larson, Sara A; Binder, Bernard Y K; Dolivo, David M; Yang, Tianhong; Dominko, Tanja; Rolle, Marsha W; Weathers, Pamela J; Medina-Bolivar, Fabricio; Cramer, Carole L; Murphy, William L; Gaudette, Glenn R

    2017-05-01

    Despite significant advances in the fabrication of bioengineered scaffolds for tissue engineering, delivery of nutrients in complex engineered human tissues remains a challenge. By taking advantage of the similarities in the vascular structure of plant and animal tissues, we developed decellularized plant tissue as a prevascularized scaffold for tissue engineering applications. Perfusion-based decellularization was modified for different plant species, providing different geometries of scaffolding. After decellularization, plant scaffolds remained patent and able to transport microparticles. Plant scaffolds were recellularized with human endothelial cells that colonized the inner surfaces of plant vasculature. Human mesenchymal stem cells and human pluripotent stem cell derived cardiomyocytes adhered to the outer surfaces of plant scaffolds. Cardiomyocytes demonstrated contractile function and calcium handling capabilities over the course of 21 days. These data demonstrate the potential of decellularized plants as scaffolds for tissue engineering, which could ultimately provide a cost-efficient, "green" technology for regenerating large volume vascularized tissue mass. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Ligament Tissue Engineering

    OpenAIRE

    Khan, Wasim Sardar

    2016-01-01

    Ligaments are commonly injured in the knee joint, and have a poor capacity for healing due to their relative avascularity. Ligament reconstruction is well established for injuries such as anterior cruciate ligament rupture, however the use of autografts and allografts for ligament reconstruction are associated with complications, and outcomes are variable. Ligament tissue engineering using stem cells, growth factors and scaffolds is a novel technique that has the potential to provide an unlim...

  20. Malignant salivary gland tumours

    International Nuclear Information System (INIS)

    Thompson, S.H.

    1982-01-01

    The most frequent malignant salivary gland tumours are the mucoepidermoid tumour, adenoid cystic carcinoma and adenocarcinoma. The major salivary glands and the minor glands of the mouth and upper respiratory tract may potentially develop any of these malignant lesions. Malignant lesions most frequently present as a palpable mass and tend to enlarge more rapidly than benign neoplasms. Pain, paresthesia, muscle paralysis and fixation to surrounding tissue are all ominous signs and symptoms. The only reliable means of differential diagnosis of these lesions is biopsy and histologic analysis. Therapy involves surgery or a combination of surgery and radiation therapy. The ultimate prognosis is governed by the intrinsic biologic behaviour of the neoplasms, the extent of disease and adequate clinical therapy

  1. Malignant salivary gland tumours

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, S.H. (University of the Witwatersrand, Johannesburg (South Africa). Dept. of Oral Pathology)

    1982-08-01

    The most frequent malignant salivary gland tumours are the mucoepidermoid tumour, adenoid cystic carcinoma and adenocarcinoma. The major salivary glands and the minor glands of the mouth and upper respiratory tract may potentially develop any of these malignant lesions. Malignant lesions most frequently present as a palpable mass and tend to enlarge more rapidly than benign neoplasms. Pain, paresthesia, muscle paralysis and fixation to surrounding tissue are all ominous signs and symptoms. The only reliable means of differential diagnosis of these lesions is biopsy and histologic analysis. Therapy involves surgery or a combination of surgery and radiation therapy. The ultimate prognosis is governed by the intrinsic biologic behaviour of the neoplasms, the extent of disease and adequate clinical therapy.

  2. Nano scaffolds and stem cell therapy in liver tissue engineering

    Science.gov (United States)

    Montaser, Laila M.; Fawzy, Sherin M.

    2015-08-01

    Tissue engineering and regenerative medicine have been constantly developing of late due to the major progress in cell and organ transplantation, as well as advances in materials science and engineering. Although stem cells hold great potential for the treatment of many injuries and degenerative diseases, several obstacles must be overcome before their therapeutic application can be realized. These include the development of advanced techniques to understand and control functions of micro environmental signals and novel methods to track and guide transplanted stem cells. A major complication encountered with stem cell therapies has been the failure of injected cells to engraft to target tissues. The application of nanotechnology to stem cell biology would be able to address those challenges. Combinations of stem cell therapy and nanotechnology in tissue engineering and regenerative medicine have achieved significant advances. These combinations allow nanotechnology to engineer scaffolds with various features to control stem cell fate decisions. Fabrication of Nano fiber cell scaffolds onto which stem cells can adhere and spread, forming a niche-like microenvironment which can guide stem cells to proceed to heal damaged tissues. In this paper, current and emergent approach based on stem cells in the field of liver tissue engineering is presented for specific application. The combination of stem cells and tissue engineering opens new perspectives in tissue regeneration for stem cell therapy because of the potential to control stem cell behavior with the physical and chemical characteristics of the engineered scaffold environment.

  3. Application of nuclear magnetic resonance (NMR) in study of thyroid gland

    International Nuclear Information System (INIS)

    Sinadinovic, J.; Ratkovic, S.; Kraincanic, M.

    1982-01-01

    A correlation was found between microstructural and biochemical changes of the thyroid gland and proton magnetic relaxation of tissue water. A significant increase of both relaxation times (T1, T2) was noted in thyroid tissue of rats treated with antithyroid drugs (PTU, C104) or TSH and was inversely correlated with thyroglobulin content in the gland and its morphological structure. When the treatment with PTU or C104 was interrupted, the relaxation times returned to normal values. These changes were in close correlation with the involution of structural changes in the thyroid gland and reaccumulation of follicular colloid (Tg). After T4, T3 or iodine treatment the relaxation times in the stimulated gland decreased following an increase of Tg content in the gland. It was observed that the relaxation times of the thyroid tissue of rats are in strong negative correlation with Tg concentration. Normal values for T1 in rat (530 msec) and guinea-pig (700 msec) thyroid glands are quite different. These species differences are related to the microstructural properties of thyroid glands, i.e. to the composition, structure, and degree of aggregation of follicular colloid (Tg). Finally, the NMR method could be applied in physiological and pathological examinations of the thyroid gland

  4. Proangiogenic scaffolds as functional templates for cardiac tissue engineering

    OpenAIRE

    Madden, Lauran R.; Mortisen, Derek J.; Sussman, Eric M.; Dupras, Sarah K.; Fugate, James A.; Cuy, Janet L.; Hauch, Kip D.; Laflamme, Michael A.; Murry, Charles E.; Ratner, Buddy D.

    2010-01-01

    We demonstrate here a cardiac tissue-engineering strategy addressing multicellular organization, integration into host myocardium, and directional cues to reconstruct the functional architecture of heart muscle. Microtemplating is used to shape poly(2-hydroxyethyl methacrylate-co-methacrylic acid) hydrogel into a tissue-engineering scaffold with architectures driving heart tissue integration. The construct contains parallel channels to organize cardiomyocyte bundles, supported by micrometer-s...

  5. Feasibility of tomotherapy for Graves' ophthalmopathy. Dosimetry comparison with conventional radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Nam P.; Krafft, Shane P. [Arizona Univ., Tucson, AZ (United States). Dept. of Radiation Oncology; Vos, Paul [East Carolina Univ., Greenville, NC (US). Dept. of Biostatistics] (and others)

    2011-09-15

    To compare the dosimetry of tomotherapy and the conventional half-beam technique (HBT) or non-split beam technique (NSBT) for target coverage and radiation dose to the lacrimal glands and lens. A retrospective review of 7 patients with Graves' ophthalmopathy who had radiotherapy because of disease progression on high steroid dose is reported: 3 patients were treated with tomotherapy and 4 patients with HBT. Compared to HBT, tomotherapy may provide better target coverage and significant reduction of radiation dose to the lacrimal glands and a higher dose to the lens. The NSBT improved target coverage but resulted in significantly higher doses to the lens and lacrimal glands. Tomotherapy may provide better coverage of the target volume and may be more effective in reducing severe exophthalmos compared to the conventional radiotherapy technique. (orig.)

  6. Biomimetic material strategies for cardiac tissue engineering

    International Nuclear Information System (INIS)

    Prabhakaran, Molamma P.; Venugopal, J.; Kai, Dan; Ramakrishna, Seeram

    2011-01-01

    Cardiovascular disease precedes many serious complications including myocardial infarction (MI) and it remains a major problem for the global community. Adult mammalian heart has limited ability to regenerate and compensate for the loss of cardiomyocytes. Restoration of cardiac function by replacement of diseased myocardium with functional cardiomyocytes is an intriguing strategy because it offers a potential cure for MI. Biomaterials are fabricated in nanometer scale dimensions by combining the chemical, biological, mechanical and electrical aspects of material for potential tissue engineering (TE) applications. Synthetic polymers offer advantageous in their ability to tailor the mechanical properties, and natural polymers offer cell recognition sites necessary for cell, adhesion and proliferation. Cardiac tissue engineering (TE) aim for the development of a bioengineered construct that can provide physical support to the damaged cardiac tissue by replacing certain functions of the damaged extracellular matrix and prevent adverse cardiac remodeling and dysfunction after MI. Electrospun nanofibers are applied as heart muscle patches, while hydrogels serve as a platform for controlled delivery of growth factors, prevent mechanical complications and assist in cell recruitment. This article reviews the applications of different natural and synthetic polymeric materials utilized as cardiac patches, injectables or 3D constructs for cardiac TE. Smart organization of nanoscale assemblies with synergistic approaches of utilizing nanofibers and hydrogels could further advance the field of cardiac tissue engineering. Rapid innovations in biomedical engineering and cell biology will bring about new insights in the development of optimal scaffolds and methods to create tissue constructs with relevant contractile properties and electrical integration to replace or substitute the diseased myocardium.

  7. Biomimetic material strategies for cardiac tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Molamma P., E-mail: nnimpp@nus.edu.sg [Health Care and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Venugopal, J. [Health Care and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Kai, Dan [NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (Singapore); Ramakrishna, Seeram [Health Care and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore)

    2011-04-08

    Cardiovascular disease precedes many serious complications including myocardial infarction (MI) and it remains a major problem for the global community. Adult mammalian heart has limited ability to regenerate and compensate for the loss of cardiomyocytes. Restoration of cardiac function by replacement of diseased myocardium with functional cardiomyocytes is an intriguing strategy because it offers a potential cure for MI. Biomaterials are fabricated in nanometer scale dimensions by combining the chemical, biological, mechanical and electrical aspects of material for potential tissue engineering (TE) applications. Synthetic polymers offer advantageous in their ability to tailor the mechanical properties, and natural polymers offer cell recognition sites necessary for cell, adhesion and proliferation. Cardiac tissue engineering (TE) aim for the development of a bioengineered construct that can provide physical support to the damaged cardiac tissue by replacing certain functions of the damaged extracellular matrix and prevent adverse cardiac remodeling and dysfunction after MI. Electrospun nanofibers are applied as heart muscle patches, while hydrogels serve as a platform for controlled delivery of growth factors, prevent mechanical complications and assist in cell recruitment. This article reviews the applications of different natural and synthetic polymeric materials utilized as cardiac patches, injectables or 3D constructs for cardiac TE. Smart organization of nanoscale assemblies with synergistic approaches of utilizing nanofibers and hydrogels could further advance the field of cardiac tissue engineering. Rapid innovations in biomedical engineering and cell biology will bring about new insights in the development of optimal scaffolds and methods to create tissue constructs with relevant contractile properties and electrical integration to replace or substitute the diseased myocardium.

  8. Functional integrity of lacrimal drainage apparatus by radionuclide dacryocystography

    International Nuclear Information System (INIS)

    Kadambi, Vivek; Victor Williams, B.

    1989-01-01

    30 patients with epiphora and related complaints were investigated by radionuclide dacrocystography. It was possible to do this procedure easily in all age groups. The site of block in the lacrimal system could be accurately determined by this non-invasive technique. (author). 7 refs., 4 figs., 3 tabs

  9. Profiling of adrenocorticotropic hormone and arginine vasopressin in human pituitary gland and tumor thin tissue sections using droplet-based liquid-microjunction surface-sampling-HPLC-ESI-MS-MS.

    Science.gov (United States)

    Kertesz, Vilmos; Calligaris, David; Feldman, Daniel R; Changelian, Armen; Laws, Edward R; Santagata, Sandro; Agar, Nathalie Y R; Van Berkel, Gary J

    2015-08-01

    Described here are the results from the profiling of the proteins arginine vasopressin (AVP) and adrenocorticotropic hormone (ACTH) from normal human pituitary gland and pituitary adenoma tissue sections, using a fully automated droplet-based liquid-microjunction surface-sampling-HPLC-ESI-MS-MS system for spatially resolved sampling, HPLC separation, and mass spectrometric detection. Excellent correlation was found between the protein distribution data obtained with this method and data obtained with matrix-assisted laser desorption/ionization (MALDI) chemical imaging analyses of serial sections of the same tissue. The protein distributions correlated with the visible anatomic pattern of the pituitary gland. AVP was most abundant in the posterior pituitary gland region (neurohypophysis), and ATCH was dominant in the anterior pituitary gland region (adenohypophysis). The relative amounts of AVP and ACTH sampled from a series of ACTH-secreting and non-secreting pituitary adenomas correlated with histopathological evaluation. ACTH was readily detected at significantly higher levels in regions of ACTH-secreting adenomas and in normal anterior adenohypophysis compared with non-secreting adenoma and neurohypophysis. AVP was mostly detected in normal neurohypophysis, as expected. This work reveals that a fully automated droplet-based liquid-microjunction surface-sampling system coupled to HPLC-ESI-MS-MS can be readily used for spatially resolved sampling, separation, detection, and semi-quantitation of physiologically-relevant peptide and protein hormones, including AVP and ACTH, directly from human tissue. In addition, the relative simplicity, rapidity, and specificity of this method support the potential of this basic technology, with further advancement, for assisting surgical decision-making. Graphical Abstract Mass spectrometry based profiling of hormones in human pituitary gland and tumor thin tissue sections.

  10. The essence of biophysical cues in skeletal muscle tissue engineering

    NARCIS (Netherlands)

    Langelaan, M.L.P.

    2010-01-01

    Skeletal muscle is an appealing topic for tissue engineering because of its variety in applications. Evidently, tissue engineered skeletal muscle can be used in the field of regenerative medicine to repair muscular defects or dystrophies. Engineered skeletal muscle constructs can also be used as a

  11. Introduction to tissue engineering applications and challenges

    CERN Document Server

    Birla, Ravi

    2014-01-01

    Covering a progressive medical field, Tissue Engineering describes the innovative process of regenerating human cells to restore or establish normal function in defective organs. As pioneering individuals look ahead to the possibility of generating entire organ systems, students may turn to this textbook for a comprehensive understanding and preparation for the future of regenerative medicine. This book explains chemical stimulations, the bioengineering of specific organs, and treatment plans for chronic diseases. It is a must-read for tissue engineering students and practitioners.

  12. Suppurative dacroadenitis causing ocular sicca syndrome in classic Wegener′s granulomatosis

    Directory of Open Access Journals (Sweden)

    Khanna Dhanita

    2011-01-01

    Full Text Available Wegener′s granulomatosis (WG is a multisystem vasculitic disorder which can commonly afflict various components of the eye. Here we describe some unusual ocular manifestations of the disease in one patient. A young male with history of upper respiratory tract symptoms including epistaxis, nasal stuffiness and maxillary sinus pain presented with bilateral lacrimal gland abscess and ptosis. Lacrimal gland biopsy revealed granulomatous vasculitis. Lung cavities, positive cytoplasmic-antineutrophil cytoplasmic antibodies and high titers of serine proteinase-3 antibodies confirmed the diagnosis of WG. The patient developed dry eyes after a month of first presentation. There was no dryness of mouth, suggesting the absence of salivary gland involvement, and antinuclear antibodies as well as antibodies against Ro and La antigens classical of primary Sjogren′s syndrome were absent. Granulomatous vasculitis of lacrimal gland leading to abscess formation and dryness of eyes has not been described in WG and reflects the aggressive nature of inflammatory process in this disease.

  13. Engineering Cardiac Muscle Tissue: A Maturating Field of Research.

    Science.gov (United States)

    Weinberger, Florian; Mannhardt, Ingra; Eschenhagen, Thomas

    2017-04-28

    Twenty years after the initial description of a tissue engineered construct, 3-dimensional human cardiac tissues of different kinds are now generated routinely in many laboratories. Advances in stem cell biology and engineering allow for the generation of constructs that come close to recapitulating the complex structure of heart muscle and might, therefore, be amenable to industrial (eg, drug screening) and clinical (eg, cardiac repair) applications. Whether the more physiological structure of 3-dimensional constructs provides a relevant advantage over standard 2-dimensional cell culture has yet to be shown in head-to-head-comparisons. The present article gives an overview on current strategies of cardiac tissue engineering with a focus on different hydrogel methods and discusses perspectives and challenges for necessary steps toward the real-life application of cardiac tissue engineering for disease modeling, drug development, and cardiac repair. © 2017 American Heart Association, Inc.

  14. Current Concepts in Scaffolding for Bone Tissue Engineering.

    Science.gov (United States)

    Ghassemi, Toktam; Shahroodi, Azadeh; Ebrahimzadeh, Mohammad H; Mousavian, Alireza; Movaffagh, Jebraeel; Moradi, Ali

    2018-03-01

    Bone disorders are of significant worry due to their increased prevalence in the median age. Scaffold-based bone tissue engineering holds great promise for the future of osseous defects therapies. Porous composite materials and functional coatings for metallic implants have been introduced in next generation of orthopedic medicine for tissue engineering. While osteoconductive materials such as hydroxyapatite and tricalcium phosphate ceramics as well as some biodegradable polymers are suggested, much interest has recently focused on the use of osteoinductive materials like demineralized bone matrix or bone derivatives. However, physiochemical modifications in terms of porosity, mechanical strength, cell adhesion, biocompatibility, cell proliferation, mineralization and osteogenic differentiation are required. This paper reviews studies on bone tissue engineering from the biomaterial point of view in scaffolding. Level of evidence: I.

  15. Adrenergic effects on secretion of epidermal growth factor from Brunner's glands

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1985-01-01

    The influence of the sympathetic nervous system and adrenergic agonists on flow rate and secretion of epidermal growth factor (EGF) from Brunner's glands has been investigated in the rat. Chemical sympathectomy by administration of 6-hydroxydopamine increased volume secretion and output of EGF from...... Brunner's glands but depleted the glands of EGF. Infusion of noradrenaline, an alpha-adrenergic agonist, inhibited basal and vasoactive intestinal polypeptide (VIP) stimulated flow rate and output of EGF from Brunner's glands and increased the amount of EGF in the tissue. Vasoactive intestinal polypeptide...... also increased the amount of EGF in Brunner's gland tissue and this was unchanged after simultaneous infusion of VIP and noradrenaline as well as VIP and isoproterenol, a beta-adrenergic agonist. Isoproterenol had no effect on basal and VIP stimulated secretion of EGF from Brunner's glands...

  16. Bovine natural killer cells are present in Escherichia coli infected mammary gland tissue and show antimicrobial activity in vitro

    NARCIS (Netherlands)

    Sipka, Anja; Pomeroy, Brianna; Klaessig, Suzanne; Schukken, Ynte

    2016-01-01

    Natural killer (NK) cells are early responders in bacterial infections but their role in bovine mastitis has not been characterized. For the first time, we show the presence of NK cells (NKp46+/CD3) in bovine mammary gland tissue after an intramammary challenge with

  17. Bovine natural killer cells are present in Escherichia coli infected mammary gland tissue and show antimicrobial activity in vitro

    NARCIS (Netherlands)

    Sipka, Anja; Pomeroy, Brianna; Klaessig, Suzanne; Schukken, Ynte

    2016-01-01

    Natural killer (NK) cells are early responders in bacterial infections but their role in bovine mastitis has not been characterized. For the first time, we show the presence of NK cells (NKp46+/CD3−) in bovine mammary gland tissue after an intramammary challenge with Escherichia (E.) coli. A small

  18. Complete Unique Genome Sequence, Expression Profile, and Salivary Gland Tissue Tropism of the Herpesvirus 7 Homolog in Pigtailed Macaques.

    Science.gov (United States)

    Staheli, Jeannette P; Dyen, Michael R; Deutsch, Gail H; Basom, Ryan S; Fitzgibbon, Matthew P; Lewis, Patrick; Barcy, Serge

    2016-08-01

    Human herpesvirus 6A (HHV-6A), HHV-6B, and HHV-7 are classified as roseoloviruses and are highly prevalent in the human population. Roseolovirus reactivation in an immunocompromised host can cause severe pathologies. While the pathogenic potential of HHV-7 is unclear, it can reactivate HHV-6 from latency and thus contributes to severe pathological conditions associated with HHV-6. Because of the ubiquitous nature of roseoloviruses, their roles in such interactions and the resulting pathological consequences have been difficult to study. Furthermore, the lack of a relevant animal model for HHV-7 infection has hindered a better understanding of its contribution to roseolovirus-associated diseases. Using next-generation sequencing analysis, we characterized the unique genome of an uncultured novel pigtailed macaque roseolovirus. Detailed genomic analysis revealed the presence of gene homologs to all 84 known HHV-7 open reading frames. Phylogenetic analysis confirmed that the virus is a macaque homolog of HHV-7, which we have provisionally named Macaca nemestrina herpesvirus 7 (MneHV7). Using high-throughput RNA sequencing, we observed that the salivary gland tissue samples from nine different macaques had distinct MneHV7 gene expression patterns and that the overall number of viral transcripts correlated with viral loads in parotid gland tissue and saliva. Immunohistochemistry staining confirmed that, like HHV-7, MneHV7 exhibits a natural tropism for salivary gland ductal cells. We also observed staining for MneHV7 in peripheral nerve ganglia present in salivary gland tissues, suggesting that HHV-7 may also have a tropism for the peripheral nervous system. Our data demonstrate that MneHV7-infected macaques represent a relevant animal model that may help clarify the causality between roseolovirus reactivation and diseases. Human herpesvirus 6A (HHV-6A), HHV-6B, and HHV-7 are classified as roseoloviruses. We have recently discovered that pigtailed macaques are naturally

  19. Advances in polymeric systems for tissue engineering and biomedical applications.

    Science.gov (United States)

    Ravichandran, Rajeswari; Sundarrajan, Subramanian; Venugopal, Jayarama Reddy; Mukherjee, Shayanti; Ramakrishna, Seeram

    2012-03-01

    The characteristics of tissue engineered scaffolds are major concerns in the quest to fabricate ideal scaffolds for tissue engineering applications. The polymer scaffolds employed for tissue engineering applications should possess multifunctional properties such as biocompatibility, biodegradability and favorable mechanical properties as it comes in direct contact with the body fluids in vivo. Additionally, the polymer system should also possess biomimetic architecture and should support stem cell adhesion, proliferation and differentiation. As the progress in polymer technology continues, polymeric biomaterials have taken characteristics more closely related to that desired for tissue engineering and clinical needs. Stimuli responsive polymers also termed as smart biomaterials respond to stimuli such as pH, temperature, enzyme, antigen, glucose and electrical stimuli that are inherently present in living systems. This review highlights the exciting advancements in these polymeric systems that relate to biological and tissue engineering applications. Additionally, several aspects of technology namely scaffold fabrication methods and surface modifications to confer biological functionality to the polymers have also been discussed. The ultimate objective is to emphasize on these underutilized adaptive behaviors of the polymers so that novel applications and new generations of smart polymeric materials can be realized for biomedical and tissue engineering applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Squamous cell carcinoma of the lacrimal caruncle : case reports

    NARCIS (Netherlands)

    van de Put, Mathijs A. J.; Haeseker, Barbara I.; De Wolff-Rouendaal, Did; De Keizer, Robert J. W.

    2014-01-01

    Purpose: To report 2 cases of squamous cell carcinoma of the lacrimal caruncle. Methods: Two patients, a 38-year-old man and a 72-year-old woman, presented with a painful mass in the medial angle of the eyelid aperture, with signs of inflammation. Biopsy was performed in both cases. Results:

  1. Do cell based tissue engineering products for meniscus regeneration influence vascularization?

    Science.gov (United States)

    Koch, Matthias; Ehrenreich, Tobias; Koehl, Gudrun; Pattappa, Girish; Pfeifer, Christian; Loibl, Markus; Müller, Michael; Nerlich, Michael; Angele, Peter; Zellner, Johannes

    2017-01-01

    Meniscus regeneration is observed within the peripheral, vascularized zone but decreases in the inner two thirds alongside the vascularization. Within this avascular area, cell-based tissue-engineering-approaches appear to be a promising strategy for the treatment of meniscal defects. Evaluation of the angiogenic potential of cell-based tissue-engineering-products for meniscus healing. Evaluation of angiogenesis induced by rabbit meniscus-pellets, meniscus-cells (MC) or mesenchymal stem-cells (MSC) in cell-based tissue-engineering-products within a rabbit meniscus-ring was performed using a transparent dorsal skin fold chamber in nude mice. Observations were undertaken during a 14 days period. Cell preconditioning differed between experimental groups. Immunohistochemical analysis of the regenerated tissue in the meniscus-ring induced by cell loaded composite scaffolds for differentiation and anti-angiogenic factors were performed. Meniscus-pellets and MSC-/MC-based tissue-engineering-products induced angiogenesis. An accelerated vascularization was detected in the group of meniscus-pellets derived from the vascularized zone compared to avascular meniscus-pellets. In terms of cell-based tissue-engineering-products, chondrogenic preconditioning resulted in significantly increased vessel growth. MSC-constructs showed an accelerated angiogenesis. Immunohistochemical evaluation showed a progressive differentiation and lower content for anti-angiogenic endostatin in the precultured group. Preconditioning of MC-/MSC-based tissue-engineering-products is a promising tool to influence the angiogenic potential of tissue-engineering-products and to adapt these properties according to the aimed tissue qualities.

  2. Alveolar bone tissue engineering using composite scaffolds for drug delivery

    Directory of Open Access Journals (Sweden)

    Tomonori Matsuno

    2010-08-01

    Full Text Available For many years, bone graft substitutes have been used to reconstruct bone defects in orthopedic and dental fields. However, synthetic bone substitutes such as hydroxyapatite or β-tricalcium phosphate have no osteoinductive or osteogenic abilities. Bone tissue engineering has also been promoted as an alternative approach to regenerating bone tissue. To succeed in bone tissue engineering, osteoconductive scaffolding biomaterials should provide a suitable environment for osteogenic cells and provide local controlled release of osteogenic growth factors. In addition, the scaffold for the bone graft substitute should biodegrade to replace the newly formed bone. Recent advances in bone tissue engineering have allowed the creation of composite scaffolds with tailored functional properties. This review focuses on composite scaffolds that consist of synthetic ceramics and natural polymers as drug delivery carriers for alveolar bone tissue engineering.

  3. A Review of Three-Dimensional Printing in Tissue Engineering.

    Science.gov (United States)

    Sears, Nick A; Seshadri, Dhruv R; Dhavalikar, Prachi S; Cosgriff-Hernandez, Elizabeth

    2016-08-01

    Recent advances in three-dimensional (3D) printing technologies have led to a rapid expansion of applications from the creation of anatomical training models for complex surgical procedures to the printing of tissue engineering constructs. In addition to achieving the macroscale geometry of organs and tissues, a print layer thickness as small as 20 μm allows for reproduction of the microarchitectures of bone and other tissues. Techniques with even higher precision are currently being investigated to enable reproduction of smaller tissue features such as hepatic lobules. Current research in tissue engineering focuses on the development of compatible methods (printers) and materials (bioinks) that are capable of producing biomimetic scaffolds. In this review, an overview of current 3D printing techniques used in tissue engineering is provided with an emphasis on the printing mechanism and the resultant scaffold characteristics. Current practical challenges and technical limitations are emphasized and future trends of bioprinting are discussed.

  4. A new approach to heart valve tissue engineering

    DEFF Research Database (Denmark)

    Kaasi, Andreas; Cestari, Idágene A.; Stolf, Noedir A G.

    2011-01-01

    The 'biomimetic' approach to tissue engineering usually involves the use of a bioreactor mimicking physiological parameters whilst supplying nutrients to the developing tissue. Here we present a new heart valve bioreactor, having as its centrepiece a ventricular assist device (VAD), which exposes...... chamber. Subsequently, applied vacuum to the pneumatic chamber causes the blood chamber to fill. A mechanical heart valve was placed in the VAD's inflow position. The tissue engineered (TE) valve was placed in the outflow position. The VAD was coupled in series with a Windkessel compliance chamber...

  5. Emerging Biofabrication Strategies for Engineering Complex Tissue Constructs

    DEFF Research Database (Denmark)

    Pedde, R. Daniel; Mirani, Bahram; Navaei, Ali

    2017-01-01

    , outlines the use of common biomaterials and advanced hybrid scaffolds, and describes several design considerations including the structural, physical, biological, and economical parameters that are crucial for the fabrication of functional, complex, engineered tissues. Finally, the applications...... of these biofabrication strategies in neural, skin, connective, and muscle tissue engineering are explored.......The demand for organ transplantation and repair, coupled with a shortage of available donors, poses an urgent clinical need for the development of innovative treatment strategies for long-term repair and regeneration of injured or diseased tissues and organs. Bioengineering organs, by growing...

  6. Design considerations and challenges for mechanical stretch bioreactors in tissue engineering.

    Science.gov (United States)

    Lei, Ying; Ferdous, Zannatul

    2016-05-01

    With the increase in average life expectancy and growing aging population, lack of functional grafts for replacement surgeries has become a severe problem. Engineered tissues are a promising alternative to this problem because they can mimic the physiological function of the native tissues and be cultured on demand. Cyclic stretch is important for developing many engineered tissues such as hearts, heart valves, muscles, and bones. Thus a variety of stretch bioreactors and corresponding scaffolds have been designed and tested to study the underlying mechanism of tissue formation and to optimize the mechanical conditions applied to the engineered tissues. In this review, we look at various designs of stretch bioreactors and common scaffolds and offer insights for future improvements in tissue engineering applications. First, we summarize the requirements and common configuration of stretch bioreactors. Next, we present the features of different actuating and motion transforming systems and their applications. Since most bioreactors must measure detailed distributions of loads and deformations on engineered tissues, techniques with high accuracy, precision, and frequency have been developed. We also cover the key points in designing culture chambers, nutrition exchanging systems, and regimens used for specific tissues. Since scaffolds are essential for providing biophysical microenvironments for residing cells, we discuss materials and technologies used in fabricating scaffolds to mimic anisotropic native tissues, including decellularized tissues, hydrogels, biocompatible polymers, electrospinning, and 3D bioprinting techniques. Finally, we present the potential future directions for improving stretch bioreactors and scaffolds. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:543-553, 2016. © 2016 American Institute of Chemical Engineers.

  7. Human adipose-derived stem cells: definition, isolation, tissue-engineering applications.

    Science.gov (United States)

    Nae, S; Bordeianu, I; Stăncioiu, A T; Antohi, N

    2013-01-01

    Recent researches have demonstrated that the most effective repair system of the body is represented by stem cells - unspecialized cells, capable of self-renewal through successive mitoses, which have also the ability to transform into different cell types through differentiation. The discovery of adult stem cells represented an important step in regenerative medicine because they no longer raises ethical or legal issues and are more accessible. Only in 2002, stem cells isolated from adipose tissue were described as multipotent stem cells. Adipose tissue stem cells benefits in tissue engineering and regenerative medicine are numerous. Development of adipose tissue engineering techniques offers a great potential in surpassing the existing limits faced by the classical approaches used in plastic and reconstructive surgery. Adipose tissue engineering clinical applications are wide and varied, including reconstructive, corrective and cosmetic procedures. Nowadays, adipose tissue engineering is a fast developing field, both in terms of fundamental researches and medical applications, addressing issues related to current clinical pathology or trauma management of soft tissue injuries in different body locations.

  8. Histomorphological study of the parathyroid gland in female Kuttanad ducks (Anas platyrhynchos domesticus

    Directory of Open Access Journals (Sweden)

    Firdous Ahmad Dar

    2013-11-01

    Full Text Available Aim: The present work was targeted to form the baseline data of normal morphological and histological picture of parathyroid gland in female Kuttanad ducks.Materials and Methods: A Histomorphological study of the parathyroid gland was carried out in twelve adult female Kuttanad ducks (Anas platyrhynchos domesticus of 20 weeks of age. Birds reared semintensively were procured from Kerala Veterinary and Animal Sciences University Poultry and Duck Farm and sacrificed humanely. Glands were collected and gross parameters were recorded. The glands were fixed in 10 percent neutral buffered formalin. The small sized glands were processed as such by routine histological methods, paraffin blocks were prepared and sectioned to a thickness of 5µ. The tissues were stained by Haematoxylin and Eosin (H&E for routine histological studies and Gomori's rapid one step trichrome method for connective tissue fibres. Micrometric parameters were recorded using ocular micrometer. Results: Parathyroid glands in Kuttanad ducks lay just caudal to the division of the innominate artery into the subclavian and common carotid arteries. Parathyroids were oval to spherical in shape, yellow in colour and smaller than thyroid gland of the representative sides. The arterial blood supply was from common carotid artery and blood from gland was drained directly into jugular vein. Although it lied close to the thyroid, thymus and ultimobranchial gland, parathyroid tissue did not merge to any of the above mentioned three glands. Parenchyma was composed irregular anatomizing cords of cells supplied by connective tissue stroma penetrated by blood capillaries. Parenchyma was predominantly made of lightly stained cell, the chief cell. The nuclei were round and contain one or two nucleoli. Oxyphil cells present in parathyroid glands of other mammals were not seen in the present study. Conclusion: Histomorphological features or characteristics of Parathyroid gland in Kuttanad duck were

  9. Physical non-viral gene delivery methods for tissue engineering.

    Science.gov (United States)

    Mellott, Adam J; Forrest, M Laird; Detamore, Michael S

    2013-03-01

    The integration of gene therapy into tissue engineering to control differentiation and direct tissue formation is not a new concept; however, successful delivery of nucleic acids into primary cells, progenitor cells, and stem cells has proven exceptionally challenging. Viral vectors are generally highly effective at delivering nucleic acids to a variety of cell populations, both dividing and non-dividing, yet these viral vectors are marred by significant safety concerns. Non-viral vectors are preferred for gene therapy, despite lower transfection efficiencies, and possess many customizable attributes that are desirable for tissue engineering applications. However, there is no single non-viral gene delivery strategy that "fits-all" cell types and tissues. Thus, there is a compelling opportunity to examine different non-viral vectors, especially physical vectors, and compare their relative degrees of success. This review examines the advantages and disadvantages of physical non-viral methods (i.e., microinjection, ballistic gene delivery, electroporation, sonoporation, laser irradiation, magnetofection, and electric field-induced molecular vibration), with particular attention given to electroporation because of its versatility, with further special emphasis on Nucleofection™. In addition, attributes of cellular character that can be used to improve differentiation strategies are examined for tissue engineering applications. Ultimately, electroporation exhibits a high transfection efficiency in many cell types, which is highly desirable for tissue engineering applications, but electroporation and other physical non-viral gene delivery methods are still limited by poor cell viability. Overcoming the challenge of poor cell viability in highly efficient physical non-viral techniques is the key to using gene delivery to enhance tissue engineering applications.

  10. Physical non-viral gene delivery methods for tissue engineering

    Science.gov (United States)

    Mellott, Adam J.; Forrest, M. Laird; Detamore, Michael S.

    2016-01-01

    The integration of gene therapy into tissue engineering to control differentiation and direct tissue formation is not a new concept; however, successful delivery of nucleic acids into primary cells, progenitor cells, and stem cells has proven exceptionally challenging. Viral vectors are generally highly effective at delivering nucleic acids to a variety of cell populations, both dividing and non-dividing, yet these viral vectors are marred by significant safety concerns. Non-viral vectors are preferred for gene therapy, despite lower transfection efficiencies, and possess many customizable attributes that are desirable for tissue engineering applications. However, there is no single non-viral gene delivery strategy that “fits-all” cell types and tissues. Thus, there is a compelling opportunity to examine different non-viral vectors, especially physical vectors, and compare their relative degrees of success. This review examines the advantages and disadvantages of physical non-viral methods (i.e., microinjection, ballistic gene delivery, electroporation, sonoporation, laser irradiation, magnetofection, and electric field-induced molecular vibration), with particular attention given to electroporation because of its versatility, with further special emphasis on Nucleofection™. In addition, attributes of cellular character that can be used to improve differentiation strategies are examined for tissue engineering applications. Ultimately, electroporation exhibits a high transfection efficiency in many cell types, which is highly desirable for tissue engineering applications, but electroporation and other physical non-viral gene delivery methods are still limited by poor cell viability. Overcoming the challenge of poor cell viability in highly efficient physical non-viral techniques is the key to using gene delivery to enhance tissue engineering applications. PMID:23099792

  11. Effects of split-dose irradiation of the rabbit's eye - a histopathological study

    International Nuclear Information System (INIS)

    Grabenbauer, G.G.

    1987-01-01

    Thirty-six rabbits were included in a study investigating into the effects of split-dose 300 KV X-irradiation on the cornea, ciliary body, nictitating membrane and lacrimal gland. In each animal, soly the right the eye was irradiated using total doses of 21 Gy, 30 Gy, 36 Gy and 45 Gy that were administered according to a fixed schedule in fractions of 3 Gy five times per week. After latency periods of six weeks, three months and six months the animals receiving 21 Gy, 30 Gy and 36 Gy showed no changes of the bulbi, eye lids and lacrimal glands that could be ascertained by histopathological evaluation. In the animals exposed to the 45 Gy dose, changes of the cornea and conjunctiva caused by radiation injuries to the lacrimal glands and conjunctival goblet cells started to appear after a minimum period of 3 months. This dose level was also the threshold for the occurrence of corneal damage or even ulceration as a result of secondary reduction or qualitative change of lacrimal secretions. (ECB) [de

  12. Childhood Salivary Gland Tumors Treatment (PDQ®)—Patient Version

    Science.gov (United States)

    Most salivary gland tumors in children are benign (not cancer) and do not spread to other tissues, but some are malignant (cancer). The prognosis for salivary gland cancer in children is usually good. Get information about of the risk factors, symptoms, tests to diagnose, and treatment of salivary gland tumors in this expert-reviewed summary.

  13. Double emulsion electrospun nanofibers as a growth factor delivery vehicle for salivary gland regeneration

    Science.gov (United States)

    Foraida, Zahraa I.; Sharikova, Anna; Peerzada, Lubna N.; Khmaladze, Alexander; Larsen, Melinda; Castracane, James

    2017-08-01

    Sustained delivery of growth factors, proteins, drugs and other biologically active molecules is necessary for tissue engineering applications. Electrospun fibers are attractive tissue engineering scaffolds as they partially mimic the topography of the extracellular matrix (ECM). However, they do not provide continuous nourishment to the tissue. In search of a biomimetic scaffold for salivary gland tissue regeneration, we previously developed a blend nanofiber scaffold composed of the protein elastin and the synthetic polymer polylactic-co-glycolic acid (PLGA). The nanofiber scaffold promoted in vivo-like salivary epithelial cell tissue organization and apicobasal polarization. However, in order to enhance the salivary cell proliferation and biomimetic character of the scaffold, sustained growth factor delivery is needed. The composite nanofiber scaffold was optimized to act as a growth factor delivery system using epidermal growth factor (EGF) as a model protein. The nanofiber/EGF hybrid nanofibers were synthesized by double emulsion electrospinning where EGF is emulsified within a water/oil/water (w/o/w) double emulsion system. Successful incorporation of EGF was confirmed using Raman spectroscopy. EGF release profile was characterized using enzyme-linked immunosorbent assay (ELIZA) of the EGF content. Double emulsion electrospinning resulted in slower release of EGF. We demonstrated the potential of the proposed double emulsion electrospun nanofiber scaffold for the delivery of growth factors and/or drugs for tissue engineering and pharmaceutical applications.

  14. Tissue Engineering of Blood Vessels: Functional Requirements, Progress, and Future Challenges.

    Science.gov (United States)

    Kumar, Vivek A; Brewster, Luke P; Caves, Jeffrey M; Chaikof, Elliot L

    2011-09-01

    Vascular disease results in the decreased utility and decreased availability of autologus vascular tissue for small diameter (requires combined approaches from biomaterials science, cell biology, and translational medicine to develop feasible solutions with the requisite mechanical support, a non-fouling surface for blood flow, and tissue regeneration. Over the past two decades interest in blood vessel tissue engineering has soared on a global scale, resulting in the first clinical implants of multiple technologies, steady progress with several other systems, and critical lessons-learned. This review will highlight the current inadequacies of autologus and synthetic grafts, the engineering requirements for implantation of tissue-engineered grafts, and the current status of tissue-engineered blood vessel research.

  15. Neuropeptidome of the Hypothalamus and Pituitary Gland of Indicine × Taurine Heifers: Evidence of Differential Neuropeptide Processing in the Pituitary Gland before and after Puberty.

    Science.gov (United States)

    DeAtley, Kasey L; Colgrave, Michelle L; Cánovas, Angela; Wijffels, Gene; Ashley, Ryan L; Silver, Gail A; Rincon, Gonzalo; Medrano, Juan F; Islas-Trejo, Alma; Fortes, Marina R S; Reverter, Antonio; Porto-Neto, Laercio; Lehnert, Sigrid A; Thomas, Milton G

    2018-05-04

    Puberty in cattle is regulated by an endocrine axis, which includes a complex milieu of neuropeptides in the hypothalamus and pituitary gland. The neuropeptidome of hypothalamic-pituitary gland tissue of pre- (PRE) and postpubertal (POST) Bos indicus-influenced heifers was characterized, followed by quantitative analysis of 51 fertility-related neuropeptides in these tissues. Comparison of peptide abundances with gene expression levels allowed assessment of post-transcriptional peptide processing. On the basis of classical cleavage, 124 mature neuropeptides from 35 precursor proteins were detected in hypothalamus and pituitary gland tissues of three PRE and three POST Brangus heifers. An additional 19 peptides (cerebellins, PEN peptides) previously reported as neuropeptides that did not follow classical cleavage were also identified. In the pre-pubertal hypothalamus, a greater diversity of neuropeptides (25.8%) was identified relative to post-pubertal heifers, while in the pituitary gland, 38.6% more neuropeptides were detected in the post-pubertal heifers. Neuro-tissues of PRE and POST heifers revealed abundance differences ( p pituitary before and after puberty.

  16. Vascularization of soft tissue engineering constructs

    DEFF Research Database (Denmark)

    Pimentel Carletto, Rodrigo

    with mechanical properties in the range of soft tissues has not been fully achieved. My project focused on the fabrication and the active perfusion of hydrogel constructs with multi-dimensional vasculature and controlled mechanical properties targeting soft tissues. Specifically, the initial part of the research...... nanotechnology-based paradigm for engineering vascularised liver tissue for transplantation”) and the Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug delivery and sensing Using microcontainers and Nanomechanics (Danish National Research Foundation (DNRF122)....

  17. Recent advances in hydrogels for cartilage tissue engineering

    Directory of Open Access Journals (Sweden)

    SL Vega

    2017-01-01

    Full Text Available Articular cartilage is a load-bearing tissue that lines the surface of bones in diarthrodial joints. Unfortunately, this avascular tissue has a limited capacity for intrinsic repair. Treatment options for articular cartilage defects include microfracture and arthroplasty; however, these strategies fail to generate tissue that adequately restores damaged cartilage. Limitations of current treatments for cartilage defects have prompted the field of cartilage tissue engineering, which seeks to integrate engineering and biological principles to promote the growth of new cartilage to replace damaged tissue. To date, a wide range of scaffolds and cell sources have emerged with a focus on recapitulating the microenvironments present during development or in adult tissue, in order to induce the formation of cartilaginous constructs with biochemical and mechanical properties of native tissue. Hydrogels have emerged as a promising scaffold due to the wide range of possible properties and the ability to entrap cells within the material. Towards improving cartilage repair, hydrogel design has advanced in recent years to improve their utility. Some of these advances include the development of improved network crosslinking (e.g. double-networks, new techniques to process hydrogels (e.g. 3D printing and better incorporation of biological signals (e.g. controlled release. This review summarises these innovative approaches to engineer hydrogels towards cartilage repair, with an eye towards eventual clinical translation.

  18. Recent advances in hydrogels for cartilage tissue engineering.

    Science.gov (United States)

    Vega, S L; Kwon, M Y; Burdick, J A

    2017-01-30

    Articular cartilage is a load-bearing tissue that lines the surface of bones in diarthrodial joints. Unfortunately, this avascular tissue has a limited capacity for intrinsic repair. Treatment options for articular cartilage defects include microfracture and arthroplasty; however, these strategies fail to generate tissue that adequately restores damaged cartilage. Limitations of current treatments for cartilage defects have prompted the field of cartilage tissue engineering, which seeks to integrate engineering and biological principles to promote the growth of new cartilage to replace damaged tissue. To date, a wide range of scaffolds and cell sources have emerged with a focus on recapitulating the microenvironments present during development or in adult tissue, in order to induce the formation of cartilaginous constructs with biochemical and mechanical properties of native tissue. Hydrogels have emerged as a promising scaffold due to the wide range of possible properties and the ability to entrap cells within the material. Towards improving cartilage repair, hydrogel design has advanced in recent years to improve their utility. Some of these advances include the development of improved network crosslinking (e.g. double-networks), new techniques to process hydrogels (e.g. 3D printing) and better incorporation of biological signals (e.g. controlled release). This review summarises these innovative approaches to engineer hydrogels towards cartilage repair, with an eye towards eventual clinical translation.

  19. Tissue engineering in the treatment of cartilage lesions

    Directory of Open Access Journals (Sweden)

    Jakob Naranđa

    2013-11-01

    Full Text Available Background: Articular cartilage lesions with the inherent limited healing potential are difficult to treat and thus remain a challenging problem for orthopaedic surgeons. Regenerative treatment techniques, such as autologous chondrocyte implantation (ACI, are promising as a treatment option to restore hyaline-like cartilage tissue in damaged articular surfaces, as opposed to the traditional reparative procedures (e.g. bone marrow stimulation – microfracture, which promote a fibrocartilage formation with lower tissue biomechanical properties and poorer clinical results. ACI technique has undergone several advances and is constantly improving. The new concept of cartilage tissue preservation uses tissue-engineering technologies, combining new biomaterials as a scaffold, application of growth factors, use of stem cells, and mechanical stimulation. The recent development of new generations of ACI uses a cartilage-like tissue in a 3-dimensional culture system that is based on the use of biodegradable material which serves as a temporary scaffold for the in vitro growth and subsequent implantation into the cartilage defect. For clinical practice, single stage procedures appear attractive to reduce cost and patient morbidity. Finally, modern concept of tissue engineering facilitates hyaline-like cartilage formation and a permanent treatment of cartilage lesions.Conclusion: The review focuses on innovations in the treatment of cartilage lesions and covers modern concepts of tissue engineering with the use of biomaterials, growth factors, stem cells and bioreactors, and presents options for clinical use.

  20. Biomechanics and mechanobiology in functional tissue engineering

    NARCIS (Netherlands)

    Guilak, F.; Butler, D.L.; Goldstein, S.A.; Baaijens, F.P.T.

    2014-01-01

    The field of tissue engineering continues to expand and mature, and several products are now in clinical use, with numerous other preclinical and clinical studies underway. However, specific challenges still remain in the repair or regeneration of tissues that serve a predominantly biomechanical

  1. Dengue virus replicates and accumulates in Aedes aegypti salivary glands

    Energy Technology Data Exchange (ETDEWEB)

    Raquin, Vincent, E-mail: vincent.raquin@univ-lyon1.fr [Insect-Virus Interactions Group, Department of Genomes and Genetics, Institut Pasteur, 75015 Paris (France); Centre National de la Recherche Scientifique, Unité de Recherche Associée 3012, 75015 Paris (France); Lambrechts, Louis, E-mail: louis.lambrechts@pasteur.fr [Insect-Virus Interactions Group, Department of Genomes and Genetics, Institut Pasteur, 75015 Paris (France); Centre National de la Recherche Scientifique, Unité de Recherche Associée 3012, 75015 Paris (France)

    2017-07-15

    Dengue virus (DENV) is an RNA virus transmitted among humans by mosquito vectors, mainly Aedes aegypti. DENV transmission requires viral dissemination from the mosquito midgut to the salivary glands. During this process the virus undergoes several population bottlenecks, which are stochastic reductions in population size that restrict intra-host viral genetic diversity and limit the efficiency of natural selection. Despite the implications for virus transmission and evolution, DENV replication in salivary glands has not been directly demonstrated. Here, we used a strand-specific quantitative RT-PCR assay to demonstrate that negative-strand DENV RNA is produced in Ae. aegypti salivary glands, providing conclusive evidence that viral replication occurs in this tissue. Furthermore, we showed that the concentration of DENV genomic RNA in salivary glands increases significantly over time, indicating that active replication likely replenishes DENV genetic diversity prior to transmission. These findings improve our understanding of the biological determinants of DENV fitness and evolution. - Highlights: •Strand-specific RT-qPCR allows accurate quantification of DENV (-) RNA in mosquito tissues. •Detection of DENV (-) RNA in salivary glands provides evidence of viral replication in this tissue. •Viral replication in salivary glands likely replenishes DENV genetic diversity prior to transmission.

  2. Dengue virus replicates and accumulates in Aedes aegypti salivary glands

    International Nuclear Information System (INIS)

    Raquin, Vincent; Lambrechts, Louis

    2017-01-01

    Dengue virus (DENV) is an RNA virus transmitted among humans by mosquito vectors, mainly Aedes aegypti. DENV transmission requires viral dissemination from the mosquito midgut to the salivary glands. During this process the virus undergoes several population bottlenecks, which are stochastic reductions in population size that restrict intra-host viral genetic diversity and limit the efficiency of natural selection. Despite the implications for virus transmission and evolution, DENV replication in salivary glands has not been directly demonstrated. Here, we used a strand-specific quantitative RT-PCR assay to demonstrate that negative-strand DENV RNA is produced in Ae. aegypti salivary glands, providing conclusive evidence that viral replication occurs in this tissue. Furthermore, we showed that the concentration of DENV genomic RNA in salivary glands increases significantly over time, indicating that active replication likely replenishes DENV genetic diversity prior to transmission. These findings improve our understanding of the biological determinants of DENV fitness and evolution. - Highlights: •Strand-specific RT-qPCR allows accurate quantification of DENV (-) RNA in mosquito tissues. •Detection of DENV (-) RNA in salivary glands provides evidence of viral replication in this tissue. •Viral replication in salivary glands likely replenishes DENV genetic diversity prior to transmission.

  3. Review: Polymeric-Based 3D Printing for Tissue Engineering.

    Science.gov (United States)

    Wu, Geng-Hsi; Hsu, Shan-Hui

    Three-dimensional (3D) printing, also referred to as additive manufacturing, is a technology that allows for customized fabrication through computer-aided design. 3D printing has many advantages in the fabrication of tissue engineering scaffolds, including fast fabrication, high precision, and customized production. Suitable scaffolds can be designed and custom-made based on medical images such as those obtained from computed tomography. Many 3D printing methods have been employed for tissue engineering. There are advantages and limitations for each method. Future areas of interest and progress are the development of new 3D printing platforms, scaffold design software, and materials for tissue engineering applications.

  4. Pictorial essay: Orbital tuberculosis

    International Nuclear Information System (INIS)

    Narula, Mahender K; Chaudhary, Vikas; Baruah, Dhiraj; Kathuria, Manoj; Anand, Rama

    2010-01-01

    Tuberculosis of the orbit is rare, even in places where tuberculosis is endemic. The disease may involve soft tissue, the lacrimal gland, or the periosteum or bones of the orbital wall. Intracranial extension, in the form of extradural abscess, and infratemporal fossa extension has been described. This pictorial essay illustrates the imaging findings of nine histopathologically confirmed cases of orbital tuberculosis. All these patients responded to antituberculous treatment

  5. Advances in tissue engineering through stem cell-based co-culture.

    Science.gov (United States)

    Paschos, Nikolaos K; Brown, Wendy E; Eswaramoorthy, Rajalakshmanan; Hu, Jerry C; Athanasiou, Kyriacos A

    2015-05-01

    Stem cells are the future in tissue engineering and regeneration. In a co-culture, stem cells not only provide a target cell source with multipotent differentiation capacity, but can also act as assisting cells that promote tissue homeostasis, metabolism, growth and repair. Their incorporation into co-culture systems seems to be important in the creation of complex tissues or organs. In this review, critical aspects of stem cell use in co-culture systems are discussed. Direct and indirect co-culture methodologies used in tissue engineering are described, along with various characteristics of cellular interactions in these systems. Direct cell-cell contact, cell-extracellular matrix interaction and signalling via soluble factors are presented. The advantages of stem cell co-culture strategies and their applications in tissue engineering and regenerative medicine are portrayed through specific examples for several tissues, including orthopaedic soft tissues, bone, heart, vasculature, lung, kidney, liver and nerve. A concise review of the progress and the lessons learned are provided, with a focus on recent developments and their implications. It is hoped that knowledge developed from one tissue can be translated to other tissues. Finally, we address challenges in tissue engineering and regenerative medicine that can potentially be overcome via employing strategies for stem cell co-culture use. Copyright © 2014 John Wiley & Sons, Ltd.

  6. Rapid prototyping technology and its application in bone tissue engineering.

    Science.gov (United States)

    Yuan, Bo; Zhou, Sheng-Yuan; Chen, Xiong-Sheng

    Bone defects arising from a variety of reasons cannot be treated effectively without bone tissue reconstruction. Autografts and allografts have been used in clinical application for some time, but they have disadvantages. With the inherent drawback in the precision and reproducibility of conventional scaffold fabrication techniques, the results of bone surgery may not be ideal. This is despite the introduction of bone tissue engineering which provides a powerful approach for bone repair. Rapid prototyping technologies have emerged as an alternative and have been widely used in bone tissue engineering, enhancing bone tissue regeneration in terms of mechanical strength, pore geometry, and bioactive factors, and overcoming some of the disadvantages of conventional technologies. This review focuses on the basic principles and characteristics of various fabrication technologies, such as stereolithography, selective laser sintering, and fused deposition modeling, and reviews the application of rapid prototyping techniques to scaffolds for bone tissue engineering. In the near future, the use of scaffolds for bone tissue engineering prepared by rapid prototyping technology might be an effective therapeutic strategy for bone defects.

  7. Rapid prototyping technology and its application in bone tissue engineering*

    Science.gov (United States)

    YUAN, Bo; ZHOU, Sheng-yuan; CHEN, Xiong-sheng

    2017-01-01

    Bone defects arising from a variety of reasons cannot be treated effectively without bone tissue reconstruction. Autografts and allografts have been used in clinical application for some time, but they have disadvantages. With the inherent drawback in the precision and reproducibility of conventional scaffold fabrication techniques, the results of bone surgery may not be ideal. This is despite the introduction of bone tissue engineering which provides a powerful approach for bone repair. Rapid prototyping technologies have emerged as an alternative and have been widely used in bone tissue engineering, enhancing bone tissue regeneration in terms of mechanical strength, pore geometry, and bioactive factors, and overcoming some of the disadvantages of conventional technologies. This review focuses on the basic principles and characteristics of various fabrication technologies, such as stereolithography, selective laser sintering, and fused deposition modeling, and reviews the application of rapid prototyping techniques to scaffolds for bone tissue engineering. In the near future, the use of scaffolds for bone tissue engineering prepared by rapid prototyping technology might be an effective therapeutic strategy for bone defects. PMID:28378568

  8. Mid-term clinical results of tissue-engineered vascular autografts

    International Nuclear Information System (INIS)

    Matsumura, Goki; Shin'oka, Toshiharu; Hibino, Narutoshi; Saito, Satoshi; Sakamoto, Takahiko; Ichihara, Yuki; Hobo, Kyoko; Miyamoto, Shin'ka; Kurosawa, Hiromi

    2007-01-01

    Prosthetic and bioprosthetic materials currently in use lack growth potential and therefore must be repeatedly replaced in pediatric patients as they grow. Tissue engineering is a new discipline that offers the potential for creating replacement structures from autologous cells and biodegradable polymer scaffolds. In May 2000, we initiated clinical application of tissue-engineered vascular grafts seeded with cultured cells. However, cell culturing is time-consuming, and xenoserum must be used. To overcome these disadvantages, we began to use bone marrow cells, readily available on the day of surgery, as a cell source. Since September 2001, tissue-engineered grafts seeded with autologous bone marrow cells have been implanted in 44 patients. The patients or their parents were fully informed and had given consent to the procedure. A 3 to 10 ml/kg specimen of bone marrow was aspirated with the patient under general anesthesia before the skin incision. The polymer tube serving as a scaffold for the cells was composed of a copolymer of lactide and ε-caprolactone (50:50) which degrades by hydrolysis. Polyglycolic or poly-l-lactic acid woven fabric was used for reinforcement. Twenty-six tissue-engineered conduits and 19 tissue-engineered patches were used for the repair of congenital heart defects. The patients' ages ranged from 1 to 24 years (median 7.4 years). All patients underwent a catheterization study, CT scan, or both, for evaluation after the operation. There were 4 late deaths due to heart failure with or without multiple organ failure or brain bleeding in this series; these were unrelated to the tissue-engineered graft function. One patient required percutaneous balloon angioplasty for tubular graft-stenosis and 4 patients for the stenosis of the patch-shaped tissue engineered material. Two patients required re-do operation; one for recurrent pulmonary stenosis and another for a resulting R-L shunt after the lateral tunnel method. Kaplan-Meier analysis in

  9. Ligament Tissue Engineering and Its Potential Role in Anterior Cruciate Ligament Reconstruction

    OpenAIRE

    Yates, E. W.; Rupani, A.; Foley, G. T.; Khan, W. S.; Cartmell, S.; Anand, S. J.

    2011-01-01

    Tissue engineering is an emerging discipline that combines the principle of science and engineering. It offers an unlimited source of natural tissue substitutes and by using appropriate cells, biomimetic scaffolds, and advanced bioreactors, it is possible that tissue engineering could be implemented in the repair and regeneration of tissue such as bone, cartilage, tendon, and ligament. Whilst repair and regeneration of ligament tissue has been demonstrated in animal studies, further research ...

  10. Tissue engineering and microRNAs: future perspectives in regenerative medicine.

    Science.gov (United States)

    Gori, Manuele; Trombetta, Marcella; Santini, Daniele; Rainer, Alberto

    2015-01-01

    Tissue engineering is a growing area of biomedical research, holding great promise for a broad range of potential applications in the field of regenerative medicine. In recent decades, multiple tissue engineering strategies have been adopted to mimic and improve specific biological functions of tissues and organs, including biomimetic materials, drug-releasing scaffolds, stem cells, and dynamic culture systems. MicroRNAs (miRNAs), noncoding small RNAs that negatively regulate the expression of downstream target mRNAs, are considered a novel class of molecular targets and therapeutics that may play an important role in tissue engineering. Herein, we highlight the latest achievements in regenerative medicine, focusing on the role of miRNAs as key modulators of gene expression, stem cell self-renewal, proliferation and differentiation, and eventually in driving cell fate decisions. Finally, we will discuss the contribution of miRNAs in regulating the rearrangement of the tissue microenvironment and angiogenesis, and the range of strategies for miRNA delivery into target cells and tissues. Manipulation of miRNAs is an alternative approach and an attractive strategy for controlling several aspects of tissue engineering, although some issues concerning their in vivo effects and optimal delivery methods still remain uncovered.

  11. Electrospun polyurethane membranes for Tissue Engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Laís P., E-mail: lagabriel@gmail.com [National Institute of Biofabrication, Campinas (Brazil); Department of Chemical Engineering, University of Campinas, Campinas (Brazil); Rodrigues, Ana Amélia [National Institute of Biofabrication, Campinas (Brazil); Department of Medical Sciences, University of Campinas, Campinas (Brazil); Macedo, Milton; Jardini, André L.; Maciel Filho, Rubens [National Institute of Biofabrication, Campinas (Brazil); Department of Chemical Engineering, University of Campinas, Campinas (Brazil)

    2017-03-01

    Tissue Engineering proposes, among other things, tissue regeneration using scaffolds integrated with biological molecules, growth factors or cells for such regeneration. In this research, polyurethane membranes were prepared using the electrospinning technique in order to obtain membranes to be applied in Tissue Engineering, such as epithelial, drug delivery or cardiac applications. The influence of fibers on the structure and morphology of the membranes was studied using scanning electron microscopy (SEM), the structure was evaluated by Fourier transform infrared spectroscopy (FT-IR), and the thermal stability was analyzed by thermogravimetry analysis (TGA). In vitro cells attachment and proliferation was investigated by SEM, and in vitro cell viability was studied by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays and Live/Dead® assays. It was found that the membranes present an homogeneous morphology, high porosity, high surface area/volume ratio, it was also observed a random fiber network. The thermal analysis showed that the membrane degradation started at 254 °C. In vitro evaluation of fibroblasts cells showed that fibroblasts spread over the membrane surface after 24, 48 and 72 h of culture. This study supports the investigation of electrospun polyurethane membranes as biocompatible scaffolds for Tissue Engineering applications and provides some guidelines for improved biomaterials with desired properties.

  12. Tissue Engineering Strategies in Ligament Regeneration

    Directory of Open Access Journals (Sweden)

    Caglar Yilgor

    2012-01-01

    Full Text Available Ligaments are dense fibrous connective tissues that connect bones to other bones and their injuries are frequently encountered in the clinic. The current clinical approaches in ligament repair and regeneration are limited to autografts, as the gold standard, and allografts. Both of these techniques have their own drawbacks that limit the success in clinical setting; therefore, new strategies are being developed in order to be able to solve the current problems of ligament grafting. Tissue engineering is a novel promising technique that aims to solve these problems, by producing viable artificial ligament substitutes in the laboratory conditions with the potential of transplantation to the patients with a high success rate. Direct cell and/or growth factor injection to the defect site is another current approach aiming to enhance the repair process of the native tissue. This review summarizes the current approaches in ligament tissue engineering strategies including the use of scaffolds, their modification techniques, as well as the use of bioreactors to achieve enhanced regeneration rates, while also discussing the advances in growth factor and cell therapy applications towards obtaining enhanced ligament regeneration.

  13. Bioprinting of a functional vascularized mouse thyroid gland construct.

    Science.gov (United States)

    Bulanova, Elena A; Koudan, Elizaveta V; Degosserie, Jonathan; Heymans, Charlotte; Pereira, Frederico DAS; Parfenov, Vladislav A; Sun, Yi; Wang, Qi; Akhmedova, Suraya A; Sviridova, Irina K; Sergeeva, Natalia S; Frank, Georgy A; Khesuani, Yusef D; Pierreux, Christophe E; Mironov, Vladimir A

    2017-08-18

    Bioprinting can be defined as additive biofabrication of three-dimensional (3D) tissues and organ constructs using tissue spheroids, capable of self-assembly, as building blocks. The thyroid gland, a relatively simple endocrine organ, is suitable for testing the proposed bioprinting technology. Here we report the bioprinting of a functional vascularized mouse thyroid gland construct from embryonic tissue spheroids as a proof of concept. Based on the self-assembly principle, we generated thyroid tissue starting from thyroid spheroids (TS) and allantoic spheroids (AS) as a source of thyrocytes and endothelial cells (EC), respectively. Inspired by mathematical modeling of spheroid fusion, we used an original 3D bioprinter to print TS in close association with AS within a collagen hydrogel. During the culture, closely placed embryonic tissue spheroids fused into a single integral construct, EC from AS invaded and vascularized TS, and epithelial cells from the TS progressively formed follicles. In this experimental setting, we observed formation of a capillary network around follicular cells, as observed during in utero thyroid development when thyroid epithelium controls the recruitment, invasion and expansion of EC around follicles. To prove that EC from AS are responsible for vascularization of the thyroid gland construct, we depleted endogenous EC from TS before bioprinting. EC from AS completely revascularized depleted thyroid tissue. The cultured bioprinted construct was functional as it could normalize blood thyroxine levels and body temperature after grafting under the kidney capsule of hypothyroid mice. Bioprinting of functional vascularized mouse thyroid gland construct represents a further advance in bioprinting technology, exploring the self-assembling properties of tissue spheroids.

  14. Tissue engineering of heart valves: in vitro experiences.

    Science.gov (United States)

    Sodian, R; Hoerstrup, S P; Sperling, J S; Daebritz, S H; Martin, D P; Schoen, F J; Vacanti, J P; Mayer, J E

    2000-07-01

    Tissue engineering is a new approach, whereby techniques are being developed to transplant autologous cells onto biodegradable scaffolds to ultimately form new functional tissue in vitro and in vivo. Our laboratory has focused on the tissue engineering of heart valves, and we have fabricated a trileaflet heart valve scaffold from a biodegradable polymer, a polyhydroxyalkanoate. In this experiment we evaluated the suitability of this scaffold material as well as in vitro conditioning to create viable tissue for tissue engineering of a trileaflet heart valve. We constructed a biodegradable and biocompatible trileaflet heart valve scaffold from a porous polyhydroxyalkanoate (Meatabolix Inc, Cambridge, MA). The scaffold consisted of a cylindrical stent (1 x 15 x 20 mm inner diameter) and leaflets (0.3 mm thick), which were attached to the stent by thermal processing techniques. The porous heart valve scaffold (pore size 100 to 240 microm) was seeded with vascular cells grown and expanded from an ovine carotid artery and placed into a pulsatile flow bioreactor for 1, 4, and 8 days. Analysis of the engineered tissue included biochemical examination, enviromental scanning electron microscopy, and histology. It was possible to create a trileaflet heart valve scaffold from polyhydroxyalkanoate, which opened and closed synchronously in a pulsatile flow bioreactor. The cells grew into the pores and formed a confluent layer after incubation and pulsatile flow exposure. The cells were mostly viable and formed connective tissue between the inside and the outside of the porous heart valve scaffold. Additionally, we demonstrated cell proliferation (DNA assay) and the capacity to generate collagen as measured by hydroxyproline assay and movat-stained glycosaminoglycans under in vitro pulsatile flow conditions. Polyhydroxyalkanoates can be used to fabricate a porous, biodegradable heart valve scaffold. The cells appear to be viable and extracellular matrix formation was induced

  15. The Role of Pineal Gland and Exogenous Melatonin on the Irradiation Stress Response of Suprarenal Gland

    Directory of Open Access Journals (Sweden)

    Selma Aličelebić

    2006-11-01

    Full Text Available Pineal gland has and antistressogenic role. Its main hormone, melatonin, has radio protective effect on endocrine and other dynamic tissues. In our previous study, we have shown that pinealectomy changes the behavior of suprarenal gland in totally irradiated rats. The aim of this study is to evaluate the effect of exogenous melatonin on suprarenal gland of rats with or without pineal gland. Four months after pinealectomy (experimental group or shampinealectomy (control group, adult Wistar male rats were daily treated with 0,2 mg of melatoninintraperitoneally, during two weeks. Thereafter, all animals were totally irradiated with 8 Gy of Gamma rays produced from Cobalt 60. Animals who survived were sacrificed on the 17(th post irradiation day. Qualitative and quantitative characteristics of the suprarenal gland were studied using histological methods. The results show that exogenous melatonin had protective role on suprarenal gland in totally irradiated rats and that those effects were more pronounced in the presence of pineal gland.

  16. A dual-color luciferase assay system reveals circadian resetting of cultured fibroblasts by co-cultured adrenal glands.

    Directory of Open Access Journals (Sweden)

    Takako Noguchi

    Full Text Available In mammals, circadian rhythms of various organs and tissues are synchronized by pacemaker neurons in the suprachiasmatic nucleus (SCN of the hypothalamus. Glucocorticoids released from the adrenal glands can synchronize circadian rhythms in other tissues. Many hormones show circadian rhythms in their plasma concentrations; however, whether organs outside the SCN can serve as master synchronizers to entrain circadian rhythms in target tissues is not well understood. To further delineate the function of the adrenal glands and the interactions of circadian rhythms in putative master synchronizing organs and their target tissues, here we report a simple co-culture system using a dual-color luciferase assay to monitor circadian rhythms separately in various explanted tissues and fibroblasts. In this system, circadian rhythms of organs and target cells were simultaneously tracked by the green-emitting beetle luciferase from Pyrearinus termitilluminans (ELuc and the red-emitting beetle luciferase from Phrixothrix hirtus (SLR, respectively. We obtained tissues from the adrenal glands, thyroid glands, and lungs of transgenic mice that expressed ELuc under control of the promoter from a canonical clock gene, mBmal1. The tissues were co-cultured with Rat-1 fibroblasts as representative target cells expressing SLR under control of the mBmal1 promoter. Amplitudes of the circadian rhythms of Rat-1 fibroblasts were potentiated when the fibroblasts were co-cultured with adrenal gland tissue, but not when co-cultured with thyroid gland or lung tissue. The phases of Rat-1 fibroblasts were reset by application of adrenal gland tissue, whereas the phases of adrenal gland tissue were not influenced by Rat-1 fibroblasts. Furthermore, the effect of the adrenal gland tissue on the fibroblasts was blocked by application of a glucocorticoid receptor (GR antagonist. These results demonstrate that glucocorticoids are strong circadian synchronizers for fibroblasts and that

  17. Mechanical stimulation improves tissue-engineered human skeletal muscle

    Science.gov (United States)

    Powell, Courtney A.; Smiley, Beth L.; Mills, John; Vandenburgh, Herman H.

    2002-01-01

    Human bioartificial muscles (HBAMs) are tissue engineered by suspending muscle cells in collagen/MATRIGEL, casting in a silicone mold containing end attachment sites, and allowing the cells to differentiate for 8 to 16 days. The resulting HBAMs are representative of skeletal muscle in that they contain parallel arrays of postmitotic myofibers; however, they differ in many other morphological characteristics. To engineer improved HBAMs, i.e., more in vivo-like, we developed Mechanical Cell Stimulator (MCS) hardware to apply in vivo-like forces directly to the engineered tissue. A sensitive force transducer attached to the HBAM measured real-time, internally generated, as well as externally applied, forces. The muscle cells generated increasing internal forces during formation which were inhibitable with a cytoskeleton depolymerizer. Repetitive stretch/relaxation for 8 days increased the HBAM elasticity two- to threefold, mean myofiber diameter 12%, and myofiber area percent 40%. This system allows engineering of improved skeletal muscle analogs as well as a nondestructive method to determine passive force and viscoelastic properties of the resulting tissue.

  18. 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

  19. Artificial urinary conduit construction using tissue engineering methods.

    Science.gov (United States)

    Kloskowski, Tomasz; Pokrywczyńska, Marta; Drewa, Tomasz

    2015-01-01

    Incontinent urinary diversion using an ileal conduit is the most popular method used by urologists after bladder cystectomy resulting from muscle invasive bladder cancer. The use of gastrointestinal tissue is related to a series of complications with the necessity of surgical procedure extension which increases the time of surgery. Regenerative medicine together with tissue engineering techniques gives hope for artificial urinary conduit construction de novo without affecting the ileum. In this review we analyzed history of urinary diversion together with current attempts in urinary conduit construction using tissue engineering methods. Based on literature and our own experience we presented future perspectives related to the artificial urinary conduit construction. A small number of papers in the field of tissue engineered urinary conduit construction indicates that this topic requires more attention. Three main factors can be distinguished to resolve this topic: proper scaffold construction along with proper regeneration of both the urothelium and smooth muscle layers. Artificial urinary conduit has a great chance to become the first commercially available product in urology constructed by regenerative medicine methods.

  20. Regenerative endodontics as a tissue engineering approach: past, current and future.

    Science.gov (United States)

    Malhotra, Neeraj; Mala, Kundabala

    2012-12-01

    With the reported startling statistics of high incidence of tooth decay and tooth loss, the current interest is focused on the development of alternate dental tissue replacement therapies. This has led to the application of dental tissue engineering as a clinically relevant method for the regeneration of dental tissues and generation of bioengineered whole tooth. Although, tissue engineering approach requires the three main key elements of stem cells, scaffold and morphogens, a conductive environment (fourth element) is equally important for successful engineering of any tissue and/or organ. The applications of this science has evolved continuously in dentistry, beginning from the application of Ca(OH)(2) in vital pulp therapy to the development of a fully functional bioengineered tooth (mice). Thus, with advances in basic research, recent reports and studies have shown successful application of tissue engineering in the field of dentistry. However, certain practical obstacles are yet to be overcome before dental tissue regeneration can be applied as evidence-based approach in clinics. The article highlights on the past achievements, current developments and future prospects of tissue engineering and regenerative therapy in the field of endodontics and bioengineered teeth (bioteeth). © 2012 The Authors. Australian Endodontic Journal © 2012 Australian Society of Endodontology.

  1. Pleomorphic adenoma of minor salivary gland: hard palate

    International Nuclear Information System (INIS)

    Garcia Canas, Wilmer; Benitez Narvaez, N.

    2006-01-01

    The pleomorphic adenoma or mixed tumor occurs in 4 to 14% of the accessory glands salivary. Different localizations exist: AEC, nasal block, lips, maxillary sinus, nasopharynx or in any other localization where salivate tissue exists, but the palate constitutes the most frequent localization, because it gathers more than 50% of minor salivary glands. In the palate, it can be developed a wide variety of tumors coming from the connective and epithelial tissue, 44% arise in the minor salivary glands. In 49 to 65% of them are benign tumors, principally pleomorphic adenomas, located preferably in the hard palate, nearby or in the union with the soft palate as in our case. We present a 42 year old patient with at pleomorphic adenoma of hard palate. (The author)

  2. Vaccine-induced rabies in a red fox (Vulpes vulpes): isolation of vaccine virus in brain tissue and salivary glands.

    Science.gov (United States)

    Hostnik, Peter; Picard-Meyer, Evelyne; Rihtarič, Danijela; Toplak, Ivan; Cliquet, Florence

    2014-04-01

    Oral vaccination campaigns to eliminate fox rabies were initiated in Slovenia in 1995. In May 2012, a young fox (Vulpes vulpes) with typical rabies signs was captured. Its brain and salivary gland tissues were found to contain vaccine strain SAD B19. The Basic Logical Alignment Search Tool alignment of 589 nucleotides determined from the N gene of the virus isolated from the brain and salivary glands of the affected fox was 100% identical to the GenBank reference SAD B19 strain. Sequence analysis of the N and M genes (4,351 nucleotides) showed two nucleotide modifications at position 1335 (N gene) and 3114 (M gene) in the KC522613 isolate identified in the fox compared to SAD B19.

  3. High Definition Confocal Imaging Modalities for the Characterization of Tissue-Engineered Substitutes.

    Science.gov (United States)

    Mayrand, Dominique; Fradette, Julie

    2018-01-01

    Optimal imaging methods are necessary in order to perform a detailed characterization of thick tissue samples from either native or engineered tissues. Tissue-engineered substitutes are featuring increasing complexity including multiple cell types and capillary-like networks. Therefore, technical approaches allowing the visualization of the inner structural organization and cellular composition of tissues are needed. This chapter describes an optical clearing technique which facilitates the detailed characterization of whole-mount samples from skin and adipose tissues (ex vivo tissues and in vitro tissue-engineered substitutes) when combined with spectral confocal microscopy and quantitative analysis on image renderings.

  4. Graft-versus-host disease and sialodacryoadenitis viral infection in bone marrow transplanted rats

    International Nuclear Information System (INIS)

    Rossie, K.M.; Sheridan, J.F.; Barthold, S.W.; Tutschka, P.J.

    1988-01-01

    The effect of a localized viral infection on the occurrence of graft-vs.-host disease (GVHD) was examined in allogeneic rat bone marrow chimeras (ACI/LEW). Animals without clinical evidence of GVHD, 62 days after bone marrow transplant, were infected in salivary and lacrimal glands with sialodacryoadenitis virus (SDAV), and sacrificed 8-25 days postinfection. Using established histologic criteria, GVHD was found more frequently in salivary and lacrimal glands of SDAV-infected chimeras than uninfected chimeras. Skin and oral mucosa, tissues not infected by the virus, showed no differences in occurrence of GVHD, suggesting that the viral infection induced only local and not systemic GVHD. GVHD and SDAV infection, which are histologically similar, were differentiated by examining tissues for SDAV antigen using immunoperoxidase technique. Histologic changes were present for at least 1 week longer than viral antigen, suggesting they represented GVHD rather than viral infection. GVHD and SDAV infection were also differentiated by looking for a histologic feature characteristic of GVHD and not found in SDAV infection (periductal lymphocytic infiltrate). This was found in SDAV-infected chimeras more frequently than uninfected chimeras, suggesting that the viral infection somehow induced GVHD. Results showed a localized increase in the occurrence of GVHD subsequent to localized viral infection

  5. The necessity of a theory of biology for tissue engineering: metabolism-repair systems.

    Science.gov (United States)

    Ganguli, Suman; Hunt, C Anthony

    2004-01-01

    Since there is no widely accepted global theory of biology, tissue engineering and bioengineering lack a theoretical understanding of the systems being engineered. By default, tissue engineering operates with a "reductionist" theoretical approach, inherited from traditional engineering of non-living materials. Long term, that approach is inadequate, since it ignores essential aspects of biology. Metabolism-repair systems are a theoretical framework which explicitly represents two "functional" aspects of living organisms: self-repair and self-replication. Since repair and replication are central to tissue engineering, we advance metabolism-repair systems as a potential theoretical framework for tissue engineering. We present an overview of the framework, and indicate directions to pursue for extending it to the context of tissue engineering. We focus on biological networks, both metabolic and cellular, as one such direction. The construction of these networks, in turn, depends on biological protocols. Together these concepts may help point the way to a global theory of biology appropriate for tissue engineering.

  6. The Crosstalk between Tissue Engineering and Pharmaceutical Biotechnology: Recent Advances and Future Directions.

    Science.gov (United States)

    Pacheco, Daniela P; Reis, Rui L; Correlo, Vítor M; Marques, Alexandra P

    2015-01-01

    Tissue-engineered constructs made of biotechnology-derived materials have been preferred due to their chemical and physical composition, which offers both high versatility and a support to enclose/ incorporate relevant signaling molecules and/or genes known to therapeutically induce tissue repair. Herein, a critical overview of the impact of different biotechnology-derived materials, scaffolds, and recombinant signaling molecules over the behavior of cells, another element of tissue engineered constructs, as well its regulatory role in tissue regeneration and disease progression is given. Additionally, these tissue-engineered constructs evolved to three-dimensional (3D) tissue-like models that, as an advancement of two-dimensional standard culture methods, are expected to be a valuable tool in the field of drug discovery and pharmaceutical research. Despite the improved design and conception of current proposed 3D tissue-like models, advanced control systems to enable and accelerate streamlining and automation of the numerous labor-intensive steps intrinsic to the development of tissue-engineered constructs are still to be achieved. In this sense, this review intends to present the biotechnology- derived materials that are being explored in the field of tissue engineering to generate 3D tissue-analogues and briefly highlight their foremost breakthroughs in tissue regeneration and drug discovery. It also aims to reinforce that the crosstalk between tissue engineering and pharmaceutical biotechnology has been fostering the outcomes of tissue engineering approaches through the use of biotechnology-derived signaling molecules. Gene delivery/therapy is also discussed as a forefront area that represents another cross point between tissue engineering and pharmaceutical biotechnology, in which nucleic acids can be considered a "super pharmaceutical" to drive biological responses, including tissue regeneration.

  7. 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.

  8. A new permanent lacrimal stent: evaluation of a modification to dacryocystorhinostomy

    Directory of Open Access Journals (Sweden)

    Dikran G Hovaghimian

    2015-01-01

    Modified DCR with the new lacrimal silicone stent is technically quick and easy to perform and can be done for all age groups with a high success rate and could be considered as a good alternative to classic DCR surgery.

  9. Applications of Biomaterials in Corneal Endothelial Tissue Engineering.

    Science.gov (United States)

    Wang, Tsung-Jen; Wang, I-Jong; Hu, Fung-Rong; Young, Tai-Horng

    2016-11-01

    When corneal endothelial cells (CECs) are diseased or injured, corneal endothelium can be surgically removed and tissue from a deceased donor can replace the original endothelium. Recent major innovations in corneal endothelial transplantation include replacement of diseased corneal endothelium with a thin lamellar posterior donor comprising a tissue-engineered endothelium carried or cultured on a thin substratum with an organized monolayer of cells. Repairing CECs is challenging because they have restricted proliferative ability in vivo. CECs can be cultivated in vitro and seeded successfully onto natural tissue materials or synthetic polymeric materials as grafts for transplantation. The optimal biomaterials for substrata of CEC growth are being investigated. Establishing a CEC culture system by tissue engineering might require multiple biomaterials to create a new scaffold that overcomes the disadvantages of single biomaterials. Chitosan and polycaprolactone are biodegradable biomaterials approved by the Food and Drug Administration that have superior biological, degradable, and mechanical properties for culturing substratum. We successfully hybridized chitosan and polycaprolactone into blended membranes, and demonstrated that CECs proliferated, developed normal morphology, and maintained their physiological phenotypes. The interaction between cells and biomaterials is important in tissue engineering of CECs. We are still optimizing culture methods for the maintenance and differentiation of CECs on biomaterials.

  10. Homeobox Genes in the Rodent Pineal Gland

    DEFF Research Database (Denmark)

    Rath, Martin Fredensborg; Rohde, Kristian; Klein, David C

    2013-01-01

    The pineal gland is a neuroendocrine gland responsible for nocturnal synthesis of melatonin. During early development of the rodent pineal gland from the roof of the diencephalon, homeobox genes of the orthodenticle homeobox (Otx)- and paired box (Pax)-families are expressed and are essential...... for normal pineal development consistent with the well-established role that homeobox genes play in developmental processes. However, the pineal gland appears to be unusual because strong homeobox gene expression persists in the pineal gland of the adult brain. Accordingly, in addition to developmental...... functions, homeobox genes appear to be key regulators in postnatal phenotype maintenance in this tissue. In this paper, we review ontogenetic and phylogenetic aspects of pineal development and recent progress in understanding the involvement of homebox genes in rodent pineal development and adult function...

  11. Investigation of optical coherence tomography as an imaging modality in tissue engineering

    International Nuclear Information System (INIS)

    Yang Ying; Dubois, Arnaud; Qin Xiangpei; Li Jian; Haj, Alicia El; Wang, Ruikang K

    2006-01-01

    Monitoring cell profiles in 3D porous scaffolds presents a major challenge in tissue engineering. In this study, we investigate optical coherence tomography (OCT) as an imaging modality to monitor non-invasively both structures and cells in engineered tissue constructs. We employ time-domain OCT to visualize macro-structural morphology, and whole-field optical coherence microscopy to delineate the morphology of cells and constructs in a developing in vitro engineered bone tissue. The results show great potential for the use of OCT in non-invasive monitoring of cellular activities in 3D developing engineered tissues

  12. Tissue Engineering the Cornea: The Evolution of RAFT

    Science.gov (United States)

    Levis, Hannah J.; Kureshi, Alvena K.; Massie, Isobel; Morgan, Louise; Vernon, Amanda J.; Daniels, Julie T.

    2015-01-01

    Corneal blindness affects over 10 million people worldwide and current treatment strategies often involve replacement of the defective layer with healthy tissue. Due to a worldwide donor cornea shortage and the absence of suitable biological scaffolds, recent research has focused on the development of tissue engineering techniques to create alternative therapies. This review will detail how we have refined the simple engineering technique of plastic compression of collagen to a process we now call Real Architecture for 3D Tissues (RAFT). The RAFT production process has been standardised, and steps have been taken to consider Good Manufacturing Practice compliance. The evolution of this process has allowed us to create biomimetic epithelial and endothelial tissue equivalents suitable for transplantation and ideal for studying cell-cell interactions in vitro. PMID:25809689

  13. Bioactive glass and glass-ceramic scaffolds for bone tissue engineering

    NARCIS (Netherlands)

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

    2010-01-01

    Traditionally, bioactive glasses have been used to fill and restore bone defects. More recently, this category of biomaterials has become an emerging research field for bone tissue engineering applications. Here, we review and discuss current knowledge on porous bone tissue engineering scaffolds on

  14. Intermittent straining accelerates the development of tissue properties in engineered heart valve tissue

    NARCIS (Netherlands)

    Rubbens, M.P.; Mol, A.; Boerboom, R.A.; Bank, R.A.; Baaijens, F.P.T.; Bouten, C.V.C.

    2009-01-01

    Tissue-engineered heart valves lack sufficient amounts of functionally organized structures and consequently do not meet in vivo mechanical demands. To optimize tissue architecture and hence improve mechanical properties, various in vitro mechanical conditioning protocols have been proposed, of

  15. Textile Technologies and Tissue Engineering: A Path Towards Organ Weaving

    OpenAIRE

    Akbari, Mohsen; Tamayol, Ali; Bagherifard, Sara; Serex, Ludovic; Mostafalu, Pooria; Faramarzi, Negar; Mohammadi, Mohammad Hossein; Khademhosseini, Ali

    2016-01-01

    Textile technologies have recently attracted great attention as potential biofabrication tools for engineering tissue constructs. Using current textile technologies, fibrous structures can be designed and engineered to attain the required properties that are demanded by different tissue engineering applications. Several key parameters such as physiochemical characteristics of fibers, pore size and mechanical properties of the fabrics play important role in the effective use of textile technol...

  16. Tissue-Engineered Solutions in Plastic and Reconstructive Surgery: Principles and Practice

    Science.gov (United States)

    Al-Himdani, Sarah; Jessop, Zita M.; Al-Sabah, Ayesha; Combellack, Emman; Ibrahim, Amel; Doak, Shareen H.; Hart, Andrew M.; Archer, Charles W.; Thornton, Catherine A.; Whitaker, Iain S.

    2017-01-01

    Recent advances in microsurgery, imaging, and transplantation have led to significant refinements in autologous reconstructive options; however, the morbidity of donor sites remains. This would be eliminated by successful clinical translation of tissue-engineered solutions into surgical practice. Plastic surgeons are uniquely placed to be intrinsically involved in the research and development of laboratory engineered tissues and their subsequent use. In this article, we present an overview of the field of tissue engineering, with the practicing plastic surgeon in mind. The Medical Research Council states that regenerative medicine and tissue engineering “holds the promise of revolutionizing patient care in the twenty-first century.” The UK government highlighted regenerative medicine as one of the key eight great technologies in their industrial strategy worthy of significant investment. The long-term aim of successful biomanufacture to repair composite defects depends on interdisciplinary collaboration between cell biologists, material scientists, engineers, and associated medical specialties; however currently, there is a current lack of coordination in the field as a whole. Barriers to translation are deep rooted at the basic science level, manifested by a lack of consensus on the ideal cell source, scaffold, molecular cues, and environment and manufacturing strategy. There is also insufficient understanding of the long-term safety and durability of tissue-engineered constructs. This review aims to highlight that individualized approaches to the field are not adequate, and research collaboratives will be essential to bring together differing areas of expertise to expedite future clinical translation. The use of tissue engineering in reconstructive surgery would result in a paradigm shift but it is important to maintain realistic expectations. It is generally accepted that it takes 20–30 years from the start of basic science research to clinical utility

  17. Tissue-Engineered Solutions in Plastic and Reconstructive Surgery: Principles and Practice.

    Science.gov (United States)

    Al-Himdani, Sarah; Jessop, Zita M; Al-Sabah, Ayesha; Combellack, Emman; Ibrahim, Amel; Doak, Shareen H; Hart, Andrew M; Archer, Charles W; Thornton, Catherine A; Whitaker, Iain S

    2017-01-01

    Recent advances in microsurgery, imaging, and transplantation have led to significant refinements in autologous reconstructive options; however, the morbidity of donor sites remains. This would be eliminated by successful clinical translation of tissue-engineered solutions into surgical practice. Plastic surgeons are uniquely placed to be intrinsically involved in the research and development of laboratory engineered tissues and their subsequent use. In this article, we present an overview of the field of tissue engineering, with the practicing plastic surgeon in mind. The Medical Research Council states that regenerative medicine and tissue engineering "holds the promise of revolutionizing patient care in the twenty-first century." The UK government highlighted regenerative medicine as one of the key eight great technologies in their industrial strategy worthy of significant investment. The long-term aim of successful biomanufacture to repair composite defects depends on interdisciplinary collaboration between cell biologists, material scientists, engineers, and associated medical specialties; however currently, there is a current lack of coordination in the field as a whole. Barriers to translation are deep rooted at the basic science level, manifested by a lack of consensus on the ideal cell source, scaffold, molecular cues, and environment and manufacturing strategy. There is also insufficient understanding of the long-term safety and durability of tissue-engineered constructs. This review aims to highlight that individualized approaches to the field are not adequate, and research collaboratives will be essential to bring together differing areas of expertise to expedite future clinical translation. The use of tissue engineering in reconstructive surgery would result in a paradigm shift but it is important to maintain realistic expectations. It is generally accepted that it takes 20-30 years from the start of basic science research to clinical utility

  18. Progress on materials and scaffold fabrications applied to esophageal tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Qiuxiang; Shi, Peina; Gao, Mongna; Yu, Xuechan; Liu, Yuxin; Luo, Ling; Zhu, Yabin, E-mail: zhuyabin@nbu.edu.cn

    2013-05-01

    The mortality rate from esophageal disease like atresia, carcinoma, tracheoesophageal fistula, etc. is increasing rapidly all over the world. Traditional therapies such as surgery, radiotherapy or chemotherapy have been met with very limited success resulting in reduced survival rate and quality of patients' life. Tissue-engineered esophagus, a novel substitute possessing structure and function similar to native tissue, is believed to be an effective therapy and a promising replacement in the future. However, research on esophageal tissue engineering is still at an early stage. Considerable research has been focused on developing ideal scaffolds with optimal materials and methods of fabrication. This article gives a review of materials and scaffold fabrications currently applied in esophageal tissue engineering research. - Highlights: ► Natural and synthesized materials are being developed as scaffold matrices. ► Several technologies have been applied to reconstruct esophagus tissue scaffold. ► Tissue-engineered esophagus is a promising artificial replacement.

  19. [Neuronal and hormonal regulatory mechanisms of tears production and secretion].

    Science.gov (United States)

    Mrugacz, Małgorzata; Zywalewska, Nella; Bakunowicz-Lazarczyk, Alina

    2005-01-01

    The ocular surface, tear film, lacrimal glands act as a functional unit to preserve the quality of the refractive surface of the eye, and to resist injury and protect the eye against bodily and environmental conditions. Homeostasis of this functional unit involves neuronal and hormonal regulatory mechanisms. The eye appears to be a target organ for sex hormones particulary the androgen, as they modulate the immune system and trophic functions of the lacrimal and Meibomian glands.

  20. Ocular surface immunity: Homeostatic mechanisms and their disruption in dry eye disease

    OpenAIRE

    Barabino, Stefano; Chen, Yihe; Chauhan, Sunil Kumar; Dana, Reza

    2012-01-01

    The tear film, lacrimal glands, corneal and conjunctival epithelia and Meibomian glands work together as a lacrimal functional unit (LFU) to preserve the integrity and function of the ocular surface. The integrity of this unit is necessary for the health and normal function of the eye and visual system. Nervous connections and systemic hormones are well known factors that maintain the homeostasis of the ocular surface. They control the response to internal and external stimuli. Our and others...

  1. Transgene-mediated suppression of dengue viruses in the salivary glands of the yellow fever mosquito, Aedes aegypti.

    Science.gov (United States)

    Mathur, G; Sanchez-Vargas, I; Alvarez, D; Olson, K E; Marinotti, O; James, A A

    2010-12-01

    Controlled sex-, stage- and tissue-specific expression of antipathogen effector molecules is important for genetic engineering strategies to control mosquito-borne diseases. Adult female salivary glands are involved in pathogen transmission to human hosts and are target sites for expression of antipathogen effector molecules. The Aedes aegypti 30K a and 30K b genes are expressed exclusively in adult female salivary glands and are transcribed divergently from start sites separated by 263 nucleotides. The intergenic, 5'- and 3'-end untranslated regions of both genes are sufficient to express simultaneously two different transgene products in the distal-lateral lobes of the female salivary glands. An antidengue effector gene, membranes no protein (Mnp), driven by the 30K b promoter, expresses an inverted-repeat RNA with sequences derived from the premembrane protein-encoding region of the dengue virus serotype 2 genome and reduces significantly the prevalence and mean intensities of viral infection in mosquito salivary glands and saliva. © 2010 The Authors. Insect Molecular Biology © 2010 The Royal Entomological Society.

  2. Cell Patterning for Liver Tissue Engineering via Dielectrophoretic Mechanisms

    Directory of Open Access Journals (Sweden)

    Wan Nurlina Wan Yahya

    2014-07-01

    Full Text Available Liver transplantation is the most common treatment for patients with end-stage liver failure. However, liver transplantation is greatly limited by a shortage of donors. Liver tissue engineering may offer an alternative by providing an implantable engineered liver. Currently, diverse types of engineering approaches for in vitro liver cell culture are available, including scaffold-based methods, microfluidic platforms, and micropatterning techniques. Active cell patterning via dielectrophoretic (DEP force showed some advantages over other methods, including high speed, ease of handling, high precision and being label-free. This article summarizes liver function and regenerative mechanisms for better understanding in developing engineered liver. We then review recent advances in liver tissue engineering techniques and focus on DEP-based cell patterning, including microelectrode design and patterning configuration.

  3. Laminin-111-derived peptide conjugated fibrin hydrogel restores salivary gland function.

    Directory of Open Access Journals (Sweden)

    Kihoon Nam

    Full Text Available Hyposalivation reduces the patient quality of life, as saliva is important for maintaining oral health. Current treatments for hyposalivation are limited to medications such as the muscarinic receptor agonists, pilocarpine and cevimeline. However, these therapies only provide temporary relief. Therefore, alternative therapies are essential to restore salivary gland function. An option is to use bioengineered scaffolds to promote functional salivary gland regeneration. Previous studies demonstrated that the laminin-111 protein is critical for intact salivary gland cell cluster formation and organization. However, laminin-111 protein as a whole is not suitable for clinical applications as some protein domains may contribute to unwanted side effects such as degradation, tumorigenesis and immune responses. Conversely, the use of synthetic laminin-111 peptides makes it possible to minimize the immune reactivity or pathogen transfer. In addition, it is relatively simple and inexpensive as compared to animal-derived proteins. Therefore, the goal of this study was to demonstrate whether a 20 day treatment with laminin-111-derived peptide conjugated fibrin hydrogel promotes tissue regeneration in submandibular glands of a wound healing mouse model. In this study, laminin-111-derived peptide conjugated fibrin hydrogel significantly accelerated formation of salivary gland tissue. The regenerated gland tissues displayed not only structural but also functional restoration.

  4. Animal models for bone tissue engineering and modelling disease

    Science.gov (United States)

    Griffin, Michelle

    2018-01-01

    ABSTRACT Tissue engineering and its clinical application, regenerative medicine, are instructing multiple approaches to aid in replacing bone loss after defects caused by trauma or cancer. In such cases, bone formation can be guided by engineered biodegradable and nonbiodegradable scaffolds with clearly defined architectural and mechanical properties informed by evidence-based research. With the ever-increasing expansion of bone tissue engineering and the pioneering research conducted to date, preclinical models are becoming a necessity to allow the engineered products to be translated to the clinic. In addition to creating smart bone scaffolds to mitigate bone loss, the field of tissue engineering and regenerative medicine is exploring methods to treat primary and secondary bone malignancies by creating models that mimic the clinical disease manifestation. This Review gives an overview of the preclinical testing in animal models used to evaluate bone regeneration concepts. Immunosuppressed rodent models have shown to be successful in mimicking bone malignancy via the implantation of human-derived cancer cells, whereas large animal models, including pigs, sheep and goats, are being used to provide an insight into bone formation and the effectiveness of scaffolds in induced tibial or femoral defects, providing clinically relevant similarity to human cases. Despite the recent progress, the successful translation of bone regeneration concepts from the bench to the bedside is rooted in the efforts of different research groups to standardise and validate the preclinical models for bone tissue engineering approaches. PMID:29685995

  5. 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.

  6. Clinical management of salivary gland hypofunction and xerostomia in head-and-neck cancer patients: successes and barriers

    DEFF Research Database (Denmark)

    Vissink, A.; Mitchell, J.B.; Baum, B.J.

    2010-01-01

    , and issues contributing to the clinical management of salivary gland hypofunction and xerostomia. These include ways to (1) prevent or minimize radiation injury of salivary gland tissue, (2) manage radiation-induced hyposalivation and xerostomia, and (3) restore the function of salivary gland tissue damaged......The most significant long-term complication of radiotherapy in the head-and-neck region is hyposalivation and its related complaints, particularily xerostomia. This review addresses the pathophysiology underlying irradiation damage to salivary gland tissue, the consequences of radiation injury...

  7. Mechanical stretching for tissue engineering: two-dimensional and three-dimensional constructs.

    Science.gov (United States)

    Riehl, Brandon D; Park, Jae-Hong; Kwon, Il Keun; Lim, Jung Yul

    2012-08-01

    Mechanical cell stretching may be an attractive strategy for the tissue engineering of mechanically functional tissues. It has been demonstrated that cell growth and differentiation can be guided by cell stretch with minimal help from soluble factors and engineered tissues that are mechanically stretched in bioreactors may have superior organization, functionality, and strength compared with unstretched counterparts. This review explores recent studies on cell stretching in both two-dimensional (2D) and three-dimensional (3D) setups focusing on the applications of stretch stimulation as a tool for controlling cell orientation, growth, gene expression, lineage commitment, and differentiation and for achieving successful tissue engineering of mechanically functional tissues, including cardiac, muscle, vasculature, ligament, tendon, bone, and so on. Custom stretching devices and lab-specific mechanical bioreactors are described with a discussion on capabilities and limitations. While stretch mechanotransduction pathways have been examined using 2D stretch, studying such pathways in physiologically relevant 3D environments may be required to understand how cells direct tissue development under stretch. Cell stretch study using 3D milieus may also help to develop tissue-specific stretch regimens optimized with biochemical feedback, which once developed will provide optimal tissue engineering protocols.

  8. Applied Induced Pluripotent Stem Cells in Combination With Biomaterials in Bone Tissue Engineering.

    Science.gov (United States)

    Ardeshirylajimi, Abdolreza

    2017-10-01

    Due to increasing of the orthopedic lesions and fractures in the world and limitation of current treatment methods, researchers, and surgeons paid attention to the new treatment ways especially to tissue engineering and regenerative medicine. Innovation in stem cells and biomaterials accelerate during the last decade as two main important parts of the tissue engineering. Recently, induced pluripotent stem cells (iPSCs) introduced as cells with highly proliferation and differentiation potentials that hold great promising features for used in tissue engineering and regenerative medicine. As another main part of tissue engineering, synthetic, and natural polymers have been shown daily grow up in number to increase and improve the grade of biopolymers that could be used as scaffold with or without stem cells for implantation. One of the developed areas of tissue engineering is bone tissue engineering; the aim of this review is present studies were done in the field of bone tissue engineering while used iPSCs in combination with natural and synthetic biomaterials. J. Cell. Biochem. 118: 3034-3042, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Interactive navigation-guided ophthalmic plastic surgery: navigation enabling of telescopes and their use in endoscopic lacrimal surgeries

    Directory of Open Access Journals (Sweden)

    Ali MJ

    2016-11-01

    Full Text Available Mohammad Javed Ali,1 Swati Singh,1 Milind N Naik,1 Swathi Kaliki,2 Tarjani Vivek Dave1 1The Institute of Dacryology, 2The Operation Eyesight Universal Institute for Eye Cancer, L.V. Prasad Eye Institute, Hyderabad, India Purpose: The aims of this study were to report the preliminary experience of using telescopes, which were enabled for navigation guidance, and their utility in complex endoscopic lacrimal surgeries. Methods: Navigation enabling of the telescope was achieved by using the AxiEM™ malleable neuronavigation shunt stylet. Image-guided dacryolocalization was performed in five patients using the intraoperative image-guided StealthStation™ system in the electromagnetic mode. The “look ahead” protocol software was used to assist the surgeon in assessing the intraoperative geometric location of the endoscope and what lies ahead in real time. All patients underwent navigation-guided powered endoscopic dacryocystorhinostomy. The utility of uninterrupted navigation guidance throughout the surgery with the endoscope as the navigating tool was noted. Results: Intraoperative geometric localization of the lacrimal sac and the nasolacrimal duct could be easily deciphered. Constant orientation of the lacrimal drainage system and the peri-lacrimal anatomy was possible without the need for repeated point localizations throughout the surgery. The “look ahead” features could accurately alert the surgeon of anatomical structures that exists at 5, 10 and 15 mm in front of the endoscope. Good securing of the shunt stylet with the telescope was found to be essential for constant and accurate navigation. Conclusion: Navigation-enabled endoscopes provide the surgeon with the advantage of sustained stereotactic anatomical awareness at all times during the surgery. Keywords: telescope, endoscope, image guidance, navigation, lacrimal surgery, powered endoscopic DCR

  10. Multi-scale learning based segmentation of glands in digital colonrectal pathology images.

    Science.gov (United States)

    Gao, Yi; Liu, William; Arjun, Shipra; Zhu, Liangjia; Ratner, Vadim; Kurc, Tahsin; Saltz, Joel; Tannenbaum, Allen

    2016-02-01

    Digital histopathological images provide detailed spatial information of the tissue at micrometer resolution. Among the available contents in the pathology images, meso-scale information, such as the gland morphology, texture, and distribution, are useful diagnostic features. In this work, focusing on the colon-rectal cancer tissue samples, we propose a multi-scale learning based segmentation scheme for the glands in the colon-rectal digital pathology slides. The algorithm learns the gland and non-gland textures from a set of training images in various scales through a sparse dictionary representation. After the learning step, the dictionaries are used collectively to perform the classification and segmentation for the new image.

  11. Immunology of the eye

    OpenAIRE

    Weronika Ratajczak; Beata Tokarz-Deptuła; Wiesław Deptuła

    2018-01-01

    The eye is an organ of sight characterized by unusual immunological properties, resulting from its anatomical structure and physiology, as well as the presence of specific elements that, through the mechanisms of innate and adaptive immunity, provide homeostasis of the eyeball. This article reviews the defensive elements of individual eye structures: conjunctiva, cornea, lacrimal gland, anterior chamber of the eye, uvea, retina and eye-associated lymphoid tissue (EALT), where we distinguish a...

  12. A systematic review of salivary gland hypofunction and xerostomia induced by cancer therapies

    DEFF Research Database (Denmark)

    Jensen, S.B.; Pedersen, A.M.L.; Vissink, A.

    2010-01-01

    submandibular and minor salivary glands, as these glands are major contributors to moistening of oral tissues. Other cancer treatments also induce salivary gland hypofunction, although to a lesser severity, and in the case of chemotherapy and immunotherapy, the adverse effect is temporary. Fields of sparse...... met by 184 articles covering salivary gland hypofunction and xerostomia induced by conventional, 3D conformal radiotherapy or intensity-modulated radiotherapy in head and neck cancer patients, cancer chemotherapy, total body irradiation/hematopoietic stem cell transplantation, radioactive iodine...... treatment, and immunotherapy. Salivary gland hypofunction and xerostomia are induced by radiotherapy in the head and neck region depending on the cumulative radiation dose to the gland tissue. Treatment focus should be on optimized/new approaches to further reduce the dose to the parotids, and particularly...

  13. TTH biological effect and thyrocyte binding in functional states of the thyroid gland

    International Nuclear Information System (INIS)

    Petrova, G.A.

    1979-01-01

    It was established in experiments made in vitro on the thyroid glands of intact animals and also on hyperplastic, functionally atrophied and inflamed thyroid glands that tritiated TTH actively incorporated into thyroid gland cells of the control animals and raised the rate of thyroxin secretion. Under the conditions of experimental hyperplasia, atrophy and thyroiditis of the thyroid gland, the hormonogenic reaction of thyrocytes and the nature of TTH binding by them was greatly disturbed. The thyrocytes of the hyperplastic and inflamed thyroid tissue did not accept the labelled TTH and did not react to its administration by intensification of thyroxin secretion. The thyrocytes of the functionally atrophied thyroid gland tissue actively bound the tritiated TTH and enhanced thyroxin secretion

  14. Vascular tissue engineering by computer-aided laser micromachining.

    Science.gov (United States)

    Doraiswamy, Anand; Narayan, Roger J

    2010-04-28

    Many conventional technologies for fabricating tissue engineering scaffolds are not suitable for fabricating scaffolds with patient-specific attributes. For example, many conventional technologies for fabricating tissue engineering scaffolds do not provide control over overall scaffold geometry or over cell position within the scaffold. In this study, the use of computer-aided laser micromachining to create scaffolds for vascular tissue networks was investigated. Computer-aided laser micromachining was used to construct patterned surfaces in agarose or in silicon, which were used for differential adherence and growth of cells into vascular tissue networks. Concentric three-ring structures were fabricated on agarose hydrogel substrates, in which the inner ring contained human aortic endothelial cells, the middle ring contained HA587 human elastin and the outer ring contained human aortic vascular smooth muscle cells. Basement membrane matrix containing vascular endothelial growth factor and heparin was to promote proliferation of human aortic endothelial cells within the vascular tissue networks. Computer-aided laser micromachining provides a unique approach to fabricate small-diameter blood vessels for bypass surgery as well as other artificial tissues with complex geometries.

  15. 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

  16. Proangiogenic scaffolds as functional templates for cardiac tissue engineering.

    Science.gov (United States)

    Madden, Lauran R; Mortisen, Derek J; Sussman, Eric M; Dupras, Sarah K; Fugate, James A; Cuy, Janet L; Hauch, Kip D; Laflamme, Michael A; Murry, Charles E; Ratner, Buddy D

    2010-08-24

    We demonstrate here a cardiac tissue-engineering strategy addressing multicellular organization, integration into host myocardium, and directional cues to reconstruct the functional architecture of heart muscle. Microtemplating is used to shape poly(2-hydroxyethyl methacrylate-co-methacrylic acid) hydrogel into a tissue-engineering scaffold with architectures driving heart tissue integration. The construct contains parallel channels to organize cardiomyocyte bundles, supported by micrometer-sized, spherical, interconnected pores that enhance angiogenesis while reducing scarring. Surface-modified scaffolds were seeded with human ES cell-derived cardiomyocytes and cultured in vitro. Cardiomyocytes survived and proliferated for 2 wk in scaffolds, reaching adult heart densities. Cardiac implantation of acellular scaffolds with pore diameters of 30-40 microm showed angiogenesis and reduced fibrotic response, coinciding with a shift in macrophage phenotype toward the M2 state. This work establishes a foundation for spatially controlled cardiac tissue engineering by providing discrete compartments for cardiomyocytes and stroma in a scaffold that enhances vascularization and integration while controlling the inflammatory response.

  17. Degradable Adhesives for Surgery and Tissue Engineering.

    Science.gov (United States)

    Bhagat, Vrushali; Becker, Matthew L

    2017-10-09

    This review highlights the research on degradable polymeric tissue adhesives for surgery and tissue engineering. Included are a comprehensive listing of specific uses, advantages, and disadvantages of different adhesive groups. A critical evaluation of challenges affecting the development of next generation materials is also discussed, and insights into the outlook of the field are explored.

  18. Strategies and applications for incorporating physical and chemical signal gradients in tissue engineering.

    Science.gov (United States)

    Singh, Milind; Berkland, Cory; Detamore, Michael S

    2008-12-01

    From embryonic development to wound repair, concentration gradients of bioactive signaling molecules guide tissue formation and regeneration. Moreover, gradients in cellular and extracellular architecture as well as in mechanical properties are readily apparent in native tissues. Perhaps tissue engineers can take a cue from nature in attempting to regenerate tissues by incorporating gradients into engineering design strategies. Indeed, gradient-based approaches are an emerging trend in tissue engineering, standing in contrast to traditional approaches of homogeneous delivery of cells and/or growth factors using isotropic scaffolds. Gradients in tissue engineering lie at the intersection of three major paradigms in the field-biomimetic, interfacial, and functional tissue engineering-by combining physical (via biomaterial design) and chemical (with growth/differentiation factors and cell adhesion molecules) signal delivery to achieve a continuous transition in both structure and function. This review consolidates several key methodologies to generate gradients, some of which have never been employed in a tissue engineering application, and discusses strategies for incorporating these methods into tissue engineering and implant design. A key finding of this review was that two-dimensional physicochemical gradient substrates, which serve as excellent high-throughput screening tools for optimizing desired biomaterial properties, can be enhanced in the future by transitioning from two dimensions to three dimensions, which would enable studies of cell-protein-biomaterial interactions in a more native tissue-like environment. In addition, biomimetic tissue regeneration via combined delivery of graded physical and chemical signals appears to be a promising strategy for the regeneration of heterogeneous tissues and tissue interfaces. In the future, in vivo applications will shed more light on the performance of gradient-based mechanical integrity and signal delivery

  19. Hydatid disease of the submandibular gland

    International Nuclear Information System (INIS)

    Ullah, N.; Yousaf, N.

    2001-01-01

    Echinococcosis is a tissue infection of the human caused by the larval stage of echinococcus granulosus or E. multilocularis. Hydatid cyst of the head and neck region is uncommon and the involvement of salivary glands, especially the submandibular gland, is very rare. A case of submandibular gland hydatid cyst is reported in this article, in a patient who was presented with swelling of this area of three months' duration. Examination revealed a soft, non-tender, mobile mass measuring 6x4 cm. Chest X-ray and abdominal ultrasonography were normal. Excision of the whole mass was performed and pathological examination confirmed the fine needle aspiration cytology report. (author)

  20. A proteomics analysis for certain signature proteins of rabbit lacrimal passages after 125I seeds brachytherapy

    International Nuclear Information System (INIS)

    Li Dandan; Liu Lin; Gao Shi; Qi Liangchen; Ma Qingjie; Jin Longyun

    2010-01-01

    To search for certain signature proteins and the expression profiles in lacrimal passage stenosis, rabbit models of lacrimal passage stenosis were treated by 125 I seed brachytherapy. All the signature proteins were separated by two-dimensional electrophoresis, and identified by mass spectrometry. The results show that the up-regulated proteins are peptidyl-prolyl cis-trans isomerase A (PPIase A), and epidermal fatty acid-binding protein (E-FABP), while the down-regulated proteins are myosin light chain 1 (isomer of skeletal muscle), myosin light polypeptide 6 (isomer 1 of smooth muscle and non-muscle), myosin light chain 1 (isomer of slow-twitch muscle A), isomer 2 of ERC protein 2, and α-crystalline family protein. The proteins may play a role in healing the wound and regulating synaptic active zone of neurons due to correlation to cell apoptosis, proliferation and migration of smooth muscle cell. These provide molecular mechanism for preventing stenosis and restenosis of lacrimal passage. (authors)

  1. 3D Bioprinting Technologies for Hard Tissue and Organ Engineering

    Science.gov (United States)

    Wang, Xiaohong; Ao, Qiang; Tian, Xiaohong; Fan, Jun; Wei, Yujun; Hou, Weijian; Tong, Hao; Bai, Shuling

    2016-01-01

    Hard tissues and organs, including the bones, teeth and cartilage, are the most extensively exploited and rapidly developed areas in regenerative medicine field. One prominent character of hard tissues and organs is that their extracellular matrices mineralize to withstand weight and pressure. Over the last two decades, a wide variety of 3D printing technologies have been adapted to hard tissue and organ engineering. These 3D printing technologies have been defined as 3D bioprinting. Especially for hard organ regeneration, a series of new theories, strategies and protocols have been proposed. Some of the technologies have been applied in medical therapies with some successes. Each of the technologies has pros and cons in hard tissue and organ engineering. In this review, we summarize the advantages and disadvantages of the historical available innovative 3D bioprinting technologies for used as special tools for hard tissue and organ engineering. PMID:28773924

  2. 3D Bioprinting Technologies for Hard Tissue and Organ Engineering

    Directory of Open Access Journals (Sweden)

    Xiaohong Wang

    2016-09-01

    Full Text Available Hard tissues and organs, including the bones, teeth and cartilage, are the most extensively exploited and rapidly developed areas in regenerative medicine field. One prominent character of hard tissues and organs is that their extracellular matrices mineralize to withstand weight and pressure. Over the last two decades, a wide variety of 3D printing technologies have been adapted to hard tissue and organ engineering. These 3D printing technologies have been defined as 3D bioprinting. Especially for hard organ regeneration, a series of new theories, strategies and protocols have been proposed. Some of the technologies have been applied in medical therapies with some successes. Each of the technologies has pros and cons in hard tissue and organ engineering. In this review, we summarize the advantages and disadvantages of the historical available innovative 3D bioprinting technologies for used as special tools for hard tissue and organ engineering.

  3. 3D Bioprinting Technologies for Hard Tissue and Organ Engineering.

    Science.gov (United States)

    Wang, Xiaohong; Ao, Qiang; Tian, Xiaohong; Fan, Jun; Wei, Yujun; Hou, Weijian; Tong, Hao; Bai, Shuling

    2016-09-27

    Hard tissues and organs, including the bones, teeth and cartilage, are the most extensively exploited and rapidly developed areas in regenerative medicine field. One prominent character of hard tissues and organs is that their extracellular matrices mineralize to withstand weight and pressure. Over the last two decades, a wide variety of 3D printing technologies have been adapted to hard tissue and organ engineering. These 3D printing technologies have been defined as 3D bioprinting. Especially for hard organ regeneration, a series of new theories, strategies and protocols have been proposed. Some of the technologies have been applied in medical therapies with some successes. Each of the technologies has pros and cons in hard tissue and organ engineering. In this review, we summarize the advantages and disadvantages of the historical available innovative 3D bioprinting technologies for used as special tools for hard tissue and organ engineering.

  4. Clinical Management of Salivary Gland Hypofunction and Xerostomia in Head-and-Neck Cancer Patients: Successes and Barriers

    International Nuclear Information System (INIS)

    Vissink, Arjan; Mitchell, James B.; Baum, Bruce J.; Limesand, Kirsten H.; Jensen, Siri Beier; Fox, Philip C.; Elting, Linda S.; Langendijk, Johannes A.; Coppes, Robert P.; Reyland, Mary E.

    2010-01-01

    The most significant long-term complication of radiotherapy in the head-and-neck region is hyposalivation and its related complaints, particularily xerostomia. This review addresses the pathophysiology underlying irradiation damage to salivary gland tissue, the consequences of radiation injury, and issues contributing to the clinical management of salivary gland hypofunction and xerostomia. These include ways to (1) prevent or minimize radiation injury of salivary gland tissue, (2) manage radiation-induced hyposalivation and xerostomia, and (3) restore the function of salivary gland tissue damaged by radiotherapy.

  5. Lacrimal sac lymphoproliferative lesion: case report.

    Science.gov (United States)

    Coloma-González, I; Ruíz-García, L; Ceriotto, A; Corredor-Casas, S; Salcedo-Casillas, G

    2015-03-01

    The case is presented of a 51 year-old woman with a firm mass at the medial canthus of the right eye of five years onset. A low-grade lymphoproliferative lesion (reactive lymphoid hyperplasia) was diagnosed from an excisional biopsy Lacrimal sac tumors are rare, with a peak incidence in the fifth decade of life. The initial clinical features are epiphora and medial canthus swelling. As it mimics nasolacrimal duct obstruction, up to 40% of these tumors are misdiagnosed until undergoing surgery. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  6. Environmental regulation of valvulogenesis:implications for tissue engineering

    NARCIS (Netherlands)

    Riem Vis, P.W.; Kluin, J.; Sluijter, J.P.G.; Herwerden, van L.A.; Bouten, C.V.C.

    2011-01-01

    Ongoing research efforts aim at improving the creation of tissue-engineered heart valves for in vivo systemic application. Hence, in vitro studies concentrate on optimising culture protocols incorporating biological as well as biophysical stimuli for tissue development. Important lessons can be

  7. Electrical stimulation directs engineered cardiac tissue to an age-matched native phenotype

    Directory of Open Access Journals (Sweden)

    Richard A Lasher

    2012-12-01

    Full Text Available Quantifying structural features of native myocardium in engineered tissue is essential for creating functional tissue that can serve as a surrogate for in vitro testing or the eventual replacement of diseased or injured myocardium. We applied three-dimensional confocal imaging and image analysis to quantitatively describe the features of native and engineered cardiac tissue. Quantitative analysis methods were developed and applied to test the hypothesis that environmental cues direct engineered tissue toward a phenotype resembling that of age-matched native myocardium. The analytical approach was applied to engineered cardiac tissue with and without the application of electrical stimulation as well as to age-matched and adult native tissue. Individual myocytes were segmented from confocal image stacks and assigned a coordinate system from which measures of cell geometry and connexin-43 spatial distribution were calculated. The data were collected from 9 nonstimulated and 12 electrically stimulated engineered tissue constructs and 5 postnatal day 12 and 7 adult hearts. The myocyte volume fraction was nearly double in stimulated engineered tissue compared to nonstimulated engineered tissue (0.34 ± 0.14 vs 0.18 ± 0.06 but less than half of the native postnatal day 12 (0.90 ± 0.06 and adult (0.91 ± 0.04 myocardium. The myocytes under electrical stimulation were more elongated compared to nonstimulated myocytes and exhibited similar lengths, widths, and heights as in age-matched myocardium. Furthermore, the percentage of connexin-43-positive membrane staining was similar in the electrically stimulated, postnatal day 12, and adult myocytes, whereas it was significantly lower in the nonstimulated myocytes. Connexin-43 was found to be primarily located at cell ends for adult myocytes and irregularly but densely clustered over the membranes of nonstimulated, stimulated, and postnatal day 12 myocytes. These findings support our hypothesis and reveal

  8. Tissue-engineering as an adjunct to pelvic reconstructive surgery

    DEFF Research Database (Denmark)

    Jangö, Hanna

    of pelvic organ prolapse (POP) are warranted. Traditional native tissue repair may be associated with poor long-term outcome and augmentation with permanent polypropylene meshes is associated with frequent and severe adverse effects. Tissue-engineering is a regenerative strategy that aims at creating...... functional tissue using stem cells, scaffolds and trophic factors. The aim of this thesis was to investigate the potential adjunctive use of a tissue-engineering technique for pelvic reconstructive surgery using two synthetic biodegradable materials; methoxypolyethyleneglycol-poly(lactic-co-glycolic acid......) (MPEG-PLGA) and electrospun polycaprolactone (PCL) - with or without seeded muscle stem cells in the form of autologous fresh muscle fiber fragments (MFFs).To simulate different POP repair scenarios different animal models were used. In Study 1 and 2, MPEG-PLGA was evaluated in a native tissue repair...

  9. The Effect of the Aqueous Extract of Bidens Pilosa L. on Androgen Deficiency Dry Eye in Rats

    Directory of Open Access Journals (Sweden)

    Chuanwei Zhang

    2016-06-01

    Full Text Available Background/Aims: Bidens pilosa L. (Bp is widely distributed in China and has been widely used as a traditional Chinese medicine. The aim of this study was to examine the effect of the extract of Bp on androgen deficiency dry eye and determine its possible mechanisms. Methods: Twenty-four rats were randomly divided into four groups: Group Con (control, Group Sal (physiological saline, Group Fin (oral finasteride, and Group Bp (oral finasteride and Bp. The dry eye model was established in group Fin and group Bp. Aqueous tear quantity was measured with phenol red-impregnated cotton threads with anesthesia. Tear film breakup time (BUT and corneal epithelial damage were evaluated by fluorescein staining. Animals were sacrificed at 28 days, and ocular tissues (lacrimal gland and cornea were evaluated with light microscopy; gene microarray analysis for inflammatory cytokines and Western blot were also performed. Results: Finasteride administration effectively induced dry eye in rats by 14 days after administration. Group Fin rats had significantly higher fluorescein staining scores and lower aqueous tear quantity and BUT than the group Con rats, and notable inflammatory cell infiltrates were observed in the lacrimal gland of group Fin rats. The fluorescein staining score, aqueous tear quantity and BUT significantly improved with Bp treatment in the group Bp rats, and the structures of the lacrimal gland were well maintained without significant lymphocyte infiltration. Cytokine antibody array data identified the cytokines B7-2/Cd86, IL-1β, IL-4, IL-6, IL-10, MMP-8, FasL, TNF-α and TIMP-1 as candidates for validation by Western blot. Expression levels of pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α, in group Fin were upregulated compared with group Con. Levels of anti-inflammatory cytokines, such as IL-4 and IL-10, in group Fin were also upregulated compared with those in group Con. Compared with group Fin, IL-1β, FasL, and TNF

  10. The Effect of the Aqueous Extract of Bidens Pilosa L. on Androgen Deficiency Dry Eye in Rats.

    Science.gov (United States)

    Zhang, Chuanwei; Li, Kai; Yang, Zichao; Wang, Yuliang; Si, Haipeng

    2016-01-01

    Bidens pilosa L. (Bp) is widely distributed in China and has been widely used as a traditional Chinese medicine. The aim of this study was to examine the effect of the extract of Bp on androgen deficiency dry eye and determine its possible mechanisms. Twenty-four rats were randomly divided into four groups: Group Con (control), Group Sal (physiological saline), Group Fin (oral finasteride), and Group Bp (oral finasteride and Bp). The dry eye model was established in group Fin and group Bp. Aqueous tear quantity was measured with phenol red-impregnated cotton threads with anesthesia. Tear film breakup time (BUT) and corneal epithelial damage were evaluated by fluorescein staining. Animals were sacrificed at 28 days, and ocular tissues (lacrimal gland and cornea) were evaluated with light microscopy; gene microarray analysis for inflammatory cytokines and Western blot were also performed. Finasteride administration effectively induced dry eye in rats by 14 days after administration. Group Fin rats had significantly higher fluorescein staining scores and lower aqueous tear quantity and BUT than the group Con rats, and notable inflammatory cell infiltrates were observed in the lacrimal gland of group Fin rats. The fluorescein staining score, aqueous tear quantity and BUT significantly improved with Bp treatment in the group Bp rats, and the structures of the lacrimal gland were well maintained without significant lymphocyte infiltration. Cytokine antibody array data identified the cytokines B7-2/Cd86, IL-1β, IL-4, IL-6, IL-10, MMP-8, FasL, TNF-α and TIMP-1 as candidates for validation by Western blot. Expression levels of pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α, in group Fin were upregulated compared with group Con. Levels of anti-inflammatory cytokines, such as IL-4 and IL-10, in group Fin were also upregulated compared with those in group Con. Compared with group Fin, IL-1β, FasL, and TNF-α were significantly decreased in group Bp. The

  11. 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

  12. Vascularization of soft tissue engineering constructs

    DEFF Research Database (Denmark)

    Pimentel Carletto, Rodrigo

    nanotechnology-based paradigm for engineering vascularised liver tissue for transplantation”) and the Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug delivery and sensing Using microcontainers and Nanomechanics (Danish National Research Foundation (DNRF122).......Vascularization is recognized to be the biggest challenge for the fabrication of tissues and finally, organs in vitro. So far, several fabrication techniques have been proposed to create a perfusable vasculature within hydrogels, however, the vascularization and perfusion of hydrogels...... with mechanical properties in the range of soft tissues has not been fully achieved. My project focused on the fabrication and the active perfusion of hydrogel constructs with multi-dimensional vasculature and controlled mechanical properties targeting soft tissues. Specifically, the initial part of the research...

  13. Advances and perspectives in tooth tissue engineering.

    Science.gov (United States)

    Monteiro, Nelson; Yelick, Pamela C

    2017-09-01

    Bio-engineered teeth that can grow and remodel in a manner similar to that of natural teeth have the potential to serve as permanent replacements to the currently used prosthetic teeth, such as dental implants. A major challenge in designing functional bio-engineered teeth is to mimic both the structural and anisotropic mechanical characteristics of the native tooth. Therefore, the field of dental and whole tooth regeneration has advanced towards the molecular and nanoscale design of bio-active, biomimetic systems, using biomaterials, drug delivery systems and stem cells. The focus of this review is to discuss recent advances in tooth tissue engineering, using biomimetic scaffolds that provide proper architectural cues, exhibit the capacity to support dental stem cell proliferation and differentiation and sequester and release bio-active agents, such as growth factors and nucleic acids, in a spatiotemporal controlled manner. Although many in vitro and in vivo studies on tooth regeneration appear promising, before tooth tissue engineering becomes a reality for humans, additional research is needed to perfect methods that use adult human dental stem cells, as opposed to embryonic dental stem cells, and to devise the means to generate bio-engineered teeth of predetermined size and shape. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. 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-engineering

  15. HEPATIC TISSUE ENGINEERING (MODERN STATE OF THIS PROBLEM

    Directory of Open Access Journals (Sweden)

    Y.S. Gulay

    2014-01-01

    Full Text Available In this article it was discussed the problem of creation implanted hepatic tissue engineering designs as a modern stage of complex investigation for working out bioartifi cial liver support systems. It was determined that for the positive decision of numerous biological and technological problems it is necessary: to use matrices with determined properties, which mimic properties of hepatic extracellular matrix; to use technology for stereotype sowing of these matrices by both parenchymal and non-parenchymal hepatic cells and to improve the technologies for making and assembling of hepatic tissue-engineering designs.

  16. Methods of Monitoring Cell Fate and Tissue Growth in Three-Dimensional Scaffold-Based Strategies for In Vitro Tissue Engineering.

    Science.gov (United States)

    Leferink, Anne M; van Blitterswijk, Clemens A; Moroni, Lorenzo

    2016-08-01

    In the field of tissue engineering, there is a need for methods that allow assessing the performance of tissue-engineered constructs noninvasively in vitro and in vivo. To date, histological analysis is the golden standard to retrieve information on tissue growth, cellular distribution, and cell fate on tissue-engineered constructs after in vitro cell culture or on explanted specimens after in vivo applications. Yet, many advances have been made to optimize imaging techniques for monitoring tissue-engineered constructs with a sub-mm or μm resolution. Many imaging modalities have first been developed for clinical applications, in which a high penetration depth has been often more important than lateral resolution. In this study, we have reviewed the current state of the art in several imaging approaches that have shown to be promising in monitoring cell fate and tissue growth upon in vitro culture. Depending on the aimed tissue type and scaffold properties, some imaging methods are more applicable than others. Optical methods are mostly suited for transparent materials such as hydrogels, whereas magnetic resonance-based methods are mostly applied to obtain contrast between hard and soft tissues regardless of their transparency. Overall, this review shows that the field of imaging in scaffold-based tissue engineering is developing at a fast pace and has the potential to overcome the limitations of destructive endpoint analysis.

  17. Value of sialography and salivary gland scintigraphy in the evaluation of rheumatoid polyarthritis

    International Nuclear Information System (INIS)

    Rousse, M.M.

    1976-01-01

    This work aims to establish the frequency and severity of salivary gland disease. Very many techniques are available for the exploration of these glands. Each patient was subjected to: a parotid sialograph, a technetium 99m exploration of the salivary glands and mouth cavity. These two methods of salivary gland exploration should be carried out together, since sialographic data are largely static and anatomical while scintigraphy mainly supplies dynamic, functional data. The scintigraphic examinations were carried out with a Picker Dyna Camera II coupled to data processing units (NUKAB system with recorded programmes). The radiotracer used is technetium 99m. 2 millicuries of technetium as pertechnetate are injected intraveinously and reach the salivary glands through their vascular networks, thus being available to the different tissues of each gland: interstitial tissue, acini, intralobular ducts, efferent ducts [fr

  18. Colloquium: Modeling the dynamics of multicellular systems: Application to tissue engineering

    Science.gov (United States)

    Kosztin, Ioan; Vunjak-Novakovic, Gordana; Forgacs, Gabor

    2012-10-01

    Tissue engineering is a rapidly evolving discipline that aims at building functional tissues to improve or replace damaged ones. To be successful in such an endeavor, ideally, the engineering of tissues should be based on the principles of developmental biology. Recent progress in developmental biology suggests that the formation of tissues from the composing cells is often guided by physical laws. Here a comprehensive computational-theoretical formalism is presented that is based on experimental input and incorporates biomechanical principles of developmental biology. The formalism is described and it is shown that it correctly reproduces and predicts the quantitative characteristics of the fundamental early developmental process of tissue fusion. Based on this finding, the formalism is then used toward the optimization of the fabrication of tubular multicellular constructs, such as a vascular graft, by bioprinting, a novel tissue engineering technology.

  19. Electrospun Nanofibrous Materials for Neural Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Yee-Shuan Lee

    2011-02-01

    Full Text Available The use of biomaterials processed by the electrospinning technique has gained considerable interest for neural tissue engineering applications. The tissue engineering strategy is to facilitate the regrowth of nerves by combining an appropriate cell type with the electrospun scaffold. Electrospinning can generate fibrous meshes having fiber diameter dimensions at the nanoscale and these fibers can be nonwoven or oriented to facilitate neurite extension via contact guidance. This article reviews studies evaluating the effect of the scaffold’s architectural features such as fiber diameter and orientation on neural cell function and neurite extension. Electrospun meshes made of natural polymers, proteins and compositions having electrical activity in order to enhance neural cell function are also discussed.

  20. 3D bioprinting for engineering complex tissues.

    Science.gov (United States)

    Mandrycky, Christian; Wang, Zongjie; Kim, Keekyoung; Kim, Deok-Ho

    2016-01-01

    Bioprinting is a 3D fabrication technology used to precisely dispense cell-laden biomaterials for the construction of complex 3D functional living tissues or artificial organs. While still in its early stages, bioprinting strategies have demonstrated their potential use in regenerative medicine to generate a variety of transplantable tissues, including skin, cartilage, and bone. However, current bioprinting approaches still have technical challenges in terms of high-resolution cell deposition, controlled cell distributions, vascularization, and innervation within complex 3D tissues. While no one-size-fits-all approach to bioprinting has emerged, it remains an on-demand, versatile fabrication technique that may address the growing organ shortage as well as provide a high-throughput method for cell patterning at the micrometer scale for broad biomedical engineering applications. In this review, we introduce the basic principles, materials, integration strategies and applications of bioprinting. We also discuss the recent developments, current challenges and future prospects of 3D bioprinting for engineering complex tissues. Combined with recent advances in human pluripotent stem cell technologies, 3D-bioprinted tissue models could serve as an enabling platform for high-throughput predictive drug screening and more effective regenerative therapies. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. AAV vector encoding human VEGF165-transduced pectineus muscular flaps increase the formation of new tissue through induction of angiogenesis in an in vivo chamber for tissue engineering: A technique to enhance tissue and vessels in microsurgically engineered tissue.

    Science.gov (United States)

    Moimas, Silvia; Manasseri, Benedetto; Cuccia, Giuseppe; Stagno d'Alcontres, Francesco; Geuna, Stefano; Pattarini, Lucia; Zentilin, Lorena; Giacca, Mauro; Colonna, Michele R

    2015-01-01

    In regenerative medicine, new approaches are required for the creation of tissue substitutes, and the interplay between different research areas, such as tissue engineering, microsurgery and gene therapy, is mandatory. In this article, we report a modification of a published model of tissue engineering, based on an arterio-venous loop enveloped in a cross-linked collagen-glycosaminoglycan template, which acts as an isolated chamber for angiogenesis and new tissue formation. In order to foster tissue formation within the chamber, which entails on the development of new vessels, we wondered whether we might combine tissue engineering with a gene therapy approach. Based on the well-described tropism of adeno-associated viral vectors for post-mitotic tissues, a muscular flap was harvested from the pectineus muscle, inserted into the chamber and transduced by either AAV vector encoding human VEGF165 or AAV vector expressing the reporter gene β-galactosidase, as a control. Histological analysis of the specimens showed that muscle transduction by AAV vector encoding human VEGF165 resulted in enhanced tissue formation, with a significant increase in the number of arterioles within the chamber in comparison with the previously published model. Pectineus muscular flap, transduced by adeno-associated viral vectors, acted as a source of the proangiogenic factor vascular endothelial growth factor, thus inducing a consistent enhancement of vessel growth into the newly formed tissue within the chamber. In conclusion, our present findings combine three different research fields such as microsurgery, tissue engineering and gene therapy, suggesting and showing the feasibility of a mixed approach for regenerative medicine.

  2. Tissue engineering for urinary tract reconstruction and repair: Progress and prospect in China.

    Science.gov (United States)

    Zou, Qingsong; Fu, Qiang

    2018-04-01

    Several urinary tract pathologic conditions, such as strictures, cancer, and obliterations, require reconstructive plastic surgery. Reconstruction of the urinary tract is an intractable task for urologists due to insufficient autologous tissue. Limitations of autologous tissue application prompted urologists to investigate ideal substitutes. Tissue engineering is a new direction in these cases. Advances in tissue engineering over the last 2 decades may offer alternative approaches for the urinary tract reconstruction. The main components of tissue engineering include biomaterials and cells. Biomaterials can be used with or without cultured cells. This paper focuses on cell sources, biomaterials, and existing methods of tissue engineering for urinary tract reconstruction in China. The paper also details challenges and perspectives involved in urinary tract reconstruction.

  3. Fabrication and characterization of scaffold from cadaver goat-lung tissue for skin tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Sweta K. [Department of Polymer and Process Engineering, Indian Institute of Technology, Roorkee (India); Dinda, Amit K. [Department of Pathology, All India Institute of Medical Sciences, New Delhi (India); Potdar, Pravin D. [Department of Molecular Medicine, Jaslok Hospital and Research Centre, Mumbai (India); Mishra, Narayan C., E-mail: mishrawise@gmail.com [Department of Polymer and Process Engineering, Indian Institute of Technology, Roorkee (India)

    2013-10-15

    The present study aims to fabricate scaffold from cadaver goat-lung tissue and evaluate it for skin tissue engineering applications. Decellularized goat-lung scaffold was fabricated by removing cells from cadaver goat-lung tissue enzymatically, to have cell-free 3D-architecture of natural extracellular matrix. DNA quantification assay and Hematoxylin and eosin staining confirmed the absence of cellular material in the decellularized lung-tissue. SEM analysis of decellularized scaffold shows the intrinsic porous structure of lung tissue with well-preserved pore-to-pore interconnectivity. FTIR analysis confirmed non-denaturation and well maintainance of collagenous protein structure of decellularized scaffold. MTT assay, SEM analysis and H and E staining of human skin-derived Mesenchymal Stem cell, seeded over the decellularized scaffold, confirms stem cell attachment, viability, biocompatibility and proliferation over the decellularized scaffold. Expression of Keratin18 gene, along with CD105, CD73 and CD44, by human skin-derived Mesenchymal Stem cells over decellularized scaffold signifies that the cells are viable, proliferating and migrating, and have maintained their critical cellular functions in the presence of scaffold. Thus, overall study proves the applicability of the goat-lung tissue derived decellularized scaffold for skin tissue engineering applications. - Highlights: • We successfully fabricated decellularized scaffold from cadaver goat-lung tissue. • Decellularized goat-lung scaffolds were found to be highly porous. • Skin derived MSC shows high cell viability and proliferation over the scaffold. • Phenotype of MSCs was well maintained over the scaffold. • The scaffold shows potential for applications in skin tissue engineering.

  4. Fabrication and characterization of scaffold from cadaver goat-lung tissue for skin tissue engineering applications

    International Nuclear Information System (INIS)

    Gupta, Sweta K.; Dinda, Amit K.; Potdar, Pravin D.; Mishra, Narayan C.

    2013-01-01

    The present study aims to fabricate scaffold from cadaver goat-lung tissue and evaluate it for skin tissue engineering applications. Decellularized goat-lung scaffold was fabricated by removing cells from cadaver goat-lung tissue enzymatically, to have cell-free 3D-architecture of natural extracellular matrix. DNA quantification assay and Hematoxylin and eosin staining confirmed the absence of cellular material in the decellularized lung-tissue. SEM analysis of decellularized scaffold shows the intrinsic porous structure of lung tissue with well-preserved pore-to-pore interconnectivity. FTIR analysis confirmed non-denaturation and well maintainance of collagenous protein structure of decellularized scaffold. MTT assay, SEM analysis and H and E staining of human skin-derived Mesenchymal Stem cell, seeded over the decellularized scaffold, confirms stem cell attachment, viability, biocompatibility and proliferation over the decellularized scaffold. Expression of Keratin18 gene, along with CD105, CD73 and CD44, by human skin-derived Mesenchymal Stem cells over decellularized scaffold signifies that the cells are viable, proliferating and migrating, and have maintained their critical cellular functions in the presence of scaffold. Thus, overall study proves the applicability of the goat-lung tissue derived decellularized scaffold for skin tissue engineering applications. - Highlights: • We successfully fabricated decellularized scaffold from cadaver goat-lung tissue. • Decellularized goat-lung scaffolds were found to be highly porous. • Skin derived MSC shows high cell viability and proliferation over the scaffold. • Phenotype of MSCs was well maintained over the scaffold. • The scaffold shows potential for applications in skin tissue engineering

  5. Tissue engineered bone versus alloplastic commercial biomaterials in craniofacial reconstruction.

    Science.gov (United States)

    Lucaciu, Ondine; Băciuţ, Mihaela; Băciuţ, G; Câmpian, R; Soriţău, Olga; Bran, S; Crişan, B; Crişan, Liana

    2010-01-01

    This research was developed in order to demonstrate the tissue engineering method as an alternative to conventional methods for bone reconstruction, in order to overcome the frequent failures of alloplastic commercial biomaterials, allografts and autografts. Tissue engineering is an in vitro method used to obtain cell based osteoinductive bone grafts. This study evaluated the feasibility of creating tissue-engineered bone using mesenchymal cells seeded on a scaffold obtained from the deciduous red deer antler. We have chosen mesenchymal stem cells because they are easy to obtain, capable to differentiate into cells of mesenchymal origin (osteoblasts) and to produce tissue such as bone. As scaffold, we have chosen the red deer antler because it has a high level of porosity. We conducted a case control study, on three groups of mice type CD1--two study groups (n=20) and a control group (n=20). For the study groups, we obtained bone grafts through tissue engineering, using mesenchymal stem cells seeded on the scaffold made of deciduous red deer antler. Bone defects were surgically induced on the left parietal bone of all subjects. In the control group, we grafted the bone defects with commercial biomaterials (OsteoSet, Wright Medical Technology, Inc., Arlington, Federal USA). Subjects were sacrificed at two and four months, the healing process was morphologically and histologically evaluated using descriptive histology and the golden standard - histological scoring. The grafts obtained in vivo through tissue engineering using adult stem cell, seeded on the scaffold obtained from the red deer antler using osteogenic medium have proven their osteogenic properties.

  6. Isolation and Tissue Distribution of an Insulin-Like Androgenic Gland Hormone (IAG of the Male Red Deep-Sea Crab, Chaceon quinquedens

    Directory of Open Access Journals (Sweden)

    Amanda Lawrence

    2017-08-01

    Full Text Available The insulin-like androgenic gland hormone (IAG found in decapod crustaceans is known to regulate sexual development in males. IAG is produced in the male-specific endocrine tissue, the androgenic gland (AG; however, IAG expression has been also observed in other tissues of decapod crustacean species including Callinectes sapidus and Scylla paramamosain. This study aimed to isolate the full-length cDNA sequence of IAG from the AG of male red deep-sea crabs, Chaceon quinquedens (ChqIAG, and to examine its tissue distribution. To this end, we employed polymerase chain reaction cloning with degenerate primers and 5′ and 3′ rapid amplification of cDNA ends (RACE. The full-length ChqIAG cDNA sequence (1555 nt includes a 366 nt 5′ untranslated region a 453 nt open reading frame encoding 151 amino acids, and a relatively long 3′ UTR of 733 nt. The ORF consists of a 19 aa signal peptide, 32 aa B chain, 56 aa C chain, and 44 aa A chain. The putative ChqIAG amino acid sequence is most similar to those found in other crab species, including C. sapidus and S. paramamosain, which are clustered together phylogenetically.

  7. Tissue engineered devices for ligament repair, replacement and ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-29

    Dec 29, 2009 ... These devices use a wide variety of materials and designs to replicate ligament mechanics and allow for new tissue regeneration. Key words: Anterior cruciate ligament (ACL), tissue engineering, cells, tensile, stress relaxation, polymer, allograft, xenograft. INTRODUCTION. The anterior cruciate ligament ...

  8. Biocompatibility of hydrogel-based scaffolds for tissue engineering applications.

    Science.gov (United States)

    Naahidi, Sheva; Jafari, Mousa; Logan, Megan; Wang, Yujie; Yuan, Yongfang; Bae, Hojae; Dixon, Brian; Chen, P

    2017-09-01

    Recently, understanding of the extracellular matrix (ECM) has expanded rapidly due to the accessibility of cellular and molecular techniques and the growing potential and value for hydrogels in tissue engineering. The fabrication of hydrogel-based cellular scaffolds for the generation of bioengineered tissues has been based on knowledge of the composition and structure of ECM. Attempts at recreating ECM have used either naturally-derived ECM components or synthetic polymers with structural integrity derived from hydrogels. Due to their increasing use, their biocompatibility has been questioned since the use of these biomaterials needs to be effective and safe. It is not surprising then that the evaluation of biocompatibility of these types of biomaterials for regenerative and tissue engineering applications has been expanded from being primarily investigated in a laboratory setting to being applied in the multi-billion dollar medicinal industry. This review will aid in the improvement of design of non-invasive, smart hydrogels that can be utilized for tissue engineering and other biomedical applications. In this review, the biocompatibility of hydrogels and design criteria for fabricating effective scaffolds are examined. Examples of natural and synthetic hydrogels, their biocompatibility and use in tissue engineering are discussed. The merits and clinical complications of hydrogel scaffold use are also reviewed. The article concludes with a future outlook of the field of biocompatibility within the context of hydrogel-based scaffolds. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Regenerative therapy and tissue engineering for the treatment of end-stage cardiac failure

    Science.gov (United States)

    Finosh, G.T.; Jayabalan, Muthu

    2012-01-01

    Regeneration of myocardium through regenerative therapy and tissue engineering is appearing as a prospective treatment modality for patients with end-stage heart failure. Focusing on this area, this review highlights the new developments and challenges in the regeneration of myocardial tissue. The role of various cell sources, calcium ion and cytokine on the functional performance of regenerative therapy is discussed. The evolution of tissue engineering and the role of tissue matrix/scaffold, cell adhesion and vascularisation on tissue engineering of cardiac tissue implant are also discussed. PMID:23507781

  10. The influence of topography on tissue engineering perspective

    International Nuclear Information System (INIS)

    Mansouri, Negar; SamiraBagheri

    2016-01-01

    The actual in vivo tissue scaffold offers a three-dimensional (3D) structural support along with a nano-textured surfaces consist of a fibrous network in order to deliver cell adhesion and signaling. A scaffold is required, until the tissue is entirely regenerated or restored, to act as a temporary ingrowth template for cell proliferation and extracellular matrix (ECM) deposition. This review depicts some of the most significant three dimensional structure materials used as scaffolds in various tissue engineering application fields currently being employed to mimic in vivo features. Accordingly, some of the researchers' attempts have envisioned utilizing graphene for the fabrication of porous and flexible 3D scaffolds. The main focus of this paper is to evaluate the topographical and topological optimization of scaffolds for tissue engineering applications in order to improve scaffolds' mechanical performances. - Highlights: • The in vivo tissue scaffold offers a three-dimensional structural support. • Graphene can be used for fabrication of porous and flexible 3D scaffold. • Topological optimization improves scaffolds' mechanical performances.

  11. The influence of topography on tissue engineering perspective

    Energy Technology Data Exchange (ETDEWEB)

    Mansouri, Negar [Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); SamiraBagheri, E-mail: samira_bagheri@edu.um.my [Nanotechnology & Catalysis Research Centre (NANOCAT), IPS Building, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2016-04-01

    The actual in vivo tissue scaffold offers a three-dimensional (3D) structural support along with a nano-textured surfaces consist of a fibrous network in order to deliver cell adhesion and signaling. A scaffold is required, until the tissue is entirely regenerated or restored, to act as a temporary ingrowth template for cell proliferation and extracellular matrix (ECM) deposition. This review depicts some of the most significant three dimensional structure materials used as scaffolds in various tissue engineering application fields currently being employed to mimic in vivo features. Accordingly, some of the researchers' attempts have envisioned utilizing graphene for the fabrication of porous and flexible 3D scaffolds. The main focus of this paper is to evaluate the topographical and topological optimization of scaffolds for tissue engineering applications in order to improve scaffolds' mechanical performances. - Highlights: • The in vivo tissue scaffold offers a three-dimensional structural support. • Graphene can be used for fabrication of porous and flexible 3D scaffold. • Topological optimization improves scaffolds' mechanical performances.

  12. Mechanics of oriented electrospun nanofibrous scaffolds for annulus fibrosus tissue engineering.

    Science.gov (United States)

    Nerurkar, Nandan L; Elliott, Dawn M; Mauck, Robert L

    2007-08-01

    Engineering a functional replacement for the annulus fibrosus (AF) of the intervertebral disc is contingent upon recapitulation of AF structure, composition, and mechanical properties. In this study, we propose a new paradigm for AF tissue engineering that focuses on the reconstitution of anatomic fiber architecture and uses constitutive modeling to evaluate construct function. A modified electrospinning technique was utilized to generate aligned nanofibrous polymer scaffolds for engineering the basic functional unit of the AF, a single lamella. Scaffolds were tested in uniaxial tension at multiple fiber orientations, demonstrating a nonlinear dependence of modulus on fiber angle that mimicked the nonlinearity and anisotropy of native AF. A homogenization model previously applied to native AF successfully described scaffold mechanical response, and parametric studies demonstrated that nonfibrillar matrix, along with fiber connectivity, are key contributors to tensile mechanics for engineered AF. We demonstrated that AF cells orient themselves along the aligned scaffolds and deposit matrix that contributes to construct mechanics under loading conditions relevant to the in vivo environment. The homogenization model was applied to cell-seeded constructs and provided quantitative measures for the evolution of matrix and interfibrillar interactions. Finally, the model demonstrated that at fiber angles of the AF (28 degrees -44 degrees ), engineered material behaved much like native tissue, suggesting that engineered constructs replicate the physiologic behavior of the single AF lamella. Constitutive modeling provides a powerful tool for analysis of engineered AF neo-tissue and native AF tissue alike, highlighting key mechanical design criteria for functional AF tissue engineering.

  13. Biocompatibility of biodegradable semiconducting melanin films for nerve tissue engineering.

    Science.gov (United States)

    Bettinger, Christopher J; Bruggeman, Joost P; Misra, Asish; Borenstein, Jeffrey T; Langer, Robert

    2009-06-01

    The advancement of tissue engineering is contingent upon the development and implementation of advanced biomaterials. Conductive polymers have demonstrated potential for use as a medium for electrical stimulation, which has shown to be beneficial in many regenerative medicine strategies including neural and cardiac tissue engineering. Melanins are naturally occurring pigments that have previously been shown to exhibit unique electrical properties. This study evaluates the potential use of melanin films as a semiconducting material for tissue engineering applications. Melanin thin films were produced by solution processing and the physical properties were characterized. Films were molecularly smooth with a roughness (R(ms)) of 0.341 nm and a conductivity of 7.00+/-1.10 x 10(-5)S cm(-1) in the hydrated state. In vitro biocompatibility was evaluated by Schwann cell attachment and growth as well as neurite extension in PC12 cells. In vivo histology was evaluated by examining the biomaterial-tissue response of melanin implants placed in close proximity to peripheral nerve tissue. Melanin thin films enhanced Schwann cell growth and neurite extension compared to collagen films in vitro. Melanin films induced an inflammation response that was comparable to silicone implants in vivo. Furthermore, melanin implants were significantly resorbed after 8 weeks. These results suggest that solution-processed melanin thin films have the potential for use as a biodegradable semiconducting biomaterial for use in tissue engineering applications.

  14. Quantitative MR imaging of intra-orbital structures: Tissue-specific measurements and age dependency compared to extra-orbital structures using multispectral quantitative MR imaging.

    Science.gov (United States)

    Watanabe, Memi; Buch, Karen; Fujita, Akifumi; Jara, Hernán; Qureshi, Muhammad Mustafa; Sakai, Osamu

    2017-08-01

    The orbit can be affected by unique pathologic conditions and often requires MRI evaluation. The purpose of this study was to investigate the age-related changes in multiple intra-orbital structures using quantitative MRI (qMRI). Thirty-eight subjects (20 males, 18 females; ages 0.5-87 years) underwent MRI with a mixed turbo spin echo sequence. T1 and T2 measurements were obtained within ROI in 6 intra-orbital structures (medial and lateral rectus muscles, medial and lateral retrobulbar fat, lacrimal gland, and optic nerve), and compared with those of corresponding extra-orbital structures (masseter muscle, subcutaneous cheek fat, buccal fat, parotid gland, and frontal white matter). Statistical analyses were performed using Pearson's correlation coefficients. T1 and T2 values of the extra-ocular muscles increased with age, with higher T1 and T2 values compared to the masseter muscles. Retrobulbar fat showed significant age-associated increases in T1 values in the lateral side and in T2 values in both sides. T1 and T2 values in the lacrimal gland increased with age, while the parotid gland showed an age-associated increase in T2 values and decrease in T1 values. Optic nerves demonstrated age-related changes, similar to that of frontal white matter; rapid decreases with age in T1 and T2 times in early stages of life, and slight increases in T1 and T2 times later in life. Intra-orbital structures demonstrated specific qMRI measurements and aging patterns, which were different from extra-orbital structures. Location-specific age-related changes of intra-orbital structures should be considered in the qMRI assessment of the orbital pathology.

  15. [Tissue engineering with mesenchymal stem cells for cartilage and bone regeneration].

    Science.gov (United States)

    Schaefer, D J; Klemt, C; Zhang, X H; Stark, G B

    2000-09-01

    Tissue engineering offers the possibility to fabricate living substitutes for tissues and organs by combining histogenic cells and biocompatible carrier materials. Pluripotent mesenchymal stem cells are isolated and subcultured ex vivo and then their histogenic differentiation is induced by external factors. The fabrication of bone and cartilage constructs, their combinations and gene therapeutic approaches are demonstrated. Advantages and disadvantages of these methods are described by in vitro and in vitro testing. The proof of histotypical function after implantation in vivo is essential. The use of autologous cells and tissue engineering methods offers the possibility to overcome the disadvantages of classical tissue reconstruction--donor site morbidity of autologous grafts, immunogenicity of allogenic grafts and loosening of alloplastic implants. Furthermore, tissue engineering widens the spectrum of surgical indications in bone and cartilage reconstruction.

  16. Simple mucin-type carbohydrate antigens in major salivary glands

    DEFF Research Database (Denmark)

    Therkildsen, M H; Mandel, U; Thorn, J

    1994-01-01

    Simple mucin-type carbohydrate antigens Tn, sialosyl-Tn and T are often markers of neoplastic transformation and have very limited expression in normal tissues. We performed an immunohistological study of simple mucin-type carbohydrate antigens, including H and A variants, with well......-defined monoclonal antibodies (MAb) on frozen and paraffin-embedded normal salivary gland tissue from 22 parotid, 14 submandibular, six sublingual, and 13 labial glands to elucidate the simple mucin-type glycosylation pattern in relation to cyto- and histodifferentiation. The investigated carbohydrate structures...

  17. The dielectric properties of human pineal gland tissue and RF absorption due to wireless communication devices in the frequency range 400-1850 MHz

    International Nuclear Information System (INIS)

    Schmid, Gernot; Ueberbacher, Richard; Samaras, Theodoros; Tschabitscher, Manfred; Mazal, Peter R

    2007-01-01

    In order to enable a detailed analysis of radio frequency (RF) absorption in the human pineal gland, the dielectric properties of a sample of 20 freshly removed pineal glands were measured less than 20 h after death. Furthermore, a corresponding high resolution numerical model of the brain region surrounding the pineal gland was developed, based on a real human tissue sample. After inserting this model into a commercially available numerical head model, FDTD-based computations for exposure scenarios with generic models of handheld devices operated close to the head in the frequency range 400-1850 MHz were carried out. For typical output power values of real handheld mobile communication devices, the obtained results showed only very small amounts of absorbed RF power in the pineal gland when compared to SAR limits according to international safety standards. The highest absorption was found for the 400 MHz irradiation. In this case the RF power absorbed inside the pineal gland (organ mass 96 mg) was as low as 11 μW, when considering a device of 500 mW output power operated close to the ear. For typical mobile phone frequencies (900 MHz and 1850 MHz) and output power values (250 mW and 125 mW) the corresponding values of absorbed RF power in the pineal gland were found to be lower by a factor of 4.2 and 36, respectively. These results indicate that temperature-related biologically relevant effects on the pineal gland induced by the RF emissions of typical handheld mobile communication devices are unlikely

  18. Emerging bone tissue engineering via Polyhydroxyalkanoate (PHA)-based scaffolds.

    Science.gov (United States)

    Lim, Janice; You, Mingliang; Li, Jian; Li, Zibiao

    2017-10-01

    Polyhydroxyalkanoates (PHAs) are a class of biodegradable polymers derived from microorganisms. On top of their biodegradability and biocompatibility, different PHA types can contribute to varying mechanical and chemical properties. This has led to increasing attention to the use of PHAs in numerous biomedical applications over the past few decades. Bone tissue engineering refers to the regeneration of new bone through providing mechanical support while inducing cell growth on the PHA scaffolds having a porous structure for tissue regeneration. This review first introduces the various properties PHA scaffold that make them suitable for bone tissue engineering such as biocompatibility, biodegradability, mechanical properties as well as vascularization. The typical fabrication techniques of PHA scaffolds including electrospinning, salt-leaching and solution casting are further discussed, followed by the relatively new technology of using 3D printing in PHA scaffold fabrication. Finally, the recent progress of using different types of PHAs scaffold in bone tissue engineering applications are summarized in intrinsic PHA/blends forms or as composites with other polymeric or inorganic hybrid materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Radioanatomic correlations in the study of the intact mammary gland

    Energy Technology Data Exchange (ETDEWEB)

    Kolganova, I P; Zolotarevskii, V B [Pervyj Moskovskii Meditsinskii Inst. (USSR)

    1981-03-01

    The technique and results of parallel X-ray and morphologic study of mammary gland preparations of 30 women of different age who have died for various reasons, are described. The whole preparation is X-rayed in the native state and after fixation in formalline under the same conditions as in the clinic. The mammary gland preparation is split layer-by-layer with the following roentgenography and the study of histological substrate of all shadow elements. The investigations permit to single out 4 types of shadows on the mammograms conditioned by connecting tissue structures with the elements of glandular tissue. A definite type of mammary gland structure on roentgenograms is characteristic of every age period (child-bearing, preclimacteric, climax).

  20. Radioanatomic correlations in the study of the intact mammary gland

    International Nuclear Information System (INIS)

    Kolganova, I.P.; Zolotarevskij, V.B.

    1981-01-01

    The technique and results of parallel X-ray and morphologic study of mammary gland preparations of 30 women of different age who have died for various reasons, are described. The whole preparation is X-rayed in the native state and after fixation in formalline under the same conditions as in the clinic. The mammary gland preparation is split layer-by-layer with the following roentgenography and the study of histological substrate of all shadow elements. The investigations permit to single out 4 types of shadows on the mammograms conditioned by connecting tissue structures with the elements of glandular tissue. A definite type of mammary gland structure on roentgenograms is characteristic of every age period (child-bearing, preclimacteric, climax) [ru