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Meibomian Glands (meibomian + gland)

Distribution by Scientific Domains
Medical Sciences100%

Terms modified by Meibomian Glands

  • meibomian gland dysfunction
    		•

    Selected Abstracts

    Sebaceous Carcinoma of the Eyelid: Analogy to Extramammary Paget's Disease

    JOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005
    J.B. Lee
    We present a 69-year-old woman with a sebaceous carcinoma of the left upper eyelid, which originated from the Meibomian gland of the tarsal plate. The intraepidermal extension involved not only the conjunctival epithelium but also the overlying skin with subsequent extension into the dermis. The discussion will include diagnostic, both clinical and microscopic, considerations along with comparison to mammary Paget's disease. Just as mammary Paget's disease, which originates from the glands in the dermis eventuating in the seeding of the overlying epidermis, so too does sebaceous carcinoma of the eyelid. Accordingly, just as mammary Paget's disease is often misdiagnosed as an inflammatory condition, so too is sebaceous carcinoma. [source]

    2435: Control of the Meibomian gland in health and disease

    ACTA OPHTHALMOLOGICA, Issue 2010
    DA SULLIVAN
    Purpose The meibomian gland is extremely important in maintaining the health and integrity of the ocular surface. This gland, through its lipid synthesis and secretion, promotes the stability and prevents the evaporation of the tear film. Conversely, meibomian gland dysfunction (MGD) leads to a decreased stability and increased evaporation of the tear film. Indeed, meibomian gland dysfunction is thought to be the major cause of dry eye syndromes throughout the world. Our goal is to advance understanding of the regulation of meibomian gland function and the mechanisms underlying MGD. Methods Procedures included the immortalization of human meibomian gland epithelial cells with human telomerase reverse transcriptase, the evaluation of cellular responsiveness, and the identification of glandular gene expression changes in MGD. Gene analyses were conducted with Illumina HumanHT-12 v3 Expression BeadChips and Geospiza bioinformatics software. Results To date we have [a] immortalized human meibomian gland epithelial cells that respond to secretagogue, growth factor, neurotransmitter and hormone exposure with alterations in proliferation, differentiation, signaling, gene expression and/or lipogenesis; [b] discovered human meibomian gland genes that may facilitate the development and/or progression of MGD. These genes encode proteins that promote keratinization and amplify inflammation. Conclusion Our findings advance our understanding of the control of the meibomian gland in both health and disease. [Acknowledgments: S.M. Richards, M. Hatton, A.M. Fay and K. Lo; Supported by grants from NIH (R01EY05612) and Alcon] Commercial interest [source]

    2431: The eyelid margin: an underestimated contributor to ocular surface health and disease

    ACTA OPHTHALMOLOGICA, Issue 2010
    E KNOP
    Purpose The eyelid margin is frequently underestimated in the consideration of factors in ocular surface health and disease. Clinically the whole free end of the lid margin is often addressed simply as "margin" without further differentiation. It is attempted to review the structure, embryology and function of the lid margin as well as its involvement in ocular surface pathology. Methods A review based on the available literature on the lid margin is prepared together with own findings on the histology of normal and pathological tissues. Results The human lid margin is divided into distinct zones that consist, coming from the skin side, of a rounded outer lid border, a free lid margin (between the eye lashes and the opening of the meibomian glands), the muco-cutaneous junction and a sharp inner lid border. The embryological development of the eye lids and their tissue components (loose connective tissue, lid muscles, ciliary hairs, Meibomian glands and vascular and neural components) takes place during the period of sealed lids. During this time the development of the Meibomian glands shows considerable similarity to that of the ciliary hairs. The sealing of the mesodermal lid folds and their eventual separation is dependent on several factors that may be involved in pathology. Various disease states, as well as the aging process, can lead to destruction of the lid margin and, conversely, this can lead to deterioration of the cornea and conjunctiva. Conclusion The eyelid margin is an underestimated contributor to ocular surface health and disease. Increased awareness of the anatomy, embryology, physiology and pathophysiology of the lid margin and it tissue components appears important for the preservation of ocular surface integrity. Support DFG KN317/11 [source]

    2331: Are the Meibomian glands "hair follicles without a hair shaft" ?

    ACTA OPHTHALMOLOGICA, Issue 2010
    E KNOP
    Purpose The Meibomian glands (MG) are atypically large sebaceous glands in the eyelids with numerous generations of secretory acini along an extensive central duct. They share similarities with the ciliary hairs in development, and hyper-keratinisation leading to obstructive MG dysfunction (MGD) represents the typical pathology. It was hence investigated which structural similarities they share with cilia. Methods Conjunctival whole-mounts including the lid margin from ten normal human body donors were embedded in paraffin. Serial sections were stained by H&E, Masson-Goldners stain and by immunohistochemistry (IHC) against cytokeratins and associated proteins. Results The terminal part (excretory duct) of the MG central duct is an ingrowth of epidermis similar to the hair follicles of the cilia. Characterization of individual cytokeratinis by IHC showed that CK14, a marker for undifferentiated cells, was expressed in the basal cell layer of the skin, MG ducts and the secretory acini. The excretory duct epithelium expressed the skin keratin CK10 and the keratinisation marker involucrin but in proximal direction along the central duct full cornification as well as both markers were gradually lost. Filaggrin, however, a marker for incipient stages of keratinisation located in keratohyalin granules continued in the superficial epithelial layer all along the MG ductal system. Conclusion All parts of the normal human MG ductal system have signs of incipient keratinisation and preserve a commitment to full cornification. This supports the assumption that the MG are basically "hair follicles without a hair shaft" in which the progression to full epithelial cornification is apparently blocked during embryological development but may reoccur under pathological influences. Support DFG KN317/11 [source]

    2435: Control of the Meibomian gland in health and disease

    ACTA OPHTHALMOLOGICA, Issue 2010
    DA SULLIVAN
    Purpose The meibomian gland is extremely important in maintaining the health and integrity of the ocular surface. This gland, through its lipid synthesis and secretion, promotes the stability and prevents the evaporation of the tear film. Conversely, meibomian gland dysfunction (MGD) leads to a decreased stability and increased evaporation of the tear film. Indeed, meibomian gland dysfunction is thought to be the major cause of dry eye syndromes throughout the world. Our goal is to advance understanding of the regulation of meibomian gland function and the mechanisms underlying MGD. Methods Procedures included the immortalization of human meibomian gland epithelial cells with human telomerase reverse transcriptase, the evaluation of cellular responsiveness, and the identification of glandular gene expression changes in MGD. Gene analyses were conducted with Illumina HumanHT-12 v3 Expression BeadChips and Geospiza bioinformatics software. Results To date we have [a] immortalized human meibomian gland epithelial cells that respond to secretagogue, growth factor, neurotransmitter and hormone exposure with alterations in proliferation, differentiation, signaling, gene expression and/or lipogenesis; [b] discovered human meibomian gland genes that may facilitate the development and/or progression of MGD. These genes encode proteins that promote keratinization and amplify inflammation. Conclusion Our findings advance our understanding of the control of the meibomian gland in both health and disease. [Acknowledgments: S.M. Richards, M. Hatton, A.M. Fay and K. Lo; Supported by grants from NIH (R01EY05612) and Alcon] Commercial interest [source]

    Expression of p73 in normal skin and proliferative skin lesions

    PATHOLOGY INTERNATIONAL, Issue 12 2004
    Makoto Kamiya
    The p73 gene is a member of the p53 gene family and the structure and functions of p73 protein are similar to those of ,p53. ,However, ,these ,two ,proteins ,have ,different ,roles. In the present study, p73 protein was found immunohistochemically to be distributed in the basal cells of the epidermis, columnar basal cells in the hair follicle and peripheral cells without lipid droplets in the sebaceous and meibomian glands; it was expressed strongly in tumor cells in basal cell carcinomas and in the basal cell-like cells in seborrheic keratosis, and weakly or negatively in the squamous cell-like cells in seborrheic keratosis and in the tumor cells in squamous cell carcinomas. No relationship was detected between p73 and p53 protein distribution and between p73 protein expression and the proliferative potential, as shown by the Ki-67 immunopositive cell ratio. The present study shows that p73 protein is likely to play important roles in skin differentiation rather than proliferation or carcinogenesis of the skin. [source]

    3221: Pathophysiology of dry eye syndrome

    ACTA OPHTHALMOLOGICA, Issue 2010
    J HORWATH-WINTER
    Dry eye or dysfunctional tear syndrome is a highly prevalent disease worldwide. It is related to a pathological condition of anyone of the parts of the "ocular surface system" that involves the cornea, conjunctiva, lacrimal gland, accessory lacrimal glands, nasolacrimal duct and the lids with the meibomian glands. These are linked as a functional system by innervation, the endocrine and immune system. Endogenous or exogenous caused alterations in one or several components of the ocular surface system or its secretions result in changes of the tear film or ocular surface provoking inflammation. With time, inflammatory reactions may lead to corneal neuropathy compromising the reflex response of the lacrimal glands. Additionally a self-perpetuating vicious circle with loss of function and damage can be initiated also by an immune-modulated inflammation. [source]

    2431: The eyelid margin: an underestimated contributor to ocular surface health and disease

    ACTA OPHTHALMOLOGICA, Issue 2010
    E KNOP
    Purpose The eyelid margin is frequently underestimated in the consideration of factors in ocular surface health and disease. Clinically the whole free end of the lid margin is often addressed simply as "margin" without further differentiation. It is attempted to review the structure, embryology and function of the lid margin as well as its involvement in ocular surface pathology. Methods A review based on the available literature on the lid margin is prepared together with own findings on the histology of normal and pathological tissues. Results The human lid margin is divided into distinct zones that consist, coming from the skin side, of a rounded outer lid border, a free lid margin (between the eye lashes and the opening of the meibomian glands), the muco-cutaneous junction and a sharp inner lid border. The embryological development of the eye lids and their tissue components (loose connective tissue, lid muscles, ciliary hairs, Meibomian glands and vascular and neural components) takes place during the period of sealed lids. During this time the development of the Meibomian glands shows considerable similarity to that of the ciliary hairs. The sealing of the mesodermal lid folds and their eventual separation is dependent on several factors that may be involved in pathology. Various disease states, as well as the aging process, can lead to destruction of the lid margin and, conversely, this can lead to deterioration of the cornea and conjunctiva. Conclusion The eyelid margin is an underestimated contributor to ocular surface health and disease. Increased awareness of the anatomy, embryology, physiology and pathophysiology of the lid margin and it tissue components appears important for the preservation of ocular surface integrity. Support DFG KN317/11 [source]

    Structure of the lid margin in laboratory animals

    ACTA OPHTHALMOLOGICA, Issue 2008
    N KNOP
    Purpose The eye lid margin is of great importance for the spreading and the limitation of the tears. The so called lid wiper which is a specialized zone at the inner lid border directly apposed to the corneal surface for spreading the preocular tear film has, at present, only been described for the human conjunctiva. We have investigated common laboratory animals (rat and rabbit) for the presence of such a zone. Methods Conjunctival whole-mount specimens and total bulbi were investigated by serial section histology in ten rats (DA and Lewis) and in ten rabbits (NZW and Chinchilla). Results The stratified squamous keratinised epidermis of the free lid margin showed a sharp transition with loss of the keratin layer at the level of the meibomian glands. Close to the inner lid border it was replaced by a small zone of an optically denser epithelium covered by para-keratinised cells. This area represented the mucocutaneous junction (MCJ) equivalent to the line of Marx in the human. The MCJ rapidly transformed into a thickened 8-12 cell layered stratified epithelium of that formed a cushion-like epithelial elevation, reclined sharply towards the inner lid border and hence formed a typically relatively sharp lip-like edge. The lid-wiper epithelium showed species-specific differences in morphology (cuboidal with goblet cells in the rabbit versus squamous without goblet cells in the rat) but it extended all along the lid margin in both species. Conclusion At the inner border of the upper and lower lid of rat and rabbit, several zones of different morphology occur similar to the human including a lid-wiper structure. Since lid wiper epitheliopathy was shown as a sensitive early indicator for human dry eye syndrome its investigation may be useful for future research in dry eye models of laboratory animals. [source]