Skin: The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.Skin Aging: The process of aging due to changes in the structure and elasticity of the skin over time. It may be a part of physiological aging or it may be due to the effects of ultraviolet radiation, usually through exposure to sunlight.Skin DiseasesSkin Neoplasms: Tumors or cancer of the SKIN.Skin Physiological Phenomena: The functions of the skin in the human and animal body. It includes the pigmentation of the skin.Skin Tests: Epicutaneous or intradermal application of a sensitizer for demonstration of either delayed or immediate hypersensitivity. Used in diagnosis of hypersensitivity or as a test for cellular immunity.Skin Absorption: Uptake of substances through the SKIN.Skin Pigmentation: Coloration of the skin.Skin, Artificial: Synthetic material used for the treatment of burns and other conditions involving large-scale loss of skin. It often consists of an outer (epidermal) layer of silicone and an inner (dermal) layer of collagen and chondroitin 6-sulfate. The dermal layer elicits new growth and vascular invasion and the outer layer is later removed and replaced by a graft.Skin Diseases, Bacterial: Skin diseases caused by bacteria.Skin UlcerEpidermis: The external, nonvascular layer of the skin. It is made up, from within outward, of five layers of EPITHELIUM: (1) basal layer (stratum basale epidermidis); (2) spinous layer (stratum spinosum epidermidis); (3) granular layer (stratum granulosum epidermidis); (4) clear layer (stratum lucidum epidermidis); and (5) horny layer (stratum corneum epidermidis).Skin Abnormalities: Congenital structural abnormalities of the skin.Staphylococcal Skin Infections: Infections to the skin caused by bacteria of the genus STAPHYLOCOCCUS.Dermatitis: Any inflammation of the skin.Dermatologic Surgical Procedures: Operative procedures performed on the SKIN.Skin Diseases, Viral: Skin diseases caused by viruses.Skin Cream: A water-soluble medicinal preparation applied to the skin.Skin Physiological Processes: Biological activities and functions of the SKIN.Mice, Hairless: Mutant strains of mice that produce little or no hair.Carcinoma, Basal Cell: A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1471)Ultraviolet Rays: That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.Dermis: A layer of vascularized connective tissue underneath the EPIDERMIS. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are SWEAT GLANDS; HAIR FOLLICLES; and SEBACEOUS GLANDS.Erythema: Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of causes.Administration, Cutaneous: The application of suitable drug dosage forms to the skin for either local or systemic effects.Administration, Topical: The application of drug preparations to the surfaces of the body, especially the skin (ADMINISTRATION, CUTANEOUS) or mucous membranes. This method of treatment is used to avoid systemic side effects when high doses are required at a localized area or as an alternative systemic administration route, to avoid hepatic processing for example.Skin Diseases, Parasitic: Skin diseases caused by ARTHROPODS; HELMINTHS; or other parasites.Papilloma: A circumscribed benign epithelial tumor projecting from the surrounding surface; more precisely, a benign epithelial neoplasm consisting of villous or arborescent outgrowths of fibrovascular stroma covered by neoplastic cells. (Stedman, 25th ed)Keratosis: Any horny growth such as a wart or callus.Wound Healing: Restoration of integrity to traumatized tissue.Sunlight: Irradiation directly from the sun.Sunscreening Agents: Chemical or physical agents that protect the skin from sunburn and erythema by absorbing or blocking ultraviolet radiation.Fibroblasts: Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.Hair Follicle: A tube-like invagination of the EPIDERMIS from which the hair shaft develops and into which SEBACEOUS GLANDS open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. (Stedman, 26th ed) Follicles of very long hairs extend into the subcutaneous layer of tissue under the SKIN.Rats, Hairless: Mutant strains of rats that produce little or no hair. Several different homozygous recessive mutations can cause hairlessness in rats including rnu/rnu (Rowett nude), fz/fz (fuzzy), shn/shn (shorn), and nznu/nznu (New Zealand nude). Note that while NUDE RATS are often hairless, they are most characteristically athymic.9,10-Dimethyl-1,2-benzanthracene: 7,12-Dimethylbenzanthracene. Polycyclic aromatic hydrocarbon found in tobacco smoke that is a potent carcinogen.Hair: A filament-like structure consisting of a shaft which projects to the surface of the SKIN from a root which is softer than the shaft and lodges in the cavity of a HAIR FOLLICLE. It is found on most surfaces of the body.Blister: Visible accumulations of fluid within or beneath the epidermis.Sunburn: An injury to the skin causing erythema, tenderness, and sometimes blistering and resulting from excessive exposure to the sun. The reaction is produced by the ultraviolet radiation in sunlight.Sebaceous Glands: Small, sacculated organs found within the DERMIS. Each gland has a single duct that emerges from a cluster of oval alveoli. Each alveolus consists of a transparent BASEMENT MEMBRANE enclosing epithelial cells. The ducts from most sebaceous glands open into a HAIR FOLLICLE, but some open on the general surface of the SKIN. Sebaceous glands secrete SEBUM.Skin Manifestations: Dermatologic disorders attendant upon non-dermatologic disease or injury.Langerhans Cells: Recirculating, dendritic, antigen-presenting cells containing characteristic racket-shaped granules (Birbeck granules). They are found principally in the stratum spinosum of the EPIDERMIS and are rich in Class II MAJOR HISTOCOMPATIBILITY COMPLEX molecules. Langerhans cells were the first dendritic cell to be described and have been a model of study for other dendritic cells (DCs), especially other migrating DCs such as dermal DCs and INTERSTITIAL DENDRITIC CELLS.Dermatitis, Contact: A type of acute or chronic skin reaction in which sensitivity is manifested by reactivity to materials or substances coming in contact with the skin. It may involve allergic or non-allergic mechanisms.Water Loss, Insensible: Loss of water by diffusion through the skin and by evaporation from the respiratory tract.Emollients: Oleagenous substances used topically to soothe, soften or protect skin or mucous membranes. They are used also as vehicles for other dermatologic agents.Dermatitis, Allergic Contact: A contact dermatitis due to allergic sensitization to various substances. These substances subsequently produce inflammatory reactions in the skin of those who have acquired hypersensitivity to them as a result of prior exposure.Dermatologic Agents: Drugs used to treat or prevent skin disorders or for the routine care of skin.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Dermatology: A medical specialty concerned with the skin, its structure, functions, diseases, and treatment.Injections, Intradermal: The forcing into the skin of liquid medication, nutrient, or other fluid through a hollow needle, piercing the top skin layer.Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.Melanocytes: Mammalian pigment cells that produce MELANINS, pigments found mainly in the EPIDERMIS, but also in the eyes and the hair, by a process called melanogenesis. Coloration can be altered by the number of melanocytes or the amount of pigment produced and stored in the organelles called MELANOSOMES. The large non-mammalian melanin-containing cells are called MELANOPHORES.Tuberculin Test: One of several skin tests to determine past or present tuberculosis infection. A purified protein derivative of the tubercle bacilli, called tuberculin, is introduced into the skin by scratch, puncture, or interdermal injection.Dermatitis, Occupational: A recurrent contact dermatitis caused by substances found in the work place.Dermatitis, Irritant: A non-allergic contact dermatitis caused by prolonged exposure to irritants and not explained by delayed hypersensitivity mechanisms.Cosmetics: Substances intended to be applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance without affecting the body's structure or functions. Included in this definition are skin creams, lotions, perfumes, lipsticks, fingernail polishes, eye and facial makeup preparations, permanent waves, hair colors, toothpastes, and deodorants, as well as any material intended for use as a component of a cosmetic product. (U.S. Food & Drug Administration Center for Food Safety & Applied Nutrition Office of Cosmetics Fact Sheet (web page) Feb 1995)Drug Eruptions: Adverse cutaneous reactions caused by ingestion, parenteral use, or local application of a drug. These may assume various morphologic patterns and produce various types of lesions.Surgical Flaps: Tongues of skin and subcutaneous tissue, sometimes including muscle, cut away from the underlying parts but often still attached at one end. They retain their own microvasculature which is also transferred to the new site. They are often used in plastic surgery for filling a defect in a neighboring region.Intradermal Tests: Skin tests in which the sensitizer is injected.Melanoma: A malignant neoplasm derived from cells that are capable of forming melanin, which may occur in the skin of any part of the body, in the eye, or, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or malignant lentigo. Melanomas frequently metastasize widely, and the regional lymph nodes, liver, lungs, and brain are likely to be involved. The incidence of malignant skin melanomas is rising rapidly in all parts of the world. (Stedman, 25th ed; from Rook et al., Textbook of Dermatology, 4th ed, p2445)Neoplasms, Radiation-Induced: Tumors, cancer or other neoplasms produced by exposure to ionizing or non-ionizing radiation.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Radiodermatitis: A cutaneous inflammatory reaction occurring as a result of exposure to ionizing radiation.Dermatomycoses: Superficial infections of the skin or its appendages by any of various fungi.Melanins: Insoluble polymers of TYROSINE derivatives found in and causing darkness in skin (SKIN PIGMENTATION), hair, and feathers providing protection against SUNBURN induced by SUNLIGHT. CAROTENES contribute yellow and red coloration.Hyperpigmentation: Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance.Ointments: Semisolid preparations used topically for protective emollient effects or as a vehicle for local administration of medications. Ointment bases are various mixtures of fats, waxes, animal and plant oils and solid and liquid hydrocarbons.Pigmentation DisordersKeratosis, Actinic: White or pink lesions on the arms, hands, face, or scalp that arise from sun-induced DNA DAMAGE to KERATINOCYTES in exposed areas. They are considered precursor lesions to superficial SQUAMOUS CELL CARCINOMA.Carcinoma, Squamous Cell: A carcinoma derived from stratified SQUAMOUS EPITHELIAL CELLS. It may also occur in sites where glandular or columnar epithelium is normally present. (From Stedman, 25th ed)Irritants: Drugs that act locally on cutaneous or mucosal surfaces to produce inflammation; those that cause redness due to hyperemia are rubefacients; those that raise blisters are vesicants and those that penetrate sebaceous glands and cause abscesses are pustulants; tear gases and mustard gases are also irritants.Soft Tissue Infections: Infections of non-skeletal tissue, i.e., exclusive of bone, ligaments, cartilage, and fibrous tissue. The concept is usually referred to as skin and soft tissue infections and usually subcutaneous and muscle tissue are involved. The predisposing factors in anaerobic infections are trauma, ischemia, and surgery. The organisms often derive from the fecal or oral flora, particularly in wounds associated with intestinal surgery, decubitus ulcer, and human bites. (From Cecil Textbook of Medicine, 19th ed, p1688)Mice, Inbred C57BLSkin Diseases, Papulosquamous: A group of dermatoses with distinct morphologic features. The primary lesion is most commonly a papule, usually erythematous, with a variable degree of scaling on the surface. Plaques form through the coalescing of primary lesions.Keratins: A class of fibrous proteins or scleroproteins that represents the principal constituent of EPIDERMIS; HAIR; NAILS; horny tissues, and the organic matrix of tooth ENAMEL. Two major conformational groups have been characterized, alpha-keratin, whose peptide backbone forms a coiled-coil alpha helical structure consisting of TYPE I KERATIN and a TYPE II KERATIN, and beta-keratin, whose backbone forms a zigzag or pleated sheet structure. alpha-Keratins have been classified into at least 20 subtypes. In addition multiple isoforms of subtypes have been found which may be due to GENE DUPLICATION.Body Temperature Regulation: The processes of heating and cooling that an organism uses to control its temperature.Forehead: The part of the face above the eyes.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Keratoacanthoma: A benign, non-neoplastic, usually self-limiting epithelial lesion closely resembling squamous cell carcinoma clinically and histopathologically. It occurs in solitary, multiple, and eruptive forms. The solitary and multiple forms occur on sunlight exposed areas and are identical histologically; they affect primarily white males. The eruptive form usually involves both sexes and appears as a generalized papular eruption.Skin Diseases, Vascular: Skin diseases affecting or involving the cutaneous blood vessels and generally manifested as inflammation, swelling, erythema, or necrosis in the affected area.Scleroderma, Localized: A term used to describe a variety of localized asymmetrical SKIN thickening that is similar to those of SYSTEMIC SCLERODERMA but without the disease features in the multiple internal organs and BLOOD VESSELS. Lesions may be characterized as patches or plaques (morphea), bands (linear), or nodules.Laser-Doppler Flowmetry: A method of non-invasive, continuous measurement of MICROCIRCULATION. The technique is based on the values of the DOPPLER EFFECT of low-power laser light scattered randomly by static structures and moving tissue particulates.Collagen: A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).Acne Vulgaris: A chronic disorder of the pilosebaceous apparatus associated with an increase in sebum secretion. It is characterized by open comedones (blackheads), closed comedones (whiteheads), and pustular nodules. The cause is unknown, but heredity and age are predisposing factors.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Mice, Inbred SENCAR: Mice selectively bred for hypersusceptibility to two-stage chemical skin carcinogenesis. They are also hypersusceptible to UV radiation tumorigenesis with single high-dose, but not chronic low-dose, exposures. SENCAR (SENsitive to CARcinogenesis) mice are used in research as an animal model for tumor production.Hypersensitivity, Delayed: An increased reactivity to specific antigens mediated not by antibodies but by cells.Dermoscopy: A noninvasive technique that enables direct microscopic examination of the surface and architecture of the SKIN.Immunoglobulin E: An immunoglobulin associated with MAST CELLS. Overexpression has been associated with allergic hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Dermatitis, Exfoliative: The widespread involvement of the skin by a scaly, erythematous dermatitis occurring either as a secondary or reactive process to an underlying cutaneous disorder (e.g., atopic dermatitis, psoriasis, etc.), or as a primary or idiopathic disease. It is often associated with the loss of hair and nails, hyperkeratosis of the palms and soles, and pruritus. (From Dorland, 27th ed)Carcinogens: Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.Edema: Abnormal fluid accumulation in TISSUES or body cavities. Most cases of edema are present under the SKIN in SUBCUTANEOUS TISSUE.Sweat Glands: Sweat-producing structures that are embedded in the DERMIS. Each gland consists of a single tube, a coiled body, and a superficial duct.Burns: Injuries to tissues caused by contact with heat, steam, chemicals (BURNS, CHEMICAL), electricity (BURNS, ELECTRIC), or the like.Exanthema: Diseases in which skin eruptions or rashes are a prominent manifestation. Classically, six such diseases were described with similar rashes; they were numbered in the order in which they were reported. Only the fourth (Duke's disease), fifth (ERYTHEMA INFECTIOSUM), and sixth (EXANTHEMA SUBITUM) numeric designations survive as occasional synonyms in current terminology.Patch Tests: Skin tests in which the sensitizer is applied to a patch of cotton cloth or gauze held in place for approximately 48-72 hours. It is used for the elicitation of a contact hypersensitivity reaction.Mice, Inbred BALB CHand DermatosesPermeability: Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.Sebum: The oily substance secreted by SEBACEOUS GLANDS. It is composed of KERATIN, fat, and cellular debris.Skin Lightening Preparations: Substances used to obtain a lighter skin complexion or to treat HYPERPIGMENTATION disorders.Ear, External: The outer part of the hearing system of the body. It includes the shell-like EAR AURICLE which collects sound, and the EXTERNAL EAR CANAL, the TYMPANIC MEMBRANE, and the EXTERNAL EAR CARTILAGES.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Hypersensitivity, Immediate: Hypersensitivity reactions which occur within minutes of exposure to challenging antigen due to the release of histamine which follows the antigen-antibody reaction and causes smooth muscle contraction and increased vascular permeability.Anura: An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.Allergens: Antigen-type substances that produce immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Self-Examination: The inspection of one's own body, usually for signs of disease (e.g., BREAST SELF-EXAMINATION, testicular self-examination).Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Ichthyosis: Any of several generalized skin disorders characterized by dryness, roughness, and scaliness, due to hypertrophy of the stratum corneum epidermis. Most are genetic, but some are acquired, developing in association with other systemic disease or genetic syndrome.PUVA Therapy: Photochemotherapy using PSORALENS as the photosensitizing agent and ultraviolet light type A (UVA).Ear: The hearing and equilibrium system of the body. It consists of three parts: the EXTERNAL EAR, the MIDDLE EAR, and the INNER EAR. Sound waves are transmitted through this organ where vibration is transduced to nerve signals that pass through the ACOUSTIC NERVE to the CENTRAL NERVOUS SYSTEM. The inner ear also contains the vestibular organ that maintains equilibrium by transducing signals to the VESTIBULAR NERVE.Needles: Sharp instruments used for puncturing or suturing.Clothing: Fabric or other material used to cover the body.Dose-Response Relationship, Radiation: The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Iontophoresis: Therapeutic introduction of ions of soluble salts into tissues by means of electric current. In medical literature it is commonly used to indicate the process of increasing the penetration of drugs into surface tissues by the application of electric current. It has nothing to do with ION EXCHANGE; AIR IONIZATION nor PHONOPHORESIS, none of which requires current.Facial DermatosesTetradecanoylphorbol Acetate: A phorbol ester found in CROTON OIL with very effective tumor promoting activity. It stimulates the synthesis of both DNA and RNA.Keratolytic Agents: Agents that soften, separate, and cause desquamation of the cornified epithelium or horny layer of skin. They are used to expose mycelia of infecting fungi or to treat corns, warts, and certain other skin diseases.Neoplasms, Adnexal and Skin Appendage: Neoplasms composed of sebaceous or sweat gland tissue or tissue of other skin appendages. The concept does not refer to neoplasms located in the sebaceous or sweat glands or in the other skin appendages.Eczema: A pruritic papulovesicular dermatitis occurring as a reaction to many endogenous and exogenous agents (Dorland, 27th ed).Mechanoreceptors: Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.Hypersensitivity: Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.Hair Color: Color of hair or fur.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Ultraviolet Therapy: The use of ultraviolet electromagnetic radiation in the treatment of disease, usually of the skin. This is the part of the sun's spectrum that causes sunburn and tanning. Ultraviolet A, used in PUVA, is closer to visible light and less damaging than Ultraviolet B, which is ionizing.Anti-Infective Agents, Local: Substances used on humans and other animals that destroy harmful microorganisms or inhibit their activity. They are distinguished from DISINFECTANTS, which are used on inanimate objects.Nevus: A circumscribed stable malformation of the skin and occasionally of the oral mucosa, which is not due to external causes and therefore presumed to be of hereditary origin.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Protective Clothing: Clothing designed to protect the individual against possible exposure to known hazards.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Nevus, Pigmented: A nevus containing melanin. The term is usually restricted to nevocytic nevi (round or oval collections of melanin-containing nevus cells occurring at the dermoepidermal junction of the skin or in the dermis proper) or moles, but may be applied to other pigmented nevi.Alopecia: Absence of hair from areas where it is normally present.Carcinoma, Skin Appendage: A malignant tumor of the skin appendages, which include the hair, nails, sebaceous glands, sweat glands, and the mammary glands. (From Dorland, 27th ed)Touch: Sensation of making physical contact with objects, animate or inanimate. Tactile stimuli are detected by MECHANORECEPTORS in the skin and mucous membranes.Epidermolysis Bullosa: Group of genetically determined disorders characterized by the blistering of skin and mucosae. There are four major forms: acquired, simple, junctional, and dystrophic. Each of the latter three has several varieties.Soaps: Sodium or potassium salts of long chain fatty acids. These detergent substances are obtained by boiling natural oils or fats with caustic alkali. Sodium soaps are harder and are used as topical anti-infectives and vehicles in pills and liniments; potassium soaps are soft, used as vehicles for ointments and also as topical antimicrobials.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Mustard Gas: Severe irritant and vesicant of skin, eyes, and lungs. It may cause blindness and lethal lung edema and was formerly used as a war gas. The substance has been proposed as a cytostatic and for treatment of psoriasis. It has been listed as a known carcinogen in the Fourth Annual Report on Carcinogens (NTP-85-002, 1985) (Merck, 11th ed).Inflammation: A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.Pemphigus: Group of chronic blistering diseases characterized histologically by ACANTHOLYSIS and blister formation within the EPIDERMIS.Scleroderma, Diffuse: A rapid onset form of SYSTEMIC SCLERODERMA with progressive widespread SKIN thickening over the arms, the legs and the trunk, resulting in stiffness and disability.Sunbathing: Exposing oneself to SUNLIGHT or ULTRAVIOLET RAYS.Dermatitis, Phototoxic: A nonimmunologic, chemically induced type of photosensitivity producing a sometimes vesiculating dermatitis. It results in hyperpigmentation and desquamation of the light-exposed areas of the skin.Physical Stimulation: Act of eliciting a response from a person or organism through physical contact.Mast Cells: Granulated cells that are found in almost all tissues, most abundantly in the skin and the gastrointestinal tract. Like the BASOPHILS, mast cells contain large amounts of HISTAMINE and HEPARIN. Unlike basophils, mast cells normally remain in the tissues and do not circulate in the blood. Mast cells, derived from the bone marrow stem cells, are regulated by the STEM CELL FACTOR.Scalp: The outer covering of the calvaria. It is composed of several layers: SKIN; subcutaneous connective tissue; the occipitofrontal muscle which includes the tendinous galea aponeurotica; loose connective tissue; and the pericranium (the PERIOSTEUM of the SKULL).Cell Movement: The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.Malassezia: A mitosporic fungal genus that causes a variety of skin disorders. Malassezia furfur (Pityrosporum orbiculare) causes TINEA VERSICOLOR.Keratosis, Seborrheic: Benign eccrine poromas that present as multiple oval, brown-to-black plaques, located mostly on the chest and back. The age of onset is usually in the fourth or fifth decade.Dermatitis, Seborrheic: A chronic inflammatory disease of the skin with unknown etiology. It is characterized by moderate ERYTHEMA, dry, moist, or greasy (SEBACEOUS GLAND) scaling and yellow crusted patches on various areas, especially the scalp, that exfoliate as dandruff. Seborrheic dermatitis is common in children and adolescents with HIV INFECTIONS.Cocarcinogenesis: The combination of two or more different factors in the production of cancer.Thermography: Imaging the temperatures in a material, or in the body or an organ. Imaging is based on self-emanating infrared radiation (HEAT WAVES), or on changes in properties of the material or tissue that vary with temperature, such as ELASTICITY; MAGNETIC FIELD; or LUMINESCENCE.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Antisepsis: The destruction of germs causing disease.Amphibian Proteins: Proteins obtained from species in the class of AMPHIBIANS.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Drug Hypersensitivity: Immunologically mediated adverse reactions to medicinal substances used legally or illegally.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Hair Diseases: Diseases affecting the orderly growth and persistence of hair.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Mice, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.Forearm: Part of the arm in humans and primates extending from the ELBOW to the WRIST.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.Warts: Benign epidermal proliferations or tumors; some are viral in origin.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Scabies: A contagious cutaneous inflammation caused by the bite of the mite SARCOPTES SCABIEI. It is characterized by pruritic papular eruptions and burrows and affects primarily the axillae, elbows, wrists, and genitalia, although it can spread to cover the entire body.Clobetasol: A derivative of PREDNISOLONE with high glucocorticoid activity and low mineralocorticoid activity. Absorbed through the skin faster than FLUOCINONIDE, it is used topically in treatment of PSORIASIS but may cause marked adrenocortical suppression.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Cold Temperature: An absence of warmth or heat or a temperature notably below an accustomed norm.Toes: Any one of five terminal digits of the vertebrate FOOT.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Pressure Ulcer: An ulceration caused by prolonged pressure on the SKIN and TISSUES when one stays in one position for a long period of time, such as lying in bed. The bony areas of the body are the most frequently affected sites which become ischemic (ISCHEMIA) under sustained and constant pressure.Keloid: A sharply elevated, irregularly shaped, progressively enlarging scar resulting from formation of excessive amounts of collagen in the dermis during connective tissue repair. It is differentiated from a hypertrophic scar (CICATRIX, HYPERTROPHIC) in that the former does not spread to surrounding tissues.Foot Dermatoses: Skin diseases of the foot, general or unspecified.Urticaria: A vascular reaction of the skin characterized by erythema and wheal formation due to localized increase of vascular permeability. The causative mechanism may be allergy, infection, or stress.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Keratin-10: A type I keratin that is found associated with the KERATIN-1 in terminally differentiated epidermal cells such as those that form the stratum corneum. Mutations in the genes that encode keratin-10 have been associated with HYPERKERATOSIS, EPIDERMOLYTIC.Bandages: Material used for wrapping or binding any part of the body.Hand: The distal part of the arm beyond the wrist in humans and primates, that includes the palm, fingers, and thumb.Feathers: Flat keratinous structures found on the skin surface of birds. Feathers are made partly of a hollow shaft fringed with barbs. They constitute the plumage.Fingers: Four or five slender jointed digits in humans and primates, attached to each HAND.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Plant Extracts: Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.Povidone-Iodine: An iodinated polyvinyl polymer used as topical antiseptic in surgery and for skin and mucous membrane infections, also as aerosol. The iodine may be radiolabeled for research purposes.Arsenic: A shiny gray element with atomic symbol As, atomic number 33, and atomic weight 75. It occurs throughout the universe, mostly in the form of metallic arsenides. Most forms are toxic. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), arsenic and certain arsenic compounds have been listed as known carcinogens. (From Merck Index, 11th ed)Croton Oil: Viscous, nauseating oil obtained from the shrub Croton tiglium (Euphorbaceae). It is a vesicant and skin irritant used as pharmacologic standard for skin inflammation and allergy and causes skin cancer. It was formerly used as an emetic and cathartic with frequent mortality.Eyelids: Each of the upper and lower folds of SKIN which cover the EYE when closed.Cytokines: Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.Cellulitis: An acute, diffuse, and suppurative inflammation of loose connective tissue, particularly the deep subcutaneous tissues, and sometimes muscle, which is most commonly seen as a result of infection of a wound, ulcer, or other skin lesions.Granulation Tissue: A vascular connective tissue formed on the surface of a healing wound, ulcer, or inflamed tissue. It consists of new capillaries and an infiltrate containing lymphoid cells, macrophages, and plasma cells.Intermediate Filament Proteins: Filaments 7-11 nm in diameter found in the cytoplasm of all cells. Many specific proteins belong to this group, e.g., desmin, vimentin, prekeratin, decamin, skeletin, neurofilin, neurofilament protein, and glial fibrillary acid protein.Gloves, Protective: Coverings for the hands, usually with separations for the fingers, made of various materials, for protection against infections, toxic substances, extremes of hot and cold, radiations, water immersion, etc. The gloves may be worn by patients, care givers, housewives, laboratory and industrial workers, police, etc.Nails: The thin, horny plates that cover the dorsal surfaces of the distal phalanges of the fingers and toes of primates.2-Propanol: An isomer of 1-PROPANOL. It is a colorless liquid having disinfectant properties. It is used in the manufacture of acetone and its derivatives and as a solvent. Topically, it is used as an antiseptic.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Staphylococcus aureus: Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications.Melanosis: Disorders of increased melanin pigmentation that develop without preceding inflammatory disease.
Dermal equivalent: The dermal equivalent is an in vitro model of the dermal layer of skin. It is constructed by seeding dermal fibroblasts into a collagen gel.Actinic elastosis: Actinic elastosis, also known as solar elastosis is an accumulation of abnormal elastin (elastic tissue) in the dermis of the skin, or in the conjunctiva of the eye, which occurs as a result of the cumulative effects of prolonged and excessive sun exposure, a process known as photoaging.Absorption (skin): Skin absorption is a route by which substances can enter the body through the skin. Along with inhalation, ingestion and injection, dermal absorption is a route of exposure for toxic substances and route of administration for medication.List of Bratz charactersBiotextile: Biotextiles are structures composed of textile fibers designed for use in specific biological environments where their performance depends on biocompatibility and biostability with cells and biological fluids. Biotextiles include implantible devices such as surgical sutures, hernia repair fabrics, arterial grafts, artificial skin and parts of artificial hearts.Skin and skin structure infection: A skin and skin structure infection (SSSI), also referred to as skin and soft tissue infection (SSTI) or acute bacterial skin and skin structure infection (ABSSSI), is an infection of skin and associated soft tissues (such as loose connective tissue and mucous membranes). The pathogen involved is usually a bacterial species.Ulcerative dermatitis: Ulcerative dermatitis is a skin disorder in rodents associated with bacterial growth often initiated by self-trauma due to a possible allergic response. Although other organisms can be involved, bacteria culture frequently shows Staphylococcus aureus.Keratinocyte: A keratinocyte is the predominant cell type in the epidermis, the outermost layer of the skin, constituting 90% of the cells found there.Interstitial granulomatous dermatitis: Interstitial granulomatous dermatitis with arthritis is a condition that most commonly presents with symmetrical round-to-oval erythematous or violaceous plaques on the flanks, axillae, inner thighs, and lower abdomen.James, William; Berger, Timothy; Elston, Dirk (2005).Calamine: Calamine is either a mixture of zinc oxide (ZnO) with about 0.5% ferric oxide (Fe2O3) or a zinc carbonate compound.Rombo syndrome: Rombo syndrome is a very rare genetic disorder characterized mainly by atrophoderma vermiculatum of the face,James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology.UVB-induced apoptosis: UVB-induced apoptosis is the programmed cell death of cells that become damaged by ultraviolet rays. This is notable in skin cells, to prevent melanoma.Papillary dermis: The papillary dermis is the uppermost layer of the dermis. It intertwines with the rete ridges of the epidermis and is composed of fine and loosely arranged collagen fibers.Necrolytic acral erythema: Necrolytic acral erythema is a cutaneous condition that is a manifestation of hepatitis C viral infection or zinc deficiency.Besins HealthcareLaryngeal papillomatosisHydrocarbon keratosis: A hydrocarbon keratosis (also known as "pitch keratosis," "tar keratosis," and "tar wart") is a precancerous keratotic skin lesion that occurs in people who have been occupationally exposed to polycyclic aromatic hydrocarbons.Freedberg, et al.Wound healing: Wound healing is an intricate process where the skin or other body tissue repairs itself after injury. In normal skin, the epidermis (surface layer) and dermis (deeper layer) form a protective barrier against the external environment.Sunlight (cleaning product): Sunlight is a brand of household soap originally produced by the British company Lever Brothers in 1884. It was the world's first packaged, branded laundry soap.Slip-Slop-Slap: Slip-Slop-Slap was the iconic and internationally recognised sun protection campaign prominent in Australia during the 1980s. Launched by Cancer Council Victoria in 1981, the Slip!Dermal fibroblast: Dermal fibroblasts are cells within the dermis layer of skin which are responsible for generating connective tissue and allowing the skin to recover from injury. Using organelles (particularly the rough endoplasmic reticulum), dermal fibroblasts generate and maintain the connective tissue which unites separate cell layers.Hair follicle nevus: Hair follicle nevus (also known as a "Vellus hamartoma") is a cutaneous condition that presents as a small papule from which fine hairs protrude evenly from the surface.Hair analysisSuction blister: Suction blistering is a technique used in dermatology to treat chronic wounds, such as non-healing leg ulcers. When a wound is not healing properly, an autologous skin graft is the best option, to prevent rejection of the tissue.Sunburn FestivalLangerin: CD207, langerin (Cluster of Differentiation 207) is a protein which in humans is encoded by the CD207 gene. Langerin is a type II transmembrane, C-type lectin receptor on Langerhans cells.Vetiver System: The Vetiver System (VS) is a system of soil and water conservation whose main component is the use of the vetiver plant in hedgerows. It is promoted by the Vetiver Network International (TVNI), an international non-governmental organization.Aquaphor: Aquaphor is a brand of over the counter skin care ointments manufactured by Beiersdorf Inc., an affiliate of Beiersdorf AG.Contact dermatitisDermatopathology: Dermatopathology (from Greek , derma, "skin"; , pathos, "fate, harm"; and , -logia) is a joint subspecialty of dermatology and pathology and to a lesser extent of surgical pathology that focuses on the study of cutaneous diseases at a microscopic and molecular level. It also encompasses analyses of the potential causes of skin diseases at a basic level.Injection site reaction: Injection site reactions are allergic reactions that result in cutaneous necrosis that may occur at sites of medication injection, typically presenting in one of two forms, (1) those associated with intravenous infusion or (2) those related to intramuscular injection.James, William; Berger, Timothy; Elston, Dirk (2005).Brain biopsyMelanocyteMantoux test: The Mantoux test or Mendel-Mantoux test (also known as the Mantoux screening test, tuberculin sensitivity test, Pirquet test, or PPD test for purified protein derivative) is a screening tool for tuberculosis (TB). It is one of the major tuberculin skin tests used around the world, largely replacing multiple-puncture tests such as the Tine test.Defatting (medical): Defatting is the chemical dissolving of dermal lipids, from the skin, on contact with defatting agents. This can result in water loss from the affected area and cause the whitening and drying of the skin which may result in cracking, secondary infection and chemical irritant contact dermatitis.List of cosmetic ingredients: Ingredients of cosmetic products are listed following International Nomenclature of Cosmetic Ingredients (INCI).Drug eruptionRotation flap: A rotation flap is a semicircular skin flap that is rotated into the defect on a fulcrum point. Rotation flaps provide the ability to mobilize large areas of tissue with a wide vascular base for reconstruction.James A. Schlipmann Melanoma Cancer Foundation: The James A. Schlipmann Melanoma Cancer Foundation is a US-based non-profit organization with a mission to fund clinical trials and research studies, and to advance education, awareness, screenings and treatment to eventually eradicate melanoma.Spaceflight radiation carcinogenesisTemporal analysis of products: Temporal Analysis of Products (TAP), (TAP-2), (TAP-3) is an experimental technique for studyingHapalonychia: Hapalonychia, also known as egg-shell nail, is a condition in which the top of a toe or finger nail becomes soft and thin, causing it to bend or break. This condition can manifest as a result of genetic discrepancy James, William; Berger, Timothy; Elston, Dirk (2005).Primary cutaneous aspergillosis: Primary cutaneous aspergillosis is a rare skin condition most often occurring at the site of intravenous cannulas in immunosuppressed patients.Amelanism: Amelanism (also known as amelanosis) is a pigmentation abnormality characterized by the lack of pigments called melanins, commonly associated with a genetic loss of tyrosinase function. Amelanism can affect fish, amphibians, reptiles, birds, and mammals including humans.Idiopathic eruptive macular pigmentation: Idiopathic eruptive macular pigmentation is a skin condition developing in young persons, with an average age of 11, characterized by asymptomatic widespread brown to gray macules of up to several centimeters in diameter on the neck, trunk, and proximal extremities.Optimmune: Optimmune is an ophthalmic ointment with ciclosporin as the active ingredient for the treatment of pannus and chronic idiopathic keratoconjunctivitis sicca in dogs. It is a veterinary product produced by Intervet, which is part of Merck.Dyschromatosis symmetrica hereditaria: Dyschromatosis symmetrica hereditaria (also known as "Reticulate acropigmentation of Dohi," and "Symmetrical dyschromatosis of the extremities") is a rare autosomally inherited dermatosis. It is characterized by progressively pigmented and depigmented macules, often mixed in a reticulate pattern, concentrated on the dorsal extremities.Squamous-cell carcinomaThroat irritation: Throat irritation can refer to a dry cough, a scratchy feeling at the back of the throat, or a sensation of a lumpy feeling or something stuck at the back of the throat.Papulotranslucent acrokeratodermaKeratin 6A: Keratin 6A is one of the 27 different type II keratins expressed in humans. Keratin 6A was the first type II keratin sequence determined.Homeothermy: Homeothermy is thermoregulation that maintains a stable internal body temperature regardless of external influence. This internal body temperature is often, though not necessarily, higher than the immediate environment (Greek: homoios = "similar", thermē = "heat").Prayer bump: A zebibah (Arabic زبيبة zabība, "raisin"), also known as a zabiba or zebiba, or browneye, is a mark on the forehead of some Muslims, apparently due to the friction generated by repeated contact of the forehead with the prayer mat during daily prayers.Cutis marmorata telangiectatica congenitaLipodermatosclerosis: Lipodermatosclerosis (also known as "Chronic panniculitis with lipomembranous changes," "Hypodermitis sclerodermiformis," "Sclerosing panniculitis," and "Stasis panniculitis") is a skin and connective tissue disease. It is a form of lower extremity panniculitis, Bruce AJ.CollagenSkin flora: The skin flora, more properly referred to as the skin microbiota, are the microorganisms which reside on the skin. Most research has been upon those that reside upon the 2 square metres of human skin, cf.Antonella Tosti: Antonella Tosti is an Italian physician and scientist with major contributions in the field of dermatology.ErythrodermaCarcinogen: A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes.Peripheral edemaHematidrosis: Hematidrosis (also called hematohidrosis or hemidrosis or blood sweat. From Greek haima/haimatos αἷμα, αἵματος, blood; hidrōs ἱδρώς blood) is a very rare condition in which a human sweats blood.BurnNeonatal toxic shock-like exanthematous disease: Neonatal toxic shock-like exanthematous disease is a cutaneous condition characterized by a generalized diffuse macular erythema or morbilliform eruption with confluence.Iodopropynyl butylcarbamateAlitretinoin
(1/19537) Glycopeptides from the surgace of human neuroblastoma cells.
Glycopeptides suggesting a complex oligosaccharide composition are present on the surface of cells from human neuroblastoma tumors and several cell lines derived from the tumors. The glycopeptides, labeled with radioactive L-fucose, were removed from the cell surface with trypsin, digested with Pronase, and examined by chromatography on Sephadex G-50. Human skin fibroblasts, brain cells, and a fibroblast line derived from neuroblastoma tumor tissue show less complex glycopeptides. Although some differences exist between the cell lines and the primary tumor cells, the similarities between these human tumors and animal tumors examined previously are striking. (+info)
(2/19537) Explanations for the clinical and microscopic localization of lesions in pemphigus foliaceus and vulgaris.
Patients with pemphigus foliaceus (PF) have blisters on skin, but not mucous membranes, whereas patients with pemphigus vulgaris (PV) develop blisters on mucous membranes and/or skin. PF and PV blisters are due to loss of keratinocyte cell-cell adhesion in the superficial and deep epidermis, respectively. PF autoantibodies are directed against desmoglein (Dsg) 1; PV autoantibodies bind Dsg3 or both Dsg3 and Dsg1. In this study, we test the hypothesis that coexpression of Dsg1 and Dsg3 in keratinocytes protects against pathology due to antibody-induced dysfunction of either one alone. Using passive transfer of pemphigus IgG to normal and DSG3(null) neonatal mice, we show that in the areas of epidermis and mucous membrane that coexpress Dsg1 and Dsg3, antibodies against either desmoglein alone do not cause spontaneous blisters, but antibodies against both do. In areas (such as superficial epidermis of normal mice) where Dsg1 without Dsg3 is expressed, anti-Dsg1 antibodies alone can cause blisters. Thus, the anti-desmoglein antibody profiles in pemphigus sera and the normal tissue distributions of Dsg1 and Dsg3 determine the sites of blister formation. These studies suggest that pemphigus autoantibodies inhibit the adhesive function of desmoglein proteins, and demonstrate that either Dsg1 or Dsg3 alone is sufficient to maintain keratinocyte adhesion. (+info)
(3/19537) Activation of telomerase and its association with G1-phase of the cell cycle during UVB-induced skin tumorigenesis in SKH-1 hairless mouse.
Telomerase is a ribonucleoprotein enzyme that adds hexanucleotide repeats TTAGGG to the ends of chromosomes. Telomerase activation is known to play a crucial role in cell-immortalization and carcinogenesis. Telomerase is shown to have a correlation with cell cycle progression, which is controlled by the regulation of cyclins, cyclin dependent kinases (cdks) and cyclin dependent kinase inhibitors (cdkis). Abnormal expression of these regulatory molecules may cause alterations in cell cycle with uncontrolled cell growth, a universal feature of neoplasia. Skin cancer is the most prevalent form of cancer in humans and the solar UV radiation is its major cause. Here, we investigated modulation in telomerase activity and protein expression of cell cycle regulatory molecules during the development of UVB-induced tumors in SKH-1 hairless mice. The mice were exposed to 180 mjoules/cm2 UVB radiation, thrice weekly for 24 weeks. The animals were sacrificed at 4 week intervals and the studies were performed in epidermis. Telomerase activity was barely detectable in the epidermis of non-irradiated mouse. UVB exposure resulted in a progressive increase in telomerase activity starting from the 4th week of exposure. The increased telomerase activity either persisted or further increased with the increased exposure. In papillomas and carcinomas the enzyme activity was comparable and was 45-fold higher than in the epidermis of control mice. Western blot analysis showed an upregulation in the protein expression of cyclin D1 and cyclin E and their regulatory subunits cdk4 and cdk2 during the course of UVB exposure and in papillomas and carcinomas. The protein expression of cdk6 and ckis viz. p16/Ink4A, p21/Waf1 and p27/Kip1 did not show any significant change in UVB exposed skin, but significant upregulation was observed both in papillomas and carcinomas. The results suggest that telomerase activation may be involved in UVB-induced tumorigenesis in mouse skin and that increased telomerase activity may be associated with G1 phase of the cell cycle. (+info)
(4/19537) Metallothionein-null mice absorb less Zn from an egg-white diet, but a similar amount from solutions, although with altered intertissue Zn distribution.
The influence of metallothionein (MT) on Zn transfer into non-gut tissues was investigated in MT-null (MT-/-) and normal (MT+/+) mice 4 h after oral gavage of aqueous 65ZnSO4solution at doses of 154, 385, 770 and 1540 nmol Zn per mouse. Zn transfer was not significantly different between MT+/+ and MT-/- mice and was directly proportional to the oral dose (slope = 0.127, r = 0.991; 0. 146, r = 0.994, respectively). Blood 65Zn and plasma Zn concentrations increased progressively in MT-/- mice at doses >154 nmol Zn, reaching levels of 2.4% of oral dose and 60 micromol/L, respectively, at the 1540 nmol Zn dose. The corresponding values for MT+/+ mice were approximately half, 1.0% and 29 micromol/L. Intergenotypic differences were found in tissue distribution of 65Zn within the body; MT-/- mice had higher 65Zn levels in muscle, skin, heart and brain, whereas MT+/+ mice retained progressively more Zn in the liver, in conjunction with a linear increase in hepatic MT up to the highest Zn dose. MT induction in the small intestine reached its maximum at an oral dose of 385 nmol Zn and did not differ at higher doses. Absorption of a 770 nmol 65Zn dose from a solid egg-white diet was only one fourth (MT+/+) and one eighth (MT-/-) of the Zn absorption from the same dose of 65Zn in aqueous solution. MT+/+ mice had greater (P < 0.05) Zn absorption from the egg-white diet than did MT-/- mice, indicating that gut MT confers an absorptive advantage, but only when Zn is incorporated into solid food. (+info)
(5/19537) Accumulation of astaxanthin all-E, 9Z and 13Z geometrical isomers and 3 and 3' RS optical isomers in rainbow trout (Oncorhynchus mykiss) is selective.
Concentrations of all-E-, 9Z- and 13Z- geometrical and (3R,3'R), (3R, 3'S) and (3S,3'S) optical isomers of astaxanthin were determined in rainbow trout liver, gut tissues, kidney, skin and blood plasma to evaluate their body distribution. Two cold-pelleted diets containing predominantly all-E-astaxanthin (36.9 mg/kg astaxanthin, 97% all-E-, 0.4% 9Z-, 1.5% 13Z-astaxanthin, and 1.1% other isomers, respectively) or a mixture of all-E- and Z-astaxanthins (35.4 mg/kg astaxanthin, 64% all-E-, 18.7% 9Z-, 12.3% 13Z-astaxanthin, and 2.0% other isomers, respectively), were fed to duplicate groups of trout for 69 d. Individual E/Z isomers were identified by VIS- and 1H-NMR-spectrometry, and quantified by high-performance liquid chromatography. Significantly higher total carotenoid concentration was observed in plasma of trout fed diets with all-E-astaxanthin (P < 0.05). The relative E/Z-isomer concentrations of plasma, skin and kidney were not significantly different among groups, whereas all-E-astaxanthin was higher in intestinal tissues and 13Z-astaxanthin was lower in liver of trout fed all-E-astaxanthin (P < 0.05). The relative amount of hepatic 13Z-astaxanthin (39-49% of total astaxanthin) was higher than in all other samples (P < 0.05). Synthetic, optically inactive astaxanthin was used in all experiments, and the determined dietary ratio between the 3R,3'R:3R, 3'S (meso):3S,3'S optical isomers was 25.3:49.6:25.1. The distribution of R/S-astaxanthin isomers in feces, blood, liver and fillet was similar to that in the diets. The ratio between (3S,3'S)- and (3R,3'R)-astaxanthin in the skin and posterior kidney was ca. 2:1 and 3:1, respectively, regardless of dietary E/Z-astaxanthin composition. The results show that geometrical and optical isomers of astaxanthin are distributed selectively in different tissues of rainbow trout. (+info)
(6/19537) Interferon-alpha does not improve outcome at one year in patients with diffuse cutaneous scleroderma: results of a randomized, double-blind, placebo-controlled trial.
OBJECTIVE: To determine whether interferon-alpha (IFNalpha) reduces the severity of skin involvement in early (<3 years) diffuse scleroderma. METHODS: In a randomized, placebo-controlled, double-blind trial, 35 patients with early scleroderma received subcutaneous injections of either IFNalpha (13.5 x 10(6) units per week in divided doses) or indistinguishable placebo. Outcomes assessed were the modified Rodnan skin score, as determined by a single observer at baseline, 6 months, and 12 months, as well as data on renal, cardiac, and lung function. Pre- and posttreatment skin biopsy samples were analyzed and blood was obtained for assessment of procollagen peptide levels. RESULTS: There were 11 withdrawals from the IFNalpha group and 3 from the placebo group due to either toxicity, lack of efficacy, or death. In the intent-to-treat analysis, there was a greater improvement in the skin score in the placebo group between 0 and 12 months (mean change IFNalpha -4.7 versus placebo -7.5; P = 0.36). There was also a greater deterioration in lung function in patients receiving active therapy, as assessed by either the forced vital capacity (mean change IFNalpha -8.2 versus placebo +1.3; P = 0.01) or the diffusing capacity for carbon monoxide (mean change IFNalpha -9.3 versus placebo +4.7; P = 0.002). Skin biopsy showed no significant decrease in collagen synthesis in the IFNalpha group, and no significant differences in the levels of procollagen peptides were seen between the 2 groups. CONCLUSION: This study suggests that IFNalpha is of no value in the treatment of scleroderma, and that it may in fact be deleterious. (+info)
(7/19537) Hydrophobic interaction of human, mouse, and rabbit interferons with immobilized hydrocarbons.
Interferons of human, mouse, and rabbit origin bind to straight chain hydrocarbons immobilized on agarose. The hydrophobic nature of binding is established by the following observations: (a) a positive correlation between the length of hydrocarbon ligand and the strength of interaction; (b) a stronger interaction with hydrocarbon ligands terminated with apolar rather than polar head groups; (c) a lack of dependence of binding on ionic strength and pH of the solvent; (d) a reversal of binding by ethylene glycol, a hydrophobic solute; (e) an increasing eluting efficacy of tetraalkylammonium ions with the length of their alkyl substituents. The hydrophobic interactions of human interferon underlie the efficiency of two-step chromatographic procedures. For example, human embryo kidney interferon can be purified about 3,600-fold by sequential chromatography on (a) concanavalin A-agarose, (b) octyl-agarose. Another two-step procedure: (a) concanavalin A-agarose, (b) L-tryptophan-agarose, gives about 10,000-fold purification. The overall recovery of interferon in both cases in close to 90%. (+info)
(8/19537) Vascular endothelial growth factor (VEGF)-mediated angiogenesis is associated with enhanced endothelial cell survival and induction of Bcl-2 expression.
Vascular endothelial growth factor (VEGF) is an endothelial cell mitogen and permeability factor that is potently angiogenic in vivo. We report here studies that suggest that VEGF potentiates angiogenesis in vivo and prolongs the survival of human dermal microvascular endothelial cells (HDMECs) in vitro by inducing expression of the anti-apoptotic protein Bcl-2. Growth-factor-enriched and serum-deficient cultures of HDMECs grown on collagen type I gels with VEGF exhibited a 4-fold and a 1.6-fold reduction, respectively, in the proportion of apoptotic cells. Enhanced HDMEC survival was associated with a dose-dependent increase in Bcl-2 expression and a decrease in the expression of the processed forms of the cysteine protease caspase-3. Cultures of HDMECs transduced with and overexpressing Bcl-2 and deprived of growth factors showed enhanced protection from apoptosis and exhibited a twofold increase in cell number and a fourfold increase in the number of capillary-like sprouts. HDMECs overexpressing Bcl-2 when incorporated into polylactic acid sponges and implanted into SCID mice exhibited a sustained fivefold increase in the number of microvessels and a fourfold decrease in the number of apoptotic cells when examined 7 and 14 days later. These results suggest that the angiogenic activity attributed to VEGF may be due in part to its ability to enhance endothelial cell survival by inducing expression of Bcl-2. (+info)
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