Resident Dendritic Cells in the Epidermis: Langerhans Cells, Merkel Cells and Melanocytes

Résumé— En plus des kératinocytes, l'épiderme contient des cellules résidentes de morphologie dendritique. Ce sont principalement la cellule de Langerhans, la cellule de Merkel et le mélanocyte. Ces cellules ont des fonctions diverses dans le tégument. Le mélanocyte assure la pigmentation cutanée et la protection contre les radiations U.V., et pourrait intervenir également dans la modulation de l'inflammation cutanée. La cellule de Langerhans intervient dans la surveillance immunologique des surfaces corporelles ecternes. La cellule de Merkel a des fonctions neuroendocrines. Cet article donne un aperçu de la structure et de la fonction de ces trois importantes populations cellulaires dans la peau. [Resident dentritic cells in the epidermis: Langerhans cells, Merkel cells and melanocytes (Cellules dentritiques résidentes de l'épiderme: cellules de Langerhans, cellules de Merkel et mélanocytes). Resumen— La epidermis contiene, además de los queratinocitos, células résidentes de morfologia dendria dendritica. Estas son principalmente las células de Langerhans, las células de Merkel y los melanocitos. Estas células tienen varias funciones en el integumento. Los melanocitos se encargan de la pigmentación y protección de la piel contra la radiación ultravioleta y tarrtbién participan en la regulación de la inflamación cutánea. Las células de Langerhans ayudan en la regulación inmunológica en la superficie externa. Las células de Merkel tienen funciones neuroendocrinas. Esta revisión da un repaso general a la estructura y función de tres importantes células de la piel. [Resident dendsuitic cells in the epidermis: Langerhans cells, Merkel cells and Melanocytes (Células résidentes en la epidermis: células de Langerhans, células de Merkel y melanocitos). Abstract— In addition to the keratinocytes, the epidermis contains resident cells of dendritic morphology. These are principally the Langerhans cell, Merkel cell and melanocyte. These cells have a number of different functions in the integument. The melanocyte is responsible for skin pigmentation and protection against UV radiation, and may also play a role in the modulation of cutaneous inflammation. The Langerhans cell aids in the immunological monitoring of the body's external surfaces. The Merkel cell has neuroendocrine functions. This review gives an overview of the structure and function of these three important cells of the skin.     

Clinical Evaluation of Three Surgical Methods for Treatment of Caudal Cervical Spondylomyelopathy of Dogs

Sixty-four dogs with caudal cervical spondylomyelopathy (CCSM) caused by chronic degenerative disc disease were treated with ventral decompression (n = 20), linear traction and interbody screw stabilization (n = 7), or linear traction and plastic plate stabilization (n = 37). Interbody screw stabilization was ineffective in treating CCSM because of an unacceptably high rate of implant failures. Ventral decompression or linear traction and plastic plate stabilization were effective in the treatment of most patients with mild to moderate neurologic deficits (neck pain, paraparesis, or ambulatory tetraparesis). Although these techniques were also used successfully in some patients with severe neurologic deficits (weakly ambulatory tetraparesis or nonambulatory tetraparesis), variable success rates and prolonged postoperative recovery periods were noted.     

Effects of Growth Factors and L-Arginine on Ischemic Skin Flaps in Rats

This study determined the effect of the polypeptide growth factors transforming growth factor-beta (TGF-β), insulin-like growth factor-I (IGF-I), and growth hormone (GH) alone and in combination with dietary L-Arginine HCL (ARG) on skin flap survival in rats. Caudally based dorsal skin flaps were created in 110 Sprague-Dawley rats. The rats were randomly assigned into three treatment groups, based on drinking water supplementation. Group 1 (n = 50) received ARG in their drinking water, group 2 (n = 50) received tap water alone, and group 3 (n = 10) received N-omega-nitro-L-arginine (L-NA) and hydralazine. Groups 1 and 2 were divided into subgroups of 10 rats each based on treatment with either: TGF-β, IGF-I, GH, or IGF-I + GH. All subgroups that received GH had significantly greater ( P <.0001) median body weight gains when compared with subgroups not receiving GH. L-arginine HCL when added to IGF-I negated the positive effects of IGF-I on both flap survival and weight gain. Although the rats in all subgroups from groups 1 and 2 had an increase in mean percent skin flap survival when compared with the water alone subgroup, only rats receiving IGF-I, or the combination of ARG with either TGF-β or GH, had statistically significant enhanced skin flap survival. Rats in group 3 did not show an increase in skin flap survival when compared with the control subgroup.     

A possible mechanism for the selective herbicidal activity of iodide in relation to thiocyanate content

In an in vivo study, the rate of iodide oxidation by horseradish peroxidase was found to be reduced by the addition of ammonium thiocyanate to the system. The seleetive herbicidal activity of sodium iodide towards dwarf bean, pea, kale and cabbage was tested while the poicnlial ihioeyanale conteni of these platits was measured, A good relationship between inereasmg thiocyanale content and inereasing resistance to iodide was observed.     

Retrobulbar Block in Combination with General Anesthesia for Equine Ophthalmic Surgery

The use of retrobulbar block in conjunction with general anesthesia was evaluated in the horse. A prospective study of 12 cases fulfilling criteria for application of retrobulbar block was compared to a retrospective survey of 25 cases (control group) in which retrobulbar block was not performed. Retrobulbar block was done using a modified Peterson technique and 2% lidocaine HCI without epinephrine. In the control group, four horses exhibited signs compatible with initiation of the oculocardiac reflex; three horses developed bradyarrhythmias and hypotension during global traction related to enucleation, and cardiac arrest occurred in one horse during cataract extraction. In the retrobulbar block group, one horse developed bradyarrhythmia subsequent to retrobulbar block.     

Cutaneous Mycobacterium avium Infection in a Cat

Abstract— A 6-year-old spayed female domestic shorthair cat with a paranasal cutaneous mass caused by Mycobacterium avium is reported. Recurrence after cryosurgery and nonresponsiveness to dapsone necessitated surgical removal. The cat remained clinically normal for 14 months when the occurrence of multiple facial nodules with acid-fast bacilli present caused the owner to elect euthanasia. Résumé— Le cas d'une chatte européenne castrée de six ans présentant une masse périnasale due àMycobacterium avium est rapporté. La rechute après cryochirurgie et l'absence de réponse à la dapsone a nécessité une ablation chirurgicale. Le chat est resté apparemment sain 14 mois après l'opération, jusqu'à l'appartion de nodules multiples sur la face avec des baciles acid-alcolorésistants. L'animal a été euthanasié. Zusammenfassung— Beschrieben wird eine kurzhaarige Hauskatze, sechs Jahre alt, weiblich, kastriert, mit einer paranasalen kutanen Zubildung, die durch Mycobacterium avium verursacht wurde. Eine Wiederauftreten nach Kryochirurgie und ein Nichtansprechen auf Dapson zwang zu einer chirurgischen Entfernung. Die Katze blieb 14 Monate lang klinisch gesund bis das Auftreten von multiplen fazialen Knoten mit histologisch nachweisbaren säurefesten Bazillen dazu führte, daß der Besitzer sich für die Euthanasié des Tieres entschied. Resumen En este artículo se estudia una gata castrada de seis años de raza moméstica de pelo corto, con una masa cutánea paranasal causada por el Mycobacterium avium. La masa fue removida quirürgicamente después del tratamiento con dapsone y la aplicación de criocirugía con la consiguiente reaparición de la misma. Por un periodo de 14 meses la gata permaneció clínicamente normal, pero después el animal desarrolló nódulos faciales multiples con la aparición de bacilos que podian ser teñidos con tinturas ácidas, ante lo cual el dueño decidió terminar con la vida del animal.     

Dystrophic (Dermolytic) Epidermolysis Bullosa in a Cat

Abstract— Dystrophic epidermolysis bullosa was diagnosed in an 8-month-old male domestic shorthaired cat. Lesions noted were paronychia, ulcers on the palate, oropharynx, gums and tongue, as well as ulceration and crusts on the metacarpal, metatarsal and digital pads. Histology of lesions showed dermal-epidermaj separation and ulceration. Immunohistochemistry showed collagen IV (characteristic of the lamina densa) located at the roof of the cleft at both the dermal-epidermal and follicular-dermal interfaces. Electron microscopy showed the dermal-epidermal cleft to be sublamina densa. Résumé— Une épidermolyse bulleuse dystrophíque a été diagnostiquée chez un chat européen à poils courts de huit mois. Les lésions étaient une paronychie, des ulcères du palai, de l'oropharynx, des gencives et de la langue ains que des ulcères et des croutes au niveau des métacarpes, métatarses et coussinets plantaires. L'examen histologique des lésions faiasait apparaitre des ulcérations et des disjonctions derme/épiderme. L'étude immunohistochimique a montré la présence de fibres de collagène IV (caractéristiques de la lamina densa) sur lew toit des bulles tant au niveau des interfaces derme/épiderme que derme/follicule. La microscopie électronique a montré que les séparations derme/épiderme se faisaient au niveau de la sublamina densa. Zusammenfassung— Eine dystrophe Epidermolysis bullosa wurde bei einer achtjährigen kurzhaarigen männlichen hauskatze diagnostiziert. Die beschriebenen Veränderungen bestanden in Paronychie, Ulzera an Gaumen, Oropharynx, Gingiva und Zunge sowie Ulzerationen und Krusten an den metacarpalen, metatarsalen und digitalen Ballen. Die Histologie der Veränderungen zeigte dermal-epidermale Trennungen und Ulzerationen. Mit der Immunhistochemie wurde Kollagen IV nachgewiesen (ein Kennzeichen der Lamina densa), das am Gewölbe der Spaltbildung sowohl an den derma-epidermalen als auch an den follikulär-dermalen Schnittstellen lokalisiert war. Die Elektronenmikroskopie zeigte, daß die dermal-epidermale Spaltbildung die Sublamina densa darstellte. Resumen En un gato macho de ocho meses doméstico de pelo corto se diagnóstico epidermolisis distrófica bullosa. Las lesiones presentes fueron paroniquia, úlceras del paladar, orofaringe, encías y lengua, así como ulceraciones y costras en las regiones del metacarpo, metatarso, y almohadillas plantares. Las lesiones histologicas consistieron de separación y ulceración a nivel de la dermis y epidermis. Exámenes inmunohistoquímicos demostraron la presencia de colágeno IV (característico de la lámina densa), localizado en el techo de las indentactiones en ambas interfases, epidermo-dérmica y foliculo-dérmica. Por medio de microscopía electrónica se comprobo que las indentaciones de la dermis y epidermis consistían de sublámina densa.