153 research outputs found

    Alopecia Areata Susceptibility in Rodent Models

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    With our current view of alopecia areata as an autoimmune disease, it is probable that disease development in an individual is dependent on multiple genetic and environmental factors interacting in a complex system. Rodent models afford the opportunity to investigate alopecia areata development and to define the significance of the different factors involved. Recently, rodent model characterization has been conducted using flow cytometry, microarray analysis, and functional studies. From these a pattern of events in alopecia areata development has emerged. Although the preliminary activation events for the onset of alopecia areata remain unknown, the response of the immune system is characterized by antigen presentation and costimulation of lymphocytes in the lymph nodes and skin, a deficiency of CD4+/CD25+ regulatory cells, and an action of activated lymphocytes on hair follicles via Fas/FasL signaling and cytokines. Thus, onset of disease may require appropriate (or inappropriate) expression of stimulatory antigens within the hair follicle, the breakdown of the putative hair follicle immune privilege, the presentation of antigens to the immune system, a failure of immune system regulation, and the ability of the activated immune system to disrupt anagen-stage hair follicles. Once the sequence of events is initiated, it may become a self-perpetuating cycle, with epitope spreading leading to a wider range of targets in chronic alopecia areata. Rodent model studies have provided significant insight into alopecia areata, but much more remains to be explained about the mechanisms of disease development

    Alopecia Areata: Treatment of Today and Tomorrow

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    It is the aim of this article to review and appraise available data on treatments for alopecia areata (AA) according to the demands of evidence based medicine. Studies evaluating the efficacy of a treatment for AA should include appropriate controls, use cosmetically acceptable hair regrowth as a parameter for treatment success, include patients with AA totalis, universalis or extensive patchy AA, and exclude patients suffering from AA for less than 3 months. Moreover, the treatment must be safe over a prolonged period of time. Among the various therapeutic approaches presently available for AA, only treatment with contact sensitizers such as diphenylcyclopropenone or squaric acid dibutylester has been shown to be effective in studies that fulfill these criteria.Improved future treatments may be immunosup-pressive or immunomodulatory targeting of the autoimmune pathogenesis of AA, or they may otherwise protect hair follicles from the injurious effects of inflammation. Such possible future therapeutic approaches include the incorporation of immunomodulatory agents into liposomes as an improved vehicle; inhibition of apoptosis mediated by the Fas-FasL system; inhibition of the lymphocyte homing receptor CD44v10; induction of tolerance

    Sequential Combination Therapy Leading to Sustained Remission in a Patient with SAPHO Syndrome

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    The SAPHO syndrome represents a variety of clinically similar disorders with the key features of hyperostotic bone lesions in combination with chronic pustular skin disease. The respective pathophysiology of bone and joint manifestations in SAPHO syndrome is still a matter of discussion. For example it does not appear to represent reactive arthritis and HLA B27 antigen, with the latter being typically present in patients with spondyloarthopathies. Treatment of SAPHO syndrome is also not well established and consists of various antiinflammatory and antirheumatic drugs. Here, we report a female patient with active SAPHO syndrome suffering from sternal swelling of unknown origin that had been known for 10 years and a 4-year-history of severe lower back pain. Remarkable were also a typical pustulous palmar erythema associated with swelling and decreased motility of both MCP-I joints. Inflammation parameters were high with an ESR 68 mm/1st hour and a CRP of 19.6 mg/l. She was initially treated with rofecoxib and doxycycline, followed by sulfasalazine with only partial clinical response. Thereafter, both articular symptoms as well as cutaneous lesions responded well to a combination therapy with methotrexate and sulfasalazine. Thus, the case illustrates nicely that methotrexate in combination with another DMARD can be successfully applied to patients with long-term active SAPHO syndrome

    Maintenance of Hair Follicle Immune Privilege Is Linked to Prevention of NK Cell Attack

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    Hair follicles (HFs) enjoy a relative immune privilege (IP) that is characterized by downregulation of major histocompatibility complex (MHC) class I and local expression of potent immunosuppressants. Normally, natural killer (NK) cells attack cells with absent/low MHC class I expression. However, because few perifollicular NK cells are found around healthy human anagen HFs, we asked how HFs escape from NK cell attack. This study suggests that this happens via an active NK cell suppression. Alopecia areata (AA), an organ-specific autoimmune disease thought to result from a collapse of HF-IP, in contrast, shows striking defects in NK cell inhibition/containment. We show that the NK cell inhibitor macrophage migration inhibitory factor is strongly expressed by the HF epithelium, and very few CD56+/NKG2D+ NK cells are observed in and around normal anagen HFs compared to AA with prominent aggregations of CD56+/NKG2D+ NK around AA-HFs. By flow cytometry, many fewer NK function-activating receptors (NKG2D, NKG2C) and significantly more killer cell Ig-like receptors-2D2/2D3 were found to be expressed on peripheral blood CD56+ NK cells of healthy controls than on those of AA patients. In addition, only weak immunoreactivity for MHC class I chain-related A gene was observed in normal anagen HFs compared to AA. To our knowledge, this defect is previously unreported and must be taken into account in AA pathogenesis and its management

    Case report of right hamate hook fracture in a patient with previous fracture history of left hamate hook: is it hamate bipartite?

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    BACKGROUND: Hamate hook fracture is a common fracture in golfers and others who play sports that involve rackets or sticks such as tennis or hockey. This patient had a previous hamate fracture in the opposing wrist along with potential features of hamate bipartite. CASE PRESENTATION: A 19 year old male presented with a complaint of right wrist pain on the ulnar side of the wrist with no apparent mechanism of injury. The pain came on gradually one week before being seen in the office and he reported no prior care for the complaint. His history includes traumatic left hamate hook fracture with surgical excision. CONCLUSION: The patient was found to have marked tenderness over the hamate and with a prior fracture to the other wrist, computed tomography of the wrist was ordered revealing a fracture to the hamate hook in the right wrist. He was referred for surgical evaluation and the hook of the hamate was excised. Post-surgically, the patient was able to return to normal activity within eight weeks. This case is indicative of fracture rather than hamate bipartite. This fracture should be considered in a case of ulnar sided wrist pain where marked tenderness is noted over the hamate, especially after participation in club or racket sports

    Clinical improvement in a patient with monostotic melorheostosis after treatment with denosumab: a case report

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    Abstract Background A 20-year-old Danish woman with melorheostosis in her right femoral shaft and disabling pain in the affected area, whose symptoms did not in the long term respond to zoledronic acid, experienced continuous remission of pain after treatment with denosumab. To the best of our knowledge, this is the first case report on denosumab treatment for melorheostosis. Case presentation Radiologic findings and bone biopsy showed irregular cortical hyperostosis in the right femoral shaft with increased tracer uptake on Tc99-bone scan. The diagnosis of melorheostosis was made based on the radiological findings. There was a good initial response to zoledronic acid administration, but after relapse of pain, the second and third administrations had a poor effect. As a second line of treatment denosumab was administered at 8-week intervals, the frequency was based on our patient’s symptoms and on biochemical markers of bone turnover. Conclusion This is the first report indicating that denosumab has a place in the treatment of melorheostosis when the effect of bisphosphonate treatment is insufficient

    Adverse Events Post Smallpox-Vaccination: Insights from Tail Scarification Infection in Mice with Vaccinia virus

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    Adverse events upon smallpox vaccination with fully-replicative strains of Vaccinia virus (VACV) comprise an array of clinical manifestations that occur primarily in immunocompromised patients leading to significant host morbidity/mortality. The expansion of immune-suppressed populations and the possible release of Variola virus as a bioterrorist act have given rise to concerns over vaccination complications should more widespread vaccination be reinitiated. Our goal was to evaluate the components of the host immune system that are sufficient to prevent morbidity/mortality in a murine model of tail scarification, which mimics immunological and clinical features of smallpox vaccination in humans. Infection of C57BL/6 wild-type mice led to a strictly localized infection, with complete viral clearance by day 28 p.i. On the other hand, infection of T and B-cell deficient mice (Rag1−/−) produced a severe disease, with uncontrolled viral replication at the inoculation site and dissemination to internal organs. Infection of B-cell deficient animals (µMT) produced no mortality. However, viral clearance in µMT animals was delayed compared to WT animals, with detectable viral titers in tail and internal organs late in infection. Treatment of Rag1−/− with rabbit hyperimmune anti-vaccinia serum had a subtle effect on the morbidity/mortality of this strain, but it was effective in reduce viral titers in ovaries. Finally, NUDE athymic mice showed a similar outcome of infection as Rag1−/−, and passive transfer of WT T cells to Rag1−/− animals proved fully effective in preventing morbidity/mortality. These results strongly suggest that both T and B cells are important in the immune response to primary VACV infection in mice, and that T-cells are required to control the infection at the inoculation site and providing help for B-cells to produce antibodies, which help to prevent viral dissemination. These insights might prove helpful to better identify individuals with higher risk of complications after infection with poxvirus

    A short-term in vivo model for giant cell tumor of bone

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    <p>Abstract</p> <p>Background</p> <p>Because of the lack of suitable <it>in vivo </it>models of giant cell tumor of bone (GCT), little is known about its underlying fundamental pro-tumoral events, such as tumor growth, invasion, angiogenesis and metastasis. There is no existing cell line that contains all the cell and tissue tumor components of GCT and thus <it>in vitro </it>testing of anti-tumor agents on GCT is not possible. In this study we have characterized a new method of growing a GCT tumor on a chick chorio-allantoic membrane (CAM) for this purpose.</p> <p>Methods</p> <p>Fresh tumor tissue was obtained from 10 patients and homogenized. The suspension was grafted onto the CAM at day 10 of development. The growth process was monitored by daily observation and photo documentation using <it>in vivo </it>biomicroscopy. After 6 days, samples were fixed and further analyzed using standard histology (hematoxylin and eosin stains), Ki67 staining and fluorescence <it>in situ </it>hybridization (FISH).</p> <p>Results</p> <p>The suspension of all 10 patients formed solid tumors when grafted on the CAM. <it>In vivo </it>microscopy and standard histology revealed a rich vascularization of the tumors. The tumors were composed of the typical components of GCT, including (CD51+/CD68+) multinucleated giant cells whichwere generally less numerous and contained fewer nuclei than in the original tumors. Ki67 staining revealed a very low proliferation rate. The FISH demonstrated that the tumors were composed of human cells interspersed with chick-derived capillaries.</p> <p>Conclusions</p> <p>A reliable protocol for grafting of human GCT onto the chick chorio-allantoic membrane is established. This is the first <it>in vivo </it>model for giant cell tumors of bone which opens new perspectives to study this disease and to test new therapeutical agents.</p
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