976 resultados para cutaneous
Resumo:
In light-skinned populations, the incidence of cutaneous melanoma is highest in summer and lowest in winter. We analyzed the seasonal variation of melanoma incidence in Northern Ireland from 1984 to 2006 according to the Breslow thickness and body site. We also reviewed earlier studies on seasonal variation in the diagnosis of melanoma. Two-thirds of melanomas in women (2028 cases) and one-third of melanomas in men (1230 cases) were diagnosed on the limbs. In both sexes, pronounced seasonal variations were observed in the incidence of invasive melanomas less than 2mm arising on the limbs. These seasonal variations were mainly noticeable in women of all ages, to a lesser degree in men aged below 50 years, and not in men aged above 50 years. No seasonal variation was observed for melanomas less than 2mm arising on the trunk or the head and neck nor for melanomas 2mm thickness or more, irrespective of the age, sex, and body site. Seasonal variations of thin melanomas were less noticeable in men because of the axial predominance of melanoma occurrence in this sex. The review of 15 earlier studies found by a systematic search of Medline supported the likelihood of our findings. This analysis suggests that ultraviolet radiation has a short-term promotional effect on melanocytes or nevocytes of the limbs, and is not associated with progression from thin to thick melanoma. Melanoma Res 21:144-151 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
Resumo:
INTRODUCTION: Breaching the skin's stratum corneum barrier raises the possibility of the administration of vaccines, gene vectors, antibodies and even nanoparticles, all of which have at least their initial effect on populations of skin cells. AREAS COVERED: Intradermal vaccine delivery holds enormous potential for improved therapeutic outcomes for patients, particularly those in the developing world. Various vaccine-delivery strategies have been employed, which are discussed in this review. The importance of cutaneous immunobiology on the effect produced by microneedle-mediated intradermal vaccination is also discussed. EXPERT OPINION: Microneedle-mediated vaccines hold enormous potential for patient benefit. However, in order for microneedle vaccine strategies to fulfill their potential, the proportion of an immune response that is due to the local action of delivered vaccines on skin antigen-presenting cells, and what is due to a systemic effect from vaccines reaching the systemic circulation, must be determined. Moreover, industry will need to invest significantly in new equipment and instrumentation in order to mass-produce microneedle vaccines consistently. Finally, microneedles will need to demonstrate consistent dose delivery across patient groups and match this to reliable immune responses before they will replace tried-and-tested needle-and-syringe-based approaches.
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Natural regression should not be advocated as a treatment option for cutaneous warts, given the infectious nature of this condition. Although there are numerous treatments for this condition reported in the literature, many trials are uncontrolled and many regimens are unsuitable for general practice. Specific treatment is influenced by age of patients, number and sites of warts and availability of treatment. This paper reviews the international literature on treatment methods, with particular emphasis on effectiveness, patient acceptability and application in family practice.
Resumo:
Three hundred and seventy-six patients attending their general practitioner with cutaneous warts at five health centres in Northern Ireland were screened for human papilloma virus (HPV) types 1 and 2 IgM antibody using an indirect immunofluorescence test. Eight-eight (23.4%) patients were positive for HPV type 1 IgM and 156 (41.5%) for HPV type 2 IgM. HPV 1 IgM antibody was significantly more likely to be associated with plantar warts than warts elsewhere (P less than 0.0001). HPV 2 IgM was present in 45 (34.1%) patients with plantar warts and 99 (45.6%) patients with warts at other sites (P = 0.1). Evidence of multiple infection by HPV types 1 and 2 was demonstrated by the finding of HPV 1 and 2 IgM antibodies in the sera of 16 (4.3%). HPV 4 was found in only 1 out of 30 biopsies and HPV 4 IgM was undetectable in 50 randomly chosen sera.
Resumo:
Patients with common hand warts and simple plantar warts attending a general practice wart clinic in Northern Ireland were assigned to one of three treatment groups - liquid nitrogen applied weekly, daily application of wart paint (lactic acid one part, salicylic acid one part, collodion four parts), or a combination of the two. Combination therapy cured 87% of common hand warts over a six week period, and was significantly more effective than either agent used separately (P
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Efficient formation of early GCs depends on the close interaction between GC B cells and antigen-primed CD4+ follicular helper T cells (TFH). A tight and stable formation of TFH/B cell conjugates is required for cytokine-driven immunoglobulin class switching and somatic hypermutation of GC B cells. Recently, it has been shown that the formation of TFH/B cell conjugates is crucial for B-cell differentiation and class switch following infection with Leishmania major parasites. However, the subtype of DCs responsible for TFH-cell priming against dermal antigens is thus far unknown. Utilizing a transgenic C57BL/6 mouse model designed to trigger the ablation of Langerin+ DC subsets in vivo, we show that the functionality of TFH/B cell conjugates is disturbed after depletion of Langerhans cells (LCs): LC-depleted mice show a reduction in somatic hypermutation in B cells isolated from TFH/B cell conjugates and markedly reduced GC reactions within skin-draining lymph nodes. In conclusion, this study reveals an indispensable role for LCs in promoting GC B-cell differentiation following cutaneous infection with Leishmania major parasites. We propose that LCs are key regulators of GC formation and therefore have broader implications for the development of allergies and autoimmunity as well as for future vaccination strategies.
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Background: Chronic kidney disease (CKD) patients on dialysis are prone to vitamin D insufficiency despite oral vitamin D supplementation. Here, we studied whether narrow-band ultraviolet B (NB-UVB) exposures improve vitamin D balance.
Methods: 14 haemodialysis patients and 15 healthy subjects receiving oral cholecalciferol 20 µg daily got nine NB-UVB exposures on the entire body. Serum 25-hydroxyvitamin D (25(OH)D) was measured by radioimmunoassay. Cutaneous mRNA expression levels of CYP27A1 and CYP27B1, two enzymes required for hydroxylation of vitamin D into its active metabolite, were also measured.
Results: The baseline serum 25(OH)D concentration was 57.6 ± 18.2 nmol/l in the CKD patients and 74.3 ± 14.8 nmol/l in the healthy subjects. The NB-UVB course increased serum 25(OH)D by 14.0 nmol/l (95% CI 8.7-19.5) and 17.0 nmol/l (CI 13.7-20.2), respectively. At baseline the CKD patients showed significantly increased CYP27B1 levels compared to the healthy subjects.
Conclusions: A short NB-UVB course is an efficient way to improve vitamin D balance in CKD patients on dialysis who are receiving oral vitamin D supplementation. The increased cutaneous CYP27B1 levels in the CKD patients suggest that the loss of renal activity of this enzyme is at least partially compensated for by the skin.
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Antimicrobial peptides (AMPs) are effectors of cutaneous innate immunity and protect primarily against microbial infections. An array of AMPs can be found in and on the skin. Those include peptides that were first discovered for their antimicrobial properties but also proteins with antimicrobial activity first characterized for their activity as chemokines, enzymes, enzyme inhibitors and neuropeptides. Cathelicidins were among the first families of AMPs discovered in skin. They are now known to exert a dual role in innate immune defense: they have direct antimicrobial activity and will also initiate a host cellular response resulting in cytokine release, inflammation and angiogenesis. Altered cathelicidin expression and function was observed in several common inflammatory skin diseases such as atopic dermatitis, rosacea and psoriasis. Until recently the molecular mechanisms underlying cathelicidin regulation were not known. Lately, vitamin D3 was identified as the major regulator of cathelicidin expression and entered the spotlight as an immune modulator with impact on both, innate and adaptive immunity. Therapies targeting vitamin D3 signalling may provide novel approaches for the treatment of infectious and inflammatory skin diseases by affecting both innate and adaptive immune functions through AMP regulation.
Resumo:
Constant exposure to a wide variety of microbial pathogens represents a major challenge for our skin. Antimicrobial peptides (AMPs) are mediators of cutaneous innate immunity and protect primarily against microbial infections. Cathelicidins were among the first AMPs identified in human skin and recent evidence suggests that they exert a dual role in innate immune defense: At first, due to their antimicrobial activity they kill pathogens directly. In addition, these peptides initiate a potent host response to infection resulting in cytokine release, inflammation and a cellular response. Disturbed cathelicidin expression and function was observed in several common inflammatory skin diseases, such as psoriasis where cathelicidin peptide converts inert self-DNA and self-RNA into an autoimmune stimulus. In atopic dermatitis decreased levels of cathelicidin facilitating microbial superinfections have been discussed. Furthermore, abnormally processed cathelicidin peptides induce inflammation and a vascular response in rosacea. Until recently, the molecular mechanisms underlying cathelicidin regulation were unknown. Recently, the vitamin D3 pathway was identified as the major regulator of cathelicidin expression. Consequently, vitamin D3 entered the spotlight as an immune modulator with impact on both innate and adaptive immunity. Therapies targeting vitamin D3 signaling may provide new approaches for infectious and inflammatory skin diseases by affecting both innate and adaptive immune functions.