Influence of the Nd:YAG laser pulse duration on the temperature of primary enamel.

The aim of this study is to evaluate the temperature change on specimens of primary enamel irradiated with different pulse duration of Nd:YAG laser. Fifteen sound primary molars were sectioned mesiodistally, resulting in 30 specimens (3.5 × 3.5 × 2.0 mm). Two small holes were made on the dentin surface in which K-type thermocouples were installed to evaluate thermal changes. Specimens were randomly assigned in 3 groups (n = 10): A = EL (extra long pulse, 10.000 µs), B = LP (long pulse, 700 µs), and C = SP (short pulse, 350 µs). Nd:YAG laser (λ = 1.064 µm) was applied at contact mode (10 Hz, 0.8 W, 80 mJ) and energy density of 0.637 mJ/mm(2). Analysis of variance (ANOVA) was performed for the statistical analysis (P = 0.46). Nd:YAG laser pulse duration provided no difference on the temperature changes on primary enamel, in which the following means were observed: A = EL (23.15°C ± 7.75), B = LP (27.33°C ± 11.32), and C = SP (26.91°C ± 12.85). It can be concluded that the duration of the laser pulse Nd:YAG increased the temperature of the primary enamel but was not influenced by different pulse durations used in the irradiation.

Different patterns of dermatological presentations in patients co-infected with human immunodeficiency virus and hepatitis C virus (HCV), and those infected with HCV alone.

BACKGROUND: Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) share the same transmission routes. About 30% of HIV-positive patients are co-infected with HCV. Of the various HCV-related extrahepatic events, those involving the skin may be the first sign of infection. AIM: To specify the skin presentations in patients co-infected with HIV and HCV (co-infected patients; CP) and compare them with those found in patients with HCV mono-infection (mono-infected patients; MP). METHODS: This was a cross-sectional study, in which the studied population consisted of MP and CP from a tertiary hospital in the South of Brazil, who underwent complete skin examination and laboratory tests. RESULTS: In total, 201 patients were assessed, of whom 108 were CP, and 93 were MP. Pruritus tended to be more common in MP. MP also had significantly more dermatological conditions (mean of 5.2) than CP (mean of 4.5). In total, 104 different skin diseases were identified. There was a higher prevalence of infectious diseases and pigmentation disorders, such as verruca vulgaris and facial melasma, in CP, whereas trunk and facial telangiectasias, palmar erythema, and varicose veins were more common in MP. CONCLUSION: We found a high prevalence of skin conditions both in MP and in CP; however, the patterns of the dermatological conditions were different. CP were found to have significantly fewer skin lesions than MP, but had a higher prevalence of infectious and pigmentation disorders. By contrast, vascular conditions were more common in MP.

Mucocutaneous manifestations of disseminated histoplasmosis in patients with acquired immunodeficiency syndrome: particular aspects in a Latin-American population.

BACKGROUND: Mucocutaneous lesions in human immunodeficiency virus (HIV)-infected patients with disseminated histoplasmosis have a wide spectrum of clinical manifestations, making its diagnosis difficult. Studies have been restricted to case reports and series with small numbers of patients not specifically focusing on the dermatological aspects of histoplasmosis. AIMS: To describe the characteristics of mucocutaneous lesions of disseminated histoplasmosis in HIV-infected patients. METHODS: A retrospective and prospective study was conducted on 36 HIV-infected patients with mucocutaneous histoplasmosis in a tertiary-care hospital in Brazil. RESULTS: Mucocutaneous histoplasmosis was diagnosed by histopathology in 33 of the 36 patients (91%) and/or culture in 23 (64%). Their CD4+ cell counts ranged from 2 to 103 cells/mm(3). The average number of different morphological types of lesions was three per patient. Despite the variability of the lesions, papules (50%), crusted papules (64%) and oral mucosal erosions and/or ulcers (58%) were the most frequent dermatological lesions. A diffuse pattern of distribution of the skin lesions was found in 58% of the cases. There was significant association between the CD4+ cell counts and the morphological variability of lesions per patient. Variation in the lesions seemed to be associated with higher CD4+ cell counts. CONCLUSION: Doctors caring for HIV-infected patients should be aware of the wide spectrum of dermatological lesions observed in disseminated histoplasmosis and the importance of detecting and isolating the fungus in mucocutaneous tissues.