Há muito o papel do ácido ascórbico (AA) no metabolismo do tecido conjuntivo tem sido reconhecido, sobretudo a partir do século 16, quando o escorbuto começou a ser prevenido com sumo de frutas cítricas. As primeiras publicações referentes ao uso tópico da vitamina C, inicialmente em cobaio, datam da década de 1960. Entretanto, só mais recentemente tem-se dado valor a essa via de aplicação. Os autores apresentam revisão sobre o assunto, discorrendo sobre o histórico da vitamina C, seus efeitos no metabolismo do tecido conjuntivo, no processo de cicatrização, sobre sua atividade antioxidante e mecanismos de ação.

New cases of LS and autoimmune disorders can be detected in first degree relatives of patients with LS. The presence of anti-TPO antibodies strongly suggests autoimmune thyroiditis. There is intra-familial association between the haplotype HLA-B*15 -DRB1*04 -DRB4* and anti-TPO,emphasizing their link with thyroiditis. New familial approaches might help to make clear the pathogenesis of LS and its association with autoimmune diseases.

Different antigens and alleles from both HLA classes I and II were seen in a significantly higher frequency in patients with psoriasis vulgaris. HLA Cw*0602 and DRB1*0701 were represented in different reports, and the former was related mainly to psoriasis type I.

Key words: vitiligo/histology/melanocytes/pigmentation/ autoimmunity Recently, Wankowicz-Kalinska et al. (2003) observed T-cell infiltrates in the dermoepidermal junction of clinically normal-pigmented skin in patients with active generalized vitiligo, displaying the microscopic disappearance of melanocytes, also called 'microdepigmentation',

Paracoccidioidomycosis is a systemic granulomatous disease caused by the dimorphic fungus Paracoccidioides brasiliensis. It is the most prevalent systemic mycosis of Latin America and 80% of the reported cases are from Brazil. Because of the great number of neutrophils found in the P. brasiliensis granuloma, studies have been done to evaluate the role of these cells during the development of the infection. Scanning and transmission electron microscopy of thin sections showed that the neutrophils ingest yeast cells through a typical phagocytic process with the formation of pseudopodes. The pseudopodes even disrupt the connection established between the mother and the bud cells. Neutrophils also associate to each other, forming a kind of extracellular vacuole where large yeast cells are encapsulated. Cytochemical studies showed that once P. brasiliensis attaches to the neutrophil surface, it triggers a respiratory burst with release of oxygen-derived products. Attachment also triggers neutrophils degranulation, with release of endogenous peroxidase localized in cytoplasmic granules. Together, these processes lead to killing of both ingested and extracellular P. brasiliensis.

The reduced frequency of positive serological markers of disease in patients and normal controls from Western Parana, as well as the absence of recurrent disease in previously identified patients, suggest that environmental antigenic stimulation of the population at risk may have decreased in recent years.

DS is the major GAG species in normal skin from different body sites. In addition, our results suggest a decrease and also a structural change in DS and an increase in the proportion of HA in scleroderma skin.

We suggest that alleles DQB1*04 may be involved in the genetic susceptibility of PR based on the significant predominance of those alleles observed in the black PR patients. We also recommend that more studies are conducted on populations of other ethnic origins, preferentially with higher resolution techniques of DNA typing.