Luiz M. Bechelli

Epidemiological Survey of Skin Diseases in Schoolchildren Living in the Purus Valley (Acre State, Amazonia, Brazil)

A total of 9,955 schoolchildren aged 6-16 years have been examined in a tropical region. The prevalence of dermatosis varied from 21 to 87% in the municipalities surveyed. The most common dermatoses were pediculosis (prevalence 50%), nevi (16.8%), pityriasis versicolor (13.2%), pyoderma (12.2%), pityriasis alba (9.9%), dermatophytosis (6.2%), viral dermatosis (6.2%), scabies (3.0%) and acne vulgaris (2.7%). The prevalence of angular stomatitis, miliaria rubra, candidiasis, piedra nigra, keratosis pilaris, ephelides and geographic tongue is lower but still relatively high. Females had higher rates of pediculosis capitis and males higher prevalence of pityriasis alba. The prevalence of pityriasis versicolor, pigmented nevus and scabies was similar in males and females. Folliculitis, macular pigmented nevi and especially pityriasis versicolor tended to increase with age. Leprosy is hyperendemic in the surveyed area and its rate in the schoolchildren examined was 0.08%. Population movement (urbanization), socioeconomic situation, living conditions, promiscuity, and lack of hygiene may be the cause of such high prevalence and of association of two or more skin conditions. Climatic conditions might have enhanced the prevalence of certain dermatoses (pityriasis versicolor, dermatophytosis, piedra nigra, candidiasis, miliaria rubra).

Lymphocyte transformation test in patients with paracoccidioidomycosis

The lymphocyte transformation test (LTT) by phytohemagglutinin was carried out on lymphocyte cultures from patients with paracoccidioidomycosis, in medium with autologous plasma (from the patient) or homologous plasma (from an unaffected individual), and lymphocyte cultures from unaffected and apparently normal individuals, in medium with autologous plasma (from the individual) or homologous plasma (from a patient with paracoccidioidomycosis). Blastogenesis was evaluated morphologically by ‘blast’ percentage, and the results analyzed according to clinical form of the disease and general condition of the patient. In the medium containing autologous plasma, percentages below the lower limit of the confidence interval for the distribution of the values for apparently normal individuals were encountered more frequently among patients with diffuse extrapulmonary paracoccidioidomycosis and in poor general condition. When the lymphocytes from patients with the disease were cultured in medium containing homologous plasma, blastogenesis increased in most cases. The lymphocytes of unaffected individuals exhibited a lower response more frequently when cultured in medium containing plasma from patients with the disease than when cultured in medium containing their own plasma. These results suggest the existence of factor(s) inhibiting blastogenesis in the plasma of these patients. In addition to such factor(s), an intrinsic lymphocyte defect may also occur in some patients, which might prevent a greater response to phytohemagglutinin even in homologous plasma. Smears of lymphocytes cultured in autologous plasma and obtained from patients, especially those with diffuse extrapulmonary diasease and in regular or poor general condition, and smears from most of the controls whose lymphocytes were cultured in the plasma of these patients revealed deeply stained cells with altered morphology and considerably reduced in number. The decreased blastic transformation might be linked with these abnormalities, possibly caused by factor(s) inhibiting blastogenesis in the culture medium containing patient plasma.

Ultrastructure of lymphocytes from patients with paracoccidioidomycosis in the lymphocyte transformation test by phytohemagglutinin

The morphology and ultrastructure of peripheral blood lymphocytes from patients with paracoccidioidomycosis (PCM) and from unaffected individuals (controls) were studied before and after Ficoll-Hypaque separation and at the end of culture, stimulated with phytohemagglutinin. Patient lymphocytes were cultured in medium with autologous plasma (from the patient himself) and with homologous plasma (from an unaffected donor), while donor lymphocytes were cultured in medium with plasma from a patient or with plasma from the donor himself. The Ficoll-Hypaque mixture caused no morphological or ultrastructural changes in the lymphocytes of patients or of unaffected donors. Patient lymphocytes cultured in medium with autologous plasma showed different degrees of cytoplasmic and nuclear alterations, such as organelle dissolution, vacuoles, amorphous masses, deformed nuclei, and absence of nucleoli. Lymphocytes from control individuals cultured in patient plasma also showed ultrastructural alterations, though they were less marked, and a reduced number of ‘blasts’. Patient lymphocytes cultured in medium with homologous plasma (from a control individual) showed a morphology similar to that of lymphocytes from control individuals cultured in medium with their own plasma, although with a lower number of ‘blasts’. On the basis of the results obtained using that methodology, we draw the following conclusions: (1) separation by Ficoll-Hypaque does not seem to alter the ultrastructure of patient or donor lymphocytes; (2) patients with diffuse PCM and more markedly impaired general condition can exhibit lymphocytes with morphological and ultrastructural alterations capable of affecting their biological systems and functionality; (3) the morphological and ultrastructural abnormalities and the reduced blastogenesis observed in patient lymphocytes cultured in autologous plasma and in control lymphocytes cultured with patient plasma appear to be due to factor(s) present in the plasma of PCM patients.

Lymphocyte Transformation Test in Patients with American Leishmaniasis

To determine the correlation between the lymphocyte transformation test (LTT) with phytohemagglutinin (PHA) and the clinical forms of American leishmaniasis (AL), duration of the disease and reaction to leishmanin, the authors studied 12 patients and compared them to 25 unaffected individuals. The ulcerated cutaneous form of the disease was observed in 4 patients, the ulcero-nodular lymphangitic form in 1, the mucous cutaneous form with destruction of the nose in 6, and the verrucous form in 1. General patient condition was satisfactory and the Montenegro reaction macroscopically positive with infiltrations of 5-15 mm in diameter. The results revealed no evidence of immunodeficiency among patients. No correlation was observed between clinical forms, duration of the disease and Montenegro reaction and LTT results. LTT with PHA does not appear to be an adequate indicator of the cell immune system in AL cases.