Comparative study on the effect of cyclic nucleotides related to the function of Biomphalaria glabrata hemocytes and human granulocytes

The biochemical processes linked up to cyclic nucleotides related to the phenomenon of phagocytosis in Biomphalaria glabrata hemocytes were studied. In hemocytes the results suggest the presence of a phagocytic capacity similar to that observed in human cells related to regulation by cyclic adenylate monophosphate (cAMP), but not by cyclic guanylate monophosphate (cGMP). This similarity and differences in the metabolic process of phagocytary capacity between human phagocytary cells and hemocytes could represent an interesting model aimed at studying the phylogenetic evolution of enzymatic complexes.

[Coccidioidomycosis: a new brazilian case]

A case of pulmonary coccidioidomycosis from the rural zone of Bertolinia, PI, is reported. The patient, a farm worker, attributed his illness to the dust inhaled while digging a water well during the dry season of the year, some weeks before the onset of the clinical manifestations. The main symptoms of the disease were severe chest pain and moderate fever. The diagnosis was made histopathologically: tissue phase fungal organisms--immature spherules and spherules with endospores--were observed in histological sections of a lung fragment obtained by open chest biopsy. This is the twelfth autochthonous case of coccidioidomycosis found so far in Brazil. All of them involved native inhabitants of the semi-arid part of Northeastern Brazil. The hot and dry environment of the region seems to favor the development of C. immitis in the soil. Humans and animals probably acquire the infection by digging the soil, when they become exposed to the conidium-bearing dust raised by this activity.

[Human adiaspiromycosis. A report of a case treated with ketoconazole]

A case of human disseminated pulmonary adiaspiromycosis is reported. The patient, from Goianésia, GO, was admitted to the Brasilia University Hospital, in November 1992, with wet cough, dyspnea and weight loss--manifestations that had appeared two months before. Prior to admission, he had been treated for a suspected miliary tuberculosis, because a chest roentgenogram had shown a diffuse reticulonodular infiltrate in both lungs. This therapy brought no improvement to the patient status. An open chest biopsy was then performed, and the microscopic examination of the lung tissue revealed the fungal nature of the disease. Ketoconazole, 400mg/day, was started and the patient discharged from the hospital. He was seen again two months later: the respiratory manifestations had disappeared and a new chest roentgenogram showed complete resolution of the pulmonary lesions. The usefulness of ketoconazole is, however, questioned, since, as there is no multiplication of the fungus in the host organism--adiaspiromycosis is believed to be, usually, a self-healing disease--the efficacy of this imidazole derivative against the agent in animal tissues remains to be confirmed.

Quantification of the population and phagocytary activity of hemocytes of resistant and susceptible strains of Biomphalaria glabrata and Biomphalaria tenagophila infected with Schistosoma mansoni

Among the determinant factors in the resistance and susceptibility of Biomphalaria to Schistosoma mansoni, hemocytes play an important role. Aiming at studying S. mansoni/Biomphalaria interactions related to hemocytes, the first step is certainly connected with the standardization of this cell population in uninfected Biomphalaria. In this way, quantification of this cell population in hemolymph, as well as its phagocitary capacity, have been determined for the first time. Furthermore, using susceptible and resistant strains of B. glabrata and B. tenagophila, the hemocytegram and phagocytary capacity of hemocytes after infection with S. mansoni were determined too. Resistant and susceptible strains of B. glabrata (BA and BH, respectively), as well as resistant and susceptible strains of B. tenagophila (TAIM and CF, respectively) were infected with 10 miracidia of the LE and SJ strains of S. mansoni, respectively. These infected snails and respective uninfected controls were assessed in relation to the number of circulating hemocytes and alteration in the phagocytary capacity, by using Zymozan and MTT. Reading was taken by means of a spectrophotometer at 5 hours and 1, 2, 5, 10, 20 and 30 days after infection. The results showed a decrease in population of the circulating phagocytary cells, 5 hours after infection. One day post-infection, the circulating cells of the susceptible snails showed an increased metabolic activity, but the same event could not be observed in the resistant strains. In the subsequent observation periods, significant differences among the strains studied could not be observed until the end of the experiment.