Mycetoma Due to Nocardia brasiliensis: First Case Report from the Union Territory of Delhi: Nocavdia brasiliensis-Myzetom: Erster Fallbericht aus der Delhi-Union

The first case of mycetoma caused by Nocardia brasiliensis from the Union Territory of Delhi is reported. The patient, a permanent resident of the Union Territory of Delhi, acquired the disease 10 years ago following an accidental injury to his right hand. The diagnosis of the case was made on the basis of demonstration of the grains in direct microscopy, isolation of the organism in culture directly from the grains, identifying the organism by the conventional tests and through histopathology of the biopsy from the affected portion.     

Reduced amount of intestinal mucus by treatment with anti-CD4 antibody interferes with the spontaneous cure of Nippostrongylus brasiliensis-infection in mice

Mechanism of spontaneous cure was studied in mice infected with mouse-nonadaptive Nippostrongylus brasiliensis. Adult BALB/c mice were cured spontaneously of infection with this strain of N. brasiliensis by Day 7 post-infection. Expulsion of intestinal worms was delayed dose-dependently by a treatment with anti-CD4 antibody. However, the treatment had no significant effect on larval recovery from the lungs. Treatment of mice with anti-IL-5 antibody suppressed intestinal tissue eosinophilia induced by the infection, but did not affect intestinal worm recovery. Antigen specific IgE antibody was not detected in the sera obtained from Days 5 to 15. Therefore, IL-5 and specific IgE antibody are probably not important in the spontaneous cure. Treatment of mice with anti-CD4 antibody had no significant effect on number of intestinal goblet cells or on expression of terminal sugars of goblet cell mucins. However, histological and quantitative analyses revealed that significantly less intestinal mucus was released in anti-CD4 antibody treated mice than in control mice. These results suggest that CD4+ lymphocytes control the amount of intestinal mucus and consequently the reduced mucus interferes with the spontaneous cure. Quantity of mucus released in the intestinal lumen may have an essential role in the spontaneous cure ofN. brasiliensis-in/fcfio/i of mice.     

Multinucleate giant cells in murine and rat lungs during Nippostrongylus brasiliensis infections. A study of the kinetics of the response in vivo, cytochemistry, IgG- and C3-mediated functions

The cytochemical and functional characteristics of broncho-alveolar multinucleate giant cells and the kinetics of the giant cell response in the lungs of mice and rats during Nippostrongylus brasiliensis infection were studied. Primary infections resulted in significantly increased numbers of recoverable giant cells for up to 30 and 50 days in rats and mice, respectively. During secondary infections in the rat the giant cell response was more rapid and greater in magnitude than in a primary infection, suggesting that it was immunologically mediated. The giant cells displayed decreased C3- and IgG-dependent binding or phagocytic potential compared with mononucleate alveolar macrophages. Fusion of mononucleate alveolar macrophages into giant cells may therefore compromise complement and antibody dependent helminthocidal activity of these cells.     

Antibody suppression in mice infected with Nippostrongylus brasiliensis

Summary A/SN mice infected with N. brasiliensis showed depressed anti-DNP antibody responses following immunization with DNP-Asc in alum. The immunosuppression was only observed when infection preceded immunization by between 2 and 7 days, and was not achieved when the interval was extended to 10 days. The suppression lasted at least 50 days, and affected IgE levels more than IgGl or IgG agglutinating anti-DNP antibodies. A high dose of infective larvae (500–1000 per mouse) was necessary to induce suppression. Use of low dose irradiation indicated a parasite-induced radiosensitive component of the mouse immune system which negatively regulated the anti-DNP IgE response. These results suggested that the parasite could induce suppression in an analogous manner to sequential antigen-induced suppression (AIS).     

Capsaicin sensitive nerves in the jejunum of Nippostrongylus brasiliensis-sensitized rats participate in a cardiovascular depressor reflex

Summary Superfusion of capsaicin onto the serosal surface of jejunum of Nippostrongylus brasiliensis-sensitized rats induces a short-lasting (1–3 min), dose-dependent (2 to 20 g) decrease in blood pressure which ranges from –5.3±1.40% to –22.6±2.20%. The hypotension evoked by capsaicin was more marked in sensitized rats than in unsensitized animals, which responded only to the highest dose (20 mg) of capsaicin tested. The hypotensive effects of capsaicin were not affected by intravenous injections of mepyramine (10 mg/kg), a histamine receptor antagonist, or by the cycloxygenase inhibitor indomethacin (10 mg/kg). However, an intravenous injection of a platelet-activating factor (PAT) antagonist, BN 52021 (20 mg/kg), or an intraperitoneal injection of guanethidine (8 mg/kg) 18 h prior to experimentation, to functionally impair the sympathetic nerves, abolished the capsaicin-induced drop in blood pressure. Treatment of neonatal rats with capsaicin reduced by 75% the hypotensive effects of capsaicin, whereas the capsaicin antagonist, ruthenium red, reduced non-significantly the hypotensive action of capsaicin. It is concluded that the activation of jejunal sensory nerves in N. brasiliensis-sensitized rats by capsaicin induced a reflex hypotension that is dependent upon PAF release from mast cells and functional sympathetic nerves. In addition, the afferent function of the sensory nerves are not totally blocked by ruthenium red as capsaicin elicits the reflex hypotension in the presence of this blocker of sensory nerve efferent function.Correspondence to: R. Mathison     

Agaricus brasiliensis mycelium and its polysaccharide modulate the parameters of innate and adaptive immunity

The biological properties of Agaricus brasiliensis mainly include immunostimulating and antitumour activities. This study evaluated the immunomodulating effect of A. brasiliensis mycelium (LPB) and its exopolysaccharides (EPS) on immunological parameters, such as phagocytosis of Candida albicans and nitric oxide (NO) production by infected macrophages, splenocytes proliferation in response to C. albicans. It also assessed the effects of the intake of LPB on the number of lymphocytes in the lymph node and spleen of treated animals and the TNF-α production. It was showed that the LPB and EPS had opposite effects; LPB had antiproliferative action and also reduced the NO levels produced by macrophages. However, the EPS showed an immune-stimulating effect potentiating the splenocytes proliferation and NO production from macrophages after stimulation with C. albicans. In addition, it also protected the macrophages from death induced by yeast. These data confirmed the immunomodulatory properties of LPB and its polysaccharides.     

Nocardia brasiliensis primary pulmonary nocardiosis with subcutaneous involvement in an immunocompetent patient

This is a report of an unusual case of Nocardia brasiliensis causing primary pulmonary nocardiosis with disseminated subcutaneous lesions in an immunocompetent patient. This case highlights the importance of considering nocardiosis as a differential diagnosis in patients with pulmonary and cutaneous lesions and the need for vigorous management for complete cure.     

Ultrastructural changes in Paracoccidioides brasiliensis yeast cells attenuated by gamma irradiation

Paracoccidioides brasiliensis is a thermally dimorphic fungus agent of paracoccidioidomycosis, a deep-seated systemic infection of humans with high prevalence in Latin America. Until now no vaccine has been reported. Ionizing radiation can be used to attenuate pathogens for vaccine development and we have successfully attenuated yeast cells of P. brasiliensis by gamma irradiation. The aim of the present study was to examine at ultrastructural level the effects of gamma irradiation attenuation on the morphology of P. brasiliensis yeast cells. Paracoccidioides brasiliensis (strain Pb-18) cultures were irradiated with a dose of 6.5 kGy. The irradiated cells were examined by scanning and also transmission electron microscopy. When examined 2 h after the irradiation by scanning electron microscopy, the 6.5 kGy irradiated cells presented deep folds or were collapsed. These lesions were reversible since when examined 48 h after irradiation the yeast had recovered the usual morphology. The transmission electron microscopy showed that the irradiated cells plasma membrane and cell wall were intact and preserved. Remarkable changes were found in the nucleus that was frequently in a very electrondense form. An extensive DNA fragmentation was produced by the gamma irradiation treatment.     

The left lung is preferentially targeted during experimental paracoccidioidomycosis in C57BL/6 mice

Paracoccidioidomycosis (PCM) is a chronic systemic mycosis caused by theinhalation of the thermally dimorphic fungus Paracoccidioidesbrasiliensis as well as the recently described P.lutzii. Because the primary infection occurs in the lungs, weinvestigated the differential involvement of the right and left lungs inexperimental P. brasiliensis infection. Lungs were collectedfrom C57BL/6 mice at 70 days after intravenous infection with 1×10⁶yeast cells of a virulent strain of P. brasiliensis (Pb18). Theleft lung, which in mice is smaller and has fewer lobes than the right lung,yielded increased fungal recovery associated with a predominant interleukin-4response and diminished synthesis of interferon-γ and nitric oxide compared withthe right lung. Our data indicate differential involvement of the right and leftlungs during experimental PCM. This knowledge emphasizes the need for anaccurate, standardized protocol for tissue collection during studies ofexperimental P. brasiliensis infection, since experiments usingthe same lungs favor the collection of comparable data among different mice.