In vivo and in vitro phagocytosis of Leishmania (Leishmania) amazonensis promastigotes by B-1 cells.

Leishmaniasis is caused by Leishmania parasites that infect several cell types. The promastigote stage of Leishmania is internalized by phagocytic cells and transformed into the obligate intracellular amastigote form. B-1 cells are a subpopulation of B cells that are able to differentiate in vitro and in vivo into mononuclear phagocyte-like cells with phagocytic properties. B-1 cells use several receptors for phagocytosis, such as the mannose receptor and third complement receptor. Leishmania binds to the same receptors on macrophages. In this study, we demonstrated that phagocytes derived from B-1 cells (B-1 CDP) were able to internalize promastigotes of L. (L.) amazonensis in vitro. The internalized promastigotes differentiated into amastigotes. Our results showed that the phagocytic index was higher in B-1 CDP compared to peritoneal macrophages and bone marrow-derived macrophages. The in vivo phagocytic ability of B-1 cells was also demonstrated. Parasites were detected inside purified B-1 cells after intraperitoneal infection with L. (L.) amazonensis promastigotes. Intraperitoneal stimulation with the parasites led to an increase in both IL-10 and TNF-α. These results highlight the importance of studying B-1 CDP cells as phagocytic cells that can participate and contribute to immunity to parasites.

Immune responses induced by Pelargonium sidoides extract in serum and nasal mucosa of athletes after exhaustive exercise: modulation of secretory IgA, IL-6 and IL-15.

The evidence that exhaustive exercise may compromise the immune response is mainly confirmed by upper respiratory tract infections which are probably related to the decrease in secretory immunoglobulin A in the upper airway mucosa and/or profile changes of systemic cytokines as well as local cytokines of the upper respiratory tract. An extract from Pelargonium sidoides roots is currently used to treat infections in the upper airways. The aim of the present study was to evaluate the action of this herbal medicine on the immune response of athletes submitted to an intense running session by analyzing the production of immunoglobulin A in their saliva and of cytokines both locally and systemically, using a placebo as control. The results show that Pelargonium sidoides extract modulates the production of secretory immunoglobulin A in saliva, both interleukin-15 and interleukin-6 in serum, and interleukin-15 in the nasal mucosa. Secretory immunoglobulin A levels were increased, while levels of IL-15 and IL-6 were decreased. Based on this evidence, we suggest that this herbal medicine can exert a strong modulating influence on the immune response associated with the upper airway mucosa in athletes submitted to intense physical activity.

Macrophage suppression following phagocytosis of apoptotic neutrophils is mediated by the S100A9 calcium-binding protein.

The clearance of apoptotic cells by phagocytes is a fundamental process during tissue remodeling and resolution of inflammation. In turn, the phagocytosis of apoptotic cells generates signals that suppress pro-inflammatory activation of macrophages. These events occur during the resolution phase of inflammation and therefore the malfunctioning of this process may lead to inflammation-related tissue damage. Here, we demonstrate that the calcium-binding protein S100A9, normally abundant in the cytoplasm of neutrophils and also released by apoptotic neutrophils, is involved in the suppression of macrophages after the uptake of apoptotic neutrophils. Both, spontaneous and induced production of inflammatory species (nitric oxide, hydrogen peroxide and TNF-alpha) as well as the phagocytic activity were inhibited when macrophages were in presence of apoptotic neutrophils, conditioned medium from neutrophil cultures or a peptide corresponding to the C-terminal region of S100A9 protein. On the other hand, macrophages kept in the conditioned medium of neutrophils that was previously depleted of S100A9 were shown to resume the activated status. Finally, we demonstrate that the calcium-binding property of S100A9 might play a role in the suppression process, since the stimulation of intracellular calcium release with ionomycin significantly reversed the effects of the uptake of apoptotic neutrophils in macrophages. In conclusion, we propose that S100A9 is a novel component of the regulatory mechanisms of inflammation, acting side-by-side with other suppressor factors generated upon ingestion of apoptotic cells.

Radiometric survey of teletherapy treatment rooms in Brazil.

The Brazilian national regulatory authority, National Commission of Nuclear Energy, requires that dose rates in the vicinity of teletherapy treatment rooms do not exceed the permissible limits for workers as well as members of the public, depending on the place considered. At the end of 2005, the Brazilian national regulatory authority reduced the permissible dose limit for controlled areas from 1000 to 400 microSv week(-1). Therefore, the aim of this work is to verify the adequacy of structural shielding to this new limit for telecobalt units that had their sources changed and clinic linear accelerators (ALs) installed before the end of 2005. Considering the ALs, measurements of dose rates in controlled areas did not exceed the new permissible limit, excepting for a single case. In the case of (60)Co units, a similar situation is observed for controlled areas, although several non-conformities to the limit of uncontrolled area could be observed.

Dosimetric audits of photon beams in radiation therapy centres in Rio de Janeiro, Brazil.

Data related to 11 y of high-energy photon radiotherapy beam dosimetry are presented and analysed. Dosimetric evaluations were carried out using water phantoms and thimble ionisation chambers and are part of the radiation protection regulatory licensing process for medicine facilities of Brazilian government. Measurements were done at reference conditions for a standard absorbed dose of 100 cGy [cGy (=1 rad)]. The absolute per cent deviation between the measured and presumed delivered doses should not exceed the tolerance level of +/-3%. The first dosimetry survey from 1996 to 1998 showed a situation that was an object of concern. Deviations of 22 and 18.7% could be measured, although small deviations were also obtained. After 1998, the improvement in dosimetry quality control by the radiotherapy centres became clear, with most of the deviations situated within the +/-3% range. The decrease in the measured deviations presents the effective success of the Institute of Radiation Protection and Dosimetry audit programme for the improvement in the control of radiotherapy photon beams in Rio de Janeiro. Also, it is possible to recommend to Brazilian regulatory organisation a decrease in the tolerance level for dosimetric deviations in order to achieve a more precise dose delivered to patients in radiotherapy centres.

Role of distinct immune components in the radiation-induced abrogation of systemic lupus erythematosus development in mice.

The New Zealand Black x New Zealand White F1 [(NZB/NZW) F1] mouse develops an autoimmune condition resembling aspects of human systemic lupus erythematosus (SLE). We investigated the effects of a novel prophylactic thoraco-abdominal gamma irradiation protocol on the onset and evolution of lupus in these animals. Survival of irradiated mice was higher when compared with nonirradiated mice. Kidney lesions were milder and autoantibody levels were lower in irradiated mice. To identify possible mechanisms involved in the radiation-induced improvement of disease, distinct components of humoral and cellular immune responses were evaluated. Because B-1 cells are known to be involved in various autoimmune diseases, we investigated the participation of these cells in SLE progression. Unexpectedly, B-1 cells were not depleted in (NZB/NZW) F1, even after several rounds of irradiation. No alterations were found in viability and physiology of B-1 cells in SLE animals with the exception of constitutive overexpression of the anti-apoptotic molecule Bcl-2, which may account for the observed radioresistance. Thus, a role for B-1 cells in murine SLE cannot be excluded, since the irradiation protocol did not effectively eliminate these cells. Additionally, we demonstrate a marked delay in the ability of splenocytes to repopulate the spleen after irradiation in (NZB/NZW) F1, in contrast to leucocytes in other cellular compartments. The implications of these findings for the fate of SLE in this model are discussed.

Efferent projections of the pigeon intergeniculate leaflet containing neuropeptide Y

The present study was performed to map efferent projections of the pigeon intergeniculate leaflet (IGL) to other visual structures, with emphasis on the pathways containing neuropeptide Y (NPY). After injections of an anterograde tracer (Phaseolus vulgaris leucoagglutinin) into the IGL, labeled axons and presumptive terminals were seen in several retinorecipient and visually-related nuclei. All such areas contained immunoreactive fibers to antibodies against NPY. Electrolytic lesion of the IGL provoked a marked reduction in the number of NPY-labeled fibers in these visual structures. The data suggest that the IGL is the source of NPY-labeles axons which occur in many visual nuclei of the pigeon brain

Escleroestenose do colo vesical apos resseccao transuretral da prostata.Etiologia e tratamento endoscopico em 198 casos. / Sclerostenosis of the vesical neck following transurethral prostatic resection. Etiology and endoscopic treatment of 198 cases

No periodo de 1948 a 1981 foram tratados 198 pacientes com escleroestenose do colovesical, apos resseccao transuretral da prostata. O diagnostico foi feito por endoscopia ou uretrocistografia e as escleroestenoses classificadas em graus: moderado (36,36%) e severo (63,64%); tipos diafragmatico (46,47%) e longo (53,53%). O trauma do colo vesical que ocorre com mais frequencia e maior intensidade nas prostatas de menor tamanho, foi considerado o fator etiologico. O tratamento endoscopico constou de incisao, com faca de Collings, do colo vesical, em 2 posicoes, correspondentes a 4 e 8 horas (17,69%), ou reseccao da porcao inferior (47,90%) ou a reseccao de toda a circunferencia do colo (34,38%).A escolha do tipo de tratamento foi aleatoria, independente do grau e tipo de escleroestenose. Os resultados obtidos em 148 pacientes controlados foi considerado otimo em 54,72% (a escleroestenose foi solucionada com a operacao); bom em 5,4% (foram necessarias dilatacoes nos primeiros 6 meses) e falho em 39,88% (houve necessidade de nova intervencao). Nao houve diferenca significativa entre os resultados obtidos com os variados metodos de tratamento. Nao houve relacao entre os resultados obtidos e os graus e tipos de escleroestenose

Transurethral resection of pedunculated congenital polyps of the posterior urethra.

Congenital posterior urethral polyps are rare, benign tumours. Five cases are reported, in ages ranging from 2 to 46 years. All were treated by transurethral resection and we would recommend that, since suitable endoscopic equipment is now available, this is the treatment of choice.

A ultra-sonografia nas afeccoes escrotais. / Ultrasonography in scrotal diseases

O valor do estudo ultra-sonografico nas lesoes escrotais e avaliado em 10 casos, revelando-se util nas lesoes cisticas, na definicao de normalidade testicular, como auxiliar no diagnostico do tumor testicular, na definicao da origem testicular ou extratesticular das lesoes e nas epididimites. Revelou-se inutil para diferenciar torcao testicular de outras lesoes solidas escrotais