Abstract in English:Interleukin-15 (IL-15) is a pleiotropic cytokine which regulates the proliferation, survival and the secretory activities of many distinct cell types in the body. This cytokine is produced by macrophages and many other cell types in response to infectious agents; it controls growth and differentiation of T and B lymphocytes, activation of Natural Killer (NK) and phagocytic cells, and contributes to the homeostasis of the immune system. The present review focuses on the biological and modulatory effects of IL-15 in microbial infections and shows that this cytokine may play a role in the host defense against infections by inducing activation of effector cells from both innate and adaptive immune system.
Abstract in English:Venoms from snakes of the Bothrops genus are proteolytic, coagulant, hemorrhagic and nephrotoxic, causing edema, necrosis, hemorrhage and intense pain at the bite site, besides systemic alterations. Many adjuvants have been added to the venom used in the sensitization of antiserum-producer animals to increase antigenic induction and reduce the envenomation pathological effects. Gamma radiation from 60Co has been used as an attenuating agent of the venoms toxic properties. The main objective was to study, comparatively, clinical and laboratory aspects of goats inoculated with bothropic (Bothrops jararaca) venom, natural and irradiated from a 60Co source. Twelve goats were divided into two groups of six animals: GINV, inoculated with 0.5mg/kg of natural venom; and GIIV, inoculated with 0.5mg/kg of irradiated venom. Blood samples were collected immediately before and one, two, seven, and thirty days after venom injection. Local lesions were daily evaluated. The following exams were carried out: blood tests; biochemical tests of urea, creatinine, creatine kinase (CK), aspartate amino-transferase (AST) and alanine amino-transferase (ALT); clotting time; platelets count; and total serum immunoglobulin measurement. In the conditions of the present experiment, irradiated venom was less aggressive and more immunogenic than natural venom.
Abstract in English:Pentavalent antimonial (SbV) is the first treatment for cutaneous leishmaniasis (CL). Other drugs present similar side effects and higher cost. Oral miltefosine is effective to treat kala-azar. The aim of the present study was to compare the efficacy of glucamine (SbV) plus topical miltefosine with glucamine in the treatment of CL. Eighty isogenic C57BL/6 mice were inoculated with Leishmania (Leishmania) amazonensis and divided into two groups: one group was treated with SbV associated with miltefosine, and the other group received SbV plus saline solution. Groups were evaluated according to the diameter of the inoculated foot pad, the culture, and the parasite count using the limiting dilution assay. There was not statistical difference. The efficacy of glucamine in CL treatment did not increase when associated with topical miltefosine.
Abstract in English:Some venomous spiders of the genus Loxosceles can reach high population densities inside and around houses. In Brazil, most spider accidents are related to Loxosceles intermedia. Control of loxoscelism should utilize integrated pest management tools, such as vacuum cleaners, to eliminate egg sacs, webs and spiders. The present study tested the efficacy of one type of vacuum cleaner (for professional and domestic use) in the control of L. intermedia populations. Cockroaches (Pycnoscelus surinamensis) were used in some tests for comparison. Vacuuming using standard accessories or a paper tube resulted in the death of all female (n=60), male (n=60), young (n=60) and just-hatched (n=60) L. intermedia, and all egg sacs (n=5) were destroyed. The removal of the plastic plate present at the bottom of the vacuuming tube inside the machine allowed some spiders to survive the vacuuming process. When kept inside a vacuum bag full of dust and debris, adult females (n=10) survived for 10 days; however, significant mortality was observed among male (n=10) and young individuals (n=10). Addition of cornstarch to the vacuum bag did not affect the spiders (n=20). Vacuum cleaners, such as the one used in the present investigation, are promising tools for integrated management of L. intermedia and other spiders in domestic environments.
Abstract in English:Mice genetically selected for high (H) and low (L) antibody production (Selection IV-A) were used as murine experimental model. The aim of the present work was to evaluate the macrophagic activity and to characterize the immune response in Mycobacterium bovis-AN5 infected mice (3X10(7) bacteria). The response profile previously observed in such strains was not similar to that obtained during M. bovis infection; however, it corroborated works carried out using Selection I, which is very similar to Selection IV-A regarding infection by M. tuberculosis and Bacillus Calmette-Guérin (BCG). Considering bacterial recovery, L IV-A mice showed higher control of the infectious process in the lungs than in the spleen, whereas H IV-A mice presented more resistance in the spleen. With respect to macrophagic activity, hydrogen peroxide (H2O2) was probably not involved in the infection control since there was an inhibition in the production of this metabolite. Nitric oxide (NO) and TNF-alpha production seemed to be important in the control of bacterial replication and varied according to the strain, period and organ. Evaluation of the antibody production indicated that the multi-specific effect commonly observed in these strains was not the same in the response to M. bovis. Antibody concentrations were higher in L IV-A than in H IV-A mice at the beginning of the infection, being similar afterwards. Such data were compared with delayed-type hypersensitivity (DTH), which was more intense in H IV-A than in L IV-A mice, indicating that antibody production is independent of the capability to trigger DTH reactions and that cellular and humoral responses to M. bovis antigens show a polygenic control and an independent quantitative genetic regulation. Differences were observed among organs and metabolites, suggesting that different mechanisms play an important role in this infection in natural heterogeneous populations, indicating that NO, TNF-alpha and Th1 cytokines are involved in the infection control.
Abstract in English:Two fibrinogenolytic enzymes, Bothrops alternatus metalloprotease isoform (BaltMP)-I and II, were purified from Bothrops alternatus venom using Diethylaminoethyl (DEAE) Sephacel, Sephadex G-75 and Heparin-Agarose column chromatography. Purified BaltMP-I and II ran as single protein bands on analytical polyacrylamide gel electrophoresis and showed molecular weights of 29000 and 36000, respectively, under reducing conditions in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). BaltMP-II, but not BaltMP-I, displayed blood-clotting activity in bovine plasma, which was about 10-fold higher than that of the crude venom. Both enzymes were proteolytically active against bovine fibrinogen as substrate. When fibrinogen and each enzyme were incubated at 37°C, at a ratio of 1:100 (w/w), BaltMP-II cleaved preferentially the Aalpha -chain and more slowly the Bbeta -chain. The action of BaltMP-I was similar, but lower. None of the proteases degraded the gamma-chain of fibrinogen. The fibrinogenolytic activity of the enzymes was inhibited by 1,10-phenanthroline, suggesting they are metalloproteases. Since both enzymes were found to cause defibrinogenation when intraperitoneally (i.p.) administered to mice, they can be of medical interest as a therapeutic agent in the treatment and prevention of arterial thrombosis.
Abstract in English:The present study aimed at investigating the susceptibility of the microorganisms Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli, Staphylococcus aureus, and Bacillus subtilis to ethanolic extracts of propolis (EEP) from three regions of Kenya (Taita, Tana and Samburu). Propolis was extracted using four different concentrations of ethanol: pure, 70%, 50%, and 30%. Ethanol (70%) and Streptomycin were used as controls. The agar diffusion method using filter paper disks was employed. Antibacterial activity was determined as an equivalent of the inhibition zones diameters (in millimeters) after incubation at 37°C for 24h. Significant differences in the antibacterial activities of propolis were observed among the three regions, depending on the test microorganisms and on the procedure used for the preparation of propolis extract. Bacillus subtilis and Staphylococcus aureus were the most susceptible bacteria and 70% EEP had the best antibacterial effect.
Abstract in English:Snake venom is characterized by hemorrhagic, coagulant, proteolytic and myotoxic activities which in Bothrops jaracussu venom are related to intraspecific variations. In the present study, female Swiss mice were divided into two groups: treated with 25µg or 50µg venom. These were subdivided into three groups of six animals each, according to blood collection: 2, 4 or 24h after venom injection. Animals were anesthetized using diethyl-ether inhalation and 1ml of blood was collected by heart puncture. Then, the following organs were removed: spleen, skeletal muscle, kidneys, liver and lungs; histological sections were obtained and stained with hematoxylin-eosin (HE). The following biochemical parameters were analyzed: aspartate aminotransferase (AST/GOT), alanine aminotransferase (ALT/GPT), total lactate dehydrogenase (LDH), glucose, creatinine and urea levels, and total protein content. Results showed significant alterations in AST, LDH, glucose and urea levels, and total protein content, as well as important tissue alterations in the liver, kidneys and lungs. It could be concluded that, even using sublethal doses of venom, there were significant changes in almost all the tested biochemical parameters as well as tissue alterations in the kidneys and lungs.
Abstract in English:The present study was carried out at the Army Central Hospital, Rio de Janeiro, Brazil, from September 2000 to December 2001, employing diethylenetriamine penta-acetic acid labeled with technetium-99m (99mTc-DTPA) to evaluate the renal function of nineteen symptomatic patients infected with S. haematobium during a peace mission in Mozambique. Results evidenced that the most frequent clinical manifestations were hematuria (68.4%) and low back pain (68.4%) and 73.7% patients had altered dynamic renal scintigraphy expressed by an increase in the excretory phase independently of the symptoms duration; furthermore, none of them had mechanical obstructive pattern. Schistosoma haematobium glomerulopathy could be considered a pathological finding without correlation with the disease clinical manifestations.
Abstract in English:Cantharidin is mainly found in the beetle families Meloidae and Oedemeridae (Insecta: Coleoptera) which are the natural producers of this terpene anhydride. Most studies to date have focused on cantharidin distribution in blister beetles, with few reports on recently found cantharidin-related compounds (CRCs). Using gas chromatography-mass spectrometry (GC-MS), the present work reported cantharidin and two CRCs, palasonin and cantharidinimide from Mylabris impressa stillata (Baudi, 1878) which was collected from Toyserkan county, Hamedan Province, Iran. Ionization provided mass spectra with characteristic fragments of cantharidin at m/z 96 and 128, demethylcantharidin at m/z 82 and 114, and cantharidinimide at m/z 70, 96 and 127. This is the first time that cantharidin and the two CRCs are found in the genus Mylabris which in turn is new to the field of venomous insects.