Above- and below-ground effects of an ecosystem engineer ant in Mediterranean dry grasslands.

Within a local assemblage, ecosystem engineers can have major impacts on population dynamics, community composition and ecosystem functions by transforming or creating new habitats. They act as an ecological filter altering community composition through a set of environmental variables. The impact of ants on their environment has been widely studied, but their multi-component effects (both trophic and non-trophic) have been rarely addressed. We investigated the roles of Messor barbarus, one of the commonest harvester ant species in south-western European Mediterranean grasslands. We analysed soil physico-chemical parameters, above-ground vegetation (e.g. species richness, plant community, micro-local heterogeneity, plant biomass) and above- and below-ground fauna (macrofauna, Collembola, Acari and nematodes). A clear and strong local impact of M. barbarus on soil, vegetation and fauna compartments emerges. The environmental filter is altered by modifications to soil physico-chemical properties, and the biotic filter by changes to plant communities and altered above- and below-ground fauna abundance, occurrence and community structure. The engineering activity of M. barbarus affects not only these separate ecosystem components but also the trophic and non-trophic relationships between them. By altering ecological filters at a local scale, M. barbarus creates habitat heterogeneity that may in turn increase ecological niches in these highly diverse ecosystems.

Effect of Hepatic Preconditioning with the Use of Methylene Blue on the Liver of Wistar Rats Submitted to Ischemia and Reperfusion.

BACKGROUND: The liver may be injured in situations where it is submitted to ischemia, such as partial hepatectomy and liver transplantation. In all cases, ischemia is followed by reperfusion and, although it is essential for the reestablishment of tissue function, reperfusion may cause greater damage than ischemia, an injury characterized as ischemia-reperfusion (I/R) damage. The aim of this work was to analyze the effect of ischemic preconditioning with the use of methylene blue (MB; 15 mg/kg) 5 or 15 minutes before I/R (IRMB5' and IRMB15', respectively) on the hepatic injury occurring after I/R. METHODS: Twenty-eight male Wistar rats were used, and liver samples submitted to partial ischemia (IR) or not (NI) were obtained from the same animal. The samples were divided into 7 groups. Data were analyzed statistically by means of the nonparametric Mann-Whitney test and Wilcoxon Matched test, with the level of significance set at 5% (P < .05). RESULTS: The rate of oxygen consumption by state 3 mitochondria was inhibited in all ischemic groups compared with the sham group (SH vs IR: P = .0052; SH vs IRMB5': P = .0006; SH vs IRMB15': P = .0048), which did not occur in the nonischemic contralateral portion of the same liver (SH vs NI: P = .7652; SH vs NIMB5': P = .059; SH vs NIMB15': P = .3153). The inhibition of the rate of oxygen consumption by state 3 mitochondria was maintained in the presence of MB (IR vs IRMB5': P = .4563; IR vs IRMB15': P = .9021). The respiratory control ratio was reduced in all ischemic groups compared with the sham group, owing to the inhibition of oxygen consumption in state 3 (SH vs IR: P = .0151; SH vs IRMB5': P = .005; SH vs IRMB15': P = .0007). CONCLUSIONS: Methylene blue had no effect on the mitochondrial respiratory parameters studied, but was able to reduce lipid peroxidation, preventing the production of reactive oxygen species (SH vs IRMB15': P = .0210).

Estimation of genetic diversity in a natural population of cambui tree (Myrciaria tenella O. Berg) using ISSR markers.

Cambui (Myrciaria tenella O. Berg) is a native species from Brazil, which belongs to the family Myrtaceae. Molecular characterization is one of the most used tools for the study of the biotechnological potential of species because the diversity level between individuals can be inferred. Analysis of genetic diversity is fundamental to the direction of the strategies necessary to form and maintain a germplasm. This study aimed to evaluate the genetic diversity in a natural population of cambui using inter-simple sequence repeat (ISSR) molecular markers. The natural population, which provided the plant material, is found at the Private Reserve of Natural Heritage of Caju, which belongs to the experimental field of Embrapa Tabuleiros Costeiros, in the municipality of Itaporanga d'Ajuda, SE, Brazil. Young leaves of each individual were collected for DNA extraction and analysis of PCR-ISSR. Thirty primers were tested and the top 10 were selected. The use of these primers resulted in 71 fragments with 98.3% polymorphism. Similarity of individuals ranged between 0.30 and 0.92. The most similar individuals were C13 and C17 and the most distant were C1 and C41. Through UPGMA, six distinct groups were identified. This information may be used for conservation of these genetic resources, germplasm exchange, creation of germplasm bank and in future studies with this species.

Foxp3 expression and nitric oxide production in peripheral blood mononuclear cells of communicants with pulmonary tuberculosis.

The understanding of the mechanisms involved in the immune response is of significant relevance to the control of tuberculosis (TB), especially in individuals living with patients with TB. To characterize the nitric oxide (NO) production and the Foxp3 marker expression in this population, peripheral blood mononuclear cells of intradomiciliary contacts of individuals with pulmonary tuberculosis with (CTb, susceptible) and without (STb, resistant) previous history of active infection were stimulated in vitro with Mycobacterium tuberculosis antigen (TbAg) and with the mitogen Concanavalin A for 24 and 48 h. The groups analysed did not present significant difference in the Foxp3 mRNA expression nor in the NO production. Negative correlation (P = 0.09) between NO and Foxp3 after a 48-h stimulation with TbAg was observed in the STb group. In this group, after a 24-h culture stimulated with TbAg (P = 0.03), this same correlation was observed. In comparison with the cytokines previously studied by our group (Cavalcanti et al., 2009), a positive correlation was observed between IL-10 and Foxp3 after a 48-h culture of cells from communicants susceptible to tuberculosis (STb) stimulated with TbAg (P = 0.04). Evaluating the entire population, a positive correlation was observed between the cytokine TNF-α and the Foxp3 marker in the cultures stimulated for 24 (P = 0.03) and 48 (P = 0.02) hours with TbAg. Therefore, considering the similarity in the exposure and the individual capacity of responding to the contact with M. tuberculosis, the present study contributes to the comprehension of the immune regulation in individuals living with patients with TB.

The scavenger receptor MARCO is involved in Leishmania major infection by CBA/J macrophages.

CBA/J mice are resistant to Leishmania major infection but are permissive to L. amazonensis infection. In addition, CBA/J macrophages control L. major but not L. amazonensis infection in vitro. Phagocytosis by macrophages is known to determine the outcome of Leishmania infection. Pattern recognition receptors (PRR) adorning antigen presenting cell surfaces are known to coordinate the link between innate and adaptive immunity. The macrophage receptor with collagenous structure (MARCO) is a PRR that is preferably expressed by macrophages and is capable of binding Gram-positive and Gram-negative bacteria. No research on the role of MARCO in Leishmania-macrophage interactions has been reported. Here, we demonstrate, for the first time, that MARCO expression by CBA/J macrophages is increased in response to both in vitro and in vivo L. major infections, but not to L. amazonensis infection. In addition, a specific anti-MARCO monoclonal antibody reduced L. major infection of macrophages by 30%-40% in vitro. The draining lymph nodes of anti-MARCO-treated mice displayed a reduced presence of immunolabelled parasite and parasite antigens, as well as a reduced inflammatory response. These results support the hypothesis that MARCO has a role in macrophage infection by L. major in vitro as well as in vivo.

[Overall experience with percutaneous occlusion of patent ductus arteriosus]. / Experiência global no fechamento percutâneo do canal arterial.

PURPOSE: To evaluate the overall experience of our institution with percutaneous occlusion of the patent ductus arteriosus. METHODS: Since December/92, 150 patients underwent 178 procedures (85-Rashkind technique; 87-Gianturco coils; 6-Duct Occlud). Median age was 6.5 years (1 to 57). Mean minimum ductal diameter was 3.05 +/- 1.24 mm (1 to 8). Clinical and echocardiographic evaluations were performed periodically. RESULTS: Adequate implantation was achieved in 143 (95.3%) patients. Prevalence of immediate residual shunting was 52.1%, falling to 15.9% during follow-up. This figure decreased to 5.2% after new additional procedures. Umbrella and coil embolization occurred in 1 and 12 procedures, respectively. Hemolysis and mild stenosis of left pulmonary artery were observed in one patient each. There was no mortality. CONCLUSION: This therapeutic modality is safe and efficacious with good follow-up results.

[Idiopathic myelofibrosis]. / Mielofibrose idiopática.

The authors make a review of recent data in the literature and compare them to their own cases between 1983 and 1988. They analyzed eight patients with idiopathic myelofibrosis confirmed with bone marrow biopsy of the posterior iliac wrist with Jamshidi's needle. Most patients were between 55 and 60 years old (5 male and 3 female). Major symptoms were weakness and bleeding (6/8 cases), weight loss and bone distress (4/8 cases). In general, physical signs were splenomegaly and anemia (7/8 cases), hepatomegaly (5/8 cases), and jaundice (2/8 cases). Laboratory features were variable. Most cases were diagnosed in an advanced stage of the disease. Therapy with busulfan, prednisone, oxymetholone and radiotherapy of the spleen was used alone or in combination to relieve compressive abdominal symptoms. This review shows that idiopathic myelofibrosis should be included in the differential diagnosis of patients with hepatosplenomegaly and anemia.

[Primary plasmacytic lambda chain leukemia: report of a case]. / Leucemia plasmocitária primária de cadeias lambda: relato de um caso.

A rare case of primary plasma cell leukaemia is presented as a plasmacytic dyscrasia with high number of plasma cells in peripheral blood and bone marrow, few osteolytic lesions and with cardiac and renal failure. The morphology of leukaemic cells were variable ranging from lymphoplasmacytic to differentiated plasma cells. Bence-Jones protein Lambda Chain was found in urine and serum. The patient was treated with chemotherapy (M2 protocol) with survival of 33 months.

Effects of Piper sp extract on pregnancy in rats.

Abortive effects on cattle have been attributed to Piper sp, popularly called Pariparoba. In the present study we tested the possible toxicity of this plant by analyzing gestational outcome parameters in female rats given 300 mg/kg of an aqueous extract of Piper sp leaves and stalks per os, daily, between the 9th and the 21st day of pregnancy. The animals were killed just before delivery and the following features were observed: numbers of corpora albicantia, fetuses and reabsorptions; weights of fetuses, placentae and fetal membranes; fetal sex and the presence of overt malformations in fetuses; and implantation and reabsorption indices. No significant differences were detected between control and treated groups. The results suggest that Piper sp does not modify gestational outcome in rats.

Controlled clinical trial of a rifampicin- trimethoprim combination (Rifaprim) and cotrimoxazole in patients with chronic urinary tract infections.

A controlled clinical trial of Rifaprim (rifampicin 600 mg plus trimethoprim 160 mg, in a single daily dose at 10 p.m.) and cotrimoxazole (two tablets b.i.d.) was carried out in two groups of twenty-one patients, each with chronic or recurrent urinary tract infections. Both treatments lasted 10 days. At the first follow-up, 3-11 days after the end of treatment, bacteriological failure was observed in two Rifaprim patients and in four contrimoxazole patients. Clinical improvement with sterile urine or markedly reduced bacterial count was observed in nineteen. Rifaprim patients and in fifteen cases of the other group. Mild allergic phenomena were observed in three Rifaprim patients, but they did not require discontinuation of treatment; anorexia was complained of by a cotrimoxazole patient. Rifaprim appears a valuable alternative in the treatment of chronic urinary tract infection, mainly because it reduces or abolishes the risk of emergence of resistance.

ABO blood groups and isoagglutinins in systemic lupus erythematosus.

In 45 patients with SLE the frequency of groups B and AB exceeded that of the controls, the difference reaching the double of the standard error. The isoagglutinin titers were quite similar in the two series. There was no association of the disease with the frequency of the secretor type nor with the quantity of group substances or isoagglutinins present in saliva and urine. The isoagglutinin titers in the sera of non-secretors were low.