Indolacetic and humic acids induce lateral root development through a concerted plasmalemma and tonoplast H<Superscript>+</Superscript> pumps activation

Increasing evidences have indicated that humic substances can induce plant growth and productivity by functioning as an environmental source of auxinic activity. Here we comparatively evaluate the effects of indole-3-acetic acid (IAA) and humic acids (HA) isolated from two different soils (Inseptsol and Ultisol) and two different organic residues (vermicompost and sewage sludge) on root development and on activities of plasmalemma and tonoplast H⁺ pumps from maize roots. The data show that HA isolated from these different sources as well as low IAA concentrations (10⁻¹⁰ and 10⁻¹⁵ M) improve root growth through a markedly proliferation of lateral roots along with a differential activation not only of the plasmalemma but also of vacuolar H⁺-ATPases and H⁺-pyrophosphatase. Further, the vacuolar H⁺-ATPase had a peak of stimulation in a range from 10⁻⁸ to 10⁻¹⁰ M IAA, whereas the H⁺-pyrophosphatase was sensitive to a much broader range of IAA concentrations from 10⁻³ to 10⁻¹⁵ M. It is proposed a complementary view of the acid growth mechanism in which a concerted activation of the plasmalemma and tonoplast H⁺ pumps plays a key role in the root cell expansion process driven by environment-derived molecules endowed with auxinic activity, such as that of humic substances.     

New insights into creatine function and synthesis

The text-book view of the role of the creatine/creatine phosphate system as an energy buffer has been expanded to include functions such as energy shuttling, proton buffering and regulating cytosolic ADP levels. There is continuous need for creatine replacement due to creatinine formation. Replacement involves a combination of diet and de novo synthesis. Creatine synthesis makes very significant demands on amino acid metabolism, in particular that of glycine, arginine and methionine. It uses about 40% of all methyl groups transferred from S-adenosylmethionine. Although the traditional view of the function of the creatine/creatine phosphate system is largely concerned with its role in skeletal and cardiac muscle, recent work obliges us to take a broader view. In particular, its role in the brain is brought into sharp focus by the neurological symptoms displayed by children suffering from inborn errors of creatine synthesis and transport, as well as by suggestions that brain creatine status may play a role in cognitive performance in adults.     

A study of the scutellum in eight Chagas disease vector species from genus Triatoma (Hemiptera, Reduviidae) using optical and scanning electron microscopy

The aim of this study was to analyze the external morphology of the scutellum through optical microscopy and scanning electron microscopy (SEM) in male specimens of Triatoma costalimai, T. delpontei, T. eratyrusiformis, T. matogrossensis, T. infestans melanosoma, T. sherlocki, T. tibiamaculata, and T. vandae. A total of 30 photographs of the scutellum were made. Magnification varied from 50X to 750X. Regarding depth and forms of the central depression, the heart-shaped form was predominant, with some exceptions, so that this shape appears to be a common characteristic for species of genus Triatoma Laporte, 1832. In T. eratyrusiformis, a kind of sensillum with important taxonomic value was observed. The different sizes and shapes of the designs found on the posterior process of the scutellum were also of important taxonomic interest. The study of the scutellum based on SEM showed valuable characteristics, allowing the use of this structure to aid the diagnosis of triatomine species. Thus, more specimens in subsequent studies and analyses of morphometric parameters should contribute to agreement on phylogenetic aspects in this genus. A Key to eight species of Triatoma based on male scutellar morphology is presented.     

Rotavirus and adenovirus in Rondônia

Acute gastroenteritis is one of the most common diseases in humans worldwide. Viral gastroenteritis is a global problem in infants and young children. In this study the incidence of diarrhea was assessed in 877 hospitalized children under five years old, over a period of 24 months and distributed in 470 cases of diarrhea and 407 age-matched group with other pathologies, as control group. Two antigen detection techniques based on enzyme immunoassay (EIA) and latex particles were used for detection of rotavirus and adenovirus. Rotavirus A was a major cause of gastroenteritis with 23.6% of cases, being 90% of these cases in young children. Adenovirus infections was detected by EIA with frequency of 6.4%. Rotavirus and adenovirus were detected in 10.1 and 1.7% of stools from control group, respectively. Interestingly, the frequency of the youngest children in the control group excreting Rotavirus A was comparable to that detected in stools from diarrheic children. We cannot rule out the existence of other enteric viruses because the etiology of 171 cases of diarrhea was not determined and active search for astrovirus and calicivirus was not done. This is the first study that shows the presence of enteric viruses in the infantile population from Western Brazilian Amazonia and it was important to help physicians in the treatment of viral gastroenteritis.     

Circulation of Campylobacter spp. in rhesus monkeys (Macaca mulatta) held in captivity: a longitudinal study

Campylobacteriosis is an extremely important zoonosis, circulating freely in the environment. In nonhuman primates kept in open facilities and bred for experimental purposes, the presence of Campylobacter spp. could cause severe damage to the production and interfere with the results of scientific research. In this paper, we assessed the circulation of Campylobacter spp. in a colony of clinically healthy rhesus monkeys (Macaca mulatta) destined to research. The analysis was carried out during seven non-consecutive years. Data showed that despite several changes made in animal management along the studied years in order to control this zoonosis, reduction of bacterial charge did not occur. Significant differences among the age groups and sex were observed. Infants showed higher susceptibility than adult animals. In general males were more infected than females. Modifications adopted in the handling techniques need to be reviewed with the intent of improving the production, reducing bacterial infection of the stock and avoiding undesirable cross reactions in the research carried out with these animals. Therefore, this paper alerts professionals that work directly with captive rhesus monkeys about the risks of Campylobacter spp. infection and possible interference on the experimental procedures.     

Brumptomyia angelae, a new species of Phlebotominae (Diptera, Psychodidae) of the Atlantic forest of the state of Paraná, Brazil

The male of Brumptomyia angelae, sp. nov., a new species of Phlebotominae (Diptera, Psychodidae) of the Atlantic forest of the state of Paraná, Brazil, is described and illustrated. This new taxon is closely related to Brumptomyia ortizi Martins, Silva & Falc?o 1971, Brumptomyia nitzulescui (Costa Lima, 1932), and Brumptomyia troglodytes (Lutz, 1922). The male genitalia of these three latter species have also been drawn.     

Soluble TNF-like cytokine (TL1A) production by immune complexes stimulated monocytes in rheumatoid arthritis

TNF-like cytokine (TL1A) is a newly identified member of the TNF superfamily of ligands that is important for T cell costimulation and Th1 polarization. However, despite increasing information about its functions, very little is known about expression of TL1A in normal or pathological states. In this study, we report that mononuclear phagocytes appear to be a major source of TL1A in rheumatoid arthritis (RA), as revealed by their strong TL1A expression in either synovial fluids or synovial tissue of rheumatoid factor (RF)-seropositive RA patients, but not RF-/RA patients. Accordingly, in vitro experiments revealed that human monocytes express and release significant amounts of soluble TL1A when stimulated with insoluble immune complexes (IC), polyethylene glycol precipitates from the serum of RF+/RA patients, or with insoluble ICs purified from RA synovial fluids. Monocyte-derived soluble TL1A was biologically active as determined by its capacity to induce apoptosis of the human erythroleukemic cell line TF-1, as well as to cooperate with IL-12 and IL-18 in inducing the production of IFN-gamma by CD4(+) T cells. Because RA is a chronic inflammatory disease with autoimmune etiology, in which ICs, autoantibodies (including RF), and various cytokines contribute to its pathology, our data suggest that TL1A could be involved in its pathogenesis and contribute to the severity of RA disease that is typical of RF+/RA patients.     

The required role of endogenously produced lipoxin A4 and annexin-1 for the production of IL-10 and inflammatory hyporesponsiveness in mice

The appropriate development of an inflammatory response is central for the ability of a host to deal with any infectious insult. However, excessive, misplaced, or uncontrolled inflammation may lead to acute or chronic diseases. The microbiota plays an important role in the control of inflammatory responsiveness. In this study, we investigated the role of lipoxin A4 and annexin-1 for the IL-10-dependent inflammatory hyporesponsiveness observed in germfree mice. Administration of a 15-epi-lipoxin A4 analog or an annexin-1-derived peptide to conventional mice prevented tissue injury, TNF-alpha production, and lethality after intestinal ischemia/reperfusion. This was associated with enhanced IL-10 production. Lipoxin A4 and annexin-1 failed to prevent reperfusion injury in IL-10-deficient mice. In germfree mice, there was enhanced expression of both lipoxin A4 and annexin-1. Blockade of lipoxin A4 synthesis with a 5-lipoxygenase inhibitor or Abs against annexin-1 partially prevented IL-10 production and this was accompanied by partial reversion of inflammatory hyporesponsiveness in germfree mice. Administration of BOC-1, an antagonist of ALX receptors (at which both lipoxin A4 and annexin-1 act), or simultaneous administration of 5-lipoxygenase inhibitor and anti-annexin-1 Abs, was associated with tissue injury, TNF-alpha production, and lethality similar to that found in conventional mice. Thus, our data demonstrate that inflammatory responsiveness is tightly controlled by the presence of the microbiota and that the innate capacity of germfree mice to produce IL-10 is secondary to their endogenous greater ability to produce lipoxin A4 and annexin-1.     

Tissue- and stimulus-dependent role of phosphatidylinositol 3-kinase isoforms for neutrophil recruitment induced by chemoattractants in vivo

PI3K plays a fundamental role in regulating neutrophil recruitment into sites of inflammation but the role of the different isoforms of PI3K remains unclear. In this study, we evaluated the role of PI3Kgamma and PI3Kdelta for neutrophil influx induced by the exogenous administration or the endogenous generation of the chemokine CXCL1. Administration of CXCL1 in PI3Kgamma(-/-) or wild-type (WT) mice induced similar increases in leukocyte rolling, adhesion, and emigration in the cremaster muscle when examined by intravital microscopy. The induction of neutrophil recruitment into the pleural cavity or the tibia-femoral joint induced by the injection of CXCL1 was not significantly different in PI3Kgamma(-/-) or WT mice. Neutrophil influx was not altered by treatment of WT mice with a specific PI3Kdelta inhibitor, IC87114, or a specific PI3Kgamma inhibitor, AS605240. The administration of IC87114 prevented CXCL1-induced neutrophil recruitment only in presence of the PI3Kgamma inhibitor or in PI3Kgamma(-/-) mice. Ag challenge of immunized mice induced CXCR2-dependent neutrophil recruitment that was inhibited by wortmannin or by blockade of and PI3Kdelta in PI3Kgamma(-/-) mice. Neutrophil recruitment to bronchoalveolar lavage induced by exogenously added or endogenous production of CXCL1 was prevented in PI3Kgamma(-/-) mice. The accumulation of the neutrophils in lung tissues was significantly inhibited only in PI3Kgamma(-/-) mice treated with IC87114. Neutrophil recruitment induced by exogenous administration of C5a or fMLP appeared to rely solely on PI3Kgamma. Altogether, our data demonstrate that there is a tissue- and stimulus-dependent role of PI3Kgamma and PI3Kdelta for neutrophil recruitment induced by different chemoattractants in vivo.