The Role of Salivary and Intestinal Complement System Inhibitors in the Midgut Protection of Triatomines and Mosquitoes

Saliva of haematophagous arthropods contain biomolecules involved directly or indirectly with the haematophagy process, and among them are encountered some complement system inhibitors. The most obvious function for these inhibitors would be the protection of the midgut against injury by the complement. To investigate this hypothesis, Triatoma brasiliensis nymphs were forced to ingest human serum in conditions in which the protection of midgut by the inhibitors is bypassed. In these conditions, the anterior midgut epithelium was injured by the complement, causing cell death. Once some insects such as Aedes aegypti have no salivary inhibitors, we hypothesized the existence of intestinal inhibitors. The inhibitory activity was investigated in the intestine of A. aegypti as well as in the saliva and intestine of other three triatomine species (T. brasiliensis, T. infestans and Rhodnius prolixus) using an immunological method able to determine the level of deposition of some complement factors (C1q, C3b, or C4b) on the surface of complement activator molecules linked to microplates. This methodology permitted to identify which points along the activation phase of the complement cascade were inhibited. As expected, soluble contents of A. aegypti's intestine was capable to inhibit C3b deposition by the classical and alternative pathways. Saliva or soluble intestinal contents, obtained from triatomines were unable to inhibit C1q deposition by the classical pathway. C4b deposition by the classical pathway was inhibited by the intestinal contents from the three triatomines. On the other hand, only T. brasiliensis saliva inhibited C4b deposition. Both, saliva and intestinal contents from all triatomines were able to inhibit C3b deposition in the classical and alternative pathways. None of the material extracted from the intestinal cell membranes from the triatomines inhibited C3b deposition in the classical pathway. The existence of complement inhibitors may have important biological consequences which are discussed in detail

Estudo comparativo da qualidade de vida, sobrecarga e sintomas musculoesqueléticos em cuidadores de idosos

The objective was to compare QoL, musculoskeletal symptoms and overloads in elderly caregivers. Seventy-six individuals were allocated to Group A (n=46) and Group B (n=27). Data were collected with the WHOQOL-BREF, QNSO and EZBI questionnaires. HRQoL was higher in Group A (3.98±0.7) than in B (3.46±0.73) (p=0.004). Light overload was mostly concentrated in Group B (9.98±2.35) and severe overload in Group A (27.75±2.63) (p=0.001). In musculoskeletal symptoms, Group A suffered lumbar (51.8%), dorsal (48.1%) and shoulder (29.6%) involvement. There were remoteness due to involvement in the lumbar (0.675**), dorsal (0.501**) and shoulders (0.320*) regions. In Group B, there were lower back (34.8%), shoulder (28%) and dorsal (21.7%) involvement. There were no remoteness in this group, despite having been overloaded and being more exposed to musculoskeletal symptoms and lower QOL, because they performed their activities anonymously, without formal ties in the performance of their functions.Objetivou-se comparar QV, sintomas osteomioarticulares e sobrecargas em cuidadores de idosos. Setenta e seis indivíduos foram alocados no Grupo A (n=46) e Grupo B (n=27). Os dados foram coletados com os questionários WHOQOL-BREF, QNSO e EZBI. A QVG foi maior no Grupo A (3,98±0,7) que no B (3,46±0,73) (p=0,004). A sobrecarga leve concentrou-se majoritariamente no Grupo B (9,98±2,35) e a sobrecarga grave no Grupo A (27,75±2,63) (p=0,001). Nos sintomas musculoesqueléticos, o Grupo A sofreu acometimentos de região lombar (51,8%), dorsal (48,1%) e ombros (29,6%). Houve afastamentos por acometimento na região lombar (0,675**), dorsal (0,501**) e ombros (0,320*). No Grupo B, houve acometimentos de região lombar (34,8%), ombros (28%) e dorsal (21,7%). Não ocorreram afastamentos neste grupo, apesar de ter sofrido maiores sobrecargas e ter sido mais exposto a sintomas musculoesqueléticos e menor QVG, por executar suas atividades de forma anônima, sem vínculo formal no desempenho de suas funções.El objetivo fue comparar la CV, los síntomas musculoesqueléticos y las sobrecargas en los cuidadores de ancianos. Setenta y seis individuos fueron asignados al Grupo A (n=46) y al Grupo B (n=27). Los datos fueron recolectados con los cuestionarios WHOQOL-BREF, QNSO y EZBI. La CVG fue mayor en el Grupo A (3.98±0.7) que en B (3.46±0.73) (p=0.004). La sobrecarga ligera se concentró principalmente en el Grupo B (9.98±2.35) y la sobrecarga severa en el Grupo A (27.75±2.63) (p=0.001). En los síntomas musculoesqueléticos, el Grupo A sufrió afectación lumbar (51.8%), dorsal (48.1%) y hombro (29.6%). Hubo lejanía debido a la participación en las regiones lumbar (0.675**), dorsal (0.501**) y hombros (0.320*). En el Grupo B, hubo afectación de la espalda baja (34.8%), hombro (28%) y dorsal (21.7%). No hubo lejanía en este grupo, a pesar de haber sido sobrecargados y estar más expuestos a los síntomas musculoesqueléticos y a reducir la CV, porque realizaban sus actividades de forma anónima, sin vínculos formales en el desempeño de sus funciones

Atividade de glicose-6-fosfato desidrogenase (G6PD) em membros de povos de terreiros de umbanda na cidade de Teresina, Piauí.

Nos eritrócitos deficientes de G6PD, a diminuição da redução do NADP em NADPH leva a um baixo potencial redutor que interfere na capacidade metabólica oxidativa do organismo, ficando vulneráveis a hemólise, podendo levar a crises hemolíticas de intensidade variável. Devido a considerável prevalência da deficiência de G6PD na população brasileira, os maiores índices ocorrem em populações com ancestralidade africana. A presente pesquisa teve como objetivo estudar a atividade da G6PD em povos de terreiro de umbanda na cidade de Teresina. A pesquisa foi do tipo descritiva, exploratória e quantitativa. A amostra foi representada por indivíduos frequentadores de terreiro, no período entre setembro a dezembro de 2011, envolvendo 62 pessoas. A atividade da G6PD foi determinada utilizando-se o kit de G6PD D+ NeoLISA – INTERCIENTÍFICA, método enzimático colorimétrico para determinação quantitativa da atividade da G6PD. O estudo envolveu 62 indivíduos de ambos os sexos, com idades que variam dos 10 anos aos 80 anos, com uma média de 38 anos. Evidenciou-se a presença de 6,5% da população com a atividade da glicose-6-fosfato desidrogenase abaixo dos valores normais. Em relação ao sexo, o estudo encontrou uma prevalência de 4,8% nas mulheres e 10% nos homens. A soma da porcentagem de negros e pardos foi de 95%. A falta de conhecimento entre os participantes sobre a deficiência de G6PD foi de 100%. Os dados refletem que os terreiros são frequentados principalmente afrodescendentes, demonstrando forte relação com a sua ancestralidade e principalmente por sua preservação

Scheme of the activation phase of the complement system showing the points potentially targeted by the inhibitors.

<p>The classic pathway is initiated by the binding of C1q, C1r and C1s (the C1 complex) to antibodies linked to the activation surface. The proteolytic activity of C1r is automatically activated by interaction with C1q. C1r then cleaves and activates C1s, which is another serine protease. C1s acts specifically on C2 and C4 activating them. Once cleaved, the fragment C4b is capable to bind covalently to the activation surface creating a binding site to C2a. The active serine protease C2a, in the C4b-C2a complex, acts on C3 producing C3b molecules which are also capable to bind covalently to the activation surface nearby its site of activation. The complex C4b-C2a-C3b acts as a C3 convertase as well as a C5 convertase generating the MAC. For activation of the alternative pathway, a small fraction of C3 present in the extracelular fluids slowly undergoes spontaneous reaction with H₂O molecules generating C3-H₂O. These molecules can interact with the protein B generating the B-C3-H₂O complex which is a substrate for D, a plasmatic serine protease. The Bb-C3-H₂O complex acts on C3 cleaving it to C3b and C3a. Most of the C3b molecules generated will combine with H₂O or other self molecules becoming inactive. On the other hand, if a C3b molecule is generated near an adequate surface such as a bacterium, it will covalently bind to it creating a binding site for factor B. The C3b-B complex is activated by the protease D generating C3b-Bb, an efficient protease capable to activate other C3 molecules. The complex C3b-Bb-C3b is an efficient C3 convertase as well as a C5 convertase generating the MAC. To simplify, the lectin pathway as well as the normal regulatory proteins were omitted.</p

Influence of pH in the operation of the human complement system.

<p>Operation of the classical (A) and alternative (B) pathways at different pHs when compared with the control at pH 7.4 (100%).</p

Percentage of inhibition of the complement system by saliva from <i>Triatoma brasiliensis, T. infestans</i> and <i>Rhodnius prolixus</i>.

<p>(n) = number of independent experiments performed for each treatment.</p><p>Asterisk (*) indicates statistical difference from control (P<0.05).</p><p>AP: Alternative Pathway, CP: Classical Pathway.</p

Apyrase activity from the crop soluble contents of <i>Rhodnius prolixus</i> after artificial and forced feeding.

<p>The activity was expressed as ng of inorganic phosphate (Pi) released in a minute by 1/12 of anterior midgut contents±standard error. The T test indicated a significant difference between groups (P<0.05).</p

Protection of anterior midgut of <i>T. brasiliensis</i> against the complement system.

<p>A- MAC deposition onto the anterior midgut wall after normal blood ingestion, B- natural fluorescence observed on the midgut wall, C- Apparatus used for the forced feeding procedure, D- MAC deposition onto the anterior midgut wall after forced feeding of 50 µL of normal human sera, E- Increased deposition of MAC onto the anterior midgut wall after forced feeding of 50 µL of 2 fold concentrated normal human sera, F- MAC deposition onto the anterior midgut wall after forced feeding of 50 µL of inactivated 2 fold concentrated normal human sera, G- Cell death in the anterior midgut epithelium after forced feeding of 2 fold concentrated normal human serum containing propidium iodide. H- Absence of cell death after forced feeding of inactivated 2 fold concentrated normal human sera containing propidium iodide.</p