Elisa Aparecida Gregório

The prophenoloxidase system and in vitro interaction of Trypanosoma rangeli with Rhodnius prolixus and Triatoma infestans haemolymph

Summary The presence of the prophenoloxidase (proPO) system in the haemolymph of Rhodnius protixus and Triatoma infestans and the role played by Trypanosoma rangeli in the in vitro activation of proPO were tested. Both R. prolixus and T. infestans whole blood preparations showed a very active ProPO system. The proPO cascade of the two insect species were differentially activated by microbial‐derived extracts: laminarin was a better activator of T. infestans haemolymph than of R. prolixus blood, and lipopolysaccharides from Shigella flexneri or Pseudomonas aeroginasa caused significant proPO activation of T. infestans haemolymph but not of R. prolixus preparations. For the two insect species, neither T. rangeli from culture nor parasite lysates were able to trigger proPO activation. The presence of the parasite in R. prolixus haemolymph/laminarin assays, however, significantly reduced the level of proPO activation to that of spontaneous activating controls. The immobilization of T. rangeli in vitro in haemolymph preparations occurred in both insect species and was dependent on the proPO activation intensity Our results suggest that the susceptibility of R. prolixus to T. rangeli haemocoel infection may be explained, at least in part, by the suppression of the insect immune defence system i.e., inhibition of proPO in the presence of this protozoan parasite.

Ultrastructural and quantitative studies of hemocytes in the sugarcane borer, Diatraea saccharalis (Lepidoptera: Pyralidae)

Seis tipos de hemocitos circulantes foram caracterizados na hemolinfa de larvas de Diatraea saccharalis (Fabricius) (Lepidoptera: Pyralidae), atraves da microscopia eletronica de transmissao e varredura: prohemocitos (PR), plasmatocitos (PL), granulocitos (GR), esferulocitos (ES), oenocitoides (OE) e vermiformes (VE). O PR foi o menor tipo celular; apresentando um nucleo grande, citoplasma com poucas organelas e superficie lisa e homogenea. O PL era polimorfico e abundante, com citoplasma rico em organelas e superficie celular com varias projecoes citoplasmaticas. O GR era abundante, apresentando dois tipos de grânulos envoltos por membrana (denso e estruturado), glicogenio, gotas de lipidio e projecoes citoplasmaticas filopodiais. O ES era uma celula grande, com citoplasma carregado de esferulas intracitoplasmaticas. O OE foi o maior tipo de hemocito encontrado, apresentando citoplasma grande, homogeneo e escassas organelas. O VE era discoide e apresentou grânulos eletrons-densos.

Morphological study of the hindgut in larvae of Anticarsia gemmatalis Hübner(Lepidoptera: Noctuidae)

The velvetbean caterpillar (Anticarsia gemmatalis Hubner) has great economical interest as it affects the soybean crop worldwide. This work describes the morphology of the hindgut in A. gemmatalis larvae emphasizing their histological aspects. Distinct morphological regions, identified as pylorus, ileum, colon and rectum, constitute the hindgut of A. gemmatalis. A thin cuticular intima, a simple epithelium and muscular layer compose the hindgut wall, independent of the region. Microspines project from the cuticular intima in the posterior interstitial ring, between the midgut and the hindgut, and the posterior pyloric region. A single circular layer of large fibers, differing from the other hindgut regions that present two layers of muscular fibers, forms the rectal musculature. The distal ends of Malpighian tubules cross the rectum wall and constitute the cryptonephric excretory system typical in Lepidoptera larvae.

The distribution of agglutinins and lytic activity against Trypanosoma rangeli and erythrocytes in Rhodnius prolixus and Triatoma infestans tissue extracts and haemolymph

Haemolymph, heads, salivary glands, crops, midguts, hindguts, and Malpighian tubules from Rhodnius prolixus and Triatoma infestans were extracted in phosphate or Tris buffer saline with calcium, and tested for agglutination and lytic activities by microtitration against both vertebrate erythrocytes and cultured epimastigote forms of Trypanosoma rangeli. Haemagglutination activity against rabbit erythrocytes was found in the crop, midgut and hindgut extracts of T. infestans but only in the haemolymph of R. prolixus. Higher titers of parasite agglutinins were found in R. prolixus haemolymph than T. infestans, whilst the converse occurred for the tissue extracts. In addition, the extracts of T. infestans salivary glands, but not those of R. prolixus, showed a trypanolytic activity that was heat-inactivated and was not abolished by pre-incubation with any of the sugars or glycoproteins tested. T. infestans, which is refractory to infection by T. rangeli, thus appears to contain a much wider distribution of agglutinating and trypanolytic factors in its tissues than the more susceptible species, R. prolixus.

Tracheobronchial consequences of the use of heat and moisture exchangers in dogs.

PurposeTo determine the effect of heat and moisture exchange (HME) on the tracheobronchial tree (TBT) using a unidirectional anesthesic circuit with or without CO2 absorber and high or low fresh gas flow (FGF), in dogs.MethodsThirty-two dogs were randomly allocated to four groups: G1 (n = 8) valvular circuit without CO2 absorber and high FGF (5 L· min−1); G2 (n=8) as G1 with HME; G3 (n=8) circuit with CO2 absorber with a low FGF (1 L· min−1); G4 (n=8) as G3 with HME. Anesthesia was induced and maintained with pentobarbital. Tympanic temperature (TT), inhaled gas temperature (IGT), relative (RH) and absolute humidity (AH) of inhaled gas were measured at 15 (control), 60, 120 and 180 min of controlled ventilation. Dogs were euthanized and biopsies in the areas of TBT were performed by scanning electron microscopy.ResultsThe G2 and G4 groups showed the highest AH (> 20 mgH2O· L−1) and G1 the lowest (< 10 mgH2O· L−1) and G3 was intermediate (< 20 mgH2O· L−1) (P < 0.01), There was no difference of TT and IGT among groups. Alterations of the mucociliary system were greatest in G1, least in G2 and G4, and intermediate in G3.ConclusionIn dogs, introduction of HME to a unidirectional anesthetic circuit with/without CO2 absorber and high or low FGF preserved humidity of inspired gases. HME attenuated but did not prevent alterations of the mucociliary system of the TBT.ObjectifDéterminer, chez des chiens, l’effet de l’échange de chaleur et d’humidité (ECH) sur l’arbre trachéobronchique (ATB) en utilisant un circuit anesthésique unidirectionnel avec ou sans absorption de CO2 et un haut ou bas débit de gaz frais (DGF).MéthodeTrente-deux chiens ont été répartis au hasard en quatre groupes: G1 (n=8), un circuit à valve sans absorption de CO2 et avec un haut DGF (5 L· min−1); G2 (n=8), comme G1 avec ECH; G3 (n = 8), un circuit avec absorption de CO2 et un bas DGF (1 L· min−1); G4 (n = 8), comme G3 avec ECH. L’anesthésie a été induite et maintenue avec du pentobarbital. La température tympanique (TT), la température des gaz inhalés (TGI), l’humidité relative (HR) et absolue (HA) des gaz inhalés ont été mesurées après 15 (témoin), 60, 120 et 180 min de ventilation contrôlée. Les chiens ont été sacrifiés et des biopsies de l’ATB ont été réalisées par microscopie électronique à balayage.RésultatsLes groupes G2 et G4 ont affiché les plus hauts taux d’HA (> 20 mgH2O· L−1), G1 avait le plus bas taux (< 10 mgH2O· L−1) et G3 était intermédiaire (< 20 mgH2O· L−1) (P < 0,01). Il n’y a pas eu de différence intergroupe concernant la TT et la TGI. Les modifications du système mucociliaire ont été plus importantes dans le G1, moindres dans les G2 et G4 et intermédiaires dans le G3.ConclusionL’introduction, chez des chiens, d’un ECH à un circuit anesthésique avec ou sans absorption de CO2 et avec un haut ou bas DGF a préservé l’humidité des gaz inhalés. L’ECH a diminué, mais n’a pas empêché, les modifications du système mucociliaire de l’ATB.

Morphologic study of the efferent ductules of the pigeon (Columba livia)

The efferent ductules of the pigeon are localized in the epididymal region and are topographically divided into proximal and distal, both portions being lined with stereociliated pseudostratified epithelium. Transmission electron microscopy shows five distinct cell types: light, dark, and angular non‐ciliated cells with possible apocrine secretory role cells and halo cells, possibly intraepithelial leucocytes. The proximal efferent ductules have the widest diameter among all ductules in the epididymal region. J. Morphol. 242:247–255, 1999.

Is Reinke's Edema a Precancerous Lesion? Histological and Electron Microscopic Aspects

The objectives of this study were to evaluate morphologic alterations and precancerous lesions in Reinkes edema. Patients included were 54 smokers with bilateral Reinkes edema submitted to surgery in the Otolaryngology Department, Botucatu Medical School, São Paulo State University, Brazil, between 2002 and 2006. All specimens were evaluated by light microscopy and five contralateral lesions were also evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The main histological alterations were edema (100%), inflammation (81.48%), basal membrane (bm) thickening (77.77%), and vessel proliferation (75.92%). Epithelium alterations were classified as grade 0 (11.11%), grade 1 (70.37%), grade 2 (14.81%), and grade 3 (3.70%). In the case included in grade 3 classification, microinvasive carcinoma was detected. SEM showed epithelial surface with some cellular desquamation, few microridges, and a polished and impermeable surface aspect. TEM showed epithelial hyperplasia, basal cells with different sizes, widening of the intercellular spaces, abnormal desmosome architecture, thickening of the bm, some electron-dense vesicles, and points of interruption. The morphological alterations presented in this study are not specific to Reinkes edema but this lesion can be the site of different grades of dysplasia and carcinoma, justifying the importance of periodic laryngeal endoscopic exams and meticulous histological analysis.

Morphological regional differences of epithelial cells along the midgut in Diatraea saccharalis Fabricius (Lepidoptera: Crambidae) larvae

The sugarcane borer, Diatraea saccharalis Fabricius, is a pest to sugarcane and many other crops. This work aims to characterize morphological variability in the epithelial cells (columnar, goblet and regenerative) along the midgut of D. saccharalis larvae. Fragments of the midgut (anterior, middle and posterior regions) were fixed and processed by light and scanning electron microscopy. There are both cytochemical and ultrastructural differences in the morphology of the epithelial cells, depending on their localization along the midgut. The apical surface of columnar cells shows an increase in both number and size of the apical protrusions from the anterior to the posterior midgut regions. There is an increase in the amount of PAS-positive (Periodic Acid-Schiff Reaction) granules detected in the cytoplasm of both the columnar and regenerative cells, from the anterior to the posterior region. The goblet cell apical surface is narrow in the anterior region, and enlarged in the posterior midgut; the chambers cytoplasm extrusion are small and thin at the apical cavity surface, being thicker, longer and more numerous at the basal portion of the cavity. Our results suggest that the sugarcane borer midgut has two morphologically different regions, the anterior and the posterior; the middle region is a transitional region.

Morphometric study of the midgut epithelium in larvae of Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae)

A larva de Diatraea saccharalis Fabricius (broca-da-cana) tem grande interesse economico, pois afeta o cultivo e aproveitamento industrial da cana-de-acucar. Entretanto, poucos sao os estudos sobre a morfologia interna desse inseto. O objetivo deste trabalho foi estudar, morfometricamente, o seu epitelio intestinal, ao longo de seu comprimento, visando caracterizar regioes estruturalmente diferentes. O intestino medio de larvas no ultimo instar foi subdividido em tres regioes: proximal, mediana e distal e os fragmentos foram processados para observacao em microscopia de luz. Os cortes histologicos foram analisados em sistema computadorizado de analise de imagens para medir comprimento, largura e area do epitelio, das diferentes celulas epiteliais, dos seus respectivos nucleos e do lumen intestinal. Os dados obtidos foram submetidos ao teste estatistico de Kruskal-Wallis e a analise multivariada. Nossos resultados mostraram que o intestino medio apresentou-se constituido, morfometricamente, por duas diferentes regioes, proximal e distal; a regiao mediana apresentou valores coincidentes tanto com a regiao proximal quanto com a distal, sugerindo ser regiao intermediaria. As celulas epiteliais (colunares, caliciformes e regenerativas), quando avaliadas pela analise estatistica multivariada, nao apresentaram diferenca morfometrica nas diferentes regioes do intestino medio. Entretanto, a analise de variância, realizada para variaveis isoladas, mostrou que as celulas regenerativas apresentaram maior variabilidade morfometrica.

Efeitos da pressão limite (25 cmH2O) e mínima de “selo” do balonete de tubos traqueais sobre a mucosa traqueal do cão

JUSTIFICATIVA E OBJETIVOS: As lesoes da mucosa traqueal em contato com o balonete do tubo traqueal sao proporcionais a pressao exercida pelo balonete e ao tempo de exposicao. O objetivo foi estudar as eventuais lesoes da mucosa do segmento traqueal em contato com o balonete do tubo traqueal insuflado com volume de ar suficiente para se obter pressao de “selo” ou com a pressao limite de 25 cmH2O, abaixo da pressao critica de 30 cm de agua para producao de lesao da mucosa traqueal. METODO: Dezesseis caes foram submetidos a anestesia venosa e ventilacao artificial. Os caes foram distribuidos aleatoriamente em dois grupos de acordo com a pressao no balonete do tubo traqueal (Portex Blue-Line, Inglaterra): Gselo (n = 8) balonete com pressao minima de “selo” para impedir vazamento de ar durante a respiracao artificial; G25 (n = 8) balonete insuflado ate obtencao da pressao de 25 cmH2O. A medida da pressao do balonete foi realizada por meio de manometro digital no inicio (controle) e apos 60, 120 e 180 minutos. Apos o sacrificio dos caes, foram feitas biopsias nas areas da mucosa traqueal adjacentes ao balonete e ao tubo traqueal para analise a microscopia eletronica de varredura (MEV). RESULTADOS: A pressao media do balonete em G25 manteve-se entre 24,8 e 25 cmH2O e em Gselo entre 11,9 e 12,5 cmH2O durante o experimento. As alteracoes a MEV foram pequenas e nao significantemente diferentes nos grupos (p > 0,30), mas ocorreram lesoes mais intensas nas areas de contato da mucosa traqueal com o balonete do tubo traqueal, nos dois grupos, em relacao as areas da mucosa adjacentes ou nao ao tubo traqueal (p < 0,05). CONCLUSOES: No cao, nas condicoes experimentais empregadas, a insuflacao do balonete de tubo traqueal em volume de ar suficiente para determinar pressao limite de 25 cmH2O ou de “selo” para impedir vazamento de ar determina lesoes minimas da mucosa traqueal em contato com o balonete e sem diferenca significante entre elas.