Flavonoids from the Amazon plant Brosimum acutifolium induce C6 glioma cell line apoptosis by disrupting mitochondrial membrane potential and reducing AKT phosphorylation.

Glioblastoma, which is highly invasive and has a poor patient prognosis, is the most common type of brain tumor. Flavonoids have known antiproliferative and antineoplastic effects, such as apoptosis induction and tumor growth inhibition. We investigated the effects of treatment with three flavonoids (BAS-1, BAS-4, and BAS-6) isolated from the Amazon plant Brosimum acutifolium on the proliferation and migration of the C6 glioma cell line. Cytotoxicity was evaluated by MTT assay, and morphological changes were evaluated by phase-contrast microscopy and by transmission electron microscopy. Apoptosis was determined using Annexin V-FITC-propidium iodide (PI) staining. A hemolysis assay was used to evaluate plasma membrane injury. Antiproliferative effects were assessed by wound migration and colony formation assays. Mitochondrial transmembrane potential (ΔΨm) was determined using JC-1 dye and flow cytometry. To identify the flavonoid targets, western blotting was performed. BAS-1 and BAS-4 reduced C6 cell proliferation in a dose-dependent manner. BAS-6 showed no effect. Due to its high toxicity toward primary glial cells and its high hemolytic index, BAS-1 was not used in the remaining experiments. BAS-4 treatment did not induce cytotoxicity in primary glial cells; however, in glioma cells, it suppressed migration and invasion and led to apoptosis through mitochondrial damage, ΔΨm loss, cell cycle arrest, and reduced AKT phosphorylation, which is a component of the main cell survival pathway. We conclude that BAS-4 showed potential activity against glioma by inducing apoptosis mediated by ΔΨm loss and AKT pathway disruption, and future studies should further evaluate BAS-4 as a promising antineoplastic agent against glioblastoma.

Accidentes ofídicos notificados al Programa Nacional de Control de Zoonosis y Centro Antirrábico Nacional, Paraguay (2015) / Ophidic related accidents notified to the National Program of Control of Zoonosis and National Anti-rabies Center, Paraguay (2015)

Introducción: Las picaduras de serpientes constituyen un grave problema de Salud Pública. Objetivo: Describir los casos de mordeduras de serpientes notificados al Programa Nacional de Control de Zoonosis y Centro Antirrábico Nacional, Paraguay durante el año 2015. Método: Estudio observacional, descriptivo, retrospectivo y de corte transversal. Los criterios de inclusión fueron toda persona que haya sido mordida por alguna serpiente y que haya sido notificado al Programa Nacional de Control de Zoonosis y Centro Antirrábico Nacional durante el año 2015. Tipo de muestreo no probabilístico. Resultados: Fueron notificados 169 casos de mordeduras de serpientes. De acuerdo con las características sociodemográficas, la mayoría de los afectados fueron varones, con una edad promedio de 26,39 ±1.36. Los lugares más frecuentes donde ocurrieron los accidentes ofídicos fueron las chacras, y en el Departamento de San Pedro. En la mayoría de las mordeduras no se pudo identificar a la serpiente agresora, y cuando fueron identificadas, fueron las del genero Bothrops, las más frecuentes. En cuanto a la localización de las picaduras, fueron más frecuentes en los miembros inferiores, siendo necesario la hospitalización para el tratamiento. No se reportaron fallecidos. Conclusión: En el año 2015 fueron notificados 169 casos, los departamentos con mayor prevalência fueron San Pedro, Itapúa y Caazapá. El perfil del afectado es un varón con promedio de edad de 26 años, trabajador rural. Las serpientes del género Bothrops causaron el 32,5% de las mordeduras. Palabras clave: Mordeduras de serpiente; Envenenamiento; Epidemiología.

Introduction: Snake bites are a serious public health problem. Objective: To describe the cases of snake bites reported to the National Zoonosis Control Program and National Anti-Rabies Center, Paraguay during 2015. Method: Observational, descriptive, retrospective and cross-sectional study. The inclusion criteria were any person who has been bitten by a snake and it has been notified to the National Zoonosis Control Program and National Anti-Rabies Center during 2015. Type of non-probabilistic sampling. Results: 169 cases of snake bites were reported. According to the sociodemographic characteristics, the majority of those affected were males, with an average age of 26.39 ± 1.36. The most frequent places where theophidic accidents occurred were the farms, and in the Department of San Pedro. In most of the bites the aggressor snake could not be identified, and when they were identified, they were those of the genus Bothrops, the most frequent. As for the location of the bites, they were more frequent in the lower limbs, requiring hospitalization for treatment. No deaths were reported. Conclusion: In the year 2015, 169 cases were notified, the departments with the highest prevalence were San Pedro, Itapua and Caazapá. The profile of the affected is a male with an average age of 26 years, a rural worker. The snakes of the genus Bothrops caused 32.5% of the bites. Keywords: Snake bites; Poisoning; Epidemiology.

Tumor maligno da bainha perineural retrobulbar e intracraniano em cão: relato de caso / Malignant neoplasm of the perineural sheath retrobulbar and intracranial in dog: case report

Os tumores da bainha perineural são pouco frequentes em animais domésticos. Relata-se o caso de um cão, sem raça definida, de cinco anos, fêmea, com histórico de aumento de volume em região retrobulbar do globo ocular direito (GOD) havia três semanas. Ao exame clínico, constatou-se a presença de uma neoformação retrobulbar direita com deslocamento do globo ocular cranialmente. Aos exames realizados durante o internamento, não foi possível localizar a origem e a extensão da neoformação. O animal veio a óbito por parada cardiorrespiratória e foi encaminhado para a necropsia. À avaliação macroscópica, observou-se neoformação esbranquiçada fixada à base do crânio em região selar, com possível origem no terceiro (III) par de nervos cranianos, a qual se infiltrava no encéfalo na altura do hipotálamo, estendia-se caudalmente em direção ao tronco encefálico e cranialmente à órbita direita, comprimindo, assim, o GOD. Microscopicamente consistia de feixes curtos entrelaçados ou enovelados de células fusiformes com pleomorfismo discreto a moderado, alternando-se a áreas de necrose multifocalmente, compatível com tumor da bainha perineural. Ao exame imuno-histoquímico, apresentou marcação fraca para S100 e GFAP e marcação positiva para vimentina, o que indica caráter maligno.(AU)

Tumors of the perineural sheath are uncommon in domestic animals. We report the case of a 5-year-old female dog with a history of increased volume in the retrobulbar region of the right eye (RE) three weeks ago. The clinical examination revealed a presence of a right retrobulbar neoformation with cranial ocular globe displacement. In the examinations carried out during hospitalization, it was not possible to locate a source and an extension of the neoformation. The animal died of cardiorespiratory arrest and was referred to an autopsy. The macroscopic evaluation revealed a whitish neoformation fixated to the base of the skull in a seal region, with a possible non-III origin of cranial nerves, infiltrating non-encephalon at the height of the hypothalamus, extending caudally towards the brainstem and cranially to the orbit right, compressing RE. Microscopically it consisted of short bundles intertwined or enovelados of spindle cells with discrete to moderate pleomorphism, alternating to areas of multifocal necrosis, compatible with tumor of the perineural sheath. Immunohistochemical examination showed weak marking for S100 and GFAP and positive marking for vimentin, indicating malignancy.(AU)

Concomitant Malignant Pulmonary Peripheral Nerve Sheath Tumour and Benign Cutaneous Peripheral Nerve Sheath Tumour in a Dog.

Peripheral nerve sheath tumours (PNSTs) are neoplastic growths derived from Schwann cells, perineural cells or both. Malignant PNSTs (MPNSTs) are uncommon in domestic animals. This report describes the concomitant occurrence of PNSTs in a 10-year-old female cocker spaniel with a clinical history of respiratory impairment. Grossly, there was a large infiltrative mass in the caudal lobe of the right lung; smaller nodules were observed in the other lobes of the right lung. Furthermore, a small encapsulated cutaneous nodule was observed on the left hindlimb. Histopathology of the pulmonary tumours revealed the proliferation of pleomorphic spindle-shaped cells with moderate mitotic index arranged in interwoven bundles and concentric Antoni A and Antoni B patterns; invasion of the adjacent pulmonary tissue was observed. The cutaneous nodule consisted of neoplastic mesenchymal cells in interwoven bundles with concentric whorls, but without the marked anisokaryosis, binucleation and infiltrative growth seen in the pulmonary tumour. Immunohistochemistry revealed that both tumours were immunoreactive for vimentin, glial fibrillary acidic protein and S100 protein, but were negative for factor VIII. These findings are indicative of a MPNST in the lung with a concomitant benign PNST in the limb. This case represents the first report of a primary MPNST in the lung of a dog. This neoplastic growth should be included in the differential diagnosis of primary malignant pulmonary tumours of dogs.

Crotoxin stimulates an M1 activation profile in murine macrophages during Leishmania amazonensis infection.

American tegumentary leishmaniasis is caused by different species of Leishmania. This protozoan employs several mechanisms to subvert the microbicidal activity of macrophages and, given the limited efficacy of current therapies, the development of alternative treatments is essential. Animal venoms are known to exhibit a variety of pharmacological activities, including antiparasitic effects. Crotoxin (CTX) is the main component of Crotalus durissus terrificus venom, and it has several biological effects. Nevertheless, there is no report of CTX activity during macrophage - Leishmania interactions. Thus, the main objective of this study was to evaluate whether CTX has a role in macrophage M1 polarization during Leishmania infection murine macrophages, Leishmania amazonensis promastigotes and L. amazonensis-infected macrophages were challenged with CTX. MTT [3-(4,5dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide] toxicity assays were performed on murine macrophages, and no damage was observed in these cells. Promastigotes, however, were affected by treatment with CTX (IC50 = 22·86 µg mL-1) as were intracellular amastigotes. Macrophages treated with CTX also demonstrated increased reactive oxygen species production. After they were infected with Leishmania, macrophages exhibited an increase in nitric oxide production that converged into an M1 activation profile, as suggested by their elevated production of the cytokines interleukin-6 and tumour necrosis factor-α and changes in their morphology. CTX was able to reverse the L. amazonensis-mediated inhibition of macrophage immune responses and is capable of polarizing macrophages to the M1 profile, which is associated with a better prognosis for cutaneous leishmaniasis treatment.

Crotoxin stimulates an M1 activation profile in murine macrophages during Leishmania amazonensis infection

American tegumentary leishmaniasis is caused by different species of Leishmania. This protozoan employs several mechanisms to subvert the microbicidal activity of macrophages and, given the limited efficacy of current therapies, the development of alternative treatments is essential. Animal venoms are known to exhibit a variety of pharmacological activities, including antiparasitic effects. Crotoxin (CTX) is the main component of Crotalus durissus terrificus venom, and it has several biological effects. Nevertheless, there is no report of CTX activity during macrophage – Leishmania interactions. Thus, the main objective of this study was to evaluate whether CTX has a role in macrophage M1 polarization during Leishmania infection murine macrophages, Leishmania amazonensis promastigotes and L. amazonensis-infected macrophages were challenged with CTX. MTT [3-(4,5dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide] toxicity assays were performed on murine macrophages, and no damage was observed in these cells. Promastigotes, however, were affected by treatment with CTX (IC50 = 22·86 µg mL-1) as were intracellular amastigotes. Macrophages treated with CTX also demonstrated increased reactive oxygen species production. After they were infected with Leishmania, macrophages exhibited an increase in nitric oxide production that converged into an M1 activation profile, as suggested by their elevated production of the cytokines interleukin-6 and tumour necrosis factor-a and changes in their morphology. CTX was able to reverse the L. amazonensis-mediated inhibition of macrophage immune responses and is capable of polarizing macrophages to the M1 profile, which is associated with a better prognosis for cutaneous leishmaniasis treatment

Physalis angulata induces death of promastigotes and amastigotes of Leishmania (Leishmania) amazonensis via the generation of reactive oxygen species.

Leishmaniasis are a neglected group of emerging diseases that have been found in 98 countries and are caused by protozoa of the genus Leishmania. The therapy for leishmaniasis causes several side effects and leads to drug-resistant strains. Natural products from plants have exhibited activities against Leishmania in various experimental models. Physalis angulata is a widely used plant in popular medicine, and in the literature it has well-documented leishmanicidal activity. However, its mechanism of action is still unknown. Thus, this study aims to evaluate the mechanism driving the leishmanicidal activity of an aqueous extract of P. angulata root (AEPa). AEPa was effective against both promastigotes and intracellular amastigote forms of Leishmania amazonensis. This effect was mediated by an increase of reactive oxygen species (ROS), but not of nitric oxide (NO). The increased production of ROS induces cell death by phenotypes seems by apoptosis cell death in Leishmania, but not autophagy or necrosis. In addition, morphological analysis of macrophages showed that AEPa induced a high number of cytoplasmic projections, increased the volume of cytoplasm and number of vacuoles, caused cytoskeleton alterations and resulted in high spreading ability. AEPa also promoted superoxide anion (O2(-)) production in both uninfected macrophages and those infected with Leishmania. Therefore, these results revealed that AEPa causes cell death by phenotypes seems by apoptosis cell death in L. amazonensis and modulates macrophage activation through morphofunctional alterations and O2(-) generation to induce Leishmania death.

Helicobacter spp. infection induces changes in epithelial proliferation and E-cadherin expression in the gastric mucosa of pigs.

Gastric disease is common in finishing pigs. Helicobacter spp. infection has been associated with gastritis, gastric ulcers and gastric neoplasia in man and animals. The aim of this study was to determine the effects of Helicobacter spp. infection on gastric morphology in pigs, with emphasis on glandular cell proliferation and E-cadherin expression. Samples of fundus and antrum from 67 finishing pigs were examined microscopically and by immunohistochemistry. The presence of Helicobacter spp. was confirmed by polymerase chain reaction (PCR). Mucosal changes were evaluated and epithelial proliferation was determined by evaluation of the morphometry of nucleolar organizer regions and counting proliferating cell nuclear antigen-positive cells and mitotic figures. Intercellular adhesion was evaluated by E-cadherin expression. In 47 (70%) pigs, Helicobacter spp. infection was confirmed by PCR. Histological findings associated with the infection included mononuclear cell infiltration of the lamina propria and glandular degeneration. There was a significant association between infection and epithelial proliferation in both regions as well as a decrease in the expression of E-cadherin in the antrum.

Malignant pilomatricoma in a dog.

An 11-year-old female German shepherd dog was presented with a history of lameness and pain in the left forelimb. Clinical examination revealed ataxia of the hindlimbs and a subcutaneous mass in the left prescapular region. Radiography revealed metastatic foci in the left humerus, lung and abdomen. Gross necropsy examination revealed a firm, white mass in the left prescapular region. Multiple nodules with similar characteristics were observed in the lung, liver and spleen. Bone lysis was noted in the humerus and the fifth to seventh lumbar vertebrae. Microscopical examination revealed a proliferation of basal cells forming irregular islands of various sizes and surrounding extensive zones of keratinized 'ghost' cells. A definitive diagnosis of malignant pilomatricoma was made. This is a rare tumour in dogs with no previous report of metastasis to the spleen and liver.

Alterações histológicas da pars esophagea de suínos e sua relação com Helicobacter spp / Histological findings in swine pars esophagea and its Helicobacter spp. relationship

A relação entre Helicobacter spp. e a presença de alterações histológicas na pars esophagea de suínos foi avaliada em 67 estômagos de animais em idade de abate. Para a identificação das helicobactérias, utilizou-se a técnica da PCR com primers específicos para o gênero Helicobacter. As alterações histológicas foram identificadas e classificadas como ulceração, erosão, degeneração epitelial, alongamento de papilas, hiperplasia, paraqueratose, intensidade do infiltrado inflamatório e aumento do número de folículos linfoides. As alterações mais frequentemente encontradas na pars esophagea foram a degeneração epitelial e o alongamento de papilas, observadas em 83,5 por cento (n=56) das amostras analisadas. Em 77,5 por cento (n=52) das amostras, observou-se paraqueratose e em 61,1 por cento (n=41) hiperplasia epitelial. Quarenta e sete (70,1 por cento) foram positivas na PCR para Helicobacter spp. Nessas amostras a erosão foi a lesão mais observada (40,2 por cento), seguida de ulceração da mucosa (11,9 por cento). Em 58,2 por cento das amostras positivas na PCR, não foram observadas ulcerações de mucosa. Observou-se associação significativa (P=0,003) entre a presença de Helicobacter spp. e a degeneração epitelial da pars esophagea de suínos em idade de abate.

The association between histological findings of gastric mucosa in pigs at slaughtering age and the presence of Helicobacter spp., identified by PCR, assay was investigated. Stomachs from 67 pigs were examined. Histological changes of pars esophagea were identified and classified as gastric ulcers, erosion, degeneration, distortion of papils, hyperplasia, paraqueratosis, and number of lymphoid follicles. Microscopic analysis revealed the most frequent alteration: 83.5 percent (n= 56) stomachs with epithelial degeneration and distortion of papils. Paraqueratosis of pars esophagea was observed in 77.5 percent (n=52) of the samples and epithelial hyperplasia in 61 percent (n=41). Forty-seven (70.1 percent) pigs were positive to Helycobacter spp. by PCR. Erosion of pars esophagea and ulceration were the most frequent findings in Helicobacter spp. PCR-positive pigs, occurring, respectively, in 40.2 percent and 11.9 percent. The frequency of animals without ulceration and Helicobacter spp. PCR-positive was 58.2 percent. It was observed a significant association (P=0.003) between Helicobacter spp. and epithelial degeneration of gastric mucosa in pigs at slaughtering age.

Some observations on the fine structure of trophozoites of the haemogregarine Cyrilia lignieresi (Adeleina: Haemogregarinidae) in erythrocytes of the fish Synbranchus marmoratus (Synbranchidae).

This communication describes the fine structure of trophozoites of the haemogregarine Cyrilia lignieresi (Laveran, 1906) found in erythrocytes of the fresh-water fish Synbranchus marmoratus from Belém, Pará, North Brazil. The parasite possesses the usual structures, such as conoid, rhoptries and micronemes, seen in members of the phylum Apicomplexa. Three structures, however, appear to be characteristic features of this parasite. The parasitophorous vacuole is unusual in containing a large number of spherical bodies. Secondly, some of the dense bodies, which are usually spherical organelles, may appear as elongated structures. Thirdly, peculiar invaginations of the inner membrane appear to divide the parasite into compartments.

High mutation detection rate in TCOF1 among Treacher Collins syndrome patients reveals clustering of mutations and 16 novel pathogenic changes.

Twenty-eight families with a clinical diagnosis of Treacher Collins syndrome were screened for mutations in the 25 coding exons of TCOF1 and their adjacent splice junctions through SSCP and direct sequencing. Pathogenic mutations were detected in 26 patients, yielding the highest detection rate reported so far for this disease (93%) and bringing the number of known disease-causing mutations from 35 to 51. This is the first report to describe clustering of pathogenic mutations. Thirteen novel polymorphic alterations were characterized, confirming previous reports that TCOF1 has an unusually high rate of single-nucleotide polymorphisms (SNPs) within its coding region. We suggest a possible different mechanism leading to TCS or genetic heterogeneity for this condition, as we identified two families with no apparent pathogenic mutation in the gene. Furthermore, our data confirm the absence of genotype-phenotype correlation and reinforce that the apparent anticipation often observed in TCS families is due to ascertainment bias.

Isolation and functional characterization of the PfNT1 nucleoside transporter gene from Plasmodium falciparum.

Plasmodium falciparum, the causative agent of the most lethal form of human malaria, is incapable of de novo purine synthesis, and thus, purine acquisition from the host is an indispensable nutritional requirement. This purine salvage process is initiated by the transport of preformed purines into the parasite. We have identified a gene encoding a nucleoside transporter from P. falciparum, PfNT1, and analyzed its function and expression during intraerythrocytic parasite development. PfNT1 predicts a polypeptide of 422 amino acids with 11 transmembrane domains that is homologous to other members of the equilibrative nucleoside transporter family. Southern analysis and BLAST searching of The Institute for Genomic Research (TIGR) malaria data base indicate that PfNT1 is a single copy gene located on chromosome 14. Northern analysis of RNA from intraerythrocytic stages of the parasite demonstrates that PfNT1 is expressed throughout the asexual life cycle but is significantly elevated during the early trophozoite stage. Functional expression of PfNT1 in Xenopus laevis oocytes significantly increases their ability to take up naturally occurring D-adenosine (K(m) = 13.2 microM) and D-inosine (K(m) = 253 microM). Significantly, PfNT1, unlike the mammalian nucleoside transporters, also has the capacity to transport the stereoisomer L-adenosine (K(m) > 500 microM). Inhibition studies with a battery of purine and pyrimidine nucleosides and bases as well as their analogs indicate that PfNT1 exhibits a broad substrate specificity for purine and pyrimidine nucleosides. These data provide compelling evidence that PfNT1 encodes a functional purine/pyrimidine nucleoside transporter whose expression is strongly developmentally regulated in the asexual stages of the P. falciparum life cycle. Moreover, the unusual ability to transport L-adenosine and the vital contribution of purine transport to parasite survival makes PfNT1 an attractive target for therapeutic evaluation.

The fine structure of Garnia gonadati and its association with the host cell.

Most of the studies on the fine structure of protozoa of the Apicomplexa group have been carried out with members of the ToxoPlasma, Eimeria, and Plasmodium genera. In the present study we analyzed the fine structure of Garnia gonadoti parasitizing the red blood cells of the Amazonian reptile Gonatodes humeralis (Reptilia; Lacertilia). Transmission electron microscopy of thin sections showed that G. gonadoti presented all structures characteristic of the group, including the apicoplast. However, four special features were observed: (1) absence of the hemozoin (malarial) pigment; (2) a group of microtubules associated with the mitochondrion; (3) a vacuole containing electron-dense material, which resembled the acidocalcisome described in trypanosomatids; and (4) a special array of the host-cell endoplasmic reticulum around the parasitophorous vacuole.

[Down syndrome associated with clinical manifestations of Kabuki syndrome: report of a case] / Síndrome de Down associada a manifestações clínicas da síndrome Cabúqui: relato de um caso.

OBJECTIVE: To describe an atypical case of Down syndrome presenting with additional clinical manifestations that might be components of Kabuki (Niikawa-Kuroki) syndrome.CLINICAL REPORT: We report the clinical history of a 19-month-old girl with a 47,XX, +21 karyotype, who presented brachycephaly, flat face, long palpebral fissures, eversion of the lateral portion of the lower eyelids, arched eyebrows with sparse lateral regions, long eyelashes, epicanthus, cortical cataract, small ears, protruding tongue, muscular hypotonia, developmental delay, hyperflexibility of joints, brachydactyly, and dermatoglyphic abnormalities.CONCLUSION: The diagnosis of Down syndrome was confirmed cytogenetically. However, the presence of additional anomalies - mainly in the ocular region - suggested that the child might also have the Kabuki syndrome.

Correlation between Waardenburg syndrome phenotype and genotype in a population of individuals with identified PAX3 mutations.

Waardenburg syndrome (WS) type 1 is an autosomal dominant disorder characterized by sensorineural hearing loss, pigmentary abnormalities of the eye, hair, and skin, and dystopia canthorum. The phenotype is variable and affected individuals may exhibit only one or a combination of several of the associated features. To assess the relationship between phenotype and gene defect, clinical and genotype data on 48 families (271 WS individuals) collected by members of the Waardenburg Consortium were pooled. Forty-two unique mutations in the PAX3 gene, previously identified in these families, were grouped in five mutation categories: amino acid (AA) substitution in the paired domain, AA substitution in the homeodomain, deletion of the Ser-Thr-Pro-rich region, deletion of the homeodomain and the Ser-Thr-Pro-rich region, and deletion of the entire gene. These mutation classes are based on the structure of the PAX3 gene and were chosen to group mutations predicted to have similar defects in the gene product. Association between mutation class and the presence of hearing loss, eye pigment abnormality, skin hypopigmentation, or white forelock was evaluated using generalized estimating equations, which allowed for incorporation of a correlation structure that accounts for potential similarity among members of the same family. Odds for the presence of eye pigment abnormality, white forelock, and skin hypopigmentation were 2, 8, and 5 times greater, respectively, for individuals with deletions of the homeodomain and the Pro-Ser-Thr-rich region compared to individuals with an AA substitution in the homeodomain. Odds ratios that differ significantly from 1.0 for these traits may indicate that the gene products resulting from different classes of mutations act differently in the expression of WS. Although a suggestive association was detected for hearing loss with an odds ratio of 2.6 for AA substitution in the paired domain compared with AA substitution in the homeodomain, this odds ratio did not differ significantly from 1.0.

[Triatoma infestans: importance, control and elimination of the species in the state of São Paulo, Brazil]. / Triatoma infestans: importância, controle e eliminação da espécie no Estado de São Paulo, Brasil.

Considerations about the control of the vectors of Chagas' disease are made in the State of Sao Paulo, mainly those activities that led to the elimination of T. infestans. First of all, the authors discuss different aspects of the biology of T. infestans mainly those that permitted it to adapt itself in rural areas of the State in the first middle of the century. Secondary factors that helped the control such as rural exodus are also analysed. The article shows that since 1965 the control became a campaign with different phases due to the epidemiological situation, the acquired knowledge and the entomological surveillance. After 25 years of work, the elimination of all the focus of T. infestans was finally reached and the campaign was ended. However, due to the possibility of reintroduction of the vector in rural areas by passive transportation besides the presence of secondary vectors (T. sordida and P. megistus) in several localities, the vector control activities were not interrupted and the surveillance is continuous.

Cell surface characterization of amastigotes of Trypanosoma cruzi obtained from different sources.

The present study analyses the morphology and the exposition of surface carbohydrates and the Ssp4 antigen of amastigote forms of Trypanosoma cruzi (Y strain) obtained from three different sources: (a) intracellular, isolated from infected Vero cells 3 days after infection, (b) extracellular, isolated from the supernatant of Vero cells 15 days after infection, and (c) axenic, obtained by incubation of tissue culture trypomastigotes in LIT medium, at 37 degrees C for 4 days. No morphological differences were observed by light microscopy among these amastigotes. Transmission electron microscopy of thin sections showed a thick cell coat easily observed on the plasma membrane of axenic amastigotes. Carbohydrate-containing sites on the surface of the three different amastigotes were analysed using lectins, agglutination assays and flow cytometry. Mannose and/or glucose residues were found on the surface of all populations, but intracellular amastigotes showed the highest number. A small group of cells from the different populations expressed galactose and N-acetyl-glucosamine residues. The presence and distribution of the Ssp4 antigen in the different amastigote populations were evaluated using FITC and gold-labelled antibodies, and observed with an electronic programmable individual cell sorter and transmission electron microscopy. Ssp4 antigen was present on the membrane lining the flagellar pocket and on the cell surface, as well as inside the cytoplasmic vesicles of the host cell. Flow cytometry analysis of different amastigote populations showed that intracellular amastigotes presented the highest percentage of Ssp4-expressing cells.