Aspectos da ecologia dos flebótomos do Parque Nacional da Serra dos Orgãos, Rio de Janeiro: IV. Frequência mensal em armadilhas luminosas (Diptera, Psychodidae, Phlebotominae)

Durante dois anos completos - outubro de 1981 a setembro de 1983 - capturamos flebótomos em armadilhas luminosas no Parque Nacional da Serra dos Órgãos. As armadilhas eram colocadas, semanalmente, em pontos estratégicos na floresta, sempre no mesmo local e hora, ficando expostas por 12 horas. Foram gastas 732 horas e obtidos 2.730 flebótomos pertencentes a 17 espécies, quatro do gênero Brumptomyia França & Parrot, 1921 e 13 do gênero Lutzomyia França, 1924. a proporção de machos em relação ao número total foi de 76,3%. As espécies L. barrettoi, L. ayrozai e L. hirsuta corresponderam a 95% do total, sendo que a primeria somou quase o dobro de exemplares das outras duas juntas. L. ayrozai foi a mais numerosa na época quente e úmida e L. hirsuta na masi fria e seca, do mesmo modo que L. barrettoi, sendo que esta só ocorreu nesta época do ano. O número de espécies e espécimens foi bem maior na área B, onde as armadilhas foram colocadas perto do solo, próximas a tocas de animais silvestres, do que na área A, onde foram instaladas afastadas do solo, em local de vegetação mais fechada e perto de árvores com raízes tabulares. Após o repouso pós-alimentar, na procura de locais adequados para a postura, acreditamos que as fêmeas tenham maior atração pela fonte luminosa, pois verificamos um número considerável de fêmeas grávidas. Também em armadilhas luminosas constatamos que a lua nova foi mais favorável à coleta de flebótomos e a lua cheia a de menor rendimento.

Alguns aspectos da ecologia dos mosquitos (Diptera: Culicidae) de uma área de planície (granjas Calábria) em Jacarepaguá, Rio de Janeiro: IV. Preferências alimentares quanto ao hospedeiro e freqüência domiciliar

Apresentamos os resultados de capturas de mosquitos, realizadas entre janeiro de 1982 e março de 1983, em Granjas Calábria, com a finalidade de avaliar suas preferências alimentares. Usamos seis iscas: homem, cavalo, vaca, carneiro, galo e sapo. O cavalo atraiu o maior número de exemplares, seguindo-se a vaca, o homem, o galo e o carneiro, sendo que o sapo não foi atacado. A isca humana foi a que atraiu mais espécies. Observamos uma tendência zoófila para as espécies locais - An. albitarsis, An. aquasalis, Ae. scapularis, Ae. taeniorhynchus, Cq. venezuelensis, Ma. titillans, Ps. ciliata, Ph. davisi e Ph. deanei sugaram principalemte cavalo e vaca, enquanto os Culex do subgênero Culex pareceram-nos mais ornitófilos e os do subgênero Microculex preferiram animais pecilotérmicos em experimentos que realizamos no laboratório. Ma. titillans foi a espécie preponderante em todas as iscas, demonstrado elevado ecletismo. Para estudar a freqüência domiciliar e peridomiciliar fizemos, mensalmente, de agosto de 1981 a julho de 1982, capturas dentro e fora de uma casa. Excetuando algumas espécies com maior propensão à endofilia principalmente An. aquasalis e Cx. quinquefasciatus, os mosquitos locais mostram-se mais exófilos. Foram visitantes ocasionais do domicílo: Ma. titillans, Ae. scapularis, Ae. taeniorhynchus e Cx. saltanensis.

Morbidade da esquistossomose no Brasil: IV. Evolução em pacientes tratados e seus controles

Um estudo comparativo sobre a evolução da morbidade da esquistossomose mansoni em pacientes tratados e não tratados em uma área endêmica, foi realizado após um e seis anos do tratamento inicial. No primeiro ano após o tratamento verificou-se uma drástica redução do número de ovos de S. mansoni por grama de fezes eliminadas pelos pacientes tratados em relação aos controles e também melhores condições clínicas dos pacientes tratados. Entretanto, ao final de seis anos de observação, embora o número de ovos de S. mansoni eliminados pelos pacientes tratados ainda fosse menor do que no grupo controle ele se aproximava do número inicial antes do tratamento. Em ambos os grupos houve evolução para formas clínicas mais graves, embora com uma certa tendência para maior gravidade no grupo controle. Recomenda-se que o tratamento da população em áreas endêmicas deva ser feito com intervalos de dois a três anos e não se dispensam medidas profiláticas como suprimento de aguá encanada nas casas e educação de base da população.

Ecology of sandflies Diptera: Psychodidae) in a restricted focus of cutaneous leishmaniasis in Northern Venezuela: IV. Sandfly monthly fluctuation and leishmaniasis incidence relationship

An attempt has been made to correlate the monthly incidence of human leishmaniasis with the temporal distribution of sandfly species at San Esteban, Northern Venezuela. Upon statistical analysis, the seasonal fluctuation of L. ovallesi population correlated strongly with the human disease, while the dynamics of L. panamensis, generally believed to be the vector in the Central area of the country, showed only a very weak correlation. These findings support the hypothesis that L. panamensis might not be the main or unique species responsible for the transmission in this area and that L. ovallesi and additionally L. olmeca bicolor might be involved in the epidemiology of the disease.

Phlébotomes de Bolive: IV. Lutzomyia (Trichophoromyia) beniensis, n.sp. (Diptera, Psychodidae)

Les auteurs décrivent le mâle et la femelle de Lutzomyia (Trichophoromyia) beniensis n.sp., capturés dans le galerie forestiére du Rio Beni (Département du Beni). L'espèce n'est pas anthropophile mais aurait des appétences omithophiles.

Mosquitos no Parque Nacional da Serra dos Orgãos, estado do Rio de Janeiro, Brasil: IV. Preferência alimentar

Como parte das observações que vimos realizando sobre a ecologia dos mosquitos culicíneos no Parque Nacional da Serra dos Órgãos, Estado do Rio de Janeiro, estudamos nesta oportunidade as preferências alimentares dos espécimens fêmeas que ali ocorrem. Através de amostragens simultâneas a nível do solo e nas imediações da copa das árvores, em diferentes períodos de 24 horas consecutivas, realizamos a captura da fauna culicideana atraída para a hematofagia por uma das iscas alí expostas: ave, gambá, lagarto e isca humana comparativa. No período de março de 1983 a setembro de 1985, a fauna culicideana apresentou-se bastante eclética, com uma ligeira tendência ao antropofilismo. A única espécie nitidamente ornitófila foi o Culex nigripalpus, enquanto Cx. (Melanoconion) sp. distribuiu-se, em baixas incidências entre o gambá e a ave nas suas preferências. Alguns sabetíneos, como Trichoprosopon similis, Tr. frontosus, Tr. reversus, Tr. thobaldi, Wyeomyia personata, Wy. confusa, Wy. mystes, Phoniomyia pilicauda, Ph. theobaldi e Limatus durhami, foram capturados, em significativos percentuais, realizando o repasto sangüíneo na ave. Entretanto, em nenhuma oportunidade, observamos o lagarto sendo utilizado para hematoagia pelos mosquitos.

Behavior of triatomines (Hemiptera: Reduviidae) vectors of Chaga's disease: IV. Fecundity, fertility and longevity of Panstrongylus megistus (Burm., 1835) pairs and virgin females starved under laboratory conditions

A laboratory study was conducted on the fecundity, fertility and life span of Panstrongylus megistus pairs and on the fecundity and life span of P. megistus virgin females submitted to starvation after the last moulting. Of the mated females, 22.2% laid eggs, 4.4% of which were fertile. Females resisted starvation more than males. Of the starved virgin females, only 10% laid eggs, with a low egg-laying rate (0.47) per female. Resistance to starvation was lower in virgin than in mated females.

Validation of an analytical method for nitrous oxide (N2O) laughing gas by headspace gas chromatography coupled to mass spectrometry (HS-GC-MS): Forensic application to a lethal intoxication.

Drug abuse is a widespread problem affecting both teenagers and adults. Nitrous oxide is becoming increasingly popular as an inhalation drug, causing harmful neurological and hematological effects. Some gas chromatography-mass spectrometry (GC-MS) methods for nitrous oxide measurement have been previously described. The main drawbacks of these methods include a lack of sensitivity for forensic applications; including an inability to quantitatively determine the concentration of gas present. The following study provides a validated method using HS-GC-MS which incorporates hydrogen sulfide as a suitable internal standard allowing the quantification of nitrous oxide. Upon analysis, sample and internal standard have similar retention times and are eluted quickly from the molecular sieve 5Å PLOT capillary column and the Porabond Q column therefore providing rapid data collection whilst preserving well defined peaks. After validation, the method has been applied to a real case of N2O intoxication indicating concentrations in a mono-intoxication.

Podoconiosis in the Ethiopian Rift Valley - Role of beryllium and zirconium

A geogenic origin has been proposed in the aetiology of non-filarial elephantiasis of the feet and legs, recently renamed podoconiosis. Soil collected in an area of the Ethiopian Rift Valley, the borough of Ocholo, known for its high prevalence of podoconiosis (5.06%), has been submitted to mineral analysis. High values of sulphur (S), cerium (Ce), lanthanum (La) and neodymium (Nd), typical for basaltic bedrocks, were found. Of special interest were the values for zirconium (Zr) and beryllium (Be), 618 +/- 87 ppm and 4.6 +/- 0.5 ppm respectively, twice as high as those recorded for soils sampled in neighbouring areas where the prevalence of podoconiosis is low. To be noted also, a high content in vanadium, above 250 ppm, in half of the soil samples collected in this region. Year-long exposure of unprotected feet to Zr and Be, known for their ability to induce granuloma formation in the lymphoid tissue of man, and present in a clay rich in colloidal silica particle, highly abrasive to skin, is doubtlessly a factor involved in the development of lymph node sclerosis leading to elephantiasis.

Acute endotoxemia inhibits microvascular nitric oxide-dependent vasodilation in humans.

Nitric oxide (NO) is crucial for the microvascular homeostasis, but its role played in the microvascular alterations during sepsis remains controversial. We investigated NO-dependent vasodilation in the skin microcirculation and plasma levels of asymmetric dimethylarginine (ADMA), a potent endogenous inhibitor of the NO synthases, in a human model of sepsis. In this double-blind, randomized, crossover study, microvascular NO-dependent (local thermal hyperemia) and NO-independent vasodilation (post-occlusive reactive hyperemia) assessed by laser Doppler imaging, plasma levels of ADMA, and l-arginine were measured in seven healthy obese volunteers, immediately before and 4 h after either a i.v. bolus injection of Escherichia coli endotoxin (LPS; 2 ng/kg) or normal saline (placebo) on two different visits at least 2 weeks apart. LPS caused the expected systemic effects, including increases in heart rate (+43%, P < 0.001), cardiac output (+16%, P < 0.01), and rectal temperature (+1.4°C, P < 0.001), without change in arterial blood pressure. LPS affected neither baseline skin blood flow nor post-occlusive reactive hyperemia but decreased the NO-dependent local thermal hyperemia response, l-arginine, and, to a lesser extent, ADMA plasma levels. The changes in NO-dependent vasodilation were not correlated with the corresponding changes in the plasma levels of ADMA, l-arginine, or the l-arginine/ADMA ratio. Our results show for the first time that experimental endotoxemia in humans causes a specific decrease in endothelial NO-dependent vasodilation in the microcirculation, which cannot be explained by a change in ADMA levels. Microvascular NO deficiency might be responsible for the heterogeneity of tissue perfusion observed in sepsis and could be a therapeutic target.

Transfer of ultrasmall iron oxide nanoparticles from human brain-derived endothelial cells to human glioblastoma cells.

Nanoparticles (NPs) are being used or explored for the development of biomedical applications in diagnosis and therapy, including imaging and drug delivery. Therefore, reliable tools are needed to study the behavior of NPs in biological environment, in particular the transport of NPs across biological barriers, including the blood-brain tumor barrier (BBTB), a challenging question. Previous studies have addressed the translocation of NPs of various compositions across cell layers, mostly using only one type of cells. Using a coculture model of the human BBTB, consisting in human cerebral endothelial cells preloaded with ultrasmall superparamagnetic iron oxide nanoparticles (USPIO NPs) and unloaded human glioblastoma cells grown on each side of newly developed ultrathin permeable silicon nitride supports as a model of the human BBTB, we demonstrate for the first time the transfer of USPIO NPs from human brain-derived endothelial cells to glioblastoma cells. The reduced thickness of the permeable mechanical support compares better than commercially available polymeric supports to the thickness of the basement membrane of the cerebral vascular system. These results are the first report supporting the possibility that USPIO NPs could be directly transferred from endothelial cells to glioblastoma cells across a BBTB. Thus, the use of such ultrathin porous supports provides a new in vitro approach to study the delivery of nanotherapeutics to brain cancers. Our results also suggest a novel possibility for nanoparticles to deliver therapeutics to the brain using endothelial to neural cells transfer.

IV thrombolysis and renal function.

OBJECTIVE: To investigate the association of renal impairment on functional outcome and complications in stroke patients treated with IV thrombolysis (IVT). METHODS: In this observational study, we compared the estimated glomerular filtration rate (GFR) with poor 3-month outcome (modified Rankin Scale scores 3-6), death, and symptomatic intracranial hemorrhage (sICH) based on the criteria of the European Cooperative Acute Stroke Study II trial. Unadjusted and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Patients without IVT treatment served as a comparison group. RESULTS: Among 4,780 IVT-treated patients, 1,217 (25.5%) had a low GFR (<60 mL/min/1.73 m(2)). A GFR decrease by 10 mL/min/1.73 m(2) increased the risk of poor outcome (OR [95% CI]): (ORunadjusted 1.20 [1.17-1.24]; ORadjusted 1.05 [1.01-1.09]), death (ORunadjusted 1.33 [1.28-1.38]; ORadjusted 1.18 [1.11-1.249]), and sICH (ORunadjusted 1.15 [1.01-1.22]; ORadjusted 1.11 [1.04-1.20]). Low GFR was independently associated with poor 3-month outcome (ORadjusted 1.32 [1.10-1.58]), death (ORadjusted 1.73 [1.39-2.14]), and sICH (ORadjusted 1.64 [1.21-2.23]) compared with normal GFR (60-120 mL/min/1.73 m(2)). Low GFR (ORadjusted 1.64 [1.21-2.23]) and stroke severity (ORadjusted 1.05 [1.03-1.07]) independently determined sICH. Compared with patients who did not receive IVT, treatment with IVT in patients with low GFR was associated with poor outcome (ORadjusted 1.79 [1.41-2.25]), and with favorable outcome in those with normal GFR (ORadjusted 0.77 [0.63-0.94]). CONCLUSION: Renal function significantly modified outcome and complication rates in IVT-treated stroke patients. Lower GFR might be a better risk indicator for sICH than age. A decrease of GFR by 10 mL/min/1.73 m(2) seems to have a similar impact on the risk of death or sICH as a 1-point-higher NIH Stroke Scale score measuring stroke severity.

Leishmaniose en Bolivie: IV. Le chien dans les cycles des leishmanioses en Bolivie

En Bolivie le chien domestique est impliqué dans le cycle de la leishmaniose viscérale (Leishmania (Le.) chagasi) das les Yungas (alt. 1,000-2,000 m) et aussi dans le cycle de la leishmaniose tégumetaire (Le. (V.) braziliensis) dans l'Alto Beni (alt. 400-600 m). Mais il joue un rôle différent dans les deux cycles. Il est le prencipal résevoir, peut-être l'unique de Le. (Le.) chagasi dans les Yungas, et la source de contamination de l'home. Dans l'Alto Beni, il n'est seulement qu'une victime, comme l'home, de Le. (V.) braziliensis, dont le réservoir reste inconnu, les soupçons se portant sur des mammifères sauvages.