A pilot study to control Lutzomyia umbratilis (Diptera: Psychodidae), the major vector of Leishmania brazileiensis guyanensis, in a peri-urban rainforest of Manaus, Amazonas State, Brazil

In the second half of 1980, 112 (or ca. 16%) of the inhabitants of the new settlement of São José, city of Manaus, contracted cutaneous leishmaniasis whilst clearing their properties of terra firme rainforest. With the aid of SUCAM, the authors carried out a pilot study to investigate the feasibility of reducing populations of Lutzomyia umbratilis, the local silvatic vector of Leishmania braziliensis guyanensis, by spraying insecticide on its favoured diurnal resting sites, the bases of the larger forest trees. Most manvector contact is at these resting sites and, therefore, it was encouraging to record a marked reduction of the tree-base populations of L. umbratilis for 21 days following just one application of D.D.T. emulsion in an area 200m square. Most of the treated trunks were not occupied by L. umbratilis for at least eleven months. Suggestions for extending the pilot study are made, and the need for collaboration with a clinical team is emphasized. Leishmania b. guyanensis is the aetiological agent of [quot ]pain bois[quot ], which is hyperendemic from French Guiana to central Amazônia. In the absence of proven vaccines or methods of vector control, some simple methods for limiting transmission of Le. b. guyanensis to man are listed.

Brain-derived neurotrophic factor enhances the hippocampal expression of key postsynaptic proteins in vivo including the monocarboxylate transporter MCT2.

Brain-derived neurotrophic factor (BDNF) promotes synaptic plasticity via an enhancement in expression of specific synaptic proteins. Recent results suggest that the neuronal monocarboxylate transporter MCT2 is a postsynaptic protein critically involved in synaptic plasticity and long-term memory. To investigate in vivo whether BDNF can modulate the expression of MCT2 as well as other proteins involved in synaptic plasticity, acute injection of BDNF was performed in mouse dorsal hippocampal CA1 area. Using immunohistochemistry, it was found that MCT2 expression was enhanced in part of the CA1 area and in the dentate gyrus 6 h after a single intrahippocampal injection of BDNF. Similarly, expression of the immediate early genes Arc and Zif268 was enhanced in the same hippocampal areas, in accordance with their role in synaptic plasticity. Immunoblot analysis confirmed the significant enhancement in MCT2 protein expression. In contrast, no changes were observed for the glial monocarboxylate transporters MCT1 and MCT4. When other synaptic proteins were investigated, it was found that postsynaptic density 95 (PSD95) and glutamate receptor 2 (GluR2) protein levels were significantly enhanced while no effect could be detected for synaptophysin, synaptosomal-associated protein 25 (SNAP25), αCaMKII and GluR1. These results demonstrate that MCT2 expression can be upregulated together with other key postsynaptic proteins in vivo under conditions related to synaptic plasticity, further suggesting the importance of energetics for memory formation.

The Distributional Consequences of Supply-Side Reforms in General Equilibrium

This paper addresses the issue on whether tax reforms consisten with lower public debt-to-GDP in the long-run can lead to a more efficient and equitable economy. To this end we solve a heterogeneous agent model comprised of a government, a representative capitalist and representative skilled and unskilled workers, under both rational expectations and adaptive learning. Our main ndings are that (i) reductions in capital taxation, while bene cial at the aggregate level, lead to increased inequality mainly due to the substitutability of un- skilled labour and capital; (ii) a fall in taxation for skilled labour is Pareto improving, which is largely explained by its complementarity with the other factor inputs; (iii) all agents would prefer increasing the tax rate on capital to increasing the tax rate on skilled and un- skilled labour since it leads to relatively lower welfare losses; and (iv) heterogeneity in initial beliefs under adaptive learning quantitatively matters for welfare.

Regional Policy Spillovers: The National Impact of Demand-Side Policy in an Interregional Model of the UK Economy

UK regional policy has been advocated as a means of reducing regional disparities and stimulating national growth. However, there is limited understanding of the interregional and national effects of such a policy. This paper uses an interregional computable general equilibrium model to identify the national impact of a policy-induced regional demand shock under alternative labour market closures. Our simulation results suggest that regional policy operating solely on the demand side has significant national impacts. Furthermore, the effects on the non-target region are particularly sensitive to the treatment of the regional labour market.

The convenient calculation of some test statistics in models of discrete choice

The paper considers the use of artificial regression in calculating different types of score test when the log

Leishmania braziliensis ssp. in the nasal mucosa of guinea pigs inoculated in the tarsi

Two lots of 20 young male guinea pigs were inoculated subcutaneously in the tarsi with 10 (elevated to fourth potency) amastigotes of Leishmania braziliensis or L. b. guyanensis to study the susceptibility of this Neotropical hystricomorph rodent the autochthonous parasites. Almost 50% of the animals showed lesions in the inoculation site and had parazitations that were infective to hamsters, as shown by inoculating homogenates of the dermal lesion, of the spleen, of the liver, and of the nasal mucosa into hamsters at 20, 40, 60 and 120 days after inoculation of the guinea pig. Smears of the above organs showed the presence of amastigotes. Parasites inoculated into the tarsi were detected early in the skin, spleen, and liver of the guinea pig host. Blood cultures made by cardiopuncture on sacrifice of the guinea pigs were uniformly negative. The nasal mucosa of nearly all animals positive in the skin or viscera was invaded early by the parasites, although with grater frequency between 60 and 120 days post-inoculation. The use of this model for the study of mucocutaneous parasitism by L. brasiliensis is discussed, together with the phenomena of parasitism at a distance from the inoculation site, the temperature of the body regions affected, and the possible genetic influence on susceptibility of the guinea pig to L. brasiliensis.

The subclinical form of experimental visceral leishmaniasis in dogs

Pathological aspects of a subclinical form of experimental canine leishmaniasis is reported here for the first time. Fifteen mongrel dogs were used in the present study. Eight dogs were infected and seven were used as control. Four of the control dogs were inoculated with spleen cells from non-infected hamsters. The eight mongrel dogs inoculated intravenously with amastigotes forms of Leishmania chagasi envolved for periods as long as 25 months without any clinical characteristic sign of classical Visceral Leishmaniasis (VL). Most of the laboratory test results were compatible to those of the seven control animals but culture of bone marrow aspirated material and serologic testing (IIF) demonstrated or provided evidence that the animals were infected. The most important and predominant histopathological lesion in infected animals were epitheloid granulomas presented in the liver, spleen, adrenal gland and lung of some animals. Channels containing erythrocytes in some granulomas of the liver suggeste that these granulomas are formed inside sinusoidal capillaries. Despite the animals were proved to be infected and presented characteristic histologic lesions, they did not present external signs of disease. The granulomatous aspect of the lesions indicates a good immunologic reactivity and suggest that a host-parasite equilibrium does exist in the dog experimental model

The geographic understanding of snail borne disease in endemic areas using satellite surveillance

The current status of research on use of earth observing satellite sensors and geographic ifnormation systems for control program management of schistosomiais and fascioliasis is reviewed.

The Type Specimens of Apoidea (Hymenoptera) Deposited in the Entomological Collection of Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil

A list of 41 Apoidea (Hymenoptera) type specimens deposited in the Entomological Collection of the Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil is presented. The types previously belonged to the Zikán and Schrottky private collections. A total of 11 holotypes and 30 paratypes are listed with their respective data and literature

Factors determining the spontaneous activation of splenic dendritic cells in culture.

Dendritic cells (DCs) serve as a link between the innate and adaptive immune systems. The activation state of DCs is crucial in this role. However, when DCs are isolated from lymphoid tissues, purified and placed in culture they undergo 'spontaneous' activation. The basis of this was explored, using up-regulation of DC surface MHC II, CD40, CD80 and CD86 as indicators of DC activation. No evidence was found for DC damage during isolation or for microbial products causing the activation. The culture activation of spleen DCs differed from that of Langerhans cells when released from E-cadherin-mediated adhesions, since E-cadherin was not detected and activation still occurred with β-catenin null DCs. Much of the activation could be attributed to DC-DC interactions. Although increases in surface MHC II levels occurred under all culture conditions tested, the increase in expression of CD40, CD80 and CD86 was much less under culture conditions where such interactions were minimised. DC-to-DC contact under the artificial conditions of high DC concentration in culture induced the production of soluble factors and these, in turn, induced the up-regulation of co-stimulatory molecules on the DC surface.

The Epidemiological Impact of Antimeningococcal B Vaccination in Cuba

The incidence of invasive meningococcal disease (IMD) before (1984-1988) and after (1989-1994), a nationwide intervention with VA-MENGOC-BC vaccination started in 1989, was compared. The prevaccination period incidence density (ID> 8.8/ 105 year-person) was higher than the postvaccination ID (ID< 6.5/ 105 year-person). The percentage proportional differences from the start to the end of each period of ID in the vaccinal period was higher (87%) than the prevaccinal (37%) with significant differences among vaccinated groups (< 25 years old). A break-point (Chow test) was confirmed by the decrease in the ID between 1989 and 1990 in children under 1 year old, 5-9, 10-14, 15-19 and 50-54 years. Comparison of ID using maps showed a decrease in IMD in all municipalities during the postvaccination period. These findings support the epidemiological impact of VA-MENGOC-BC vaccination in the reduction of IMD morbidity.

The central projection of cephalic mechanosensory axons in the haematophagous bug Triatoma infestans

The projections of mechanosensory hairs located on the dorsal and lateral head of the adult haematophagous bug Triatoma infestans were analyzed by means of cobalt filling. Axons run into the anterior and posterior tegumentary nerve and project through the brain to the ventral nerve cord. The fibres are small in diameter and run as a fascicle. Some branches run into suboesophageal and prothoracic centres; others run as far as to the mesothoracic ganglion. These sensory projections resemble that of wind-sensitive head hairs of the locust. The functional role of this sensory system in this species is discussed.