Contrasting human cytokine responses to promastigote whole-cell extract and the Leishmania analogue receptor for activated C kinase antigen of L. amazonensis in natural infection versus immunization.

It is known that the same antigen can induce different immune responses, depending upon the way that it is presented to the immune system. The objective of this study was to compare cytokine responses of peripheral blood mononuclear cells (PBMC) from cutaneous leishmaniasis patients and subjects immunized with a first-generation candidate vaccine composed of killed Leishmania amazonensis promastigotes to a whole-cell promastigote antigen extract (La) and to the recombinant protein LACK (Leishmania analogue receptor for activated C kinase), both from L. amazonensis. Thirty-two patients, 35 vaccinees and 13 healthy subjects without exposure to Leishmania, were studied. Cytokine production was assessed by enzyme-linked immunosorbent assay and enzyme-linked immunospot assay. The interferon (IFN)-gamma levels stimulated by La were significantly higher and the levels of interleukin (IL)-10 significantly lower than those stimulated by LACK in the patient group, while LACK induced a significantly higher IFN-gamma production and a significantly lower IL-10 production compared with those induced by La in the vaccinated group. LACK also induced a significantly higher frequency of IFN-gamma-producing cells than did La in the vaccinated group. The contrast in the cytokine responses stimulated by LACK and La in PBMC cultures from vaccinated subjects versus patients indicates that the human immune response to crude and defined Leishmania antigens as a consequence of immunization differs from that induced by natural infection.

Acute phenobarbital administration induces hyperalgesia: pharmacological evidence for the involvement of supraspinal GABA-A receptors.

The aim of the present study was to determine if phenobarbital affects the nociception threshold. Systemic (1-20 mg/kg) phenobarbital administration dose dependently induced hyperalgesia in the tail-flick, hot-plate and formalin tests in rats and in the abdominal constriction test in mice. Formalin and abdominal constriction tests were the most sensitive procedures for the detection of hyperalgesia in response to phenobarbital compared with the tail-flick and hot-plate tests. The hyperalgesia induced by systemic phenobarbital was blocked by previous administration of 1 mg/kg ip picrotoxin or either 1-2 mg/kg sc or 10 ng icv bicuculline. Intracerebroventricular phenobarbital administration (5 microg) induced hyperalgesia in the tail-flick test. In contrast, intrathecal phenobarbital administration (5 microg) induced antinociception and blocked systemic-induced hyperalgesia in this test. We suggest that phenobarbital may mediate hyperalgesia through GABA-A receptors at supraspinal levels and antinociception through the same kind of receptors at spinal levels.

Acute phenobarbital administration induces hyperalgesia: pharmacological evidence for the involvement of supraspinal GABA-A receptors

The aim of the present study was to determine if phenobarbital affects the nociception threshold. Systemic (1-20 mg/kg) phenobarbital administration dose dependently induced hyperalgesia in the tail-flick, hot-plate and formalin tests in rats and in the abdominal constriction test in mice. Formalin and abdominal constriction tests were the most sensitive procedures for the detection of hyperalgesia in response to phenobarbital compared with the tail-flick and hot-plate tests. The hyperalgesia induced by systemic phenobarbital was blocked by previous administration of 1 mg/kg ip picrotoxin or either 1-2 mg/kg sc or 10 ng icv bicuculline. Intracerebroventricular phenobarbital administration (5 æg) induced hyperalgesia in the tail-flick test. In contrast, intrathecal phenobarbital administration (5 æg) induced antinociception and blocked systemic-induced hyperalgesia in this test. We suggest that phenobarbital may mediate hyperalgesia through GABA-A receptors at supraspinal levels and antinociception through the same kind of receptors at spinal levels

[Understanding the person with schizophrenia from the point of view of Merleau-Ponty]. / Compreendendo o ser com diagnóstico de esquizofrenia à luz do pensamento de Merleau-Ponty.

Schizophrenia is a precocious dementia (dementia praecox), essentially characterized by affective symptoms, which are manifested through the isolation of the schizophrenic from the real world, as a way of protecting oneself from the surrounding hostilities. Based on the perspective of Merleau Ponty, the objective of the present research is to understand the schizophrenic person by revealing his/her position towards the world and towards him/herself as well as his/her perception of the society he/she is living in. Data were collected through guided interviews with five patients from two private hospitals. A phenomenological framework, based on the hermeneutic circle, was used to analyze the data. Results showed references to their body, time, world and people related to them outlining an interlink between these references, based on the perception of those who are close or not at the moment.

Efeito do flúor presente no fosfato de rocha de Araxá sobre a produçäo hepática de AMP-cíclico em frangos de corte / Effect of dietary fluorine from Araxá rock phosphate on the hepatic production of cyclic-adenosine monophosphate in broilers

A produçäo de adenosina 3, 5 - monofosfato cíclico (AMPc) foi avaliada em fatias de fígado de frangos de corte que receberam dieta experimental contendo fosfato bicálcico ou fosfato de rocha de Araxá, com alto teor de flúor, como fonte de fósforo, em dois períodos distintos do 1§ ao 42§ e do 21§ ao 42§ dias de idade. A ingestäo da dieta formulada com fosfato de rocha de Araxá desde o 1§ dia de vida, provocou elevaçäo da produçäo de AMPc no fígado dos frangos de corte. Entretanto a utilizaçäo da mesma dieta a partir do 21§ de idade näo alterou significativamente (P>0,05) a produçäo hepática de AMPc nas aves, sugerindo que a influência da alta ingestäo do flúor presente no fosfato de rocha de Araxá sobre o AMPc hepático dos frangos de corte é dependente da idade em que a administraçäo da dieta é iniciada

Ageing and acetylcholine release by tityustoxin from brain cortical slices.

The ability of tityustoxin to trigger acetylcholine release was studied in cerebral cortical slices from 2, 12 and 23-month-old rats. The effect of tityustoxin to induce the release of acetylcholine was reduced by 60% in senescent animals. This result suggests that ageing reduces the sensitivity of cerebral cortical nerve terminals to tityustoxin.

The association of Schistosoma mansoni infection with deficiency of vitamin A in mice.

Verificou-se que o desenvolvimento somatico do Schistosoma mansoni foi retardado em camundongos com deficiencia de vitamina A, quando comparado com aquele obtido no grupo controle. A diferenca foi mais acentuada no 12o. dia. A proporcao de vermes no 1o., 2o. e 3o. estagios de desenvolvimento foi de 66,5%; 31,0 e 2,5%, respectivamente, para os camundongos em avitaminose A, e 26,4; 37,4 e 36,2%, respectivamente, para os controles. No 18o. dia apos a exposicao cercariana, a proporcao de vermes no 1o., 2o., 3o., 4o. e 5o. estagios foi de 4,4; 0,0%; 46,45; 36,44 e 12,66% para os camundongos com deficiencia de vitamina A, e 0,0; 0,0; 17,54; 54,84 e 27,62%, respectivamente, para os controles. A oviposicao foi praticamente a mesma em ambos os grupos. Nao foi possivel detectar caroteno ou vitamina A nos vermes obtidos de animais em avitaminose A. Nos esquistossomos recuperados de animais-controles, os niveis de caroteno e vitamina A foram 1020 e 0,086 microgramo/g de verme, respectivamente.Alguns animais desenvolveram uma neuropatia, com consequente amputacao espontanea de uma das patas dianteiras. Nos grupos controle e dificientes de vitamina A infectados, a incidencia desta neuropatia foi de 4,9 e 23,1% respectivamente