Cross-protective efficacy from a immunogen firstly identified in Leishmania infantum against tegumentary leishmaniasis.

Experimental vaccine candidates have been evaluated to prevent leishmaniasis, but no commercial vaccine has been proved to be effective against more than one parasite species. LiHyT is a Leishmania-specific protein that was firstly identified as protective against Leishmania infantum. In this study, LiHyT was evaluated as a vaccine to against two Leishmania species causing tegumentary leishmaniasis (TL): Leishmania major and Leishmania braziliensis. BALB/c mice were immunized with rLiHyT plus saponin and lately challenged with promastigotes of the two parasite species. The immune response generated was evaluated before and 10 weeks after infection, as well as the parasite burden at this time after infection. The vaccination induced a Th1 response, which was characterized by the production of IFN-γ, IL-12 and GM-CSF, as well as by high levels of IgG2a antibodies, after in vitro stimulation using both the protein and parasite extracts. After challenge, vaccinated mice showed significant reductions in their infected footpads, as well as in the parasite burden in the tissue and organs evaluated, when compared to the control groups. The anti-Leishmania Th1 response was maintained after infection, being the IFN-γ production based mainly on CD4(+) T cells. We described one conserved Leishmania-specific protein that could compose a pan-Leishmania vaccine.

Prophylactic properties of a Leishmania-specific hypothetical protein in a murine model of visceral leishmaniasis.

In this work, the effect of vaccination of a newly described Leishmania infantum antigenic protein has been studied in BALB/c mice infected with this parasite species. The LiHyD protein was characterized after a proteomic screening performed with the sera from dogs suffering visceral leishmaniasis (VL). Its recombinant version was expressed, purified and administered to BALB/c mice in combination with saponin. As a result of vaccination and 10 weeks after challenge using an infective dose of L. infantum stationary promastigotes, vaccinated mice showed lower parasite burdens in different organs (liver, spleen, bone marrow and footpads' draining lymph nodes) than mice inoculated with the adjuvant alone or the vaccine diluent. Protected mice showed anti-Leishmania IgG2a antibodies and a predominant IL-12-driven IFN-γ production (mainly produced by CD4(+) T cells) against parasite proteins, whereas unprotected controls showed anti-Leishmania IgG1 antibodies and parasite-mediated IL-4 and IL-10 responses. Vaccinated mice showed an anti-LiHyD IgG2a humoral response, and their spleen cells were able to secrete LiHyD-specific IFN-γ, IL-12 and GM-CSF cytokines before and after infection. The protection was correlated with the Leishmania-specific production on nitric oxide. Altogether, the results indicate that the new LiHyD protein could be considered in vaccine formulations against VL.

Cerebral vasoreactivity to arterial carbon dioxide tension in preterm infants: the effect of ibuprofen.

Cerebral vasoreactivity to CO(2), calculated by linear regression of total cerebral hemoglobin, measured by near infrared spectroscopy, and corresponding PaCO(2), in infants <32 weeks' gestation, was found to be unaffected by the administration of ibuprofen, which was given on the first postnatal day as prophylaxis against patent ductus arteriosus.

Comparative evaluation of the effects of indomethacin and ibuprofen on cerebral perfusion and oxygenation in preterm infants with patent ductus arteriosus.

OBJECTIVE: To compare the effects on cerebral perfusion and oxygenation of intravenous ibuprofen and indomethacin as treatment for patent ductus arteriosus in preterm infants. STUDY DESIGN: Sixteen infants receiving mechanical ventilation (< 31 weeks gestation) with patent ductus arteriosus received either 0.2 mg/kg indomethacin (n = 8) or 10 mg/kg ibuprofen (n = 8) infused over 1 minute. Near-infrared spectroscopy was used to measure changes in cerebral blood volume and in oxidized cytochrome oxidase concentration. Cerebral blood flow velocity in the pericallosal artery was measured using Doppler ultrasonography. RESULTS: Indomethacin caused a significant reduction of CBV (maximal changes in cerebral blood volume: -320 +/- 171 microL/100 gm) and, in four of eight patients, a fall in oxidized cytochrome oxidase concentration (maximal change in oxidized cytochrome oxidase concentration in the eight patients: -0.68 +/- 0.98 mumol/L, NS). Cerebral blood flow velocity fell significantly. Ibuprofen caused no significant reduction of cerebral blood volume, oxidized cytochrome oxidase concentration, or cerebral blood flow velocity, whereas a significant increase of cerebral blood volume (+207 +/- 200 microL/100 gm) was observed after 60 minutes. Ductus closure was seen in six of eight infants after the first dose of indomethacin and in five of eight infants after the first dose of ibuprofen. The therapeutic cycle involved administration of a second and third dose, provided no side effects occurred. Treatment was effective in all infants. CONCLUSION: Compared with indomethacin, treatment with ibuprofen does not significantly reduce cerebral perfusion and oxygen availability; the observed increase in cerebral blood volume requires further investigation.