Immunization with Transgenic Rodent Malaria Parasites Expressing Pfs25 Induces Potent Transmission-Blocking Activity.

An anti-malarial transmission blocking vaccine (TBV) would be an important tool for disease control or elimination, though current candidates have failed to induce high efficacy in clinical studies. The ookinete surface protein P25 is a primary target for TBV development, but heterologous expression of P25 with appropriate conformation is problematic and a pre-requisite for achieving functional titers. A potential alternative to recombinant/sub-unit vaccine is immunization with a non-pathogenic, whole-parasite vaccine. This study examines the ability of a purified transgenic rodent-malaria parasite (PbPfs25DR3), expressing Plasmodium falciparum P25 in native conformation on the P. berghei ookinete surface, to act as a TBV. Vaccination with purified PbPfs25DR3 ookinetes produces a potent anti-Pfs25 response and high transmission-blocking efficacy in the laboratory, findings that are then translated to experimentation on natural field isolates of P. falciparum from infected individuals in Burkina Faso. Efficacy is demonstrated in the lab and the field (up to 93.3%/97.1% reductions in transmission intensity respectively), with both a homologous strategy with one and two boosts, and as part of a prime-boost regime, providing support for the future development of a whole-parasite TBV.

Increased microvascular permeability contributes to preferential accumulation of Stealth liposomes in tumor tissue.

Stealth liposomes have recently emerged as a promising antitumor drug delivery system, yet no studies have been reported to examine their dynamic behavior at the microcirculatory level. In this investigation, we have used in vivo fluorescence videomicroscopy to study the decay in plasma concentration and the interstitial accumulation of Stealth and conventional liposomes in tumor and granulating tissue microcirculatory preparations. Fluorescently labeled Stealth or conventional liposomes were injected i.v. into rats bearing dorsal skinflap window chambers, some of which contained a vascularized mammary adenocarcinoma. After injection, fluorescent light intensities arising from liposomes within blood vessels and the interstitium were measured over time. These measurements were used to derive plasma pharmacokinetics and vascular permeability coefficients for each liposome species in both tumor and granulating normal tissues. Within the first 90 min after injection, Stealth liposome accumulation in the tumor interstitium was 3-4-fold that for conventional liposomes. The percentage of administered liposomes remaining in the circulation at the end of 90 min was 60.2% for Stealth and 20.4% for conventional liposomes. Tumor vascular permeability was 3.42 +/- 0.78 x 10(-7)cm/s for Stealth and 1.75 x 0.38 x 10(-7)cm/s for conventional liposomes. In normal granulating tissues permeability for the 2 constructs was equivalent at 0.8-0.9 x 10(-7)cm/s. In conclusion, preferential accumulation of Stealth liposomes in tumors was attributable to a combination of slower plasma clearance and higher vascular permeability relative to conventional liposomes. Our method of combining in vivo microscopy with a tumor microcirculatory model provides a unique approach to study quantitatively the delivery of liposomes to tumor tissues, since it can be used to study the process in real time at the microcirculatory level.

Comparative assessment of transmission-blocking vaccine candidates against Plasmodium falciparum.

Malaria transmission-blocking vaccines (TBVs) target the development of Plasmodium parasites within the mosquito, with the aim of preventing malaria transmission from one infected individual to another. Different vaccine platforms, mainly protein-in-adjuvant formulations delivering the leading candidate antigens, have been developed independently and have reported varied transmission-blocking activities (TBA). Here, recombinant chimpanzee adenovirus 63, ChAd63, and modified vaccinia virus Ankara, MVA, expressing AgAPN1, Pfs230-C, Pfs25, and Pfs48/45 were generated. Antibody responses primed individually against all antigens by ChAd63 immunization in BALB/c mice were boosted by the administration of MVA expressing the same antigen. These antibodies exhibited a hierarchy of inhibitory activity against the NF54 laboratory strain of P. falciparum in Anopheles stephensi mosquitoes using the standard membrane feeding assay (SMFA), with anti-Pfs230-C and anti-Pfs25 antibodies giving complete blockade. The observed rank order of inhibition was replicated against P. falciparum African field isolates in A. gambiae in direct membrane feeding assays (DMFA). TBA achieved was IgG concentration dependent. This study provides the first head-to-head comparative analysis of leading antigens using two different parasite sources in two different vector species, and can be used to guide selection of TBVs for future clinical development using the viral-vectored delivery platform.

Endomorphin-1 reduces carrageenan-induced fos expression in the rat spinal dorsal horn.

Intraplantar injection of carrageenan induced significant Fos expression in the superficial and deep spinal dorsal horn at the L(4)-L(5)segments and extensive peripheral edema of the ipsilateral foot in rats. Intraplantar injection of endomorphin-1, endogenous ligand for mu opioid receptor, in the same region produced dose-dependent reduction of carrageenan-induced Fos expression and peripheral edema, which were completely blocked by co-administration of intraplantar injection of naloxone (20 microgram). The systemic injection of the highest dose of endomorphin-1 (50 microgram) had no significant reductory effect on Fos expression and peripheral edema. These results further provided a strong evidence for involvement of mu opioid receptor in peripheral analgesia, particularly in inflammation pain.

Methyl parathion activation by a partially purified rat brain fraction.

Organophosphorus pesticides are one of the most commonly used insecticide classes. They act through a potent inhibition of acetylcholinesterase (AChE). Many of them must undergo transformation into the corresponding oxon analogs to inhibit AChE. This study showed that a brain tissue subfraction transformed methyl parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) in vitro. Methyl parathion activation was assayed by solvent extraction of the products followed by HPLC and GC-MS analyses and, indirectly, by the inhibition of AChE present in the incubation mixture. The lack of impairment of AChE after 2 h of incubation of the brain subfraction with methyl parathion and, alternatively, with NADPH, CO, SKF 525-A, piperonyl butoxide or nitrogen indicated that this brain subfraction transformed methyl parathion without the involvement of a mixed-function oxidative pathway. The results from HPLC analysis did not show a peak corresponding to methyl paraoxon (O,O-dimethyl O-p-nitrophenylphosphate), but showed the production of an unidentified peak which eluted nearby standard methyl parathion (retention times of 10.65 and 8.86 min, respectively). GC-MS analysis suggested that the unidentified product could be a methyl parathion isomer.

Hyperprolactinemia associated to calcification of the pituitary stalk. Case report.

In this work, the authors report the case of a female patient with 24 years of age with hyperprolactinemia, who presented a pituitary stalk calcification as seen by CT scan. Once other possible etiologies were excluded, we concluded that the calcification was probably related to hyperprolactinemia caused by interruption of the input of dopamine to the pituitary gland.

[Comparison of the nutritional value between brown rice and white rice]. / Comparação do valor nutricional entre arroz integral e polido.

Cereals are considered an important source of nutrients both in human and animal nourishment. In this paper nutritional value of brown rice is compared to that of white rice in relation to nutrients. Results show that despite higher nutrients contents of brown rice compared to white rice, experimental datas does not provide evidence that the brown rice diet is better than the diet based on white rice. Possible antinutricional factors present in brown rice have adverse effects on bioavailability of this cereal nutrients.

Stress dependent infection cost of the human malaria agent Plasmodium falciparum on its natural vector Anopheles coluzzii.

Unraveling selective forces that shape vector-parasite interactions has critical implications for malaria control. However, it remains unclear whether Plasmodium infection induces a fitness cost to their natural mosquito vectors. Moreover, environmental conditions are known to affect infection outcome and may impact the effect of infection on mosquito fitness. We investigated in the laboratory the effects of exposition to and infection by field isolates of Plasmodium falciparum on fecundity and survival of a major vector in the field, Anopheles coluzzii under different conditions of access to sugar resources after blood feeding. The results evidenced fitness costs induced by exposition and infection. When sugar was available after blood meal, infected and exposed mosquitoes had either reduced or equal to survival to unexposed mosquitoes while fecundity was either increased or decreased depending on the blood donor. Under strong nutritional stress, survival was reduced for exposed and infected mosquitoes in all assays. We therefore provide here evidence of an environmental-dependant reduced survival in mosquitoes exposed to infection in a natural and one of the most important parasite-mosquito species associations for human malaria transmission.

Antiplasmodial activity and cytotoxicity of 10ß-aminoquinolinylethylethers of artemisinin.

Each year roughly 800 000 people die of malaria, with 95% being African children. The shortcomings of the current drugs and the emergence of P. falciparum resistance to the artemisinin class of compounds warrant the search for new classes or derivatives. In search for such compounds, a series of 10ß-amino-quinolinylethylethers of artemisinin, previously synthesized from this laboratory were screened for antimalarial activity against both the chloroquine-susceptible 3D7 and -resistant K1 strains of P. falciparum. Their cytotoxicity was also assessed against HEK 293 and HepG2 cell lines.The parasitic and mammalian cells were incubated with compounds at various concentrations for 72 h. The antimalarial activity was determined using SYBR Green I-based fluorescence. For cytotoxicity determination, cells were grown to confluence and CellTiter-Glo luminescent cell viability assay was used.All derivatives proved to be active against both strains with good selectivity towards the parasitic cells. The derivative 11 featuring 2 artemisinin moieties and an aminoethylpiperazine linker was the most active of all. It possessed 17- and 166-fold more potency than artemether against 3D7 (EC50: 9.5 vs. 166 nM) and K1 (10.9 vs. 1723.3 nM), respectively, while was found to be as potent as artesunate against both strains.Derivative 11 stands as a good candidate to be further investigated primarily in vitro in comparison with an equimolar combination of chloroquine (CQ) and artemisinin to ascertain its advantages, if any, over the combination.

Commercial cuts and carcass characteristics of sheep and goats supplemented with multinutritional blocks / Cortes comerciales y característica de la canal de borregos y cabritos suplementados con bloques multinutricionales

ABSTRACT Objective. Aimed to identify the weight and yield of the commercial cuts, muscularity, and adiposity in the carcasses of sheep and goats grazing in the Caatinga supplemented with different sources of supplementations; these include feed-blocks. Material and methods. Sixty non-castrated males an initial average body weight of 18.63 ± 1.93 kg were used: 30 goats and 30 sheep all animals did not have a defined breed standard (WDBS). The experimental design used was entirely randomized (DIC), in factorial scheme 3x2 (three types of supplementation: mineral salt, MBs and MBs + buffel hay, and two species: sheep and goats) and 10 replications. Animals were raised in a rangeland grazing system in an area with vegetation characteristic of Caatinga ecosystem under three types of supplementation: 1: only mineral salt; 2: Feed blocks (MBs); and 3: MBs + buffel hay There were measured the weight, yield and the components of left half-part of carcass of lambs and kids. Results. The sheep were superior to goats in carcass conformation, loin-eye area, index of muscularity of the leg and compactness index of the leg while the goats were superior to sheep in leg muscles weight. Conclusions. Sheep and Goats, when fed with supplementation of pasture feeding blocks in the Caatinga ecosystem; Supplementation with mineral salt and Multinutritional Blocks with and without Buffel can be used to improve herds in the caatinga, with similar results among the three. Sheep show more adiposity of meat than goats, in contrast, goats have higher musculature than sheep when fed with feed blocks.

RESUMEN Objetivo. Con el objetivo de identificar el peso y rendimiento de los cortes comerciales, musculatura y adiposidad en las canales de borregos y cabritos pastando en la Caatinga suplementado con diferentes fuentes de suplementos; Estos incluyen bloques de alimentación. Materiales y métodos. Se utilizaron 60 machos no castrados con un peso corporal medio inicial de 18,63 ± 1,93 kg: 30 borregos y 30 cabritos, todos los animales no tenían un estándar de raza definido (WDBS). El diseño experimental utilizado fue totalmente al azar (DIC), en esquema factorial 3x2 (tres tipos de suplementación: sal mineral, MBs y MBs + heno buffel, y dos especies: borregos y cabritos) y 10 repeticiones. Los animales fueron criados en un sistema de pastoreo de pastizales en un área con vegetación característica del ecosistema de Caatinga bajo tres tipos de suplementación: 1: sal mineral solamente; 2: Bloques de alimentación (MBs); Y 3: MBs + heno buffel Se midió el peso, el rendimiento y los componentes de la mitad izquierda de la carcasa de corderos y cabritos. Resultados. Las cordeiros fueron superiores a los cabritos en conformación de carcasas, área de lomo, índice de musculatura de la pierna y índice de compacidad de la pierna mientras que los cabritos fueron superiores a las cordeiros en el peso de los músculos de las piernas. Conclusión. Cordeiros y cabritos, cuando se alimentan con suplementos de bloques de alimentación de pasto en el ecosistema de Caatinga; La suplementación con sal mineral y Bloques Multinutritivos con y sin Buffel puede ser utilizada para mejorar los rebaños en la caatinga, con resultados similares entre los tres. Las cordeiros muestran más adiposidad de carne que los cabritos, en contraste, las cabritos tienen mayor musculatura que las cordeiros cuando se alimentan con bloques de alimentación.

No Paragonimus in high-risk groups in Côte d'Ivoire, but considerable prevalence of helminths and intestinal protozoon infections.

BACKGROUND: Paragonimiasis is a neglected tropical disease caused by an infection with lung flukes that is transmitted through the consumption of undercooked crabs. The disease is often confused with tuberculosis. Paragonimiasis is thought to be endemic in south-western Côte d'Ivoire. METHODS: Two cross-sectional surveys were carried out in the first half of 2009 in patients attending two tuberculosis centres of Abidjan. A third cross-sectional survey was conducted in May 2010 in children of two primary schools in Dabou, where crabs are frequently consumed. Patients with chronic cough provided three sputum samples plus one stool sample. Sputum samples were examined for tuberculosis with an auramine staining technique and for Paragonimus eggs using a concentration technique. Stool samples were subjected to the Ritchie technique. Schoolchildren provided a single stool sample, and samples were subjected to the Kato-Katz and an ether-concentration technique. A pre-tested questionnaire was administered to patients and schoolchildren to investigate food consumption habits. Additionally, between June 2009 and August 2010, shellfish were purchased from markets in Abidjan and Dabou and examined for metacercariae. RESULTS: No human case of paragonimiasis was diagnosed. However, trematode infections were seen in 32 of the 272 shellfish examined (11.8%). Questionnaire results revealed that crab and pig meat is well cooked before consumption. Among the 278 patients with complete data records, 62 had tuberculosis, with a higher prevalence in males than females (28.8% vs. 13.9%, χ2 = 8.79, p = 0.003). The prevalence of helminths and intestinal protozoa was 4.6% and 16.9%, respectively. In the school survey, among 166 children with complete data records, the prevalence of helminths and intestinal protozoa was 22.3% and 48.8%, respectively. Boys had significantly higher prevalences of helminths and intestinal protozoa than girls. Hookworm was the predominant helminth species and Entamoeba coli was the most common intestinal protozoon species (13.8%). CONCLUSIONS: Not a single case of Paragonimus was found in two high-risk groups of Côte d'Ivoire, most likely explained by food consumption habits. However, other helminth and intestinal protozoon infections were common.