96 research outputs found

    The aromatic amino acid hydroxylase genes AAH1 and AAH2 in Toxoplasma gondii contribute to transmission in the cat

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    The Toxoplasma gondii genome contains two aromatic amino acid hydroxylase genes, AAH1 and AAH2 encode proteins that produce L-DOPA, which can serve as a precursor of catecholamine neurotransmitters. It has been suggested that this pathway elevates host dopamine levels thus making infected rodents less fearful of their definitive Felidae hosts. However, L-DOPA is also a structural precursor of melanins, secondary quinones, and dityrosine protein crosslinks, which are produced by many species. For example, dityrosine crosslinks are abundant in the oocyst walls of Eimeria and T. gondii, although their structural role has not been demonstrated, Here, we investigated the biology of AAH knockout parasites in the sexual reproductive cycle within cats. We found that ablation of the AAH genes resulted in reduced infection in the cat, lower oocyst yields, and decreased rates of sporulation. Our findings suggest that the AAH genes play a predominant role during infection in the gut of the definitive feline host

    Disruption of Skin Stem Cell Homeostasis following Transplacental Arsenicosis; Alleviation by Combined Intake of Selenium and Curcumin

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    Of late, a consirable interest has grown in literature on early development of arsenicosis and untimely death in humans after exposure to iAs in drinking water in utero or during the childhood. The mechanism of this kind of intrauterine arsenic poisoning is not known; however it is often suggested to involve stem cells. We looked into this possibility by investigating in mice the influence of chronic in utero exposure to arsenical drinking water preliminarily on multipotent adult stem cell and progenitor cell counts at the beginning of neonatal age. We found that repeated intake of 42.5 or 85ppm iAs in drinking water by pregnant BALB/c mice substantially changed the counts of EpASCs, the progenitor cells, and the differentiated cells in epidermis of their zero day old neonates. EpASCs counts decreased considerably and the differentiated / apoptosed cell counts increased extensively whereas the counts of progenitor cell displayed a biphasic effect. The observed trend of response was dose-dependent and statistically significant. These observations signified a disruption in stem cell homeostasis. The disorder was in parallel with changes in expression of biomarkers of stem cell and progenitor (TA) cell besides changes in expression of pro-inflammatory and antioxidant molecules namely Nrf2, NFkB, TNF-α, and GSH. The biological monitoring of exposure to iAs and the ensuing transplacental toxicity was verifiable correspondingly by the increase in iAs burden in hair, kidney, skin, liver of nulliparous female mice and the onset of chromosomal aberrations in neonate bone marrow cells. The combined intake of selenite and curcumin in utero was found to prevent the disruption of homeostasis and associated biochemical changes to a great extent. The mechanism of prevention seemed possibly to involve (a) curcumin and Keap-1 interaction, (b) consequent escalated de novo GSH biosynthesis, and (c) the resultant toxicant disposition. These observations are important with respect to the development of vulnerability to arsenicosis and other morbidities later in life after repeated in utero or postnatal exposure to iAs in drinking water that may occur speculatively through impairment of adult stem cell dependent innate tissue repair mechanism

    Input Utilization for Sustainable Yields in Dryland Areas

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    ABSTRACT India's population touched 1.198 98, 96, 85, 80, 79, 71, 66 an

    Sarcocystis cymruensis: discovery in Western Hemisphere in the Brown rat (Rattus norvegicus) from Grenada, West Indies: redescription, molecular characterization, and transmission to IFN-Îł gene knockout mice via sporocysts from experimentally infected domestic cat (Felis catus)

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    Rodents are intermediate hosts for many species of Sarcocystis. Little is known of Sarcocystis cymruensis that uses the Brown rat (Rattus norvegicus) as intermediate hosts and the domestic cat (Felis catus) as experimental definitive host. Here, we identified and described Sarcocystis cymruensis in naturally infected R. norvegicus from Grenada, West Indies. Rats (n = 167) were trapped in various locations in two parishes (St. George and St. David). Microscopic, thin (\u3c 1 ÎŒm) walled, slender sarcocysts were found in 11 of 156 (7.0%) rats skeletal muscles by squash examination. A laboratory-raised cat fed naturally infected rat tissues excreted sporocysts that were infectious for interferon gamma gene knockout (KO) mice, but not to Swiss Webster outbred albino mice. All inoculated mice remained asymptomatic, and microscopic S. cymruensis-like sarcocysts were found in the muscles of KO mice euthanized on day 70, 116, and 189 post inoculation (p.i.). Sarcocysts from infected KO mice were infective for cats at day 116 but not at 70 days p.i. By transmission electron microscopy, the sarcocyst wall was Btype 1a.^ Detailed morphological description of the cyst wall, metrocytes, and bradyzoites is given for the first time. Additionally, molecular data on S. cymruensis are presented also for the first time. Molecular characterization of sarcocysts 18S rDNA and 28S rDNA, ITS-1, and cox1 loci showed the highest similarity with S. rodentifelis and S. muris. In conclusion, the present study described the natural infection of S. cymruensis in Brown rat for the first time in a Caribbean country and provided its molecular characteristics

    Chemical Protection Studies of Activated Carbon Spheres based Permeable Protective Clothing Against Sulfur Mustard, a Chemical Warfare Agent

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    Technological advancements in the field of chemical threat have made it possible to create extremely dangerous chemical warfare agents (CWA). Hence, the effective protection of personnel is very important in a chemical warfare scenario amidst the current climate of terrorism awareness. In particular, body protection plays a substantial role in the chemical defence considering the urgency of situation in the nuclear, biological and chemical environment. Activated carbon spheres (ACS) based permeable chemical protective clothing (coverall) was developed for protection against CWA. The adsorbent material i.e, ACS used in this protective clothing provided higher adsorption capacity (1029 mg/g in terms of iodine) and low thermal burden (34 °C WBGT index) compared to earlier indigenously developed NBC suit. This article focuses on the extensive evaluation of chemical protective clothing against sulfur mustard (HD), a CWA. The results revealed that the developed protective clothing provided more than 24 h protection against HD. This chemical protective suit is light weight (< 2.75 kg for XL size). It also has higher air permeability (> 30 cm3/s/cm2) as well as less water vapour resistance (< 9.6 m2Pa/W). With continued innovations in materials and attention to key challenges it is expected that advanced, multifunction chemical protective suit will play a pivotal role in the CWA protection scenario

    Sarcocystis oreamni, n. sp. (Apicomplexa : Sarcocystidae) from the mountain goat (Oreamnos americanus)

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    Numerous species of Sarcocystis have been reported from wild ruminants but none has been named from the Rocky Mountain goat (Oreamnos americanus). Mature sarcocysts were found in frozen muscle samples of three of seven mountain goats from Alaska, USA. Two morphological types of sarcocysts were found; one had Sarcocystis cornagliai-like sarcocysts, previously named from the Alpine ibex (Capra ibex) from Europe. Two other goats were infected with a new species, Sarcocystis oreamni. Sarcocystis oreamni sarcocysts were microscopic with 2 ÎŒm-thick sarcocyst wall. By transmission electron microscopy, the sarcocyst wall had 1.7 ÎŒm-thick with unusual molar tooth-like villar protusions (vp), type 29. The vp had electron dense core and two disc-shaped plaques at the tip with fine microtubules. Bradyzoites were 8.6-9.1 ÎŒm long. Single nucleotide polymorphism (SNP) identified in 18S rRNA, and 28S rRNA loci of rDNA regions that suggested S. oreamni molecularly apart from related species. The phylogenetic analysis based on 18S rRNA, and 28S rRNA sequences suggested S. oreamni is related with Sarcocystis species that employ members of Canidae family as their definitive host.R. Calero-Bernal is a postdoctoral fellow (ref. PO12010) funded by the Department of Employment and Innovation of the Regional Government of Extremadura (Spain) and the European Social Fund.http://link.springer.com/journal/4362016-11-11hb201

    Sarcocystis mehlhorni n. sp. (Apicomplexa : Sarcocystidae) from the black-tailed deer (Odocoileus hemionus columbianus)

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    Infection with Sarcocystis is common in many species of wild cervids but none is reported from the black-tailed deer (Odocoileus hemionus columbianus). Here, we report Sarcocystis infection in two black-tailed deer from northwest USA for the first time. Sarcocysts were microscopic, up to 556 ÎŒm long and mature. The sarcocyst wall was up to 1.39 ÎŒm thick, and had rectangular 1.17 ÎŒm long villar protrusions, type 17, with thin (230 nm) electron dense ground substance layer. Molecular characterization and phylogenetic analysis indicated that Sarcocystis in the black-tailed deer is related to structurally distinct Sarcocystis species in cervids. A new name, Sarcocystis mehlhorni, is proposed for the Sarcocystis species in black-tailed deer.http://link.springer.com/journal/4362016-12-08hb201

    Adjuvanted multi-epitope vaccines protect HLA-A*11:01 transgenic mice against Toxoplasma gondii

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    We created and tested multi-epitope DNA or protein vaccines with TLR4 ligand emulsion adjuvant (gluco glucopyranosyl lipid adjuvant in a stable emulsion [GLA-SE]) for their ability to protect against Toxoplasma gondii in HLA transgenic mice. Our constructs each included 5 of our best down-selected CD8(+) T cell-eliciting epitopes, a universal CD4(+) helper T lymphocyte epitope (PADRE), and a secretory signal, all arranged for optimal MHC-I presentation. Their capacity to elicit immune and protective responses was studied using immunization of HLA-A*11:01 transgenic mice. These multi-epitope vaccines increased memory CD8(+) T cells that produced IFN-Îł and protected mice against parasite burden when challenged with T. gondii. Endocytosis of emulsion-trapped protein and cross presentation of the antigens must account for the immunogenicity of our adjuvanted protein. Thus, our work creates an adjuvanted platform assembly of peptides resulting in cross presentation of CD8(+) T cell-eliciting epitopes in a vaccine that prevents toxoplasmosis
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